2019-08-18T01:30:00Z https://academicjournals.org/oai-pmh/handler
oai:academicjournals.org:IJPS:5A1F05A10895 2006-09-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Potential for rock polishing enterprises in Southwestern Nigeria Aigbedion I. Full Length Research Paper Various igneous and metamorphic rocks constitute the basement complex especially much of southwestern Nigeria. They are composed of different proportion of felsic to mafic constitutions. Textural characteristics are also wide ranging. Based on petrographic and physical parameters, the majority holds good promise to be utilized for polished items. However, industrial exploitation may be constrained by a number of features, in some cases. On the other hand, sustaining viable projects in ornament stones, would demand support for further geological appraisals, technical facilities, adequate capital and relevant manpower. Key words: Mining of rocks, porosity, environmental degradation, specific gravity. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/5A1F05A10895 en Copyright © 2006 Aigbedion I.
oai:academicjournals.org:IJPS:2E9289B10911 2006-09-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Blended cement and lightweight concrete using scoria: Mix design, strength, durability and heat insulation characteristics Khandaker M. Anwar Hossain Full Length Research Paper This paper reports the results of an investigation on the potential industrial utilization of volcanic scoria. The scoria is assessed for its utilization as a cement additive. Pozzolanic activity of ground scoria is tested according to the Italian standards and found to be acceptable. X-Ray Diffraction (XRD) analysis and Differential Scanning Calorimetry (DSC) are conducted on finely ground scoria based blended cement paste and mortar for the characterization of hydration products. The strength activity index with Portland cement and the effectiveness of scoria admixture in controlling alkali-silica reactions and autoclave expansion are tested according to ASTM standards using different mixes. The results satisfy the ASTM requirements and confirm the viability of using ground scoria as a cement additive. The suitability of using scoria as both fine and coarse aggregate in lightweight concrete production is assessed and compared with other lightweight aggregates. The properties of scoria concrete (SC) are evaluated by conducting comprehensive series of tests on workability, air content, density, strength, drying shrinkage, and water permeability. Developed SC mixtures have attained required strength and density to be accepted as structural lightweight concrete. The utilization of scoria as a heat-insulating material is also tested and the results are also found to satisfy the ASTM requirements. Scoria concrete shows good heat-insulating characteristics and can be used in building construction as an energy saver. Key Words: Scoria, Lightweight concrete; Pozzolanic activity; Alkali-silica reaction, Autoclave expansion, Drying shrinkage; Permeability; X-Ray Diffraction; Differential Scanning Calorimetry. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/2E9289B10911 en Copyright © 2006 Khandaker M. Anwar Hossain
oai:academicjournals.org:IJPS:908070D10917 2006-09-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Energy- angular correlation of medium energy particles produced in heavy Ion collisions N.M. Hassan, N.M. Sadek, Jamila Elsweedy and M.T. Hussein Full Length Research Paper The information carried by the medium energy nucleons (gray particles) emitted in heavy ion collisions is studied. A canonical thermo dynamical model is proposed to deal with the interacting nuclei as nucleon gas system. The predictions of the model are compared with a complete set of measured data for the reactions of proton, helium, carbon and neon nuclei with the nuclear emulsion at 4.2 A GeV. It is found that the angular distribution of the knocked on nucleons is almost independent of the projectile mass. A strong correlation between the energy of the gray particles and their emission angles is found. The gray particles emitted in the forward hemisphere show linear correlation with their average kinetic energy which reflects that these particles are emitted in non-equilibrium states. On the other hand, backward emission shows uniform behavior that represents particle emission in an almost equilibrium state. Key words: Heavy Ionn Collision, thermodynamic model,energy- angle correlation PACS: 25.70.Pq. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/908070D10917 en Copyright © 2006 N.M. Hassan, N.M. Sadek, Jamila Elsweedy and M.T. Hussein
oai:academicjournals.org:IJPS:793472210923 2006-09-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Biosorption of lead ions from aqueous solution by maize leaf N. A. Adesola Babarinde, J. Oyebamiji.Babalola and R. Adebowale Sanni Full Length Research Paper The removal of lead ions from dilute aqueous solution using maize (Zea mays) leaf as the adsorbent is reported in this paper. The effects of pH, initial metal ion concentration and contact time were studied at 27ordm;C. The analysis of residual Pb(II) ions was determined using atomic absorption spectrophotometer. Maximum adsorption occurred at pH 3. The adsorption isotherms obtained at 27ordm;C and optimum pH fitted well into both the Freundlich and Langmuir isotherms. The Freundlich and Langmuir equations are log Г =0.504 log Ce+0.6939 and 1/Г = 0.176/Cendash;0.03, respectively. The correlation factors are 0.9959 and 0.9939. The result of the pH experiment shows that the initial pH would play a vital role in the removal of the lead ions from solution. The kinetic studies show that uptake of lead ions increases with time and that maximum adsorption was obtained within the first 30 min of the process. These results indicate that maize leaf has potential for removing lead ions from industrial wastewater. Key words: Adsorption, Pb(II), Freundlich isotherm, Langmuir isotherm, maize leaf. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/793472210923 en Copyright © 2006 N. A. Adesola Babarinde, J. Oyebamiji.Babalola and R. Adebowale Sanni
oai:academicjournals.org:IJPS:EA86E0510935 2006-09-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Cyclic oxidation behavior of Ni- and Fe-based superalloys in air and Na2SO4-25%NaCl molten salt environment at 800 oC T.S. Sidhu, Ajay Malik, S. Prakash, R.D. Agrawal Full Length Research Paper The present investigation aims to evaluate the high-temperature oxidation and hot corrosion behaviour of Ni-based superalloy (Superni 75) and Fe-based superalloy (Superfer 800H). The superalloy specimens were exposed to air and molten salt (Na2SO4-25%NaCl) environment at 800 deg;C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe micro analyser (EPMA) techniques were used to characterize the corrosion products. The hot corrosion resistance of Ni-based superalloys was found to be better than that of Fe-based superalloys. The formation of scale rich in Cr2O3, NiO and spinel NiCr2O4 has contributed for the better oxidation and hot corrosion resistance of Superni 75, whereas relatively lesser hot corrosion resistance of Superfer 800H is due to the formation of non-protective oxide of iron, and sulphides of iron and nickel. Key Words: Superalloys, Hot corrosion, Oxidation, Molten salt environment Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/EA86E0510935 en Copyright © 2006 T.S. Sidhu, Ajay Malik, S. Prakash, R.D. Agrawal
oai:academicjournals.org:IJPS:D6E58DA10941 2006-09-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Non-Fitted Prediction of Clay Soil Aggregate Shrinkage V.Y. Chertkov Full Length Research Paper All available models of soil shrinkage curves, despite their essential differences, are based on fitting the model parameters. We try to construct a model that enables one to predict the shrinkage curve based on physical parameters, that is, parameters that can be measured or calculated without fitting, independently of an experimental shrinkage curve. Such a model is constructed for real aggregates of clay soils (i.e., soils with clay content approximately gt; 40% by weight). The intra-aggregate matrix is considered to be a clay matrix that embraces silt and sand grains. An available microstructure-based model of the clay matrix shrinkage curve is used. For data analysis we derive an estimate for the liquid limit of the intra-aggregate matrix. We compare predicted and observed shrinkage curves using available data on aggregates of 31 different swelling soils that are mostly clay soils. As expected the generalized model works for clay soil aggregates with clay content approximately gt;40% (21 of 31 soils under study). The obtained results of the clay soil aggregates are a prerequisite of the next step relating to the shrinkage modeling of an aggregated soil without fitting. Keywords: Modeling without fitting; shrinkage; aggregates; clay microstructure. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/D6E58DA10941 en Copyright © 2006 V.Y. Chertkov
oai:academicjournals.org:IJPS:2277DF310964 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Prediction of Early Strength of Concrete: A Fuzzy Inference System Model M.C. Nataraja, M.A. Jayaram and C.N. Ravikumar Full Length Research Paper The strength development in concrete with its age is essentially a constant volume solidification process, which is controlled by multivarious parameters. However, the concrete mixes are designed for 28 dayrsquo;s target compressive strength. In a more general characterization, it can be said that increase in strength of concrete is achieved by decrease in water cement ratio and decrease in aggregate cement ratio. However, it is impossible to develop a precise mathematical model that can predict crisp numerical values of strength that correspond to crisp values of w/c ratio and a/c ratio. This is due to uncertainties involved in these parameters, the uncertain behavior of constituent materials, and tolerances. The potential of fuzzy logic in developing a model for characterization by approximate reasoning really lies here. This paper presents a modest attempt made to characterize 28 dayrsquo;s strength of concrete using Fuzzy Inference System (FIS). The methodology consists of two steps; (1) developing the basic model using generalized Abramrsquo;s law and (2) validating the basic model, using the experimental data. The water-cement ratio and aggregate-cement ratio are treated as antecedents and 28 dayrsquo;s strength is the consequent. The results have shown that, the fuzzy inference system provides a prudent way to capture uncertainty (non-statistical) in relationships among parameters that control the early strength of concrete. Key words: Early strength of concrete, water-cement ratio, aggregate-cement ratio, fuzzy inference system, antecedents, consequents, approximate reasoning. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/2277DF310964 en Copyright © 2006 M.C. Nataraja, M.A. Jayaram and C.N. Ravikumar
oai:academicjournals.org:IJPS:AFBAD2A10971 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Mechanical behaviors of concrete combined with steel and synthetic macro-fibers Zongcai Deng and Jianhui Li Full Length Research Paper In this paper, hybrid fibers including high elastic modulus steel fiber and low elastic modulus synthetic macro-fiber (HPP) as two elements were used as reinforcement materials in concrete. The flexural toughness, flexural impact and fracture performance of the composites were investigated systematically. Flexural impact strength was analyzed with statistic analyses method; based on ASTM and JSCE method, an improved flexural toughness evaluating method suitable for concrete with synthetic macro-fiber was proposed herein. The experimental results showed that when the total fiber volume fractions () were kept as a constant (=1.5%), compared with single type of steel or HPP fibers, hybrid fibers can significantly improve the toughness, flexural impact life and fracture properties of concrete. Relative residual strength, impact ductile index and fracture energy GF of concrete combined with hybrid fibers were respectively 66-80%, 5-12 and 121-137 N/m, which indicated that the synergistic effects (or combined effects) between steel fiber and synthetic macro-fiber were good. Keywords: Hybrid fibers; Steel fiber; Synthetic macro-fiber; Residual strength; Flexural impact; Fracture; Toughness; Concrete Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/AFBAD2A10971 en Copyright © 2006 Zongcai Deng and Jianhui Li
oai:academicjournals.org:IJPS:BB8708511003 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Can we use the aa geomagnetic activity index to predict partially the variability in global mean temperatures? M.A. El-Borie and S.S. Al-Thoyaib Full Length Research Paper Data for geomagnetic activity index aa and solar sunspot number Rz for 1868-2004 were subjected to correlation analysis with the global surface temperature (GST). The annual-means GT show that it had two warming phases and one cooling period. Observations of the Earth#39;s near-surface temperature showed a global-mean temperature increase of approximately 1.1deg; C since 1877, occurred from 1887 to 1940 and from 1970 to the 1998. The temperature change over the past 35 years (1970-2004) is unlikely to be entirely due to internal climate variability. Attribution of the warming early in the century has proved more elusive. The correlation analysis between the variation of global temperature and both aa geomagnetics and solar activity are +0.5 plusmn; 0.05, for any lag or lead, indicating a significant role in such variation. All graphs have illustrated strong correlations between the solar activity and geomagnetics and surface global temperature. Our results do not, by any means, rule out the existence of important links between solar activity and terrestrial climate. Our results displayed that the present changes in aa geomagnetics may reflect partially some future changes in the global surface temperatures. Key words: Geomagnetic induction, Atmospheric sciences, Climatology, Climate and interannual variability. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/BB8708511003 en Copyright © 2006 M.A. El-Borie and S.S. Al-Thoyaib
oai:academicjournals.org:IJPS:F604F9E11014 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
INS Study on Physical Mechanisms of Bioprotection S. Magazugrave;, F. Migliardo and A. J. Ramirez-Cuesta Full Length Research Paper The present work is aimed to investigate by Inelastic Neutron Scattering the vibrational behaviour of a class of bioprotectant systems, such as homologous disaccharides, trehalose, maltose and sucrose, in water mixtures. The obtained neutron scattering findings point out that disaccharides, and in particular trehalose, have a destructuring effect on the water tetrahedral network, as emphasised by the analysis of the librational modes region, and emphasise their kosmotrope character. The ldquo;cryptocrystallinerdquo; character, shown by the bending modes region features, has been investigated and linked to the different bioprotective effectiveness of disaccharide as a function of concentration. Keywords: disaccharides; trehalose; tetrahedral network; vibrational properties; neutron scattering. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/F604F9E11014 en Copyright © 2006 S. Magazugrave;, F. Migliardo and A. J. Ramirez-Cuesta
oai:academicjournals.org:IJPS:03F3D1911024 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Boundary compatibility condition and rotation in elasticity Surya N Patnaik and Shantaram S. Pai Short Communication The boundary compatibility condition in elasticity that was missed for more than one century has been formulated. The new condition has completed the Beltrami-Michell formulation in elasticity. The completed formulation can solve stress, displacement, and mixed boundary value problems. The boundary compatibility condition, which is not a rotation, should be imposed on an indeterminate boundary. The use of the new condition is illustrated through the solution of a mixed boundary value problem. Key words: Indeterminate, Completed, Beltrami, Michell. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/03F3D1911024 en Copyright © 2006 Surya N Patnaik and Shantaram S. Pai
oai:academicjournals.org:IJPS:2C5630111037 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Seismicity of the Carpathian region Dmytro Malytskyy Full Length Research Paper Carpathian complex prognostic poligon has being created for testing of new methods and equipment and their implementation into the practice of seismotectonic investigations in the Transcarpathians. The polygon consists of a network of regime geophysical stations (RGS). I analyzed seismicity of the Ukrainian sector of the Carpathians. It is determined by local earthquakes and strong subcrustal earthquakes of the Vrancea zone in Romania. In this paper, I estimate the most fundamental parameters describing earthquakes: seismic energy E and energy class K=log(E) in a time window of 40 years (1961-2001). Our results show that, the aring;E plot against time may be a good tool for understanding of a local earthquake activity, although the shape of the plot is strongly influenced by extreme events. Also, we have found a correlation between seismic moment M0 and energy class K of the local earthquakes for Transcarpathian region. Key words: seismicity, energy class, seismic energy, seismic moment, geodynamic polygon, catalogue. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/2C5630111037 en Copyright © 2006 Dmytro Malytskyy
oai:academicjournals.org:IJPS:FFF03D411044 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
An Appraisal of The Abura Field Aigbedion I and S.E Iyayi Full Length Research Paper Petrophysical analysis was carried out for all the identified hydrocarbon intervals, from the four wells studied in the Abura Field using suites of geophysical well logs. From the analysis of the geological logs comprising gamma-ray, spontaneous potential, electrical resistivity, neutron and density logs, the total porosity in the hydrocarbon bearing zone was found to range from 18.0% to 28.0% and the water saturation range from 16.0 to 54.0%. Good well-to-well lithologic correlation was established across the fields studied .The researcher found that the bulk of the hydrocarbon encountered in the Niger Delta basin was found to be within a depth range of 2510.0-3887.0 m. The hydrocarbon reservoirs were found to be in the Agbada formation, which is in conformity with the geology of the Niger Delta, Nigeria. This study was carried out to find out if the petrophysical parameters computed in the field will encourage deeper drilling in the area of study. Key words: Resistivity, Lithologic correlation, Reservoir, Hydrocarbon, Porosity, Water saturation Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/FFF03D411044 en Copyright © 2006 Aigbedion I and S.E Iyayi
oai:academicjournals.org:IJPS:9C3760C11053 2006-10-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Mechanochemical route to synthesize Co3O4/CuO composite nanopowders Aidong Tang , HuamingYang , Xiangchao Zhang Full Length Research Paper Co3O4/CuO composite nanopowders have been successfully synthesized by heating the precursor obtained via a mechanochemical reaction. The precursor and the nanopowders were characterized using thermogravimetric (TG), X-ray diffraction (XRD) and transmission electron spectroscopy (TEM). Subsequent thermal treatment of the precursor at 550-700 deg;C in air for 2 h resulted in the formation of Co3O4/CuO nanopowders with an average crystal size of about 25-50 nm, varying with the calcination temperature. The mechanism of nanocrystallite growth is primarily investigated. The morphology of the synthesized Co3O4/CuO nanopowders is in irregular polyhedron shape and the mechanism of NaCl used as diluent have been analyzed. The mechanochemical route is a novel, cheap and convenient technique suitable for large-scale synthesis of composite nanomaterials. Keywords: Composite nanopowders; Co3O4/CuO; Mechanochemical reaction; Nanocrystallite growth. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/9C3760C11053 en Copyright © 2006 Aidong Tang , HuamingYang , Xiangchao Zhang
oai:academicjournals.org:IJPS:85ED35C11286 2006-11-30T00:00:00Z AcademicJournals IJPS IJPS:2006
A new pozzolanic material for cement industry: Bamboo leaf ash V.N. Dwivedia , N.P.Singhb , S.S.Dasa and N.B.Singha Full Length Research Paper Bamboo leaf fired in an open atmosphere and then heated at 600oC for 2h in a furnace was found to be an amorphous material containing amorphous silica. The ash was characterized by chemical analysis, powder X-ray diffraction and SEM techniques. Reactions of the ash with calcium hydroxide showed it to be pozzolanic in nature. The pozzolanic reactivity increased with time and temperature. When 20 wt% bamboo leaf ash was mixed with Portland cement, the compressive strength at 28 days of hydration was comparable to that without ash. This was due to pozzolanic reactions. The mechanism of pozzolanic reactivity has been discussed. Keywords: Bamboo leaf ash, Pozzolana, Portland cement, Hydration, Calcium hydroxide Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/85ED35C11286 en Copyright © 2006 V.N. Dwivedia , N.P.Singhb , S.S.Dasa and N.B.Singha
oai:academicjournals.org:IJPS:FF688CB11297 2006-11-30T00:00:00Z AcademicJournals IJPS IJPS:2006
The early heat of hydration of blended cements incorporating GGBFS and ground basaltic pumice (GBP) Hanifi BİNİCİ, İsmail H. Ccedil;AĞATAY, Mustafa TOKYAY and Mehmet M. KOuml;SE Full Length Research Paper In this study, the effect of blended cements containing additives on the heat of hydration and the rate of heat liberation was investigated. The blended cements were prepared by using clinker, ground granulated blast-furnace slag (GGBFS) and ground basaltic pumice (GBP). Two groups of specimens were prepared by the grinding method of intergrinding and separate grinding. For each group of specimen, two Blaine values of 2800 plusmn;30 cm2/g and 4800 plusmn;30 cm2/g and four different ratios of additives, which were 0%, 10%, 20% and 30% of clinker by weight, were used. The effects of the grinding method, the fineness and the amount of additives on the heat of hydration were also investigated. It was found that the heat of hydration was affected by the grinding method. Also, interground coarser blended cement specimens resulted in extended time to reach the second peak compare to the separately ground finer ones. A significant reduction in the total heat of hydration was achieved in the interground coarser specimens with 30% additives. The minimum heat of hydration was obtained from the interground specimens with 30% additives and Blaine value of 2800 plusmn;30 cm2/g. Due to lower heat of hydration this cement can be used for mass concrete construction. Keywords: Hydration; Grinding Method; Additives; GGBFS; Ground Basaltic Pumice Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/FF688CB11297 en Copyright © 2006 Hanifi BİNİCİ, İsmail H. Ccedil;AĞATAY, Mustafa TOKYAY and Mehmet M. KOuml;SE
oai:academicjournals.org:IJPS:B26E65B11307 2006-11-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Efficiency of densification process in preparation of carbon-carbon composites M. Klučaacute;kovaacute; Full Length Research Paper Material balance of densification process was made to assess its efficiency in dependence on impregnation conditions. Theoretical values of apparent porosity, bulk density and apparent specific gravity were computed and compared with experimental ones. Densification efficiency was determined as the ratio of volume of added matrix to volume of pores. Key Words: Composites, Polymers, Structural behaviour, Porosity Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/B26E65B11307 en Copyright © 2006 M. Klučaacute;kovaacute;
oai:academicjournals.org:IJPS:9969B0E11315 2006-11-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Theoretical and experimental studies in hydrogen bonded glass forming systems S. Magazugrave;, G. Maisano, F. Migliardo, N. P. Malomuzh, I. V. Blazhnov Full Length Research Paper The aim of this work is to clarify some features of glass forming systems, such as temperature dependence of density, thermal expansion coefficient and shear viscosity. They are first discussed from the theoretical point of view and then experimentally tested for glycerol. The parameters y, interpreted as the effective number of degrees of freedom related to the a-relaxation process, and j, the specific volume occupied by heterogeneous nuclei, are introduced. Both they provide an explanation of the temperature dependence of density and thermal expansion coefficients in liquid, solid amorphous, glassy and crystal states.Furthermore, the relation between the macroscopic and microscopic definitions of fragility is showed and discussed. Keywords: glass forming systems; density; thermal expansion coefficient; shear viscosity; temperature dependence; glycerol. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/9969B0E11315 en Copyright © 2006 S. Magazugrave;, G. Maisano, F. Migliardo, N. P. Malomuzh, I. V. Blazhnov
oai:academicjournals.org:IJPS:296AD3011348 2006-11-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Dielectric, optical and thermodynamical properties of liquid crystal sample exhibiting SmA phase Rajiv Manohar, Abhishek Kumar Srivastava, Jyotishman, J.P ShuklaA.K.Prajapati and N.L.Bonde Full Length Research Paper The dielectric constant and dielectric loss with dielectric anisotropy have been measured as a function of temperature in the frequency range of 1 kHz to 10 MHz for a newly synthesized liquid crystal sample-exhibiting SmA phase. The measurement in SmA phase indicates dielectric relaxation at frequency 4.778 kHz for 80 0C. The Enthalpy of activation was found to be 14.57 Kcal/mole. The results have been explained on the basis of Maier and Meier theory. The optical anisotropy study, white light transmittance study has also been carried out on the sample. Phase transition temperature matches very well as obtained from all the above mentioned measurement techniques. Optical anisotropy data has been used to determine order parameter by Vuks approach and its variation with temperature has been discussed. Key words: Liquid Crystals, Dielectric Properties, Refractive Indices, Optical Transmittance. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/296AD3011348 en Copyright © 2006 Rajiv Manohar, Abhishek Kumar Srivastava, Jyotishman, J.P ShuklaA.K.Prajapati and N.L.Bonde
oai:academicjournals.org:IJPS:E2304AB11360 2006-11-30T00:00:00Z AcademicJournals IJPS IJPS:2006
Modeling relative influence of environmental and socio-cultural factors on context-specific functions Debajyoti Pati and Godfried Augenbroe Full Length Research Paper Traditional models in building physics are based on theories in physics and physiology, typically characterized by a-contextual settings and domain-specific articulations. It is, however, commonly understood and appreciated that physics and physiology, alone, do not entirely explain observed patterns of user behavior in buildings-in-use, and that people do not experience various aspects of a setting in isolation. This study at the Georgia Institute of Technology, using Post-Occupancy Evaluation (POE) data from 26 courtrooms, developed a set of models that: 1) integrated variables from multiple domains, 2) developed a smaller set of aggregated functional dimensions intuitive to building stakeholders, 3) were context specific, 4) captured instrumental as well as abstract functions, and 5) articulated the relative influence of variables on the aggregated outcome measures. POEs started as a methodology to provide user input in building design and has expanded to a practice that incorporates user feedback along with technical and financial performance. Starting with one-off studies during the late 1960s, POEs have expanded considerably in terms of building types, tools, methods, and scope. The POE data in this study included physical, environmental, as well as user attribute data. Physical and environmental data were collected using scientific instruments widely accepted in the building evaluation community. User evaluations of the courtrooms on multiple dimensions were collected using 7-point ordinal scale measures. Environmental and user attribute data were regressed on aggregated performance dimensions (resulting from Principal Component Analyses) to arrive at the integrated models, presented in this paper. The authors argue that the modeling approach supplements the traditional paradigm in two ways: 1) by validating traditional building physics models, and 2) by enabling validation from the clientsrsquo; perspective, focused on higher-level functional requirements. Keywords: Building Performance, Integrated Models, Post-occupancy Evaluation. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/E2304AB11360 en Copyright © 2006 Debajyoti Pati and Godfried Augenbroe
oai:academicjournals.org:IJPS:18623EA11384 2006-12-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Deterioration and corrosion in scoria based blended cement concrete subjected to mixed sulfate environment Khandaker M. Anwar Hossain Full Length Research Paper The use of blended cements incorporating supplementary cementing materials and cements with low C3A content is becoming common to prevent the deterioration of concrete structures subjected to aggressive environments. This paper presents the results of an investigation on the performance of finely ground volcanic scoria (VS) based ASTM Type I and Type V (low C3A) blended cement concrete mixtures with varying immersion period of up to 48 months in environments characterized by the presence of mixed magnesium-sodium sulfates. The concrete mixtures comprise a combination of two Portland cements (Type I and Type V) and two VS based blended cements with two water-to-binder ratio of 0.35 and 0.45. Background experiments (in addition to strength and fresh properties) including X-ray diffraction (XRD), Differential scanning calorimetry (DSC), mercury intrusion porosimetry (MIP) and rapid chloride permeability (RCP) were conducted on all concrete mixtures to determine phase composition, pozzolanic activity, porosity and chloride ion resistance. Deterioration of concrete due to mixed sulfate attack and corrosion of reinforcing steel were evaluated by assessing concrete weight loss and measuring corrosion potentials and polarization resistance at periodic intervals throughout the immersion period of 48 months. Plain (Type I/V) cement concretes, irrespective of their C3A content performed better in terms of deterioration and corrosion resistance compared to Type I/V VS based blended cement concrete mixtures in mixed sulfate environment. Keywords: volcanic scoria, sulfate attack, blended cement concrete, corrosion/deterioration Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/18623EA11384 en Copyright © 2006 Khandaker M. Anwar Hossain
oai:academicjournals.org:IJPS:4C2970811602 2006-12-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Magnetocatalytic adiabatic spin torque orbital transformations for novel chemical and catalytic reaction dynamics: The Little Effect Reginald B. Little Full Length Research Paper In this manuscript the theory and some phenomena associated with the Little Effect are introduced as the spin induced orbital dynamics of confined fermions under strong magnetic and thermal environments. This Little Effect is considered in details for the electron transfer reactions associated with redox processes of Cu-Ag alloy within de-ionized water and for the orbital dynamics during the iron catalyzed covalent bond rearrangements associated with amorphous carbon conversion to diamond. Furthermore, prolong extreme conditions of 74,000 amps, 403 V, strong Lorentz compression, and thermal stresses upon this Cu-Ag- H2O system on the basis of the Little Effect of high spin and thermally induced orbital dynamics are predicted and demonstrated to cause the magnetically organized reverse beta, electron capture, proton capture and neutron capture processes for various infrequent pycnonuclear transmutations within the Cu-Ag coil. The general experimental verification and the broad implications of this Little Effect on chemistry are demonstrated within these two ideal systems: an ionic case and a molecular case. The Little Effect is contrasted with the Hedvall Effect as a dynamical phenomenon causing the kinematics of the Hedvall Effect. The compatibility of the Little Effect with the Woodward-Hoffmann Rule is demonstrated. The Little Effect provides greater understanding of order in systems far from equilibrium. The implications of the Little Effect for other interesting phenomena such as ferromagnetism, unconventional magnetism, superparamagnetism, superconductivity, and pycnonuclear effects are concluded. Key words: chemical reaction dynamics, magnetic field, magnetism, pycnonuclear reactions, magnons, rotons, phonons. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/4C2970811602 en Copyright © 2006 Reginald B. Little
oai:academicjournals.org:IJPS:1CFF21E11605 2006-12-31T00:00:00Z AcademicJournals IJPS IJPS:2006
Adjustable filtering structure design dedicated to a programmable hearing aid apparatus Mongi Lahiani, Nidhal Ben Amor, Hamadi Ghariani, and Ahmed Ben Hamida Full Length Research Paper This research concerns the conception and the development of one specific circuit for a programmable hearing aid. In fact, actual hearing aid prosthesis should be flexible and programmable apparatus to the pathological case. First of all, it must be adjusted according to the pain threshold conserving all dynamics sound. Second, it must be adapted to different patient audiogram levels. In this article, we present the design of our conception using an adjustable amplifying chain formed by five analogue filters. In particular, such filters could be adjusted according to patient audiogram in order to compensate the considered hearing loss. Amplifier structure in this filtersrsquo; chain were independently controlled using current sources conceived by MOS transistors. At each amplifying structure, one could distinguish two stages referred as Amg and Amf : Amg was conceived to control the filterrsquo;s gain where Amf was conceived to control frequency band width. On the other hand, one MOS transistor current source was commanded by a Digital to Analogue Converter assuring then the possibility of programmability. The overall circuit was conceived using MOS technology in order to satisfy the low power incessant need for such biomedical applications. Key words: Programmable hearing aid, Filter, Amplifier, Digital to Analogue Converter. Academic Journals 2006 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/1CFF21E11605 en Copyright © 2006 Mongi Lahiani, Nidhal Ben Amor, Hamadi Ghariani, and Ahmed Ben Hamida
oai:academicjournals.org:IJPS:46967F212833 2007-01-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Patient dose reduction methods in computerized tomography procedures: A review M. A. AWEDA and R. A. AROGUNDADE Review Health hazards are associated with medical exposures to ionizing radiation, including during Computed Tomography (CT) procedures. Rapidly increasing number of CT facilities worldwide is accompanied by enhanced staff, patient and public radiation doses and these needs to be controlled to minimize health risks. This paper reviews the relevant patient and CT scanning parameters that influence patient dose during the common diagnostic procedures. These include scanning geometry, tube current, applied high potential (kVp), scanning mode and length, collimation, couch speed and pitch, gantry rotation speed and radiation shielding. The paper also presents some strategies for limiting patient dose through modulation of exposure parameters and design of technical devices for image processing. These include collimation, filtration, automated modulation of tube current, use of adaptive reconstruction and noise filters. Patient weight and size of the scanned anatomical part influence the absorbed dose, x-ray beam collimation and filtration can reduce dose by 17% to 50%, tube current modulation can lead to 10% to 60% reduction, projection adaptive reconstruction filter can reduce dose by 30% to 60% while noise filters can produce 17% reduction in noise variance compared with the conventional filters. Key phrases: Computerized Tomography, Patient Dose Reduction; Scanning Parameters Modulation. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/46967F212833 en Copyright © 2007 M. A. AWEDA and R. A. AROGUNDADE
oai:academicjournals.org:IJPS:5371F5812841 2007-01-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Comparative study on the adsorption kinetics and thermodynamics of dyes onto acid activated low cost carbon M. Hema and S. Arivoli Full Length Research Paper Batch experiments are carried out for the sorption of Congo red, Malachite green and Rhodamine B dyes onto acid activated carbon. The operating variables studied are initial dye concentration, pH, temperature and contact time. The equilibrium data are fitted to the Langmuir and Freundlich isotherm equations. From these the adsorption efficiency, adsorption energy, adsorption capacity, intensity of adsorption and dimensionless separation factor are calculated. The rate constant value for the adsorption process is calculated. The temperature thermodynamic parameters like ∆Gdeg;, ∆Hdeg;, and ∆Sdeg; are calculated from the effect of temperature. The mechanism of dye adsorption for that dye onto carbon is investigated by using the experimental results. Key words: Pandanus carbon, Congo red, Malachite green, Rhodamine B dyes, Adsorption isotherms-Langmuir and Freundlich isotherms, Adsorption energy, Adsorption efficiency, Kinetic studies, Thermodynamic parameters, pH effect, Effect of other ions, Regeneration pattern. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/5371F5812841 en Copyright © 2007 M. Hema and S. Arivoli
oai:academicjournals.org:IJPS:14274AE12860 2007-01-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Precision of sensitivity in the design optimization of indeterminate structures Surya N. Patnaik, Shantaram S. Pai and Dale A. Hopkins Full Length Research Paper Design sensitivity is central to most optimization methods. The analytical sensitivity expression for an indeterminate structural design optimization problem can be factored into a simple determinate term and a complicated indeterminate component. Sensitivity can be approximated by retaining only the determinate term and setting the indeterminate factor to zero. The optimum solution is reached with the approximate sensitivity. The central processing unit (CPU) time to solution is substantially reduced. The benefit that accrues from using the approximate sensitivity is quantified by solving a set of problems in a controlled environment. Each problem is solved twice: first using the closed-form sensitivity expression, then using the approximation. The problem solutions use the CometBoards testbed as the optimization tool with the integrated force method as the analyzer. The modification that may be required, to use the stiffness method as the analysis tool in optimization, is discussed. The design optimization problem of an indeterminate structure contains many dependent constraints because of the implicit relationship between stresses, as well as the relationship between the stresses and displacements. The design optimization process can become problematic because the implicit relationship reduces the rank of the sensitivity matrix. The proposed approximation restores the full rank and enhances the robustness of the design optimization method. Key words: Approximate sensitivity, design, optimization, singularity, implicit relationship, indeterminate structure. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/14274AE12860 en Copyright © 2007 Surya N. Patnaik, Shantaram S. Pai and Dale A. Hopkins
oai:academicjournals.org:IJPS:32F72A212872 2007-02-28T00:00:00Z AcademicJournals IJPS IJPS:2007
Environmental effect of mineral exploitation in Nigeria Aigbedion, I and Iyayi, S. E Review The three stages of mineral development, viz exploration, mining and processing, have caused different types of environmental damages, which include ecological disturbance, destruction of natural flora and fauna, pollution of air, land and water, instability of soil and rock masses, landscape degradation and radiation hazards. The environmental damage has in turn resulted in waste of arable land, as well as economic crops and trees. Since much of the damage is inevitable, if the minerals must be developed, both the government and the mineral industry must be involved in taking precautionary and remedial measures that can minimize the ill-effects of mineral development. Emphasis should shift from waste disposal to waste minimization through sorting, recycling of reagents and water. While the government should provide the regulatory legislation with appropriate sanctions, the mineral-producing companies are expected to carry out mandatory precautions, remedies or compensation for the damage done. Key words: Minerals, rock, mining, environmental degradation Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/32F72A212872 en Copyright © 2007 Aigbedion, I and Iyayi, S. E
oai:academicjournals.org:IJPS:7D99A2412877 2007-02-28T00:00:00Z AcademicJournals IJPS IJPS:2007
Effect of coconut fibre filler on the cure characteristics physico–mechanical and swelling properties of natural rubber vulcanisates Egwaikhide, P. A; Akporhonor, E. E and Okieimen, F. E Full Length Research Paper Investigation into the effect on the rheological, physico ndash; mechanical and swelling properties of natural rubber vulcanizates using coconut fibre as fillers were carried out. The coconut fibre was characterized in terms of pH, moisture content, ash content, loss on ignition, conductivity, particle size and surface area. The physico ndash; mechanical properties as well as the equilibrium swelling characteristics of the vulcanizates in organic solvents were measured as a function of filler loading and compared with the values obtained using commercial grade carbon black (N330). The coconut fibre showed good processing safety in terms of torques and scorch. For coconut fibre filled vulcanizates, optimum tensile strength of 7.35 MPa at 60 ph was recorded. It was found that vulcanizates with 60 ph showed maximum tensile properties. Hardness of filled vulcanizates with coconut fibre increased with filler loading. Abrasion resistance decreases marginally with increasing filler loading. A flex resistance and percentage compression set decreased with increasing filler loading. The equilibrium sorption in organic solvents of natural rubber vulcanizates filled with coconut fibre and carbon black decreased with increasing filler loading. However, the resistance to swelling of natural rubber compound is dependent on the amount of filler loading: the higher the filler content, the lower the equilibrium sorption values obtained. Key words: Vulcanizate, rheological properties, abrasion resistance, equilibrium sorption. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/7D99A2412877 en Copyright © 2007 Egwaikhide, P. A; Akporhonor, E. E and Okieimen, F. E
oai:academicjournals.org:IJPS:0C78C7E12892 2007-02-28T00:00:00Z AcademicJournals IJPS IJPS:2007
Utilization of coconut fibre carbon in the removal of soluble petroleum fraction polluted water P. A. Egwaikhide, E. E. Akporhonor and F. E Okieimen Short Communication Activated carbon powder was obtained by treating coconut fibre with ammonium chloride and carbonized at 400oC. The powdered activated carbon was sieved. The portion that passed through a 212 um and retained on a 90 um mesh size was used for this study. The treatment was done to increase the surface area and the adsorption site of the carbon. The activated carbon was characterized in terms of pH, surface area, loss on ignition, moisture content and bulk density. The adsorption pattern of soluble petroleum fraction (kerosene and diesel) on coconut fibre carbons as a function of time was studied. The removal of diesel and kerosene from aqueous solutions measured by changes in the chemical oxygen demand shows that removal efficiency was less than 45% corresponding to about 6.8 mg/l/g decreases in chemical oxygen demand (COD). The removal of diesel and kerosene from aqueous solution followed a psuedo first order rate law. Key words: Activated carbon, adsorption, chemical oxygen demand, characterisation, carbonisation. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/0C78C7E12892 en Copyright © 2007 P. A. Egwaikhide, E. E. Akporhonor and F. E Okieimen
oai:academicjournals.org:IJPS:F93E47212900 2007-02-28T00:00:00Z AcademicJournals IJPS IJPS:2007
Some electromagnetic transition properties and mixing ratios of tellurium isotopes Harun Reşit Yazar and İhsan Uluer Full Length Research Paper IBM-2 calculation is presented for the low-lying states in the even-even 122-128Te core nucleus. We developed the projection by using the F-spin formalism from the operator of IBA-2 model over the operator of IBA-1 model space. With the help of this projection IBA-2 Hamitonian parameters are obtained and we explore the energy levels and the electric quadrupole transition probabilities B (E2;Ii reg; If) and g-ray E2/M1 mixing ratios for selected transitions. It was found that the calculated positive parity low spin state energy spectra of the even-even 122-128Te isotopes agree quite well with the experimental data. Key words: Interacting boson model, the electric quadrupole transition probability, mixing ratios, Low spin states, PACS: 21.60. Fw, 23.20.Lv, 27.70. +q Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/F93E47212900 en Copyright © 2007 Harun Reşit Yazar and İhsan Uluer
oai:academicjournals.org:IJPS:66F5B4A12933 2007-03-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Determination of some trace metal levels in Asa river using AAS and XRF techniques Eletta O. A. A. Full Length Research Paper The determination of Fe, Mn, Pb, Zn, Cr and Cu concentrations in Asa River using Atomic Absorption Spectrophotometery (AAS) and X ndash; ray fluorescence (XRF) is discussed. Statistical analysis showed there was no significant difference in the concentrations of Cr, Zn, Pb and Cu using the two techniques but significant differences were observed at 5% probability level for Mn and Fe. This was attributed to differences in sample preparation as the two metals have been observed to be mainly of natural origin. It is suggested that they could have been trapped in the micro - particles in water since no digestion was carried out prior to XRF analysis. The boxplots were carried out using SPSS and the statistical analysis using ANOVA. Keywords: Atomic Absorption Spectrophotometry, X ndash; ray Fluorescence, micro ndash;particles Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/66F5B4A12933 en Copyright © 2007 Eletta O. A. A.
oai:academicjournals.org:IJPS:117B41112942 2007-03-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Characterization and physicochemical treatment of wastewater from rubber processing factory Asia, I. O. and Akporhonor, E. E. Full Length Research Paper Wastewater collected from rubber processing factory was characterized for their pollution characteristic. Results of the analysis show that the total solids, TS, suspended solid, SS and dissolve solid, DS, were 1528.5, 1078.5 and 450 mg/l respectively, the turbidity was 702 FTU. These values are high when compared to Federal Environmental Protection Agency (FEPA) effluent discharge standard for industrial wastewater. The dissolved oxygen content was 4.72 mg/l, the biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) were 2610.18 and 3142 mg/l respectively. The total bacterial count was 6.0 x 108 /100 ml. These results show that the wastewater has high pollution potentials and so need to be treated before discharged to the environment. The values for ammonia, Nitrate and Phosphate were 1.49, 1.36, 1.32 mg/l respectively. Heavy metals contents were within FEPA effluent discharge standard for industrial wastewater. The ratio of COD to BOD was 1.2:1, meaning that, the extent of biodegradation of the wastewater from this factory is less than 50%. This shows that biological treatment may not be suitable for its treatment. It conductivity is 320 Scm-1suggesting that the wastewater contain ions and so physicochemical method of coagulation and flocculation may be a good alternative for the treatment of this wastewater. Physicochemical treatment of this wastewater yielded substantial reduction in the solid concentration, BOD and COD, nitrate, phosphorus, and bacteria counts and so the treated effluent could be discharged safely into the environment without the fear of pollution. Keywords: Wastewater, rubber processing factory, pollution, physicochemical treatment, effluent discharge standard, environment. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/117B41112942 en Copyright © 2007 Asia, I. O. and Akporhonor, E. E.
oai:academicjournals.org:IJPS:34CA22912950 2007-03-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Spectrophotometric study of the solution interactions between riboflavin, sodium salicylate and caffeine Bolotin P. A., Baranovsky S. F., Chernyshev D. N. and Evstigneev M. P. Full Length Research Paper The self-association of Vitamin B2 (Riboflavin, RBF) and its hetero-association with Sodium Salicylate (NAS) and Caffeine (CAF) have been studied in aqueous solution by UV-Vis spectrophotometry. Using modified Benesi-Hildebrand approach equilibrium hetero-association constants were obtained for RBF-NAS [K = (25 plusmn; 4) M-1] and RBF-CAF [K = (69 plusmn; 4) M-1] systems at T = 298K. Absorption spectra of the vitamin in the mixed solutions with CAF/NAS evidence a bathochromic and hyperchromic shifts which are indicative of the hetero-association process between the dissolved molecules, most likely occurring via vertical stacking of their chromophores. Addition of Urea to the solutions of RBF-NAS and RBF-CAF decreases the stability of the hetero-complexes downto K = (17 plusmn; 3) M-1 and K = (51 plusmn; 7)M-1, respectively. Key words: Spectrophotometry, riboflavin, caffeine, nicotinamide, urea, hetero-association Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/34CA22912950 en Copyright © 2007 Bolotin P. A., Baranovsky S. F., Chernyshev D. N. and Evstigneev M. P.
oai:academicjournals.org:IJPS:B251D2112957 2007-03-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Photocatalytic degradation of methyl orange in aqueous TiO2 under different solar irradiation sources M. N. Rashed and A. A. El-Amin Full Length Research Paper The main causes of surface water and groundwater contamination are industrial discharges. Updating the field of polluted water treatment by photochemical technique has led to an important in oxidative degradation processes applying solar photochemical methods using crystal TiO2 as a catalyst. Photocatalytic oxidation of methyl orange dye under different irradiation sources (Halogen lamp 1000 W, fluorescent lamp and natural sun light ) have been studied over TiO2 catalyst. The effect of initial dye concentrations, irradiation time and light intensity were also studied. The results revealed that dyes under go fast degradation with the natural sun light than the halogen and fluorescent lamp sources. On other hand, fast degradation was obtained with increasing time of the Halogen and fluorescent lamps as a light source. The rate of decolorization was estimated from residual concentration spectro- photometrically. At the used experimental conditions the substrate photo-oxidation rate follows pseudo-first order kinetics. Keywords: Photodegradation, solar irradiation, dyes, pollution, treatment, catalyst Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/B251D2112957 en Copyright © 2007 M. N. Rashed and A. A. El-Amin
oai:academicjournals.org:IJPS:0295D5912976 2007-04-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Global dynamic of a mathematical model of competition in the chemostat M. S. Zaki Full Length Research Paper The purpose of this paper is to offer a complete global analysis of the behavior of solutions of either the variable - yield two microbial growths, limited by a single scare nutrient, or of competition between two microbial populations for a single limiting nutrient. Basically, we confirm that the variable - yield models make the same predictions concerning the growth of asingle population and concerning by out come of competition between two microbial populations, as the simpler constant - yield models. Key words: Chemostat, global stability, population dynamics, and equilibria. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/0295D5912976 en Copyright © 2007 M. S. Zaki
oai:academicjournals.org:IJPS:6CF786B13044 2007-04-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Implementation of a new 4th order runge kutta formula for solving initial value problems (I.V.Ps) G. U. Agbeboh, U .S. U Aashikpelokhai and I. Aigbedion Full Length Research Paper A new method for solving singular initial value problems in ordinary differential equations is developed and implemented using the test problem in (1). Results generated through a FORTRAN program were found to be highly accurate and consistent with minima errors in the solution of some selected singular ivps. A comparison of the results generated from the formula was carried out with other Runge Kutta formulae and were found to compare favourably well. Keywords: Discontinuity, Singularities, Runge- Kutta, Initial Value Problem (ivp). Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/6CF786B13044 en Copyright © 2007 G. U. Agbeboh, U .S. U Aashikpelokhai and I. Aigbedion
oai:academicjournals.org:IJPS:DEFE41513050 2007-04-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Ligand-dependent reactivity of cysF9(93)β of minor duck hemoglobin induced by inositol hexakisphosphate N. A. Adesola Babarinde, J. Oyebamiji Babalola and Olufemi O. Adeyemi Full Length Research Paper The reactivities of the sulphydryl groups of minor component of duck hemoglobin with 5,51-dithiobis-(2-nitrobenzoic acid), DTNB, in the presence of inositol hexakisphosphate (inositol-P6) have been studied. The reaction has been monitored as a function of pH (pH 7.0 ndash; 9.0) and at ionic strength of 50 mmolL-1. The carbonmonoxy and aquomet derivatives were used for the study. Biphasic time courses were obtained under all experimental conditions and the two kinetic phases were well separated along the time axis. From the observed pseudo-first order rate constants, kobs, the apparent second-order rate constants, kapp, were calculated. Inositol-P6 reduced the rates of all reactions for the two derivatives for both CysF9(93)beta; and CysB5(23)beta;. The reaction of CysF9(93)beta; gave an increase of 0.88 unit of pKa for the aquomet derivative but a decrease of 0.40 unit of pKa for the carbonmonoxy derivative. The salt-bridge formed between HisHC3 and AspFG1 is more strengthened by inositol-P6 in aquomet than in carbonmonoxy derivative. Key words: Duck, hemoglobin, sulphydryl, inositol-P6. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/DEFE41513050 en Copyright © 2007 N. A. Adesola Babarinde, J. Oyebamiji Babalola and Olufemi O. Adeyemi
oai:academicjournals.org:IJPS:E3EAA4713065 2007-04-30T00:00:00Z AcademicJournals IJPS IJPS:2007
A sonar system modeled after spatial hearing and echolocating bats for blind mobility aid Bitjoka Laurent and Takougang Noupowou Alain Christian Full Length Research Paper This paper present a sonar system modeled after human spatial hearing and echolocating bats. Itrsquo;s composed of three transducers, one transmitter which plays the role of the mouth of the bat that transmits echolocating signal and two receivers located respectively near the left ear and the right ear so as to mimic human ears configuration. Inaudible ultrasound echoes captured at the receivers are converted into audible sound using the Doppler shift frequency induced by the user during his movement. The two resulting audible Doppler signals are conveyed binaurally to the user through stereophonic earphones. The amplitude of these audible signals depends on the reflecting properties of the objects detected and their location. It increases as the distance between the system and the object decreases of about 10 decibels per meter. The intensity difference between them increases linearly with the azimuth of 0.34 decibel per degree. Experiments carried out with this sonar system show that it can be helpful to blind people in spatial sensing by supplying information regarding his movement as well as objects movement and their spatial location at the left side, at the right side or in front of him. Key words: Sonar system, blind mobility aid, spatial hearing, Doppler effect. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/E3EAA4713065 en Copyright © 2007 Bitjoka Laurent and Takougang Noupowou Alain Christian
oai:academicjournals.org:IJPS:59CA35213127 2007-05-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Heavy metal pollution and human biotoxic effects Duruibe, J. O., Ogwuegbu, M. O. C. and Egwurugwu, J. N. Full Length Research Paper Some heavy metals have bio-importance as trace elements but, the biotoxic effects of many of them in human biochemistry are of great concern. Hence, there is the need for proper understanding of the conditions, such as the concentrations and oxidation states, which make them harmful, and how biotoxicity occurs. It is also important to know their sources, leaching processes, chemical conversions and their modes of deposition to pollute the environment, which essentially supports lives. Literature sources point to the fact that these metals are released into the environment by both natural and anthropogenic sources, especially mining and industrial activities, and automobile exhausts (for lead). They leach into underground waters, moving along water pathways and eventually depositing in the aquifer, or are washed away by run-off into surface waters thereby resulting in water and subsequently soil pollution. Poisoning and toxicity in animals occur frequently through exchange and co-ordination mechanisms. When ingested, they combine with the bodyrsquo;s biomolecules, like proteins and enzymes to form stable biotoxic compounds, thereby mutilating their structures and hindering them from the bioreactions of their functions. This paper reviews certain heavy metals and their biotoxic effects on man and the mechanisms of their biochemical activities. Keywords: Biochemical, biotoxic, environment, heavy metals, pollution. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/59CA35213127 en Copyright © 2007 Duruibe, J. O., Ogwuegbu, M. O. C. and Egwurugwu, J. N.
oai:academicjournals.org:IJPS:A3A556013133 2007-05-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Adsorption kinetics and intraparticulate diffusivities for bioremediation of Co (II), Fe (II) and Cu (II) ions from waste water using modified and unmodified maize cob Igwe, J. C. and Abia, A. A. Full Length Research Paper Heavy metals constitute pollution problems to the environment and they are toxic to both man and aquatic organisms. The passive removal of toxic heavy metals such as cobalt (II) (Co(II)), iron (II) (Fe(II)) and copper (II) (Cu(II)) by inexpensive biomaterials, termed biosorption, requires that the substrate displays high metal uptake and selectivity, as well as suitable mechanical properties for applied remediation scenarios. The kinetics and intraparticulate diffusivities for the adsorption of these metal ions onto modified and unmodified maize cob was investigated. The amount of the metal ions adsorbed increased as time increased. The trend of the sorption capacity was found to be Co(II) gt; Fe(II) gt; Cu(II) for unmodified and Co(II) gt; Cu(II) gt; Fe for EDTA modified maize cob. The mechanism of adsorption of the metal ions followed particle diffusion model. The pseudo-first order and pseudo- second order kinetic equations were used to model the adsorption kinetics, with the second order giving a better fit, as seen from the correlation coefficient (R2) which ranged from 0.2329 to 0.9958 for pseudo first order and 0.9994 to 1.008 for pseudo-second order model. The applicability of the Elovich equation to the sorption kinetics was also investigated. This work therefore shows that modified and unmodified maize cob could be used to remove Co(II) Fe(II) and Cu(II) ions from waste water and also established their mechanism of sorption. Key words: Bioremediation, adsorption kinetics, heavy metal, maize cob. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/A3A556013133 en Copyright © 2007 Igwe, J. C. and Abia, A. A.
oai:academicjournals.org:IJPS:F7D333A13138 2007-05-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Completed Beltrami-Michell formulation in polar coordinates Surya N. Patnaik and Dale A. Hopkins Full Length Research Paper A set of conditions had not been formulated on the boundary of an elastic continuum since the time of Saint-Venant. This limitation prevented the formulation of a direct stress calculation method in elasticity for a continuum with a displacement boundary condition. The missed condition, referred to as the boundary compatibility condition, is now formulated in polar coordinates. The augmentation of the new condition completes the Beltrami-Michell formulation in polar coordinates. The completed formulation that includes equilibrium equations and a compatibility condition in the field as well as the traction and boundary compatibility condition is derived from the stationary condition of the variation functional of the integrated force method. The new method is illustrated by solving an example of a mixed boundary value problem for mechanical as well as thermal loads. Key words: Elasticity, Boundary, Compatibility, Variational, Derivation. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/F7D333A13138 en Copyright © 2007 Surya N. Patnaik and Dale A. Hopkins
oai:academicjournals.org:IJPS:B277E1213148 2007-06-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Effect of temperature on the solubility of haemoglobin modified with acetyl-3,5-dibromosalicylic acid Victor O. Njoku Full Length Research Paper Haemoglobin A was acetylated using acetyl-3,5-dibromosalicylic (dibromoaspirin). The acetylated haemoglobin showed enhanced solubility compared to the unmodified haemoglobin and its solubility was found to increase with temperature in the range 13deg;-37deg;C. From the plot of log solubility against the reciprocal of temperature, the DHdeg; was calculated to be 23.74 and 30.06 kJmol-1, for the modified and unmodified haemoglobin respectively. This indicates a reduction in the DHdeg; for the modified species. Since the solubility of haemoglobin is enhanced by acetylation with dibromoaspirin, dibromoaspirin might be an effective antisickling agent when administered at optimum temperature. Key words: Haemoglobin, acetyl-3,5-dibromosalicylic acid, protein, sickle cell anaemia, antisickling agent. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/B277E1213148 en Copyright © 2007 Victor O. Njoku
oai:academicjournals.org:IJPS:77813C413156 2007-06-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Reservoir fluid differentiation case study from Oredo field in the Niger Delta – Nigeria Aigbedion I. Full Length Research Paper The formations in the Niger Delta-Nigeria consist of sands and shales with the former ranging from fluvial (channel) to fluviomarine (Barrier Bar), while the latter are generally fluviomarine or lagoonal. These Formations are mostly unconsolidated and it is often not feasible to take core samples or make drill stem tests. Formation evaluation is consequently based mostly on logs, with the help of sidewall samples and wireline formation tests. From the comparison between the FDC/CNL (Formation Density/Neutron Logs spell out) separation and SWS (sidewell sample) petrophysical data, it is possible for fluid differentiation to be done from SWS measurement with a good measure of reliability, in the absence of production data and FDC/CNL logs. This may not apply to liquid ndash; rich gas and condensate reservoirs. The FDC/CNL log responses are better defined in thick clean sands as against thin marginal sands in this case study. Key words: Formations, Gas/Oil, Sands and Shales, Hydrocarbon, Porosity, Resistivity. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/77813C413156 en Copyright © 2007 Aigbedion I.
oai:academicjournals.org:IJPS:25FB69513166 2007-06-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Image enhancement using second generation wavelet super resolution M. El-Sayed Wahed Full Length Research Paper Second generation wavelet based super resolution algorithms developed in this research are presented in this paper. Generalization of the Second generation wavelet super resolution (SGWSR) algorithm to handle arbitrarily irregular 2-D grids as opposed to the semi-regular grids handled in the previous algorithm is introduced. A consequence is the ability to incorporate the projective camera motion model into the framework. Simultaneous noise filtering with super resolution is achieves. The generalization to the arbitrary 2-D version is subsequently described. Simulation results which demonstrate the improved performance of the developed super resolution algorithms in comparison to other approaches are also presented. Key words: Super resolution, second generation wavelets, blind deconvolution, optimal thresholding, blur support determination Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/25FB69513166 en Copyright © 2007 M. El-Sayed Wahed
oai:academicjournals.org:IJPS:31FE05413195 2007-07-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Levels of essential micronutrients in soils and growing plants around refuse dumpsites in Akure, Nigeria P. O. Oviasogie, A. A. Oshodi and E. Omoruyi Full Length Research Paper In the present study, the levels of some essential micronutrients (Fe, Mn, Zn and Cu) were determined in the soils and growing plants at the base and 25 m away from refuse dumpsites located in Akure, Ondo state, Nigeria. The soils and plants obtained were processed and analysed for these metals using the Bulk scientific GVP 210 atomic absorption spectropho-tometer. The results showed that the levels of Fe in soils at the base of the dumpsites were higher at the various locations investigated, the highest being 745.00 mg/kg at Oja oshodi, while the highest level at 25 m away from the sites was 441.00 mg/kg detected also at Oja Oshodi. This trend was followed by Mn with the highest amount (354.00 mg/kg) determine at the base of the refuse dumpsite at Idanre and Igbatoro roads respectively. Similarly, Zn and Cu had their highest levels (198.00 mg/kg Zn, 29.00 mg/kg Cu) in soils obtained from the base at the Oke-Ijebu and Oja Oshodi dumpsites respectively. The concentration of these metals in the roots tissue indicated that Fe was highest in the roots of Amaranthus cruentus (142.50 mg/kg dry matter). The level of Fe obtained was higher than the amount determined in the plants at 25m away from the dumpsites. There were equally various distributions of Mn Zn and Cu in the different tissues of the plants around the dumpsites. These study also revealed that the accumulation or uptake of these micronutrients depended not only on the availability of these metals as enriched at the base of the dumpsites but also on other factors which were not considered in the study. Key words: Micronutrients, dumpsite, uptake and plant tissue. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/31FE05413195 en Copyright © 2007 P. O. Oviasogie, A. A. Oshodi and E. Omoruyi
oai:academicjournals.org:IJPS:69B629713202 2007-07-31T00:00:00Z AcademicJournals IJPS IJPS:2007
The effect of moisture imbibition on cellulosic bast fibres as industrial raw materials U.U. Modibbo, B.A. Aliyu, I. I. Nkafamiya and A. J. Manji Full Length Research Paper The moisture imbibition on four Cellulosic bast fibres, Roselle (Hibiscus Sabdariffa), Okra (Hibiscus esculentus), Baobab (Adansonia digitata) and Kenaf (Hibiscus Cannabinus), were investigated. The fibres were chemically purified by retting, scouring, bleaching and mercerizing. Thereafter, moisture sorption method was adopted. The moisture imbibition ranking of the fibres is in the order. The materials were treated with 10, 15, 20 and 25% NaOH. The moisture imbibition for the treated materials were as follows: Roselle 20 gt; 25 gt; 10 gt; 15%; Okra 20 gt;15 gt;25gt;10%; Baobab 15 gt; 20 gt; 25 gt; 10% and Kenaf 20gt; 15 gt;10 gt;25%. These results suggest that the aforementioned fibres are viable industrial raw materials and have been a best alternative to inorganic/mineral - based reinforcing fibres. Key words: Moisture imbibition, bast fibres, moisture sorption. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/69B629713202 en Copyright © 2007 U.U. Modibbo, B.A. Aliyu, I. I. Nkafamiya and A. J. Manji
oai:academicjournals.org:IJPS:3E2A52B13206 2007-07-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Study of some physical properties of urea formaldehyde and urea proparaldehyde copolymer composite for emulsion paint formulation Osemeahon, S. A. and Barminas, J. T. Full Length Research Paper Copolymerization of urea formaldehyde (UF) and urea proparaldehyde (UP) was successfully carried out. Physical properties which include gel time, viscosity, density, melting point, moisture uptake, refractive index and formaldehyde emission level were evaluated. The infrared analysis of the pure amino resins and their copolymer (UF + UP) showed chemical interaction between UF and UP resins. Resin from the copolymer showed better results on optical property, flexibility, softness, density, water resistance and lower formaldehyde emission than the conventional UF resin. Physical properties of the copolymer such as viscosity, refractive index, moisture uptake, melting point and density are in agreement with values obtained in literature for other types of binders used in paint formulation. However, the gel time is relatively too high and hence the need for inclusion of a curing agent to increase the rate of cure of the copolymer resin. UF and UP copolymer resin present itself as a potential binder for emulsion paint formulation. Key words: Paint binder, amino resins, urea formaldehyde, urea proparaldehyde, copolymerization. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/3E2A52B13206 en Copyright © 2007 Osemeahon, S. A. and Barminas, J. T.
oai:academicjournals.org:IJPS:7620D3013215 2007-07-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Adsorption of lead ions from aqueous solution by okra wastes Mohsen A. Hashem Full Length Research Paper Okra wastes from food canning processes were used as a potential adsorption of lead removal from various aqueous solutions was performed. Parameters such as pH, temperature of the solution, particle size of okra wastes and the concentrations of adsorbent and adsorbate were studied to optimize the conditions to be utilized on a commercial scale for the decontamination of effluents using a batch adsorption technique. Adsorption parameters were determined using both Langmuir and Freundlich isotherms. The optimum pH for lead removal was between 4 and 6, the percentage of lead removal at equilibrium increases with increasing the amount of okra wastes and temperature. Better adsorption at higher temperatures. The removal of Pb2+ions attained 99%., this means that Pb2+ can be effectively removed from aqueous solutions by okra wastes. The mechanisms for adsorption of Pb2+ ions on to okra wastes involved ion exchange or the formation of hydroxyl complexes. The results obtained could be useful for the application of agricultural wastes for heavy metal removal from industrial wastewater. Key words: Adsorption, Pb2+ ion, Agricultural wastes, okra wastes. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/7620D3013215 en Copyright © 2007 Mohsen A. Hashem
oai:academicjournals.org:IJPS:76AD9E013220 2007-07-31T00:00:00Z AcademicJournals IJPS IJPS:2007
On asymptotic behaviour of a second order delay differential equation M. S. Zaki Short Communication In this paper, the relation between the oscillatory behavior of the solutions of second order differential equation and the oscillatory behaviour of the solutions of the corresponding delay differential equation is established. Also a necessary and sufficient condition for every bounded solution of the delay differential equations to have nonooscillatory solutions is given. A.M.S.C.: 34C10, 34C11, 34K15. Key words: Zeros, oscillatory and nonoscillatory solutions. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/76AD9E013220 en Copyright © 2007 M. S. Zaki
oai:academicjournals.org:IJPS:882889513231 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Removal of chromium from an aqueous solution using Azadirachta indica (neem) leaf powder as an adsorbent P. Venkateswarlu, M. Venkata Ratnam, D. Subba Rao and M. Venkateswara Rao Full Length Research Paper In the present investigation, Azadirachta indica (neem) leaf powder is used as an adsorbent for the removal of chromium from aqueous solutions. The equilibrium studies are systematically carried out in a batch process, covering various process parameters that include agitation time, adsorbent size and dosage, initial chromium concentration, volume of aqueous solution and pH of the aqueous solution. Adsorption behavior is found to follow Freundlich and Langmuir isotherms. The adsorption mechanism is described by a pseudo second order kinetics. Key words: Adsorption, neem, chromium, kinetics. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/882889513231 en Copyright © 2007 P. Venkateswarlu, M. Venkata Ratnam, D. Subba Rao and M. Venkateswara Rao
oai:academicjournals.org:IJPS:89BB55713234 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Free chlorine residual content within the drinking water distribution system Rosalam HJ. Sarbatly and Duduku Krishnaiah Full Length Research Paper This paper explains the principle of chlorination and reveals the free chlorine residual content within a drinking water distribution system located in peninsular Malaysia. The study found that the free chlorine at user points was slightly greater than 0.3 mg/l, which is higher than the WHO standard at 0.2 - 0.3 mg/l. Despite that it was not a guarantee to lower the level of the microbial since the results showed that the total coliform count was higher than the level suggested by Malaysian Water Association. Therefore, the tap water at the in-take point cannot be used for direct consumption but additional treatments such as filtration and boiling are required. Key words: Drinking water distribution system, free chlorine residual, coliform. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/89BB55713234 en Copyright © 2007 Rosalam HJ. Sarbatly and Duduku Krishnaiah
oai:academicjournals.org:IJPS:85C61F613237 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Pollution profiles of non-metallic inorganic and organic pollutants of drinking and potable waters due to mining activities in Ishiagu (Ebonyi State) of Nigeria Duruibe, Joseph O., Ogwuegbu, M. O. C. and Egwurugwu, Jude N. Full Length Research Paper The pollution of drinking and potable water sources due to mining activities in Ishiagu District of Ebonyi State of Nigeria, by non-metallic inorganic and organic pollutants was investigated. Water samples were abstracted from the Ivo River (IR), Ishiagu Central School borehole (IB), Amaokwe General Hospital borehole (AB), Amaeke community well (AW1) and Amata community well (AW2). The Ivo River courses through the areas of metal deposits and intensive mining activities at Ishiagu. The parameters analysed for were pH, conductivity, colour, odour, total suspended solids (TSS), total dissolved solids (TDS), total alkalinity, total acidity, Cl-, SO42-, NO3- PO43-, biochemical oxygen demand (BOD) and chemical oxygen demand (COD). The results showed that all the water sources had PO43- concentrations exceeding WHOrsquo;s tolerance limit, and the river water source was unwholesome for consumption due to high acidity; BOD and COD values for the well water sources do not support life and had high total solids (TS) and conductivity, while the borehole sources, though showing moderate to high conductivities and TS, seemed most suitable for consumption. Key words: Pollution, mining, Ishiagu, tolerance limits, NAFDAC. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/85C61F613237 en Copyright © 2007 Duruibe, Joseph O., Ogwuegbu, M. O. C. and Egwurugwu, Jude N.
oai:academicjournals.org:IJPS:D8CAE9213239 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Isotherm and thermodynamic studies of the biosorption of Cd(II) from solution by maize leaf N. A. Adesola Babarinde, J. Oyebamiji Babalola and S. Olalekan Sanni Full Length Research Paper The removal of Cd(II) from dilute solutions using maize (Zea mays) leaf as the biosorbent was studied. The effects of pH, contact time and initial metal ion concentration on the biosorption were monitored. The residual Cd(II) in solution was determined using atomic absorption spectrophotometer. The biosorption was found to be pH-dependent and the optimum pH for the biosorption was pH 3. The biosorption was also time-dependent as maximum biosorption was obtained after 2 h. The Freundlich equation obtained for the biosorption was log Г = 0.8775 log Ce + 1.095 while the Langmuir equation was 1/ Г = 0.0982/Ce ndash; 0.0058. The correlation factors were 0.9943 and 0.9869, respectively. The remo-val efficiency decreases with increase in initial Cd(II) concentration due to reduction in available binding site on the biosorbent for Cd (II). The free energy change for the biosorption at 300 K with an initial Cd(II) concentration of 100 mgL-1 and pH 3 was ndash;7.17 kJmol-1. These results indicate that maize leaf has potential for the uptake of Cd(II) from industrial effluents. Key words: Biosorption, Cd (II), adsorption isotherms, maize leaf, Zea mays. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/D8CAE9213239 en Copyright © 2007 N. A. Adesola Babarinde, J. Oyebamiji Babalola and S. Olalekan Sanni
oai:academicjournals.org:IJPS:70020C713242 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Synthesis and molluscicidal activity of some new substituted-furan and furo[2,3-d]pyrimidine derivatives Fathy M. Abdelrazek, Farid A. Michael and Sherif F. El-Mahrouky Full Length Research Paper 1-benzoyl-3-bromo-2-phenylpropenedinitrile derivative 1 reacted with potassium hydroxide to afford the furan derivatives 4 and 5. The furan derivative 5 reacted with formamide, phenyl isothiocyanate, malononitrile, and trichloroacetonitrile to afford the furo[2,3-d] pyrimidine derivatives 6, 8, 11 and 16 respectively. The reaction of 5 with ethyl cyanoacetate afforded however the furo[2,3-b]pyridine derivative 15. The molluscicidal activity of the synthesized compounds towards Biomphalaria alexanrina snails (the intermediate host of Schistosoma mansoni) was investigated and showed weak to moderate activity. Key words: 1-benzoyl-3-bromo-2-phenylpropenedinitrile, furans, furo [2, 3-d] pyrimidines. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/70020C713242 en Copyright © 2007 Fathy M. Abdelrazek, Farid A. Michael and Sherif F. El-Mahrouky
oai:academicjournals.org:IJPS:2D6DC1A13248 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
A robust nonlinear observer for states and parameters estimation and on-line adaptation of rotor time constant in sensorless induction motor drives M. Messaoudi, L. Sbita and M. N. Abdelkrim Full Length Research Paper This paper presents a robust non linear observer for variables and parameters estimation in sensorless Indirect Field Oriented Control (IFOC) of induction motors (IM). Based on the reduced order of the IM model, the rotor fluxes and time constant are estimated with the High Gain Observer (HGO) using only the stator currents and voltages. This reduced order model offers many advantages for real time identification and fault diagnosis of the IM. The major contributions of this work are: first, avoid the use of fluxes and speed sensors which increases the installation cost and degrades the mechanical robustness. Second, by reducing the order of the IM model, the implementation of the proposed observer doesnrsquo;t require a very effective Digital Signal Processor (DSP). Finally, we show that the proposed control scheme is not sensitive to disturbances and parametric errors and it is robust against load variations and measurement noises. Simulation results are provided to prove the effectiveness of the proposed method. Key words: Induction motor, field oriented control, sensorless, nonlinear observer, parameters estimation. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/2D6DC1A13248 en Copyright © 2007 M. Messaoudi, L. Sbita and M. N. Abdelkrim
oai:academicjournals.org:IJPS:4E06C1013258 2007-08-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Influence of electroporation on matrix metalloproteinases (MMPs) pattern activity in malignant glioma cells propagated ex vivo Monira M. Rageh, Anwar A. Elsayed, Amr A. Abd-Elghany, Mohammed S. Mohammed Full Length Research Paper Cells exposed to short and intense electric pulses become permeable to a number of various ionic molecules. This phenomenon was termed electroporation or electropermeabilization and is widely used for in vitro drug delivery into cells and gene transfection. The present work is a trial to study the effect of single exponential pulsed electric field (PEF) using intensity range 0.3 to 5.7 KV /cm and 1 m sec duration on human malignant glioma cells (U251MG). Under electrical conditions maintaining cell viability, no permeabilization can be detected for macromolecules such as DNA for pulse durations shorter than 1m sec. The aim of this study was to find optimum values of field strengths: First, to maintain cell viability for gene transfection and electrochemotherapy for further investigations. The above range of field strengths was used because a strong increase in the electric field intensity may increase transport of macromolecules, but as it may induce a loss in cell viability, indicated by the morphological observations in this study; it is associated with a decrease in plasmid expression. Second, to investigate the influence of PEF on metastatic biomolecules secreted in the cultured media such as matrix metalloproteinases (MMPs). MMPs enzyme activity was reduced at electric field intensities (0.3 - 1.15 KV/cm) by a factor of (25 - 100%). It is recommended to use the field intensity 0.85 KV/cm to put the glioma cells under biochemical stress during the electroporation protocol using single exponential pulse and 1 ms duration. Key words: Malignant glioma cells, electroporation, MMPs. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/4E06C1013258 en Copyright © 2007 Monira M. Rageh, Anwar A. Elsayed, Amr A. Abd-Elghany, Mohammed S. Mohammed
oai:academicjournals.org:IJPS:49DC7DD13266 2007-09-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Concentrations of residues from organochlorine pesticide in water and fish from some rivers in Edo State Nigeria Ize-Iyamu, O.K., Asia, I. O. and Egwakhide, P. A. Full Length Research Paper The levels of organochlorine pesticide residues in water and fish from some rivers in Edo State were determined. The water samples were extracted with 15% diethyl ether in hexane, the extracts were treated with copper tunings for the elimination of sulphur interference and analyzed using a gas chromatograph fitted with an electron capture detector. In all the water samples analyzed, the organochlorine pesticide residues determined (Lindane, Aldrin, pp-DDE, op-DDD, pp-DDD, op-DDT, and pp-DDT) were present, except in Ikoro River, where the water samples exhibited non-detectable levels of pp-DDE and pp-DDT. The level of pp-DDT, (0.7442 ppb) was highest in Ogba River, followed by Lindane (0.7130 ppb), Aldrin (0.5985ppb). Lindane (0.7928 and 0.5912ppb) was found to be highest in river Ovia and Ikoro respectively followed by Aldrin (0.7731 and 0.4867 ppb). The other organochlorine pesticides were present in varied levels from 0.3097 - 0.4860 ppb in Ogba River; ND-0.3100 ppb in Ikoro River and 0.3019 - 0.5557 ppb in Ovia River. The pesticides residues in fish samples were extracted by Soxhlet extraction process using a mixture of hexane and acetone, the extracts cleaned and analyzed using a gas chromatograph fitted with an electron capture detector. The organochlorine pesticide residues detected in water were also present in the fishes but at higher concentrations. This can be due to OCPs being lipophilic. The concentrations of these OCP residues were more in the bottom to middle feeders (Cts) than in the top to middle feeders (Tzs). Lindane levels (0.063 mg/g); 0.054 and 0.039 mg/g were detected in fish from Ovia, Ogba and Ikoro rivers respectively. While Aldrin was found present in 0.059 and 0.027 mg/g in the bottom and top feeders from Ovia river. However these levels were quite high when compared with the allowable Federal Environmental Protection Agency (FEPA) now Federal Ministry of Environment limits and can be harmful if the trend is not checked. Key words: Organochlorine, pesticide residues, rivers, fishes, safety, water, seafood. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/49DC7DD13266 en Copyright © 2007 Ize-Iyamu, O.K., Asia, I. O. and Egwakhide, P. A.
oai:academicjournals.org:IJPS:EFDD63C13271 2007-09-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Effect of urea formaldehyde viscosity on some physical properties of a composite from reactive blending of urea formaldehyde with natural rubber Osemeahon, S. A, Barminas, J. T and Aliyu, B. A Full Length Research Paper In this work, the effect of urea formaldehyde (UF) viscosity on a composite derived from reactive blend-ing of UF with natural rubber (NR) was investigated. Some physical properties of the urea formal-dehyde-natural rubber (UF-NR) obtained at different UF viscosities (2.1-256.3mPa.s) were evaluated. The melting point, refractive index, density and formaldehyde emission were found to increase with increase in UF viscosity while the dry time, moisture uptake and elongation at break were found to decrease with increase in viscosity. UF viscosity below 30.55mPa.s was found to produce UF-NR blend soluble in water and beyond this value the composite became insoluble in water. Thus processing of UF-NR blend for emulsion paint formulation could be suggested below this viscosity level. The result obtained from this experiment will offer formulators different options and to control formulation processes towards developing a paint binder for emulsion paint formulation from UF-NR blend, which may be acceptable to the coating industry. Key words: Paint binder, amino resins, urea formaldehyde, natural rubber, viscosity. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/EFDD63C13271 en Copyright © 2007 Osemeahon, S. A, Barminas, J. T and Aliyu, B. A
oai:academicjournals.org:IJPS:3D9701213275 2007-09-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Evaluation of soil profile on aquifer layer of three locations in Edo state O.M. Alile, W.A Molindo and M.A. Nwachokor Full Length Research Paper This investigation was carried out in three locations (Ekpoma, Irrua, and Uromi) all in Esan central and North-East region respectively of Edo state, Nigeria. The aim was to find out how soil profile depth is related to aquifer layer. Verifying how relief and (physical properties) such as heat, temperature, and resistivity affects the aquifer layer. Result of the study proved that location, relief, and the factors, such as radiation, heat, temperature, resistivity and moisture contributed to either a low or high aquifer layer. Increased radiation resulted to increment in temperature, heat, resistivity, and less moisture content in the soil profile horizon. Whereas relief was an over riding factor that influence the aquifer depth. With maximum soil profile depth of 528.90, 476.67, and 495.96 m, the aquifer layers for Ekpoma, Irrua, and Uromi respectively indicated that relief played a prominent role as observed in their topography. Therefore in hydrological investigation the contribution of this study would give a guide on effective aquifer layer position in the studied location in Edo State Nigeria. Key words: Evaluation, soil profile, aquifer layer. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/3D9701213275 en Copyright © 2007 O.M. Alile, W.A Molindo and M.A. Nwachokor
oai:academicjournals.org:IJPS:C42196513277 2007-09-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Registration of totally aliased signals M. El-Sayed Wahed Full Length Research Paper In this paper, we present a new method for signal reconstruction from multiple sets of samples with unknown offsets which can be written as a set of polynomial equations in both the unknown signal coefficients and the offsets. The solution can then be computed using Groebner bases. In any practical setting, the samples are corrupted by noise, and then there is no algebraic solution. Thus, the next step is to address this noisy version of the problem, and to show how a good approximation can be obtained from multiple Groebner bases for subsets of samples. This provides us with an elegant solution method for the initial nonlinear problem. We show two examples for the reconstruction of polynomial signals and Fourier series. Keywords: Algebraic geometry, deconvolution, exact deconvolution, finite response, Groebner Basis, multichannel, multidimensional, multivariate. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/C42196513277 en Copyright © 2007 M. El-Sayed Wahed
oai:academicjournals.org:IJPS:000452513283 2007-10-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Diversifying Nigeria’s Petroleum Industry Aigbedion, I and Iyayi S.E Review The petroleum industry in Nigeria has brought unprecedented changes to the Nigerian economy, particularly in the past five decades when it replaced agriculture as the cornerstone of the Nigeria economy. The oil industry has risen to the commanding heights of the Nigerian economy, contributing the lion share to gross domestic product and accounting for the bulk of federal government revenue and foreign exchange earnings since early 1970. However, Nigeriarsquo;s considerable endowment in fossil fuel has not translated into an enviable economic performance; rather, the nationrsquo;s mono-cultural has assumed a precarious dimension in the past decades susceptible to the vagaries of the international oil markets. Nigeriarsquo;s extreme reliance on the crude oil market has triggered structural difficulties for the economy, as earnings from crude oil fluctuate along with market trends which are exacerbated by the countryrsquo;s neglect of other productive sectors of the economy. This negative trend has persisted despite various economic reforms embraced by successive Nigerian governments since 1980. Unless the country deepens its economic reform initiatives to include effective diversification of the petroleum sector, the performance of the economy will continue its unimpressive trend. Diversification of the economy should also extend beyond the Petroleum sector so that the country can become a major force in the emergent global economic order of the 21st century. Policy makers should develop the nationrsquo;s vast resources in the agricultural and solid mineral sectors for the global markets and reap the benefits that accompany economic diversification. Key words: Crude oil, natural gas reserve, minerals, environmental effect, export diversification Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/000452513283 en Copyright © 2007 Aigbedion, I and Iyayi S.E
oai:academicjournals.org:IJPS:47588DB13288 2007-10-31T00:00:00Z AcademicJournals IJPS IJPS:2007
The effects of petroleum exploration and production operations on the heavy metals contents of soil and groundwater in the Niger Delta Asia, I. O., Jegede, S. I., Jegede, D. A., Ize-Iyamu O. K. and Akpasubi E. Bernard Full Length Research Paper Soil and water samples obtained from four sampling points; around an oil well head, flare site, waste pit and effluent discharge point in an exploration area in the Niger Delta were analysed for their heavy metals contents. The results showed that the amount of lead present in the soil ranges from 3.40 ndash; 99.40 mg/kg, copper values were in the range of 5.10 ndash; 49.30 mg/kg, Nickel concentration vary from 1.60 ndash; 13.80 mg/kg, values for cadmium, iron, zinc, and chromium were 0.04 ndash; 0.95 mg/kg, 536.00 ndash; 12,872.00 mg/kg, 11.1 ndash; 274.00 mg/kg and 1.30 ndash; 165.00 mg/kg respectively. Apart from zinc and nickel, all other heavy metals were higher than the toxicity limits for heavy metals in natural soil; this implies pollution of the soil by heavy metals. Also the waters were found to be polluted by lead, the pH of the water samples was found to deviate significantly from DPR limits and W.H.O. standard for potable water. This also implies pollution. Remediation measures were suggested so as to render the soil and ground water fit for use. Key words: Soil, water, heavy metals, pollution, exploration area, Niger Delta. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/47588DB13288 en Copyright © 2007 Asia, I. O., Jegede, S. I., Jegede, D. A., Ize-Iyamu O. K. and Akpasubi E. Bernard
oai:academicjournals.org:IJPS:DC444BE13291 2007-10-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Covariance transformations for flame-propagation modeling R. C. Aldredge Full Length Research Paper The covariance transformation used in earlier theoretical studies of turbulent-flame and isothermal-front propagation is defined and mathematically derived. This transformation provides the covariance associated with fluctuations of a turbulent scalar or vector-component variable in terms of the statistical properties of another fluctuating scalar or vector-component variable when the Fourier transforms of the two variables in transverse-wave number and frequency space are linearly dependent. Key words: Covariance, turbulence, turbulent combustion, front propagation, flame propagation Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/DC444BE13291 en Copyright © 2007 R. C. Aldredge
oai:academicjournals.org:IJPS:710EAC013294 2007-10-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Effect of the rotation matrix factorization on the quality of images rotation Bitjoka Laurent and Boukar Ousman Full Length Research Paper Most efficient algorithms for rotating 2D images are based on the succession of three translations, following the lines, then the columns and the lines of the image again (LCL). These translations result from the decomposition of the rotation matrix into a product of an upper triangular matrix, a lower triangular matrix and an upper triangular matrix (ULU). We have shown in this paper that the decomposition of the rotation matrix is not unique and have separated it into a product of a lower triangular matrix, an upper triangular matrix and a lower triangular matrix (LUL). This new decomposition led to a new algorithm based on a succession of three translations following the columns, then the lines and the columns of the images again (CLC). Statistical analysis of experimental results showed that the computational complexity of images rotation does not depend significantly (pgt;0.05) on the factorization ULU or LUL,whereas the precision depends on it significantly (plt;0.05). Each of the two algorithms of rotation is more precise for certain images and for certain angles. The method can be generalized in a case of 3D image rotation using the Euler angles. Key words: Images rotation, rotation matrix, matrix factorization, LCL algorithm, CLC algorithm. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/710EAC013294 en Copyright © 2007 Bitjoka Laurent and Boukar Ousman
oai:academicjournals.org:IJPS:35FCF5613301 2007-11-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Analysis of street dust for heavy metal pollutants in Mubi, Adamawa State, Nigeria Shinggu, D. Y., Ogugbuaja, V. O.., Barminas, J. T., and Toma, I. Full Length Research Paper This study is aimed at determining the elemental concentrations of heavy metal pollutants that may be present in street dust samples in Mubi, Adamawa state, Nigeria. Dust samples were collected in mechanical workshops (MWK), motor parks (MPK), market areas (MKA), roundabouts/highways (RHW) and residential areas (RDA). The dust samples were digested using aqua regia digestion method and Flame Atomic Absorption Spectrophotometer was used for the elemental analyses. The variation in concentration of most of the heavy metals determined from different sites decreases in an order represented as MWK gt;MPK gt;MKA gt;RHW gt; RDA. The heavy metals showed a variation that indicated that Fe gt;gt;gt; Zn gt;gt; Pb gt;gt; Cu gt;gt; Cd, Iron (Fe) had the highest concentration in all the sampling areas with range of 5330.50 plusmn; 499. 80 minus; 24100.00 plusmn; 968.20 g/g. A lower value was observed for Cd with respective range of 0.59 plusmn; 0.19 minus; 1.33 plusmn; 0.36 g/g. Cobalt and Selenium were not detected in all the samples. Statistical analysis by ANOVA and t-test showed a significant difference (Plt;0.05) between the elements determined. This suggested that, the heavy metal pollutants in street dust samples of Mubi did not originate from common anthropogenic sources becausesome heavy metals are soil derived. Probably automobile emission, welding of metal and exhaust from generators may be the major sources of the elements. Key words: Metal pollution, dust, sampling sites, automobile emission, atomic absorption spectrophotometer, toxic substances, concentration. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/35FCF5613301 en Copyright © 2007 Shinggu, D. Y., Ogugbuaja, V. O.., Barminas, J. T., and Toma, I.
oai:academicjournals.org:IJPS:529BE5F13303 2007-11-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Preliminary evaluation on the application of grafted membranes for sorption of lead and copper ions in aqueous solution S. A. Osemeahon, J. T. Barminas, B. A. Aliyu and H. M. Maina Full Length Research Paper Blend membrane of sodium alginate (Na-Alg) and poly (acrylamide) grafted konkoli gum (KG-g-PAAM) in the ratio of 80:20 was studied for sorption of Pb2+ and Cu2+ in aqueous solution. Membrane sorption capacities for Pb2+ and Cu2+ were found to be 99.18% and 63.32% respectively. The sorption behavior with respect to contact time, initial pH, temperature, ionic strength and initial metal ion concentration were investigated in order to determine the optimum sorption conditions. Results showed that metal ion uptake by the membrane decreases with increasing temperature and ionic strength while increase in initial metal ion concentration led to increase in metal ion uptake. Maximum sorption was found to occur at pH 5 for both metal ions studied. The ability of the grafted membrane to remove some heavy metals from aqueous solution is encouraging and may be used in bioremediation of wastewaters. Key words: Konkoli gum, blending, sodium alginate, membrane, sorption, metal ions. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/529BE5F13303 en Copyright © 2007 S. A. Osemeahon, J. T. Barminas, B. A. Aliyu and H. M. Maina
oai:academicjournals.org:IJPS:DFE94FE13305 2007-11-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Isotherm and thermodynamic studies of the biosorption of copper (II) ions by Erythrodontium barteri N. A. Adesola Babarinde, O. O.Oyesiku and Omolola F. Dairo Full Length Research Paper The biosorption of Cu(II) from dilute aqueous solution using Erythrodontium barteri as a biosorbent has been studied as a function of pH, contact time and initial Cu(II) ion concentration at the temperature of 27oshy;shy;shy;C. The residual Cu(II) in solution was determined using atomic absorption spectrophotometer. The pH study shows that pH dependence of biosorption and optimum pH was 5. The study on contact time shows that the biosorption is time dependent and maximum biosorption was obtained after 150 min. The adsorption isotherms obtained fitted well into the Freundlich and Langmuir isotherms. The Freundlichequation obtained is log Gamma; = 0.8549log Ce + 1.5566 while the Langmuir equation is: = 0.0254/Ce + 0.0026 with correlation factors of 0.9917 and 0.9907, respectively. The standard deviations are 0.0159 and 0.0006, respectively. The free energy change (Delta;G˚) obtained for the biosorption of Cu(II) at the temperature of 297K, initial Cu(II) concentration of 100 mgL-1 and pH 5 is -11.108 kJmol-1. This result indicates that the biosorption process is highly spontaneous and therefore shows that Erythrodontium barteri biomass could be successfully used for the biosorption of Cu(II) from waste streams. Key words: Biosorption, Erythrodontium barteri, copper (II), isotherm. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/DFE94FE13305 en Copyright © 2007 N. A. Adesola Babarinde, O. O.Oyesiku and Omolola F. Dairo
oai:academicjournals.org:IJPS:937512C13308 2007-11-30T00:00:00Z AcademicJournals IJPS IJPS:2007
Enhanced measured synchronization of unsynchronized sources: inspecting the physiological significance of synchronization analysis of whole brain electrophysiological recordings Luis Garciacute;a Domiacute;nguez, Richard Wennberg, Joseacute; L. Peacute;rez Velaacute;zquez, Ramoacute;n Guevara Erra. Full Length Research Paper The analysis of synchronization, particularly phase locking, is being increasingly used in neuroscience to explore coordinated brain activity. The application of this methodology to magnetoencephalographic (MEG) and electroencephalographic (EEG) recordings would seem promising because these two recording techniques are not invasive and have great temporal resolution. However, current methods of synchronization analysis applied directly to raw MEG/EEG data may produce distorted results. In this work we introduce a model of brain activity based on random current dipoles that reproduces the main characteristics observed in measurements of real data synchronization, even when no synchronized activity is taking place among the sources. In particular we describe the effect of field superposition alone when secondary currents are excluded. It is also shown that the enhanced local synchronization, previously described in some studies of epileptic seizures, may result from the activity of only a few unsynchronized sources. We suggest three lines of research for further development and improvement to obtain more precise physiological interpretations of the synchronization analysis. Key words: Phase synchronization, Magnetoencephalography, Epilepsy Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/937512C13308 en Copyright © 2007 Luis Garciacute;a Domiacute;nguez, Richard Wennberg, Joseacute; L. Peacute;rez Velaacute;zquez, Ramoacute;n Guevara Erra.
oai:academicjournals.org:IJPS:6AB00C513313 2007-12-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Software development: An attainable goal for sustainable economic growth in developing nations: The Nigeria experience Momodu Ibrahim Bayo, Nnebe Samuel Ekene, Agbasi Kenneth C. and Sadiq Fatai Idowu Survey Recently, there has been increasing demand in the knowledge and application of quality software to improve the socio-economic growth in Nigeria. This becomes necessary in the face of unique position software products and processes helping to generate revenue in most advanced nations and some developing nations in the world. This paper surveys software development and its impact to both developed and developing nations with emphasis on the Nigerian economy. We outlined the range of considerations specific to software within Information and Communication Technologies (ICTs) planning and discuss government role in accelerating and shaping that growth in support of social, culture and economic priorities. The problems faced by software growth in the industry are also addressed with a view to proffer solutions. Keywords: ICT; IT; Software; Software development;Information; economic growth. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/6AB00C513313 en Copyright © 2007 Momodu Ibrahim Bayo, Nnebe Samuel Ekene, Agbasi Kenneth C. and Sadiq Fatai Idowu
oai:academicjournals.org:IJPS:D73D83513314 2007-12-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Multiplicity distributions in 24Mg-emulsion collisions at 4.5 A GeV/c. M. E. Solite and A. Abd El-Daiem Full Length Research Paper The experimental results of target multiplicity distributions in 24Mg emulsion collisions at 4.5 A GeV/c are reported. The multiplicity distributions of target fragments, the correlations between the multiplicity distributions and the projectile fragments, as well as the correlations between the black and gray fragments are given. A comparison between theory and experiment among24Mg and 16O at various energies is reported too. Key words: Multiplicity, angular distribution and correlation measurements, projectile and target fragmentation, multifragment emission and correlation. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/D73D83513314 en Copyright © 2007 M. E. Solite and A. Abd El-Daiem
oai:academicjournals.org:IJPS:9E6A41513315 2007-12-31T00:00:00Z AcademicJournals IJPS IJPS:2007
Prediction and measurement of the elastic modulus of the RCC: Case of the low cement proportioning Mustapha Zdiri , Mongi Ben Ouezdou and Nor-edine Abriak Full Length Research Paper The Roller Compacted Concrete (RCC), which is presented as an evolutionary technology for a large diversity of applications (Dams, roads...), is considered, like conventional concretes and other construction materials, as an elastic material. The RCC in pavement supports many stresses which involve deformations and reciprocally. The knowledge of the relation between strength and deformation, for a material such as the RCC, presents a capital interest for the structural design of rigid pavements. The authors treat, in this work the experimental evaluation and the estimation, through a model, of the Young#39;s elastic modulus E of the RCC for pavement manufactured with low cement proportioning. This work includes experimental measurements of the elastic modulus E on standardized specimens prepared according to the method of the French National Project quot;BaCaRaquot;. It contains also the comparison of the measured modulus with those estimated by the models. Key words: Roller Compacted Concrete (RCC), granular materials, Elasticity, Elastic modulus, models. Academic Journals 2007 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/9E6A41513315 en Copyright © 2007 Mustapha Zdiri , Mongi Ben Ouezdou and Nor-edine Abriak
oai:academicjournals.org:IJPS:545B3F114358 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Groundwater fluoride levels in villages of Southern Malawi and removal studies using bauxite Sajidu, S. M. I., Masamba, W. R. L., Thole, B. and Mwatseteza, J. F. Full Length Research Paper Dental and skeletal fluorosis are known to be caused by excessive fluoride ingestion particularly from drinking water sources. Dental fluorosis is common in some parts of Malawi but studies on fluoride levels of drinking water sources have not been adequately done. This paper presents our findings in fluoride levels of some drinking water sources in selected rural areas of Southern Malawi and studies on the potential of locally sourced bauxite in water defluoridation at laboratory scale. The work has revealed high levels of fluorides (gt;1.5 mg/L) in some parts of the study area. A positive correlation was observed between the pH of the water and fluoride concentrations. No correlation existed between fluoride concentration and electroconductivity. Experiments on water defluoridation with bauxite showed that the raw bauxite has a capacity of 93.8 % at a dose of 2.5g/200 ml of 8 mg/L F- solution. Powder X-ray diffraction characterization of the raw bauxite showed gibbsite (Al(OH)3) and kaolinite (Al2Si2O5(OH)4) as the major components. The high defluoridation capacity of the bauxite is thus attributable to gibbsite and kaolinite minerals. Precipitation of AlF3 is predicted to be the fluoride removal mechanism with the gibbsite while exchange of OH- groups in the gibbsite layers of the kaolinite with F- ions occurs in the kaolinite component of the defluoridation material. Evaluated by the residual fluoride concentration in solution the fluoride uptake reaction kinetics of the system was found to be consistent with pseudo-first-order kinetics. Key words: Fluoride, bauxite, Southern Malawi, gibbsite, kaolinite. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/545B3F114358 en Copyright © 2008 Sajidu, S. M. I., Masamba, W. R. L., Thole, B. and Mwatseteza, J. F.
oai:academicjournals.org:IJPS:AA3E72F14364 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
On the solution of an HIV- immune dynamic system Zeinab A. Elsady Full Length Research Paper Some mathematical properties of nonlinear system associated with an HIV- Immune dynamic model will be given. The considered model will be solved numerically. The numerical method permits the examination of the behaviour of the dynamic system on long-term. In the same time, it is easy to implement, fast convergent and has a very competitive stability results. Numerical results demonstrate the effect of improving the function of the thymus on the viral growth and T cell population. Key words: Mathematical immunology, dynamic system, HIV, critical points, finite difference, convergence. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/AA3E72F14364 en Copyright © 2008 Zeinab A. Elsady
oai:academicjournals.org:IJPS:9A240BE14368 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Complex of nickel (II) with isonicotinohydroxamic acid Aliyu, A.O. and Nwabueze, J. N. Full Length Research Paper Isonicotinohydroxamic acid (INHA) was synthesized, characterized, and its pKa determined spectrophotometrically as 8.680.05 at 25oC and in buffers of 0.1 mol dm-3 ionic strength (I). A spectroscopic investigation of its reaction with NiII in aqueous solution revealed the sole formation of the 1:2 complex at equilibrium. Spectra and magnetic studies of the isolated complex indicate octahedral coordination via the (N) atom of the hydroxamate group. Microbial sensitivity test on eight microorganisms used showed no activity. Key words: Nickel (II), spectrophotometry, buffer, hydroxamate group, octahedral coordination microbial sensitivity. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/9A240BE14368 en Copyright © 2008 Aliyu, A.O. and Nwabueze, J. N.
oai:academicjournals.org:IJPS:B663F2B14371 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Extraction of Eu(III) from nitrate medium by CYANEX921 using solvent extraction technique Nasser S. Awwad , H. M. H.Gad and H. F. Aly Full Length Research Paper The extraction of Eu(III) was investigated from nitrate medium by CYANEX921 (C921). It was found that the chemical formula of the main extracted species in the organic phase is Eu(NO3)3.3[C921] for extraction by C921. It was found that the Eu(III) percent extracted from toluene, n-hexane, cyclohexane and kerosene was nearly similar but with faster phase separation in favor of toluene. The relation between the shaking time and the percent of extracted C921 (%E) was studied at different pH. It was found that the best shaking time is 20 min at pH between 0.5-1.0, whereas at pH 2.0 the best shaking time is 15 min. The maximum extraction of Eu(III) was found to be after 5 min at pH 3.0. The extraction of Eu(III) increase with increasing of pH, however, the extraction precent increase from 28.5% at pH 0.5 to 98% at pH 3.0 The calculated average for the extraction constant is 6.58 at pH 3.0 under various C921 concentrations. From the data obtained, it was found that arsenazoIII (AIII) is a good stripper for Eu from organic phase which reach to 65% at pH 2. The stripping of Eu decreased from 57% to 2% when rising the pH from 0.5 to 11. Key word: Solvent extraction, europium(III), CYANEX92, nitrate media, stripping. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/B663F2B14371 en Copyright © 2008 Nasser S. Awwad , H. M. H.Gad and H. F. Aly
oai:academicjournals.org:IJPS:5C3DF4A14378 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Rb-Sr and U-Pb age dating of granite rocks by inductively coupled plasma mass spectrometry J. Hefne, O. Aldayel, M. A. Amr, O. Alharbi Full Length Research Paper Inductively coupled plasma-mass spectrometry (ICP-MS) was used as alternative to thermal ionization mass spectrometer (TIMS) for age dating of granite samples originating from different magmatic volcanic rock formations on the Arabian shield. Cation exchange chromatography was used to avoid isobaric overlap of 87Rb with87Sr and 204Hg with 204Pb ions signals to the largest possible extent, while mathematical correction was applied to correct for the remaining interference. Sr was separated from its matrix using a crown ether-Eichrom#39;s Sr resin. Pb separated from its matrix by developing a method using a crown ether-Eichrom#39;s Sr resin. The accuracy of the method developed was evaluated by means of isotopic analysis of strontium carbonate SRM-987 and common lead SRM-981 isotopic standards from NIST. Precisions of 87Sr/86Sr and 206Pb/204Pb isotope ratios measurements are lt; 0.1% and 0.3% (1), respectively. Overall, this case study shows the merits of ICP-MS for exploratory age determinations and studies of 87Sr/86Sr and 206Pb/204Pb isotope ratios which can differentiate between magmatic origin of granite. Key words: Age dating, ICP-MS, granite, U-Pb, Rb-Sr. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/5C3DF4A14378 en Copyright © 2008 J. Hefne, O. Aldayel, M. A. Amr, O. Alharbi
oai:academicjournals.org:IJPS:8FAE50114381 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Calculation of the Mie scattering field inside and outside a coated spherical particle Honoh Suzuki and I-Yin Sandy Lee Full Length Research Paper A procedure to compute intensity distributions generated by the Mie scattering from a single coated sphere is described, and applied to a nanoshell and a microshell. The obtained information on the near-field intensity and the absorbed energy density is shown to be useful in predicting optical properties of the core-shell structure for applications. Key words: Nanoparticles, Mie theory, near-field effects, absorbed energy density. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/8FAE50114381 en Copyright © 2008 Honoh Suzuki and I-Yin Sandy Lee
oai:academicjournals.org:IJPS:31835C214384 2008-01-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Laser-induced emission from dye-doped nanoparticle aggregates of poly (DL-lactide-co-glycolide) Honoh Suzuki, I-Yin Sandy Lee, and Naomi Maeda Short Communication Stable nanoparticles of poly (DL-lactide-co-glycolide) (PLGA) have been prepared, which is photosensitized with near-infrared chromophores doped into the particle. Laser-induced white-light emission is observed from aggregates of the dye-doped nanoparticles, which shows spatial interference of nonlinear optical processes as the underlying mechanism. The accompanied break-up of the aggregates is promising as a possible mechanism for laser-triggered release of drugs. Key words: Nanoparticles, poly(DL-lactide-co-glycolide), aggregates, near-infrared laser, multiple scattering Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/31835C214384 en Copyright © 2008 Honoh Suzuki, I-Yin Sandy Lee, and Naomi Maeda
oai:academicjournals.org:IJPS:44C05C314400 2008-02-29T00:00:00Z AcademicJournals IJPS IJPS:2008
Effect of mixture components on the properties of MUF resin Awang Bono, Rosalam Sarbatly, Subalinee Kaluvan, Mariani Rajin and Duduku Krishnaiah Full Length Research Paper The effect of disodium tetraborate decahydrate (DTD) on the properties of melamine-urea-formaldehyde (MUF) resin was studied. The leachability from the MUF resin into solvents was investigated. The solvents chosen in this research were distilled water, 10% ethanol, and 30% ethanol. The main constituents that contribute to the leaching in water are melamine, additional urea, and DTD concentrations. Based on the statistical analysis using Response Surface Methodology, it was found that melamine and DTD should be reduced and additional urea required to get the least leach out in water. For 10% ethanol, the components that contribute to the leaching were melamine, initial urea. Therefore, these should be reduced to get the least leach out in 10% ethanol. The similar trend was also observed in the case of 30% ethanol solvent. On the other hand, addition of DTD resulted in longer resinrsquo;s shelf-life and better water solubility. However, DTD gave higher resin viscosity and pH. Key words: Melamine-urea-formaldehyde resin, disodium tetraborate decahydrate, leachability, shelf-life, viscosity. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/44C05C314400 en Copyright © 2008 Awang Bono, Rosalam Sarbatly, Subalinee Kaluvan, Mariani Rajin and Duduku Krishnaiah
oai:academicjournals.org:IJPS:E24095914405 2008-02-29T00:00:00Z AcademicJournals IJPS IJPS:2008
Kinetic, isotherm and thermodynamic studies of the biosorption of zinc (II) from solution by maize wrapper N. A. Adesola Babarinde, J. Oyebamiji Babalola and Olasumbo B. Adebisi Full Length Research Paper The removal of Zn2+ from dilute aqueous solution using maize (Zea mays) wrapper as the biosorbent is reported in this paper. Batch experiments were carried out to assess biosorption kinetic and equilibrium behaviour of Zn2+ by varying parameters such as pH, contact time and initial metal ion concentration at 27ordm;C. The analysis of residual metal ions was determined using atomic absorption spectrophotometer. The pH study shows that the initial pH would play a vital role in the biosorption of the Zn2+ from solution. The optimum pH obtained was in the range pH 5 - 7, therefore pH 6 was used for other studies. The kinetic study shows that uptake of Zn2+ increased with time and that maximum biosorption was obtained within 60 min of the process. The result obtained showed that the pseudo-first order model correlated with the experimental data better than the pseudo-second order model examined in this study. Freundlich and Langmuir isotherm models were used to analyse the experimental data of the biosorption process. The Freundlich and Langmuir equations obtained are log Г = 0.643 log Ce + 1.1177 and 1/Г = 0.0411/Ce + 0.009, respectively. The correlation factors are 0.9971 and 0.9889, respectively. The free energy change for the biosorption of Zn2+ at 27ordm;C, initial concentration of 100 mg L-1 and pH 6 is ndash;7.663 kJ mol-1 within 60 min. These results indicate that maize wrapper has potential for the removal of Zn2+ from industrial wastewater. Key words: Biosorption, Zn(II), isotherm, maize wrapper, kinetic studies. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/E24095914405 en Copyright © 2008 N. A. Adesola Babarinde, J. Oyebamiji Babalola and Olasumbo B. Adebisi
oai:academicjournals.org:IJPS:707B96C14412 2008-02-29T00:00:00Z AcademicJournals IJPS IJPS:2008
Effect of pH and concentration on the complexation of calcium ions with humic acid extracted from composted oil palm bunches P. O. Oviasogie and P.O.Okolo Full Length Research Paper The reaction (complexation) between calcium ions at certain concentrations (1.000, 0.500, 0.250 and 0.125 M) and pH (2, 4, 6, and 8) and humic acid obtained from composted oil palm (Elaeis guineensis Jacq) bunches were investigated in this study. The results obtained showed that at maximum total calcium concentrated (1.000 M) few or no Ca2+ was complexed to the humic acid at pH 2 and 8 respectively, while some degree of complexation was exhibited at pH 4 and 6. Similarly, at 50% total calcium level, more Ca2+ reacted with the humic acid at pH 4 and 6 respectively. Interestingly, all the points on the plotted graph of Log10[Ca2+] versus Log10 [CaT] converged at the lowest total Ca2+ concentration. Furthermore, the study revealed that depending on the total Ca2+ concentration, effective interaction occur at and between pH 4 and 6 with the humic acid. This feature can be employed in regulating the release or retention of Ca2+ by the application of the humic acid in calcareous or limestone rich soils. Key words: Humic acid complexation, Ca2+, pH. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/707B96C14412 en Copyright © 2008 P. O. Oviasogie and P.O.Okolo
oai:academicjournals.org:IJPS:9E1CB0214420 2008-02-29T00:00:00Z AcademicJournals IJPS IJPS:2008
On non-standard finite difference schemes for initial value problems in ordinary differential equations E. A. Ibijola, J. M. S. Lubuma and O. A. Ade-Ibijola Full Length Research Paper In this paper, we present the theory of non-standard finite difference schemes which can be used to solve some initial value problems in ordinary differential equations. Methods of construction and mode of implementation of these methods are also discussed. We also examine the stability properties of the constructed schemes. Keywords: Non-standard, stability, non-local approximation, initial value problem, ordinary differential equations. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/9E1CB0214420 en Copyright © 2008 E. A. Ibijola, J. M. S. Lubuma and O. A. Ade-Ibijola
oai:academicjournals.org:IJPS:DC64EE014457 2008-02-29T00:00:00Z AcademicJournals IJPS IJPS:2008
Optimizing friction behaviour of clutch facings using pin-on-disk test Khamlichi, A., Bezzazi, M., Jabbouri, A., Reis P. and Davim, J. P. Full Length Research Paper In this work, a rational approach based on Taguchi technique and Pin-on-disk test is used in order to study the friction coefficient behaviour of clutch facings as function of material formulation. Experiments were designed according to the orthogonal array L8 where the chosen factors are temperature and sliding speed. A complex interaction exists between the surface texture of the produced clutch facings and the used manufacturing process parameters, particularly those associated to molding and grinding operations. Since it is not straightforward to render this effect in terms of explicit factors, it is roughly considered here as noise affecting a chosen wear path during Pin-on-disk testing. Signal over noise ratio should be sufficiently high in order that qualification of test results obtained for a given material formulation could be possible. For the set of parameters considered during the actual experiment, the friction coefficient behavior of clutch facings was shown to be mainly controlled by the sliding speed or by the interaction between the sliding speed and temperature. Key words: Friction coefficient, clutch facings, pin-on-disk, Taguchi method. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/DC64EE014457 en Copyright © 2008 Khamlichi, A., Bezzazi, M., Jabbouri, A., Reis P. and Davim, J. P.
oai:academicjournals.org:IJPS:E4EB4F914471 2008-03-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Thermodynamic and isothermal studies of the biosorption of cadmium (II) from solution by maize wrapper N. A. Adesola Babarinde, , J. Oyebamiji Babalola and Olumide Olukanni Full Length Research Paper The removal of Cd (II) from dilute aqueous solution using maize (Zea mays) wrapper as a biosorbent was studied. The biosorption was pH-dependent with an optimum pH of 5 - 7. It was also time-dependent and maximum biosorption was obtained after 100 minutes. The adsorption isotherms obtained fitted well into the Freundlich and Langmuir isotherms. The Freundlich equation obtained was log Г = 1.0813 logCe + 0.958 while the Langmuir equation obtained was 1/ Г = 0.1535/Ce ndash; 0.013. The correlation factors were 0.99 and 0.99 while the standard deviation values were 0.051and 0.003 respectively. The free energy change obtained for the biosorption at 300 K, initial Cd (II) concentration of 100mg L-1 was ndash;7.11kJmol-1. These results indicate that maize wrapper has potential for the uptake of Cd (II) from industrial effluents. Keywords: Biosorption, Cd (II), Freundlich isotherm, Langmuir isotherm, maize or wrapper. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/E4EB4F914471 en Copyright © 2008 N. A. Adesola Babarinde, , J. Oyebamiji Babalola and Olumide Olukanni
oai:academicjournals.org:IJPS:6B47C4E14480 2008-03-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Dielectric study of moisture laden soils at X-band microwave frequency Chaudhari, H. C. and Shinde, V. J. Full Length Research Paper Interaction of electromagnetic waves with the materials of planet earth provides the information for microwave remote sensing. From the reflected wave it is possible to reveal the information, which is useful for the measurement of dielectric properties. The dielectric properties of material are function of its chemical constituents and physical properties. Measurements of real (epsilon;rsquo;) and imaginary (epsilon;rsquo;rsquo;) parts of the complex dielectric constant (epsilon;*) of soil with varied moisture content were made at 9.65 GHz. The X-band microwave setup in the TE10 mode with slotted section and a crystal detector is used for measurements. Infinite sample method is found suitable for measurement of these soils. The measurements are made at room temperature. The dielectric properties of dry soil samples are in good agreement with the earlier work. The value of epsilon;rsquo; and epsilon;rsquo;rsquo; first increases slowly and then increase rapidly with moisture content. From this data, the a.c. conductivity and relaxation time are also reported. The result shows the change in electrical properties of dry and moisture-laden soils. These results provide a basis for using high-frequency electromagnetic sensors in the detection of soil moisture content or in ground-penetrating radar. Also precise microwave dielectric measurements of soils and recognition of their dependence on physical and chemical composition are interesting and can be used in support of radar investigations of the Earthrsquo;s geology. Keywords: Dielectric constant, dielectric loss, conductivity, relaxation time. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/6B47C4E14480 en Copyright © 2008 Chaudhari, H. C. and Shinde, V. J.
oai:academicjournals.org:IJPS:F44A05814488 2008-03-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Numerical simulation of aerodynamic and thermal fields inside a cylinder of an alternative engine Z. Barbouchi and J. Bessrour Full Length Research Paper We are interested in the study of turbulent and instationary flow inside a cylinder of an alternative engine. The finite element method is used to solve equations model. As the domain of the flow is changing with time due to the moving piston, an arbitrary Lagrange eulerian technique is chosen to reply to this problem. The modelisation is based on classic k- epsilon; model. In this paper, we will present instantaneous velocity, streamlines and temperature maps obtained at various crank angles. We validate our results with other numerical predictions. Key words: Aerodynamic, turbulence, simulation, finite elements, arbitrary Lagrangian Eulerian, alternative engine. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/F44A05814488 en Copyright © 2008 Z. Barbouchi and J. Bessrour
oai:academicjournals.org:IJPS:2AE1CE614499 2008-04-30T00:00:00Z AcademicJournals IJPS IJPS:2008
Application of ultrasonic waves coupled with functional link neural network for estimation of carrageenan concentration Duduku Krishnaiah, D. M. Reddy Prasad, Awang Bono, P.M. Pandiyan and Rosalam Sarbatly Full Length Research Paper In this paper, a simple functional link neural network (FLNN) model is developed for the quantification of polysaccharides using ultrasonic waves. Every material has its own intensity to absorb the sound waves. The sound absorption capability of Carrageenan is based on its concentration in the solution. The sound pressure leave obtained from the one third octave band frequency spectrum is given as input to the FLNN and the carrageenan concentration is estimated as output. Two simple modifications in the architectures of FLNN are newly proposed and its performances are compared with the conventional FLNN method. In the first architecture, a hidden layer is newly introduced in a FLNN and trained by Error Back Propagation (EBP) procedure. In the second architecture, the Functional Link concept is extended to the neuron in the hidden layer and the network is trained by EBP procedure. The proposed procedure has minimized the training time as well as the number of failures. Key words: Ultra sonic waves, carrageenan concentration, frequency spectrum, Functional Link Neural Networks. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/2AE1CE614499 en Copyright © 2008 Duduku Krishnaiah, D. M. Reddy Prasad, Awang Bono, P.M. Pandiyan and Rosalam Sarbatly
oai:academicjournals.org:IJPS:6CBCBCD14513 2008-04-30T00:00:00Z AcademicJournals IJPS IJPS:2008
A quadratic based integration scheme for the solution of singulo-stiff differential equations Aashikpelokhai, U. S. U and Momodu, I. B. A Full Length Research Paper In this term paper, we designed a quadratic based integration scheme for the solution of initial value problem (IVPs) in ordinary differential equation (ODEs). This was achieved by considering the rational interpolating operator satisfying A class of rational integrator formula given by in Aashikpelokhai (1991) with K=14 was also implemented and the results compared. The vector q= (q1, q2hellip;hellip;hellip;qk) are obtained from the simultaneous linear equation (SLE) Sq=b where P0 = yn, The results as analyzed with the computer show that the integrator copes favourably well with singular problems, stiff problem and singulo-stiff problems. Keywords: Rational Integrators, region of absolute stability, Integration Scheme, Consistency, convergence, stiff and singular problems. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/6CBCBCD14513 en Copyright © 2008 Aashikpelokhai, U. S. U and Momodu, I. B. A
oai:academicjournals.org:IJPS:F1CF97314520 2008-04-30T00:00:00Z AcademicJournals IJPS IJPS:2008
Extraction of zinc (II) by triphenylphosphite (TPP) in hydrochloric acid: Kinetics and mechanism Alafara A. Baba and F. A. Adekola Full Length Research Paper The extraction of Zinc (II) in chloride medium with triphenyl phosphite (TPP) in kerosene has been investigated under different experimental conditions in order to have a better understanding of the extraction mechanism. The extraction yield was found to depend on the concentrations of Zinc (II) and TPP, and pH. The extraction yield can easily be predicted based on an established linear expression. The effect of salting-out agents: LiCl, NaCl and NH4Cl were also studied and they ranked NaCllt;NH4Cllt;LiCl in increasing order of the extraction yield. This study suggests that Zn (II) forms a binuclear complex with TPP, according to the equation: . On the other hand, the stripping study showed that 0.5M HCl was satisfactory for the stripping of about 79.42% of zinc from the organic phase in a single stage. Finally, the findings on the possible re-use of TPP in kerosene showed that the TPP continuously losses its extraction ability with successive re-use. This has been attributed to its gradual degradation or transformations, and decrease in the number of co-ordination sites available for the divalent metal ion. Key words: Zinc (II) extraction, triphenylphosphite, mechanism. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/F1CF97314520 en Copyright © 2008 Alafara A. Baba and F. A. Adekola
oai:academicjournals.org:IJPS:3ED5F2814537 2008-05-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Annual effective dose and concentration levels of heavy metals in different types of tea in Egypt Y. F. Lasheen, N. S. Awwad, A. El-khalafawy and A. A. Abdel-Rassoul Full Length Research Paper Six marked brands of black tea (S1, S2, S4, S5, S6, and S7) and one type of green tea (S3) which commonly consumed in Egypt, were collected from local markets. The total alpha and beta gross activities in different tea samples were measured. The annual effective dose (mSv/y) for both total alpha and beta gross activities (Bq/2 gm) related to different types of tea drink corresponding to each radionuclide was calculated based on the dose conversion factors. The qualitative and quantitative assessment of tea sample S1 supplied from Ceylon proved the presence of different naturally occurring radionuclides. Also, the total contents of heavy metals in different types of tea were measured and the data obtained show the ability of them to accumulate the heavy metals, particularly Mn and Fe. The results of metal contents in infusion of different types of tea show that the concentration values of Mn for the all types were the highest concentration values and the concentration levels of Cu were the lowest concentration values. The studied heavy metals could be arranged in descending order according to their contents in tea brew as the following Mn gt; Fe gt; Zn gt; Cu gt; Pb. Key word: Tea/annual effective dose/ alpha and beta gross/ heavy metals/ assessment. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/3ED5F2814537 en Copyright © 2008 Y. F. Lasheen, N. S. Awwad, A. El-khalafawy and A. A. Abdel-Rassoul
oai:academicjournals.org:IJPS:9BE69DD14558 2008-05-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Removal OF EMG and ECG artifacts from EEG based on real time recurrent learning algorithm H. N. Suresh and C. Puttamadappa Full Length Research Paper EEG (Electroencephalograph) recording from the scalp has biological artifacts and external artifacts. Biological artifacts, which are generated, can be EMG (Electromyograph) signal, EOG (Electrooculograph) signal or ECG (Electrocardiograph) signal. These artifacts appear as noise in the recorded EEG signal individually or in a combined manner. Usually physicians are misled by these noisy signals and the EEG analysis can go wrong. This paper presents noise cancellation i.e. removal of noise signal which can be either EMG, ECG or a combination of these two artifacts from the corrupted EEG signal and also signal enhancement both using recurrent learning technique. For this purpose, we have implemented the RTRL (Real Time Recurrent Learning) algorithm, which is the most recent and sophisticated real time neural networks algorithm. This algorithm is coded using C language and is executed on the DSP processor TMS320CV5402. The obtained result is verified using MATLAB. Key words: Electroencephalograph (EEG), Recurrent Multilayer Perceptron (RMLP), Real Time Recurrent Learning (RTRL). Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/9BE69DD14558 en Copyright © 2008 H. N. Suresh and C. Puttamadappa
oai:academicjournals.org:IJPS:3553AFB14569 2008-05-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Estimation of solar radiation at Uturu, Nigeria I. U. Chiemeka Full Length Research Paper The estimation of the solar radiation at Uturu latitude 05.33oN and 06.03oN was carried out in this work. The temperature data were obtained from 5th ndash; 31st October, 2007) using the maximum and minimum thermometer placed in the Stevenson screen at 1.5 m The Hargreaves equation was used to estimate the solar radiation at Uturu. The mean global solar radiation obtained for the period is 1.89 plusmn; 0.82 kwh per day. A comparison of the mean solar radiation result obtained at Uturu and that obtained by Chineke (2007) at Umudike (5o29rsquo;N, 7o33rsquo;E) in October, 1997 and Chineke (2002) at Owerri (5o28rsquo;N, 7o2rsquo;E) in October, 1997 showed that the solar radiation obtained at Uturu is low. This difference may be attributed to the fact that Uturu is bounded on the West and South by a hilly escarpment. Key words: Global solar radiation, Hargreaves equation. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/3553AFB14569 en Copyright © 2008 I. U. Chiemeka
oai:academicjournals.org:IJPS:E707E2D14579 2008-05-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Phase and conductivity dynamics of strontium hexaferrite nanocrystals in a hydrogen gas flow A. A. Fargali, M. K. Zayed, M. H. Khedr and A. F. Moustafa Full Length Research Paper The phase and conductivity dynamics of strontium hexaferrite nanocrystals were isothermally studied at different temperatures during a constant flow of hydrogen gas at normal atmospheric pressure. The nanocrystals were prepared by self-flash combustion of acetate precursors. While the formed phase was characterized using XRD, TEM, and optical microscopy after hydrogen exposure, the electrical conductivity was in-situ measured during reduction. The temporal changes in conductivity as well as the formed phases at partial and complete reduction were found to be significantly affected by the operating temperature.Nanocrystals reduced at lower temperatures showed formation of lower oxygen content phases of strontium-iron oxides (SrFe12O19, Sr2Fe2O5, Sr7Fe10O22), and iron oxides (Fe3O4, FeO), while those reduced at higher reducing temperature showed the formation of metallic iron responsible for higher electric conductivity during reduction. Metallic iron nanocrystals of increased sizes were formed at higher reducing temperatures and longer reducing times. Temporal conductivity changes during hydrogen gas flow at different temperatures showed three regions corresponding to removal of surface oxygen, surface reduction, and bulk reduction of the nanocrystals. Nanocrystals reduced at temperatures higher than 400oC showed three reduction regions corresponding to these mechanisms, whereas those reduced at 400oC only two regions could be detected. The activation energies of the oxygen desorption, surface reduction and bulk reduction were found to be 55.5, 40.2, and 44.1 kJ mol-1 respectively. This indicates that oxygen desorption follows a chemical reaction controlled mechanism, while surface and bulk reductions are of combined gas diffusion and interfacial chemical reaction controlled mechanisms. The results obtained from the conductivity measurements were further supported by thermo-gravimetric measurements. Key words: Strontium hexaferrite (SrFe12O19) nanocrystals, phase changes, electrical conductivity, reduction, thermogravimetric. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/E707E2D14579 en Copyright © 2008 A. A. Fargali, M. K. Zayed, M. H. Khedr and A. F. Moustafa
oai:academicjournals.org:IJPS:17296FD14586 2008-05-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Inhibiting effect of cetyl pyridinium chloride (CPC) on the corrosion of mild steel in acidic medium Atul Kumar Full Length Research Paper The inhibiting effect of Cetyl Pyridinium Chloride (CPC) on mild steel in 1M Hydrochloric acid has been studied by using three techniques namely: weight loss, electrochemical polarization and metallurgical research microscopic techniques. Results obtained reveal that CPC is good inhibitor and shows very good corrosion inhibition efficiency (IE). The IE was found to vary with concentration of inhibitor and temperature. The electrochemical polarization result revealed that CPC is anodic in nature. Key words: Corrosion inhibition, mild steel, electrochemical polarization. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/17296FD14586 en Copyright © 2008 Atul Kumar
oai:academicjournals.org:IJPS:8080FA814610 2008-06-30T00:00:00Z AcademicJournals IJPS IJPS:2008
Study on the morphology of polyacrylamide – silica fumed nanocomposite thin films Mukhles Sowwan, Maryam Faroun, Ishaq Musa, Imad Ibrahim, Sami Makharza, Wadie Sultan and Hasan Dweik Full Length Research Paper Silica fumed nanoparticles were dispersed in polyacrylamide thin films by direct mixing. Atomic Force Microscopy study was carried out in order to analyze the surface roughness. Height distribution of surface roughness changes from Gaussian like for polyacrylamide to skew asymmetric when increasing the silica concentration. The length of the distribution tail increases, indicating the formation of multi-scale features that increase in number and size, as the silica increase. Key words: Polyacrylamide, nanocompsite, surface roughness, AFM. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/8080FA814610 en Copyright © 2008 Mukhles Sowwan, Maryam Faroun, Ishaq Musa, Imad Ibrahim, Sami Makharza, Wadie Sultan and Hasan Dweik
oai:academicjournals.org:IJPS:B22DA6714618 2008-06-30T00:00:00Z AcademicJournals IJPS IJPS:2008
Electronically tunable current mode second order high pass filter for different value of Q G. N. Shinde and D. D. Mulajkar Full Length Research Paper This paper presents realization of current-mode active-R filter in order to increase the speed of circuits for analog signal processing and to decrease the supply voltages of integrated circuits. The proposed filter is constructed using operational amplifiers [OA] and resistors. The circuit capable of realizing quadratic transfer function .The proposed second order high pass filter circuit works ideal for Q gt;=1 at center Frequency F0 = 50 KHz .The gain roll-off of this configuration is 40dB/decade. Since the circuit is composed only of resistances, it is suitable for high frequency operation and monolithic implementation. The filters developed were successful in obtaining passive sensitivities less than unity in magnitude and active sensitivities are half in magnitude, which is a noteworthy achievement. Key words: Current mode filter, second order, high pass, center frequency. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/B22DA6714618 en Copyright © 2008 G. N. Shinde and D. D. Mulajkar
oai:academicjournals.org:IJPS:F42F3E614633 2008-06-30T00:00:00Z AcademicJournals IJPS IJPS:2008
Application of geochemical parameters for characterization of oil samples using GC-MS technique Idris, H. K., Salihu, A., Abdulkadir, I. and Almustapha, M. N. Full Length Research Paper Geochemical characterization of eleven (11) oil samples has been carried out; using diagnostic biomarker parameters related to thermal maturity, organic matter source, age and depositional environment. Oleanane was only found in the Nigerian oil, serving as a primary feature in distinguishing it from other oils. All the oil samples appeared to have mixed organic matter input with samples of the same region closely related to each other based on the parameters measured. Biodegradation of some of the samples may have contributed to some of the observed variabilities. Key words: Biomarker, Oleanane, biodegradation, thermal maturity. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/F42F3E614633 en Copyright © 2008 Idris, H. K., Salihu, A., Abdulkadir, I. and Almustapha, M. N.
oai:academicjournals.org:IJPS:4B2B96A14642 2008-06-30T00:00:00Z AcademicJournals IJPS IJPS:2008
Friedelanone and other triterpenoids from Hymenocardia acida Igoli, O. John and Gray I. Alexander Short Communication The stem barks of the plant Hymenocardia acida Tul. (Hymenocardiaceae) has yielded five triterpenoids which were identified by spectroscopic methods as friedelan-3-one, betulinic acid, lupeol, beta;-sitosterol, stigmasterol and the fatty acid, oleic acid. These compounds are being reported for this plant material for the first time. Key words: Hymenocardia acida, hymenocardiaceae, Nigeria, friedelanone, betulinic acid, lupeol, oleic acid. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/4B2B96A14642 en Copyright © 2008 Igoli, O. John and Gray I. Alexander
oai:academicjournals.org:IJPS:26B17CD14685 2008-07-31T00:00:00Z AcademicJournals IJPS IJPS:2008
A robust observer design for chaos synchronization of uncertain systems using LMI criterion Xiaojue Ma Full Length Research Paper In this paper, considering the effect of exoteric perturbation on systemrsquo;s parameters, a robust observer, based on Lyapunov theory, is designed for the output synchronization of a class of uncertain systems when the full state vector is not available. With the help of LMI criterion and then using the MATLAB LMI Toolbox, the observer gain L is derived, which can not only make the outputs of both master and slave systems reach Hinfin; synchronization with the passage of time but also reduce the influence of the disturbance within a prescribed level. In the end, we take the perturbed Chuarsquo;s circuit as an example to illustrate that the proposed method is effective and quite robust against the effect of exoteric perturbation. Key words: Chaos synchronization, the observer method, Lyapunov theory, linear matrix inequality (LMI), PACC: 0545. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/26B17CD14685 en Copyright © 2008 Xiaojue Ma
oai:academicjournals.org:IJPS:3F715E014698 2008-07-31T00:00:00Z AcademicJournals IJPS IJPS:2008
Complexation of cobalt (II) with nicotinohydroxamic acid and its microbial sensitivity Aliyu A. O. and Nwabueze J. N. Full Length Research Paper Complex of cobalt (II) with nicotinohydroxamic acid (NHA) has been investigated by spectroscopic method at 25 plusmn; 0.1oC in aqueous solution of 0.1mol dm-3 ionic strength. The results reveal the sole formation of 1:2 complex at equilibrium. Spectra and magnetic studies of the isolated complex indicate octahedral mixed coordination mode (N.O). Microbial sensitivity test on eight micro-organism (that is, four gram +ve and four gram - ve bacterial strains) showed activity. Key words: Complex, hydroxamic acid, spectroscopic investigations, microbial activity, cobalt (II). Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/IJPS/article-abstract/3F715E014698 en Copyright © 2008 Aliyu A. O. and Nwabueze J. N.
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