International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2529

IJPS Articles

A nonlocal integral boundary value problem of nonlinear integro-differential equations of fractional order

September 2013

This study discussed the existence of solutions for a nonlinear fractional integro-differential equation of order  with four-point nonlocal integral boundary conditions. The given problem is transformed to an equivalent fixed point problem in terms of an operator equation. Then, by means of Banach contraction principle and a fixed point theorem due to Krasnoselskii, the existence results are obtained. The last...

Author(s): Bashir Ahmad, Ahmed Alsaedi and Safa Alsulami

Role of Rose Bengal-Mannitol system for generation of electrical energy in photogalvanic cell

September 2013

Photogalvanic effect was studied in photogalvanic cells containing Rose Bengal as dyes and Mannitol as reductants. The photogalvanic cells were determined by the photo potential, photocurrent, conversion efficiency, power of cell and performance of cell. The effects of various parameters like pH, light intensity, diffusion length, reductant concentration and dye concentration on the electrical output of the cell is...

Author(s): Mahesh Chandra, Anoop Singh and R. C. Meena

Excessive correlated shifts in pH within distal solutions sharing phase-uncoupled angular accelerating magnetic fields: Macro-entanglement and information transfer

September 2013

Entanglement or “excess correlation” between physical chemical reactions separated by significant distances has both theoretical and practical implications. In 24 experiments, the inverse shifts in pH were noted in two quantities of spring water separated by 10 m that shared rotating magnetic fields (0.5 µT) with changing angular velocities when one solution was injected with proton donors (weak acetic...

Author(s): Blake T. Dotta, Nirosha J. Murugan, Lukasz M. Karbowski and Michael A. Persinger

Magneto hydrodynamic (MHD) squeezing flow of a Casson fluid between parallel disks

September 2013

Squeezing flow of a Casson fluid is considered between two parallel disks. Upper disk is taken to be impermeable but capable of moving towards or away from the lower fixed and porous disk. Governing equations are derived with the help of conservation laws combined with suitable similarity transforms. Homotopy analysis method (HAM) is then been employed to determine the solution to resulting ordinary differential...

Author(s): Naveed Ahmed, Umar Khan, Sheikh Irfanullah Khan, Yang Xiao-Jun, Zulfiqar Ali Zaidi, and Syed Tauseef Mohyud-Din

Determination of the vertical variations in temperature and longwave radiation within the gray Earth’s troposphere using radiative equilibrium profile model

September 2013

This study estimated the vertical variation in mean temperatures within the tropospheric layer using the radiative equilibrium profile model and longwave radiation with Stefan-Boltzmann equation at a tropical meteorological station located besides Physics Building (7.55°N:4.56°E), Obafemi Awolowo University, Ile-Ife, Nigeria. In the model, the height of the troposphere was assumed to be...

Author(s): Mudasiru A. Olajire and Olaniran J. Matthew

Numerical and experimental evaluation of bearing capacity factor Nγ of strip footing on sand slopes

September 2013

Results of laboratory model tests and numerical studies on the behavior of a strip footing adjacent to a sand slope are investigated and presented in this paper. The investigated parameters include the effects of depth of the first reinforcement layer, vertical spacing, number of reinforcement layers, and distance between the edges of footings on bearing capacity. Results were analyzed to determine the effects of each...

Author(s):   Mohd Raihan Taha and Enas B. Altalhe

Plasma properties of nano-second laser ablated iron target in air

September 2013

In the present work, we studied the optical emission spectra of iron (Fe) plasma produced by the fundamental (1064 nm) and second (532 nm) wavelengths of an Nd: YAG laser. The plasma emission has been recorded spatially using five spectrometers covering the spectral region from 200 to 720 nm. The laser beam was focused on target material by placing it in air at atmospheric pressure. The experimentally observed line...

Author(s): Muhammad Salik, Muhammad Hanif , Jiasheng Wang and Xiqing Zhang

Wavelet based dynamic Mel Frequency Cepstral Coefficients (MFCC) and block truncation techniques for efficient speaker identification under narrowband noise conditions

September 2013

Speaker identification strategies are well convincing in their performance when clean speeches are scrutinized. But the performance degrades when speech samples are corrupted by narrowband noise. Block truncation of the cepstral coefficients ensures that not all the features are affected by narrowband noise but it cannot reduce the extent of degradation. This work is focused towards improving the performance of speaker...

Author(s): S. Selva Nidhyananthan, R. Shantha Selva Kumara and D. S. Roland

Performance analysis of a Ĉuk regulator applying variable switching frequency

September 2013

This paper examines the performance of Ĉuk regulator to convert three phase alternating current (ac) to direct current (dc). Firstly, three phase ac is rectified with bridge diode. The rectified dc voltage is applied to input of a Ĉuk regulator.  Three phase harmonics filter is introduced at the input of the diode rectifier to improve the shape of the input current. The main technique applied here to improve the...

Author(s): Md. Nazmul Hasan, Md. Shamimul Haque Choudhury, M. Shafiul Alam, and Muhammad Athar Uddin,

Geoelectrical studies for the delineation of potential groundwater zones at Oduma in Enugu State, Southeastern Nigeria

September 2013

This work evaluates the use of geoelectrical method in the delineation of potential groundwater zones at Oduma in Enugu state, Southeastern Nigeria. Oduma lies within latitudes 6°02Ë¡ N to 6°07Ë¡ N and longitudes 7°35Ë¡ E to 7°41Ë¡ E with an area extent of about 102.6 km2. The area is underlain by Awgu Shale group with its lateral arenaceous facie; Owelli Sandstone outcropping south...

Author(s): Austin, C. OKONKWO and Isaac, I. UJAM

Structural health monitoring and damage assessment Part I: A critical review of approaches and methods

September 2013

Aging and deterioration of existing structures and the need for rapid assessment and evaluation of these structures for hazard mitigation have significantly expanded the research efforts in the field of structural health monitoring (SHM). SHM involves monitoring of a structure using periodically sampled measurements, extraction of damage sensitive features from these measurements, and assessment of the current health...

Author(s): Burcu Gunes and Oguz Gunes

Singulo oscillatory – stiff rational integrators

September 2013

In this paper, we derive a general singulo oscillatory – stiff rational integrator of order (S+3) for s = 0, 1, 2, 3, 4,… for the solution of initial value problems in ordinary differential systems that are singular, oscillatory or stiff. We compared our integrators with certain maximum order second derivative hybrid multi-step methods, certain Tau and Euler methods, the adaptive implicit and classical...

Author(s): Elakhe O. A. and Aashikpelokhai U. S. U.

Effect of dielectric constant on energy losses in lead sulphide thin films grown by solution method at room temperature

September 2013

Thin films of lead sulphide (PbS) were deposited using chemical bath deposition (CBD) at different lead ion concentrations. A mixture of  sodium hydroxide, varied concentrations of lead nitrate, triethanolamine (TEA), ammonia solution, thiourea, di-ionized and distilled water were used. A dip time of 120 min and pH of 9 at room temperature were maintained. It was found out that dielectric constants of the films...

Author(s): Mosiori, Cliff Orori

Second-order kinetic model for the adsorption of divalent metal ions on Sida acuta leaves

September 2013

The removal of metal ions from effluents is of importance to many countries of the world both environmentally and for water re-use. A comparison was made of the linear least-squares method of the widely used pseudo-second order kinetic model for the sorption of some divalent metal ions onto Sida acuta leaves. Four pseudo-second order kinetic linear equations were used for this study. The results obtained from...

Author(s): Oboh I. O., Aluyor E. O. and Audu T. O. K.

Influence of fuel in the microwave assisted combustion synthesis of nano α-alumina powder

September 2013

Microwave assisted combustion synthesis is used for fast and controlled processing of advanced ceramics. Single phase and sinter active nano crystalline alpha alumina powders were successfully synthesized by different fuel-to-oxidant molar ratios using aluminium nitrate as an oxidiser, glycine as a reducing agents and millipore water as a solvent by microwave assisted combustion synthesis. Thermodynamic modelling of the...

Author(s): Ramesh G., Mangalaraja R. V., Ananthakumar S. and Manohar P.

Synthesis and characterization of nano-hydroxyapatite (n-HAP) using the wet chemical technique

August 2013

Hydroxyapatite nanoparticles were synthesized, using a wet chemical technique with diammonium hydrogen phosphate and calcium nitrate tetrahydrate precursors, respectively. The pH of the system was maintained at 10.8 throughout the stirring process, by using 0.1 M sodium hydroxide. The mixture was allowed to remain stirred overnight and a white precipitate was formed. The precipitate was vacuum dried and cleaned with...

Author(s): Arunseshan Chandrasekar, Suresh Sagadevan and Arivuoli Dakshnamoorthy

Multiband fractal based reconfigurable antenna with introduction of RF MEMS switches for next generation devices

August 2013

Next generation network’s main requirements are compact size and also support to heterogeneous network. Fractal antennas have useful applications in cellular telephone and microwave communications. Video conferencing, streaming video are main applications that are included in next generation networks and requirements for these applications are high data rates require to have high bandwidth. But as size of antenna...

Author(s): Paras Chawla and Rajesh Khanna

Almost quaternionic integral submanifolds and totally umbilic integral submanifolds

August 2013

In this work, we consider a Riemannian manifold which admits an integrable distribution  with an almost quaternionic structure V. We show that the torsion tensor of an almost quaternionic structure  is independent of the choice of bases. We prove that the integral submanifolds are totally umbilic under the condition of the conjugate shape operator is skew-adjoint. We give another condition...

Author(s): Fatma Özdemir

Synthesis and characterization of polyindole with liquid crystalline azobenzene as side chains

August 2013

In this study, a series of azobenzene-functionalized liquid crystalline (LC) polyindole derivatives: poly{2-[N-ethyl-N-[4-[4'-(nitrophenyl)azo]phenyl]amino]ethyl-3-indolyl acetate}, poly(In3AA-RedI), poly{2-[N-ethyl-N-[4-[4'-(nitrophenyl)azo]phenyl]amino]ethyl-3-indolyl acetate-co-indole}, poly(In3AA-RedI-co-In), poly{2-[N-ethyl-N-[4-[4'-(nitrophenyl)azo]phenyl] amino]ethyl-3-indolyl...

Author(s): Seyed Hossein Hosseini and Maryam Ashjari

Effect of stabilizers on stiffness modulus of soil layers: A review

August 2013

Subgrade layer has a significant contribution in the pavement structure, and the quality of this layer has a great impact on the subsequent pavement design. Pavement design guide as specified in the AASHTO (2002), incorporates engineering properties of unbound and stabilized subgrade soils, since in many cases fatigue or rutting failure in pavements are due to insufficient stiffness modulus in soil layers. Subgrade...

Author(s): Dariush Moazami, Zainuddin Md. Yusoff, Ratnasamy Muniandy and Hussain Hamid

Optical properties of as-deposited TiO2 thin films prepared by DC sputtering technique

August 2013

Amorphous titanium dioxide TiO2 thin films have been deposited using the dc sputtering technique. The structure of the films was analyzed by X-ray diffraction and the results showed non-crystalline behavior. The optical properties of these thin films have been investigated by means of optical reflectance and transmittance spectra. The optical energy gap Eg, the Urbach tails Eu, the single oscillator energy Eo, the...

Author(s): M. M. Abd El-Raheem, and Ateyyah M. Al-Baradi

Structural and DC Ionic conductivity studies of carboxy methylcellulose doped with ammonium nitrate as solid polymer electrolytes

August 2013

Solid polymer electrolytes have been prepared by solution casting technique. Carboxy methylcellulose (CMC)-ammonium nitrate (AN) films were studied with varied AN salt concentration from 5-50 wt.% at ambient temperature. X-ray diffraction (XRD) pattern shows the amorphous nature of polymer electrolyte samples. IR-spectra confirm the polymer-salt complexes in the range of 1633 - 829 cm-1. Impedance analysis reveals that...

Author(s): K. H. Kamarudin and M. I. N. Isa

Flow behaviour of polyvinyl alcohol (PVOH) modified blends of polyvinyl acetate (PVAc)/natural rubber (NR) latexes

August 2013

During compounding processes, polymer latexes are mixed with various colloidal systems (in particular, PVOH) or surface-active agents to modify the flow behaviour in order to suit the manufacturing process. In this study, the flow behaviour of aqueous dispersed PVAc, NR and different mixed dispersions were investigated both in the absence and presence of PVOH as flow modifier, using an Ostwald glass capillary...

Author(s): Stephen Shaibu Ochigbo

Synthesis, structural and optical characterizations of cadmium oxide (CdO) thin films by chemical bath deposition (CBD) technique

August 2013

Thin films of cadmium oxide (CdO) were synthesized and characterized using chemical bath deposition (CBD) technique. The XRD studies revealed amorphous CdO thin films which upon annealing at 623K transformed to polycrystalline structure. The optical studies showed that the CdO films have high average transmittance over 60% in the visible region and direct optical bandgaps of 2.02 ± 0.05 eV, 2.03 ± 0.05eV...

Author(s): B. A. Ezekoye, V. A. Ezekoye, P. O. Offor and S. C. Utazi

Performance of community based organizations in managing sustainable urban water supply and sanitation projects

August 2013

The advocacy of climatic change and ever increasing poverty has its impact on environmental degradation. Most of underdeveloped countries have experienced this impact through technical, economic, institutional and social constraints on water supply and sanitation infrastructures. The impact has much effect in urban areas (informal settlements) due to the nature of such settlements. Lack of a sustainable approach and an...

Author(s): G. E. Kifanyi, B. M. B. Shayo and J. M. Ndambuki

Studies on drying rates of brined and spiced Clarias gariepinus (Catfish) using solar dryer

August 2013

The objective of this study was to determine the effect of brining and spicing with ginger or garlic on the drying rate of cat fish in a passive solar dryer. Samples of cat fish were solar dried under three different conditions: brine only, spiced with garlic and spiced with ginger. Their respective weight losses were used to determine the reduction in moisture contents. Graphs of drying rate versus time were plotted in...

Author(s): Oparaku, Nkiruka and Ojike, Onyekwere

trans-[PtCl2(NH2C6H4CO2H)2]: a platinum complex forming a two-dimensional hydrogen-bonded network

August 2013

The compound trans-[PtCl2(NH2C6H4CO2H)2] has been prepared from the hydrolysis of a platinum diimine complex, and has been characterised by X-ray crystallography. The crystal structure revealed that the compound forms a two-dimensional hydrogen-bonded network in the solid state, with pairs of O–H···O hydrogen bonds between carboxylic acid groups linking the molecules into zigzag tapes,...

Author(s): Ayi A. Ayi, Andrew D. Burrows, Mary F. Mahon and Anna J. Warren

Experimental determination of layers films thicknesses

August 2013

The determination of particle induced x-ray emission (PIXE) cross sections and the concentration of elements in a material require the knowledge of the target sample thickness. In this aim, measurements of the thickness by three different methods have been performed. These are absorption of X-rays by a 55Fe source, transmission of alpha particles by a 241Am source and Rutherford backscattering of alpha...

Author(s): S. Ourabah, A. Amokrane,  and M. Abdesselam

Role of finite element method (FEM) in predicting transverse modulus of fiber-reinforced polymer (FRP) composites: A revelation

August 2013

The present investigation aims to validate finite element method (FEM) in micromechanical analysis of a unidirectional continuous fiber reinforced composites and experimental verification of results in case of fiber-matrix debond. Available analytical models are reviewed, compared and are seldom in agreement with each other in case of transverse modulus of unidirectional continuous fiber reinforced composites. Reasons...

Author(s): Srihari P. Anne, Ramana K. V., Balakrishna Murthy V. and Rao G. S.

Improved energy efficiency of photogalvanic cell with four dyes as photosensitizers in Tween 60- Ascorbic acid system

August 2013

The objective of this work was to increase the energy efficiency of photogalvanic cell using four dyes; Amido Black 10B, Bromocresol purple, Carmine and Biebrich scarlet as photosensitizers in Tween 60-Ascorbic acid system. Observed values of photopotential, photocurrent, fill factor, conversion efficiency and storage capacity for Tween 60 -  Amido Black 10B - Ascorbic acid system were 996 mV, 420 µA, 0.38,...

Author(s): K. R. Genwa and C. P. Sagar

Evaluation of extraction methods for the analysis of selected polybrominated diphenyl ethers and hexabromobiphenyl (BB-153) – application to aqueous environmental samples

August 2013

The increasing evidence of the presence of organic pollutants in different aqueous matrices has led to the development of many analytical techniques. The isolation of these compounds from the aqueous matrices remains an integral component of these techniques. In this study, the performance of three different extraction methods, namely separatory funnel, magnetic stirring and solid-phase extraction methods commonly...

Author(s): Daso, Adegbenro P.,, Fatoki, Olalekan S. and Odendaal, James P.

Theoretical study on structural and electronic properties of 4-[(E)-[4-(trifloromethyl)-1,3-benzothiazol-2-yl]azo]naphthalen-1-ol and 1-[(E)-[4-(trifloromethyl)-1,3-benzothiazol-2-yl]azo]naphthalen-2-ol using density functional theory (DFT)

August 2013

In this work, the structural and electronic properties of 4-[(E)-[4-(trifloromethyl)-1,3-benzothiazol-2-yl]azo]naphthalen-1-ol (ortho-OH) and 1-[(E)-[4-(trifloromethyl)-1,3-benzothiazol-2-yl]azo]naphthalen-2-ol (para-OH) using density functional theory (DFT) were presented. The calculated vibrational frequencies were compared very well with experimental. The total energy for the isomers A and B were -4277242.55 and...

Author(s): Bello Isah Adewale and Semire Banjo

Assessment of leachate effects to the drinking water supply units in the down slope regions of municipal solid waste (MSW) dumping sites in Lahore Pakistan

July 2013

The aim of this study was to evaluate seasonal as well as moderate temporal effects on deep groundwater quality by the dumpsites leachate in the Lahore Metropolitan with a population of about 8 million. Groundwater samples for this study ware drawn from groundwater supply units installed by local government for the provision of drinking water to the residents. The groundwater in down slope regions from municipal solid...

Author(s): Khalid Mahmood, Syeda Adila Batool, Asim Daud Rana, Salman Tariq, Zulfiqar Ali, and Muhammad Nawaz Chaudhry

Novel method of iron removal from underground dug well waters in communities around Okada town, Ovia North-East L.G.A. Edo State

July 2013

Some indices of pollution were studied in water samples from 25 dug wells randomly selected from Okada town and it’s environ. Physicochemical parameters measured include temperature, pH, colour, turbidity, total dissolved solids (TDS), toxic shock syndrome (TSS), total hardness, Ca, Mg, Fe, Mn, nitrate and phosphate etc. The results of the study showed that dug wells from this area contain Fe and Mn concentrations...

Author(s): Chike Luke Orjiekwe,  Kehinde Oguniran and Solola Saheed Abiodun

Modelling of solar radiation for West Africa: The Nigerian option

July 2013

The United Nations Framework Convention on Climate Change (UNFCCC) reports indicate that those who are least responsible for climate change are also the most vulnerable to its projected impacts. In no place is this more evident than in Sub Saharan Africa, where greenhouse gas (GHG) emissions are negligible from a global scale. In Africa, energy demands could be the major factor that may lead to the increase of its...

Author(s): Cecily Nwokocha, Raymond Kasei and Urias Goll

Study of the effect of particles size and volume fraction concentration on the thermal conductivity and thermal diffusivity of Al2O3 nanofluids

July 2013

In this study we present new data for the thermal conductivity enhancement in four nanofluids containing 11, 25, 50, and 63 nm diameter Aluminum oxide (Al2O3) nanoparticles in distilled water. The nanofluids were prepared using single step method (that is, by dispersing nanoparticle directly in base fluid) which was gathered in ultrasonic device for approximately 7 h. The transient hot-wire laser beam displacement...

Author(s): Faris Mohammed Ali, W. Mahmood Mat Yunus and Zainal Abidin Talib

A method for placement of distributed generation (DG) units using particle swarm optimization

July 2013

Nowadays, the penetration of distributed generation (DG) in power networks takes special place worldwide and is increasing in developed countries. In order to improve voltage profile, stability, reduction of power losses etc, it is necessary that, this increasing of installation of DGs in distribution system should be done systematically. This paper introduces an optimal placement method in order to sizing and sitting...

Author(s): Noradin Ghadimi

Anti-islanding protection based on voltage and frequency analysis in wind turbines units

July 2013

This paper introduces a new islanding detection algorithm method based on voltage and frequency analysis for wind turbines as distributed resource units at the distribution voltage level. The proposed method is based on processing of the rate of change of q-axis component of voltage and accelerates of change of frequency. This method detects the islanding conditions with the analysis of these signals. The studies...

Author(s): Behrooz Sobhani and Noradin Ghadimi

Application of regression and multiple correlation analysis to morning hours solar radiation in Lapai

July 2013

Solar radiation in Lapai within the morning hours has been estimated by correlating meteorological parameters. This was achieved by applying the first and second order regression and multiple correlation analysis method. The correlation coefficient based on the first and second order equations in temperature and relative humidity were 0.828, 0.692, 0.860 and 0.622 while the correlation coefficient based on the multiple...

Author(s): Agbo G. A., Alfa B., Ibeh G. F. and Adamu I. S.

Adaptive neuro-fuzzy inference system (ANFIS) islanding detection based on wind turbine simulator

July 2013

This paper presents a passive islanding detection method based on means of a neuro-fuzzy approach for wind turbines. Several methods based on passive and active detection scheme have been proposed. While passive schemes have a large Non detection zone (NDZ), concern has been raised on active method due to its degrading power quality effect. Reliably detecting this condition is regarded by many as an ongoing challenge as...

Author(s): Noradin Ghadimi and Behrooz Sobhani

Neuro-fuzzy decision learning on supply chain configuration

July 2013

This paper describes the computational automatic supply chain configuration (SCC) based on fuzzy logic prediction actualizing automatically the chain stages considering different customer service level petitions. Each level is selected in accordance with the inference and the knowledge base process supplies (KBPS). The SCC model as an intelligent processes selector (IPS), allows dynamical configuration in accordance...

Author(s): J. C. Garcia Infante, J. J. Medel Juarez and J. C. Sanchez Garcia

Quantum chemical calculations on molecular structures and solvents effect on 4-nitropicolinic and 4-methoxypicolinic acid

July 2013

The density functional theory (DFT) (B3LYP) was used to study the solvents effect on electronic properties of 4-methoxypicolinic acid (4MOPIC) and 4-nitropicolinic acid (4NPIC). The calculated vibration frequencies at DFT/6-311++G** were compared to that of un-substituted picolinic acid to know the effect of donor/acceptor substituent on the molecules. Five solvents namely acetone, ethanol, diethyl ether, N,...

Author(s): Semire Banjo and Adeoye Idowu Olatunbosun

Synthesis, characterization and neuropharmacological activity of novel angular pentacyclic phenothiazine

July 2013

13H-5,14-dihydroquinoxalino[2,3-a]phenothiazine (a new pentacyclic ring system) was synthesized by condensation of diphenylamine and sulphur, which on nitration yielded 1-nitrophenothiazine. Reduction of this compound afforded 1-aminophenothiazine dihydrochloride and subsequent protection of this product with acetic anhydride gave 1-acetylaminophenothiazine. The nitration of this acetylated compound yielded two isomeric...

Author(s): Odin E. M., Onoja P. K. and Saleh J. F.

Assessment of arsenic levels in Guguletu and Langa rivers in Cape Town, South Africa

July 2013

This study investigates the baseline environmental levels of arsenic (As) in two rivers; one of which traverses through Guguletu (R1) and the other running by the peripheral of Langa (R2) residential areas in Cape Town. The rivers were monitored for As in upstream, midstream and downstream stations for twelve months, during consecutive summer and winter seasons between 2011 and 2012. The collected water samples were...

Author(s): Akinsoji O., Fatoki O. S., Ximba B. J., Opeolu B. O. and Olatunji O. S.

Design and evaluation of combined solar and biomass dryer for small and medium enterprises for developing countries

July 2013

A small scale demonstration model consisting of a combined solar and biomass cabinet dryer with 3 equally spaced drying trays was designed, constructed and evaluated. The results, obtained using fresh yam chips as test material over a four day test period, were satisfactory and useful for optimization purposes. Maximum tray temperature of 53°C was obtained in combination with solar and biomass heating sources even...

Author(s): Okoroigwe E. C., Eke M. N. and Ugwu H. U.

Geoelectrical evaluation of groundwater potentials of Bwari basement area, Central Nigeria

July 2013

An investigation has been made of the groundwater potentials of Bwari basement area using solely geoelectric surveys. Twenty vertical electrical soundings along different transverses were conducted with maximum electrode spacing of 300 m. The results revealed that the area is characterized with 3 to 6 geoelectric subsurface layers with variability in resistivities and thicknesses of the different layers. The overburden...

Author(s): A. E. Adeniji, D. N. Obiora, O. V. Omonona and R. Ayuba

The ability to use light emtting diode (LED) as emergency, instead of gas lamp or tingistin lamp in home lighting

July 2013

An electric circuit was made and connected to an alternative current that was passing through lower transformer. This process would produce a current the value of which was 500 mA and a voltage of 6 volt was used to charge battery. When the voltage source (alternative current) was cut, the circuit started lighting. We measured the charge and discharge in addition to time lapses to compare them with the results of the...

Author(s): Jassim M. Najim

Experimental study of air-water turbulent flow structures on stepped spillways

July 2013

Stepped chute flows are characterized by intense turbulence and strong flow aeration, but most studies did not investigate the turbulence characteristics. In this study, highly turbulent air-water flows skimming down a large-size stepped chute were systematically investigated. An experimental study of detailed air-water flow properties measurements were introduced in different types of flow regimes on a stepped chute...

Author(s): Mohammad Reza Beheshti, Amir Khosrojerdi and Seyed Mahmud Borghei

Potential reduction of concrete deterioration through controlled DEF in hydrated concrete

June 2013

Delayed ettringite formation (DEF) is a chemical reaction with proven damaging effects on hydrated concrete. Ettringite crystals can cause cracks and their widening due to pressure on cracked walls caused by the positive volume difference in the reaction. Concrete may show improvements in strength at early ages but further growth of cracks causes widening and spreading through the concrete structure. In this study,...

Author(s): Samo Lubej and Milan Radosavljevic

Dissolved and particulate trace elements’ configuration: Case study from a shallow lake

June 2013

Trace element distribution was monitored for Uluabat lake water polluted with point and non-point sources in Bursa. An examination of Zn, Cr, Ni, Cu, Pb, As, B concentrations during the study period indicated that the particulate phase at the bottom of the water column were high in regard to dissolved phase. The source of trace elements in thedeeper parts of the water column was derived from the higher...

Author(s): Feza Karaer, Aslıhan Katip, Saadet İleri, Sonay Sarmaşik and Nurcan Aydoğan

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