Magnetocatalytic adiabatic spin torque orbital transformations for novel chemical and catalytic reaction dynamics: The Little Effect
December 2006
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...
Adjustable filtering structure design dedicated to a programmable hearing aid apparatus
December 2006
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...
A new pozzolanic material for cement industry: Bamboo leaf ash
November 2006
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...
The early heat of hydration of blended cements incorporating GGBFS and ground basaltic pumice (GBP)
November 2006
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...
Efficiency of densification process in preparation of carbon-carbon composites
November 2006
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...
Theoretical and experimental studies in hydrogen bonded glass forming systems
November 2006
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...
Dielectric, optical and thermodynamical properties of liquid crystal sample exhibiting SmA phase
November 2006
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...
Modeling relative influence of environmental and socio-cultural factors on context-specific functions
November 2006
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...
Prediction of Early Strength of Concrete: A Fuzzy Inference System Model
October 2006
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 day’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....
Mechanical behaviors of concrete combined with steel and synthetic macro-fibers
October 2006
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...
Can we use the aa geomagnetic activity index to predict partially the variability in global mean temperatures?
October 2006
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's near-surface temperature showed a global-mean temperature increase of approximately 1.1° C since 1877, occurred from 1887 to 1940 and...
INS Study on Physical Mechanisms of Bioprotection
October 2006
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...
Boundary compatibility condition and rotation in elasticity
October 2006
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...
Seismicity of the Carpathian region
October 2006
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...
An Appraisal of The Abura Field
October 2006
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...
Mechanochemical route to synthesize Co3O4/CuO composite nanopowders
October 2006
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 °C in air for 2 h resulted in the formation of Co3O4/CuO nanopowders with an...
Potential for rock polishing enterprises in Southwestern Nigeria
September 2006
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...
Blended cement and lightweight concrete using scoria: Mix design, strength, durability and heat insulation characteristics
September 2006
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...
Energy- angular correlation of medium energy particles produced in heavy Ion collisions
September 2006
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...
Biosorption of lead ions from aqueous solution by maize leaf
September 2006
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 27ºC. The analysis of residual Pb(II) ions was determined using atomic absorption spectrophotometer. Maximum adsorption occurred at pH 3. The adsorption isotherms obtained at 27ºC and optimum pH fitted...
Cyclic oxidation behavior of Ni- and Fe-based superalloys in air and Na2SO4-25%NaCl molten salt environment at 800 oC
September 2006
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 °C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. X-ray diffraction (XRD), scanning...
Non-Fitted Prediction of Clay Soil Aggregate Shrinkage
September 2006
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.,...
Page 52 of 52, showing 22 records out of 2572 total, starting on record 2551, ending on 2572
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