Search

This paper presents comparison between optimal homotopy asymptotic method and homotopy perturbation method for the solution of two-dimensional steady flow of an incompressible Maxwell fluid over a transpiration channel within a porous medium due to a impulsively moving wall. The results obtained using HPM for injection case fails to be in accordance with the available analytical data.

The evolution of the structural and magnetic characteristics of Ta/Ni81Fe19 multilayered structures was investigated using small angle x-ray diffraction and transmission electron microscopy. The results suggested that grain growth was concurrent with grain boundary diffusion of Ta in Ni81Fe19. The evolution of the soft magnetic properties of the sample after annealing treatment was consistent with the observed changes in microstructure.

Numerous studies have shown the interesting properties of trivalent lanthanide ions when doped in different types of glasses. This article examines the physical, structural and optical properties of series of strontium magnesium borate glasses doped with dysprosium ion (Dy3+) and synthesized using the melt-quenching technique. Physical and optical properties such as density, molar volume, ion concentration, molar refractivity, polaron radius, reflection loss, inter-nuclear distance and molar polarizability for each concentration of the dopant were calculated and reported. The results revealed diverse variations in density with other measured parameters. The amorphous behaviour of the glass samples was confirmed by X-ray diffraction spectroscopy. FTIR spectra measurements revealed the presence of various functional groups and their associated assignments. Optical properties of the activated glass samples with different concentrations of Dy3+ were determined by measuring the absorption and luminescence spectra in the visible region. The UV–Vis–NIR spectrophotometer analysis indicated the presence of eight inhomogeneous transition bands in various positions and intensities with hypersensitive transition at 1260 nm (6H15/2 → 6F11/2). The experimental oscillator strength (fexp) for each calculated absorption band showed higher magnitudes at hypersensitive transition. The optical energy band gap in the current work showed a decrease in values with increasing ion concentrations. The luminescence spectra of the prepared glass phosphors showed three unique transitions at 4F9/2 → 6H15/2 (490 nm), 4F9/2 → 6H13/2 (585 nm) and 4F9/2 → 6H11/2 (689 nm). [ABSTRACT FROM AUTHOR]

The magnetic and structural properties of epitaxial (100)Ni80/Fe20 films grown on Cu/Si(100) substrates reveal that the epitaxial films have atomically abrupt interfaces. Kerr effect magnetometry yields the magnetic properties of these films. The magnetic field is inversely proportional to the uniaxial anisotropy.

This is a brief report on the present status and perspectives of the research programs with negative muon beams. Intense negative muon beams provide new research opportunities for neutrino nuclear responses and nuclear isotope detection and their production. We started the program at the Research Center for Nuclear Physics (RCNP), Osaka University, and now it is continuing at RCNP, J-PARC and the Paul Scherrer Institute (PSI). Gamma rays following ordinary muon capture reactions are used for studies of nuclear responses for anti-neutrinos associated with double beta decays and astro-neutrinos, and for high-sensitivity nuclear-isotope detection and high-efficiency nuclear-isotope production. Recently, we have started a new research project for these subjects in collaboration with Universiti Teknologi Malaysia (UTM) Johor Bahru, RCNP Osaka and the Joint Institute for Nuclear Research (JINR) Dubna. We discuss briefly recent results and perspectives regarding the muon experiments. [ABSTRACT FROM AUTHOR]

Current study evaluated the synergistic potential of propolis and vitamin E against sub-acute toxicity of aluminum chloride on different biochemical parameters and liver histology. Swiss albino mice (n=42) were randomly divided into seven groups. Group I received 0.2 ml of 0.9 % saline solution, Group II received Propolis (50 mg/kg b.w.), Group III received vitamin E (150 mg/kg b.w.), Group IV received AlCl3 50 mg/kg b.w., Group V received AlCl3 + Propolis, Group VI received AlCl3 + vitamin E and Group VII received AlCl3 + propolis + vitamin E. Blood and tissue samples were collected after 7 and 21 days. The body weight of the animals significantly increased in all groups except Group IV. The concentration of serum high density lipoprotein significantly decreased in Group IV and increased in Group V, VI and VII. The level of aspartate aminotransferase, alanine transferase, alkaline phosphatase, triglycerides, total cholesterol, and low density lipoprotein significantly increased in AlCl3 treated group and increased in Group V, VI and VII. Tissue sections were processed and stained by hematoxylin and eosin. Group II showed cellular necrosis. Group V, VI showed decreased number of vacuolization, sinusoidal spacing and macrophage cell infiltration. Group VI showed less degenerative changes in the third week. Vitamin E and propolis in combination with Al provides more protection against AlCl3 induced toxicity. [ABSTRACT FROM AUTHOR]

The present study investigates the conjugate heat transfer in a square cavity heated by a triangular solid and saturated with Al2O3-water nanofluid. Two-phase Buongiorno's model is used for modeling the nanofluid heat transfer. The finite element method is used for numerical solution of the dimensionless governing equations subject to the boundary conditions. Comparisons of the proposed method with previously published experimental and numerical works show a good agreement. The effects of some parameters such as the Rayleigh number, thermal conductivity ratio, dimensionless triangular wall thickness and nanofluid volume fraction on heat transfer and nanoparticle distributions are completely studied and discussed. The results show clockwise rotations for streamlines and nanoparticle migration. Also the Nusselt number increases with the nanofluid volume fraction. A continuous reduction is seen for the mean Nusselt number by increasing the dimensionless triangular wall thickness for all the considered values of the Rayleigh number. [ABSTRACT FROM AUTHOR]

Traffic signals at intersections have a significant effect on traffic emissions. They interrupt traffic flow and create additional acceleration and deceleration driving modes. Therefore, the objective of this paper is to perform the optimization process of vehicle delay and exhaust emissions at isolated signalized intersections. Three-leg intersection located in Kafr El-Sheikh City, Egypt was selected in this study. Field delay times were estimated based on vehicle speed and acceleration profiles using GPS device. On-road measurements of vehicle speeds and emissions were collected simultaneously for all movements of all approaches at the selected intersection. The micro-simulation software VISSIM was used to model and analyze the selected intersection. The model was calibrated and validated using the collected data. Signal timing model was developed for the selected intersection and used for optimization of delay time and vehicle emissions. It was found that the changing of signal timing was effective in improving the operational and environmental performance of the traffic signal under study. Also, the results indicated that when the traffic flow rate is higher, the optimal cycle time corresponding to the performance index function increases. Optimization of the delay times and exhaust emissions gives traffic engineers the option of minimizing vehicle emissions in the designing of the signalized intersections or timing a signal system. [ABSTRACT FROM AUTHOR]