The nanocrystalline porous silicon (PS) films are prepared by electrochemical etching ECE of p -type silicon wafer with current density (10mA/cm ) and etching times on the formation nano -sized pore array with a dimension of around different etching time (10 and 20) min. The films were characterized by the measurement of XRD, atomic force microscopy properties (AFM). We have estimated crystallites size from X -Ray diffraction about nanoscale for PS and AFM confirms the nanometric size Chemical fictionalization during the electrochemical etching show on the surface chemical composition of PS. The atomic force microscopy investigation shows the rough silicon surface, with increasing etching process (current density and etching time) porous structure nucleates which leads to an increase in the depth and width (diameter) of surface pits.
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Time-domain spectral matching commonly used to define seismic inputs to dynamic analysis in terms of acceleration time history compatible with a specific target response spectrum is used in this study to investigate the second-order geometric effect of P-delta on the seismic response of base-isolated high-rise buildings. A synthetic time series is generated by adjusting reference time series that consist of available readings from a past earthquake of the 1940 El Centro earthquake adopted as an initial time series. The superstructure of a 20-story base isolated building is represented by a 3-D finite element model using ETABS software. The results of the base isolated building show that base isolation technique significantly reduces inter-s
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Adsorption capacity of a waste biomass, date stones, for phenolic compounds such as phenol (Ph) and p-nitro phenol (PNPh) was investigated. The characteristics of such waste biomass were determined and found to have a surface area and iodine number of 495.71 m²/g and 475.88 mg/g, respectively. The effects of temperature, initial sorbate concentration, and contact time on the adsorption process were studied. Experimental equilibrium data for adsorption of Ph and PNPh on date stones were analyzed by the Langmuir, Freundlich and Sips isotherm models. The results show that the best fit was achieved with the Sips isotherm equation with maximum adsorption capacities of 147.09 and 179.62 mg/g for Ph and PNPh, respectively. The kinetic data wer
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Agent technology has a widespread usage in most of computerized systems. In this paper agent technology has been applied to monitor wear test for an aluminium silicon alloy which is used in automotive parts and gears of light loads. In addition to wear test monitoring، porosity effect on
wear resistance has been investigated. To get a controlled amount of porosity, the specimens have
been made by powder metallurgy process with various pressures (100, 200 and 600) MPa. The aim of
this investigation is a proactive step to avoid the failure occurrence by the porosity.
A dry wear tests have been achieved by subjecting three reciprocated loads (1000, 1500 and 2000)g
for three periods (10, 45 and 90)min. The weight difference a
The enhancement of ZnSe/Si Heterojunction by adding some elements (V, In and Cu) as impurities is the main goal because they contribute to the manufacturing of renewable energy equipment, such as solar cells. This paper describes the preparation of thin films ZnSe with V, In and Cu doped using thermal evaporation method with a vacuum of 10–5 Torr. The thin film was obtained from this work could be applied in heterojunction solar cell because of several advantages including high absorption coefficient value and direct band gap. The samples prepared on a glass and n-type Si wafer substrate. These films have been annealed for 1 h in 450 K. X-ray diffraction XRD results indicated that ZnSe thin film possesses poly-crystalline structure after
... Show MoreNew metal complexes of some transition metal ions Co(II), Cu(II) , Cd(II) and Zn(II) were prepared by their reaction with previously prepared ligands HLI= (P-methyl anilino) phenyl acetonitrile and HLII = (P-methyl anilino) –P– chloro phenyl acetonitrile . The two ligands were prepared by Strecker’s procedure which includ the reaction of p- toluidine with benzaldehyde and P- chlorobenzaldehyde respectively. Structures were proposed depending on atomic absorption , i.r. and u.v.visible spectra in addition to magnetic susceptibility and electrical conductivity measurements.
At thermal energies near stellar conditions, nuclear reactions are sensitive to resonance strengths of the nuclear reaction cross-section. In this paper, the resonance strengths of nuclear reaction were evaluated numerically by means of nuclear reaction rate calculations using a written Matlab code, at the energies of interest in stellar nuclear reactions. The results were compared with standard reaction before and after application of a statistical analyses, to select the best parameters that made theoretical results as close as possible to the standard values. Fitting was made for different temperature ranges up to 10 GK, 0.6 GK and 0.25 GK. The evaluated results showed that as the temperature range becomes narrower, more error is ad
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