Abstract:Porous Silicon (PSi) has been produced in this work by using Photochemical (PC) etching process by using a hydrofluoric acid (HF) solution. The irradiation has been achieved using quartz- tungsten halogen lamp. The influence of various irradiation times on the properties of PSi اmaterial such as layer thickness, etching rate and porosity was investigated in this work too. The XRD has been studied to determine the crystal structure and the crystalline size of PSi material

In composite steel-concrete structures, shear connectors in the form of headed steel studs are commonly utilized to transfer longitudinal shear force developed at the interface between the two materials. To overcome the shortcomings of design codes, which frequently understate shear capacity and fail to take advantage of sophisticated computational methods, this paper presents an optimization attempt to estimate the shear strength of headed steel studs utilizing the Grey Wolf Optimizer (GWO) technique using MATLAB software. Data from 234 experimental tests are employed to identify and highlight key input parameters influencing the shear strength of headed steel studs. These key parameters include concrete compressive strength (f’c

Tin Oxide (SnO2) films have been deposited by spray pyrolysis technique at different substrate temperatures. The effects of substrate temperature on the structural, optical and electrical properties of SnO2 films have been investigated. The XRD result shows a polycrystalline structure for SnO2 films at substrate temperature of 673K. The thickness of the deposited film was of the order of 200 nm measured by Toulansky method. The energy gap increases from 2.58eV to 3.59 eV when substrate temperature increases from 473K to 673K .Electrical conductivity is 4.8*10-7(.cm)-1 for sample deposited at 473K while it increases to 8.7*10-3 when the film is deposited at 673K

Electrochemical method was used to prepare carbon quantum dots (CQDs). Size of matter was nature when evaluate via X-ray diffraction (XRD). A distinct peak at 2θ equal to 31.6° and three other small peaks at 38.28°, 56.41° and 66.12° were observed. The measures of Fourier Transform Infrared Spectroscopy (FTIR) showed the bonds in the transmittance spectrum are manufactured with carbon nanostructures in view. The first peaks are the O–H stretching vibration bands at (3417 and 2922) cm−1, (C–O–H at 1400, and 1317) cm−1, (C–H), (C=C), (C–O–H), (C=O), and (C–O) bonds at 2850, 1668, 1101, and 1026 cm−1 sequentially. The transmission electron microscopy (TEM) results presented that the spherical CQDs are in shape and on a

The double-skin profiled composite wall (DSPCW) system, filled with concrete material, is favorable in modern structures due to its high strength and ductility. Openings may be required within this composite wall (DSPCW) for various reasons, similar to a conventional bearing wall, which can lead to a reduction in bearing capacity. Therefore, to avoid changes in the geometry, materials, and thickness of this DSPCW wall, a new internally stiffening concept has been suggested by providing embedded cold-formed steel tube (CFST) columns. For this purpose, two full-scale DSPCW specimens were tested under static axial load, one of which was fabricated with a large opening size and stiffened with two octagonal CFST columns, while the other

In this work, (ZnO)1-x(MnO2)x compounds were synthesized with composition (x=0, 0.1, 0.2, 0.3, 0.4, and 0.5) of manganese oxide content using solid state reaction. Thin films were prepared from these compounds on glass substrates at room temperature using pulsed laser deposition method. The structure of the prepared compounds and thin films were analyzed using x-ray diffraction while the optical properties was measured using UV-visible spectrophotometry. It was found that the synthesized composites declared many peaks in the diffraction pattern which indicate polycrystalline structure with hexagonal wurtzite hexagonal structure of ZnO, and MnO2 and Mn2O3 secondary phases. A narrowing in the optical energy gap was found as Mn content increas

     The study aims at showing the role of tax audit in Impact the quality of tax statements. Tax audit is one of the most important means used by tax management to identify taxable revenues in a just, fair manner. The quality of statements relies on the extent to which the information provided by taxpayers is true and accurate. Tax audit works is compatible with the strategy of increasing tax adherence and detecting non-adherence cases and penalizing those who commit such violations. The study reached a number of results and conclusions. One of the most important results is that tax audit helps improve the information content of the taxpayers tax statements. This leads to recalculating taxable incomes and re-fixing t

The development of human resources training programs can assist in agreat deal in creating products of high quality with quantitive advantage for the economicunit;through the sale of products by prices higher of the peer products price in the arket,or decreasing production costs which lead into increusing the unet  profits. for these reasons, the human resources have got great importance for their great role in  any economy,and they havestarled to consentrate on accounting these resource.From this point of view, this research has handied human resources accounting and their effect on quality costs.  In(MID-Refinery Company),quality costs are determined ,then we have larified the reality of training and development in the o

In despite of the expansion of using the dummy variables as a explanatory variables, but their using as a dependent variables is still limited, and the reason of that may be return to may problems when using dummy variables as a dependent variables. the study aimed to using the quality Response Models to Measuring Efficiency of cows farms by random sample including (19) farm from (Abi gherak district). The study estimating the transcendental logarithmic production function by using stochastic frontier Analysis (SFA) to interpret the relation between the return achieved from the cows farms as a dependent variables and each of labor and capital as an independent variables. the function indicates that increasing in labor by (100%) will