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
An effort is made to study the effect of composite nanocoating using aluminum-9%wt silicon alloys reinforced with different percentage (0.5,1,2,4)wt.% of carbon nanotubes (CNTs) using plasma spraying. The effect of this composite on corrosion behavior for AA6061-T6 by extrapolation Tafel test in sea water 3.5wt% NaCl was invested. Many specimens where prepared from AA6061-T6 by the dimension (15x15x3)mm as this first set up and other steps include coating process, X-ray diffraction and SEM examination .The results show the CNTs increase the corrosion rate of the nanocomposite coatings with increasing the weight percentage of CNTs within the Al-Si matrix. Al-9wt%Si coating layer itself has less corrosion rate if compared with both n
... Show MoreThis study focuses on the use of an optimum amount of Sodium Polyacrylate (SP) for designing cement slurry with the high performance of rheological properties and displacement efficiency. A laboratory study has been carried out on the cement slurry which prepared with SP as superabsorbent polymer. SP has been providing an internal water source that helps in the hydration process, and curing and ultimately increases the cement strength. Also improves the cement performance by improving the cement stability. Several batches were prepared to determine the proper amount of SP to add it in the cement slurry. Also, we studied its effect on cement density, amount of free water in order to observe the rheological properties, and thickening time.
... Show MoreSamples of Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor were prepared by solid-state reaction method to study the effects of gold nanoparticles addition to the superconducting system, Nano-Au was introduced by small weight percentages (0.25, 0.50, 0.75, 1.0, and 1.25 weight %). Phase identification and microstructural
characterization of the samples were investigated using XRD and SEM. Moreover, DC electrical resistivity as a function of the temperature, critical current density Jc, AC magnetic susceptibility, and DC magnetization measurements were carried to evaluate the relative performance of samples. x-ray diffraction analysis showed that both (Bi,Pb)-2223 and Bi-2212 phases coexist in the samples having an orthorhombic crystal struct
Optical properties and surface morphology of pure and doped Polystyrene films with different divalent metals of Zn, Cu and Sn and one concentration percentage have been studied. Measurements of UV-Vis spectrophotometer and AFM spectroscopy were determined. The absorbance, transmittance and reflectance spectrums were used to study different optical parameters such as absorption coefficient, refractive index, extinction coefficient and energy gap in the wavelengths rang 200-800nm. These parameters have increased in the presence of the metals. The change in the calculated values of energy gaps with doping metals content has been investigated in terms of PS matrix structural modification. The value of opt
... Show MoreDue to the specific characteristic of porcelain, the insertion of Beryllium oxide has been studied. The basic materials and quantities were selected carefully. In this work, porcelain containing 32 wt% feldspar, 24 wt% quartz and 44 wt% clay was synthesized and beryllium oxide (BeO) (1 wt.%, 3 wt.%, 5 wt% and 7wt%) were add. The basic and new composition porcelain powders were uniaxially compacted into standard samples dimensions and fired at various sintering temperatures, 1100°C, 1300°C, and 1450°C then held for 2 hour in a furnace.
The effects of sintering temperatures and beryllium oxide content on mechanical, electrical and structural properties were studied. The increasing of sintering temperature on the basi
... Show More The study is focused on the modification of the standardized newspaper with natural polymers chitosan and keratin hydrolysate applied on the paper surface from polymer solution. This modification is based particularly on the formation of the complexes between acidic surface groups on cellulose fibers and the natural polymers which improved the mechanical properties of the paper and the positive results which were observed particularly in folding endurance of the newspaper.
Carbon nanoparticles are prepared by sonication using carbon black powder. The surface morphology of carbon black (CB) and carbon nanoparticles (CNPs) is investigated using scanning electron microscopy (SEM). The particles size ranges from 100 nm to 400 nm for CB and from 10 nm to 100 nm for CNPs. CNPs and CB are mixed with silicon glue of different ratios of 0.025, 0.2, 0.05, and 0.1 to synthesis films. The optical properties of the prepared films are investigated through reflectance and absorbance analyses. The ratio of 0.05 for CNPs and CB is the best for solar paint because of its higher solar water heater efficiency and is then added to the silicon glue . Temperature of cold water and temperature of hot water in storage tank were ta
... Show MoreIn this work, samples of Cd2Si1-xGexO4 prepared by powder technology for (x = 0, 0.3, 0.6) were studied. The effect of (Ge) additives at different ratio of Ge (x=0, 0.3, 0.6) on the behavior of dielectric constant, dielectric loss and a,c conductivity were measured as a function of temperature at a selected frequencies (0.01 – 10) MHz in the temperature range 298 K to 473 K. The dielectric constant and dielectric loss obtained different behavior with the additives of (Ge). The activation energy for the electrical conduction process was studied.
Propaganda speech in the Gulf press articles about the Qatari crisis, an analytical study in the political articles published in the newspapers (Riyadh) Saudi Arabia and (Al-Ittihad) UAE from 5/6/2017 to 5/9/2017, University of Baghdad, College of Media, Press Department, 2019. The problem of the research was to monitor the contents of propaganda messages to Saudi Arabia and the UAE regarding the Qatari crisis, especially with the escalation of propaganda media campaigns between the four boycotting countries on the one hand and Qatar on the other hand, in light of crises and conflicts in the Gulf region and the Arab region in general. The researcher used the survey method to answer the research questions and achieve its results. This res
... Show MoreThe study aims to assess some physical, chemical, and bacterial characteristics of two drinking water treatment plants of Al- Dora and Al-Qadisiya in the area of ​​Karkh, Baghdad, Iraq. The areas covered by each plants and these sites of areas selected as the nearest and the farthest point from plants, for winter and summer season. Some physicochemical parameters of water quality were taken in this study and these parameters were temperature water, pH, electrical conductivity, total dissolved solids, free residual chlorine, calcium, magnesium, nitrate, nitrite, sulphate and heavy metals (lead). In addition to four bacterial indicators of drinking water pollution (APC, Total Coliform, Fecal Coliform
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