Gongcheng Kexue Yu Jishu/Advanced Engineering Science

Abstract : The study was carried out under an experimental protocol for obtaining metallic aluminum foams with varied porosity. The protocol was based on the infiltration method in water-soluble preforms; sodium oxide (Na2O) was used as preform material, with sizes of 3, 5 and 7 mm respectively, which were placed in a pyramid shape. A metallographic analysis was carried out to determine the most relevant properties of the metallic foams, such as relative density, porosity and bond thickness. As a result of this analysis, an average relative density of the foams of 0.504 and an average porosity percentage of 49.578% were obtained. To know the ligament thickness, the Image J computer program was used, and a thickness of approximately 0.94, 1.5 and 1.8 mm was obtained for pore diameters of 3, 5 and 7 mm, respectively. As part of this research, quasi-static compression testing was performed to obtain the energy absorbed by integrating the area under the stress-strain curve. To complete the mechanical test, a dynamic compression test was carried out by frontal impact of a pendulum designed for automotive applications, in order to observe the behavior of the foams as shock absorbers. Finally, the energy absorbed was studied by calculation and demonstrates the great capacity of this type of foams to absorb deformation energy..
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Abstract : The main objective of this research project is to perform some experimental procedures to study the ability of the novel adsorbent used in this project. The chemical modification of the adsorbent is the chemical oxidation of pure powder chitosan using some specific redox pairs which are potassium dichromate and sodium bisulphite. After preparing the modified chitosan, there are some parameters that must be discussed during the adsorption process. The first parameter is the time parameter, showing experimentally the optimum time for adsorption under certain conditions by collecting values of absorbance and concentration of thymol blue adsorbed after the process from the spectrophotometer showing that the optimum time is 120 minutes. While for the optimum pH experiment, it is shown that optimum pH is 4, 0.5% v/v is optimum concentration and 0.05 grams is the optimum dose for the adsorbent. Then after computing these conditions and values of absorbance, some mathematical calculations and classifications are done to show the reaction kinetics classification of the process. By performing some equations using mathematical rules it is provided that the reaction is not a first order reaction, showing by calculations and graphs that the reaction is a second order reaction..
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Abstract : Recently, the medical applications of cold plasma have received a wide range of attention due to its high efficiency in treating a wide range of diseases, and the absence of collateral damage from its use on living tissues and organs. The DBD) plasma system was designed and built to produce a cold plasma that can be used for different applications. The system will have two electrodes and the applied voltage will be (8 and 10) kVp−p and the frequency will be almost (21kHz), the results of this study should that cold atmospheric plasma jet was generated with flowrate of 4 (slm) of different gases (Ar, He and mixed gases) and conditions to diagnose different characteristics. Staphylococcus aureus samples were obtained and cultured on a Mueller hinton agar. Then they were treated with cold plasma. The treatment periods were (5, 10, 15, 20) minutes. The results showed that the growth of bacteria-type cells decreases with increasing treatment period and thus leads to the killing of bacterial cells. Cold plasma technology is a promising and safe technology that has succeeded in eliminating Staphylococcus aureus bacteria without causing any damage to the living tissues..
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Abstract : Babylon Governorate is located approximately in the center of Iraq, about 100 km away from the capital, Baghdad. Its area is 5,119 km2, which constitutes 2% of the total area of Iraq. It is dominated by a desert climate, which is characterized by a low amount of rainfall, ranging from 50 to 200 mm annually, and high temperatures in summer may reach 50 ° C, dominated by northwest winds. The engineering study of sand dune soils revealed that the grain size distribution of the sand reached 99%. The sand is of the type (Sp), which is sandy poorly graded according to USCS, the values of the bulk density of sand dune soils for the locations of the study area ranged between 1.287 - 1.376 g / cm3, where the minimum was 1.287 g / cm3 in the Bermana area (the third site), while the maximum was 1.376 g / cm3 in the Ramlet Rashid site (the first site) at a average of 1.3315 g/cm3. From the direct shear test, the values of internal friction angle (Ø) for sand dune soils for the study area sites ranged between 33-34, where the minimum was 33 in Ramlet Rashid site, while the maximum was 34 in the Albu Faris site. with a rate of 33.5. The convergence of the values of the internal friction angle (Ø) for the sand dunes reflects the environment of deposition and the nature of the geometric shape of the sand dunes. The values of the cohesion (C) for all sites are zero because the soil is SP without cohesion and clays. The petrographic study of sand dune soils revealed that quartz is the most light mineral found in all locations, followed by rock fragments, which include: sedimentary rocks (calcareous rocks, carbonates, chert, evaporites, and clay rock fragments), followed by feldspar (alkali and plagioclase feldspar), and igneous rock fragments. metamorphic rocks and mud-covered grains. As for its heavy minerals components, mostly opaque minerals, the chlorite group, the mica group, the amphibole group, the pyroxene group, zircon, termolite, garnet, rhyolite, staurolite, kainite, rutile, and other minerals by 1%. X-ray diffraction test revealed the presence of quartz, albite and calcite, and X-ray fluorescence tests showed the presence of silica (Si02) and lime (CaO)..
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Abstract : The urge to introduce renewable energy sources along with the conventional sources is highly increasing by the time. This is witnessed through the installed solar photovoltaic (PV) power plants around the world including the most recent Benban solar park-Aswan-Egypt. However, some challenges still hinder renewable energy projects from being widely applicable. The most serious challenges on spot are soiling, followed by temperature rise. This paper aimed at studying the PV panel performance on applying a coating made of nano-titania TiO2 with the addition of nano-alumina Al2O3 and a base of glycerol. Three coatings were prepared using different nano particles compositions. It was found out after an outdoor study held at El-Shrouk City-Egypt that the highest PV panel performance was obtained when the coating was prepared using Al2O3 and TiO2 nano particles composition with a ratio of 3:1. Cooling techniques such as using water basin and cooling fans for both the front and back surface were also implemented along with the coating. The aforementioned set-up resulted in increasing the PV power efficiency by 3.17% at adjusted wind speed of 4.2 m/s. This is also illustrated from the forced turbulence generated by the fan that has limited the excessive elevation of temperature by 44.7%..
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