In this work, carbon-doped copper oxide thin films were deposited by the reactive DC sputtering method for use as selective absorbents. The properties of the DC discharge plasma were studied, using the emission spectrum, in the presence of pure argon and by mixing it with oxygen once and carbon dioxide again to know the effect of adding these gases on the properties of the resulting plasma used in the deposition of films. The structural properties of the deposited thin films prepared with different flow ratio of carbon dioxide gas were studied using x-ray diffraction. To examine the selective absorber coatings, the reflectance within the UV-Vis spectrum was measured to calculate the percentage of energy absorbed by solar radiation using numerical integration. The reflectance was also measured in the range from 2.5 to 25 μm to calculate the thermal emission of the solar heater within a temperature of 373 K. Measurements showed good efficiency as a selective absorption layer. The best absorptance of the solar spectrum (α) was 0.8750, and the lowest emittance (ε) in the infrared region was 0.254 at 25% percentage of carbon dioxide in the reactive gas of the sputtering system. So, this ratio has the highest efficiency as a selective absorber.
In the current study, new derivatives were synthesized by reaction of N-hydroxyphthalimide with chloro acetyl chloride in the presence of Et3N as a base to form 1,3-dioxoisoindolin-2-yl 2-chloroacetate (B1), which in turn enters several reactions with different amines where it interacts with primary amines to give 1,3-dioxoisoindolin-2-yl acetate derivatives (B2-B4) in basic medium, in the same way it interacts with these amines but with adding KNCS to form thiourea derivatives (B5-B7). It also reacts with diamines to give bis(azanediyl) derivatives (compounds B8-B10). The prepared derivatives were diagnosed using infrared FTIR and 1HNMR,13CNMR for some derivatives. Compounds B4, B5 and B9 were measured as corrosion inhibitors the inhibitio
... Show MoreThis research deals with the effect of gallium oxide and cerium oxide as dopants on the structural and optical characteristics of tin oxide. Gallium and cerium oxide doped tin oxide was prepared with different doping concentrations (0, 0.03, 0.05 and 0.07) wt. pure and doped tin oxide thin films were prepared by the pulsed laser deposition technique. X-ray diffraction and UV-Visible spectrophotometer were employed to investigate both oxides doping effects. Results showed that all prepared samples have poly-crystalline structure with a preferred plane of crystal growth along (110), where the crystal size grew from 40.3 nm to 64.5 nm and to 43.5 nm for Ga2O3 and CeO2 doped tin oxide thin films, res
... Show MoreIn this work, the electrical properties and optimum conditions of the plasma sputtering system have been studied. The electrical properties such as Paschen's curve, current-voltage, current pressure relations, the strength of magnetic field as a function of inter-electrode distance, the influence of gas working pressure and argon-oxygen ratio on the electrical characterization were studied to determine the basic optimum condition of the system operation. the discharge current as a function of discharge voltage showed high discharge current at 2.5 cm. These parameters represent the basic conditions to operate any plasma sputtering system which are the right behavior to build up and design the discharge an el
... Show MoreIn this research work, some low complexity and efficient cryptanalysis approaches are proposed to decrypt password (encryption keys). Passwords are still one of the most common means of securing computer systems. Most organizations rely on password authentication systems, and therefore, it is very important for them to enforce their users to have strong passwords. They usually ignore the importance of usability of the password for the users. The more complex they are the more they frustrate users and they end up with some coping strategies such as adding “123” at the end of their passwords or repeating a word to make their passwords longer, which reduces the security of the password, and more importantly there is no scientific basis
... Show MoreAn experimental analysis was included to study and investigate the mass transport behavior of cupric ions reduction as the main reaction in the presence of 0.5M H2SO4 by weight difference technique (WDT). The experiments were carried out by electrochemical cell with a rotating cylinder electrode as cathode. The impacts of different operating conditions on mass transfer coefficient were analyzed such as rotation speeds 100-500 rpm, electrolyte temperatures 30-60 , and cupric ions concentration 250-750 ppm. The order of copper reduction reaction was investigated and it shows a first order reaction behavior. The mass transfer coefficient for the described system was correlated with the aid of dimensionless groups as fo
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