The electrical properties of Poly (ethylene oxide)-MnCl2 Composites were studied by using the impedance technique. The study was carried out as a function of frequency in the range from 10 Hz to 13 MHz and MnCl2 salt concentration ranged from 0% to 20% by weight. It was found that the dielectric constants and the dielectric loss of the prepared films increase with the increase of the MnCl2 concentration; The A.C. conductivity increases with the increase of the applied frequency, and the MnCl2 content in the composite membrane. Relaxation processes were observed to take place for composites which have a high salt concentration. The observed relaxation and polarization effects of the composite are mainly attributed to the dielectric behaviour of the MnCl2 filler and polarity of the polymer PEO. However, the results were explained on the basis of the interfacial (space charge) polarization dipolar polarization and the decrease of the hundrance of the polymer matrix with the ionic mobility and impurities in the composite.
Sol-gel derived CuCo-oxide coatings as solar selective surfaces, synthesized onto aluminium substrates at various annealing temperatures, are analysed by correlating their structural, chemical bonding states, and surface morphological topographies. As the annealing progressed, all the coatings displayed a Cu0.56Co2.44O4 (ICSD 78-2175) phase with preferential orientation along (400) reflection plane. Rietveld refinement of X-ray diffraction (XRD) data indicate that residual stress and microstrains developed around the coating surfaces are reduced resulting in mechanically stable thin films. Enhancement of the crystallite size and preferred orientation of the surface were confirmed via XRD, field emission scanning electron microscopy (FESEM),
... Show MoreThe present study focuses on synthesizing solar selective absorber thin films, combining nanostructured, binary transition metal spinel features and a composite oxide of Co and Ni. Single-layered designs of crystalline spinel-type oxides using a facile, easy and relatively cost-effective wet chemical spray pyrolysis method were prepared with a crystalline structure of MxCo3−xO4. The role of the annealing temperature on the solar selective performance of nickel-cobalt oxide thin films (∼725 ± 20 nm thick) was investigated. XRD analysis confirmed the formation of high crystalline quality thin films with a crystallite si
In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase fr
... Show MoreIn this work, InSe thin films were deposited on glass substrates by thermal evaporation technique with a deposit rate of (2.5∓0.2) nm/sec. The thickness of the films was around (300∓10) nm, and the thin films were annealed at (100, 200 and 300)°C. The structural, morphology, and optical properties of Indium selenide thin films were studied using X-ray diffraction, Scanning Electron Microscope and UV–Visible spectrometry respectively. X-ray diffraction analyses showed that the as deposited thin films have amorphous structures. At annealing temperature of 100°C and 200°C, the films show enhanced crystalline nature, but at 300°C the film shows a polycrystalline structure with Rhombohedral phase with crystallites size of 17.459 nm. Th
... Show MoreDensity Functional Theory (DFT) with B3LYP hybrid exchange-correlation functional and 3-21G basis set and semi-empirical methods (PM3) were used to calculate the energies (total energy, binding energy (Eb), molecular orbital energy (EHOMO-ELUMO), heat of formation (?Hf)) and vibrational spectra for some Tellurium (IV) compounds containing cycloctadienyl group which can use as ligands with some transition metals or essential metals of periodic table at optimized geometrical structures.
The core objective of this study was to investigate the physicochemical characteristics and fatty acid composition of the oils of sunflower, olive, virgin coconut and ginger oils, as well as the separation of their unsaturated fatty acids. The data indicated a significant variation in physicochemical properties (acid, saponification, ester, and iodine values) among oils. Transesterification process was carried out at a molar ratio of 1:7:0.1 of oil: methanol: KOH. Fatty acid methyl esters of oils were analyzed by infrared (IR) and gas chromatography–mass (GC-MS) spectrometry. Twelve fatty acids were identified, where the major fatty acid of olive oil was found to be oleic acid (89%), whereas those of sunflower and ging
... Show MoreCutaneous leishmaniasis (CL) also known under local names like (tropical sore, oriental sore and Baghdad sore) is the most common form of leishmaniasis. It is a public health and a social problem in many developing countries. The Old World disease primarily is caused by Leishmania major in dry desert areas and Leishmania tropica in urban areas. Recently, metal oxide nanoparticales have been versatile platforms for biomedical applications and therapeutic interventions. There is an urgent need to develop new types of antileishmanial agents instead of classical drug (pentostam), especially, when its efficacy showed a decline towards some strains of Leishmania. Therefore, the present work was aimed to evaluating antileishmanial activity of z
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