A single-crystalline semi-polar gallium nitride (11-22) was grown on m-plane (10-10) sapphire substrate by metal organic chemical vapor deposition. Three-step approach was introduced to investigate the grain size evolution for semi-polar (11-22) GaN. Such approach was achieved due to the optimized gallium to ammonia ratio and temperature variations, which led to high quality (11-22) oriented gallium nitride epilayers. The full width at half maximum values along (-1-123) and (1-100) planes for the overgrowth temperature of 1080°C were found to be as low as 0.37° and 0.49°, respectively. This was an indication of the enhanced coalescence and reduction in root mean square roughness as seen by atomic force microscopy. Surface analysis via atomic force microscopy indicated the orientation towards semi-polar plane. Field emission scanning electron microscopy analysis further indicates that higher temperature of 1080°C during the deposition of the overgrowth promoted closely packed surface coalescence. Room temperature Raman revealed that the overgrowth temperature of 1080°C portrayed compressive strain free as compared to other overgrowth temperature. Based on these results, the promising overgrowth temperature of 1080°C can be further utilized in future work for optoelectronics devices.
Phase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time
... Show MoreThe current study included, studying the ability of eight genera of plants belong to Brassicaceae family, Brassica tournifortii, Cakile Arabica, Capsella bursa – pastoris,Carrichtera annua, Diplotaxis acris, Diplotaxis haru , Eruca sativa and Erucaria hispanica to accumulate ten heavy metals Cadmium, Chromium , Copper, Mercury, Manganese ,Nickel ,Lead ,and Zinc . Plant leaves samples were collected from Al-Tib area during spring of 2021.The data demonstrated that, the highest conc. of Cd was 2.7 mg/kg in Diplotaxis acris leaves and lower value was 0.3 mg/kg in Cakile Arabica leaves. For Co, the highest conc.was 1.3 mg/kg in Capsella bursa – pastoris leaves, whereas the lower value was 0.5 mg/kg in Cakile arabica leaves. As for Cr ele
... Show MoreThis study includes the direct influence of (single & multi) dose of Cold Atmospheric Plasma (CAP) on the no. of platelets for mice for different exposure time (15, 30, 60, and 120) sec. the influence of CAP on mice was measured after 1, 2, 3, 7, and 14 day from exposure.
The results obtained in this study indicate that the effect of low doses of CAP on platelets was stimulatory effect in the first few hours from exposure (1day) but the high dose was inhibitory, It was found that after two weeks of exposure that the number of platelets became normal comparable to the control one, and this indicates that plasma effect was removed after this period.
The importance of internal audit in the growing demand for services in the public and private economic units, and in the rapid growth of its systems professional, has also been recognition of the importance of internal audit quality and the quality of information provided in a long time, as well as the importance of achieving the greatest possible quality in his work to reduce accounting risks of financial reports misleading or fraudulent, which is one of the important features of the audit.
The internal audit quality are linked with the ability of auditors to detect errors in the financial statements, and their willingness to express an opinion technical neutral and non-aligned based on the results of th
... Show MoreA field experiment was carried out in Horticulture Department / Collage of Agricultur e/University of Baghdad to study influence of adding ascorbic acid(asa) and bread yeast extract in snap bean cv.primel under irrigation with saline water using sodium chloride salt (NaCl) during spr ing season of 2016 .A factorial experiment using Randomized Complete Block Design( RCBD) with three replications wereconducted . The first factor includes three treatments of salinity which were tap water ( S0), 4ds.m-1(S1) and 8ds.m-1 (S2) . The second factor includes three treatments which were control treatment without any adding (C) ,ascorbic acid 0.3g.l-1( A ) and yeast extract 12g.l -1( Y ). Results showed significant and gradually decreases in all studie
... Show MoreThe issue of insurance against unlawful risks raises a jurisprudential and judicial debate between two opposing trends: the first considers coverage of these risks invalid due to their impact on public order or morals, while the second—which this research analyses—calls for the possibility of covering these risks in specific circumstances, based on contractual considerations in accordance with the principle that the contract is the law of the contracting parties, and based on the obligation to compensate the harmed third party—the victim—who has no connection to the unlawful act. In this context, our research highlights that contractual considerations can justify coverage of some unlawful risks, provided that the goal is to achieve
... Show Moreنحو تعزيز المشاركة السياسية للطالبات الجامعيات الفلسطينيات