Thin films of ZnSe arc deposited on glass substrates by thermal evaporation in vacuum with different thickness (1000, 2700, 4000) A° temperature (293-373) °K are studies the electrical properties before and after annealing. The result show decrease D.0 conductivity and increasing the activation energy Eat.
In this paper, thermal performance of a zig-zig solar air heater (ZZSAH) with and without using steel wire mesh on the absorber plate of the collector is experimentally investigated. The experimental work includes four inclination angles of the collector 20o, 30o, 45o, and 60o and four air mass flow rates of 0.03, 0.04, 0.06, and 0.08 kg/s under varieties of operating conditions of a geographic location of Baghdad. New correlation equations of Nusselt number are obtained from experimental results for both types of collectors where the effect of varying of the inclination angle of collector taken into consideration in the experiment. The correlations show good agreement wi
... Show MoreCircular thin walled structures have wide range of applications. This type of structure is generally exposed to different types of loads, but one of the most important types is a buckling. In this work, the phenomena of buckling was studied by using finite element analysis. The circular thin walled structure in this study is constructed from; cylindrical thin shell strengthen by longitudinal stringers, subjected to pure bending in one plane. In addition, Taguchi method was used to identify the optimum combination set of parameters for enhancement of the critical buckling load value, as well as to investigate the most effective parameter. The parameters that have been analyzed were; cylinder shell thickness, shape of stiffeners section an
... Show Moreتضمن هذا العمل تحضير ليكند قاعدة شيف جديدة مشتقة من مادة البولي أكريلاميد والكلوترالديهايد [(2S, 2'S) – N, N' - (pentane-1, 5-diylidene) bis (2- methylbutan amide)] مع بعض المعادن الثقيلة (Cr + 3 Mn + 3 , Fe + 3 , ,Co + 2, Ni + 2 ,Cu + 2 Zn + 2 , Cd + 2,) لتنتج المعقدات المقابلة. تم تشخيص قواعد شيف ومعقداتها المعدنية بأستخدام طيف الأشعة تحت الحمراء والأشعة المرئية وفوق البنفسجية، والتوصيلية ,وقيم المغناطيسية والتحليل الحراري الوزني وحيود الأشعة السينية ومجه
... Show MoreThe human blood physiology is an active system that is closely connected with environmental and lifestyle changes, which affect such processes as erythropoiesis, coagulation, platelet activity, nitric oxide (NO) signaling system, and oxygen transport. It is a synthesis of evidence based on recent research (2020-2026) on four modulators that relate to each other physically: exercise, high-altitude hypoxia, climate change-induced high and low temperatures, and consumption of non-nutritive sugar substitutes such as erythritol. Adaptive changes that are generally observed in response to exercise and altitude are increased erythropoiesis and improved vascular functions, whereas maladaptive changes, including oxidative stress, inflammator
... Show MoreDesigning high-performance solid polymer electrolytes (SPEs) remains a key challenge, primarily due to their inherently low ionic conductivity, which hampers the advancement of all-solid-state lithium-ion batteries (ASSLiBs). In this work, we address this limitation by developing a green, crosslinked polymer blend comprising carboxymethyl cellulose (CMC) - extracted and functionalized from palm frond fibers - and poly (vinyl alcohol) (PVA). Citric acid (CA) was utilized as a crosslinking agent, while lithium perchlorate (LiClO4) was incorporated as a dopant to enhance ionic conductivity. The SPE membranes were fabricated via solution casting, with the optimized formulation - designated CP-15X-Li25 - containing 15 wt.-% CA and 25 wt.-% LiClO
... Show MoreBackground: University students in Iraq face rising obesity risk linked to physical inactivity, prolonged sedentary behavior, insufficient sleep, and academic stress. Longitudinal evidence examining the combined influence of these behaviors on weight status in Iraqi universities remains limited. Objective: This study examined six-month longitudinal associations of physical activity, sedentary behavior, sleep duration, and perceived stress with body mass index and percentage body fat among Iraqi university students. Methods: A prospective multi-behavioral study was conducted at six public universities in Iraq. Six hundred undergraduate students aged 18–25 years were followed monthly during one academic semester. Validated questionn
... Show MoreA series of novel hybrid molecules containing 1,3,4-oxadiazole and 1,3,4-thiadiazole moieties bearing an ibuprofen moiety were designed, synthesized, and evaluated for their in vitro antibacterial activity against Gram-positive and Gram-negative bacteria. A carboxylic acid compound with a 1,3,4-thiadiazole unit was synthesized via the coupling reaction of 5-(1-(4-isobutylphenyl) ethyl)-1,3,4-thiadiazol-2-amine with benzoic acid. This compound was then used as the starting material to make several new 1,3,4-oxadiazole derivatives through ring closure reactions, after first converting it to its ester (methyl 4-(5-(1-(4-isobutylphenyl)ethyl)-1,3,4-thiadiazol-2-yl) benzoate) and then to the acid hydrazide (4-(5-(1-(4-isobutylphenyl) eth
... Show MoreThe new tridentate Schiff base ligand (HL)namely 2-{[1-(3-amino-phenyl)-ethylidene]-hydrazono methyl}- phenol containing (N N O)as donors atoms was prepared in two steps:Step (1): By the reaction of 3- aminoacetophenone with hydrazine monohydrate under reflux in methanol and drops of glacial acetic acid gave the intermediate compound 3-(1- hydrazono ethyl)-phenol amine.Step (2): By the reaction of 3-(1-hydrazono ethyl)-phenol amine with salicyaldehyde under reflux in methanol, gave the ligand (HL).The prepared ligand was characterized by I.R, U.V-Vis,1H- 13C NMR spectra and melting point and reacted with some metal ions under reflux in methanol with (1:1) ratio gave complexes of the general formula: [MClL]. Where: M= Mn(II), Fe(II), Co(II),
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