Experimental and numerical studies have been conducted for the effect of injected air bubbles on the heat transfer coefficient through the water flow in a vertical pipe under the influence of uniform heat flux. The investigated parameters were water flow rate of (10, 14 and 18) lit/min, air flow rate of (1.5, 3 and 4) lit/min for subjected heat fluxes of (27264, 36316 and 45398) W/m2. The energy, momentum and continuity equations were solved numerically to describe the motion of flow. Turbulence models k-ε was implemented. The mathematical model is using a CFD code Fluent (Ansys15). The water was used as continuous phase while the air was represented as dispersed. phase. The experimental work includes design, build and instrument a test rig for that purpose. A
circular vertical copper pipe test section of (length=0.7m, diameter= 0.05m, thickness= 1.5mm) is . designed and constructed, heated by an electrical heater fixed on its outer surface. Water . temperature at inlet is kept constant at (32°C). Water inlet and outlet temperatures, as well as radial temperature distribution within the pipe at seven sections along it between pipe surface and its center are measured. The results revealed that the secondary flow created by air bubbles have
significant effects on heat transfer enhancement and temperature profile. It is observed, that averaged Nusselt number enhancement for low heat flux of 27264 W/m2 and 4 lit/min air bubbles was 33.3 % and 23% in numerical and experimental, respectively.
Reaction of Na2PdCl4 with benz-1,3-imidazole-2-thione or (bzimtH) benz-1,3-thiazoline2-thione (bztztH) in ethanol / NE3 afford complexes of the type [Pd(bzimt)2](1) and [Pd(bztzt)2](2) respectively. Treatment of [Pd(L)2] L= bzimt or bztzt with bidentate ligands (N^N) where N^N= bipyridine (Bipy) , phenanthroline (Phen) , ethylene diamine , or N,N′dimethylethylene diamine afford mononuclear complexes of the type [PdL2(N^N)]. The bzimt and bztzt ligands are coordinated as bidentate chelating ligands through the S and N in (1) and (2) whereas bonded as a monodentate fashion via the sulfur atom in other complexes. The prepared complexes were characterized by elemental CHN analysis, ir and 1H nmr spectra.
New tetradentate Schiff base [H2L] namely [2,2׳ -(ethane-1,2- diylbis (azan-1-ylylidene) diacetic acid)] was prepared from condensation of ethylenediamine with glyoxylic acid in ethanol as a solvent in presence of drops of 48% HBr .The structure of ligand (H2L) was characterized by,F-IR, U.V-Vis.,1H-,13C-NMR, pectrophotometer,melting point and elemental microanalysis C.H.N. Metal complexes of the ligand (H2L) in general Molecular formula [M(L)(H2O)2], where M= Co(II), Ni(II), Cu(II), Mn(II) and Hg(II); L=(C6H8N2O4) were synthesized were characterized by, Atomic absorption, F-IR, U.V-Vis. spectra, molar conductivity and magnetic susceptibility.It was found that all the complexes showed octahedral geometries.And
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This research deals with the detection of possible surface soil pollution by radon emissions for an area located inside the university of Baghdad campus at AL-Jadiriyah / Baghdad. The area is about 5625 m2 and located near the College of Science for Women. The area used as construction rubbles dump yard in the past, while recently it is covered with Silty - Clayey soil furnished with grass and used as a playground. A surface survey performed on October 2018 by gridding the area into 36 stations where surface radiometric pollution readings recorded and soil samples collected by using an auger for the top 30 Cm which represents the root zone of the area. Soil samples tested in the laboratory by using can technique with CR-
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Acinetobacter baumannii (A. baumannii ) is considered a critical healthcare problem for patients in intensive care units due to its high ability to be multidrug-resistant to most commercially available antibiotics. The aim of this study is to develop a colorimetric assay to quantitatively detect the target DNA of A. baumannii based on unmodified gold nanoparticles (AuNPs) from different clinical samples (burns, surgical wounds, sputum, blood and urine). A total of thirty-six A. baumannii clinical isolates were collected from five Iraqi hospitals in Erbil and Mosul provinces within the period from September 2020 to January 2021. Bacterial isolation and biochemical identification of isolates
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In this work, thiadiazole derivatives were prepared by taking advantage of active sites in (2-amino-5-mercapto-1, 3, 4-thiadiazole) as a starting material base. The main heterocyclic compounds (1, 3, 4-thiadiazole, oxazole) etc, 2-amino-5-mercapto-1,3,4-thiadiazole compound (1) was prepared by cyclic closure of thiosemicarbazide compound with anhydrous sodium carbonate and carbon disulfide. Oxidation of (1) via hydrogen peroxide, to have (2) which was treated with chloro acetyl chloride to get (3). Preparation of thiazole ring (4) was from reacting of (3) with thiourea. Synthesis of diazonium salts (5) from compound (4) using sodium nitrite and HCl. Compound (5) reacted with different ester compounds to prepare a new azo compounds (6–8).C
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A series of new 4-(((4-(5-(Aryl)-1,3,4-oxadiazol-2-yl)benzyl)oxy)methyl)-2,6-dimethoxy phenol (6a-i) were synthesized from cyclization of 4-(((4-hydroxy-3,5-dimethoxy benzyl)oxy)methyl)benzohydrazide with substituted carboxylic acid in the presences of phosphorusoxy chloride.The resulting compounds were characterized by IR, 1H-NMR, 13C-NMR, and HRMS data. 2,2-Diphenyl-1-picrylhydrazide (DPPH) and ferric reducing antioxidant power (FRAP) assays were used to screen their antioxidant properties. Compounds 6i and 6h exhibited significant antioxidant ability in both assay. Furthermore, type of substituent and their position of the aryl attached 1,3,4-oxadiazole ring at position five are play an important roles in enhancing or declining the antio
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