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In this work, an experimental investigation has been done for heat transfer by natural-convection through a horizontal concentric annulus with porous media effects. The porous structure in gap spacing consists of a glass balls and replaced by plastic (PVC) balls with different sizes. The outer surface of outer tube is isothermally cooled while the outer surface of inner tube is heated with constant heat flux condition. The inner tube is heated with different supplied electrical power levels. Four different radius ratios of annulus are used. The effects of porous media material, particles size and annulus radius ratio on heat dissipation in terms of average Nusselt number have been analyzed. The experimental results show that the average Nusselt number increases with increasing annulus radius ratio and particle diameter for same porous media material. Furthermore, two empirical correlations of average Nusselt number with average Rayleigh number for glass and PVC particles are developed. The present experimental results are compared with previously works and good correspondence is showed. |
The purpose of this study was to investigate the effect of omega-3 poly unsaturated fatty-acids co-administered with the therapeutic dose of lornoxicam on liver of healthy rats. Twenty-eight adults male rats weighing 180-200g were used in this study and the animals were randomly divided into four groups of seven rats each. Group I: negative control/rats intraperitoneally injected with normal saline in a dose 5ml/kg/day; Group II: rats intraperitoneally injected with lornoxicam at dose 0.7 mg/kg/day; Group III: rats orally-administered omega-3 only at a dose 185mg/kg/day; Group IV: rats co-administered omega-3 (185mg/kg/day) orally and in
... Show MoreColloidal crystals (opals) made of close-packed polymethylmethacrylate (PMMA) were fabricated and grown by Template-Directed methods to obtain porous materials with well-ordered periodicity and interconnected pore systems to manufacture photonic crystals. Opals were made from aqueous suspensions of monodisperse PMMA spheres with diameters between 280 and 415 nm. SEM confirmed the PMMA spheres crystallized uniformly in a face-centered cubic (FCC) array. Optical properties of synthesized pores PMMA were characterized by UV–Visible spectroscopy. It shows that the colloidal crystals possess pseudo photonic band gaps in the visible region. A combination of Bragg’s law of diffraction and Snell’s law of refraction were used to calculate t
... Show MoreFabrication of porous clay refractory insulating specimens from Iraqi kaolin with different percentage of Expanded Polystyrene (EPS) waste crumbs additions were investigated. After mixing and forming by hand molding, the specimens was dried and fired at 1300 oC. The structural, physical, mechanical and thermal properties of the refractory insulating products were measured. Maximum addition of EPS (1.25 wt%) lead to reduce the linear shrinkage to less than 1.7% and increased apparent porosity up to 50 %. As well as, the density, Modulus of rupture and thermal conductivity were reduced to 1.39 g/cm3, 4.1 MPa and 0.21 W/m.K, respectively. The final outcome, addition of EPS showed good results in the formation of pores without distorting the
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An experimental model is used to simulate the loss of soil lateral confinement due to excavation nearby an individual axially loaded pile. The effects of various parameters, such as the horizontal distance of excavation, depth of excavation and pile slenderness ratios are investigated. The experimental analysis results showed the effect of excavation is more remarkable as the horizontal distance of excavation becomes closer to the pile than half pile length. The effect of excavation diminishes gradually as the horizontal distance increases beyond that distance for all the investigated pile slenderness ratios and depths of excavation. The pile head deflection, settlement and bending moments along pile increase with decreasing horizontal d
... Show MoreCopper (I) complex containing folic acid ligand was prepared and characterized on the basis of metal analyses, UV-VIS, FTIR spectroscopies and magnetic susceptibility. The density functional theory (DFT) as molecular modeling calculations was used to determine the donor atoms of folic acid ligand which appear clearly at oxygen atoms binding to hydrogen. Detection of donation sights is supported by theoretical parameters such as geometry, mulliken population, mulliken charge and HOMO-LUMO gap obtained by DFT calculations.
The research is the realization of a manuscript of Abdul Baqi al-Omari nicknamed (Farouk) relative to Al-Faruq Omar bin al-Khattab (Radha) and (Mosli) relative to the city of Mosul in Iraq and (immediate) to improvisation of poetry immediately lived during the era of the Ottomans. Entitled (Picture written by the whole secret sea embroidered crown literary style genius with wisdom poetry and magical prose Hazrat Abdul Baqi Effendi Omari comforting and congratulated to Sheikh Ali Talabani dear) and the manuscript in two versions, the subject of my brothers, in which congratulations and condolences Sheikh Ali Talabani, an administrative position in the Ottoman Empire, And the importance of the manuscript Baha The twist on the hair of Abdul
... Show MoreIt included the introduction to the research and its importance, as the knee joint is one of the important joints in the human body that are susceptible to injury, and among these injuries is the roughness of the knee that occurs as a result of weakness and imbalance in the work of the quadriceps muscle, so its treatment is through rehabilitation exercises to treat weakness and gain flexibility and strength.Hence the importance of the research by developing rehabilitation exercises with different resistances in the water medium and restoring flexibility and muscular strength for patients with knee roughness for ages from 30-40 years, and the experimental method was used to solve the research problem, and the research sample included (6) of
... Show MoreBackground: ?-L-Fucose is a methyl pentose sugar similar to L-galactose except for the loss of alcohol group on carbon number 6. The objective of this study is to evaluate the biochemical and antioxidant effect of intracrevicular injection of fucose into rabbits periodontium, throughout measuring the levels of total protein (TP), total fucose (TF), protein bound fucose PBF) , Malondialdehyde (MDA) , and vitamin C in sera of fucose injected rabbit groups. ) Materials and Methods: The existing study was carried out on 55 male rabbits and were divided randomly into three groups ; first group was injected with 50µl of 150mM fucose solution into gingival sulcus ; second group was injected with 50 µl of normal saline ; while the third group was
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