Heat transfer process and fluid flow in a solar chimney used for natural ventilation are investigated numerically in the present work. Solar chimney was tested by selecting different positions of absorber namely: at the back side, front side, and at the middle of the air gap. CFD analysis based on finite volume method is used to predict the thermal performance, and air flow in two dimensional solar chimney under unsteady state condition, to identify the effect of different parameters such as solar radiation. Results show that a solar chimney with absorber at the middle of the air gap gives better ventilation performance. A comparison between the numerical and previous experimental results shows fair agreement.
Praise be to God alone, and after:
This is a research entitled: “A fundamental study of judicial jurisprudence rules and their applications in the Hanbali school of thought,” in which the researcher studied eight legal jurisprudential rules considered by the Hanbalis and others.
At the conclusion of his research, the researcher reached a number of results, including: the importance of taking care of judicial rules, and the need for judges and their assistants to them, including: the need for students of science in Hanbali jurisprudence to study these rules according to the doctrine, and to highlight their applications to them, including: the importance of the rules under study, and their impact on rulings Jurisprudenc
... Show MoreTherapeutically and prophylactically using Microspheres containing doxycycline isolated from shell of shrimp. Low molecule weight poly lactic acid was prepared. In this study, Poly lactic acid (PLA)/ poly vinyl alcohol (PVA)/poly ethyleneglycol(PEG) loading doxycycline blend solutions was prepared. Also Poly lactic acid (PLA)-Tannin blend via solvent evaporation method was prepared. Microspheres of chitosan/gelatin microsphere loading doxycycline was prepared by emulsion crosslinking technique. Both microsphere and blends were characterized by Fourier transform infrared (FTIR) spectrophotometer. The FTIR spectra were shown distinguish bands. The in vitro release of doxcycline from its matrix at pH 7 was studied. The prophylactic
... Show MoreNew isatinic hydrazone Schiff-base ligands, namely furan-2-carboxylic acid (2-oxo-1,2-dihydro-indol- 3-ylidene)-hydrazide (L1), thiophene-2-carboxylic acid (2- oxo-1,2-dihydro-indol-3-ylidene)-hydrazide (L2) and 2-(pyridine-2-yl-hydrazono)-1,2-dihydro-indol-3-one) (L3) are reported. The ligands were prepared by the condensation of furan-2-carboxylic acid hydrazide (L1), thiophene- 2-carboxylic acid hydrazide (L2), and 2-hydrazino pyridine (L3) with isatine. Monomeric complexes were prepared from the reaction of the corresponding metal chloride with the ligands. The ligands and their nine new complexes of the general formulae [M(Ln)2]Cl2 [where M = Co(II), Zn(II) and Cd(II); n = L1, L2 and L3] were characterised by spectroscopic methods (FTI
... Show MoreThis work concerns the synthesis of two types of composites based on antimony oxide named (Sb2O3):(WO3, In2O3). Thin films were fabricated using pulsed laser deposition. The compositional analysis was explored using Fourier transform infrared spectrum (FTIR), which confirms the existence of antimony, tungsten, and indium oxides in the prepared samples. The hall effect measurement showed that antimony oxide nanostructure thin films are p-type and gradually converted to n-type by the addition of tungsten oxide, while they are converted almost instantly to n-type by the addition of indium oxide. Different heterojunction solar cells were prepared from (Sb2O3:WO
... Show MoreThe design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 5
... Show MoreIn this paper thermo-hydrodynamic characteristics were investigated experimentally for a new type shell-helical coiled tube heat exchanger used as a storage tank of closed loop solar water heater system. Triple concentric helical coils were made of copper tubes of (12.5mm OD and 10mm ID) with coils diameter of (207, 152.2, 97mm) for outer, middle and inner coils respectively. The experiments were carried out during a clear sky days of (March and April 2012). The parameters studied in this work are: history of average temperature of shell side of the storage tank, collector heat gain, heat rejected from coils to shell side of the storage tank, collector efficiency, thermal effectiveness of the heat exchanger (storage tank), and pressure d
... Show MoreThis paper demonstrates the spatial response uniformity (SRU) of two types of heterojunctions (CdS, PbS /Si) laser detectors. The spatial response nonuniformity of these heterojunctions is not significant and it is negligible in comparison with p+- n silicon photodiode. Experimental results show that the uniformity of CdS /Si is better than that of PbS /Si heterojunction
Background: Oral SCC is a complex malignancy where environmental factors, viral infections and genetic alterations most likely interact, and thus give rise to the malignant condition. The HSP70 play a direct role in apoptosis inhibition by aligning the improved integrity of a cell’s proteins with the improved chances of that particular cell’s survival.P21 gene produces p21 protein which is a potent cyclin-dependent kinase inhibitor that plays a significant role in carcinogenesis. The aims of the study were to evaluate and compare the immun-histochemical expression of the HSP70 and cell cycle protein p21in NOM, OED, and OSCC. Correlate both marker expressions with each other. Materials and methods: Forty six formalin-fixed, par
... Show More