This work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated from burnt herbs and collected in a smoke generator to delivered through the prototype room. The numerical results were compared with those obtained from experiments, the correspondence between numerical and experimental was fairly good and also, a fair comparison was found with other workers in this field.
A particular solution of the two and three dimensional unsteady state thermal or mass diffusion equation is obtained by introducing a combination of variables of the form,
η = (x+y) / √ct , and η = (x+y+z) / √ct, for two and three dimensional equations
respectively. And the corresponding solutions are,
θ (t,x,y) = θ0 erfc (x+y)/√8ct and θ( t,x,y,z) =θ0 erfc (x+y+z/√12ct)
Geographic information system (GIS) is utilized in a variety of tasks such as, resource management, urban planning, emergency planning in case of accident, and rapid response etc. The aim of this study is to produce a digital map with the aid of GIS and a survey data. A survey data is conducted with Total Station technique on sanitary planning positions. The campus of Baghdad University is chosen to test the execution and accuracy of the results for sewer manholes locations. During the field survey, Total Station (Nikon Nivo) is used to identify the 3-D coordinates for each location. Finally, Geographical Information System (GIS) are utilized to present the digital map of the network sewer pipe line to the end users. Although Geographic Inf
... Show MoreThis research was conducted to measure the safety of heat stable enterotoxin a (STa) produced by enterotoxigenic Escherichia coli, through studying its toxic effect on human blood lymphocyte, since it showed a promising effect in reducing the proliferation of colorectal cancer cells. the cytogenetic effects of (STa) by using five different concentrations (100, 200, 400, 800 and 1600μg/ml) in comparison with negative (PBS, Phosphate buffer saline) and positive (MMC, Mitomycin C) at concentration of 5μg/ml, controls on human blood lymphocytes obtained from both (10) normal healthy persons and (20) colorectal cancer patients was measured by employing the following parameters: mitotic index, blast index, chromosomal aberrations and micronucle
... Show MoreAim of the study: This study's goal was to determine how laser surface alteration affected wettability of injectable thermoplastic acrylic and heat cure acrylic denture base materials. Materials and methods: Injectable thermoplastic acrylic resin (Deflex) and heat cure acrylic (Procryla) were used in this study to produce forty-disc shaped specimens, 20 specimens for each material type. The control group was made up of ten samples of each type of plastic denture base material. The other ten samples were treated with a nano-pulse fiber-optic lens Nd:YAG laser. The results were looked at with the Kruskal-Wallis test and the unpaired t-test (a=.05). Results: Compared to the control groups, the laser-treated groups were more likely to sti
... Show MoreExperimental model was done for pile model of L / D = 25 installed into a laminar shear box contains different saturation soil densities (loose and dense sand) to evaluate the variation of pore water pressure before and after apply seismic loading. Two pore water pressure transducers placed at position near the middle and bottom of pile model to evaluate the pore water pressure during pullout tests. Seismic loading applied by uniaxial shaking table device, while the pullout tests were conducted through pullout device. The results of changing pore water pressure showed that the variation of pore water pressure near the bottom of pile is more than variation near the middle of pile in all tests. The variation of pore water
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The present study investigates the effect of acetic acid on corrosion behavior and its potential of hydrothermally sealed anodized AA2319-Al-alloys. Anodizing treatment was performed in stagnant phosphoric acid electrolyte with or without addition of acetic acid. Hydrothermal sealing was carried out in boiling water for each anodized specimen. The open circuit potential of the unsealed and sealed anodized samples was examined using open circuit potential measurement for the purpose of starting in scanning polarization diagrams. The potentiostatic polarization technique measurements were performed to assess corrosion behavior and sealing quality (i.e., degree of sealing) of
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In the present work the effect of bearing compliance on the performance of high speed misaligned journal bearing lined with a compliant PTFE liner lubricated with bubbly oil at high speeds has been studied. The effect of induced oil film temperature due to shearing effect has been implemented. Hydrodynamic effect of the complaint bearing and the influence of aerated oil have been examined by the classical thermohydrodynamic lubrication theory modified to include the effect of oil film turbulence and oil film temperature with suitable models for bubbly oil viscosity and density. The effect of liner elastic deformation has been implemented by using Winkler model. The effects of variable density and s
... Show MoreRoller-Compacted Concrete is a no-slump concrete, with no reinforcing steel, no forms, no finishing and wet enough to support compaction by vibratory rollers. Due to the effect of curing on properties and durability of concrete, the main purpose of this research is to study the effect of various curing methods (air curing, 7 days water curing, and permanent water curing) and porcelanite (local material used as an Internal Curing agent) with different replacement percentages of fine aggregate (volumetric replacement) on some properties of Roller-Compacted Concrete and to explore the possibility of introducing practical Roller-Compacted Concrete for road pavement with minimum requirement of curing. Specimens were sawed fro
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