Conjugate heat transfer has significant implications on heat transfer characteristics, particularly in thick wall applications and small diameter pipes. In this study, a three-dimensional numerical investigation was carried out using commercial CFD software “ANSYS FLUENT” to study the influence of conjugate heat transfer of laminar flow in mini channels at constant heat flux wall conditions. Two parameters were studied and analyzed: the wall thickness and thermal conductivity and their effect on heat transfer characteristics such as temperature profile and Nusselt number. Thermal conductivity of (0.25, 10, 202, and 387) W/m2C and wall thickness of (1, 5, and 50) mm were used for a channel of (1*2) mm cross-sectional dimensions. Taking the Reynolds number 800 for all cases. The results demonstrate that the conjugate conduction impact is observed at high conductivities and for large wall thicknesses in the studied materials. This impact flattened the wall temperature distribution along the channel wall instead of being an augmented linear profile. Also, it flattens the local Nusselt number due to the axial heat conduction along the walls. It reduces the effect of the entrance region of high Nusselt number while making the fluid temperature profile curved and redistributing the wall heat flux and accumulating it toward the leading edge. A decrease was observed in the average Nusselt number of 8% when increasing wall thickness from 1 mm to 50 mm for the same thermal conductivity of 10 W/m2C, while an increase in Nusselt number of 19% with thermal conductivity changes from 0.25 W/m2C to 10 W/m2C.
Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength, poor thermal conductivity. The purpose of this study was to evaluate the effect of addition a composite of surface treated Nano Aluminum oxide (Al2O3) filler and plasma treated polypropylene fiber (PP) on some properties of denture base material. Materials and methods: One hundred fifty prepared specimens were divided into 5 groups according to the tests, each group consisted of 30 specimens and these were subdivided into 3 groups (unreinforced heat cured acrylic resin as control group),reinforced acrylic resin with( 0.5%wt Nan
... Show MoreHemorrhagic insult is a major source of morbidity and mortality in both adults and newborn babies in the developed countries. The mechanisms underlying the non-traumatic rupture of cerebral vessels are not fully clear, but there is strong evidence that stress, which is associated with an increase in arterial blood pressure, plays a crucial role in the development of acute intracranial hemorrhage (ICH), and alterations in cerebral blood flow (CBF) may contribute to the pathogenesis of ICH. The problem is that there are no effective diagnostic methods that allow for a prognosis of risk to be made for the development of ICH. Therefore, quantitative assessment of CBF may significantly advance the underst
ABSTRACT
Agricultural production, food security and safety, public health animal welfare, access to markets and alleviation of rural poverty have been achieved by controlling on veterinary services to prevent animal disease. World organization for animal health guidelines focus on controlling of animal disease which depends on good governance and veterinary services quality. The aim of veterinary services is controlling and preventing animal disease some of other aspects; it's responsibility of early detection, rapid response to outbreaks of emerging or re-emerging animal disease, optimizing quality and effectiveness of disease
... Show MoreThe current study aimed to determine the relation between the lead levels in the blood traffic men and the nature of their traffic work in Baghdad governorate. Blood samples were collected from 10 traffic men and the age about from 20-39 year from Directorate of Traffic Al Rusafa/ Baghdad and 10 samples another control from traffic men too with age 30-49 year and they livedrelatively in the clear cities or contained of Very few traffic areas. The levels of lead in blood estimated by used Atomic Absorption Spectrometry.
The result stated that there is no rising of the levels of lead in blood of traffic men Lead concentration was with more a range from 14 ppm in Traffic police are not healthy They are within the permissible limits, Ap
Bumpiness in the atmosphere is the vertical movement of air, whether
upward or downward movement and the bumpiness is accompanied by areas
of unrest in the air and wind. And contribute to each of the coups thermal
fronts, wind, wind and thunderstorms. Moreover, bumpiness is net of the
reasons that lead to circumstances is appropriate to cut the wind, and this
contributes to the formation of bumpiness in the atmosphere. The study found
that the noon of the times, which is expected to occur where clear-air
bumpiness during flights because of the warmth of the earth's surface. The
study found increased incidence of air hole during the summer, especially
July, due to increased incidence of coup surface, while the s
Metaphor has been occupied first place among eloquent methods to build metaphors;
poetry with the latter becomes senseless thing. Metaphor is necessary part of energy that
sustains the poetry. Sentence of metaphor regarded more eloquent than the reality since it
does not conduct directly to the meaning , but rather get to it indirectly. Metaphor is
considered one of the most tools for the poet since it is a means of expression about his
sensation and feelings . Andalus paid concerns over metaphors as that being incited by their
country beauty and nature. The poet might resort to contradiction as to picture contraries
within himself.
Through pictures of contradictions depicted by the poets , it has explained that t
Manganese is considered as one of heavy metals with high toxicity .This element has been used widely in various industries and it is spread with huge quantities in polluted industries areas. As a result the concentrations of this element in the environment have increased and consequently producing acute toxic effects in different tissues and organs of all organisms. A study has been conducted on (30) female of Swiss albino mice, to find out the effect of manganese chloride in histopathological changes of ovaries. The study includes, giving the manganese chloride with concentrations (150, 200 and 250 mg/kg) for (15, 30 and 45 day) for each concentration. The
... Show MoreThe pathogenicity of S. saprophyticus was studied in mice. A group of white mice were injected transurethrally using a catheter with S. saprophyticus S67 cell suspension in a concentration reached 109 CFU/ml. concomitantly, the role of its peptidoglycan in the pathogenicity was studied by injecting another group of mice with 0.3 mg/0.2 ml of partially purified S. saprophyticus S67 peptidoglycan extract. After autopsy, kidneys and urinary bladder showed several histopathological changes both in cells and peptidoglycan injected mice, included: hydropic degeneration, glomerulus shrinkage, congestion of renal vessels, infiltration of inflammatory cells, and dekeratinization in urinary bladder.
The present study is concerned with the role of income tax in implementing economic goals in Iraq and treating the problems and pitfalls in the Iraq economy.
The study also aims at investigating the role of income tax in attracting promising favorite effects into economy.
The study was performed on data covering the period (2003 - 2012) with respect to the variables of (income tax, oil profits) as independent variables and (private consuming expenditure, private investmental expenditure, and standard figure of prices) as dependent variables. To analyze these data, a number of statistical descriptive and analytical techniques were used such as (percentage, standard variance, mediums, F test, T test and SPSS). It has been c
... Show MoreThe objective of this study is to determination the content of some heavy metals (lead, cadmium, chromium) in colored tattoo stickers. twelve kinds of colored tattoo stikcers were collected from Baghdad markets, it was estimated heavy metals using atomic absorption spectrophotometer (Shimadzu A5000). The results indicated the concentrations of lead in all samples (1.61_1.00 mg / kg) and chromium in the three samples (0.85_0.97 mg / kg) while other samples are free of chromium , and cadmium. These elements are the components of printing inks and dyes in tattoo stickers, and this does not conform to the health and safety conditions for the packaging of food according to the organizations of the health and safety of
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