The two dimensional steady, combined forced and natural convection in vertical channel is
investigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontal
inlet and exit segments have been added to the vertical channel. The vertical walls of the channel are
maintained at constant but different temperature while horizontal walls are insulated. A finite
difference method using up-wind differencing for the nonlinear convective terms, and central
differencing for the second order derivatives, is employed to solve the governing differential
equations for the mass, momentum, and energy balances. The solution is obtained for stream
function, vorticity and temperature as dependent variables by iterative technique known as successive
substitution with overrelaxation. The flow and temperature patterns in the channel are obtained for
Reynolds numbers and Grashof number ranging from 25 to 100 and (100 to 1,000,00,) respectively.
A computer program ( Fortran 90 ) is built to calculate the fraction factor and the total
average Nusselt number (Nu) also the average heat transfer Q in steady state and for Aspect ratio Ar
(10) and Grashof number GR (10 2 − 10 5 ), the fluid Prandtl number is fixed at (Pr=0.733) and
Reynolds number Re (25-100).
The results show reasonable representation to the relation between Nusselt number and friction
factor with other parameters (Ar, GR and Re). Nu is increased with increasing Re and GR but it
decreases with Ar increase and (Q) is increased with increasing Re ,GR and Ar. At the same time, the
product friction factor(fRe) increased with (GR) and (Ar)increased and (Re )decrease.
Comparison of the result with the previous work shows a good agreement
In this study, the synoptic analysis of dust storm for spring and summertime in Iraq were investigated. The images for dust provided by NASA are used to emphasize the dust storm days, while the composite maps of wind vector and geopotential 850hPa are mapped to investigate the pressure and wind direction patterns appearing with the dust condition in the same days. Spring has more dust frequency than summertime, especially in May. The frontal type of dust storm is dominant on spring, the cold air pushes the warm air that picking up the sand to the air through the vertical wind, but the southwestern high-speed wind and drought condition were controlled on the dust in summer. The northwestern wind is the main factor that carries the dust for l
... Show MoreReview Article Immunomodulatory Role of Cytokines in Periodontal Disease Batool Hassan Al-Ghurabi*, Maha Adel Mahmood, Zainab A. Aldhaher, Sahar Hashim Al-Hindawi Adv. life sci., vol. 11,...
This study presents an updated checklist of the dipteran-borne diseases in Iraq, together with their original name combinations and synonyms. According to this checklist, 152 species, 40 genera within 14 families. Furthermore, minor corrections were applied to some authors’ names and years of publication.
This work, introduces some concepts in bitopological spaces, which are nm-j-ω-converges to a subset, nm-j-ω-directed toward a set, nm-j-ω-closed mappings, nm-j-ω-rigid set, and nm-j-ω-continuous mappings. The mainline idea in this paper is nm-j-ω-perfect mappings in bitopological spaces such that n = 1,2 and m =1,2 n ≠ m. Characterizations concerning these concepts and several theorems are studied, where j = q , δ, a , pre, b, b.
Phytoremediation is one of the methods to remove various types of pollutants from water and soil using plants. Salvinia molesta, an aquatic plant, is chosen in this study to determine its ability to degrade diesel as the pollutant in synthetic wastewater with different diesel concentrations (0, 8,700, 17,400, and 26,100 mg/L) for 14 days. Total petroleum hydrocarbon (TPH) has been used as an indicator to represent diesel concentration variation in wastewater. Degradation of TPH was 85.1% for diesel concentration of 8,700 mg/L, compared with only 53.9% in the corresponding control without plant. While, acute toxicity on S. molesta exposed in diesel concentrations of 17,400 and 26,100 mg/L was observed and eventually had
... Show MoreA colorectal polyp (CRP) is a growth on the lining of the colon or rectum. The incidence of CRPs is rapidly increasing with age. They are most often benign. The rectum is the most commonly affected site.
To determine the incidence, clinical presentation, and histopathologic types of CRP in Iraqi patients.
It is a cross-sectional screening study conducted in the medical c
The population density witnessed by the capital, Baghdad, due to successive wars and unemployment, is linked to the phenomenon of urbanization, which is a global phenomenon that means the increasing tendency of the rural population to reside in cities (urban), especially concentration in the capital, Baghdad. Therefore, the phenomenon of urbanization is associated with 3 terms: migration, countryside, and city. Migration is when a person or a group leaves their place of residence to move to live in another place with the intention of staying in the new place for a long time. As for the countryside: they are the areas surrounding cities usually, and the countryside is characterized by natural and agricultural areas and is considered an outle
... Show MoreBack ground; Selective re-absorption and secretion are the functions of the collecting tubules and ducts, in addition to concentrate urine through ADH-regulated and ADH-independent water channels.Method; twenty four male rats were used, they were divided into two groups of animals: Group (A) included twelve rats of five weeks old age (before puberty) that were divided into three subgroups, four rats in each subgroup. Subgroup I was control one, subgroups II and III were treated orally with melatonin in a dose of 250 & 500 µg/kg body weights subsequently. Group (B) included twelve rats of seventeen weeks old age (after puberty) that were divided into the same subgroups and treated with the doses of melatonin as in the rats of group (
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