Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulus and solved by using Laplace method to
determine the variation of bulk water temperature. The experimental investigation included a set of experiments carried out to investigate the temperature variation along the heat source for power increase transient of (5%, 10%, 15% and 20%) of its nominal value during and after reaching the steady state condition. Estimation of the boiling safety factor is predicted and compared with the theoretical values. Reliable agreement between experimental and theoretical approaches is reached. The later showed that the elapsed time required for the clad surface temperature to reach its steady state values after each transient is less than that related to bulk water temperature. New correlation for prediction of critical heat flux, CHF based on inlet water temperature and water mass flux are investigated and compared with CHF correlations obtained from previous researches. Specific recommendations concerned with preventive measured required to eliminate the effect of boiling crisis are concluded based on theoretical and experimental results related to transients setting times obtained from each case study.
Background: Exposure to microwaves radiation from microwave oven may be harmful for users especially for the one who have highest contact with microwave oven. Because the body is electrochemical in nature, any force that disrupts or changes human electrochemical events will affect the physiology of the body by destabilization and interruption of many chemical body substance including growth factors.The insulin-like growth factors (IGFs) are a family of mitogenic proteins that control growth, differentiation, and the maintenance of differentiated function in numerous tissues. It fulfils an important role in growth and development of teeth, mandible, maxillae, and tongue. Platelet derived growth factors (PDGF) are proteins that regulate cell
... Show MoreIdioms are a very important part of the English language: you are told that if you want to go far (succeed) you should pull your socks up (make a serious effort to improve your behaviour, the quality of your work, etc.) and use your grey matter (brain).1 Learning and translating idioms have always been very difficult for foreign language learners. The present paper explores some of the reasons why English idiomatic expressions are difficult to learn and translate. It is not the aim of this paper to attempt a comprehensive survey of the vast amount of material that has appeared on idioms in Adams and Kuder (1984), Alexander (1984), Dixon (1983), Kirkpatrick (2001), Langlotz (2006), McCarthy and O'Dell (2002), and Wray (2002), among others
... Show MoreBekhme formation, Dernir Dagh well -1 has been divided into two facies units using core
sample slides and depending on sedimentary structures and diagenetic processes .The facies
reflect the environment of the foreslope.This work proves the absence of Bekhme formation
in Dernir Dagh
Well- 1 as a tongue as reported by the Oil Exploration Company. Some species and genera of
bentonic foraminifera were identified. The age of Bekhme formation was estimated
depending on the recognized index fossils to be lower Maastrichtian.
Background: Oral health is important to the quality of life of all individuals. Oral lesions can cause discomfort or pain that interferes with mastication, swallowing, and speech. Oral disease is a health problem that is not only a matter of oral hygiene and local condition, but can also be a precursor to other dangerous and potentially life threatening illnesses. The present study was designed to analyze the main clinicopathological aspects of most common oral lesions in patients who visit the Oral Diagnosis Clinic of the College of Dentistry, University of Sulaimani, Kurdistan region, Iraq. Patients and methods: This prospective study was performed on 3144 patients from July 2009-July 2010. In this study a total of 3144 patients were e
... Show MoreThin films of CdS:Cu were deposited onto glass substrate temperature 400 °c. The optieal properties have been studied for Cds doped with (1,3, 8) wt% of Cu before and after Gamma irradiation. It was found that the irradiation caused an ( Frenkel defects) where the atom is displaced from its original site leaving vacancy and forming on interstitial atom. It was found the irradiation caused an absorption edge shifting towards long wavelength as a result of the increasing of Cu concentration.
Thermal conductivity of compacted bentonite is one of the most important properties where this type of clay is proposed for use as a buffer material. In this study, Lee's disc method was used to measure the thermal conductivity of compacted bentonite specimens. The experimental results have been analyzed to observe the three major factors affecting the thermal conductivity of bentonite buffer material. While the clay density reaches to a target value, the measurement is taken to evaluate the thermal conductivity. By repeating this procedure, a relationship between clay dry density and thermal conductivity has been established in specimens after adjusting the water contents of the bentonite by placing its specimens in a drying oven for diffe
... Show MoreLipopolysaccharide (LPS) of Campylobacter coli was extracted using digestive enzyme and hot phenol water method. Anti-LPS was prepared by injecting rabbits with different concentration of LPS. The result showed that the titer of anti-LPS antibodies using precipitation test is 40, the result also showed Histopathological effect of partial pure LPS. It was found that the LPS caused slightly effect represent as intestinal villi atrophy and aggregation of hyperplasia of lymphocyte cells payers patch, while effect on liver was sinusoids dilation with few inflammation cell infiltration, congestion and dispersed necrotized hepatocyte. Also we found effects on spleen cell as widening of white and red pulp, diffused hyperplasia of lymphoid cells and
... Show More

