The current study presents an experimental investigation of heat transfer and flow characteristic for subcooled flow boiling of deionized water in the microchannel heat sink. The test section consisted of a single microchannel having 300μm wide nominal dimensions and 300μm height (hydraulic diameter of 300μm). The test section formed of oxygen-free copper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux (78-800) kW/m2, mass flux (1700 and 2100) kg/m2.s at 31˚C subcooled inlet temperature. The boiling heat transfer coefficient is measured and compared with existing correlations. Also, the experimental pressure drop is measured and compared with microscale pressure drop correlations. The results showed that higher mass flux leads to higher boiling heat transfer coefficient, and the dominant mechanism is convective boiling. Also, the experimental pressure drop decrease with increasing heat flux in a single-phase region while it increases in a two-phase region. Comparing the experimental results in the experimental condition range, showed that an existing correlation provides a satisfactory prediction of heat transfer coefficient and pressure drop.
Abstract
The Classical Normal Linear Regression Model Based on Several hypotheses, one of them is Heteroscedasticity as it is known that the wing of least squares method (OLS), under the existence of these two problems make the estimators, lose their desirable properties, in addition the statistical inference becomes unaccepted table. According that we put tow alternative, the first one is (Generalized Least Square) Which is denoted by (GLS), and the second alternative is to (Robust covariance matrix estimation) the estimated parameters method(OLS), and that the way (GLS) method neat and certified, if the capabilities (Efficient) and the statistical inference Thread on the basis of an acceptable
... Show MoreThe research aims mainly to the role of the statement style costs on the basis of activity based on performance (PFABC) to reduce production cost and improve the competitive advantage of economic units and industrial under the modern business environment dominated by a lot of developments and changes rapidly, which necessitates taking them and criticize them to ensure survival and continuity. The research problem is the inability of traditional cost methods of providing useful information to the departments of units to take many administrative decisions, particularly decisions related to the product and calculating the costs of the quality of the sound and the availability of the need and the ability to replace methods capa
... Show MoreAn experimental of kinetics investigation of the solution free radical polymerization of isopropylacrylamide (IPAM) initiated with potassium persulfate (PPS) was conducted. The reactions were carried out at constant temperature of 60 °C in distilled water under unstirred and inert conditions. Using the well-known conversion vs. time technique, the effects of initiator and monomer concentration on the rate of polymerization (Rp) were investigated over a wide range. Under the conditions of our work, the orders 0.38 and 1.68 were found with respect to initiator and monomer, respectively. However, the rate of polymerization (Rp) is not straight forwardly corresponding monomer concentration. The value 46.11 kJ mol1 was determined as the o
... Show MoreFor in the Holy Qur’an there are vivid examples and speaking models that tell stories of the tyrants who filled the world with tyranny and overwhelmed it with tyranny, and the Holy Qur’an presents these proverbs to people, not so that they may be amused by them, but rather so that they consider and bite with them. For every tyrannical tyrant, he lives within a framework of self-loss, according to him from life he lives and suffices, even without attachment to a principle or an ideal, and in the world of the unconscious with his whims, without any regard for death that is closer to him than his jugular vein, or for an account that does not leave small or great Therefore, the title of my research came to this (Qarun in the Holy Qur’a
... Show MoreOut of 180 children, 60 (33.3%) have Amoebiasis infection as diagnosed by direct wet smear and Saturated Salt Solution (SSS). SSS method is more significant (P=0.001) in diagnosis of the disease. Number of children infected with Amoebiasis infection is higher in infants aged 1-6 months, but without any significant difference to ages 6-12 or 12-18 months. In contrast, infants aged 18-24 months are significantly differant (P=0.01) as the infection rate is 16.6%. Gender also is seen to be reduced in significance (P= 0.001) for females aged 18-24 months. Blood profile of the involved infants has shown a significant variation (P=0. 01) for all blood profile parameters (RBC (P=0.05), WBC (P=0.001), Lymphocytes (P=0.05), Granulated WBC (P=0.05),
... Show MorePraise be to God, and may blessings and peace be upon the Messenger of God, his family and companions, and from his family and after ...
It is the right of every nation to be proud of its heritage, science and civilization among the nations, taking pride in the efforts of its construction and the keenness of its scholars and dedication to serve their nation and their history, and from the great sciences that boast and honor our great nation and distinguish it over others the science of attribution and the preservation of the novel over generations and ages. The novel is preserved from the plagiarism of the nullified, the excess of the deceitful and the liars, and the science of isnad from religion as the scholars said, and without the
Background: The influence of glucose metabolism is seen in many infectious diseases, making diabetic patients more vulnerable to sepsis and other serious sequelae of bacterial invasion such as UTI and vaginitis.Patients and method: sixty two patients (women) were suffering from GUTIs consulting Al-Elwya hospital from November- 2009 to March -2010. Two samples were taken from those patients (urine samples and vaginal swabs); these samples were cultured on Blood, Chocolate, and MacConkey's agar for isolation of bacteria.Results: The study group consists of sixty two women suffering from (GUTI), their ages range from 18-55 years. Thirty eight of them were diabetic women and twenty four of them were non- diabetic women. Twenty t
... Show MoreThe aim of the study was comparative between oxidative stress in diabetes mellitus using the measurement of some biophysical and biochemical parameters on two groups of diabetic patients, were conducted in the Al-Yarmuk Teaching Hospital,30 patients insulin dependent diabetes mellitus (IDDM) or type 1 ,their ages ranged between (15-45) and30 patients non- insulin dependent diabetes mellitus (NIDDM) or type 2,their ages ranged between (42-65).This study has been compared with 30 healthy subjects. The present study was demonstrated to evaluate the alteration in oxidative stress as measured by plasma and red blood cells Malondialdehyde (MDA) andchanges in antioxidant mechanism as measured by plasma and red blood cells Glutathione (GSH)
... Show MorePraise be to God, who has seen uniting the wonders of manufactures, and pronounced Pthamidh oddity Alambdoat, and swam his creation in different languages, Glory is not equal to one in the earth and the heavens, praise Him, and I bear witness that there is no god but Allah alone with no partner certificate towering branches, and I bear witness that Muhammad is His slave and Messenger sent swage Arab government balance, and clearest statement, and the highest residence and Ohllagha words, and Oovaha Zmama, he pointed the way and advised the creation, and the month of Islam, breaking idols, and showed provisions, uncle Balanaam, God separated blessings and peace upon our Prophet Muhammad and the God of the good and virtuous and his compani
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