The printed circuit heat exchanger is a plate type heat exchanger with a high performance and compact size. Heat exchangers such as this need a unique form of bonding and other techniques to be used in their construction. In this study, the process of joining plates, diffusion bonding, was performed and studied. A special furnace was manufactured for bonding purposes. The bonding process of copper metal was carried out under specific conditions of a high temperature up to 700 oC, high pressure of 3.45 MPa, and in an inert environment (Argon gas) to make tensile samples. The tensile samples are cylindrical shapes containing groves representing the flow channels in the printed circuit heat exchanger and checking their tensile strength in addition to the standard shape of the tensile specimen to check the yield and ultimate strength of the copper. A higher tensile strength was obtained for diffusion bonded specimens than the yield strength of copper, up to 1.35 times the copper yield strength. The tensile strength decreases with the increase in the number of groves and the decrease in the distance between one grove and another. This is because the stress is concentrated in the sharp corners. A prototype heat exchanger of two plates and a header to be tested for its compressive strength was also manufactured. The results showed that the bond bears an air pressure of up to 8 bar without fail. It was also found to withstand a hydraulic pressure of up to 60 bar until it reached failure.
Results of a study of alloys and films with various Pb content have been reported and discussed. Films of of thickness 1.5
This research deals with the form of the physical identity which is concerned with the features and characteristics that distinguish the shape of the city from other existing cities and reveal its similarity with the self (itself) and objective difference with others. Accordingly, these features must be sophisticated and variable resulting the shape of the city, while preserving the continuity of time, and eventually leads to the emergence of the whole shape. Physical identity is conceptually equivalent with the terms "personality" and "sense of place". The research determined the criteria for evaluating the physical identity as follows:
... Show MoreAim: To evaluate the wettability and microhardness of Zirconium (ZrO2) dental material when coated with different concentrations of Faujasite. Materials and methods: 30 circular disks produced from ZrO2, then each group is classified into 10 control groups, 10 coated groups with 3% Faujasite, and 10 coated groups with 7% faujasite by electro-spun tool to study variable properties in hardness and water contact angle of implant materials. Results: This study stated the high hardness in 7% of faujasite concentration for ZrO2, in addition, the contact angle decreased gradually until reach 0 ᵒ in 7% concentration of faujasite with ZrO2 Conclusion: Water contact angle (WCA) declined till disappeared in (7% wt.) of faujasite coated with the Z
... Show MoreThis study investigates the ionic conduction dependence on the size of alkaline cations in gel polymer electrolytes based on double iodide can enhance by incorporating a salt having a bulky cation.
... Show MoreIn The Name of Allah Most Gracious Most Merciful
Cheating is one of the forbidden actions and reprehensible morals that are forbidden by Islamic law, because it involves an assault on rights, whether they are the rights of God Almighty or the rights of God.
people, or self-rights, and because it involves harming others.
Since the Sunnah of the Prophet is the second source of Islamic law, many of the noble hadiths of the Prophet forbid and prohibit cheating.
This study sheds light on it.
The enemies of religion are still following the approach of undermining the Islamic faith in various ways through the diversity of methods of smear campaigns by raising suspicions to obliterate the Islamic identity and threaten security and stability of social life under the Islamic religion in Islamic societies, as we find that they have employed the doctrine of atheistic thought in order to distance people from the path of truth, distort the features of religion, destabilize psychological security and family stability, and thus destroy societal security by questioning the tolerant faith at times, and by raising suspicions at other times.
Hence, this research came to review the legal duty that requires Islamic scholars to protec
... Show MoreObjective: The aim of this study is to determine the role of spiral Computerized Tomography in the diagnosis and
detection the types of stroke.
Methodology: One hundred sixty two patients (162) (99 males and 63 females) their ages ranging from (13 – 80)
year, all of them are suffering from stroke. They were collected randomly from spiral Computerized Tomography
unit in Baquba Teaching hospital during the period from November / 2010 to December / 2011 .All the patients
were examined clinically and then done spiral Computerized Tomography examination.
Results : The results of this study showed that the stroke effected different age groups and both sex but males is
more affected than the females .The results of spiral
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 MoreMoisture induced damage can cause a progressive deterioration in the performance of asphalt pavement by the loss of adhesion between asphalt binder and aggregate surface and/or loss of cohesion within the binder in the presence of water. The objective of this paper is to improve the asphalt mixtures resistance to moisture by using hydrated lime as an anti-stripping additive. For this purpose, two types of asphalt binder were utilized; asphalt grades (40-50) and (60-70) with one type of aggregate of 19.0 mm aggregate nominal maximum size, and limestone dust as a mineral filler. Marshall method was adopted to find the optimum asphalt content. Essentially, two parameters were determined to evaluate the moisture susceptibili
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