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.
The social networking sites have brought about fundamental changes and a qualitative shift in the marketing industry and its strategies. The Iraqi ministries have used this site i.e. Facebook to spread and disseminate values in order to consolidate it in Iraqi society which has witnessed many changes in all aspects of life.
The researcher studies the pages of both ministries to know the values contained in the publications of the pages of these two ministries, the quality of grooming as well as the forms in which these values are marketed.
The researcher uses a survey method and content analysis for the publications of these two pages during the study period starting from January 1, 2
... Show MoreBackground: The bond strength of the root canal sealers to dentin is very important property for maintaining the integrity and the seal of root canal filling. The aim of this study was to evaluate and compare the push-out bond strength of root filled with total fill Bioceramic, AH Plus and Gutta-flow®2 sealers using GuttaFusion®obturation system versus single cone obturation technique. Materials and method: sixty of mandibular premolars teeth with straight roots were used in this study, these roots were instrumented using Reciproc system, instrumentation were done with copious irrigation of 3 mL 5.25% sodium hypochlorite solution (NaOCl) during all the steps of preparation, and smear layer will be removed with 1 ml of 17% EDTA kept in
... Show MoreVarious visual media are becoming an increasingly important and active instrument of communication. This fact has led some political parties and leading personalities in Iraq to make use of them as an accepted forum for the discussion of public affairs usually in a manner that conforms to their declared policy. They have to draw as much popular support as they could for the causes which they fight for. As a result, a state of great confusion has been created from the contradictory statements made by the contending parties and gave left grave consequences on all types of the audience receiving them. The problem of the study can be summarized in one major question: What is the opinions of the audience as regards the statements made by the
... Show MoreThe main aim of this study is to investigate the ability of four local entomopathogenic isolates Beauveria bassiana (Bals.) and Metarhizium anisopliae (Met.) to control the mosquito larvae in the lab. The results revealed that the isolate (MARD48) B .bassiana reduced the survival rate of the mosquito larvae to (80%) followed by the isolate M. anisopliae (MARD10) to (90%) in the first two days of treatment, and 60 and 66% respectively in the third day. The results also showed that the isolate B. bassiana (MARD48) killed 50% of the population (LC50) with the concentration 1×104 conidia/ml compared to 1×107 conidia/ml for the isolates B. bassiana (MARD14) and M. anisopliae (MARD10), and 1×108 conidia/ml for the isolate B .bassiana (MARD76).
... Show Moreackground: Escherichia coli is one of the most
important bacterial pathogen that can cause several
disease to human being . In our study we try to
investigate the sensitivity resistance pattern of
Escherichia coli against three antibiotics ( Amikacin,
Nalidixic acid and Cephalexin).
Methods: For this purpose we collected 51 clinical
isolates of Escherichia coli from stool and urine of
outpatient and inpatient patients from different wards
of AL-SADER Teaching Hospital in AL-NAJAF
AL-ASHRAf, IRAQ, and tested by culture and
sensitivity test .
Results: The results appeared that Amikacin show
the highest percentage of sensitivity ( 66.66 % ) ,
while Cephalexin show the lowest percentage of
sensiti
The current research aims to determine the extent of the impact of the strategic direction to the business process reengineering, in the Office of the Ministry of Oil To reach that goal was a sample of community research study consisted (50) members of the senior leadership represent the problem in organization researched in the ambiguity of the strategic direction of knowledge of the compatibility of the strategic direction with Business Process Reengineering and used questionnaire, interview and observation to obtain the information needed to search was addressing data by the statistical system spss percentage and the arithmetic mean, standard deviation and coefficient of variation .
... Show MoreThe corrosion behavior of low carbon steel in washing water of crude oil solution has been studied potentiostatically at five temperatures in the range (30–70)°C .The corrosion potential shifted to more negative values with increasing temperature and the corrosion current density increased with increasing temperature. Folic acid had on inhibiting effect on the corrosion of low carbon steel in washing water at a concentration (5× 10-4-- 5× 10-3 ) mol/dm3 over the temperature range (30–70)°C. Values of the protection efficiency were calculated from the corrosion current density .From the general results for this study, it can be seen that thermodynamic and kinetic function were also calculated (?G, ?S, ?H and Ea )
... Show MoreAbstract
The main question raised in this paper is: Is it possible to translate the ‘genre’
of Quran? And if this ‘genre’ is Quran specific, a ‘genre’ of its own, i.e. a unique one,
how can the Quranic text be translated from Arabic into English or any other
language? This question has been raising a lot of controversy among translation
theorists, linguists, philosophers and scholars of Islam and specialists in the sciences
of Arabic language let alone Quran exegetes. Scholars of the Arabic language and
scholars of Islam have argued that because of the genre of Quran is the genre of (ijaz),
translatability can never be possible. Equivalence, thus, cannot be achieved especially
if we know that so far