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Mechanical Integrity of Printed Circuit Heat Exchanger
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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.

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Publication Date
Sat Oct 27 2018
Journal Name
Surface And Coatings Technology
Effect of surface treatment of zirconia-ceramic dental restorations
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The zirconia ceramic restoration (ZCR) is used as substitutes for the metal-ceramic restoration. Clinical studies demonstrating of ZCRs showed a high fracture incidence of veneering layer than metal-ceramic restorations. This attributed to the low bond strength of zirconia to veneering ceramic as a result of lacking of glass content in its matrix. Surface treatment was proposed to improve the bonding strength between zirconia and veneering ceramic. Several studies revealed that some treatment such as airborne particle abrasion (APA) is responsible for generating chipping of veneering ceramic. The study aimed to develop a new zirconia coatings to increase bonding strength between zirconia substrate and veneering porcelain. Three groups of 15

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Publication Date
Fri Apr 01 2022
Journal Name
Baghdad Science Journal
Fractographic Analysis of Tensile Failures of Zirconia Epoxy Nanocomposites
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This work characterizes the fractographic features of the neat epoxy and ZrO2 epoxy nanocomposites. All samples were subjected to a tensile test to determine the tensile strength and tensile modulus. SEM images were used to study the morphology of the fractured surface. The fractographic of the fracture surfaces were studied by microstructure analysis program (j-images) to specify the effect of ZrO2 nanoparticles on tensile performance and failure mechanism for ZrO2 epoxy nanocomposites. The tensile test results show that the addition of ZrO2 nanoparticles (2, 4, 6, 8, and 10 vol.%) to the epoxy matrix leads to increase the tensile strength about 40% for optimal content of ZrO2 nanop

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Publication Date
Tue Nov 30 2021
Journal Name
Research Journal Of Pharmacy And Technology
Effect of Palliative Radiotherapy in controlling pain of Malignancy
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Background: Radiation therapy reported to be an effective in palliating pain. Objective: To describe roles of palliative radiotherapy in controlling pain in metastatic cancerous patients, and evaluation of radio-therapy doses in pain management. Methods: A prospective observational study carried out at the Baghdad Radiotherapy and Nuclear Medicine Center/Baghdad Medical City Complex, Baghdad, Iraq, from 1st of December 2018 to 30th of May 2019. 88 Patients, were included. Patients were assessed before applying radiotherapy, and at the end of treatment. Pain scoring used from 0 to 10. Kaplan Meier survival curve used. Result: The mean±SD of age was 55.44±11.1 years, and the most frequent age group was 41-50years as 37(42.1%). Breas

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Publication Date
Wed Mar 01 2017
Journal Name
International Journal Of Scientific Research In Knowledge
Monitoring of the Compressibility Characteristics of Asphalt Stabilized Subgrade
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The subgrade soil is the foundation plate form of the roadway; it should sustain its structural characteristics throughout the design life of the roadway with minimal requirements for maintenance. When Gypseous soil is implemented in the construction of subgrade, problems regarding collapsibility and poor structural capacity usually occur when the subgrade came in touch with excess water. Asphalt stabilization could furnish a proper solution to such problems. In this investigation, an attempt has been made to monitor the variations in compressibility characteristics of asphalt stabilized subgrade soil subjected to 30 cycles of (freezing-thawing) and (heating-cooling). Data have been observed after each 10 cycles, and compared with that of r

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
THIAMINE – INDUCED FORMATION OF THE MONOPYRROLE MOIETY OF PRODIGIOSIN
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Thiamine stimulates the production of a red pigment , which is chromatographically and spectrophotometrically identical to prodigiosin , by growing cultures of serratia marcescens mutant 9-3-3 . this mutant is blocked in the formation of 2- methyl -3- amyl pyrorol( MAP),the monopyrrole moiety of prodigiosin , but accumulates 4-methoxy-2, 2-bipyrrole -5- carboxaldehyde (MBC) and can couple this compound with( MAP) to form prodigiosin . Addition of thiamine caused production of( MAP) , and as little as 0.02 mg of thiamine / ml in peptone- glycerol medium stimulated production of measurable amounts of prodigiosin. Phosphate saltes and another type of peptone decreased the thiamine- induced formation of prodigiosin ,yeast extract and glyc

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Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Biotechnology Research Center
Cytotoxicity of myriocin against axenic culture of Leishmania mexicana
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Serine Palmitoyltransferase SPT is the key enzyme in the de novo sphingolipids biosynthesis pathway in eukaryotes, including the intracellular parasite Leishmania. Previous studies showed that this enzyme SPT is expressed only in divided promastigote forms and it is non-essential in the amastigotes form of Leishmania major, which is known as the old world leishmaniasis. In this study we have studied the viability of new world lesihamniasis, Leishmania mexicana. Cytotoxicity test used to determine the effect of the SPT inhibitor myriocin which did not significantly affect the viability of the two forms of the in vitro cultures of the parasite p<0.05, procyclic promastigotes and amastigotes, in which cell viability for miltefosine trea

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Publication Date
Sun Sep 02 2012
Journal Name
Baghdad Science Journal
Product of Conjugacy Classes of the Alternating Group An
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For a nonempty subset X of a group G and a positive integer m , the product of X , denoted by Xm ,is the set Xm = That is , Xm is the subset of G formed by considering all possible ordered products of m elements form X. In the symmetric group Sn, the class Cn (n odd positive integer) split into two conjugacy classes in An denoted Cn+ and Cn- . C+ and C- were used for these two parts of Cn. This work we prove that for some odd n ,the class C of 5- cycle in Sn has the property that = An n 7 and C+ has the property that each element of C+ is conjugate to its inverse, the square of each element of it is the element of C-, these results were used to prove that C+ C- = An exceptio

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Evaluation of Laser Doping of Si from MCLT Measurement
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The measurement of minority carrier lifetime (MCLT) ofp-n Si fabricated with aid of laser doping technique was reported. The measurement is achieved by using open circuit voltage decay (OCVD) technique. The experiment data confirms that the value of MCLT and proftle of Voc decay were very sensitive to the doping laser energy.

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Publication Date
Sat Dec 28 2024
Journal Name
Medicni Perspektivi
The impact of Sudafed on spleen of albino mice
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Pseudoephedrine (PSE), often known as Sudafed, belongs to a class of medications known as sympathomimetic amines, which affect the digestive system, respiratory system, and cardiovascular system. This drug has a long history of medical use; it is helpful in treating symptoms of the common cold and flu, sinusitis, asthma, and bronchitis. Due to its central nervous system (CNS) stimulant properties and structural similarity to amphe­tamine, it is also used for non-medical purposes such as doping agent, to increase focus, and as a substance that gets rid of exhaustion and drowsiness. Nevertheless only a few studies, backed up its impact on solid abdominal organs. The aim of this task is to investigate the effect of some dosages of PSE

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Publication Date
Tue Jul 17 2012
Journal Name
مجلة مركز بحوث التقنيات الاحيائية
Effecienty of Immobilization technique of Bacillus Sublilis Asperginase producer
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Abstract Twenty Bacillus isolated were obtained from different sample food and water. Bacillus B1 isolated was the highest asparaginase producer, it was identified as a strain of B. subtilis. The highest production of asparaginase was observed when mineral salt medium containing 0.3% asparagen, pH 8 and incubated at 40°c for 24 hrs. B. subtilis B1 cells were immobilized by entrapment methods (calcium alginate and agar), and by adsorption on solid surface such as sawdust and cotton. The result showed that the immobilized cells by adsorption on sawdust was the best, the immobilized cell retained 88% of asparginase activity after 48h while free cell retained 65%. Cells immobilized by adsorption on sawdust was incubated at different temperatu

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