Electrical Discharge Machining (EDM) is a widespread Nontraditional Machining (NTM) processes for manufacturing of a complicated geometry or very hard metals parts that are difficult to machine by traditional machining operations. Electrical discharge machining is a material removal (MR) process characterized by using electrical discharge erosion. This paper discusses the optimal parameters of EDM on high-speed steel (HSS) AISI M2 as a workpiece using copper and brass as an electrode. The input parameters used for experimental work are current (10, 24 and 42 A), pulse on time (100, 150 and 200 µs), and pulse off time (4, 12 and 25 µs) that have effect on the material removal rate (MRR), electrode wear rate (EWR) and wear ratio (WR). A Minitab software environment was used to adopt Taguchi method to analyze the effect of input on output parameters of EDM. The results of the present work showed that the best of MRR in copper and brass electrodes with (current 42 A, pulse on time 100 µs and pulse off time 25 µs) are (84.355×10-3 g/min) and (43.243×10-3 g/min) respectively, and the MRR predicted by Taguchi are (86.1751×10-3 g/min) in copper electrode by using the parameters with (current 10 A, pulse on time 200 µs and pulse off time 25 µs) and (43.2979×10-3 g/min) in brass electrode at current 42 A, pulse on time 100 µs, and pulse off time 25 µs. The lowest EWR occurs with a value of (1.4510×10-3 g/min) with (current 10 A, pulse on time 100 µs, pulse off time 4 µs) variables when using a copper electrode. The highest WR (2.602508) was found for the brass electrode with (current 24 A, pulse on time 200 µs, pulse off time 4 µs) variables.
The rent is one of the sources of investment that generates returns for the owner of the housing unit, and it is also one of the importance expenditure for the tenant.
The importance of this research comes in addressing the deficiency in the field of analyzing the factors affecting the rental value of residential units, which affects many segments of the population of Baghdad.
The aim of this research is analyze and evaluate related variables on the rent value of residential units in neighbourhood 409 in city of BAGHDAD, which is a hypothesis that: There are a set of variables affecting the rental value, including those related to the internal environment of the dwelling, such as: income level, plot area, building area, n
... Show MoreObjective: In order to evaluate the effect of different typed of Separating Medium on the roughness of the fitted
tissue surface of acrylic denture base.
Methodology: Chosen three types of separating medium (Group A Tin foil), (Group B Detery Isolant),(Group C
Cold Mould Seal),used 30 samples of hot cure acrylic resin ,10 samples for each group, after complete curing of
these samples , Profilometer device was used to measure the surface roughness of each sample in all groups.
Results: Using One Way ANOVA Test and LSD test, the results were highly significant in differences among all
groups. Although (Group A) showing lest roughness, (Group B) showing a satisfactory result of roughness, While
(Group C) Showing the hig
Background: In the Thermafil as a root canal obturation, system little is known about the effect that varying rates of insertion have on the adaptability of thermoplasticized GP and the amount of apical extrusion. Materials and methods: thirty simulated root canals were obturated with thermafil obturators and Apexit Plus sealer at three different insertion rates. The obturated canals were sectioned at three different levels, the sealer average film thickness for each section was calculated and the amount of apical extrusion for each canal was conducted. Results: the higher adaptability was seen with the faster insertion rate while the slower insertion rate showed fewer tendencies to cause apical extrusion. Conclusions: the intermediate i
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Background: ?-L-Fucose is a methyl pentose sugar, had the ability to kill bacteria, controlling infection and normalize immune function. The objective of this study is to determine the effect of sulcular injection of fucose on rabbits periodontium , throughout measuring the level of some proinflammatory cytokine ; interlukine 1beta ( IL-1beta) and tumor necrosis factor ( TNF-alpha) in sera of rabbits before fucose injection and at 3 days after fucose injection. Materials and Methods: The study was carried on using ( 20 ) male rabbits of the same species weighted (1-1.5 kg ) , the blood samples were collected from hearts of 20 rabbits before fucose injection and consider as( non injected group) , and after 3 days of fucose injection and con
... Show MoreA Laboratory study was conducted in quality control department ,state company for food stuff trading ministry of trade (2005-2006) on sunflower oil imported to Iraq from different origins included 12 trade marks, Complete random design was used with four replication .The purpose of the study is to know the origins effect on fatty acid percent and study the simple correlation between them, the result showed Turkish origin for trademark (Narin) was superior in Palmitic and Stearic fatty acid (10.41,3.29%).While Omanian origin for trademark Alsafwa was superior in Oleic(35.09%) and Syrian origin for trade mark Alnahraen was superior in Linoleic fatty acid percent 66.53% whereas Egyptian origin for trademark Alasel was superior in the percent
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The aim of this research to study.
The dimensions of organizational learning have been defined(learning dynamics, individuals empowerment, knowledge management and technology application) as well as the dimensions of learning organization have been defined (culture values, knowledge transfer, communication and employee characteristics), Asset completion questionnaire was used to collect data of this research from a purposely sample represent forty employees who works in Iraqi Planning Ministry at different positions. The research divided to four parts :
The first to the research methodology, the second to the theoretical review o
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The lesser grain boner Rhizopertha dominica is an important insect on grain in Iraq . in this study phenol and coumarin were isolated from Albizzia lebbek . the addition of there compounds to artificial diet at concentration of 3.4,5% couse high effects on the development of the studed insect larva.the larva were unable to complete its development to adult stage. More over, using 5% coumarin larva were died.Seed germination was not affected when seed were sprayed with concentration of 3,4,5% of coumarin and phenol.
This research is addressing the effect of different ferrocene concentration (0.00, 2.15x10-3, 4.30x10-3, 8.60x10-3, and 12.9x10-3) on the bulk free radical polymerization of methyl methacrylate monomer in benzene using benzoyl peroxide as initiator. The polymerization was conducted at 60º C under free oxygen atmosphere. The resulting polymers were characterized by FTIR. The results were compared with the presence and absence of ferrocene at 10% conversion. The %conversion was 3.04% with no ferrocene present in the polymerization medium and its increase to 9.06 with a first lowest ferrocene concentration added, i.e. 2.15 x10-3mol/l. This was positively reflected on the poly(methyl methacrylate) molecular weight measured by viscosity techniq
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Transparency considered being one of the modern administrational terms which started to be largely used in the last period, because of its political, economical, social and cultural dimensions. As well as, its administrational dimension that helps to create a work environment marked by order and flawless from wrong practices and Transparency provides credibility to the sides that pursue it in their practices, till it became a mean of distinction. The choice of the subject of the research ((Transparency and its effect on Level of Job satisfactions of Workers in General Insurance company)), which aims to measure the effect of Transparency in Level of Job satisfactions of Workers in Insurance company. Came in the time when many countries te
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