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Studying and Modeling the Effect of Graphite Powder Mixing Electrical Discharge Machining on the Main Process Characteristics
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Abstract

This paper concerned with study the effect of a graphite micro powder mixed in the kerosene dielectric fluid during powder mixing electric discharge machining (PMEDM) of high carbon high chromium AISI D2 steel. The type of electrode (copper and graphite), the pulse current and the pulse-on time and mixing powder in kerosene dielectric fluid are taken as the process main input parameters. The material removal rate MRR, the tool wear ratio TWR and the work piece surface roughness (SR) are taken as output parameters to measure the process performance. The experiments are planned using response surface methodology (RSM) design procedure. Empirical models are developed for MRR, TWR and SR, using the analysis of variance (ANOVA).The best results for the productivity of the process (MRR) obtained when using the graphite electrodes, the pulse current (22 A), the pulse on duration (120 µs) and using the graphite powder mixing in kerosene dielectric reaches (82.84mm³/min). The result gives an improvement in material removal rate of (274%) with respect to the corresponding value obtained when copper electrodes with kerosene dielectric alone. The best results for the tool wear ratio (TWR) of the process obtained when using the copper electrodes, the pulse current (8 A), the pulse on duration (120 µs) and using the kerosene dielectric alone reaches (0.31 %). The use of graphite electrodes, the kerosene dielectric with 5g/l graphite powder mixing, the pulse current (8 A), the pulse on duration (40 µs) give the best surface roughness of a value (2.77 µm).This result yields an improvement in SR by (141%) with respect to the corresponding value obtained when using copper electrodes and the kerosene dielectric alone with the same other parameters and machining conditions.

Keywords: EDM, RSM, MRR, TWR, SR, AISI D2die steel, graphite powder mixing.

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Publication Date
Sun Jan 02 2011
Journal Name
Journal Of Educational And Psychological Researches
The necessary characteristics of the kindergarten teachers who have been recently appointed from the point of view of the kindergarten managers.
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One of the difficulties that the kindergarten institution face is the lack of specialized teachers to work with the children at the kindergarten age for the majority  of this stage teachers were prepared to teaech in the elementary stage while the kindergarten child needs ateacher who is aware of the characteristics  and the demands of his growth and his behavioral emotional and social problems.

Therefore the best teacher must be chosen for the kindergarten and qualifying  her educationally in all that this qualifying  includes of  knowledge's.

The aims of the research:

The present research aims at the identification  of the n

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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Re-engineering management processes and its impact on the strategic decision-making process Field study on the College of Education / University of Mustansiriya / Iraq
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The aim of the research is to identify both the re-engineering of management processes and the strategic decision-making process in the research community and determine the nature of the correlation between the two variables and know the relationship between them to achieve the research goal. The researcher used a descriptive and analytical method. The research community consists of a group of professors and staff of the College of Education affiliated to the University of Mustansiriya in Baghdad, which their number were (45),  the researcher has distributed the forms to all members of the sample,  only (3) forms were excluded for invalidity and thus the number of forms approved in the analysis were (42) forms. The rese

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Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
The effect of increasing the volume of debt on the volume of trading (applied research on a sample of private banks listed on the Iraq Stock Exchange)
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This research worked on identifying the effect of increasing the volume of indebtedness by companies listed on the Iraq Stock Exchange on the trading volume of those companies, and this research included some theoretical concepts related to both debt financing and trading volume, and it represents the research community of the joint-stock companies listed in The Iraq Stock Exchange (the banking sector). As for the research sample, it was deliberately chosen represented by companies with continuous trading without stopping, which reached 10 joint-stock companies, and the period of research was extended during the period 2011-2015, and a set of indicators and financial methods were used In measuring research v

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Publication Date
Sat Nov 10 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effect of Maternal Age on the Mother and Neonatal health in Baghdad Maternity Hospitals
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Objectives: to compare health of mothers and neonatal among age groups, to find out the correlation between
age groups and mother and neonatal health.
Methodology: A descriptive study was carried out at delivery rooms of three teaching hospitals in Baghdad city
from Feb. 28th through May. 28th
, 2013. A purposive (non-probability) sample of 300 laboring women was selected
from delivery rooms categorized into three groups, group 1 (≤19) years, group 2 their age between (20-35) years
old and group 3 their age (≥35) years. The data were collected through the use of constructing questionnaire, an
interview technique with mothers and reviewing their medical records as means of data collection; The
questionnaire con

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Publication Date
Sun May 07 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study the Effect of Annealing Temperature on the Structural, Optical and Electrical Properties of ZnS Thin Films
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The structural, optical and electrical properties of ZnS films prepared by vacuum
evaporation technique on glass substrate at room temperature and treated at different
annealing temperatures (323, 373, 423)K of thickness (0.5)µm have been studied. The
structure of these films is determined by X-ray diffraction (XRD). The X-ray diffraction
studies show that the structure is polycrystalline with cubic structure, and there are strong
peaks at the direction (111).
The optical properties investigated which include the absorbance and transmittance
spectra, energy band gab, absorption coefficient, and other optical constants. The results
showed that films have direct optical transition. The optical band gab was

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Publication Date
Sun Feb 26 2012
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
Study the Effect of Annealing Temperature on the Structural, Optical and Electrical Properties of ZnS Thin Films
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The structural, optical and electrical properties of ZnS films prepared by vacuum evaporation technique on glass substrate at room temperature and treated at different annealing temperatures (323, 373, 423)K of thickness (0.5)µm have been studied. The structure of these films is determined by X-ray diffraction (XRD). The X-ray diffraction studies show that the structure is polycrystalline with cubic structure, and there are strong peaks at the direction (111). The optical properties investigated which include the absorbance and transmittance spectra, energy band gab, absorption coefficient, and other optical constants. The results showed that films have direct optical transition. The optical band gab was found to be in the range t

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Publication Date
Sun May 12 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect of Quenching Media Variations on the Mechanical Behavior of Martensitic Stainless Steel
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The purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie

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Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Words and structures refer in Alms Studying Languagal
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Alms (or Zakat) is one of the Pillar of Islam and it was atask imposed on
Muslims. Becomes of the importance of this task and its influence on the human
Psychic in particular and on the Society in general this study aims at Studying the
words that it refers to in the Holy Quran, At the beginning the researcher has
introduced the words it refers to, and the significance of each in the Holy Quran and
the Speciality of each one of such words, then the Structures they donet have been
also introduced, whether such structures are descriptive, adverbial or verbal.This was
introduced in addition to explaining the influence of changing the Shape of such
words in emphasizing the meaning and the influence of Portraiting styl

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Publication Date
Thu Sep 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
The Role of Continuous Improvement Strategy (Kaizen) in organizational innovation: An analytical research in the General Company of Electrical and Electronic Industries /The Ministry of Industry and Minerals
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This paper aims at the fact that most organizations today suffer from a waste of time, effort, and cost, and they have difficulty in achieving the best performance situations and compete strongly. The researcher distributed 108 questionnaires as a statistical analyzable sample society where the sample intentionally consists of general managers, department head, and division head. The questionnaire was formulated according to the Likert scale. The use of personal interviews and observations are additional tools for data collection and a number of statistical methods is used for data analysis such as simple regression and correlation coefficient (Pearson). One of the most prominent conclusions is that the company has adequate and c

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Publication Date
Mon Sep 25 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Annealing Temperature on the Structural Characteristics of(Sb203) Compound.
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The crystal structure and unit cell dimensions of the (S03) compound have  been determined by employing the principles of crystallography.

The X-Ray diffraction spectra of (Sb203) which recorded as a function  of   different  annealing  temperatures  (100,150,200  and

 

250)±5c and for durations (0.5  hr,

0

 

1hr, l.Shr and 2hr), showed a

 

noticeable improvement, a decreasing in the unit cell dimensions and

an increasing in the number of diffraction spectra.

Indexing of diffraction spectra and refinement of  unit cell

dimensions showed that the compound (Sb203)  which is a

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