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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
Wed Nov 13 2019
Journal Name
Al-kindy College Medical Journal
Disturbances of Amino Acid Metabolism in Neurologic Disorders detected by fluorescent high performance liquid chromotograghy (HPLC) in Baghdad - IRAQ
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Background:Amino acid disorders are a major group of inborn error metabolism (IEM) with variable clinical presentation; its diagnosis constitutes a real challenge in a community with high consanguinity rate and no systematic newborn screening.

Objectives: to provide data about amino acid disorders detected in high-risk Iraqi children by using quantitative amino acid fluorescent high performance liquid chromatography (HPLC) analysis.

Type of the study: Cross-sectional study.

Methods: a descriptive cross sectional study from 1st February to 1st December 2014, at Neurological ward and clinic of the Children Welfare teaching Hospital, in Baghdad - Ira

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Publication Date
Fri Nov 09 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Screening Program for Idiopathic Scoliosis by Adam's Bending Forward Test of Prepubertal Children at Primary Schools in Baghdad City
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Objective: The study aimed to screen the prepubertal children for idiopathic scoliosis at earlier stages, and find
out the relationship between idiopathic scoliosis and demographic data such as age, sex, body mass index,
heavy backpacks, and heart & lung diseases.
Methodology: A descriptive study was conducted on screening program for prepubertal children in primary
schools at Baghdad city, starting from 24th of February to the end of October 2010. Non- probability
(purposive) sample of 510 prepubertal children were chosen from primary schools of both sides of Al-Karkh
and Al-Russafa sectors. Data was collected through a specially constructed questionnaire format include (24)
items multiple choice questions, and

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Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Evaluation of CTLA-4 Gene polymorphism SNP 49 G/ A Association with Diabetes Mellitus Type 1 in Egyptian Population
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The (CTLA-4) encodes of the T cell receptor involved in the control of T cell
proliferation and mediates T cell apoptosis. The contribution of CTLA-4 gene
variants to type 1 diabetes has been analyzed in several ethnic groups. In this study,
the association of CTLA-4 +49 A/G polymorphism with type 1 diabetes was
investigated in Egyptian patients. Sixty type 1 diabetic patients (25 males and 35
females) and 60 healthy individuals (33 males and 27 females) subjects formed the
studied populations. CTLA-4 A/G polymorphism at position 49 in exon 1 was
identified using allele specific methods. Patient numbers with A/G, A/A and G/G
genotypes were 45 (75.0 %), 6 (10.0 %) and 9 (15.0%) while in healthy controls,
these w

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Publication Date
Sat Dec 28 2024
Journal Name
Journal Of Baghdad College Of Dentistry
Elevation in surface temperature of root canals obturated with different thermoplasticized gutta-percha obturation techniques-an in vitro study
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Background: Many studies have been conducted to evaluate the effect of using a hot material in the root canal and its potential for causing damage to the tooth supporting structure. Materials and methods: thirty permanent premolars were obturated with thermoplasticized Gutta-Percha using three different obturation techniques: soft core, Thermafil, and obtura to evaluate the rise in temperature on the root surface using a multipurpose digital thermometer. Results: temperature increases was significantly greater for Obtura versus Soft core (p<0.003), not significant for Thermafil versus Soft core (p<0.087), and Thermafil versus Obtura (p<0.125). Conclusions: temperatures rise on the root surface were below the critical level and, therefore, s

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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Assessment of Heavy Metal Contamination in Euphrates River Sediments from Al-Hindiya Barrage to Al-Nasiria City, South Iraq
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The degree of contamination in the sediments of the Euphrates River (Shatt Al-
Hindiya), for the metals As, Cd, Co, Cu, Cr, Mn, Ni, Pb, Sc Se, Sr, V and Zn has
been evaluated using the index of geo-accumulation (I-geo), Enrichment factor (EF),
Contamination factor (CF) and pollution load index (PLI), whereat the I-geo has
been widely utilized as a measure of pollution in freshwater sediment. Enrichment
factor (EF) is one widely used as approach to characterize the degree of
anthropogenic pollution to establish enrichment ratios, while the pollution load
index (PLI) represents the number of times by which the heavy metal concentrations
in the sediment exceeds the background concentration, and gives a summative
i

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Publication Date
Mon May 27 2019
Journal Name
Al-academy
A Hypothesis of Architectural Environment Exercise for Actor Training (Continuous exercise space workshop – A model): هيثم عبد الرزاق علي
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The peculiarity of the theater does not lie in its dramatic content because many literary genres and other artistic styles share with it in this content. The peculiarity of the theater lies in contemplating the drama through what is architectural, and this architectural axis is what distinguishes its character. It is a spatial poetry which is composed by the laws of physics and chemistry, (Weight, height, distance, rhythm, gravity, impulses and chemical excretions). i.e., what cannot be expressed in words. This is a game of space to exchange and organize energy and communicate in space by the living body, which contains the possibilities of the living drawing in space: in the time and place. This research deals with the importance of the

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Publication Date
Sat Dec 28 2024
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of Propolis from Kurdistan region as a new resinous sealer in root canal obturation-part I biocompatibility study
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Background: Many materials were proposed as root canal obturating materials but the biocompatibility issue remains to be a critical one. Propolis has been used as a therapeutic agent since the time of Hippocrates. It is known that propolis exhibits some pharmacological activities, such as antibacterial, antiviral, antifungal and anti inflammatory activity. Materials and methods: Eighteen albino rats were used in the study and divided randomly into three groups of 6 animals for each group. Each group was scheduled to be sacrificed at different time periods, which were three days, one week and three weeks. Propolis and ZOE sealer implants of 4mm in diameter and 0.5 gm in weight were implanted in the dorsal side of the rats. At the end of the

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Publication Date
Fri Jan 26 2024
Journal Name
Iraqi Journal Of Science
Rapidly growing non-tuberculosis mycobacterial (NTM) in sputum samples of Iraqi T.B. patients in TB reference lab. in Baghdad
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Non tuberculous mycobacteria (NTM) present in the environment, mainly in water and not transmitted from human to human. The lung is the most common target of NTM infections in human. The symptoms of NTM infection are: fever, weight loss and abdominal pain.
114 sputum samples were examined microscopically using Ziehl-Nelsen stain, all were positive. They cultured on Lowenstein-Jensen media.
The results of this study indicate presence of 3 (2.6%) of rapidly growing mycobacteria, phenotypically they resemble T.B. bacilli. They were diagnosed by biochemical tests, they were positive for catalase and pyruvate, negative for niacin, nitrate reduction test, sensitive for Thiophene-2-carboxyl acid hydrozide test& resistant for Para nitr

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Publication Date
Fri Dec 14 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of Women's Self-care Instructions concerning Wound, Perineal & Urinary System Care post cesarean section in Baghdad teaching hospital
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Aim: to determine the effectiveness of women's self-care instructions on their post cesarean section care in Baghdad
teaching hospital.
Methodology: The present study used quasi-experimental study design in maternity words in Baghdad teaching
hospital. The sample was collected and follow up for the period (15) January 2014 until 15 May 2014 Nonprobability
(purposive sample) of (100) women post cesarean section divided in to two groups (50) women post
cesarean section considered as a study group, and another (50) women post cesarean section considered as the
control one, A questionnaire designed as a tool to collect data fit the purpose of the study a questionnaire include
demographic variables, Reproductive variables

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Publication Date
Mon Aug 01 2022
Journal Name
Baghdad Science Journal
Detection of Methamphetamine using Nanobentonite as a Novel Solid Phase Extraction Column Matrix Assisted with Gas Chromatography- Mass Spectroscopy
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          This study was done to evaluate a new technique to determine the presence of methamphetamine in the hair using nano bentonite-based adsorbent as the filler of extraction column. The state of the art of this study was based on the presence of silica in the nano bentonite that was assumed can interact with methamphetamine. The hair used was treated using methanol to extract the presence of methamphetamine, then it was continued by sonicating the hair sample. Qualitative analysis using Marquish reagent was performed to confirm the presence of methamphetamine in the isolate.The hair sample that has been taken in a different period confirmed that this current developing method can be used to analyzed methamphetamine. This m

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