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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
Sat Dec 24 2022
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Study the Effect of 12-Hydroxyoctadecanoic Acid Concentration on Preparation and Characterization of Floating Organogels using Cinnarizin as Modeling Drug
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This work targeted studying organogel as a potential floating system. Organgel has an excellent viscoelastic properties, floating system posses a depot property.  Different formulations of 12-hydroxyoctadecanoic acid (HOA) in sesame oil were gelled and selecting F1, F3 and F5 HOA organogels for various examinations: tabletop rheology, optical microscopy, and oscillatory rheology studies. Also, the floating properties studies were conducted at in vitro and in-vivo levels. Lastly, the in-vitro release study using cinnarizine (CN) was to investigate the organogel depot property. Based on the results, the selected concentrations of HOA in sesame oil organogels showed temperature transitions fr

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Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
Numerical Analysis for Streamer Discharge at the Discharge Transition from the Second to the Third Mode in Transformers Oil
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     This study is a numerical analysis of the transition process from the second to the third mode in transformer oil. In this study, it was determined how to change from the second to the third mode, which is thought to be a precursor to the process of electrical breakdown, which results in a significant loss of electrical energy and harm to electrical devices and equipment. The initiation time, length, rate of propagation velocity, and radius of the streamer discharge were determined. The transition from the second to the third mode during the electrical discharge process may lead to the occurrence of an electrical breakdown, which is one of the greatest challenges facing scientists and engineers who deal with the

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Publication Date
Wed Jun 26 2019
Journal Name
Iraqi Journal Of Science
Well-Controlled Generation Process of Bimetallic Ag//Au Colloidal Nanoparticles by Non-Thermal Plasma DC Glow Discharge
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In this paper, an inexpensive, simple and well-accurate process of the generation of bimetallic silver Ag//gold Au core//shell is colloidal metal nanoparticles (MNPs). This is achieved via an atmospheric pressure non-thermal plasma glow discharge between two electrodes. One of these electrodes is a capillary tube placing over solution about (1 cm) that acts as the cathode, while the other electrode is a metal disk immersed in the solution and acts as an anode. Glow discharge process carried out at room temperature using a home-made cell with (6 KV) applied voltage and direct current (DC) about (1.8 mA) for different discharge periods. A wide range of bimetallic Ag//Au colloidal MNPs was rapidly synthesized as a result of non-thermal plas

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
The effect of the repurchase policy in stock tradingIn financial markets - case study
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The research dealt with the case stock repurchase policy of Emaar Real Estate Company one of listed companies in Dubai Stock exchange. The research has launched from the cognitive dimensions of repurchasing policy which took great concern in the literatures of financial management, and also this policy became as substitute for distributing the monitory profit in the last three decades in the international financial markets, but it did not get any importance in the Arab Markets such as that of the Arab Gulf in addition to the Iraqi Stock Exchange.

The research summarized a set of conclusions, the most important one was the consistence of analysis result with the test of the major two hypotheses (The first

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Publication Date
Fri Sep 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Mathematical Modeling of a Hollow Fiber Module Used in Pressure-Retarded Osmosis Process
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   Pressure retarded osmosis (PRO) can be considered as one of the methods for utilizing osmotic power, which is a membrane-based technology. Mathematical modeling plays an essential part in the development and optimization of PRO energy-generating systems. In this research, a mathematical model was developed for the hollow fiber module to predict the power density and the permeate water flux theoretically. Sodium chloride solution was employed as the feed and draw solution. Different operating parameters, draw solution concentration (1 and 2 M), the flow rate of draw solution (2, 3, and 4 L/min), and applied hydraulic pressure difference (0 - 90 bar) was used to evaluate the performance of PRO process of a hollow fiber module. The eff

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Publication Date
Thu Jun 02 2022
Journal Name
Neuroquantology
The effect of the relationship of leptin hormone and live body weight on some chemical characteristics of the blood serum of local laying hens
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The study was conducted out at the Ministry of Agriculture's Poultry Research Station/Animal ResourcesDepartment/Agricultural Research Center. To see how body weight (BW) and leptin hormone (LEP) levels inbreeder blood affect fertility and hatchability. 140 Iraqi local laying chickens (120 females + 20 males) aged 28weeks were used in the study. Following the numbering of The experiment was divided into three periods,each lasting 28 days, during which the breeder's live body weight was recorded and divided into two categories(greater than 1.5 kg and less than 1.5 kg), and blood samples were collected at the end of each period todetermine the concentration of leptin hormone in the breeders' blood. For comparison between mothers'performance,

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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Measurement Integration of business model disclosure with qualitative characteristics of accounting information (Relevant and Raithful Representation)
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The research aims at integrating the disclosure of the business models with the qualitative characteristics of accounting information. To achieve this, the elements of the business model should be identified and disclosed, and then study the possibility of integrating the disclosure of the business model with the qualitative characteristics of accounting information.

To achieve this objective, the research was based on the indicators of disclosure of the business model of the International Accounting Standards Board to measure the disclosure of the business model.

The research reached a number of conclusions, the most important of which were as follows:

Fi

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Publication Date
Sun Jun 11 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Gibberellic Acid and Brassinolide and Their Interaction on Some Chemical Characteristics of Plant Dill Anethum graveolens L.
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   The experiment for the growing season. 2015-2016 to study the effect of gibberellic acid at concentrations (0 and 50)mgL-1 and BL at five concentrations (0, 0.5 ,1 ,2 and 3)mg.L-1 and their interaction on some chemical characteristics for Dill plant . The experiment was designed according to Randomized Complete Block Design (RCBD) with three replicates per treatment, using less significant difference at the level of probability (0.05) , the results showed the following:- 1- The effect of brassinolide with it,s concentrations led to obtain on a significant increase in all the studied characteristics, so the superiority of the concentration of 2 mg.L -1 of brassinolide in each of nitrogen, potassium and protein, And the superi

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Publication Date
Mon Jul 01 1996
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
THE EFFECT OF DIFFERENT LEVELS OF NEMATODE POPULATION DENSITIES ON SEED GERMINATION PERCENTAGE AND SEEDLING CHARACTERISTICS OF SEVERAL CROPS
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Labrotary experiment was conducted to study the effect of different levels of nematode population densities of Meloidogyne spp on seed germination percentage and seedling characteristics of Vigna sinensis, Ahelmoschus esculentus, Cicer arietinum, Helianthus annuus and Rap-hanus sativus. Four different levels of nematode populat-ion densities ranged from 1 to 4 prepared from radish in-fected roots and used as inoculating agent to infect all seed types in the experiment Seed germination percentage of Vigna sinensis and Ablemoschus eseulentus were highly reduced (at 0.01 level of significance) with increased nematode population level from 1 to 4. Seedling length of the remaining seed types were significantly reduced (at 0.01 level of signif

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Publication Date
Sun Aug 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of public debt on financial stability in Iraq
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Countries have faced the challenges of high levels of public debt and seek to define the optimum limits to reduce risks to which the financial system can be exposed and its impact on the economy as a whole. Hence the importance of research in studying the impact of internal and external public debt components on indicators of stability of the financial system for the period 2005-2017 for the purpose of knowing the extent of the financial stability indicators response to the high level of the public debt from its optimum ratio, as the aim of the research is to estimate and analyze the dynamic relationship of short and long term between the components of public debt and indicators of financial stability using the (ARDL) model that

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