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Comparative Experimental and Numerical Investigation on Electrical Discharge Drilling of AISI 304 using Circular and Elliptical Electrodes
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This work introduces a new electrode geometry for making holes with high aspect ratios on AISI 304 using an electrical discharge drilling (EDD) process. In addition to commercially available cylindrical hollow electrodes, an elliptical electrode geometry has been designed, manufactured, and implemented. The principal aim was to improve the removal of debris formed during the erosion process that adversely affects the aspect ratio, dimensional accuracy, and surface integrity. The results were compared and discussed to evaluate the effectiveness of electrode geometry on the machining performance of EDD process with respect to the material removal rate (MRR,) the electrode wear rate (EWR), and the tool wear ratio (TWR). Dimensional features and surface characteristics of the drilled holes were also evaluated in aspects of overcut (OC), aspect ratio (AR), and surface roughness (SR). The experimental results revealed that an elliptical electrode is preferable for producing holes with good dimensional accuracy and improved surface quality. In addition, 3D models of flow field with liquid, gas, and solid phases are proposed for analyses of the interelectrode gap within the machining zone. Based on the results obtained from models, the elliptical electrode also exhibited good flushing capability for effective debris removal.

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Publication Date
Fri Jan 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Study of the Effectiveness of Tin on the Thermal Conductivity Coefficient and Electrical Resistance of Se60Te40-xSnx Chalcogenide Glass
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     This research calculated the effect of partial replacement of Trillium with tin by weight ratios x=0, 5, 10, 15, and 20 of the weight of manufactured samples on the thermal conductivity coefficient of Se60Te40-xSnx chalcogenide glasses. The thermal conductivity coefficient of the samples was calculated using a disk- Lee. The results showed that increasing the concentration of tin improves the thermal insulation ability by decreasing the thermal conductivity value and then determining the optimal weight ratios at which a large thermal insulation is obtained.

 The electrical resistivity as a function of temperature was studied. The electrical resistivity (rd.c) was calculated as a function of temperature for all

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Publication Date
Mon Aug 01 2011
Journal Name
Journal Of Engineering
NATURAL CONVECTION HEAT TRANSFER IN AN INCLINED CIRCULAR CYLINDER
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Experiments were carried out to investigate natural convection heat transfer in an inclined uniformly heated circular cylinder . The effects of surface heat flux and angle of inclination on the temperature and local Nusselt number variations along the cylinder surface are discussed . The investigation covers heat flux range from 92 W/m² to 487 W/m², and angles of inclination 0° ( horizontal) , 30° , 60° and 90° (vertical) . Results show an increase in the natural convection as heat flux increases and as angle of inclination moves from vertical to horizontal position. An empirical equation of average Nusselt number as a function of Rayliegh number was deduced for each angle of inclination .

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Publication Date
Sun Apr 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study the Partial Subistituation and Annealing on Electrical Properties of Compound Tl2-xAg2-ySryBayCa2Cu3O10+& Superconductor Fabricated by Nano Technique
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The crystal compounds Tl2-xAg2-ySryBayCa2Cu3O10+& are successfully prepared in different concentrations (x, y=0.1, 0.2, 0.3, 0.4, 0.5) by solid state reaction process. The samples were then subjected to Nano technique under hydrolic pressure 8 ton/cm2. samples have been annealed in (850 C0) for 72 hours. The results show a best value at x, y=0.3 ratio of Ag, Ba. Electrical resistivity at x, y= 0.3 of Ag, Ba are obtained when the best value of Tc= 141 K. Samples morphology were also observed by AFM (in three dimensions), the best value of Nano is 91.74 nm at x, y= 0.3. Morphological structures of the surface were also observed by (SEM) and (EDX) show that there are dark regions and light which indicate the presence of heavy elements a

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Publication Date
Sat Jun 19 2021
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Development, Characterization and Pharmacological Investigation of Umbelliferone Conjugates of NSAIDs
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The present investigation developed the ester prodrugs of Non-steroidal anti inflammatory drugs (NSAIDs), Mefenamic acid and Flurbiprofen by conjugating with the natural antioxidant, 4-methyl umbelliferone that resulted the formation of Mefenamic acid-umbelliferone ester prodrug and Flurbiprofen-umbelliferone ester prodrug .The principal objective this study is the synthesis of the ester prodrugs of NSAIDs with the enhanced therapeutic activity and minimized side effects. Prodrugs were synthesized by coupling method using N,N- dicyclohexylcarbodiimide/4-dimethylaminopyrimidine, subjected to  physical, chemical characterization, spectral characterization (IR, 1H NMR, 13C NMR and Mass spectra),hydro

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Publication Date
Thu Nov 11 2021
Journal Name
Iraqi Journal Of Science
Impacts of porous medium on unsteady helical flows of generalized oldroyd-B fluid with two infinite coaxial circular cylinders
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Scopus (7)
Scopus
Publication Date
Sun Nov 25 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Cu doping on the electrical Properties of ZnTe by Vacuum Thermal Evaporation
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In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hal

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Crossref (1)
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Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Engineering
MIXED CONVECTION PHENOMINA AFFECTED BY RADIATION IN A HORIZONTAL RECTANGULAR DUCT WITH COCENTRIC AND ECCENTRIC CIRCULAR CORE
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The numerical investigation has been performed to study the radiation affected steady state laminar mixed convection induced by a hot inner varied positions circular core in a horizontal rectangular channel for a fully developed flow. To examine the effects of thermal radiation on thermo fluid dynamics behavior in the eccentric geometry channel, the generalized body fitted co-ordinate system is introduced while the finite difference method is used for solving the radiative transport equation. The governing equations which used are continuity, momentum and energy equations. These equations are normalized and solved using the Vorticity-Stream function. After validating numerical results for the case without radiation, the detailed rad

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Crossref
Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Engineering
MIXED CONVECTION PHENOMINA AFFECTED BY RADIATION IN A HORIZONTAL RECTANGULAR DUCT WITH COCENTRIC AND ECCENTRIC CIRCULAR CORE
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The numerical investigation has been performed to study the radiation affected steady state laminar mixed convection induced by a hot inner varied positions circular core in a horizontal rectangular channel for a fully developed flow. To examine the effects of thermal radiation on thermo fluid dynamics behavior in the eccentric geometry channel, the generalized body fitted co-ordinate system is introduced while the finite difference method is used for solving the radiative transport equation. The governing equations which used are continuity, momentum and energy equations. These equations are normalized and solved using the Vorticity-Stream function. After validating numerical results for the case without radiation, the detailed radiatio

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Publication Date
Sun Aug 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Relational leadership and its effect on organizational energy (A comparative study in the Rafidain and Rashid banks)
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This research aims to test the relationship between "relational leadership as an independent variable and organizational energy as a dependent variable. The current research variables are among the recent and important variables for the development of organizations, and for the purpose of explaining the relationship and influence between the variables, a set of goals has been formulated, including providing the interested and scientific and theoretical information explaining the nature of the variables The research, and the extent to which its causes are reflected in the research sample to increase the interest of the research organization’s organization and make it more appropriate to the required performance in light of a cha

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Publication Date
Tue Feb 04 2020
Journal Name
International Journal Of Psychosocial Rehabilitation
A Comparative Study on the Probability of Diabetes and Psychosocial Deficiency of Badminton Players Youth Category
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Many people believe that diabetes appears after a psychological crisis, which is a misconception but it could be in them before having a crisis ore the crisis. But emotion increases the appearance of symptoms, and athletes are at risk of developing diabetes. Hypoglycemia is not unusual for athletes, and during physical activity the sugar level changes in the blood. Therefore, it is important to conduct tests for the measurement of sugar before and immediately after the activity, for the purpose of detecting the sharp drop in the sugar level and treating it, and the early detection is necessary to avoid the possibility of diabetes, the concept of psychological immunity in psychology is considered a positive concepts that maintain the balance

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