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Townsend Discharge and Streamer Breakdown within Sphere-Air-Sphere Configuration
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     The main aim of the present paper is to study the electric breakdown in a uniform electric discharge system. The system consists of two spheres separated by a dielectric. The dielectric is dry air. Certain boundary conditions are taken into consideration as applied voltage, pressure, and domain. The formation of discharge types as Townsend and streamer under different distance gaps (1, 0.9,0.8, 0.6, 0.4, 0.2, 0.1) mm was sudied. The temperature effect on the breakdown voltages for the discharge process is also included. Seven different temperature steps are chosen in the study.  Comsol Multiphysics software is used for the simulation model as a plasma model. Results show that as the gap distance increases the breakdown voltage increases for each of the discharges. For maximum electric field, as the distance increases the field also increases. For gap distance, the temperature effects are more apparent at the higher values of the pressure.  The maximum electric field increases as the voltage increases with the temperature.

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Publication Date
Mon Jul 01 2019
Journal Name
Journal Of Physics: Conference Series
Fusion Power Density and Radiation Losses Characteristics for Tritium Fusion Reactions
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A new data for Fusion power density has been obtained for T-3He and T-T fusion reactions, power density is a substantial term in the researches related to the fusion energy generation and ignition calculations of magnetic confined systems. In the current work, thermal nuclear reactivities, power densities of a fusion reactors and the ignition condition inquiry are achieved by using a new and accurate formula of cross section, the maximum values of fusion power density for T-3He and TT reaction are 1.1×107 W/m3 at T=700 KeV and 4.7×106 W/m3 at T=500 KeV respectively, While Zeff suggested to be 1.44 for the two reactions. Bremsstrahlung radiation has also been determined to reaching self- sustaining reactors, Bremsstrahlung values are 4.5×

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Publication Date
Thu Oct 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Pressure Control of Electro-Hydraulic Servovalve and Transmission Line Effect
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The effected of the long transmission line (TL) between the actuator and the hydraulic control valve sometimes essentials. The study is concerned with modeling the TL which carries the oil from the electro-hydraulic servovalve to the actuator. The pressure value inside the TL has been controlled by the electro-hydraulic servovalve as a voltage supplied to the servovalve amplifier. The flow rate through the TL has been simulated by using the lumped π element electrical analogy method for laminar flow. The control voltage supplied to servovalve can be achieved by the direct using of the voltage function generator or indirect C++ program connected to the DAP-view program built in the DAP-card data acqu

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Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Colloid And Interface Science
Impact of nanoparticles on the CO2-brine interfacial tension at high pressure and temperature
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Hypothesis Nanofluid flooding has been identified as a promising method for enhanced oil recovery (EOR) and improved Carbon geo-sequestration (CGS). However, it is unclear how nanoparticles (NPs) influence the CO2-brine interfacial tension (γ), which is a key parameter in pore-to reservoirs-scale fluid dynamics, and consequently project success. The effects of pressure, temperature, salinity, and NPs concentration on CO2-silica (hydrophilic or hydrophobic) nanofluid γ was thus systematically investigated to understand the influence of nanofluid flooding on CO2 geo-storage. Experiments Pendant drop method was used to measure CO2/nanofluid γ at carbon storage conditions using high pressure-high temperature optical cell. Findings CO2/nano

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Publication Date
Sun Mar 04 2012
Journal Name
Baghdad Science Journal
Effect of Temperature on Reliability and Degradation of 0.63?m Laser Diode
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The reliability of optical sources is strongly dependent on the degradation and device characteristics are critically dependent on temperature. The degradation behaviours and reliability test results for the laser diode device (Sony-DL3148-025) will be presented .These devices are usually highly reliable. The degradation behaviour was exhibited in several aging tests, and device lifetimes were then estimated. The temperature dependence of 0.63?m lasers was studied. An aging test with constant light power operation of 5mW was carried out at 10, 25, 50 and 70°C for 100hours. Lifetimes of the optical sources have greatly improved, and these optical sources can be applied to various types of transmission systems. Within this degradation range,

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Publication Date
Sun Sep 03 2017
Journal Name
Baghdad Science Journal
Keys for Isolation suborders and Families and genera and species of Book and Bark lice in Baghdad and Babylon [Order PSOCOPTERA]
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A taxonomic keys was established of book and bark lice Order Psocoptera to isolated insects in Iraq from different localities of Baghdad and Babylon provinces. Thirteen species belong to eight genera and five families have been studied and described in details, these species were recorded for the first time in Iraq. These species are: Belaphopsocus badonneli New, 1971; Belaphotroctes oculeris Bodonnel, 1973; Embodopsocosis newi Bodonnel, 1973; Epipsocus stigamaticus Mockeord, 1991; Lepinotus huoni Schmidt and New, 2008; Liposcelies decolor Peramane 1925 Liposcelies paeta Pearman 1942 Liposclies bostrychphila Badonnel 1931; Liposclies brunnea Mostchulsky 1852; Liposclies entoophila Enderlein 1907; Neopsocopsis minuscule Li 2002 ;

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Analysis and Control of PWM Buck-Boost AC Chopper Fed Single-Phase Capacitor Run Induction Motor
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Single phase capacitor-run induction motors (IMs) are used in various applications such as home appliances and machine tools; they are affected by the sags or swells and any fault that can lead to disturb the supply and make it produce rms voltage below or above the rated motor voltage, which is 220V. A control system is designed to regulate the output voltage of the converter irrespective to the variation of the load and within a specific range of supply voltage variation. The steady-state equivalent circuit of the Buck-Boost chopper type AC voltage regulator, as well as the analysis of this circuit are presented in this paper. Switching device for the regulator is an IGBT Module. The proposed chopper uses pulse width modulation (PWM) c

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Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Engineering
Theoretical and Experimental Investigation of Transient Temperature Distribution in Friction Stir Welding of AA 7020-T53
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Finite element modeling of transient temperature distribution is used to understand physical phenomena occurring during the dwell (penetration) phase and moving of welding tool in friction stir welding (FSW) of 5mm plate made of 7020-T53 aluminum alloy at 1400rpm and 40mm/min.
Thermocouples are used in locations near to the pin and under shoulder surface to study the welding tool penetration in the workpiece in advance and retreate sides along welding line in three positions (penetrate (start welding) , mid, pullout (end welding)).
Numerical results of ANSYS 12.0 package are compared to experimental data including axial load measurements at different tool rotational speeds (710rpm.900rpm.1120rpm and 1400rpm) Based on the experiment

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Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Study the effect of different temperatures in the growth and development of Been Beette Acanthoselides obtectus (Coleoptera: Bruchidae)
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This research includes a study of the effect of four temperatures (25, 30, 35, 40m◦) with relative humidity 65% on some biological aspects of the Bean beetle Acanthoselides obtectus on the Bean seeds under laboratory conditions. The results showed that the effect of different temperatures is clear on biological of Bean beetle. Differed period necessary for the growth and development of each stage of the insect in different temperatures . The results of statically analysis showed a significant difference in the life cycle when all temperatures except the period between temperature 35 and 40m◦ , respectively. Where the average of those period, 60.75, 35.5, 20.34 and 19.27 days and also different temperatures significant effects is clea

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Publication Date
Mon Mar 01 2021
Journal Name
Journal Of Physics: Conference Series
fMRI and Artifact computation and Analysis
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Abstract<p>Over the years, the field of Medical Imagology has gained considerable importance. The number of neuroimaging studies conducted using functional magnetic resonance imaging (fMRI) has been exploding in recent years. fMRI survey gives to rise to large amounts of noisy data with a complex spatiotemporal correlation structure. Statistics play great role in clarifying the features of the data and gain results that can be used and explain by neuroscientists. Several types of artifacts can happen through a functional magnetic resonance imaging (fMRI) scanner Because of software or hardware problems, physical limitation or human physiologic phenomenon. Several of them can negatively affect di</p> ... Show More
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Publication Date
Thu Dec 31 2020
Journal Name
College Of Islamic Sciences
Religion and atheism suspicions and reaction.
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This research is about his life in his life. The Status of the Import of the Arts of Information. And the danger lies in the effects that translate in the lives of people from the occurrence of the second life or not to occur, the experimentalists claim in this matter is not tangible and not tried in a sense not proven by science through experience and analysis All that is proven by science from this road is committed to it, and unless proven from this path no one has the right to speak it, and in their view, this is not the way to prove knowledge and facts. The search is based on the consideration of the origin of knowledge. Is it possible to prove without experience something or not? The question is whether religion has a basis

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