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alkej-629
Parametric study of thermal behavior of thrust chamber cooling channels
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A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber  wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for  different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the coolant is indicated. The radiation has a considerable effect on the  computed wall temperature values.

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Publication Date
Tue Jun 01 2021
Journal Name
Al-khwarizmi Engineering Journal
Modeling and Simulation for Performance Evaluation of Optical Quantum Channels in Quantum key Distribution Systems
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In this research work, a simulator with time-domain visualizers and configurable parameters using a continuous time simulation approach with Matlab R2019a is presented for modeling and investigating the performance of optical fiber and free-space quantum channels as a part of a generic quantum key distribution system simulator. The modeled optical fiber quantum channel is characterized with a maximum allowable distance of 150 km with 0.2 dB/km at =1550nm. While, at =900nm and =830nm the attenuation values are 2 dB/km and 3 dB/km respectively. The modeled free space quantum channel is characterized at 0.1 dB/km at =860 nm with maximum allowable distance of 150 km also. The simulator was investigated in terms of the execution of the BB84 p

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Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Coupled channels calculations of fusion reactions for 46Ti+64Ni, 40Ca+194Pt and 40Ar+148Sm systems
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In this work, the fusion cross section ,  fusion barrier distribution  and the probability of fusion  have been investigated by coupled channel method  for the systems 46Ti+64Ni, 40Ca+194Pt and 40Ar+148Sm with semi-classical and quantum mechanical approach using SCF and CCFULL Fortran codes respectively. The results for these calculations are compared with available experimental data. The results show that the quantum calculations agree better with experimental data, especially bellow the Coulomb barrier, for the studied systems while above this barrier, the two codes reproduce the data.

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Publication Date
Tue Jun 01 2021
Journal Name
Al-khwarizmi Engineering Journal
Modeling and Simulation for Performance Evaluation of Optical Quantum Channels in Quantum key Distribution Systems
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In this research work, a simulator with time-domain visualizers and configurable parameters using a continuous time simulation approach with Matlab R2019a is presented for modeling and investigating the performance of optical fiber and free-space quantum channels as a part of a generic quantum key distribution system simulator. The modeled optical fiber quantum channel is characterized with a maximum allowable distance of 150 km with 0.2 dB/km at =1550nm. While, at =900nm and =830nm the attenuation values are 2 dB/km and 3 dB/km respectively. The modeled free space quantum channel is characterized at 0.1 dB/km at =860 nm with maximum allowable distance of 150 km also. The simulator was investigated in terms of the execution of the BB84 prot

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels
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The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element

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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Study the effect of thermal annealing on some physical properties of thin Cu2SiO3 films prepared by pulsed laser deposition
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The Cu2SiO3 composite has been prepared from the binary compounds (Cu2O, and SiO2) with high purity by solid state reaction. The Cu2SiO3 thin films were deposited at room temperature on glass and Si substrates with thickness 400 nm by pulsed laser deposition method. X-ray analysis showed that the powder of Cu2SiO3 has a polycrystalline structure with monoclinic phase and preferred orientation along (111) direction at 2θ around 38.670o which related to CuO phase. While as deposited and annealed Cu2SiO3 films have amorphous structure. The morphological study revealed that the grains have granular and elliptical shape, with average diameter of 163.63 nm. The electrical properties which represent Hall effect were investigated. Hall coeffici

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Publication Date
Sat Mar 31 2018
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Study of the Performance of Paraffin Wax as a Phase Change Material in Packed Bed Thermal Energy Storage System
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The present work deals with an experimental investigation of charging and discharging processes in thermal storage system using a phase change material PCM. Paraffin wax was used as the PCM which is formed in spherical capsules and packed in a cylindrical packed column which acted as an energy storage system. Air was used as the heat transfer fluid HTF in thermal storage unit. The effect of flow rate and inlet temperature of HTF on the time of charging and discharging process were studied. The results showed that the faster storage of thermal energy can be made by high flow rate of heat transfer fluid HTF and high inlet temperature of heat transfer fluid. It was found that at 65°C HTF inlet temperature, the melting and solidification pr

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Publication Date
Thu Oct 01 2020
Journal Name
International Communications In Heat And Mass Transfer
Thermal behaviour of the flow boiling of a complex nanofluid in a rectangular channel: An experimental and numerical study
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Publication Date
Sun Dec 17 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Simulation of Natural Heat Convection from Finned Vertical Plate with Different Inclinations
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In this work an experimental simulation is made to predict the performance of steady-state natural heat convection along heated finned vertical base plate to ambient air with different inclination angles and configurations of fin array. Two types of fin arrays namely vertical fins array and V-fins array on heated vertical base plate are used with different heights and spaces. The influence of inclination angle of the plate , configuration of fins array and fin geometrical parameters such as fin height and fin spacing on the temperature distribution, base convection heat transfer coefficient and average Nusselt number have been plotted and discussed. The experimental data are correlated to a formula between average Nusselt number versus R

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Publication Date
Mon Jul 04 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The possibility of adopting strategic management accounting techniques to increase competitiveness Iraqi economic units in light of the variables of the contemporary business environment.
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The accession of countries to the World Trade Agreement and the openness of markets to each other without restrictions led to the emergence of the philosophy of "a world without borders and business units without countries", which required adapting the modern business environment to that philosophy, which is considered as objectives for the activities of the units that must be implemented in order to achieve competition. The objective of the units has changed from making profit to meeting the desires of customers, which is what imposed a new role for management accounting as a field of knowledge renewed in it visions of competitiveness between units. Because of the increasing needs for information in light of environmental change

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Publication Date
Mon Dec 26 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
ESTIMATION OF THE CHEMICAL COMPONENTS OF WASTES PRESSED GRAPES A STUDY THE EFFECT OF THERMAL EXTRACTS TRANSACTIONS IN INHIBITING THE GROWT OF MICROORGANISMS.: ESTIMATION OF THE CHEMICAL COMPONENTS OF WASTES PRESSED GRAPES A STUDY THE EFFECT OF THERMAL EXTRACTS TRANSACTIONS IN INHIBITING THE GROWT OF MICROORGANISMS.
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The chemical composition of wastes of pressed grapes and found that the main components of wastes of pressed grapes, represented by the percentage of moisture was 6.47%, and the proportions are 3.71%. Either carbohydrates amounted to 85.77 %, either in fat models using petroleum ether Petroleum ether) was the increase of 0.27%. estimated the percentage of ash in the sampls was 3.78%, either fiber reached 69.47 %,, in addition to the test extracts towards the growth of seven types of bacteria, which included Bacillus subtilis, Bacillus cereus, Bacillus stearothermophilus, Escherishia coli, Staphylococcus aureus, Salmonella typhimurium and Pseudomonas fluorescens and yeast Candida albicans and Kluyveromyces marxianus, ( diffusion method ).

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