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Natural Convection Effect on Solidification Enhancement in a Multi-Tube Latent Heat Storage System: Effect of Tubes’ Arrangement
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The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, including uniform distribution of the tubes as well as non-uniform distribution, i.e., tubes concentrated at the bottom, middle and the top of the PCM shell. The model was first validated compared with previous experimental work from the literature. The results show that the heat rate removal from the PCM after 16 h was 52.89 W (max) and 14.85 W (min) for the cases of uniform tube distribution and tubes concentrated at the bottom, respectively, for the proposed dimensions of the heat exchanger. The heat rate removal of the system with uniform tube distribution increases when the distance between the tubes and top of the shell reduces, and increased equal to 68.75 W due to natural convection effect. The heat release rate also reduces by increasing the temperature the tubes. The heat removal rate increases by 7.5%, and 23.7% when the temperature increases from 10 °C to 15 °C and 20 °C, respectively. This paper reveals that specific consideration to the arrangement of the tubes should be made to enhance the heat recovery process attending natural convection effects in phase change heat storage systems.

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Publication Date
Wed Apr 12 2017
Journal Name
Int'l Journal Of Computing, Communications & Instrumentation Engg.(ijccie)
Variant Parameters effect on OFDM Estimation Power Consumption
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Publication Date
Mon Jun 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Effect of Operating Cconditions on Hydrodesulfurization of Vacuum Gas Oil
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This study was conducted according to contract with the North Refineries Company-Baiji and deals with the hydrodesulphurization of vacuum gas oil of Kirkuk crude oil, boiling range 611-833 K. A trickle bed reactor packed with a commercial cobalt-molybdenum on alumina catalyst was used. The operating conditions were: temperature range 583-643 K, liquid hourly space velocity range 1.50-3.75 1/h, hydrogen to oil ratio about 250 l/l and pressure kept constant at 3.5MPa.
The results showed that the aromatic content decreased and sulfur removal increased with increasing temperature and decreasing space velocity. The properties (viscosity, density, flash point and carbon residue) of the products decrease with temperature increasing, but the

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Publication Date
Wed May 17 2023
Journal Name
Journal Of Engineering
Effect of Metakaolin on Properties of Lightweight Porcelinate Aggregate Concrete
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Research in Iraq has expanded in the field of material technology involving the properties of the lightweight concrete using natural aggregate. The use of the porcelinate aggregate in the production of structural light concrete has a wide objective
and requires a lot of research to become suitable for practical application. In this work metakaolin was used to improve compressive strength of lightweight porcelinate concrete which usually have a low compressive strength about 17 MPa . The effect of metakaolin on compressive, splitting tensile, flexure strengths and modulus of elasticity of lightweight porcelinate concrete have been investigated. Many experiments were carried out by replacing cement with different percentages of
met

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Publication Date
Wed Feb 19 2020
Journal Name
International Journal Of Development In Social Sciences And Humanities
The Effect of Context on the Comprehension of English Idioms
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DBN Rashid, International Journal of Development in Social Sciences and Humanities, 2020

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Publication Date
Wed Feb 29 2012
Journal Name
Al-khwarizmi Engineering Journal
Effect of Construction Joints on Performance of Reinforced Concrete Beams
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Construction joints are stopping places in the process of placing concrete, and they are required because in many structures it is impractical to place concrete in one continuous operation. The amount of concrete that can be placed at one time is governed by the batching and mixing capacity and by the strength of the formwork. A good construction joint should provide adequate flexural and shear continuity through the interface.

In this study, the effect of location of construction joints on the performance of reinforced concrete structural elements is experimentally investigated.

Nineteen beam specimens with dimensions of 200×200×950 mm were tested. The variables investigated are the location of the construction joints

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Publication Date
Sat May 15 2010
Journal Name
International Journal Of Poultry Science
Effect of Dietary Linseed on Egg Quality of Laying Quail
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This experiment was performed to investigate the effect of dietary supplementation with linseed on egg quality of laying quail. A total of 320 9-week-old Japanese quail (Coturnix coturnix japonica) 9-wk old were allocated to 4 treatment groups with 4 replicates containing 20 quail each. Birds were fed a commercial diet containing 0% (C), 2% (T1), 4% (T2), or 6% (T3) linseed. Birds received water and diet ad libitum during the total period of the experiment. Egg quality characteristics were monitored over 3 consecutive 21-d periods. Egg quality criteria involved in this experiment were egg weight, yolk diameter, yolk height, yolk weight, albumen height, albumen weight, shell weight, shell thickness, Haugh unit, albumen percentage, yolk perce

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Publication Date
Sat Oct 01 2016
Journal Name
World Journal Of Pharmaceutical Research
EFFECT OF LEVETIRACETAM ON THE CEREBRAL CORTEX OF NEWBORN RAT
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Background: Levetiracetam is a member of the new antiepileptic drugs and has a broad spectrum effect, used as an adjunctive therapy in addition to monotherapy in the treatment of partial onset-seizures. The effect of levetiracetam on the development of embryo nervous system after maternal exposure during pregnancy has not been identified. Objective: to evaluate the effect of antiepileptic drug, levetiracetam (LEV) within its therapeutic dose 350mg/Kg body weight on albino female rat to clarify its effect on the developing cerebral cortex histologically. Material And Methods: Ten pregnant female rats were separated into two groups, control group and experimental group. They were obtained from the animal house of the high institute of inferti

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Publication Date
Sun Mar 03 2013
Journal Name
Baghdad Science Journal
Effect of Magnetic Water Treatment on Prevention of CaCO3 Scales
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Permanent magnets of different intensities were used to investigate the effect of a magnetic field in the process of preventing deposits of calcium carbonate. The magnets were fixed on the water line from the tap outside. Then heating a sample of this water in flasks and measuring the amount of sediment in a manner weighted differences. These experiments comprise to the change of the velocity of water flow, which amounted to (0.5, 0.75, 1) m/sec through the magnetic fields that are of magnetic strength (2200, 6000, 9250, 11000) Gauss, and conduct measurements, tests and compare them with those obtained from the use of ordinary water.The results showed the effectiveness of magnetic treatment in reducing the rate of deposition of calcium carb

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Publication Date
Sun May 01 2022
Journal Name
Journal Of Ovonic Research
Effect of antimony on characteristics of HgBa2CaCu2-xSbxO8+δ superconducting
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In this work, HgBa2CaCu2-xSbxO8+δ compounds with (x = 0.2, 0.4, 0.6 and 0.8) have been prepared by the solid-state reaction method. Structural, morphological, and electrical properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Using the 4-probe technique to study the effect of antimony-substitution for Copper on the electrical properties of HgBa2CaCu2-xSbxO8+δ (Hg-1212) phase was investigated by measuring the resistivity as a function of temperature. Results indicate that the addition of antimony (Sb) increases the volume fraction of the phase and changes the superconducting transition temperature Tc of the superconductor to a normal state. The dielectric loss factor and ac

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Publication Date
Sat Apr 16 2016
Journal Name
World Journal Of Experimental Biosciences
Effect of pregabalin on ovary tissue of albino female rats
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The present study aimed to investigate effect of Pregabalin (PGB) on ovary tissue and number of follicles in female albino rats. Three groups of healthy adult female albino rats, fifteen rats in each group were used in current study. The rats of groups, G2 and G3 were administered orally with two doses 150 mg and 300mg/kg b.wt/day of pregabalin, respectively. The doses were given daily for 1 month, 2 months, and 3 months. Animals of group G1 (Control) were given saline alone. After the experimental periods, the rats were sacrificed and the isolated ovaries were histologically examined. The results of histological analysis of the ovaries in treated rats (G2, and G3) showed a significant (P≤0.05) decrease in the number of preantral, antral,

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