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Intensifying the Charging Response of a Phase-Change Material with Twisted Fin Arrays in a Shell-And-Tube Storage System
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A twisted-fin array as an innovative structure for intensifying the charging response of a phase-change material (PCM) within a shell-and-tube storage system is introduced in this work. A three-dimensional model describing the thermal management with charging phase change process in PCM was developed and numerically analyzed by the enthalpy-porosity method using commercial CFD software. Efficacy of the proposed structure of fins for performing better heat communication between the active heating surface and the adjacent layers of PCM was verified via comparing with conventional longitudinal fins within the same design limitations of fin material and volume usage. Optimization of the fin geometric parameters including the pitch, number, thickness, and the height of the twisted fins for superior performance of the proposed fin structure, was also introduced via the Taguchi method. The results show that a faster charging rate, higher storage rate, and better uniformity in temperature distribution could be achieved in the PCMs with Twisted fins. Based on the design of twisted fins, it was found that the energy charging time could be reduced by up to 42%, and the energy storage rate could be enhanced up to 63% compared to the reference case of straight longitudinal fins within the same PCM mass limitations.

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Publication Date
Sat Oct 01 2011
Journal Name
Journal Of Engineering
MAGNETO HYDRODYNAMIC NATURAL CONVECTION FLOW ON A VERTICAL CYLINDER WITH A PRESENCE OF HEAT GENERATION AND RADIATION
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The present work investigates the effect of magneto – hydrodynamic (MHD) laminar natural convection flow on a vertical cylinder in presence of heat generation and radiation. The governing equations which used are Continuity, Momentum and Energy equations. These equations are transformed to dimensionless equations using Vorticity-Stream Function method and the resulting nonlinear system
of partial differential equations are then solved numerically using finite difference approximation. A thermal boundary condition of a constant wall temperature is considered. A computer program (Fortran 90) was built to calculate the rate of heat transfer in terms of local Nusselt number, total mean Nusselt number, velocity distribution as well as te

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Publication Date
Thu Jan 02 2025
Journal Name
Journal Of The College Of Languages
Transformation of Slogans and Stereotypes in Response to Shifts in Political Discourse
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This study examines the transformation of political slogans, clichés, and stereotypes in Russia and Iraq during periods of political regime change in the late 20th and early 21st centuries. The main objective of the work is to identify and comparatively analyze the linguistic and cultural changes that accompanied political transformations in both countries. The research is based on theoretical concepts of political myth, framing, and critical discourse analysis. The research methodology includes content analysis of political texts, comparative analysis of linguistic transformations, and analysis of statistical data on cultural consumption. The main hypothesis is that, despite the presence of common trends in linguistic and cultural

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Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Evaluation of Convective Heat Transfer and Natural Circulation in an Evacuated Tube Solar Collector
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The evacuated tube solar collector ETC is studied intensively and extensively by experimental and
theoretical works, in order to investigate its performance and enhancement of heat transfer, for Baghdad climate
from April 2011 till the end of March 2012. Experimental work is carried out on a well instrumented collector
consists of 16 evacuated tubes of aspect ratio 38.6 and thermally insulated tank of volume 112L. The relation
between convective heat transfer and natural circulation inside the tube is estimated, collector efficiency, effect of
tube tilt angles, incidence angle modifier, The solar heating system is investigated under different loads pattern (i.e
closed and open flow) to evaluate the heat loss coefficient

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Publication Date
Mon Dec 25 2000
Journal Name
Journal Of Advanced Research In Fluid Mechanics And Thermal Sciences
Enhancement of nanofluid heat transfer in elliptical pipe and helical micro tube heat exchanger
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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Transfocation Technique to Overcome Atmospheric Scintillation Effect on a Laser Detection and Tracking System (LDTS)
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Atmospheric transmission is disturbed by scintillation, where scintillation caused more beam divergence. In this work target image spot radius was calculated in presence of atmospheric scintillation. The calculation depend on few relevant equation based on atmospheric parameter (for Middle East), tracking range, expansion ratio of applied beam expander's, receiving unit lens F-number, and the laser wavelength besides photodetector parameter. At maximum target range Rmax =20 km, target image radius is at its maximum Rs=0.4 mm. As the range decreases spot radius decreases too, until the range reaches limit (4 km) at which target image spot radius at its minimum value (0.22 mm). Then as the range decreases, spot radius increases due to geom

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Publication Date
Fri Nov 11 2022
Journal Name
Surgical Neurology International
Brown-Sequard syndrome associated with a spinal cord injury caused by a retained screwdriver: A case report and literature review
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Background:

Nonmissile penetrating spine injury (NMPSI) represents a small percent of spinal cord injuries (SCIs), estimated at 0.8% in Western countries. Regarding the causes, an NMPSI injury caused by a screwdriver is rare. This study reports a case of a retained double-headed screwdriver in a 37-year-old man who sustained a stab injury to the back of the neck, leaving the patient with a C4 Brown-Sequard syndrome (BSS). We discuss the intricacies of the surgical management of such cases with a literature review.

Methods:

PubMed database was searched by the following combined formula of medical subjects headings,

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Publication Date
Wed Oct 05 2022
Journal Name
Heat Transfer
Numerical investigation of natural convection in a square enclosure partially filled with horizontal layers of a porous medium
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Abstract<p>Two‐dimensional buoyancy‐induced flow and heat transfer inside a square enclosure partially occupied by copper metallic foam subjected to a symmetric side cooling and constant heat flux bottom heating was tested numerically. Finite Element Method was employed to solve the governing partial differential equations of the flow field and the Local Thermal Equilibrium model was used for the energy equation. The system boundaries were defined as lower heated wall by constant heat flux, cooled lateral walls, and insulated top wall. The three parameters elected to conduct the study are heater length (7 ≤ <italic>ζ</italic> ≤ 20 cm), constant heat flux (150 ≤ <italic>q<</italic></p> ... Show More
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Publication Date
Tue Sep 08 2020
Journal Name
Baghdad Science Journal
Convergence Analysis for the Homotopy Perturbation Method for a Linear System of Mixed Volterra-Fredholm Integral Equations
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           In this paper, the homotopy perturbation method (HPM) is presented for treating a linear system of second-kind mixed Volterra-Fredholm integral equations. The method is based on constructing the series whose summation is the solution of the considered system. Convergence of constructed series is discussed and its proof is given; also, the error estimation is obtained. Algorithm is suggested and applied on several examples and the results are computed by using MATLAB (R2015a). To show the accuracy of the results and the effectiveness of the method, the approximate solutions of some examples are compared with the exact solution by computing the absolute errors.

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Publication Date
Thu Mar 31 2022
Journal Name
Journal Of The College Of Education For Women
The Impact of a Counseling Program with a Cognitive Reconstruction Method on the Development of the Psychological Hardness among Middle School Students
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The current research aims to determine the impact of the cognitive reconstruction program on the development of psychological hardness among middle school students through the experimental verification of three hypotheses. The research sample consisted of (16) out of (450) students selected from Ibn Rushud preparatory school- Al-Rusafa 2. These participants have been randomly distributed into two equal groups. The researcher has used the method of cognitive reconstruction with the experimental group, whereas with the controlling group, he used nothing. The researcher has further used the scale of psychological hardness of Kobassa with the participants; the scale has been built in a way that suits the sample of the study, which consisted

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Publication Date
Sun Apr 06 2014
Journal Name
Journal Of Educational And Psychological Researches
Effectiveness of cooperative learning in at the implementation of floral material for celli graph and decoration
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The purpose of this resesrh know (the effectiveness of cooperative lerarning implementation of floral material for calligraphy and ornamentation) To achieve the aim of the research scholar put the two zeros hypotheses: in light of the findings of the present research the researcher concluded a number of conclusions, including: -
1 - Sum strategy helps the learner to be positive in all the information and regulations, monitoring and evaluation during the learning process.
2 - This strategy helps the learner to use information and knowledge and their use in various educational positions, and to achieve better education to increase its ability to develop thinking skills and positive trends towards the article.
In light of this, the

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