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Numerical Investigation of Transient Heat Conduction through a Thermal Insulation of Temperature Dependant Thermal Properties
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The two-dimensional transient heat conduction through a thermal insulation of temperature dependent thermal properties is investigated numerically using the FVM. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner surface with a step change in temperature and subjected at its outer surface with a natural convection boundary condition associated with a periodic change in ambient temperature and heat flux of solar radiation. Two thermal insulation materials were selected. The fully implicit time scheme is selected to represent the time discretization. The arithmetic mean thermal conductivity is chosen to be the value of the approximated thermal conductivity at the interface between adjacent control volumes. A temperature dependent specific heat capacity proposed by a 4th Degree polynomial is fitted. A good agreement is obtained when the predicted results are compared with those obtained from the analytical solution.

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Publication Date
Sun Dec 27 2020
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Phytochemical Investigation of Aerial Parts of Iraqi Cardaria draba
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 The aim of this study was to study chemical constituents of aerial parts of Cardaria draba since no phytochemical investigation had been studied before in Iraq. Aerial parts of Cardaria draba were defatted by maceration in hexane for 72 h. The defatted plant materials were extracted using Soxhlet apparatus, the aqueous Methanol 90% as a solvent extraction for 18 h, and fractionated with petroleum ether- chloroform (CHCl3)- ethylacetate- and n-butanol respectivly. The ethyl acetate, n-butanol, and n-butanol after hydrolysis fractions were investigated by high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) for its phenolic acid and flavonoid contents. Flavono

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Publication Date
Mon Apr 04 2022
Journal Name
Journal Of Educational And Psychological Researches
The Degree of Implementation of the Coronavirus Prevention Standards (Covid-19) In the Kingdom Of Saudi Arabia (A COMPARATIVE STUDY BETWEEN FAMILIES OF PEOPLE WITH INTELLECTUAL DISABILITIES AND FAMILIES OF ORDINARY PEOPLE)
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The study aims to identify the degree of implementation of the coronavirus prevention standards (covid-19) in the kingdom of Saudi Arabia and compare it with the families of intellectual disabilities. The study population consisted of all families residing in the Kingdom of Saudi Arabia. To achieve the objectives of the research, the analytical descriptive approach was employed. The study sample consisted of (372) families, among them (84) families with intellectual disabilities, and (288) families without intellectual disabilities. They were chosen from the Saudi community according to what is available for collection in a simple random way, using the standard criteria for the prevention of coronavirus (Covid- 19) Prepared by the resear

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Publication Date
Wed Jan 11 2023
Journal Name
J. Of Kirkuk Univ. For Agri. Sci.
THE HARMFUL CONSEQUENCES OF HEAT STRESS ON CHICKENS INDUSTRY
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This article dealt with identifying the importance of heat stress in poultry flocks and the damages resulting from the production of eggs and meat and the spread of pathogens, in addition to that ways to mitigate the harmful effects of heat stress, including physiological, nutritional, engineering and genetics, in order to ensure preservation of the product and reduce damages

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Publication Date
Tue May 23 2023
Journal Name
Journal Of Engineering
EXPERIMENTAL AND THEORETICAL STUDY OF TWO-PHASE HEAT PIPE
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In this study, thermal characteristics of a two-phase closed heat pipe were investigated experimentally and theoretically. A two-phase closed heat pipe (copper container, Fluorocarbon FC-72 (C6F14) working fluid) was fabricated to examine its performance under the effect of input heat flux range of 250–1253 W/m2 , 70% fill charge ratio and various tilt angles. The temperature distribution along the heat pipe, input heat to evaporator section, and output heat from condenser were monitored. A comprehensive mathematical model was developed to investigate the steadystate heat transfer performance of a two-phase closed heat pipe. A steady state analytical model, is presented to determine important parameters on the design of two-phase close

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Publication Date
Fri Oct 14 2016
Journal Name
International Journal For Computational Methods In Engineering Science And Mechanics
Simultaneous determination of time-dependent coefficients and heat source
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Publication Date
Wed Mar 20 2019
Journal Name
Al-khwarizmi Engineering Journal
Enhancement of Heat Exchanger Performance by Using Dimpled Tube
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The enhancement of heat exchanger performance was investigated using dimpled tubes tested at different Reynolds numbers, in the present work four types of dimpled tubes with a specified configuration manufactured, tested and then compared performance with the smooth tube and other passive techniques performance. Two dimpled arrangements along the tube were investigated, these are inline and staggered at constant pitch ratio X/d=4, the test results showed that Nusselts number (heat transfer) of the staggered array is higher than the inline array by 13%.  The effect of different depths of the dimple (14.5 mm and 18.5 mm) has been also investigated; a tube with large dimple diameter enhanced the Nusselts number by about 25% for the ran

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Publication Date
Sat Aug 12 2017
Journal Name
Journal Of Engineering
Influence of Temperature Upon Permanent Deformation Parameters of Asphalt Concrete Mixes
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        The performance of asphalt concrete pavement has affected by many factors, the temperature is the most important environmental one which has a large effect on the structural behavior of flexible pavement materials. The main cause of premature failure of pavement is the rutting, Due to the viscoelastic nature of the asphalt cement, rutting is more pronounced in hot climate areas because the viscosity of the asphalt binder which is
inversely related to rutting is significantly reduced with the increase in temperature resulting in a more rut susceptible paving mixtures. The objective of this study is to determine the effect of temperatures variations on the permanent deformation parameters (perm

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Publication Date
Sat May 01 2021
Journal Name
Key Engineering Materials
The Effect of Temperature Width on Dielectric Constant of Vanadium Dioxide
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A significant influence of temperature width found on the vanadium oxide properties, it plays a major role in highlighting the thermal limits of the three phases (metallic, semiconductor, and dielectric). Two values of the temperature width , and , had taken and studied their effect on both the dielectric constant and its two parts; refractive index, and extinction coefficient, and. It found that: as the temperature width is greater, the more the properties of the three phases for . In addition to increasing the thermal range for phases which can be reached to when , while it's at . Our results have achieved great compatibility with the published results globally. In addition to the effect of both ultraviolet, visible, and infrared

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Publication Date
Mon Sep 25 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Annealing Temperature on the Structural Characteristics of(Sb203) Compound.
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The crystal structure and unit cell dimensions of the (S03) compound have  been determined by employing the principles of crystallography.

The X-Ray diffraction spectra of (Sb203) which recorded as a function  of   different  annealing  temperatures  (100,150,200  and

 

250)±5c and for durations (0.5  hr,

0

 

1hr, l.Shr and 2hr), showed a

 

noticeable improvement, a decreasing in the unit cell dimensions and

an increasing in the number of diffraction spectra.

Indexing of diffraction spectra and refinement of  unit cell

dimensions showed that the compound (Sb203)  which is a

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Publication Date
Sat Jun 03 2023
Journal Name
Iraqi Journal Of Science
Investigation of Giardia lamblia and other parasites in tap water as a potential source of transmission in some regions of Baghdad
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Samples from tap water were chosen to be examined as one of the possible modes of G. lamblia and other parasites transmission. 144 domestic filter units were randomly distributed to houses in Baghdad in Al-Sadr City and surrounding regions then the suspended materials were examined microscopically by direct wet mount after centrifugal sedimentation method, and after staining with modified Ziehl-Neelsen (acid fast) stain. The results showed that 5/144 (3.47%) samples contained G. lamblia cysts, 3/144 (2.08%) contained E. histolytica/E. dispar cyst, while each of Cryptosporidium spp. and Cyclospora cayetanensis oocysts were observed in two samples (1.38%); also free living amoeba, ciliates and flagellates were detected in all samples. This

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