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Experimental Study on the Effect of Using Metallic Brushes on the Charging and Discharging Time of Thermal Energy Storage Unit
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Phase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time for melting for (ϵ=90%) up to 4.49 times as compare with the case of no brush. It can be seen that the addition of brushes in air side helped to reduce the solidification time and increase the convection heat transfer coefficient as the brush void fraction decreased. Also the minimum velocity (v = 1 m/s) gave maximum outlet temperature.

 

 

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Publication Date
Sat Nov 27 2021
Journal Name
Lecture Notes In Civil Engineering
An Experimental Study on Concavely Curved Soffit Reinforced Concrete Beams Externally Bonded with FRP
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Publication Date
Fri Jul 01 2022
Journal Name
Iraqi Journal Of Science
The Solar Attraction Effect on Orbital Elements of the Moon
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In this paper, the solar attraction effect on the Moon orbital elements had been studied. The solar attraction considered a third body perturbation. The initial values of the Moon orbital elements at 2015-1-21.5 which are used (semi major axis=380963.78 km, eccentricity =0.056o, Eular angles (Ω=30°, ω=40°, , i=18.4°). The Moon in a perigee of its orbit at the initial time. A program which designed, was used to calculate the Moon position ,velocity and orbital elements through the years (2015-2035). The position and velocity components of the Moon were calculated by solving the equation of Kepler for elliptical orbit using Newton Raphson's method for (1000) periods and hundred steps of time for each period. The results show a secular

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Publication Date
Wed Jan 01 2020
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees20
Studying the effect of the annealing on Ag2Se thin film
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Publication Date
Mon Dec 16 2024
Journal Name
Light & Engineering
The Design and Experimental Realization of a Laser-Based Heating System Using Recycled Laser Module
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Laser is a powerful device that has a wide range of applications in fields ranging from materials science and manufacturing to medicine and fibre optic communications. One remarkable

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Publication Date
Sat Jun 03 2023
Journal Name
Iraqi Journal Of Science
Study of Thermal Stability of Tetraphenanthroporphyrazine and SomeMetal Complexes By Thermogravimetric Analysis .
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The thermal stability of previously prepared tetraphenanthroporphyrazine (TPPH2) and its complexes with VO(IV) , Co(II) , Cu(II) , Zn(II) , Mg(II) , Ca (II) ions were studied by thermogravimetric analysis (TG & DTG) at temperature range (20-1000oC). The results indicated that these compounds have a high thermal stability comparable to those of phthalocyanine compounds (PC) and higher than those of hemiporphyrazine compounds (HP) . In general metal complexes were more stable than parent ligand . Data of magnetic susceptibility and electrical conductivity were also obtained as further support for the studied compoundes .

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Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Effect of thickness on the structure, morphology and A.C conductivity of Bi2S3 thin films
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Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic

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Publication Date
Wed May 25 2022
Journal Name
Iraqi Journal Of Science
The Effect of Cold Plasma on pH, Creatine, and the Concentration of the Most Trace Elements in Human's Nails by Using X-ray Fluorescent Method
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     The aim of this study is to determine the effect of cold plasma on nails pH, creatine levels and the accumulative of some trace elements in humans nails. Creatine levels in the blood, as well as pH and trace elements, were measured before and after (1, 2) months of plasma exposure in both gender (men and women) between the ages of 22 and 25 years. Nails are exposed to  cold plasma with a voltage of (175 volts) and (2 gas flow). After one month of exposure, there was no significant change in the levels of all parameters, but after 2 months, the concentration of creatine and pH had  reached  a near- neutral value. In both men and women,  calcium concentration increased and showed a positive response to cold plasma, while the v

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Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
The effect of heat treatment on the optical properties of organic semiconductor (NiPc/C60) thin films
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Thin films of the blended solution of (NiPc/C60) on glass substrates were prepared by spin-coated method for three different ratios (100/1, 100/10 and 100/100). The effects of annealing temperature and C60 concentration on the optical properties of the samples were studied using the UV-Vis absorption spectroscopy and FTIR spectra. The optical absorption spectrum consists of two main bands, Q and B band, with maxima at about (602-632) nm and (700-730) nm for Q1 and Q2 respectively, and (340-375) nm for B band. The optical energy gap were determined from optical absorption spectra, The variation of optical energy gap with annealing temperature was nonsystematic and this may be due to the improvement in crystal structure for thin films. Whi

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Publication Date
Fri Nov 15 2024
Journal Name
Iraqi Journal Of Science
Study of the Spectral Energy Distribution Model of the Protoplanetary Disk Geometric around the Brown Dwarf CFHT-BD-Tau 4
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The accretion circumstellar disk of young stars and the Brown dwarf plays an essential role in the formation and evaluation of the planet. Our main work in this paper is to investigate the geometrical shape model for the protoplanetary disk around one of the Brown Dwarfs. The photometric measurements for the brown dwarf CFHT-BD-Tau 4 were extracted from the Vizier archive. We used a numerical simulation to build a model of the spectral energy distribution of our target CFHT-BD-Tau 4. The spectral energy distribution model was fitted with observational data for the brown dwarf CFHT-BD-Tau 4. A transitional disk has been assumed around CFHT-BD-Tau 4. We obtained physical properties of the two disks and the size of the gap between them

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Publication Date
Tue Jun 01 2021
Journal Name
Iraqi Journal Of Physics
Influence of Laser Energy on the Structural and Optical Properties of (CdO):(CoO) Thin Films Produced by Laser-Induced Plasma (LIP)
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In this work, (CdO)1-x (CoO)x thin films were prepared on glass slides by laser-induced plasma using Nd:YAG laser with (λ=1064 nm) and duration (9 ns) at different laser energies (200-500 mJ) with ratio (x=0.5), The influence of laser energy on structural and optical properties has been studied. XRD patterns show the films have a structure of polycrystalline wurtzite. As for AFM tests results for the topography of the surface of the film, where the results showed that the grain size and the average roughness increase with increasing laser energy. The optical properties of all films were also studied and the results showed that the absorption coefficient for within the wavelength range (280-1100 nm), The value of the optical power gap fo

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