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Numerical Investigation of Natural Convection Heat Transfer in Partially Filled Porous Enclosure Subjected to Constant Heat
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Steady natural convection in a square enclosure with wall length (L= 20 cm) partially filled by saturated porous medium with same fluid (lower layer) and air (upper layer) is investigated. The conceptual study of the achievements of the heat transfer is performed under effects of bottom heating by constant heat flux (q=150,300,450,600W/m2 ) for three heaters size (0.2,0.14,0.07)m with symmetrically cooling with constant temperature on two vertical walls and adiabatic top wall. The relevant filled studied parameters are four different porous medium heights (Hp=0.25L,0.5L, 0.75L, L), Darcey number (Da1) 3.025×10-8 and (Da2) 8.852×10-4 ) and Rayleigh number range (60.354 - 241.41), (1.304×106 – 5.2166×106 ) for Da1 and Da2 cases respectively. Numerically, COMSOL Multiphysics 5.5a® based on the Galerkin finite element method is used for solving the governing equations with depending Brinkman- Darcy extended mode for porous media region. The results show that, effects of increasing the Rayleigh number on the temperature profile besides the progressively increasing the average Nusselt number. Moreover, symmetrical distribution of local Nu along the bottom heated wall and it is be minimum at midpoint of bottom. Also, the heat transfer and fluid flow are affected by thickness of porous layer and are maximum at porous layer thickness (0.25L) which clearly observed with large heater size to be approximately (93%) for the average Nu. Generally, the heat transfer is enhanced for large Darcy number (8.852×10-4 ) and influenced by the convection regime improvement while it is mainly conduction mode for (Da1) for all Raleigh number with a little effect of convection when increase (Ra).

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Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Investigation of Size-dependent Nonlinearity of Ag Nano-Fluids using Self-defocusing Technique
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In this work, the effect of different particle size on the nonlinear optical properties of silver nanoparticles in de-ionized water was studied. The experimental observation of the far field diffraction patterns by CCD camera in two and three dimensions. The maximum change of nonlinear refractive index and the relative phase shift were calculated. The self-defocusing technique was used with a continuous-wave radiation from DPSS Blue laser .The wavelength is 473 nm with an output power of 270 mW. All the Ag colloids samples containing the sizes 15, 30, 50, and 70 nm of silver nanoparticles used in the study were chemically prepared. It was found that the nonlinear refractive index is a particle size dependent and of the order of 10-7 cm2/

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Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Engineering
Numerical and Experimental Investigations of the Effect of PVD and Vacuum Pressure on the Degree of Saturation
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    Soft clays are generally characterized by low shear strength, low permeability and high compressibility. An effective method to accelerate consolidation of such soils is to use vertical drains along with vacuum preloading to encourage radial flow of water.  In this research numerical modeling of prefabricated vertical drains with vacuum pressure was done to investigate the effect of using vertical drains together with vacuum pressure on the degree of saturation of fully and saturated-unsaturated soft soils.  Laboratory experiments were conducted by using a specially-designed large consolidometer cell where a central drain was installed and vacuum pressure was applied. All tests were conducted

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Publication Date
Wed Mar 30 2016
Journal Name
College Of Islamic Sciences
Message in detail what was said in the parents of the Prophet  Ibn Kamal Pasha (d. 940 e) study and investigation
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After Hamdallah and his success on the realization of this manuscript (a letter in detail what was said in the parents of the Prophet  Ibn Kamal Pasha (d. 940 e) study and investigation I will review some of the results reached in the realization of this manuscript:
1. The hadiths mentioned in this manuscript are mostly placed or weak.
2 - We are not entitled to speak about the silence of the law for saying Almighty ﭽ ﮮ ﮯ ﮰ ﮱ ﯓ ﯔ ﯕ ﯖ ﯗ ﯘ ﯙ ﭼ Table: 101.
3 in which harm to our Holy Prophet  وله تع ﮂ ﮃ ﮄ ﮅ ﮆ ﮈ ﮉ ﮊ ﮋ ﮌ ﮍ ﮎ ﭼ parties: 57.
4 Because the parents of the Prophet  of the people of the period ordered them to God for the Almighty ﭽ ﯨ ﯩ ﯪ ﯫ ﯬ

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Publication Date
Tue Mar 05 2024
Journal Name
Scientific Reports
Mesoporous Ag@WO3 core–shell, an investigation at different concentrated environment employing laser ablation in liquid
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Abstract<p>In this study, silver-tungsten oxide core–shell nanoparticles (Ag–WO<sub>3</sub> NPs) were synthesized by pulsed laser ablation in liquid employing a (1.06 µm) Q-switched Nd:YAG laser, at different Ag colloidal concentration environment (different core concentration). The produced Ag–WO<sub>3</sub> core–shell NPs were subjected to characterization using UV–visible spectrophotometry, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive spectroscopy, electrical analysis, and photoluminescence PL. The UV–visible spectra exhibited distinct absorption peaks at around 200 and 405 nm, which attributed to the occurrence of surface Plasmon reson</p> ... Show More
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Publication Date
Sun Aug 01 2021
Journal Name
Safety Science
Evaluating OSHA’s fatality and catastrophe investigation summaries: Arc flash focus
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Publication Date
Fri Jan 01 2021
Journal Name
Desalination And Water Treatment
Elucidation of the removal of trivalent and divalent heavy metal ions from aqueous solutions using hybrid-porous composite ion-exchangers by nonlinear regression
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Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
Influence of Varying Temperature and Concentration on Magnetohydrodynamics Peristaltic Transport for Jeffrey Fluid with a Nanoparticles Phenomenon through a Rectangular Porous Duct
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A mathematical model constructed to study the combined effects of the concentration and the thermodiffusion on the nanoparticles of a Jeffrey fluid with a magnetic field effect the process of containing waves in a three-dimensional rectangular porous medium canal. Using the HPM to solve the nonlinear and coupled partial differential equations. Numerical results were obtained for temperature distribution, nanoparticles concentration, velocity, pressure rise, pressure gradient, friction force and stream function. Through the graphs, it was found that the velocity of fluid rises with the increase of a mean rate of volume flow and a magnetic parameter, while the velocity goes down with the increasing a Darcy number and lateral walls. Also, t

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Publication Date
Sat Jan 01 2022
Journal Name
Optik
Plasma parameters of Au nano-particles ablated on porous silicon produced via Nd-YAG laser at 355 nm for sensing NH3 gas
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a laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the rod that appears for Au NPs, in addition to that, TEM has been an indication of the fact that syn

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Publication Date
Thu Nov 04 2021
Journal Name
Optik - International Journal For Light And Electron Optics
Plasma parameters of Au nano-particles ablated on porous silicon produced via Nd-YAG laser at 355 nm for sensing NH3 gas
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The current study aimed the syntheses and characterizations of Gold nanoparticles (Au NPs) using a laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the

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Publication Date
Thu Aug 01 2024
Journal Name
Materials Science In Semiconductor Processing
Enhancing charge transfer in 0D/2D cobalt sulfide/boron-doped graphitic carbon nitride heterojunction photocatalyst for degradation of organic pollutants under LED illumination
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Semiconductor-based photocatalytic processes are widely applied as ecofriendly technology for degrading organic pollutants. Establishing photocatalytic heterojunctions with Z-type photocarriers transfer pathways is projected to be a superb strategy to enhance photocatalytic behavior. In this paper, novel and stable (0D/2D) heterojunctions of CoS-embedded boron-doped g-C3N4 (CoS/BCN) with a high rate of charges transfer/separation were assembled for degradation of malachite green dye (MG). The CoS/BCN photocatalyst achieves a photodegradation efficiency of 96.9 % within 1 h of LED illumination, which is 2.5 and 1.4-fold enhancement compared with bare g-C3N4 and BCN, respectively. Besides, the results of species-trapping trials exhibited that

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