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Experimental study of natural convection heat transfer on an enclosure partially filled porous medium heated from below by constant heat flux
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This study reports on natural convection heat transfer in a square enclosure of length (L=20 cm) with a saturated porous medium (solid glass beads) having same fluid (air) at lower horizontal layer and free air fill in the rest of the cavity's space. The experimental work has been performed under the effects of heating from bottom by constant heat flux q=150,300,450,600 W/m2 for four porous layers thickness Hp (2.5,5,7.5,1) cm and three heaters length δ(20,14,7) cm. The top enclosure wall was good insulated and the two side walls were symmetrically cooled at constant temperature. Four layers of porous media with small porosity, Rayleigh number range (60.354 - 241.41) and (Da) 3.025x10-8 has been investigated. The obtained data of temperature from testing rig are used to extract the temperature distribution, local Nusselt number and average Nusselt number. Moreover, a comparison between the numerical result of the same problem published recently and present experimental results has been executed and discussed. It is evinced that; the heat transfer and fluid flow are affected by thickness of porous layer and be maximum at porous layer thickness (0.25L) with larger heater length(20cm) and heat flux (q= 600 Watt/m2) which is approximately (180%) for the average Nu when compared with (Hp=0.75L). Also, the effect of the increasing in heater length (δ) on the averaged heat transfer enhancement is more pronounced for large heater size and 25% of average enhancement is achieved for (δ=20cm) compared to (δ=7cm). However, the greater temperature distribution is found at Hp=2.5cm and 5cm at bottom and first quarter of the cavity (heater surface height Y=0 cm and Y=5 cm) respectively and minimum temperature at top (insulation wall Y=20 cm). Nearly, same shape for heat transfer for different case with clearly difference at small heater (δ=7cm).

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Publication Date
Mon Mar 01 2021
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of the Influence of Nanoparticles Additive to Diesel Fuel on the Emission Characteristics
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The present experimental work is conducted to examine the influence of adding Alumina (Al2O3) nanoparticles and Titanium oxide (TiO2) nanoparticles each alone to diesel fuel on the characteristic of the emissions. The size of both Alumina and Titanium oxide nanoparticles which have been added to diesel fuel to obtain nano-fuel is about 20 nm and 25 nm respectively. Three doses of (Al2O3) and (TiO2) were prepared (25, 50, and 100) ppm. The nanoparticles mixed with gas oil fuel by mechanical homogenous (manual electrical mixer) and ultrasonic processor. The study reveals that the adding of Aluminum oxide (Al2O3) and Titanium oxide (TiO2) to g

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Publication Date
Thu Jun 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Experimental Study of Thermophysical Properties of TiO2 Nanofluid
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Titanium-dioxide (TiO2) nanoparticles suspended in water, and ethanol based fluids have been prepared using one step method and characterized by scanning electron microscopy (SEM), and UV–visible spectrophotometer. The TiO2 nanoparticles were added to base fluids with different volume concentrations from 0.1% to1.5% by dispersing the synthesized nanoparticles in deionized water and ethanol solutions. The effective thermal conductivity, viscosity and pH of prepared nanofluids at different temperatures from 15 to 30 oC were carried out and investigated. It was observed that the thermal conductivity, pH, and viscosity of nanofluids increases with the increase in TiO2 nanoparticle volume fraction

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Publication Date
Wed Jun 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
Estimating Stock Returns Using Rough Set Theory: An Exploratory study With An Evidence From Iraq Stock Exchange
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‎ This research aims to estimate stock returns, according to the ‎Rough Set Theory ‎approach, ‎test ‎its effectiveness and accuracy in predicting stock returns and their potential in the ‎field of ‎financial ‎markets, and rationalize investor decisions. The research sample is totaling (10) ‎companies traded at Iraq Stock Exchange. The results showed a remarkable ‎ ‎Rough Set Theory application in data reduction, contributing to the rationalization of ‎investment ‎decisions. The most prominent conclusions are the capability of rough set theory ‎in ‎dealing with financial data and applying it for forecasting stock ‎returns.‎The ‎research provides those interested in investing stocks in financial

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Publication Date
Tue Jun 01 2021
Journal Name
Journal Of The College Of Languages (jcl)
Heated and silent adoration in the novel of " Desert of Love" by Francois Mauriac: Passions dévorantes et cachées dans Le Désert de lʼAmour de François Mauriac
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  François Mauriac’s novel The Desert of Love (1949) puts the reader before an experienced sociologist who is skillfully able to analyze the most mysterious human emotions and feelings.  The writer's starting point is that people are similar in feelings but different in behavior. He severely criticized the aristocratic class and uncovered its defects and faults.

         The novelist presents Courege's family as an example of the aristocratic class. It is a family torn by hatred, selfishness and disagreements due to absence of intimacy and love. This poisoned environment pushes the father and his son, Raymond, to search away for emotional ventures and banned relations

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Publication Date
Sun Dec 12 2010
Journal Name
Journal Of Planner And Development
A documentary study of natural resources and ways of protecting them
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The problem of research is that there are ways to protect and sustain environmentally important sites in Iraq. There are no documentary sources for these sites, such as the natural landscape of natural and important natural resources, which suffer from severe environmental neglect

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Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
The effect of current density on the structures and photoluminescence of n-type porous silicon
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Porous silicon (PS) layers were formed on n-type silicon (Si) wafers using Photo- electrochemical Etching technique (PEC) was used to produce porous silicon for n-type with orientation of (111). The effects of current density were investigated at: (10, 20, 30, 40, and50) mA/cm2 with etching time: 10min. X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon. The maximum crystal size of Porous Silicon is (33.9nm) and minimum is (2.6nm) The Atomic force microscopy (AFM) analysis and Field Emission Scanning Electron Microscope (FESEM) were used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of p

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Publication Date
Thu Jan 31 2019
Journal Name
Journal Of Engineering
Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material
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In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant

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Publication Date
Wed Jun 01 2005
Journal Name
Alustath Journal For Human And Social Sciences
An evaluation study of Islamic websites on the Internet
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The study aims to introduce the Islamic sites available on the Internet and determine the criteria that contribute to evaluating these sites to indicate their value, topics, and services, while evaluating a simple random sample of the general Islamic sites, which number (35) sites. The results were presented in (8) tables. The study concluded To a set of conclusions, including: (465) “Islamic” websites were seized during the research period, and they are constantly increasing. They were classified according to the name of the website (domain name) com, org, net, edu, and also according to topics such as general Islamic websites and websites of holy places. Mosques, sites of sheikhs, etc. Among the best general Islamic websites are: Isla

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Publication Date
Wed May 15 2024
Journal Name
Ieee Sensors Journal
Surface Crack Size Estimation Based on Quantification and Decoupling of Magnetic Flux Leakage (MFL) Signals of Circular Array Sensors
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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Baghdad College Of Dentistry
A Comparative Evaluation of Apical Seal Associated with Ultrasonic Retrograde Cavities Filled with Bioactive Material ( in Vitro Study )
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Background: The aim of this study was to evaluate and compare the apical microleakage around retrograde cavities prepared with ultrasonic technique and filled with (Biodentineâ„¢) Materials and methods: 40 extracted single rooted human permanent maxillary teeth with mature apices were selected. The roots were prepared chemo-mechanically using k-files with crown-down technique and then obturated with lateral condensation gutta-percha technique. Teeth were divided into four main groups according to the cavity preparation method either manual or ultrasonic technique: Group A (n=10): A class I retrograde cavity at root end was prepared with traditional handpeice equipped and placement of Biodentine with manual condensation. Group B (n=10):

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