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Experimental Study on the Performance of Gradient Pores Density Metal Foam in a Rectangular Channel
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ABSTRACT<p>Various approaches are employed to enhance the heat transfer coefficient and Nusselt number inside the channels. One of the techniques employed for these enhancements is the utilization of porous media. In the current article, a practical investigation of forced convection heat transfer in a rectangular cross‐section channel (0.05 × 0.1 m<sup>2</sup>) with 0.25 m length is conducted. A heater with a heat flux range (450–6000 W/m<sup>2</sup>) is imposed under a copper plate, and the other sides are covered by insulation layers. The air is considered as a working fluid with <italic>Re</italic> (600–2100). The test section is fully filled with gradient pores per inch (PPI) metal foam by taking three different pores densities PPI (10, 20, and 40 PPI) and studying its effects on the temperature of copper plate, the local heat transfer coefficient, average Nusselt number, pressure drop, friction factor, and the performance factor. Three cases were studied inside the channel: one empty case and two with gradient pore density case A (40–20–10) PPI and case B (10–20–40) PPI. The results showed that inserting the metal foam inside the channel improves <italic>h</italic> and <italic>Nu</italic>. Case B appeared the best of this improvement in <italic>h</italic> and <italic>Nu</italic> by 12% and 25%, respectively, compared with that in case A. While the friction factor was the same for two cases A and B. So, the performance factor in case B showed an improvement of around 25% and 50% in comparison to case A and the empty case, respectively.</p>
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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of Mixed Convection in an Enclosure with a Cold Movable Top Wall and Hot Bottom Wall
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Mixed convection heat transfer to air inside an enclosure is investigated experimentally. The bottom wall of the enclosure is maintained at higher temperature than that of the top wall which keeps in oscillation motion, whereas the left and right walls are well insulated. The differential temperature of the bottom and top walls changed several times in order to accurately characterize the temperature distribution over a considerable range of Richardson number. Adjustable aspect ratio box was built as a test rig to determine the effects of Richardson number and aspect ratio on the flow behavior of the air inside the enclosure. The flow fields and the average Nusselt number profiles were presented in this wo

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
ORGANIZATIONAL VALUES AND ITS IMPACT ON STRATEGIC PERFORMANCE A field study a comparison between Two Universities of Baghdad & Al-Nahrain
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ABSTRACT

     The researcher seeks to shed light on the relationship analysis and the impact between organizational values in all its dimensions (Administration Management, Mission, relationship management, environmental management) and strategic performance (financial perspective, customer perspective, the perspective of internal processes, learning and development) in the presidency of Two Universities of Baghdad & Al-Nahrain, it has been formulating three hypotheses for this purpose.

      The main research problem has been the following question: Is there a relationship and the impact of bet

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
strategic direction and its impact on institutional performance An exploratory study in the Directorate General of Curricula
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The objective of the research is to determine the nature of the strategic direction of the institution and its impact on enhancing the indicators of institutional performance. The strategic direction is the main purpose for which it was found. Therefore, it is the main engine for all activities and tasks that the institution can carry out to achieve its objectives within the environment in which it operates. The promotion of corporate performance indicators is one of the major challenges that senior management must address in order to help the organization invest its human resources in the best possible way.

The research problem was determined by means of the intentional sample, consisting of (33) members

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Publication Date
Fri Aug 12 2022
Journal Name
International Journal Of Health Sciences
Employing documentaries in the Iraqi satellite channel to reveal the crimes of the former regime
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This study is one of the descriptive studies, where the researcher used the survey method, which seeks to provide an accurate and appropriate description of the main and sub-categories of the content of the research for television documentaries on the Iraqi satellite channel, relying on the research questions and objectives to analyze the content of the documentaries according to the approach referred to above. The objectives of the research were summarized to identify the function of the documentary programs in Al-Iraqiya channel to detect the crimes of the former regime, to know the frameworks highlighted by the documentary programs in Al-Iraqiya channel to reveal the crimes of the former regime, to identify the extent of the circ

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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
Wed Aug 26 2020
Journal Name
International Journal Of Research In Social Sciences And Humanities
THE ROLE OF A PROTEAN CAREER IN HIGH PERFORMANCE
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Publication Date
Fri Sep 15 2023
Journal Name
Journal Of Baghdad College Of Dentistry
Osseointegration effects of whey protein (histological and histomorphological observations): An experimental study on rabbits
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Background: Whey protein is the green-yellow colored, liquid portion of the milk, and it is also called the cheese serum, it is obtained after the separation of curd, during the coagulation of the milk. It contains a considerable amount of α-helix pattern with an evenly distributed hydrophobic and hydrophilic as well as basic and acidic amino acids along with their polypeptide chain. The major whey protein constituents include β-lactoglobulin (β-LG),α-lactalbumin (α-LA), immunoglobulins (IG), bovine serum albumin (BSA), bovine lactoperoxidase (LP), bovine lactoferrin (BLF) and minor amounts of a glycol macro peptide (GMP). Osseointegration can be defined as a process that is immune driven which leads to the formatio

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Publication Date
Sat Sep 01 2007
Journal Name
Al-khwarizmi Engineering Journal
Flutter Speed Limits of Cantilever Rectangular and Tapered Plates
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The aerodynamic and elastic forces may cause an oscillation of the structure such as the high frequency of the airfoil surfaces and the dynamic instability occurring in an aircraft in flight and failure may occur at a speed called flutter speed. In this work, analytical and numerical investigations of flutter limits of thin plates have been carried out. The flutter speed of rectangular plates were obtained and compared with some published results. Different design parameters were investigated such as aspect ratio, thickness and their effects on flutter velocity. It was found that the structural mode shape plays an important role in the determination of the flutter speed and the coupling between the bending and torsional mode is the main

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Publication Date
Thu Jan 30 2020
Journal Name
Journal Of Engineering
Study Impact of Unified Power Flow Controller (UPFC) on a Transmission Line Performance under Different Loading Conditions
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Now-a-days the Flexible AC Transmission Systems (FACTS) technology is very effective in improving the power flow along the transmission lines and makes the power system more flexible and controllable. This paper deals with the most robust type of FACTS devices; it’s a Unified Power Flow Controller (UPFC). Many cases have been taken to study how the system behaves in the presence and absence of the UPFC under normal and contingency conditions. The UPFC is a device that can be used to improve the bus voltage, increasing the loadability of the line and reduce the active and reactive power losses in the transmission lines, through controlling the flow of real and reactive power. Both the magnitude and the phase angle of th

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Publication Date
Fri May 19 2023
Journal Name
Revista Iberoamericana De PsicologÍa Del Ejercicio Y El Deporte
THE EFFECT OF SPECIAL EXERCISES ACCORDING TO A DESIGNED DEVICE IN DEVELOPING THE PERFORMANCE OF A KINETIC CHAIN ON THE BALANCE BEAM DEVICE
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