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An Experimental Study on the Effect of Shape and Location of Vortex Generators Ahead of a Heat Exchanger
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An experimental study is carried out on the effect of vortex generators (Circular and square) on the flow and heat transfer at variable locations at (X = 0.5, 1.5, 2.5 cm) ahead of a heat exchanger with Reynolds number ranging from 62000< Re < 125000 and heat flux from 3000 ≤ q ≤ 8000 W/m2 .

In the experimental investigation, an apparatus is set up to measure the velocity and temperatures around the heat exchanger.                     

The results show that there is an effect for using vortex generators on heat transfer. Also, heat transfer depends on the shape and location. The circular is found to be the best shape for enhancing heat transfer at location [Xm=0.5 cm] distance before heat exchanger is the best location for enhancing heat transfer. The square is the best shape for enhancing heat transfer at location [Xm=2.5 cm] distance before heat exchanger is the best location for enhancing heat transfer.

The results of flow over heat exchanger with vortex generators are compared with the flow over heat exchanger without vortex generators. Heat transfer around heat exchanger is enhanced (56%, 50%, 36%) at location            (X=0.5, 1.5, 2.5cm) respectively by using circular vortex generators without turbulator and heat transfer around heat exchanger is enhanced (39%, 42%, 51%) at location (X=0.5, 1.5, 2.5cm) respectively by using square shape vortex generators without turbulator.

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Strategic orientation and its reflection on the Learning organization: Survey study of a sample of Makers decision the Iraqi Ministry of Communications
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The current research focuses on the extent to which the strategic orientation(entrepreneurial orientation, customer orientation, technology orientation, learning orientation, and investment orientation) affects the learning organization (building common vision, systemic thinking, personal dominance, mental models, team learning)The first hypothesis to test the connection relation between research variables and The second hypothesis was to test the relationship between these variables. In order to ascertain the validity of the hypotheses, the research was based on a questionnaire questionnaire prepared according to a number of In addition to building a fifth sub-variable for the strategic orientation (investment orientation) based

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Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The risks of derivatives contracts and their reflections on the global financial crisis Analytical study in (Toronto – Dominion) bank
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The research tacklets the role of risks arising from the excessive use of derivative contracts for trading in financial crises, including the recent global financial crisis in (2008) which is known the mortgage crisis.

   In order to prove the hypothesis of the research, the risk index of derivative contracts has been chosed as expressed in the measure of (value at risk) to be the main field for testing the hypothesis of research. The duration of the contract  has been also chased  for (15) years between the years (2001- 2015), the period preceding the global financial crisis, while the second represents the period of time that followed. The research reached a number of conclusions, bu

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Publication Date
Wed Jun 01 2022
Journal Name
Journal Of The College Of Languages (jcl)
Free will between Slavery and Freedom: A Study of Linda Brent in Incidents in the Life of a Slave Girl by Harriet Jacobs
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Harriet Jacobs was a writer and a reformer. As a female writer in the nineteenth century, Jacobs wrote her narrative as a means of resisting the system of slavery. She wrote her book Incidents in the Life of a Slave Girl: Written by Herself, (1842) to reflect upon the exploitation of the black people and the need to change the hierarchal attitude that governs white/black relations. She was engaged in many abolitionist events and her anti-slavery approach appeared clearly in her writings. She shares Du Bios ideas about freedom and emancipation and the need for a political and cultural change. Thus, Du Bois’s theory provides a framework for her autobiographical novel where she portrays Linda Brent, the main character, a strong w

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Publication Date
Sun Jun 01 2008
Journal Name
Baghdad Science Journal
Laboratory study on the effects of nutrient enrichment on a phytoplankton population in Sawa Lake, Iraq
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Nutrient enrichment of Sawa lake water was made using different nitrogen and phosphorus concentrations during autumn and spring at three stations. Different concentrations of nitrogen, phosphorus and N: P ratios were used to test variations in phytoplankton population dynamics. Nitrogen at a concentration of 25 µmole.l-1 and N: P ratio of 10:1 gave highest phytoplankton cell number at all stations and seasons. A total of 64 algal taxa dominated by Bacillariophyceae followed by Cyanophyceae and Chlorophyceae were identified. The values of Shannon index of diversity were more than one in the studied stations.

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Publication Date
Thu Jun 01 2023
Journal Name
Magazine Aldhakwat Albedh
The methodology of Ibn Mamati (d. 606 AH) in his book Laws of Diwans - A Civilizational Study
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The book The Laws of Duwan of Mamati's Son (T, 606 E) His approach to his narratives is a topic of historical and civilized importance. The Fatimid Age of the People of Jehovah has expanded its influence and authority, including ministers, writers, doughnuts and foreshores. One of the Christian families that shined in the late Fatmi era was "Mamati", who lived in "Assiut" from Upper Egypt, then moved to Cairo, and enrolled in the service of the Fatimids, where their sons held important positions in State offices.Ibn Mamati became in charge of the Army Office and then added to it the Finance Office, which became the most important downs in Egypt. Through his work in the Duwan Law Books, this book was a living record of the Dawawans in the Ay

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Publication Date
Wed Nov 01 2023
Journal Name
Case Studies In Thermal Engineering
Augmenting the thermal response of helical coil latent-heat storage systems with a central return tube configuration
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Low-temperature stratification, high-volumetric storage capacity, and less-complicated material processing make phase-changing materials (PCMs) very suitable candidates for solar energy storage applications. However, their poor heat diffusivities and suboptimal containment designs severely limit their decent storage capabilities. In these systems, the arrangement of tubes conveying the heat transport fluid (HTF) plays a crucial role in heat communication between the PCM and HTF during phase transition. This study investigates a helical coil tube-and-shell thermal storage system integrated with a novel central return tube to enhance heat transfer effectiveness. Three-dimensional computational fluid dynamics simulations compare the proposed d

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Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
The Organiational challenges and thier effect of organiational rituals
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Administrative leaders conserned to understand the challenges which are faced their organizations and try to assimilate and adapt with the extent that achieves to it efficiency and effective- ess, and standing face to face to faceing any challenge.that threaten it’s existence thro- ugh using modern inputs reached to that level of these  challenges and applied the study on a sample deliberate random from teaching hospitals of the Directorate General for Health Baghdad Karkh, and the Directorate General for Health Baghdad Rusafa and the City of Medicine , The importance of t

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Publication Date
Fri Dec 31 2021
Journal Name
Political Sciences Journal
Pakistan: The most dangerous terrorist extremism hotbed (a study information, limitations, and factors)
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   Receipt date:10/27/2021    accepted date:12/15/2021     Publication date:31/12/2021

        Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

The phenomenon of extremist extremism (terrorism) was one of the most prominent issues that took a large space in the twenty-first century, in which cognitive motives were mixed with strategic and ideological motives, leading to the emergence of terrorist extremi

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Publication Date
Tue Jun 14 2005
Journal Name
Iraqi Journal Of Laser
Design and Operation of Mini-TEA CO2 Laser and Investigation of Preionization Effect
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A Mini-TEA CO2 laser system was designed and operated to obtain a pulse at 10.6 μm. Output energy of 30 mJ, with preionization pins, and pulse duration of 100ns were obtained. While an output energy of 6mJ and pulse duration of 100 ns in absence of pre-ionization were obtained. The system was operated with Ernest profile main-discharge electrodes. Dependencies of supply voltage and output laser energy on the pressure inside laser cavity were investigated as well as dependencies of supply voltage and output energy on the main capacitor(8CO2 : 8N2 : 82He :2CO). Efficiency of was calculated to be 4.4%.

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Publication Date
Wed Jun 07 2023
Journal Name
Journal Of Educational And Psychological Researches
The Impact of the Sowt Strategy on the Development of Systemic Intelligence among Students of the Ibn Rushd College of Education for the Humanities
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The aim of the current research is to identify the impact of the SWOT strategy on developing systemic intelligence among students of the Ibn Rushd College of Education for Human Sciences University of Baghdad / College of Education Ibn Rushd for Human Sciences. The current research community consists of (8590) male and female students, divided into (7) departments. The current research relied on one of the partial control designs, which is the design of non-random groups: experimental group and a control group with a pre and post-test. As for the research tool, It was represented by Tourmanin’s Systemic Intelligence Scale (2012) of (50) items that measure the eight components of systemic intelligence. The results of the Mann Whitney te

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