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The Convective Instability of BEK Family of Non-Newtonian Rotating Boundary-Layer Flows
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The BEK family of flows have many important practical applications such as centrifugal pumps, steam turbines, turbo-machinery and rotor-stator devices. The Bödewadt, Ekman and von Kármán flows are particular cases within this family. The convective instability of the BEK family of rotating boundary-layer flows has been considered for generalised Newtonian fluids, power-law and Carreau fluids. A linear stability analysis is conducted using a Chebyshev collocation method in order to investigate the effect of shear-thinning and shear-thickening fluids for generalised Newtonian fluids on the convective Type I (inviscid crossflow) and Type II (viscous streamline curvature) modes of instability. The results reveal that shear-thinning power-law fluids have a universal stabilising effect across the entire BEK family of flows. However, the convective instability characteristics for the shear-thinning and shear-thickening Carreau fluids are affected by the value of the relaxation parameter k. The results reveal that Shear-thinning Carreau fluids have a small destabilising effect, while shear -thickening fluids have a slight stabilising effect on the Type I and Type II mode for the BEK family of flows when k =100. On the other hand, shear-thinning and shear-thickening Carreau fluids are found to have stabilising and destabilising effect, respectively for optimal relaxation value ko. The results are presented in terms of neutral curves and growth rates. Furthermore, an energy analysis is presented to gain insight into the underlying physical mechanisms behind the stabilising effects of generalized Newtonian fluids. In conclusion, the use of shear-thinning power-law and Carreau fluids with optimal value ko can be recommended to reduce skin-friction drag in enclosed rotor-stator devices for the entire BEK family of flows.

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Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Study on the Effect of the Curvature of Solar Collector on Wind Loading Coefficients and Dynamic Response of Solar Collector
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In the current research, the work concentrated on studying the effect of curvature of solar parabolic trough solar collector on wind loading coefficients and dynamic response of solar collector. The response of collector to the aerodynamic loading was estimated numerically and experimentally. The curvature of most public parabolic trough solar collectors was investigated and compared. The dynamic response of solar collector due to wind loading was investigated by using numerical solution of fluid-structure interaction concept. The experimental work was done to verify the numerical results and shows good agreement with numerical results. The numerical results were obtained by using finite element software package (ANSYS 14). It was found

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Analysis of the structure of salaries of public sector workers for strategic planning purposes An analytical study in the general body of groundwater
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The research discusses the problem of salaries in the public sector in terms of the process of analyzing its structure and the possibility of benefiting from the information provided by the analysis process for the strategic planning process, and the General Authority for Groundwater has been adopted and one of the formations of the Ministry of Water Resources, which is centrally funded, to represent the salary structure of its employees (1117) employees be a field of research, as the salary structure in it was analyzed for the period between (2014-2019) using the quantitative approach to analysis and by relying on a number of statistical tools in the analysis process, including mathematical circles, upper limits, lower limits, p

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Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
The role of corporate merger in achieving synergy (Analytical research in a sample of companies of the Iraqi Ministry of Industry and Minerals)
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The research aims to shed light on the recent experience in the Iraqi business environment, which is the experience of the merger. To evaluate a recent experience in an important sector of the Iraqi business sectors, namely the industrial sector to enable decision-makers to review that experience to judge the extent of its success and address some of the lapses that experience that by measuring synergies can be judged on the success of the merger experience or not. The research community is the governmental industrial sector. The research sample included six cases of merger (14) companies before the merger. The Holt method was used to predict the net sales and total cost values ​​before the merger as if it were not merged. Th

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Publication Date
Thu Dec 15 2022
Journal Name
Al-academy
Strategies of brain-based learning theory and its impact on the achievement of students of the Department of Art Education in Teaching Methods
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The aim of the current research is to reveal the effect of using brain-based learning theory strategies on the achievement of Art Education students in the subject of Teaching Methods. The experimental design with two equal experimental and control groups was used. The experimental design with two independent and equal groups was used, and the total of the research sample was (60) male and female students, (30) male and female students represented the experimental group, and (30) male and female students represented the control group. The researcher prepared the research tool represented by the cognitive achievement test consisting of (20) questions, and it was characterized by honesty and reliability, and the experiment lasted (6) weeks

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Publication Date
Thu Aug 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Viral Marketing Technologies on Consumer Behavior _ A survey of a sample of students from the college of administration and economics
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Abstract:

Viral marketing has become one of the modern strategies adopted by organizations in the marketing of products and services. The idea of viral marketing focuses on the social relations between individuals and groups. As a result of the technological development, most organizations have resorted to using the Internet and its applications and social media to market and promote their products. To reach the largest number of consumers to display their products and services in many ways, including text, audio, visual or video and thus affect the behavior of the consumer.

The problem of the study was the following question (do viral marketing technologies have an impact on consumer behavior?)

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Publication Date
Wed Mar 23 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of a strategy (fahs) in the development of grammar skills of a sample of secondary school Female Students in Saudi Arabia
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The aim of the present research is to measure the degree of strategic effectiveness (fahs) in the development of grammar skills of high school students in the Kingdom of Saudi Arabia and to achieve the goal of the researcher the researcher used the semi-experimental approach; On ten arbitrators specializing in grammar, morphology, curricula and methods of teaching the Arabic language. After confirming the validity of the guideline, the researcher prepared an achievement test consisting of (22) paragraphs of the type of short answer and multiple choice. The researcher trained a teacher to apply the strategy to the experimental research sample using the (screening) component of (30) students, and the same parameter taught the control sampl

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Publication Date
Sun Sep 01 2013
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Impact of applying the third of basel committee11 conventions(market disciplin) in the efficient of significance components for factors of banking capital risks
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We have focused the research problem through an assessment of the applicability of the third pillar of the decisions of the Basel Committee 11 (market discipline) or not and its impact on both the adequacy of bank capital, supervisory oversight and banking risks and the statement weaknesses commitment banking institutions and which in turn lead to the stability of the financial system as a whole.                         .
The research is important statement on the importance of big capital in the banking business and the attributes of a role in the absorption of losses suffered by the bank, which reflects the willin

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Publication Date
Tue Dec 11 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Impact of spastic cerebral palsy upon the quality of life of children under the age of 12 years in Erbil City: parents’ reports
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Objectives: This study aims to assess the quality of life of cerebral palsy children less than 12 years old reported by
parents in Erbil city/Iraq.
Methodology: A descriptive study was conducted during 2014, to describe the quality of life of cerebral palsy
children. One hundred mothers have cerebral palsy children were participated in this study. The study took place at
Helena Center for handicapped children in Erbil City. Questionnaire was used to collect data, which consists of two
main parts. The first part is divided into two sections; section one was described the mothers’ demographic
characteristics, while the second section was for identifying the demographical characteristics of cerebral palsy
children. Th

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Publication Date
Mon Jun 30 2014
Journal Name
Modern Sport
Communication and decision-making skills for managers from the point of download of employees in the Faculty of Mathematical Education – University of Baghdad
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The research aims to identify the strengths and weaknesses in communication skills and decision-making among managers of the Faculty of Physical Education - University of Baghdad from the perspective of staff and faculty members. May be the research community to all employees (faculty and staff) all in the Faculty of Physical Education - Baghdad University for the academic year 2012-2013 and totaling 208 faculty members and 123 staff members, has been selected a random sample of members of the faculty's (100 ) and employees (50) and distributed them to identify the study and collecting them (75) The identification of the faculty and (40) of the staff, and ruled out (35) to identify the lack of validity. After having identified researcher co

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Crossref
Publication Date
Sat Jul 13 2019
Journal Name
Journal Of Northern Europe Academy For Studies & Research Denmark
The relationship between motor response speed and performance of the volleyball smash skill for students at the University of Baghdad - College of Physical Education and Sports Sciences
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