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Experimental and Numerical Research on Flow-Induced Vibration in Valves
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Abstract  

All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of real geometrical, operational, and boundary conditions are simulated to obtain best similarity with real operation conditions. Comparisons performed between experimental data and numerical results (one-way and two-way simulation) to verify the results. The main conclusion was drawn from the study that the dominant source of vibration for valve is the water pulsation in addition to amount of water hammering. In addition, the main source of water pulsation in globe valve is the vortex shedding and pressure difference between upstream and downstream of valve. The vibration amplitude was increased with increasing flow rate until to be maximum when the flow rate around 30% and then decreased until flow rate reaches to around 85% and then trends to be constant.

Keywords: Flow-induced vibration, vortex shedding, pressure pulsation, valve, finite element, ANSYS, fast Fourier transform (FFT).

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Publication Date
Tue Nov 09 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Enhancing the effectiveness of the company in light of the practice of leadership empowerment: Applied research in the National Insurance Company
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The aim of the research is to demonstrate the importance of leadership empowerment in its dimensions (knowledge, participation in decision-making, incentives, trust between the leader and subordinate, delegation of authority and communication) and its impact on enhancing the effectiveness of the company in its dimensions Represented by (achievement of objectives, quality of insurance service, adaptation to work environment and job satisfaction), by adopting the questionnaire as a main tool in collecting data from officials in the National Insurance Company, numbering (56) surveyed in job sites (section manager, division official and unit official) Their answers were analyzed using the SPSS statistical program in calculating the a

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of accounting disclosure in the efficient performance of the tax authority: Applied research in the General Commission for Taxes
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               Starting with a problem of the weakness of accounting disclosure in some companies administration when preparing and presenting the financial reports which are submitted to the Tax authority. This problem impacts on Tax authority performance (The effect on the quality of the performance of the tax authority), because of the lack of conviction for the information contained in those reports, and the  failure to achieve accurate results in tax authority performance that leads to a negative impact on determining taxable income and affect tax revenue, as well as negative impact on  determining taxable income and affect tax revenue, as well as negati

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Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Employment of critical success factors in achieving the strategy Entrepreneurship: A field research for my company Oil Products Distribution and Midland Refineries
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Abstract

        The critical success factors of the means of the most modern in determining the main directions for organizations to achieve competitive advantage. and can be a critical success factors in organizations that overlap in the functional areas of the organization. that successful organizations use these factors to get to the uniqueness and distinction. as the entrance of critical success factors with the capacity Evaluative phase correction because discovery increases the perception of managers of what is important to the organization and using them to get to the Strategic Entrepreneurship. as it begins in terms of permanence of success and

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Publication Date
Fri Apr 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Organizational renewal capabilities with the framework of Strategic leadership An Analytical comparative Research At some Hospitals in Baghdad
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Strategic leadership is the main source to enable organizations of excellence in light of turbulent environment, it is also the capabilities of organizational renewal organization’s ability to anticipate changes that take place or possible occurrence.

As a result of the many changes that characterize the environment where they operate researched hospitals, many of them began looking for ways to help it achieve a lot of their own competitive advantages.

The subject of organizational renewal capabilities of subjects that are not obvious interest in the Arab environment in general and Iraq in particular, and longer. The problem of the research and field presence of deficiencies in

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Publication Date
Fri Sep 30 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Dimensions of organizational immunity and its relationship Enhancing the strategic capabilities of the company: applied research in the Iraqi General Insurance Company
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The aim of the research is to diagnose the nature of the relationship between the dimensions of organizational immunity with its dimensions represented by (organizational memory, organizational DNA, organizational learning) in enhancing the strategic capabilities of the company with its dimensions represented by (marketing capabilities, administrative capabilities, technological capabilities, creative capabilities), and the degree of arrangement of those dimensions According to priority, as well as revealing the differences in the respondents’ response to the two variables according to the personal and functional variables, and the importance of the expected results, the researchers adopted the questionnaire as a tool for collecting da

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Publication Date
Sun Jun 30 2019
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
New Study of Mgo Nps in Drilling Fluid to Reduce Stick-Slip Vibration in Drilling System
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Stick-slip is kind of vibration which associated with drilling operation in around the bottom hole assembly (BHA) due to the small clearance between drill string & the open hole and due to the eccentric rotating of string. This research presents results of specific experimental study that was run by using two types of drilling mud (Fresh water Bentonite & Polymer), with/without Nanoparticle size materials of MgO in various ratios and computes the rheological properties of mud for each concentration [Yield point, plastic viscosity, Av, PH, filter loss (30 min), filter cake, Mud Cake Friction, Friction Factor]. These results then were used to find a clear effects of Nanoparticle drilling mud rheology on stick - slip strength by sev

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Publication Date
Sat Oct 01 2022
Journal Name
Al–bahith Al–a'alami
PRESS COVERAGE OF CRISES: (A Research Drawn from a Doctoral Thesis)
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Media is one of the main and effective factors; and it is a tool of crisis management equipment. Media is one of the most dangerous, effective and decisive weapons in modern conflicts; a tool for making events and influencing their events and trends as a means of reporting as the enormous capabilities of media which help media to move very quickly, and cross borders; and overcome obstacles, through many means of audio, reading and visual. As its ability, moreover, to influence the psychological and intellectual control of communities, and behaviors.

Intelligent media is, then, used in crises management and coverage. Crises have been existed with the presence of man on Earth. Thei

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Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The impact of financial reporting of earnings per share on the quality of financial reporting
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This research deals with the case of the Iraqi joint-stock companies listed on the Iraq Stock Exchange study in terms of compliance with the requirements of IAS 33 "Earnings per share" and the research problem Alrtash concentrated in a statement the commitment of those companies the requirements of the International Standard 33, which may adversely affect the quality of financial reporting where and in particular the quality of accounting information and content of the primary and secondary characteristics make them be of interest to the decisions of its users, so the aim of this research to the statement of financial reporting earnings per share on the quality of financial reporting in listed shareholding in Iraq Stock Exchange

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Reflection of applying the requirement of IFRS 9 regards impairment of Banks loans on earning management in Iraqi Banks
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Impairment of financial assets defined according to IFRS 9 as the difference between all contractual cash flows that are due to an entity in accordance with the contract and all the cash flows that the entity expects to receive, the entity should estimates all the cash flows through looking to the contract terms during the life time period of the assets or for shorter period if possible, the cash flow should include the amounts of selling any collateral taken or any other enhancement. On the other hand, the Central bank of Iraq guidelines regards impairment differ from the IFRS 9 that’s does not consider the collateral value on calculating the impairment that’s effects on the net profit through recognizing exaggerated loss an

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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Leadership Skills and their Impact on Strategic Planning: Applied Research in the Iraqi Ministry of Planning
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The present search addressed the " leadership skills and their impact on strategic planning " Where has the objective of leadership skills and strategic planning of increasing importance at the present time , for being fairly modern topics ,which have a tremendous impact on the success of organizations..                                                                        &n

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