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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
Wed Apr 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Dimensions of performance to provide nursing services: a comparative analytical research in Baghdad of Rusafa Health Organization
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     This research aims to study the performance of operations to provide nursing services, which included dimensions (quality, timeliness, leadership skills, behavioral manifestations, relationships with others, problem-solving and decision-making, job performance) and its effects in nursing performance. The research to prove the value of the performance of service delivery processes dimensions by nursing staffs working in Iraqi hospitals, nursing and measuring performance. To find out the nature of nursing services, and a comparison between hospitals to measure the extent of the application dimensional among themselves, and that by relying on the dimensions of a global study, which was measu

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Publication Date
Wed May 01 2019
Journal Name
Journal Of The College Of Education For Women
The Complex Relationship Between Darwinism, Geopolitics and Geographic Colonization Research the Relationship Between Geopolitics and Ethnography
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Research on geopolitical and geopolitical studies relates to a range of sciences that can be called auxiliary sciences, such as political science, international relations in particular, and history, but their focus is rarely on science and ethnography

That the issues and problems of the world today has become so large and complex that does not allow a specific field or knowledge to solve one of the need for the newly known knowledge integration (geopolitics and geopolitics) in particular to move towards cognitive integration to understand many of the problems and global issues that faced The importance of this study comes to clarify the relationship between Darwinism, geopolitics and geopolitics. The geopolitics in modern terms d

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Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of empowerment strategies on the characteristics of work enrichment An exploratory research to the views of a sample of the leaders of the Ministry of Oil in Iraq
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The study aimed to investigate the relationship between empowerment strategies and their impact on the success of enrichment work, it included the dimensions of empowerment strategies (power, knowledge, information, rewards), The dimensions of Job enrichment are (Skill variety, Task identity, Task significance, Autonomy, Feedback). The study was conducted at the headquarters of the Iraqi Oil Ministry in Baghdad and was based on a sample of the leadership of the ministry of managers consisting of 215 people. The data were collected using the questionnaire method based on scientific standards adopted in previous st

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Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of the tax examiner's procedures in increasing or decreasing tax revenue : Applied research in the General Authority for Taxes
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Abstract:

               The tax is one of the elements of the general revenues of the state and contributes to covering its expenses. Taxes are imposed in most countries of the world. The tax proceeds depend on a set of factors that contribute either positively or negatively to the tax share by increasing or decreasing it. Therefore, the research aims to demonstrate the role of the tax examiner's procedures in achieving the validity of the taxable base and its reflection on the tax proceeds, as well as reviewing the tax examiner's procedures related to the tax return process. Examination and tax audit of the financial statements, as well as presenting the financial statements to an independent and i

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Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
The impact of re-engineering of human resources in enhancing the morale of employees: Analytical research in Al - Rafidain University College
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This research aims to study the degree to which human resources re-engineering programs contribute to enhancing the morale of employees , as it constitutes re-HR Software Engineering contemporary trend to redesign activities and tasks that can HR do a way that helps their organization to achieve its goals as part of the operating environment including dealing with all activities related variables, and the promotion of workers' morale is one of the selections that have to be addressed so that the senior management helps the organization to invest their human resources best possible way as posing the most valuable and rarest of resources enjoyed by comparison with her competitors.

The research problem has

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Publication Date
Fri Oct 19 2018
Journal Name
Journal Of Economics And Administrative Sciences
The impact of social capital in enhancing the psychological empowerment of workers Applied research in the Directorate of the Municipality of Samawah
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 The current research aims to study social capital and its effect in enhancing the psychological empowerment of workers through the two variables of social capital within its dimensions (structural, relational, cognitive) and the variable of psychological empowerment within its components (ability, meaning, personal will and influence). The questionnaire was used as a main tool in the collection of data and with data collected from a sample of 168 employees in the Municipality of Samawa Municipality, which is part of the Ministry of Construction, Housing, Municipalities and Public Works. The results of the research (The impact of social capital in enhancing the psychological empowerment of workersApplied research in the Dire

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Publication Date
Tue Dec 29 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Evaluating the disclosure level due to Standards & Poor’s (S&P) Indicators And its effect on relevant accounting information An applied research in Baghdad bank
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The world and the business environment are constantly witnessing many economic changes that have led to the expansion of the business' volume due to mergers and the increase in an investments volume and the complexity of business and the transformation of some systems, which was reflected on the size of the risk and uncertainty which led to necessity of a presence of transparent and objective accounting information In the way that reflects the financial performance of the economic units to be available to all users of that information, therefore, The need for the existence of indicators for transparency in the disclosure of accounting information that these units adhere to. Standards & Poor's indicators, which included items

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Measuring the impact of internal control on tax performance using balanced score card indicators: An applied research in a sample of the branches of the General Tax Authority in Iraq
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This research dealt with the impact of internal control on tax performance using balanced scorecard indicators because of its special importance in improving tax performance and reform. The internal control system is a safety valve for senior management in all organizations, it plays an important role in the regularity and development of work and the fight against corruption To provide reliable and accurate data and information, follow up on compliance with laws, regulations and instructions. The aim of this research is to demonstrate how control affects tax performance and how to adapt internal control components to improve tax performance. In the General Authority for taxes and its branches,. The research resulted in a number of conclu

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Constructing fuzzy linear programming model with practical application
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This paper deals with constructing a model of fuzzy linear programming with application on fuels product of Dura- refinery , which consist of seven products that have direct effect ondaily consumption . After Building the model which consist of objective function represents the selling prices ofthe products and fuzzy productions constraints and fuzzy demand constraints addition to production requirements constraints , we used program of ( WIN QSB )  to find the optimal solution

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Publication Date
Tue Feb 16 2016
Journal Name
The Iraqi Journal Of Agricultural Sciences
MEASURING VIBRATION AT TRACTOR PLATFORM , STEERING WHEEL AND SEAT EFFECTIVE AMPLITUDE TRANSMISSIBILITY FACTOR DURING OPERATION TILLAGE
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Field experiment conducted to measure vibrations on three axes longitudinal X, lateral Y and vertical Z on steering wheel, platform tractor and vertical vibration in seat tractor and seat effective amplitude transmissibility (SEAT) factor during operation tillage in silt clay loam soil with depth 18 cm in Baghdad. Split – split plot design under randomized complete block design with three replications least significant design 5 % used. Three factor were used in this experiment included two types of plows included chisel and disc plows which represented main plot, three tires inflation pressure was second factor included 1.1 ,1.8 and 2.7 bar, and three forward speeds of the tillage was third factor included 2.35 , 4.25 and 6.50 km/hr. Resu

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