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alkej-347
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 Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Land Use/Cover Change Analysis Using Remote Sensing Data: A Case Study, Zhengzhou Area, Henan Province, China
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In the last two decades, arid and semi-arid regions of China suffered rapid changes in the Land Use/Cover Change (LUCC) due to increasing demand on food, resulting from growing population. In the process of this study, we established the land use/cover classification in addition to remote sensing characteristics. This was done by analysis of the dynamics of (LUCC) in Zhengzhou area for the period 1988-2006. Interpretation of a laminar extraction technique was implied in the identification of typical attributes of land use/cover types. A prominent result of the study indicates a gradual development in urbanization giving a gradual reduction in crop field area, due to the progressive economy in Zhengzhou. The results also reflect degradati

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Publication Date
Fri Dec 16 2022
Journal Name
Journal Of The College Of Languages (jcl)
The official business style of the Russian literary language. Problems of formation.: Официально-деловой стиль русского литературного языка. Проблематика формирования.
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In the article we consider features of official style, its functions and factors which influence the definition of the style. The topicality of the issue can be explained by rapid development of market economy which affects in its turn business correspondence. In this regard, there are a lot of cliché, terms and professionalisms appeared recently. Only correct usage of them can serve as a key to successful communication in Russian as well as other languages. This work highlights documents that are part of the diplomatic style such as declarations, credentials, notes, resolutions and other documents. The administrative style can include orders and instructions.

Аннотация.

 В данной статье рассмо

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Publication Date
Tue Nov 13 2018
Journal Name
Arab Science Heritage Journal
الثروة الثروة المائية في المغرب العربي من القرن 4 – 7 هـ/ 10 م – 13 م دراسة تاريخية
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Water resources would be differentiate in Morocco specially in Morocco  which appear as form of eyes ,rivers as dissolved water of mountain.

The human takes care of water either as rains to store and use in necessity trying to bring it to Maracas  by  helping from state

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Publication Date
Mon Nov 12 2018
Journal Name
Arab Science Heritage Journal
رسالة رسالة في طبقات القراء لتاج الدين أحمد عبد القادر بن مكتوم القيسي (ت 749هـ) دراسة وتحقيق
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 The writer of this messagewas Tajaddin Ahmad Abdulqader bin Maktoom Al-Qaisy Al-masry.

This message dealt with the biographies of twenty scientists of readers about Quran readings in Cairo . He comprehended these biographies and make it an appendage

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Publication Date
Sat Dec 31 2022
Journal Name
Journal Of Economics And Administrative Sciences
Seemingly Unrelated Regression Model to Measure the Profitability of Some Iraqi Private Commercial Banks with Presence of Outliers
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A seemingly uncorrelated regression (SUR) model is a special case of multivariate models, in which the error terms in these equations are contemporaneously related. The method estimator (GLS) is efficient because it takes into account the covariance structure of errors, but it is also very sensitive to outliers. The robust SUR estimator can dealing outliers. We propose two robust methods for calculating the estimator, which are (S-Estimations, and FastSUR). We find that it significantly improved the quality of SUR model estimates. In addition, the results gave the FastSUR method superiority over the S method in dealing with outliers contained in the data set, as it has lower (MSE and RMSE) and higher (R-Squared and R-Square Adjus

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Publication Date
Tue Jan 01 2008
Journal Name
Alustath Journal For Human And Social Science
أثر شكل سبعة المعرفي في اكتساب المفاهيم الفيزيائية و فهم طبيعة العلم لدى طالبات الصف الرابع العام
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Publication Date
Wed Oct 04 2023
Journal Name
Arab Science Heritage Journal
المدراس الثانوية في الاعظمية ( ثانوية كلية بغداد- ثانوية الأعظمية للبنين – ثانوية الأعظمية للبنات - ثانوية الحريري للبنات) أنموذجاً
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Education received the attention of the monarchy in Iraq, especially after the developments that the country witnessed after Iraq gained independence and joined the League of Nations in 1932 AD in all political, economic and cultural aspects.  In this regard, due to its distinguished geographical location, where the atmosphere, the natural environment and the religious and political standing were available, which made it a center of attraction for most Iraqi families and political figures.  Learning and pioneering the path of knowledge, so it witnessed a great prosperity in secondary education, so several important schools appeared that contributed to advancing the wheel of learning forward, including Baghdad College High Schoo

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Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Psychological Capital: Behavioral Insight for Study of Spirituality at the Workplace
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Abstract

      This research aims to identify the role of Psychological Capital (PsyCap) in the Spirituality at the Workplace (SAW) for a sample of the teaching staff of the four Colleges of the University of Kufa reached (200) out of (470) teaching, and to achieve the objective of this research and through access to research and studies of foreign adopted researchers standards scales of research variables, since it relied on the model (Luthans, Youssef, et al., 2007) to represent the components of Psychological Capital (self-efficacy, and hope, and optimism, and resilience), and given the attention organizations in the human element because of it

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Publication Date
Sun Mar 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Use the path analysis method to diagnoseFactors influencing the intentions of the employees of the University of Dhi Qar To introduce Internet behavior
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The purpose of this study is to diagnose factors that effect Thi-Qar behavioral intention to use internet. A sample of (127) internet users of university staff was taken in the study and were analyzed by using path analyze . The study concluded that there is a set of affecting correlation. It was founded that exogenous variables (gender, income, perceived fun, perceived usefulness, Image, and ease of use) has significant effect on endogenous (behavioral intention) . The result of analysis indicated that image hopeful gained users comes first, ease of use secondly, perceived fan and perceived usefulness on (dependent variables (daily internet usage and diversity of internet usage. Implication of these result are discussed . the st

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Publication Date
Sun Jan 03 2010
Journal Name
Journal Of Educational And Psychological Researches
اثر برنامج إرشادي في تنمية بعض المفاهيم التربوية المستنبطة من بعض المواقف اليومية التي يعيشها طفل الروضة
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It has became necessary helping the children to developing same of educational values which can be drawn from daily situations which the live. Especially the childhood stage is the basic building of value individual content since its establishment the societies take care of learning children and take care of them. Through their institutes which depended on, in this function. Therefore the importance of this, research is coming from the importance of this age stage and from importance and necessity of children aguirement the educational values and its development to them, and  the importance this research  coming from depending on guidance program with  new content and it is (al bum of pictures) fro

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