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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
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
أستخدام الضريبة البيئية للحد من الملوثات الناجمة عن عوادم السيارات: أنموذج مقترح للضريبة البيئية في العراق
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 The researcher tried to show the importance of using environmental taxes as an effective economic factor for reducing contaminators resulting from cars exhausts, and presenting a suggested pattern for  environmental taxes as a nucleus and a starting point for a wider implementing of environmental taxes in Iraq.                                                                      &nbs

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Publication Date
Wed Dec 29 2021
Journal Name
Journal Of The College Of Education For Women
A Speech Acts Analysis of English COVID-19 News Headlines: مثنى نجيب المرسومي, جمعة قادر حسين
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News headlines are key elements in spreading news. They are unique texts written in a special language which enables readers understand the overall nature and importance of the topic. However, this special language causes difficulty for readers in understanding the headline. To illuminate this difficulty, it is argued that a pragmatic analysis from a speech act theory perspective is a plausible tool for a headline analysis. The main objective of the study is to pragmatically analyze the most frequently employed types of speech acts in the news headlines covering COVID-19 in Aljazeera English website. To this end, Bach and Harnish's (1979) Taxonomy of Speech Acts has been adopted to analyze the data. Thirty headlines have been collected f

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Publication Date
Mon May 25 2026
Journal Name
Al-qadisiya Journal
معالجة النقص التشريعي بالاجتهاد القضائي المسؤولية التقصيرية الناشئة عن الذكاء الاصطناعي انموذجًا
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Publication Date
Fri Jun 28 2024
Journal Name
The Iraqi Journal Of Veterinary Medicine
جرثومة الزائفة الزنجارية كاشف فعال للتحري عن المستخلصات النباتية المثبطة لاستشعار النصاب
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استشعار النصاب (Quorum sensing, QS) هو آلية معروفة تستخدمها جراثيم عديدة للسيطرة على عوامل الضراوة الهامة من خلال الإنتاج والاستجابة اللاحقة ل .)N-acylhomoserine (AHLs جرى تسجيل تثبيط استشعار النصاب (QSI) ، الذي يستهدف الإشارات المعتمدة على AHL، كاستراتيجية للسيطرة على الأمراضية الجرثومية. وبالتالي، تهدف هذه الدراسة إلى البحث عن قدرة جرثومة الزائفة الزنجارية كمؤشر للفحص السريع عن QSI المحتمل المتسبب عن المستخلصات النباتية على أسا

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Publication Date
Mon Feb 28 2022
Journal Name
Journal Of Educational And Psychological Researches
The Counseling Needs of Behavioral Problems among Students with Academic Learning Disabilities
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Learning Disabilities are described as a hidden and puzzling disability. Children with these difficulties have the potential to hide weaknesses in their performance because they are a homogenous group of disorders that consist of obvious difficulties in acquiring and using reading, writing, Mathematical inference. Thus, the research aims to identify the disabilities of academic learning in (reading, writing, mathematics), identify the problems of behavior (general, motor, social). Identify the relationship among behaviour problems. The research also aims to identify the counseling needs to reduce the behavioral problems. The researcher adopted the analytical descriptive method by preparing two main tools for measuring learning disabiliti

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Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Educational And Psychological Researches
الاستقلال عن المجال الإدراكي والإتكال عليه وعلاقته بمستوى الطموح ومفهوم الذات الأكاديمي
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The impedance from the cognitive field and reliance on it, ambition  level, and the academic ego concept are concepts on which too many varied studies had been conducted. The current research aims to the followings:

First:

Measuring the independence from the cognitive field and the reliance on it of the college students and this done for: the whole sample, the equalization among the degrees in accordance to the sex variable (male, female), specialty variable (scientific, humanistic).

Second:

Measuring the ambition level of the college students and this done for: the whole sample, the equalization among the degrees in accordance to the sex variable (male, female) and specialty variable (scientific, hum

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Publication Date
Thu Mar 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The relationship between the gap of knowledge and the strategic performance gap
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Address the intellectual controversy nature of the gap of knowledge and the strategic performance gap. The researcher start off from this intellectual controversy to seek to test the nature of the relationship and impact between them across a sample of (61) academics in the colleges of business and economics at the universities in Baghdad ,as the more specialized in the fields of knowledge and the strategic performance, The researcher is attain to the existence of relationship and impact of knowledge gap in strategic performance gap, the research included four axes first went to the methodology and second to theoretical frame and the third to view and analyze the results and test hypotheses while the fourth was devoted to the con

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Publication Date
Thu Mar 31 2022
Journal Name
Psychological Science
The health and social repercussions of the epidemic crisis (Covid-19) on women (An exploratory study for some private universities - Baghdad / Karkh)
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The current research aims to first - reveal the social repercussions of COVID-19 on women A - The impact of the epidemiological crisis on the social structure of the family B - Psychological and social pressures that women are exposed to during the Covid pandemic C - Social isolation resulting from the injury of a member Second - Understanding the health consequences of COVID-19 on women A- Mechanisms of differentiation in the treatment of Covid-19 treatment, home or hospital As for the limits of the research, the current research is determined by some private universities of students, female employees and teaching staff in Karkh district, which number eight (Al-Hikma, Al-Farahidi, Al-Farabi, Tigris, AlTurath, Al-Rashid, Al-Mashreq, Al-Nuso

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Publication Date
Fri Jul 19 2024
Journal Name
Baghdad Science Journal
Study of the Relationship for Neutron and Proton Skin Thickness on the Neutron Equation of State for 18Ne-18O Pair Mirror Nuclei
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Within the framework of the shell model, the single-particle wave functions of Hartree-Fock approximation adopted with Skyrme interactions like kxtb, Skxs25, Sly4 and Bsk9 to get the thickness of the neutron skin, the mirror radii and the charges mirror radii for 18Ne-18O pair mirror nucleus. The wave functions were calculated using the NuShellX@MSU shell model code. The computed values of root-mean-square-radii are inuenced by the type of interaction employed. The symmetry energy and its slope at nuclear saturation density and the mirror energy displacement were also determined. Comparisons between theoretical and experimental data were made and it was concluded that the data are well described in of this pair mirror nucleus

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Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
The Influence of Different Light Wavelengths on Growth, Enzymes Activity and Photosynthesis of the Marine Microalga Dunaliella parva W.Lerche 1937
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Light is an important factor that influences the growth and photosynthetic efficiency of microalgae; however, little is known about how light intensity together with the wavelength affect the photosynthetic capacity and growth of marine microalgae. In the present study, the growth of the marine green microalga Dunaliella parva was studied and optimized under different light intensities (25 ~ 70 μmol m-2 s-1) and qualities (blue, green, and red) in comparison with white light at 40 μmol m-2 s-1 as a control. The growth was monitored by counting the cell number, pigment content, Chl a, Chl b, and carotenoids concentrations. The optimal growth and highest photosyntheti

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