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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
Mon Jun 01 2020
Journal Name
Journal Of The College Of Languages (jcl)
The Labyrinths of the Contemporary French Novel Through the Texts of Patrick Modiano: Les Labyrinthes du Roman Français Contemporain à travers l’Œuvre de Patrick Modiano
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The current paper aims to study the different forms by which the theme of labyrinth imposes itself as a preferred narrative structure in the novels of the French writer Patrick Modiano. Theoretically speaking, the current research paper will limit itself to the theoretical framework of the textual poetics which relies on the study of literary texts without paying much attention, neither to the context, nor to the life of its author. The analysis of the strong and varied links that Modiano's novels establish with labyrinth represents a field which has not received adequate attention by the critical studies dedicated to this French writer. As it will be shown throughout the current paper, Modiano views labyrint

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Publication Date
Sun Jan 01 2017
Journal Name
مجلة علوم الرياضة في جامعة ديالى
إتخاذ القرار و علاقته بإنماط الشخصية و الإدراك البنائي لدى مدراء منتديات الشباب و الرياضة في محافظات الفرات الأوسط و الجنوبية.
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Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
/ E-Readiness, UTAUT Model, Social Commerce
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Abstract

Objective / Purpose: Online social relationships through the emergence of Web 2.0 applications have become a new trend for researchers to study the behavior of consumers to shop online, as well as social networking sites are technologies that opened up opportunities for new business models. Therefore, a new trend has emerged, called social trade technology. In order to understand the behavioral intentions of the beneficiaries to adopt the technology of social trade, the current research aims at developing an electronic readiness framework and UTAUT model to understand the beneficiary's adoption of social trade technology.

Design/ methodology/ Approach: To achieve the obje

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Engineering
Unity Sliding Mode Controller Design for Active Magnetic Bearings System
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Active Magnetic Bearings (AMBs) are progressively being implemented in a wide variety of applications. Their exclusive appealing features make them suitable for solving traditional rotor-bearing problems using novel design approaches for rotating machinery.  In this paper, a linearized uncertain model of AMBs is utilized to develop a nonlinear sliding mode controller based on Lyapunov function for the electromechanical system. The controller requires measurements of the rotor displacements and their derivatives. Since the control law is discontinuous, the proposed controller can achieve a finite time regulation but with the drawback of the chattering problem. To reduce the effect of this problem, the gain of the uni

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Publication Date
Sat Oct 30 2021
Journal Name
Iraqi Journal Of Science
Variational Approximate Solutions of Fractional Delay Differential Equations with Integral Transform
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     The idea of the paper is to consolidate Mahgoub transform and variational iteration method (MTVIM) to solve fractional delay differential equations (FDDEs). The fractional derivative was in Caputo sense. The convergences of approximate solutions to exact solution were quick. The MTVIM is characterized by ease of application in various problems and is capable of simplifying the size of computational operations.  Several non-linear (FDDEs) were analytically solved as illustrative examples and the results were compared numerically. The results for accentuating the efficiency, performance, and activity of suggested method were shown by comparisons with Adomian Decomposition Method (ADM), Laplace Adomian Decompos

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Scopus (4)
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Publication Date
Sun May 06 2007
Journal Name
كلية التربية البدنية وعلوم الرياضة/جامعة بغداد .
تأثير التمرينات الاوكسجينية واللاأوكسجينية في الوحدة التدريبية لتطوير بعض القدرات الوظيفية والبدنية للاعبي كر ة القدم بعمر (13-14)سنة. رسالة ماجستير
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Publication Date
Mon Jan 07 2019
Journal Name
Arab Science Heritage Journal
تعيين عنصر الزئبق السام بتراكيز نزرة في نماذج غذائية ومائية مختلفة باستخدام منظومة بخار الزئبق البارد المرتبطة مع جهاز الامتصاص الذري اللهبي
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الخلاصة

     يتضمن البحث تعيين عنصر الزئبق السام بتراكيزنزرة عالية الدقة (نانوغرام) باستخدام منظومة يخار الزئبق البارد لنماذج غذائية (لحوم حمراء ، لحوم بيضاء ) مختلفة ونماذج مائية (ماء النهر، مياه صناعية ، ماء الشرب) وربط المنظومة بتقنية الامتصاص الذري اللهبي.

     ان عنصر الزئبق من اشد العناصر سمية وان التراكيز المسموح بها عالميا لايتعدى جزء واحد

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Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
معوقات تطبيق الإدارة الإلكترونية في وزارة التربية والتعليم بسلطنة عمان(البوابة التعليمية الإلكترونية أنموذجاً) من وجهة نظر موظفي المديرية العامة لتقنية المعلومات
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Drawbacks of Implementing Electronic Management in the Ministry of Education (A sample: Oman Educational Portal) from the Point of View of IT Staff. The study aimed at discovering the drawbacks of implementing electronic management in the Ministry of Education (a sample: Oman Educational Portal) from the point of view of IT staff, and that is by answering the following questions: - What are the main drawbacks (administrative, financial, technical and drawbacks related to human resources) that hinder implementing the electronic management in the Ministry of Education (a sample: Oman Educational Portal) from the point of view of IT staff? - Are there any statistical significance differences at the level (0.05) between study samples on the

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Publication Date
Sun Mar 26 2023
Journal Name
Arab Science Heritage Journal
الاديب الكاتب والمؤرخ الفقيه يحيى بن خلدون (ت 780هـ/ 1379م) كاتب ديوان الانشاء في دولة بني زيان (633-962هـ/ 1235-1554م) بتلمسان
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    A prominent figure such as Yahya bin Khaldoun and a scholar of the moroccan countries in the medieval era, and had a special place in the history of the country and the state of Bani Zayan, and the positions he occupied in it and left his scientific, literary and historical traces, leaving him an imprint in the course of history and its events, and in this study
I dealt with the research: his personal life : his name and lineage, then his upbringing and his family.

    The aim of the study is to know this character in the details of his personal and scientific life, according to the historical descriptive research method, including description and presentation of events, and linking them in a

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Publication Date
Wed Jun 30 2010
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Producing Oil from Dead Oil Wells Using injected LPG
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In order to reduce hydrostatic pressure in oil wells and produce oil from dead oil wells, laboratory rig was constructed, by injecting LPG through pipe containing mixture of two to one part of East Baghdad crude oil and water. The used pressure of injection was 2.0 bar, which results the hydrostatic pressure reduction around 246 to 222 mbar and flow rate of 34.5 liter/hr fluid (oil-water), at 220 cm injection depth. Effects of other operating parameters were also studied on the behavior of two phase flow and on the production of oil from dead oil wells.

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