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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 Dec 28 2021
Journal Name
Arab Science Heritage Journal
ام المؤمنين ام سلمة ودورها في رواية الحديث النبوي
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    There was a huge role in the history of a muslim woman and several books have mentioned that politically or in religion and even scientifically and socially which leaded a lot of women to look up to           these women who helped in keeping the religion just in the right form for other generations

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Publication Date
Sun Jan 01 2006
Journal Name
Journal Of Educational And Psychological Researches
التعليم المصغر وتطبيقه في برامج إعداد معلمي مادة التاريخ
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مشكلة البحث:

بين الحين والآخر تتصاعد الصيحات مطالبة بإصلاح النظام التعليمي لكي يتوافق هذا النظام مع ما يحدث في العالم من تطورات علمية وتكنولوجية تترك بصماتها على مختلف قطاعات الحياة .

ويعد المعلم وبلا شك ركنا أساسيا في هذا النظام ،وذلك لما للمعلم من تأثير أساسي في عملية التعليم والتعلم . ماذا يجدي إذا ما طورنا مناهجنا، واحسنا مباني مدارسنا، وأكثرنا من الوسائل والتقنيات ،ولم نوفر المع

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Publication Date
Mon Apr 04 2022
Journal Name
Journal Of Educational And Psychological Researches
Towards a proposed conception of the role of the professional practice specialist for social work In the field of social care for corona patients (A field study at the Iraqi Ministry of Social Affairs)
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This study aimed to identidy the role of a professional social worker practice specialist in the field of social care for Corona patients, in light of some demographic variables such as (gender, marital status, economic status,), through a field study at the Iraqi Ministry of Social Affairs. A random sample of (50) social workers in the Iraqi Ministry of Social Affairs in various places affiliated with the ministry was chosen. a questionnaire developed by the researcher about the role of the social worker in the field of social care for Corona patients was administered to the study sample to collect the needed data. The results showed that there is a positive statistically significant correlation relationship at the level (0.01) between

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Publication Date
Sun Jun 23 2019
Journal Name
Arma
Safe Mud Weight Window Determination: A Case Study from Southern Iraq
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ABSTRACT:. The Lower Cretaceous Zubair formation is comprised of sandstones intercalated with shale sequences. The main challenges that were encountered while drilling into this formation included severe wellbore instability-related issues across the weaker formations overlaying the reservoir section (pay zone). These issues have a significant impact on well costs and timeline. In this paper, a comprehensive geomechanical study was carried out to understand the causes of the wellbore failure and to improve drilling design and drilling performance on further development wells in the field. Failure criteria known as Mogi-Coulomb was used to determine an operating mud weight window required for safe drilling. The accuracy of the geomechanical

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Publication Date
Sun Jun 09 2019
Journal Name
Al-kindy College Medical Journal
The Effectiveness of Calcaneal Drilling for Treatment of Resistance Cases of Plantar Heel Pain
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Background: Plantar heel pain is a clinical syndrome characterized by pain and tenderness beneath the heel which is typically worse in the morning and improves after the first few steps in the day. It is a common and frequently disabling clinical complaint that may be caused by a broad spectrum of osseous or soft tissue disorders.

Objective: To evaluate the effectiveness of an operation of multiple drilling of calcaneum for resistant plantar heel pain syndrome.

Methods: During the period from November 2012 to August 2016, 17 patients (17heels) were enrolled in a cohort clinical study at the orthopedic unit in AL-Sheikh Zayed and Al-Wassity Hospitals.

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Publication Date
Tue Oct 30 2018
Journal Name
Al-kindy College Medical Journal
The Effectiveness of Calcaneal Drilling for Treatment of Resistance Cases of Plantar Heel Pain
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Background: Plantar heel pain is a clinical syndrome characterized by pain and tenderness beneath the heel which is typically worse in the morning and improves after the first few steps in the day. It is a common and frequently disabling clinical complaint that may be caused by a broad spectrum of osseous or soft tissue disorders. Objective: To evaluate the effectiveness of an operation of multiple drilling of calcaneum for resistant plantar heel pain syndrome. Methods: During the period from November 2012 to August 2016, 17 patients (17heels) were enrolled in a cohort clinical study at the orthopedic unit in AL-Sheikh Zayed and AlWassity Hospitals. Result: Drilling of the calcaneum is a simple procedure achieving 70.6% cure in resistant as

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Publication Date
Sun Jan 03 2016
Journal Name
Journal Of Educational And Psychological Researches
Psychological pressure for students who are subject to physical education.
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The current research involves psychological pressure (educational,environment andemotionly) for secondary level to 2013-2014.This research includes comparison among students who are trained and not trained  in physical education .The sample is(126) students from each gender from first education.Al-Karkh and the research found out that physical education  has an effect in lessing emotional and educational in a big degree in student in secondary  which affect them  positively in their  study.                                     &n

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Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
دراسة مقارنة بين بعض الطرائق الحصينة في تقدير معلمات انموذج الانحدار الخطي باستخدام اسلوب المحاكاة التجريبي في حالة وجود بيانات تتضمن مشاهدات شاذة
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In linear regression, an outlier is an observation with large residual.  In other words, it is an observation whose dependent-variable value is unusual given its values on the predictor variables. An outlier observation may indicate a data entry error or other problem.

An observation with an extreme value on a predictor variable is a point with high leverage. Leverage is a measure of how far an independent variable deviates from its mean. These leverage points can have an effect on the estimate of regression coefficients.

Robust estimation for regression parameters deals with cases that have very high leverage, and cases that are outliers. Robust estimation is essentially a

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Publication Date
Wed May 01 2024
Journal Name
Journal Of Physics: Conference Series
Analyze the Structure and Electrical Properties of PbBr<sub>2</sub> Ca<sub>1.9</sub>Sb<sub>0.1</sub>Cu<sub>3</sub>O<sub>8+</sub> <sub>δ</sub> Superconducting Gamma Irradiation
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The purpose of the current work was to evaluate the effect of Radiation of Gamma on the superconducting characteristics of the compound PbBr2Ca1.9Sb0.1Cu3O8+δ utilizing a 137Cs source at doses of 10, 15, and 20MRad. Solid state reaction technology was used to prepare the samples. Before and after irradiation, X-ray diffraction (XRD) and superconductor properties were examined. Results indicated that the tetragonal structure of our chemical corresponds to the Pb-1223 phase with an increase in the ratio c/a as a result of gamma irradiation. (Tc (onset) ) and on set temperature Tc (offset)) were also dropping from 113 to the 85.6 K and 129.5 to 97 K, respectively, for a transition temperatu

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Publication Date
Sat Sep 01 2018
Journal Name
Polyhedron
Novel dichloro (bis {2-[1-(4-methylphenyl)-1H-1, 2, 3-triazol-4-yl-κN3] pyridine-κN}) metal (II) coordination compounds of seven transition metals (Mn, Fe, Co, Ni, Cu, Zn and Cd)
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