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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 Sep 01 2022
Journal Name
Archives Of Razi Institute
Effects of Avena sativa and Glycyrrhiza glabra Leaves Extracts on Immune Responses in Serum Cytokine and Liver Enzyme Levels in NIH Mice
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In addition to their high quantities of active chemicals, medicinal plants are well-known for their pharmacological qualities, which include immunological modulation. T Consequently, this study aimed to examine the effects of Avena sativa and Glycyrrhiza glabra leaf extracts on immunological responses as measured by blood cytokine and liver enzyme levels. The phytochemical analysis of Avena sativa crude leaf extracts revealed the presence of alkaloids,flavonoids, tannins, phenolic compounds, and saponins but the absence of resins and violet oils. On the other hand, violet oils, flavonoids, tannins, saponins, and glycosides were detected in significant concentration in Glycyrrhiza glabra ethanolic extract, although resins and phenolic compou

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Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Performance Evaluation Strategy and its Impact on the Achievement of Organizational Effectiveness
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Abstract

The research aims to determine the impact of the strategy performance evaluation and of the Standards (leadership, people, knowledge, processes, financial) in the achievement of organizational effectiveness in accordance with the dimensions (planning and setting goals, Exploitation of the Environment, achieve the goals, the ability to adapt, information management and communications) and the relationship between them, the problem of the research in the growing interest in the process of performance evaluation for organizations, the erroneous belief that the performance evaluation activity is useful, and the fact that performance evaluation process is one of the main tasks of the work of the Office of the Inspecto

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation Status Of Central Laboratories In Al- Kadhimya Teaching Hospital According To ISO/IEC 17025 In 2005
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This research aims to analyze and evaluate  the reality of the total quality management for the central laboratories by comparing systems of work in the laboratories of Al- Kadhimiya Didactic Hospital with the requirements of ISO 17025 to determine the degree of compatibility and the willingness to adapt to the requirements of the above specification and to show the ability of building an applicable quality management system and to identify problems and their mitigations and prevention to increase.

This study gains its importance from the importance of the labs which stems from the fact that the process of health is a set of interrelated activities, Medical examinations and tests con

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Publication Date
Wed Feb 05 2020
Journal Name
Journal Of Physical Education
The Effect of Group Investigation Model on Learning overhead and underarm Pass in Volleyball
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Volleyball is one of the sports that require physical and skill abilities thus many teaching models appeared to teach these abilities like group investigation model. The research aimed at identifying the effect of group investigation model on learning underarm and overhead passing in volleyball. The researchers hypothesized statistical differences between pre and posttests in learning underarm and overhead passing in volleyball as well as differences in posttests of controlling and experimental groups in learning underarm and overhead passing in volleyball. The researcher used the experimental method on (30) second year female students of physical education and sport sciences college/ university of Baghdad. Group investigation model was app

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Effect of Saline Water and Potassium Fertilizer on Nitrogen Fixation in Pisum sativum L.
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Field experiment was conducted to test the effect of saline water 2 and7 dSm-1 potassium fertilizer rate 150,300 and 450 kg/donum on nitrogen fixation in Pisum sativum L. nodules. The experiment included anatomy study .Results water salinity ( 2,7 dSm-1) as a main plot and fertilizer rates as a sub plot. Results indicated that irrigation with saline water 7 dSm-¹ caused a significant decrease in N contents especially in the lower parts of the plants. The percentage of the N decreased in lower leaves to (0.01%) under 7dSm-¹ and 300 kg/donum fertilizer; however the percentage increased in the upper leaves to (2.80%) under with 2dSm-¹of irrigation water and 300 kg/ donum fertilizer rate. Fresh weight decreased to 6.26g under 7 dSm

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Publication Date
Wed Dec 12 2018
Journal Name
Iop Conference Series: Materials Science And Engineering
Effect of silicon calcium, boron on Proline and relative water contents in Apple leaves
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Publication Date
Wed Jan 01 2020
Journal Name
Indian Journal Of Ecology
Study on major constraints and problems in transfer of technology by agricultural extension organization
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Scopus
Publication Date
Wed Dec 09 2020
Journal Name
Banks And Bank Systems
Cooperative decision-making on fiscal and monetary policy in Iraq using the prisoner’s dilemma
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This paper investigates the interaction between fiscal and monetary policy in Iraq after 2003 using the prisoner’s dilemma.The paper aims to determine the best form of coordination between these policies to achieve their goals; payoff matrix for both policies was constructed. To achieve the purpose, the quantitative approach was applied using several methods, including regression, building payoff matrices and decision analysis using a number of software.The results of the monetary policy payment function show that inflation rate has an inverse relationship with the auctions of selling foreign currency and a positive relationship with the government’s activity, while the fiscal policy function shows that real growth is positively

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Publication Date
Sun Sep 06 2015
Journal Name
Baghdad Science Journal
The effect of obesity and Insulin Resistance on Liver Enzymes in Type2 Diabetes Mellitus
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Diabetes mellitus (DM) has been defined as a clinical syndrome that is characterized by abnormal carbohydrate metabolism. The chronic hyperglycemia of diabetes is associated with long term damage, dysfunction, and failure of different organs, especially the liver .This study was conducted to assess the effect obesity and insulin resistance on liver enzymes in diabetic Iraqi patients.A comparative study of (90) Iraqi adults divided to three subgroup(30) obese ,(30) nonobese diabetic patients and(30)person had used as control. The analysis included Liver enzyme ALP,ALT,AST,GGT ,Fasting Plasma Glucose (FBG) , Lipid Profile , Hemoglobin A1C , insulin and homeostasis model assessment of insulin resistance (HOMA IR) were measured. Subjects

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Publication Date
Thu Jun 12 2025
Journal Name
Folia Medica 67(3): E149216
Impact of thumb sucking on salivary melatonin, Candida albicans, and dental caries in children
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Introduction: Salivary melatonin is a critical antioxidant that contributes to oral health by mitigating oxidative stress. Psychological stress linked to thumb sucking may disrupt oral homeostasis, leading to conditions such as dental caries and fungal infections. Aim: This study explores the relationships between thumb sucking, salivary melatonin levels, dental caries, and the presence of Candida albicans (CA) in children. Materials and methods: A case-control study was conducted with 60 children aged 4-5 years at the University of Baghdad’s College of Dentistry. Participants were divided into thumb-sucking (n=30) and non-thumb-sucking (n=30) groups. Salivary melatonin levels were measured using enzyme-linked immunoso

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