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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
Tue Jun 28 2011
Journal Name
Iraqi Journal Of Pharmacy
Effects of different concentrations of aqueous green tea extract against methotrexate-induced nephrotoxicity in rats
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Objective: The concentration-dependent nephroprotective effects of orally-administered aqueous green tea extract (AGTE) were studied. Materials and Methods: Forty rats of both sexes (weighing ٢٠٠-٢٥٠g) with various concentrations {٠.٦٢٥%, ١.٢٥% and ٢.٥% of aqueous green tea extract (AGTE)} as their main source of drinking fluid ٧ days before and ٥ days after administration of methotrexate (MTX). The parameters of oxidative stress, malondialdehyde (MDA) and reduced glutathione (GSH) were daily measured in kidney homogenate in addition to histopathological examinations after killing. Results: Analysis of data revealed significant amelioration of oxidative stress in groups of animals treated with different concentrations of AG

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Publication Date
Mon Jun 12 2023
Journal Name
Frontiers In Pharmacology
Protective effect of cafestol against doxorubicin-induced cardiotoxicity in rats by activating the Nrf2 pathway
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Doxorubicin (DOX) is an efficient antineoplastic agent with a broad antitumor spectrum; however, doxorubicin-associated cardiotoxic adverse effect through oxidative damage and apoptosis limits its clinical application. Cafestol (Caf) is a naturally occurring diterpene in unfiltered coffee with unique antioxidant, antimutagenic, and anti-inflammatory activities by activating the Nrf2 pathway. The present study aimed to investigate the potential chemoprotective effect of cafestol on DOX-induced cardiotoxicity in rats. Wistar albino rats of both sexes were administered cafestol (5 mg/kg/day) for 14 consecutive days by oral gavage alone or with doxorubicin which was injected as a single dose (15 mg/kg intraperitoneally at day 14) to i

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Publication Date
Wed Jan 01 2020
Journal Name
Research Journal Of Pharmacy And Technology
The effectiveness of topical vitamin k cream 1% in the treatment of steroid-induced rosacea
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Publication Date
Tue Oct 15 2013
Journal Name
: Journal Of Advances In Chemistry
Effect of Aqueous Extract of Vitis Vinifera l. Leaf on the Rabbit Females Have Highly Thyroxine Induced by Levothyroxine Sodium
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Publication Date
Sun Oct 13 2013
Journal Name
Journal Of Advances In Chemistry
Effect of Aqueous Extract of Vitis Vinifera l. Leaf on the Rabbit Females Have Highly Thyroxine Induced by Levothyroxine Sodium‏
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L-Thyroxine(T4) and triiodothyronine(T3)are iodine-containing hormones produced from thyroglobulin in the thyroid follicular cells. The stimulation of metabolic rate and regulation of growth and development by these hormones appear to be due to their effects on DNA transcription and, thus, protein synthesis. The aqueous extract of vitis vinifera L. was investigated for its effect on hormones in rabbits. The aqueous extract of plant at a dose level of 50µg/rabbit showed highly significant (p<0.05)on levels of hormones T4, TSH but TSH no significant. L-thyroxine sodium treated group showed a highlysignificant increase in T3 and T4 while there was a highly significant decrease in TSH. From the above results, it is concluded for the first time

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Publication Date
Thu Feb 01 2024
Journal Name
Journal Of Engineering
Performance Evaluation of Two Stages Parallel Flow Indirect Evaporative Cooling with Aspen Pads in Baghdad Climate Conditions
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This study delves into the realm of advanced cooling techniques by examining the performance of a two-stage parallel flow indirect evaporative cooling system enhanced with aspen pads in the challenging climate of Baghdad. The objective was to achieve average air dry bulb temperatures (43 oC) below the ambient wet bulb temperatures (24.95 oC) with an average relative humidity of 23%, aiming for unparalleled cooling efficiency. The research experiment was carried out in the urban environment of Baghdad, characterized by high temperature conditions. The investigation focused on the potential of the two-stage parallel flow setup, combined with the cooling capability of aspen pads, to surpass the limitat

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Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
A comparative study of stylistic kriging and Co - kriging Multivariate on the barley crop in Iraq
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  This paper deals  the prediction of the process of  random spatial data of two properties, the first is called  Primary variables  and the second is called secondary  variables ,   the method  that were used in the  prediction process for this type  of data is technique Co-kriging  , the method is usually used when the number of primary variables  meant to predict for one of its elements is measured in a particular location a few (because of the cost or difficulty of obtaining them) compare with secondary variable which is the number of elements  are available and  highly correlated with primary variables, as was the&nbs

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Publication Date
Mon Feb 25 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
بحث تطبيقي في مصرف الرافدين: An Applied Research in the Rafidain Bank
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Banks was one of the institutions that are highly concerned with the issue of performance evaluation, in order to achieve optimal use of resources that enable them to achieve operational and strategic objectives both in light of the global competition fierce for the start of the research problem of banks to adopt in assessing the performance of the realization of just the traditional financial indicators which has become insufficient to keep pace with the constant evolution in the business environment, which requires work on the use of the necessary information needed to evaluate the performance of all the Bank's activities through

the use of the Balanced Scorecard method. The research aims to shed light on the dimensions of perf

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Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of changing interest rates on net interest income and earnings per share in commercial banks
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ABSTRACT:

              Interest rates are one of the important aspects that affect the banking business directly, which is characterized by unstable dynamic dynamics, which must be viewed on a daily and continuous basis through the macroeconomic view, which directly affects the bank’s income realized from loans as interest received or interest paid on its deposits as an expense. Hence the earnings per share. The relationship between interest rates and between net income and earnings per share was measured and a correlation was found between them, and then the effect between them was measured using regression equations and they were applied and th

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Publication Date
Sat Jun 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Drag Reduction of Crude Oil Flow in Pipelines Using Sodium Dodecyl Benzene Sulfonate Surfactant
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In the present work, a closed loop circulation system consist of three testing sections was designed and constructed. The testing sections made from (3m) of commercial carbon steel pipe of diameters(5.08, 2.54 and 1.91 cm) . Anionic surfactant  (SDBS )with  concentrations  of (50,  100,  150, 200 and 250 ppm)  was tested as a drag reducing  agent.  The additive(SDBS)studied using crude oil from south of Iraq. The flow rates of crude oil were used in 5.08 and 2.54 cm I.D. pipes are (1 - 12) m3/hr while (1-6) m3/hr were used in 1.91 cm J .D. pipe . Percentage drag reduction (%Dr) was found to increase by increasing solution velocity, pipe diameter and additives concentration (i.e. increasi

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