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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 Nov 29 2018
Journal Name
Journal Of Electronic Materials
Numerical Modeling of 193-nm Excimer Laser Ablation on CR-39 Polymer
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Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The influence of human resources Accounting on cost reduction
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The development of human resources training programs has an applied and important role in the preparation of human cadresin terms of capacity to absorb technical sciences and skills and scientific and practical practices at faster rates in order to bealighed with continous development. Hence the recognition of the significant role that human resources play in the economy of any country,which has stressed the interest towards the economic unity of the qualified staff that it needsin atimely manner through the ongoing training process in the era of high technology day by  day  In this regard ,the current research deal with accounting of human resources and its impact on reducing costs in the military establishment and the

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Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of operational efficiency on some financial indicators according to the CAMEL model of banking financial stability: An applied research on a sample of Iraqi private banks for the period 2010-2020
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Abstract

          The research aims to determine the nature of the Iraqi market in terms of banking financial stability and the extent impact of the operational efficiency on it, Accordingly, chosen 15 relational banks were chosen as an intentional sample that could represent the Iraqi banking system for the period 2010-2020. The operational efficiency variable was measured according to the data envelope model, and banking financial stability used  CAMELS model which includes five indicators (capital adequacy, asset quality, management quality, profitability, and liquidity), so for testing the research hypotheses used the random regression model by adopting the S

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Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Experimental Evidence of Chaotic Resonance in Semiconductor Laser
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In this paper, an experimental study has been conducted regarding the indication of resonance in chaotic semiconductor laser.  Resonant perturbations are effective for harnessing nonlinear oscillators for various applications such as inducing chaos and controlling chaos. Interesting results have been obtained regarding to the effect of the   chaotic resonance by adding the frequency on the systems. The frequency changes nonlinear dynamical system through a critical value, there is a transition from a periodic attractor to a strange attractor. The amplitude has a very relevant impact on the system, resulting in an optimal resonance response for appropriate values related to correlation time. The chaotic system becomes regular under

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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Animal Behaviour And Biometeorology
Comprehension of the zinc chloride's ameliorative apoptotic and genotoxic effects on mice with cadmium-induced hepatotoxicity
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Publication Date
Wed Jan 01 2020
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees20
Synthesis of zinc nanoparticles by laser induced plasma and its effects on levels of thyroid hormones
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In the present study, the effect of Zinc nanoparticles on levels of (T3 , T4 and TSH) hormones was investigated. Zinc nanoparticles were synthesized by Laser induced plasma.The Nd: YAG Nd: YAG laser with a wavelength of 1064 nm was used to generate nanomaterials of the elements (zinc) upon collision with target atoms. Plasma generated by different laser intensity is generated. After confirming the preparation of zinc nanoparticles, XRD, AFM was examined, and the effect of these substances on the thyroid gland (T3, T4, TSH) was observed for two doses of each component (1 ml / kg, 4 ml / kg) after conducting a cytotoxicity examination of the lymphocytes of the rats extracted from Rat spleen was 1.8% less toxic to zinc, and as noted The

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Investment portfolio risks of the insurance company and their impacts on profitability ratios: An applied research at the national insurance co. for the period 2004-2014
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The research is trying to identify the investment portfolio risks of the insurance company and their impact, on the Profitability ratios of the company, and whether the company's scientific methods followed in the measurement of these risks, and conducted research in the National Insurance Company. by relying on its annual budget as well as the annual reports, The search dealing with these data in theoretical and practical major premise to statistically significant between to investment portfolio risk and financial performance correlation and reach a set of conclusions and recommendations which are the following.                

investments include many ri

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Publication Date
Mon Aug 01 2011
Journal Name
Journal Of Engineering
NUMERICAL INVESTIGATION OF LAMINAR MIXED CONVECTION IN TROMBE WALL CHANNEL
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The two dimensional steady, combined forced and natural convection in vertical channel is
investigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontal
inlet and exit segments have been added to the vertical channel. The vertical walls of the channel are
maintained at constant but different temperature while horizontal walls are insulated. A finite
difference method using up-wind differencing for the nonlinear convective terms, and central
differencing for the second order derivatives, is employed to solve the governing differential
equations for the mass, momentum, and energy balances. The solution is obtained for stream
function, vorticity and temperature as dependent variables

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Publication Date
Tue Jan 25 2011
Journal Name
Journal Of Cellular Biochemistry
Phytoestrogens directly inhibit TNF-α-induced bone resorption in RAW264.7 cells by suppressing c-fos-induced NFATc1 expression
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TNF-α-induced osteoclastogenesis is central to post-menopausal and inflammatory bone loss, however, the effect of phytoestrogens on TNF-α-induced bone resorption has not been studied. The phytoestrogens genistein, daidzein, and coumestrol directly suppressed TNF-α-induced osteoclastogenesis and bone resorption. TRAP positive osteoclast formation and resorption area were significantly reduced by genistein (10(-7) M), daidzein (10(-5) M), and coumestrol (10(-7) M), which was prevented by the estrogen antagonist ICI 182,780. TRAP expression in mature TNF-α-induced osteoclasts was also significantly reduced by these phytoestrogen concentrations. In addition, in the presence of ICI 182,780 genistein and coumestrol (10(-5) -10(-6) M) augmente

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of financial policy instruments to reduce the deficit of the State budget to the IMF terms: Applied Research at the Iraqi Ministry of finance - budget service
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Abstract search seeks to clarify the role and the importance of financial and fiscal policy adopted by the Iraqi Government during the years (2015 – 2018) to meet federal public deficit, as the Iraqi economy to shocks from falling global oil prices and terrorist attack ISIS, so the State budget suffered from a severe lack of income as a result of its reliance on revenues from selling crude oil and in return the high proportion of public expenditures. Especially military to counter these attacks that by studying the results of the implementation of budgets and analysis and statement Causes of disabilities and assessment of these policies and procedures imposed by the International Monetary Fund. the research aims to show how increased g

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