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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
Fri Jun 01 2018
Journal Name
Journal Of Engineering
Experimental Study on Tribological Characteristics of AA 6061 Alloy Reinforced with Al2O3 and B4C Particles
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Two different composite materials were prepared by stir casting method of AA 6061 alloy as a matrix reinforced with two addition different ceramic materials Al2O3 and B4C of grain size   20 µm by 2.5, 5, 7.5 and10% in weight. The composite material with aluminum alloy as a matrix possesses a unique mechanical properties such as: high specific strength and hardness, low density, and high resistance to corrosion and friction wear. This composite is widely used in automotive parts space and marine applications.

Pin-on-disc technique was used to calculate the wear rate for each addition of Al2O3 and B4C particles. Rockwell hardness test and

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Publication Date
Thu Jan 31 2019
Journal Name
Journal Of Engineering
Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material
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In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant

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Publication Date
Sun Jun 30 2019
Journal Name
Journal Of Engineering
Energy, Exergy and Anergy Analysis of Vertical Split Air Conditioner Under experimental ON-OFF Cycling
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A time series analysis can help to observe the behavior of the system and specify the system faults. In addition, it also helps to explain the various energy flows in the system and further aid in reducing the thermodynamic losses. The intelligent supervisory LabVIEW software can monitor the incoming data from the system by using Arduino microcontroller and calculates the important parameters. Energy, exergy, and anergy analysis present in this paper to investigate the system performance as well as its components. To accomplish this, a 4-ton vertical split air conditioner based on vapor compression refrigeration cycle charged with refrigerant R-22 was modified for experimental analysis. The results showed that during 540

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Publication Date
Thu Sep 22 2022
Journal Name
Veterinary Medicine International
Mentha piperita Oil Exerts an Antiepileptic Effect in Pilocarpine and Pentylenetetrazol-Induced Seizures in Mice
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Introduction. Epilepsy is a progressive, chronic neurological disorder characterized by recurrent seizures. Peppermint (Mentha piperita L.) (MP) is one of the most commonly ingested herbal teas or tisanes with a single component. Aim. We aimed to assess the potential antiepileptic and neuroprotective features of MP essential oil (MPO) in pilocarpine (P) and pentylenetetrazol (PTZ) models of epilepsy. Methods. The study used eight groups of mice to assess the anticonvulsant activity of MPO in both the P and PTZ acute models in mice. P (350 mg/kg, i.p.) was given 30 minutes after MPO (1.6, 3.2, and 6.4 ml/kg, i.p.). As a positive control group, diazepam (1 mg/kg, i.p) was used. PTZ (95 mg/kg, i.p.) was given 30 minutes after M

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Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
The Use Of Some Parametric And Non parametric Methods For Analysis Of Factorial Experiments With Application
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summary

In this search, we examined the factorial experiments and the study of the significance of the main effects, the interaction of the factors and their simple effects by the F test (ANOVA) for analyze the data of the factorial experience. It is also known that the analysis of variance requires several assumptions to achieve them, Therefore, in case of violation of one of these conditions we conduct a transform to the data in order to match or achieve the conditions of analysis of variance, but it was noted that these transfers do not produce accurate results, so we resort to tests or non-parametric methods that work as a solution or alternative to the parametric tests , these method

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Publication Date
Wed Sep 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Thymosin Beta 4 on Developing Dental Tissue (Experimental Study on Rats)
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Background: Odontogenisis is a complex process controlled by dynamic and reciprocal interactions that regulated by various molecules. Thymosin β4 is a small bioactive peptide with wide spectrum biological effects on much cell types. The present study was designed to highlight the effect of synthetic exogenous Tβ4 on developing dental tissue of the upper central teeth of rats, by histological examination and immunohistochemical evaluation of TGFβ1. Materials and method: Thirty six Albino Wister pregnant rat 18control group received intraperitoneal injection of normal saline and the others are experimental group received 50µg/300µl of Tβ4 injection. The animals were sacrificed at periods 16th and 18th day I.U.L and one day p

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Publication Date
Tue Apr 04 2023
Journal Name
International Journal Of Professional Business Review
Leadership and Internal Communication Strategies in Public Organizations: Analytical Research
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Purpose: As managers can lead a set of ways to improve internal communication in public organizations, and leadership can cultivate a common understanding of goals within the organization and share the vision in preparation for its way to better performance, the purpose of the research is to assess the type and strength of the relationship between internal communication and different forms of leadership.   Theoretical framework: The study demonstrates how leaders in public organizations improve internal communication, related to employees' perceptions of public organizations' routines and performance.   Design/methodology/approach: The  study  uses the  ordinary  least  squares  (OLS) and  applied multiple  regression A sa

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Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
A proposed model program to audit the contribution of municipal institutions to achieving the environmental dimension of sustainable development "applied research"
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Abstract

               The research aimed to prepare an audit program focusing on the activities of municipal institutions related to the environmental dimension as one of the dimensions of sustainable development, and applying the program for the purpose of preparing an oversight report related to assessing the impact of the activities of municipal institutions on the environmental reality as the main channel through which municipal institutions contribute to achieving the part related to it. Among the requirements of sustainable development, the proposed program was prepared and applied to the institutions affiliated to the Directorate of Mu

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Publication Date
Mon Nov 01 2010
Journal Name
Iraqi Journal Of Physics
Streams and plasma parameters experimental studies in He-CO gas mixtures
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DC glow discharges were generated between a thin cylindrical anode and a flat cathode, streamers are thought to propagate by photo-ionization; the parameters of photo-ionization depend on the He: CO ratio. Therefore we study streamers in He ( 90%, 80% and 70% ) with (10%, 20% and 30%) CO respectively. The streamer diameter is essentially the change by increase for similar voltage and pressure in all He-CO mixtures.

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Publication Date
Sun Apr 07 2013
Journal Name
Journal Of Educational And Psychological Researches
Determinants of using experimental groups and choosing reasons in psychological researches
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Until The Second Half Of Nineteenth Century  , Psychology Depended On Philosophy In Its Experiences Which Means It Depend On Individuals Feelings Toward Psychological Experiences And Rapid Observation . As For The Scientific Organized Experimentation And Observation By Machines Have Been Used Later   .

The Experimentation Looking For The Cause Of  Phenomena And How Is That Happened   Also Reveal The Causal Relationship Between Among Phenomena . The Experiences In Psychology Field Include In Its Simplest Form Only One Variable ( Effective) Which Is Called Independent Variable As Well As Another Variable ( Affected )   That Called  Dependent Variable .

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