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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
Sat Apr 01 2023
Journal Name
Baghdad Science Journal
Influence of Glow and Afterglow Times on the Discharge Current of Argon at Low Pressure
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     An experimental investigation of the variation of argon discharge current with a glow and afterglow time intervals of a square discharge voltage was carried out at low pressure (6-11 mbar). The discharge was created between two circular metal electrodes of diameter (7.5 cm), separated horizontally by a distance (10 cm) at the two ends of a Pyrex cylindrical tube. A composite of two Gaussian functions has been suggested to fit and explain the variation graphs clearly. It is shown that the necessary times of glow and afterglow needed to attain a maximum discharge current are (70 us) and (60 us), respectively. The discharge current is observed to drop to the lowest value when the two times are serially longer than (85 us) and (72 u

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Publication Date
Wed May 01 2013
Journal Name
Chemical And Process Engineering Research
Synthesis and Characterization of Polycyclicacetal Derived from PEG & Erythro-Ascorbic Acid Derivative and Study Its Effect on the Activity of ACh Enzyme (In Vitro)
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Polycyclicacetal was prepared from the reaction of PEG with aldehyde derived from Erythro-ascorbic acid (pentulosono-ɣ-lactone-2,3-enedianisoate).All these compounds were characterized by Thin Layer Chromatography (TLC) and FTIR spectra and aldehyde was also characterized by (U.V-Vis), 1HNMR, 13CNMR, and mass spectra.The inhibitory effect of prepared polymer on the activity of human serum AcetylCholinesterase has been studied in vitro. The polymer showed a remarkable activity at low concentration (4.7x10-3 – 4.7x10-8M).

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Publication Date
Sat Jul 01 2023
Journal Name
The Egyptian Journal Of Hospital Medicine
Evaluation of the Antibiofilm Activity of Laurus nobilis Leaves Extract and Assessment of Its Effect on fimA and papC genes in Escherichia coli isolates
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Background: The beneficial gut bacterium E. coli can cause blood poisoning, diarrhoea, and other gastrointestinal and systemic disorders. Objective: This study amid to examines the antibiofilm activity of Laurus nobilis leaves extract on E. coli isolates and compares pre- and post-treatment gene expression of fimA and papC genes. Subjects and Methods: Ten isolates of E. coli were obtained from the Genetic Engineering and Biotechnology Institute, University of Baghdad, which was previously collected from Baghdad city hospitals and diagnosed by chemical tests, the diagnosis was confirmed using VITEK-2 System. The preparation of the aqueous and methanolic Laurus nobilis leaves extracts was done by using the maceration method and Soxhlet appara

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Publication Date
Sun Mar 01 2015
Journal Name
Baghdad Science Journal
The Effect of Age and Gender on Fetuin-A and Some Biochemical parameters in Blood Sera of Iraqi patients with T2DM: A comparative study
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The serum protein test includes measurement of the level of total protein(albumin, globulin). Fetuin-A is a blood protein made in liver. It can inhibit insulin receptor, enhance insulin sensitivity and make the individuals more likely to develop type 2 diabetes, then disorder in lipid profile (Total cholesterol(TC), low density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c), Triglyceride(TG) and very low density lipoprotein cholesterol (VLDL-c) . To evaluate Fetuin-A, total protein, albumin, globulin, HbAlc and lipid profile in 200 adult and elderly Iraqi patients with type 2 Diabetes Mellitus were taken and compare them with 200 subjects as a healthy control. The laboratory analysis(for patients and

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Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
Biological and chemical Study to evaluate the types of water used for drinking in the Al-youssiffiyah area and its effect on public health
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Election study included four sites for the waters in area of Youssifiyah south of Baghdad (river water, tank water, liquefactions water, and water filtrate and seethed and purifier by alum and chloride), the samples were collected during the month of June in 2007. Temperature, electrical conductivity and acidity are measured. Also , the concentration of chloride , sulphate , carbonate , nitrate , sodium , calcium , magnesium , hard total and total dissolved substances are determined , as well as heavy metals assess environmental risk (such as Cu, Pb, Zn, Fe). It was also a study of bacterial totals included both total Bacteria (TB) and Total Coliform Bacteria (TC) and Fecal Coliform (FC) and Fecal Streptococci (FS). The stu

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Publication Date
Thu Feb 23 2023
Journal Name
International Journal Of Emerging Technologies In Learning (ijet)
A Training Program According to Interactive Teaching Strategies and its Impact on Achievement and Creative Problem Solving for Fourth-Grade Preparatory Students in Chemistry
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The aim of the research is to know the effect of a training program based on interactive teaching strategies on achievement and creative problem solving among fourth-grade students in chemistry of the directorate of education Rusafa first, the sample was divided into two groups, one experimental and numbering (29) students and the other control group numbering (30) students. The experimental group underwent the training program in the first semester of the year (2021-2022) and the control one studied according to the usual method. Two tools were built, the first being an academic achievement test consisting of (40) multiple-choice items, and the second a test of creative problem-solving skills in a chemistry subject and consisting o

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Publication Date
Sat Feb 09 2019
Journal Name
Journal Of The College Of Education For Women
(عمل الاطفال مشكلة لابد من الحد منها (بحث مستل من رسالة ماجستير
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This study focuses on the phenomenon of child labour, which is regarded as a problem not only in Iraq or in developing countries but also in many other countries around the world .In fact, this problem is ignored and not given enough attention for there are millions of children working and doing different works in economically poor societies. Those children often work for long hours and are being exploited, doing works incompatible with their abilities and energy, preventing them from enjoying their childhood, developing both mentally and physically and joining school. The research introduced some suggestions aiming at preventing children from all forms of harmful and unhealthy works are presented. In fact, this is the very aim that most

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Publication Date
Tue Jan 29 2019
Journal Name
Journal Of The College Of Education For Women
Drugs addiction
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The growing phenomenon of drug abuse in light of the increasing psychological and social pressures experienced by members of the community of wars and crises of the Iraqi society in the middle of the last decade was Andv societies that are free of the phenomenon of drug addiction, but with a high level events, wars and economic crises and the deterioration of the situation security and lack of control on the border with the neighboring countries, it has become a breeding ground and the focus of drug-smuggling gangs, all of which led to the spread of drug abuse, especially among the youth category, and undoubtedly the seriousness of drug abuse Taatmd negative community impacts, Valmtaati drug becomes a member unproductive and unable to ea

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Publication Date
Tue Dec 22 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
دور معايير المحاسبة الدولية في القطاع العام ( IPSAS ) في تفعيل أداء المؤسسات الاقتصادية والأجهزة الحكومية: بحث تطبيقي في محافظة ذي قار
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One of the most distinguished instrumentsis being used by the state for implementing its strategy andachieving perfectly and effectively its goals and policies, and economizing the Public Finance and uplifting the services level for the sake of people, is truly thegovernmental accounting system.

 Thus, through this system the upper hand is located for supplying the accurate information, which does make the complete and just expressing concerning the budget implementing results. So,this research comes here because of the hugeness in this sector and the associations largeness and the dread of the governments failure in fulfilling its obligations and the provided services, and the required need for the effective and capable inf

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Publication Date
Fri Dec 12 2003
Journal Name
Iraqi Journal Of Laser
The Influence of Short Wavelength Laser on the Pupae Development of the Old World Screw- Worm Fly (OWSWF) Chrysomya bezziana Villeneuve (Diptera: Calliphoridae)
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The biological effects of pulsed N2-laser on the old world screw-worm fly, Chrysomya bezziana Villeneuve in the pupal stage were investigated. Different laser parameters were involved in this work. The old pupae of 1, 2, 3, 4 and 5 days were exposed to laser radiation during 10, 30 and 60 second with repetition rate 10, 20 and 30 pulse/second. The percent of normal adults emergence (female and male) was investigated. The results showed that the adults emergence was highly decreased as the repetition rate and exposure time increased when the pupae irradiated for 1, 2 and 3 days old as compared with 4 and 5 days. The results also indicated that the pupal period was significantly increased of irradiated pupae for 1, 2, 3 and 4 days old, whi

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