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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 Dec 28 2017
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Increasing Carbon Concentration Increasing on the Mechanical Properties of TiCx Thin Films
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Carbides or nitrides thin films present materials with good mechanical properties for industrial applications as they can be coatings at low temperatures serve temperature sensitive surfaces. In this work the effect of the C percentage on the mechanical properties represented by the Young modulus (E) of combinatorial magnetron sputtered TiCx (34%x˂65%) has been studied. The structure of the produced films is TiC independent on the C concentration. The mechanical properties are increased with increasing the C concentration up to 50%, and then decreasing with further C % increasing. These results can be explained by considering the resultant residual stresses.

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Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
Effects of 650 nm Diode Laser and 532 nm Frequency-Doubled Q-Switched Nd:YAG Laser on The Growth of Candida albicans, With and Without Photosensitizers
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This work describes an experimental setup to evaluate the photodynamictoxicity of 650 nm diode laser and 532 nm Frequency-doubled Q-Switched Nd:YAG laser on the growth of Candida albicans as well as the potential fungicidal effect when combining the laser irradiation with specific photosensitizers namely methylene blue, toluidine blue, acridine orange and safranin O. In this study the findings showed that the number of colony-forming units per millilitre (CFU/ml) of C. albicans decreased with increasing exposure time. In particular in the case of the frequency doubled Nd:YAG laser combined with safranin O, the best lethal effect occurred at 11 minutes exposure time with 2.26 J/cm² energy density (89.18% reduction) in comparison with the

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Publication Date
Tue Jun 30 2015
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
Study the effect of ozone gas and ultraviolet radiation and microwave in the degredation of aflatoxin B1 produce by Aspergillus flavus on stored Maize grains.: Study the effect of ozone gas and ultraviolet radiation and microwave in the degredation of aflatoxin B1 produce by Aspergillus flavus on stored Maize grains.
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This study was conducted in the plant protection department/ College of Agriculture/ University of Baghdad to evaluate the efficiency of physical agents ozone, ultraviolet radiation, microwave for destroying afla produced in corn seeds. An isolate af A.flavus producing Aflatoxin B1 was obtained from plant protection dept. college of Agric. University of Baghdad. Results showed destroy toxin AFLA B1 the effect of radiation microwave in the media of Japex degree 80 and 100 co 57.14% and 85.71%, respectively, and for 20 sec, compared to the treatment comparison 0.00% as found significant differences were apparent between transactions and the treatment of comparison, as and notes the existence of a significant dif

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Publication Date
Fri Sep 30 2022
Journal Name
Journal Of The Iraqi University
Exclusion optimal portfolio from outlier by using fuzzy c-means clustering - analytical research at the Iraqi Stock Exchange
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This research aims to solve the problem of selection using clustering algorithm, in this research optimal portfolio is formation using the single index model, and the real data are consisting from the stocks Iraqi Stock Exchange in the period 1/1/2007 to 31/12/2019. because the data series have missing values ,we used the two-stage missing value compensation method, the knowledge gap was inability the portfolio models to reduce The estimation error , inaccuracy of the cut-off rate and the Treynor ratio combine stocks into the portfolio that caused to decline in their performance, all these problems required employing clustering technic to data mining and regrouping it within clusters with similar characteristics to outperform the portfolio

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Publication Date
Sat Sep 30 2023
Journal Name
Al–bahith Al–a'alami
Political Use of the Photograph: A Semiotic Study of the Photograph of Al-Kadhimi's Visit to Fallujah on the Anniversary of the Victory Over ISIS
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The research aims to determine what a photograph intends to convey as a visual text. Photographs are not captured randomly, especially those of politicians. Each photograph carries a message, even if interpretations of that message vary from person to person. The research adopts a methodology based on semiotic analysis, applying Laurent Gervero's model to analyze a photograph of the Iraqi Prime Minister Mustafa Al-Kadhimi's visit to Fallujah on the anniversary of the victory over ISIS. The photographs in question constitute a visual language built upon a sequence of iconic symbols and signs. These elements coalesce to give rise to an image centered around a particular theme, one designed to convey a precise messag

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Publication Date
Sat Dec 31 2022
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
THE ROLE OF COMMODITY DUMPING IN ENCOURAGING THE IRAQI CONSUMER TO BUY NON- ESSENTIAL GOODS: THE ROLE OF COMMODITY DUMPING IN ENCOURAGING THE IRAQI CONSUMER TO BUY NON- ESSENTIAL GOODS
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ABSTRACT

The research aims to study the effect of the commodity dumping phenomenon that Iraq suffered after 2003 on the consumption pattern of individuals, towards the acquisition of non-essential goods (luxury). To achieve our goal we relied on the questionnaire as a main tool for obtaining information related to the research, and it was distributed on a random sample of consumers in the city of Baghdad with 250 questionnaires. The answers of the research sample were analyzed using the statistical program (SPSS). The percentage weights and the factorial analysis method were used also to arrange the variables that affected on changing consumption patterns. The research reached a set of conclusions:

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Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
Disadvantages of Abortion and its Impact on Society
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As we have said that the reasons for abortion are many and varied them to be for
the purpose of treatment or the protection of the mother of the loss or that the abortion
of an act intended purpose of birth control or other reasons is the statistics that are
spread in the world that about 50-60 million abortions annually in the world If this
abortion criminal who is loss of the lives of fetuses and a disgrace to the preachers to
the progressive and liberal, secular, and because they were not able to maintain
human life after leaving the obligation to approach Islam and because life support is
the highest things, which is one of the necessities of the five obligatory street
maintenance came verses warn those who un

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Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Relatives marriage and its genetic effect on children
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Marriage is a characteristic of the human race, as it is one of the oldest organization, asoldas human beign marrige is a legitimale relationsbip between male and female in the name of Allah "o mankind !Be dutiful to your lord, Who created you from a single person (Adam), and from him (Adam) He created his Wife (Eve), and from them both He created mang men and women
Marriage is a requirement of human life to ensure tle continuity and survival of the human species and established it in a legal, social and legitimate frame,according to certain criteria and conditions so that the individual earns psychological and social comfort in the name of Allah and Allah has made for you Azwaj ( mates or wives), sons and grand sons, and has bestowed

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Publication Date
Thu Jan 01 2015
Journal Name
Political Sciences Journal
Rectifier technology and its impact on US policy
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كان لنهاية الحرب الباردة وعولمة العالم على وفق رؤية كونية تتجاوز حدود ومفاهيم السيادة الوطنية والقومية الاثر الواضح في ترتيب العلاقات الدولية , واصبحت تلك العلاقات تدور حول محورين الاول .. هو الاعتماد المتبادل بين الدول من اجل الوصول الى خطوط مشتركة للمصالح المختلفة بين هذه الدول . والآخر.. هو تبعية الدول الضعيفة للدول القوية لافتقار الاولى توفير الحاجيات الى مواطنيها . هذا يشير الى نشأة علا

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Publication Date
Fri Jun 30 2023
Journal Name
نسق
Semiotic Isotopy and Its Effect on Reading Comprehension
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