Preferred Language
Articles
/
alkej-347
Experimental and Numerical Research on Flow-Induced Vibration in Valves
...Show More Authors

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).

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
Study of Television Advertising and its Impact on Consumer Behavior in a Sample of Children Aged 9-12 Years
...Show More Authors

The aim of this study was to study TV advertising and consumer behavior in children and to meet the needs of children. The study included 100 children from Baghdad who were randomly selected from different regions ranging in age from 9-12 years of both males and females. The current research was based on the interview and the completion of special forms prepared for this purpose. This age group was selected for the rare studies conducted on television advertising and limited to different sectors. Data on age and sex were documented, as the results of this study proved The afternoon period was the preferred period for watching the TV show in males, where it was 22%, while the morning period was the female favorite, and it was 23%. The ind

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Business Risk Assessment Using Client Strategy Analysis Approach in order to Increase the Efficiency and Effectiveness of the Audit Process
...Show More Authors

Abstract

This study aimed to identify the business risks using the approach of the client strategy analysis in order to improve the efficiency and effectiveness of the audit process. A study of business risks and their impact on the efficiency and effectiveness of the audit process has been performed to establish a cognitive framework of the main objective of this study, in which the descriptive analytical method has been adopted. A survey questionnaire has been developed and distributed to the targeted group of audit firms which have profession license from the Auditors Association in the Gaza Strip (63 offices). A hundred questionnaires have been distributed to the study sample of which, a total of 84 where answered and

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Oct 21 2018
Journal Name
Al–bahith Al–a'alami
“Usages of the Youth in the Emirati Society for the Dubbed Turkish Series on the Arab Satellite Channels and the Satisfactions Achieved”
...Show More Authors

The research topic is summarized in the importance of studying the measuring the extent of the university youth’s exposure in the Emirati Society to those series and the resulting achieved satisfaction. The most important results and recommendations of the study are as follows: a high rate of the respondents’, sample individuals, exposure to the dubbed Turkish series since it is evident that almost three-fourths of the study individuals watch the dubbed Turkish series,.”. The most significant positive aspects of the dubbed Turkish series are: “they focus on the most important tourist attractions in Turkey” and “ improving the audience›s knowledge and information on the traditions of the Turkish society”. The most apparent

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jul 01 2023
Journal Name
مجلة الادارة والاقتصاد
اثر ممارسات القيادة الالكترونية في الجاهزية التنظيمية بحث ميداني في الشركة العامة للمنتوجات الغذائي
...Show More Authors

Publication Date
Fri Jan 01 2021
Journal Name
مجلة الدنانير
تأثير بناء المقدرات الجوهرية في إدارة الإيرادات الضريبية/ بحث تحليلي في الهيئة العامة للضرائب
...Show More Authors

هدف البحث الى بيان تأثير بناء المقدرات الجوهرية المتمثل ابعادها بـ (التعلم التنظيمي ، المرونة الاستراتيجية ، المقدرات التكنولوجية، رأس المال البشري) في ادارة الايرادات الضريبية المتمثلة ابعادها بـ (فاعلية الادارة الضريبية ، الكفاءة في العمل ، التشريعات الضريبية) وتم اعتماد الاستبانة كأداة رئيسة في جمع البيانات والمعلومات من العينة البالغ عددها (35) مبحوثاً ممن هم بموقع (مدير قسم ، وكيل مدير قسم، مسؤول شعبة) ف

... Show More
Preview PDF
Publication Date
Thu Jan 23 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تاثير المبــادرة الزراعيـة في نشـاط الإقراض المصرفي والارباح: بحث تطبيقي في المصرف الزراعي التعاوني
...Show More Authors

This study has pursued to identify the agricultural initiative (the independent variable) with all its subordinate variables  in profits and bank lending activity (the dependent variable), as an applied study in cooperative agricultural bank, which stemms from a problem that includes:-

  1. The policy variance of agricultural initiative lending and variation of the cooperative agricultural bank lending policies.
  2. decreasing the demand on the loans of the cooperative agricultural bank and increasing the demand on the agricultural initiative by the individuals (citizens).

 The purpose of the study is represented by clarifying the practical reality of applying the agricultural initiative and its

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 16 2019
Journal Name
Al–bahith Al–a'alami
press Coverage Of Youth Social Problems An analytical Study of Al- Sabah Newspaper
...Show More Authors

The tremendous political transformations that took place in Iraq after 2003 led by the USA and its allies led to a change of its political system under the slogan of liberating Iraq from dictatorship, establishing a democratic system and spreading freedom among members of the society.
However, democracy was a mantle under which the US intended to achieve its expansionist ambitions in the region. It did not come to liberate Iraq as it claimed, but it occupied Iraq and all its materialistic and human resources. Thus, this change resulted in lots of negative events and societal pests that affected the entire social system and values. Youth is an important segment; it is one of the most affected age groups with the happenings and accident

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Jul 25 2024
Journal Name
Journal Of Administration And Economics
ادارة الاحتواء العالي وتأثيرها في سلوك العمل الاستباقي: بحث تحليلي في مجلس محافظة بغداد
...Show More Authors

يهدف البحث الحالي الى اختبار علاقة الارتباط والتأثير بين إدارة الاحتواء العالي وسلوك العمل الاستباقي ، ومن اجل تحقيق ذلك تم اختيار مجلس محافظة بغداد ميداناً لتطبيق البحث، وشمل البحث متغيرين إدارة الاحتواء العالي عبر ابعاده الفرعية )ممارسات التطوير، المكافآت، مشاركة المعلومات، التمكين(، وسلوك العمل الاستباقي عبر ابعاده )تولي المسؤولية، صوت الموظف، المبادرة الشخصية(، وضمت عينة البحث ) 97 ( فرداً من الموظفين ا

... Show More
View Publication
Crossref
Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
A New Fractal Printed Dipole Antenna Based on Tent Transformations for Wireless Communication Applications
...Show More Authors

In this paper, a compact multiband printed dipole antenna is presented as a candidate for use in wireless communication applications. The proposed fractal antenna design is based on the second level tent transformation. The space-filling property of this fractal geometry permits producing longer lengths in a more compact size. Theoretical performance of this antenna has been calculated using the commercially available software IE3D from Zeland Software Inc. This electromagnetic simulator is based on the method of moments (MoM). The proposed dipole antenna has been found to possess a considerable size reduction compared with the conventional printed or wire dipole antenna designed at the same design frequency and using the same substrate

... Show More
View Publication Preview PDF
Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Laser
PDF Influence of Er:Cr;YSGG laser Desensitization on SBS of resin cement to dentin
...Show More Authors

Background: Crown preparation of vital teeth involve the removal of a sound tooth structure, and when enamel removed this lead to exposed dentin with an   increase in the number of open dentinal tubules also the diameter of dentinal tubules will increase, furthermore lead to increase movement of fluids inside the tubules all that causes post preparation sensitivity. The aim of this study is to evaluate the effect of desensitizing by Er:Cr:YSGG laser on shear bond strength of prepared tooth and resin cement. Materials and methods: Thirty sound maxillary premolars, grouped into three groups(n=10). Group A is the control group, group B irradiated by Er:Cr:YSGG laser with (0.25 W, 20 Hz, 1

... Show More
View Publication Preview PDF