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alkej-347
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
Wed Dec 14 2011
Journal Name
Journal Of Kerbala University
Effect of prey type on some reproductive aspects in crustacean zooplankton Macrocyclops albidus (Copepoda:cyclopoida)
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The experiment was conducted to investigate the effect of prey type (Artemia nauplii, mosquito larvae and paramecium) on some reproductive aspects in crustacean zooplankton M. albidus which included reproductive period, post reproductive period, period spend to egg appearance and the period from appearance of egg to nauplii releasing. Results revealed that females fed on mosquito larvae had the highest mean of postreproductive period and lowest mean of the period spend to egg appearance, which differed significantly (P < 0.05) compared with the means of females who fed on Artemia nauplii and paramecium on the other hand the differences were not significant in reproductive period and the period from appearance of egg to nauplii releasing.

Publication Date
Sat Feb 28 2026
Journal Name
Imam Jaafar Al-sadiq University Journal Of Human And Social Sciences
قياس فجوة تطبيق ابعاد القيادة الملهمة في المنظمات العامة بحث تحليلي في المديريات العامة لمقـــــــــــــــــــــــــــر وزارة التربية العراقية
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يهدف البحث الى قياس مدى التطبيق والتبني للقيادة الملهمة في المنظمات العامة، وقد اشتقت مشكلة البحث النظرية من وجود فجوة معرفية وذلك لقلة الدراسات والبحوث التي تناولت متغير البحث بأبعاده (الرؤية المستقبلية، الثقة بالنفس، تمكين العاملين، ادارة التغيير)، واعتمد البحث المنهج التحليلي عن طريق استعمال الاستبانة في المنظمة التي تم اختيارها وذلك لكونها تعد من المنظمات الاساسية في تقديم الخدمات التعليمية المهمة في

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تقويم أداء لجنة التدقيق في القطاع المصرفي العراقي ـــ أنموذج مقترح: بحث تطبيقي في عينة من المصارف العراقية
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The audit committees are considered to be one of the most important committees because of the role they play in supervising and monitoring the process of formation of the financial statements and correction of the internal supervising system also strengthening the independency of the internal and external audit. Matters which increases the efficiency and integrity of the financial statements which reflects positively on competence of board of directors and then enhance the position of the company through increasing the trust of the users of the financial statement within the company. 

Therefore, this research deals with the evaluation of the performance of the audit committees in Iraqi banks according to the local rules and

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Publication Date
Thu Dec 03 2015
Journal Name
Iraqi Journal Of Science
New multispectral images classification method based on MSR and Skewness implementing on various sensor scenes
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Publication Date
Tue Jan 01 2019
Journal Name
Journal Of Southwest Jiaotong University
Multi -Focus Image Fusion Based on Stationary Wavelet Transform and PCA on YCBCR Color Space
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The multi-focus image fusion method can fuse more than one focused image to generate a single image with more accurate description. The purpose of image fusion is to generate one image by combining information from many source images of the same scene. In this paper, a multi-focus image fusion method is proposed with a hybrid pixel level obtained in the spatial and transform domains. The proposed method is implemented on multi-focus source images in YCbCr color space. As the first step two-level stationary wavelet transform was applied on the Y channel of two source images. The fused Y channel is implemented by using many fusion rule techniques. The Cb and Cr channels of the source images are fused using principal component analysis (PCA).

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Publication Date
Tue May 23 2023
Journal Name
Journal Of Sensors
On-Board Digital Twin Based on Impedance and Model Predictive Control for Aerial Robot Grasping
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Aerial manipulation of objects has a number of advantages as it is not limited by the morphology of the terrain. One of the main problems of the aerial payload process is the lack of real-time prediction of the interaction between the gripper of the aerial robot and the payload. This paper introduces a digital twin (DT) approach based on impedance control of the aerial payload transmission process. The impedance control technique is implemented to develop the target impedance based on emerging the mass of the payload and the model of the gripper fingers. Tracking the position of the interactional point between the fingers of gripper and payload, inside the impedance control, is achieved using model predictive control (MPD) approach.

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Publication Date
Wed Mar 29 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Estimation Pore and Fracture Pressure Based on Log Data; Case Study: Mishrif Formation/Buzurgan Oilfield at Iraq
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Prediction of the formation of pore and fracture pressure before constructing a drilling wells program are a crucial since it helps to prevent several drilling operations issues including lost circulation, kick, pipe sticking, blowout, and other issues. IP (Interactive Petrophysics) software is used to calculate and measure pore and fracture pressure. Eaton method, Matthews and Kelly, Modified Eaton, and Barker and Wood equations are used to calculate fracture pressure, whereas only Eaton method is used to measure pore pressure. These approaches are based on log data obtained from six wells, three from the north dome; BUCN-52, BUCN-51, BUCN-43 and the other from the south dome; BUCS-49, BUCS-48, BUCS-47. Along with the overburden pressur

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Publication Date
Tue Sep 19 2017
Journal Name
Al-academy
Peer Education Strategy and its Impact on the Development of Skill of Perspective Drawing
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       After the twenty – first century become  necessary for us motorcade era in educational a chevements by searching  for the best  strategies and teaching methods and  techniques  artotalbagesh  resorting to the strategy

Did not use in use in the teaching of the foreseeable  material  general by voice and teaching  perspective  for the student of the class fourth science

In particular ,so the researcher asking the question follows:

Can the peer education strategy to have an impact in perspective drawing skill development ?

   From here it demonstrated the importance of current research know the impact of  p

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Publication Date
Tue Nov 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Proposal of Using Principle of Maximizing Entropy of Generalized Gamma Distribution to Estimate the Survival probabilities of the Population in Iraq
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In this research we been estimated the survival function for data suffer from the disturbances and confusion of Iraq Household Socio-Economic Survey: IHSES II 2012 , to data from a five-year age groups follow the distribution of the Generalized Gamma: GG. It had been used two methods for the purposes of estimating and fitting which is the way the Principle of Maximizing Entropy: POME, and method of booting to nonparametric smoothing function for Kernel, to overcome the mathematical problems plaguing integrals contained in this distribution in particular of the integration of the incomplete gamma function, along with the use of traditional way in which is the Maximum Likelihood: ML. Where the comparison on the basis of the method of the Cen

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Publication Date
Tue Aug 13 2024
Journal Name
الترجمة و اللسانيات - جمعية المترجمين العراقيين
تأثير تفاسير الترجمة الارامية لأسفار المكتوبات (بحث مقارن بين العبرية والارامية)
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