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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
Tue Jun 01 2021
Journal Name
Periodicals Of Engineering And Natural Sciences
Steganography using dual tree complex wavelet transform with LSB indicator technique
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Image steganography is undoubtedly significant in the field of secure multimedia communication. The undetectability and high payload capacity are two of the important characteristics of any form of steganography. In this paper, the level of image security is improved by combining the steganography and cryptography techniques in order to produce the secured image. The proposed method depends on using LSBs as an indicator for hiding encrypted bits in dual tree complex wavelet coefficient DT-CWT. The cover image is divided into non overlapping blocks of size (3*3). After that, a Key is produced by extracting the center pixel (pc) from each block to encrypt each character in the secret text. The cover image is converted using DT-CWT, then the p

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Publication Date
Tue Sep 08 2020
Journal Name
Baghdad Science Journal
A Proposed Analytical Method for Solving Fuzzy Linear Initial Value Problems
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     In this article, we aim to define a universal set consisting of the subscripts of the fuzzy differential equation (5) except the two elements  and , subsets of that universal set are defined according to certain conditions. Then, we use the constructed universal set with its subsets for suggesting an analytical method which facilitates solving fuzzy initial value problems of any order by using the strongly generalized H-differentiability. Also, valid sets with graphs for solutions of fuzzy initial value problems of higher orders are found.

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Publication Date
Tue Dec 05 2023
Journal Name
Baghdad Science Journal
Recognizing Different Foot Deformities Using FSR Sensors by Static Classification of Neural Networks
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Sensing insole systems are a promising technology for various applications in healthcare and sports. They can provide valuable information about the foot pressure distribution and gait patterns of different individuals. However, designing and implementing such systems poses several challenges, such as sensor selection, calibration, data processing, and interpretation. This paper proposes a sensing insole system that uses force-sensitive resistors (FSRs) to measure the pressure exerted by the foot on different regions of the insole. This system classifies four types of foot deformities: normal, flat, over-pronation, and excessive supination. The classification stage uses the differential values of pressure points as input for a feedforwar

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Publication Date
Sun Jan 30 2022
Journal Name
Iraqi Journal Of Science
Direct sum of π-projective semimodules
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      Let A, and N  are a semiring ,and  a left A- semimodule, respectively. In this work we will discuss two cases: 

  1. The direct summand of π-projective semi module is π-projective, while the direct sum of two π-projective semimodules in general is not π-projective . The details of the proof will be given.
  2. We will give a condition under which the direct sum of two π-projective semi modules is π-projective, as well as we also set conditions under which π-projective semi modules are projective.

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Publication Date
Wed Jan 11 2017
Journal Name
Journal: Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of some Metal Complexes with (3Z ,5Z, 8Z)-2-azido-8-[azido(3Z,5Z)-2-azido-2,6- bis(azidocarbonyl)-8,9-dihydro-2H-1,7-dioxa-3,4,5- triazonine-9-yl]methyl]-9-[(1-azido-1-hydroxy)methyl]-2H1,7-dioxa-3,4,5-triazonine – 2,6 – dicarbonylazide(L-AZ) .
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The reaction of LAs-Cl8 : [ (2,2- (1-(3,4-bis(carboxylicdichloromethoxy)-5-oxo-2,5- dihydrofuran-2-yl)ethane – 1,2-diyl)bis(2,2-dichloroacetic acid)]with sodium azide in ethanol with drops of distilled water has been investigated . The new product L-AZ :(3Z ,5Z,8Z)-2- azido-8-[azido(3Z,5Z)-2-azido-2,6-bis(azidocarbonyl)-8,9-dihydro-2H-1,7-dioxa-3,4,5- triazonine-9-yl]methyl]-9-[(1-azido-1-hydroxy)methyl]-2H-1,7-dioxa-3,4,5-triazonine – 2,6 – dicarbonylazide was isolated and characterized by elemental analysis (C.H.N) , 1H-NMR , Mass spectrum and Fourier transform infrared spectrophotometer (FT-IR) . The reaction of the L-AZ withM+n: [ ( VO(II) , Cr(III) ,Mn(II) , Co(II) , Ni(II) , Cu(II) , Zn(II) , Cd(II) and Hg(II)] has been i

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Publication Date
Sun Mar 20 2005
Journal Name
الجامعة المستنصرية / كلية التربية الأساسية
اثر استخدام استراتيجية بوليا واستراتيجية التمثيل المعرفي في تحصيل واستبقاء مادة الرياضيات لدى طلبة المرحلة المتوسطة
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Publication Date
Fri Mar 01 2024
Journal Name
مجلة المستنصرية لعلوم الرياضة
الأداء الابداعي لدى اللجنة الأولمبية الوطنية العراقية من وجهة نظر أعضاء الهيئات الإدارية في الاتحادات الرياضية
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Publication Date
Fri Jun 30 2023
Journal Name
مجلة دراسات وبحوث التربية الرياضية
تأثير تدريب الاسلوب المتباين في تنمية بعض القدرات البدنية والمهارات الاساسية للاعبي كرة القدم للصالات الشباب
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الملخص: تعد عناصر اللياقة البدنية العمود الفقري للألعاب الرياضية وخصوصا في الالعاب الجماعية ومنها لعبة كرة القدم للصالات والتي تعد من الالعاب الرياضية التي تتطلب بذل جهود كبيرة خلال المنافسة نظرا لطبيعة الاداء الذي يمتاز بالقوة والسرعة طيلة شوطي المباراة وهذا يتطلب من اللاعب امتلاكه للياقة بدنية عالية تؤهله للإيفاء بهذه المتطلبات خلال المنافسة، لذا نجد المدربين يتبعون كافة الاساليب وطرائق التدريب في سب

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Publication Date
Wed Jan 15 2025
Journal Name
Misan Journal For Physical Education Sciences
تأثير اسلوب تدريب المقاومات المرنة في تطوير القوة المميزة بالسرعة والتحمل الخاص للاعبي كرة القدم للصالات
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ملخص البحث: يعد اسلوب تدريب المقاومات المرنة واحد من اساليب تدريب القوة العضلية فهو النظام الذي يتم من خلاله استخدام تمرينات يتم ادائها ضد مقاومات متغيرة مثل الحبال المطاطية او اشرطة الساندو، ويمتاز هذا الاسلوب بتغير الشدة خلال اداء التمرين الواحد اي ان كلما تم مط الحبل المطاطي ازدادت مقاومته وبالتالي فان اللاعب يستخرج قوته اكثر كلما اقترب الى مركزية الحركة في التمرين وهذا هو جوهر الاختلاف بينه وبين استخد

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Publication Date
Tue Feb 21 2023
Journal Name
مجلة علوم الرياضة
تأثير منهج إرشادي نفسي لتخفيف الضغوط النفسية المصاحبة قبل أداء المباراة للحكام الدوليون في كرة القدم
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