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
Fri Mar 31 2017
Journal Name
Al-khwarizmi Engineering Journal
Design of Nonlinear PID Neural Controller for the Speed Control of a Permanent Magnet DC Motor Model based on Optimization Algorithm
...Show More Authors

In this paper, the speed control of the real DC motor is experimentally investigated using nonlinear PID neural network controller. As a simple and fast tuning algorithm, two optimization techniques are used; trial and error method and particle swarm optimization PSO algorithm in order to tune the nonlinear PID neural controller's parameters and to find best speed response of the DC motor. To save time in the real system, a Matlab simulation package is used to carry out these algorithms to tune and find the best values of the nonlinear PID parameters. Then these parameters are used in the designed real time nonlinear PID controller system based on LabVIEW package. Simulation and experimental results are compared with each other and showe

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
General Hospital and Baghdad Teaching General Hospital
...Show More Authors

Abstract:

      This research aims to identify the type of cultural values prevailing in the Ramadi General Hospital, and Baghdad, educational, and whether the organization's culture values play a role in improving the quality of nursing care service in hospitals, and how different cultural values of the nurses between Ramadi Teaching Hospital  and General education Baghdad Hospital because of the nature social and cultural Different each region, including the research sample of all nurses working in Baghdad Teaching Hospital, and Ramadi educational-General, adopted Find descriptive analytical approach adopted scale developer (Hofstede, 1991) and (Furrer et al, 2000) And pres

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
Natural Products of Lactococcus Overcome Nosocomial Infection in Some of Baghdad Hospitals in Iraq
...Show More Authors

Nosocomial infections (NIs) are hospital-acquired associated infections, and also contracted due to the infections or toxins that exist in some location, like hospital. Therefore in our study, 4 Lactic acid bacteria (LAB) isolates were obtained from dairy product (Lactobacillus brevis, L. acidophilus, Lactococcus raffinolactis and Lactococcus lactis) and were tested for Bacteriocin production to select Lactococcus lactis among them. Cell free supernatant (CFS), Lipid and partial purification of protein La. Lactis had high inhibitory effect against test pathogens (E. coli, Bacillus cereus, Staphylococcus aureus and Streptococcus). 30 isolates that diagnosed by Vitec, were isol

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Thu Oct 18 2018
Journal Name
Al–bahith Al–a'alami
Public exposure to news satellite channels and its relationship to levels of preference and evaluation of programs: Survey study on a sample of the audience of Baghdad City Cente
...Show More Authors

The media, especially the satellite channels in our time, are one of the most important pillars of daily life, public and private, for society and people, and are considered by sociologists and sociologists as one of the most important factors of social upbringing and the most important, as a result of the technological and technological development of the media as well as increasing their numbers and vertical and horizontal expansion locally, As well as entering into the lives of individuals and people and leading them to important sites within their interests and preferences, not to mention the long time spent exposure to those media and benefit from the programs offered or broadcast. , The problem of this research is that there is a l

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jun 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
التجربة الصينية في الإصلاح والتنمية : بحث في خصوصية المنهج والدروس المستخلصة
...Show More Authors

The Chain's experience of reform and development monopolized with deep and exclusive concerns of the world.

Starting from the academic departments of universities and researches and study centers to the world's organizations and institutes passing through the government and the official systems in many countries that get affected , positively or negatively, now or later by china's economic development .

Searching in the china's experience of reform and development  is important because it takes place in a developing country in which the leadership is succeeded in choosing the right methodology an model of changing and operating economics, making use of all the past national a

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jun 21 2025
Journal Name
Journal Of University Of Anbar For Pure Science
Semi – automated analysis for the Nanoscale determination of Chlorpheniramine maleate drug using sodium nitroprusside by continuous flow feed via homemade NAG-SSP Photometer
...Show More Authors

This study presents a rapid, sensitive, and straightforward approach to measure chlorpheniramine maleate (CPM) by using turbidity CFIA. The method involves CPM reacting with sodium nitroprusside (Nitropress) to produce a pale white precipitate. The NAG-SSP-5S1D analyzer was used to measure turbidity at 0°–180° angle to detect the attenuation of incident light as a result of collision on the surfaces of the precipitate particles. The linear range of CPM measurements was between 0.008 and 11 m.mol/L, with correlation coefficient of 0.9983 and R2% = 99.65. The limit of detection was determined to be 0.0328 µg/sample from the lowest concentration in the calibration curve, and the repeatability of the method (RSD%) was less than 0.4% (n = 6

... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Baghdad Science Journal
Some Results on Normalized Duality Mappings and Approximating Fixed Points in Convex Real Modular Spaces
...Show More Authors

  In this paper, the concept of normalized duality mapping has introduced in real convex modular spaces. Then, some of its properties have shown which allow dealing with results related to the concept of uniformly smooth convex real modular spaces. For multivalued mappings defined on these spaces, the convergence of a two-step type iterative sequence to a fixed point is proved

View Publication Preview PDF
Scopus (5)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
On Blow-up Solutions of A Parabolic System Coupled in Both Equations and Boundary Conditions
...Show More Authors

This paper is concerned with the blow-up solutions of a system of two reaction-diffusion equations coupled in both equations and boundary conditions. In order to understand how the reaction terms and the boundary terms affect the blow-up properties, the lower and upper blow-up rate estimates are derived. Moreover, the blow-up set under some restricted assumptions is studied.

View Publication Preview PDF
Scopus (11)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Dec 11 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of Preoperative Psycho-educational Program on Stress of Cardiac Surgery Patients
...Show More Authors

Objective: The study aimed to determine the effectiveness of preoperative psycho - education al
program on cardiac surgery patients information and their level of stress. And find out the differences
in the Psycho educational
program with regard to patients demographic characteristics such as age and gender.
Methodology Aquazi-experimental study was carried out to determine the effectiveness of
preoperative education program on stress for cardiac surgery patients in Baghdad city from the 28th of
March, 2010 , to 19th of September ,2011.
The preoperative psycho - educational program, as well as the questionnaire was constructed as a tool of
data collection for the purpose of the study. Purposive (non probability) s

... Show More
View Publication Preview PDF
Publication Date
Sat Mar 30 2013
Journal Name
College Of Islamic Sciences
 The responses of the army overseer to the grammarians in the preposition section
...Show More Authors

This is a contextual study in face and isotope science, and I have made it in one of the terms faces and isotopes, which is the word (bad). Quranic also, and that is at every aspect they mentioned.
The nature of the research required that it be divided into three sections:
The first topic: I singled it out to show the types of contextual connotations.
- The second topic: I singled it out to define the word bad and its meaning.
- The third topic: I devoted it to the study of the word bad and explaining the significance of the Quranic context on the additional meaning and the original meaning.
Conclusion: It mentioned the most important results, which are:
1- The significance of the Quranic context is one of the most impo

... Show More
View Publication Preview PDF