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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
Fri Aug 20 2021
Journal Name
Iraqi Journal Of Laser
Design of Tunable Optical Band Pass Filter based on in-Line PM-Mach Zehnder Interferometer
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In this paper, tunable optical band-pass filters based on Polarization Maintaining Fiber –Mach Zehnder Interferometer presented. Tunability of the band-pass filter implemented by applying different mechanical forces N on the micro-cavities splicing regions (MCSRs). The micro-cavity formed by using three variable-lengths of single-mode polarization-maintaining fiber with (8, 16, 24) cm lengths, splice between two segments of (SMF-28) with (26, 13) cm lengths, using the fusion splicing technique.  Ellipsoidal shape micro-cavities experimentally achieved parallel to the propagation axis having dimensions between (12-24) μm of width and   (4-12) μm of length. A micro-cavity with width and length as high as 24 μm and 12 μ

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Measuring and analysis of the impact of public budget deficit on external debt in lraq with in the framework of joint integration of the period (1990 – 2016 )
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The concept of deficit in public budget becomes a chronic economic phenomenon in most of the world, whether the advanced countries or developing countries. Despite  the difference in the visions of the economic schools to accept or reject the deficit in public budget but the opinion that prevailed is the necessity of the state to reduce the public spending which led to a continuous deficits in the public budget which consequently increased the government borrowing ,increase income taxes and wealth, consequently this weakened the in motivation in private investment which contributed to the increase of in factionary stagnation , so that governments have to cover the lack of local funding sources which become difficult to be eq

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Publication Date
Fri Nov 09 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
The Effect of Polycystic Ovarian Syndrome on the Physical Status of Women in Reproductive Age
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Objectives: To Assess the Effect of Physical Status of Polycystic Ovarian Syndrome on Women in Reproductive Age,
To Find out the Relationship Between Polycystic Ovarian Syndrome and Women's Physical Health (Acne , Hirsutism ,
Weight Gain , Irregular Menstrual Period),&To Identify the Association of Physical Status to polycystic ovarian
syndrome and Some Socio Demographic Characteristic (Age ,Occupation & Obesity ), and Reproductive
Characteristic(Gravida ,Para ,Abortion &Menstrual Regularity).
Methodology :a descriptive analytical study was conduct on Non-probability (purposive sample) of (100)women who
suffering from polycystic ovarian syndrome in reproductive age in infertility counseling from three hospit

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Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
"The Impact of International Public Sector Accounting Standards (IPSASs) on the Public Budget in Iraq"
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     The aim of the research is to determine the impact of the Iraqi public budget on IPSASs by conducting the questionnaire; the research was based on the hypothesis that "there is an impact of the adoption of the International Accounting Standards in the general budget of Iraq”. The research concluded that the government accounting system closely interferes with the general budget at all stages. The shifting towards the accrual basis is the first element of the reform package towards reaching the reform of the state budget. Without reforming government accounting, it is almost impossible to develop the budget. IPSASs are a recognized reference to the assessment and development of governmen

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of strategic Supremacy on strategic success A case study in Thi Qar Governorate
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Purpose To test the effect of strategic Supremacy on strategic success A case study in Thi Qar Governorate, methodology/approach – this is a mandatory entry.

a case study was used and applied to the Department managers of Government of the province of Thi Qar, Research limitations/implications – It is clear that the strategic Supremacy variable is not being used effectively to achieve strategic success.

Practical implications – use strategic supremacy positively to Support for strategic success. implementing and monitoring ignorance of them in how to use thi

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Publication Date
Thu Jan 04 2024
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Creative accounting practices for supply contracts and the role of internal audit in reducing them: An exploratory study on a sample of industrial companies in Iraq
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Abstract:

                The internal control is the tool through which it is possible to verify and ensure the implementation of tasks in accordance with the established plans and programs and to evaluate the level of performance that is implemented within the different companies.

A guarantee from the supplier with the absence of a specialized technical committee that follows up the stages of implementing the contract and disbursing all amounts of financial dues to the supplier before completing the implementation of the contract and overlooking the non-implementation of some clauses of the contract by the committee in charge of

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Publication Date
Mon Apr 03 2023
Journal Name
Chemistryselect
Development and Validation of Spectrophotometric Methods for the Quantitative Determination of Doxycycline Hyclate in Pure Form and Pharmaceutical Formulations Using Flow‐Injection and Batch procedures: A Comparative Study
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Abstract<p>Doxycycline hyclate is an antibiotic drug with a broad‐spectrum activity against a variety of gram‐positive and gram‐negative bacteria and is frequently used as a pharmacological agent and as an effector molecule in an inducible gene expression system. A sensitive, reliable and fast spectrophotometric method for the determination of doxycycline hyclate in pure and pharmaceutical formulations has been developed using flow injection analysis (FIA) and batch procedures. The proposed method is based on the reaction between the chromogenic reagent (V<sup>4+</sup>) and doxycycline hyclate in a neutral medium, resulting in the formation of a yellow compound that shows maximum absorbance at 3</p> ... Show More
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Publication Date
Sun Dec 27 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Limitation of liability and reinsurance and its role in increasing production insurance: بحث أستطلاعي في شركة التامين العراقية العامة
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The liability limit liability limit and reinsurance re factors insurance are important in influencing the achievement of company's competitive goals and achieve success and excellence in the market and because the limit of liability and reinsurance aimed to increase output with the stability of inputs leading to increased insurance business and increase profits. The study was based on two variables presidents interact with each other to form the intellectual and philosophical framework has two ( the limit of liability and reinsurance ) . The study was launched from a problem expressed by a number of targeted questions answered from the elucidation of theoretical philosophy and intellectual goals of these variables and highlight the impor

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Publication Date
Fri Nov 11 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of auditing in analyzing the relationship between the governance of investment policy and the cost of debt and its reflection on the continuity of the institution: (بحث تطبيقي في عينة من الشركات المدرجة في سوق العراق للأوراق المالية)
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The research aims to determine the effectiveness of auditing in light of the relationship between the governance of investment policy and the cost of debt in companies listed on the Iraqi Stock Exchange. The problem of the research is to raise the question about the effect of the governance of investment policy and the cost of debt on the effectiveness of auditing and auditors. During the research, the most important of them were: the existence of an impact relationship on the effectiveness of auditing through the relationship between the governance of investment policy and the cost of debt. The companies listed in the Iraqi Stock Exchange lack an effective proposed guide or framework dealing with the governance of investment policy desp

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Publication Date
Thu Feb 01 2024
Journal Name
Journal Of Engineering
Assessment of Bearing Capacity and Settlement Characteristics of Organic Soil Reinforced by Dune Sand and Sodium Silicate Columns: A Numerical Study
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Organic soil is problematic soils in geotechnical engineering due to its properties, as it is characterized by high compressibility and low bearing capacity. Therefore, several geotechnical techniques tried to stabilize and improve this soil type. In this study, sodium silicate was used to stabilize sand dune columns. The best sodium silicate concentration (9%) was used, and the stabilized sand dune columns were cured for seven days. The results for this soil were extracted using a numerical analysis program (Plaxis 3D, 2020).In the case of studying the effect of (L/D) (where ‘’L” and ‘’D’’ length and diameter of sand dune columns) of a single column of sand dunes stabilized with sodium silicate with a diff

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