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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 Jan 01 2021
Journal Name
Annals Of Tropical Medicine & Public Health
Newly developed method for determination of methyldopa drug using ammonium ceric (IV) nitrate by continuous flow injection analysis via homemade NAG-ADF-300-2 analyser
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A new, simple, sensitive and fast developed method was used for the determination of methyldopa in pure and pharmaceutical formulations by using continuous flow injection analysis. This method is based on formation a burgundy color complex between methyldopa andammonium ceric (IV) nitrate in aqueous medium using long distance chasing photometer NAG-ADF-300-2. The linear range for calibration graph was 0.05-8.3 mmol/L for cell A and 0.1-8.5 mmol/L for cell B, and LOD 952.8000 ng /200 µL for cell A and 3.3348 µg /200 µL for cell B respectively with correlation coefficient (r) 0.9994 for cell A and 0.9991 for cell B, RSD % was lower than 1 % for n=8. The results were compared with classical method UV-Spectrophotometric at λ max=280 n

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Publication Date
Fri Dec 14 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of Teaching Program on Nurses' Knowledge Concerning the Side Effects of Chemotherapy among Children with Leukemia at Oncology Wards in Baghdad City
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Objective(s): to assess the effectiveness of educational program on nurses' knowledge concerning the side
effects of chemotherapy among children with leukemia.
Methodology: A descriptive analytic (quasi – experimental) design study was carried out at Baghdad City from
2
nd of October to 27th of June 2015. Non-probability sample of (35) male and female nurses was selected from
the Oncology Wards in Children Welfare, Child's Central and Baghdad Teaching Hospital. The study
instruments consisted of two major parts to meet the purposes of study. The first part is related to nurses'
demographic characteristics and the second part (four domains) is related to nurses' knowledge concerning the
side effects of chemothera

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
Die sytaktische Struktur und semantische Bedeutung der konzessiven Ausdrucksmöglichkeiten im Deutschen und Arabischen Eine interpretierende Studie
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Die vorliegende Forschung erklärt ein sprachliches Phänomen im Deutschen und Arabischen, dessen Aspekte die Grund-Folge-Relation (Kausalität) im Allgemeinen sowie den wirkungslosen Gegengrund (Konzessivität) im Besonderen behandeln.

In diesem Kontext wird der Unterschied der verschiedenartigen Gründe der Kausalität im Deutschen, wie wirklicher Grund (kausal), möglicher Grund (konditional) und wirkungsloser bzw. unzureichender Gegengrund (konzessiv) gezeigt.

Die theoretischen Darlegungen der konzessiven Ausdrucksmittel in dieser Forschungsarbeit werden durch diverse praktische Beispiele aus der deutschen und arabischen Literatur fundamentiert.

Das Hauptziel dieser For

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Publication Date
Fri Jun 30 2023
Journal Name
College Of Islamic Sciences
Belief in the Last Day and its impact on building a Muslim's personality
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Research Summary

        The doctrine of belief in the Last Day is one of the pillars of faith, and the doctrine of resurrection and reckoning are part of this day.

 Belief in the Last Day puts a person in constant control over himself, as this control creates in this person happiness and a decent life, and he renounces the world and turns away from all vices and adorns all virtues.

        On the other hand, we find that the person who does not believe in this day does not stand before his eyes anything that prevents him from doing injustices and corruption in the land. The doctrine of belief in the Last Day alone is

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Publication Date
Thu Dec 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of transformational leadership in achieving administrative creativity: Search exploratory sample of the views of officials in the office Iraqi Ministry of Education
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Testing the current research and effect correlation between Transformational leadership variable manufacturing and variable administrative creativity, as it represented the research problem the extent of the role of transformational leadership in achieving administrative creativity in the office of the Iraqi Ministry of Education, it has been used questionnaire as a tool for data collection, as is the distribution (32) for the sample of the research, which was selected intentional and as director general and assistant general manager and director and deputy director and head of the Division, and represented the premise of the major search existence of liaison and the impact of significantly between transformational leadership and achieve

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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Harnessing Innovative Solutions for Achieving Continuous Quality Improvement Requirements in Water Treatment Plants: A Case Study of Continuous Quality Improvement in Baghdad Water Authority.
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Abstract

This Research aims for harnessing critical and innovative thinking approaches besides innovative problem solving tools in pursuing continual quality improvement initiatives for the benefit of achieving operations results effectively in water treatment plants in Baghdad Water Authority. Case study has been used in fulfilling this research in the sadr city water treatment plant, which was chosen as a study sample as it facilitates describing and analyzing its current operational situation, collecting and analyzing its own data, in order to get its own desired improvement opportunity be done. Many statistical means and visual thinking promoting methods has been used to fulfill research task.

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Effect of the Quality of Accounting Information on the Efficiency of Investment Decisions
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Abstract

The entities responsible for regulating the financial market are seeking to provide high quality accounting information, to provide appropriate protection to investors, and thus encourage them and attract them to increase their investments. the research reached several conclusion, the most prominent of which comes  :-

1-The production of high quality accounting information reduces investment costs and costs of processing accounting information.

2- The production of high quality accounting information helps investors identify the best investment opportunities.

3- The results of the statistical analysis showed that there is significant

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Publication Date
Sun Dec 12 2010
Journal Name
Journal Of Planner And Development
The stage of change and institution-building and its impact on the structure of housing policy in Iraq
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The research examines the reality of the housing sector in Iraq and the stage of change and institution-building, which is increasingly challenging to respond to development needs. The legal legislation in Iraq over the last five years indicates a significant shift towards decentralization, with powers and services being delegated from federal ministries to regional levels Localization and growth in cities and urban centers is an added factor that requires responses from local governments to strengthen the capacity of their institutions to engage in national policy debate at the re
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Publication Date
Sat Dec 31 2022
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
EFFECT OF USING DIFFERENT LEVELS OF CAMEL FAT (HUMP FAT) ON PHYSIOCHEMICAL COMPOSITION OF SAUSAGE FROM BEEF CAMEL AND CHICKEN : EFFECT OF USING DIFFERENT LEVELS OF CAMEL FAT (HUMP FAT) ON PHYSIOCHEMICAL COMPOSITION OF SAUSAGE FROM BEEF CAMEL AND CHICKEN
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ABSTRACT

This study was conducted to determine the effect of various levels of hump fat (HF) used in manufacturing of camel, beef and chicken sausage to understand the effect of (HF) on physicochemical composition sausage, Different levels of hump fat (5, 7, and 10 %) were used, physicochemical compositions like (moisture, protein, fat, Ash, water holding capacity, shrinkage, cooking loss and pH) were determined. Results of the study revealed that moisture content showed high significant differences (P≤0.01)among treatments groups, Camel sausage and beef sausage tended to have highest values while chicken sausage reported the lowest value. The study showed no significant difference (P≤0.05) among the

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Publication Date
Mon Dec 05 2022
Journal Name
Baghdad Science Journal
Short Text Semantic Similarity Measurement Approach Based on Semantic Network
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Estimating the semantic similarity between short texts plays an increasingly prominent role in many fields related to text mining and natural language processing applications, especially with the large increase in the volume of textual data that is produced daily. Traditional approaches for calculating the degree of similarity between two texts, based on the words they share, do not perform well with short texts because two similar texts may be written in different terms by employing synonyms. As a result, short texts should be semantically compared. In this paper, a semantic similarity measurement method between texts is presented which combines knowledge-based and corpus-based semantic information to build a semantic network that repre

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