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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 Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
The relationship between social capital and knowledge sharing and their impact on improving the educational service quality: an analytical study of the views of a sample of academic staffs in the government universities in the Kurdistan Region of Iraq
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Abstract

This study aims to find the relationships between social capital (social network, social trust, shared goals) and knowledge sharing (knowledge Donating, knowledge collecting) as independent variables and their impact on improving the quality of educational services (academic staffs quality, Quality of teaching methods and study curriculums). This research is an important, because it attempts to identify the relationship between social capital and the knowledge sharing and their effect on improving the quality of educational service for universities. The study problem was determined in several questions related to the nature of the correlation relationship - the impact between the different independent variables (

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Publication Date
Wed Mar 01 2023
Journal Name
Journal Of Engineering
Experimental Study on the Behavior of Square-Skirted Foundation Rested on Gypseous soil Under Inclined Load
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This work investigates experimentally the effect of using a skirt with a square foundation of 100 mm width resting on dry gypseous soil (i.e., loose soil with 33% relative density), and subjected to an inclined load. Previous works did not study the use square skirted foundation rested on gypseous soil and subjected to inclined load. The investigated soil was brought from Tikrit city with 59% gypsum content. Standard physical and chemical tests on selected soil were carried out. Model laboratory tests were carried out to determine the effect of using a skirt with a square foundation on the load-settlement behavior of gypseous soil and subjected to inclined load with various Skirt depth (Ds) to foundation width (B) ratio

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Publication Date
Wed Mar 29 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Study of Iraqi Spinach Leaves (Phytochemical and Protective Effects Against methotrexate-Induced hepatotoxicity in rats)
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Spinach, Spinacia oleracea L is a popular vegetable belonging to the family Chenopodiaceae. This study was concerned with extraction of compounds in Iraqi spinach leaves, preliminary phytochemical evaluation, identification of two biological important flavonols, quercetin and kaempferol in spinach leaves and evaluation of the protective effect of aqueous spinach extract on methotrexate (MTX) induced hepatotoxicity in rats. The percentage yield of extraction procedure, identification of spinach by chemical tests and identification of flavonols by thin layer chromatography (TLC) and High performance liquid chromatography (HPLC) were fully described in this study. The results indicate that the percentage of quarce

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Publication Date
Fri Jul 01 2011
Journal Name
Saudi Pharmaceutical Journal
Free radical scavenging activity of silibinin in nitrite-induced hemoglobin oxidation and membrane fragility models
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Publication Date
Sat May 15 2004
Journal Name
Journal Of Biotechnology Research Center
The Morphological and Histopathological Liver Abnormalities Caused by Carbamazepine-Induced Injury in Female Albino Mice
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Background: The adverse effects of drugs can damage various organs, especially the liver, leading to a hepatic injury known as hepatotoxicity. Drug-induced liver injury (DILI) is challenging nowadays because of the large number of different drugs used, one of the offending medications that cause DILI is carbamazepine (CBZ), since the liver has an array of functions including detoxification, it will deal with several damages caused by exposure to the drugs. Objective: investigate the effect of (CBZ) 20mg/kg/day on female mice liver after 14 and 30 days of treatment on morphological and histopathological levels. Materials and Methods: 20mg/kg/day of CBZ was administered orally for (14) days to (10) female mice, another (10) mice were taking t

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Publication Date
Fri Mar 01 2019
Journal Name
Iraqi Journal Of Physics
Influence of working pressure and lasing energy of Al plasma in laser-induced breakdown spectroscopy
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Aluminum plasma was generated by the irradiation of the target
with Nd: YAG laser operated at a wavelength of 1064 nm. The
effect of laser power density and the working pressure on spectral
lines generating by laser ablation, were detected by using optical
spectroscopy. The electron density was measured using the Stark
broadening of aluminum lines and the electron temperature by
Boltzmann plot method it is one of the methods that are used. The
electron temperature Te, electron density ne, plasma frequency
and Debye length increased with increasing the laser peak
power. The electron temperature decrease with increasing gas
pressure.

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
OPEN CIRCUIT HEAT EXCHANGER DYNAMICS DURING FLOW REDUCTION TRANSIENT IN THEIR SECONDARY LOOPS
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An experimental and theoretical analysis was conducted for simulation of open circuit cross flow heat
exchanger dynamics during flow reduction transient in their secondary loops. Finite difference
mathematical model was prepared to cover the heat transfer mechanism between the hot water in the
primary circuit and the cold water in the secondary circuit during transient course. This model takes under
consideration the effect of water heat up in the secondary circuit due to step reduction of its flow on the
physical and thermal properties linked to the parameters that are used for calculation of heat transfer
coefficients on both sides of their tubes. Computer program was prepared for calculation purposes which
cover a

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Publication Date
Fri Oct 13 2023
Journal Name
Engineering, Technology & Applied Science Research
The Experimental and Theoretical Effect of Fire on the Structural Behavior of Laced Reinforced Concrete Deep Beams
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A Laced Reinforced Concrete (LRC) structural element comprises continuously inclined shear reinforcement in the form of lacing that connects the longitudinal reinforcements on both faces of the structural element. This study conducted a theoretical investigation of LRC deep beams to predict their behavior after exposure to fire and high temperatures. Four simply supported reinforced concrete beams of 1500 mm, 200 mm, and 240 mm length, width, and depth, respectively, were considered. The specimens were identical in terms of compressive strength (  40 MPa) and steel reinforcement details. The same laced steel reinforcement ratio of 0.0035 was used. Three specimens were burned at variable durations and steady-state temperatures (one

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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The impact of the Roundtable and Self-Questioning strategies on achievement and self-efficacy For students of the Faculty of Education in the subject of research curricula
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The current research aims to identify "the impact of the round table strategies and the question of self-achievement and self-efficacy among students of the Faculty of Education in research methodology course.” The research sample consisted of (75) male and female-third stage students in the department of Life Sciences / College of Education for Pure Sciences / University of Dhi Qar for the academic year (2018-2019. The researcher adopted the experimental approach to achieving the study objectives. The researcher prepared two tools: the achievement test and the self-efficacy scale were applied to the collected sample to obtain the needed data. The result showed that there was a statistically significant difference at the level (0.05) b

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Publication Date
Mon Dec 01 2025
Journal Name
Toxicology Reports
The protective role of nicardipine in dextran sulfate sodium-induced colitis in mice: Modulating inflammation and apoptosis
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Ulcerative colitis (UC) is a chronic inflammatory bowel disease associated with persistent inflammation, oxidative stress, and epithelial apoptosis. Nicardipine, a dihydropyridine calcium channel blocker, exhibits anti-inflammatory and anti-apoptotic properties, but its therapeutic potential in UC remains unclear. This study evaluated the effects of nicardipine on dextran sulfate sodium (DSS)-induced colitis in mice, focusing on inflammatory, oxidative, and apoptotic pathways. Fifty BALB/c mice were assigned to five groups (n = 10): control, DSS, nicardipine 12 mg/kg, nicardipine 24 mg/kg, and 5-aminosalicylate (ASA) 75 mg/kg. Treatments were administered for 3 days before and 10 days during DSS exposure. Disease severity was assessed by bo

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