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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
Thu Apr 13 2023
Journal Name
Sustainability
Experimental Study of the Effect of Tack Coats on Interlayer Bond Strength of Pavement
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The performance and lifetime of the flexible asphalt pavement are mainly dependent on the interfacial bond strength between layer courses. To enhance the bond between layers, adhesive materials, such as tack coats, are used. The tack coat itself is a bituminous material, which is applied on an existing relatively non-absorbent surface to ensure a strong bond between the old and newly paved layer. The primary objective of this study was to evaluate the effects of various types of tack coat materials on interlayer bond strength and to determine the optimal application rate for each type. The tack coat types used in this paper were RC-70, RC-250, and CSS-1h. Both laboratory-prepared and field-constructed hot mix asphalt concrete pavements usin

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Publication Date
Thu Jan 01 2015
Journal Name
Journal Of Engineering
Experimental Study of the effect of closed cavity wall on buildings cooling loads saving
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The experimental study showed the use of closed cavity wall (the thickness of the cavity 5cm) made a percentage reduction in the cooling load caused by heat gain from the wall by (21.5 %) compared with the conventional wall. also the thermal resistance of the closed cavity was an average (0.2 m2.oC/W).

The experimental results of the study showed that the use of closed cavity wall reduced the average temperature of the inner surface of the wall during the day, and that the reduction was an average (0.45 oC)  when compared with the conventional wall , as well as the use of closed cavity wall reduced the temperature difference range of the inner surface of the wall during the day, and that the

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Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Engineering
Experimental Investigating of Unsupported Excavation Considering Its Effect on a Nearby Axially Loaded Pile
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An experimental model is used to simulate the loss of soil lateral confinement due to excavation nearby an individual axially loaded pile. The effects of various parameters, such as the horizontal distance of excavation, depth of excavation and pile slenderness ratios are investigated. The experimental analysis results showed the effect of excavation is more remarkable as the horizontal distance of excavation becomes closer to the pile than half pile length. The effect of excavation diminishes gradually as the horizontal distance increases beyond that distance for all the investigated pile slenderness ratios and depths of excavation. The pile head deflection, settlement and bending moments along pile increase with decreasing horizontal d

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Publication Date
Tue Sep 15 2020
Journal Name
Arab World English Journal
A Cognitive-Semantic Analysis of Preposition on: An Experimental Study at University of Baghdad
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Publication Date
Sat Nov 27 2021
Journal Name
Lecture Notes In Civil Engineering
An Experimental Study on Concavely Curved Soffit Reinforced Concrete Beams Externally Bonded with FRP
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Publication Date
Sun Apr 03 2016
Journal Name
Journal Of Educational And Psychological Researches
Psychological stress in unemployed individuals and its association with well being
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The aim of this study is to detect the level of psychological stress among unemployed individuals and the level of their wellbeing by finding the correlation between these two variables.

          The research sample consisted of (99) people who are currently unemployed and registered at the Ministry of Labor Affairs.

Schafer (1996) scale for psychological stress was used and alongside Ziout's (2012) scale for wellbeing.

          The results of the research showed an inverse relation between being unemployed and having wellbeing.

 &nb

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Publication Date
Fri Sep 29 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Evaluation of The Effect of Fisetin against Cyclophosphamide-Induced Myelosuppression and Oxidative Stress in Male Albino Rats
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Myelosuppression is a serious disease that is related to the malfunction of blood cells production that leads to cytopenia which is the most serious hematologic toxicity of cancer chemotherapies including cyclophosphamide, which is a strong oxazaphosphorine [a nitrogen mustard alkylating agent] that can be used alone or combined with other chemotherapeutic agents for the treatment of different malignant diseases. It induces severe bone marrow suppression by damaging hematopoietic stem cells through the generation of oxidative stress. Fisetin is a hydrophobic polyphenolic compound with a wide range of pharmacological properties such as antioxidant, anti-inflammatory, antimicrobial, osteoprotective, antidiabetic, and anti-carcinogenic activit

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Publication Date
Fri Sep 29 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Evaluation of The Effect of Fisetin against Cyclophosphamide-Induced Myelosuppression and Oxidative Stress in Male Albino Rats
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Myelosuppression is a serious disease that is related to the malfunction of blood cells production that leads to cytopenia which is the most serious hematologic toxicity of cancer chemotherapies including cyclophosphamide, which is a strong oxazaphosphorine [a nitrogen mustard alkylating agent] that can be used alone or combined with other chemotherapeutic agents for the treatment of different malignant diseases. It induces severe bone marrow suppression by damaging hematopoietic stem cells through the generation of oxidative stress. Fisetin is a hydrophobic polyphenolic compound with a wide range of pharmacological properties such as antioxidant, anti-inflammatory, antimicrobial, osteoprotective, antidiabetic, and anti-carcinogenic

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Publication Date
Mon Dec 23 2019
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Evaluate the Protective Effect of Lactobacillus against Collateral Damage Induced by Ciprofloxacin and Levofloxacin in Iraqi Patients
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Abstract:                                                                                                                Fluoroquinolones drugs are an important class of wide

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Publication Date
Fri Jun 16 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Study The Lung-Protective Effects of Riboflavin and Cyanocobalamin Against Lung Toxicity-Induced by Cyclophosphamide in Rats
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Cyclophosphamide (CP) is a cytotoxic alkylating agent it's used associated with different side effects including lung toxicity. Vitamin B2 and vitamin B12 have lung-protective effects. This study was designed to evaluate lung-protective effects of both vitamins against lung toxicity induced by cyclophosphamide. seventy healthy adult albino male and female rats divided into seven groups each group containing ten rats were used in the present study and treated for seven days. On day eight rats were sacrificed and serum was obtained for glutathione and total antioxidant capacity measurement and lung extracted for immunohistochemical study; both vitamins significantly (P<0.05) increased glutathione and total antioxidant capacity in compar

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