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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
Tue Jan 05 2010
Journal Name
Political Sciences Journal
واقع العلاقات التركية الالمانية والبحث عن نموذج للاستقرار
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واقع العلاقات التركية الالمانية والبحث عن نموذج للاستقرار

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Detecting Textual Propaganda Using Machine Learning Techniques
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Social Networking has dominated the whole world by providing a platform of information dissemination. Usually people share information without knowing its truthfulness. Nowadays Social Networks are used for gaining influence in many fields like in elections, advertisements etc. It is not surprising that social media has become a weapon for manipulating sentiments by spreading disinformation.  Propaganda is one of the systematic and deliberate attempts used for influencing people for the political, religious gains. In this research paper, efforts were made to classify Propagandist text from Non-Propagandist text using supervised machine learning algorithms. Data was collected from the news sources from July 2018-August 2018. After annota

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Publication Date
Fri Jun 02 2023
Journal Name
المجلة العراقية للعلوم السياسية
طبيعة العلاقة بين ركائز مفهوم المسؤولية عن الحماية
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بعد الانحرافات التي شابت تنفيذ المسؤولية عن الحماية في ليبيا عام 2011، دعت البرازيل الى اتباع التسلسل في تنفيذ الركائز الثلاث للمسؤولية عن الحماية عند معالجة الازمات الانسانية ذات الصلة بجرائم الحرب والجرائم ضد الانسانية وجريمة الابادة الجماعية وجريمة التطهير العرقي، في حين دعا الامين العام للامم المتحدة في العديد من تقاريره السنوية بشأن المسؤولية عن الحماية بانه لاينبغي التقيد بالتسلسل واعتبر ان الركائز ا

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Publication Date
Tue Nov 21 2023
Journal Name
مجلة كلية الحقوق ـ جامعة النهرين
مسؤولية منتسبي قوى الامن الداخلي عن اعمالهم الشخصية
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يتناول البحث مسؤولية منتسبي قوى الامن الداخلي عن اعمالهم الشخصية

Publication Date
Fri Mar 01 2019
Journal Name
الاطروحة
الامتناع عن اغاثة ملهوف خطا موجبا للمسؤولية التقصيرية
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Publication Date
Tue Jul 11 2023
Journal Name
Journal Of Educational And Psychological Researches
Detecting Suicidal Tendencies among Secondary School Students
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The current research aims to detect the level of suicidal tendencies among secondary school students in terms of gender and educational stage (intermediate school students and high school students). The researcher adopted Al Hafeez's (2017) scale for suicidal tendencies, it consists of (57) items including six domains, namely: suicidal ideation, social motives for suicide, tendency to self-harm, desire for death, indifference and pessimism about life, willingness to commit suicide. The scale was modified to be (42) items after it was exposed to a group of experts. The scale was applied to a sample of (200) male and female students from secondary schools in Baghdad Governorate (Karkh - Rusafa) for the academic year 2021-2022. The results

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Using Markov chains to forecast the exports of Iraqi crude oil
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       In this paper, the topic of forecasting the changes in the value of Iraqi crude oil exports for the period from 2019 to 2025, using the Markov transitional series based on the data of the time series for the period from January 2011 to November 2018, is real data obtained from the published data of the Central Agency Of the Iraqi statistics and the Iraqi Ministry of Oil that the results reached indicate stability in the value of crude oil exports according to the data analyzed and listed in the annex to the research.

Keywords: Using Markov chains

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Publication Date
Wed Sep 01 2021
Journal Name
Baghdad Science Journal
Effect of Testosterone Enanthate Modeling of Polycystic Ovary on Liver Irs-2 mRNA Expression in Rats: A Brief Report
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There are many animal models for polycystic ovary (PCO); using exogenous testosterone enanthate is one of the methods of induction of these models. However, induction of insulin resistance should also be studied in the modeling technics. Therefore, the present study aims to investigate the expression of insulin receptor substrate (Irs)-2 mRNA in the liver tissue of rat PCO model. Nineteen Wistar rats were divided into three groups; (1) PCO modeling group (N =7) received daily 1.0 mg/100g testosterone enanthate solved in olive oil along with free access dextrose water 5%, (2) vehicle group (N =6), which handled like the PCO group, but did not receive testosterone enanthate, (3) control group (N =6) with standard care. Al

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Publication Date
Mon Dec 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Effect of Chloride Ions on the Corrosion Behavior of Al – Zn Alloy in NaOH Solution at Four Different Temperatures
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This research involves study effect of chloride ions in concentration range (0.01 – 0.50 mol.dm-3) on the corrosion behavior of Al-Zn alloy in basic media of 1x10-3 mol.dm-3 NaOH at pH=11 and four different temperatures in the range (298-313 K). Cathodic and anodic Tafel slopes (bc &ba) and transfer coefficients (αc & αa) were calculated and the results interprets according to the variation of the rate – determining steps. The results also indicate that the chloride ions are bonded chemically in the interface as an initial step of formation of different mixed oxohydroxy – and chloro complexes. Polarization resistance (Rp) is calculates

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Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Estimating concentration of toxic ions Arsenic in water by using Photonic Crystal Fiber based on Surface Plasmon Resonance (SPR)
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In this work, an enhanced Photonic Crystal Fiber (PCF) based on Surface Plasmon Resonance (SPR) sensor using a sided polished structure for the detection of toxic ions Arsenic in water was designed and implemented. The SPR curve can be obtained by polishing the side of the PCF after coating the Au film on the side of the polished area, the SPR curve can be obtained. The proposed sensor has a clear SPR effect, according to the findings of the experiments. The estimated signal to Noise Ratio (SNR), sensitivity (S), resolution (R), and Figures of merit (FOM) are approaching; the SNR is 0.0125, S is 11.11 μm/RIU, the resolution is 1.8x〖10〗^(-4), and the FOM is 13.88 for Single-mode Fiber- Photonic Crystal Fiber- single mode Fiber (SMF-P

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