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joe-221
Numerical Investigation Using Harmonic and Transient Analysis To Rotor Dynamics
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The rotor dynamics generally deals with vibration of rotating structures. For designing rotors of a high speeds, basically its important to take into account the rotor dynamics characteristics. The modeling features for rotor and bearings support flexibility are described in this paper, by taking these characteristics of rotor dynamics features into standard Finite Element Approach (FEA) model. Transient and harmonic analysis procedures have been found by ANSYS, the idea has been presented to deal with critical speed calculation. This papers shows how elements BEAM188 and COMBI214 are used to represent the shaft and bearings, the dynamic stiffness and damping coefficients of journal bearings as a matrices have been found with the variation of rotation speed of the rotor which are vary with eccentricity of journal with bearings and this eccentricity is a function of Sommerfeld number, the first critical speed analysis has been done from Campbell diagram, the critical speed it is the speed at which resonance case happen, the unbalance response analysis has been done with changing the unbalance mass then finding the maximum response of the rotor for each unbalance mass case, by Campbell diagram plot recognizing the stability of the system and find the line of un stability, above and down this line the system is stable and if speed lies on this line the system is unstable, the main reason of analysis of rotor dynamics is to help Engineers to characterize the lateral dynamics characteristics of a given design with Campbell diagram plot, can find the critical speed, the unbalance response and the system stability .

 

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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Numerical simulation to the effect of applying rationing system on the stability of the Earth canal: Birmana canal in Iraq as a case study
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Abstract<p>Extreme conditions will cause the water level of high fill canal segment to change suddenly, which will affect the velocity and pore pressure of the slope. A 9 km irrigation earth canal in the city of Alsyahy, 15 km away from Al-Hilla city, and branching off from the left side of Shatt Al-Hilla at 57 km, was studied. The aim of this work is to study and analyze the effect of rationing system on the Birmana earthen canal during rapid drawdown case. Finite element modeling with Geo-Studio software was used in the present study to analyze the combined seepage and slope stability for three cycles. The resulting minimum safety factor obtained from the analysis using the saturated and</p> ... Show More
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Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
''The use of factor analysis to identify the leading factors to high blood pressure.''A field study in Baghdad hospitals
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Abstract :

    In view of the fact that high blood pressure is one of the serious human diseases that a person can get without having to feel them, which is caused by many reasons therefore it became necessary to do research in this subject and to express these many factors by specific causes through studying it using (factor analysis).

  So the researcher got to the five factors that explains only 71% of the total variation in this phenomenon is the subject of the research, where ((overweight)) and ((alcohol in abundance)) and ((smoking)) and ((lack of exercise)) are the reasons that influential the most in the incidence of this disease.

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Publication Date
Sun Mar 13 2011
Journal Name
Baghdad Science Journal
Population Dynamics of the Terrestrial - Isopod species Armadillidium vulgare Latrielle , 1804 in AL - Jadriyia District -Baghdad - Iarq .
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The Present Work includes the study of the population dynamics of Armadillidium vulgare in AL- Jadiriya region in Baghdad. Monthly samples were collected using a quadrat 0.0625 m2 from November 2007 to November 2008.. The population density of A.vulgare, ranged from 880 ind/m2 in May to251 ind/m2 in January respectively. This species showed high aggregation dispersion in the study area. The sex ratio showed that the number of females were more than that of males and significantly differd (P < 0.05) during the reproductive months. Furthermore, it was found that the juveniles of species were present at most time of the year, But the large sized groups have been observed during summer and spring. And showed a positive linear correlations betwe

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Publication Date
Mon Aug 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Building a mathematical model of the transportation problem under the dynamics of demand restrictions with practical application
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Abstract\

In this research we built a mathematical model of the transportation problem  for data of General Company for Grain Under the environment of variable demand ,and situations of incapableness to determining the supply required quantities as a result of economic and commercial reasons, also restrict flow of grain amounts was specified to a known level by the decision makers to ensure that the stock of reserves for emergency situations that face the company from decrease, or non-arrival of the amount of grain to silos , also it took the capabilities of the tanker into consideration and the grain have been restricted to avoid shortages and lack of processing capability, Function has been adopted

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Publication Date
Mon Jun 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Using the Box Jenkins models to predict Iraq's cement production and to demonstrate its adequacy under future construction projects
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تعد صناعة السمنت في العراق من اقدم الصناعات الحديثة واكثرها تطورا وتقدما ومن اقواها تاثيرا في الاقتصاد القومي. واذ توفر في صناعة السمنت العراقي كافة المستلزمات الناجحة من حيث توفر المواد الاولية والخبرات الفنية والتقنية واسواق ثابتة وراسخة محليا وعالميا فقد كان من المفروض ان يتم التوسع في هذه الصناعة، وان التخطيط لهذه الصناعة امرا ضروريا خاصة وان مادة السمنت هي احدى اهم المواد الرئيسة التي يؤثر توفره

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Publication Date
Tue Jun 30 2020
Journal Name
Membranes
Experimental and Theoretical Analysis of Lead Pb2+ and Cd2+ Retention from a Single Salt Using a Hollow Fiber PES Membrane
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The present work reports the performance of three types of polyethersulfone (PES) membrane in the removal of highly polluting and toxic lead Pb2+ and cadmium Cd2+ ions from a single salt. This study investigated the effect of operating variables, including pH, types of PES membrane, and feed concentration, on the separation process. The transport parameters and mass transfer coefficient (k) of the membranes were estimated using the combined film theory-solution-diffusion (CFSD), combined film theory-Spiegler-Kedem (CFSK), and combined film theory-finely-porous (CFFP) membrane transport models. Various parameters were used to estimate the enrichment factors, concentration polarization modulus, and Péclet number. The pH values signif

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Scopus (35)
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Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Educational And Psychological Researches
Analysis of the Content of the Computer Textbook for the Second Intermediate Grade According to Scientific and Moral Values
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The purpose of this research is to design a list of the scientific and moral values that should be found in the content of the computer textbook for the second intermediate grade, as well as to analyze the content of the above- mentioned book by answering the following question:

 What is the percentage of availability of scientific and moral values in the content of the computer textbook for Second Intermediate grade issued by the Iraqi Ministry of Education / the general directorate of the curriculum, for the academic year (2017-2018)? 

In order to achieve the research objectives, the descriptive method (content analysis method) was adopted. The research community has been iden

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Publication Date
Sun Apr 30 2023
Journal Name
Al-kindy College Medical Journal
Circulating Interleukin-23 Levels in Rheumatoid Arthritis and its Relationship to Disease Activity: a Systematic Review with Meta-Analysis
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Background: Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease that is characterized by severe synovial inflammation, cartilage erosion, bone loss, and generalized vasculopathy. Although the immunologic mechanism of RA is still unclear, it is now thought to be a primarily Th17-driven disease. Along with other factors, IL-23 stimulates the expansion of Th17 cells from naive CD4+ T cells.

Objective: The objective of this study is to assess the circulating levels of interleukin (IL)-23 in rheumatoid arthritis (RA) and determine the correlation between plasma/serum IL-23 levels and disease activity. So, we performed a systematic review with meta-analysis comparing

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Publication Date
Tue Jan 01 2019
Journal Name
Izvestiya Of Saratov University. New Series. Series: Philology. Journalism
To the Question of Internal Inflection of the Roots in Arabic and Russian (Inflected Analysis of the Root Structure)
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Publication Date
Tue Feb 15 2022
Journal Name
International Journal Of Early Childhood Special Education
Analysis of science books ( two chemistry units ) for the first and second grades of intermediate according to Environmental Ethics
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The aim of the current research is to analyze the content of the two science books (chemistry units) for the two grades ( first and second intermediate ) according to environmental ethics, as the research community and its sample of the two science books (chemistry units) for the two grades ( first and second intermediate ), approved by the Iraqi Ministry of Education for the academic year ( 2021-2022 ), and the two researchers adopted the descriptive ( analytical ) approach, and the researchers built a standard for environmental ethics, and the validity of the tool was confirmed by presenting it to a group of experts, and then the researchers analyzed the two books in light of the standard prepared based on the implicit explicit idea, and

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