The present work considers an alternative solution for a complex configuration of rotor discs by applying Galerkin Method. The theoretical model consists of elastic shaft carrying number of discs and supported on number of journal bearings. The equation of motion was discretized to finite degree of freedom in terms of the system generalized coordinates. The various effects of the dynamical forces and moments arising from the bearing, discs and shaft were included. Rayleigh beam model is used for analyzing the shaft while the discs are considered rigid . The validity and convergence of the present analysis was carefully checked by comparing with the Finite Element solution. An example of rotor consists of three different size discs and supported by two journal bearing was considered for the numerical solution .The results shows good agreements between the two methods ,where the maximum error not exceeds 5%. The convergence test showed that using few modes (not more than 6) are sufficient for the accurate analysis. The forward and backward whirl was investigated experimentally .The experimental results of a two discs rotor ,show a reasonable agreement where the maximum error not exceeds 11%. The unbalance response, Cambpell diagram, orbit response were plotted .The effects of geometry, disc sizes , location and arrangement on the unbalance response and natural frequencies of three discs rotor were further investigated .
The present research included sampling and analysis of 41 soil samples , the samples cover various areas of Nasiriyah city (industrial,commercial,residential and agricultural ) to estimate pollution levels of lead element and determine the correlation between lead concentration and natural factors in soil which represent sedimentary organic matter content, granular gradient, clay minerals and non-clay minerals . The results of the current study showed that the average concentration of lead in the soil samples was 61.12 ppm , it was noticed an increase in the concentration of lead in environmental components in the area of this study especially in residential , industrial and commercial location and the impact of natural factors of the so
... Show MoreAphid Aphis spp (Hemiptera:Aphididae) and Thrips Thrips spp (Thysanoptera: Thripidae) an economically important pests on several crops in the world and Iraq, that transfer many viruses diseases to it. Field studies were conducted to assessment the population density of these insects and susceptibility of six varieties (Barin, Revera, Divela, Rudlph, Alazata and Pleny) to infestation during 2013 spring season. The results were showed that all Potato varieties were infested by Aphis and Thrips on spring plantation but with different percentage. The Divela variety was higher percentage of infestation and high population density of aphid which averaged 1.47 insect/ leaf while in Alazata was the lower population density which averaged 1.02 in
... Show Moreلخلاصة تشغل قضايا الهوية محور اهتمام الكثير من الباحثين والدارسين في بنية المجتمعات ومستقبل الدول, وفي كثير من الدراسات التي كتبها هؤلاء كان هناك ميل نحو دراسة الهوية وعلاقتها بحركة الدول تقدما وتراجعا ,فهناك من عزا تقدم دولة ما إلى نجاح نخبها السياسية في صناعة هوية جامعة لحالة التنوع الذي يميز مجتمعها, ويمكن ان تشير الى الولايات المتحدة الامريكية كأنموذج للنجاح في هذا الاطار.وهناك من ارجع
... Show MoreThe activation and reaction energies of the C-C and C-H bonds cleavage in pyrene molecule are calculated applying the Density Functional Theory and 6-311G Gaussian basis. Different values for the energies result for the different bonds, depending on the location of the bond and the structure of the corresponding transition states. The C-C bond cleavage reactions include H atom migration, in many cases, leading to the formation of CH2 groups and H-C≡C- acetylenic fragments. The activation energy values of the C-C reactions are greater than 190.00 kcal/mol for all bonds, those for the C-H bonds are greater than 160.00 kcal/mol. The reaction energy values for the C-C bonds range between 56.497 to 191.503 kcal/mol. As for the C-H cleavage rea
... Show MoreThe aim of this research is to know the effect of two strategies of active learning, the five fingers and traffic signals, on the first grade intermediate level student's achievement and personal intelligence. The research sample was chosen from the Al- Mansour intermediate school for boys, including (101) students divided into three groups chosen randomly which represented the first experimental group (32) students, the second experimental group (34) students, and the control group (33) students. To achieve the research aims, the research prepared a physics achievement test containing (26) items, and a personal intelligence test containing (20) items. The psychometric characteristics, of the tests were checked up the following results were
... Show MoreBN Rashid, International Journal of Research in Social Sciences and Humanities, 2019 - Cited by 1
The research aims to investigate the existence of a direct causal relationship between selected agricultural variables: agricultural output (as a representative of growth in the agricultural sector), agricultural terms of trade as a completely new variable in agricultural studies in recent years, agricultural labour which is an important part in the total workforce for Iraq, and finally, agricultural investment because of its importance and vital role in the production process, creating job opportunities, and then raising the level of employment, then it's role to achieving agricultural growth and development. For this purpose, the researchers used the Toda-Yamamoto causality methodology for a time series covering from 1990 to 2019. The res
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The Paper highlights on one of the main activities in marketing management. That is the internal marketing in the commercial banks and its relationship with the quality services offered to satisfy customers needs and wishes in order to reach he ultimate objectives of those banks. Two state and five private banks in Basrah city (Iraq) were taken in a field study. The survey covered the opinions of (184) state bank employees and (158) clients . The analysis of the survey shows that there is a strong relationship between the internal marketing ( in the banks covered by the survey) and the quality of banking objective services and the private banks show greater interest and concern to the internal ma
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