The importance of vibrations in rotating rotors in engineering applications has been examined, as has the best approach to interpreting vibration data. The most extensively used analytical approaches for rotating shaft vibration analysis have been investigated. In this research, a detailed study was made of the Rayleigh and Dunkerley methods due to their importance in the special calculations to find the amplitude of vibrations in the rotation system. The multi-node method was used to calculate both Dunkerley's and Rayleigh's methods. An experimental platform was built to study the vibrations that occur in the rotating shafts, and the results were compared with theoretical calculations and with different distances of the bearings. It proved that there is very little error between the experimental and theoretical results. The vibration signal from the sensors was analyzed using the LABVIEW program. Rayleigh's method was compared to the exact method, and it was considered the most accurate method. It was found that it made very little difference, up to about 0.06%. As for the Dunkerley method, the difference between it and the proper method is about 4%, which is acceptable. Then a comparison was made between Rayleigh's and Dunkerley's methods, and it was found that Dunkerley's method is the most appropriate in the calculations.
تقدير النموذج اللوجستي باستخدام اوزان بيز المتسلسل
This study aimed to study the effect of Ziziphus spina christi Aqueous cold and Alcoholic leaves and fruits extracts on the growth and activities of the following types of bacteria :( Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes ). The results appeared outweigh the alcoholic extract of leaves and fruits of Sidr that prepared by saxholate extractor by addition of ethanol 95% significant superiority as compared with aqueous extract that prepared by using distilled water as was its influence inhibitor to the growth and effectiveness of bacteria , about the treatment of in-vivo to cause injury to these types of bacteria diagnosed laboratory mice and treated with alcoholic extract of the leaves o
... Show MoreIn this paper, a polymer-based composite material was prepared by hand Lay-up method consisting of epoxy resin as a base material reinforced by magnesium oxide powder once and silicon dioxide powder again and with different weight ratios (3, 6, 9 and 12) wt %. The three-point bending test was performed in normal conditions and after immersion in sulfuric acid. The results showed that the bending value decreased with the increase of the weighted ratio of the reinforcement material (MgO, SiO2). The Bending of samples reinforced by SiO2 was found to be less than the bending of samples reinforced by particles (MgO). For example, the bending of the SiO2 sample (0.32 mm) at the weighted ratio (3%) and for the MgO (0.18mm) sample at the weight
... Show MoreEn el contexto de la disponibilidad léxica, Esta investigación surge de la necesidad de enseñar, a los estudiantes extranjeros de comunicación que cursan sus estudios en nuestra universidad, el español especializado que realmente necesitan. La metodología disponibilidad léxica ofrece una oportunidad en cuanto a la elaboración de los manuales.
Abstract
This article presents the lexical availability as a practical tool, this research can be exploited didactically in the teaching of vocabulary as a foreign languages LE.
يهدف هذا البحث إلى تحليل محتوى كتابي الحاسوب للمرحلة المتوسطة في العراق وفقاً لنظرية الذكاءات المتعددة عن طريق الإجابة عن السؤال الآتي: ما نسبة توافر الذكاءات المتعددة في محتوى كتابي الحاسوب المقرران على طلبة المرحلة المتوسطة (الصفين الأول والثاني) للعام الدراسي (2017-2018) م؟ ولتحقيق هدف البحث اتبعت الباحثة منهج البحث الوصفي التحليلي (تحليل المحتوى)، واعتمدت الفكرة الصريحة وحده للتسجيل، أما أداة البحث فهي أداة
... Show MoreThe research aims at analyzing the indicators of the sovereign credit of oil and without oil to determine the face of the Iraqi economy from the challenges that would impede the process of growth and economic development for the period (2004-2015).
the research tries to show some lessons to be learned from those indicators, Many of the most important conclusions, acceptance of the hypothesis of research and the weakness of sovereign credit capacity in Iraq to bear the sovereign debt and its burden and work to achieve sustainable economic and social development "in an economy in which oil is neutralized as a single commodity depends on them to meet the requirements of efficiency and efficiency
... Show MoreThe research considers The Analysis Dimensions of The organizational citizen ship Behavior for a sample of the Faculty of the university of Baghdad through the five Dimensions of citizenship ((Altruism– couscientiosness– sportsmanship courtesy– civic virtue))
The sample contains (120) professor from four colleges of the Baghdad university.
The most Important conelusion is the rise of citizenship behavior level for the Iraqi professor through his generaliaed compliance for most dimensions of the citizenship behavior the most important recommanelations presenteel in research is the encouragement and development for this behavior because of its oby viosis impact on the p
... Show Moreيهدف هذا البحث الى تصميم قائمة بمؤشرات القيم العلمية والاخلاقية التي ينبغي توافرها في محتوى كتاب الحاسوب للصف الثاني المتوسط، وتحليل محتوى الكتاب المذكور آنفاً وفقاً لها، وذلك عن طريق الإجابة عن السؤال الآتي: ما نسبة توافر القيم العلمية والأخلاقية في محتوى كتاب الحاسوب المُعد لطلبة الصف الثاني المتوسط الصادر من وزارة التربية العراقية/ المديرية العامة للمناهج في العام الدراسي ( 2017-2018) م؟ ولتحقيق هدفا البحث أ
... Show MoreATTAPULGITE clay was modified in this study by the graphene oxide sheets and the clay was diagnosed before and after modification using several techniques (Fourier-transform infrared spectroscopy FT-IR, X-ray powder diffraction XRD, Scanning electron microscope SEM , energy dispersive spectroscopy EDX ) ,The surface of the attapulgite clay (before (Ata) after modification by graphene oxide (Ata-GO) ) was applied to adsorption of the Alizarin dye from its water solutions through the application of several kinetic models (pseudo first-order model , pseudo second -order model , intraparticle diffusion model ),It was found that the practical results follow pseudo second -order model. The process of modification on the surface of the mud has imp
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