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.
Wielands Hauptwerk die Geschichte des Agathon (1766/73,1794) ist
der wichtigste Roman der Aufklärungsepoche (1720-1785). Die Verlegung der
Handlung in die Antike widerspiegelt die kulturelle Blüte der vorbildhaften Zeit
zwischen 5. und 4. Jhd. v. Chr.
Beim Lesen des Romans findet man unzählige (über 70) Namen aus der
Antike; von Herrschern, Strategen, Philosophen, Dichtern, Künstlern . . . etc,
woüber man unbedingt informiert werden muss, um deren Zusammenhang in der
Geschichte zu verstehen. Vorübergehend erwähnte Personennamen gibt Wieland
meistens als Beispiel für eine Situation oder ein Verhalten. Dies gab mir den
Anstoß, die wichtigsten Figuren
... Show MoreTwo quantitative, environment-friendly and easily monitored assays for Ni (II) and Co (III) ions analysis in different lipstick samples collected from 500-Iraqi dinars stores located in Baghdad were introduced. The study was based on the reaction of nickel (II) ions with dimethylglyoxime (DMG) reagent and the reaction of cobalt (III) ions with 1-nitroso-2-naphthol (NN) reagent to produce colored products. The color change was measured by spectrophotometric method at 565 nm and 430 nm for Ni and Co, respectively, with linear calibration graphs in the concentration range 0.25-100 mg L-1 (Ni) and 0.5-100 mg L-1 (Co) and LOD and LOQ of 0.11 mg L-1 and 0.36 mg L-1 (Ni), and 0.15 mg L-1 an
... Show MoreThe problem of independent motion control of mobile robot (МR) in conditions when unforeseen changes of conditions of interaction of wheels with a surface are considered. An example of such changes can be sudden entrance МR a slippery surface. The deployment of an autonomous unmanned ground vehicle for field applications provides the means by which the risk to personnel can be minimized and operational capabilities improved. In rough terrain, it is critical for mobile robots to maintain good wheel traction. Wheel slip could cause the rover to lose control and become trapped. This paper describes the application of fuzzy control to a feedback system within slippery environment. The study is conducted on an example of М
... Show MoreSome aspects of population dynamics of both corbicula species inhabiting intertidal zone of
shatt al-Arab are described. These informations are explained in accordance with the possible
occurrence of competition between the two related species.
Due to the importance of the relationship between the phenomenon of inflation and the exchange rate in the formulation of monetary policy in Iraq, the exchange rate plays a strategic role in limiting the inflation caused by the monetary expansion due to government spending, as a point of a view, the inefficiency of interest to achieve the monetary market balance and stability of the general level of prices as an overall goal of monetary policy in Iraq, the exchange rate has emerged as a brake on inflation in Iraq, as the research found that the monetary authority in the period 2003-2018 provided a methodical development in the formulation of monetary policy towards realizing the effects of inf
... Show Moreالأهداف: تهدف الدراسة إلى التعرف على مستوى نزاع العمل والأسرة لدى الممرضات في المستشفيات التعليمية في مدينة
الناصرية , تحديد العلاقة بين نزاع العمل والاسرة و عمر الممرضات في المستشفيات التعليمية في مدينة الناصرية.
منهجية البحث: تم إجراء دراسة ذات تصميم وصفيي في المستشفيات التعليمية بمدينة الناصرية خلال الفترة من 1 نوفمبر 2020 إلى 1 أبريل 2021 من أجل تحديد ا
... Show MoreAbstract. This study presents experimental and numerical investigation on the effectiveness of electrode geometry on flushing and debris removal in Electrical Discharge Drilling (EDD) process. A new electrode geometry, namely side-cut electrode, was designed and manufactured based on circular electrode geometry. Several drilling operations were performed on stainless steel 304 using rotary tubular electrodes with circular and side-cut geometries. Drilling performance was characterized by Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Tool Wear Ratio (TWR). Dimensional features and surface quality of drilled holes were evaluated based on Overcut (OC), Hole Depth (HD), and Surface Roughness (SR). Three-dimensional
... Show MoreWhen searching for an answer to the following question: What are the reasons for the reluctance of female physical education teachers in secondary schools to referee sports competitions according to the variable of years of service? It was found that the research aimed to reveal the differences between the opinions of the research sample of physical education teachers in secondary schools (girls) about refereeing sports competitions according to the variable of years of service. To achieve the research goal, it is assumed that there are significant differences between the average opinions of the research sample of female teachers and their reluctance and the reasons for the differences in the practice of refereeing sports competitions accor
... Show MoreBackground: The treatment of dental tissues proceeding to adhesive procedures is a crucial step in the bonding protocol and decides the clinical success ofrestorations. This study was conducted in vitro, with the aim of evaluating thenanoleakage on the interface between the adhesive system and the dentine treated by five surface modalities using scanning electron microscopy and energydispersiveX-ray spectrometry. Materials and methods: Twenty five extracted premolars teeth were selected in the study. Standardized class V cavities were prepared on the buccal and lingual surfaces then the teeth divided into five main groups of (5 teeth in each group n=10) according to the type of dentine surface treatment that was used: Group (A): dentine was
... Show MoreBackground: The treatment of dental tissues proceeding to adhesive procedures is a crucial step in the bonding protocol and decides the clinical success ofrestorations. This study was conducted in vitro, with the aim of evaluating thenanoleakage on the interface between the adhesive system and the dentine treated by five surface modalities using scanning electron microscopy and energydispersiveX-ray spectrometry. Materials and methods: Twenty five extracted premolars teeth were selected in the study. Standardized class V cavities were prepared on the buccal and lingual surfaces then the teeth divided into five main groups of (5 teeth in each group n=10) according to the type of dentine surface treatment that was used: Group (A): dentine was
... Show More