Report 16: Photoelastic Analysis of Journal Bearings: Preliminary Investigations

Author(s):  
R. W. T. Preater

Determination of the stress distributions associated with composite shell bearings under static and dynamic loading conditions is discussed briefly. Experimental work recently started at The City University, using the three-dimensional ‘frozen stress’ photoelastic technique, is described. Preliminary static loading tests have been carried out over a range of low temperatures, prior to stress freezing, on a simple bearing and shaft assembly made in Araldite. One successful stress freezing cycle has been completed and the pressure distribution at the point of stress freezing is shown compared with low temperature distributions for a constant duty parameter. It is anticipated that, at the time of presentation of this report, the stress distribution at the lubrication surface, as determined by analysis, may be shown compared with the recorded pressure distribution.

1971 ◽  
Vol 93 (4) ◽  
pp. 1275-1279
Author(s):  
I. M. Daniel

A three-dimensional photoelastic analysis using the stress-freezing and slicing techniques was conducted to obtain stress and load distributions in a hypoid gear pair. Precise full-scale plastic models of a gear and pinion were manufactured. A special mounting fixture was designed and built of the same photoelastic plastic as that used for the model. A set-up gage was also designed and manufactured for gaging the gear and pinion settings. Fine adjustments were made by means of shims. The desired contact, calculated to produce maximum fillet stresses, was checked with a marking compound and gaged with a stock-dividing gage. A loading device was used to apply pure torque to the pinion. The assembled model was loaded and taken through the stress-freezing cycle. Subsequently, the teeth under engagement were sliced and analyzed to obtain contact and fillet stress distributions.


1996 ◽  
Vol 40 (01) ◽  
pp. 22-27
Author(s):  
V. M. Pashin ◽  
V. A. Bushkovsky ◽  
E. L. Amromin

A method for solving inverse three-dimensional problems in hydromechanics is proposed which makes it possible to fit desired pressure distributions within design constraints immediately in the course of calculations. Examples of the method of application are given for bodies of revolution in flows at nonzero drift angles. These flows are not axisymmetric. Bodies of revolution in them are very handy examples of demonstrations of the method, and these examples have many technical applications.


1983 ◽  
Vol 50 (1) ◽  
pp. 190-193 ◽  
Author(s):  
S. B. Batdorf

Inadequate knowledge of the local stress distributions in damaged composites has been a major obstacle to progress in the understanding of damage accumulation and ultimate failure of such materials. Theoretical treatments of three-dimensional uniaxially reinforced composites are difficult, and direct experimental observations of stresses around interior flaws are not feasible. An experimental determination of stress distributions can be made using an electric analogue. A scaled model of the composite including the damage is made with the fibers replaced by conducting rods and the matrix replaced by an electrolyte. The resistivity ratio of rods to electrolyte is taken equal to the elastic modulus ratio of matrix to fiber. A tensile force applied in the fiber direction is modeled by applying a potential gradient in the rod direction. The displacement distribution in the composite is then modeled by the potential distribution in the analogue to an accuracy somewhat better than that given by shear lag theory. Thus stress distributions can be found by measuring potentials in the analogue with the aid of an electric probe.


1969 ◽  
Vol 4 (4) ◽  
pp. 297-305 ◽  
Author(s):  
A J Durelli ◽  
J A Clark ◽  
A Kochev

This paper deals with the photoelastic analysis of stress waves in a thick ring subjected to transient high-frequency loading. The device used to apply the loading is a piezo-electric transducer which initially produces four cycles of a 31·25 kHz toneburst. The loading pulse can be reproduced with high precision. The ring is illuminated with a flash of approximately 0·5 μs duration which can be delayed in a continuously adjustable manner. Isochromatics and isoclinics can be directly observed as static patterns. Photoelastic data are supplemented by measurements obtained with a capacitance gauge used as a dynamic lateral extensometer. Satisfactory agreement is found between tangential stresses near the free boundary of the ring determined from photoelastic data and those determined from capacitance-gauge measurements. As examples of complete determination of stress distributions, the separated principal stresses are obtained along an axis of symmetry and a vectorial representation of the principal stresses is given. A wave interpretation of the data is developed and comparisons are made with available solutions of related problems.


Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.


2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Raka Maulana ◽  
Yulianti Pratama ◽  
Lina Apriyanti

<p>Some areas in the city of Bandung is an area that dilitasi by the flow of the river, to prevent the introduction of garbage into the river basin is necessary to note the waste management systems in residential areas along the river. Cidurian river has a length of 24.86 Km along the river flow. Consists of the city of Bandung and Bandung regency. Administrative regions Cidurian River past eight (8) districts, from the region in the District Kiaracondong precisely Village Babakan Babakan Sari and Surabaya populous and the most densely populated. Thus, there should be community-based waste management in the form of a reduction in resources to prevent potential entry of waste into the river basin. Planning waste reduction will be divided into two, namely the reduction of inorganic waste with waste bank then the reduction of organic waste with absorption holes biopori, and bio reactor mini determination of the reduction is determined by the results of the analysis of the sampling covers the composition and garbage, then the result of the measurement characteristics test and analysis results questionnaire.</p>


2018 ◽  
Vol 19 (3) ◽  
pp. 19-24
Author(s):  
A. S. Povzun ◽  
V. I. Mazurov

The purpose of the work was to study the nosological structure of rheumatologic patients hospitalized  in emergency hospitals. The analysis of the obtained distribution and its comparison with the structure  of patients at the Scientific Research Institute of emergency care named after I. I. Djanelidze and the City  Rheumatology Center were done. Determination of the current structure of hospitalization of rheumatologic  patients can serve as a basis of its forecasting for the subsequent periods.


Широкое распространение безнадзорных животных на территории городов несет за собой потенциальную угрозу распространения зооантропонозных заболеваний, одним из которых является демодекоз. Невозможно разработать мероприятия, направленные на борьбу с заболеванием и его профилактику, без анализа данных особенностей возникновения и распространения инвазии среди всей популяции восприимчивых животных. Поэтому целью нашей работы явилось изучение распространения демодекоза среди безнадзорных собак и кошек в городе Тюмени. В задачи исследования входило изучение распространения демодекоза и его клинического проявления среди бездомных собак и кошек в условиях города Тюмени и определение сезонной динамики заболевания. Работу выполняли в 2016-2018 гг. на базе кафедры анатомии и физиологии ФГБОУ ВО ГАУ Северного Зауралья, в лаборатории акарологии ВНИИВЭА – филиала ТюмНЦ СО РАН, а также в производственных условиях на базе пункта временного содержания безнадзорных домашних животных МКУ «ЛесПаркХоз». Демодекозная инвазия распространена среди бездомных кошек и собак. Наиболее часто демодекоз встречается у собак, экстенсивность инвазии от 0,65 до 0,72%. Заболевание демодекозом у бездомных собак регистрировали на протяжении всего года, но 54,6% больных собак поступали в апреле и мае. Большинство больных демодекозом – это молодые собаки в возрасте от 1,5 месяцев до 2-х лет – 75,76%, животные старше двух лет гораздо реже страдали от демодекоза – 24,24%. Генерализацию демодекоза регистрировали у 21 собаки (63,64%), а локализованные очаги – у 12 собак (36,36%). Наиболее распространенной формой проявления демодекоза у бездомных собак является пустулезная, или пиодемодекоз. Данная форма заболевания была отмечена у 16 собак (48,49%), чешуйчатая форма отмечалась у 10 собак (30,30%), а смешанная – у 7 собак (21,21%). The widespread use of stray animals in urban areas carries with it the potential threat of the spread of zooanthroponotic diseases, one of which is demodicosis. It is impossible to develop measures aimed at combating the disease and its prevention without analyzing the data on the characteristics of the occurrence and spread of invasion among the entire population of susceptible animals. Therefore, the purpose of our work was to study the distribution of demodicosis among street dogs and cats in the city of Tyumen. The objectives of the study included the study of the spread of demodicosis and its clinical manifestation among stray dogs and cats in the conditions of the city of Tyumen and the determination of the seasonal dynamics of the disease. Demodectic invasion is common among stray cats and dogs. Most often, demodicosis occurs in dogs, with extensive invasion from 0.65 to 0.72%. Demodecosis in stray dogs was recorded throughout the year, but 54.6% of sick dogs were reported in April and May. The majority of patients with demodicosis are young dogs between the ages of 1.5 months and 2 years old - 75.76%, animals older than two years suffer less from demodicosis, only 24.24%. Generalization of demodicosis was recorded in 21 dogs (63.64%), and localized foci in 12 dogs (36.36%). The most common form of demodicosis in stray dogs is pustular or pyodemodecosis. This form of the disease was observed in 16 dogs (48.49%), scaly form, was observed in 10 dogs (30.30%), and mixed in 7 dogs (21.21%).


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