A Few Aspects on Lubricant Selection for Stepless Chain Coverters: Efficiency and Service Life

1992 ◽  
Author(s):  
G. Schönnenbeck
Keyword(s):  
Friction Coefficient ◽  
Service Life ◽  
Standardized Test ◽  
Test Methods ◽  
Long Term Stability ◽  
Friction Disk ◽  
The Individual ◽  
And Control ◽  
Selection Of

Abstract Stepless vehicle drives will assume their place next to automatic switching units throughout the world if they meet their expected fuel-saving potential. This necessitates optimizing the individual components of the CVT as regards their efficiency. The main source of losses are the hydraulic supply units and the losses which result specifically from non-positive transmission. In the case of stepless chain conveners, these result mainly from friction disk deformation. These losses account for 50 to 70 % of total CVT losses. Both loss components are influenced by the lubricant to a significantly greater extent than it would appear at first sight: In the case of fully-hydraulic clamping and control systems, the viscosity and its long-term stability determines the degree of leakage losses and therefore the size of the pump or pump combinations. This applies to pressure levels between 20 and 40 bar. This in turn is directly proportional to the hydraulic losses on the CVT. The friction coefficient of the lubricant determines the level of the necessary clamping forces. These are responsible for friction-disk deformation. Also of importance as far as the selection of lubricant is concerned is its influence on the CVT service life. The critical service life limits for chain converters are chain breakage (not the subject of this report) and evidence of wear, i.e. grey staining, sheave-grooving, pitting, scoring and rocker pin wear. Standardized test methods exist at P.I.V. for both wear manifestations and for the friction coefficient, these tests allowing a targeted selection of lubricants.

scholarly journals ON THE BEHAVIOR OF ARMOR UNIT IN THE COVERLAYER

1986 ◽  
Vol 1 (20) ◽  
pp. 157
Author(s):  
Hans Werner Pertenscky ◽  
John Rutte ◽  
Reinold Schmidt
Keyword(s):  
Large Scale ◽  
Standardized Test ◽  
Model Tests ◽  
Scale Model ◽  
Test Procedures ◽  
Long Term Stability ◽  
Number Of Factors ◽  
The Stability ◽  
The Individual

As a result of the large-scale failure of the rubblemound breakwater at SINES, Portugal in 1978 a number of research programs were begun. At present, however, very little information is available from technical publications regarding new design criteria, recommendations, or test procedures for model tests of rubblemound breakwaters. The need still exists, therefore, for economically practical model tests and standardized test procedures so that more tests can be conducted and reproducible results from different institutions can be compared. At the same time, a number of factors related to the stability of rubblemound surface elements, and the interrelationships between those factors, have not been adequately examined or explained. Apparently without extensive model tests, for example, it has been suggested that greater stability can be obtained by using elements with greater unit weights (comparing elements of the same absolute weight) , either by adding scrap metal or denser materials, such as granite, to the concrete. Furthermore, susceptibility to breakage is of major importance to the long-term stability of armour layer units, particularly for dolos and similar less massive element types. This aspect has been generally neglected in laboratory tests, however, and attempts to simulate the lower ultimate strength of elements in reduced-scale model tests appear extremely difficult, as well as costly in terms of time and materials. Several other factors which can significantly affect the stability of an armour layer include the surface roughness of the individual elements, as well as boundary conditions such as the beach slope.

scholarly journals Agenesis of Maxillary Lateral Incisors: Treatment Involves Much More Than Just Canine Guidance

2016 ◽  
Vol 10 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Giordani Santos Silveira ◽  
José Nelson Mucha
Keyword(s):  
Decision Making ◽  
Literature Review ◽  
Clinical Features ◽  
Congenital Absence ◽  
Term Stability ◽  
Long Term Stability ◽  
Canine Guidance ◽  
The Individual ◽  
Inform Decision Making

Objective: In this study, we aimed highlight some clinical features present in patients whose maxillary lateral incisors are missing, and proposed more logical, rational and predictable solutions to inform decision making in rehabilitation procedures. Methods: Literature review and discussion. Conclusion: Choosing the best possible treatment for congenital absence of maxillary lateral incisors depends on the multidisciplinary diagnosis of facial, occlusal, functional and periodontal features. It also depends on the individual long-term stability, and it does not only rely on canine-guided disocclusion.

Control Strategy of Soluble Boron-Free Operation for a Small PWR

2017 ◽  
Author(s):  
Guangwen Bi ◽  
Chuntao Tang ◽  
Bo Yang
Keyword(s):  
Control Strategy ◽  
Power Distribution ◽  
Short Term ◽  
Control Rod ◽  
Burnable Poison ◽  
Power Operation ◽  
And Control ◽  
Power Distribution Control ◽  
Selection Of

Elimination of soluble boron will be a challenge to reactor operation for PWR. This paper is to promote a control strategy of soluble boron-free operation for a small PWR, through selection of burnable poison (BP), BP loading and control rod loading, based on the reactivity balance and manage requirement. The analysis for on-power operation and shutdown condition indicated that this strategy could be suitable for long-term and short-term reactivity and power distribution control for soluble boron-free operation.

Alkali Activity of Granite Aggregates and Control in the Concrete of the Three Gorges Project

2013 ◽  
Vol 539 ◽  
pp. 249-254
Author(s):  
Zai Qin Wang ◽  
Chong Xi Liu ◽  
Zi Yun Wen ◽  
Zhen Li ◽  
Liang Xiao
Keyword(s):  
Standardized Test ◽  
Expansion Ratio ◽  
Test Methods ◽  
Observation Time ◽  
Three Gorges Project ◽  
Three Gorges ◽  
Concrete Aggregates ◽  
The Three Gorges ◽  
The Three Gorges Project ◽  
And Control

On the basis of the existing standardized test methods of concrete aggregates alkali activity, the alkali activity of the granite aggregates is studied by extending the observation time. The results showed that the alkali reaction expansion ratio of the fresh granite broke through the 0.1% criterion limit after a decade of time. The reactant microstructure characteristic is similar to the structure of the alkali-silica reaction, the thickness of reaction layer is about 2~4 µm. Controlling the total alkali content of the dam concrete and replacing cement by mixing a certain proportion of fly ash can effectively prevent the occurrence of the AAR in the Three Gorges Project.

Comparison of Standardized Test Methods for Determining the Permeability of the Surface Layer of Concrete

2015 ◽  
Vol 1122 ◽  
pp. 141-144
Author(s):  
Tereza Komárková ◽  
Monika Králíková ◽  
Dalibor Kocáb ◽  
Petr Misák ◽  
Tomáš Stavař
Keyword(s):  
Surface Layer ◽  
Water Permeability ◽  
Standardized Test ◽  
Test Methods ◽  
Standardized Assessment ◽  
Depth Of Penetration ◽  
The Individual ◽  
Durability Of Concrete

The durability of concrete can be assessed based on the quality of the surface layer of concrete, for which there are a few standardized assessment test methods. Usually, the quality of the surface layer of concrete is evaluated based on its air and water permeability. The aim of this experiment was to compare the outputs which provide some methods for determining the permeability of the surface layer of concrete (GWT, ISAT, TPT, the depth of penetration of water under pressure). The measured values using the individual methods of assessing the permeability of the surface layer of concrete very closely correspond.

Physical Evaluation of Insole Materials Used to Treat the Diabetic Foot

2008 ◽  
Vol 98 (3) ◽  
pp. 229-238 ◽  
Author(s):  
Angel Camp Faulí ◽  
Cristina Llobell Andrés ◽  
Norberto Porta Rosas ◽  
Maria José Fernández ◽  
Enrique Montiel Parreño ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Standardized Test ◽  
Technical Information ◽  
Test Methods ◽  
Cellular Materials ◽  
Test Results ◽  
Filling Materials ◽  
Materials Used ◽  
Selection Of

Background: The selection of materials for the production of multilayer insoles for diabetic feet is a difficult task owing to the lack of technical information about these materials. Therefore, objective criteria were established for the selection of these materials. Methods: Mechanical- and comfort-related tests for the mechanical characterization of different materials and their combinations were considered. These tests were conducted according to standardized test methods for polymeric cellular materials. Results: Criteria for the use of cellular materials were obtained. The properties of accommodation, cushioning, and filling materials were established and the most adequate polymer nature for each of the three applications was identified. Variables that affect the properties of these material combinations were studied. Conclusions: These test results will allow podiatrists to select insoles in a more objective way, thus achieving a more successful treatment for diabetic foot-related injuries. (J Am Podiatr Med Assoc 98(3): 229–238, 2008)

scholarly journals Amphiphilic azopolymers capable to generate photo-sensitive micelles

2011 ◽  
Vol 9 (6) ◽  
pp. 1117-1125 ◽  
Author(s):  
Ioana Moleavin ◽  
Constanta Ibanescu ◽  
Anca Hodorog-Rusu ◽  
Ecaterina Peptu ◽  
Florica Doroftei ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Critical Concentration ◽  
Fluorescence Emission ◽  
Good Control ◽  
Fluorescence Emission Spectrum ◽  
Long Term Stability ◽  
Micellar Aggregates ◽  
Preliminary Study ◽  
And Control

AbstractAmphiphilic macromolecular micelles are advantageous for drug delivery applications due to the decrease of side-effects, ease of screening drugs against degradation, long-term stability, targeted delivery and control of the amount of the released drug. A series of amphiphilic azo-polymers having a flexible or rigid main-chain were synthesized and characterized. The presence of chlorobenzyl side-groups allowed both the easy bonding of photo-sensitive or hydrophilic groups and good control of the degree of substitution. The chemical structure was confirmed by 1H-NMR. The critical concentration of aggregation (CCA) was calculated using the fluorescence emission spectrum of pyrene. The interest was focused on a preliminary study concerning the disaggregation capacity of micelles under UV irradiation. The presence of micellar aggregates was confirmed by DLS and SEM and different organization of the amphiphilic polymers was evidenced depending on polymers concentration and polymers structure. In low polymer concentrations in water predominantly globular aggregates were formed. The increase in concentration increased the polydispersity index due to the fusion of micelles and formation of associates of globular aggregates, inter-micellar associates (clusters) and vesicles.

Avian influenza virus: prospects for prevention and control by vaccination

2005 ◽  
Vol 6 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Chang-Won Lee ◽  
David L. Suarez
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Prevention And Control ◽  
Control Program ◽  
Antigenic Drift ◽  
And Control ◽  
Selection Of ◽  
The Ideal

AbstractAlthough vaccination does not always prevent infection of avian influenza (AI) virus, the clear benefit of vaccination is in its ability to prevent disease and to reduce the amount of virus in circulation. Thus, judicious use of vaccination can be an important component of an AI control program. However, the long-term use of vaccination without eradication may result in the selection of the antigenically divergent strains, which compromises the value of vaccination. In this review, the effectiveness of currently available and future AI vaccines is discussed with suggestions for the ideal use of vaccination even with antigenic drift of the virus.

scholarly journals Auditing and controlling as a tool for sme marketing risk management

2021 ◽  
pp. 225-235
Author(s):  
Vaclav Kupec ◽  
Premysl Písar
Keyword(s):  
Risk Management ◽  
Corporate Culture ◽  
Experimental Testing ◽  
The European Union ◽  
Term Stability ◽  
Long Term Stability ◽  
Business Environments ◽  
Marketing Risk ◽  
The Individual

The current hyper-competitive environment, rapid marketing tools, and modern techniques provide many opportunities for small and medium-sized businesses. Such opportunities could bring much in the way of rewards both for the individual companies and the wider economy. However, there are many threats associated with these business environments which cannot be overlooked. Small and medium-sized businesses are a significant stabilizing economic power within the European Union. Therefore, it is not surprising that small and medium-sized businesses competitiveness and their long-term stability are vital factors for European cohesion and development. This research aims to analyze risk management within small and medium-sized businesses, identify critical risk factors, and develop risk management, which could be applied to small and medium-sized businesses. The authors analyzed risk management's consequences and explained the variables as follows: ROA, Auditing, Controlling Management, Marketing, and Corporate Culture. Based on the research findings, the goal was to increase their interaction effectiveness, focusing on small and medium-sized businesses long-term stability and competitiveness. For achieving these aims, the paper provides two research questions and designs three hypotheses. This research was conducted from 2017 to 2020 on sample n = 432 EU small and medium-sized businesses. The reached data were analyzed by statistical method and experimental «in practice» testing. Based on the result and its experimental testing, a marketing risk management model was designed, tested, and verified using practical methods. This model could be used for the identification and avoidance of potential risks when developing a marketing strategy. The findings reached should be used to advance research and similarly for practical use within the business sphere.

scholarly journals Forecasting combat readiness of military personnel of information and technical divisions of the Russian aerospace forces

2020 ◽  
Vol 5 (3) ◽  
pp. 133-144
Author(s):  
Vladislav Petrov ◽  
Evgeniya Panferova
Keyword(s):  
Military Personnel ◽  
Military Service ◽  
Standardized Test ◽  
Expert Assessment ◽  
Combat Training ◽  
The Individual ◽  
Intellectual Potential ◽  
Personal Questionnaire ◽  
Selection Of ◽  
Combat Readiness

The article is devoted to the development and verification of a model for psychodiagnostic forecasting of readiness of military personnel of information and technical units of the Russian aerospace forces to perform combat duty. The longitudinal study used standardized test tools (the method "Motivational profile of the individual", the personal questionnaire "Big five", the method of diagnosing the tendency to deviate behavior, the multi-level personal questionnaire" Adaptability", the method of studying the features of thinking), a questionnaire and expert assessment. Participants were 119 experts and 255 military personnel serving under a contract. The main difference in subgroups of military personnel of various degrees of readiness for combat duty was the presence of purposefulness and awareness of activity. In the regression model of predicting military readiness, the success of activity is associated with the presence of adaptive abilities, consciousness and intellectual potential. Combat readiness is reduced due to the soldier's tendency to aggression and violence, power and recognition, as well as utilitarian motivation. The results of the research allow us to improve the procedure for professional psychological selection of candidates for military service under a contract and preventative work with personnel, optimize training and combat training of military personnel, and ultimately increase the combat readiness of units and formations of constant readiness.

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