CVT Rolling Traction Drives—A Review of Research Into Their Design, Functionality, and Modeling

2005 ◽  
Vol 128 (5) ◽  
pp. 1165-1176 ◽  
Author(s):  
S. Akehurst ◽  
D. A. Parker ◽  
S. Schaaf

In this paper we detail a review of the current state of published work regarding the modeling of rolling traction drive Continuously Variable Transmissions (CVTs). An overview of CVTs operating by traction through small contact areas is performed, the layouts and kinematics of leading examples are reviewed, including the factors affecting design optimization. Properties of the traction contacts are considered in detail, with particular attention to elastohydrodynamic lubrication and asperity contact. Factors affecting the traction coefficient are reviewed and fundamental empirical predictions are contrasted with modern modeling computations. Finally measurements of the rheology of traction fluids are considered, leading to a definition of ideal properties and the development of proprietary fluids.

2018 ◽  
Vol 64 ◽  
Author(s):  
A.S. Onikienko ◽  
A.A. Khlyupin

In this paper, the problem of a new concept of “emergency response center” was studied in detail. The definition of such a concept as "emergency". Analyzed the current state of the introduction of the concept of the center of rapid response and its practical implementation. Internal and external factors affecting the location of the rapid response center were studied. Based on the factors, the main criteria are formulated that influence the position of the emergency response center in an urban environment.


2015 ◽  
Vol 10 (2) ◽  
pp. 105-116 ◽  
Author(s):  
D.V. Melnikova ◽  
M.G. Debolskiy

The paper is devoted to penal stress and its manifestations at the convicts, suspects and accused persons. This topic has been poorly studied. It is necessary to identify the groups of people especially most in need of prevention and correction of stress state and to define the target effects. The paper presents a theoretical analysis of the concepts of biological and psychological stress. Our theoretical work is mainly devoted to phenomenon of penal stress and factors affecting its formation. We suggested the definition of penal stress concept on the basis of the analyzed literature. The sample included 69 male persons (31 from predetention center, 38 from penal colony), aged 19 to 47 years old. Experimental psychological method of research was mainly used. In the practical part of the paper presents data on the prevalence of the penal stress in predetention centers and penal colonies. In addition, we have studied the relationship of penal stress with punishment stage, the crime characteristics of subjects, individual psychological characteristics, current state. The study allows us to reveal the groups of people in need of the prevention and correction of the penal stress state. We identified some target corrective action also.


Author(s):  
Kazuyuki Yagi ◽  
Kazuki Nishida ◽  
Joichi Sugimura

This study describes traction behaviours of lubricant films having anomalous shapes under elastohydrodynamic lubrication conditions. The traction generated at a point contact area between a glass or sapphire disc and a steel ball was measured by changing the slide-to-roll ratio. Three alcohols, 1-dodecanol, ethylene glycol and glycerol, and two alkanes of n-tetradecane and n-hexadecane were used as lubricants. Lubricants developing anomalous film shapes exhibited a solid-like behaviour with a sharp traction peak at low slide-to-roll ratios. On the contrary, other lubricants having conventional film shapes indicated a gradual increase in traction coefficient with increasing slide-to-roll ratios. The similarity of the traction behaviour to that of traction fluids supports the solidification of the film, which developed anomalous film shapes.


Author(s):  
E. M. Ratnikov ◽  
D. O. Milko

Annotation Purpose. Development of a program and methods for conducting experimental studies of the extrusion process with the definition of parameters and modes of operation of the extruder to improve its energy performance. Methods. Methods of mathematical statistics, synthesis, analysis, description and modeling were used. Results. The application of mathematical methods, in particular mathematical planning, reduces the number of experiments several times, and allows to evaluate the role of influencing factors, obtain a mathematical model of the process and determine the optimal conditions for its parameters and modes, etc. Conclusions. The methodology for experimental studies of a screw extruder is presented with the necessary equipment and methodology for processing the obtained experimental data. A mathematical method of planning, which reduces the number of experiments several times, allows us to evaluate the role of factors affecting productivity and energy intensity is presented. Keywords: extruder, auger, nutrients, research methodology, extrusion, processing, feed.


2020 ◽  
Vol 27 (12) ◽  
pp. 1231-1245
Author(s):  
Filippo Maffezzoni ◽  
Teresa Porcelli ◽  
Andrea Delbarba ◽  
Letizia Pezzaioli ◽  
Carlo Cappelli ◽  
...  

: Biological markers (biomarkers) play a key role in drug development, regulatory approval and clinical care of patients and are linked to clinical and surrogate outcomes. : Both acromegaly and Growth Hormone Deficiency (GHD) are pathological conditions related to important comorbidities that, in addition to having stringent diagnostic criteria, require valid markers for the definition of treatment, treatment monitoring and follow-up. GH and insulin-like growth factor-I (IGF-I) are the main biomarkers of GH action in children and adults while, in acromegaly, both GH and IGF-I are established biomarkers of disease activity. : However, although GH and IGF-I are widely validated biomarkers of GHD and acromegaly, their role is not completely exhaustive or suitable for clinical classification and follow-up. Therefore, new biological markers for acromegaly and GH replacement therapy are strongly needed. : The aim of this paper is to review and summarize the current state in the field pointing out new potential biomarkers for acromegaly and GH use/abuse.


The term “element” is typically used in two distinct senses. First it is taken to mean isolated simple substances such as the green gas chlorine or the yellow solid sulphur. In some languages, including English, it is also used to denote an underlying abstract concept that subsumes simple substances but possesses no properties as such. The allotropes and isotopes of carbon, for example, all represent elements in the sense of simple substances. However, the unique position for the element carbon in the periodic table refers to the abstract sense of “element.” The dual definition of elements proposed by the International Union for Pure and Applied Chemistry contrasts an abstract meaning and an operational one. Nevertheless, the philosophical aspects of this notion are not fully captured by the IUPAC definition, despite the fact that they were crucial for the construction of the periodic table. This pivotal chemical notion remains ambiguous and such ambiguity raises problems at the epistemic, logical, and educational levels. These aspects are discussed throughout the book, from different perspectives. This collective book provides an overview of the current state of the debate on the notion of chemical element. Its authors are historians of chemistry, philosophers of chemistry, and chemists with epistemological and educational concerns.


Author(s):  
Paul Chaisty ◽  
Nic Cheeseman ◽  
Timothy J. Power

This chapter summarizes the main parameters of coalitional presidentialism and the key concepts, definitions, explanatory frameworks, indicators, and propositions. It summarizes our understanding of coalitional presidentialism; the distinction between coalition formation and maintenance; the definition of coalitions; the multidimensional understanding of coalition management (the ‘presidential toolbox’); and an analytical framework that emphasizes the motivation of presidents to achieve cost minimization under constraints determined by system-level, coalition-level, and conjunctural factors. It also summarizes our main empirical findings: (1) the characteristics of presidential tools, (2) the substantive patterns of their deployment, (3) the factors that shape the costs of using these tools, (4) the actual (observed) costs of using them, and (5) the potential for imperfect substitutability of these tools. Finally, it concludes with some reflections on the current state of the research on comparative presidentialism.


2021 ◽  
pp. 112972982198916
Author(s):  
Ton Van Boxtel ◽  
Mauro Pittiruti ◽  
Annemarie Arkema ◽  
Patrick Ball ◽  
Giovanni Barone ◽  
...  

The need for filtering intravenous infusions has long been recognized in the field of venous access, though hard scientific evidence about the actual indications for in-line filters has been scarce. In the last few years, several papers and a few clinical studies have raised again this issue, suggesting that the time has come for a proper definition of the type of filtration, of its potential benefit, and of its proper indications in clinical practice. The WoCoVA Foundation, whose goal is to increase the global awareness on the risk of intravenous access and on patients’ safety, developed the project of a consensus on intravenous filtration. A panel of experts in different aspects of intravenous infusion was chosen to express the current state of knowledge about filtration and to indicate the direction of future research in this field. The present document reports the final conclusions of the panel.


2021 ◽  
Vol 22 (15) ◽  
pp. 7942
Author(s):  
Chiara Agrati ◽  
Alessandra Sacchi ◽  
Eleonora Tartaglia ◽  
Alessandra Vergori ◽  
Roberta Gagliardini ◽  
...  

In severe COVID-19, which is characterized by blood clots and neutrophil-platelet aggregates in the circulating blood and different tissues, an increased incidence of cardiovascular complications and venous thrombotic events has been reported. The inflammatory storm that characterizes severe infections may act as a driver capable of profoundly disrupting the complex interplay between platelets, endothelium, and leukocytes, thus contributing to the definition of COVID-19-associated coagulopathy. In this frame, P-selectin represents a key molecule expressed on endothelial cells and on activated platelets, and contributes to endothelial activation, leucocyte recruitment, rolling, and tissue migration. Briefly, we describe the current state of knowledge about P-selectin involvement in COVID-19 pathogenesis, its possible use as a severity marker and as a target for host-directed therapeutic intervention.


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3366
Author(s):  
Daniel Suchet ◽  
Adrien Jeantet ◽  
Thomas Elghozi ◽  
Zacharie Jehl

The lack of a systematic definition of intermittency in the power sector blurs the use of this term in the public debate: the same power source can be described as stable or intermittent, depending on the standpoint of the authors. This work tackles a quantitative definition of intermittency adapted to the power sector, linked to the nature of the source, and not to the current state of the energy mix or the production predictive capacity. A quantitative indicator is devised, discussed and graphically depicted. A case study is illustrated by the analysis of the 2018 production data in France and then developed further to evaluate the impact of two methods often considered to reduce intermittency: aggregation and complementarity between wind and solar productions.


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