Laboratory for Validation of Rolling-Resistance Models

2021 ◽  
Author(s):  
M. L. Larsen ◽  
J. Cesbron ◽  
F. Anfosso-Lédée ◽  
C. Ropert ◽  
J. C. Dyre ◽  
...  
Keyword(s):  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Rolling Speed ◽  
Surface Textures ◽  
Degree Of Control ◽  
The Time Domain ◽  
High Degree ◽  
Accuracy And Repeatability ◽  
Clear Increase ◽  
Control Accuracy

In this paper, a versatile drum setup for measuring rolling resistance of small wheels is presented. The purpose is to provide a flexible setup for testing of models for rolling resistance under controlled circumstances. To demonstrate this, measurements of rolling resistance with a series of sandpapers of different grit sizes representing surface textures were carried out. The measurements show a clear increase in the rolling-resistance coefficient with increasing surface roughness, rolling speed and load. Numerical calculations in the time domain for a visco-elastic contact model run on equivalent surfaces agree with the trends found experimentally. We conclude that this approach to simplifying the experiment in order to obtain a high degree of control, accuracy and repeatability is useful for validating and testing models for calculating the rolling resistance for a given surface texture.

An Adaptive Cooperative Control Method for Nonlinear System Based on Directed Graph

2013 ◽  
Vol 328 ◽  
pp. 67-71
Author(s):  
Zhao Ming Li ◽  
Yong Ming Gao ◽  
Ya Feng Niu
Keyword(s):  
Nonlinear System ◽  
Directed Graph ◽  
Cooperative Control ◽  
Control Method ◽  
Actual State ◽  
Control Law ◽  
Degree Of Control ◽  
The Difference ◽  
High Degree ◽  
Control Accuracy

In consideration of the disturbance influence, the system always has nonlinear terms. This paper proposes an adaptive autonomous cooperative control method for a class of nonlinear system based on the directed graph. The directed graph is used to describe the topology relationship among individuals in the system. The difference between desired and actual value of the system state is defined as error, by exchanging error information among individuals, and online-updating the nonlinear terms, all individual states are synchronized up to the desired value. The differential of the actual state is not needed, which reduces the requirements for relative measurment between individuals efficiently. Finally, the numerical simulation results show the correctness of the control law, and by configuring the control parameters reasonably, we can achieve high degree of control accuracy.

Autonomous Cooperative Control for a Class of Linear System Based on Directed Graph

2013 ◽  
Vol 710 ◽  
pp. 558-562
Author(s):  
Zhao Ming Li ◽  
Ya Feng Niu ◽  
Yong Ming Gao
Keyword(s):  
Linear System ◽  
Directed Graph ◽  
Cooperative Control ◽  
Control Algorithm ◽  
Control Method ◽  
Control Law ◽  
Degree Of Control ◽  
The Difference ◽  
High Degree ◽  
Control Accuracy

This paper proposes an autonomous cooperative control method for a class of linear system based on the directed graph, and the proof is given. The directed graph is used to describe the topology relationship among individuals in the system. The difference between desired and actual value of the system state is defined as error, and by exchanging error information among individuals, all individual states are synchronized up to the desired value. The control algorithm proposed in this paper has high robustness. Finally, the numerical simulation results show the correctness of the control law, and by configuring the control parameters reasonably, we can achieve high degree of control accuracy.

Tissue section lifting for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 86-87
Author(s):  
Adrian F. van Dellen
Keyword(s):  
Infectious Disease ◽  
Electron Microscopy ◽  
Tissue Culture ◽  
Organ System ◽  
Surrounding Tissue ◽  
Paraffin Sections ◽  
Surface Areas ◽  
Specific Determination ◽  
High Degree ◽  
Accuracy And Repeatability

The morphologic pathologist may require information on the ultrastructure of a non-specific lesion seen under the light microscope before he can make a specific determination. Such lesions, when caused by infectious disease agents, may be sparsely distributed in any organ system. Tissue culture systems, too, may only have widely dispersed foci suitable for ultrastructural study. In these situations, when only a few, small foci in large tissue areas are useful for electron microscopy, it is advantageous to employ a methodology which rapidly selects a single tissue focus that is expected to yield beneficial ultrastructural data from amongst the surrounding tissue. This is in essence what "LIFTING" accomplishes. We have developed LIFTING to a high degree of accuracy and repeatability utilizing the Microlift (Fig 1), and have successfully applied it to tissue culture monolayers, histologic paraffin sections, and tissue blocks with large surface areas that had been initially fixed for either light or electron microscopy.

Displacements of Simulium damnosum and strategy of control against onchocerciasis

1979 ◽  
Vol 287 (1022) ◽  
pp. 277-288 ◽  
Keyword(s):  
Sensu Stricto ◽  
Control Programme ◽  
West African ◽  
Simulium Damnosum ◽  
Logistic Problem ◽  
Degree Of Control ◽  
High Degree ◽  
Onchocerciasis Control ◽  
Upper Volta ◽  
West African Savannah

Regular aerial treatment of 14000 km of watercourses has achieved and maintained, over an area of 700000 km 2 of West African savannah, a very high degree of control of the larvae of Simulium damnosum sensu stricto and S. sibanum , the vectors of onchocerciasis in this area. However, particular and relatively restricted parts of this area, mainly in northern Ivory Coast and neighbouring parts of Upper Volta, experience regular and prolonged reinvasions by parous female vectors, which have already taken bloodmeals (and many of them carrying the parasites) and arrive from unknown sources probably hundreds of kilometres away, from directions probably between southwest and north. This reinvasion, now experienced in three successive years, represents the outstanding scientific, epidemiological and logistic problem still facing the WHO Onchocerciasis Control Programme. An outline is presented of the multidisciplinary investigations being undertaken to find a solution.

Rethinking Incentives

2020 ◽  
pp. 154-166
Author(s):  
Lea Shaver
Keyword(s):  
Writing Process ◽  
For Profit ◽  
Degree Of Control ◽  
High Degree

This chapter begins by describing an experience of Iceland that casts Samuel Johnson's claim that “No man but a blockhead ever wrote, except for money” into serious doubt. With only 350,000 speakers, the potential readership for Icelandic books is truly small; yet Iceland's publishing scene is thriving. It discusses the counterproductive effect of financial rewards as the strongest for activities that people find psychologically rewarding because they are fun, culturally valued, or otherwise meaningful. An author can experience the writing process as play, in which the creator enjoys a high degree of control over the outcome and may also feel gratified for having made a contribution to society, advancing knowledge in an area that one cares about, or the pure satisfaction of self-expression. The chapter further clarifies that people internalize the notion that doing something for profit makes it less praiseworthy and being financially rewarded may undermine the sense of pride or virtue associated with it.

scholarly journals Limitations of vehicle movement resistances: rolling resistance

2018 ◽  
Vol 19 (12) ◽  
pp. 256-259
Author(s):  
Piotr Wrzecioniarz ◽  
Wojciech Ambroszko ◽  
Aleksandra Pindel
Keyword(s):  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Rolling Resistance Coefficient ◽  
Vehicle Movement

In the paper limitations and exemplary methods of rolling resistance minimization are described. Changes of value of rolling resistance coefficient during years and values for exemplary rolling pairs are presented. Conclusions about future progress are formulated.

scholarly journals Rolling Resistance Estimation for PCR Tyre Design Using the Finite Element Method

2020 ◽  
Author(s):  
Sutisna Nanang Ali
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Total Force ◽  
Exhaust Gas Emission ◽  
Deformation Force ◽  
Rolling Resistance Coefficient ◽  
Alternative Designs ◽  
Element Method

This study presents rolling resistance estimation in the design process of passenger car radial (PCR) tyre by using finite element method. The rolling resistance coefficient of tyres has been becoming one of main requirements within the regulation in many countries as it is related to the level of allowable exhaust gas emission generated by vehicle. Therefore, the tyre being designed must be digitally simulated using finite element method before the tyre is manufactured to provide a high confident level and avoid unnecessary cost related to failure physical product testing. The simulation firstly computes the deformation of several alternative designs of tyres under certain loading, and then the value of deformation force in each tyre component during deformation took place is calculated. The total force of deformation is considered as energy loss or hysteresis loss resulted in tyre rolling resistance. The experiment was carried out on three different tyre designs: two grooves, three grooves, and four grooves. The four groove tyre design gave the smallest rolling resistance coefficient (RRC). Finally, the simulation was continued to compare different crown radius of the tyres and the result shows that the largest crown radius generates the lowest rolling resistance.

scholarly journals A Fast Calculation Method for Improving the Steering Arm of Mining Trucks with Macpherson Suspension

2021 ◽  
Vol 11 (18) ◽  
pp. 8614
Author(s):  
Jianwei Wu ◽  
Qidi Fu ◽  
Jianrun Zhang ◽  
Beibei Sun
Keyword(s):  
Calculation Method ◽  
Rolling Resistance ◽  
Economic Cost ◽  
Coupling Model ◽  
Resistance Coefficient ◽  
Extreme Conditions ◽  
Fast Calculation ◽  
Vehicle Velocity ◽  
Steering Mechanism ◽  
Improvement Scheme

The steering arm has recently been frequently broken in a kind of mining truck with Macpherson suspension. To accelerate replacing the broken parts and minimize the economic cost, a fast calculation method for improving the steering arm is proposed in this paper. In this method, the forces on the steering arm are calculated by quasi-static analysis under a low vehicle velocity. Dynamic characteristics of the tire and road are partly included by considering the ranges of the rolling resistance coefficient and friction coefficient from the empirical values, which determines the torque on the steering arm under extreme conditions. The rigid–flexible coupling model for the left steering mechanism in ANSYS Workbench is established and solved to obtain the distribution stress on the steering arm under extreme conditions. Then, the reliability of the simulation results based on this fast calculation method is verified by the experiment. After determining an improvement scheme considering the economic and time cost, the satisfactory strength is obtained. The results illustrate that the strength of the improved steering arm has nearly doubled. Finally, the effectiveness of the improved steering arm is demonstrated by the users’ feedback after it is manufactured, installed, and used.

Real-World Contexts

2015 ◽  
Author(s):  
Diana C. Mutz
Keyword(s):  
Real World ◽  
Production Quality ◽  
Political Conflict ◽  
The Political ◽  
Causal Inferences ◽  
Camera Perspective ◽  
Degree Of Control ◽  
Experimental Treatments ◽  
High Degree ◽  
The Impact

This chapter looks at the characteristics of the experimental treatments that are used to manipulate incivility, as well as the kinds of people used in the experiments. Because of the high degree of control over the political content of the broadcasts, the participants involved in the conflicts, and the way in which the cameras covered the dispute, it is possible to draw strong causal inferences about the impact that incivility and camera perspective have on viewers' experiences of political conflict. Although the professional production quality meant that none of the subjects voiced suspicions about the programs themselves, it is still plausible that other, unidentified differences between the real world and this exchange may have altered the outcomes.

PLAYING IN THE FRONTIERS OF THE WOODWARD-HOFFMANN RULES

2021 ◽  
Author(s):  
Carlos Silva López ◽  
Keyword(s):  
Organic Synthesis ◽  
Microscopic Level ◽  
Pericyclic Reactions ◽  
Computational Tools ◽  
New Era ◽  
Eye Opening ◽  
Degree Of Control ◽  
Chiral Centers ◽  
High Degree

Pericyclic reactions are known for their exquisite selectivity and, in many cases, the formation of multiple chiral centers with a high degree of control. With the advent of accurate computational tools, this control was translated into predictability, and the design and exploitation of this set of reactions opened a new era in organic synthesis. Suddenly, highly complex and profusely decorated polycyclic structures were accessible in relatively short reaction sequences. Out interest in exploring the limits of application of the rules that govern these reactions with ironfist led us to discover a range of eye opening post-transitional effects that are key to ultimately understand reactivity at a microscopic level.

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