scholarly journals Controlled Degradation of Lubricating Media by Means of an Accelerated Electron Beam

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1452
Author(s):  
Jiří Stodola ◽  
Petr Stodola
Keyword(s):  
Oxidative Degradation ◽  
Preliminary Test ◽  
Pilot Project ◽  
Combustion Engines ◽  
Test Results ◽  
Special Equipment ◽  
Operating Load ◽  
The Coefficient Of Friction ◽  
Motor Oils

The article deals with the possibilities of using electron accelerator for controlled aging of lubricating media used in special vehicles. During use, e.g., in combustion engines, the lubricants get contaminated and thermo-oxidative degradation also occurs. The pilot project confirms the hypothesis that ionizing radiation makes it possible to simulate the operating load of lubricating media, which was repeatedly confirmed by long-term monitoring of changes in viscosity of statistically significant samples of motor oils used in special equipment. Preliminary test results also show that there are likely to be possibilities to influence other selected properties, such as the coefficient of friction depending on the radiation dose. The authors describe physicochemical processes during irradiation and, in the example of kinematic viscosity, present summary results for selected lubricating media.

PROSPECTS OF USING MICROARC OXIDATION TECHNOLOGY FOR INTERNAL COMBUSTION ENGINES

2020 ◽  
pp. 38-42
Author(s):  
ANATOLIY V. CHAVDAROV ANATOLIY V. ◽  
◽  
VYACHESLAV A. DENISOV VYACHESLAV A.
Keyword(s):  
Internal Combustion Engines ◽  
Piston Ring ◽  
Friction Pair ◽  
Microarc Oxidation ◽  
Preliminary Test ◽  
Combustion Engines ◽  
Test Results ◽  
Oxidation Technology ◽  
Development Tendency ◽  
Engine Development

microarc oxidation (MAO) technology. The authors reveal an engine development tendency to replace cast-iron blocks and liners with aluminum ones with special coatings obtained by electroplating methods. It is noted that this method does not involve the use of repair technologies, which signifi cantly aff ects consumer costs. The paper shows the prospects of using MAO technology both in the manufacturing of engine parts and restoration operations. To assess the eff ectiveness of the proposed technology, practical study was performed on covering the working part of the cylinder used in small-size agricultural machinery. The engines were tested at 5.1 kW at 3,600 rpm for 300 hours. After testing, no defects or wear were found on the cylinder face. Preliminary test results of the assembled engine showed no loss of power over 10,000 hours of car mileage, which indicates that the geometric parameters of the parts are preserved. The authors emphasize that the most optimal combination is the friction pair of two parts with an MAO coating. It has been established that the introduction of nano-additives in a MAO-coating leads to a decrease in the coeffi cient of friction between the cylinder and the piston ring and reduces the wear of piston rings and the cylinder face in more than 10 times. A conclusion is made about the feasibility of introducing the considered technology into the mass production of engines and pistons, as well as developing a set of repair equipment.

Development of Portable Tester for Measuring Skid Resistance and Its Speed Dependency on Pavement Surfaces

1996 ◽  
Vol 1536 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Kazuo Saito ◽  
Takashi Horiguchi ◽  
Atsushi Kasahara ◽  
Hironari Abe ◽  
John Jewett Henry
Keyword(s):  
Coefficient Of Friction ◽  
International Association ◽  
Constant Load ◽  
Skid Resistance ◽  
Test Results ◽  
Maintenance Program ◽  
Service Period ◽  
Friction Component ◽  
The Coefficient Of Friction

Skid resistance is an important factor in a rational maintenance program for pavement surfaces. Therefore, the skid resistance of a road surface is monitored by maintaining skid resistance inventories; in addition, spot checks are made at high accident sites. The equipment, called the dynamic friction tester (DF tester), is a disc-rotating-type tester that measures the friction force between the surface and three rubber pads attached to the disc. The disc rotates horizontally at a linear speed of about 80 to 20 km/hr under a constant load, so the DF tester can measure the skid resistance at any speed in this range with a single measurement. At the same time, the results provide speed dependency of skid resistance that will be as close as possible to the results obtained by other testing modes. The DF tester can measure on flat as well as rutted surfaces, the depths of which are less than 6 mm. In that case, the coefficient of variation is found to be less than 10 percent. The long-term characteristics of the coefficient of friction were measured by the DF tester, the British pendulum tester and the mini-texture meter. The coefficient of friction increases moderately with the traffic service period (up to 35 weeks) and decreases with increasing speed. The test results showed a significant speed dependency on the coefficient of friction measured by the DF tester although there was a high relationship between the coefficient of friction of the DF tester and the British pendulum number at each point and at each measuring speed. A weak relationship was found between the coefficient of friction and the sensor-measured texture depth values produced by the texture meter. Results of the Permanent International Association of Road Congresses experiment to compare and harmonize texture and skid resistance measurements indicate that the DF tester is capable of reporting the friction component (F60) of the international friction index using the friction coefficient at 60 km/hr.

Parents' long-term adjustment to the genetic test results of minors at risk for Long QT Syndrome

2004 ◽  
Author(s):  
K. S. W. H. Hendriks ◽  
F. J. M. Grosfeld ◽  
A. A. M. Wilde ◽  
J. van den Bout ◽  
I. M. van Langen ◽  
...  
Keyword(s):  
At Risk ◽  
Long Qt Syndrome ◽  
Genetic Test ◽  
Test Results ◽  
Long Qt ◽  
Genetic Test Results ◽  
Qt Syndrome

The Implementation Of Make A-Match Model In Social Science Learning To Improve Student Learning Outcomes In Class IV SDN 115 Manado

2019 ◽  
Vol Volume 2 Nomor 2 ◽  
Keyword(s):  
Social Science ◽  
Learning Outcomes ◽  
Teaching And Learning ◽  
Science Learning ◽  
Design Activity ◽  
Test Results ◽  
Match Model ◽  
Fourth Grade Students ◽  
Improve Student Learning

There is a tendency in the education field today to return to the idea that children will learn better if the environment is created naturally. Learning will be more meaningful if children "experience" themselves what they are learning, not 'knowing' it. Target-oriented learning of material mastery proves to be successful in short-term 'remembering' competitions, but fails to equip children to solve problems in long-term life. The problems that would to be studied in this study are: (a) how is the improvement of Social Science learning outcomes by applying the Make A-Match Model to it? (b) how does the Make A-Match Model apply towards the learning motivation? The objectives of this study are: (a) want to know the improvement in Social Science learning achievement after the implemetation of the Make A-Match Model. (b) want to know the effect of Make A-Match Model towards students’ motivation of the subject after it is applied. This research is used two rounds of action research. In each round consists of four stages, namely: design, activity and observation, reflection and revision. The target of this research is the fourth grade students of Mongodow. The data obtained in the form of formative test results, observation sheets of teaching and learning activities. From the results of analysts obtained student achievement has increased from cycle I to cycle II namely, cycle I (65%), cycle II (83%). The conclusion of this research is the Make A-Match Model of Social Science learning could positively influence the motivation of learning of central students, and this learning model could be used as an alternative to Social Science learning.

Long Term Field Test Results of Experimental EPDM and PUF Roofing

1990 ◽  
Author(s):  
David M. Bailey ◽  
Stuart D. Foltz ◽  
Myer J. Rosenfield
Keyword(s):  
Field Test ◽  
Test Results ◽  
Term Field

Improving the Strength of Abrasive Wheels and Optimizing the Control over the Strength of Composite Abrasive Materials

2019 ◽  
Vol 946 ◽  
pp. 380-385
Author(s):  
Boris A. Chaplygin ◽  
Viacheslav V. Shirokov ◽  
Tat'yana A. Lisovskaya ◽  
Roman A. Lisovskiy
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Key Factors ◽  
Special Equipment ◽  
Material Density ◽  
Factors Affecting ◽  
Control Factors ◽  
Reinforcing Material ◽  
Special Studies ◽  
First Time

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

Friction-Instability: A New Design Parameter for Brakes

1971 ◽  
Vol 93 (4) ◽  
pp. 1225-1228 ◽  
Author(s):  
W. L. Starkey ◽  
T. G. Foster ◽  
S. M. Marco
Keyword(s):  
Quality Control ◽  
Coefficient Of Friction ◽  
Design Parameter ◽  
Control Device ◽  
Experimental Facility ◽  
Test Results ◽  
Effective Manner ◽  
The Coefficient Of Friction ◽  
Brake Lining ◽  
The Right

A new design parameter, friction-instability, is defined in this paper. Friction-instability is a variation in the coefficient of friction which may occur at any time during the life of a brake lining. A friction-index is defined which measures this variation. A lining which has a high friction index may tend to cause an automobile to swerve either to the right or to the left. A unique experimental facility is described by means of which the friction-instability characteristics of brake linings can be measured. Test results using this facility are presented and interpreted. The friction-index is proposed as a new parameter which should be taken into consideration when brakes are designed and, developed. This index should be particularly useful as a quality control device to insure that machines which use mass-produced braking systems will perform in a safe and effective manner.

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