Problems of Friction Force Measurement between Cylindrical Outdoor and Internal Slide Parts

Abstract The article presents the determination of an exemplary measure in the assessment of the technical state of sets of mechanical objects at the stage of manufacture, use and maintenance. The technical state of the assemblies is influenced by the quality of the friction-cooperating elements, the quality of basic functions, the surroundings and the diameter clearance of kinematic node components. Energy wasted to overcome the frictional resistance is a significant part of the energy supplied, which is why current friction losses are minimized. The article includes analysis of the phenomena occurring in the cylindrical pairs in the presence of static and kinetic friction. The many factors affecting the course and values of friction force between cylindrical elements performing relative reciprocating motion have been indicated. The subject of the article is the method of measuring the friction force between a fixed and movable cylindrical element of the mechanical object. The gradual increase of the friction force component takes place by means of easily accessible force. The results of experimental tests of the friction force in different laboratory conditions under are also included. The effect on the measured friction force was investigated: of friction elements geometry and the surface condition after manufacture and/or operation. Scatter results of static friction force depending on the geometry and surface state can be significant. Examples of surface state images are shown. A friction force model was also developed depending on factors affecting its value.

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Optimization of Design and Technology of Injector Nozzles in Terms of Minimizing Energy Losses on Friction in Compression Ignition Engines

Applied Sciences ◽

10.3390/app11167341 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7341

Author(s):

Jan Monieta ◽

Lech Kasyk

Keyword(s):

Surface Condition ◽

Engine Performance ◽

Optimization Methods ◽

Operating Conditions ◽

Technical State ◽

Design And Technology ◽

Design Parameters ◽

Pressure Losses ◽

Injection Apparatus

The operation of injection apparatus in self-ignition engines results from the design, manufacturing technology and wear and tear during operation. The technical state of the injector apparatus significantly affects the engine performance, fuel consumption, toxicity and smoke opacity of outlet gases. The most unreliable element of the injection apparatus is the injector nozzle, the quality of which depends on the quality of construction and production, operating conditions and the of the fuels used, etc. One of the design parameters of the injector nozzles, determining the technical state is the geometry of the nozzle holes. An attempt was made to optimize the selection of the dimensions and surface condition of the spray holes to significantly affect the flow properties of the injector nozzles and, consequently, to decide on the size and form of fuel dosed streams to individual cylinders of a self-ignition engine and the quality of fuel atomization. In work, a simulation model was developed, and the pressure losses and the mass fluid of the injected fuel were minimized for selected significant geometric features, taking into account the influence of operating conditions. With the use of Mathematica software, simulation optimization methods and methods based on evolutionary algorithms were elaborated.

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Customer’s satisfaction on service quality at Vietnam Technological and Commercial Joint Stock Bank – An Giang Branch

Science & Technology Development Journal - Economics - Law and Management ◽

10.32508/stdjelm.v4i3.564 ◽

2020 ◽

Vol 4 (3) ◽

pp. First

Author(s):

Tran Minh Hieu ◽

Nguyen Duong Ngoc Mai Chi

Keyword(s):

Customer Satisfaction ◽

Service Quality ◽

Test Method ◽

Quality Of Services ◽

Factors Affecting ◽

Factors Influencing ◽

Alpha Reliability ◽

Survey Results ◽

Development Orientation

This study applied SERVQUAL scale of Parasuraman et al to measure factors affecting customer satisfaction on service quality at Vietnam Technological and Commercial Joint Stock Bank - An Giang Branch (Techcombank An Giang). The study was conducted to survey 207 customers who have been using the service at Techcombank An Giang. The survey results were analyzed by the Cronbach's Alpha reliability test method, then used Exploratory factor analysis (EFA) to verify and evaluate the scale of service quality. The results of the regression analysis show that customer's satisfaction about service quality at Techcombank An Giang includes four factors: The factor with the highest level is the Empathy with Beta = 0.253, the second of factor is the Responsibility with Beta = 0.248, ranked third in the influence level is the Tangible with Beta = 0.235, and the lowest impact level is the Reliability with Beta = 0.144. The research also uses statistical methods to describe and test the differences of demographic factors with customer's satisfactionon service quality.The analysis results show that there is no difference between customer's satisfaction on service quality and factors such as gender, age, income, number of transaction banks, regular transaction banks, and time to use the service at Techcombank An Giang. Through the research results, the author would like to propose some ideas to improve the quality of services, thereby attracting new customers and importantly, keeping traditional customers because the development orientation of Techcombank is to take care of old customers to cross sell other products of the bank. The Stud results offer a basis for the branch to identify the factors influencing customer satisfaction on their service quality, thereby having an appropriate strategy to improve customer satisfaction.

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"A Study on the Factors Affecting the Quality of Employment for Persons with Hearing Impairment*"

JOURNAL OF SPECIAL EDUCATION & REHABILITATION SCIENCE ◽

10.23944/jsers.2018.06.57.2.16 ◽

2018 ◽

Vol 57 (2) ◽

pp. 357-383

Author(s):

Seung-Mi Ha ◽

Dal-Yob Lee

Keyword(s):

Hearing Impairment ◽

Factors Affecting

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THE STUDY ON TA VAT WINE PRODUCTION FROM SUGAR PALM (ARENGA PINNATA) SAP

HUE UNIVERSITY JOURNAL OF SCIENCE AGRICULTURE AND RURAL DEVELOPMENT ◽

10.26459/jard.v83i5.3080 ◽

2014 ◽

Vol 83 (5) ◽

Author(s):

Nguyễn Thị Hồng Thu ◽

Đặng Minh Nhật ◽

Nguyễn Hoàng Dung

Keyword(s):

Room Temperature ◽

Fermentation Process ◽

Inoculum Size ◽

Wine Fermentation ◽

Wine Production ◽

Factors Affecting ◽

Natural Fermentation ◽

Tropical Asia ◽

Best Parameters

Sugar palm (Arenga pinnata) is a feather palm native to tropical Asia. In Vietnam, it is named Búng Báng or Đoác and grown only on the highlands in the central or northern part of Vietnam. It is utilized for many purposes, especially for Ta Vat wine production - a characteristic and unique product of Co Tu ethnic minority. However, because of the natural fermentation used in the production, the product quality is inconsistent. The purpose of this study was to examine a new procedure of using palm sap for making Ta Vat wine. Some characteristics of the sap, which was collected at Nam Giang district, Quang Nam province are determined, proving the potential of the sap for making wine product. The quality of sap changes quickly at room temperature. At low temperature (4 - 60C), the changes in sap quality are apparently slower. Examining some factors affecting its quality during the wine fermentation process, we determined the best parameters for the fermentation process as follows: inoculum size of 3% with cell density of about 1x108 cells/ml, the addition of the extract from the bark of Ceylon ironwood (Mesua ferrea L.) 4%. Keywords: Arenga pinnata, sap, Ceylon ironwood bark, Mesua ferrea L., wine fermentation.

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