scholarly journals Determination of Bearing Quality Using Frequency Vibration Analysis

2021 ◽  
Vol 71 (2) ◽  
pp. 343-350
Author(s):  
Žiaran Stanislav ◽  
Chlebo Ondrej ◽  
Šooš Ľubomír
Keyword(s):  
Frequency Distribution ◽  
Vibration Analysis ◽  
Time History ◽  
Acoustic Energy ◽  
Frequency Range ◽  
Vibration Acceleration ◽  
Maximum Acceleration ◽  
Required Quality

Abstract The paper proposes two methods for determining the quality of industrially manufactured bearings, where the vibro-acoustic energy is expressed by measuring the vibration acceleration. The determined criteria were verified and 100 % agreement was reached in determining the required quality of the bearings. Unwanted bearing noise emissions and its faults can be monitored over the maximum acceleration value determined from the time history, the frequency distribution and the r.m.s. value of the determined frequency range.

scholarly journals Research on the relative productivity of a drum mill type SAG 8.5×5.3

2020 ◽  
Vol 168 ◽  
pp. 00012
Author(s):  
Ivan Minin
Keyword(s):  
Energy Consumption ◽  
Control Parameters ◽  
Operational Mode ◽  
Operational Parameters ◽  
Technological Parameters ◽  
Expected Performance ◽  
Relative Productivity ◽  
Required Quality

The determination of the optimal operational mode of drum mills can be assessed by different criteria. The most important of them can be formulated as follows: “To be specified and established the values of the mill operational parameters regarding to which it is possible to be provided the user’s expected performance at the required quality of the final product and the same to be achieved at minimal energy consumption”. For the fulfillment of this condition, there has to be determined the laws of productivity variation, the final product quality and the energy consumption in function of the adequately chosen representative control parameters of the mill. There are obtained mathematical models, describing the most important technological parameters of the machine and are made conclusions about the factors influencing on them.

An interlaboratory study of the determination of digoxin by immunoassay.

1980 ◽  
Vol 26 (3) ◽  
pp. 480-486
Author(s):  
D M Fast ◽  
W H Hannon ◽  
C A Burtis ◽  
D D Bayse
Keyword(s):  
Frequency Distribution ◽  
Statistical Difference ◽  
Analytical Data ◽  
Statistical Information ◽  
Mean Values ◽  
Clinical Laboratories ◽  
The Mean ◽  
Computational Procedures

Abstract We conducted a voluntary survey of laboratories and manufacturers to assess the current quality of analytical assays for serum digoxin. More than 300 clinical laboratories and 18 manufacturers responded, giving data on methods, instruments, computational procedures, and results for five survey samples. We sorted the analytical data to provide statistical information on the grand mean values separately for manufacturers and clinical laboratories, the frequency distribution of all reported values, and the mean values by method of interpolation and algorithms used for linear transformation. There was no statistical difference (alpha = 0.05) between the means for each specimen as determined by the kit manufacturers as a group and the clinical laboratories as a group.

Determination of the Bearing Quality by Means of Vibroacoustic Response

2015 ◽  
Author(s):  
Stanislav Ziaran ◽  
Milos Musil ◽  
Ondrej Chlebo
Keyword(s):  
Quality Evaluation ◽  
Dynamical Response ◽  
Frequency Interval ◽  
Maximum Acceleration ◽  
Operational Conditions ◽  
Means Of Measurement ◽  
Damage Type ◽  
The Given

A signal of mechanical and acoustical vibration generated during a bearing’s quality testing contains variety of useful information about their operational conditions. At defined testing speeds, the bearings generate a periodical and a non-periodical vibroacoustic signal of different intensities, which are dependent on the quality of bearings and/or their damage type. A dynamical response of the tested bearings recorded in time characterizes also the nature of the unwanted noise of bearings. Therefore the dynamical response of the maximum acceleration recorded in time is one of the major criteria of bearing quality evaluation in terms of noisiness. The second criterion is a determination of statistically significant frequency interval for the equivalent acceleration value expressed in decibels. Consequently, from the effective acceleration value, the bearing quality can be determined in terms of its vibration severity, as well as its noise level. This objective methodology substitutes the evaluation bearing quality by means of measurement of the vibration acceleration on the given test device and simultaneously evaluation of the noise quality and its intensity auditorily. Verifying the proposed methodology 100 % conformity was achieved between the methodology currently used and the new methodology, which eliminates the subjective quality evaluation of bearings auditorily.

Determination of Soil Polluted with Kerosene Using Electromagnetic Cell

2014 ◽  
Vol 567 ◽  
pp. 183-188
Author(s):  
Hashem Al-Mattarneh ◽  
Mohamad Dahim ◽  
Rabah Ismail ◽  
Muhd Fadhil Nuruddin
Keyword(s):  
Petroleum Hydrocarbons ◽  
Electrochemical Techniques ◽  
Geophysical Methods ◽  
Analytical Techniques ◽  
Dielectric Behavior ◽  
Complex Dielectric Constant ◽  
Frequency Range ◽  
Measuring Techniques

Soil contamination with petroleum hydrocarbons has become one of the most serious problems due to its negative repercussion on ecosystems. For this reason, different analytical techniques have been developed to evaluate the quantity and the quality of organic pollutants using electrochemical techniques, and a geophysical methods have been developed which utilizes the contrast caused by the contaminant on physical properties of the soil dielectric methods shows high potential for characterization kerosene contaminated soil and determination of the level of contaminant. The potential of dielectric measuring techniques for soil characterization has not been fully explored. For this purpose, dielectric measurements, in the frequency range from 100 kHz to1000 kHz, were carried out in sandy soil samples, contaminated with solutions of kerosene, at different concentrations. The differences of the dielectric behavior with contaminant content suggest that the monitoring of complex dielectric constant has the potential to quantify contaminants.

DETERMINATION OF THE VALUE OF SINGLE RAPID VOLTAGE CHANGES IN NETWORKS SUPPLYIND ELEKTRIC WEIDING INSTALLATIONS

2019 ◽  
pp. 58-65
Author(s):  
Yryskeldi Kargabaev ◽  
Kubat Osmonaliev
Keyword(s):  
Power Systems ◽  
Power Supply ◽  
High Performance ◽  
Electromagnetic Compatibility ◽  
Electric Energy ◽  
Industrial Enterprises ◽  
Supply Systems ◽  
Required Quality

The article deals with the tasks of ensuring the required quality of electricity in modern power systems of industrial enterprises. The main tasks of designing and operating modern power supply systems for industrial enterprises are in addition to the rational choice of elements of power supply systems, it is also to ensure the required quality of electricity at the terminals of the power receivers. Ensuring the required quality of electricity is generally associated with the electromagnetic compatibility of the supplynetwork. The intensification of production processes is associated with the improvement of technological processes and the introduction of advanced technologies, with the use of high-performance equipment, in particular, valve converters, welding plants, powerful metalworking machines are being introduced. They are currently controlled using digital technology, these devices strictly impose high demands on the quality of electrical energy.In connection with the requirements of the quality of electricity, in the Russian Federation every 10-15 years new standards are developed, where the indicators of the quality of electric energy are normalized

scholarly journals Evaluation of efficiency of buses “Volgabus” with determination of critical values of vibration acceleration of transmission

2018 ◽  
Vol 224 ◽  
pp. 02097
Author(s):  
Galina Chernova ◽  
Aleksey Sinkov ◽  
Yuriy Moiseev
Keyword(s):  
Rapid Diagnosis ◽  
Critical Values ◽  
Instrumental Method ◽  
Vibration Acceleration ◽  
Operational Factors

The article provides a rationale for diagnosing the condition of the driving shafts of buses “Volgabus”. It is determined that the efficiency of the transmission depends not only on the influence of operational factors, but also on the quality of maintenance. The authors monitored the malfunctions of the driving shafts of buses and determined the task of diagnosing the transmission without removing the units and aggregates. The technique of fast diagnostics of the bus transmission by the instrumental method is offered. The article presents the results of a study of vibration acceleration of the buses “Volgabus” transmission with different mileage values. Critical values of vibration acceleration at which buses cannot be used are determined. The recommendations for the rapid diagnosis of the transmission of buses are given.

An interlaboratory study of the determination of digoxin by immunoassay.

1980 ◽  
Vol 26 (3) ◽  
pp. 480-486 ◽  
Author(s):  
D M Fast ◽  
W H Hannon ◽  
C A Burtis ◽  
D D Bayse
Keyword(s):  
Frequency Distribution ◽  
Statistical Difference ◽  
Analytical Data ◽  
Statistical Information ◽  
Mean Values ◽  
Clinical Laboratories ◽  
The Mean ◽  
Computational Procedures

Abstract We conducted a voluntary survey of laboratories and manufacturers to assess the current quality of analytical assays for serum digoxin. More than 300 clinical laboratories and 18 manufacturers responded, giving data on methods, instruments, computational procedures, and results for five survey samples. We sorted the analytical data to provide statistical information on the grand mean values separately for manufacturers and clinical laboratories, the frequency distribution of all reported values, and the mean values by method of interpolation and algorithms used for linear transformation. There was no statistical difference (alpha = 0.05) between the means for each specimen as determined by the kit manufacturers as a group and the clinical laboratories as a group.

scholarly journals Changes in the kinematic viscosity of engine oil during the operation of marine diesel engines

2021 ◽  
Vol 2131 (3) ◽  
pp. 032060
Author(s):  
V Zhukov ◽  
O Melnik ◽  
E Khmelevskaya
Keyword(s):  
Diesel Engines ◽  
Kinematic Viscosity ◽  
Environmental Safety ◽  
Engine Oil ◽  
Engine Oils ◽  
Marine Diesel ◽  
Required Quality

Abstract A prerequisite for the long-term and safe operation of marine diesel engines is the high quality of operational materials, which include engine oils and coolants. The required quality of operational materials is ensured by the introduction of additives into their composition, which are now increasingly used as nanoparticles. During operation, as a result of the destruction of additives, the operational properties of coolants and engine oils deteriorate. The conducted studies allowed us to evaluate the change in the lubricating ability of engine oils of two brands that are used in marine diesels during operation. As a characteristic of the lubricating ability of the oil, its kinematic viscosity was used. The experimental determination of the kinematic viscosity of engine oil samples having different periods of operation, and the subsequent mathematical processing of the experimental results made it possible to determine the dependencies characterizing the change in the kinematic viscosity of engine oil during its operation. The research results confirm the possibility of scientific justification for extending the use of marine diesel engine oils, which reduces operating costs and increases the environmental safety of marine diesel engines.

scholarly journals Analytical determination of the rational amount of low-alumina coal of grade DG in the charge for coke production the specified properties

2019 ◽  
Vol 1 (1) ◽  
pp. 93-96
Author(s):  
Starovoit A ◽  
Sorokin Ye ◽  
Shumeiko T
Keyword(s):  
Linear Models ◽  
Coke Production ◽  
Response Surfaces ◽  
Analytical Determination ◽  
Optimum Quantity ◽  
Coal Charge ◽  
Main Factors ◽  
Required Quality

In this paper we consider mathematical calculations for the study of optimal content of fractions of weakly-coagulated coal of a certain density, which is part of the coal charge for coking. The methods of mathematical calculations, which were carried out with the help of the method of PFE 22 and TSKOP, are presented. As a result of the analysis, the authors found that the main factors that affect the quality of the final product are the granulometric composition and the degree of its metamorphism. On the basis of the calculations, the authors found that the obtained linear models of PFE 22 are inadequate and are not acceptable for their further use. In this way, the article is devoted to a detailed study of mathematical calculations, namely, the regression equation and response surfaces obtained with the help of the TsKOP method, which showed in which optimum quantity it is possible to use a fraction of poorly sparing coal to produce the required quality coke.

Tingkat Pemahaman Kompetensi Guru Pada Mahasiswa Pendidikan Geografi Sebagai Calon Guru Geografi

2020 ◽  
Vol 21 (1) ◽  
pp. 102-117
Author(s):  
Novia Zalmita ◽  
Muhajirah Muhajirah ◽  
Abdul Wahab Abdi
Keyword(s):  
Prospective Teachers ◽  
Prospective Teacher ◽  
Quantitative Description ◽  
Population Data ◽  
Geography Education ◽  
Teacher Competence ◽  
Education Department ◽  
Long Time

One that influences human resource indicators is education. The teacher is a profession as a job of academic specialization in a relatively long time in college. Understanding related to teacher competence is very important to have by a prospective teacher because it can affect the quality of performance as a professional teacher. The teacher's competence is known as pedagogic, professional, social and personality competencies. The issue in this study is how the competency of the teacher of the Department of Geography Education FKIP Unsyiah as a prospective teacher of geography? The purpose of this study was to determine the competence of teachers in the Department of Geography Education FKIP Unsyiah as prospective geography teachers. Quantitative description approach is used in this study to find answers to the issue. The population in this study were students of the Department of Geography Education FKIP Unsyiah class of 2015 and 2016 who had been declared to have passed the Micro Teaching and Magang Kependidikan 3 course totaling 50 people. Because the population is small and can be reached, the determination of the sample using total sampling techniques so that the sample in this study is the whole population. Data collection is done by distributing test questions to respondents. The data was analyzed using the descriptive statistics percentage formula. The results of the study indicate that the level of teacher competence of Geography Education Department students as prospective teachers is in the moderate category, namely as many as 22 respondents (44%). A total of 12 respondents (24%) were in the high category, 15 respondents (30%) were in the low category and 1 respondent (2%) were in the very low category.

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