scholarly journals Assessment of the switching time and fluid type influence on the transient quality in hydro-mechanical systems

2021 ◽  
Vol 2131 (2) ◽  
pp. 022058
Author(s):  
A V Osipov ◽  
D N Kurilkin
Keyword(s):  
Power Transmission ◽  
Switching Time ◽  
Operating Time ◽  
Mechanical Power ◽  
Working Fluid ◽  
Fluid Type ◽  
Torque Converters ◽  
Main Factor

Abstract The number of transients in hydro-mechanical power transmissions accounts for a significant portion of the total operating time and has a significant impact on drive economy. The quality of the transients largely depends on their duration and the type of working fluid used. The purpose of the work is to analyze the transients in the hydro-mechanical system, taking into account the effect of the duration of switching processes and the type of working fluid used. Determination of transient parameters in the hydro-mechanical power transmission was performed on the basis of mathematical dependences describing the switching process of two torque converters depending on the duration of the filling and emptying process and the influence of the type of working fluid used. Analysis of the calculated characteristics of transients in hydromechanical power transmissions showed that the main factor in the switching of torque converters, is the combination of filling and emptying processes, depending on the type of working fluid used. The obtained results give grounds to propose recommendations on coordination of filling and emptying processes in order to increase the efficiency of the hydromechanical drive.

Analysis of Thyristor Switched Three-Phase Capacitor

2013 ◽  
Vol 722 ◽  
pp. 311-316 ◽  
Author(s):  
Tian Xiang Yan ◽  
Xiao Lan Xie ◽  
Xin Yu Chen ◽  
Peng Niu
Keyword(s):  
Reactive Power ◽  
Power Transmission ◽  
Switching Time ◽  
Transition Process ◽  
Fundamental Principle ◽  
Safe Operation ◽  
Voltage Quality ◽  
Three Phase ◽  
Selection Of

it can limit the reactive power transmission to improve the voltage quality of power grid by installing parallel capacitors for reactive power compensation. But due to presence of transient transition process during power capacitors switching, it will seriously affect the service life of power capacitors and the safe operation of power system if the switching process of capacitors is not properly controlled. Firstly, this article described the fundamental principle and switching conditions of Thyristor Switched Capacitor (TSC). Secondly, the selection of switching time was analyzed for Thyristor Switched Three-phase Capacitor (TSTC). Finally, the simulation for TSTC was carried out by using MATLAB to verify the feasibility of analysis.

scholarly journals Evaluación tecnológica explotativa del motocultor Dongfeng DF 151L en preparación de suelo para sembrar maíz

2020 ◽  
pp. 47
Author(s):  
Byron Leonardo Quimís Guerrido ◽  
Felipe Franco-Plaza ◽  
Carlos Loor-Guerrero ◽  
Víctor Sempertegui-Campi ◽  
Juan Quimís-Pin
Keyword(s):  
High Reliability ◽  
Operating Time ◽  
Observation Area ◽  
Palabras Clave ◽  
Maize Cultivation ◽  
Soil Preparation ◽  
Technological Evaluation ◽  
Productive Time

Exploitative technological evaluation of the Dongfeng DF 151L motor cultivator in soil preparation for sowing maize Resumen La presente investigación se realizó en la “Finca Juanito”, coordenadas 1o19’46’’ LS y 80o35’3’’ LO, cantón Jipijapa, provincia de Manabí, Ecuador.  El objetivo es determinar los índices tecnológicos, explotativos y calidad de trabajo del motocultor marca DONGFENG DF 151L con rotovator en la preparación de suelo para siembra de maíz.  Para determinación de las condiciones del área de observación y evaluación tecnológico-explotativa del motocultor DONGFENG 151L con rotovator, se utilizaron las metodologías de las normas cubanas NC 3447:2003 y NC 3437:2003    respectivamente.  Las propiedades físico - mecánicas y granulometría del suelo, mediante norma AASHTO T-88, se determinaron en laboratorios de INIAP y la UTM.  Los resultados dieron certeza que el suelo es apropiado para el cultivo de maíz, de textura arcilloso - limoso; densidad aparente 1,28 g/cm3; humedad gravimétrica 13%; y resistencia a la penetración de 1,8 MPa, lo cual sugiere que la compactación no es restrictiva y presenta buenas condiciones para el cultivo de maíz; la obstrucción por residuos de cosecha anterior fue 0,21 kg/ha.  Los índices de productividad por hora de tiempo limpio (W01); de tiempo operativo (W02); y de tiempo productivo (W04) registran valores similares de 0,04 ha/h, se consideran aceptables.  Los coeficientes de explotación alcanzaron valores cercanos e iguales a 1,0, se debe a la alta fiabilidad y seguridad técnica del motocultor.  La evaluación tecnológica explotativa del motocultor DONGFENG 151L con rotovator cumple con la exigencia agrotécnica, para el cultivo de maíz.  El ancho; profundidad; y velocidad de trabajo, registraron valores de 0,69 m ± 0,01 m; 14,6 cm ± 1,3 cm; y 1,28 km/h ± 0,06 km/h respectivamente.  Las fracciones de terrones alcanzaron valores de < 2,38 mm - 9,5 mm, adecuados para el cultivo de maíz. Mediante precipitaciones pluviales, el suelo adquirió humedad apropiada, se utilizó la herramienta manual espeque, para siembra directa de la semilla de maíz. Palabras clave: Besanas; calidad de trabajo; gasto de combustible específico; pendiente alta; productividad. Abstract This research was carried out in the "Finca Juanito", coordinates 1o19'46'' LS and 80o35'3'' LO, canton Jipijapa, province of Manabí, Ecuador. The objective is to determine the technological, exploitative and working quality indices of the DONGFENG DF 151L motor cultivator with rotovator in the preparation of soil for maize sowing.  For the determination of the conditions of the observation area and technological-exploitative evaluation of the DONGFENG 151L cultivator with rotovator, the methodologies of the Cuban standards NC 3447:2003 and NC 3437:2003 respectively were used.  The physical - mechanical properties and soil granulometry, by AASHTO T-88, were determined in INIAP and UTM laboratories.  The results gave certainty that the soil is suitable for maize cultivation, of clay - silty texture; bulk density 1,28 g/cm3; gravimetric humidity 13%; and penetration resistance of 1,8 MPa, which suggests that compaction is not restrictive and presents good conditions for the cultivation of maize; obstruction by residue from previous harvest was 0,21 kg/ha. The productivity rates per hour of clean time (W01); of operating time (W02); and of productive time (W04) record similar values of 0,04 ha/h, are considered acceptable. The exploitation coefficients reached values close to and equal to 1,0, due to the high reliability and technical safety of the motocultor. The exploitative technological evaluation of the DONGFENG DF 151L cultivator with rotovator meets the agrotechnical requirement, for the cultivation of maize.  The width; depth; and working speed, recorded values of 0,69 m ± 0,01 m; 14,6 cm ± 1,3 cm; and 1,28 km/h ± 0,06 km/h respectively.  The fractions of clods reached values of < 2,38 mm – 9,5 mm, suitable for maize cultivation.  By means of rainfall, the soil acquired appropriate humidity, and the manual tool was used for direct sowing of the maize seed. Keywords:  Besanas; quality of work; specific fuel consumption; high slope; productivity.

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.

6. Evaluation of Five Extraction Protocols for Determination of Endotoxin in Metal Working Fluid Aerosol

2001 ◽  
Author(s):  
K. Bartlett ◽  
J. Phipps ◽  
K. Kulhankova ◽  
P. Thorne
Keyword(s):  
Working Fluid ◽  
Metal Working

INFLUENCE OF HEAT TREATMENT OF MOUNTAIN MASSIVE ON TEMPERATURE MODE OF GEOTHERMAL CIRCULATION SYSTEM

2018 ◽  
pp. 44-50
Author(s):  
Yu. P. Morozov
Keyword(s):  
Heat Transfer ◽  
Operating Time ◽  
Fluid Motion ◽  
Coolant Temperature ◽  
Circulation System ◽  
Thermal Processes ◽  
Temperature Mode ◽  
Heat Influx ◽  
Stationary Heat Transfer

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.

Fluctuations of Annual Precipitation and Water Resources Quality in Ukraine

2016 ◽  
Vol 10 (4s) ◽  
pp. 621-629
Author(s):  
Valentina Pidlisnyuk ◽  
◽  
John Harrington JR ◽  
Yulia Melnyk ◽  
Yuliya Vystavna ◽  
...  
Keyword(s):  
Water Resources ◽  
Surface Waters ◽  
Precipitation Amount ◽  
Ion Concentration ◽  
Annual Precipitation ◽  
Resource Quality ◽  
Phosphate Ion ◽  
Regional Trends

The article focuses on examining the influence of fluctuations in annual precipitation amount on the quality of surface waters. Water quality was estimated with data on BOD, COD and phosphate–ion concentration within five selected regions of Ukraine. Analysis of the precipitation data (1991 – 2010) showed different regional trends. Using the statistics, determination of the interconnection between precipitation amount and water resources quality were done. The obtained regularities and associated uncertainties can be used for prediction of changes in water resource quality and as a guide for future adaptation to possible climate change.

POTENSI PENGEMBANGAN SADE SEBAGAI DESA WISATA LOMBOK

2016 ◽  
Vol 20 (2) ◽  
pp. 69-82
Author(s):  
W. Suprihatin ◽  
H. Hailuddin
Keyword(s):  
Analytical Hierarchy Process ◽  
Environmental Aspect ◽  
Priority Level ◽  
Highest Weight ◽  
Local Tradition ◽  
Tourist Village ◽  
Hierarchy Process ◽  
Initial Pattern

The background of the problems in this study is the decreasing quality of Sade hamlet amid rising tourist arrivals. From the environmental aspect, the conditions of the hamlet began to decline, in which the initial pattern of Sade has started a lot of changes towards the deficient and began to leave the local tradition. One effort to improve the condition of Sade hamlet in social, cultural and the environmental aspect is through the formulation of a sustainable structuring, the presence and identity maintaining and making a sustainable Tourism Village. Through analysis of AHP (Analytical Hierarchy Process) by collecting the perceptions of some experts through interviews and questionnaires, obtained by weighting the priority of the experts, namely the preservation of culture as an element of priority-level goals to be achieved in the development of Sade Hamlet as a tourist village at 0,476. While the determination of the level of the main criteria in the achievement of these objectives is the highest weight while maintaining a typical village environment at 0.319. Priority strategies that get the highest weight of the experts is that Sade Hamlet Revitalization with a priority weighting of 0.583. The second priority is the relocation of Hamlet at 0.235. Lowest weighting or last priority is Replication Sade Hamlet at 0.182.

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