scholarly journals Experimental oscillation-assisted cylindrical plunge grinding

2021 ◽  
pp. 1-36
Author(s):  
Witold Pawlowski ◽  
Norbert Kepczak ◽  
Grzegorz Bechcinski ◽  
Jakub Sikorski
Keyword(s):  
Measurement System ◽  
Rotational Speed ◽  
Experimental Studies ◽  
Ground Surface ◽  
Positive Influence ◽  
Distance Measurement ◽  
Outer Diameter ◽  
Plunge Grinding ◽  
Average Value

Abstract The paper presents experimental studies of the influence of amplitude, frequency, time of oscillation and average value of the rotational speed of the workpiece on the waviness of the ground surface during cylindrical outer diameter plunge grinding on a mass-produced cylindrical grinder. Oscillations were introduced in order to counteract the development of self-excited vibrations during spark-out. The waviness of the surface was determined by a laser distance measurement system. The results of the experiments indicate the important positive influence of the oscillations applied during spark-out on the waviness of the ground surface. The conclusions of the study regarding the process as well as technology of cylindrical plunge grinding are presented.

The influence of probiotic drug Biolax-U on morphological and biochemical parameters of blood in cows

2020 ◽  
pp. 70-76
Author(s):  
A. Farkhutdinova
Keyword(s):  
Biochemical Parameters ◽  
Hematological Parameters ◽  
Experimental Studies ◽  
Positive Influence ◽  
Biologically Active ◽  
Feed Consumption ◽  
Control Group ◽  
Animal Blood ◽  
Black And White ◽  
White Breed

The expediency of using the probiotic drug Biolax-U in the rations of lactating and dry cows of Black-and-White breed has been studied and scientifically proved. The influence of this drug on the morphological and biochemical parameters of animal blood has been determined. The composition of the probiotic drug Biolax-U consists of eight strains of a balanced complex of living lactic acid bacteria, yeast and actinomycetes, as well as biologically active substances. For experimental studies conducted on 2 groups of cows have been selected by the method of pairs-analogs, the influence of feeding of feed have been prepared with the use of the microbiological drug with probiotic action Biolax-U on feed consumption, morphological and biochemical changes in blood has been studied. Analysis of the rations of cows indicates that the content of calcium, phosphorus, magnesium, sulfur and trace elements such as manganese, copper, zinc and cobalt in the feed has been reduced. It has been found by studies that the use of probiotic drug Biolax-U had the positive influence on the feed intake, digestibility and better assimilation of feed nutrients and contributed to the improvement of blood morphological and biochemical parameters. For example, in animals of the experimental group hemoglobin has increased by 3,6 % (Р < 0,05), red blood cells by 10,1 (P ≤ 0,05), the content of leukocytes by 4,43, carotene by 9,6, glucose by 3,4; reserve alkalinity by 15,6, calcium by 19,4 (P ≤ 0,01), and phosphorus by 18,4 % compared with the control group of animals. During the lactation significantly improved hematological parameters including alkalinity reserve by 5,11 %, calcium level by 11,1, phosphorus by 8,6, hemoglobin by 14,2 %, the content of erythrocytes by 12,3, leukocyte by 3,86, and carotene 11,1 % against the parameters of animals of control group. The improvement of morphological and biochemical parameters of blood of cows indicates about stimulating effect on hematopoiesis and the general clinical condition of animals that contributes to the improvement of metabolic processes when using feed prepared with the use of microbiological drug with probiotic action Biolax-U.

ON SHALLOW‐HOLE TEMPERATURE MEASUREMENTS—A TEST STUDY IN THE SALTON SEA GEOTHERMAL FIELD

Geophysics ◽  
1977 ◽  
Vol 42 (3) ◽  
pp. 572-583 ◽  
Author(s):  
Tien‐Chang Lee
Keyword(s):  
Numerical Methods ◽  
Ground Surface ◽  
Nonlinear Least Squares ◽  
Geothermal Gradient ◽  
Geothermal Field ◽  
The Other ◽  
Temperature Measurements ◽  
Salton Sea ◽  
Depth Interval ◽  
Average Value

Shallow‐hole (<13 m) temperature measurements made at various depths and/or times may yield reliable values of geothermal gradient and thermal diffusivity if the groundwater table is shallow (a few meters) such that the effect of time‐dependent moisture content and physical properties is negligible. Two numerical methods based on nonlinear least‐squares curve fitting are derived to remove the effect of annual temperature wave at the ground surface. One method can provide information on the gradient and diffusivity as a function of depth while the other gives average value over the depth interval measured. Experiments were carried in six test holes cased with 2 cm OD PVC pipes in the Salton Sea geothermal field. A set of 5 to 7 thermistors was permanently buried inside the individual pipes with dry sand. Consistent gradient determinations have been obtained with both numerical methods from six monthly observations. By linearly extrapolating the depths to the 100°C and 200°C isotherms from the calculated gradients and mean ground temperatures, we have found good agreement with the nearby deep‐well data for four holes. Discrepancy is found for two holes, one of which is located near the field of [Formula: see text] mud volcanoes and the other near the volcanic Red Hill, reflecting complicated local hydrologic conditions.

Non-contact sensors for distance measurement from ground surface

1996 ◽  
Vol 33 (3) ◽  
pp. 155-165 ◽  
Author(s):  
Jeyong Lee ◽  
Minoru Yamazaki ◽  
Akira Oida ◽  
Hiroshi Nakashima ◽  
Hiroshi Shimizu
Keyword(s):  
Ground Surface ◽  
Distance Measurement ◽  
Contact Sensors

A 60 GHz Six-Port Distance Measurement System With Sub-Millimeter Accuracy

2009 ◽  
Vol 19 (10) ◽  
pp. 644-646 ◽  
Author(s):  
K. Haddadi ◽  
M.M. Wang ◽  
D. Glay ◽  
T. Lasri
Keyword(s):  
Measurement System ◽  
Distance Measurement ◽  
60 Ghz

scholarly journals IMPROVING DYNAMIC REGIME OF ROLLING FOR INCREASING DURABILITY OF BALL-ROLLING MILL ROLLS

2019 ◽  
Vol 61 (12) ◽  
pp. 927-932 ◽  
Author(s):  
V. Yu. Rubtsov ◽  
O. I. Shevchenko ◽  
M. V. Mironova
Keyword(s):  
Contact Pressure ◽  
Rotational Speed ◽  
Rolling Mill ◽  
Experimental Studies ◽  
Rolling Process ◽  
Operating Conditions ◽  
Frequency Method ◽  
Rolling Mills ◽  
Ball Rolling ◽  
Progressive Technology

One  of  the  important  reasons  for  the  downtime  of  ball  rolling  mills  is  replacement  of  rolls  due  to  their  wear  and  tear.  The  degree  and  zones  of  critical  wear  of  ball  rolling  rolls  are  investigated  in  the  article, where the greatest wear is observed over the flanges in zone of billet  capture.  Conditions  necessary  to  capture  the  blank  and  to  perform  rolling  process  are  analytically  determined.  Variable  frequency  method  of  roll  rotations  is  proposed  as  a  progressive  technology  for  blank supply. The results of tests for its variations in accordance with  linear  and  quadratic  law  are  presented.  Known  formulas  determining  average  strain  rate  at  rolls  rotational  speed  change  are  converted  for  linear and quadratic dependences. Experimental studies have been carried  out  in  conditions  of  EVRAZ  Nizhnetagilsky  Metallurgical  Plant  ball rolling mills during rolling of 60mm ball made of Sh-3G steel. Experiments  were  performed  for  given  parameters  of  manual  change  in  rolls rotation speed at blank capture by rollers. The results have shown  a  significant  effect  of  change  in  rotational  speed  on  average  specific  pressure during blank capture. Evaluation of torque-time and average  contact  pressure  for  calculated  and  experimental  data  are  presented.  Empirical characteristics are also described at variable rotational speed  of rolls according to linear and quadratic law. Acceptable convergence  of results of calculated and empirical characteristics is determined. Engineering solution has been proposed for that task. It consists in installation of a thyristor converter. This solution allows reduction of rolls  speed before blank capture. Also, this solution will increase frequency  to  the  nominal  value  according  to  the  given  law  after  blank  capture.  As an obtained result, there is uniform distribution of average contact  pressure over the entire length of the roll under different operating conditions  of  mill  in  automatic  mode. Application  of  this  technique  will  reduce wear degree of the rolling tool. At the same time, productivity  of ball rolling mill will be maintained. Rolls consumption and number  of rolls change will decrease due to rolls wear.

scholarly journals Impact of foreign direct investment on economic growth in the world during 1975–2015

2018 ◽  
Vol 20 (91) ◽  
pp. 28-32
Author(s):  
B. B. Brychka
Keyword(s):  
Economic Growth ◽  
Literature Review ◽  
Regression Models ◽  
Trade Openness ◽  
Positive Influence ◽  
Linear Regression Models ◽  
Average Value ◽  
Gdp Growth Rate ◽  
The World ◽  
The Impact

The study is concentrated on examination the impact of FDI on economic growth in the World during 1975–2015. The study consists of four consecutive parts, including introduction, literature review, model and methodology, data, empirical results and conclusion. Each part of the study is focused on its own goals. According to the results of the literature review, there is positive influence of FDI on economic growth in various countries. Economic growth is one of the most important goals of any country. The country image on the international level is dependent on its economic power. Economic growth provides an opportunity to improve the living standards in the country. Most researchers conclude that there is a positive influence of FDI on the countries’ economic growth. However, the impact of FDI is strong in developing countries. Moreover, this relationship is stronger in countries with higher educational and technological level, trade openness and development of the countries’ stock markets. Economists often build regression models to estimate the relationship between the variables. In order to find the impact of FDI on economic growth, we are going to apply linear regression models. We take two variables as indicators of the countries’ economic growth, including current GDP expressed in U.S dollars, and annual GDP growth rate. Taking into account that the World’s GDP in current U.S dollar is a factor variable with the mentioned resulting variables, the regression equation looks as follows: The R-squared of the built model is 0.99, indicating that roughly 100% of changes in the World’s GDP is caused by the chosen factors. As it is seen from the SAS output, the residuals of dependent variable and factors variables are distributed normally among its average value. Thus, non-normality is not observed in the model. Taking into account the coefficients of the factor variables, the log GDP is most sensitive to the changes in trade as a percent of GDP. The log GDP is not quite sensitive to the changes in FDI, since the coefficient of 0.000128 means that increasing of FDI by one unit increase the logarithmic value of GDP by $ 0.000128.

scholarly journals ANALISIS FAKTOR-FAKTOR YANG MEMPENGARUHI IMPLEMENTASI ANGGARAN BERBASIS KINERJA

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Kaillin Lalli Randa ◽  
Ida Ayu Purba Riani ◽  
Balthazar Kreuta
Keyword(s):  
Data Analysis ◽  
Organizational Commitment ◽  
Positive Influence ◽  
Least Square ◽  
Ordinary Least Square ◽  
Average Value ◽  
Data Analysis Technique ◽  
Analysis Technique ◽  
Partial Analysis ◽  
The Mean

The purpose of the study was to analyze what factors influence the Performance Based Budget by using a sample of 87 respondents working at the Secretariat of the Papuan People's Representative Council. While the data analysis technique used is the Ordinary least square (OLS) technique. The results of the study are indicated by the calculation of the mean (mean) of 32 item questions and 87 respondents and the result is 137.31. If the value is compared to the criteria that the author has set, then the average value is included in the "Very Good" category. While the results of the partial analysis of organizational commitment (X1) have a significant and positive influence on the performance-based budget of 1,261. Keywords: Performance Based Budget

scholarly journals Performance improvement of the heat recovery unit with sequential type heat pipes using TiO2 nanofluid

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1755-1764 ◽  
Author(s):  
Ahmet Ozturk ◽  
Mehmet Ozalp ◽  
Adnan Sozen ◽  
Metin Guru
Keyword(s):  
Thermal Performance ◽  
Heat Recovery ◽  
Experimental Studies ◽  
Heat Pipes ◽  
Outer Diameter ◽  
Distilled Water ◽  
Condenser Section ◽  
Recovery System ◽  
Heat Recovery System ◽  
Set Up

This paper deals with the improvement of thermal performance of the heat recovery system in air-to-air unit by using a nanofluid of TiO particles and distilled water. The 2 experimental set-up equipped with 15 copper pipes of a 1000 mm length, 10.5 mm inner diameter, and 12 mm outer diameter was used. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volumes of heat pipes were filled with working fluids. Experiments were carried out at temperatures between 25?C and 90?C by using five different cooling air-flows (40, 42, 45, 61, and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine heat removed from the condensation section. Trials were performed for distilled water and nanofluid respectively, and the results were compared with each other. Results revealed that a 50% recovery in the thermal performance of the heat pipe heat recovery system was achieved in the design using TiO nanofluid as the working liquid, at a heating power of 3 kW, air 2 velocity of 2.03 m/s and air-flow of 84 g/s.

scholarly journals Penerapan Model Pembelajaran Problem Based Learning (PBL) terhadap Hasil Belajar Siswa SMAN 7 Palu Kelas XI pada Materi Larutan Penyangga

2018 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Amsar T. Beddu ◽  
Sri Mulyani Sabang ◽  
Purnama Ningsih
Keyword(s):  
Problem Based Learning ◽  
Positive Influence ◽  
Control Group ◽  
Homogeneity Test ◽  
Distributed Data ◽  
Test Statistics ◽  
Control Group Design ◽  
Average Value ◽  
Kolmogorov Smirnov ◽  
Normally Distributed

This research aims to investigate the result of a study in applying the model of problem-based learning (PBL) the students of SMAN 7 Palu on the topic buffer. This method use quasy experiment with pretest-posttest control group design. The population is a class XI students of SMAN 7 Palu, where the sample is a 23 students in class XI IPA 3 as the experimental group and 23 students in class XI IPA 4 as the control group, which is determined by purposive sampling. The result of student learning to the average value of the experimental class is bigger than for class control experiment was 82.61 and for the control, class is 8.65. Test normality using the Kolmogorov-Smirnov test values obtained for the experimental class Sig 0.20 > 0.05 and class control 0.20 > 0.05, it means that both at data are normally distributed. Homogeneity test using the test statistics Lavene which gained value of Fhitung 0.37 > 0.54 Ftabel for experimental classes.200 Sig > 0.05 and for grade control 0.20 > 0.05, it means that both of normally distributed data, there is similarities variant between a group or the means homogeneous. Testing hypothesis use t-test two parties where the significance value of 0.06, it means at the value of Sig > 0.05, that Ho rejected and Ha accepted. Based on the statistical test, PBL learning model on material buffer has a positive influence on results for students at SMAN 7 Palu

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