scholarly journals DETERMINATION OF THE STANDARD RESISTOR TEMPERATURE COEFFICIENTS AND THEIR UNCERTAINTIES

2019 ◽  
Vol 21 (3) ◽  
pp. 219
Author(s):  
Muhammad Azzumar ◽  
Lukluk Khairiyati ◽  
Agah Faisal
Keyword(s):  
Temperature Coefficient ◽  
Numerical Approach ◽  
Alpha Coefficient ◽  
Measurement Result ◽  
Temperature Coefficients ◽  
Taylor Series Approximation ◽  
Measurement Results ◽  
Beta Coefficient ◽  
Definition Of

<p>SNSU TK-BSN’s capability in determining the temperature coefficients of a standard resistor has been improved. The temperature coefficient is one of the important parameter in determining the definition of the standard resistor. Currently, the measurement result has been reported together with the measurement uncertainty. The determination itself is based on a numerical approach of Taylor Series Approximation (TSA) instead of based on a fitting to a certain equation. And by this determination, the uncertainty was calculated. The determination was validated by comparing the measurement result committed by SNSU TK-BSN to that of by the manufacturer. The equation for the temperature coefficient follows the parabolic equation with an alpha coefficient of -5.30 x 10-8 Ω/Ω/°C and beta coefficient of -4.70 x 10-8 Ω/Ω/°C<sup>2</sup>, with the respective uncertainties of 2.4 x 10-8 Ω/Ω/°C and 1.6x 10-8 Ω/Ω/°C<sup>2</sup>, respectively. SNSU TK-BSN measurement results in determining the temperature coefficient in agreement with the manufacturer's measurement results show an appropriate value. This correspondence has an equivalent degree of 0.20 for the alpha temperature coefficient and 0.27 for the beta coefficient.</p>

scholarly journals Investigation of hydraulic fitting losses

2018 ◽  
Vol 168 ◽  
pp. 02011 ◽  
Author(s):  
Marian Bojko ◽  
Milada Kozubková
Keyword(s):  
Flow Direction ◽  
Experimental Methods ◽  
Numerical Approach ◽  
Model Verification ◽  
Hydraulic Systems ◽  
Mathematical Methods ◽  
Standards And Regulations ◽  
Definition Of ◽  
Resistance Coefficients

Fluid flow in hydraulic systems, fittings, and piping causes hydraulic losses due to the change of flow direction and friction in the fluid. The main consequence of the resulting losses is the increase in the overall pressure gradient of the circuit. The paper is focused on the investigation of valve losses and the determination of resistance coefficients, the definition of which depends on the valve type. Methods of determination are of two types, i.e. experimental methods and mathematical methods. In the case of experimental methods, the procedures prescribed by the standards and regulations must be respected. Mathematical methods are related to defining an appropriate mathematical model and numerical approach. Both methods are applied to the ball valve and model verification is performed at the same time. The output of the thesis is the methodology for determination of resistance coefficients of valves with other diameters and other flowing media based on verified mathematical modeling.

Temperature Coefficient of Vulcanization of Buna-S

1944 ◽  
Vol 17 (2) ◽  
pp. 412-420
Author(s):  
La Verne E. Cheyney ◽  
Robert W. Duncan
Keyword(s):  
Temperature Coefficient ◽  
Chemical Nature ◽  
The United States ◽  
Rate Of Change ◽  
Effect Of Temperature ◽  
Physical Test ◽  
Temperature Coefficients ◽  
Chemical Combination ◽  
General Range

Abstract Temperature coefficient of vulcanization may be defined as the increase in time of vulcanization necessary to produce a given property in the vulcanizate per unit range of temperature decrease, the latter being taken usually as either 10° F or 10° C. Coefficients of vulcanization for natural rubber stocks have been determined by several investigators. Although the data vary somewhat with the worker and with the stock investigated, the general range of temperature coefficients is close to 2.0 per 10° C. This is regarded as evidence of the chemical nature of the vulcanization reaction. The values obtained from physical test data do not always agree with those from combined sulfur analyses. This has been interpreted as an indication that the chemical reaction between the rubber and sulfur is not a simple bimolecular one, and that the rate of change of physical properties is not directly related to the rate of chemical combination of rubber and sulfur. A number of studies were published recently on the effect of variables on the vulcanization of Buna-S (now called GR-S in the United States) and on the properties of the resulting vulcanizates. In addition, compounding reports have been issued by manufacturers of rubber chemicals, as well as confidential reports submitted to the Rubber Director's office by rubber manufacturers. None of the published investigations, however, have been concerned with the determination of numerical relations among the properties of vulcanizates obtained at various temperatures. The properties of Buna-S vulcanizates differ markedly from those of rubber in certain characteristics, while possessing certain similarities in others. The only published mention of the effect of temperature on Buna-S stocks was in a release from the office of the Rubber Director, giving tables for conversion of cure to a standard temperature. These tables are based on a temperature coefficient of 1.43 per 10° F. The source of this information is not available, however.

scholarly journals XX.—The Bifilar Magnetometer, its Errors and Corrections, including the Determination of the Temperature Coefficient for the Bifilar employed in the Colonial Observatories

1861 ◽  
Vol 22 (3) ◽  
pp. 467-489
Author(s):  
John Allan Broun
Keyword(s):  
Temperature Coefficient ◽  
Royal Society ◽  
Temperature Coefficients

In 1845, a paper by me on the balance magnetometer was read to the Royal Society of Edinburgh (see Trans. vol. xvi. p. 67), which contained an examination of some of the difficulties to be considered and overcome in relation to that instrument. No similar examination has yet appeared, as far as I am aware, of the bifilar magnetometer. When it is considered that the value of the results obtained from this instrument in so many observatories is dependent on an exact knowledge and elimination or correction of its errors; and, as will appear hereafter, that the temperature coefficients employed in the discussion of the Colonial observations are in some cases so erroneous that the unconnected observations would have been nearer the truth than after correction, the following communication may not appear unnecessary.

Validation and revision of the RANO Leptomeningeal Metastasis Group scorecard for response assessment.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e13546-e13546
Author(s):  
Emilie Le Rhun ◽  
Patrick Devos ◽  
Thomas Boulanger ◽  
Marion Smits ◽  
Dieta Brandsma ◽  
...  
Keyword(s):  
Leptomeningeal Metastasis ◽  
Response Assessment ◽  
Observer Agreement ◽  
Alpha Coefficient ◽  
Magnetic Resonance Imaging Mri ◽  
Definition Of ◽  
Measurable Lesion ◽  
Similar Assessment

e13546 Background: The Response Assessment in Neuro-Oncology (RANO) group has proposed a scorecard to evaluate response assessed by magnetic resonance imaging (MRI) during treatment of leptomeningeal metastasis (LM). Methods: To validate the LM-RANO scorecard, cerebrospinal MRI of 22 patients with LM from solid tumors were rated by 10 neuro-oncologists and 9 neuroradiologists at baseline and during follow-up after treatment. The original scorecard and its instructions were sent to the raters. The inter-observer agreement for the evaluation of single items was assessed using the Krippendorff alpha coefficient. The agreement between numerical parameters including scores at baseline and at follow-up after treatment and total scores was determined using the intraclass coefficient of correlation (ICC). Results: Instructions of the scorecard were not clear for the majority of raters. The alpha concordance coefficients obtained for the rating of single items at baseline and at follow-up were low (Krippendorf alpha coefficient < 0.61 for all raters). The best concordances were noted for spinal nodules (0.60). The worst concordances were obtained for brain linear leptomeningeal enhancement and cranial nerve enhancement. The concordance was better among neuroradiologists than among neuro-oncologists. A poor agreement was also noted when evaluating changes between baseline and follow-up and for total scores (ICC < 0.65 for the best score for all raters). Conclusions: Assessing response of LM by MRI remains challenging. The definition of a measurable lesion and the determination of response were the most important challenges. A central review is therefore recommended for clinical trials in LM. Based on this study we propose a new scorecard that will require a similar assessment as conducted here.

A Numerical Approach to the Design of Sailing Yacht Masts

1991 ◽  
Author(s):  
Dario Boote ◽  
Mario Caponetto
Keyword(s):  
Stress Analysis ◽  
Numerical Approach ◽  
Load Model ◽  
Peculiar Characteristic ◽  
Correct Calculation ◽  
Non Linear ◽  
Complete Procedure ◽  
Sailing Yacht ◽  
Definition Of

In this paper a complete procedure for the design of sailing yacht rigs is presented. The procedure starts from the definition of the load model and the determination of the aerodynamic forces developed by sails and continues with the stress analysis of the rig in the non-linear domain. For the correct calculation of the sail forces a program has been realised by the authors on the basis of the lifting surface theory. For stress analysis, another dedicated program has been developed starting from a multipurpose finite element code operating in the non-linear domain, A peculiar characteristic of this procedure is that it can be run on a personal computer.

Operation of voltage transformer in grids with distorted signals

2011 ◽  
Vol 59 (4) ◽  
pp. 551-554 ◽  
Author(s):  
A. Kasprzak ◽  
M. Orlikowski ◽  
D. Brodecki
Keyword(s):  
Power Grids ◽  
Nonlinear Loads ◽  
Voltage Transformer ◽  
Higher Harmonics ◽  
Measurement Results ◽  
Definition Of ◽  
Sinusoidal Currents ◽  
Typical Measurement

Operation of voltage transformer in grids with distorted signals Non-sinusoidal currents and voltages caused by nonlinear loads appear in power grids more and more frequently. Determination of the voltage transformer accuracy in such conditions makes a problem. Firstly, due to lack of definition of errors for distorted signals and secondly, typical measurement bridges do not accept higher harmonics. In the paper, the new definition of transformation error for distorted voltages has been proposed and some measurement results have been presented.

State Failure and the Political Violence Phenomenon: A Comparative Analysis of Iraq and Syria Cases

2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle
Keyword(s):  
Cold War ◽  
Political Violence ◽  
State Failure ◽  
The Political ◽  
Collective Violence ◽  
Short Run ◽  
Definition Of ◽  
The Cold War

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.

DEFINITION OF TIME SPENT ON REPAIR OF BUS TRANSMISSION UNITS TAKING INTO ACCOUNT TECHNOLOGICAL EQUIPMENT RELIABILITY

2020 ◽  
Vol 2020 (9) ◽  
pp. 29-33
Author(s):  
Sergey Bulatov
Keyword(s):  
Negative Impact ◽  
Probabilistic Method ◽  
Technological Equipment ◽  
Quality And Safety ◽  
Transmission Unit ◽  
Equipment Reliability ◽  
Hours Of Work ◽  
Definition Of ◽  
Time Decrease

The paper purpose is the effectiveness estimation in the technological equipment use, taking into account its reliability and productivity for defective transmission units of buses. The problem consists in the determination of time to be spent on repair of bus transmission units taking into account technological equipment reliability. In the paper there is used a probabilistic method for the prediction bus transmission units, and also a method of the dynamics of averages which allow ensuring minimum of costs for units downtime during repair and equipment cost. The need for repair of transmission units (gear box) arises on an average after 650 hours, the average productivity of the bench makes 4.2 bus / hour. The bench fails on the average after 4600 hours of work, the average time of the bench makes 2 hours. In such a way the solution of the problem specified allows analyzing the necessity of time decrease for transmission unit repair to avoid long downtimes of buses in repair areas without negative impact upon high repair quality and safety during the further operation.

Tests of jackhammers (formation of bench techniques)

2020 ◽  
pp. 28-32
Author(s):  
V.S. Vanaev
Keyword(s):  
Impact Energy ◽  
Bench Tests ◽  
Measuring Complex ◽  
Energy Indicators ◽  
Definition Of ◽  
Determination Of Parameters ◽  
Dynamic Indicators

Development of complex determination of parameters of jackhammers at bench tests is studied. The modern support of tests of jackhammers for the purpose of definition of their energy, vibration and noise indicators is considered. Descriptions of the SORP universal bench and UIPU measuring complex are given. Keywords jackhammer, bench, tests, processing object, energy indicators, impact energy, dynamic indicators [email protected]

Actual issues of valuation of businesses of the economic entity

2017 ◽  
Vol 31 (2) ◽  
pp. 156-162 ◽  
Author(s):  
O. V. Schneider
Keyword(s):  
Discount Rate ◽  
Accurate Prediction ◽  
Economic Activities ◽  
Business Valuation ◽  
Economic Entity ◽  
The World ◽  
Definition Of

The article summarizes the main approaches in the definition of business valuation the economic entity. In the process of business valuation, taking into account the risks of financial and economic activities necessary to obtain information on what stage the owner implements the business will receive income. The most difficult task is the impossibility of accurate prediction in determining the level of income and the determination of a discount rate capitalization of future incomes due to the instability of the economy, both in the country and around the world.

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