DETERMINATION OF INSULATION PARAMETERS OF CURRENT TRANSFORMERS AT MULTIPLE MEASUREMENTS IN MONITORING SYSTEMS UNDER WORKING VOLTAGE

Abstract The importance of removing the small amounts of residual organics is increasing as the sources of clean surface water decrease. Knowledge of the nature of these soluble residual organics will be needed in order to assess the type of treatment required for their removal. Residual organics in three different biological treatment plants were analyzed and compared. An attempt was made to characterize these organics by a molecular size distribution on a Sephadex column monitored by differential ultraviolet and refractive index detectors. The organic carbon and chemical oxygen demand of the fractions collected from the column was also determined. An investigation of some of the problems inherent in the monitoring systems was conducted.

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Multivariate Analysis of Photoacoustic Spectra for the Detection of Short-Chained Hydrocarbon Isotopologues

Molecules ◽

10.3390/molecules25092266 ◽

2020 ◽

Vol 25 (9) ◽

pp. 2266 ◽

Cited By ~ 2

Author(s):

Alain Loh ◽

Marcus Wolff

Keyword(s):

Multivariate Analysis ◽

Continuous Wave ◽

Light Sources ◽

Least Squares Regression ◽

Detection Scheme ◽

Concentration Determination ◽

Multiple Measurements ◽

Interband Cascade Lasers ◽

Cascade Lasers

We report, to our knowledge, the first optical detection scheme for short-chained hydrocarbon isotopologues. The sensor system is based on photoacoustic spectroscopy (PAS). Two continuous wave, thermoelectrically cooled, distributed feedback interband cascade lasers (DFB-ICLs) with emission wavelengths around 3.33 and 3.38 μm, respectively, served as light sources. The investigations comprised the main stable carbon isotopologues of methane (12CH4, 13CH4), ethane (12CH3-12CH3, 13CH3-12CH3, 13CH3-13CH3), and propane (12CH3-12CH2-12CH3, 13CH3-12CH2-12CH3). They were selected because of their importance for numerous applications from climate and planetary research to natural gas exploration. Multiple measurements of single components in nitrogen and synthetic mixtures were conducted at room temperature and atmospheric pressure. Depending on the investigated hydrocarbon isotopologue, detection limits ranging from 0.043 ppmv to 3.4 ppmv were achieved. For a selective concentration determination, multivariate analysis (MVA) was applied. Partial least-squares regression (PLSR) was used to calculate concentrations from the PA spectra. The implementation of MVA has shown that the PA setup in principle works reliably and that the selective concentration determination of short-chained hydrocarbon isotopologues is possible.

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Monitoring of the process of Flash-Butt Welding

Soldagem & Inspeção ◽

10.1590/s0104-92242013000100005 ◽

2013 ◽

Vol 18 (1) ◽

pp. 31-38 ◽

Cited By ~ 3

Author(s):

Yevgenia Chvertko ◽

Mykola Shevchenko ◽

Andriy Pirumov

Keyword(s):

Neural Networks ◽

Real Time ◽

Statistical Methods ◽

Welded Joints ◽

Welding Parameter ◽

Monitoring Systems ◽

Butt Welding ◽

On Line ◽

Welding Processes

Statistical methods of analysis are currently widely used to develop control and monitoring systems for different welding processes. These methods allow to obtain information about the process including effect of all factors on its results, which is often difficult to evaluate due to the complexity of the process. The authors made efforts to apply these methods to develop the system for monitoring the parameters of flash-butt welding in real-time mode. The paper gives brief information about the features of flash-butt welding of reinforcement bars and some basic limitation of this process application. The main reasons of formation of defects in welded joints are given as well as analysis of possibility of application of monitoring systems for their determination. The on-line monitoring system based on neural networks was developed for evaluation of process deviations. This system is believed to be adequate for determination of process violations resulting in disturbances of welding parameter and can be used for prediction of possible defects in the welded joints.

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A simple method for determination of ratio error and phase angle in current transformers

Electrical Engineering ◽

10.1109/ee.1941.6434660 ◽

1941 ◽

Vol 60 (12) ◽

pp. 1369-1370

Keyword(s):

Phase Angle ◽

Current Transformers ◽

Simple Method ◽

Ratio Error

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Statistical Recognition of Trends in Health Monitoring Systems

Methods of Information in Medicine ◽

10.1055/s-0038-1635269 ◽

1980 ◽

Vol 19 (02) ◽

pp. 106-112 ◽

Cited By ~ 6

Author(s):

P. L. Brockett ◽

J. H. B. Kemperman

Keyword(s):

Health Monitoring ◽

Warning Signal ◽

Relevant Information ◽

Statistical Technique ◽

World Health ◽

Monitoring Systems ◽

Response Data ◽

Voluntary Response ◽

Health Monitoring Systems

The determination of when trends are present in an active health monitoring system is considered. The type of data collected is often voluntary response data usually of unknown, or perhaps of low quality or reliability. Often, even if the data themselves are perfectly reliable, the different monitoring stations are usually not comparable in size or scope, so aggregrate measures would tend to mask rather than detect trends for the whole system.Examples of such monitoring systems are the World Health Organization’s Research Center for International Monitoring of Adverse Reactions to Drugs and the »Programa de Investigacion de Modelos Operacionales de Prestacion de Servicios de Salud« (PRIMOPS) operating in Cali, Columbia. We study a »Center-Batch matrix« by using a transformation to a matrix of ranks. It incorporates most of the relevant information. A relatively simple statistical technique is presented for generating a warning signal whenever a pattern of increasing adverse events does occur. This rank Center-Batch method avoids some of the pitfalls of the previous methods used and in fact is often quite superior.

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