scholarly journals Degradation Monitoring of Insulation Systems Used in Low-Voltage Electromagnetic Coils under Thermal Loading Conditions from a Creep Point of View

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3696
Author(s):  
Kai Wang ◽  
Haifeng Guo ◽  
Aidong Xu ◽  
Michael Pecht
Keyword(s):  
Creep Deformation ◽  
High Frequency ◽  
Thermal Loading ◽  
Point Of View ◽  
Electromagnetic Coils ◽  
Degradation Monitoring ◽  
Insulation Degradation ◽  
Insulation Systems ◽  
Micro Level ◽  
Turn Insulation

Electromagnetic coils are a key component in a variety of systems and are widely used in many industries. Because their insulation usually fails suddenly and can have catastrophic effects, degradation monitoring of coil insulation systems plays a vital role in avoiding unexpected machine shutdown. The existing insulation degradation monitoring methods are based on assessing the change of coil high-frequency electrical parameter response, whereas the effects of the insulation failure mechanisms are not considered, which leads to inconsistency between experimental results. Therefore, this paper investigates degradation monitoring of coil insulation systems under thermal loading conditions from a creep point of view. Inter-turn insulation creep deformation is identified as a quantitative index to manifest insulation degradation changes at the micro level. A method is developed to map coil high-frequency electrical monitoring parameters to inter-turn insulation creep deformation in order to bridge the gap between the micro-level and macro-level changes during the incipient insulation degradation process. Thermally accelerated tests are performed to validate the developed method. The mapping method helps to determine the physical meaning of coil electrical monitoring parameters and presents opportunities for predictive maintenance of machines that incorporate electromagnetic coils.

scholarly journals Particle Filtering Based Remaining Useful Life Prediction for Electromagnetic Coil Insulation

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 473
Author(s):  
Haifeng Guo ◽  
Aidong Xu ◽  
Kai Wang ◽  
Yue Sun ◽  
Xiaojia Han ◽  
...  
Keyword(s):  
Particle Filtering ◽  
Remaining Useful Life ◽  
Electrical Parameters ◽  
Degradation Model ◽  
Accelerated Degradation ◽  
Insulation Failure ◽  
Electromagnetic Coils ◽  
Degradation Monitoring ◽  
Insulation Degradation ◽  
Useful Life

Electromagnetic coils are one of the key components of many systems. Their insulation failure can have severe effects on the systems in which coils are used. This paper focuses on insulation degradation monitoring and remaining useful life (RUL) prediction of electromagnetic coils. First, insulation degradation characteristics are extracted from coil high-frequency electrical parameters. Second, health indicator is defined based on insulation degradation characteristics to indicate the health degree of coil insulation. Finally, an insulation degradation model is constructed, and coil insulation RUL prediction is performed by particle filtering. Thermal accelerated degradation experiments are performed to validate the RUL prediction performance. The proposed method presents opportunities for predictive maintenance of systems that incorporate coils.

scholarly journals Creating Self-Aware Low-Voltage Electromagnetic Coils for Incipient Insulation Degradation Monitoring for Smart Manufacturing

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 69860-69868 ◽  
Author(s):  
Kai Wang ◽  
Haifeng Guo ◽  
Aidong Xu ◽  
Noel Jordan Jameson ◽  
Michael Pecht ◽  
...  
Keyword(s):  
Low Voltage ◽  
Smart Manufacturing ◽  
Electromagnetic Coils ◽  
Degradation Monitoring ◽  
Insulation Degradation

Constitution-making and institutional design. The transformations of presidentialism in Argentina

1999 ◽  
Vol 40 (2) ◽  
pp. 193-232 ◽  
Author(s):  
Gabriel L. Negretto
Keyword(s):  
Institutional Design ◽  
Political Competition ◽  
Analytical Framework ◽  
Point Of View ◽  
Collective Decision Making ◽  
Constitutional Design ◽  
Constituent Assembly ◽  
Political Resources ◽  
Micro Level ◽  
Constitution Making

This paper presents an analytical framework for the study of constitutional design from the point of view of the structure of interaction and mechanisms of institutional selection that affect the behavior and choices of the actors involved in a constitution-making process. This framework is used to explain the various limitations introduced to the powers of the President in the Argentine constitution of 1994. I argue that two levels of causation determined this reform. At the macro level, the limitation of presidential powers was the outcome of a distribution of political resources and a configuration of preferences among the actors that made possible the resolution of conflicts by means of compromise. At the micro level, the new set of institutions derived from the limited influence of the incumbent executive over constitutional design, the pluralism of the constituent assembly that approved the constitution, and the prevalence of bargaining as a mechanism of collective decision-making. Both levels of action facilitated a consensual constitution-making process from which emerged a powersharing structure that has the potential to lower the stakes of political competition for presidential office and create new rules of mutual trust between government and opposition.

scholarly journals Optimization of plastic foam composition for insulation systems

2019 ◽  
Vol 91 ◽  
pp. 02017 ◽  
Author(s):  
Anton Pilipenko ◽  
Ekaterina Bobrova ◽  
Alexey Zhukov
Keyword(s):  
Heat Loss ◽  
Experimental Studies ◽  
Point Of View ◽  
Structural Safety ◽  
Vapor Permeability ◽  
Building Structures ◽  
Polystyrene Foam ◽  
Building Systems ◽  
Insulation Systems ◽  
Extruded Polystyrene Foam

Construction insulation systems should provide solutions to the problems of creation of suitable conditions of load-bearing construction elements and whole construction, reduction of heat loss through thermal insulation layer, and creation of living comfort in buildings. The article presents the results of experimental studies, the purpose of which is to optimize the composition of extruded polystyrene foam, the formation of methods for selecting its composition and the development of systems for the use of products based on extruded polystyrene foam. Main provisions of the method of analytical optimization, which allows significantly reducing the material and time costs for processing the experimental results, are also provided. Aspects of the implementation of building systems using extruded polystyrene foam both from the point of view of minimizing heat loss through contact areas and the degree of influence of vapor permeability of building structures on the temperature and humidity conditions of premises are studied. Mandatory criteria for construction with the use of building systems are safety conditions, including both structural safety (including maintenance-free cycle) and fire safety.

scholarly journals Big Data as a Source for Official Statistics

2015 ◽  
Vol 31 (2) ◽  
pp. 249-262 ◽  
Author(s):  
Piet J.H. Daas ◽  
Marco J. Puts ◽  
Bart Buelens ◽  
Paul A.M. van den Hurk
Keyword(s):  
Big Data ◽  
High Frequency ◽  
Electronic Devices ◽  
Point Of View ◽  
Data Sources ◽  
The Internet ◽  
Official Statistics ◽  
Daily Lives ◽  
Media Messages ◽  
Loop Detection

Abstract More and more data are being produced by an increasing number of electronic devices physically surrounding us and on the internet. The large amount of data and the high frequency at which they are produced have resulted in the introduction of the term ‘Big Data’. Because these data reflect many different aspects of our daily lives and because of their abundance and availability, Big Data sources are very interesting from an official statistics point of view. This article discusses the exploration of both opportunities and challenges for official statistics associated with the application of Big Data. Experiences gained with analyses of large amounts of Dutch traffic loop detection records and Dutch social media messages are described to illustrate the topics characteristic of the statistical analysis and use of Big Data.

Reduction Methods of Structure Models for Control System Purposes

2016 ◽  
Vol 248 ◽  
pp. 119-126 ◽  
Author(s):  
Andrzej Koszewnik ◽  
Zdzisław Gosiewski
Keyword(s):  
Control System ◽  
High Frequency ◽  
Closed Loop ◽  
Flexible Structures ◽  
Low Frequency ◽  
Point Of View ◽  
Closed Loop Systems ◽  
System A ◽  
Reduction Methods ◽  
The Stability

To design vibration control system for flexible structures their mathematical model should be reduced. In the paper we consider the influence of the model reduction on the dynamics of the real closed-loop system. A simply cantilever beam is an object of consideration since we are able to formulate the exact analytical model of such structure. As a result of reduction the model with low frequency resonances is usually separated from the high frequency dynamics because high frequency part of the model is naturally strong damped. In order to estimate dynamical system for control purposes in the paper we applied a few orthogonal methods such as: modal, Rayleigh-Ritz and Schur decompositions. As it is shown all methods well calculate resonances frequencies but generate different anti-resonances frequencies. From control strategy in point of view of the flexible structures these anti-resonances have significantly influence on the stability and dynamics of the closed-loop systems.

The Sekondi Archives

1978 ◽  
Vol 5 ◽  
pp. 365-370 ◽  
Author(s):  
James B. Silver
Keyword(s):  
Point Of View ◽  
Political Scientist ◽  
Western Region ◽  
Capitalist Mode ◽  
National Archives ◽  
Micro Level ◽  
The Western Region ◽  
Western Regional ◽  
The Relationship ◽  
Mode Of Production

In the late 1950s, the National Archives of Ghana (NAG) began a decentralizaton programme which has progressed to the point where there is now a NAG regional depository in eight of the country's nine regions, the only exception so far being the Upper Region. Furthermore, unlike many of the efforts at bureaucratic decentralization in Ghana, which have been more de jure than de facto -- archival decentralization in Ghana is a reality. As a result, the historical researcher who limits his efforts to the Accra branch of the NAG is risking the loss of considerable richness of detail, as a recent trip to Sekondi made abundantly clear to me.Sekondi houses the Western Regional Branch of the NAG. The Western Region is, in many respects, one of Ghana's most interesting areas. Until relatively recently it was, at one and the same time, the major center of foreign business activity in the country, and one of the country's most backward and underdeveloped areas. While ironic, this juxtaposition is certainly not surprising. But more importantly, from the point of view of the researcher into Ghana's history, it affords the opportunity for a more detailed micro-level historical examination of, for instance, the relationship between “modernity” and “tradition,” or between the “capitalist mode of production” and the “pre-capitalist mode of production.” The Western Region has been almost an ideal type in this respect, and as a consequence is virtually a laboratory, not only for the historian, but also for the historically-minded sociologist, economist, and political scientist.

scholarly journals First mitotic spindle formation is led by sperm centrosome-dependent MTOCs in humans

Reproduction ◽  
2021 ◽  
Vol 161 (5) ◽  
pp. V19-V22
Author(s):  
Yoshiteru Kai ◽  
Hiroomi Kawano ◽  
Naoki Yamashita
Keyword(s):  
Mitotic Spindle ◽  
High Frequency ◽  
Point Of View ◽  
Cell Stage ◽  
Spindle Formation ◽  
Microtubule Organizing Centers ◽  
High Incidence

Unlike in mice, multinucleated blastomeres appear at a high frequency in the two-cell-stage embryos in humans. In this Point of View article, we demonstrate that the first mitotic spindle formation led by sperm centrosome-dependent microtubule organizing centers may cause a high incidence of zygotic division errors using human tripronuclear zygotes.

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