• Title/Summary/Keyword: Aging processes

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A study on the On-Line Diagnostic Technique of High Voltage Induction Motor by partial discharge Pattern Analysis (부분방전 패턴분석에 의한 고압유도전동기 무정전 진단기법 연구)

  • Jung, Young-Ill;Lee, Eun-Suk;Kim, Duck-Keun;Lim, Yung-Bae;Kim, Jong-Seo
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1685-1687
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    • 2002
  • High voltage(H.V.) induction motors have been applied to various industrial applications. But aging and failure of induction motors are initiated by electrical, mechanical, thermal and chemical processes during manufacturing or in-service. These detects reduce locally the dielectric strength of the insulation. At such defects partial discharges can occur, which cause further degradation of the insulation and reduce the life time of the H.V induction motors. Consequently in this paper, we studied the partial discharge pattern analysis of H.V. induction motor for on-site applications.

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Analysis on the Mechanism of Fluting in the Bending of Low Carbon Steels (저탄소강판을 이용한 굽힘 가공에서 발생하는 꺾임 현상에 대한 발생기구 해석)

  • Park, K.C.;Yoon, J.B.
    • Transactions of Materials Processing
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    • v.16 no.4 s.94
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    • pp.317-322
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    • 2007
  • In order to investigate the cause and condition of fluting in tangential bending of low carbon steel sheet, an analytic analysis, an experiment and a series of finite element analysis for bending process were done. The fluting in bended sheet was related with the yield point elongation of material. Due to the yield point elongation, unstable plastic hinge was occurred in course of bending of elastic perfectly plastic sheet. According to the analysis and computational results, lower yield point elongation than 5% was required to prevent fluting in 0.5-0.6t sheet in $15{\sim}25mm$ radius bending. The tendency of fluting occurrence was reduced as decreasing the radius of bending, increasing thickness of bended sheet, and removing irregularity in sheet and bending processes.

A Study on Characterization of Sn-Ag-Cu and Sn-Cu Lead-free Solders by Adding of P (P(인)의 첨가에 따른 Sn-Ag-Cu계 및 Sn-Cu계 솔더의 특성에 관한 연구)

  • 김경대;김택관;황성진;신영의;김종민
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.05a
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    • pp.104-108
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    • 2002
  • This paper was investigated the lead free solder characteristics by P mass percentage chang e. Tension test, wetting balance test, spread test, and analysis of intermetallic compound after isothermal aging of Sn-2.5Ag-0.7Cu-0.005P, Sn-2.5Ag-0.7Cu-0.01P, Sn-2.5Ag-0.7Cu-0.02P, Sn-0.7Cu-0.005P were performed for estimation. By adding P on the solder alloys, it was showe d improvement of tensile strength, reduction of intermetallic compound growth and reduction of oxidization of fusible solder under wave soldering processes. After comparing solder alloy containing P with tin lead eutectic solder alloy, p containing solder alloys showed much better solderability than eutectic solder alloys.

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The Effect of Ginseng Supplementation on Psychomotor Performance, Indices of Physical Capacity and Plasma Concentration of some Hormones in Young Well Fit Men.

  • Ziemba Andrzej W.
    • Proceedings of the Ginseng society Conference
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    • 2002.10a
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    • pp.145-158
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    • 2002
  • Since immemorial time Panax ginseng has been known as therapeutic, tonic, prophylactic and restorative agent in ancient Korea, China and Tibet and at present time is also used as a food supplement by Western societies (6). Various ginseng preparations in a form of powders, teas, tinctures or extracts, very often mixed with other substances are recommended for attenuation of degenerative processes caused by aging or fatigue, as well as for treatment of various disorders and diseases in several organs (e.g. circulatory and nervous system, liver, kidney). One of the most commonly known properties of ginseng is its possibly positive influence on physical and mental performance and general well being. Because of these adaptogenic properties promoting vitality and resistance to stress ginseng is considered as an ergogenic aid. During almost 40 years in many laboratories attempts have been made to find out whether ginseng can be 'a remedy for today's problems'. The present work is focused on the results obtained in human studies and concerning an influence of ginseng root extracts on exercise and mental performance.

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Electrochemical Studies of Viologens in Homogeneous Aqueous and Sodium Dodecyl Sulfate Micellar Solutions

  • Park Joon Woo;Ko Seung Hyeon;Park Jong-Yoon
    • Bulletin of the Korean Chemical Society
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    • v.13 no.3
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    • pp.259-265
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    • 1992
  • Cyclic voltammetric behavior of symmetric (dimethyl, diheptyl, dioctyl, dibenzyl) and asymmetric (methyloctyl, methyldodecyl, methylbenzyl) viologens was investigated in homogeneous aqueous solution and sodium dodecyl sulfate (SDS) micellar media. In SDS-free 0.1 M NaCl solutions, the reduction potential is less negative as the chain length of alkyl substituent is longer. This is due to the stabilization of the reduced cationic radical and neutral form of viologen by adsorption on electrode surface. The adsorbed species show the "aging-effect". With the exceptions of methyldodecyl viologen and methylbenzyl viologen, the viologens show strong tendency of conproportionation reaction between viologen dications and neutral forms. In cases of methyldodecyl viologen and methylbenzyl viologen, the conproportionation reaction is kinetically disfavored, though it is thermodynamically favorable. SDS micelles dissolve the adsorbed species and the viologens exhibit two reversible redox processes in SDS micellar solutions. The reduction potentials of viologens in SDS micellar solutions depend little on the length of alkyl chain. Benzyl-substituted viologens are more easily reduced than the alkyl substituted viologens, presumably due to electron-withdrawing character of benzyl group.

Analyses on Management Situations of 'A' and 'B' Corporations as the Environment-Friendly Agricultural Organization at Asan (친환경농업 A영농법인과 B농업회사법인의 경영실태 분석- 충남 아산의 친환경 생산자조직을 사례로 -)

  • Kim, Ho
    • Korean Journal of Organic Agriculture
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    • v.30 no.4
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    • pp.471-483
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    • 2022
  • This study analyzed management situations of two organizations that have produced environment-friendly agricultural and processed meat products. 'A' farming corporation sells environment-friendly agricultural products like as grains, vegetables, fruits and processing foods. 'B' agricultural corporation processes and sells environment-friendly processed meat products, specially organic and antibiotic-free beef products. Recently, members and production areas of 'A' farming corporation have decreased because of their aging and labor shortage. And Indices for the management analysis are stability ratio, activity ratio and profitability ratio. Stability ratio indices are debt ratio, net worth ratio, fixed ratio and current ratio. Activity ratio ones include fixed assets turnover and net worth turnover. And profitability ratio is showed through return on investment, net return on sales and return on equity.

Clinical features and molecular mechanism of muscle wasting in end stage renal disease

  • Sang Hyeon Ju;Hyon-Seung Yi
    • BMB Reports
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    • v.56 no.8
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    • pp.426-438
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    • 2023
  • Muscle wasting in end-stage renal disease (ESRD) is an escalating issue due to the increasing global prevalence of ESRD and its significant clinical impact, including a close association with elevated mortality risk. The phenomenon of muscle wasting in ESRD, which exceeds the rate of muscle loss observed in the normal aging process, arises from multifactorial processes. This review paper aims to provide a comprehensive understanding of muscle wasting in ESRD, covering its epidemiology, underlying molecular mechanisms, and current and emerging therapeutic interventions. It delves into the assessment techniques for muscle mass and function, before exploring the intricate metabolic and molecular pathways that lead to muscle atrophy in ESRD patients. We further discuss various strategies to mitigate muscle wasting, including nutritional, pharmacological, exercise, and physical modalities intervention. This review seeks to provide a solid foundation for future research in this area, fostering a deeper understanding of muscle wasting in ESRD, and paving the way for the development of novel strategies to improve patient outcomes.

Data-Driven Approach for Lithium-Ion Battery Remaining Useful Life Prediction: A Literature Review

  • Luon Tran Van;Lam Tran Ha;Deokjai Choi
    • Smart Media Journal
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    • v.11 no.11
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    • pp.63-74
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    • 2022
  • Nowadays, lithium-ion battery has become more popular around the world. Knowing when batteries reach their end of life (EOL) is crucial. Accurately predicting the remaining useful life (RUL) of lithium-ion batteries is needed for battery health management systems and to avoid unexpected accidents. It gives information about the battery status and when we should replace the battery. With the rapid growth of machine learning and deep learning, data-driven approaches are proposed to address this problem. Extracting aging information from battery charge/discharge records, including voltage, current, and temperature, can determine the battery state and predict battery RUL. In this work, we first outlined the charging and discharging processes of lithium-ion batteries. We then summarize the proposed techniques and achievements in all published data-driven RUL prediction studies. From that, we give a discussion about the accomplishments and remaining works with the corresponding challenges in order to provide a direction for further research in this area.

Involvement of Immune Cell Network in Aortic Valve Stenosis: Communication between Valvular Interstitial Cells and Immune Cells

  • Seung Hyun Lee;Jae-Hoon Choi
    • IMMUNE NETWORK
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    • v.16 no.1
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    • pp.26-32
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    • 2016
  • Aortic valve stenosis is a heart disease prevalent in the elderly characterized by valvular calcification, fibrosis, and inflammation, but its exact pathogenesis remains unclear. Previously, aortic valve stenosis was thought to be caused by chronic passive and degenerative changes associated with aging. However, recent studies have demonstrated that atherosclerotic processes and inflammation can induce valvular calcification and bone deposition, leading to valvular stenosis. In particular, the most abundant cell type in cardiac valves, valvular interstitial cells, can differentiate into myofibroblasts and osteoblast-like cells, leading to valvular calcification and stenosis. Differentiation of valvular interstitial cells can be trigged by inflammatory stimuli from several immune cell types, including macrophages, dendritic cells, T cells, B cells, and mast cells. This review indicates that crosstalk between immune cells and valvular interstitial cells plays an important role in the development of aortic valve stenosis.

Inclusive Design in Digital Medical Interface Adaptation for the Elderly

  • Liu Ming Hua
    • International Journal of Advanced Culture Technology
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    • v.12 no.1
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    • pp.100-107
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    • 2024
  • Addressing challenges posed by an aging society, this study explores inclusive design orientations for digital medical interfaces catering to the elderly. The aim is to enhance inclusiveness and optimize interactive experiences within the medical system for senior users. Employing inclusive design concepts, the study analyzes characteristics through literature, focusing on functional purpose, interactive behavior, and emotional expression in digital medical interface design for the elderly. User research methods, including in-depth interviews and field research, generate user personas and behavioral analysis diagrams, organizing and categorizing pain points for elderly patients with chronic diseases. The study proposes principles for improving service touchpoints based on inclusiveness, optimizing pain point types and design processes in age-friendly services. These enhancements aim to help the elderly adapt to and integrate into a digital lifestyle.Incorporating inclusive design principles enhances the inclusiveness of service design, improving the service experience for the elderly. Age-friendly service design with inclusiveness serves as a valuable entry point for research targeting elderly populations and provides practical strategies for age-friendly medical service process design.