• 제목/요약/키워드: Ageing process

검색결과 93건 처리시간 0.031초

천연고무의 전기전도기구에 관한 기술 동향 (A Technical Trend on Natural Rubber Electrical Conduction Mechanism)

  • 백재욱;손상철;김영근;오재한;김형곤;최용성;문종대;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1970-1971
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    • 2007
  • The efficiency of such work highly depend on the worker's safety, who is protected by tools such as gloves, sleeves, blankets and flexible coverings among other manufactured natural-rubber goods. Use, storage and maintenance of these tools guarantee the quality and durability of the material. However, it might be observed that good tools made of such material are disapproved of when received from manufacturers or when they are removed from the warehouse for replacement. This work shows the experimental results obtained from ageing at a temperature of $100^{\circ}C$ for 48, 70 and 312 h, although the application of AC electrical tension in samples and the measuring of current leakage are presented. The measurements in samples were carried out with samples prepared from the deformulated commercial materials and respectively reformulated into thin films. The obtained results showed the mechanisms of conduction of samples in low and high electric fields. It was also identified an electric tension transition showing that in low fields it prevails the Ohm's law conduction, and in high electric fields it prevails the conduction of space charge limited current (SCLC). These results can support the natural rubber formulation process having as their main objective the reducing of the mechanisms that occur under high conduction current in high electric fields, which leads the material to a dielectric breakdown. It is necessary to research this raw material from different internationally standard clones to characterize dielectric and electric properties for industrial applications. Moreover, this natural material has a low commercial price when compared to the synthetic ones.

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가속 열화 후 해수 담수 침지된 Chlorosulfonated Polyethylene의 이온 점도와 압축 강도의 특성 변화 (The Behavior Variation of the Ion Viscosity and the Compressive Strength of the Seawater and Freshwater Flooded Chlorosulfonated Polyethylene After Accelerated Thermally Ageing)

  • 홍소영;김민주;정은미;김진표;신용덕
    • 한국전기전자재료학회논문지
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    • 제32권6호
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    • pp.490-495
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    • 2019
  • This study performs the thermal aging of chlorosulfonated polyethylene (CSPE) for 807.36 and 1,614.48 hours at $110^{\circ}C$, which is equivalent to 40 and 80 years of aging at $50^{\circ}C$ in nuclear power plants, respectively. Flat-type CSPEs were soaked in seawater for five days and then dried for five days at room temperature. Furthermore, the soaked CSPEs were cleaned for 5 days with fresh water and dried for 1,100 days at room temperature. Through this process, the log IV of the CSPEs decreases, whereas the dissipation factor of the CSPEs increases as thermally accelerated aged years increase at the measured frequency. Although the phase degree of the response voltage versus excitation voltage of the CSPEs increases, that of the response current versus excitation voltage decreases with the thermally accelerated aging. The thermal conductivity of the CSPEs increases slightly, but the thermal diffusivity does not vary with the thermally accelerated aged year increase. The displacement of the compressive strength of the CSPEs decreases gradually as the thermally accelerated aged years increase.

항노화 효능을 가진 천연물에 대한 최신 연구 동향에 관한 연구 (A Study on the Latest Research Trends in Natural products with Anti-Aging Effects)

  • 표영희;유선희
    • 융합정보논문지
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    • 제9권12호
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    • pp.286-293
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    • 2019
  • 본 연구에서는 식약청 고시 원료인 레티놀, 레티닐팔미테이트, 아데노신, 폴리에톡실레이티드레틴아마이드 4종류와 항 노화의 효능을 가진 천연 원료인 금송, 하고초, 맨드라미, 브라질린, 여뀌, 황기, 연교, 자근, 대황, 육종용에 대한 연구 동향을 살펴보았다. 현재까지의 항 노화 연구는 주로 콜라겐 생성과 엘라스타아제 합성 억제 기전을 중심으로 이루어지고 있는 것이 확인되었다. 하지만, 피부의 노화 과정은 여러 가지 원인에 의해서 발생하는 것으로 볼 때, 다양한 기전에 맞춰 피부 항노화에 도움을 줄 수 있는 안전하고 효과적인 천연 원료를 활용한 항노화 연구가 지속적으로 이루어져야할 것으로 사료되어 진다.

스마트 거울을 활용한 실시간 자세교정 피트니스 시스템 (Fitness System for Correcting Real-time Posture Using Smart Mirror)

  • 서재식;신민호;문미경
    • 전기전자학회논문지
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    • 제23권1호
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    • pp.74-79
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    • 2019
  • 인구 고령화와 웰빙 열풍으로 인해 건강관리 욕구가 증가하면서 피트니스에 대한 관심은 점점 더 높아지고 있다. 사람들은 운동을 하기 위해 헬스장을 가지만, 많은 이들이 운동하는 방법을 몰라 운동 순서나 운동 자세를 틀리게 하는 경우가 많다. 이러면 운동 효과도 미비할 뿐만 아니라 부상의 위험도 커진다. 본 논문에서는 스마트 거울 앞에서 영상을 보며 혼자서 운동을 따라 할 수 있고 운동 자세가 잘못되었을 경우 실시간으로 틀린 곳을 확인시켜주는 스마트 거울을 활용한 피트니스 시스템의 개발 내용에 대해 기술한다. 이 시스템을 사용함으로써 사람들은 혼자서도 트레이너의 도움 없이 바른 자세로 운동을 할 수 있게 될 것이며, 이로 인해 그룹 또는 개인 트레이너를 기다려야 하는 시간이나 비용의 제약에 얽매이지 않고 운동을 할 수 있게 될 것이다.

Wine quality grading by near infrared spectroscopy.

  • Dambergs, Robert G.;Kambouris, Ambrosias;Schumacher, Nathan;Francis, I. Leigh;Esler, Michael B.;Gishen, Mark
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1253-1253
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    • 2001
  • The ability to accurately assess wine quality is important during the wine making process, particularly when allocating batches of wines to styles determined by consumer requirements. Grape payments are often determined by the quality category of the wine that is produced from them. Wine quality, in terms of sensory characteristics, is normally a subjective measure, performed by experienced winemakers, wine competition judges or winetasting panellists. By nature, such assessments can be biased by individual preferences and may be subject to day-to-day variation. Taste and aroma compounds are often present in concentrations below the detection limit of near infrared (NIR) spectroscopy but the more abundant organic compounds offer potential for objective quality grading by this technique. Samples were drawn from one of Australia's major wine shows and from BRL Hardy's post-vintage wine quality allocation tastings. The samples were scanned in transmission mode with a FOSS NIR Systems 6500, over the wavelength range 400-2500 ㎚. Data analysis was performed with the Vision chemometrics package. With samples from the allocation tastings, the best correlations between NIR spectra and tasting data were obtained with dry red wines. These calibrations used loadings in the wavelengths related to anthocyanins, ethanol and possibly tannins. Anthocyanins are a group of compounds responsible for colour in red wines - restricting the wavelengths to those relating to anthocyanins produced calibrations of similar accuracy to those using the full wavelength range. This was particularly marked with Merlot, a variety that tends to have relatively lower anthocyanin levels than Cabernet Sauvignon and Shiraz. For dry white wines, calibrations appeared to be more dependent on ethanol characteristics of the spectrum, implying that quality correlated with fruit maturity. The correlations between NIR spectra and sensory data obtained using the wine show samples were less significant in general. This may be related to the fact that within most classes in the show, the samples may span vintages, glowing areas and winemaking styles, even though they may be made from only one grape variety. For dry red wines, the best calibrations were obtained with a class of Pinot Noir - a variety that tends to be produced in limited areas in Australia and would represent the least matrix variation. Good correlations were obtained with a tawny port class - these wines are sweet, fortified wines, that are aged for long periods in wooden barrels. During the ageing process Maillard browning compounds are formed and the water is lost through the barrels in preference to ethanol, producing “concentrated” darkly coloured wines with high alcohol content. These calibrations indicated heaviest loadings in the water regions of the spectrum, suggesting that “concentration” of the wines was important, whilst the visible and alcohol regions of the spectrum also featured as important factors. NIR calibrations based on sensory scores will always be difficult to obtain due to variation between individual winetasters. Nevertheless, these results warrant further investigation and may provide valuable Insight into the main parameters affecting wine quality.

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노인의 삶의 만족도에 자산이 미치는 영향: 비동거 자녀와의 경제적, 정서적 지지교환의 매개효과 (Assets of the Elderly and their Life Satisfactions: Mediating Effects of Financial and Emotional Support with their Children Not Living Together)

  • 원도연;노재현;신용석
    • 한국노년학
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    • 제37권3호
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    • pp.687-705
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    • 2017
  • 본 연구는 노인의 삶의 만족도에 미치는 자산의 영향력과 이들의 관계에서 비동거 자녀와 교환하는 경제적, 정서적 지지의 매개효과를 확인하고자 하였다. 연구 목적을 위해 고령화연구패널조사(Korean Longitudinal Study of Ageing)로부터 수집된 제5차 자료에서 자녀와 분거중인 65세 이상의 노인 1,977명을 대상으로 SPSS 23.0과 SPSS Process Macro를 활용하여 분석하였다. 연구 결과를 요약하면 다음과 같다. 첫째, 노인의 자산은 삶의 만족도에 직접적인 영향을 미치고 있었다. 둘째, 노인의 자산은 자녀와의 경제적 지지교환을 매개로 삶의 만족도에 간접적인 영향을 미치고 있었다. 셋째, 노인의 자산은 자녀와의 정서적 지지교환을 매개로 삶의 만족도에 간접적인 영향을 미치고 있었다. 이러한 연구결과를 바탕으로 노인들의 삶의 만족을 높이기 위한 자산관리 및 노부모-자녀 간 지지교환측면의 사회복지 실천적, 정책적 방안을 제시하였다.

지역사회 성인남성에서의 하부요로증상 및 전립선비대증 의료이용과 사회경제적 요인의 관련성 (Relationship of Socioeconomic Factors with Medical Utilization for Lower Urinary Tract Symptoms and Benign Prostatic Hyperplasia in a South Korean Community)

  • 김한해;공경애;이훈재;윤하나;이보은;문옥륜;박혜숙
    • Journal of Preventive Medicine and Public Health
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    • 제39권2호
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    • pp.141-148
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    • 2006
  • Objectives : We wanted to evaluate the medical underutilization for benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) among Korean elderly men and we wanted to determine their associated factors. Methods : This study was conducted on 239 men with LUTS and 116 men with BPH who were compatible with the diagnostic criteria from a total of 641 participants. These participants were over 50 years old and they were randomly chosen in a community-based study for estimating the prevalence of BPH. Using a self-reported questionnaire, we surveyed the sociodemographics, health status, quality of life, lower urinary tract symptoms, medical utilization and reasons for not seeking treatment. Results : Only 27.6% of the men with LUTS and 31.0% of the men with BPH reported having visited a doctor for urinary symptoms. The reasons for not visiting a doctor were, in order of responses from the group with LUTS: 'considered the symptoms as a part of the normal ageing process', 'not enough time to visit a doctor', 'financial difficulty' and 'the symptoms were not severe or bothersome'. Regarding BPH, the responses were the same as those of the group with LUTS however, 'financial difficulty' placed second. Among the men with experience of visiting a doctor for urinary symptoms, 33.3% of those with LUTS and 28.1% of those with BPH were not treated. The most common reason in both groups was 'the symptoms were not severe to be treated'. On a multiple logistic regression analysis, the larger size household (odds ratio (OR) 3.03, 95% confidence interval (CI)=1.40-6.54) and an unsatisfactory quality of life related with urinary symptoms (OR 2.98, 95% CI=1.23-7.21) were associated with medical utilization in the group of LUTS. For BPH, the current employment status was related with the medical utilization (OR 2.80, 95% CI=1.10-7.11), in addition to the larger size household (OR 3.24, 95% CI=1.14-9.21). Conclusions : Many men with urinary symptoms do not visit a doctor. This medical underutilization for people with LUTS and BPH may be associated with economic status in Korea.

변화하는 케어-타임 다이아몬드: 한국의 21세기 사회적 돌봄의 확대 (The Changing Shape of Care-time Diamond: Social Care Expansions in the 21st Century in Korea)

  • 안미영
    • 한국사회정책
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    • 제19권2호
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    • pp.137-161
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    • 2012
  • 전통적으로 아동과 노인의 돌봄은 가족의 책임으로 여겨지고 관행적으로 실천되어 왔다. 한국정부는 가족에 의해서 돌봄을 받지 못하는 아동과 노인에 국한된 잔여적 제도를 구축해 왔다. 그러나 21세기에 들어서 고령화, 저출산, 여성의 노동시장 참여 증가, 가족의 형성과 해체의 변화, 가족 내의 돌봄 제공에 대한 인식 변화 등의 사회적 변인들은 돌봄 제공에 있어서 국가의 개입의 필요성 형성의 주요한 요인들로 작용해왔다. 이 논문은 유엔사회개발연구소의 돌봄의 정치사회경제학 연구에서 개발된 케어 다이아몬드 개념을 적용하여 한국의 사회적 돌봄 정책 발전을 국가, 시장, 가족, 제3의 부문 간의 제도적 분배의 변화를 분석하고자 한다. 분석 결과, 아동 돌봄의 경우, 정부와 시장의 역할이 증대된 반면, 제3의 부문의 역할은 줄었다. 노인 돌봄의 경우, 정부, 시장, 제3의 부문의 개입의 성장을 보였다. 그러나 한국의 가족 중심의, 특히 여성에 의한, 돌봄 제공 원칙은 변화하지 않았다.

한국 노인의 노화궤적 연구 (Multiple Aging Trajectories of the Elderly in Korea)

  • 김소진
    • 한국노년학
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    • 제39권1호
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    • pp.37-60
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    • 2019
  • 이 연구는 한국 노인들의 노화과정을 추적해 노화의 궤적을 도출하고, 그 특성을 파악하고자 시도된 것이다. 특별히 연구는 Rowe와 Kahn이 제시한 성공노화모델을 분석틀로 삼고, 집단중심 다중궤적모형을 활용해 귀납적 방식으로 노화궤적을 도출하였다. 또한 주요 인구사회적 특성들을 기본 예측요인으로 삼아 각 노화궤적의 특성들을 다항로지스틱 분석으로 파악하고자 했다. 분석을 위해 활용된 자료는 고령화연구패널(KLoSA)의 1~6차 조사자료이며, 분석대상은 65세이상 74세이하의 전기노인 2,682명이다. 다중궤적모형에 활용된 분석지표는 만성질환, 신체기능, 인지기능, 우울증상, 그리고 사회참여활동이다. 분석을 통해 도출된 노화궤적은 5개이며, 각각은 5개 지표의 변화양상에 따라 일반노화군(33.9%), 경도인지장애동반군(22.1%), 건강기능저하군(18.2%), 성공노화군(17.8%), 병적노화군(7.9%)로 명명되었다. 한편, 다항로지스틱분석을 실시한 결과 일반적으로 성공 노화는 남성, 저연령, 고학력, 고소득, 유배우자 집단이 경험할 가능성이 컸다. 반면, 저학력, 저소득, 그리고 고연령의 경우 상대적으로 어려운 노화의 과정을 겪을 가능성이 컸다. 특히, 경도인지장애동반노화를 겪을 가능성은 배우자가 없는 저학력, 저소득, 그리고 고연령 여성에게서 크게 나타났다.

Vitamin D Attenuates Pain and Cartilage Destruction in OA Animals via Enhancing Autophagic Flux and Attenuating Inflammatory Cell Death

  • JooYeon Jhun;Jin Seok Woo;Ji Ye Kwon;Hyun Sik Na;Keun-Hyung Cho;Seon Ae Kim;Seok Jung Kim;Su-Jin Moon;Sung-Hwan Park;Mi-La Cho
    • IMMUNE NETWORK
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    • 제22권4호
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    • pp.34.1-34.19
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    • 2022
  • Osteoarthritis (OA) is the most common form of arthritis associated with ageing. Vitamin D has diverse biological effect on bone and cartilage, and observational studies have suggested it potential benefit in OA progression and inflammation process. However, the effect of vitamin D on OA is still contradictory. Here, we investigated the therapeutic potential of vitamin D in OA. Six-week-old male Wistar rats were injected with monosodium iodoacetate (MIA) to induce OA. Pain severity, cartilage destruction, and inflammation were measured in MIA-induced OA rats. Autophagy activity and mitochondrial function were also measured. Vitamin-D (1,25(OH)2D3) and celecoxib were used to treat MIA-induced OA rats and OA chondrocytes. Oral supplementation of vitamin D resulted in significant attenuations in OA pain, inflammation, and cartilage destruction. Interestingly, the expressions of MMP-13, IL-1β, and MCP-1 in synovial tissues were remarkably attenuated by vitamin D treatment, suggesting its potential to attenuate synovitis in OA. Vitamin D treatment in OA chondrocytes resulted in autophagy induction in human OA chondrocytes and increased expression of TFEB, but not LC3B, caspase-1 and -3, in inflamed synovium. Vitamin D and celecoxib showed a synergistic effect on antinociceptive and chondroprotective properties in vivo. Vitamin D showed the chondroprotective and antinociceptive property in OA rats. Autophagy induction by vitamin D treatment may be a promising treatment strategy in OA patients especially presenting vitamin D deficiency. Autophagy promoting strategy may attenuate OA progression through protecting cells from damage and inflammatory cell death.