• 제목/요약/키워드: aged deterioration

검색결과 128건 처리시간 0.028초

765 kV용 400 kN 현수애자 개발 (Development of Extra High Voltage(400kN) Porcelain Insulator for Transmission Lines)

  • 최인혁;최장현;이동일;최연규
    • 대한전기학회논문지:전기물성ㆍ응용부문C
    • /
    • 제52권8호
    • /
    • pp.348-353
    • /
    • 2003
  • This paper was the research of high voltage suspension insulator (400 [kN]) including pottery stone, feldspar, clay and alumina of 17 [wt%]. The slurry was fabricated after ball milling mixed raw materials. Green compacts were made by the extrusion of jiggering method and were sintered at 1300[$^{\circ}C$] for 50 [min.] in the tunnel kiln. The sintered density was reached to 97% of theoretical density, and the bending strength was 1658 [k $g_{f}$/$\textrm{cm}^2$] and hardness and fracture toughness which was measured by ICL( indentation crack length ) method were 1658 (kgf/$\textrm{cm}^2$) and 27.5 [Gpa], respectively. In measurement of tana and insulation break voltage of 400 (kN) porcelain, tan$\delta$ took some numerical value between 17${\times}$10$_{-3}$ and 61${\times}$10$_{-3}$ and insulation break voltage value was 19.9$\pm$1.4 [㎸/mm]. The test was performed to research whether the shape of pin affect a overvoltage break load or not As a consequence, when a pin was designed a pin diameter 51 [mm] with the bottom form of two-step constructed with straight in the suspension insulator, Insulator showed overvoltage break load 52 [ton] of the highest value and reflected a fine characteristic in aged deterioration test which is one of the accelerated aging test. Also it could be confirmed a fine characteristic through performing the test that electrical property of insulator was established correctly in accordance with IEC 60383-1 standards.s.

무릎 전치환술 환자의 통증과 심리적 안녕에 관한 연구 (A Study of Pain and Psychological Well-Being in Total Knee Replacement Patients)

  • 채정병;정주현
    • PNF and Movement
    • /
    • 제18권2호
    • /
    • pp.233-244
    • /
    • 2020
  • Purpose: The study investigated pain and falls as psychological factors in Total Knee Replacement patients and examined the relationship between these factors. Methods: Ninety-six total knee replacement patients aged 69.31±7.01 (male: 21, female: 75) participated in the study. Post-surgery pain was assessed on a visual analog scale, and fall risk scores were evaluated on fall fear and fall efficacy scales. Other psychological factors assessed included national anxiety and trail anxiety, fear prevention, Beck depression score, and psychological health measures. The data were analyzed using SPSS version 22.0. Results: A statistically significant correlation was found between pain before surgery and FES fall fear score before surgery (p < 0.05). A statistically significant correlation was found between pain after surgery and PWBS fall fear score after surgery (p < 0.05). A statistically significant correlation was found between state anxiety and PWBS, Trail anxiety (p < 0.05). A statistically significant correlation was also found between trail anxiety and BDI, PWBS (p < 0.05). State anxiety and fear avoidance before surgery were found to affect trail anxiety, and pain before surgery and fall fear score before surgery were found to affect FES. In addition, PWBS was found to affect BDI. Conclusion: The study confirms that increased pain in Total Knee Replacement patients can be a risk factor for falls. In addition, fall fears increase fear avoidance and cause psychological deterioration. This suggests that efforts should be made to reduce pain and to manage psychological factors.

The Effects of National Health Insurance Denture Coverage Policies for the Elderly on the Unmet Dental Needs of the Edentulous Elderly

  • Ahn, Eunsuk;Hwang, Ji-Min;Han, Ji-Hyoung
    • 치위생과학회지
    • /
    • 제18권3호
    • /
    • pp.182-187
    • /
    • 2018
  • As the elderly population increases, they are increasingly affected by oral health problems. Therefore, efforts are being made to improve the oral health of older people, alleviate mental discomfort, and reduce unmet dental needs. This study was conducted to confirm the relationship between the National Health Insurance Elderly Denture Coverage and the unmet dental need for the edentulous elderly, as part of the protection policy. We analyzed the 2011 and 2013 Community Health Survey data of the edentulous elderly, aged 75 years or older, before 2012. In order to more precisely confirm the effects of the denture donation policy on unmet dental care, basic life recipients who were subject to the free elderly prosthetic project were excluded from the analysis. The final analysis included 20,400 subjects. According to our investigation of the factors that affect the unmet dental needs of the elderly, the National Health Insurance Elderly Denture Coverage did not affect unmet dental needs. The statistically significant variables that affected the unmet dental needs of the elderly were education and income levels, which are representative socioeconomic status variables. The lower the level of education, the unhealthier the dental care experience, and income levels showed a similar tendency. The elderly who have a low socioeconomic status are more likely to experience unmet dental needs because they lack the knowledge and socioeconomic ability to pay for dental care. Therefore, the policy for health protection of the entire elderly population should be continuously expanded. In addition, the socioeconomically vulnerable groups may have health problems due to the restriction of medical use, which may lead to quality of life deterioration.

상수도시설 콘크리트 수조구조물에서의 염화이온 침투저항 특성분석 (Property Analysis of Waterproofing and Corrosion-Resistant Performance in Concrete Water Supply Facilities)

  • 곽규성;마승재;최성민;오상근
    • 한국건설순환자원학회논문집
    • /
    • 제3권2호
    • /
    • pp.122-131
    • /
    • 2015
  • 본 논문에서는 국내 외 관련 문헌 자료 및 규정에 대한 고찰과, 20년 이상 된 수조 구조물 현장의 사례 조사를 통해 수밀 콘크리트와 침투방지재의 염소이온 투과에 대한 실험적 평가 등을 통하여 결론을 도출하고. 방수층 및 부식저항기술을 음용수조 구조물(상수조 등)의 각 시설물별 방수 방식에 대한 성능을 동시에 만족하여야 할 필요성을 정립하는 것이다. 이는 수조 구조물들이 방수 및 침투방지재가 확실히 필요하다는 사실을 확언 할 수 있고, 또한 여러 가지의 콘크리트 침식을 발생시키는 요소와 원인들에서부터 장기적인 내구성을 화보할 수 있다.

콘크리트용 고성능 수축저감제 개발에 대한 기초적 특성 (Fundamental Properties on the Development of High Performance Shrinkage Reducing Agent for Concrete)

  • 박종필;정용욱
    • 한국산학기술학회논문지
    • /
    • 제16권6호
    • /
    • pp.4298-4307
    • /
    • 2015
  • 최근 콘크리트 구조물의 내구성 저하에 따른 성능저하로 유지 보수나 보강등에 상당한 비용이 증가함에 따라 콘크리트의 고유 특성인 균열 저감에 대한 연구가 필요한 실정이다. 특히 장기간 운영에 따른 지하 전력구의 노후화로 유지 보수에 어려움이 상존함에 따라 전력구 설계단계에서 균열을 획기적으로 저감할 수 있는 저수축 콘크리트용 수축저감제 기술 개발이 필요하다. 본 연구는 콘크리트 구조물의 내구성 저하에 따른 균열을 방지하고자 균열을 획기적으로 저감할 수 있는 저수축 콘크리트를 개발하기 위한 것으로 수축저감 물질을 선정하고 모르타르 및 콘크리트 특성을 검토한 결과 클리콜계의 경우 압축강도 특성 및 건조수축 길이변화 실험결과에서 우수한 것으로 나타나 수축저감제로서의 가능성을 확인하였다. 추후 수축저감제의 범용적인 적용성 검토를 위하여 수축저감제의 사용량 및 사용재료 변화 등에 대한 다양한 재료변수 요인 검토를 통하여 수축저감제의 성능 검토가 필요할 것으로 사료된다.

나사조임토크에 따른 전선접속부의 열적특성에 관한 연구 (A Study on the Thermal Characteristics of Wire Connection Part Depending on the Screw Torque)

  • 김시국;지승욱;박상민;이춘하
    • 한국화재소방학회논문지
    • /
    • 제26권4호
    • /
    • pp.82-88
    • /
    • 2012
  • 본 논문은 나사조임 단자대에 접속되는 전선접속부의 나사조임토크에 따른 열적특성을 분석하고자, 나사조임토크를 KS C 2625에서 규정한 정상조임토크와 시공불량 및 경년변화 등의 원인으로 인해 나사조임의 풀림으로 발생될 수 있는 이상조임토크를 실험의 변수로 하였다. 이때, 정상조임토크와 이상조임토크에 동일한 부하를 인가한 후, 열화상카메라를 이용하여 전선접속부의 열적특성을 측정한 후 비교 분석하였다. 도출된 결과를 바탕으로 향후 전기안전점검 시 단자대 접속개소의 조임토크 불량으로 인한 발열을 사전에 감지하고, 전기화재의 위험성이 나타날 가능성을 최소화 할 수 있는 대책자료로 활용하고자 한다.

A classification of electrical component failures and their human error types in South Korean NPPs during last 10 years

  • Cho, Won Chul;Ahn, Tae Ho
    • Nuclear Engineering and Technology
    • /
    • 제51권3호
    • /
    • pp.709-718
    • /
    • 2019
  • The international nuclear industry has undergone a lot of changes since the Fukushima, Chernobyl and TMI nuclear power plant accidents. However, there are still large and small component deficiencies at nuclear power plants in the world. There are many causes of electrical equipment defects. There are also factors that cause component failures due to human errors. This paper analyzed the root causes of failure and types of human error in 300 cases of electrical component failures. We analyzed the operating experience of electrical components by methods of root causes in K-HPES (Korean-version of Human Performance Enhancement System) and by methods of human error types in HuRAM+ (Human error-Related event root cause Analysis Method Plus). As a result of analysis, the most electrical component failures appeared as circuit breakers and emergency generators. The major causes of failure showed deterioration and contact failure of electrical components by human error of operations management. The causes of direct failure were due to aged components. Types of human error affecting the causes of electrical equipment failure are as follows. The human error type group I showed that errors of commission (EOC) were 97%, the human error type group II showed that slip/lapse errors were 74%, and the human error type group III showed that latent errors were 95%. This paper is meaningful in that we have approached the causes of electrical equipment failures from a comprehensive human error perspective and found a countermeasure against the root cause. This study will help human performance enhancement in nuclear power plants. However, this paper has done a lot of research on improving human performance in the maintenance field rather than in the design and construction stages. In the future, continuous research on types of human error and prevention measures in the design and construction sector will be required.

40대 이상 성인의 치주질환 여부가 건강관련 삶의 질에 미치는 영향에 관한 융합연구 (A Convergence Study on the Effect of Periodontal Disease on Health-related Quality of Life in Adults Over 40s)

  • 유지수;황수현
    • 한국융합학회논문지
    • /
    • 제12권6호
    • /
    • pp.49-56
    • /
    • 2021
  • 본 연구는 국민건강영양조사 제7기(2016-2018)의 자료를 활용하여 40세 이상의 성인 중 삶의 질에 중대한 영향을 미치는 악성종양을 가진 자를 제외한 8,035명을 대상으로 치주질환의 여부에 따른 건강관련 삶의 질에 영향을 미치는 요인을 살펴보고자 하였다. 건전치주군에 비해 치주질환군에서 1.32배 삶의 질 저하가 될 위험이 더 높았으며, 영향 요인으로는 50세 이상의 연령, 2개 이상의 만성질환이 동반되는 경우 등으로 확인 되었다. 이러한 결과로 치주질환을 가진 성인의 경우 만성질환을 적게 가지고 있음에도 부정적인 삶의 질을 인식하는 시기가 빨라지는 것을 확인할 수 있었으며, 향후 성인대상의 치주질환을 예방하고 건강관련 삶의 질 향상을 위한 건강증진 프로그램 개발에 필요한 기초자료로 활용할 수 있으리라 생각된다.

요양병원에서 응급실로 전입된 노인환자의 경향분석, 2014-2019 (The Tendency of Elderly Patients Who Transferred from Long-term Care Hospital to Emergency Room, 2014-2019)

  • 고성근;김선지;이태영;이진희
    • 보건행정학회지
    • /
    • 제32권2호
    • /
    • pp.173-179
    • /
    • 2022
  • Background: This study aimed to identify patterns of elderly patients who transferred from long-term care hospitals to emergency rooms and provide the evidence of emergency medical systems to prepare for a super-aged society. Methods: The data source was the National Emergency Department Information System database from January 2014 to December 2019 in Korea. We performed a cross-sectional study among elderly patients (≥65 years) who transferred from a long-term care hospital to an emergency room. Trend analysis was conducted by year. Results: We identified 225,765 elderly patients who were transferred from long-term care hospitals to emergency rooms between January 1, 2014 and December 31, 2019. The proportion of the study population and their mean age were recently increased (p<0.001, respectively). The proportion of elderly patients being re-transferred (p=0.049) and the patients re-transferred to long-term care hospitals is significantly increased (p=0.005). Conclusion: The establishment of efficient emergency medical services for an aging society is important. It is necessary to develop a healthcare network with the government, long-term care hospitals, and medical institutions in the community suitable for preventing disease deterioration.

매립형 분리식 전단연결재를 적용한 PSC교 콘크리트 바닥판 교체공사의 경제성 분석 (Economic Analysis of Concrete Panel Replacement of PSC Bridge with Embedded Demountable Shear Connector)

  • 이순환;김종언;김재규;박세현;정대성
    • 한국건설순환자원학회논문집
    • /
    • 제10권4호
    • /
    • pp.376-385
    • /
    • 2022
  • 국민의 안전과 편의성에 직결되는 도로 인프라인 PSC거더교의 바닥판 손상 및 노후화로 인한 교체공사를 대비하여 매립형 분리식 전단연결재가 개발되었다. 분리식 전단연결재는 바닥판 철거 공정에서 파쇄를 최소화하고 교체공사를 위한 전단연결재 재시공이 용이하여 시공성 향상으로 인한 공사기간 감소로 도로이용자의 불편과 손실을 최소화할 수 있다. 공법별 공사기간과 공사기간 중 교통차단으로 인해 발생하는 도로이용자비용을 산출하여 비교하는 방법으로 기존 공법 대비 매립형 분리식 전단연결재를 적용한 PSC거더교의 경제성을 도로이용자(국민) 입장에서 분석하였다. 매립형 분리식 전단연결재가 적용된 교량 바닥판 교체공사 시 도로이용자비용은 34일 1,404,687,725원으로 기존 ∩형태 전단철근 노출 전단연결재가 적용된 경우(54일, 1,924,740,367원) 대비 공사기간 20일, 도로이용자비용 27.02 %를 절감할 수 있는 것으로 분석되었다.