• 제목/요약/키워드: CFs

검색결과 342건 처리시간 0.027초

탄소섬유쉬트로 보강된 철근콘크리트보의 계면박리해석 (An Analysis of Interface Debonding Failure on Reinforced Concrete Beams Strengthened with Carbon Fiber Sheet)

  • 심종성;배인환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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    • pp.839-844
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    • 1998
  • The purpose of this study is to analyze the interface debonding failure on RC beams strengthened with carbon fiber sheet(CFS). The behavior of damaged RC beams strengthened with CFS is analytically investigated using both linear elastic fracture mechanics (LEFM) approach and the finite element method. This study includes the investigation of the separation mode by interface fracture of the strengthening materials due to the interfacial shear and normal stresses.

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아라미드 스트랩으로 프리스트레싱 횡구속된 RC 원형기둥의 일축압축거동에 관한 실험적 연구 (An Experimental Study on Uniaxial Compressive Behavior of RC Circular Columns Laterally Confined with Prestressing Aramid Fiber Strap)

  • 한상훈;홍기남;이재범
    • 콘크리트학회논문집
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    • 제21권2호
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    • pp.159-168
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    • 2009
  • 본 연구에서는 기존의 연구방법을 개선한 프리스트레스가 도입된 아라미드 스트랩으로 횡 구속된 RC 원형기둥의 일축압축 거동에 대하여 강도와 변위에 의한 강성 및 구속효과에 대하여 연구하였으며, 그 프리스트레싱 보강방법 및 과정에 대하여 비교적 상세히 소개하였다. 이 방법으로 보강된 기둥의 파괴형태는 초기 능동 구속압의 작용으로 인하여 변위 증가율이 매우 낮으며 이후 최종 파괴시까지도 그 형상이 유지되는 매우 안정적인 파괴형태를 보이게 된다. 파괴하중 비교 결과 일반 RC 기둥과 비교하여 73% 이상 강도증진 효과를 나타내었다. 또한 변형 증가율이 매우 작으며 이로 인한 변위구속효과가 매우 우수함을 확인할 수 있었다. 기존의 보강방법 (CFS, GFS)과의 비교를 통하여, 상대적으로 작은 면적으로 우수한 강도증진을 보이며 강성증가로 인한 구속효과 역시 우수하며 체적 증가율도 팽창하지 않는 결과를 보였다. 특히, 콘크리트 팽창 이후부터 발휘되는 기존 방법의 구속효과와는 달리, 초기부터 도입되는 프리스트레스트 긴장력에 의한 초기변형 구속효과가 매우 탁월하며, 최종 파괴시까지 체적 변형률이 팽창하지 않는 안정적인 결과를 나타낸다.

Clinical Study on Constitutional Herbal Tea for Treating Chronic Fatigue

  • Park, Soo-Jung;Bae, Young-Chun;Choi, Na-Rae;Ryu, Seung-Yeob;Kwon, Young-Mi;Joo, Jong-Cheon
    • 대한약침학회지
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    • 제17권4호
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    • pp.55-60
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    • 2014
  • Objectives: This study was designed to evaluate the efficacy and the safety of constitutional herbal tea for treating chronic fatigue with no diagnosed cause, which is called Mibyeong in Korea. Methods: Males and females with ages between 40 and 59 years who had complained of fatigue for 1 month consistently or for 6 months intermittently without a definite cause were recruited. At the same time, a Chalder fatigue scale (CFS) score of 19 was essential for participation in this study. Sixty five subjects completed the entire process, including blood tests and tests with medical devices. Five assessments of health status were accomplished over 8 weeks by using the CFS and the visual analogue scale (VAS). To ensure that the constitutional herbal tea was being safely used, we conducted and analyzed renal function and liver function tests. For the diagnosis of the Sasang constitution, the Sasang Constitutional Analysis Tool (SCAT) was used, and a specialist in Sasang constitutional medicine made the final diagnosis based on the SCAT result. Constitutional herbal tea was served four weeks after the first visit. The subjects took the constitutional herbal tea twice a day for one month. Results: The results are as follows: The CFS and the VAS scores were significantly improved for the subjects in the constitutional herbal tea. No abnormalities were found on the blood tests to evaluate safety after taking the constitutional herbal tea. The improvements in the CFS and the VAS scores due to the constitutional herbal tea had no significant differences according to the Sasang constitution. Conclusion: Constitutional herbal tea may be used to reduce fatigue and improve health and has no adverse effect on either the kidney or the liver.

개별 인용 필드의 인용 매칭에 대한 영향력 평가 (Evaluating an Influence of Individual Citation Field on Citation Matching)

  • 구희관;강인수;정한민;이승우;성원경
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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    • pp.414-417
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    • 2007
  • 인용 매칭(Citation Matching, CM)은 동일한 논문을 지칭하는 인용레코드(Citation Record)를 군집화하는 방법이다. 일반적으로, 저자, 논문제목, 게재지명이나 출판연도 등의 인용 필드로 구분하는 인용 필드 분해가 인용 매칭 보다 선행하게 된다. 상당히 많은 연구가 인용 매칭과 인용 필드 분해의 문제를 해결하고자 했지만, 인용 필드 분해와 인용 매칭과의 상관관계에 대한 연구는 부족하였다. 인용 매칭에 대한 인용 필드 분해의 여러 측면 중에, 본 논문은 인용 매칭에 가장 영향력이 있는 인용 필드를 밝히고자 한다. 첫 번째 시도로, 수작업으로 인용 필드 분해를 수행한 다양한 크기의 인용 필드 집합에 대하여 인용 매칭의 성능을 비교하였고, 그 결과 많은 인용 필드를 사용한 인용 매칭이 인용 레코드를 더 잘 군집화 할 수 있다는 것을 확인하였다.

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진동대 실험을 통한 조립식 스틸 전단 패널의 비선형 동적 거동 (Nonlinear Dynamic Behavior of a Cold-Formed Steel Shear Panel by Shaketable Tests)

  • 김태완;이문성
    • 한국지진공학회논문집
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    • 제9권6호
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    • pp.31-39
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    • 2005
  • 본 연구의 목적은 인장으로만 저항하는 경사진 스트랩과 기둥으로 구성된 조립식 스틸 (CFS) 전단 패널의 지진하중에 대한 비선형 거동을 조사하는 것이며, 이를 위해 실제 크기의 2층 건물을 설계한 후 진동대 실험을 수행하였다. CFS 전단 패널은 연성이 큰 경사진 스트랩이 주 횡 저항 시스템으로 작용하며, 중력 저항 부재인 기둥은 'ㄷ'자 형태의 스터드를 용접한 것으로서 비콤펙트단면을 가지며 국부 좌굴로 인해 자신의 최대 모멘트 강도를 발휘하지 못한다. 진동대 실험을 통하여 스트랩이 대부분의 에너지를 인장측만으로 핀칭 형태를 가지며 소산하며, 기둥은 국부 좌굴로 인해 기둥은 자신의 최대 강도를 발휘하지 못하나 전체 에너지 소산에 공헌을 하고 있음을 보여주었다. 본 연구 결과, 비록 구조물이 단순할지라도 지진 시 실제 비선형 거동을 진동대 실험으로 조사하는 것은 매우 중요한 과정임을 확인하였다.

섬유시트로 보강된 철근콘크리트 기둥의 압축강도 특성에 관한 실험적 연구 (An Experimental Study on the Compressive Strength Characteristics of Reinforced Concrete Columns Strengthened with Fiber Sheets)

  • 김정섭;최진석;조철희;고송균
    • 한국건축시공학회지
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    • 제3권2호
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    • pp.119-127
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    • 2003
  • Test specimen test was performed using concrete reinforced with fiber sheet and the test variables were based on the kinds of fiber and the number of reinforcement layers. Using steel-concrete reinforced with fiber sheet, compression tests were performed and the test variables were the kinds of fiber, number reinforcement layers and reinforcement layer order. The following results were obtained: 1) It was demonstrated that compressive strength of the test specimen reinforced during test specimen test and member test increased as the number of reinforcement layers increased. 2) It was shown that non-reinforced test, specimen were destroyed during the member tests, but the specimen reinforced with CFS destroyed and the GFS-reinforced specimen and composite reinforced specimen showed ductile destruction. 3) As a result of tests on kinds of reinforcement fiber, it was demonstrated that CFS-reinforced test specimen had higher compressive strength in a 공시체 test. In the member test, 2ply-and 3ply-GFS reinforced specimens except lplied one had higher compressive strength. It was because partial destruction occurred due to the rate of height/section. 4) For layer strength order, compared with test specimen reinforced only with a single reinforced material, test specimen reinforced with CFS and GFS, and test specimen reinforced with CFS first showed better results in compressive strength and ductility judgement.

Antifungal Activity of Lactic Acid Bacteria Strains Isolated from Natural Honey against Pathogenic Candida Species

  • Bulgasem, Bulgasem Y.;Lani, Mohd Nizam;Hassan, Zaiton;Yusoff, Wan Mohtar Wan;Fnaish, Sumaya G.
    • Mycobiology
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    • 제44권4호
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    • pp.302-309
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    • 2016
  • The role of lactic acid bacteria (LAB) in honey as antifungal activity has received little attention and their mechanism of inhibitory of fungi is not fully understood. In this study, LAB were isolated from honey samples from Malaysia, Libya, Saudi Arabia, and Yemen. Twenty-five isolates were confirmed LAB by catalase test and Gram staining, and were screened for antifungal activity. Four LAB showed inhibitory activity against Candida spp. using the dual agar overlay method. And they were identified as Lactobacillus plantarum HS isolated from Al-Seder honey, Lactobacillus curvatus HH isolated from Al-Hanon honey, Pediococcus acidilactici HC isolated from Tualang honey and Pediococcus pentosaceus HM isolated from Al-Maray honey by the 16S rDNA sequence. The growth of Candida glabrata ATCC 2001 was strongly inhibited (>15.0 mm) and (10~15 mm) by the isolates of L. curvatus HH and P. pentosaceus HM, respectively. The antifungal activity of the crude supernatant (cell free supernatant, CFS) was evaluated using well diffusion method. The CFS showed high antifungal activity against Candida spp. especially The CFS of L. curvatus HH was significantly (p < 0.05) inhibited growth of C. glabrata ATCC 2001, C. parapsilosis ATCC 2201, and C. tropicalis ATCC 750 with inhibitory zone 22.0, 15.6, and 14.7 mm, respectively. While CFS of P. pentosaceus HM was significantly (p < 0.05) effective against C. krusei, C. glabrata, and C. albicans with inhibition zone 17.2, 16.0, and 13.3 mm, respectively. The results indicated that LAB isolated from honey produced compounds which can be used to inhibit the growth of the pathogenic Candida species.

만성피로증후군에 대한 소요산(逍遙散)과 그 변방(變方)의 효과 : 메타분석을 통한 체계적인 문헌고찰 (Effectiveness of Soyo-san (Xiaoyao-san) and its Modifications on Chronic Fatigue Syndrome: a Systematic Review and Meta-analysis)

  • 김준열;송정윤;남동현
    • 동의생리병리학회지
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    • 제34권3호
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    • pp.117-125
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    • 2020
  • The purpose of this review is to confirm whether Soyo-san (Xiaoyao-san) and its modifications is effective on alleviating clinical symptoms in chronic fatigue syndrome (CFS) patients. We collected clinical trials (randomized controlled trial, quasi-randomized controlled trial, controlled clinical trial) to investigate the effects of Soyo-san and its modifications on general symptoms, fatigue, depression and anxiety in CFS patients. The databases used for data retrieval were Pubmed, Central Cochrane, Embase, CNKI, CQVIP, Wanfang, CiNii, OASIS, RISS, and Koreamed. We performed selection/exclusion process from the found studies to conform with prespecified criteria, and assessed the final included trials according to the Cochrane risk of bias tool. The included studies were classified based on the interventions in experimental and control group. Eight randomized controlled trials and one controlled clinical trial (total 921 participants) were eligible and their results were synthesized in the meta analysis. The synthesis showed a considerable effect of Soyo-san and its modifications on improvement of general symptoms (relative risk 0.27 [95% CI 0.19 to 0.39], Z=7.03, P<0.00001; I2=0%) and fatigue severity (SMD -1.20 [95% CI -1.46 to -0.93], Z=8.78, P<0.00001; I2=52%) in CFS patients, while Effect on depression and anxiety were inconclusive. We found that Soyo-san and its modifications were effective for improvement of general symptoms and fatigue severity in CFS post-treatment.

Evaluating Interactive Fatigue Management Workshops for Occupational Health Professionals in the United Kingdom

  • Ali, Sheila;Chalder, Trudie;Madan, Ira
    • Safety and Health at Work
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    • 제5권4호
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    • pp.191-197
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    • 2014
  • Background: Disabling fatigue is common in the working age population. It is essential that occupational health (OH) professionals are up-to-date with the management of fatigue in order to reduce the impact of fatigue on workplace productivity. Our aim was to evaluate the impact of one-day workshops on OH professionals' knowledge of fatigue and chronic fatigue syndrome (CFS), and their confidence in diagnosing and managing these in a working population. Methods: Five interactive problem-based workshops were held in the United Kingdom. These workshops were developed and delivered by experts in the field. Questionnaires were self-administered immediately prior to, immediately after, and 4 months following each workshop. Questionnaires included measures of satisfaction, knowledge of fatigue and CFS, and confidence in diagnosing and managing fatigue. Open-ended questions were used to elicit feedback about the workshops. Results: General knowledge of fatigue increased significantly after training (with a 25% increase in the median score). Participants showed significantly higher levels of confidence in diagnosing and managing CFS (with a 62.5% increase in the median score), and high scores were maintained 4 months after the workshops. OH physicians scored higher on knowledge and confidence than nurses. Similarly, thematic analysis revealed that participants had increased knowledge and confidence after attending the workshops. Conclusion: Fatigue can lead to severe functional impairment with adverse workplace outcomes. One-day workshops can be effective in training OH professionals in how to diagnose and manage fatigue and CFS. Training may increase general knowledge of fatigue and confidence in fatigue management in an OH setting.

무경운 벼 유기농업이 토양 미생물 생태에 미치는 영향 (Impacts of Organic Farming System on the Soil Microbial Ecology in No-till Paddy)

  • 이영한;안병구;곽연식
    • 한국토양비료학회지
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    • 제44권5호
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    • pp.814-818
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    • 2011
  • 무경운 유기농업과 경운 관행농업의 벼 생육 단계별 토양 미생물 개체수 변화를 분석하였다. 수확기 토양의 호기성 세균 개체수와 곰팡이 개체수는 무경운 유기농업이 경운 관행농업 보다 유의적으로 많았으며 담수 이전 그람음성 세균 개체수도 경운 관행농업 보다 유의적으로 많았다. 호기성 세균, 그람음성 세균 그리고 곰팡이 개체수는 담수 이후 급격하게 감소하였다. 그람음성 세균 개체수는 무경운 유기농업과 경운 관행농업 토양 미생물 생태를 가장 잘 구분할 수 있는 특성을 보였다.