• 제목/요약/키워드: strengthening length

검색결과 188건 처리시간 0.029초

가시오가피의 종자 후숙처리시 배의 생장과 개갑 특성 (Characteristics of Embryo Growth and Dehiscence during the After-ripening Period in Eleutherococcus senticosus)

  • 박호기;박문수;김태수;김선;최경구;박기훈
    • 한국작물학회지
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    • 제42권6호
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    • pp.673-677
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    • 1997
  • 가시오가피 종자는 채종직후 미분화 상태의 배로 발아를 위해서는 후숙이 필요하다. 가시오가피 종자의 후숙을 위하여 습윤층적처리한 후 미분화 배의 생장과 개갑특성을 조사한 결과는 다음과 같다. 1. 가시오가피의 내과피를 포함한 종자의 형태는 길이 7.1$\pm$0.9mm, 폭 3.0$\pm$0.3mm, 두께 1.47$\pm$0.12mm 정도이었으며 1,000 입중 18.5$\pm$1.9g 정도이었다. 2. 가시오가피 종자의 후숙전 0.30$\pm$0.06mm 정도이며 배장율은 .4.8%의 미분화 배로 층적처리 20일 전후에 배의 생장이 시작되었고 40일 전후에 배축과 자엽이 분화되었다. 3. 후숙기간과 배장율과는 높은 정의 상관(r=0.845)을 보였으며 배의 생장은 층적처리 후 60~80일 사이에 급격히 증가하였고 후숙 80일 이후에는 증가폭이 다소 둔화되었다. 4. 가시오가피 종자는 배가 어느 정도 생장하면 종피의 봉선이 터져 열개되는 개갑종자이었으며 배장율 60~70%에서 가장 높은 개갑빈도를 나타냈다. 5. 개갑율은 후숙 40일에 15.3%가 개갑되었고 60일 이후 개갑율이 급격히 증가되었으며 후숙 150일에 76.5%가 개갑되었다.

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전위 펀치 영역 모델링에 의한 입자 강화 금속지지 복합재의 입자 크기 의존 파손 해석 (Particle Size-Dependent Failure Analysis of Particle-Reinforced Metal Matrix Composites using Dislocation Punched Zone Modeling)

  • 서영성
    • 대한기계학회논문집A
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    • 제38권3호
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    • pp.275-282
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    • 2014
  • 입자강화 금속기지 복합재는 입자와 기지재간의 열팽창계수 차이와 탄소성 강성도의 차이에 따라 변형률 구배가 발생하고 이로 인한 기하적 필수 전위가 입자 주위에 형성됨에 따라 변형시 입자 크기 의존 길이 스케일에 의한 강화 효과를 가지고 있다. 본 연구에서는 유한요소법을 활용하여 복합재를 압밀 성형할 때 입자 주위에 펀칭되는 기하적 필수 전위에 의한 강도 증가를 입자 주위 영역에 부가시켜 입자 의존 길이 스케일이 복합재의 입자 경계 파손 및 기지재의 연성 파손에 미치는 영향을 살펴 보았다. 파손 거동은 입자의 크기와 체적비를 달리하고, 특히 분리 에너지와 강도 등의 경계 파손 물성값을 변화시켜가는 매개변수적 계산을 수행하여 관찰하였다. 두 개의 파손 모드는 서로 영향을 미치면서 입자 크기 의존 길이 스케일에 밀접하게 연관됨을 보였다. 즉 입자의 크기가 작은 경우에 입자의 크기가 큰 경우에 비하여 입자를 둘러싸고 있는 기하적 필수 전위가 상대적으로 더 집적됨으로 인해 입자경계와 기지재의 연성 파손에 의한 복합재의 파손 개시가 지연되고 파손이 진행되는 동안의 유동 응력 감소도 상대적으로 작은 것을 보였다.

기후변화에 대한 어업인 인식의 특성 분석 (An Analysis of Fishermen's Perception to Climate Change in Korea)

  • 김봉태;이상건;정명생
    • 수산경영론집
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    • 제45권3호
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    • pp.71-84
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    • 2014
  • This study indicates that 84.5% of fishermen have perceived climate change and 74.9% of fishermen have responded that frequency and intensity of the impacts of climate change are increasing. The results of regression analysis have shown that the level of fishermen experiencing the impacts of climate change differs according to individual's characteristics including age, length of experience, sea area (fishing area) and types of fisheries. About half of the respondents have shown that they are not taking any actions against the effects of climate change. The main reasons are that they either have lack of knowledge on how to respond to the impacts of climate change or have the perception that climate change is irresistible. The majority of respondents have responded that they are not aware of the government's climate change policy and emphasized that it is necessary to have effective countermeasures strengthening the provision of information about climate change policy. The result of perception survey have highlighted that it is essential for the government and the fishermen to share relevant information and to consider method of cooperation.

보행 시 지지면 급변에 따른 연령별 운동학적 반응 형태 비교 (Comparison of Gait Pattern during the Support Phase after Perturbation According to Age)

  • 천영진;신인식
    • 한국운동역학회지
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    • 제21권3호
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    • pp.281-288
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    • 2011
  • The purpose of this study was to analyze the difference in reaction patterns during the support phase after perturbation in gait according to different age. A total of 12 subjects participated; 5 elderly and 7 adults(control), to investigate the differences between normal and perturbed gait. The step length didn't change during normal and perturbed gait but was longer in the control group. There was no difference in the step width. When the right foot was perturbed, the control group's left foot speed was faster than the elderly group's which was to maintain stability. The elderly flexed both right and left knees more than the control group. After the perturbation, the elderly group had a larger trunk anterior flexion. With the larger flexion of both legs of the elderly group it shows that the lack of knee flexion strength is a factor, that could cause falling and so a prevention program should focus on strengthening the quadriceps. With the excessive trunk flexion after the perturbation by the elderly group observed, it is suggested that while walking everyday a good routine of walking with an upright posture should be developed.

무윤활 미끄럼 마찰하에서 SiC 휘스커 및 입자강화 청동기지 복합재의 마모특성 (The Dry Sliding Wear Properties of $SiC_w$ and $SiC_p$ Reinforced Bronze Matrix Composites)

  • 이상로;허무영
    • Tribology and Lubricants
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    • 제9권2호
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    • pp.49-55
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    • 1993
  • The dry sliding wear properties of the sintered Cu-10 wt%Sn bronze alloys reinforced with $SiC_w$ and $SiC_p$ were investigated by a pin-on-disc wear testing machine. The worn surfaces and the cross sections of the wear specimens and the wear debris were observed by SEM to study the effect of the variation of the ceramic phase contents in the composite and the wear condition on the wear behaviors. The wear of bronze matrix was dominated by the adhesive wear. The transition from mild to severe wear was found in the bronze matrix specimens at the applied load higher than 20N where the surface delamination caused the severe wear. The addition of $SiC_w$ and $SiC_p$ reinforcements in the romposites was proved to reduce the wear rate by the matrix strengthening at the applied load higher than 20N. SiC whiskers having a large length to diameter ratio which hold the deformed matrix were effective to hinder the crack propagation near the worn surface. Thus the maximum wear resistance was obtained in the composite reinforced by $SiC_w$ at the higher applied load.

강섬유를 혼입한 고강도 콘크리트 보의 탄소섬유쉬트 보강에 관한 연구 (A Study on Carbon Fiber Sheet Rehabilitation of High Strength Reinforced Concrete Beams Mixed Steel Fibrous)

  • 곽계환;곽경헌;정태영;고성재
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.491-496
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    • 2001
  • In recent years, the research and development about the new material proceed rapidly and actively in the building industry. As building structures become bigger, higher and more specialized, so does the demand for material with higher strength. In the future, we will need to research repair and rehabilitation to make high strength concrete mixed steel fibrous building safe. The carbon fiber reinforced plastic bonding method is widely used in reinforcing the existing concrete structure among the various methods. The repair of initiate loaded reinforced high-strength concrete beams mixed steel fibrous with epoxy bonded Carbon Fiber Sheets(CFS) was investigated experimentally. The CFS thickness and length were varied to assess the peel failure at the curtailment of CFS, The behaviour of the repaired beams was represented by load-longitudinal steel strain relation and failure modes were discussed. The test results indicate that CFS is very effective for strengthening the demand beams and controlling deflections of reinforced high strength concrete beams mixed steel fibrous happen diagonal crack, the increase in the number of CFS layers over two layers didn't effect the increase in the strength of beams.

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빈곤이 아동의 건강에 미치는 영향 (The Effect of Poverty on Children's Health)

  • 권은선;구인회
    • 한국사회복지학
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    • 제62권4호
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    • pp.129-148
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    • 2010
  • 본 연구는 2004년 초등학교 4학년에 재학 중인 아동 1,785명과 그 부모를 대상으로 한 서울아동 패널 1~5차년도 자료를 이용하여 빈곤이 아동건강에 미치는 영향을 종단적으로 분석하였다. 아동건강에 영향을 미치는 것으로 확인되어 온 특성들을 통제한 상태에서 빈곤은 아동의 건강에 부정적인 영향을 미쳤다. 특히 지속빈곤, 일시빈곤, 비빈곤으로 나눠 살펴본 결과 지속빈곤의 아동건강에 대한 악영향이 두드러지게 나타났다. 이러한 빈곤의 아동건강에 대한 악영향은 주로 부모-아동간 유대관계 약화와 부부간의 갈등을 통해 작용하는 것으로 판단된다. 이러한 발견은 빈곤아동의 건강을 향상시키기 위해서는 소득지원 등 경제적 차원의 정책적 개입이 중요하고, 가족 관계에 대한 지지활동도 고려될 필요가 있음을 시사한다.

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The Beneficial Effect of Adenophorae Radix on DSS-induced Colitis in Mice

  • Jung, Ji-Wook;Oh, Sa-Rang;Ahn, Eun-Mi;Yang, Eun-Ju;Kim, Su-Jin
    • 대한의생명과학회지
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    • 제19권3호
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    • pp.188-194
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    • 2013
  • Ulcerative colitis (UC) is an inflammatory bowel disease, which is a chronic gastrointestinal disorder. Adenophorae Radix (AR) has been used as a traditional medicine for various diseases including strengthening cardiac function, allaying a fever, and easing pain and cough. However, the regulatory effects of AR in intestinal inflammation are not yet understood. This study attempted to determine the effect of AR in dextran sulfate sodium (DSS) - induced colitis in mice. The colitis mice were induced by drinking water containing 5% DSS for 7 days. The results showed that mice treated with DSS showed remarkable clinical signs, including weight loss, and reduced colon length. Administration of AR attenuated weight loss, colon shortening and inhibited the levels of interleukin (IL) - 6 in DSS - treated colon tissues. These results provide experimental evidence that AR might be a useful therapeutic medicine for patients with UC.

기혼 여성에 있어서 성생활의 질: 그 요인 구조와 결정 변인 (Quality of Sexual Life in Married Women: Its Factor Structure and Determinants)

  • 양은영
    • 여성건강간호학회지
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    • 제13권2호
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    • pp.77-87
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    • 2007
  • Purpose: This study was examined the quality of the sexual life among married women in terms of the factor structure of Sexual Quality of Life(SQOL) and evaluated the predictive value of 11 variables for SQOL. Method: Two hundred and ninety-three married women completed the Korean version SQOL scale with information on age, education, length of marriage, family income, health, sexual knowledge, coital frequency, harmony with family members, levels of affection, and general and sexual communication. Data were analysed with principal components and regression analyses. Result: The SQOL scale had two clearly defined factors, Negative Quality of Sexual Life and Positive Quality of Sexual Life, on which all scale items were significantly loaded, accounting for 54.3% of the total variance. Independent regression analysis showed all variables except education to be significant predictors of SQOL with interpersonal variables (general and sexual communication, affection and harmony with family members) being the most powerful predictors. However when the 11 variables were combined together in stepwise analysis, only 6 variables (general communication, age, affection, coital frequency, sexual knowledge and health) were significant, accounting for 39% of the total variance. Conclusion: The Korean version SQOL scale is a good measure to tackle SQOL in married women. To enhance SQOL, strengthening interpersonal interaction focusing on general/sexual communication, affection and harmony with family members seems to be more important than sexual activities and personal characteristics.

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현장계측을 통한 기존선 철도 구조물 접속부의 거동분석 (Dynamic Analysis of Structure's Approaches through Field Tests in the Conventional Railway)

  • 박준오;이상배;홍원표
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.1864-1874
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    • 2007
  • Korean trains pass many mountain areas, so the volume of structures like bridge and tunnel has large part of railway lines. Train speed-up naturally needs a straight line in railway, then structures are increasing, and the length of structure has more than 70% in Kyongbu high-speed railway. The stiffness of bridge and tunnel is higher than the soil in the roadbed in spite of dynamic difference in vibration and displacement. Differences in stiffness have more dynamic effects and increase the deformation and destruction in the track and roadbed. This influences passenger's comfort and the safety of operation, and it needs more track maintenance. This study selected tunnel with ballast track, tunnel with concrete track, and structure's approaches with short maintenance cycle in the roadbed and had track acceleration tests and track liner inspections using track master in the field. This study will measure periodically to structure's approaches which have very fast track irregularity and analyze dynamic differences and track irregularity near structure's approaches, so realize the cause of track irregularity of structure's approaches and use basic data for reasonably strengthening method of structure's approaches.

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