• 제목/요약/키워드: Mean Load

검색결과 970건 처리시간 0.031초

현행(現行) 허용응력설계법(許容應力設計法)으로 설계(設計)되는 RC 휨부재(部材)의 신뢰성(信賴性)과 안전율(安全率) 고찰(考察) (An Investigation of Reliability and Safety Factors in RC Flexural Members Designed by Current WSD Standard Code)

  • 신현묵;조현남;정환호
    • 대한토목학회논문집
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    • 제1권1호
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    • pp.33-42
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    • 1981
  • 현행(現行) 철근(鐵筋)콘크리트 표준시방서(標準示方書)는 WSD와 USD의 재래적(在來的)인 두 가지 설계편(設計編)으로 구성(構成)되어 있는데 이들 설계기준(設計基準)은 ACI 318-63 및 318-71 Code에 기초를 두고 있다. 이와 같이 주로 ACI 318-63 시방서(示方書)에 기초를 둔 우리의 WSD와 USD의 안전율(安全率)은 우리의 설계(設計) 및 시공실무(施工實務)에 비(比)해 부적절(不適切)한 것으로 받아들여지고 있다. 더구나 ACI의 안전율(安全率)도 확률적(確率的)으로 결정(決定)된 것이 아니고 주로 경험(經驗)과 현실성(現實性)을 고려하여 결정(決定)된 것이다. 본(本) 연구(硏究)는 현행(現行) 허용응력설계(許容應力設計) 안전율규정(安全率規定)으로 설계(設計)되는 휨 부재(部材)의 안전수준(安全水準)을 2차(次)모멘트 신뢰성이론(信賴性理論)에 의해 고찰(考察)하고, 일관성(一貫性)있는 목표신뢰성(目標信賴性)을 제공(提供)하는 철근(鐵筋) 및 콘크리트의 공칭안전율(公稱安全率)과 휨 허용응력(許容應力)을 합리적(合理的)이고도 효율적(效率的)으로 결정(決定)하는 방법(方法)을 제안(提案)하였다. Cornell의 제(第)1계(階) 이차(二次)모멘트법(法)을 하중(荷重)과 저항(抵抗) 결과변화(結果變化)의 대수변환(對數變換)에 의해 적용(適用)하는 방법(方法)을 본(本) 연구(硏究)의 신뢰성해석법(信賴性解析法)으로 사용하였다. 최적(最適) 철근비(鐵筋比)를 갖는 극한강설계(極限强設計)의 과소철근(過少鐵筋)보에 대응하는 균형철근비(均衡鐵筋比)로 설계(設計)되는 균형단면(均衡斷面)이 되도록 하는 독특한 방법으로 콘크리트의 허용압축응력(許容壓縮應力)을 유도하였다. 우리의 시공(施工) 및 설계실무(設計實務)의 수준(水準)에 적합(適合)한 ${\beta}_0=4$를 안전율(安全率) 결정(決定)을 위한 목표신뢰성지수(目標信賴性指數)로 택하였다. 현행(現行) WSD 시방서(示方書)로 설계(設計)되는 RC 휨 부재(部材)의 안전(安全) 및 신뢰성(信賴性)을 여러 수치계산(數値計算)을 통해 고찰(考察)해본 결과(結果), 현행(現行) WSD 기준(基準)에 의한 설계(設計)는 비정당적(非定當的)이며 일관성(一貫性)없는 신뢰성(信賴性)으로 인하여 비경제적(非經濟的)인 설계(設計)도 된다는 사실(事實)을 알 수 있었다. 적절(適切)한 목표신뢰성지수(目標信賴性指數) ${\beta}_0=4$에 따른 휨 부재(部材)의 철근(鐵筋)과 콘크리트의 합리적(合理的)인 허용응력(許容應力)을 본(本) 연구(硏究)의 신뢰성이론(信賴性理論)에 의해 제안(提案)하였다.

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장거리 (마라톤)선수에서의 전 경기중 심박동수의 변화 (Changes of Heart Rate During Marathon Running)

  • 김인교;이중우;하종식;유연희;최정옥;김기호
    • The Korean Journal of Physiology
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    • 제13권1_2호
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    • pp.1-12
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    • 1979
  • To evaluate the present status of physical fittness of Korean long distance runners, body fat, pulmonary functions, maximal oxygen intake and oxygen debt were measured in 5 elite marathoners (A group), 6 college student runners (B group) and 3 middle school student runners (C group). After laboratory tests, full course marathon running was performed in 2 elite marathoners during which their heart rates were monitored continuously. The results are summerized as follows: 1) Total body fat in all three groups are in the range of 13-15% of their body weight. 2) In all three groups, average values of various pulmonary functions were within the normal limits, but those of tidal volume were higher and respiratory rate were lower in comparison to normal values. These phenomena may represent respiratory adaptations against training. The average resting oxygen consumptions in A,B and C were $322{\pm}23$, $278{\pm}14$ and $287{\pm}16$m1/min, respectively. 3) In all three groups, resting blood pressures were in the normal range, but the resting heart rate was slightly lower in groups A $(56{\pm}3\;beats/min)$ and B $(64{\pm}2\;beats/min)$ and higher in group C $(82{\pm}9\;beats/min)$ in comparison to normal values. These changes in cardiovascular functions in marathoners may also represent adaptive phenomena. 4) During treadmill running the minute ventilation and oxygen consumption of the runners increased lineally with work load in all three groups. When the oxygen consumption was related to heart rate, it appeared to be a exponential function of the heart rate in all three groups. 5) The average maximal heart rates during maximal work were $196{\pm}3$, $191{\pm}3$ and $196{\pm}5\;beats/min$ for groups A,B and C, respectively. Maximal oxygen intakes were $84.2{\pm}3.3\;ml/min/kg$ in group A, $65.2{\pm}1.1\;ml/min/kg$ in group B and $58.7{\pm}0.4\;ml/min/kg$ in group C. 6) In all three groups, oxygen debts and the rates of recovery of heart rate after treadmill running were lower than those of long ditsance runners reported previously. 7) The 40 km running time in 2 elite marathoners was recorded to be $2^{\circ}42'25'$, and their mean speed was 243 m/min (ranged 218 to 274 m/min). The heart rate appeared to increase lineally with running speed, and the total energy expenditure during 40 km running was approximately 1360.2 Calories. From these it can be speculated that if their heart rates were maintained at 166 beats/min during the full course of marathon running, their records would be arround $2^{\circ}15'$. Based on these results, we may suspect that a successful long distance running is, in part, dependent on the economical utilization of one's aerobic capacity.

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수심이 얕은 저수지에서 용존산소 동적 모니터링을 통한 인 내부부하 평가 (Evaluation of Internal Phosphorus Loading through the Dynamic Monitoring of Dissolved Oxygen in a Shallow Reservoir)

  • 박형석;최선화;정세웅;지현서;오정국;전항배
    • 환경영향평가
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    • 제26권6호
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    • pp.553-562
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    • 2017
  • 최근 농업용 저수지는 용수공급과 함께 지역의 관광, 문화, 위락시설 등으로 활용되고 있다. 그러나 많은 농업용 저수지들은 부영양호로 분류되며 높은 유기물 오염도를 보이고 있다. 특히, 1945년 이전에 준공된 노후화된 농업용 저수지의 44.7%는 농업용수 수질 환경기준을 초과하고 있다. 노후화된 저수지의 경우 외부기원 오염부하 이외에 누적된 퇴적물로부터 발생하는 내부부하는 영양염류 공급에 중요한 역할을 한다. 본 연구의 목적은 수심이 얕은 M 저수지(평균 수심 약 1.7 m)를 대상으로 2015년과 2016년에 수심별 수온과 저층 용존산소(DO) 농도를 연속 측정하여 저층 수환경의 동적변화를 모니터링함으로써 영양염류의 내부 부하 가능성을 조사하는데 있다. 또한, 물질수지해석을 통해 내부 인부하가 저수지 전체 인부하량에 미치는 영향에 대해 평가하였다. 연구결과 수심이 얕은 M 저수지에서 약한 수온성층과 강한 DO 성층 현상이 나타났다. 그리고, 저수지 저층에서 DO의 동적변화를 관찰한 결과, 여름철 무강우 기간동안 지속적인 저산소 (DO 2 mg/L 미만) 상태가 2015년과 2016년에 각각 87일과 98일간 발생하였다. DO 농도는 대기온도 강하와 강우발생 기간 동안 간헐적으로 증가하였다. 물질수지분석결과, 수온상승과 함께 조류성장이 촉진되는 8월에는 $PO_4-P$ 내부 부하량이 무강우시 전체 부하량 대비 2015년과 2016년에 각각 37.9%와 39.7%로써 큰 비중을 차지하였다. 따라서 지속적인 저층 저산소 상태가 유지되는 경우에는, 퇴적층의 영양염류 용출을 억제하기 위한 DO 공급 대책이 유효 할 것으로 판단된다.

단기간의 수산화 칼슘 적용이 상아질 파절강도에 미치는 영향 (The effects of short-term application of calcium hydroxide on dentin fracture strength)

  • 신은정;박영준;이빈나;장지현;장훈상;황인남;오원만;황윤찬
    • Restorative Dentistry and Endodontics
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    • 제36권5호
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    • pp.425-430
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    • 2011
  • 연구목적: 인간의 영구치에서 수산화 칼슘을 근관계에 단기간(1주 또는 4주)으로 적용하였을 때 파절강도에 미치는 영향을 알아보고자 하였다. 연구 재료 및 방법: 단일 치근을 가지며, 유사한 크기 및 상아질 두께를 보이고, 우식이나 수복물이 없는 32개의 하악 소구치를 이용하였다. 16개의 치아에는 수산화 칼슘을 충전한 후 임시가봉 하였고, 나머지 16개의 치아는 대조군으로서 충전하지 않은 상태에서 임시가봉 하였다. 모든 시편의 치근단을 레진으로 밀봉한 후, $37^{\circ}C$ 식염수에 보관하였다. 1주와 4주 후에 시편을 파절시키기 위해 필요한 힘의 최대값을 측정하여 통계학적으로 분석하였다. 결과: 1주, 4주 후 두 그룹의 평균 파절강도는 유사하였다. 수산화 칼슘을 근관 내에 4주간 적용한 경우에는 파절강도가 대조군에 비해 8.2% 감소하였다. 그러나 통계학적으로 실험군간, 시간대별 유의한 차이는 보이지 않았다. 결론: 수산화 칼슘을 단기간 적용할 경우 치아의 파절강도에 큰 영향을 미치지 않는다. 따라서, 근관치료 과정 동안 수산화 칼슘을 단기간으로 적용할 수 있다.

한국인 젊은 여성에서 셀룰로오스 및 펙틴이 식이성 발열효과에 미치는 영향 (Effects of Cellulose and Pectin on Diet-induced Thermogenesis in Young Women)

  • 오승호;박정진;최인선;노희경
    • 한국식품영양과학회지
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    • 제36권2호
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    • pp.194-200
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    • 2007
  • 본 연구에서는 불용성 식이섬유인 셀룰로오스와 수용성 식이섬유인 펙틴이 식사성 열생성에 미치는 영향을 관찰하기 위하여 건강한 여자 대학생을 대상으로 식이섬유 제한식인 CD를 대조군으로 셀룰로오스식인 CED, 펙틴식인 PTD를 급식시켜 식후 3시간 동안의 DIT와 체온, 심박수를 측정하여 다음과 같은 결과를 얻었다. 대상자들의 나이는 평균 22.3 1.9세이었고, 신장과 체중은 각각 평균 $159.7{\pm}4.7cm$$52.5{\pm}8.6kg$이었다. 대상자들의 휴식대사량은 평균 $0.79{\pm}0.02kcal/min$이었다. 시간에 따른 DIT는 모든 실험식에서 식후 30분에 최고치를 나타내었다가 이후 감소하는 경향이었다. 실험식사 섭취 후 3시간 동안 측정한 DIT의 반응면적$(\Delta-AUC)$은 CD, CED 및 PTD가 각각 $59.77{\pm}2.66kcal,\;39.91{\pm}2.65kcal$$47.26{\pm}5.76kcal$를 기록하여 섭취한 열량의 $14.05{\pm}0.62%,\;9.33{\pm}0.62%$$11.07{\pm}1.35%$이었다. 식이섬유를 첨가한 실험군인 CED와 PTD가 CD에 비해 식후 3시간 동안의 DIT가 유의적으로 낮았으나, 식이섬유간 DIT는 유의적인 차이가 없었다. 실험식사 섭취 후 3시간 동안 측정한 체온의 반응면적$(\Delta-AUC)$은 실험식 간에 유의한 차이가 없었으나, 심박수로 측정한 교감신경계는 CD가 CED 및 PTD에 비하여 유의적으로 높았고, 식이섬유 간의 차이는 없었다. 이상에서와 같이 동량의 종류를 달리하여 제공한 셀룰로오스식과 펙틴식이 식후 열생성을 유의적으로 낮추었다. 그러나 대상자의 심박수, 체온, 체조성과 같은 제요인과의 상관성을 밝히지 못하여, 이의 기전을 밝히기 위한 추후 연구가 필요하다.

AN EXPERIMENTAL STUDY OF NEWLY DESIGNED IMPLANT WITH RBM SURFACE IN THE RABBIT TIBIA : RESONANCE FREQUENCY ANALYSIS AND REMOVAL TORQUE STUDY

  • Won Mi-Kyoung;Park Chan-Jin;Chang Kyoung-Soo;Kim Chang-Whe;Kim Yung-Soo;Isa Zakiahbt Mohd;Ariffin Yusnidar Tajul
    • 대한치과보철학회지
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    • 제41권6호
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    • pp.720-731
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    • 2003
  • Statement of problem. The importance of fixture design and surface treatment. Purpose. The clinical success of dental in plants is affected by many factors such like as degree of osseointegration, the effective load dispersion for the prostheses, and a lot of attempts have been made to overcome the difficulties. In this study, efforts were made to find the possibility of clinical acceptance of the dental implants of newly designed surface and resorbable blast media surcace. Materials and methods. In this study, two groups of custom-made, screw-shaped implants were prepared. The first with the consisting of Branemark clone design and the other with the new design. These implants were divided into four groups according to the kinds of surface treatment. Four implants($AVANA^{(R)}$, Osstem, Busan, Korea)of each group were installed in twenty rabbits. Group A was consisted of Branemark done implant left as machined, Group B with Branemark clone implants with RBM(Resorbable blast media) surface, Group C with newly designed implants left as machined and Group D with newly designed implants with RBM surface. One of the twenty rabbits died from inflammation and the observation was made for six weeks. Specimens from four groups were observed using scanning electron microscopy with 40, 100, 1000 magnification power and microsurface structures were measured by white-light scanning interferometry for three dimensional surface roughness measurements(Accura $2000^{(R)}$, Intek-Plus, Korea.). Removal torque was measured in 17 rabbits using digital torque gauge(MGT 12R, Mark-10 corp., NY, U.S.A.) immediately after the sacrifice and two rabbits were used for the histologic preparation(EXAKT $310^{(R)}$, Heraeus Kulzer, wehrheim, Germany) of specimens and observed under light microscope. Resonance frequency measurement($Osstell^{(R)}$) was taken with the 19 rabbits at the beginning of the implant fixation and immediately after the sacrifice. Results. Following results were taken from the experiment. 1. The surface of the RBM implants as seen with SEM had rough and irregular pattern with reticular formation compared to that of fumed specimens showing different surface topographies. 2. The newly designed implant with RBM surface had high removal torque value among four groups with no statistical significance. The average removal torque was $49.95{\pm}6.70Ncm$ in Group A, $51.15{\pm}4.40Ncm$ in Group B, $50.78{\pm}9.37Ncm$ in Group C, $51.09{\pm}4.69Ncm$ in Group D. 3. The RFA values were $70.8{\pm}4.3Hz$ in Group A, $71.8{\pm}3.1Hz$ in Group B, $70.9{\pm}2.5Hz$, $72.7{\pm}2.5Hz$ in Group D. Higher values were noted in the groups which had surface treatment compared to the untreated groups with no statistical significance. 4. The results from the histomorphometric evaluation showed a mean percentage of bone-to-implant contact of $45{\pm}0.5%$ in Group A, $55{\pm}3%$ in Group B, $49.5{\pm}0.5%$ in Group C, and $55{\pm}3%$ in Group D. Quite amount of newly formed bone were observed at the surface RBM-treated implants in bone marrow space.

정상인(正常人) 및 당뇨병환자(糖尿病患者)에서의 경구당부하시(經口糖負荷時) 혈중(血中) Insulin과 C-Peptide의 변동(變動) (A Study of the Insulin and the C-Peptide Responses to Oral Glucose Load in Nondiabetic and Diabetic Subjects)

  • 이명철;최성재;김응진;민헌기;고창순
    • 대한핵의학회지
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    • 제11권1호
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    • pp.17-32
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    • 1977
  • The present study was undertaken to evaluate the significance of the insulin and the C-peptide rseponse to oral glucose loads in normal and diabetic subjects and to establish the effects of the obesity. In this study, the authors have measured plasma insulin and C-peptide by means of radioimmunoassay in 10 nonobese normal, 5 obese normal, 13 nonobese moderate diabetic patients, 9 obese moderate diabetic patients and 9 severe diabetic patients. The results obtained were as follows; 1. In 10 nonobese normal subjects, the plasma insulin level at fasting state and at 30, 60, 90, and 120 min after oral glucose loads were $15.7{\pm}3.4,\;48.3{\pm}9.8,\;40.4{\pm}6.7,\;37.4{\pm}6.5\;and\;26.0{\pm}4.2uU/ml(Mean{\pm}S.E.)$ and C-peptide were $1.9{\pm}0.3,\;3.9{\pm}0.6,\;6.3{\pm}0.6,\;5.7{\pm}0.5\;and\;4.0{\pm}0.5ng/ml$. The change of C-peptide was found to go almost parallel with that of insulin and the insulin value reaches to the highest level at 30 min whereas C-peptide reaches to its peak at 60min. 2. The plasma insulin level in 5 obese normal subjects were $38.9{\pm}12.3,\;59.5{\pm}12.3,\;59.2{\pm}17.1,\;56.1{\pm}20.0\;and\;48.4{\pm}17.2uU/ml$ and the C-peptide were $5.5{\pm}0.4,\;6.8{\pm}0.5,\;7.9{\pm}0.8,\;7.9{\pm}0.8\;and\;7.8{\pm}2.0ng/ml$. The insulin response appeared to be greater than nonobese normal subjects. 3. In 13 nonobese moderate diabetic patients, the plasma insulin levels were $27.1{\pm}4.9,\;44.1{\pm}6.0,\;37.3{\pm}6.6,\;35.5{\pm}8.1\;and\;34.7{\pm}10.7uU/ml$ and the C-peptide levels were $2.7{\pm}0.4,\;4.9{\pm}0.7,\;6.5{\pm}0.5,\;7.0{\pm}0.3\;and\;6.7{\pm}1.0ng/ml$. There was little significance compared to nonobese normal groups but delayed pattern is noted. 4. In 9 obese moderated diabetic patients, the plasma insulin levels were $22.1{\pm}7.9,\;80.0{\pm}19.3,\;108.0{\pm}27.0,\;62.0{\pm}17.6\;and\;55.5{\pm}10.1uU/ml$ and the C-peptide levels were $5.2{\pm}0.4,\;8.0{\pm}1.0,\;10.4{\pm}1.6,\;10.4{\pm}1.7\;and\;10.1{\pm}1.0ng/ml$ and its response was also greater than that of nonobese moderate diabetic patients. 5. The plasma insulin concentrations in 9 severe diabetic subjects were $8.0{\pm}3.8,\;12.1{\pm}3.5,\;16.8{\pm}4.6,\;19.6{\pm}5.2\;and\;15.0{\pm}5.0uU/ml$ and the C-peptide levels were $1.6{\pm}0.3,\;2.4{\pm}0.4,\;4.1{\pm}0.6,\;4.0{\pm}0.8\;and\;4.5{\pm}0.7ng/ml$ and the insulin and C-peptide responses were markedly reduced in severe diabetic groups. 6. There were-significant differences between each groups of patients on the magnitude of total insulin or C-peptide areas, the insulinogenic index and the C-peptide index.

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How effective has the Wairau River erodible embankment been in removing sediment from the Lower Wairau River?

  • Kyle, Christensen
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2015년도 학술발표회
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    • pp.237-237
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    • 2015
  • The district of Marlborough has had more than its share of river management projects over the past 150 years, each one uniquely affecting the geomorphology and flood hazard of the Wairau Plains. A major early project was to block the Opawa distributary channel at Conders Bend. The Opawa distributary channel took a third and more of Wairau River floodwaters and was a major increasing threat to Blenheim. The blocking of the Opawa required the Wairau and Lower Wairau rivers to carry greater flood flows more often. Consequently the Lower Wairau River was breaking out of its stopbanks approximately every seven years. The idea of diverting flood waters at Tuamarina by providing a direct diversion to the sea through the beach ridges was conceptualised back around the 1920s however, limits on resources and machinery meant the mission of excavating this diversion didn't become feasible until the 1960s. In 1964 a 10 m wide pilot channel was cut from the sea to Tuamarina with an initial capacity of $700m^3/s$. It was expected that floods would eventually scour this 'Wairau Diversion' to its design channel width of 150 m. This did take many more years than initially thought but after approximately 50 years with a little mechanical assistance the Wairau Diversion reached an adequate capacity. Using the power of the river to erode the channel out to its design width and depth was a brilliant idea that saved many thousands of dollars in construction costs and it is somewhat ironic that it is that very same concept that is now being used to deal with the aggradation problem that the Wairau Diversion has caused. The introduction of the Wairau Diversion did provide some flood relief to the lower reaches of the river but unfortunately as the Diversion channel was eroding and enlarging the Lower Wairau River was aggrading and reducing in capacity due to its inability to pass its sediment load with reduced flood flows. It is estimated that approximately $2,000,000m^3$ of sediment was deposited on the bed of the Lower Wairau River in the time between the Diversion's introduction in 1964 and 2010, raising the Lower Wairau's bed upwards of 1.5m in some locations. A numerical morphological model (MIKE-11 ST) was used to assess a number of options which led to the decision and resource consent to construct an erodible (fuse plug) bank at the head of the Wairau Diversion to divert more frequent scouring-flows ($+400m^3/s$)down the Lower Wairau River. Full control gates were ruled out on the grounds of expense. The initial construction of the erodible bank followed in late 2009 with the bank's level at the fuse location set to overtop and begin washing out at a combined Wairau flow of $1,400m^3/s$ which avoids berm flooding in the Lower Wairau. In the three years since the erodible bank was first constructed the Wairau River has sustained 14 events with recorded flows at Tuamarina above $1,000m^3/s$ and three of events in excess of $2,500m^3/s$. These freshes and floods have resulted in washout and rebuild of the erodible bank eight times with a combined rebuild expenditure of $80,000. Marlborough District Council's Rivers & Drainage Department maintains a regular monitoring program for the bed of the Lower Wairau River, which consists of recurrently surveying a series of standard cross sections and estimating the mean bed level (MBL) at each section as well as an overall MBL change over time. A survey was carried out just prior to the installation of the erodible bank and another survey was carried out earlier this year. The results from this latest survey show for the first time since construction of the Wairau Diversion the Lower Wairau River is enlarging. It is estimated that the entire bed of the Lower Wairau has eroded down by an overall average of 60 mm since the introduction of the erodible bank which equates to a total volume of $260,000m^3$. At a cost of $$0.30/m^3$ this represents excellent value compared to mechanical dredging which would likely be in excess of $$10/m^3$. This confirms that the idea of using the river to enlarge the channel is again working for the Wairau River system and that in time nature's "excavator" will provide a channel capacity that will continue to meet design requirements.

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운동훈련(運動訓練)에 대(對)한 심폐기능(心肺機能)의 적응(適應)에 관(關)한 연구(硏究) (Cardio-pulmonary Adaptation to Physical Training)

  • 조강하
    • The Korean Journal of Physiology
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    • 제1권1호
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    • pp.103-120
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    • 1967
  • As pointed out by many previous investigators, the cardio-pulmonary system of well trained athletes is so adapted that they can perform a given physical exercise more efficiently as compared to non-trained persons. However, the time course of the development of these cardio-pulmonary adaptations has not been extensively studied in the past. Although the development of these training effects is undoubtedly related to the magnitude of an exercise load which is repeatedly given, it would be practical if one could maintain a good physical fitness with a minimal daily exercise. Hence, the present investigation was undertaken to study the time course of the development of cardio-pulmonary adaptations while a group of non-athletes was subjected to a daily 6 to 10 minutes running exercise for a period of 4 weeks. Six healthy male medical students (22 to 24 years old) were randomly selected as experimental subjects, and were equally divided into two groups (A and B). Both groups were subjected to the same daily running exercise (approximately 1,000 kg-m). 6 days a week for 4 weeks, but the rate of exercise was such that the group A ran on treadmill with 8.6% grade for 10 min daily at a speed of 127 m/min while the group B ran for 6 min at a speed of 200 m/min. In order to assess the effects of these physical trainings on the cardio-pulmonary system, the minute volume, the $O_2$ consumption, the $CO_2$ output and the heart rate were determined weekly while the subject was engaged in a given running exercise on treadmill (8.6% grade and 127 m/min) for a period of 5 min. In addition, the arterial blood pressure, the cardiac output, the acid-base state of arterial blood and the gas composition of arterial blood were also determined every other week in 4 subjects (2 from each group) while they were engaged in exercise on a bicycle ergometer at a rate of approximately 900 kg m/min until exhaustion. The maximal work capacity was also determined by asking the subject to engage in exercise on treadmill and ergometer until exhaustion. For the measurement of minute volume, the expired gas was collected in a Douglas bag. The $O_2$ consumption and the $CO_2$ output were subsequently computed by analysing the expired gas with a Scholander micro gas analyzer. The heart rate was calculated from the R-R interval of ECG tracings recorded by an Offner RS Dynograph. A 19 gauge Cournand needle was inserted into a brachial artery, through which arterial blood samples were taken. A Statham $P_{23}AA$ pressure transducer and a PR-7 Research Recorder were used for recording instantaneous arterial pressure. The cardiac output was measured by indicator (Cardiogreen) dilution method. The results may be summarized as follows: (1) The maximal running time on treadmill increased linearly during the 4 week training period at the end of which it increased by 2.8 to 4.6 times. In general, an increase in the maximal running time was greater when the speed was fixed at a level at which the subject was trained. The mammal exercise time on bicycle ergometer also increased linearly during the training period. (2) In carrying out a given running exercise on treadmill (8.6%grade, 127 m/min), the following changes in cardio·pulmonary functions were observed during the training period: (a) The minute volume as well as the $O_2$ consumption during steady state exercise tended to decrease progressively and showed significant reductions after 3 weeks of training. (b) The $CO_2$ production during steady state exercise showed a significant reduction within 1 week of training. (c) The heart rate during steady state exercise tended to decrease progressively and showed a significant reduction after 2 weeks of training. The reduction of heart rate following a given exercise tended to become faster by training and showed a significant change after 3 weeks. Although the resting heart rate also tended to decrease by training, no significant change was observed. (3) In rallying out a given exercise (900 kg-m/min) on a bicycle ergometer, the following change in cardio-vascular functions were observed during the training period: (3) The systolic blood pressure during steady state exercise was not affected while the diastolic blood Pressure was significantly lowered after 4 weeks of training. The resting diastolic pressure was also significantly lowered by the end of 4 weeks. (b) The cardiac output and the stroke volume during steady state exercise increased maximally within 2 weeks of training. However, the resting cardiac output was not altered while the resting stroke volume tended to increase somewhat by training. (c) The total peripheral resistance during steady state exercise was greatly lowered within 2 weeks of training. The mean circulation time during exorcise was also considerably shortened while the left heart work output during exercise increased significantly within 2 weeks. However, these functions_at rest were not altered by training. (d) Although both pH, $P_{co2}\;and\;(HCO_3-)$ of arterial plasma decreased during exercise, the magnitude of reductions became less by training. On the other hand, the $O_2$ content of arterial blood decreased during exercise before training while it tended to increase slightly after training. There was no significant alteration in these values at rest. These results indicate that cardio-pulmonary adaptations to physical training can be acquired by subjecting non-athletes to brief daily exercise routine for certain period of time. Although the time of appearance of various adaptive phenomena is not identical, it may be stated that one has to engage in daily exercise routine for at least 2 weeks for the development of significant adaptive changes.

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난소적출로 유발된 랫트 갱년기 장애에 대한 가감귀비온담탕의 생리활성 효과 평가 (Anti-climacterium Effects of Gagamguibiondam-tang in Ovariectomized Rats)

  • 한상겸;김동철
    • 대한한방부인과학회지
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    • 제30권4호
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    • pp.18-44
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    • 2017
  • 목 적: 이 연구에서는 한의학에서 다양한 부인과 질환에 사용되어온 전통 복합 처방인 귀비탕과 가미온담탕을 합방, 가감한 가감귀비온담탕 열수 추출물의 갱년기 장애 개선 효과를 심혈관 장애, 비만, 고지혈증, 골다공증, 장기 지방축적 및 신경정신 장애를 포함한 다양한 사람의 갱년기 장애를 나타내는 것으로 알려진 난소적출(Ovariectomized, OVX) 랫트 모델을 이용하여 평가하였다. 방 법: 난소적출수술 28일 후부터 가감귀비온담탕 추출물(수율 : 22.03%)을 각각 100, 50 및 25 mg/ml의 농도로 멸균 증류수에 용해시키고, 체중 kg 당 5 ml의 용량(500, 250 및 125 mg/kg)으로 매일 1회씩 84일(12주 : 3개월)간 경구 투여한 다음, 항비만효과, 항자궁위축효과 및 골다공증 억제 효과의 3가지 생리활성 효과로 구분하여 평가하였다. 항비만 효과 및 항자궁위축효과를 평가하기 위해, 체중 및 증체량, 혈청중 에스트라디올 함량, 복부 축적 지방 및 자궁의 중량의 변화와 복부 축적 지방의 두께 및 평균 지방세포 직경, 자궁 전체, 상피 및 점막의 두께와 점막내 자궁샘이 차지하는 비율의 변화를 각각 평가하였다. 또한 골다공증 개선효과, 즉 골 보호효과를 평가하기 위해, 대퇴골, 경골 및 요추골의 습, 건조 및 탄화 중량, 골밀도, 골강도, 혈중 osteocalcin 및 bone specific alkaline phosphatase(bALP) 함량, 골량 및 구조와 골흡수에 대한 조직병리학적 변화를 각각 측정하였다. 실험군(5개군; 군당 8마리의 랫트 사용) 거짓수술 대조군(거짓수술 후, 증류수 투여 대조군) 난소적출 대조군(난소적출 수술 후, 증류수 투여 대조군) GGOT500(난소적출 수술 후, 가감귀비온담탕 추출물 500 mg/kg 투여 고용량 실험군) GGOT250(난소적출 수술 후, 가감귀비온담탕 추출물 250 mg/kg 투여 중간용량 실험군) GGOT125(난소적출 수술 후, 가감귀비온담탕 추출물 125 mg/kg 투여 저용량 실험군) 결 과: 난소적출 대조군에서는 거짓수술 대조군에 비해 현저한 체중 및 증체량, 사료 및 물 섭취량, 축적 복부 지방 중량, 혈청 중 osteocalcin 함량의 증가가 자궁, 대퇴골, 경골 및 L5 중량과 혈중 bALP 및 에스트라디올 함량의 감소와 함께 인정되었으며, 현저한 복벽 축적 지방 두께의 증가 및 자궁의 위축, 대퇴골, 경골 및 L4의 골량 및 구조의 감소 소견이 골 흡수 지표(Ocn 및 OS/BS)의 현저한 증가와 함께 조직병리학적 및 조직형태계측학적으로 인정되었다. 즉, 전형적인 에스트로겐 결핍성 갱년기 장애가 난소적출에 의해 유발되었다. 한편 이러한 난소적출에 의한 에스트로겐 결핍성 폐경기 관련 갱년기 장애 소견이, 가감귀비온담탕 추출물 500, 250 및 125 mg/kg의 84일에 걸친 연속 경구 투여에 의해 투여 용량 의존적으로 억제되었다. 결 론: 이상의 결과에서, 가감귀비온담탕 500, 250 및 125 mg/kg의 경구투여는 난소적출 랫트에서 에스트로겐 결핍성 폐경기 관련 갱년기 장애 개선 효과를 투여 용량 의존적으로 나타내었다. 따라서 가감귀비온담탕은 효과적인 갱년기 장애 개선제로서 개발 가능성이 높을 것으로 기대되며, 특히 에스트로겐 결핍성 비만 및 골다공증의 개선에 유효할 것으로 판단된다. 한편 가감귀비온담탕은 총 18종의 약제로 구성되어 있고, 각각 수많은 생리활성 물질을 함유하고 있어, 이후 생리활성을 나타내는 화학성분의 검색과 더불어 다양한 방면으로 기전적인 연구가 체계적으로 수행해야 할 것으로 판단된다.