• 제목/요약/키워드: state change of water

검색결과 433건 처리시간 0.032초

혈장 삼투질 농도 변동에 따른 항이뇨 호르몬과 Aldosterone 분비조절 : 한국청년 (Role of Plasma Osmolality in AVP and Aldosterone Release in Korean Young Men)

  • 이원정;주영은;구자훈
    • The Korean Journal of Physiology
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    • 제21권2호
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    • pp.297-304
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    • 1987
  • A study was carried out to find out the relationship between arginine vasopressin (AVP) release and plasma osmolality in 15 young men (age: 21.4 yr). After an overnight fasting, wale. (20 ml/kg) was imbibed, and venous blood and urine samples were collected every 30 min for 90 min. then 5% saline was infused (0.06 ml/min/kg) for 120 min. AVP was extracted on Sep-Pak column and measured by radioimmunoassay. Under basal condition, plasma osmolality (pOsm), AVP (pAVP) and aldosterone (pAldo) levels were 286.5 mOsm/kg, 1.1 pg/ml, and 140 pg/ml, respectively. pAVP became undetectable during maximum water diuresis, and increased in response to hypertonic saline infusion. pAVP level began to increase when pOsm was above 280 mOsm/kg. Changes in urinary AVP excretion (uAVP) was parallel to pAVP levels. The fall in pAVP was followed by a decrease in uAVP, uOsm and an increase in free water clearance, while the later rise in pAVP was followed by an increase in uAVP, uOsm and a decrease in free water clearance. When pooling all data together, relationships between pAVP and pOsm, and uAVP and uOsm were best expressed by an exponential relationship (r=0.78, 0.86, respectively). pAldo level decreased to 71 pg/ml after water ingestion, and decreased further to 30 pg/ml 2 hr after 5% saline infusion. Even at the same pNa, pAldo level during dehydration state was significantly higher than during hydration state. Negative exponential relation (r=-0.59) was observed between pAldo and pNa. Response to change in body fluid volume was greater in aldosterone than in AVP release.

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빅 데이터와 클라우드 컴퓨팅 기반의 수자원 정보 관리 방안에 관한 검토 (A Review on the Management of Water Resources Information based on Big Data and Cloud Computing)

  • 김연수;강나래;정재원;김형수
    • 한국습지학회지
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    • 제18권1호
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    • pp.100-112
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    • 2016
  • 최근 국내 외 수자원 정책의 방향은 전통적인 이 치수 부문과 함께 삶의 질을 향상을 위해 지속가능한 물 관리에 대한 필요가 강조되면서 수자원 정보의 수집, 관리 및 제공의 중요성이 증대되고 있다. 과거 수자원 정보는 제공하고자 하는 목적을 이미 정하고 거기에 맞도록 데이터를 효과적으로 분석하는 기술에 초점이 맞추어져 있었다. 그러나 최근에는 정형 데이터뿐만 아니라 비정형 데이터를 연계함으로써 새로운 가치를 도출할 수 있는 빅 데이터와 클라우드 컴퓨팅에 대한 관심이 부각되면서 수자원 정보에도 변화를 가져오고 있다. 이에 본 논문에서는 수자원 정보 관리의 패러다임 변화에 능동적으로 대처하고, 수자원 정보의 효율적인 관리 및 이용을 위해 수자원 분야에서 빅 데이터와 클라우드 컴퓨팅의 적용 방안을 검토 및 제언하고자 하였다. 국내외 수자원 정보 관리의 현황과 방향을 살펴보고, 빅 데이터의 3대 요소인 크기(Volume), 속도(Velocity), 다양성(Variety)과 함께 추가적으로 언급되고 있는 정확성(Veracity), 가치(Value)개념을 연계하였다. 그리고 클라우드 컴퓨팅을 통해 증가하는 수자원 관련 빅 데이터와 수요자의 변화에 대해 신속하고 유연한 대처방안에 대하여 논의하였다. 앞으로의 수자원 정보 관리는 정보의 크기(Volume), 속도(Velocity), 다양성(Variety) 등의 빅 데이터와 클라우드 컴퓨팅 적용을 통한 인명과 재산의 보호 등 공공의 목적, 물 관리 및 재난의 예방과 대응에 필요한 정확한(Veracity) 정보의 생산, 그리고 다른 분야와의 융합 등에 적극적으로 활용함으로써 수자원 정보의 가치(Value)를 높이는 방행으로 나아가야 한다.

냉매 충전량과 팽창장치 변화에 따른 열펌프 시스템의 성능특성에 관한 연구 (The Performance of a Heat Pump with a Variation of Expansion Valve at Various Charging Conditions)

  • 최종민;김용찬
    • 설비공학논문집
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    • 제15권8호
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    • pp.661-666
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    • 2003
  • Constant area expansion devices such as capillary tubes, short tube orifices are being gradually replaced with electronic expansion valves (EEVs) because of increasing focus on comfort and energy conservation. In this study, the performance of a water-to-water heat pump as a function of refrigerant charge is investigated in steady state, cooling mode operation with expansion devices of a capillary tube and an EEV. The performance of the capillary tube system varies drastically according to the change of refrigerant charge amount and inlet temperature of the secondary fluid in the condenser. Cooling capacity and COP of the EEV system show little dependence on the refrigerant charge, while those are strongly dependent on the secondary fluid temperature at the condenser inlet. In general, for a wide range of operating conditions the EEV system shows much higher performance as compared with the capillary tube system. The performance of the EEV system can be optimized by adjusting EEV opening to maintain a constant superheat at all test conditions.

Improvement of bioavailability of poorly water soluble drugs by size reduction technique

  • Choi, Woo-Sik;Kim, Hyun-Il;Kwak, Seong-Shin;Choi, Hee-Kyu;Ha, Jong-Hak;Hwang, Sun-Hwan;Lee, Dong-Beom
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.225.2-226
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    • 2003
  • The prolonged mechanical grinding process may enhance the bioavailability of the drugs due to the change of solid state such as micronization and decrease of crystallinity. A series of attempts to enhance the bioavailability of insoluble drugs have been made by the fine grinding technique using a planetary mill. The objective of the present study is to investigate the possibility of improving the dissolution properties of poorly water- soluble drugs such as diphenyl hydrantoin (phenytoin) and diphenyl dimethyl dicarboxylate (DDB) based on the molecular interaction between drug and additives during pharmaceutical processing to be related with the bioavailability behavior. (omitted)

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온도 조건에 따른 비소 이온의 수중 상태 변화 특성 및 독성 예측 (Feature of the Change of the Arsenic Ionic State and Prediction of Toxicity in Aqueous Environment depending on Temperature Condition)

  • 원유라;김동수
    • 한국물환경학회지
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    • 제29권2호
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    • pp.176-183
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    • 2013
  • The variation of the stable region of arsenic compounds in aqueous environment with temperature has been investigated by constructing the Pourbaix diagram of arsenic at different temperatures. The standard potential corresponding to the boundary between arsenic compounds with different charge valence was estimated to be decreased with temperature, which means the stability of arsenic compound with +5 charge valence increases. The distribution diagram of the most highly oxidized arsenic compound showed that arsenic acid is formed at higher pH and arsenate is generated at lower pH as temperature rises. The aquatic toxicity due to arsenic compounds was considered to be decreased with temperature in the neutral pH condition based on the $LD_T$ value defined in this study.

Nucleophilic Substitution Reaction of α-Methoxy-α-(trifluoromethyl)phenylacetyl Chloride in Alcohol-Water Mixtures

  • 구인선;이성인;안선경;양기열;이익춘
    • Bulletin of the Korean Chemical Society
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    • 제20권12호
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    • pp.1451-1456
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    • 1999
  • Solvolyses of α-methoxy-α-(trifluoromethyl)phenylacetyl chloride in H₂O, D₂O, CH₃OD, 50% D₂O-CH₃OD, and in aqueous binary mixtures of acetone, dioxane, ethanol and methanol are investigated at 25.0℃. The Grunwald-Winstein plots of first-order rate constants for α-methoxy- α-(trifluoromethyl)phenylacetyl chloride with $Y_{Cl}$ show a dispersion phenomenon. Solvent nucleophilicity N has been shown to give considerable im-provement when it is added as an 1N term to the original Grunwald-Winstein for the solvolyses of α-methoxy- α-(trifluoromethyl)phenylacetyl chloride. The dispersions in the Grunwald-Winstein correlations in the present studies are caused by solvent nucleophilicity. The magnitude of l and m values associated with a change of solvent composition predicts the associative $S_N2$ transition state. The kinetic solvent isotope effects determined in deuterated water and methanol are consistent with the proposed mechanism of the general base catalyzed associative $S_N2$ or $S_AN$ mechanism for the of α-methoxy- α-(trifluoromethyl)phenylacetyl chloride.

빙축열조의 방냉과정에 대한 해석 (Analysis on the Coldness Release Process of Ice Storage Tank)

  • 유호선;김영인
    • 설비공학논문집
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    • 제1권1호
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    • pp.9-20
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    • 1989
  • This paper presents an analysis to predict thermal behaviors of water in ice storage tank during the coldness release process. To deal with complicated transient phenomena due to ice-water phase change and the density inversion, a theoretical model which consists of initial perfectly mixed, stratified and thermal diffusion state was introduced and a criterion on the growth of thermal boundary layer was developed. The analysis includes considerations on the type of ice-making heat exchanger, refrigerator on/off and tank arrangement. Also, discussions on the various parameters and operating conditions which have influence on the performance of the system were made. Finally, simulated results were shown, which agreed with experiments in trends reasonably.

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RECENT DEVELOPMENTS IN HYDROSYSTEMS

  • Larry-W.Mays
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 1993년도 수공학연구발표회논문집
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    • pp.3-26
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    • 1993
  • I have briefly described some of the important advances in hydrosystems and to remark on the important scientific research priorities in hydrological sciences. We have concentrated on data collection systems, real-time control of hydrosystems, global climate change and decision support systems and GIS. In summary, I would like to stress the following points: - the advances in data collection systems, advanced methodologies for interfacion hydrologic, hydraulic, and optimization models through optimal control approaches; and the advances in decision support systems and GIS will allow the interfacing of all these technologies into some sophisticated and much needed tools for operating hydrosystems; - the ability to better understand the hydrologic processes and their relationships to other earth processes is important to understanding and modelling of the hydrologic cycle and its interactions with the ocean-atmosphere system; - and the solution to a better understanding of hydrologic sciences needs to be an international effort such as the GEWEX program briefly discussed above. I would like to thamk each of you for listening to my lecture and to once again thank those responsible for me being here today. Thank you.

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유한변형률 압밀이론에 의한 남해안준설토의 압밀특성에 관한 연구 (The Study on the Consolidation Characteristics of South Coast Spoil Reclaimed Ground by Finite Strain Consolidation Theory)

  • 송명규;임종철;권정근;주인곤
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.1170-1180
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    • 2009
  • Recently this country has carried out the coast reclamation centering on the west and south coast for effective practical use of a country, considering purchase of materials and environmental problem, most reclaiming work is processing to spoil reclamation which is easy to secure the amount of materials. In case of weak ground that is formed by spoil reclamation like this, initial moisture content is high, as slurry state that is rarely revealed ground strength, compressibility and water permeability have been shown nonlinear change by compaction progress. Analysis of weak ground is unreasonable because the existing Terzaghi compaction theory analyzes compaction fixed number to regular invariable number for prediction of compaction state. This study computes the relation with void ratio-effective pressure and void ratio-finite transformation which is the most basic matter to predict finite strain compaction state of the south coast spoil, and analyze the basic feature to predict compaction feature of the south coast spoil reclaimed ground.

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인삼박(人蔘粕) 및 인삼엽(人蔘葉)으로 제조(製造)한 Mosquito Coil Powder가 Rat 및 Mouse에 미치는 독성(毒性)에 관한 연구(硏究) (Toxicity Test of Mosquito Coil Powder Made of Ginseng Leaf and Ginseng Residue after Extraction with Ethanol- Water System)

  • 허재두;심순주;김용주;오정균;김재백
    • Journal of Pharmaceutical Investigation
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    • 제9권3호
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    • pp.22-26
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    • 1979
  • This report was carried out toxicity test for the mosquito coil made of Ginseng leaf and the residue after extraction of Ginseng root. This results are as follows: In the first group, was not shown any special difference on the body weight, the motion and dissection. In the second group, was not shown any Special difference on the body weight, considerable difference on the motion and considerable loss of appetite besides very slight loss, but came cack soon again to normal state by change of air after a moment. In the third group, the body weight and appetite was depressed very slightly and the motion was shown very slightly difference, but came back soon again to normal state by chenge of air after a moment too. No one was died, and all the animal were the normal state on the reslt of dessection, Therefore, we have positive evidence that this mosquito coil powder is applied to animals without any toxicity.

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