• 제목/요약/키워드: water-weak

검색결과 817건 처리시간 0.028초

산성 전해수가 보리(Hordeum vulgae L.) 엽록체의 발달에 미치는 영향 (The Effects of Acidic Electrolytic Water on the Development of Barley Chloroplast)

  • 정화숙;송승달;노광수;송종석;박강은
    • 한국환경과학회지
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    • 제8권2호
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    • pp.255-261
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    • 1999
  • To investigate the effects of strong acidic electrolytic water on the chloroplast, barley leaves were treated with strong acidic electrolytic water(pH 2.5). And to investigate the effects of weak acidic electrolytic water on the chloroplast development, etiolated barley leaves were treated with weak acidic electrolytic water(pH 6.5) during greening period. Chl contents, Fo, Fv, and Chl fluorescence quenching coefficient in barley leaves were measured during and after treatment of acidic electrolytic water. The following results were obtained. Chl a, b, and carotenoid were decreased with treatment of strong acidic electrolytic water. Chl contents were significantly decreased than that of the control after 5 min. These results provide evidence that the strong acidic electrolytic water dissimilate the Chl and so that the value of Fo was slightly increased. The strong acidic electrolytic water damaged PS II because Fo was increased and Fv, Fm, and Fv/Fm ratio were decreased. qP, qNP and qE were decreased. On the other hand qI was increased than that of the control. But Chl content and Chl fluorescence patterns were a little changed as the pH increase over 4.0 Chl a, b, and carotenoid were increased with treatment of weak acidic electrolytic water during greening period. Chl contents were significantly increased than that of control after 12 hours greening. These results provide evidence that the weak acidic electrolytic water accelerated the chlorophyll synthesis. And the weak acidic electrolytic water accelerated PS II development because Fv, Fm, qP and Fv/Fm ratio were increased than that of the control.

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단효용 LiBr/물 흡수식 냉동사이클의 성능특성에 관한 연구 (A Study on Performance Characteristics of A Single Effect LiBr/Water Refrigeration Cycle)

  • 연제문;임삼택;오주원;이경우
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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    • pp.95-99
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    • 2001
  • As a way to use energy effectively, the present study is aimed at investigating the performance characteristics of a Single Effect LiBr/Water Absorption Refrigerator using a low temperature driving heat-source. It was carried out by changing the driving heat-source temperature, the cold water outlet temperature(the refrigeration load), the cooling water inlet temperature, and the weak solution flow rate and this study compares the performance characteristics of refrigerator against the existence and non-existence of the Recirculation of the Weak solution which is used as a method to improve the performance of refrigerator. In case of Recirculation of the weak solution, more improved the Refrigeration Capacity and COP was obtained, and these effects became more larger in the high temperature of driving heat-source and large quantity of solution.

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허약아와 성장지표의 상관성에 대한 연구 (A Study on Comparison between Growth Indices of Weak Children Groups via Analyzing Bone Age and Body Composition)

  • 이혜림;한재경;김윤희
    • 대한한방소아과학회지
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    • 제28권2호
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    • pp.1-22
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    • 2014
  • Objectives The purpose of this study is to investigate the relationship between weak children and growth indices. Methods One hundred twenty-six of the first and the second grade elementary school students who didn't have to develop yet their secondary sexual characteristics answered the questionnaire. Their bone age and body composition were measured. Results 1. According to the Weak Children questionnaire analysis, respiratory problem was one of the biggest problems in the weak children group (35.7%), followed by digestive problems (23.0%), psycho-neurological problems (22.2%), neuromotor problems (9.5%), and urogenital problems (8.7%). 2. From the comparison between growth indices of weak children and that of normal children are as follows: 1) The group of children who had problem in their digestive system had lower growth indices than the normal average children group. The growth indices includes mean height, weight, total body water, protein mass, mineral mass, body fat, skeletal muscle mass, body fat percentage, body mass index (BMI), and basal metabolic rate (BMR). 2) The children who had urogenital weakness had lower mean height, RH (Recent Height), RH - MPH {Recent Height(%) - Mid-Parental Height(%)}, RUS (Radius, Ulna and Short bone) score, weight, protein mass, body fat, BMI, and visceral fat than the normal children group. 3. The results of the multiple comparisons of growth indices and weak children groups are as follows: 1) Digestive weak children were the lowest in total body water, protein mass, mineral mass, skeletal muscle mass, and basal metabolic rate. 2) Urogenital weak children were the lowest in height, RH, RH - MPH, RUS score, and weight. Conclusion These results showed that children's growth is strongly correlated to their own growth problems, especially to those children who have digestive and urogenital problems. Therefore, this may be an effective way for children growth treatment in Korean medicine to treat weak symptoms.

Strengthen the Construction of Water Resources Monitoring Ability, Support the Strictest System of Water Resources management

  • Jiang, Yun-Zhong;Yi, Wan
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.27-33
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    • 2012
  • At present, the overall water resources monitoring ability in China is weak since there is an absence of a sound monitoring system and comprehensive monitoring information. In addition to the problem of weak management ability in monitoring, measurement and information, it can hardly meet the need of implementing the strictest management system of water resource and also restricts the practice of the system to some extent. The production states the necessity of further development of water resources monitoring ability and points out the concept of "One Country, One Account" for constructing water resources information. There is an analysis on the demand on further development of water resources monitoring ability and profound discussion about the strategies for supporting "three red-line" management.

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Microwave-assisted Weak Acid Hydrolysis of Proteins

  • Seo, Mi-Yeong;Kim, Jin-Hee;Park, Se-Hwan;Lee, Ji-Hye;Kim, Tae-Hee;Lee, Ji-Hyeon;Kim, Jeong-Kwon
    • Mass Spectrometry Letters
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    • 제3권2호
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    • pp.47-49
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    • 2012
  • Myoglobin was hydrolyzed by microwave-assisted weak acid hydrolysis with 2% formic acid at $37^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$ for 1 h. The most effective hydrolysis was observed at $100^{\circ}C$. Hydrolysis products were investigated using matrixassisted laser desorption/ionization time-of-flight mass spectrometry. Most cleavages predominantly occurred at the C-termini of aspartyl residues. For comparison, weak acid hydrolysis was also performed in boiling water for 20, 40, 60, and 120 min. A 60- min weak acid hydrolysis in boiling water yielded similar results as a 60-min microwave-assisted weak acid hydrolysis at $100^{\circ}C$. These results strongly suggest that microwave irradiation has no notable enhancement effect on acid hydrolysis of proteins and that temperature is the major factor that determines the effectiveness of weak acid hydrolysis.

공기-물 이상매질 충격파관 문제에 대한 정확한 Riemann 해법 (EXACT RIEMANN SOLVER FOR THE AIR-WATER TWO-PHASE SHOCK TUBE PROBLEMS)

  • 염금수;장근식
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2010년 춘계학술대회논문집
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    • pp.365-367
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    • 2010
  • In this paper, we presented the exact Riemann solver for the air-water two-phase shock tube problems where the strength of the propagated sock wave is moderately weak. The shock tube has a diaphragm in the middle which separates water medium in the left and air medium in the right. By rupturing the diaphragm, various waves such as rarefaction wave, shock wave and contact discontinuity are propagated into water and air. Both fluids are treated as compressible, with the linearized equations of state. We used the isentropic relations for the air and water assuming a weak shock wave. We solved the shock tube problem considering a high pressure in the water and a low pressure in the air. The numerical results cleary showed a left-traveling rarefaction wave in the water, a right-traveling shock wave in the air, and the right-traveling material interface.

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취약대가 존재하는 제방의 누수 탐지를 위한 전기비저항 탐사의 적용성 연구 (A Study on Application of Electrical Resistivity Survey to Detect the Leakage of Embankment with Weak Zone)

  • 박삼규;김재홍
    • 한국지반환경공학회 논문집
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    • 제14권4호
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    • pp.5-13
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    • 2013
  • 댐 및 저수지 제방의 누수현상은 통관 주변에서 주로 일어나며 평상 시에는 제방에 큰 영향을 미치지 않지만, 호우나 장마철과 같이 저수지 수위가 상승하면 제방의 붕괴 위험을 가져온다. 따라서 이러한 수맥과 경로를 조사하는 것은 재해 예방과 제방 관리의 측면에서 매우 중요하다. 본 연구에서는 수치적인 방법과 실험적인 방법을 사용하여 통관이 취약대로 작용하는 댐 및 제방에서의 누수현상을 분석하였다. 누수탐지에는 전기비저항 탐사를 사용하여 그 유용성을 검토하였다. 수치해석의 결과에서는 취약대의 크기와 위치에 따라 전극 간격의 설정이 중요함을 보여주었고, 모형제방의 누수실험에서는 전극간격을 0.3m로 쌍극자 배열을 사용하는 것이 가장 좋은 결과를 얻을 수 있을 것으로 판단되었다. 누수현상의 분석을 통하여 댐 및 제방시설물의 누수탐지에 전기 비저항 탐사가 유용함을 확인하였다.

FDR 센서를 활용한 제체 누수특성의 실내 모형 실험 연구 (Physical Model Experiment on the Seepage Characteristics through a Dam by using FDR Sensor)

  • 김규범;임은상;류호철;황찬익;김형종
    • 지질공학
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    • 제28권4호
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    • pp.715-726
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    • 2018
  • 제체의 누수를 탐지하는 방법으로서 물리탐사, 온도 계측, 광섬유 등 다양한 방법이 개발되어 왔다. 본 연구에서는 FDR 센서의 유전율상수를 이용한 누수 탐지의 가능성을 파악하기 위하여 취약부와 미취약부로 구성된 물리모형을 제작하였으며 유전율상수, 온도 및 간극수압 센서를 설치하였다. 누수가 형성됨에 따라 유전율상수는 미취약부보다 취약부에서 빠르게 변화되었다. 또한, 취약부에서 간극수압, 온도 및 유전율 상수를 비교하면 유전율 상수의 반응이 가장 빠르고 하류 계측 지점에서도 쉽게 인지되는 특성을 보였다. 이와 같은 특성을 고려할 때, 제체 하류 구간에서 분포형으로 유전율을 측정한다면 누수 탐지에 빠르고 효율적으로 대처할 수 있을 것으로 파악되었다.

암모니아-물 흡수식 열교환 사이클의 운전 특성 (Operating Characteristics of Ammonia-Water Absorber Heat Exchange Cycle)

  • 강인석;김남진;김종보
    • 에너지공학
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    • 제10권4호
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    • pp.357-362
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    • 2001
  • 충진농도, 냉매 팽창밸브 개도, 그리고 약용액의 유량 변화에 따른 벤치타입 암모니아-물 흡수식 열교환 사이클에 대한 실험을 수행한 결과 시스템의 충진농도가 증가할수록 냉방능력이 증가하였으며, 최적의 충진농도가 존재함을 알았다. 그리고 냉매 팽창 밸브의 개도는 응축기 출구의 직접적인 영향을 주고 있으며 최적의 과냉도가 0~4$^{\circ}C$임을 알았다. 또한 약용액의 유량이 증가시킬수록 증발압력과 강용액의 농도가 즐어들었으며, 냉방능력과 COP가 최대가 되는 최적의 약용액 유량이 존재하였다.

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VOF 수치해석을 통한 고절수형 위생도기 개발에 관한 연구 (A Study on Development of High Efficiency Toilets with VOF Numerical Analysis)

  • 안일용;이영림;조우석;김진호
    • 한국생산제조학회지
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    • 제21권6호
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    • pp.946-953
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    • 2012
  • When water shortage has been getting worse recently, toilet water-saving is one of the most effective way to solve the water shortage. Therefore, in this study, toilet flushing performance was investigated with VOF(Volume Of Fluid) model to obtain the basic design data for the development of high-efficiency toilets. The result showed that the shorter trapway, the longer the flushing duration time. However, the shorter trapway is found to have disadvantage in exhausting dirt due to relatively weak siphon and higher curvature. Since the remaining water in a trapway appears to help siphon, it is also an important factor in developing high-efficiency toilets. Although higher water level in the water tank shows better performance in flushing, lower water level is preferred to save water. Too low water level may cause dirt to clog the trapway due to relatively weak siphon.