• 대기
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• 제24권2호
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• pp.141-150
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• 2014

This study investigates the characteristics of the Gross Moist Stability (GMS) over the tropics. The GMS summarizes the relationship between large-scale entropy forcing due to radiation and surface fluxes and the response of smaller-scale convection. The GMS is able to explain both to where moist entropy is advected by the atmospheric circulation and how deep the moisture flux convergence is in the tropical region. In the deep convective region, positive GMS appears over the warm pool region due to the strong column-integrated moisture convergence and the ensuing export of moist entropy to the environment. The vertical advection of moist entropy dominates over the horizontal advection in this region. Meanwhile, over the eastern tropical ITCZ region, which is characterized by shallow convective area, import of moist entropy by horizontal winds is dominant compared to the vertical moist entropy advection. Future changes in the GMS are also examined using the 22 CMIP5 model simulations. A decrease in the GMS appears widely across the tropics, but its increase occurs over the western-central equatorial Pacific. It is evident that the increased GMS region corresponds to an increased region of precipitation, implying that strengthened convection in the future due to increased entropy forcing exports the enhanced moist energy to stabilize the environment.

• 한국건축시공학회지
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• 제17권2호
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• pp.127-134
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• 2017

최근 국내 아파트의 외벽 거푸집공사의 경우 대부분 갱폼 시스템을 통해 철근콘크리트 구조체를 시공하고 있다. 이러한 갱폼 거푸집을 사용한 콘크리트의 경우는 거푸집 탈형 후 외부환경에 노출되고 특히, 건조한 봄, 가을과 일사량이 높은 서중시기의 벽량이 많은 아파트 측벽에 다량의 균열이 발생되어지고 있다. 이에, 본 연구에서는 신축 아파트 건설현장 중심으로 균열량이 많은 아파트 측벽부분의 갱폼시스템에 습윤양생 자동설비장치를 적용하여 초기 콘크리트 양생에 필요한 수분을 공급함으로써 콘크리트의 품질확보와 다량의 측벽균열 저감을 통한 습윤양생 자동장치의 효율성 및 활용성을 검토하고자 하였는데, 그 결과, 양생 효과 및 낙수량 고려 시 습윤양생 자동장치에 0.3mm 사이즈의 노즐을 사용하여 살수양생을 실시할 경우, 자원낭비 없이 콘크리트의 품질향상 및 균열저감에 효과적인 것으로 판단되었다.

• Fisheries and Aquatic Sciences
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• 제11권4호
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• pp.190-194
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• 2008

We estimated the digestibility and growth rate of juvenile olive flounder (Paralichthys olivaceus) on three diets: raw fish-based moist pellets, moist pellets, and extruded pellets. The diets were created using commercially available methods, and a basic formulated powder. A reference diet was used to compare feed digestibility and the fish growth rate achieved using the experimental diets. The apparent digestibility coefficients (ADCs) of protein for raw fish-based moist pellets and moist pellets were significantly higher (P<0.05) than those for extruded pellets and the reference diet. The ADCs of nitrogen-free extracts (NFE) of extruded pellets and moist pellets were significantly higher (P<0.05) than those for raw fish-based moist pellets and the reference diet. Fish that were fed with the raw fish-based moist pellets showed the greatest weight gain (452.4%), which was not significantly different from that of fish fed with extruded pellets (414.4%; P>0.05). These results indicate that the higher protein efficiency in fish fed with extruded pellets can result in good growth performance within flounder culture systems.

• 한국전산유체공학회지
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• 제17권4호
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• pp.93-102
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• 2012

Once the condensation of water vapor in moist air around a thin airfoil occurs, liquid droplets nucleate. The condensation process releases heat to the surrounding gaseous components of moist air and significantly affects their thermodynamic and flow properties. As a results, variations in the aerodynamic performance of airfoils can be found. In the present work, the effects of upstream Mach number and thickness ratio of airfoil on the transonic flow of moist air around a thin airfoil are investigated by numerical analysis. The results shows that a significant condensation occurs as the upstream Mach number is increased at the fixed thickness ratio of airfoil($\epsilon$=0.12) and as the thickness ratio of airfoil is increased at the fixed upstream Mach number($M_{\infty}$=0.80). The condensate mass fraction is also increased and dispersed widely around an airfoil as the upstream Mach number and thickness ratio of airfoil are increased. The position of shock wave for moist air flow move toward the leading edge of airfoil when it is compared with the position of shock wave for dry air.

• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.307-315
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• 1995

The purpose of this study was to assess the efficacy of several thermal therapies using ice pack, moist-hot pack and ultrasound, separately and concomitantly and to obtain the background information on the vascular changes after thermophysical therapies. The author had used 15 healthy subjects were examined and the subjects were divide into 5 groups : ice pack, moist-hot pack, ultrasound, ice pack and moist-hot pack, ice pack and ultrasound. Observation were made immediate before and 0,5,10,20,30,45,60,90 minutes after treatment. Thermography was performed in an Agema 870 thermovisio with 0.1$^{\circ}C$ difference of gradual temperature shift. The results were as follows : 1. Using ice pack only, the surface temperature of the masseter region was increased lapse of time, and most remarkably 90 minutes after the treatment. 2. Using moist-hot pack only, the surface temperature of the region was remarkably increased immediately after the treatment, but decreased lapse of time. 3. Using moist-hot pack with ice pack, the surface temperature of the face was remarkably increased immediately after the treatment, and decreased lapse of time, Hyperthermia was maintained for a longer time as compared with the group of moist-hot pack only. 4. Using ultrasound only, the surface temperature of the region was increased gradually, and most remarkably 30 minutes after the treatment, but decreased in the course of time. 5. Using ultrasound combined with ice pack, the surface temperature of the region was gradually decreased until 30 minutes after the treatment, and decrease to some extend at 45 minute. And then a gradual increase observed over the remaining period of the experiment. 6. Hyperthermia were maintained for a long time in the groups using ice pack combined with moist-hot pack and ultrasound as compared with the other groups. Our data suggest that ice pack can promote the efficacy of other thermal therapies.

• 한국재난정보학회 논문집
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• 제13권3호
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• pp.348-357
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• 2017

본 연구에서는 생갯벌을 잔골재 대신 치환한 모르타르의 물리적 특성에 대한 실험을 진행하여 벽돌로써의 활용 가능성을 분석하였다. 플로우 측정결과 시멘트와 잔골재의 배합비가 높을수록 플로우 값이 증가하였으며, 생갯벌의 치환율이 감소할수록 플로우값이 감소하는 것으로 나타났다. 염화물 함유량 측정결과 생갯벌의 치환율이 감소할수록 염화물 함유량 또한 감소하는 것으로 나타났다. 압축강도 측정결과, 대부분의 배합비에서 생갯벌의 치환율이 감소할수록 압축강도는 반비례하여 증가하는 것으로 나타났다. 인장강도 측정결과, 압축강도와 비슷한 경향을 나타냈다. 그리고 생갯벌 치환율이 감소할수록 강도가 증가하는 것으로 나타났다.

• 한국양식학회지
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• 제9권3호
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• pp.247-254
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• 1996

조피볼락 배합 사료로써 dry pellet (DP)의 사용 가능성을 조사하기 위하여, 2회에 걸쳐 사육 실험을 실시하였다. 두 실험에 사용된 사료 조성은 단백질원으로 북양어분이 $56\%$ 첨가된 사료(실험1)와 경제적인 측면을 고려하여 북양어분을 $38\%$로 줄이는 대신, 대두박과 콘글루텐 밀을 $25\%$ 첨가한 사료(실험 2)를 설계하여 각각 DP 및 moist pellet (MP) 형태로 제조하였고, 양어가들이 주로 사용하고 있는 생사료(법동 메가리)와 시판 분말 사료를 1 : 1로 혼합한 생사료 MP(raw h-based MP : RMP)를 제조하였다. 4.7 g 전후의 치어를 11주간 3반복으로 사육한 실험 1의 결과, 최종적으로 평균체중 및 일일 증체율이 DP, MP 및 RMP 사료간에서 서로 유의차가 없었으며, 전어체의 단백질, 지질 및 수분 함량도 사료간에 차이가 없었다(P>0.05). 사료효율은 세 실험구 중에서 RMP구가 가장 높았고(P<0.05), 사료 조성비가 같은 DP와 MP사이에서는 유의차가 없었다. 11 g 전후의 조피볼락을 8주간 사육한 실험 2에서는 성장 및 일일증체율이 RMP 실험구가 DP 실험구보다 좋았지만, MP와 RMP 실험구간에서는 유의한 성장차이가 없었다(P>0.05), 사료효율은 DP구가 가장 낮고 RMP구가 가장 높은 결과를 보였다(P<0.05). 이러한 차이는 사료 단백원 중 식물성 대체 단백원(대두박, 콘글루텐 밀)이 차지하는 비율과 RMP구의 단백질 함량이 $57\%$로 타 실험구보다 높았기 때문인 것으로 판단된다. 실험 1과 2의 결과들로부터 실험 배합 사료의 물성은 조피볼락의 성장이나 사료효율에 큰 영향을 미치지 않을 것으로 보여, 보다 적합한 실용배합 사료가 개발되면, DP도 조피볼락의 배합사료로써 손색이 없을 것으로 전망된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.2121-2126
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• 2003

Supersonic free jets discharging from an orifice or a nozzle have long been research subject with a number of engineering applications and have mainly been investigated using dry air or other gas without any condensation effects. The major characteristics of those supersonic jets are now well known in terms of jet pressure ratio and ratio of specific heats of gas. Recently, the supersonic jets of superheated steam or moist air are being used in many industrial applications, in which case is expected that the condensation effects might alter the fundamental structure of the dry air jet. The present study aims to investigate the supersonic moist air jet and to clarify the condensation effects on the jet structure. An experiment is carried out using an indraft wind tunnel facility. The relative humidity of moist air is controlled at the nozzle supply, and the jet pressure ratio is varied to obtain the moderately under expanded flows at the exit of the nozzle. It is found that the relative humidity of moist air can change the diameter and location of Mach Disk.

• Restorative Dentistry and Endodontics
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• 제23권2호
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• pp.676-681
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• 1998

The purpose of this study is to explain theoretically the mechanism of the frequency-dependent apex locator which can detect the apex of the root in moist canals with blood or other conductible canal irrigants. The frequency-dependent apex locator is based on measuring the ratio of the two impedances of the two alternating currents with different frequencies. We analyzed the changes of the ratio between the two impedances by using differential calculus. Our analysis shows that : 1. When the file is in the moist canal, the ratio between the two impedances is almost constant. 2. As the file approaches the apex of the root, the ratio decreases sharply. By this mechanism, the frequency-dependent apex locator can detect the apex of the-root quite accurately in moist canals.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.768-773
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• 2004

When a gas expands through a convergent nozzle in which the ratio of the ambient to the stagnation pressures is higher than that of the critical one, the issuing jet from the nozzle is underexpanded. If a flat plate is placed normal to the jet at a certain distance from the nozzle, a detached shock wave is formed at a region between the nozzle exit and the plate. In general, supersonic moist air jet technologies with nonequilibrium condensation are very often applied to industrial manufacturing processes. In spite of the importance in major characteristics of the supersonic moist air jets impinging to a solid body, its qualitative characteristics can not even know. In the present study, the effect of the nonequilibrium condensation on the underexpanded moist air jet impinging on a vertical flat plate is investigated experimentally. Flow visualization and impact pressure measurement are performed for various relative humidities and flat plate positions. The obtained results show the plate shock and Mach disk are dependent on the nozzle pressure ratio and the relative humidity, but for a given nozzle pressure ratio, the diameters of the plate shock and Mach disk depend on the stagnation relative humidity. The impact pressure deviation from the flow of without condensation is large, as the relative stagnation humidity increases.