• 환경영향평가
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• 제11권2호
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• pp.79-91
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• 2002

Four dimensional data assimilation (FDDA) technique was considered for 3 dimensional wind field in coastal area and a set of 3 numerical experiments including control experiments has been tested for the case of the synoptic weather pattern of the weak northerly geostrophic wind with the cloud amount of less than 5/10 in autumn. A three dimensional land and sea breeze model with the sea surface temperature (SST) of 290K was performed without nudging the observed wind field and surface temperature of AWS (Automatic Weather System) for the control experiment. The results of the control experiment showed that the horizontal temperature gradient across the coastline was weakly simulated so that the strength of the sea breeze in the model was much weaker than that of observed one. The experiment with only observed horizontal wind field showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated. However, the horizontal wind speed and vertical motion in the convergence zone were weakly simulated. The experiment with nudgings of both the surface temperature and wind speed showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated even though the ending time of the sea breeze was delayed due to oversimulated temperature gradient along the shoreline.

• 대한기계학회논문집A
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• 제32권11호
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• pp.951-956
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• 2008

The high temperature creep properties of the generating plant's high temperature tube, pipe and header and such are very significant in accordance with long-time exposure to the high temperature and pressure environment. Not only this, but as the welding procedure is compulsory for the cohesion of components, the creep properties regarding the local microstructures of steel weldment are very important. In order to understand the creep properties regarding the local microstructures of steel weldment, the SP-Creep test which is easy to get sample from the field component was conducted. The local microstructure of steel weldment, that is, W.M. and B.M.'s microstructures were observed using the SEM. The rupture time of W.M. was longer as 110 % averagely in a same condition, which is the consequence of the difference of the microstructure. Each lethargy coefficient of B.M. and W.M. is evaluated by the relation among the temperature, load and the rupture time from SP-Creep Test. The life estimation equation can be induced by the transformation of Power-law. B.M. and W.M. for each $550\;^{\circ}C$ and $575\;^{\circ}C$, the very similar to normal temperature of the domestic thermal power generation in working, are estimated.

• 한국지리정보학회지
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• 제15권1호
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• pp.144-158
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• 2012

도시의 국지기후 분석에 충분한 공간해상도의 정확한 분석을 위해서는 이를 지원할 정밀한 공간정보가 필요하다. 1~4m 해상도의 항공 LiDAR(Light Detection And Ranging) 자료와 KOMPSAT-2(Korea Multi-Purpose Satellite-2) 위성영상 자료를 이용하여 초고해상도(5m) 입체적 지형 지면 토지피복 모델을 개선하였다. CAS(Climate Analysis Seoul)를 이용하여 도시내부의 지표면 속성비율과 건물의 밀집도 높이 면적에 따른 열적용량과 국지규모 기온을 분석하였다. 자료의 정밀도 향상 결과가 국지규모 기온 분석에 미치는 효과를 평가하기 위해, 개선이전 및 이후 국지기온 분석 결과와 ASTER 위성영상 지표면온도 및 지상 기온관측 자료를 각각 비교 분석하였다. 그 결과 개선이후 국지규모 기온분석 결과와 ASTER 지표면온도 비교시, 건물(BS)지역에서 높은(R=0.76) 상관관계가 나타났다. 지상 기온관측과의 비교에서도 그 편차가 개선이전 1.27K보다 개선되어 0.70K로 나타났다. 본 연구 결과로부터 초고해상도 공간정보가 현실을 잘 반영할 뿐만 아니라 이를 이용한 상세한 기온분석이 가능함을 알 수 있었다. 향후 도시 개발 계획 시나리오에 대한 상세도시기후 예측 및 분석에 본 연구의 정밀한 지형 지면 토지피복 모델 기술 등이 활용될 수 있을 것이다.

• 한국축산식품학회지
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• 제35권4호
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• pp.524-532
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• 2015

The objective of this study was to investigate the effects of high post-mortem temperature application on development of pale, soft, exudative (PSE) turkey meat characteristics in terms of local slaughter conditions. Within this scope, it was targeted to obtain PSE-like muscles benefiting from different post-mortem temperature applications. Immediately after slaughter, turkey Pectoralis major (n=15) muscles were kept at various post-mortem temperatures (0, 10, 20, 30, and 40℃) for 5 h. pH values of 40°C treatment were lower than four other treatments (p<0.05). L* values, drip loss, cook loss, and thawing loss of 40℃ group were higher than the other groups (p< 0.05). Napole yield of 40℃ treatment indicated that high post-mortem temperature decreases brine uptake. Protein solubility of 40℃ group was lower than 0℃ group (p<0.05). Expressible moisture did not differ between 0 and 40℃ treatments. Hardness, gumminess and chewiness of 40℃ treatment were higher than 0℃ treatment. The results of this research showed that high post-mortem temperature treatment induced development of PSE-like turkey meat, with lower pH, paler color, higher technological and storage losses, and reduced protein solubility and texture.

• Journal of Advanced Marine Engineering and Technology
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• 제30권1호
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• pp.22-29
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• 2006

Gas turbine engine among Principal internal combustion engines has been mainly applied as an aero and industrial Power plant. In order to increase its thermal efficiency. it has been raised their pressure ratio of compressor and the turbine inlet temperature. To operate above the limit temperature of turbine material, turbine nozzle vanes should be cooled. For this the cooling air is bled from the compressor section of 9as turbine. Meanwhile, to keep high thermal efficiency of 9as turbine, turbine vanes are to be cooled by using small cooling air Therefore, the complex cooling passages are requested to be designed and evaluated the effectiveness of vane cooling by measuring turbine vane temperature. But it is very difficult or impossible for us to measure local turbine temperatures at actual temperature When local heat transfer coefficients are known these can be calculated, therefore this study has been investigated on obtaining these coefficients of turbine vane at room temperature using TLC.

• 열처리공학회지
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• 제23권5호
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• pp.249-256
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• 2010

Water jet impingement cooling has been widely used in a various engineering applications; especially in cooling of hot steel plate of steelmaking processes and heat treatment in hot metals as an effective method of removing high heat flux. The effects of cooling water temperature on water jet impingement cooling are primarily investigated for hot steel plate cooling applications in this study. The local heat flux measurements are introduced by a novel experimental technique that has a function of high-temperature heat flux gauge in which test block assemblies are used to measure the heat flux distribution during water jet impingement cooling. The experiments are performed at fixed flow rate and fixed nozzle-to-target spacing. The results show that effects of cooling water temperature on the characteristics of jet impingement heat transfer are presented for five different water temperatures ranged from 5 to $45^{\circ}C$. The local heat flux curves and heat transfer coefficients are also provided with respect to different boiling regimes.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.113-123
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• 1998

The present study is to investigate the effect of experimental parameters on the heat transfer characteristics of a spherical capsule storage system using paraffins. N-Tetradecane and mixture of n-Tetradecane 40% and n-Hexadecane 60% were used as paraffins. Water with inorganic material was also tested for the comparison. The experimental parameters were varied for the Reynolds number from 8 to 16 and for the inlet temperature from -7 to 2$^{\circ}C$. Measured local temperatures of spherical capsules in the storage tank were utilized to calculate charging and discharging times, dimensionless thermal storage amount, and the average heat transfer coefficients in the tank. Local charging and discharging times in the storage tank were significantly different. The effect of inlet temperature on charging time was larger than that on discharging time, but the effect of Reynolds number on charging time was smaller than that on discharging time. Charging time of paraffins was faster by 11~72% than that of water with inorganic material, but little difference of discharging time was found among them. The effect of Reynolds number on the dimensionless thermal storage was less during charging process and more during discharging process than the effect of inlet temperature. The effect of the inlet temperature and the Reynolds number on the average heat transfer coefficient of the storage tank was stronger during discharging process than during charging process. The average heat transfer coefficients of the spherical capsule system using paraffins were larger by 40% than those using water.

• 천문학회지
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• 제22권2호
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• pp.127-140
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• 1989

Problem of the diffuse radiation (DFR) transfer is solved exactly for pure hydrogen nebulae of uniform density, and accuracies of the on-the-spot (OTS) approximation are critically examined. For different values of density and spectral types of the central star, we have calculated the degree of ionization and the kinetic temperature of electrons as functions of distance from the central star, and compared them with the corresponding results of the OTS approximation. At most locations inside an HII region. the DFR ionizes considerable amount of hydrogen; therefore, the OTS approximation under-estimates the size of ionized regions. The exact treatment of the DFR transfer results in an about 10 to 20 percent increase in the classical $Str{\ddot{o}}mgren$ radius. The OTS approximation overestimates the local heating rate by raising the density of neutral hydogens. Consequently, it predicts higher values for the local electron temperature. The OTS approximation also exaggerates the dependence of electron temperature on density. When the hydrogen density is changed from $10/cm^3$ to $10^3/cm^3$ with an 06.5V star, the OTS approximation shows an about 3,000 K difference in the electron temperature, while the exact treatment of the DFR-transfer reduces the difference to about 1,000 K. The OTS approximation fails to demonstrate the brightening of the electron temperature close to the ionization boundary.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.239-240
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• 2022

In winter, low outdoor temperature can casue reduction of concrete strength. Therefore, thermal protection is required when curing concrete in winter to maintain a certain level or higher surface temperature. Accordingly, in domestic construction sites, a curing method in which surrounds casting areas by tents and operates hot air blowers are widely applied. However, local low-temperature areas may occur due to airtightness of the curing tents. If additional heat is supplied to prevent occurrence of local low-temperature areas, energy consumption increases. Therefore in this study, a plan for improvement method of concrete curing was considered and the performance was evaluated through numerical analysis. A plan to improve the airtightness of the wall opening was applied, but the analysis showed that if only a part of the curing area is shielded, the temperature of the unshielded area decreases,making it inappropriate to improve curing performance.

• 한국해안·해양공학회논문집
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• 제20권1호
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• pp.34-41
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• 2008

미래 연안 생태환경변화 예측을 위한 기후변화에 따른 수온변화 예측이 필요하며, 연안 수온변화는 GCM 자료에서 제공하는 미래 기온변화 예측자료를 국지적인 기온자료로 Downscaling 기법을 적용하여 사용할 수 있다. 본 연구에서는 선형회귀분석기법을 이용하여 2000년${\sim}$2005년 우리나라 평균기온자료를 연안해역의 국지적인 기온자료로 Downscaling 하는 방법을 제안하고, 제안한 방법의 검증을 수행하였다. Downscaling 방법의 보정과정에서의 RMS오차 평균은 1.584정도이며, 2006년${\sim}$2007년 자료를 이용한 검정과정에서의 RMS 오차 평균은 1.675, 1.448 정도로 추정오차는 보정과정에서의 오차수준을 유지하고 있는 것으로 파악되었다. 또한, NSC 값도 보정과정에서는 0.962, 2006년${\sim}$2007년 자료를 이용한 검정과정에서는 0.955, 0.963으로 보정과정에서의 일치수준을 유지하고 있는 것으로 파악되어 선형회귀분석 기법을 이용한 우리나라 연안의 국지적인 기온은 RMS 오차 $1.0{\sim}2.0^{\circ}C$ 수준으로 전국 평균기온을 이용하여 추정할 수 있다.