• Title/Summary/Keyword: ground temperature

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Estimation of the Heat Budget Parameter in the Atmospheric Boundary Layer considering the Characteristics of Soil Surface (지표면의 특성을 고려한 대기경계층내의 열수지 parameter 추정 -열수지 parameter를 이용한 중규모 순환의 수치예측-)

  • 이화운;정유근
    • Journal of Environmental Science International
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    • v.5 no.6
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    • pp.727-738
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    • 1996
  • An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

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Evaluation on the Compressive Strength of the Ground Granulated Blast-Furnace Slag Mortar with the Curing Temperature (양생온도에 따른 고로슬래그 미분말 모르타르의 압축강도 평가)

  • Lee, Bo-Kyeong;Kim, Gyu-Yong;Shin, Kyoung-Su;Koo, Kyung-Mo;Choe, Gyeong-Cheol;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.257-258
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    • 2012
  • With regard to the carbon reduction that has become an international problem, we have examined the effects of compressive strength of the ground granulated blast-furnace slag mortar with the curing temperature. Also, we evaluated the mechanical properties of steel slag powder produced during the steelmaking process in order to examine the possibility as admixture.

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Changes in the Spawning Ground Environment of the Common Squid, Todarodes pacificus due to Climate Change (기후변화에 따른 살오징어(Todarodes pacificus) 산란장 환경 변화)

  • Kim, Yoon-ha;Jung, Hae Kun;Lee, Chung Il
    • Ocean and Polar Research
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    • v.40 no.3
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    • pp.127-143
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    • 2018
  • This study analyzed the influence of climate change on the spawning ground area of the common squid, Todarodes pacificus. To estimate long term changes in the area of the spawning ground of the common squid, water temperature at 50 m deep that can be inferred from sea surface temperature (SST) based on both NOAA/AVHRR (1981.07-2002.12) and MODIS/AQUA (2003.01-2009.12) ocean color data was analyzed. In addition, five climate indices, Arctic Oscillation Index (AO), Siberian High Index (SH), Aleutian Low Pressure Index (ALP), East Asia Winter Monsoon Index (EAWM) and Pacific Decadal Oscillation (PDO) which are the main indicators of climate changes in the northwestern Pacific were used to study the relationship between the magnitude of the estimated spawning ground and climate indices. The area of the estimated spawning ground was highly correlated with the total catch of common squid throughout four decades. The area of the estimated spawning ground was negatively correlated with SH and EAWM. Especially, PDO was negatively correlated with the area of the spawning ground in the northwestern Pacific (r = -0.39) and in the southern part of the East Sea (r = -0.38). There was a positive relationship between the AO and the area of the spawning ground in the northwestern Pacific (r = 0.46) as well as in the southern part of the East Sea (r = 0.32). Temporally, the area of the winter spawning ground in the southern part of the East Sea in the 1980s was smaller than those areas in the 1990s and 2000s, because the area was disconnected with the western coastal spawning ground of Japan in the 1980s, while the area had been made wider and more continuous from the Korea strait to the western coastal water of Honshu in the 1990s and 2000s.

Analysis of Temperature Variations in Groundwater in the Taegu Area (지하수온도 자료분석에 의한 대구지역 지하수 특성 연구)

  • 성익환
    • The Journal of Engineering Geology
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    • v.3 no.3
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    • pp.267-278
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    • 1993
  • Ground-water temperature is one of the parameters for observing diarges in the state of the ground-water regime in time and space, which relate to conditions for recharge as well as the influence of various natural and man-induced fadors on the regime. Because ground-water satura tes much of the rock materiats in the upper layer of the earth's csust the water temperature reflects in part the temperature of the water-bearing rocks. The mobffity and thennal capadty of groud-waters, however, serves to redistribute some of the heat within the stratosphere and to influence the developement of the geothermal regime within this sphere. The utilization of temperature data of the study area(25 points) in the solution of hydrogeologic problems requires an understanding of some of the fundamental aspects of subsurtice temperatures. These include the depth of penetration of heat waves generated of the surtace, the rate of propagation of the waves, and the geothermal gradient in the study area of Taegu.

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In-situ Performance Evaluation of a Ground Source Heat Pump for an Air Conditioning System (공조시스템용 지열히트펌프의 실증평가에 관한 연구)

  • Park, Youn-Cheol;Park, Seong-Koo
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.1
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    • pp.66-72
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    • 2008
  • In this study, the ground source heat pump was installed at a research center in Jeju Island to verify the performance of the system and to give an information for a economic feasibility. The performance test was conducted until the heat storage tank temperature reached at $5^{\circ}C$ from $50^{\circ}C$ in the cooling operation, and until the storage temperature goes up to $50^{\circ}C$ from $10^{\circ}C$ in the heating mode. As results, the system performance shows that $2.2{\sim}3.5$ for the cooling operation and $2.5{\sim}3.5$ for heating operation. It is found that the underground is good heat source for the heat pump with $3{\sim}10^{\circ}C$ variation range. The ground source heat pump could be connected one of air conditioning system without any problem in system performance. Based on the economic analysis, the initial cost for the ground source heat pump will be compensated after 4 years operation. If the system runs 20 years, approximately 300 million Won will be saved when the air conditioning system adapt the ground source heat pump based on Life Cycle Cost analysis.

Numerical modeling of Atmosphere - Surface interaction considering Vegetation Canopy (식물계를 고려한 지표-대기 상호작용의 수치모의)

  • 이화운;이순환
    • Journal of Environmental Science International
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    • v.3 no.1
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    • pp.17-29
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    • 1994
  • An one dimensional atmosphere-vegetation interaction model is developed to discuss of the effect of vegetation on heat flux in mesoscale planetary boundary layer. The canopy model was a coupled system of three balance equations of energy, moisture at ground surface and energy state of canopy with three independent variables of $T_f$(foliage temperature), $T_g$(ground temperature) and $q_g$(ground specific humidity). The model was verified by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HYPEX-MOBHLY experiment. As the result, both vegetation and soil characteristics can be emphasized as an important factor iii the analysis of heat flux in the boundary layer. From the numerical experiments, following heat flux characteristics are clearly founded simulation. The larger shielding factor(vegetation) increase of $T_f$ while decrease $T_g$. because vegetation cut solar radiation to ground. Vegetation, the increase of roughness and resistance, increase of sensible heat flux in foliage while decrease the latent heat flux in the foliage.

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A Study on the Surface Grinding using the Machining Center (II) (머시닝센터를 이용한 평면 연삭가공에 관한 연구 (II))

  • Lee, S. M.;Choi, H.;lee, J. C.;Cheong, S. H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.880-883
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    • 2000
  • Temperature generated in the workpiece during grinding process can cause thermal damages. Therefore it is important to understand surface temperature generated during grinding process. In this paper, a theoretical and experimental investigation were performed for the grinding temperature. Grinding experiments were performed in machining center using vitrified bonded CBN cup-type wheel. The surface temperature was measured using thermocouple and calculated through a model of the partition of energy between wheel and workpiece. The residual stress and hardness of ground surface were measured. The experimental results indicate that the surface temperature was in good agreement with theoretical ones. Residual stress and hardness of ground surface were more affected by the change of table speed than the depth of cut.

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Fiber optic distribution temperature sensing in a borehole heat exchanger system (광섬유 센서를 이용한 지중 열교환기 시스템 온도 모니터링)

  • Shim, Byoung-Ohan;Lee, Young-Min;Kim, Hyoung-Chan;Song, Yoon-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.451-454
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    • 2006
  • Fiber optic distributed temperature sensing and thermal line sensor are applied in an observation borehole and a loom deep borehole heat exchanger. For the case of permanently installed system fiber optic DTS is very useful. By comparing with TLS, fiber optic DTS shows good accuracy and reliability. Ground water flow can give influences at heat exchange rate of the heat pump system. According to the hydraulic characteristics and temperature-depth profile, we consider that temperature-depth profile do not seem to be dependent on ground water flow. A permanent installation of fiber optic cable is expected as a reliable temperature measurement technique in a borehole heat exchanger system.

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Change of the Moisture and Temperature in Planting Ground as Effected by Different Soil Thickness, Soil Mixture Ratios and Ground Cover Plants in the Green Roof System (옥상녹화에서 토심, 토양배합비 및 지피식물에 따른 식재지반 수분 및 온도변화)

  • Ju, Jin Hee;Yoon, Young Han
    • KIEAE Journal
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    • v.10 no.3
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    • pp.11-16
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    • 2010
  • This paper has attempted to investigate the change in soil moisture volume and temperature of architecture by planting ground(soil thickness and soil mixture ratio) and ground cover plants(Sedum sarmentosum, Zoysia japonica, Chrysanthemum zawadskii) for middle region green roof system. For this, a test was conducted on the roof of Konkuk University building from April 2009 to October 2009. In terms of treatment, five types(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) depending on soil mixture ratio and two types(15cm, 25cm) by soil depth were created. Results of soil moisture volume by soil mixture ratio in the 15cm soil thickness showed that the difference was significance between simple soil and mixture soil treatment, however, the statistical significance was not recognized according to soil mixture ratio. In case of 25cm soil thickness, soil moisture volume by soil mixture ratio was more higher 7Vol.%~10Vol.% in the mixture soil than simple soil treatment. In terms of districts planted ground cover plants, soil volume moisture differed among plants in the order Zoysia japonica 17.74 Vol.%$34.86^{\circ}C$, district non-planted $27.49^{\circ}C$, Sedum sarmentosum $25.11^{\circ}C$, Chrysanthemum zawadskii $23.08^{\circ}C$, Zoysia japonica $24.45^{\circ}C$ respectively So, concrete surface showed more higher $5^{\circ}C{\sim}15^{\circ}C$ than other things among the all the time. Result of inner temperature of the architecture and soil, it was measured inner of architecture $25.69^{\circ}C$, inner district non-planted $24.29^{\circ}C$, Chrysanthemum zawadskii $23.90^{\circ}C$, Zoysia japonica $24.02^{\circ}C$, Sedum sarmentosum $25.13^{\circ}C$, respectively.

Oceanographic Condition and Fishing Condition of the Set Net Fishing Ground in Yeosu Bay (여수연해 정치망어장의 해황과 어황에 관한 연구)

  • Kim, Dong-Soo;Lee, Cho-Chool;Park, Yong-Seak
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.24 no.4
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    • pp.150-157
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    • 1988
  • The oceanographic condition around the set net fishing ground in Yeosu Bay was investigated by the oceanographic observation in June, July and August, 1988. Also the catch of the set net was analized by daly catch data of the three set net fishing ground from April to September, 1988. The results obtained are as follows: 1) The coastal surface water is high temperature and low salinity through the influence of land, and the off shore water and bottom water are low temperature and high salinity. 2) The eddy current and the sharp thermocline in June appeared in August at the set net fishing ground, and a good catch appeared in June and August. 3) The surface temperature and salinity at the set net fishing ground are 11$^{\circ}C$ to 27$^{\circ}C$ and 31.60$\textperthousand$ to 34.80$\textperthousand$. The surface temperature and salinity of a maximum good catch are 21$^{\circ}C$ and 33.80$\textperthousand$ to 33.99$\textperthousand$ respectively. 4) The dominant species of fish were spanish mackerel, scad, anchovy, sardine, common mackerel, hairtail, crab, yellow tail, in order of catch.

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