• 한국환경과학회지
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• 제22권10호
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• pp.1337-1344
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• 2013

We examined urban heat island intensity in Seongseo, Dae gu, South Korea, where a large area of water is located within the suburb. We found a maximum urban heat island intensity of $4.2^{\circ}C$, which occurred around 7 PM in the summer season. Throughout the remainder of the year, we observed the largest heat island intensity levels during late night hours. In contrast, the winter season displayed the smallest values for heat island intensity. Our results conflicted with heat island intensity values for cities where suburbs did not contain water areas. Generally, cities with suburbs lacking water displayed the largest heat island intensity levels before sunrise in the winter season. We also observed negative urban heat island intensity levels at midday in all seasons except for the summer, which is also in contrast with studies examining suburbs lacking water areas. The heat island intensity value observed in this study ($4.2^{\circ}C$) was relatively large and fell between the averages for, Asia and Europe according to the relationship between urban population and heat island intensity.

• 설비공학논문집
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• 제17권9호
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• pp.855-862
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• 2005

An experimental investigation has been carried out for aluminum foam heat sink inserted into the annulus to examine the feasibility as a heat sink for high performance forced water cooling in the annulus. The local wall temperature distribution, inlet and outlet pressures and temperatures, and heat transfer coefficients were measured for heat flux of 13.6, 18.9, 25.1, 31.4 $kw/m^2$ and Reynolds number ranged from 120 to 2000. Experimental results show that the friction factor is higher than clear annulus without aluminum foam, while the significant augmentation in Nu is obtained. This technique can be used for the compactness of the heat exchanger.

• 한국환경과학회지
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• 제24권10호
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• pp.1265-1272
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• 2015

To investigate the thermal environment over the summertime asphalt pavements, an automatic weather observation system was installed at a parking lot paved with asphalt to observe various meteorological parameters and surface temperature from July 1 to September 30, 2014. Since the number of rainy days in summer of 2014 particularly after the mid July is more than that of average data, a ratio of daily peak surface temperature above $45^{\circ}C$ was 28% which was lower than the average. The observational data about hourly average surface temperature and various heat balance factors at days where daily peak surface temperature is above $45^{\circ}C$ are as follows: An hour that had the daily maximum temperature was around 15 pm and the value was $49^{\circ}C$ approximately. Net shortwave radiation was the highest at 12pm as $800W/m^2$ and much radiation of $500W/m^2$ was absorbed at the ground between 11am and 17pm. Sensible heat that was delivered from the ground to the atmosphere was evaluated as $200W/m^2$ between 10am and 19pm. underground transfer heat up to $100W/m^2$ was measured as negative from 19pm to the next day 8am, which indicated the lower atmosphere was heated at night.

• 한국축산시설환경학회지
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• 제20권2호
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• pp.63-68
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• 2014

Environmental heat stress by global warming has a severe effect on the productivity of livestock and, in particular, on that of dairy cattle. Heat stress during high temperature environment directly and indirectly affects milk yield, milk quality and physiological response. This study was conducted to investigate the effects of heat stress on productivity and physiological responses of livestock. Temperature-humidity data logger were established inside the feedlot for measuring real time changes in the feedlot environment. Milk was collected every day for analysing the productivity of dairy cattle. Blood sample and respiration of dairy cattle were collected once in a week for investigating the physiological response factors. Blood component concentration associated with lipolysis metabolism and milk production showed change during tropical night period. Temperature humidity index (THI) of a specific location inside the feedlot showed continuously high levels.

• 한국태양에너지학회 논문집
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• 제39권6호
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• pp.67-82
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• 2019

This study aims to examine the impacts of built environmental features on the nocturnal and diurnal temperatures during the heat wave season in Gwangju, Korea. Built environmental measures are summarized at micro-scale level, such as 50 meters and 100 meters from temperature monitoring spots. Regressing the built environment on nocturnal and diurnal temperatures, we estimate how the artificial constructs contribute to temperature either day and night times. We found that impervious surface ratio is positively and negatively associated with nocturnal and diurnal temperatures, respectively. Buildings and structures tend to construct high thermal mass and absorb heat during day time and emit it for the night time. This property contributes to the nocturnal temperature model. On the other hand, urban areas with more vertical structure tend to block sun radiation more than rural, and it is more likely to find the negative relationship between impervious surface ratio and the diurnal temperatures.

• KIEAE Journal
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• 제13권4호
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• pp.33-41
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• 2013

The impervious area on the surface of urban area has been increased as buildings and artificial land cover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural ecosystem. There arise the environmental problems to urban area including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate flood discharge and heat reduction effect according to the green roof system and to quantify effect by analyzing through simulation water and heat cycle before and after green roof system. For the analysis, Distributed hydrologic model, WEP (Water and Energy transfer Processes) and WEP+ model were used. WEP was developed by Dr. Jia, the Public Works Research Institute in Japan (Jia et al., 2005), which can simulate water and heat cycle of an urban area with complex land uses including calculation of spatial and temporal distributions of water and heat cycle components. The WEP+ is a visualization and analysis system for the WEP model developed by Korea Institute of Construction Technology (KICT).

• 건축사
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• 제3권8호통권8호
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• pp.17-22
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• 1968

Until now this article described the heat produced by the sun. Now we can learn about the heat given off by all matter. What is the essence of heat? How is the environment effected by heat? How can we best used heat in architecture?

• Journal of Radiation Protection and Research
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• 제28권4호
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• pp.281-290
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• 2003

The KN-12 spent nuclear fuel transport cask, which is a Type B(U) package designed to comply with the requirements of Korea Atomic Energy Act[1], IAEA Safety Standards Series No.TS-R-1[2] and US 10 CFR Part 71[3], is designed for carrying up to 12 PWR spent fuel assemblies in a basket structure. The cask has been licensed in accordance with Korea Atomic Energy Act and was fabricated in Korea in accordance with the requirements of ASME B&PV Sec.III, Div.3[4]. The cask must maintain thermal integrity in accordance with the related regulations and be evaluated to verify that the thermal performance of the cask complies with the regulatory requirements. The temperatures of the cask and components were determined by using finite elements methods with a numerical tool, safety tests using an 1/8 height slice model of the real cask were conducted to demonstrate verification of the numerical tool and methods, and heat transfer tests for normal transport conditions were performed as a fabrication acceptance test to demonstrate the heat transfer capability of the cask.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1190-1195
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• 2005

Biomass burning is a source of greenhouse gases, carbon dioxide, methane, and nitrous oxide. Under the ideal conditions of complete combustion, the burning of biomass produces carbon dioxide and water vapor. Since complete combustion is not achieved under any conditions of biomass burning, other carbon species, including carbon monoxide, methane, non-methane hydrocarbons and particulate carbon are produced. In this study, we analyze the combustion characteristics of rice-husk, such as heat release rate, smoke production rate, the percentage variation of CO and $CO_2$, oxygen consumption rate, and mass loss under different heat fluxes (20, 50 and 70kW). As a result, at 20kW incomplete combustion is occurred so that the percentage of CO is high in initial burning and total smoke release is higher than the others. At 50kW and 70kW, the combustion behaviors is very similar except the variation of CO percentage.

• Journal of Ceramic Processing Research
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• 제20권spc1호
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• pp.86-91
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• 2019

A solid-state route was used to prepare sodium titanium oxide (NTO, Na2Ti3O7) as a solar heat protecting material with an impressive solar reflectance (TSR = 94.3%) using a high refractive index rutile TiO2. The solar reflectance of the synthesized NTO was measured using UV-Vis-NIR spectrophotometer. Solar reflectance property of the synthesized compound depends on the calcination temperature. The solar reflectance property of the synthesized NTO powder was compared with commercial rutile TiO2. The compound synthesized at 900 ℃ for 24 hrs had remarkable solar reflectance 94.3% than that calcined below 900 ℃. Crystalline nature, structural property, morphology and optical properties of NTO powders were characterized and analyzed using XRD, FE-SEM, EDS and UV-Vis-NIR spectrophotometer. From the results, we guessed that NTO would be a suitable "solar heat protecting candidate" for energy-saving applications in coating industries.