• 한국환경복원기술학회지
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• 제19권2호
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• pp.55-69
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• 2016

Significant efforts are being devoted in mitigating the urban heat island effect, and extensive green roofs are an option for mitigation. The purpose of this study was to compare the surface temperature, vegetation types, and plant species on an extensive green roof. Test beds were created in May 2015, and the surface temperature was monitored from June to August. The test beds comprised polyculture and monoculture. Polyculture was divided into three types, and monoculture comprised eight plant species. An extensive green roof is effective in reducing temperature by forming a shade and preventing sunlight from falling on the surface of buildings, which mitigates the urban heat island effect. Consequently, the surface temperature of the green roof and that of concrete during summer reduced from $17.8^{\circ}C$ to $7.3^{\circ}C$. The temperature reduction was greater on using polyculture than on using monoculture, but monocultures of Sedum takesimense, Hemerocallis dumortieri, Allium senescens, Aster yomena, Belamcanda chinensis, and Aster koraiensis also produced good results. The temperature reduction effects of Polygonatum odoratum var. pluriflorum f. variegatum, Phlox subulata, and Thymus quinquecostatus var. japonica were excellent compared with those of concrete but were less than those of other plant species. Careful attention is needed for the management of extensive green roofs. Studies on the plant species and types of extensive green roof should continue to mitigate the urban heat island effect.

• Journal of Biosystems Engineering
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• 제11권1호
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• pp.52-63
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• 1986

This study was performed to find out drying characteristics and develop drying model for the design of an efficient dryer or drying system of red peper. The basic model which describes drying phenomenon of red pepper was firstly established, and drying tests were conducted at 14-different drying conditions. In this test, the effects of drying air temperature and relative humidity on the rate of drying were undertaken. Finally, a new drying model based on these experimental results was developed to describe the drying characteristics of red pepper. The results from this study may be summarized as follows. 1. Drying constant of the basic model established from Lewis' experimental model and diffusion equation was theoretically deduced as a function of moisture content and inner-temperature of red pepper. 2. From the results of drying tests, drying air temperature was found to have the greatest effect on the rate of drying. However, the effect of temperature was small for the condition of high relative humidity, and for low temperature, the effect of relative humidity was found to be large even though the range of relative humidity was low. 3. Modified Henderson equation was found to be better than Chung equation as the EMC model for the estimation of the equilibrium moisture content of red Pepper. 4. Constant-rate drying period did not exist in the red pepper drying test. And falling-rate drying period was divided into three distinct phases. Drying rate was dependent on the moisture content, the inner-temperature of red pepper and the change of physical property due to drying. 5. Drying constant increased with decrease of free moisture content, but it decreased at the end of the drying period. Also, drying constant was dependent on the drying air temperature and relative humidity. 6. The new drying model developed in this study was found to be most suitable in describing the drying characteristics of red pepper. Therefore, it may be concluded that drying time could be accurately estimated by the new drying model.

• 인간식물환경학회지
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• 제24권5호
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• pp.519-527
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• 2021

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.

• 한국수산과학회지
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• 제21권1호
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• pp.11-15
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• 1988

건제품으로 가공, 저장되고 있는 다시마는 조직이 연약하여 건조중 상당한 수축현상을 일으키는데 이의 기초적인 자료를 얻기 위하여 일정한 온도 $(50\%,\;10/^{\circ}C)$, 상대습도 $(30\%)$ 및 풍속 (0.4m/s)으로 열풍 건조를 행하여 가로와 세로의 길이변화, 표면적 수축변화 및 수축속도의 변화등에 관하여 조사한 결과를 요약하면 다음과 같다. 1) 가로수축이 세로수축보다 건조시간 90분까지 약2배 더 많이 수축하였다. 2) 다시마의 표면적 수축은 건조시간 90분까지는 직선적으로 나타났으며, 전건조과정에서 보인 2단계의 수축곡선은 건조속도곡선의 2단계와 잘 일치하였다. 3) 수축속도는 감률건조1단계에서 급속히 증가하여 감률건조2단계의 초기에 최대의 수축에 달하였다.

• 한국식품영양과학회지
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• 제11권1호
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• pp.37-43
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• 1982

말쥐치육(肉)의 건조속도(乾燥速度)는 열풍온도(熱風溫度)가 높을수록 열풍온도(熱風速度)가빠를수록 크다. 여러 가지 조건중(條件中) $70^{\circ}C$(상대습도 6%) 3m/sec에서는 재료(材料)가 과속건조(過速乾燥)로 인(因)하여 표면경화현상(表面硬化現象)이 현저하게 일어남을 관찰할 수 있었다. 온도가 낮고 풍속(風速)이 느린 경우는 평형함수율(平衡含水率)에 도달(到達)하는 건조시간(乾燥時間)이 길어져서 비능률적(非能率的)임을 알았다. 따라서 온도가 $60^{\circ}C$(상대습도 8%)이고 풍속(風速)이 3m/sec때는 표면경화현상(表面硬化現象)이 적은 상태에서 건조(乾燥)가 진행(進行)되어 평형함수율(平衡含水率)에 이르는 시간(時間)은 $70^{\circ}C$, 1m/sec때보다 2시간이나 빠르고 다른 조건(條件)보다는 월등히 짧고 함수율 20%(wet basis)에 이르는 시간은 1.5시간 정도(程度) 느리나, $70^{\circ}C$보다 유효(有效)라이신의 변화나 표면경화(表面硬化) 등(等) 품질변화(品質變化)가 적으므로 적절(適切)한 조건(條件)이라 할 수 있겠다. 또 식(式)에 의(依)하여 산출(算出)된 확산계수(擴散係數)로 계산한 건조(乾燥)시간과 실험(實驗)에서 나타난 건조시간(乾燥時間)이 일치(一致)됨을 알았다.

• 한국식품과학회지
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• 제18권1호
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• pp.61-65
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• 1986

홍옥(紅玉)을 시료(試料)로 하여 건조조건(乾燥條件)을 다르게하여 건조특성(乾燥特性), 수분이동현상(水分移動現像), 건조중(乾燥中) 시료온도(試料溫度) 및 내부수분(內部水分)의 분포(分布)를 조사하였다. 사과의 수분확산계수(水分擴散係數)는 $1.1470{\sim}2.2148{\times}10^{-5}cm^2/sec$, 확산활성화(擴散活性化)에너지는 6.6 kcal/g mole 이었으며 Fick's law에서 아래의 식을 유도할 수 있었다. $${\In}\;{\Delta}t=In\;{\Delta}to-{\frac{D{\pi}^2{\theta}}{4d^2}}$$ 건조중(乾燥中) 내부수분분포(內部水分分布)의 이론치(理論値)와 실측치(實測値)는 거의 일치하였다.

• 한국식품영양과학회지
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• 제21권1호
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• pp.64-69
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• 1992

Blanching 처리가 고추의 건조율 및 색도에 미치는 효과를 조사하고자 실험실 규모의 열풍 건조기를 제작하였으며 strain gage형의 load cell과 strain amplifier를 이용하여 건조 중의 중량을 연속적으로 기록, 측정하였다. 고추의 건조특성곡선은 대조군에서는 예비, 항율, 감율건조기간이 뚜렷한 반면, blanching 처리군은 감율건조기간만 존재하였으며, 시료의 건조율과 건조상수 값은 blanching 처리 온도와 시간에 비례하여 증가하는 경향이었고, $100^{\circ}C$, 3분 blanching 처리군이 가장 높게 나타났다. Capsanthin 함량 역시 대조군에 비해 처리군이blanching 처리온도와 시간에 비례하였으며 색도 값의 경우 $80^{\circ}C$, 3분 blanching군이 가장 우수하였다. blanching 처리는 전반적으로 고추의 건조율 증진 및 색도 보존에 효과적이며 $80^{\circ}C$, 3분 blanching 처리가 비교적 적합하였다.

• 한국환경복원기술학회지
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• 제14권2호
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• pp.47-57
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• 2011

This study monitored forest plant species vulnerable to climate change in Jiri Mountain, one of Korea's representative alpine regions, in order to securely preserve plant genetic resources susceptible to climate change and to utilize the results as basic data for bioclimatology prediction and management on a long-term basis. A majority of indicator plants tended to blossom one week to one month later in 2010 than in 2009. As with the blooming dates, the falling dates of blossoms became later in most species, with the exception for Weigela florida and Oplopanax elatus. Leaf bursting as well fell on later dates in a majority of species excluding Carpinus laxiflora and Cupressus sempervirens, displaying the most obvious differences among the data of analysis of the 2009-2010 physiological cycle changes. It is believed that was due to the fact that temperatures in February, March and April, which affect plants' blossoming and leaf bursting, were lower in 2010 than in 2009 and that cold temperatures in the winter lasted for a longer period in 2010 than in 2009. The dates of leaves being changed to red were similar in 2009 and 2010 by being or later or earlier by several weeks in 2010 than in 2009 without any regularity. Most species' leaves began to fall at similar dates in 2009 and 2010 or at later dates by one to two weeks in 2010 than in 2009. The temperature differences in late 2009 and late 2010 were not so large, resulting in similar dates of falling leaves, and gaps in several indicator plants' physiological cycles without any regularity can be attributed to each individual plant's physiological and environmental characteristics.

• Nuclear Engineering and Technology
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• 제48권6호
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• pp.1330-1337
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• 2016

A visualization test of the fuel-coolant interaction in the Test for Real cOrium Interaction with water (TROI) test facility was carried out. To experimentally simulate the In-Vessel corium Retention (IVR)- External Reactor Vessel Cooling (ERVC) conditions, prototypic corium was released directly into the coolant water without a free fall in a gas phase before making contact with the coolant. Corium (34.39 kg) consisting of uranium oxide and zirconium oxide with a weight ratio of 8:2 was superheated, and 22.54 kg of the 34.39 kg corium was passed through water contained in a transparent interaction vessel. An image of the corium jet behavior in the coolant was taken by a high-speed camera every millisecond. Thermocouple junctions installed in the vertical direction of the coolant were cut sequentially by the falling corium jet. It was clearly observed that the visualization image of the corium jet taken during the fuel-coolant interaction corresponded with the temperature variations in the direction of the falling melt. The corium penetrated through the coolant, and the jet leading edge velocity was 2.0 m/s. Debris smaller than 1 mm was 15% of the total weight of the debris collected after a fuel-coolant interaction test, and the mass median diameter was 2.9 mm.

• 한국식품과학회지
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• 제10권4호
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• pp.398-403
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• 1978

고체입자를 열매체로 유동화시킨 유동층내에서 오징어를 고정시켜 건조시킬 때 유동화입자, grid로 부터의 오징어 고정위치, 온도가 오징어의 건조속도와 품질에 미치는 영향을 검토하였으며 또한 감율건조기간중 수분의 이동 메카니즘을 추론하였다. 1) 유동화입자로는 식염이 가장 바람직했고 풍속 3.8 m/sec에서 최적 유동화상태를 얻었다. 2) 유동층내에서의 균일온도 분포는 grid로 부터 4 cm 이상거리에서 얻었으며 따라서 오징어의 고정위치는 이 거리 이상에서 바람직한 것으로 관찰되었다. 3) 풍속 3.8m/sec, grid로부터 4 cm 이상되는 오징어의 고정위치에서 건조속도에 대한 최적온도는 $35^{\circ}C$에서 얻었으며 이 조건에서 초기수분 80.8%로 부터 최종수분 $18{\sim}22%$까지 건조하는 데 소요되는 시간은 8.5시 간 이었다. 4) 건조자료는 측정된 수분함량범위에서 비정상상태의 확산방정식 $ln{\frac{(W-We}{(Wc-We)}=-m{\theta}$의 경험식에 따랐으며 m의 값은 $0.32hr^{-1}$로 계산되었다. 또 이들 결과는 감율 건조기간중 수분의 이동이 액체확산에 의한 것임을 시사했다. 5) 오징어의 건조는 초기 짧은 시간 동안만 항율건조되고 그 이후는 감율건조에 의해 지배되는 것으로 나타났으며 동일온도에서 동일잔존수분까지 건조시키는 데 소요되는 유동층건조에 대한 통기 열풍건조의 건조시간비율은 1 : 1.4였다. 6) 유동충건조된 오징어 제품은 시판 천일건조 오징어 제품과 비교하여 품질상 유의차가 없었다.