• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.157-164
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• 2023

Codonopsis lanceolata (S. et Z.) Trautv. is mainly cultivated in Korea and China as a medicinal crop. C. lanceolata is difficult to produce plug seedlings in the summer, because C. lanceolata has a low germination rate and is vulnerable to high temperatures. Cold treatment is effective in breaking dormancy of seeds and increasing the germination rate. Shading cultivation can control the solar irradiance received by plants and reduce the damage by high temperatures and strong light. This study was conducted to examine the appropriate cold treatment period for the improving germination of C. lanceolata, and shading level during the summer seedling period. Cold treatment experiments were conducted for 0 (control), 1, 2, 3, and 4 weeks at 4℃ before sowing. In the shading experiment, C. lanceolata was grown for 45 days with 0 (non-treatment), 45, 75% shading levels. Cold treatment for one week significantly improved the germination energy. The plant height, leaf area, and fresh and dry weights of C. lanceolata seedlings were significantly increased under the 45% shading level. Total root length, root surface area, and the number of root tips were significantly higher in shading treatment (45 and 75%) than in non-treatment. The C. lanceolata seedling's compactness and Dickson's quality index were the highest at 45% shading level. Therefore, these results recommended sowing C. lanceolata after cold treatment for one week at 4℃, and 45% shading level could stably culture C. lanceolata plug seedlings during the high temperature period.

• Environmental engineer
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• s.181
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• pp.70-75
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• 2001

본 연구는 '99년 7월에 벤처형 중소기업 기술개발 지원사업으로 신규 계약된 과제로서 상수원수의 전처리 및 하수 2차 침전수의 재처리 공정에 활용될 생물 산화 여과지를 개발하는 것이다. 생물 산화 여과 system은 상수 원수의 전처리, 상수도의 고도정수 처리, 하수 및 폐수처리에 이용될 수 있는 것으로, 특히 물리적 여과기능과 포기 과정을 통한 산화 기능을 포함하는 생물학적 분해 및 자연정화처리환경을 유지하여 수질이 악화된 상수도의 전·후처리나 하.폐수의 3차 처리에 적용하기 위한 것이다. 생물 산화 여과 시스템은 여과지의 하부 장치에 균등한 공기(산소)공급시설을 하여 여과층에 연속적으로 공기를 공급하면서 여과를 함으로서 생물막 여과 및 산화 기능으로 유기물질, 철, 망간 등을 제거하고 공기의 부상력에 의하여 조류, 부유물질, 냄새 등을 동시에 제거하는 System이다. 현재 상수처리 공정으로서의 생물 산화 여과지 개발을 위해 Bench-scale과 semi-pilot plant를 거쳐 Y시 M취수장애 pilot plant를 설치하여 연구를 진행중에 있으며, 또한, G시 G하수처리장에 하수처리 공정에 관한 연구를 위해 pilot plant를 설치하고 하수 3차 처리와 저농도 하·폐수 처리를 중심으로 연구중에 있다. 아래의 연구 결과는 정수처리 공정 연구를 위한 Bench-scale plant실험을 통해 얻은 결과치이며 현재까지 진행된 연구는 주로 정수처리 공정 중심으로 이루어 졌으나 pilot plant에서는 정수 및 하수처리에서의 생물산화여과공정의 연구가 진행중이다. 현재 연구가 진행중이므로 각 인자별 최적운전조건 등은 계속적인 실험과 연구를 통해 찾아지겠으나 현재까지 수행된 연구자료를 기반으로 볼 때 생물산화 여과장치는 탁도, SS, VSS 등의 제거에 탁월한 효능을 보이고 있다. 수처리용 장치로서의 이러한 기본적인 기능 이외에 NPOC, DOC 제거에도 뛰어난 효능을 보이고 있으며 특히 정수처리 공정에서 문제시 되고 있는 동절기 암모니아성 질소제거 또한 큰 가능성을 보여주고 있다. 그 동안 외국기술에 전면 의존해 오던 생물 산화 여과방식의 국내개발은 비용 절감뿐만 아니라 국내 실정에 맞는 기술개발이라는 점에서 향후 그 적용 범위를 넓혀 갈 수 있을 것이다.

• Journal of Animal Environmental Science
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• v.9 no.2
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• pp.103-112
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• 2003

In this study, the distributions of internal climates such as air temperature, humidity, dust, ammonia gas, and air velocity were systematically measured at a mechanically ventilated broiler houses during summer season, with local weather data. The analysis was focused on the suitability, stability, and uniformity of internal climate, resulting in serious stress on chickens and decrease of productivity In the mechanically ventilated broiler house, the difference between measured and recommended air temperatures(suitability) was 10.4C in maximum during the summer time. The difference of air temperature in the house between day and night was $8.7^{\circ}C$ in maximum. And maximal hourly range of internal air temperature at 0.4m height from the floor was $3.7^{\circ}C$ suggesting it maintained thermal uniformity in the broiler house. The $NH_3$ and dust concentrations were pretty low because ventilation was fully performed. The air speed at chicken location was measured 2.2m/s and 1.7m/s, respectively without and with chicken existence.

• Journal of Animal Environmental Science
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• v.9 no.1
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• pp.9-18
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• 2003

Most of broiler houses in Korea have the trouble of environmental control such as suitability, stability, and uniformity of internal climate, resulting in serious stress on chickens. Accordingly, it is very urgent to develop optimum designs of naturally and mechanically ventilated broiler houses for Korean climate. In this study, the internal climates such as air temperature, humidity, dust, ammonia gas, and air velocity were measured at a naturally ventilated broiler house. The data were collected during summer season including local weather data. It was found that the difference between measured and optimum air temperatures was $14.0^{\circ}C$ in maximum during the summer time. The daily maximum range of internal averaged air temperature was found $10.5^{\circ}C$ while the uniformity was $5.2^{\circ}C$ in maximum. The maximum, average, and minimum internal averaged relative humidity were 89.3%, 73.7%, and 49.2%, respectively while locally measured were 95.1% and 47.2%, respectively in maximum and minimum. Considering Temperature-humidity index, during summer season, over 97% of totally rearing period was shown that counter plan is needed for thermal stress while it was very dangerous situation for 22% of the rearing period. The ammonia gas and dust concentrations were seriously affected by the broilers activity, growth level, and relative humidity.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.54-62
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• 2005

The present study was to determine how seasonal rainfall intensity influences nutrient dynamics, ionic contents, oxygen demands, and suspended solids in a lotic ecosystem. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of rainfall. Dissolved oxygen (DO) had an inverse function of water temperature (r = = = - 0.986, p<0.001). Minimum pH values of<6.5 were observed in the late August when rainfall peaked in the study site, indicating an ionic dilution of stream water by precipitation. Electrical conductivity (EC) was greater during summer than any other seasons, so the overall conductivity values had direct correlation (r = 0.527, p<0.01) with precipitation. Ionic dilution, however, was evident 4 ${\sim}$ 5 days later in short or 1 ${\sim}$ 2 weeks in long after the intense rain, indicating a time-lag phenomenon of conductivity. Daily COD values varied from 0.8 mg $L^{-1}$ to 7.9 mg $L^{-1}$ and their seasonal pattern was similar (r = 0.548, p<0.001) to that of BOD. Total nitrogen (TN) varied little compared to total phosphorus (TP) and was minimum in the base flow of March. In contrast, major input of TP occurred during the period of summer monsoon and this pattern was similar to suspended solids, implying that TP is closely associated (r = 0.890, p<0.01) with suspended inorganic solids. Mass ratios of TN : TP were determined by TP (r= -0.509, p<0.01) rather than TN (r= -0.209, p<0.01). The N : P ratios indicated that phosphorus was a potential primary limiting nutrient for the stream productivity. Overall data suggest that rainfall intensity was considered as a primary key component regulating water chemistry in the stream and maximum variation in water quality was attributed to the largest runoff spate during the summer monsoon.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.488-491
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• 2006

There is a principle of Korean Traditional Housing to be adapted for the nature using adaptable shapes to regional climate and easily available materials from the region then these environmentally friendly characteristics keep indoor environment from climate changes. These environmentally friendly characteristics to control indoor environment are very available for contemporary housing in that current issues, housing amenity and wellbeing, have basic goals same with what Korean Traditional Housing has. Therefore, this study begins to suggest fundamental data on indoor thermal environment control elements of Korean Traditional Housing to adapt those into contemporary housing through measurement of indoor thermal environment elements and evaluation on thermal sensation vote for Korean traditional housing. There was 24 hours measurement for indoor and outdoor thermal environmental elements to figure out competence to control indoor thermal environment of Korean Traditional Housing in summer. And subjective tests with 11 subjects was held in the morning, afternoon and night at intervals of 3${\sim}$4 hours to evaluate feeling and amenity for temperature and humidity of users.

• KIEAE Journal
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• v.10 no.4
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• pp.59-66
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• 2010

Natural ventilation is major strategy of 'sustainable building'. It aims to supply fresh air to the indoor, and to remove heat from the indoor during summer. In the latter point of view, natural ventilation can be grouped into two main strategies, daytime ventilation and night cooing. If we take advantage of these two natural ventilation strategies, indoor thermal comfort can be significantly improved. This study focused on grasping the current situation and problem of indoor thermal comfort of the naturally ventilated residential buildings to seek for direction of later studies. Additionally, thermal comfort of residence where the interior blind and exterior insulation were applied was analyzed. It was analyzed that the percentage of the time which satisfy the indoor acceptable operative temperature during summer was 90 ~ 95% and the heat control performance of natural ventilation has a limitation. When the interior blind and exterior insulation were applied, indoor thermal comfort was significantly improved. However, it still need more improvement.

• KIEAE Journal
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• v.16 no.6
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• pp.115-122
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• 2016

Purpose: The study is to measure indoor air pollutants concentration of existing housing and to analyze the causes and assess in accordance with the government's criteria. The research result could be used as data for public health through indoor air quality management of existing housing and more as a reference for new housing. Method: It was investigated 24 middle class housings of metropolitan area in summer which have been built for the past 30 years. Concentration of HCHO, TVOC was investigated in living room at morning and night and concentration of $CO_2$ was investigated in living room and master bedroom at morning and night. SKT100-X5 was used for concentration of HCHO, TVOC and ZGm053UK for concentration of $CO_2$. Result: Average concentration of TVOC was 1.31 times more than that of HCHO and standard deviation of that was 1.73 times higher. Average concentration of $CO_2$ was almost nearly close to 1,000ppm being criteria of the Ministry of Environment.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.111-122
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• 2014

The purpose of this study is to understand daily variation of short-wave radiation trends according to the state of surface and observation of atmosphere conditions in downtown and suburban observation area. The followings are main results from this study. 1) We found out daily air temperature variation of downtown is less than that of suburban area because of bigger heat capacity of artificial elements such as massive buildings and pavements. 2) It is more effective to estimate of air condition by water vapor pressure than relative humidity in the atmosphere. 3) The difference of solar radiation ratio between downtown and suburban area is dependant on different atmosphere conditions at two observation stations.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.105-116
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• 2014

The objective of this study was to compare and analyze of radiation environment between downtown and suburban area by observation of short, diffuse and long-wave radiation during summer season. The followings are main results from this study. 1) The trends of long-wave radiation is increasing from May to August and the variation of daily range is decreased. It is confirmed that the temperature was closely relevant to long wave radiation. 2) During observation period, suburban area is higher than downtown the value of direct solar radiation. 3) There are much direct solar radiation in suburban area than downtown. But, it was measured much more horizontal solar radiation at the downtown area. From the this result, we can conclude that diffuse radiation play a important role at horizontal solar radiation.