Black carbon (BC), which is mainly contained in fine particulate matters, is one of the typical anthropogenic air pollutants that are generated from the incomplete combustion process and discharged into the atmosphere, and its various health effects particularly on children have been a growing concern. In this study, BC and particulate matters were closely analyzed in an elementary school adjacent to a high- traffic road in a large metropolitan city. The investigation showed that black carbon behaved similarly to ultrafine dust of 0.3 μm or less in the air, accounting for 20%-40% of it. The occurrence of high concentration outdoor pollution influences the BC content in indoor particulate matters. The average I/O value was 0.7 during the class-hours, and 0.8 without students. However, when students played in the classroom, the range of BC concentrations varied from 0.25 to 1.15, wider than 0.41-1.13 without students. Although this study was conducted with regard to just one elementary school, it can be considered to represent the typical air quality status of domestic schools, and it is believed to present valuable data which can be utilized to assist with preparing measures to enhance the air quality management of schools.

N-nitrosodimethylamine (NDMA) is a potent carcinogen that is frequently detected nitrosamine from water chloramination. This study investigated the occurrence of NDMA and its potential precursor, ranitidine (RNT), in four wastewater treatment plants (WWTPs). Additionally, the effects of chloramination methods and oxidative pretreatment on the NDMA formation potential (FP) were assessed. Concentration levels of NDMA in the WWTPs waters ranged from 2.5 (detection limit) to 72.6 ng/L, while RNT values ranged from 1.32 to 186.9 ng/L. Further study indicated that the NDMA-FPs from chloraminated wastewaters varied between 36.2 and 227.8 ng/L. Nonetheless, chloramination methods and oxidative pretreatment significantly impacted the NDMA-FP levels. For example, breakpoint chlorination and stepwise chloramination promoted NDMA-FP when compared to preformed chloramination, which could be attributed to the formation of dichloramine and chlorine species. In contrast, prechlorination was found to effectively mitigate NDMA-FP, based on integrated ultraviolet (UV) irradiation. Notably, UV irradiation with free chlorine (UV/Cl2) or permanganate (UV/MnO4 -) reduced NDMA-FP by up to 70%. This study suggests that UV/MnO4 - and UV/Cl2 may be used as alternative mitigation strategies for reducing nitrosamine-FP in the water treatment process.

Recently, home workout has attracted attention as it can be done easily and conveniently at home. Accordingly, many types of home workout equipment are produced but, these kinds of exercise equipment using dumbbells or weights are too heavy to use for at-home-workout and they are too bulky in size. This paper studies a form of exercise done at home which is using a motor instead of dumbbells and weights that are originally used in the exercise equipment. DAFUL, a multi-body dynamics analysis program, is used to verify the dynamic performance of the proposed equipment. Therefore, motor-based exercise equipment is expected to be smaller than existing exercise equipment and more suitable for use at home.

The results of internal temperature. productivity and immunity analysis of the laying hen house by the thermal environment and the supply of cold drinking water were as follows. The external temperature was changed from the minimum of 18℃ at night and the maximum of 36℃ during the day, and the internal temperature of the laying hens varied from 20~31℃. Thermal imaging analysis showed that the body temperature of the laying hen decreased by 2.4℃ with the supply of drinking water. The laying hen amount increased 2.36g and laying hen rate increased 3.62%p. Albumin increased 6.1%, decreased AST 15%, and decreased cholesterol 12.7%. Immune activators increased and T cells and B cells increased to increase immunity.

With the recent accelerated policy-making and interests in new renewable energy, plans to develop and supply the new renewable energy have been devised across multiple regions in Korea. Solar energy, in particular, is being applied to small-scale power supply in provincial areas, as solar cells are used to convert solar energy into electric energy to produce electric power. Nonetheless, in the case of solar power plants, the need for a large stretch of land and considerable sum of financial support implies that the planning step should take into consideration the most suitable meteorological and geographical factors. In this study, the proxy variables of meteorological and geographical factors associated with solar energy were considered in analyzing the vulnerable areas regarding the photovoltaic power generation facility across the nation. GIS was used in the spatial analysis to develop a map for assessing the optimal location for photovoltaic power generation facility. The final vulnerability map developed in this study did not reveal any areas that exhibit vulnerability level 5 (very high) or 1 (very low). Jeollanam-do showed the largest value of vulnerability level 4 (high), while a large value of vulnerability level 3 (moderate) was shown by several administrative districts including Gwangju metropolitan city, Jeollabuk-do, Chungcheongbuk-do, and Gangwon- do. A value of vulnerability level 2 (low) was shown by the metropolitan cities including Daegu, Ulsan, and Incheon. When the 30 currently operating solar power plants were compared and reviewed, most were found to be in an area of vulnerability level 2 or 3, indicating that the locations were relatively suitable for solar energy. However, the limited data quantity for solar power plants, which is the limitation of this study, prevents the accuracy of the findings to be clearly established. Nevertheless, the significance of this study lies in that an attempt has been made to assess the vulnerability map for photovoltaic power generation facility targeting various regions across the nation, through the use of the GIS-based spatial analysis technique that takes into account the diverse meteorological and geographical factors. Furthermore, by presenting the data obtained for all regions across the nation, the findings of this study are likely to prove useful as the basic data in fields related to the photovoltaic power generation.

Experiments of local cooling and heating on crown and root zone of forcing cultivation of strawberry ‘Seolhyang’ using heat pump and root pruning before planting were conducted. During the daytime, the crown surface temperature of the crown local cooling treatment was maintained at 18 ~ 22oC. This is suitable for flower differentiation, while those of control and root zone local cooling treatment were above 30oC. Budding rate of first flower clusters and initial yields were in the order of crown local cooling, root zone local cooling and control in root pruning plantlet and non pruning plantlet, except for purchase plantlet. Those of root pruning plantlet were higher than those of non pruning plantlet. These trends were evident in the yield of the first flower cluster until February 14, 2018, and the effect of local cooling and root pruning decreased from March 9, 2018. The budding rates of the second flower cluster according to the local cooling and root pruning treatments were not noticeable compared to first flower cluster but showed the same tendency as that of first flower cluster. In the heating experiment, root zone local heating(root zone 20oC+inside greenhouse 5oC) and crown local heating(crown 20oC+inside greenhouse 5oC) saved 59% and 65% of heating fuel, respectively, compared to control(inside greenhouse 9oC). Considering the electric power consumption according to the heat pump operation, the heating costs were reduced by 55% and 61%, respectively.

The drinking water supply system applicable to the laying hen consists of air-water heat pumps, drinking water tanks, heat stroage tank, circulation pumps, PE pipes, nipples, and control panels. When the heat pump system has power of 7.7 to 8.7 kW per hour, the performance coefficient is between 3.1 and 3.5. The supply temperature from the heat pump to the heat stroage tank was stabilized at about 12±1°C, but the return temperature showed a variation of from 8 to 14°C. Stratified temperature in the storage tank appeared at 12.°C, 13.5°C and 14.4°C, respectively. The drinking water supply temperature remained set at 15°C and 25°C, and the conventional tap water showed a variation for 23°C to 30°C. As chickens grow older, the amount of food intake and drinking water increased. y = -0.0563x2 + 4.7383x + 8.743, R2 = 0.98 and the feed intake showed y = -0.1013x2 + 8.5611x. In the future, further studies will need to figure out the cooling effect on heat stress of livestock.

In order to effectively utilize thermal energy, we analyzed the performance of the high efficiency latent heat storage system which can be used for greenhouse heating by using the developed phase change material. The system consists of hot water boiler, heat storage material, heat storage box, heat storage tank, circulation pump, control panel, and storage material. As a result, the latent heat and latent heat temperature of sodium acetate hydrate as latent heat storage material are 231.6 ~ 264.8kJ/kg, 54.95 ~ 55.48℃. As the number of cooling and heating increased, the latent heat temperature showed a slight change, but the latent heat decreased 33.1kJ/kg as the number of repetition increased. In the case of sodium acetate hydrate, large supercooling phenomenon was observed, and it was found that mixing of additives such as nucleating agent, thickener and supercooling agent can control the supercooling more effectively. The consumption of kerosene decreased until the temperature of the heat storage tank was raised to the set temperature by the closed circuit for 4 hours in the initial stage of the boiler operation. The heat exchange rate according to the change of the flow rate was maintained at the set temperature inside the heat storage tank after 4 hours of operation, Consumption was high. As the flow rate increased, the inlet and outlet temperature difference decreased, the heat exchange rate increased, and the heat exchange efficiency was in the range of 57.4 ~ 60.5%.

본 연구에서는 풍환경에 따른 열손실을 분석하는데 있어 필요한 풍속 기초자료를 제공하기 위하여 주요 11개 해안지역 중 온실밀집지역을 선정하여 기상환경 및 온실 방위를 조사 분석하였다. 대상지역은 난방온실 재배면적과 풍환경 기준으로 선정하였고 온실밀집지역은 50,000m2 이상인 지역을 대상으로 하였다. 11곳의 기상자료 중 기온,풍속, 풍향을 대상으로 30년간 자료를 수집하여 분석하였고 기온은 최저, 평균, 최고 기온을 나누고 풍속 및 풍향 기준은 기상청 분석 기준을 적용하였다. 온실의 배치방향은 형태가 대칭인 점을 감안하여 0~180o 범위로 자료를 수집하였다. 또한, 각 지역마다 풍향이 있으며 온실길이방향을 기준으로 하였을 때 적용되는 풍향은 달라질 수 있으며 이를 상대풍향으로 지칭하고 중복되는 점을 고려하여 0~90o 범위로 자료를 수집하였다. 11개 지역의 기온은 중부지방에 있는 보령, 영광 지역과 남부지방에 있는 9개 지역의 기온차이가 구분되었다. 중부해안 대상지역은 1월 최저기온은 약 3~4oC 정도 온 도가 높은 것을 확인할 수 있었고 평균기온은 약 3oC 정도 높았으며 월별 기온 중 최저기온을 선정할 때에 1 월 기온을 고려해야 되는 것으로 판단된다. 대상지역의 주풍향에 대한 월별 차이는 크게 발생하지 않았으며 풍향 분포에 따라 지역별로 서해안측, 서해 및 남해 경계 해안측, 남해안측으로 구분되어졌다. 풍속은 영광을 제외 한 10개 지역은 월간 풍속 포차이가 크게 발생하지 않는 것으로 판단된다. 대상지역의 온실의 방향은 길이방향 기준으로 분석하였으며 보령과 영광, 남해 지역은 60%이상 집중되어 있는 방향이 존재하였고 해남, 통영 지역은 약 90% 집중되어있는 방향이 존재하였으며 이는 경지정리로 인하여 방향이 편향되어있는 지역이 존재하는 것으로 판단된다.

쓰레기 소각장이나 산업체의 폐열을 농업에 활용한 사례는 몇몇 있었다. 그러나 온배수를 농업에 활용한 사례는 전무하였으며, 치어, 종패 등을 양식하는 수산업이 대부분이었다. 본 연구에서는 화력발전소의 온배수(폐열)를 열원으로 이용하는 120 RT 규모의 냉난방시스템을 제주특별자치도 서귀포시 안덕면 소재의 5,280m2 아열대 작물(망고) 재배 온실에 설치, 10월에서 다음해 2월까지 약 5개월 동안 난방을 실시하여 난방에너지 비용 절감 효과 등 분석하였다. 난방에너지 비용 절감효과는 면세경유에 대하여 87%이였으며, 또한 발전소의 온배수를 에너지원으로 재활용함으로 서 62%의 이산화탄소 배출 저감 효과를 얻었다. 본 연구를 계기로 2015년에 해수가 수열에너지 분야로 재생에너지에 포함되었다. 해수의 표층의 열을 히트펌프를 사용하여 변환시켜 얻은 에너지라는 수열에너지 분야의 기준과 범위를 볼 때, 이는 온배수가 재생에너지에 포함되었다고 말해도 과언이 아닐 것으로 사료된다. 그 이유는 온배수도 해수임에도 불구하고 온도가 일반 해수 보다 7~8oC 높아, 일반 해수를 히트펌프의 열원으로 이용하는 것보다 온배수를 열원으로 이용했을 때 히트펌프의 성능이 높기 때문이다. 또한 같은 해 농식품부의 폐열 재이용 시설 지원 사업이 발표되어, 발전소 온배수뿐만 아니라 산업체와 소각장의 폐열을 농업에 활용하면 지원을 받을 수 있게 되었다. 이 사업에 의하여 2015년 당진시, 하동군, 제주시, 곡성군이 선정되었으며, 2016년 태안군, 서귀포시 등이 선정되어, 2016년 말 곡성군과 제주시가 공사를 완료, 농업에 폐열을 활용하고 있으며(제주시는 발전소, 곡성군은 산업체 폐열을 이용하고 있음), 기타 지역은 추진 중이다.

This study aims at providing a basic data for the development of high energy efficient environment system in the cage (poultry buildings) and cold potable water supply to reduce the summer heat stress. For this study, the cage area size was 273m 2 and the air-to-water heat pump capacity was 20RT for heating and cooling. As the result of this study, the temperature of the drinking water supplied by heat pump was maintained at the set temperature of 15℃. However, the water temperature of control was 23~28 ℃ due to the effect of outside temperature. The average internal cage temperature was 25.3 ℃ in the test group and 28.1 ℃ in the control group, which was 2.8 ℃ higher than that of the control group. The relative humidity was 76.2% in the test group and 75.0% in the control group. The broiler drank 23.2 L / day in the test group and 21.5 L / day in the control group. Daily feed intake was 937 g and and 725 g in the cold water and control water respectively. The feed intake of 212 g was higher than that of cold water. The feeding rates were 1.8 and 1.9. Body weights were 1,523 g and 1,164 g in the cold water and control water respectively. The weight gain was 359 g in the test group fed with cold water and 392 g in the control group. When compared with the control group, the mortality rate was reduced by 84% in the cold water feeding test. It is necessary that future research will continue to reduce the incidence of such livestock accidents.’.

탄산칼슘은 칼슘 보충제 및 식품 첨가물 등으로 식품산업에 널리 활용되고 있다. 산업 또는 환경 폐기물인 조개나 굴 껍데기인 개각과 산호 등은 천연 탄산칼슘 소재이므로 이를 식품, 의약 제품 등의 상품을 개발하는 것은 부가가치가 높은 산업적으로 의미가 큰 연구다. 하지만, 탄산칼슘은 물에 대한 낮은 용해도로 인해 생체 흡수성이 떨어지는 것이 문제점으로 알려져 있다. 따라서, 본 연구에서는 소성 가공한 후, 구연산을 첨가하여 용해도를 향상시킨 식용 가능한 패각 유래 칼슘 보충제를 개발하고자 하였다. 굴패각 유래 가공 시료로는 구리 패각을 미분 가공 후 550~1000°C에서 산화 소성을 거쳐 마그네슘을 첨가 후 400~1000°C에서 환원 소성한 시료(CS1, CaO 30%)와 이에 구연산을 첨가한 시료 (CS2) 두 가지를 준비하였고, 이들의 물리화학적 특성을 나노 레벨의 섬유상 탄산칼슘(CS3, CaO 40%)과 시중에 판매되고 있는 산호 유래 시판 칼슘 보조제인 코랄 칼슘(CS4)과 비교 분석하였다. 용해도 측정은 시료를 20°C에서 증류수 50 mL에 시료 0.1 g을 넣고 흔들어 방치한 후, 2.5 μm paper filter로 필터링 한 시료 10 mL과 증류수 10 mL의 무게 차이로 측정하였으며, 이를 100°C에서 12시간 동안 건조 후 측량한 시료의 무게로 확인하였다. 준비된 시료 중 CS3의 용해도(0.72 mg/g)가 가장 높았고 CS2 (0.42 mg/g), CS1 (0.5 mg/g), CS4 (0.06 mg/g)의 순으로 물에 잘 용해되지 않았다. 수산화칼슘이나 산화칼슘이 물에 용해되면 강염기를 나타내는 것으로 알려져 있는데, 관찰된 시료별 용해도의 차이가 pH에 영향이 있는지 확인하기 위해 용해된 용액의 pH를 측정하였다. 그 결과 CS1(12.5) CS2(12.4) CS3(9.5) CS4(8.8)의 순으로 높은 pH를 나타내어 용해도 차이로 인해 pH의 차이가 나타남을 알 수 있었다. 수산화칼슘의 경우, 수용액상 강염기를 나타내기 때문에 항균 능력이 있는 것으로 알려져 있으므로 용해도에 따라 그 항균력의 차이가 나타날 것으로 생각되어 시료별 항균성 실험을 진행하였다. LB 배지에 액체배양한 대장 균을 20 μm분주하여 도말해주고 그 위에 다시 각각의 시료를 분주하여 도말해서 48시간 배양한 결과 CS1, CS3에서는 항균성이 나타났지만 CS2, CS4에서는 항균성이 나타나지 않았다. 이와 같은 현상이 산화칼슘이 용해되어 수산화칼슘이나 탄산칼슘으로 변화되고, 또 결정의 구조 변화에 기인한 것인지 알아보기 위해 XRD를 이용하여 그 구조를 분석하였다. 그 결과, CS1, CS2는 CaCO3-Rhombohedral, CaO Lime-Cubic, 그리고 Ca(OH)2-Hexagonal 세 가지로 구성되어 있고 수산화칼슘의 비중이 CS2 보다 CS1에서 더 높았다. CS3는 CaCO3-Rhombohedral과 Ca(OH)2-Hexagonal 두 가지로 구성되었으며 대부분이 탄산칼슘으로 되어있다. CS4는 CaCO3-Rhombohedral의 단일 성분으로 구성되었다.

Graphene has shown exceptional properties for high performance devices due to its high carrier mobility. Of particular interest is the potential use of graphene nanoribbons as field-effect transistors. Herein, we introduce a facile approach to the fabrication of graphene nanoribbon (GNR) arrays with ~200 nm width using nanoimprint lithography (NIL), which is a simple and robust method for patterning with high fidelity over a large area. To realize a 2D material-based device, we integrated the graphene nanoribbon arrays in field effect transistors (GNR-FETs) using conventional lithography and metallization on highly-doped Si/SiO2 substrate. Consequently, we observed an enhancement of the performance of the GNRtransistors compared to that of the micro-ribbon graphene transistors. Besides this, using a transfer printing process on a flexible polymeric substrate, we demonstrated graphene-silicon junction structures that use CVD grown graphene as flexible electrodes for Si based transistors.