This study was conducted to investigate the potential of infrared assisted air drying (IRAD) to dry dorumuk (Arctoscopus japonicus). The IRAD system is composed of a far infrared lamp, convection fan, data loggable electronic balance, and proportional-integral-differential temperature controller. The infrared lamp provided radiative energy for temperature increase and substance moisture vaporization. The convection fan removed the moisture outside the drying chamber. Various IRAD conditions were tested at 40oC & 5 m/s, 40oC &11 m/s, 50oC & 5 m/s, 50oC & 11 m/ s, 60oC & 5 m/s, or 60oC & 11 m/s. The IRAD of 40oC & 5 m/s could reduce the moisture content by 42.2 %. The IRAD of 60oC and 11 m/s could further reduce the moisture content to 16.7% within 17 h. During the IRAD test, electrical energy consumption ranged from 1.16 to 1.38 kWh which is lower than that of hot air drying. IRAD resulted in dried dorumuk with yellow color and crispy texture. In this study, IRAD showed potential for the production of high-quality, dried dorumuk products.

The most important role of air defense system is to attack the air target of enemy to defend the important military unit or facilities. In order to attack the target as soon as it is detected, fast and precise fire signal transfer using the fire control stick is very important. However, it was found that firing is not conducted in the test for fire control stick. In order to find the reason of such problem and improve life cycle of fire control stick, the test was conducted and it was found that chattering occurred and this led to malfunction of signal transfer from control stick to fire control unit of air defense system. In order to draw resolution for this problem, two contact plate made of beryllium copper is suggested to add to the control stick to enhance the contact and reduce chattering effect. The four fire switch prototypes were tested for 100,000 times and it showed its reliability of use.

In case vehicle system has low travel distance and short duration of engine operation, this can be relatively susceptible to engine scuffing related problem. Users also experience inconvenience in system maintenance that they have to manually start engine periodically in cold night during winter. In order to solve such problems and improve system's life cycle, the automatic engine start system is developed. In order to develop the automatic engine start sytem for air defense system BIHO, two types of engine start sytem and the engine sub system are studied and four steps to start and control the automatic engine start system is suggested. The prototype of automatic engine start system was tested for the single assembly and vehicle-installed test and all requirement of the system was madeto prove its possible application.

최근 지구의 기후변화는 온실가스가 원인으로 전 세계적 대기환경문제로 크게 부각되고 있다. 국내에서도 기후변화에 적극 대응하기 위한 기술개발이 꾸준히 진행되고 있다. 날씨의 이상고온으로 인한 환경에 미치는 영향과 갑작스런 집중호우가 환경에 미치는 영향을 대상으로 하였다. 우리생활 주변 대기온도가 상승하였을 때 온도변화에 의한 대기오염발생에 미치는 영향을 연구하고자 한다. 본 연구의 실험조건은 선박 디젤기관에서 회전수 1400 rpm, 1600 rpm 그리고 1800 rpm, 부하는 0 %에서 25 %씩 100 %까지 하였고, 흡기 온도변화 는 20℃에서 50℃까지 구분하여 연구하였다. 연구한 결과 흡기온도가 증가함에 따라 일산화탄소 및 탄화수소는 약간 감소하였으나 연료 소비율, 질소산화물, PM은 약간 증가하였다. 또한 연소온도는 큰 변화가 없었다.

도심 산지형 공원 내 식생유형별 요인이 공기이온에 미치는 영향력을 파악하고자 충주시 탄금대 공원을 대상으로 수행하였다. 측정지점은 능선부 내 수종, 흉고직경, 울폐도, 층위구조에 따라 설정하였으며, 기상요소와 공기이온을 측정하였다. 공기이온 측정결과, 양이온 발생량은 평균 610.90±50.27ea/㎤, 음이온 발생량은 평균 723.58±64.25ea/㎤, 이온지수는 1.19±0.10 이였다. 식생유형에 따른 분석결과는 다음과 같다. 첫째, 공기이온은 수종, 흉고직경, 층위구조에 따라 차이가 발생하였으며, 통계적으로 유의한 것으로 분석되었다. 둘째, 이온지수와 식생유형과의 관계에서 수종, 흉고직경, 울폐도, 층위구조 모두에서 정의 상관관계로 분석되었으며, 양이온의 경우 수종, 흉고직경, 울폐도와 부의 상관관계, 음이온의 경우 수종, 흉고직경, 울폐도, 층위구조에서 정의 상관관계로 분석되었다. 셋째, 능선부 내 이온지수의 영향요인은 기상요인과 식생유형을 비교한 결과 식생유형의 상관계수가 더 높았으며, 세부적으로는 수종 > 층위구조 > 울폐도 > 흉고직경의 순이었다. 본 연구에서는 능선부를 대상으로 공기이온을 평가한 한계점이 존재한다. 이에 향후 공기이온에 대한 연구에서 지형구조, 식생유형을 모두 고려한 분석이 이루어져야할 것이며, 계절에 따른 변화·비교연구가 필요할 것으로 판단되었다.

This research proposes an optimal flushing operation technique in an effort to prevent secondary water pollutions and accidents in aged pipes, and to improve the cleaning effect of unidirectional flushing. Water flow directions were analyzed using EPANET 2.0, while flushing and air scouring experiments in forward and reverse directions were performed in the field. In 42 experiments, average residual chlorine concentration and turbidity were improved after cleaning compared to before cleaning. It was found that even when the same cleaning method was used, further improvement of cleaning effect was possible by applying air injection and reverse direction cleaning techniques. By means of one-way ANOVA(Analysis of variance), it was also possible to statistically verify the need of actively utilizing air injection and reverse direction cleaning. Based on correlation between turbidity and TSS, the total amount of suspended solids removal was estimated for 874 flushing operations and 194 air scouring operations. The result showed that air scouring used more discharge water than flushing by an average of 4.9 m3 yet with larger amounts of suspended solids removal by an average of 145.9 g. The result of analysis on turbidity values from 887 flushing operations showed low cleaning effect of unidirectional flushing for the pipes with diameters over 300 mm. In addition, the turbidity values measured during cleaning showed an increasing tendency as pipe age increased. The methodology and results of this research are expected to contribute to the efficient maintenance and improvement of water quality in water distribution networks. Follow-up research involving the measurement of water quality at regular time intervals during cleaning would allow a more accurate comparison of discharge water quality characteristics and cleaning effects between different cleaning methods. To this end, it is considered necessary to develop a standardized manual that can be used in the field and to provide relevant trainings.

본 연구에서는 단순 폐기 되는 농업폐기물(토마토, 고추, 파프리카)을 고형연료로 재활용하기 위한 열 풍건조장치를 개발하고 실험을 통해 그 성능을 확인하고자 하였다. 연구를 위해 건조용량 500 kg/hr인 쓰레기소각장 폐열을 열원으로 사용하는 건조기를 제작하였다. 경상남도 진주시 농산물 시장에서 구입 한 남해산 시금치를 실험원료로 사용하였다. 열교환기에서 스팀 열교환에 의해 가열된 건조공기를 열풍 으로 사용하여 절단 원료 투입량(126, 250, 300 kg), 원료교반여부(수동 교반, 수동 비교반), 건조방식 (건조물 정치, 건조물 이송), 건조시간(0.25, 0.5, 0.6 hr)에 따른 건조특성을 파악하였다. 투입 원료의 함수율은 85.65%로 측정되었으며, 소각장 공급 스팀에 의해 열교환기에서 가열된 건조공기온도는 건조 기에 투입된 실험원료의 퇴적고에 따른 압력저항에 의해 다소 차이를 보였으며 약 108 내지 144℃로 측정되었다. 동일 건조방식, 투입량, 건조시간, 건조공기온도에서 상하층간 원료를 교반하는 하는 경우가 그렇지 않은 경우에 비해 약 2배 정도의 높은 건조속도를 보였다. 각 실험에서 건조용량은 약 500 kg/hr으로 나타났다. 국내 농산물 건조기 157개의 농업실용화재단 검사성적서를 기준으로 투입 에너지에 대한 건조 소요에너지 비를 나타내는 건조효율을 비교한 결과 국내 농산물 건조기 57.76%, 개발 된 농업폐기물 건조기 33.46%로 기존 농산물 건조기에 비해 낮게 나타났다. 개발된 농업폐기물 건조기는 건조시간이 1시간 이내로 건조시간이 짧으며, 건조 중 많은 풍량이 손실되어 건조효율이 저하된 것으로 판단되었다. 소각장 폐열을 직접 건조열원으로 사용하는 경우 건조공기온도는 최저 160℃ 이상으로 예상 되는 바 건조용량이 크게 향상될 것으로 예측된다.

Since the implementation of the Odor Prevention Act in 2005, the number of odor complaints has continuously increased due to the increased interest in the living environment. The current odor control means is a concentrationbased method for the source of odor. That is why there is a difference between the odor sensitivity and the result of the odor measurement in the odor damage area. The government is considering the introduction of the grid method, which is the odor management method of Germany, as the method of odor investigation in the odor damage area in the second comprehensive Odor Prevention Policy (2019-2028). The grid method is receptor-based odor measurement method that investigators use to judge odors in the field, task that expensive and requires substantial manpower and time. To study an odor measurement method that is suitable for domestic conditions, this study compared the correlation between results based on the odor frequency concept grid method around the livestock facilities and the result of ammonia concentration measured by passive air sampler. The correlation coefficient (R) that is between the frequency of odor per spot for the entire odor and the ammonia concentration that was measured by passive air sampler was 0.65 which is relatively good. Among the entire odor detected by the grid method, the correlation coefficient (R) between the odor frequency selected only for livestock odor and the ammonia concentration was significantly increased to 0.80. In addition, the correlation between odor exposure (ECPexist) and the ammonia concentration for the overall odor was 0.81 (linear) and 0.86 (index). If only the livestock odors were selected, the correlation between odor exposure and the ammonia concentration was very high at 0.96 (linear) and 0.95 (index).

The use of air cleaners has become popular to quickly remove contaminants present in indoor air such as fine dust and fungi. However, fungal information is rarely available in the filters equipped in the air cleaners. This study was conducted in winter to examine fungal concentration and species in the air cleaner filters of ten residential houses located in Incheon, Seoul, Hwaseong, and Gimpo cities. Fungi were detected in nine out of eleven filters from the ten houses. The level of fungi in the filters ranged from 0 CFU/cm2 to 2,370 CFU/cm2. There were differences in the fungal concentration among the eleven filters. Filters from three houses revealed levels over 1,000 CFU/cm2. The operation time of air cleaners did not seem directly related to the level of fungal concentration. A total of 326 isolates were obtained and classified as six genera belonging to Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium, and Trichoderma. Among these six genera, 20 species including one Alternaria, one Aspergillus, three Cladosporium spp., two Fusarium spp., eleven Penicillium spp., and two Trichoderma were identified. There were species that cause allergic reaction, pneumoniae, mycosis, and plant disease. Three species were known species of mycotoxin producers. Aspergillus niger, Cladosporium cladosporioides, and Penicillium brevicompactum were the most frequently detected fungi both in the air and in the air cleaner filters. This is the first report of fungal communities present in the air cleaner filters of residential houses in Korea.

The objective of this study was to investigate the effect of shoe dust on the indoor environment, and the effectiveness of shoe dust control on indoor air quality. Test dust was resuspended to reach a mass concentration of particles (2.5-10 μm size) more than 3 times compared to background level, and 1.5 times for particles less than 1 μm in size. The shoes, which were used for actual walking purposes in the outdoor environment, increased indoor PM10 concentration by 118±9%. The removal of shoe dust by water washing and mechanical suction brought about an improvement of indoor air quality. In particular, in circumstances where 27 people walked for one hour into the indoor environment, the mechanical suction of shoe dust decreased PM10 concentration by about 17% (based on the mass balance analysis).