최근 농지 및 수자원의 염류화로 인해 염생식물에 대한 작물화와 생육 조건 구명을 위한 연구 필요성이 높아지고 있다. 그러나 재배 조건 변화에 따른 작물의 생육 및 기능성 성분 변화 분석을 위해서는 양액 및 작물 생육부 시료를 채취하여 이를 전처리 및 분석해야 하여 시간적, 인적 자원의 소모가 높다. 본 연구에서는 염생식물의 최적 생육 조건 구명을 효율적으로 수행하기 위해 비파괴적으로 재배 현장에서 실시간으로 작물 생육부와 수경재배 근권부의 염분 농도를 모니터링할 수 있는 시스템을 개발하였다. 개발 시스템을 통해 NaCl 0 mM, 50 mM, 150 mM, 300 mM의 4가지 농도 조건에서 갯방풍을 대상으로 재배실험을 수행한 결과, 재배 중 염분 농도 수치의 변화 및 염분 농도가 높을수록 생체중이 감소하는 것을 확인하였다. 실제 생육 분석 결과에 따르면 개발 시스템을 통한 모니터링 결과에 상응하는 생체중 결과를 확인하여 염생식물의 생육 모니터링 적용이 가능할 것으로 평가되었다. 그러나 단위 생체중 당 기능성물질 함량의 경우, NaCl 농도가 증가할수록 증가하는 것으로 나타나 갯방풍의 상업적 재배 조건의 구명을 위해서는 생체중 외에 기능성 성분의 모니터링을 위한 시스템 보완이 필요하다고 판단되었다.

The Saemangeum has a dry surface characteristic with a low moisture content ratio due to the saline and silt soil, so the vegetation cover is low compared to other areas. In areas with low vegetation cover, wind erosion has a high probability of scattering dust. If the vegetation cover is increased by cultivating crops that can withstand the Saemangeum reclaimed environment, scattering dust can be reduced by reducing the flow rate at the bottom. Thus, the purpose of this study is to analyze the effect of suppressing the generation of fine dust and scattering dust by cultivating winter forage crops on the Saemangeum reclaimed land. While growing 0.5 ha of barley and 0.5 ha of triticale in Saemangeum reclaimed land, the concentration of fine dust was monitored according to agricultural work and growth stage. Changes in the concentrations of PM-10, PM-2.5, and PM-1.0 were monitored on the leeward, the windward and centering on the crop field. As a result of monitoring, PM-1.0 had little effect on crop cultivation. the concentration of PM-10 and PM-2.5 increased according to tillage and harvesting, and tillage had a higher increasing the concentration of PM-10 and PM-2.5 than that of harvesting. According to the growth stage of crops, the effect of suppressing scattering dust was shown, and the effect of suppressing scattering dust was higher in the heading stage than in the seedling stage. So, it was found that there was an effect of suppressing scattering dust other than the effect of land covering. Through this study, it was possible to know about the generation and suppression effect of scattering dust according to crop cultivation.

In this study, we investigated the Indoor and Outdoor concentrations of PM10 in Y area, Jeollanam-do. We conducted personal exposure concentration estimates, and Exposure and Risk Assessments using the Time-weighted Average Model. The concentration of Indoor PM10 was 49.38 μg/m3 and that of Outdoor PM10 was 48.02 μg/m3, with the Indoor/ Outdoor Ratio value being 1 or more, and it was found that there was an indoor source of pollution. The Indoor/Outdoor Cr ratio value was 1 or more, and the source of Cr was confirmed to be indoor. Based on our analysis, there was a positive correlation between heavy metals Ni, Cr, and Mn (p<0.05). Using the Time-Weighted Average model, we determined the PM10 personal exposure concentration to be 49.36 μg/m3 and confirmed the feasibility of this model in utilizing the PM10 personal exposure concentrations. In this study, the findings are likely to provide useful data that can be used to determine the concentration of indoor pollutants that are not easy to survey. However, to accurately evaluate indoor air quality, more factors need to be considered and evaluated.

Volatile organic compounds (VOCs) are chemicals to which humans are exposed frequently via various mediums, including vehicle emissions that contain fine dust and heavy metals, use of organic solvent building materials, furniture, and smoking. Exposure to high concentrations of VOCs may result in loss of consciousness, paralysis, convulsions, and, in the most severe cases, death. Therefore, the present study investigated the indoor and outdoor concentrations of total volatile organic compounds (TVOC) and five types of VOCs (benzene, toluene, styrene, m,p-xylene, and o-xylene) in apartments, a representative residential environment accounting for ~55% of the housing in the Seoul metropolitan area. The research was conducted over four seasons from May 2020 to February 2021, and the levels of VOC concentrations were analyzed by classifying them by season, weekday/weekend, and indoor/outdoor locations. The seasonal trend in VOC concentrations showed that TVOC concentration was highest in summer, with values of 1630.93 ± 1184.10 μg/m3 and 1610.36 ± 1363.43 μg/m3 for indoor and outdoor environments, respectively. The seasonal trends of the concentrations of the five types of VOCs showed that concentrations of benzene and toluene were highest in spring, the concentrations of m,p-xylene and o-xylene were highest in summer, and the concentration of styrene was highest in winter, irrespective of spatial characteristics such as indoor/outdoor environments. In all four seasons, the indoor concentrations were higher than the outdoor concentrations. These results reveal the spatial and temporal distribution characteristics of the VOCs and so can serve as useful basic data for managing indoor and outdoor levels of VOCs.

Fungi have been known as an irritant or causal agent of asthma. Thus, information on their concentration and diversity in indoor air of asthmatic patient’s houses is valuable for the management of these micro-organisms. The present study was performed to investigate fungal concentration and diversity in indoor air of resident spaces in two adult patient’s houses in winter. Air samples were collected in February of 2018 from living rooms and bedrooms of two asthma patients’ houses located in two different places in Incheon city using an impaction method. The average concentrations of airborne fungi did not exceed the 500 CFU/m3 level which is recommended by the Enforcement Managements of the Indoor Air Quality, Ministry of Environment, Korea. A total of four genera and 23 species were identified based on morphological and molecular methods. Aspergillus and Penicillium were two major genera. Aspergillus pseudoglaucus and Penicillium citrinum were commonly found between the two patient’s houses. Among the identified fungi, three species, Aspergillus venenatus, Penicillium jamesonlandense, and Penicillium salami were found to be unrecorded species in Korea. The morphological and molecular characteristics of these three unrecorded species were described. Since these species produce spores well and a lot, they are considered to be a species that needs management. This study provides basic information on the fungi for indoor air quality management in the living spaces of asthma patients in winter in Korea.

최근 동아시아 지역에서 인위적 배출량의 감소에도 불구하고, 봄철에 한국에서는 잦은 연무 사례가 발생하고 있 다. 북동 태평양에서 자주 발생하는 대기 블로킹은 지구 규모 대기 변동과 동아시아 지역의 서풍 기류를 정체시키기도 한다. 2019년 3월 동아시아 지역의 온난하고 정체적인 종관 기상 특성이 알래스카 대기 블로킹이 발생한 6-7일 후에 일어나고 있었다. 특히, 2019년 3월 18-24일에 발생한 알래스카 대기 블로킹은 3월 25-28일 동안 한국에서 일평균 미 세먼지(particulate matter; PM10) 질량농도가 50 μg m−3을 넘는 고농도 PM10 연무 사례가 발생하는 데 영향을 미치고 있 었다. 한편, WRF-Chem 모델을 활용하여 한국의 고농도 PM10 연무 사례에 대한 인위적 배출의 장거리 수송 기여도는 30-40%를 나타내고 있었다. PM10 에어로졸 구성 성분인 황산염, 질산염, 암모늄, 블랙 카본, 유기 탄소, 기타 무기물의 장거리 수송 기여도는 각각 10-15, 20-25, 5-10, 5-10, 5-10, 15-20%를 나타내었다. 질소 산화물이 온난하고 정체적인 대기에서 암모늄과의 광화학 반응으로 형성된 질산암모늄은 한국의 고농도 PM10 연무 사례에 대한 장거리 수송 기여도 가 PM10 에어로졸 중 가장 큰 비중을 나타내고 있었다.

In this study, the removal performance of high-concentration H2S and complex odors was evaluated for bio-filters installed in sewage treatment plants and manure treatment plants. The amount of odor generation according to temperature was found to be higher in summer than in spring. It was found that the longer the empty bed retention time of the bio-filter, the higher the odor removal efficiency. Therefore, in order to effectively remove odors, it is necessary to maintain a sufficiently long residence time when designing a bio-filter. In addition, a case in which a bio-filter and a wet pre-treatment system were combined to remove high-concentration odors was studied. The result showed that the wet pre-treatment was effective in removing high-concentration odors. In particular, most of the hydrogen sulfide could be adequately removed by wet pre-treatment.

This study was designed to verify what effect the use of a natural ventilation system can have on improving indoor air quality with regard to radon in various concentration ranges in an apartment house. The results show that both high (2~3 times higher than 148 m3) and low (similar to 148 Bq/m3) levels of indoor radon concentrations can be reduced close to and/or below the Korean IAQ guideline within 6 hours when the natural ventilation system is operated at approximately an air change rate of 0.5. In the case of an air change rate of 0.3, however, the indoor radon levels cannot meet the national guidelines and the reduction effect was insufficient with regard to various radon concentrations. Typically, the air change rate of a natural ventilation system is affected by meteorological factors such as temperature, relative humidity, wind speed, pressure. Its effectiveness varies according to such factors, for that reason, the reduction effects on radon did not increase proportionally with the ventilation time in this study.

Odor is a type of sensory pollution that can stimulate the human sense of smell when it occurs, causing discomfort and making it difficult to create a pleasant environment. For this reason, there is a high possibility of complaints regarding odors if odors occur in pigsties near residential properties, and the number of such complaints is also increasing. In addition, odors emanating from pigsties around military installations can cause physical and psychological harm, not only to the soldiers living in these type of facilities but also to the families belonging to military personnel living there as well. Because the concentration of odors varies due to diverse factors such as temperature, humidity, wind direction, wind speed, and interaction between causative materials, predicting odors based on only one factor is not proper or appropriate. Therefore, in this work, we sought to construct models that are based on several regression techniques of machine learning using data collected in field. And we selected and utilized the model that has the highest-accuracy in order to notify and warn residents of odors in advance. In this work, 3672 data items were used to train and test the model. The several machine learning algorithms to build the models are polynomial regression, ridge regression, K-nearest neighbor regression (KNN Regression), and random forest. Comparing the performance of models based on each algorithm, the study found that KNN Regression was the most suitable model, and the result obtained from KNN regression was significant.

The purpose of this study is to analyze the effect of temperature and humidity on the measured Particulate Matter (PM) concentrations recorded by PMS5003T, a low-cost light scattering type measuring tool. A regression analysis was performed on the ratio of PM concentrations measured by the light scattering method and the beta-ray absorption method according to temperature and humidity in an outdoor environment. As the temperature decreased, the PM concentration ratio increased, and this tendency intensified below 0oC. As the humidity increased, the PM concentration ratio increased, but the effect was less than the temperature effect. The coefficients of determination for temperature and humidity were R2 = 0.325 and 0.003, respectively, and the effects of temperature and humidity on the measured values w ere formulated and compensated for. As a result of the compensation, R2, relative precision, accuracy and RMSE improved from 0.927 to 0.958, from 91.183% to 96.651%, from 31.383% to 74.058%, and from 13.517 μg/m³ to 6.690 μg/m³, respectively. Finally, results from this study indicate that the reliability of the low-cost light scattering type PM sensor can be improved by applying the temperature and humidity compensation method.

Aster koraiensis Nakai (A. koraiensis) which has been used as a food and medicinal plant in the past, is valuable as functional food material. Therefore, the aim of this study was to determine the antioxidant properties and major phenolics of A. koraiensis extracts with different ethanol concentrations (0, 50, 70, and 100% aqueous ethanol solution). When ethanol concentration in the extraction solvent was increased, extraction yield decreased; 34.2, 23.2, 21.0, and 5.5% in 0, 50, 70, and 100% ethanolic extracts, respectively. Total phenolics content and antioxidant activities of extracts were increased in an ethanol concentration-dependant manner. The major phenolics in the extracts were chlorogenic acid (21.264~58.666 mg/g), isochlorogenic acid A (10.432~145.353 mg/g), and isochlorogenic acid C(0.239~13.148 mg/g), and these phenolic contents were higher in 70 and 100% ethanolic extracts than other extracts. Significant correlations were observed between ethanol concentration of extraction solvent, antioxidant properties, and major phenolics. These results indicated that the optimal ethanol concentration for extraction was 70%.

MMBR system has been suggested as a promising system to resolve harvesting problems induced from low settling efficiency of microalgae. And recently, a lot of research on reducing fouling at the MMBR system has investigated focused on EPS in many cases. EPS of microalgae mainly consists of polysaccharides and protein components, and is produced through photosynthesis and nitrogen-carbon metabolic pathways. Especially, P-EPS is one of major compounds which occur membrane fouling phenomenon, as its hydrophobic protein components cause floc formation and cake layer accumulation. And it is already known that almost every microalgae can metabolize P-EPS or Chl-a when nitrogen sources as a substrate is insufficient or exhausted situation. With the above backgrounds, uptake rates of P-EPS or Chl-a by Scenedesmus quadricauda according to the type of carbon source and nitrogen concentration were evaluated in order to verify correlation between carbon source vs P-EPS production, and indeed Scenedesmus quadricauda uses P-EPS or Chl-a when the amounts of nitrogen sourc es in the feed is not satisfied. As a result, it was shown that P-EPS and Chl-a production were increased proportional to nitrogen concentration under organic carbon condition. And especially, the amo unts of P-EPS and Chl-a in the cell were diminished with the nitrogen source becomes insufficient or exhausted. Because P-EPS accelerates fouling at the MMBR system, P-EPS degradation by Scenedesmus quadricauda in order to get nitrogen source may contribute to reducing fouling. About a affects of N-consumed Chl-a to the MMBR fouling, more survey is needed. On the contrary, considering the purpose of MMBR system of this study, i.e. harvesting useful high value microalgae efficiently feeding adequate industrial process wastewater, it seems like difficult to maintain satisfied metabolic activity and to harvest with high yield rate using nitrogen-poor MMBR feed.

본 연구는 염화나트륨에 의한 비생물적 스트레스가 생육과정 중의 느타리에게 미치는 영향을 자실체의 생육특성, 그리고 구성아미노산함량과 향기패턴 분석을 통해 확인하였다. 농도별로 염화나트륨을 처리한 톱밥배지에서 수확한 느타리 자실체의 생육특성을 조사한 결과, 처리구별 수량은 무처리구 대비 염화나트륨 0.5%처리구에서의 값은 비슷 했으며, 염화나트륨 처리 농도가 1.0%에서 2.0%으로 증가하면서 수량이 확연히 감소하였다. 자실체의 구성아미노산함량 분석결과, 무처리구 대비 모든 염화나트륨 처리구에서 glutamic acid과 proline을 제외한 aspartate, threonine, serine, glycine, alanine, methionine, valine, isoleucine, leucine, phenylalanine, tyrosine, lysine, histidine, arginine의 14종 구성아미노산의 함량이 낮음을 확인하였다. 자실체의 향기패턴 분석결과, 염화나트륨 처리구에서 버섯고유의 향을 나타내는 octane compound로 추정되는 물질의 intensity가 감소하였음을 chromatography상에서 확인하였다.

본 연구는 NaF 경구 투여가 Sprague Dawley계 수컷 흰쥐의 혈청 중 non-esterified fatty acid (NEFA), blood urea nitrogen (BUN), creatinine, uric acid 및 전해질 농도에 미치는 영향을 조사 하기 위하여, 기본식이를 급여한 대조군인 BG군과 기본식이에 NaF 경구 투여군(NF3~50군) 9그룹의 식이군으로 나누어 5주간 실험사육을 행하였다. 흰쥐의 NEFA와 BUN, creatinine, uric acid 농도는 NaF 농도에 비례적으로 증가하였으며, 고농도의 NaF 투여군에서 대조군보다 유의적인 차이로 높게 관찰되었다(α=0.05). 한편, 전해질 농도 중 total calcium (T-Ca)과 인(Pi) 농도는 대조군보다 NaF 투여군에서 낮게 동정되었으며, NaF 20 mg 이상 경구 투여한 군에서 유의적인 차이를 보였다(α=0.05). 흰 쥐의 NaF 경구 투여 처리는 농도가 증가함에 따라 NEFA 및 BUN, creatinine, uric acid의 농도가 상승하였으며, 전해질 농도는 저하되는 것으로 나타나 신장 기능 장애 등 바람직하지 않은 영향을 주는 것으로 확인되었다.

본 실험은 계란피단을 제조할 때 파란율이 적은 도포법의 장점과 생산 속도가 빠른 침지법의 장점을 동시에 획득할 수 있는 피단의 새로운 생산방법으로 종이로 감싼 후 폴리비닐로 포장하여 침지액을 첨가한 후 포장하는 방법을 착안하여, 제조기간의 단축과 알카리 용액의 사용량 감소 및 파란율 저하 가능성을 확인함으로써 계란피단 생산을 위한 기초자료를 제시하고자 수행하였다. 대조구는 계란의 총 중량과 동량의 용액을 NaOH 5%, NaCl 7%의 농도로 제조하여 침지 하였으며, 포장법은 킴테크 티슈 두장으로 감싼 계란에 25ml의 침지액을 주입하였다(T1: NaOH 3%, NaCl 5% T2: NaOH 4%, NaCl 6%, T3: NaOH 5%, NaCl 7%). pH는 난백과 난황에서 침지기간이 경과에 따라 유의적으로 증가하였다 (p<0.05). 농도가 높을수록 유의적 차이가 적었으며, 난황에서는 침지법으로 침지한 대조구가 가장 높았다. 난중량 변화는 침지기간이 경과함에　 따라 증가하여(p<0.05), 16일차에 가장 높게 나타났다. 침지법이 포장법보다 난중량이 크게 증가하였고, 침지액의 농도는 난중량 변화에 영향을 미치지 않았다. Hunter color는 난백의 경우 처리구들의 L*은 차이를 나타내지 않았고, a*와 b*는 침지기간의 경과에 따라 유의적으로 증가하여 (p<0.05), 16일차에 가장 높았다. 난황의 경우 모든 처리구들의 L*, a*과 b*는 침지기간이 경과함에 따라 유의적으로 감소하였다(p<0.05). TBARS 는 제조방법과 침지용액의 농도에 따른 유의적 차이는 나타나지 않았다. VBN은 난백, 난황 모두 침지기간이 경과함에 따라 증가하였으며(p<0.05), 침지액의 농도와 비례하여 높았다. 파란율은 대조구가 처리구보다 높았으며, 침지기간의 경과와 침지액 농도의 차이는 파란율에 영향주지 않았다. 대조구와 T3구는 제조기간과 완성도에서는 유사한 결과를 나타내었고, 저장성도 큰 차이가 나타나지 않았다. 침지포장 실험구들은 농도의 증가에 따라서 약간의 침투 효과 차이는 나타났으나, 대조구와 비교하여 파란율을 현격하게 낮출 수 있었다. 따라서, 알카리성의 침지액 사용량을 절반이하로 줄일 수 있고, 파란율을 낮출 수 있는 포장방법이 더 효율적인 피단의 제조방법으로 이용될 수 있다고 판단된다.