PURPOSES : In this study, the characteristics of fine particulate matter (PM2.5) concentrations under different weather conditions of different types of bus stops, such as enclosed-type and open-type bus stops, were analyzed using statistical methods. METHODS : Data was collected inside and outside an enclosed bus stop on sunny and rainy days to compare and analyze the characteristics of fine particulate matter concentration in the target bus stop. The probability distributions were estimated for each data point using the Anderson–Darling test. Based on the estimated probability distributions, probability density functions were computed, and the values were used to estimate and compare probability for each air quality index inside and outside the bus stop under different weather conditions RESULTS : For the results of descriptive statistics, the average concentrations of fine particulate matter inside and outside the bus stop were 42.296 and 35.482 μg/m3 on a sunny day and 40.831 and 39.321 μg/m3 on a rainy day, respectively. Results of the statistical method, obtained using the Anderson-Darling test, indicate that the probability of the air quality index inside the bus stop reaching high concentrations on a sunny day was "high" or "very high," compared to that outside the bus stop. However, on rainy days, the differences in fine particulate matter concentrations inside and outside the bus stops were difficult to identify based on statistical evidence. CONCLUSIONS : It was found that the open-type bus stop had an advantage of preventing fine particulate matter effects on sunny days, compared to the enclosed-type bus stops. Furthermore, there were slight differences in fine particulate matter concentrations inside and outside the bus stop on a rainy day because of atmospheric flow and stormwater.

본 연구는 원통형 종이포트를 활용한 토마토 육묘시, 염스트레스를 활용하여 고온기 도장 억제가능성을 검토하기 위하여 수행되었다. 시험구는 K2SO4, KCl과 KH2PO4을 각 5, 10 dS·m-1로 처리하였고, 또한, 토마토 모종에 고염도의 칼륨을 처리하여 수분 및 저온스트레스 환경에서의 적응성 및 생존성을 조사하였다. 조사결과, 처리 농도가 높아질수록 지상·지하부 건물중, 옆면적, 순동화율 (NAR)이 감소하고, 경경과 충실도는 증가하였다. 수분 스트레스 처리 이후, 대조구는 심한 위조현상을 보였지만, KCl처리구는 양호하였다. 상대수분함량은 대조구에서 23%, KCl처리구에서 8% 감소 하였다. 또한, 대조구에 비하여 KCl 처리구는 저장시(9, 12 및 15°C) 모종의 손상 비율이 낮았다. 이와 같은 결과로 보아, KCl과 같은 고농도의 칼륨 처리가 원통형 종이포트 토마토 육묘의 도장 억제에 효과적이며 환경 스트레스 내성을 향상시키는 것으로 판단된다.

The effect of the change in air inflow velocity has been investigated at the opening of the malodor emission source to determine its influence on the Complex odor concentration. Both the Complex odor collection efficiency and concentrations were measured according to the change in airflow velocity. When the air inflow velocity was 0.1 m/s, it was observed that some of the generated gas streams were diffused to the outside due to low collection efficiency. In contrast, only the increased gas collection volume up to 0.5 m/s showed no substantial reduction of the Complex odor concentration, which indicates an increase in the size of the local exhaust system as well as the operation cost for the Complex odor control device. When the air inflow velocity reached 0.3 m/s, the Complex odor concentrations not only were the lowest, but the odorous gas could also be collected efficiently. The air inflow velocity at the opening of the malodor emission source was considered the key factor in determining the gas collection volume. Therefore, based on the results of this study, an optimal air inflow velocity might be suggestive to be 0.3 m/s.

Mold is one of the harmful biological pollutants in the indoor environment. To investigate how the contamination degree of mold existing in the indoor environment differs according to the characteristics of the house, the concentration of mold in the indoor air was investigated for the houses damaged by leakage or flooding. As a result of a survey of 20 houses located in Gyeonggi-do and Chungcheong-do, the concentration of mold in indoor air surprisingly exceeded more than two times the recommended indoor air quality standard of 500 CFU/m3 in all the houses investigated. The fungal concentration was high in houses with condensation and mold odors. As for the housing type, the pollution degree was higher in detached houses than in row houses. As for the type of water damage, mold contamination was higher in the leaky houses than in the flooded houses. The degree of mold concentration was 1,237 CFU/ m3 in the leaky houses. In terms of housing age, pollution was very high in houses over 20 years old. The occurrence of these measured mold concentrations was correlated at a significant level with respect to the properties of the house. This study shows that in the case of water damaged houses, careful management of mold contamination is required.

The objectives of this study were (i) to evaluate the effects of temperature and relative humidity on two electrochemical sensors measuring hydrogen sulfide and ammonia using a laboratory testing system for various sensors, and (ii) to propose a calibration method for those concentrations to collect more reliable monitoring data. The effect of temperature and relative humidity was tested under three different conditions, respectively. The linearities measured data under all different conditions for the relative humidity and temperature were excellent, indicating more than 0.99 of R2 for both odor sensors. Under the condition of zero concentration, baselines (intercepts) at zero increased with increasing relative humidity for both hydrogen sulfide and ammonia sensors. The rate of gas concentration according to ADC variation (slopes) increased with increasing relative humidity about only the hydrogen sulfide sensor. In this study, slope, and intercept are utilized for calibration of hydrogen sulfide and ammonia concentration, and the reliability of the data of hydrogen sulfide and ammonia sensors is further enhanced by the relational expression obtained by this paper.

We investigated the growth response and population regeneration of four halophyte species: Suaeda japonica, Salicornia europaea, Suaeda maritima and Suaeda glauca, when climate change proceeds caused by increased CO2 concentration and temperature. The plants collected from habitat in 2018 were transplanted into Wagner pots, and cultivated for two years in greenhouse divided into a control (ambient condition) and a treatment (elevated CO2+elevated temperature). The shoot length of halophytes was measured in July of each year, and the population regeneration rate was measured in October 2019. The shoot lengths of S. japonica and S. glauca had no difference between control and treatment for two years. Those of S. europaea were longer in control than treatment for two years. Those of S. maritima had no difference between control and treatment in 2018 but were longer in control than treatment in 2019. In control, the shoot lengths of S. japonica, S. europaea and S. glauca had no difference between years while those of S. maritima were longer in 2018 than in 2019. In treatment, those of S. japonica, S. europaea and S. maritima were shorter in 2019 than 2018 but S. glauca had no difference between years. The regeneration rates of S. japonica, S. europaea and S. glauca were lower treatment than control, and there was no difference in the regeneration rate of S. maritima. In conclusion, if climate change progresses caused by the increase of CO2 concentration and temperature, the shoot lengths of S. japonica, S. europaea and S. maritima will be shortened, and the regeneration rate of population will be increased only in the S. maritima.

This study was performed to investigate the characteristics of VOCs and carbonyl compounds emitted by smallscale master, offset, and screen printing facilities. During the printing process, concentration measurements of indoor samples were made at each on the printer equipment and the indoor center of the facility. In each case, the window or door served as natural ventilation, and concentration measurements of outdoor samples were made at each air exit point. The results showed that in all printing facilities, the levels of VOCs and carbonyl compounds were much higher in printer equipment compared to indoor levels. Comparative examination of VOCs between printer equipment and the indoors of the facility, the main species of master and offset printer equipment were Methyl isocyanide, 2,2,6-Trimethyloctane, 2,2-Dimethyldecane, 3,7-Dimethyldecane, Toluene, Acetonitrile, and 3- Methoxy-3-methylbutanol. The main species of the indoors of master and offset facilities were Toluene, 2,2,6- Trimethyl-octane, Isopropyl alcohol, 3-Methoxy–3- methylbutanol, Nonane, and Acetone. However, in the screen printing facility, the printer and indoor emission compounds were the same such as 2-Methyl-cyclopentanone, Cyclohexanone, Ethylbenzene, and p-Xylene. Among the compounds released to the outside, Toluene and Acetone were the most abundant species of VOCs and carbonyl compounds, respectively.

Radon is known to be one of the representative carcinogen materials, and may cause severe health damage to the human body with long-term exposure. Without proper treatment such as natural and mechanical ventilation, indoor radon concentration tends to increase as time passes. In this aspect, it is necessary to maintain indoor radon concentration below the domestic indoor air quality (IAQ) management standard by continuous monitoring. However, the number of practical devices which can detect radon concentration is scarce and most of the existing devices are very costly. Among such devices, the RS9A, a prototype of a radon detector, detects indoor radon concentration and is priced significantly lower compared to other existing radon detectors. In this paper, we investigated the RS9A for the continuous detection of indoor radon gas and compared its performance to a commercially available radon detector (RadonEye). We measured indoor radon concentrations at two separate sites by using both detectors simultaneously. The indoor radon concentrations measured by the aforementioned detectors revealed a high correlation. Therefore, the RS9A can be considered as an appropriate candidate for use as a continuous indoor radon monitoring system.

Since 1974, the urban subway has been used as a major form of public transportation in Seoul, Korea. The air quality in the subway environment depends on the introduction of air pollutants from roadway air and its generation is caused by subway operation in the tunnel. In the subway tunnel, PM10 concentration was monitored from March 8 to 15, 2018 and from March 26 to 28, 2018, and compared with concentrations that are routinely monitored at the subway concourse and the nearest roadside air quality monitoring station (RAQMS). Overall PM10 concentration at the concourse was similar to that of the RAQMS. However, PM10 concentration in the tunnel was significantly higher than those of the subway concourse and RAQMS, and showed distinct diurnal variation caused by train operation. The dominant peak concentrations were highly correlated with the number of train operations per hour. The minimum PM10 concentration was observed between 2 am to 5 am when the train was not operated. This was similar to that of the RAQMS. Although the diurnal variation of the PM10 concentration at the concourse is not significant, the overall trend is similar to that in the tunnel.

Evodiae Fructus is the dried unripe fruit of Evodia rutaecarpa, and has traditionally been used for treating stomachache and diarrhea. Evodiamine and rutaecarpine, the major biologically active compounds of Evodiae Fructus, are reported to have anti-oxidative and anti-inflammatory effects, as well as inhibit proliferation and metastasis of various cancer cells. The current study investigates the anti-oxidative and anti-cancer effects of the Evodiae Fructus extract, considering varying concentrations of methanol extraction (40, 80, and 95%). High contents of total phenolic compounds were determined in the order of extracts 80, 95, and 40%. Evaluating contents of the 95, 80, and 40% extracts revealed 36.77, 7.29, and 1.86 μg/mg evodiamine, respectively, and 53.02, 17.16, and 3.79 μg/mg rutaecarpine, respectively, with the highest content of both compounds obtained in the 95% extract. DPPH radical scavenging activity was observed to be inversely proportional to the contents of total phenolic compounds, with decreasing SC50 values obtained in the order 80, 95, and 40% extract. The 95 and 80% extracts exerted toxicity to AGS gastric cancer cells, but the 40% extract was non-toxic. Evodiamine is a known anti-cancer agent, and could be responsible for the observed toxicity. Cleavage of PARP, and Caspase-3, -7, -8 and -9 was observed in the 95% extract-treated AGS cells, indicating that cell toxicity exerted by the 95% extract could be attributed to apoptosis.

본 연구는 고농도 염화칼슘 처리 토양에서 토양개량제인 하이드로볼, 활성탄의 처리와 수크령 식재 유무에 따른 토양침출수 의 화학적 특성과 토양 내 염분 저감 효과에 미치는 영향을 규명하고자 수행하였다. 고농도 제설제처리 염분토양에서 토양개량 제 하이드로볼, 활성탄의 염분 저감 효과 및 수크령의 식재 효과를 알아보기 위하여 2018년 4월부터 10월까지 유리온실에 직경 10 cm, 높이 9 cm의 플라스틱 포트에 수크령을 식재하고 무처리 (Cont.), 하이드로볼 (H), 활성탄 (AC), 수크령식재 (P), 하이드로볼 + 수크령식재 (H + P), 활성탄 + 수크령식재 (AC + P) 총 6개의 처리구로 나누었다. 염화칼슘 (CaCl2) 처리는 10 mg/L 농도의 수용액을 조제하여 2주 간격 1회 200mL씩 분주하였다. 토양침출수 분석은 pH와 EC, 염류계 치환성양이온 (K+, Ca2+, Na+, Mg2+) 함량을 측정하였고, 수크령의 생육은 초장, 엽장, 엽폭, 엽수를 측정한 뒤 실험종료 후 생체중, 건물중, 건물률, T/R률을 조사 분석하였다. 토양침출수 화학성 분석결과, 토양산도는 처리구별 뚜렷한 차이를 보이지는 않았으나 모든 처리구에서 약산성을 띄었으며, 전기전도도는 H + P, P, AC + P, H, AC, Cont. 순으로 감소하는 경향을 보였다. 염류계 치환성양이온함량에 있어서 토양 염류도의 지표라 할 수 있는 Ca2+ 항목에서 Cont., P, H, AC, H + P, AC + P 순으로 높아지는 경향을 보였다. 수크령의 생육변화는 H + P, AC + P, P 순으로 초장, 엽장, 엽폭, 엽수 모든 항목에서 상대생장률이 통계적으로 유의하게 높게 나타났다. 따라서 하이드로볼과 활성탄은 제설제 피해지역 토양개량제로 활용가치가 높으며 수크령은 토양 내 고농도 염화칼슘 염분저감 식물소재로 적합한 수종이라 판단된다.

PURPOSES : This study analyzes the characteristics of generated fine particulate matter (PM2.5) and nitrogen oxide (NOX) at roadsides using a statistical method, namely, a generalized linear model (GLM). The study also investigates the applicability and capability of a machine learning methods such as a generalized regression neural network (GRNN) for predicting PM2.5 and NOX generations. METHODS : To analyze the characteristics of PM2.5 and NOX generations at roadsides, data acquisition was conducted in a specific segment of roads, and PM2.5 and NOX prediction models were estimated using GLM. In addition, to investigate the applicability and capability of a machine learning methods, PM2.5 and NOX prediction models were estimated using a GRNN and were compared with models employing previously estimated GLMs using r-square, mean absolute deviation (MAD), mean absolute percentage error (MAPE), and root mean square error (RMSE) as parameters. RESULTS : Results revealed that relative humidity, wind speed, and traffic volume were significant for both PM2.5 and NOX prediction models based on estimated models from a GLM. In addition, to compare the applicability and capability of the GLM and GRNN models (i.e., PM2.5 and NOX prediction models), the GRNN model of PM2.5 and NOX prediction was found to yield better statistical significance for r-square, MAD, MAPE, and RMSE as compared with the same parameters used in the GLM. CONCLUSIONS : Analytical results indicated that a higher relative humidity and traffic volume could lead to higher PM2.5 and NOX concentrations. By contrast, lower wind speed could affect higher PM2.5 and NOX concentrations at roadsides. In addition, based on a comparison of two statistical methods (i.e., GLM and GRNN models used to estimate PM2.5 and NOX), GRNN model yielded better statistical significance as compared with GLM.

This experiment was aimed to identify concentrations of mineral nutrients in leaf lettuce (Lactuca sativa) grown on hydroball aquaponics and in the water for growing fish by conducting two experiments. The experiment I (Expt. I) was conducted with 12 fishes (F12) with and without filter, hydroball and plants (H12 (12 fishes, hydroball), FHP12 (12 fishes, filter, hydroball, 6 plants) and HP12 (12 fishes, hydroball, 6 plants)), and the experiment II (Expt. II) was with and without plants (FH15 (15 fishes, filter, hydroball), FHP15 (15 fishes, filter, hydroball, 6 plants)). The pH level in the water of all the treatments was decreased during the growing period, and the pH and EC of the water were lower in all the treatment with plants than those without plants in both Expt. I and Expt. II. When compared with adequate nutrient concentrations for hydroponics, nitrate nitrogen (NO3-N) and phosphorus (P) concentrations in the fish growing water were higher under the FHP15 treatment in Expt. II; however, potassium (K), calcium (Ca), and magnesium (Mg) were only 16, 49, and 82% of hydroponics, representatively, and iron (Fe) was not detected. The fresh weight of lettuce harvested from the FHP15 treatment was 38 g, only a 30% of marketable lettuce yield. The T-N and P contents of the leaf tissue grown under the FHP15 treatment were close to the optimal level; however, the K, Ca, and iron (Fe) contents were less than the optimal with no deficiency symptom.

The purpose of this study was to evaluate indoor air pollutants of children’s facilities in libraries. The indoor pollutants, which were managed under the “Indoor Air Quality Control Standards” and “Environmental Safety Standards for Children’s Activity Zones,” were measured within five months. The new environmental pollutants such as phthalates and pesticides were also measured. The pollutant-measuring device was installed in children’s spaces in libraries and children’s libraries of the metropols. The result of investigating indoor pollutants showed that the concentration of fungus and floating bacteria had low distributions due to the use of air purifiers in all libraries. The concentration of HCHO and TVOCs was also measured lower than the environmental standards in well-ventilated libraries. On the other hand, phthalates and pesticides were detected in all libraries. In the case of heavy metals, they were mainly found in the finishing materials of the library walls and floors. As a result, indoor pollutants are managed under court receivership. On the other hand, phthalates and pesticides, which are not regulated by environmental standards should be managed because they were detected in all libraries.

Glaucoma is one of the leading causes of blindness worldwide and is characterized by degeneration of the optic nerve. Elevated intraocular pressure (IOP) is the major contributing factor to optic nerve damage. However, some patients develop glaucoma even with normal IOP. Other factors, including age, race, myopia, and nutrition, can affect glaucoma risk. Dietary fat intake and serum fatty acid composition are closely related with the fatty acid profile of the retina and thus can modulate glaucoma risk. In this study, we collected serum samples from 34 glaucoma patients (26 primary open angle glaucoma (POAG) and 8 normal tension glaucoma (NTG)) and 45 healthy controls and analyzed their serum phospholipid fatty acid concentrations. The results show that the ratio of oleic acid to stearic acid (OA/SA), which is an indicator of stearoyl-CoA desaturase activity, was higher in POAG patients when compared to normal controls. The ratio of eicosapentaenoic acid to arachidonic acid (EPA/AA), which is an indirect marker of eicosanoid biosynthesis, was also higher in glaucoma patients (p=0.048). These results imply that dietary fatty acid intake and serum fatty acid profile can influence glaucoma risk. Additional study is necessary to identify the relationship between fatty acids and glaucoma.

본 연구는 L-alanine을 적용한 스크러버의 주류공장 내 CO2 제거효율, 모니터링 데이터 분석/ 평가 및 에너지 저감효율을 평가하였다. 스크러버의 평균 제거율은 90.45%로 10,000 ppm이상의 고농도 CO2가 유입됨에도 제거효율이 뛰어난 것을 확인하였다. 스크러버 작동 후 작업장 내 CO2는 2,000ppm 이 하로 유지하여 약 74% 이상의 이산화탄소 저감 효율을 확인하였다. 또한 소비되는 전력량을 측정한 결과 스크러버 작동 후 230 kWh로 약 7.26%의 에너지가 절감되는 것으로 나타났다. 즉, 본 개발제품을 적용한 결과로 작업장 내 이산화탄소 농도를 외기유입 없이 낮은 농도로 유지함에 따라 근무자의 작업환경을 개선 시킬 수 있었으며 에너지 소비량 또한 저감할 수 있었다. 그러므로 식품, 주류공장 내 고농도 CO2 제거 공 정으로써 스크러버가 유용할 것으로 기대된다.

ZnO thin films are of considerable interest because they can be customized by various coating technologies to have high electrical conductivity and high visible light transmittance. Therefore, ZnO thin films can be applied to various optoelectronic device applications such as transparent conducting thin films, solar cells and displays. In this study, ZnO rod and thin films are fabricated using aqueous chemical bath deposition (CBD), which is a low-cost method at low temperatures, and environmentally friendly. To investigate the structural, electrical and optical properties of ZnO for the presence of citrate ion, which can significantly affect crystal form of ZnO, various amounts of the citrate ion are added to the aqueous CBD ZnO reaction bath. As a result, ZnO crystals show a nanorod form without citrate, but a continuous thin film when citrate is above a certain concentration. In addition, as the citrate concentration increases, the electrical conductivity of the ZnO thin films increases, and is almost unchanged above a certain citrate concentration. Cu(In,Ga)Se2 (CIGS) solar cell substrates are used to evaluate whether aqueous CBD ZnO thin films can be applicable to real devices. The performance of aqueous CBD ZnO thin films shows performance similar to that of a sputter-deposited ZnO:Al thin film as top transparent electrodes of CIGS solar cells.