This study interrogated multi-layer heterojunction anodes were interrogated for potential applications to water treatment. The multi-layer anodes with outer layers of SnO2/Bi2O3 and/or TiO2/Bi2O3 onto IrO2/Ta2O5 electrodes were prepared by thermal decomposition and characterized in terms of reactive chlorine species (RCS) generation in 50 mM NaCl solutions. The IrO2/Ta2O5 layer on Ti substrate (Anode 1) primarily served as an electron shuttle. The current efficiency (CE) and energy efficiency (EE) for RCS generation were significantly enhanced by the further coating of SnO2/Bi2O3 (Anode 2) and TiO2/Bi2O3 (Anode 3) layers onto the Anode 1, despite moderate losses in electrical conductivity and active surface area. The CE of the Anode 3 was found to show the highest RCS generation rate, whereas the multi-junction architecture (Anode 4, sequential coating of IrO2/Ta2O5, SnO2/Bi2O3, and TiO2/Bi2O3) showed marginal improvement. The microscopic observations indicated that the outer TiO2/Bi2O3 could form a crack-free layer by an incorporation of anatase TiO2 particles, potentially increasing the service life of the anode. The results of this study are expected to broaden the usage of dimensionally stable anodes in water treatment with an enhanced RCS generation and lifetime.

Two sewage treatment facilities were selected to identify odor emission characteristics, focusing on volatile organic compounds (VOCs) and sulfur compounds. The complex odor, 5 kinds of sulfur compounds and 23 kinds of VOCs were analyzed from gas and sludge storages. Hydrogen sulfide was detected in the highest concentration and had the highest odor quotient among the odorous compounds monitored in this study, demonstrating that the contribution of hydrogen sulfide to the complex odor reached up to 90%. For VOCs, the overall contribution to the complex odor was not critical but VOCs can sufficiently trigger an odorous sensation because the sum of the odor quotient reached up to 2.89.

벼 이앙기별 인산에 의한 논조류 발생과 제초제에 의한 방제 효과는 다음과 같다. 1. 단작 및 이모작 벼 재배지에서 총출현 종수는 61종으로 녹조류 34종, 규조류 16종, 유글레나 7종, 그리고 남조류 4종이 발생하였고, 녹조류, 규조류는 이모작지가 많았고, 유글레나는 같았으며 남조류는 단작이 많았다. 2. 인산을 이앙전에 50%처리하고 분얼기에 50% 시비하였을 때 총인이 0.06 mg L-1로 가장 높았고, 조류 발생량도 무인산 대비 6월 6일 이앙한 구에서 14.8 mg 20 ml-1으로 3배 이상, 6월 20일에 이앙한 구에서 9.8 mg 20 ml-1 2배 이상 증가하였다. 3. 벼 생육단계별 분얼기, 유수형성기, 그리고 수잉기의 토양 인산의 함량은 관행 및 인산분시별로 유수형성기가 인산의 함량이 116.5~191.8 mg kg-1으로 가장 높은 경향이었으며 무 처리구에서는 15.5~29.1 mg kg-1로 낮았다. 이앙시기별로는 이앙이 빠를수록 높은 경향이었으며, 인산분시별로는 관행에 비해 분시하였을 때 높은 경향을 보였다. 4. 클로로필-a 함량은 6월 6일 이앙한 구에서는 제초제 처리 후 7일에 가장 낮은 6.3 mg m-3 이고, 7월 상순에 무처리구에서 75.8 mg m-3 로 가장 높았다. 6월 20일 이앙한 구에서는 제초제 처리후 7일에 가장 높은 경향이었으며 제초제 처리 후 14일과 21일은 감소하는 경향이었다 5. 논조류 억제율은 quinoclamine이 단작에서 59.2%, 이모 작에는 44.4%로 가장 높았으며, 다음으로 bromobutide + imazosulfuron + pyraclonil > benzobicyclon + mefenacet + peno xsulam >무처리 순이었다.

A total of 594 reservoirs (17%), which are managed by KRC, equipped with earthquake-resistant facilities whereas remaining ones did not. In addition, reservoirs were placed without the effect of geological structures (i.e., fault and lineament). Therefore, development on technique for alleviating the potential hazards by natural disasters along faults and lineaments has required. In addition, an effective reinforcement guideline related to the geological vulnerabilities around reservoirs has required. The final goal of this study is to suggest the effective maintenance for the safety of earth fill dams. A radius 2 km, based on the center of the reservoir in the study area was set as the range of vulnerability impacts of each reservoir. Seismic design, precise safety diagnosis, seismic influence and geological structure were analyzed for the influence range of each reservoir. To classify the vulnerability of geological disasters according to the fault distribution around the reservoir, evaluation index of seismic performance, precise safety diagnosis, seismic influence and geological structure were also developed for each reservoir, which were a component of the vulnerability assessment of geological disasters. As a result, the reservoir with the highest vulnerability to geological disasters in the pilot district was analyzed as Kidong reservoir with an evaluation index of 0.364. Within the radius of 100km from the epicenter of the Pohang earthquake, the number of agricultural infrastructure facilities subject to urgent inspections were 1,180 including reservoirs, pumping stations and intakes. Four reservoirs were directly damaged by earthquake among 724 agricultural reservoirs. As a result of the precise inspection and electrical resistivity survey of the reservoir after the earthquake, it was reported that cracks on the crest of reservoirs were not a cause of concern. However, we are constantly monitoring the safety of agricultural facilities by Pohang aftershocks.

경상북도 봉화군 토석류 발생지 40개소를 대상지로 선정하여 강우의 특성 및 다양한 산림환경인자 별 로 조사하여 토석류발생 특성을 분석하였다. 토석류 발생 수는 총 40개소였으며, 토석류 발생 평균 발생 면적은 1,614.1㎡, 평균 발생토사량은 2,450㎥, 평균 길이는 120.7m, 평균 폭 11.8m로 나타났다. 토석류 가 비교적 많이 발생한 산림환경인자는 사면경사도(41°이상), 북서사면, 해발(401m~500m 이하), 종단사면 (복합), 횡단사면(오목), 침엽수, 변성암, 하천차수는(0차), 사면위치(산복), 임종(인공림), 수고(11m~15m), 흉고직경은 중경목(17cm 이상)에서 나타났다. 토석류 발생길이와 산림환경인자와의 상관분석을 실시한 결과는 사면경사(31°~40°), 종단사면(복합) 횡단사면(오목) 에서 1% 수준 내에서 정의 상관관계를 보였 고, 사면경사(41°이상), 종단사면(직선)에서 1% 수준 내에서 부의 상관관계를 보였다.

As the modern society is rapidly developing and people become affluent in materials, many new chemical compounds in different forms of products (e.g., antibiotics, pesticides, detergents, personal care products and plastic goods) are produced, used, and disposed of to the environments. Some of them are persistently having a harmful impact on the environment and mimicking endocrine properties; in general they are present in the environment at low concentrations, so they are called organic pollutants. These organic micropollutants flow to sewage treatment plants via different routes. In this study, the generation characteristics, exposure pathways, detection levels, and environmental impacts of organic micropollutants were critically reviewed. In addition, currently available risk assessment methods and management systems for the compounds were reviewed. The United States Environmental Protection Agency (US EPA), for example, has monitored organic micropollutants and set the monitoring and management of some of the compounds as a priority. To effectively manage organic micropollutants in sewer systems, therefore, we should first monitor organic micropollutants of potential concern and then make a watch list of specific substances systematically, as described in guidelines on listing water pollutants in industrial wastewater.

Pine wilt disease (PWD) is one of the hazardous pine tree diseases in whole world. In Korea, PWD has been spreading since it was first observed in Busan in 1988. Dispersion of PWD is mainly mediated by its vectors such as Japanese pine sawyer. In this study, we characterized environmental condition including meteorological factors, geographical factors, and land use factors influencing on the occurrence of PWD. The occurrence data of PWD were collected at 153 sites where were the initial occurrence sites of PWD in local government regions such as city, Gun, or Gu scale. We used Akaike Information Criterion (AIC) to evaluate the relative importance of environmental variables on the discrimination of occurrence or absence of PWD. The results showed that altitude, slope, and distance to road were the most influential factors on the occurrence of PWD, followed by distance to building. Finally, our study presented that human activities highly influenced on the long term dispersal of PWD.

This Paper deals with the measurement and analysis of the brake squeal noise, the wheel’s and block brake’s vibration. The squeal noise, a kind of self-excited vibration, is generated by the friction between the rim of the revolving wheel and the block brake. The goal of this paper is to investigate experimental the relation between brake squeal noise and vibration mode of railway wheel with block brake to the track of friction surface on tread of railway wheel and the tread rake angle of railway wheel. Experimental results with Mode Analysis and Run Mode Analysis show that vibration mode of railway wheel with block brake is related with brake squeal noise.

안산시는 피레스로이드계 살충제들과 Bti 그리고 이산화탄소 유인 트랩 등을 활용하여 주로 모기 발생을 관리하고있다. 안산시에서 발생하는 모기 종들은 약 16종으로 얼룩날개모기류 7.2%, 흰줄숲모기 0.4%, 작은빨간집모기 1.2%등 질병매개와 관련된 매개체 발생율은 약 9% 미만이었다. 가장 흔한 모기 종은 빨간집모기(82.4%)이었고 다음으로금빛어깨숲모기(3.9%)였다. 모기 유충 발생지에서 관찰된 식물은 26과 47속 56분류군이었고 동물은 8속 8종이었다.거주지 인근 하천에서 발생하는 성충 모기를 관리하는 수단으로서 검정색과 노란색 점착트랩의 활용성이 높아보였고, 고인 웅덩이나 논 등에서 발생하는 모기 유충은 개구리밥의 활용도 검토할 만 하였다. 또한 잔효력에기반한 살충제 침지한 네트의 효율성 평가로 향후 안산시의 환경적 특성을 고려한 모기 관리 수단으로서 이들방법들의 유기적인 조합을 도출할 예정이다.

시설고추에서 대만총채벌레와 꽃노랑총채벌레는 정식 후 6월 하순부터 7월 상순까지 최대 발생량을 보였고,Taylor Power Law(TPL) 분석 결과 집중분포를 하는 것으로 밝혀졌다. 고추에 발생하는 대만총채벌레와 꽃노랑총채벌레는 주로 잎을 가해하며 과실의 상품성을 저하시켜 경제적 손실을 야기하는 중요한 해충이다. 두 해충의 조사를위해 황색끈끈이트랩을 설치하여 일주일 간격으로 발생량을 조사한 결과 3개 지역 모두 6월 중순 경부터 급격히밀도가 증가하는 양상을 보였으며 6월 하순부터 7월 상순에 최대 발생량을 보였다. 이 두 총채벌레의 포장 내조사지점별 밀도를 비교한 결과 주로 하우스 측면과 입구 쪽에서 밀도가 높은 것이 확인되었으나 통계적 차이는없었다. TPL 분석의 직선회귀에서 꽃노랑총채벌레와 대만총채벌레 모두 기울기 b값은 “1” 이상으로 집중분포양상을 보였고 R2는 각각 0.9279와 0.9384로 신뢰성이 높았다. 추후 TPL 상수를 이용한 고정정확도 수준에서 조사주에따른 표본조사를 중지할 수 있는 총채벌레 누적마리수를 추정하여 적정 표본조사 중지를 결정할 계획이다.

우리나라에서 주로 재배되고 있는 핵과류인 복숭아, 자두, 매실, 체리나무에서의 깍지벌레 발생현황과 우점깍지벌레의 1세대 발생특성을 조사하였다. 뽕나무깍지벌레(Pseudaulacaspis pentagona), 말채나무공깍지벌레(Lecanium corni),무화과깍지벌레(Coccus hesperidum), 가루깍지벌레류(Pseudococcus sp.) 등 총 4종이 발견되었다. 뽕나무깍지벌레는4종의 핵과류 모두에서 발견되었으며 총 113과원 중 103과원에서 발견(발생과원율 91.2%)되어 핵과류에서 가장중요한 깍지벌레인 것으로 나타났다. 그 외의 깍지벌레는 방제를 요하는 수준은 아니었다(발생과원율: 2∼3%,발생밀도: 1∼8마리/가지). 뽕나무깍지벌레 암컷성충은 몸체가 깍지로 덮여 있어서 약액에 노출되지 않아 방제약제를살포해도 효과가 낮으므로 반드시 약충기에 방제해야 한다. 뽕나무깍지벌레는 5월 상순부터 부화를 시작하는데,암컷성충 1마리가 평균 75.5개(47∼159개)의 알을 낳으며 모든 알이 부화하는데 약 19일이 소요되므로 5월 20일경이되어야 월동성충의 모든 알이 부화하게 된다. 그리고 6월 중순부터 성충이 발생 시작하므로 1세대 방제는 2령약충 발생 시작 즈음인 5월 하순(5.25일경)에 1차 방제하고, 약 2주 후(성충 발생 전_6.10일 이전)에 2차 방제해야방제효과를 높일 수 있다.

경기･강원도 7개 군, 중국 길림성과 요령성의 벼, 옥수수, 콩, 감자, 맥류 노지 포장에서 발생하는 주요 해충들을조사하였다. 국내 북부지역 벼에서 벼물바구미, 멸강나방, 애멸구; 옥수수에서 멸강나방, 조명나방; 콩에서 톱다리개미허리노린재, 세줄콩들명나방; 감자에서 큰28점박이무당벌레 등이 주로 발생했다. 북방 유사지역인 길림성과 요령성주요 식량작물 포장에 발생하는 해충들은 발생밀도에 차이는 있으나, 국내 북부지역과 유사하게 발생하는 특성을보였다. 유효적산온도를 이용하여 북방 지역에서의 벼물바구미의 월동성충 및 신성충 이동시기를 추정하면, 북방서부지역의 월동성충은 국내발생과 비슷하였지만 북방지역의 내륙 및 북부지역에서는 발생시기가 늦어질 것으로 나타났다. 또한 평양, 신의주, 안주 등의 신성충 발생시기는 국내 서해안 지역과 비슷한 양상을 보였으나, 북부지역에서는늦어졌고 일부지역은 이들이 발생해도 성충까지 완전하게 발육하지는 못할 것으로 추정되었다.

도심 내 매미의 생태적 특성을 이해하기 위하여 총 31개 공원, 71개 방형구 내에서 여러 환경요인들(서식지유형, 미소서식지 환경)과 매미 종구성 및 발생량을 비교 분석하였다. 서식지 유형은 반경 500m의 토지피복 추출후, 산림 비율 기준으로 서식지 유형을 구분한 결과 도심형공원 및 주거지역이 산림형공원에 비해 말매미의 발생량이높게 나타났다. 토지피복도 및 방형구 내 미소서식지요인을 이용한 SOM 분석에서는 말매미가 도심 비율이 높고,고도가 낮을수록 많은 발생량을 보였으며, 애매미는 산림의 특성(고도, 토양유기물, 낙엽량 등)이 높은 지점에서많은 발생량을 보였다. 참매미와 유지매미는 초지, 수역 및 식생 비율이 높은 곳에서 많은 발생량을 보였다. 결론적으로서식지 유형, 미소서식지 환경은 매미의 종 구성 및 발생량의 차이를 야기 시킨다. 따라서 본 연구 결과는 도심내 매미의 효율적 서식지 관리를 위한 자료로 활용 가능할 것이다.

During the decay process of food waste, odor and leachate are generally produced because food is easily decomposed due to its high organic and moisture contents. In this study, various food waste samples, including samples artificially prepared and collected from actual waste containers, were tested to determine odor and leachate production as the samples were decomposed at a constant temperature of 35°C. In the air phase, total volatile organic compounds (TVOCs), acetaldehyde (AA), methyl mercaptan (MM), hydrogen sulfide (H2S), and dimethyl sulfide (DMS) were measured as a function of the decay period for four days. The results of the experiment showed that TVOC and AA were produced at higher concentrations in the actual food waste than in all artificial wastes. The AA concentration accounted for about 90% of the TVOC in all of the waste samples except for the food waste containing meat and fish only. The concentrations of volatile sulfur compounds (VSCs) were generally lower than 100 μg/kg, and the concentration of DMS was the highest among the VSCs. In the waste sample containing meat and fish only; however, the concentration of VSCs increased up to 1,700 μg/kg, and mostly consisted of MM and DMS. Complex odor concentrations were found to be the highest after a decay period of 12-48 hours. In addition, the complex odor was mostly related to VSCs with low odor thresholds rather than the TVOC. The pH values mostly decreased from 5 to 3.5 as the waste samples were in the decomposition periods, while the pH value increased to 6 in the food waste containing meat and fish only. Consequently, odor intensity and leachate production were the highest in the 12-48 hour range as the decomposition started, and thus an appropriate control strategy needs to be implemented based on the waste composition and the decay period.

The aim of this study was to examine indoor fungal concentration and fungal volatile organic compounds(VOCs) in single-person households. A total of 22 houses occupied by one person were investigated in this study. 19 VOCs detected in the field were estimated as fungi-derived VOCs through a review of the literature, and 11 VOCs were confirmed as fungal VOCs by laboratory experiments. Exposure to fungal VOCs in the indoor environment has been confirmed to be highly influenced by airborne fungal concentration and indoor humidity. 3-octanone was characterized by a clear generation profile in Aspergilus versiocolor, and n-decane in Pencillum chrysogenum. ntetradecane emitted by Stachybotrys chartarum exhibited a tendency to occur consistently. The observations made in this study demonstrated that single-person households can easily be exposed to fungi, and MVOCs can be used as an indicator of fungal exposure in indoor environments.

In this study, the behavior of dominant microbial communities was investigated in the treatment of porcine carcasses using an anaerobic high temperature burial composting method. The correlation between odor emission and bacterial community structure was analyzed through principal component analysis and extended local similarity analysis. In the burial layer of porcine carcass, the dominant bacteria were Bacillaceae (46%), Thermoactinomycetaceae (15%) and Lactobacillaceae (4%) in the early stage and Bacillaceae (46%), Thermoactinomycetaceae (15%), Lactobacillaceae (4%) in the end. Clostridiaceae (CH3SH), Bacillacea ((CH3)2S2), Clostridium ((CH3)2S2), Clostridial (H2S), Oceanobacillus (H2S), and Thermoanaerobacteraceae (H2S) were closely related to the sulfurous odorants, which are the highest odor contributions. The emission of sulfurous odor substances such as H2S, CH3SH, (CH3)2S, and (CH3)2S2 showed a positive correlation with each other, but showed a negative correlation with nitrogenous odorants (NH3 and TMA), aldehydes, organic acids, and VOCs. The results of this correlation analysis can provide useful information that enables us to understand the characteristics of microbial communities and odor generation during the degradation of carcasses and to manage odors and burial sites in the treatment of carcass.

The purpose of this study is to find and compare the differences in stress level, stressor, and coping style of high school students according to their personality traits. And to identify the personality traits contributing to stress reduction. The results of the study can be used as basic data for reducing the stress of adolescents to improve their academic achievement and maintain mental and physical stability. The questionnaire survey was conducted for 10 days from June 7 to June 16, 2017 for S high school students in Chungbuk Province. The study employed four measuring instruments as Ego-gram, Ok-gram, stressor scale, and stress coping type scale. Individual personality traits were classified into ego-states and ok-states in TA (Transactional Analysis). Stressors are classified into 5 categories (school life, home life, human relationship, myself, environment) and stress coping styles are classified into 4 categories (problem-focused coping, social-support coping, feeling-focused coping, hope-thinking coping) used in the previous studies. The collected data were analyzed using T-test, ANOVA, and multiple regression analysis. As a result, the stress level of high school students showed significant differences according to sex, year, grade, sleeping time, personality traits, and coping styles. Personality traits that contributed to the stress increase were NP, AC, ‘you positive’, ‘i negative’ and personality trait that contributes to stress reduction is ‘you negative.’ Therefore, we can judge that individual personality traits have significant effects on stress level, stressor, and coping style and need to find the effective stress management method suitable for individual personality traits using counseling, repetition training, self-suggestion etc.

The problem of disposal of brine due to increased MD/RO desalination plant has recently become a big social issue. The chlor-alkali process through electrolysis of brine has been studied as a method to overcome this problem. In order to increase the electrolysis efficiency, a pretreatment process for removal of hard substances must be preceded. In this study, we investigated the mechanism of removal of hardness through chemical precipitation. As a result, Ca was greatly influenced by addition of Na2CO3, and Mg was strongly influenced by pH. Also, the addition of NaOH and Na2CO3 enabled simultaneous removal of Ca and Mg, and showed a removal efficiency of 99.9% or more. Finally, the residual concentrations of Ca and Mg in the brine after the reaction were 0.14 and 0.13 mg/L, respectively. Saturation index was calculated using Visual MINTEQ 3.1, and solid phase analysis of the precipitate was performed by FE-SEM and PXRD analysis. It was confirmed that precipitate formed by the formation of calcite and brucite.

It is very important to treat infected livestock carcasses safely and quickly. In this study, the degradation characteristics and odor generation characteristics of carcasses were investigated during the treatment of swine carcasses using the anaerobic burial composting method. While the carcasses were decomposed, the temperature remained high, at 40~55°C on average, and most of the carcasses were decomposed rapidly. The major odorcontributing substances in the buried composting method are sulfuric odor substances such as H2S, CH3SH, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), and the odor contribution of these substances is 93~99%. Among them, CH3SH, which accounts for about 56~89% of odor contribution, was the most representative indicator substance. Despite the anaerobic digestion process, the methane concentration in the digestion process was as low as 0.5~0.8% at the burial point of the carcass. The odor and methane produced during the decomposition of the carcasses decreased considerably during the discharge to the surface layer through the buried layer consisting of compost. These results suggest that anaerobic high temperature burial composting is one of the most useful methods to treat carcasses of infected livestock.