• 한국지하수토양환경학회지:지하수토양환경
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• 제12권2호
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• pp.65-71
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• 2007

토양복원의 기술로 마이크로파를 이용할 시 휘발성물질((PAH)s 등)) 및 준휘발성((PCB)s 등) 물질 등을 처리하는데 효과적인 것으로 알려져 있다. 본 연구에서는 휘발성 물질인 BTEX를 마이크로파를 이용하여 수분변화 및 전력변화에 따른 제거특성을 연구하였다. 10%, 20%, 30%, 50%의 함수율 변화에 따른 BTEX 제거율은 20%일 때가 제거율이 가장 높음을 제거상수를 통해 도출할 수 있었으며, 전력의 변화에 따른 BTEX 제거율 및 제거율에 도달하는 시간은 비슷한 것으로 나타났다. 각각 다른 함수율이 마이크로파 처리 시 한계함수율에 도달하는 시간을 측정한 결과, 한계함수율에 도달하는 시간은 함수율이 10%, 20%, 30%일 때는 2 kW와 4 kW는 큰 차이가 없음을 알 수 있었고, 함수율이 50%일 경우는 한계함수율에 도달하는 시간이 4kW가 더 빠른 것으로 나타났다. 수분함수율에 따른 최적전력을 도출하면 수분함량이 $10{\sim}30%$ 시 2 kW가 경제적으로 나타났으며, 함수율이 50% 일 경우는 전력이 4 kW일 때 경제적인 것으로 나타났다.

• 한국축산시설환경학회지
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• 제2권1호
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• pp.79-86
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• 1996

축사뇨오수의 전처리단계로 고액 분리기를 제작하여 분리효율에 관한 시험을 수행한 결과는 다음과 같다. 진동체 고액분리기는 최저 15%에서 최고 26%까지 분리율을 나타내었으며, 분리고형물의 수분함량은 85~88% 사이였다. 회전원통형 고액분리기도 최저 16%에서 최고 39%까지 분리율을 나타내었으며, 고형물의 수분함량은 86~89% 사이였다. 최대의 분리고형물량은 진동체 고액분리기의 경우에 체의 경사도 $10^{\circ}$와 진동모터 가진력 100%, 회전원통형 고액분리기에서는 회전속도 40rpm과 경사각 19$^{\circ}$에서 얻을 수 있었다. BOD 제거율은 회전원통형 고액분리기가 26%로 진동체 고액분리기의 21% 보다 다소 높았다. 관리측면에서는 회전원통형 고액분리기는 주기적으로 세척을 하여 주어야 한다.

• Journal of the Korean Wood Science and Technology
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• 제44권2호
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• pp.283-293
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• 2016

Owing to an increase in the air tightness of recent buildings, the natural ventilation rate was significantly lowered and the removal of accumulated moisture became difficult in these buildings. The hygrothermal performance of these buildings should be carefully considered to provide comfortable indoor environment by removing the moisture condensation risk and the mold growth potential. In this study, hygrothermal performance of two selected wall structures was investigated based on WUFI simulation program. The results displayed that the indoor temperature had impact on the moisture accumulation in the insulation layer for both modeled walls, showing that lower indoor temperature resulted in higher moisture accumulation, especially in the wood frame structure. Also, the yearly moisture accumulation profile exhibited a downward shift throughout the year by adding a vapour retarder with a lower sd-value. In addition, both of the two walls have condensation risk in winter, due to low temperature level. The wood frame structure has a bigger fluctuation and higher condensation risk than the concrete structure.

• 한국전기전자재료학회논문지
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• 제37권4호
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• pp.347-357
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• 2024

Oxide semiconductor gas sensors are widely used for detecting toxic, explosive, and flammable gases due to their simple structure, cost-effectiveness, and potential integration into compact devices. However, their reliable gas detection is hindered by a longstanding issue known as humidity dependence, wherein the sensor resistance and gas response change significantly in the presence of moisture. This problem has persisted since the inception of oxide semiconductor gas sensors in the 1960s. This paper explores the root causes of humidity dependence in oxide semiconductor gas sensors and presents strategies to address this challenge. Mitigation strategies include functionalizing the gas-sensing material with noble metal/transition metal oxides and rare-earth/rare-earth oxides, as well as implementing a moisture barrier layer to prevent moisture diffusion into the gas-sensing film. Developing oxide semiconductor gas sensors immune to humidity dependence is expected to yield substantial socioeconomic benefits by enabling medical diagnosis, food quality assessment, environmental monitoring, and sensor network establishment.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.106-111
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• 2012

5 kg/hr 벤치규모 기류건조기를 이용한 고수분 석탄의 건조 특성을 알아보았다. 도착시료 기준으로 원료 석탄의 수분 함량 및 발열량은 각각 29.74 wt%, 4,270 kcal/kg이다. 가스유입온도 및 가스유입속도는 각각 $400{\sim}600^{\circ}C$ 및 10~20 m/sec이다. 원료 석탄의 입자크기는 $100{\sim}2,000{\mu}m$로 분쇄 및 분급하였다. 원료석탄의 수분제거율은 가스유입온도는 증가하고 가스유입속도는 감소할수록 급격하게 증가하였다. 건조석탄의 발열량은 5,100~5,900 kcal/kg으로 증가하였다. 기류건조를 통한 고수분 석탄 표면에서의 발생하는 화학적인 변화를 알아보기 위하여 FT-IR 스펙트럼 분석을 실시하였다. 그 결과 하이드록실, 카르복실 및 카보닐 피크에서 주요한 변화가 일어나는 것을 확인할 수 있었다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.101-112
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• 1995

In order to improve the recovery efficiency of heavy water vapour from the atmosphere inside a reactor building, and to recover and upgrade the heavy water which escape, special treatments, such as reducing the ingress of light water vapour, are studied in the design of the CANDU reactor systems. This is considered in controlled method of the humidity over drawing fresh air through a desiccant dehumidifier which dries the air by absorption. Comparing with the moisture loads between summer and winter operations, the moisture removal rates are calculated. Those are proportional to the difference between the controlled space and the surrounding environment Installation of a new dehumidifier will be able to reduce the moisture loads from the cooling systems, improving overall system efficiency and saving operating costs.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.196.2-196
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• 2002

• Asian Journal of Atmospheric Environment
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• 제4권2호
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• pp.63-71
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• 2010

The removal characteristics for aromatic and aliphatic VOCs by electron beam (EB) were discussed in terms of several removal variables such as initial VOC concentration, absorbed dose, background gas, moisture content, reactor material and inlet temperature. It was reviewed that only reactor material was an independent variable among the potential control factors concerned. It was also suggested that main mechanism by EB should be radical reaction for the VOC removal rather than that by primary electrons. It was discussed that the removal efficiency of benzene was lower than that of hexane due to a closed benzene ring. In the case of aromatic VOCs, it was observed that the decomposition of the VOCs with more functional groups attached on the benzene ring was much easier than those with less ones. As for aliphatic VOCs, it was also implied that the longer carbon chain was, the higher the removal efficiency became. An EB-catalyst hybrid system was discussed as an alternative way to remove VOCs more effectively than EB-only system due to much less by-products. This hybrid included supporting materials such as cordierite, Y-zeolite, and $\gamma$-alumina.

• 드라이브 ㆍ 컨트롤
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• 제16권2호
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• pp.51-58
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• 2019

In this study, flow analysis and dehumidification experiment were conducted on hollow fiber membrane module to determine the dehumidification characteristics of its various configurations. A quantitative analysis of the CFD for four different models with a temperature of $30^{\circ}C$ and 30%RH inlet humidity was conducted. Each model has different shape parameters i.e. the number of hollow fiber membranes and the presence or absence of baffles. After comparison between the flow analysis results and dehumidification experiment results, the percentage error was found to be approximately 2%. The moisture removal rate for each model was calculated using flow analysis data. It was found that the moisture removal rate of refined model with three baffles and eight hollow fiber membranes was highest among the four modeled modules of hollow fiber membrane one, i.e. about 60%.

• 한국치위생학회지
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• 제4권2호
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• pp.277-291
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• 2004

The purpose of this study is to analyze the dental hygienists' overall performance in operative restoration and the clinical performance in operative restoration according to dental hygienists' career and to provide basic data for establishing the appropriate range of dental hygienists' work. Subjects of this study are 339 dental hygienists working at dental clinic and hospital nationwide, selected by their working place, career, type of clinic, and location of clinical institution. The distribution of people who responded to the survey shows that 81 belong to beginner level(less than 2 years since entering clinic), 115 intermediate level(2 to 3 years since entering clinic), 81 higher level(4 to 5 years since entering clinic) and 62 advanced level(more than 6 years since their entering clinic). In terms of the types of clinical institution, 178 belong to dental clinics and 161 belong to dental hospitals. The survey used in this study are focused on perception about clinical performance in operative dentistry and adequacy of the work. Operative dentistry consists of operative restoration and endodontic therapy. The operative restoration consists of 15 categories such as patient welcoming, examination and diagnosis, planning of treatment, anesthesia, control of moisture, cavity preparation, pulp protection, matrix band application, amalgam filling, resin filling, glass ionomer cement filling, abrasive strip removal, rubber dam removal, bite check and polishing, patient education, and arrangement. The reliability was Cronbach's Alpha .9453. SPSS 10.0 for Windows was used to analyze the responses. One way ANOVA was utilized to verify the differences in the dental hygienists' job performance in operative restoration and their job performance according to career. When significant difference was found. Duncan multi comparison post hoc was done. To sum up the results of this study, patient welcoming look the first place in the operative restoration. It was followed by patient education, examination and diagnosis, introducing treatment plan, resin filling, glass ionomer cement filling, amalgam filling, bite check and polishing, anesthesia, pulp protection, control of moisture, abrasive strip removal, cavity preparation, matrix band application, rubber dam removal, and anesthesia. In terms of the clinical performance by career, there were significant differences in 19 activities such as medical eraluation, oral examination, patient charting, intra oral readio graphs, firm developing fixing mounting, curing light gun, education of attention content after operation. Based on the results of this study, the specific range of operative restoration for dental hygienists should be focused on providing basic data for dentists' diagnosis, alleviation of fear and aching accompanied by injection and anesthesia, data providing for dentists' decision of anesthesia degree, and maximization of control of moisture.