• 한국환경보건학회지
• /
• 제27권1호
• /
• pp.1-7
• /
• 2001

Ammonia is used in the manufacture of fertilizers, refrigerants, stabilizers and many household cleaning agents. These wide applications resulted in ammonia contamination in water. Ammonia can be removed from water by physical, biological, and chemical methods. Ozonation is effictive in the treatment of water with low concentration of ammonia. This study is undertaken to provide kinetic data for the ozonation of ammonia with or without hydrogen peroxide. The results were as follows; The destruction rate of ammonia increased gradually with the influent hydrogen peroxide concentration up to 0.23 mM and inhibited in the range of 0.23~11.4mM, and the maximum removal rate of ammonia achieved at 0.23mM of hydrogen peroxide, and the overall kinetics was first order. The combination effect of hydrogen and ozone to oxide ammonia in aqueous solution was better than ozone alone. The reacted ammonia was converted completely to nitrate ion.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1629-1633
• /
• 2004

Liquid is commonly introduced as transversal jets in venturi scrubber which is one of the gas cleaning equipments. The jet dynamics such as penetration and breakup is of fundamental importance to the dust-collection efficiency. We have developed a model that can numerically simulate the breakup of the liquid jet in crossflow. This simulation consists of models on liquid column, jet surface breakup, column fracture and secondary droplet breakup. These models have been embedded in the KIVA3-V code. We have calculated such parameters as the jet penetration, jet trajectory, droplet size, velocity field and the volume flux distribution. The results are compared with the experimental data in this paper.

• 한국의류학회지
• /
• 제27권2호
• /
• pp.200-208
• /
• 2003

The purpose of this study is to propose scientific data and to develop complex\ulcornermultifunctional fibers by applying microcapsules containing rosewood oil on wool fabric. Polyurea was used as wall material of microcapsules. The parameters for adoptable condition are 20min of agitation time, 5000rpm of agitation speed, 4% of emulsifier concentration according to the observation with SEM and particle analyzer. The melting peak of microcapsules was shown to be 280$^{\circ}C$ The amount of released rosewood from microcapsules at 25$^{\circ}C$ was below 1 % and at 40% was below 3%. Therefore, polyurea microcapsules is capable of preserving rosewood oil for long self-life at normal temperature. Antimicrobial activity to dry cleaning and ironing cycle of wool fabric treated with microcapsules were maintained.

• 환경위생공학
• /
• 제17권2호
• /
• pp.1-10
• /
• 2002

Ammonia is used in the manufacture of fertilizers, refrigerants, stabilizers and many household cleaning agents. The wide applications result in ammonia contamination in water. Ammonia can be removed from water by physical, biological, and chemical methods. Especially ozonation is effective in the treatment of water with low concentration of ammonia. Therefore, this study is undertaken to provide kinetic data for the ozonation of ammonia with bromide. The results were as follows; Ammonia oxidized by ozone with bromide catalysis. The denitrification rate of the ammonia increased proportionally to the concentration of bromide, and the overall reaction order was zero. It was also found that the effect of bromide ion concentration on the denitrification can be expressed by Monod type equation and there was no more effect above a proper bromide ion concentration. The reacted ammonia was converted completely to nitrate ion without bromide, but the denitrification of ammonia by ozone was conducted in the presence of bromide.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2009년도 추계학술발표논문집
• /
• pp.212-213
• /
• 2009

본 연구의 목적은 소방공무원이 현장에서 겪는 충격 스트레스로 발생하는 외상 후 스트레스장애 (posttraumatic stress disorder, PTSD) 분석을 통해 위기상황 스트레스 해소 교육 프로그램 기초 자료를 제시하고자 하는 데 있다. 연구 목적을 달성하기 위하여 독립변인(업무부담감, 스트레스, 스트레스 대응) 3개, 매개변인(현장충격 스트레스) 1개, 종속변인(신체적 증상)으로 구성하여 영향력을 파악하였다. 본 연구 대상자는 전국 970명 소방공무원으로 2007년 3월부터 12월까지 구조화된 설문지를 이용하여 조사하였다. 자료분석은 SPSS 14.0과 구조방정식 모형인 AMOS 7.0 통계패키지를 사용하였으며, 정확한 코딩데이터의 입력확인을 위해 데이터클리닝(data cleaning) 작업을 실시하였다. 가설검증을 위하여 구조방정식 모형분석을 실시한 결과, 업무부담감, 스트레스, 현장충격 스트레스가 낮고, 스트레스 대응이 높을 때 신체적 증상이 낮아지는 것으로 나타났다. 서울소방학교와 공동으로 총 10개 차시로 웹기반 교육을 구성하였으며, 2010년 1월부터 소방공무원 전체를 대상으로 웹기반 교육을 실시하고자 한다.

• 한국공작기계학회논문집
• /
• 제15권5호
• /
• pp.37-43
• /
• 2006

The target of this study is development of web based mold discrimination system by matching vision information with CAD database. The use of 2D vision image makes possible speedy mold discrimination from many databases. The image processing such as preprocessing, cleaning is done for obtaining vivid image with object information. The web-based system is a program which runs to exchange messages between a server and a client by making of ActiveX control and the result of mold discrimination is shown on web-browser. For effective feature classification and extraction, signature method is used to make sensible information from 2D data. As a result, the possibility of proposed system is shown as matching feature information from vision image with CAD database samples.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
• /
• pp.205.2-205.2
• /
• 2011

Micro hydraulic turbines take a growing interest because of its small and simple structure as well as high possibility of applying to micro and small hydropower resources. The differential pressure exiting within the city water pipelines can be used efficiently to generate electricity like the energy generated through gravitational potential energy in dams. In order to reduce water pressure at the inlet of water cleaning centers, pressure reducing valves are used widely. Therefore, pressure energy is wasted. Instead of using the pressure reduction valve, a micro counter-rotating hydraulic turbine can be replaced to get energy caused by the large differential pressure found in the city water pipelines. In this study, in order to acquire design data of counter-rotating tubular type micro-turbine, output power, head, and efficiency characteristics due to the diffuser.

• International Journal of Contents
• /
• 제12권3호
• /
• pp.17-21
• /
• 2016

The purpose of this study was to obtain qualitative data on Korean-American dry cleaners' concerns about work-related health and safety and their attitudes toward the use of PPE(Personal Protective Equipment). Two focus group discussions were conducted with convenient samples of Korean-American drycleaners in middle-eastern state. A total of 13 individuals participated in two focus groups. Participants had concerns as both owners and workers. As owners, they were concerned mostly about compliance of environmental regulation and economic depression. The participants knew very little about the hazards of chemical exposure and expressed vague concerns about chemical exposure and health. Majority of participants do not use PPE and had no intention of using it in the future because of their limited knowledge about the hazardous nature of chemical exposure. The findings from this study would guide the development of intervention to increase drycleaners knowledge of chemical exposure and use of PPE.

• Environmental Analysis Health and Toxicology
• /
• 제15권1_2호
• /
• pp.39-43
• /
• 2000

Linear alkyl sulfonates (LAS) constitute a large fraction of the surfactants used in cleaning processes in households, trade and industry Despite the industrial significance and the possible environmental impact of these compounds, the fast and inexpensive determination of LAS concentrations is still a difficult task. In this study, near infrared (NIR) spectroscopy which is a rapid spectroscopic analysis method compared with a traditional analytical method for the measurement of LAS concentration such as HPLC, GC and standard wet chemistry method. NIR spectra of LAS between 0.313 and 25.0% (w/v) in water were utilized to develop a calibration model. The best results (R ＝ 0.998, SEP ＝ 0.244% (w/v)) obtained by using partial least-squares regression with spectral data treatment and 2nd derivatization were comparable to the results (SEC ＝ 0.186% (w/v), SEP ＝ 0.206% (w/v)) obtained by using multiple linear least-squares regression (MLR). However, models based on derivative spectra have no significant advantage with MLR.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
• /
• pp.202-206
• /
• 1994

Mathematical model of the pollution rate of substation insulators is constructed, taking the model parameters as wind speed, wind direction, typhoon conditions and rainfall in an hourly basis. The main feature of model construction is to distinguish the effect of each parameter by separately analyzing the positive and negative pollution causing factors. Model parameters for the insulators of Karatsu substation, Saga, Japan were estimated and model validation was done using the actual data, in which the pollution deposits on the insulators were measured using pilot insulator and 'salt meter'. The proposed model of the pollution rate [mg/cm$^{2}$/hr] enables the identification of the effective parameters and prediction of the pollution rate so that it helps for the automatic decision making for insulator cleaning or the model can be used as a tool for the substation engineers to make precautionary measures.