• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.485-490
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• 2011

Tetrafluoromethane($CF_4$) has been used as etching and chamber cleaning gases for semiconductor manufacturing processes. These gases need to be removed efficiently because of their strong absorption of infrared radiation and long atmospheric lifetime which causes the global warming effect. We have developed a waterjet gliding arc plasma system in which plasma is combined with waterjet and investigated optimum operating conditions for efficient $CF_4$ destruction through enlarging discharge region and producing large amount of OH radicals. The operating conditions are waterjet flow rate, initial $CF_4$ concentration, total gas flow rate, specific energy input. Through the parametric studies, the highest $CF_4$ destruction of 97% was achieved at 2.2% $CF_4$, 7.2 kJ/L SEI, 9 L/min total gas flow rate and 25.5 mL/min waterjet flow rate.

• Clean Technology
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• v.9 no.3
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• pp.107-113
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• 2003

Printing process generates a vast amount of toxical waste and wastewater by the development of printing and publishing industry. The regulations for various environmental pollution material, which were indispensably used in printing industries, were getting stronger. The printing industries should develop the cleaner technologies in order to avoid the regulations. In this paper, the separation characteristics of microfiltration, ultrafiltration, reverse osmosis were surveyed to make basic data for the optimization of process as cleaner technologies for printing industries. The $2kg/cm^2$ of operation pressure were suitable to the U/F System. Because of the permeate of U/F was below 3 NTU as turbidity, which was probed to be possible using the rinsing water in printing process. U/F System,

• KOMUNHWA
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• no.64
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• pp.47-74
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• 2004

The aim of this research is to investigate various aspects and its meanings of Daegu Yangnyongshi Hanbang(韓方: traditional herb medicines) culture being handed down 350 years ago for understanding korean folk medicine. Yangnyongshi(藥令市: Medicinal Herb Mark

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.646-653
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• 2016

This study performed a microbiological hazard analysis, which is required for the application of HACCP (Hazard Analysis Critical Control Point) system to Pteridium aquilinum and Platycodon grandiflorum. The manufacturing process was made by referring to the typical manufacturing process. Based on microbiological hazard analysis, grandiflorum root contained $6.2{\times}10^3CFU/g$ of bacteria, which has the largest amount of bacteria among the agricultural materials. On the other hand, microbiological hazard analysis of the raw materials and after the disinfecting process of confectionery showed a safe result. A microorganism test of the manufacturing environment and workers suggests that the microbiological hazard should be reduced through systematic cleaning, disinfection and accompanied by personal hygiene based on hygiene education for workers.

• Journal of Sensor Science and Technology
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• v.6 no.4
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• pp.307-315
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• 1997

In this paper, a sample chamber which provide easy replacement of ISFET sensor and consume only small sample volume for electrolyte analysis is designed and a 4-channel electrolyte analyzer employing 2-point calibration method is implemented. In addition, we proposed sample loading detection circuit for minimizing sample and calibration solutions and implemented it. Developed electrolyte analyzer consists of control system part and flow system part. For the effective control of the developed hardware, system software is developed as three individual routines ; measuring routine, calibration routine and washing routine.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.225-234
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• 2021

The purpose of this paper is to examine commercialization model of appropriate technology through the case of the Lao-Korea Science and Technology Center (LKSTC). LKSTC has developed washing, water treatment, and sterilization technology in the agrifood sector and three types of pico-hydro generator, Pico-solar hybrid system, and energy remote monitoring technology in the renewable energy sector. Commercialization of appropriate technology was successfully carried out through the establishment of Kaipan community business, school enterprises, and social enterprise. The policy implications are as follows. First, the commercialization of appropriate technology in developing countries should enhance the linkage with the regional development policies of the recipient countries. Second, in order to minimize market risk, innovative technology development and local startup networks should be properly established. Finally, the mid and long term efforts are needed to increase the sustainability of the business.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.457-463
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• 2013

The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of dressing. The hazard analysis examined the main materials, industrial water, microbial evaluation, and airborne microorganisms of each working area, as well as the pathogenic microbial contamination risk. The survey was conducted at SJ Company in Jincheon (Chungchengbuk-do), Korea for 30 days from April 1, 2012 to April 30, 2012. The results showed that raw material microorganisms had a total plate count in industrial water below $3.00{\times}10$ CFU/mL in working room I, working room II, the packing room, washing water, and the inspection room for five times in each place. During dressing production (including heat treatment and mixing), general bacteria were detected at an average of $3{\times}10$ CFU/mL, but yeast, mold, and pathogenic bacteria were not detected. Airborne microbiological evaluation (for total plate count, yeast, and mold) found levels below the legal limit at each working area. While workers were positive for microbes in total plate counts, coliform and Staphylococcus aureus were not detected. In conclusion, standards for hygienic management should be established to prevent and decrease hazards, such as general bacteria and pathogenic microorganisms (for example, E. coli, B. cereus, Listeria spp, Salmonella spp, Staph. aureus, Clostridium perfringens, yeast, and mold), and to found critical limits for microorganisms with an HACCP system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.51-57
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• 2021

The seawater cooling system of naval ships is installed to remove the toxic substances generated by CBR (Chemical, Biological, and Radiological) warfare and reduce the infrared signature of naval ships from outside the hull. The dispersion range of the nozzle is determined according to the injection pressure of seawater and the nozzle type. Therefore, it is necessary to select the appropriate injection pressure and design the optimal nozzles to increase the seawater dispersion area and maximize the efficiency of the cooling system. In this study, the applying feasibility of 3D printing technology to produce an injection nozzle for the seawater cooling system was examined. To this end, the extruded plastic specimens were fabricated by 3D printing, and the physical properties of the specimens were estimated through tensile testing. After this, the strain and stress of the nozzle as a function of the pressure were simulated by applying the estimated results to the finite element analysis. The finite element analysis results showed that the nozzle remained within the elastic range at the optimal pressure. The nozzle was estimated to be structurally stable, and the possibility of this study was confirmed.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.15-15
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• 2023

2020년 기준 국내 상수도 보급률은 99.1% 차지하고 있으며(환경부, 2019), 수도관리차원에서 수돗물은 먹는 물로 시판되어질 만큼 우수한 관리체계를 유지하고 있다. 그 반면에 지하수는 생활용수, 식품가공, 농·축산, 양어, 군부대를 비롯한 전국지역에서 연간 10억 8천만톤 용수를 소비하고 있음에도 (환겨례 신문, 2013; 환경부, 2019) 사용되는 지하수의 약 65%가 음용수 불가판정을 받았으며, 최근 지하수의 오염비율은 급격히 증가하는 추세이다. 특히, 지하수관정의 관리부주의에 의한 수질오염 및 수인성 다제내성균(슈퍼박테리아) 등에 의한 오염사례가 국내는 물론, 국제적으로 다수 보고되고 있는 실정이다 (환경부, 2013). 현재 지하수 수질관리는 공공기관 및 지자체 지정기관을 통해 진행되고 있으며, 검사기간은 수질채취로부터 통상 7~15일정도 소요되어 수질 관리 및 기준, 검사주기에 대한 애로가 많다. 현장 지하수관정에서 실시간 수질을 모니터링하고 이에 연동된 자동 수처리 시스템의 개발 및 도입은 나날이 심각해지는 환경오염 상황에서 선제적 예방과 해결방법으로 중요한 요소기술이다. 현재 지하수오염 및 부적합 음용의 수질처리는 화학약품, 필터여과, UV살균, O₃ (플라즈마)을 이용하는 것이 대표적이나, 화학약품의 경우 2차 오염이나 식품 세척 및 가공에 있어 부적합성의 한계점이 있다. 필터여과의 대표적인 RO필터의 경우 약 50% 순손실이 발생하고, UV 살균의 경우 UV에 의한 사용관리자의 위험 및 장비의 광부식 문제, O₃ 의 경우 고압전류 사용에 따른 위험성 등의 한계점이 나타나고 있다. 지하수 수질정화를 위한 광유도 활성산소(¹O₂, ·O^-₂)는 광감응제에 가시광의 빛 조사를 통해 생성되는 활성산소로의 에너지 및 전자 전이가 동시 진행되어 단일항 산소(¹O₂)와 슈퍼옥사이드 이온(·O^-₂)을 생성하게 된다. 생성된 활성산소는 유해미생물 또는 유기화학물과 개열, 제거, 치환 반응 등을 통해 미생물사멸 및 유해화학물질들이 분해 가능하다. 이를 이용한 지하수 유해미생물 사멸기술, 장비, 실시간 지하수의 분석기술 및 정수처리, 지하수 물순환 시스템 개발뿐만 아니라 지하수 음용수 및 오염개선, 지하수 기저유출에 의한 오염원 저감으로부터 지류·지천, 하천 본류 수질개선 등의 대상지역에 활용 가능하다. 또한 광유도 활성산소는 기존 상수도 수처리에 있어 오존(O₃) 처리와 이산화티탄을 이용한 AOP과정을 단일처리 공정으로, 기존 O₃ 의 특성상 확산 거리가 매우 길어 사람을 포함한 생체 내에 유입 시 다양한 부작용 발생과 O₃ 차폐시설 요구의 문제점 극복의 대안으로 환경 및 인체에 무해한 광유도 활성산소 시스템을 적극적으로 도입 및 적용해야 한다. 본 연구 목적은 정류상태 흡광분광기술을 이용한 실시간 수질 모니터링과 광유도 활성산소를 이용한 유해 미생물의 멸균효능 및 지하수 수질관리 기술로의 적용 가능성을 제시하고자 한다.

• Clean Technology
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• v.30 no.2
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• pp.94-104
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• 2024

Remanufacturing re-commercializes a used product to achieve an equal or higher performance level than the original product by disassembling, cleaning, inspecting, repairing, reconditioning, and reassembling the used product. The remanufacturing industry is a key industry necessary to realize carbon neutrality by 2050. This study uses life cycle assessment to analyze the resource reduction and greenhouse gas reduction effects with and without considering the avoided effect for an injector, which is an automobile part that is actively being remanufactured. The results of this study showed that the resource reduction effect and greenhouse gas reduction effect induced by injector remanufacturing were reduced by 95.30% and 93.88%, respectively, based on one unit without considering the avoided effect. However, when considering the avoided effect, which in this case is the environmental impact of not disposing of the used injector and not having to use natural resources to manufacture a new injector because the used injector was reused during remanufacturing, the resource reduction effect and greenhouse gas reduction effect were 190.91% and 188.33%, respectively. The results of this study are expected to be used in the future to evaluate the amount of environmental impact reduction while considering the avoided effect during remanufacturing and to help develop research methodology for remanufacturing.