• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.656-662
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• 2013

The iron oxide ($Fe_3O_4$) particles in the coolant of the secondary system of a nuclear power plant reduce the heat transfer performance or induce corrosion on the surface of the heat transfer tube. To prevent these problems, we conducted a study to improve the dispersion stability of iron oxide using polymeric dispersant injection in simulated secondary system water. The three kinds of anionic polymers containing carboxyl groups were selected. The dispersion characteristics of the iron oxide particles with the polymeric dispersants were evaluated by performing a settling test and measuring the transmission, the zeta potential, and the hydrodynamic particle size of the colloid solutions. Polymeric dispersants had a significant impact on the iron oxide dispersion stability in an aqueous solution. While the dispersant injection tended to improve the dispersion stability, the dispersion stability of iron oxide did not increase linearly with an increase in the dispersant concentration. This non-linearity is due to the agglomerations between the iron oxide particles above a critical dispersant concentration. The effect of the dispersant on the dispersion stability improvement was significant when the dispersant concentration ratio (ppm, dispersant/magnetite) was in the range of 0.1 to 0.01. This suggests that the optimization of dispersant concentration is required to maximize the iron oxide removal effect with the dispersant injection considering the applied environments, the iron oxide concentration and the concentration ratio of dispersant to iron oxide.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.453-466
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• 2020

As the demand for eco-friendly energy increases to overcome the energy shortage and environmental pollution crisis, hydrogen economy has been proposed as a potential solution. Accordingly, an economical and efficient hydrogen production is considered to be an essential industrial process. Research on applying hydrogen separation membranes for H₂/CO₂ separation to the production of highly concentrated hydrogen by purifying H₂ and capturing CO₂ simultaneously from synthetic gas produced by gasification is in progress nowadays. In high temperature environments, the membrane separation process using glassy polymeric membrane with H₂ selectivity has the potential for CO₂ capture performance, and is an energy and cost effective system since polybenzimicazole (PBI)-based separators show excellent chemical and mechanical stability under high-temperature operation conditions. Thus, the development of high-performance PBI hydrogen separators has been rapidly progressing in recent years. This overview focuses on the recent developments of PBI-based membranes including structure modified, cross-linked, blended and carbonized membranes for applications to the industrial hydrogen separation process.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.723-732
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• 2017

As the development of ICT technology, in order to solve the problem of scattered water information's availability, WINS(Water management Information Networking System) by the Ministry of Land, Infrastructure and Transport was established and has been operated since 2004. However, there has been a disadvantage of providing specialized and limited information to the water resources sector mainly and a lack of active sharing of information because of no compulsory provision of information sharing between participants. In order to solve these problems, this paper carried out system development study, to do this, the status of domestic water information was surveyed and domestic and overseas related systems were compared and analyzed. The latest ICT technology was used to realize the contents as screen, and the user interface definition was created to present a role model of integrated water management through maximizing visualization by combining GIS and realtime data and providing space-time integrated information. These prior studies reached to actual construction of the ICT-based integrated management system for water information by K-water. This system is in service to the public installed in the water information portal, "MyWater".

• Proceedings of the Membrane Society of Korea Conference
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• 1996.06a
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• pp.91-120
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• 1996

경제발전과 더불어 산업의 많은 분야에서 순수 및 초순순의 사용이 증가하고 있으나, 환경오염에 의한 원수의 오염에 따라 순수 및 초순순제조의 장치비와 처리비용의 증가가 야기되고 있다. 현재 국내에는 화력, 원자력발전소를 비롯하여 열병합발전소, 석유화학공장, 제약회사, 전기 전자부품회사, 반도체회사 및 철강회사 등 많은 분야에서 순수 및 초순수 제조장치의 구성과 성능이 많은 차이를 나타내고 있다. 국내의 초순수 제조장치는 90% 이상이 이온교환수지를 사용하는 이온교환법과 UF, R/O System과 같은 Membrane을 사용하는 Membrane System을 병행하여 적용하고 있다. 국내 초순수처리 Plant에서는 통상 전처리 System과 1차 순수제조 System 및 초순수 System이 상호 연결되어 Plant가 구성 운영되고 있다. 전처리 System에는 응집침전, 여과 흡착, 살균 등이 적용되고 있으며 여과 System에 Membrane을 적용할 수 있으나 국내에서는 특별한 경우를 제외하고 대부분 전처리 여과 System에 Media Filter를 사용한다. 전처리 System도 순수처리 장치의 전처리로는 없어서는 안되는 System이지만 여기에는 전처리 System을 제외하고 국내에서 적용하고 있는 초순수처리 System의 공정현황과 각 System별 특징을 설명하고 있다. 초순순 System에는 요구 수질에 따라 다소 차이가 있지만 반도체 공업에서 사용되는 초순수 System이 이중 최고의 Grade로 반도체공업에서 적용되고 있는 System을 기준하였다. 특히 Membrane을 적용한 초순수제조 System이 증가하고 있어 R/O, ED, EDR, CDI, (EDI)와 같은 Membrane System의 특성과 원리를 검토하였다.대적으로 높은 산소확산계수와 물에 대해서는 낮은 투과도를 가져야 한다. 높은 산소확산계수는 반응을 빠르게 하는 잇점이 있으며 물에 대한 낮은 투과도는 센서내의 전해질 물질을 유지보호하는 역할을 한다. 분리막이 산소전극에 이용될 경우 높은 산소 확산계수 이외에도 적절한 기계적 강도, 열적 안정성 등이 요구된다. 몰입이 가능하여 임계치가 저하된 것으로 여겨진다. 또한 광학적 이득의 존재는 이 구조에 의한 극단파장 반도체 레이저다이오드의 실현 가능성을 나타내는 것이다.548 mL에 비해 통계학적으로 의의 있게 적었다(p<0.05). 결론: 관상동맥우회로 조성수술에서 전방온혈심정지액을 사용할 때 희석되지 많은 고농도 포타슘은 fliud overload와 수혈을 피하고 delivery kit를 사용하지 않음으로써 효과적이고 만족할 만한 심근보호 효과를 보였다.를 보였다.4주까지에서는 비교적 폐포는 정상적 구조를 유지하면서 부분적으로 소폐동맥 중막의 비후와 간질에 호산구 침윤의 소견이 특징적으로 관찰되었다. 결론: 분리 폐 관류는 정맥주입 방법에 비해 고농도의 cisplatin 투여로 인한 다른 장기에서의 농도 증가 없이 폐 조직에 약 50배 정도의 고농도 cisplatin을 투여할 수 있었으며, 또한 분리 폐 관류 시 cisplatin에 의한 직접적 폐 독성은 발견되지 않았다이 낮았으나 통계학적 의의는 없었다[10.0%(4/40) : 8.2%(20/244), p>0.05]. 결론: 비디오흉강경술에서 재발을 낮추기 위해 수술시 폐야 전체를 관찰하여 존재하는 폐기포를 놓치지 않는 것이 중요하며, 폐기포를 확인하지 못한 경우와 이차성 자연기흉에 대해서는 흉막유착술에 더 세심한 주의가 필요하다는 것을 확인하였다. 비디오흉강경수술은 통증이 적고, 입원기간이 짧고, 사회

• Journal of the Korean Wood Science and Technology
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• v.12 no.1
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• pp.11-30
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• 1984

This study was executed to offer the basical data needed to the plywood industry as examining on the wood characteristics of veneer species that grow in Korea. According to the aggravation of log import from foreign countries caused by the gradual exhaustion of wood resources in recent years, the study on wood characteristics of veneer species growing in Korea should be carried out preferentially in promotion of the domestic timber utilization and development of it's processing technique for plywood industry. 50 commercial veneer species in this study were selected from 33 genuses, and general macroseopical wood characteristics for them were examined and described by the species. And also keys for the identification based on gross features were briefly prepared and presented by gymnosperm and angiosperm respectively.

• 대한공업교육학회지
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• v.41 no.2
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• pp.134-150
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• 2016

This study has analyzed the subjects of transportation technology problem solving activities at Energy and Transportation Technology unit in the 12 kinds of middle school Technology Home Economics textbooks of the 2009 national revised curriculum. An analysis frame was developed with systems and environmental mediums which are common elements of transportation and the subjects were analyzed. As a result of this study, first, 8 kinds of subjects among 20 subjects in analysis frame were suggested in the textbooks. Second, according to the environmental, there are 13 terrestrial activities, 2 atmospheric activities, and 1 marine activity in the textbooks. However, there is no space related activity. Third, according to the system, there are 13 activities for the structure, 12 activities for the propulsion and suspension system, 5 activities related to the control system, and 1 activity regarding guidance system. Fourth, there are 4 kinds of problem solving activities depending on categorizing result of the analysis of the activities.

• 대한공업교육학회지
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• v.40 no.2
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• pp.216-238
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• 2015

The purpose of this study was to identify the improvement plan of Korea Network for Occupations and Workers(KNOW) in terms of the information quality and usefulness for undergraduate students.'Homework of occupational information exploration'as research instrument was assigned to the engineering students taking career courses at KoreaTech in Chungnam province, Korea. Data was collected from two-hundred sixty six college students. The main results were as follows: The percentage of awareness of KNOW was very low(7.5%), but the mean of preference(73.5) and usefulness of career readiness(70.6) of KNOW were likely to be high. The information quality of KNOW was analysed in terms of both menu bar and evaluative components. In menu bar, the highest mean of information quality was'wage, job satisfaction, and job outlook'menu bar(71.7). On the other hand'task information on the job'had the lowest mean. In evaluative component, the highest mean of information quality was understandability(73.4), whereas the completeness was at the bottom(63.7). These results implied that the KNOW has the usefulness for engineering students to explore the occupational information and to make ready for career. Nevertheless, it is needed to publicize KNOW and to redeem menu bar and contents for the improvement of this online system.

• 대한공업교육학회지
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• v.31 no.2
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• pp.307-331
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• 2006

The purpose of this study is to find out what the constituents of career development competency are for the students who are majoring in engineering. In this study, the career development competency means that the students in an engineering college should initiatively choose, prepare and adapt themselves for their future career in their lifetime. This study examined all the career-related references that are determined to be linked with the competencies of career development. Also, other references inside and outside of the country that are related to the career key competencies and engineering basic competencies were investigated in this study. Especially, the career development competency in this study was approached with two points of views; the process of career development for students and the ability to maintain and develop the future career in an engineering field. Ultimately, this study derived the conclusion that there are 8 categories and 42 subordinate constituents in the career development competency for the students in an engineering college.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.368-368
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• 2012

부사호는 당초 유역면적이 $288km^2$로 이 중에서 상류 유역에 건설된 보령댐 유역면적 $163.6km^2$(57%)가 제외됨에 따라 부사호로 유입량이 급격히 줄어들어 약간의 가뭄에도 수질악화가 반복되고 있다. 부사호의 합리적인 용수 수급 관리를 위해 정확한 부사호 유입량의 추정은 절실하다. 부사호 유입량은 보령호 방류량과 부사호 지류 유역 유입량으로 구성되며, 보령호 방류량은 소수력 발전용수, 관개용수, 하천유지용수, 홍수조절 방류량, 월류량으로 구성된다. 부사호 지류 유역으로부터 자연유량에서 하천에서 취수한 공업용수를 공급하고, 웅천읍의 생활용수 $1,164m^3$/일로부터 회귀수가 유입되고, 보령댐 수혜답 1039.5 ha에 관개용수를 공급하고 회귀수가 유입되고, 부사호에서 양수하여 공급한 부사 유역 수혜답 1,141 ha의 회귀수가 유입되고, 6개 저수지 수혜답 396.5 ha의 회귀수가 유입되는 등 지류 유입량의 구성은 매우 복잡하다. 하천에서 취수하여 공급하는 공업용수는 서해화력 5천 $m^3$/일, 보령화력 15천 $m^3$/일로 구성된다. ONE (One parameter New Exponential) 모형을 근간으로 유입량 모형을 구성하였고, 보령댐 자료로 매개변수를 결정하여, 1966~2011년의 부사호 일 유입량을 모의한 결과를 요약하면 다음과 같다. 첫째, 유역면적 $124.4km^2$인 부사호의 지류 유입량과 보령댐 방류량을 고려한 부사호 유입량 자료로부터 유황을 분석한 결과는 연평균하여 풍수량은 2.1 mm/d, $3.083m^3/s$, 평수량은 0.89mm/d, $1.280m^3/s$, 저수량은 0.48 mm/d, $0.695m^3/s$, 갈수량은 0.30 mm/d, $0.428m^3/s$였으며, 연 유입량은 127.23백만 $m^3$에 이르렀다. 둘째, 유역면적 $288km^2$인 보령호 유역의 포함한 부사호의 자연 유입량 자료로부터 즉 보령댐이 없는 경우 유황을 분석한 결과는 연평균하여 풍수량은 1.4 mm/d, $4.599m^3/s$, 평수량은 0.51 mm/d, $1.689m^3/s$, 저수량은 0.20 mm/d, $0.664m^3/s$, 갈수량은 0.06 mm/d, $0.204m^3/s$, 연 유입량은 197.00백만 $m^3$에 이르렀다. 셋째, 보령호가 있는 경우와 없는 경우 유황을 비교하면 있는 경우에서 부사호의 유입량은 고수위의 유량은 감소하고, 저수위의 유량은 증가하는 전형적 상류에 위치한 댐의 저류효과 영향을 여실히 나타내고 있었다. 넷째, 한국하천 유황곡선식에 의한 유역면적 $288km^2$인 부사호 유입량의 풍수량은 1.29 mm/d, $4.292m^3/s$, 평수량은 0.59 mm/d, $1.964m^3/s$, 저수량은 0.33 mm/d, $1.093m^3/s$, 갈수량은 0.13mm/d, $0.424m^3$이르렀다. 결론하면, 보령댐이 있는 경우 연 유입량은 70백만 $m^3$ 감소하였으나, 평갈수기 유입량은 증가하였다.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.235-241
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• 2022

According to the World Water Development Report 2015 released by the United Nations, drinking water is expected to decrease by 40% by 2030. This does not mean that the amount of water decreases, but rather that the water source is contaminated due to environmental pollution. Because microbes are deeply related to water quality, the analysis of microbe is very important for water quality management. While the most common method currently used for microbial analysis is microscopic examination of the shape and feature after cell culture, as the gene analysis technology advances, quantitative polymerase chain reaction (qPCR) can be applied to the microscopic microbiological analysis, and the application method has been studied. Among them, a reverse transcription (RT) step enables the analysis of RNA by RT-PCR. Integrated cell culture (ICC)-qPCR shortens the test time by using it with microbial culture analysis, and viability qPCR can reduce the false positive errors of samples collected from natural water source. Multiplex qPCR for improved throughput, and microfluidic qPCR for analysis with limited amount of sample has been developed In this paper, we introduce the case, principle and development direction of the qPCR method applied to the analysis of microorganisms.