• 한국지반환경공학회 논문집
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• 제11권6호
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• pp.31-37
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• 2010

본 연구에서는 multi-bed 플레이트로 폐열재생 부분과 촉매반응 부분으로 구성되어 있는 복합열산화 시스템(Hybrid Thermal Oxidation System)을 이용하여 저온에서 주입 밸브 교체 시간간격과 유입유량을 변화시켜 VOCs(MEK와 Toluene) 제거를 평가하고자 하였다. $350^{\circ}C$의 연소온도 조건에서 VOCs는 완전히 전환되었으며 당량비에 따른 전환율 또한 100%에 근접하였고, HTO 시스템의 연소실은 좌우측의 온도가 균형을 이루며 열효율이 매우 높아 폐열회수 및 재생이 효율적이었다. 주입 밸브 교체 시간간격과 유입 유량 변화에 따른 HTO시스템에서의 VOCs 제거 효율은, MEK와 Toluene 모두 안정적으로 높은 91.1~97.4%의 효율을 나타내었으며, 보조연료량 증가보다는 밸브교대시간을 길게 하였을때 제거 효율이 증가하는 경향을 보여 보조연료량 증가보다 밸브교대시간을 증가시키는 것이 제거 효율을 높이는데 효율적으로 판단된다. 이와 같은 연구결과를 고려할 때 HTO시스템은 저농에서도 VOCs 제거, 특히 MEK과 Toluene 제거에 매우 안정적이며 콤팩트한 시스템으로 판단되며, 적은 설치 부지로 중소기업이 요구하는 새로운 VOCs 제거 시스템으로 적용 가능하리라 판단된다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.290-297
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• 2002

This paper presents analysis results for the effect of power control strategies on the part load performance of gas turbine based power generation systems utilizing exhaust heat of the gas turbine such as cumbined cycle power plants and regenerative gas turbines. For the combined cycle, part load efficiency variations were compared among different single shaft gas turbines representing various technology levels. Power control strategies considered were fuel only control and IGV control. It has been observed that gas turbines with higher design performances exhibit superior part load performances. Improvement of part load efficiency by adopting air flow modulation was analyzed and it is concluded that since the average combined cycle performance is affected by the range of IGV control as well as its temperature control principle, a control strategy appropriate for the load characteristics of the individual plant should be adopted. For the regenerative gas turbine, it is likewise concluded that maintaining exhaust temperature as high as possible by air flow rate modulation is required to increase part load efficiency.

• 한국유체기계학회 논문집
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• 제6권3호
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• pp.28-35
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• 2003

This paper presents analysis results for the effect of power control strategies on the part load performance of gas turbine based power generation systems utilizing exhaust heat of the gas turbine such as combined cycle power plants and regenerative gas turbines. For the combined cycle, part load efficiency variations were compared among different single shaft gas turbines representing various technology levels. Power control strategies considered were fuel only control and IGV control. It has been observed that gas turbines with higher design performances exhibit superior part load performances. Improvement of part load efficiency of the combined cycle by adopting air flow modulation was analyzed and it was concluded that since the average combined cycle performance is affected by the range of IGV control as well as its temperature control principle, a control strategy appropriate for the load characteristics of the individual plant should be adopted. For the regenerative gas turbine, it is likewise concluded that maintaining exhaust temperature as high as possible by air flow rate modulation is required to increase part load efficiency.

• 한국수소및신에너지학회논문집
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• 제29권2호
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• pp.148-154
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• 2018

This paper presents a comparative analysis of thermodynamic performance of ammonia-water Rankine cycles with and without regeneration and Kalina cycle for recovery of low-temperature heat source. Special attention is paid to the effect of system parameters such as ammonia mass fraction and turbine inlet pressure on the characteristics of the system. Results show that maximum net power can be obtained in the regenerative Rankine cycle for high turbine inlet pressures. However, Kalina cycle shows better net power and thermal efficiency for low turbine inlet pressures, and the optimum ammonia mass fractions of Kalina cycle are lower than Rankine cycles.

• 한국수소및신에너지학회논문집
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• 제34권4호
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• pp.334-341
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• 2023

The purity of hydrogen finally purified in the hydrogen purification process system is greatly influenced by the uniformity of the purification temperature of the dry tower. A in-house code that can be easily used by field designers has been developed to predict the capacity of the appropriate heat source and the time to reach the temperature of the dry tower. A code was developed to predict unsteady heat transfer using Visual Basic for Applications. To verify the developed code, a grid independence test was performed, and finally, calculations were performed for two cases. In the first case, the time for the temperature of the heater jacket to reach 360℃ was about 1,400 seconds when the supply heat source was 1,000 W. And in the second case, the time for the temperature of the heater jacket to reach 360℃ was about 710 seconds when the supply heat source was 2,000 W. It was confirmed that the developed code well describes the actual test data of the regeneration process of adsorption and desorption, and it is judged that the code developed in the design process of various capacity systems will be effectively applied to the heat capacity calculation in the future.

• KIEAE Journal
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• 제13권2호
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• pp.131-139
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• 2013

The aim of this dissertation is establishing internal indicator list for achieving policy goal of Carbon Neutrality Green City. First of all, it started to construct the basic system of planning indicator based on through comprehension of current studies such as advanced researches, government guidelines and green building certifications. And then it was set up final indicator list through inspecting FGI (Focus Group Interview), Verification of suitability, and Analysis of importance). As a result of this research, the planning indicator divided three steps and there were classified four fields in the top-level; Green Land and Ecology, Green Energy, Green Resource and Transportation, Green Living and Institution. According to the data, it deducted four items (ratio of green land, site plan, heat island and management of climate, base of nature ecology) and twelve index in the field of green land and ecology, three item(energy conservation and self-supporting, energy efficiency, new regeneration energy) and twelve index in the field of green energy and regeneration, five items(water resources utilize and circulation, other resource reduction and circulation, public transportation, green transportation plan) and fifteen index. Totally, Planning Indicators of forty nine were deducted. Therefore, there was the result of importance analysis that the indicators of plan and maintain management as the side of space for carbon neutrality were more appreciated than carbon reduction of individual building.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1461-1467
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• 2009

The electric railway is a clean and energy saving system, because it requires relatively less energy than automobiles by transporting the same passengers or goods. Six thousands of vehicles are operated on Korean urban transit system. This system is 95% of regeneration system. Especially, the VVVF-Inverter vehicle has a merit of the highest regeneration rate. Energy consumption is 90% for traction and 10% for auxiliary supply. Braking energy is about 40% of energy consumption. Up to 40% of the tractive power of vehicles capable of returning energy to the power supply can be regenerated during braking and that this energy can be used to feed vehicles which are accelerating at the same time. The energy generated by braking vehicle would simply be converted into waste heat by its braking resistors if no other vehicle is accelerating at exactly the same time. Such synchronized braking and accelerating can not be coordinated, the ESS(energy storage system) stores the energy generated during braking and discharges it again when a vehicle accelerates. This paper presents field tests about the energy saving rate of the developed ESS. when the ESS is on/off, energy saving rate of the ESS is tested. The verification test in the field focused on energy saving.

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.453-462
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• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

• 식물조직배양학회지
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• 제24권5호
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• pp.295-303
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• 1997

Japonica 벼 품종 Taipei 309 성숙 종자의 배반에서 유도된 캘러스로부터 유기 시킨 세포 현탁 배양체에서 원형질체를 분리하여 filter membrane과 feeder 세포를 이용한 여러가지 조건에서 배양하였다. 이러한 조건들은 gelling agents, feeder 세포와 원형질체 밀도, feeder 세포의 종류 및 heat shock 처리 등이며 이들이 filter membrane 배양 방법에서 원형질체 평판 효율에 미치는 효과들을 조사하였다. 원형질체 평판 효율은, Lolium multiflorum을 feeder 세포로 사용하고 (10 mL의 원형질체 배양 배지당 0.5 mL pcv) 원형질체를 mL 당 $5\;\times\;10^{5}$개로 하여 Sea Plague agarose 배지에 원형질체를 배양 했을때 최고치를 얻었다. 원형질체에 heat shock 처리를 했을 때 원형질체 평판 효율은 변화가 없었다. carbohydrate source로서 sucrose로서 sucrose 대신에 maltose를 사용했을 때 식물체 재분화율이 높았으며 원형질체로부터 재분화된 이들 식물체들은 임성을 나타내었다.

• 한국지리정보학회지
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• 제24권1호
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• pp.54-67
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• 2021

현재 셉테드(CPTED) 사업은 지역의 범죄예방을 통해 주민들의 범죄로부터 불안감을 감소시키고 환경개선 등의 효과를 보이고 있다. 하지만 대부분의 셉테드(CPTED) 사업이 주민의 삶의 질, 주민 만족도 제고 등과의 관계에 대한 체계적이고 실증적인 검증 없이 물리적 환경개선 위주로 이루어지고 있다. 따라서 본 연구는 지역 주민을 대상으로 한 AHP 분석과 멘탈맵(mental map) 시각화를 활용 하여 주민의 삶의 질 개선을 위한 도시재생사업에 셉테드(CPTED) 적용 방안을 제시하였다. 이를 위하여 부산지역 4곳의 사례지역을 선정하고, 주민을 대상으로 한 AHP분석을 통해 셉테드(CPTED) 프로그램의 우선순위를 도출하였다. 사회적 무질서에 대한 주민의 멘탈 맵(mental map)을 시각화하여 셉테드(CPTED) 프로그램의 사각지대를 분석하였다. 셉테드(CPTED) 프로그램 우선순위 분석결과 CCTV 및 가로등 설치가 가장 중요한 요소인 것으로 나타났다. 주민의 멘탈 맵(mental map) 분석 결과 기존의 방범시설과 셉테드(CPTED) 프로그램이 물리적인 무질서에 대하여 대부분 해소하고 있는 것으로 분석되었다. 하지만 사회적 무질서에 대해 주민이 느끼는 심리적인 요소는 여러 곳의 사각지대가 존재하는 것으로 나타났다.