• 한국수소및신에너지학회논문집
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• 제31권2호
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• pp.234-241
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• 2020

This paper presents a thermodynamic performance analysis of a combined cycle consisting of regenerative organic Rankine cycle (ORC) and liquefied natural gas (LNG) Rankine cycle to recover low-grade heat source and the cold energy of LNG. The mathematical models are developed and the system performances are analyzed in the aspect of thermodynamics. The effects of the turbine inlet pressure and the working fluid on the system performance such as the mass flow rates, heat transfers at heat exchangers, power productions at turbines, and thermal efficiency are systematically investigated. The results show that the thermodynamic performance of ORC such as net power production and thermal efficiency can be significantly improved by the regenerative ORC and the LNG cold energy.

• 유기물자원화
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• 제29권4호
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• pp.77-86
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• 2021

본 연구에서는 유기성폐자원에너지 인센티브제도의 기초자료로 활용하고자 음식물폐기물, 음폐수 및 다양한 유기성폐기물이 처리되는 혐기소화조의 운영방식의 물질수지와 에너지수지 산정 결과를 통하여 에너지효율을 평가하고자 한다. 바이오가스화 시설 11개소의 물질수지 분석 결과 유기성폐기물을 제외한 반입물 중 공정수 21.1%, 시상수 25.7 % 다량 투입되는 것을 확인하였다. 그에 따라 연계처리수의 전체 유출물의 87.6 %를 차지하였다. 또한 총 유입물량의 15.7 %가 바이오가스로 전환되며, 총고형물(TS)가 평균 22 %임을 감안할 때 평균 75 %의 물질 전환율을 확인하였다. 에너지수지 분석 결과, 유입물의 잠재에너지 대비 바이오가스 열량을 분석하여 에너지 전환율은 평균 78.5%을 확인하였다. 바이오가스를 생산하기 위한 외부에너지원을 포함한 바이오가스 생산효율은 평균 69.4 %이며, 미이용된 유출에너지를 적용한 바이오가스 플랜트 효율은 평균 58.9 %로 나타났다.

• 한국물환경학회지
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• 제25권1호
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• pp.18-25
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• 2009

Nitrogen removal and methane production from piggery wastewater were investigated in two-phase anaerobic digestion (TPAD) coupled with biological nitrogen removal (BNR) process at $35^{\circ}C$. Methane production rate was about $0.7L/L{\cdot}day$ at organic loading rate (OLR) of $1.2g{\cdot}TCOD/L{\cdot}day$ in methanogenic UASB. Conversion efficiency of the removed TCOD into methane in UASB was as high as 72% and overall TCOD removal efficiency in this system was over 97%. Ammonia nitrogen were stably removed in BNR system and overall efficiency were 98%. With recirculation of the nitrified final effluent to TPAD, nitrogen oxides were completely removed by anaerobic denitrification in the acidogenic reactor, which did not inhibit the acidogenic activities. Overall TN removal efficiency in the TPAD-BNR system was as high as 94%.

• 한국초지조사료학회지
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• 제27권4호
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• pp.275-280
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• 2007

본 시험은 유기조사료 생산에 적합한 동 하계 사료작물을 선정하고, 이를 통한 지역별 유기조사료 생산을 위한 적정 작부체계를 선발하기 위하여 수행되었다. 관행재배 조건과 유기재배 조건에서의 사료작물별 생육특성의 차이는 하계사료작물에서 현저하게 나타났다. 즉 사료용 옥수수는 잡초 발생으로 생육이 억제되어 관행재배에 비해 현저한 수량감소를 나타낸 반면 수수$\times$수단그라스 교잡종은 잡초 발생이 없어 관행 옥수수 대비 높은 수량을 나타내었다. 동계사료작물은 관행재배와 유기재배에 의한 차이는 크지 않았으나, 생산성 측면에서 이탈리안 라이그라스 보다 호밀이 우수하였다. 따라서 작부체계에 영향을 미치는 요인이 하계 사료작물에서는 잡초의 발생여부, 동계사료작물에서는 사료작물의 종류에 기인됨이 밝혀졌다. 이를 종합적으로 고려한 중부지역에서 유기조사료 생산을 위한 최적 작부체계는 중부지역에서는 수수$\times$수단그라스와 호밀이라 할 수 있다.

• 한국수소및신에너지학회논문집
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• 제19권2호
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• pp.145-155
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• 2008

This paper deals with an economic evaluation of hydrogen production by fermentation. We evaluate the economic feasibility of domestic hydrogen production by fermentation utilizing glucose and waste water sludge in terms of hydrogen production prices. In addition, we make some sensitivity analysis of hydrogen prices by changing the values of input factors such as the price of glucose, the capital cost of the hydrogen production system, and the hydrogen production yields. The estimated hydrogen prices of the two-step dark-light hydrogen production by fermentation utilizing glucose was $5,347won/kgH_2$, and the single-step hydrogen production by anaerobic fermentation utilizing waste water sludge was $4,255won/kgH_2$, respectively. It is expected that the hydrogen production price by anaerobic fermentation can be reduced if we produce methane or hydrogen utilizing by-products such as alcohols and organic acids, or the government imposes some legal regulations on the treatment of waste water sludge.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.597-603
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• 2016

In this paper a comparative thermodynamics analysis is carried out for organic Rankine cycle (ORC) and ammonia-water Rankine cycle (AWRC) utilizing low-grade heat sources. Effects of the working fluid, ammonia concentration, and turbine inlet pressure are systematically investigated on the system performance such as mass flow rate, pressure ratio, turbine-exit volume flow, and net power production as well as the thermal efficiency. Results show that ORC with a proper working fluid shows higher thermal efficiency than AWRC, however, AWRC shows lower mass flow rate of working fluid and lower pressure ratio of expander than ORC.

• 한국유기농업학회지
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• 제19권spc호
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• pp.255-258
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• 2011

When kiwifruit root system infected with nematodes was treated by hot water dipping treatment, the maximum temperature for this treatment was suggested as $50^{\circ}C$. The lowest killing temperature of internal root-knot in the root tissue was $48^{\circ}C$. Consequently, root-knot nematodes could be killed without damaging root tissues by the hot water dipping treatment at $48^{\circ}C$ for 10 minutes. This could be useful for organic production and distribution of kiwifruit seedlings by avoiding the synthetic nematicides which are not easily decomposed in soil once applied.

• KSBB Journal
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• 제19권6호
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• pp.484-488
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• 2004

본 연구에서는 식품부산물을 원료로 사용하여 회분식 발효를 통한 Propionibacterium acidipropionici의 유기산 생산성을 검토하고 세포재순환식 연속발효를 통해 유기산의 대량생산을 위한 기초자료를 마련하고자 하였다. CSL의 함유량에 따른 회분식 발효를 실시하여 균주의 생산성이 최대가 되는 발효조건을 구하여 연속 발효공정에 적용하였다. 희석률을 $0.1{\sim}0.2\;hr^{-1}$로 변화시키며 세포재순환식 연속발효를 실시한 결과 $0.2\;hr^{-1}$에서 최대 세포량은 150 g drycell/L으로 회분식 발효에 비해 21배 증가하였으며, 유기산의 최대 생산성은 3.32 g total acids/L/h로서 13배가 향상된 것으로 나타났다. 따라서 이 발효공정을 scale-up한다면 유기산뿐만 아니라 바이오매스 자원으로서 세포량의 대량생산도 가능할 것으로 판단된다.

• 한국기계가공학회지
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• 제15권5호
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• pp.100-108
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• 2016

In various industries, many researches studies have been done in using nano thin film fabrication technology. In the field of printed electronics, various electronic devices can be fabricated using a direct printing process of on multiple functional materials. It has the advantages of low prices, environment-friendly environmentally friendly, flexibleility, large scale, mass production produced, simple process and so on. In this study, a viable thin film fabrication technology has beenwas introduced using the surface acoustic wave mechanism for thin film deposition. Fabrication of thin films using organic, inorganic and composite of organic/inorganic materials have been were analyzed through the experimental research. In this experiment, organic material MEH:PPV, inorganic material ZnO and composite material MEH:PPV/ZnO have been depo sited as thin films.

• 한국의류학회지
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• 제46권5호
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• pp.927-943
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• 2022

This study explores the organic form generation method, which reflects the evolving biomimetic approaches converging in fashion technology and considers the characteristics of the organic relationship between the body and the clothing to be represented in contemporary fashion. A literature review on biomimetic architecture and design-related theory and a case study on biomimetic fashion were both conducted. Images, articles, and data related to biomimicry fashion and clothing, including the increase in virtual fashion cases around 2020, were analyzed based on the literature review. Biomimicry was used to derive interdisciplinary similarities in the organic morphogenesis principle, and the result was categorized as a network system, folds and unfolds, pneumatic structures, auxetic growth, and membranes. The biomimetic fashion characteristics, including externalization of the body's interior, expansion of the body structure and silhouette, body protection, independence from the body, and post-human expression through virtualization, were analyzed. Morphogenetic processes performed through biomimetic vision are expected to aid in generating research on the possibility of mass production or popularization in the future through various experimental technical studies.