• 신재생에너지
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• 제10권4호
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• pp.29-35
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• 2014

Non-used waste heat has recently been paid special attention due to several global warming regulation and energy cost rising. In this study, therefore, thermal energy storage system which uses a solid type heat media has been investigated about the possibility of heat accumulation and heat release for thermal energy storage system. 35kWh of bench-scale thermal storage system was used to investigate the characteristics of the solid type heat media. From the result, it is shown that a solid type heat media should be divided to supply constant heat to the customers' side. It is also shown the flow direction should be considered to reduce temperature difference between top and bottom sides in the thermal storage system.

• 한국군사과학기술학회지
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• 제13권6호
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• pp.1153-1171
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• 2010

Hydrogen is the most abundant element in the universe. Although hydrogen can produce three times more energy than gasoline and seven times than coal, the most challenging problem in utilizing hydrogen as energy carrier is its storage problem. In contrast to the liquid hydrocarbon, hydrogen can not be stored or transported easily and safely because of its extremely low boiling point(21K). Recently scientists have made a tremendous achievement in storing hydrogen capacity in solid state materials such as carbon based and metal organic frameworks materials as well as metal hydrides. In this review the author reviewed the status of the hydrogen storage technologies in solid state, the advantages and disadvantages in each category of materials and the future prospects of hydrogen storage.

• Korean Chemical Engineering Research
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• 제43권4호
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• pp.439-451
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• 2005

수소저장기술은 수소경제를 달성하기 위해 개발해야할 핵심요소기술이다. 이 논문에서는 고체수소저장기술의 최신 개발 동향을 고찰하였다. 나노구조 탄소계 물질(nanostructured carbon materials), 유기금속구조물(metal organic framework, MOFs), 금속수소화물(metal hydrides), 클래스레이트수화물(clathrate hydrates), 금속착수소화물(complex chemical hydrides)과 같은 고체수소저장매체를 중점적으로 고찰하였다. 그 결과 지금까지 개발된 고체수소저장재료의 수소저장용량은 고체의 표면적에 비례하여 증가함을 알 수 있었다. 또한 수송용 탑재형 수소저장 응용을 목적으로 안전하면서도 가역적 고밀도 수소저장이 가능한 기능성 신 나노재료의 개발 방향을 제시하였다.

• 한국식품저장유통학회지
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• 제5권2호
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• pp.127-132
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• 1998

In order to fad out an efficient way of topdressing nitrogen fertilizer in mulch-cropping system of onion(Allium cepa L.), solid, slow-release, and liquid forms of nitrogen fertilizers were allied to cv. 'Changnyungdaego' various number of times at different time, with 5 topdress applications of solid fertilizer serving as a control. Whole basal application of conventional solid fertilizer and 2 slow-release fertilizers were labor-saving and showed improved storage quality of bulbs, but resulted in poor plant growth and considerably low yield due to fertilizer shortage from early April. This suggests that topdress application is necessary. Liquid form of nitrogen fertilizer was more effective for plant growth and yield and saving labor than the solid form. Early applications was effective for increasing yield and storage quality of onion bulbs harvested. Thus two applications of liquid form of nitrogen fertilizer in February and March at rome month interval are recommended in mulch crowing system of onion.

• Composites Research
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• 제37권1호
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• pp.32-39
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• 2024

고체수소저장은 수소 기반 경제 발전과 에너지 저장 기술 혁신의 핵심 주제로 부각되고 있다. 이러한 저장 방식은 압축 및 액화수소 저장 등 기존 방식에 비해 안전성과 저장 및 운용 효율성 측면에서 우수한 특성을 보여주고 있다. 본 연구에서는 다양한 구조적 설계 요소 별로 나노튜브 표면에서의 고체수소저장 성능을 평가하고자 한다. 본 연구는 나노튜브의 저장 메커니즘을 밝히고자 분자 역학 시뮬레이션(MD)을 도입하여 수행되었다. 본 연구의 시뮬레이션에는 다양한 직경, 다중벽 구조(MWNT), 단일벽 구조(SWNT)의 탄소나노튜브(CNT) 및 붕소-질소 나노튜브(BNNT)가 도입되어 진행되었다. 방사형 밀도 함수(RDF)를 통해 다양한 조건에서 수소의 저장 및 효과적인 방출을 분석한 결과, 반경 감소와 이중벽 구조가 고체 수소 저장을 높이는 데 기여하는 것으로 나타났다. 또한, 붕소-질소 나노튜브의 수소 저장 용량은 탄소 나노튜브에 비해 낮게 측정되었지만, 유효 수소 저장 측면에서는 탄소 나노튜브를 훨씬 능가하는 것으로 나타났다.

• 한국전기전자재료학회논문지
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• 제37권1호
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• pp.11-25
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• 2024

Lithium-ion batteries (LIBs) have attracted great attention as the common power source in energy storage fields of large-scale applications such as electrical vehicles (EVs), industries, power plants, and grid-scale energy storage systems (ESSs). Insertion, alloying, and conversion reactions are the main electrochemical energy storage mechanisms in LIBs, which determine their electrochemical properties and performances. The electrochemical reaction mechanisms are determined by several factors including crystal structure, components, and composition of electrode materials. This article reviews a new strategy to compensate for the intrinsic shortcomings of each reaction mechanism by introducing the material systems to form a single compound with different types of reaction mechanisms and to allow the simultaneous hybrid electrochemical reaction of two different mechanisms in a single solid solution phase.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.247-254
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• 2022

Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m³ class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H₂) could also be lowered by about 41.7% compared with liquid hydrogen storage.

• 원예과학기술지
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• 제17권3호
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• pp.341-343
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• 1999

기기적인 분석 방법과 관능검사에 의해 '신고' 배 과실의 품질을 조사하여 저장력 판정의 기준을 정하고자 하였다. 상온저장고 및 $2^{\circ}C$ 저온저장고에 저장한 과실을 주요 품질 요인인 당함량과 경도에 따라 구분한 후 각각의 요인에 따른 식미인지도를 조사하였다. 저장 방식별 저장 가능기간은 식미인지도에 근거한 당함량과 경도의 변화 정도를 조사하여 설정하였다. 수확 60일 후 '신고' 배 과실을 이용하여 식미인지도를 조사한 결과, 경도의 경우 $3.3kg/8mm{\emptyset}$ 이상을 보이는 과실이 적정 식미를 보이는 것으로 평가되었고 당함량의 경우에는 13.0% 이상일 때 식미에 적합한 수준으로 평가되었다. 그러나 당함량은 저장중 지속적인 증가 경향을 보임으로써 저장기간 설정의 기준으로는 부적합한 요인으로 판정되었다. 과실의 경도를 기준으로 볼 때, 적정 식미를 유지하는 '신고' 배의 저장가능 기간은 상온저장이 30일, $2^{\circ}C$에서의 저온 저장은 120일 정도인 것으로 평가되었다.

• 정보저장시스템학회논문집
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• 제11권2호
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• pp.22-25
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• 2015

In this paper, we demonstrate solid-immersion lens based confocal microscopy using super-continuum generation effect. Using super-continuum generation effect, we could diversify the excitation wavelength of confocal microscopy. Further, high refractive index of solid-immersion lens would increase the resolution of confocal microscopy. As a result, by applying the super-continuum generation effect and solid-immersion lens to confocal microscopy, some problems of confocal fluorescent microscopy, the excitation wavelength and the resolution, could be overcome. To verify it, we made home-built solid-immersion lens based confocal microscopy using super-continuum generation effect, and evaluate the performance of the system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.307-308
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• 2019

The Pohang Light Source (PLS) - II is a 3 GeV third-generation synchrotron radiation facility. To inject electron beam from LINAC, a kicker modulator system and kicker magnets are installed in the PLS-II storage ring tunnel. The injected beam then falls into the storage ring beam dynamic aperture. This paper describes the design and implementation of the solid-state kicker modulator for PLS-II. The solid-state kicker modulator is consisted of high voltage solid state switch stacks. the technical considerations of the solid-state switch stacking for kicker modulator is discussed. The achieved capability of the solid-state kicker modulator demonstrates that is fulfills the design requirement of providing half-sine pulsed current of 10kA (peak), 6us (Base-width), with jitter < 2ns (Standard deviation). simulation and experimental results are presented to demonstrate the performance of the solid-state kicker modulator.