• 전기화학회지
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• 제22권1호
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• pp.43-52
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• 2019

리튬이차전지(Lithium Secondary Batteries)를 에너지원으로 채용하는 분야가 다양해짐에 따라, 기존 요구 특성뿐만 아니라 각 분야에 특화된 성능 평가 결과까지 요구하고 있다. 이에 대응하기 위해 각 전지 제조사는 연구 인력을 충원하고 고가의 장비를 지속적으로 도입해서 다수의 전지를 오랜 기간 평가해야 하는 어려움을 겪고 있다. 이를 해소하기 위해, 전지 모델링(Modeling)을 기반으로 한 모사(Simulation) 기법을 도입하여, 실험 횟수를 최소화하고 실험 시간도 단축하려는 시도를 지속하고 있다. 현재까지 다양한 리튬이차전지 모델링 기법이 보고되고 있으며, 목적에 따라 최적 기법이 선택 및 활용되어 왔다. 본 리뷰 논문에서는 뉴만(Newman) 모델을 기반으로 한 전기화학적 모델링(Electrochemical Modeling) 기법을 상세히 설명한다. 특히, 전극 반응속도를 나타내는 버틀러-볼머식(Butler-Volmer Equation), 각 상(Phase)에서 전자와 이온의 균형 방정식 (Material and Charge Balance Equations), 그리고 전지의 온도 변화를 설명할 수 있는 에너지 균형 방정식 (Energy Balance Equation)의 물리적 의미를 쉽게 설명하고, COMSOL Multiphysics를 이용한 간단한 해석 과정과 결과를 제시한다.

• Macromolecular Research
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• 제11권6호
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• pp.399-409
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• 2003

The first esterification reactor in the continuous polymerization of poly(ethylene terephthalate) has been analyzed by solving the material balances for the two-phase system with respect to the solubility of terephthalic acid. The Newton-Raphson method was used to solve the material balance equations instead of the Simplex method that is frequently used for finding a minimum point of a residual rather than a solution of an equation. A solution for the material balance equations, with the constraint of non-zero liquid phase fraction, could not be obtained with the solubility data of Yamada et al., but could be obtained with solubilities over a minimum value that is larger than their data. Thus, the solubility data of Yamada et al. are considered to be too small. On the other hand, the solubility data of Baranova and Kremer are so large that they gave a solution with the liquid phase only. Based on our results, several typical solubility curves satisfying the constraint of a non-zero liquid phase fraction are suggested in this study; we studied the reaction characteristics of the system using these curves. A higher temperature and a lower pressure are preferred for reducing the content of diethylene glycol.

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.581-592
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• 2008

In this study, a conceptual pyroprocess flowsheet has been devised by combining several dry-type unit processes; its applicability as an alternative fuel cycle technology was analyzed. A key point in the evaluation of its applicability to the fuel cycle was the recovery yield of fissile materials from spent fuels as well as the proliferation resistance of the process. The recovery yields of uranium and transuranic elements (TRU) were obtained from a material balance for every unit process composing the whole pyroprocess. The material balances for several elemental groups of interest such as uranium, TRU, rare earth, gaseous fission products, and heat generating elements were calculated on the basis of the knowledge base that is available from domestic and foreign experimental results or technical information presented in open literature. The calculated result of the material balance revealed that uranium and TRU could be recovered at 98.0% and 97.0%, respectively, from a typical PWR spent fuel. Furthermore, the anticipated TRU product was found to emit a non-negligible level of $\gamma$-ray and a significantly higher level of neutrons compared to that of a typical plutonium product obtained from the PUREX process. The results indicate that the product from this conceptual pyroprocessing should be handled in a shielded cell and that this will contribute favorably to retaining proliferation resistance.

• 복식문화연구
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• 제6권4호
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• pp.84-103
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• 1998

The purpose of this study si focused on Futurism style and contemporary fashion in the 20th century, by researching the Giacomo Balla, Fortunato Depero, Tullio Crali, Erenesto Thayate characteristics fashion design. The results of this study are following as : The general traits of Futurism style are classified with aesthetics, formative characteristics. First, aesthetic characteristics are based on H. Bergson's life-phylosophy and F. Nietzche's art theory. Second, formative characteristics is Dynamism. Futurism Dynamism are classified with psychological Dynamism and physical Dynamism. Futurism trends in the costume : first, dynamism in fashion design, second, asymmetrical balance, third, formativeness, forth, technology, fifth, anti-traditionalism. Dynamism are expressed textile, pattern and costuem shape in contemporary dress. Asymmetrical balance are expressed costume silhouette shape and framework through the geometrical asymmetrical balance. Formativeness are agree with Paco Rabanne's fashion design expressed body and movement and phychological world of human through the secondly fabric. Technology are expressed new mechanical dynamism in used technology art and new fashion material by metal. The last, anti-traditionalism is recognized new value and idea in fashion.

• Smart Structures and Systems
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• 제8권4호
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• pp.399-412
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• 2011

This study compares the performance of two smart isolation systems that utilize superelastic shape memory alloys (SMAs) for seismic protection of bridges using energy balance concepts. The first isolation system is a SMA/rubber-based isolation system (SRB-IS) and consists of a laminated rubber bearing that decouples the superstructure from the bridge piers and a SMA device that provides additional energy dissipation and re-centering capacity. The second isolation system, named as superelastic-friction base isolator (S-FBI), combines the superelastic SMAs with a flat steel-Teflon bearing rather than a laminated rubber bearing. Seismic energy equations of a bridge structure with SMA-based isolation systems are established by absolute and relative energy balance formulations. Nonlinear time history analyses are performed in order to assess the effectiveness of the isolation systems and to compare their performance. The program RSPMatch 2005 is employed to generate spectrum compatible ground motions that are used in time history analyses of the isolated bridge. Results indicate that SRB-IS produces higher seismic input energy, recoverable energy and base shears as compared to the S-FBI system. Also, it is shown that combining superelastic SMAs with a sliding bearing rather than rubber bearing significantly reduce the amount of the required SMA material.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.103-107
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• 2002

Ethyl silicate was used as organic binder for alumina refractories. In the present work only 15% of the water required for complete hydrolysis of ethyl silicate was initially added. The balance was provided from the atmosphere under controlled conditions of temperature and rh. The purpose of detailing the possible binder problem areas is more to indicate that the binder can have an effect on ceramic operations.

• 한국환경농학회지
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• 제31권4호
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• pp.308-312
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• 2012

본 연구는 녹비작물-벼 재배 작부체계에서 볏짚과 녹비작물을 전량 회수하여 사료작물로 활용시 농경지 비옥도 관리를 위한 양분수지를 평가하였다. 녹비보리와 헤어리베치 혼파비율에 따른 녹비작물 생산량은 B75H25에서 가장 높게 나타났다. B75H25 처리구의 벼 수량은 NPK 처리구 대비 90%를 보였다. 녹비작물과 볏짚을 전량 회수시 NPK, B100, B75H25, B50H50, B25H75, H100 처리구의 질소 수지는 각각 2.0, -80.8, -104.0, -93.5, -82.9, 76.2 kg N/ha 이었다. 그리고 질소 수지가 가장 낮은 B75H25 처리구의 인산수지는 -50.3 kg P/ha로 가장 낮았다. 따라서 녹비작물-벼 재배 작부체계에서 녹비작물과 볏짚을 전량 사료로 활용시 농경지 비옥도 유지를 위해서 각각 약 90 kg N /ha, 50 kg P/ha의 질소와 인산 시비가 필요한 것으로 나타났다. 그리고 금후 녹비작물을 사료로 활용하고자 할 경우 화학비료 시용량과 적정 녹비작물의 회수량에 관한 연구가 필요한 것으로 판단된다.

• 대한기계학회논문집B
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• 제23권9호
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• pp.1201-1212
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• 1999

A numerical analysis is performed to predict the thermal response and ablation rate for charring or non-charring material which is designed to be used as thermal protection system (TPS). The numerical program composed of in-depth energy balance equation and the aerotherm chemical equilibrium (ACE) program. The ACE program calculates various thermochemical state from ablation products. The developed numerical program is verified by comparing the reported results from literature. The sensitivity tests for input parameters are performed. The thermal behavior of ablating material is mainly affected by density of ablating material, convective heat transfer coefficient and recovery enthalpy of flow field.

• Coupled systems mechanics
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• 제8권5호
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• pp.377-391
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• 2019

The present paper is focused on analyzing the delamination of inhomogeneous multilayered rods of circular cross-section loaded in torsion. The rods are made of concentric longitudinal layers of individual thickness and material properties. A delamination crack is located arbitrary between layers. Thus, the internal and external crack arms have circular and ring-shaped cross-sections, respectively. The layers exhibit continuous material inhomogeneity in radial direction. Besides, the material has non-linear elastic behavior. The delamination is analyzed in terms of the strain energy release rate. General solution to the strain energy release rate is derived by considering the energy balance. The solution is applied to analyze the delamination of cantilever rod. For verification, the strain energy release rate is derived also by considering the complementary strain energy.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.388-389
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• 2005