• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.282-288
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• 2005

This study was carried out to estimate aboveground carbon contents associated with four years of thinning treatment of Quercus acuta stands in Wando Arboretum, Jeonnam. Stand thinning was conducted over four years using stand table projection for each thinning treatment. Ten sample trees were cut in the surveyed area. Estimation of aboveground biomass was made using the equation model $W=aD+bD^2$ where W is oven dry weight and D is DBH in cm. The total aboveground biomass for each intensity treatment area was : control (148.4 ton/ha), light (105.6 ton/ha), moderate (68.7 ton/ha) and heavy (39.1 ton/ha). Aboveground carbon storage for Quercus acuta stands was found by multiplying dry weigh t (ton/ha) by 0.5. Carbon storage and increment after four years was: control (74.2 tonC/ha), light (52.8 tonC/ha), moderate (34.3 tonC/ha) and heavy thinning intensity area (38.2tonC/ha).

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.246-248
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• 2001

본 연구에서는 섬유상담체가 설치된 고정화 생촉매 air-lift bioreactor를 개발하여 HDS(hydrodesulfuriza tion)를 거친 디젤유를 대상으로 고심도 탈황을 시도하였다. 생촉매의 활성유지와 세포성장에 필요한 탄소원으로는 glucose보다 sucrose가 더 유리한 것으로 나타났다. 반복회분탈황반응을 통하여 약 60 시간 만에 디젤 중 황함량이 550ppm 에서 50ppm 이하로 감소되었다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.82-82
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• 2011

최근 국내외 섬유시장은 생활패턴의 변화로 레저 활동 인구가 급증하고, 스포츠 및 케쥬얼 의류의 대한 수요가 증가하고 있어 다기능성을 발휘하는 소재에 대한 관심이 높아지고 기존의 기능성과 차별화된 신소재 및 기능성 소비자 needs가 증가되고 있다. 코코넛 활성탄소 함유 PET 원사는 최근 H사에서 코코넛 열매껍질을 원료로 탄화시켜 얻어진 활성탄소를 polyester에 혼입 방사하여 상용화 단계에 있는 원사로 우수한 흡한속건성, 항균, 소취성 그리고 UV 차단 기능성 등 최근 소비자의 needs에 맞는 고기능성 신섬유 소재로 기존의 유사 기능성 섬유(숯, 대나무, 기능성 무기물 혼입 원사 등)에 비해 물질의 표면적과 공극이 넓어 보다 탁월한 성능을 발휘하는 것으로 알려져 있지만 활성탄소를 함유한 원사로 짙은 원착색으로 인해 의복의 심미성이 크게 떨어지는 단점이 있어 이를 보완 할 필요성이 있다. 본 연구에서는 상용화 단계의 코코넛 활성탄소 함유 PET 원사의 심미성을 보완 할 수 있는 편직기술과 활성탄소 입자 소실을 방지하고 기능성 발현에 알맞은 염색 가공 공정을 확립하여 심미성과 기능성을 갖는 기능성 원단을 개발하였고 개발된 원단의 물성과 기능성을 평가하였다.

• Composites Research
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• v.13 no.6
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• pp.55-62
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• 2000

The strength test was done for the Carbon/Carbon rotor disk which is the critical part of a carbon/carbon brake system in an operating time. The loading fixture was designed for the static strength test of a single carbon/carbon brake disk using finite element analysis. To simulate the real dynamic system in a static condition, the friction surface of the rotor disk was fixed and static load was applied to the rotor slot in the circumferential direction. The described failure mechanism of the brake disk can be described as matrix cracking occurred first at the contact surface of the rotor slot, subsequent delamination from the cracked contact surface, and the final fracture at the notch of the rotor.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.181-195
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• 2020

Characteristics of carbonized biomass obtained from a Wood charcoal briquette manufacturing process using an open hearth kiln are analyzed in this research, and differences in the characteristics based on the results of a mechanical screening process and the position within the kiln. One type of biomass and five types of carbonized biomass were collected from a Wood charcoal briquette manufacturer. After screening and grinding processes were performed on samples of 1 type of biomass and 5 types of carbonized biomass extracted from a Wood charcoal briquettes manufacturer to classify by particle size, fixed carbon, ash, volatile matters, elemental composition, and high heating value (HHV) were measured. Experimental results showed that the carbonized biomass collected from the middle layer had the highest HHV, 20.4 MJ/kg, and therefore had the highest fuel quality. In terms of particle size, the carbonized biomass below 100 mesh had the lowest ash content and the highest HHV, carbon content, and fixed carbon content. Correlation analyses showed that ash content had negative correlations with HHV, volatile matters, fixed carbon, and carbon content, which suggested that ash content affected negatively on fuel quality.

• Polymer(Korea)
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• v.34 no.2
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• pp.150-153
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• 2010

In this research, biomolecule-immobilized multi-walled carbon nanotubes (MWCNTs) were prepared by using radiation-induced graft polymerization. For the immobilization of biomolecules, the surface of MWNCTs was functionalized by radiation-induced graft polymerization of acrylic acid. Based on the results of TGA and Raman spectroscopy it was found that acrylic acid was effectively graft-polymerized on the MWCNTs. Biomolecules such as DNA and proteins were immobilized onto the resultant poly(acrylic acid)-grafted MWCNTs. The results of the X-ray photoelectron spectroscopy and fluorescence microscopy confirmed that the biomoelcules were successfully immobilized on the poly(acrylic acid)-grafted MWCNTs.

• Computational Structural Engineering
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• v.4 no.1
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• pp.73-82
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• 1991

Recently, the finite element method has been sucessfully extended to treat the rather complex phenomena such as nonlinear buckling problems which are of considerable practical interest. In this study, a finite element program to evaluate the elasto-plastic buckling stress is developed. The Stowell's deformation theory for the plastic buckling of flat plates, which is in good agreement with experimental results, is used to evaluate bending stiffness matrix. A bifurcation analysis is performed to compute the elasto-plastic buckling stress. The subspace iteration method is employed to find the eigenvalues. The results are compared with corresponding exact solutions to the governing equations presented by Stowell and also with experimental data due to Pride. The developed program is applied to obtain elastic and elasto-plastic buckling stresses for various loading cases. The effect of different plate aspect ratio is also investigated.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.198-199
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• 2009

킬레이팅 고분자를 메조기공 탄소 표면 위에 흡착시킴으로써 금속이온과 착물을 형성할 수 있는 기능성 나노구조체를 제조하였다. 악티늄족 원소를 단일입자 내에 영구처분을 위한 예비연구로서 Eu을 대용물(surrogate)로 사용하여 기능성 나노 구조체에 주입한 후 메조기공 입구를 고분자반응을 통해 봉쇄함으로써 Eu의 단일입자 내 고정화를 시도하였다. 시간에 따라 침출현상을 분석한 결과, 고분자로 메조기공을 blocking 하였을 때 Eu의 침출현상이 크게 완화되는 것을 확인하였다. 이는 시멘트화나 유리화 등과 같은 고비용 공정을 거치지 않고도 단일입자 내 유해 금속의 영구처분이 가능하다는 것을 의미한다. 더 나아가, 이러한 접근방법은 지지체로 메조기공 탄소에 국한되지 않고 실리카와 같은 다른 메조기공 금속산화물에 적용될 수 있다는 점에서 큰 강점이 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.11
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• pp.1004-1009
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• 2012

Carbon nanotube are nanostructure with extraordinary field emission properties like high current density, low driving voltage and long time stability, because of their high electrical conductivity, high aspect ratio for geometrical field enhancement and superior thermal stability. But, there is some problem to mate metal and carbon nanotube, we have resolved this problem by using interfacial graphene. This approach takes advantage of superior electric and thermal conductivity between metal and carbon nanotube and shows superior performance compared to the existing field emitters. This result shows that such a carbon nanotube emitter in a stage where it can be used for Field Emission Electric Propulsion (FEEP).

• Journal of the Korean Electrochemical Society
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• v.12 no.3
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• pp.287-294
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• 2009

Desalination effects of Capacitive deionization(CDI) process using activated carbon $TiO_2$ composite electrode. In this study, we made the activated carbon electrod and activated carbon $TiO_2$ composite electrode, which analysed at cyclic voltammetry and charge-discharge. The results measured for discharge capacitance in cyclic voltammetry were 125 F/g in activated carbon electrode and capacitance of activatd carbon composite electrode was increased about two time, 243 F/g. The $TiO_2$ content of activated carbon composite electrode was 10 wt.%. When it was added wtih TiO2, electric double layer adsorption content was increased, so it was increased 25% in ion removal ratio of activated carbon electrode.