• 폴리머
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• 제36권3호
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• pp.302-308
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• 2012

본 연구의 목적은 대기압 플라즈마 처리된 평판형 폴리프로필렌(polypropylene, PP) 필름 표면 위에 폴리비닐피롤리돈(poly($N$-vinyl-2-pyrrolidone), PVP)을 그래프트 공중합시키기 위한 최적 조건을 찾는데 있다. 대기압 플라즈마 처리 조건은 RF power 200W, Ar 유속 6 LPM, 처리시간 30초, 처리 후 노출시간은 5분으로 고정하였다. 그래프트 공중합에서는 중합 시간, 중합 온도, 비닐피롤리돈($N$-vinyl-2-pyrrolidone, NVP) 농도의 조건을 각각 달리하여 표면 그래프트도의 변화를 조사하였다. 그 결과, 중합 시간 6시간, 중합 온도 $90^{\circ}C$, NVP 농도 40%에서 가장 높은 그래프트도를 나타내었다. ATR-FTIR, X-ray photoelectron spectroscopy(XPS), SEM 분석을 통해서도 PVP의 도입을 확인할 수 있었다.

• 폴리머
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• 제36권1호
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• pp.65-70
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• 2012

글리시딜메타크릴레이트(GMA)의 플라즈마 유도 그래프트 공중합을 통해 기재로 사용한 평판형 폴리프로필렌 위에 에폭시 그룹을 도입하였다. 그래프트 공중합은 에멀젼 공중합법을 적용하였고, 기존의 용액 공중합과 비교하여 그 효과를 확인하고자 하였다. 대기압 플라즈마 처리 조건은 RF power 200 W, 처리시간 30초, Ar 기체 유속 6 LPM으로 고정하였고, 처리 후의 대기 중 노출시간 역시 5분으로 고정하였다. 중합반응에서는 GMA의 농도, 반응온도, 반응시간에 따라 표면 그래프트도의 변화를 최적화하였다. 그 결과, GMA 농도 12%, 반응온도 $90^{\circ}C$, 반응시간 5시간으로 중합하였을 때 가장 높은 그래프트도를 나타내었다. 분석 결과, 같은 반응조건 하에서 에멀젼 중합이 용액 중합에 비하여 더 많은 에폭시 그롭 도입에 효과적임을 확인하였다.

• 폴리머
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• 제26권2호
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• pp.160-167
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• 2002

E-beam 전조사법을 이용하여 HPP-g-GMA 공중합체와 아민화 반응을 통한 아민화 HPP-g-GMA 이온교환체를 합성하였다. 그라프트율은 GMA 단량체 농도가 증가함에 따라 증가하였으며 GMA 단량체 농도가 1.46 M에서 그라프트율이 130%로 최대를 나타냈다. 아민화율은 그라프트율이 증가함에 따라 증가하는 경향을 나타내었으며, 그라프트율이 100%일 때 37.4%로 최대값을 나타내었다. 아민화 HPP-g-GMA 섬유이온교환체의 이온교환용량은 약 3.78 meq/g으로써 흡착 성능이 매우 우수한 소재임을 확인하였다. BET 분석결과 아민화 HPP-g-GMA의 비표면적은 54.83 $\m^2/g$, 기공크기는 $26\AA$으로 반응전보다 비표면적은 감소하였고 기공크기는 약간 증가하는 경향을 보였다. 또한 SEM 분석 결과, 반응 후 섬유의 두께가 굵어짐을 관찰하였으며 기공 막힘현상이 관찰되지 않았으며 이로부터 본 연구에서 합성한 섬유이온교환체가 음이온 흡착.분리에 적합함을 확인하였다.

• The Journal of Korean Physical Therapy
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• 제12권2호
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• pp.191-201
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• 2000

This study was investigated the effects of a direct current and ultrasound on transdermal transport of dexamethasone into the rabbits which had contusion in the thigh. Each group was treated under the tallowing conditions. 1. EXP group I : $10\%$ dexamethasone ointment and ultrasound 2. EXP group II : $1\%$aqueous solution of dexamethasone and iontophoresis 3. EXP group III : the application of $10\%$ dexamethasone ointment 4. Control group : No treatment The degree of anti-inflammation was evaluated by the naked eye, the change in girth of thigh, and a light microscope. The results were as follows. 1.8y the naked eye. an inflammation sign was seen in all groups and especially. symptoms of redness. heat swelling were prominent in EXP group I. 2. In comparision in the change of girth of thigh, only EXP group II showed no significant change. Therefore, it meant that there was effective anti-inflammatory reaction in EXP group II. 3. The infiltration of inflammation cells, the degree of swelling, and the degree of crosslinking of connective tissues were evaluated with a light microscope. As a result, EXP group II showed the most effective anti-inflammatory reaction. And, in order of EXP group III, control group, the effect of anti-inflammation reaction was decreased. 4. EXP group I showed more intensive inflammation than control group.

• 한국운동역학회지
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• 제18권3호
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• pp.71-82
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• 2008

본 연구의 목적은 $20^{\circ}$ 경사로에 서 앞 뒤 보행 동작 시 지면반력 형태를 비교 분석하고자 한다. 본 연구를 위해서 두 대의 지면 반력기를 통해 전 후, 좌 우, 수직 지면반력값, 최대값, 최소값, 평균값 압력 중심 변위, 부하율과 감소율을 측정하였다. BD보행 시 RTO 시점에서 수직 지면반력값이 FU 보행에 비해 유의하게 높은 수치를 보인 반면, $RHC_2$ 시점에서는 더 낮은 수치를 보였다. 이는 보행 동작의 차이와 보행 시 발목과 무릎의 위치 변화, 무게 중심의 변화가 지면 반력의 형태에 직접적인 영향을 미치는 것으로 판단되어진다. 전 후 압력중심변위는 하향 보행 시 상향 보행에 비해 낮은 변화를 보였는데 이는 하향 시 생기는 불안정성을 상쇄하기 위해 더 강한 제동력이 발생되어 진 것으로 사료되어 진다. BD보행 시 부하율이 다른 보행에 비해 낮은 것을 알 수 있는데 이러한 결과를 통해 등산로에서 후방 보행 동작이 하지 근골격계에 지속적인 스트레스를 감소시켜 상해를 예방할 수 있는 방법으로 제시될 수 있을 것이다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.103-108
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• 1998

A hydrophobic substrate triolein was hydrolyzed by lipase in a mono-phase reaction system containing cyclodextrin(CD) as emulsifier. The triolein was transformation to an emulsion-like state in the CD containing reaction system in contrast to the oil-droplet like state without CD due to the formation of an inclusion complex between the lipids and CDs. The hydyrolysis reaction increased substantially in the CD containing reaction system, and the optimum reaction conditions including the amount of lipase, ${\beta}$-CD concentration, and mixing ratio of triolein and ${\beta}$-CD, were determined. The performance of the enzyme reaction in a mono-phase reaction system was compared with that of a two-phase reaction system which used water immiscible hexane as the organic solvent. The role of a CD in the mono-phase reaction system was elucidated by comparing the degree of the inclusion complex formation with triolein and oleic acid, Km and Vmax values, and product inhibition by oleic aicd in aqueous and CD containing reaction systems. The resulting enhanced reaction seems to be caused by two phenomena; the increased accessibility of lipase to triolein and reduced product inhibition by oleic acid through the formation of an inclusion complex.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.187-187
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• 2010

In this study, we investigated the effect of electrodes on resistance switching of TaOx film. Pt, Ni, TiN, Ti and Al metal electrodes having the different oxidation degree were deposited on TaOx/Pt stack. Unipolar resistance switching behavior in Pt or Ni/TaOx/Pt MIM stacks was investigated, but bipolar resistance switching behavior in TiN, Ti or Al /TaOx/Pt MIM stacks was shown. We investigated that the voltage dependence of capacitance was decreased with higher oxidation degree of metal electrodes. Through the C-V results, we expected that linearity ($\alpha$) and quadratic ($\beta$) coefficient was reduced with an increase of interface layer between top electrode and Tantalum oxide. Transmission Electron Microscope (TEM) images depicted the thickness of interface layer formed with different oxidation degree of top electrode. Unipolar resistance switching behavior shown in lower oxidation degree of top electrode was expected to be generated by the formation of the conducting path in TaOx film. But redox reaction in interface between top electrode and Tantalum oxide may play an important role on bipolar resistance switching behavior exhibited in higher oxidation degree of top electrode. We expected that the resistance switching characteristics were determined by oxidation degree of metal electrodes.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.369-373
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• 2002

The liquid phase oxidation of p-xylene has been carried out with oxygen-enriched gas, and the manganese component was precipitated probably via over-oxidation to $Mn^{4+}$. The precipitation increased with rising oxygen concentration in the reaction gas and occurred mainly in the later part of the oxidation. The activity of the reaction decreased, and the blackening of the product and side reactions to carbon dioxide increased with the degree of precipitation. Precipitation can be decreased with the addition of metal ions, such as cerium, chromium and iron.

• 한국세라믹학회지
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• 제32권6호
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• pp.677-684
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• 1995

The effect of catalytic graphitization of petroleum cokes by the addition of aluminum were investigated. The degree of graphitization carbon body only fired at 230$0^{\circ}C$ was 0.5. But when the aluminum additive was added, the degree of graphitization was increased to 0.93. And Ts-effect was appeared as the catalytic effect. This effect was occurred by the formation-decomposition of aluminum carbide through the reaction of aluminum and cokes.

• 대한치과의사협회지
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• 제11권12호
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• pp.783-786
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• 1973

The healing response may very with the tissue, the site and the degree of wound. the author observed histochemically the epithelial regeneration in the har palate wound of healthy male albino rats, varying in age from 120 to 150 days, and weighing about 100 gm. The deep wounds were made antero-posterior linealy by surgical knife to the depth of bone level. They were sacrified by ether anesthesia on 1, 2, 4, 7, 10 and 14 days after wounding. the staining methods used were Mcmanus' PAS reaction, Mowry's modification of the Hale reaction employing Muller's colloidal iron reagent, alloxan-Schiff reaction and hematoxylin-eosin stain. The results were as follows : 1. In the wound healing of hard palate, the epithelium had marked PAS positive reaction in the granular and the prickle cell layers on the from 2nd to 7th day. 2. Alloxan-Schiff reactions of regenerated epithelium were slightly increased on 7th day.