• 공업화학
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• 제10권1호
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• pp.118-123
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• 1999

본 연구에서는 자동차의 instrument panel로부터 분리, 회수된 재생 PC/ABS계에 흡착되어 있는 PU foam이 가공온도조건에 따라 PC/ABS계의 모폴로지 및 기계적 물성에 미치는 영향을 조사함으로써 상용화제 첨가없이 PU의 열적성질을 이용한 모폴로지 제어에 의해 큰 폭의 물성저하를 막아 재생 PC/ABS를 자동차 라디에디터 그릴 소재로 적용하고자 하였다. 가공 온도조건에 따른 PU의 열적특성에 초점을 맞추어 고온 ($260^{\circ}C$) 및 저온 ($220^{\circ}C$)에서 재생PC/ABS와 신재 PC/ABS를 다양한 조성으로 용융 블렌드하여 고차구조 및 기계적 물성을 조사하였다. 신재 함량이 증가함에 따라 물성이 향상되었고, 고온 및 저온용융 블렌드물의 물성에는 큰 차이가 없었으나 충격강도는 고온용융 블렌드물이 월등히 우수하였다. 이것은 PU foam이 고온에서 높은 전단응력을 받아 보다 미세하고 균일하게 분산되었기 때문이라는 것을 발견했다.

• 동의신경정신과학회지
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• 제15권2호
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• pp.103-118
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• 2004

Objective : This experiment was designed to investigate the effect of KongJin-dan(KJD) on the Alzheimer's disease. Method : The effects of KJD on $LI-1{\beta}$, IL-6, $TNF-{\alpha}$, amyloid precursor proteins(APP), acetylcholinesterase(AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 and THP-1 cell treated by CT105 and AChE activity, APP production of PC-12 cell lysate treated by CT105 were investigated, respectively. Results : 1. KJD suppressed $LI-1{\beta}$, IL-6, $TNF-{\alpha}$, APP, AChE, GFAP mRNA in THP-1 and PC-12 cell treated by CT105. 2. KJD suppressed AChE activity and production of APP significantly in cell lysate of PC-12 cell treated by CT105. Conclusions : This study shows that KJD might be usefully applied for prevention and treatment of Alzheimer's disease.

• 동의생리병리학회지
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• 제20권1호
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• pp.138-148
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• 2006

This research investigated the effect of the CMT and SCMT on Alzheimer's disease. The effects of the CMT and SCMT extract on expression of proinflammatory cytokine(IL-$1{\beta}$, IL-6, TNF-$\alpha$) in the THP-1 cell; amyloid precursor proteins(APP), acetylcholinesterase(AChE) mRNA of PC-12 cells treated with CT105; the AChE activity and the APP production of PC-12 cell lysate treated with CT105 were investigated. The CMT and SCMT extract suppressed overexpression of IL-$1{\beta}$, IL-6, TNF-$\alpha$ in the THP-1 cell treated dy LPS; the expression of APP, AChE mRNA in PC-12 cells treated with CT105; the AChE activity and the production of APP in PC-12 cell Iysate treated with CT105 significantly. This study suggest that CMT and SCMT may be effective for the prevention and treatment of Alzheimer's disease.

• 한국표면공학회지
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• 제41권1호
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• pp.33-37
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• 2008

Polycarbonate has a high transmittance to light, low specific gravity, flexibility and cost-effectiveness that extends the application field of the polymer to bio-engineering, optics, electronic parts, etc. Moreover, electro plating of metallic film on PC could endow the parts the electromagnetic interference shielding capability. However, poor adhesion of copper on PC limited the wide usage in the industry. In this work, a composite(PC/ABS) and MmSH(Momentary mold Surface Heating) injection process were used to improve the plating characteristics; plating thickness, gloss and adhesion. Also plasma treatment and chemical treatment were employed for improving adhesion. Plating characteristics on PC/ABS were better than those on PC due to the anchoring effect of butadiene. MmSH injection process could ameliorate the gloss and coating adhesion. Also plating thickness and adhesion of PC and PC/ABS were increased by plasma treatment.

• Korea-Australia Rheology Journal
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• 제18권1호
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• pp.1-8
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• 2006

Blend of bisphenol-A polycarbonate (PC) and (acrylonitrile-styrene-acrylic rubber) terpolymer (ASA) having excellent balance in the interfacial properties and mechanical strength was developed for the automobile applications. Since interfacial adhesion between PC and styrne-acrylonitrile copolymer (SAN) matrix of ASA is not strong enough, two different types of compatibilizers, i.e, diblock copolymer composed of tetramethyl polycarbonate (TMPC) and SAN (TMPC-b-SAN) and poly(methyl methacrylate) (PMMA) were examined to improve interfacial adhesion between PC and SAN. TMPC-b-SAN was more effective than PMMA in increasing interfacial adhesion between PC and SAN matrix of ASA (or weld-line strength of PC/ASA blend). When blend composition was fixed, PC/ASA blends exhibited similar mechanical properties except impact strength and weld-line strength. Impact strength of PCI ASA blend at low temperature was influenced by rubber particle size and its morphology. PC/ASA blends containing commercially available PMMA as compatibilizer also exhibited excellent balance in mechanical properties and interfacial adhesion.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.906-909
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• 2001

곤충병원성 선충으로부터 각각 공생박테리아를 분리하여 flask 상에서 7일간 배양하여 공생박테리아의 성장정도, 단백질 분해 효소의 생성, 배양상등액의 꿀벌부채명나방 유충에 대한 살충성 및 지방산 함량에 관한 연구를 수행한 결과 XR-PC 및 XR-MK의 성장 및 살충성이 가장 우수한 것으로 나타났으며 protease 활성은 XR-DR이 배양 4일째 최대 활성을 보였으며, 지방산 함량의 경우 XR-PC 및 XR-HY가 다른 종의 지방산 함량에 비해 12:0, 14:0, 13:0 iso, 16:1 cis 5, 17:0 cyclo에서 함량의 차이를 나타내었다.

• ETRI Journal
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• 제8권1호
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• pp.16-24
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• 1986

본고에서는 network controller인 82588을 이용한 EENET interface board로 IBM PC간의 LAN(Local Area Network)을 구성하고, 각 PC들간의 자원공유와 메세지 전송을 위한 network support programs의 개발에 관하여 기술한다.

• Journal of Astronomy and Space Sciences
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• 제37권1호
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• pp.19-27
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• 2020

Pc1 pulsations are important to consider for the interpretation of wave-particle interactions in the Earth's magnetosphere. In fact, the wave properties of these pulsations change dynamically when they propagate from the source region in the space to the ground. A detailed study of the wave features can help understanding their time evolution mechanisms. In this study, we statistically analyzed Pc1 pulsations observed by a Bohyunsan (BOH) magneto-impedance (MI) sensor located in Korea (L = 1.3) for ~one solar cycle (November 2009-August 2018). In particular, we investigated the temporal occurrence ratio of Pc1 pulsations (considering seasonal, diurnal, and annual variations in the solar cycle), their wave properties (e.g., duration, peak frequency, and bandwidth), and their relationship with geomagnetic activities by considering the Kp and Dst indices in correspondence of the Pc1 pulsation events. We found that the Pc1 waves frequently occurred in March in the dawn (1-3 magnetic local time (MLT)) sector, during the declining phase of the solar cycle. They generally continued for 2-5 minutes, reaching a peak frequency of ~0.9 Hz. Finally, most of the pulsations have strong dependence on the geomagnetic storm and observed during the early recovery phase of the geomagnetic storm.

• Asia pacific journal of information systems
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• 제32권2호
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• pp.307-326
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• 2022

Currently, Mobile-commerce is active around the world, and consumers' online activities have changed significantly from pc-base to mobile-base. Unlike IT advanced countries such as the United States, which experienced PC-based online commerce (hereafter, PC-commerce) before Mobile-commerce, developing countries such as Vietnam have a relatively short history of PC-commerce. Consumers' experience with PC-commerce may affect their acceptance and use of Mobile-commerce. In this study, we tried to see if different online commerce histories differently affect consumers' online purchasing behavior. We selected the United States and Vietnam, with longer PC-commerce experience and shorter one, respectively. Data were collected for the following four groups: 1) the U.S. PC-commerce (n=256), 2) the U.S. Mobile-commerce (n=283), 3) the Vietnamese PC-commerce (n=159), and 4) the Vietnamese Mobile-commerce (n=225). As results, it was first confirmed that different e-commerce histories in developed and developing countries make the online shopping process different. Second, navigability has a huge impact on consumers' decision support satisfaction in Vietnam where PC-commerce history is shorter. Third, we identified that pre-purchase phase is more related with decision support satisfaction and that purchase phase is more related with task support satisfaction.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.433-434
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• 2015

분산전원 연계용 PCS에 적용되는 UL인증은 UL 1741로서 PCS의 H/W Safety를 검사하는 인증 기준이며, UL 1998은 UL 1741의 하위 참조 인증으로 S/W Functional Safety를 요구한다. UL1741은 Grid Code 기준으로 IEEE 1547.1을 요구하며, H/W 관련하여 안정성 측면에서 특정 요구 수준의 달성 유무를 중심으로 검증한다. 본 논문에서는 UL 1741 인증 기준과 S/W 인증인 UL 1998 인증 기준을 분석하고 이를 적용하여 개발한 1MW EES PCS에 대하여 기술한다.