• 생명과학회지
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• 제19권7호
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• pp.859-865
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• 2009

미세소관은 세포골격단백질의 중요한 구성 단백질로 축삭돌기 내에서는 세포막 방향으로 정렬되어 있다. Kinesin superfamily (KIFs)는 세포 내에서 미세소관을 따라 세포 내 소포들을 운반하는 분자 자동차 (molecular motor) 단백질이다. 본 연구에서 우리는 효모 two-hybrid system을 사용하여 KIF1A의 coiled-coil 영역과 결합하는 단백질로 미세소관 불안정화 요소인 SCG10 단백질을 분리하였다. SCG10은 KIFs에서 KIF1A와만 특이적으로 결한 하며, KIF1A의 400에서 820아미노산 부위가 SCG10과의 결합에 필수적임을 효모 two-hybrid assay로 확인하였다. 또한 SCG10의 coiled-coil영역은 KIF1A와의 결합에 필수영역임을 확인하였으며 단백질간의 결합은 Glutathione S-transferase pull-down assay를 통하여 확인하였다. 생쥐의 뇌 파쇄액에 SCG10항체로 면역침강을 행하여 KIF1A를 확인한 결과KIF1A는 SCG10과 특이적으로 같이 침강하였다. 이러한 결과들은 KIF1A는 SCG10와 결합하여 SCG10이 포함된 소포를 미세소관을 따라 이동시킴을 시사한다.

• 농업생명과학연구
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• 제46권6호
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• pp.157-163
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• 2012

새송이버섯(Pleurotus eryngii)은 인기 있는 식용버섯 중의 하나로서 항산화, 항암 또는 면역조절 기능 등의 인체에 유익한 생리활성 기능을 지닌다. 본 연구에서는 새송이버섯 균사체 배양 시 커피음료 생산과정으로부터 폐기되는 커피박(spent coffee ground: SCG) 첨가에 의한 균사체의 생장과 기능성의 변화를 조사하였다. 그 결과, SCG(1-10%, w/v) 첨가 시 생장속도가 상당히 증가하는 경향을 나타내었다. 특히 1% SCG 첨가 시 무첨가에 비해 건조중량이 2.5배 증가함으로써 SCG가 탁월한 새송이버섯 균사체의 생장촉진제 기능이 제시되었다. SCG 첨가에 의하여 균사체의 polysaccharide 함량은 변화가 없었으나 polyphenol량 및 항산화능의 증대를 확인할 수 있었다.

• 대한전자공학회논문지TC
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• 제38권11호
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• pp.9-18
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• 2001

인터넷을 이용한 대부분의 VPN(Virtual Private Network)은 기업 데이터만을 보호하는 형태로 구성되어 있다. 그러므로 다양한 형태의 VPN 구성이 필요하다. 최근에 SCG(Secure Communication Group) 개념을 이용하여 VPN을 구성하는 방법이 연구되고 있다. 본 논문에서는 SCG 구성 방법인 Path-definition 방식과 Arca-definition 방식의 문제점을 분석하고, 인트라넷 VPN 환경에서 SCG 개념을 사용한 VPN 중 적용 가능한 여러 형태의 VPN 모델을 검토한다. 그리고 인터넷에 Area-definition 방식을 적용하고 SCG number를 이용한 계층적 VPN 구성 방법을 제안한다. 제안한 방식의 특성을 각 entity가 관리해야 할 키수 및 인증 회수에 대해 정량적으로 분석하고, 본 방식이 유효함을 나타낸다.

• Composites Research
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• 제36권4호
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• pp.264-269
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• 2023

Spent coffee grounds (SCG) are a ubiquitous byproduct of coffee consumption, representing a significant waste management challenge, as well as an untapped resource for economic development and sustainability. Improper disposal of SCG can result in environmental problems such as methane emissions and leachate production. This study aims to investigate the physicochemical properties of SCG and their potential as a reinforcement material in polypropylene (PP) to fabricate an eco-friendly composite via extrusion and injection molding, with SCG filler ratios ranging from 5-20%. To evaluate the effect of SCG on the morphological and mechanical properties of the bio- composite, thermogravimetric analysis, SEM, tensile, flexural, and impact tests were conducted. The results demonstrated that the addition of SCG lead to a slight increase in brittleness of the composite but did not significantly affect its mechanical properties. Impressively, the presence of a significant organic component in SCG contributed to the enhanced thermal performance of PP/SCG composites. This improvement was evident in terms of increased thermal stability, delayed onset of degradation, and higher maximum degradation temperature as compared to pure PP. These findings suggest that SCG has potential as a filler material for PP composites, with the ability to enhance the material's properties without compromising overall performance.

• 한국포장학회지
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• 제28권2호
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• pp.89-95
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• 2022

The goal of this study was to evaluate the effect of spent coffee grounds (SCG) biofiller on the morphological, thermal, mechanical and hydrolytic degradation characteristics of poly(lactic acid) (PLA) based biocomposites. The PLA-based biocomposite films were fabricated by using a high-viscosity kneading and hot-pressing machine. The PLA/SCG biocomposites were analyzed with SEM, DSC, TGA, UTM and hydrolytic degradation test. Aggregation in the PLA matrix is a result of increasing SCG concentrations. In the thermal properties, it was described that the cold crystallization temperature (T_cc) decreased as SCG was added to PLA. When SCG was incorporated to PLA, the degradation onset temperature (T_onset) revealed a diminish. The elastic modulus increased while tensile strength of PLA diminished as SCG was applied. Through hydrolysis analysis, the decomposition of PLA was accelerated with the addition of SCG. This research confirmed the possibility of devloping an eco-friendly packaging material with high degradability as SCG hasten the breakdown of PLA.

• 대한전기학회논문지
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• 제39권2호
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• pp.142-148
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• 1990

This paper deals with the desing method of Superconducting AC Generator (SCG). The establishment of design principle and design procedure of SCG are included in this study. Electric characteristics of SCG, such as synchronous reactance and sub-sub-transient reactance, are specified first as constraints and the size of SCG is calculated. Synchronous reactance and sub-sub-transient reactance are important factors because they determine the steady state and transient characteristics of SCG, respectively. A 20KVA SCG with double-shielded single-rotor is chosen for the case study. The design procedure proposed in this papar will also be applicable to large scale generators.

• 대한전기학회논문지
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• 제40권6호
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• pp.562-566
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• 1991

Many research and development activities have found that Superconducting Generators (SCG) have advantages such as high efficiency, light weight, small size, large unit size and good steady-state stability over conventional ones. However the transient stability of SCG is comparable to that of conventional ones. One way to improve the transient stability of SCG is to apply quick-response excitation system to the SCG. For this purpose, an SCG with an electrothermal shield of short electric time constants should be developed. In this paper, a new electrothermal shield, called slitted electrothermal shield(SES), is proposed. The SES can easily transmit radiated heat into the ends of the shield as in the conventional electrothermal shields(CES) and can easily pass magnetic flux produced by armature and field windings. By finite element analysis and experimental test, the slitting effects of SES on magnetic shielding are compared. Good agreement is obtained between simulated and test results.

• Environmental Engineering Research
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• 제25권4호
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• pp.470-478
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• 2020

Spent coffee grounds (SCG), the residue after brewing coffee beverage, is a promising biodiesel feedstock due to its high oil contents (15-20%). However, SCG should be pretreated to reduce the high free fatty acid content, which hampers transesterification reaction. To overcome this, we explored a direct transesterification reaction of SCG using ultrasound irradiation and identified the optimal sonication parameters. A high fatty acid methyl ester (FAME) content, up to 97.2%, could be achieved with ultrasound amplitude of 99.2 ㎛, irradiation time of 10 min, and methanol to oil ratio of 7:1 in the presence of potassium hydroxide concentration of 1.25 wt.%. In addition, we demonstrated that ultrasound irradiation is an efficient method to produce biodiesel from untreated SCG in a short time with less energy than the conventional mechanical stirring method. The physical and chemical properties of the SCG biodiesel met the requirements for an alternative fuel to the current commercial biodiesel.

• Journal of Electrochemical Science and Technology
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• 제13권1호
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• pp.159-166
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• 2022

The assembly of the micron-sized Si/CNT/carbon composite wrapped with graphene (SCG composite) is designed and synthesized via a spray drying process. The spherical SCG composite exhibits a high discharge capacity of 1789 mAh g^-1 with an initial coulombic efficiency of 84 %. Moreover, the porous architecture of SCG composite is beneficial for enhancing cycling stability and rate capability. In practice, a blended electrode consisting of spherical SCG composite and natural graphite with a reversible capacity of ~500 mAh g^-1, shows a stable cycle performance with high cycling efficiencies (> 99.5%) during 100 cycles. These superior electrochemical performance are mainly attributed to the robust design and structural stability of the SCG composite during charge and discharge process. It appears that despite the fracture of micro-sized Si particles during repeated cycling, the electrical contact of Si particles can be maintained within the SCG composite by suppressing the direct contact of Si particles with electrolytes.

• 한국지반환경공학회 논문집
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• 제16권4호
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• pp.41-48
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• 2015

현재 우리나라의 커피소비량은 매년 증가하는 추세에 있으며 이에 따라 연간 약 20만 톤의 커피박(Spent Coffee Grounds, SCG)이 발생되고 있으며 SCG는 폐유기물질로 대부분 음식물쓰레기로 분리되어 연간 27만 톤이 수분이 함유된 채로 버려져 심각한 환경적 이슈가 되고 있는 현실이다. 본 연구에서는 커피박의 활용가능성을 평가하기 위해 이화학적 특성분석과 중장기 생육실험을 수행하였으며, 실험결과 기존의 기반재에 SCG를 혼합하는 경우 보습력의 증가와 유기물함량의 보강으로 초기발아나 초기생육은 기존 기반재에 비해 저조하나 중기적으로 발아와 성장이 촉진되는 현상을 보이며 특히 관수중단 등의 상황에서 기존 기반재에 비해 고사율이 낮고 양분의 부족으로 인한 여러 현상이 줄어들고 있는 것으로 확인되었다. 따라서 SCG는 질소성분이 풍부한 폐유기물로 초기성장을 저해하는 특성이 있으나 보습능력과 유기물의 공급으로 장기생장에 유리한 성질을 가지고 있는 것으로 확인되어 기존의 기반재를 대체하거나 보완할 수 있는 재료인 것으로 판단된다.