• 한국산학기술학회논문지
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• 제14권7호
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• pp.3474-3481
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• 2013

본 논문에서는 결함접지구조와 가유전체 기판구조를 이용하여 새로운 초고주파 대역 전송선로 구조가 제안된다. 결함접지구조는 전송선로의 단위길이당 등가의 인덕턴스를 증가시켜 동일한 선폭일 때 전송선로의 특성 임피던스를 키우면서 선로의 길이를 줄여준다. 가유전체 기판구조는 전송선로의 단위길이당 등가의 커패시턴스를 증가시켜, 동일한 선폭일 때 전송선로의 특성 임피던스를 낮추면서 선로의 길이를 줄여준다. 따라서 결함접지구조와 가유전체 기판구조는 모두 전송선로의 길이를 줄이면서 선폭에 대해서는 상보적인 역할을 한다. 그러므로 두 구조가 결합되면 전송선로의 특성 임피던스는 크게 변하지 않은 채 길이만 더욱 줄일 수 있으므로, 초고주파 회로의 소형화에 크게 유리하다. 본 논문에서는 결함접지구조와 가유전체 기판구조를 모두 결합시킨 $35{\sim}100{\Omega}$ 전송선로를 설계하고, 실제로 제작 및 측정하여 그 결과를 제시하는데, 특성 임피던스의 예측값과 측정값이 잘 일치함을 보인다. 동일한 전기적 길이에 대하여 제안한 전송선로는 Fig.준형 마이크로스트립 전송선로에 비하여 불과 55.4~76.9% 물리적 길이를 갖는다.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1077-1086
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• 2001

The sprA and sprB gene encoding chymotrypsin-like proteases Streptomyces griseus protease A (SGPA) and Streptomyces griseus protease B (SGPB) and the sprT gene that encodes Streptomyces griseus trypsin (SGT) were cloned from Streptomyces griseus ATCC10137 and overexpressed in Streptomyces lividans TK24 as a heterologous host. The chymotrypsin activity of tole culture broth measured with the artificial chromogenic substrate , N-succinyl-ala-ala-pro-phe-p-nitroanilide, was 10, 14 and 14 units/mg in the transformants haboring the sprA, sprB and sprD genes, respectively. The growth of S. lividans reached the maximum cell mass after 4 days of culture, yet SGPA and SGPD production started in the stationary phase of cell growth and kept increasing for up to 10 days of culture in an R2YE medium. The trypsin activity of the culture broth measured with the artificial chromogenic substrate , N-${\alpha}$-benzoyl-DL- arginine-p-nitroanilide , was 16 units/mg and SGT production started in the stationary phase of cell growth and kept increasing for up to 10 days of culture in an R2YE medium. The introduction of the sprA gene into S, lividans TK24 triggered the biosynthesis of pigmented antibiotics, actinorhodin and undecylprodigiosin, and induced significant morphological changes in the colonies in Benedict, R2YE, and R1R2 media. In addition, the introduction of the sprT gene also induced morphological changes in the colony shape without affecting the antibiotic production, thereby implying that certain proteases would appear to play very important and specific roles in secondary-metabolites formation and morphological differentiation in Streptomyces.

• 보존과학회지
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• 제35권1호
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• pp.19-31
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• 2019

To study the cleaning effects and post-treatment stability assessment of various methods of cleaning textiles with metal thread, six naturally-soiled historical textiles with metal thread were investigated at the Metropolitan Museum of Art, New York. Prior to the cleaning of fabricated gold, silver, and copper thread that had been glued onto a paper substrate, the artificial deterioration was carried out in a controlled environment with light(UV and daylight), and temperature and humidity factors which would weaken and damage the samples. A synthetic soil mixture was applied to the samples to imitate soil found on the historic and archaeological textiles with metal thread; the cleaning effect and post-treatment assessment were investigated by use of three textile cleaning methods: mechanical cleaning, wet cleaning, and solvent cleaning. While investigating the naturally-soiled textiles with metal thread, it was determined that the soil colors and sizes of contaminating particles of each textile were different due to the diversity of original environmental factors and conditions. After cleaning with kneaded rubber, Stoddard solvent, n-decane or n-hexane, a bright, clean effect was apparent. Kneaded rubber was successful in picking up both large and small particles, but its stickiness caused some of the metal leaf to peel off. Stoddard solvent produced a good cleaning effect, but after use of n-hexane and n-decane in the cleaning process, a white layer of residue remained on the textile's surface. Wet cleaning was not effective and the rapid humidity changes between wet and dry conditions caused the edges of the paper substrate to lose their original shape.

• 대한의용생체공학회:의공학회지
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• 제41권6호
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• pp.228-234
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• 2020

Superparamagnetic iron oxide nanoparticles (SPIONs) are approved by the Food and Drug Administration (FDA) in the United States. SPIONs are used in magnetic resonance imaging (MRI) as contrast agents and targeted delivery in nanomedicine using external magnet sources. SPIONs act as an artificial peroxidase (i.e., nanozyme), and these reactions were highly stable in various pH conditions and temperatures. In this study, we report a nanozyme ability of the clustered SPIONs (CSPIONs) synthesized by the oil-in-water (O/W) method and coated with biocompatible poly(lactic-co-glycolic acid) (PLGA). We hypothesize that the CSPIONs can have high sensitivity toward H2O2 derived from the reaction between a fixed amount of glucose and glucose oxidase (GOX). As a result, CSPIONs oxidized a 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) commonly used as a substrate for hydrogen peroxidase in the presence of H2O2, leading to a change in the color of the substrate. We also utilized a colorimetric assay at 417 nm using various glucose concentrations from 5 mM to 1.25 μM to validate β-D-glucose detection. This study demonstrated that the absorbance value increases along with increasing the glucose level. The results were highly repeated at concentrations below 5 mM (all standard deviations < 0.03). Moreover, the sensitivity and limit of detection were 1.50 and 5.44 μM, respectively, in which CSPIONs are more responsive to glucose than SPIONs. In conclusion, this study suggests that CSPIONs have the potential to be used for glucose detection in diabetic patients using a physiological fluid such as ocular, saliva, and urine.

• 접착 및 계면
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• 제25권2호
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• pp.43-49
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• 2024

최근 유연 유기 시냅스 트랜지스터(flexible organic synaptic transistor, FOST)는 유기 반도체를 채널층으로 하여 유연성, 생체 적합성, 손쉬운 공정성, 복잡성 감소로 인해 주목받고 있다. 또한 기존의 무기 시냅스 소자에 비해 간단한 구조와 낮은 제조 비용으로 인간 뇌의 가소성을 모방할 수 있으므로 차세대 웨어러블 장치 및 소프트 로보틱스 기술에 적용이 가능하다. 유연 유기 시냅스 트랜지스터에서 유기 기판은 소자의 준비 온도에 민감하고 고온 처리 공정은 유기 기판의 열변형을 일으켜 고성능 소자를 제조하기 위해서는 저온용액 기반의 공정 기술이 필요하다. 본 총설에서는 저온 용액 기반 유연 유기 시냅스 트랜지스터 소자의 최신 공정 기술 연구 상황을 요약하고, 이에 따른 문제점과 해결해야 할 과제를 제시하고자 한다.

• 한국응용과학기술학회지
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• 제35권3호
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• pp.857-864
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• 2018

현대인의 눈높이에 맞는 친환경적인 고급품질의 인조진주 제품개발이 세계의 악세사리 및 생활용품 시장에서 요구되고 있다. 본 연구는 고품질의 인조진주 제품을 경제적으로 대량생산하기 위한 방법으로 유기안료를 인조진주 제조용 친환경 무기안료로 대체하고 기존 제조 방식에서 사용하는 주재료였던 니트로셀룰로오스를 우레탄 바인더로 대체하여 광택도가 73.4%에서 86.7%로 증가하였으며 CVD 마감처리 후에는 96%의 높은 광택도를 가졌다. 색차분석 결과 CVD 코팅으로 인하여 빛의 간섭효과 때문에 a*와 b*값이 각각 +37.7에서 +31.9로, +24.5에서 +14.2로 감소하면서 다양한 색을 발현하여 영롱한 빛깔의 인조진주가 제조되었다. 마감 증착된 고품질의 인조진주의 내화학성, 광택도, 색차계, 표면 거칠기, 내마모성, 중금속함량검사, 염수분무테스트 등을 분석하여 품질향상 및 인체 무해성을 확인하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제29권2호
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• pp.198-206
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• 2014

The olive fly Bactrocera oleae (Rossi) is the key pest for olive cultivation worldwide. Substantial effort has been invested in the development of the sterile insect technique (SIT) to control this pest. One of the limitations to develop SIT technology for olive fruit fly is the low ability of wild females to lay eggs in other medium than olive fruits, and their slow adaptation to oviposition in artificial substrates. In the present study, fruit grapes were used as an alternative egg collection medium to harvest eggs and young larvae from freshly colonized wild strains originating from France, Italy, Spain and Croatia. The larvae were allowed to develop into the fruits until the second instar, before they were extracted out and further reared on a standard artificial diet. Furthermore, F1 to F4 female flies were alternatively offered wax bottles to oviposit. Finally, the performance of hybrid strains created from crosses between wild and long colonised flies was assessed. The results showed that females of all 4 wild strains readily oviposited eggs in grapes and from the F2 generation onward, females from all strains were adapted to laying eggs in wax bottles. No difference was observed in eggs and pupae production among all strains tested. The findings are discussed for their implications on SIT application against olive fruit fly.

• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.23-29
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• 2016

In this paper, in order to quantify the peristalsis occurrence in a guinea pig's large intestine, a miniaturized air-gap capacitive pressure sensor was fabricated through micro-electro-mechanical system (MEMS). The proposed pressure sensor is a two-layered biocompatible polyimide substrate consisting of an air-gap capacitive plates between the substrates. The proposed pressure sensor was designed with a careful consideration of the structure and motility mechanism of the guinea pig's large intestine. Artificial pellets were mounted on a prototype pressure sensor to provide some redundancies in the form of size and shape of the guinea pig feces. Capacitance of a prototype sensor was recorded to be 2.5 ~ 3 pF. This capacitance value was later converted to count value using a lab fabricated data conversion system. Sensitivity of the pressure sensor was recorded to be below 1 mmHg per atmospheric pressure. During in vivo testing, artificial peristalsis caused by drug injection was measured by inserting the prototype pressure sensor into the guinea pig's large intestine and pressure data obtained due to artificial peristalsis was graphed using a labview program. The proposed pressure sensor could measure the pressure changes in the proximal, medial, and distal parts of the large intestine. The results of the experiment confirmed that pressure changes of guinea pig's large intestine was proportional to the degree of drug injection.

• 현장농수산연구지
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• 제20권1호
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• pp.35-47
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• 2018

흰깔대기버섯(Clitocybe maxima) 총 6균주를 한국, 중국, 대만에서 수집 확보하였으며, 중국과 대만에서 각각 수집한 C. maxima와 L. giganteus는 중국명이 동일하고 배양적 특성 결과 동일종으로 판단되었다. 수집된 흰깔대기버섯 균주의 균사생장은 한천배지에서는 큰 차이가 없었으나 액체배양에서는 YPMG에서 가장 좋았다. 또한 균사생장 최적온도는 25℃, 자실체 유도 최적온도는 30℃로 밝혀졌으며 균사생장 최적 pH는 6.0-8.0으로 밝혀졌다. 흰깔대기버섯을 인공재배하기 위하여 농산부산물 및 임업부산물을 이용하여 배양적 특성 및 인공재배를 실시하였으며, 볏짚, 미루나무톱밥, 콘코브, 미송배지에서 균사 생장이 양호하여 이를 재배용 배지 재료로 선발하였다. 공시균주를 접종한 7 종류의 배지에서 균사생장 속도는 폐면, 혼합배지2, 미루나무톱밥 순으로 균사 생장이 양호하였다. 흰깔대기버섯을 인공재배하기에 가장 적합한 배지는 혼합배지2(배합비 : 활엽수톱밥 55%, 면실피펠렛 5%, 면실박 10%, 비트펄프 15%, 팽연왕겨 15%)이며, 배양에서부터 수확까지 30여일 소요되어 느타리버섯보다 빠른 수확이 가능하였다. CMA-003 균주는 공시된 모든 배지에서 자실체 유도처리 8~10일 후 자실체 원기 형성되었고, CMA-003 균주는 다발성 발이를, 그 외의 균주들은 개체발이를 보이며, 원기 발생 후 7~17일 생육으로 자실체 수확 할 수 있었다. 다발성인 CMA-003 균주의 대길이, 갓직경과 개체중량은 개체 발이하는 다른 균주들보다 작았지만, 수확률이 높아 농가 재배용 균주를 선발하였다. 흰깔대기버섯 자실체 유도 및 생육에 적합한 온도는 25~30℃, 백색형광등 8시간/1일 조사, 상대습도 : 90~95%, 재배실 CO₂ 농도 1,500 ppm 이하로 유지하여, 국내의 여름철 고온기에 냉방시설이 없는 간이재배사, 영세 느타리버섯 재배 농가에서 재배 가능하였다.

• 한국버섯학회지
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• 제5권3_4호
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• pp.91-97
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• 2007

Shiitake mushroom (Lentinula edodes) is usually cultivated on the oak log. Log cultivation of this mushroom is getting difficult to get oak logs and has a weak point of its long cultivation period. Recently sawdust cultivation is getting increase. It is important to make mycelia browning on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. The development of methods for the rapid mycelia browning is quite required. In this article we would like to discuss about the enzymatic activities related mycelia browning and search the methods of cultivation period reduction.