• 전기화학회지
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• 제21권3호
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• pp.55-60
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• 2018

최근 휴대용 기기의 급속한 발전이 이뤄지고, 다양한 전자제품에서 높은 성능의 이차 전지가 요구됨에 따라 고에너지밀도 특성을 가능케 하는 전극 재료의 연구가 주목받고 있다. 음극의 경우, 기존에 사용하고 있는 흑연재료를 대체하기 위하여 실리콘, 주석 등의 소재와 전이금속 산화물을 새로운 음극재료로 사용하려고 한다. 리튬 바나듐 옥사이드는 리튬 전이금속 산화물 기반의 음극 소재로서 흑연 대비 1.5배의 부피당 용량을 나타낼 수 있다는 장점을 가지고 있으나, 낮은 전기전도도와 입자 파쇄현상으로 인하여 전해질의 분해가 가속화되어 성능이 열화되는 문제점을 가지고 있다. 본 연구에서는 이러한 문제를 개선시키기 위하여 전해질 첨가제를 도입하여 전극/전해질 계면의 개질에 따른 리튬 바나듐 옥사이드의 전기화학적 거동 특성을 보고자 하였다.

• 대한기계학회논문집B
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• 제28권3호
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• pp.265-270
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• 2004

Experiment study on a down scaled two-phase catalytic reactor is presented. As a preliminary step for the development of catalytic reactor, nano-particulate catalyst was prepared. Perovskite La$\_$0.8/Sr$\_$0.2/CoO$_3$is chosen and synthesized as a catalyst considering superior catalytic performance in reduction and oxidation process where oxygen is involved among the reagent. Reactor that has a scale of 2${\times}$10${\times}$25mm was made by machining of A1 block as a layered structure considering further extension to micro-machining. Hydrogen peroxide of 70wt% was adopted as reactant and was provided to the reactor loaded with 1.5 g of catalyst. Reactant flow rate was varied by precision pump with a range of 0.15cc/min to 17.2cc/min. Temperature distribution within reactor was recorded by 3 thermocouples and total amount of liquid product was measured. Temperature distribution and factors that affect temperature were observed and relation between temperature distribution and production rate was also analyzed. Relative time scale plays a significant role in the performance of the reactor. To obtain steady state operation, appropriate ratio of flow rate, catalyst mass and reactor geometry is required and furthermore to get more efficient production rate temperature distribution should be evenly distributed. The database obtained by the experiment will be used as a design parameter for micro reactor.

• 복식문화연구
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• 제15권5호
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• pp.902-915
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• 2007

This study examines decorative features found in the traditional costume of the Miao, one of the minority groups in China, and adapts them for the development of modern Korean-style fashion designs in order to present visual sample data and to introduce techniques. As for the research method, both literature and visual data are examined: the former includes Miao-related books and theses; the latter, pictures from various documents and real-life data in the possession of Seoul Women's University. The study result is as follows: 1. The basic structure of Miao costume is consist of a Caftan-type upper garment and an accentuated lower garment, pleats skirt although they are decorated luxuriously with various techniques such as delicate embroidery and dyeing. 2. Details and trimmings in modern shapes are developed and presented by adding modern materials to satin, twists, cross-stitch embroidery, stripe patterns, geometrical patchwork, machine pleats and smoking, trimmings of fringe & feather, and the border line decoration of coloration, braids, piping, embroidery, belts tied and wound with colorful threads. 3. Detachable accessaries such as front reinforcement strips, back reinforcement strips, belts, decorative aprons and patchwork skirts are developed and designed by adapting highlighted layered effects. 4. The silver decoration used as an necessary by the Miao is suitable for modern fashion design in futuristic sense. Various techniques and decorative features of Miao costume display their true value all the more in modern fashion stream in which ethnic trends draw much attention.

• 복식문화연구
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• 제5권4호
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• pp.68-79
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• 1997

In this thesis which takes fashion advertising that functions a marketing communication as an objective, I try to bear witness to the signifying system of garments though analyzing with semiotic methodology the signifying procedure on the base of the structural concept of Ferdinand de Saussure and the advertisement semiotic theory of Roland Barthes, to make clear their signifying structure and it meaning by understanding the characteristics of contemporary society and its cognitive system. Each sign of fashion advertising transfers the brand image through syntagmatic signification which contains the mythology of goods. Mannish style is encoded as tailored jacket, white shirt, H-silhouette and pants, non-color or being color, and it is presented as a clothing sign of casual wear for career women. Feminine style is encoded as X-silhouette, soutien collar suit style, various colors, and other details with womanly image, and it is presented as a clothing sign for maid or young wife 20\`s or 30\`s. Formal style is encoded as jacket vest, inner wear(blouse), two and three piece dress by pants or skirt and one-piece dress, and it is used in every age and class. Casual style is similar to formal style, but differs only in textile code. Clothing sign for housewives in middle age is encoded as H-silhouette of formal style, long jacket and pants and brown, being and grey colors. Contemporary popular phenomena in the signification of fashion advertising, and its temporal ideology reflected are as follows; According to the context of fashion advertising in the middle of 1990\`s, its fashion is that first, military look applied from the designs of various sort of military uniform and vest look and pant style applied from dandy-style imitated from man\`s wear are popuar. This mean that it reflects the change of point of view on woman\`s role in society today. That is, due to the equality between man and woman, it mirrors the ideology of feminism, and then, describes beautifully professional woman with carrer. Second, because that individualism is underlied for the change of consumer\`s consciousness, standardized popularity is disappeared, and in accordance with the mixture of various trends and personalities proposed every season, layered look that emphasizes individualism, easiness and naturalness is popular.

• 한국결정성장학회지
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• 제24권3호
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• pp.94-98
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• 2014

$LiCoO_2$는 박막 베터리의 양극재료로써 많은 관심을 받고 있다. 본 연구에서는 스핀 코터를 이용한 졸-겔 합성공정과 열처리 과정에 의해서 Au 지지체 위에 $LiCoO_2$ 박막을 합성하였다. 합성된 박막의 구조는 X-선회절분석, 라만분광 광도계를 이용하여 분석하였다. 박막의 입자 형태는 전자현미경에 의해 관찰하였다. X-선회절분석, 라만분광광도계의 결과로부터, $550^{\circ}C$와 $750^{\circ}C$에서 합성된 박막은 스피넬구조와 층상 암염 형 구조를 가지는 박막으로 보이며, $650^{\circ}C$에서 합성된 박막은 층상 암염 형 구조와 스피넬 구조가 혼재되어져 있는 것으로 생각된다. $750^{\circ}C$에서 합성된 박막은 다른 낮은 온도에서 합성된 박막보다 큰 결정질의 균일한 분포의 입자를 가지는 것으로 확인되었다.

• 한국세라믹학회지
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• 제39권3호
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• pp.294-298
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• 2002

다결정 층상 페로브스카이트형 $La_{2.1}Sr_{1.9}Mn_3O_{10}$를 성공적으로 합성하였으며, $La_{2.1}Sr_{1.9}Mn_3O_{10}$의 열기전력, 전기전도 및 자기적 특성을 조사하였다. 0.85T의 자장의 인가 시 자기전이 온도 $T_c$보다 매우 낮은 120K에서 금속-비금속전이 및 약 120%의 음의 $MR(-{\Delta}{\rho}/{\rho}_0)$이 관측되었다. 고온영역에서 small polaron의 특징중의 하나인 매우 큰 전기적 저항 및 열기전력의 활성화 에너지 차가 관측되었다. 전체적인 실험 결과는 small polaron hopping 모델로 설명가능 하였다.

• 한국세라믹학회지
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• 제50권2호
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• pp.122-126
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• 2013

The surface roughness of the inner and outer surfaces of a tube is an important requirement for nuclear fuel cladding. When an inner SiC clad tube, which is considered as an advanced Pressurized Water Cooled Reactor (PWR) clad with a three-layered structure, is fabricated by Chemical Vapor Deposition (CVD), the surface roughness of the substrate, graphite, is an important process parameter. The surface character of the graphite substrate could directly affect the roughness of the inner surface of SiC deposits, which is in contact with a substrate. To evaluate the effects of the surface roughness changes of a substrate, SiC deposits were fabricated using different types of graphite substrates prepared by the following four polishing paths and heat-treatment for purification: (1) polishing with #220 abrasive paper (PP) without heat treatment (HT), (2) polishing with #220 PP with HT, (3) #2400 PP without HT, (4) polishing with #2400 PP with HT. The average surface roughnesses (Ra) of each deposited SiC layer are 4.273, 6.599, 3.069, and $6.401{\mu}m$, respectively. In the low pressure SiC CVD process with a graphite substrate, the removal of graphite particles on the graphite surface during the purification and the temperature increasing process for CVD seemed to affect the surface roughness of SiC deposits. For the lower surface roughness of the as-deposited interlayer of SiC on the graphite substrate, the fine controlled processing with the completed removal of rough scratches and cleaning at each polishing and heat treating step was important.

• 한국의류학회지
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• 제34권11호
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• pp.1767-1778
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• 2010

This study investigates applying $TiO_2$ (titanium dioxide) nanoparticles to polypropylene nonwoven fabrics via electrospinning for the development of UV-protective materials. To fabricate uniform nanocomposite fibers, three types of $TiO_2$ nanoparticles were applied: powder, colloid, and $TiO_2$ coated polymer pellets. $TiO_2$/polyurethane (PU) and $TiO_2$/poly(vinyl alcohol) (PVA) nanocomposite fibers were electrospun and the morphology was examined using a field-emission scanning electron microscope and a transmission electron microscope. Layered fabric systems with electrospun $TiO_2$ nanocomposite fiber webs were developed at various concentrations of $TiO_2$ in a range of the web area density. The effects of $TiO_2$ concentration and web area density on UV-protective properties were examined. When $TiO_2$ colloid was added into a PVA polymer solution, uniform nanocomposite fiber webs in which $TiO_2$ particles were evenly dispersed were produced. Water-soluble PVA nanofiber webs were given a heat treatment to stabilize the electrospun PVA fibrous structure against dissolution in water. $TiO_2$/PVA nanoeomposite fiber webs with 2wt% $TiO_2$ and 3.0g/$m^2$ web area density exhibited an ultraviolet protection factor of greater than 50, indicating excellent UV protection.

• 방송공학회논문지
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• 제19권6호
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• pp.934-941
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• 2014

본 논문에서에서는 FDTD법을 이용하여 크기가 작은 RFID 판독용 2-층 미앤다 내장형 안테나를 나타낸다. FDTD 법으로 얻은 시간영역의 결과를 Fourier 변환하여 최적화된 입력 임피던스, 전반사손실, 정재파비를 주파수 영역에서 계산하였다. 안테나의 최대 대역폭은 $S11{\leq}-10dB$ 에서 0.895~0.93 GHz의 주파수 특성을 보였다. 제안된 소형 내장형 안테나의 측정된 이득은 2.3dBi이며, 상대적으로 높은 이득과 광대역 특성을 제공할 수 있다. 안테나의 반사손실과 이득에 대한 실험데이터도 나타내었으며, FDTD 결과와 비교적 잘 일치하는 특성을 보였다. 이 안테나는 이동통신 분야, 에너지 분야, RFID(Radio Frequency Identification), 가정 네트워크, 방송용, 그리고 다른 이동용 소형 시스템에 적용할 수 있다.

• 대한미생물학회지
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• 제11권1호
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• pp.1-11
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• 1976

Escherichia coli(ATCC 11115)에 실험실등에서 상용하는 여러가지 항균제를 시간별로 처리, 그 변화양상을 전자현미경으로 관찰한 바 그 결과를 요약하면 다음과 같다. 1) 대조군은 3층의 단일막으로 형성된 세포벽에 둘러쌓여 있으며 세포질은 전자밀도가 낮은 nucleoid와 ribosme들이 산재하여 있음을 관찰할 수 있었다. 2) 70% ethanol용액 처리군은 핵물질을 관찰할 수 없었고 세포질은 세포 중앙부로 응집되어 있었으며 세포벽의 외부에서는 bleb 들을 관찰 할 수 있었다. 3) 3% $H_2O_2$ 용액 처리군은 세포내용물의 변화는 70% ethanol 처리군과 대동소이(大同小異)하였으나 세포벽에서는 심한 굴곡현상이 관찰되었다. 4) 5% lysol 용액처리군은 세포질 및 핵물질 부위가 완전히 구분되어 나타났으며 세포질내의 ribosome과립들은 시간이 경과할수록 그 응집현상이 심하였고 세포 외부에는 ribosome 양 과립들이 부착하고 있음이 관찰되었다. 5) 1% DDEGH 용액 처리군은 세포질의 응집 및 세포막과 세포벽이 뚜렷이 관찰되지 않았으며 세포외부에 세포내용물과 동일한 물질로 생각되는 물질이 부착되어 있음을 관찰할 수 있었다. 6) 고압멸균 처리군은 세포막 및 세포벽의 파괴, 탈락 및 세포내용물의 유출현상이 관찰되었다.