• Title/Summary/Keyword: anti-reflection

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4,5-Diaryl-2,2-Dimethyl-3(2Η)Furanone Derivatives as COX-2 Inhibitors-Next Generation Anti-Arthritis Candidate-

  • Shin, Song-Seok;Noh, Min-Soo;Byun, Young-Joo;Park, Jin-Kyu;Kim, Ji-Young;Lim, Kyung-Min;Ha, Jun-Yong;Kim, Jin-Kwan;Lee, Chang-Hoon
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.3-6
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    • 2001
  • Inflammation is an outcome or an end effect of disruption of complex immunological balance. A variety of approaches to control immunological unbalance have been tried, and some of them are in practice in the clinic. Since inflammatory disorders are reflection of very complex immunological responses, it should be difficult to have such disorders under complete control. Thus, most of the drugs, being marketed and under development, possess some degrees of undesired side offsets originating from disruption of immunological balance. Steroids are excellent drugs suppressing inflammation in short term, however, long-term use of steroids would incur a serious side effect of "rebound". Another example is TNF-${\alpha}$-neutralizing agents, such as enbrel and infliximab. TNF-${\alpha}$ has been known to play a key role in the exacerbation of inflammation, and knock-out of TNF-${\alpha}$ is regarded essential to control of chronic inflammation. The TNF-${\alpha}$-neutralizing drugs in the market are regarded very efficient in the management of rheumatoid arthritis. Upon long term use, however, those drugs cause sepsis to a certain proportion of patients. It is ironical that a high plasma level of TNF-${\alpha}$ is known to be responsible for sepsis, and that the drugs scavenging TNF-${\alpha}$ cause sepsis. The above two examples illustrate well the difficulty of discovering an anti-inflammatory drug without unwanted immunological side effects. An anti-inflammatory drug would make a case in the market, as long as the drug has huge therapeutic benefits compared to its expected but unwanted immunological side effects, where cyclooxygenase-2 inhibitors are positioning. In this presentation, will be discussed general aspects of cyclooxygenase-2 inhibition in conjunction with 3(2Η)furanone derivatives, a novel class of COX-2 inhibitors.

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Preparation of Hydrophobic Coating Layers Using Organic-Inorganic Hybrid Compounds Through Particle-to-Binder Process (유-무기 하이브리드 화합물과 Particle-Binder 공정을 이용한 소수성 코팅막 제조)

  • Hwang, Seung-Hee;Kim, Hyo-Won;Kim, Juyoung
    • Journal of Adhesion and Interface
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    • v.21 no.4
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    • pp.143-155
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    • 2020
  • Hydrophobic Organic-Inorganic (O-I) hybrid materials prepared by sol-gel process have been widely used at functional coating fields such as coatings for anti-corrosion, anti-icing, self-cleaning, anti-reflection. The key point for fabricating hydrophobic surface is to optimize the surface energy and roughness of the coating films. There are typical processes to control the surface energy and roughness which are 'In situ fabricating', 'Pre-fluorinating/Post-roughening', 'Pre-roughening/ Post-fluorinating'. In this study, particle-binder process was used for in-situ fabrication of hydrophobic coating films. Various O-I hybrid compounds prepared using several kinds of alkoxysilane compounds were used as a binder for silica nanoparticles at particle-binder process. To study effect of fluorine content and weight ratio of particle : binder on the hydrophobicity and surface morphology, Hydrophobic coating films were prepared onto glass substrate at various content of fluorine content of O-I hybrid binder and weight ratio of particle : binder. The coating films prepared using O-I hybrid binder (GPTi-HF10) having 10 wt% of fluorine content showed the highes water contact angle (107.52±1.6°). The coating films prepared at 1:3 weight ratio of GPTi-HF10 : silica nanoparticle exhibited the highest water contact angle (130.84±1.99°).

Performance Parameters of a Bifacial PV Device and Accurate Measurement Method for the Parameters (양면형 태양광발전 소자의 성능변수 및 이에 대한 정확한 측정방법)

  • Ahn, Seungkyu;Ahn, SeJin;Eo, Young Joo;Yoo, Jinsu;Park, Joo Hyung;Kim, Kihwan;Cho, Ara;Cho, Jun-Sik;Yun, Jae-Ho;Shin, Donghyup;Jung, Inyoung;Gwak, Jihye
    • Current Photovoltaic Research
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    • v.5 no.3
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    • pp.89-94
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    • 2017
  • We have examined the issues on the measurement of bifacial photovoltaic(PV) devices that should be considered in order to ensure a measurement accuracy beyond a certain level and the comparability between the bifacial PV devices. Based on the results of various experiments and previous studies, solutions for these measurement issues are suggested. The most significant technical issues in the performance measurement of the bifacial PV devices are 1) elimination of the effect due to the light reflection on the sample holder surface and 2) the measurement of the expected power generation gain in outdoor operation. The effect due to the light reflection on the sample holder surface can be eliminated by using an anti-reflective sample holder. In case of a reflective sample holder, if the bifacial device have a linear characteristic with respect to the irradiance of incident light, it has been confirmed (through some previous studies and additional experiment) that exact measurement results can be obtained by the correction of the measurement data. In addition, it was also confirmed that the expected power generation gain in the outdoor operation can be obtained by three different methods along with the basic concepts of the bifaciality coefficient, the albedo, and the effective front irradiance.

An Exploration of Multicultural Concepts in Bestselling Children's Picture Books (베스트셀러 그림책에 나타난 다문화교육내용 분석)

  • Kim, Miai;Yoon, Jae Hui
    • Korean Journal of Childcare and Education
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    • v.11 no.4
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    • pp.81-107
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    • 2015
  • Ninety-eight bestselling children's picture books from 2008 to 2014 were analyzed for multicultural education. The criteria used for the analysis included Culture, Diversity, Identity, Equity, Anti-bias, and Cooperation that were drawn from Kim & Park (2011). An examination of the books revealed that they contained concepts of Cooperation, Identity, Culture, and Diversity in their orders of frequency while ideas of Equity and Anti-bias were barely depicted. Differences between domestic and translated books were found. Translated picture books reflected Diversity more frequently than domestic ones. Under a criterion of Culture, Recognizing Differences and Similarities was more frequently portrayed in translated books while Respecting for Cultures was more frequently found in domestic ones. Findings were discussed in terms of bestselling picture books' limitations of dealing with critical multicultural issues, domestic picture books' lack of reflection of changing multicultural realities, fantasy picture books'dealing with critical multicultural issues through metaphors, and possible problems of the books conveying biased or confusing messages. It was suggested that an adult's role is essential when the bestselling literature is used for the purpose of multicultural education. Their deliberate guidance can help young children engaged in critical issues of race, gender, and ability and develop their multicultural sensitivities through literature.

On the Evolution of Hong Kong's Nativism and Its Public Law Solutions (论香港本土主义的流变及其公法应对)

  • Man, Lai Pui;Yinhao, Tan
    • Analyses & Alternatives
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    • v.3 no.1
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    • pp.93-133
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    • 2019
  • Throughout history, there are three clues of dualistic structures for the development of Hong Kong's nativism. First, inward attribution and outward lookingare two paths to the formation of Hong Kong's nativism. In the dualistic framework of "self-others", nativism is formed. The formation path of "outward looking"can be seen everywhere in the construction history of Hong Kong's nativism. It is under the reflection of "two mirrors" with Britain and Chinese mainland that Hong Kong people acquire the concept of "Hong Kong's nativism". Second, there are two aspects of Hong Kong's nativism: economic and cultural aspect and political aspect. With the gradual development of Hong Kong's history, these two aspects come into being and are closely bound up, thus constituting Hong Kong's nativism today. The third clue is the most critical one. The subjectivity of colonization and decolonization are two different forms of Hong Kong people's subjectivity. These three clues run through the whole process of the construction of Hong Kong nativism, and are carried out in three stages of development: "Origin (1960s-1970s): Preliminary Construction of Hong Kong's Nativism", "Development of Hong Kong's Nativism (1980s-1997): Awakening of Political Aspect" and "Formation and Alienation of Hong Kong's Nativism (1997-present): Deformed "decolonization". Along the evolution of Hong Kong's nativism, with the disintegration of colonialism, Hong Kong people have gradually transited from the subjectivity of colonization to the subjectivity of decolonization, but the process of "decolonization" has not been completed up to now.When nativism loses its native complex from the perspective of "inherent in China", and further develops into the "separatism" of anti-constitutional system and anti-national continuity and unity, it will challenge the stability of the relationship between the central government and the Special Administrative Region under the "one country, two systems". At the same time, it will have a greater impact on the political structure and the rule of law system of Hong Kong, and trigger a series of public law problems that need to be solved urgently. In this regard, on the one hand, we should re-clarify the relationship between the central government and the region under the "one country, two systems" in light of the new situation of democratic political development in Hong Kong, and improve Hong Kong's governance mechanism on the basis of the constitution and the basic law; on the other hand, we should actively learn from the German defensive democracy system to systematically interpret, integrate and apply Hong Kong's existing legal resources so as to effectively curb the development of local separatist forces.

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Optical and Electrical Properties of ZnO Hybrid Structure Grown on Glass Substrate by Metal Organic Chemical Vapor Deposition (유기금속화학증착법으로 유리기판 위에 성장된 산화아연 하이브리드 구조의 광학적 전기적 특성)

  • Kim, Dae-Sik;Kang, Byung Hoon;Lee, Chang-Min;Byun, Dongjin
    • Korean Journal of Materials Research
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    • v.24 no.10
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    • pp.543-549
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    • 2014
  • A zinc oxide (ZnO) hybrid structure was successfully fabricated on a glass substrate by metal organic chemical vapor deposition (MOCVD). In-situ growth of a multi-dimensional ZnO hybrid structure was achieved by adjusting the growth temperature to determine the morphologies of either film or nanorods without any catalysts such as Au, Cu, Co, or Sn. The ZnO hybrid structure was composed of one-dimensional (1D) nanorods grown continuously on the two-dimensional (2D) ZnO film. The ZnO film of 2D mode was grown at a relatively low temperature, whereas the ZnO nanorods of 1D mode were grown at a higher temperature. The change of the morphologies of these materials led to improvements of the electrical and optical properties. The ZnO hybrid structure was characterized using various analytical tools. Scanning electron microscopy (SEM) was used to determine the surface morphology of the nanorods, which had grown well on the thin film. The structural characteristics of the polycrystalline ZnO hybrid grown on amorphous glass substrate were investigated by X-ray diffraction (XRD). Hall-effect measurement and a four-point probe were used to characterize the electrical properties. The hybrid structure was shown to be very effective at improving the electrical and the optical properties, decreasing the sheet resistance and the reflectance, and increasing the transmittance via refractive index (RI) engineering. The ZnO hybrid structure grown by MOCVD is very promising for opto-electronic devices as Photoconductive UV Detectors, anti-reflection coatings (ARC), and transparent conductive oxides (TCO).

A Study of Contingency Found in Soft Sculpture and Fashion -Focused on Maurice Frechuret's Type Analysis- (부드러운 조각과 패션에 나타난 우연성에 관한 고찰 -프레쉬레의 유형분석을 중심으로-)

  • Kim, Bo-Young;Geum, Key-Sook
    • Journal of the Korean Society of Costume
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    • v.59 no.5
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    • pp.41-52
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    • 2009
  • In contemporary art, soft materials are used in various forms and ways as a medium expressing contingency beyond a simple nature of materials. In the late 1960's, the appearance of soft sculpture as a refusal of the stereotyped 'Erection' characteristic of traditional sculpture served as an opportunity for more attention to soft materials. Fashion is the reflection of age, and the mirror of society, culture and arts. In other words, soft sculpture and fashion are artistic behaviors in the same context, which have neither been fixed nor erected. This study finds its significance in analyzing correlation between soft sculpture and fashion, and the importance of contingency as artistic expression means in this age when boundaries between genres are obscure, and artistic values are given to fashion. By doing so, it aims to present the direction toward which fashion should face in the future, establishing a new aesthetic consciousness with which more creative and various expressions are available in fashion as well. This study presented as its theoretical background the concept of soft sculpture affected by Marcel Duchamp among representative examples of the contingency that started to appear in art starting in the early 20th century. It also analyzed the soft sculpture appeared in 1960s and the expression methods and features of contingency appeared in fashion after late 1990s through a new approach of piling up, hanging up, and tying, three categories classified by Maurice $Fr{\acute{e}}churet$. Common features of the contingency expressed in soft sculpture and fashion were derived in the analysis, which are intensive effects of energy, values given to physical properties themselves, and esthetics of anti-form.

Atomic layer deposited $Al_2O_3$ for the surface passivation of crystalline silicon solar cells ($Al_2O_3$ 부동화 막의 태양전지 응용)

  • Kim, Sun Hee;Shin, Jeong Hyun;Lee, Jun Hyeok;Lee, Hong Jae;Kim, Bum Sung;Lee, Don Hee
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.73.1-73.1
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    • 2010
  • 태양광 시장은 세계적인 금융 위기 속에서도 점점 그 규모가 확대되고 있다. 시장의 규모가 확대되고 있음에도 불구하고 금융 위기를 겪으면서 생산자 중심의 시장에서 수요자 중심의 시장으로 바뀌게 되었다. 이에 따라 더 적은 비용으로 높은 출력의 제품만이 경쟁력을 가지게 됨으로써 효율이 더욱 이슈화되었다. 여러 태양전지 중 가장 점유율이 높은 결정질 태양전지는 일반적인 양산 공정만으로 효율을 높이는데 한계가 있으므로 selective emitter, back contact, light induced plating 등의 새로운 공정을 도입하여 효율을 높이려는 경향이 나타나고 있다. 본 연구에서는, ALD 장치를 사용하여 결정질 태양전지의 후면을 passivation 함으로써 효율을 높이는 방법을 모색하였다. 부동화 층으로는 $Al_2O_3$를 사용하였으며 셀을 제조하여 평가하였다. 실험방법은 p-type의 웨이퍼를 이용하여 습식으로 texturing 후 $POCl_3$ 용액으로 p-n junction을 형성하였고 anti-reflection 막인 SiNx는 PECVD를 사용하여 R.I 2.05, 80nm 두께로 증착하였다. 그런 다음 후면의 n+ layer를 제거하기 위하여 SiNx에 영향을 미치지 않는 용액을 사용하여 후면을 식각하였다. BSF 층은 screen printer로 Al paste를 printing하여 형성하였고 Al etching용액으로 여분의 Al제거한 후 ALD 장치를 이용하여 $Al_2O_3$를 증착하였다. 마지막으로 전극을 형성한 후 laser로 isolation하여 효율을 평가하였다.

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Study on SiNx double layer anti-reflection coating for crystalline solar cell application (결정질 태양전지 적용을 위한 SiNx 이중구조 반사방지막에 관한 연구)

  • Gong, Daeyeong;Park, Seungman;Yi, Junsin
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.93.1-93.1
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    • 2010
  • 반사방지막은 태양전지 표면에서의 광 반사를 낮춰주며, Si wafer 표면에서의 carrier의 재결합을 줄이는 passivation 역할을 한다. 이를 위한 다양한 물질이 반사방지막으로 사용된다. 단일박막은 passivation 효과가 미미하여 최근 passivation 향상에 도움이 되는 이중구조 반사방지막이 널리 연구되어지고 있다. 하지만 물질이 다양해짐에 따라 공정시간 및 비용이 늘어나고, passivation에 최적화된 물질사용이 필수적으로 요구되는 단점이 있다. 따라서 본 연구에서는 기존에 passivation 효과가 뛰어나다고 알려진 SiNx의 굴절률 가변을 통하여 이중구조를 갖는 박막을 반사방지막으로 이용하여 그 특성을 비교, 분석하였다. SiNx 이중반사방지막은 0.8 Torr~1 Torr의 압력에서 $450^{\circ}C$의 기판온도로 PECVD를 이용하여 증착되었으며 이때의 plasma power는 180mW/$cm^2$으로 고정 하였다. 굴절률 1.9 및 2.3을 갖는 가스 조성비를 이용하여 각 layer의 두께를 20/60nm, 30/50nm, 40/40nm로 가변하였다. 샘플 제작 후 Sun-Voc 측정을 통하여 implied Voc 및 효율을 측정하였다. 단일반사방지막을 사용한 샘플의 경우 608mV의 implied Voc가 측정되었으며, FF는 82.8%, 효율은 17.6%로 측정되었다. 가장 우수한 특성을 나타낸 20/60nm의 두께로 증착된 샘플의 경우 implied Voc는 625mV, FF는 84.1%, 효율은 18.3%로 우수한 결과를 나타내었다. 반사도 측정 결과 단일반사방지막은 2.27%로 높았으나 SiNx 이중구조를 이용한 반사방지막은 1.67%로 낮은 값을 확인 하여 이중구조의 반사방지막이 반사도 저감 및 passivation 효과 향상에 도움이 되는 것을 확인할 수 있었다.

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Characteristics of SiO2 Based Asymmetric Multilayer Thin Films for High Performance Flexible Transparent Electrodes (고성능 유연 투명전극용 SiO2 기반 비대칭 다층 박막의 특성)

  • Jeong, Ji-Won;Kong, Heon;Lee, Hyun-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.1
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    • pp.25-30
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    • 2020
  • Oxide (SiO2)/Metal(Ag)/Oxide(SiO2, ITO, ZnO) multilayer films were fabricated using a magnetron sputtering technique at room temperature on Si (p-type, 100) and a glass substrate. The electrical and optical properties of the asymmetric multilayer films depended on the thickness of the mid-layer film and the type of oxide in the bottom layer. As the metal layer becomes thicker, the sheet resistance decreases. However, the transmittance decreases when the metal layer exceeds a threshold thickness of approximately 10~12 nm. In addition, the sheet resistance and transmittance change according to the type of oxide in the bottom layer. If the oxide has a large resistivity, the overall sheet resistance increases. In addition, the anti-reflection effect changes according to the refractive index of the oxide material. The optical and electrical properties of multilayer films were investigated using an ultraviolet visible (UV-Vis) spectrophotometer and a 4-point probe, respectively. The optimum structure is SiO2 (30 nm)/Ag (10 nm)/ZnO (30 nm) multilayer, with the highest FOM value of 7.7×10-3 Ω-1.