• Title/Summary/Keyword: AM materials

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A Study on the Electrical Physical Properties of Organic Thin Films for Manufacture in Power Device

  • Song, Jin-Won;Lee, Kyung-Sup
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.1
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    • pp.18-21
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    • 2005
  • Monolayers of lipids on a water surface have attracted much interest as models of biological membranes, but also as precursors of multilayer systems promising many technical applications. Until now, many methodologies have been developed in order to gain a better understanding of the relationship between the structure and function of the monolayers. Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuirfilms. MDC flowing across monolayers is analyzed using a rod-like molecular model. A linear relationship between the monolayer compression speed a and the molecular area Am. Compression speed a was about 30, 40, and 50 mm/min. Langmuir-Blodgett(LB) layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Aul Arachidic acid! AI, the number of accumulated layers are $9{\sim}21$. Also, we then examined of the Metal-Insulator-Metal(MIM) device by means of I-V. The I-V characteristics of the device are measured from -3 to+3 V. The insulation property of a thin film is better as the distance between electrodes is larger.

A Study of Creole Languages' Pronunciation in the West Indies - Centering on Central American $Gar\acute{i}funa$ and Cuban Patois (서인도제도의 로망스어 관련 혼성어 발음에 관한 고찰 - 중미의 $Gar\acute{i}funa$어와 큐바내 Patois어를 중심으로 -)

  • Kim, Woo-Joong
    • Speech Sciences
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    • v.5 no.2
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    • pp.93-107
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    • 1999
  • This study deals with a general review of $Gar\acute{i}funa$ and Patois, creole languages which developed out of the sociohistorical situation of the last centuries and are mainly spoken in the West Indies and Carribean Coasts. In this paper, I present some notes and ideas on the linguistic developments and features of these languages. Especially I describe their function connected with a variety of social circumstances and their phonetical/phonological changes from the base languages. This is a result of fieldwork conducted in Honduras, Belize, Cuba and Mexico, from January 1996 to February 1998, using some surveys and collecting words from different materials and texts. And I hope this paper will contribute to research in 'mixed' languages as well as to historical linguists. I am very grateful to Mr. Mauricio $Tom\acute{a}s$, the only uriversity student in $Traves\acute{i}a$, a small town in nothern Honduras and to Mr. Carlos Marcos, a medical student who is from a Haitian family in Santiago de Cuba. Without their cooperation, I couldn't have conducted this research.

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Effect of a Probiotic Strain, Enterococcus faecium, on the Immune Responses of Olive Flounder (Paralichthys olivaceus)

  • Kim, Yu-Ri;Kim, Eun-Young;Choi, Sun-Young;Hossain, Muhammad Tofazzal;Oh, Ryun-Kyoung;Heo, Won-Seok;Lee, Jong-Min;Cho, Young-Chai;Kong, In-Soo
    • Journal of Microbiology and Biotechnology
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    • v.22 no.4
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    • pp.526-529
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    • 2012
  • The present study was aimed to investigate the effect of a probiotic, Enterococcus faecium, on the immune responses against infection with the marine fish pathogen Lactococcus garvieae in olive flounder (Paralichthys olivaceus). The immune responses were assessed by lysozyme activity, complement activity, protease activity, and expression of proinflammatory cytokines by RT-PCR. The lysozyme and complement activities were increased between 9 to 15 and 9 to 13 days, respectively, and antiprotease activity was slightly elevated after 5 days of probiotic treatment. The TNF-${\alpha}$ and IL-$1{\beta}$ expressions were observed from kidney and spleen. The results of this study reveal that E. faecium induces immune-responsible materials and protects olive flounder from lactococcosis.

Interfacial Electronic Structures of Poly[N-9''-hepta-decanyl-2,7-carbazole-alt- 5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] and [6,6]-phenyl C60 Butyric Acid Methyl Ester

  • Lee, Jung-Han;Seo, Jung-Hwa;Schlaf, Rudy;Kim, Kyoung-Joong;Yi, Yeon-Jin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.277-277
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    • 2012
  • PCDTBT (Poly[N-9''-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]) is an attractive material as a semiconducting polymer for organic thin film transistor (OTFT) and organic solar cell (OSC). High power conversion efficiency (~6%) under simulated AM 1.5G solar illumination of bulk-heterojunction solar cell with PCDTBT and [6,6]-phenyl C60 butyric acid methyl ester (PC61BM) blend was reported. In OSC, it is known that the band alignment at the interface between donor and acceptor is critical. Therefore, we studied the interfacial electronic structures of PCDTBT and PC61BM. The polymers are deposited by electro-spray on gold and In-situ x-ray and ultraviolet photoelectron spectroscopy measurements revealed the interfacial electronic structures. We obtained the energy level alignment between two materials and the different interface formation was observed with different deposition order.

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Synthesis of Palladium Nanocubes/Nanorods and Their Catalytic Activity for Heck Reaction of Iodobenzene

  • Ding, Hao;Dong, Jiling
    • Applied Microscopy
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    • v.46 no.2
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    • pp.105-109
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    • 2016
  • Palladium has been used as a catalyst not only in Suzuki and Heck cross coupling reaction in organic chemistry, but also in automobile industry for the reduction of vehicle exhausts. The catalytic activity of Pd nanoparticles depends strongly on their size and exposed crystalline facets. In this study, the single crystalline palladium nanocubes/nanorods were prepared in the presence of polyvinyl pyrrolidone (PVP) and potassium bromide (KBr) using the polyol method. Selected area diffraction pattern and high-resolution transmission electron microscopy (TEM) were performed by TEM. The result shows that the ratio of KBr/PVP is the key factor to determine whether the product is cubes or rods. The as-prepared Pd nanocubes were highly uniform in both size and shape. The ordered packing structures including monolayer and multilayer can be fabricated via the rate-controlled evaporation of solution solvent. The catalytic activity of these Pd nanocubes towards heck reaction of iodobenzene with acrylate or acrylic acid was found to be higher than that of Pd nanorods. We suspect it is caused by the difference of energy state while Pd nanocubes is {100} plane and nanorods is {111} plane.

A Study on the Location and Spatial Organization in YeonSan DonAm SeoWon (연산(連山) 돈암서원(遯岩書院)의 입지(立地)와 공간구성(空間構成)에 관한 연구)

  • Choi, Jong-Hee;Moon, Chang-Soon
    • The Journal of Natural Sciences
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    • v.19 no.1
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    • pp.95-111
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    • 2008
  • This paper aims to discussion the characteristics of location and spatial organization on the Donam SeoWon(confucian academy). To do this, we studied in analysis of the present conditions and photographing, research materials about the from of physical structure and review of historical documents. The result of analysis in the sight of the location and spatial organization was good matched. The spatial organization of the Donam SeoWon(confucian academy) was divided into entry space, lecturing space, management space and sacrificial space. Jonhakhumyo constructs axis of “Sanangru - Ipdeokmun - Yangseongdang - Naesammun - Sungryesa” and Eungdodang that not removed hall with 1880 shows characteristics a right angle in the left side of axis remove to location of present 1971. The result of this study, analysis of axis and Spatial structure shows backgrounds of these locations shows that the political and social, economical phenomena were influenced to the locations and spatial organization of the Donam SeoWon(confucian academy).

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Temperature Analysis of Nozzle in a FDM Type 3D Printer Through Computer Simulation and Experiment

  • Park, Jung Hyun;Lyu, Min-Young;Kwon, Soon Yong;Roh, Hyung Jin;Koo, Myung Sool;Cho, Sung Hwan
    • Elastomers and Composites
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    • v.51 no.4
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    • pp.301-307
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    • 2016
  • Additive manufacturing (AM), so called 3D Printing is a new manufacturing process and is getting attraction from many industries. There are several methods of 3D printing. Among them fused deposition modeling (FDM) type is most widely used by reason of cheap maintenance, easy operation and variety of polymeric materials. Articles manufactured by 3D printing have weak deposition strength compared with conventionally manufactured products. Deposition strength of FDM type 3D printed article is highly dependent of deposition temperature. Subsequently the nozzle temperature in the FDM type 3D printing is very important and it is controlled by heat source in the 3D printer. Nozzle is connected with heat block and barrel, and heat block contains heat source. Nozzle becomes hot through heat conduction from heat source. Nozzle temperature has been predicted for various thermal boundary conditions by computer simulation and compared with experimental measurement. Nozzle temperature highly depends upon thermal conductivities of heat block and nozzle. Simulation results are good agreement with experiment.

A Study on Polymerization of Oxocane High Explosives

  • Kim, Joon-Tae
    • Journal of Integrative Natural Science
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    • v.7 no.4
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    • pp.266-272
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    • 2014
  • Oxocane high explosives substituted to explosive group such as azide (-CH2N3), nitrate (-CH2ONO2), and hydrazine (-CH2N2H3) are investigated theoretically the acid catalyzed reaction using the semiempirical MINDO/3, MNDO and AM1 methods to use as the guidelines of high explosives. The nucleophilicity and basicity of oxocane high explosives can be explained by the value of negative charge on oxygen atom of oxocane and the reactivity in propagation step can be represented by the value of positive charge on carbon atom and low electrophile LUMO energy. It was known that carbenium ion was favorable due to the stable energy (11.745~25.461 Kcal/mol) between oxonium ion and carbenium ion in the process of cyclic oxonium ion of oxocane high explosives being converted to open carbenium ion in oxocane high explosives. The value of concentration of cyclic oxonium ion and open carbenium ion in equilibrium status was found to be a major determinant of mechanism, it was expected to react faster in the prepolymer propagation step in SN1 mechanism than in that of SN2.

Development of flexible 3.5' QCIF (176 X144 pixels) OTFT driven OLED;Integration technologies compatible with normal semiconductor processes

  • Kang, Seung-Youl;Ahn, Seong Deok;Oh, Ji-Young;Kim, Gi-Hyun;Koo, Jae Bon;You, In-Kyu;Kim, Chul-Am;Hwang, Chi-Sun;KoPark, Sang-Hee;Yang, Yong-Suk;Chung, Sung-Mook;Lee, Jeong-Ik;Chu, Hye-Yong;Suh, Kyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.62-65
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    • 2007
  • Conventional semiconductor processes have been utilized to fabricate 3.5-inch OTFT-driven OLEDs with a resolution of $176\;{\times}\;144$ pixels on plastic substrates. By using a PC-OVD method to deposit a pentacene layer and optimizing patterning and the following processes, we could complete a uniform and reliable integration procedure for an active matrix organic light emitting devices on a plastic substrate. The technical importance of ours is the applicability of conventional semiconductor process to organic materials on plastic substrates. Although there are many hurdles to overcome, our approach and technical improvements are proved to be applicable to plastic electronics.

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A Nanoindentation Based Study of Mechanical Properties of Al-Si-Cu-Mg Alloy Foam Cell Wall (나노인덴테이션에 의한 Al-Si-Cu-Mg 합금 폼 셀 벽의 기계적 물성 연구)

  • Ha, San;Kim, Am-Kee;Lee, Chang-Hun;Lee, Hak-Joo;Ko, Soon-Gyu;Cho, Seong-Seock
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.382-387
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    • 2004
  • Nanoindentation technique has been used to measure the mechanical properties of aluminium alloy foam cell walls. Al-Si-Cu-Mg alloy foams of different compositions and different cell morphologies were produced using powder metallurgical method. Cell morphology of the foam was controlled during production by varying foaming time and temperature. Mechanical properties such as hardness and Young's modulus were calculated using two different methods: a continuous stiffness measurement (CSM) and an unloading stiffness measurement (USM) method. Experimental results showed that hardness and Young's modulus of Al-5%(wt.)Si-4%Cu-4%Mg (544 alloy) precursor and foam walls are higher than those of Al-3%Si-2%Cu-2%Mg (322 alloy) precursor and foam walls. It was noticed that mechanical properties of cell wall are different from those of precursor materials.

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