• Title/Summary/Keyword: National Defense R%26D

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The Development of High Performance Nano-composites with Carbon Nanotube (카본나노튜브를 이용한 고성능 나노복합재료의 개발 동향)

  • Lee, Min-Kyung;Bae, Soo Bin;Park, Jong Kyoo;Lee, Seung Geol
    • Textile Coloration and Finishing
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    • v.26 no.2
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    • pp.71-78
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    • 2014
  • This review paper is a state of the art report of the development of high performance nano-composites with carbon nanotube. We investigate the research and development (R&D) trends of high performance nano-composites with carbon nanotube by analyzing technical trends in research institutes and industry. We report the R&D and technology trends for the properties and applications of fabrication of hybrid composites with aligned carbon nanotubes, multifunctional fiber/carbon nanotube composites. We discuss the specific topics including unidirectional carbon nanotube, carbon nanotube forests, transfer-printing carbon nanotube technology, deposition of carbon nanotube by electrophoresis, vapor grown carbon fiber (VGCF), cup-stacked carbon nanotube, bucky paper and carbon nanotube yarns in this review paper.

Optimal Design of Quadrilateral Typed-Overboarding Mechanism for Drop/Lift Automation of Towed Object (예인체의 투하 및 인양 자동화를 위한 사변형 Overboarding Mechanism의 최적설계)

  • Kang, Seok Jeong;Chung, Won Jee;Park, Seong Hak;Choi, Jong Kap;Kim, Hyo Gon;Lee, Jun Ku
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.1
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    • pp.74-81
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    • 2017
  • A crane is typically used as a means to lift and load equipment or materials. A surface vessel uses a towed object for underwater activity. Such a mechanism for dropping and lifting of equipment is necessary, and is called an overboarding unit. The present study is focused on the overboarding unit used for a crane structure. This paper deals with new overboarding mechanism design and GA-based $MATLAB^{(R)}$ optimization. By using a quadrilateral link mechanism, it is possible to set the constraint function for optimizing the GA method. The optimization with $MATLAB^{(R)}$ is followed by the $SolidWorks^{(R)}$ simulation and verification. When applying the proposed mechanism, the operator is expected to have a big advantage in safety and efficiency of operations. Furthermore, the technology developed in this study will be helpful in similar circumstances and in the proposed mechanism.

Kinematic/Inverse Kinematic Analysis of Captive Trajectory Simulation System with Functional Redundancy (기능적 여유자유도를 가지는 CTS 시스템의 기구학/역기구학 해석)

  • Lee, Do Kwan;Lee, Sang Jeong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.3
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    • pp.263-271
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    • 2017
  • A captive trajectory simulation (CTS) system is used to investigate the separation behavior of the store model by moving the model to an arbitrary pose and position based on aerodynamic data. A CTS system operated inside a wind tunnel is designed to match the structure of the wind tunnel facility. As a result, each CTS system has different kinematic structure, and inverse kinematic analysis of the system is necessary. In this study, kinematic/inverse kinematic analysis for the CTS system with functional redundancy is performed. Inverse kinematic analysis with combined numerical and analytical approach is especially proposed. The suggested approach utilizes the redundancy to improve the safety of the system, and has advantages in real time analysis.

A Synthetic Tul4 and FopA Peptide Cocktail of Francisella tularensis Induces Humoral and Cell-Mediated Immune Responses in Mice

  • Oh, Hanseul;Kim, C-Yoon;Kim, Chang-Hwan;Hur, Gyeung-Haeng;Park, Jae-Hak
    • Journal of Microbiology and Biotechnology
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    • v.26 no.9
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    • pp.1613-1619
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    • 2016
  • Francisella tularensis is a highly virulent pathogen of humans and other mammals. Moreover, F. tularensis has been designated a category A biothreat agent, and there is growing interest in the development of a protective vaccine. In the present study, we determine the in vitro and in vivo immune responses of a subunit vaccine composed of recombinant peptides Tul4 and FopA from epitopes of the F. tularensis outer membrane proteins. The recombinant peptides with adjuvant CpG induced robust immunophenotypic change of dendritic cell (DC) maturation and secretion of inflammatory cytokines (IL-6, IL-12). In addition, the matured DCs enabled ex vivo proliferation of naive splenocytes in a mixed lymphocyte reaction. Lastly, we determined the in vivo immune response by assessment of antibody production in C57BL/6 mice. Total IgG levels were produced after immunization and peaked in 6 weeks, and moreover, Tul4-specific IgG was confirmed in the mice receiving peptides with or without CpG. Based on these results, we concluded that the recombinant peptides Tul4 and FopA have immunogenicity and could be a safe subunit vaccine candidate approach against F. tularensis.

Biotic and Abiotic Factors Affecting Homoharringtonine Contents of Cephalotaxus koreana Nakai (개비자나무의 homoharringtonine 함량에 영향을 미치는 생물 및 무생물적 환경인자)

  • Jung, Myung-Suk;Hyun, Jung-Oh;Lee, Uk;Baik, Eul-Sun
    • Korean Journal of Plant Resources
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    • v.23 no.2
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    • pp.172-178
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    • 2010
  • This study was carried out to investigate abiotic and biotic environmental factors affecting homoharringtonine (HHT) contents of Cephalotaxus koreana, whereby, to provide basic information of high value-added industry production of HHT as a promising anti-cancer agent. For correlation between abiotic environmental factors (soil moisture, soil pH, habitat density and temperature) and HHT contents, the contents were highly correlated with soil moisture (0.77) and soil pH (-0.68). For multiple regression analysis of relationship between abiotic environmental factors (soil moisture and soil pH) and HHT contents, soil moisture appeared to be strongly affecting the contents relatively due to being significant at only its regression coefficient ($26.48^{***}$). For the effect of biotic environmental factors (damage index) affecting HHT contents, the contents was quadratic with equation of $H=278.23+1242D-398.87D^2$, also, damage index had strong effect on the contents. Finally, for the result of the most influencing an environmental factor on HHT contents, both damage index and soil moisture were suitable in second polynomial regression, also, damage index ($R^2=0.73^{***}$) was turned out to be more influencing factor than soil moisture ($R^2=0.67^{**}$) on HHT contents relatively. Therefore, we predict that HHT contents in the trees of Cephalotaxus koreana is produced as a chemical defense mechanism triggered by a stress-related damage of fungi or insects.

Effect of Stabilization Processing Conditions on the Thermal Shrinkage and the Thermal Stability of Rayon Fabrics Untreated and Surface-Treated with Phosphoric Acid (인산처리 유·무에 따른 레이온직물의 열수축과 열안정성에 미치는 안정화 공정 조건의 영향)

  • Cho, Donghwan;Lee, Jongmoon;Park, Jong Kyoo
    • Journal of Adhesion and Interface
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    • v.5 no.3
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    • pp.10-17
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    • 2004
  • We investigated the effect of stabilization processing parameters on the thermal shrinkage, thermal stability and microstructure of rayon fabrics stabilized under various conditions such as heating rate, stabilization temperature, atmosphere gas, and chemical treatment. The presence and absence of phosphoric acid treatment and the heating rate have most importantly influenced the thermal shrinkage and the weight change of rayon fabrics. Especially, the phosphoric acid treatment decreases the reduction of thickness, length, and weight of the fabrics by about 80%, 20%, and 26%, respectively, in comparison with the untreated counterparts, showing the protective effectiveness of the thermal shrinkage involved. The thermal stability of stabilized rayon fabrics is also affected by all the processing conditions used: stabilization temperature, phosphoric acid treatment, atmosphere gas, and heating rate. In addition, the surface and diameter of the stabilized fiber significantly depend on the treatment of phosphoric acid prior to stabilization process.

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Fabrication and Characteristics of Mesophase Pitch-Based Graphite Foams Prepared Using PVA-AAc Solution (PVA-AAc 용액을 사용한 메조페이스 핏치기반 그라파이트 폼의 제조 및 특성)

  • Kim, Ji-Hyun;Lee, Sangmin;Jeong, Euigyung;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.26 no.6
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    • pp.706-713
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    • 2015
  • Graphite foams (GFs) were prepared by adding different amounts of mesophase pitch (MP) into polyvinyl alcohol-acrylic acid (PVA-AAc) solution followed by the heat treatment. It was confirmed that the pore diameters of GFs were controlled by the slurry concentration, which was the mesophase content added in polymer solution, and their thermal conductivity and compressive strength were also controlled by porosities of GFs formed at different conditions. The resulting GFs in this study had the highest thermal conductivity of $53.414{\pm}0.002W/mK$ and compressive strength of $1.348{\pm}0.864MPa$ at 0.69 in porosity. The thermal conductivity of MP based GFs increased approximately 23 times higher than that of using isotropic pitch based GFs due to the developed graphitic structure.