• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.739-740
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• 2010

• 한국공간구조학회논문집
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• 제3권3호
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• pp.85-93
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• 2003

Steel, concrete and their combination materials are the most 6commonly used materials for civil engineering structural systems such as buildings, bridge structures and other structures. Recently, however, fiber reinforced polymer (FRP) composites, a relatively new composite material made of fibers and polymer resins, have been gradually used in structural systems as an alternative structural material. This paper describes a comparison of design strength equations for steel column and FRP composite column based on design philosophies. The safety factors used in allowable stress design (ASD) are relatively higher in FRP structural design than steel structural design. Column critical stress equations of FRP composites column from an experimental study can be represented by Euler elastic buckling equation at the long-range of slenderness, and an exponential form at the short-range of slenderness as defined in Load and Resistance Factor Design (LRFD) of steel column. The column strength of steel and FRP composite columns in large slenderness is independent of material strength, this result verified the elastic buckling equation as derived by Eq. (15) and Eq. (5).

• 대한기계학회논문집A
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• 제30권7호
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• pp.794-799
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• 2006

In recent years, the use of natural fiber as reinforcement in polymer composites to replace synthetic fiber such as glass fiber is receiving increasing attention. Because of increasing usage according to the high demand, the cost of thermoplastic has increased rapidly over the past decades. We used a thermoplastic polymer(polypropylene) as the matrix and a lignocellulosic material(rice-husk flour) as the reinforcement filler to prepare a particle-reinforced composite to examine the possibility of using lignocellulosic material as reinforcement filler and to determine data of test results for physical, mechanical and morphological properties of the composite according to the reinforcement filler content in respect to thermoplastic polymer, In this study, PLA/PP rice-husk fiber-reinforced thermoplastic composites that made by the hot press molding method according to appropriate manufacturing process was evaluated as mechanical properties.

• Journal of Electrochemical Science and Technology
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• 제3권3호
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• pp.143-148
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• 2012

The unique effects of highly conductive conducting polymer/SWNT (single walled carbon nanotube) composite nanoparticles in electric double layer capacitors are studied for the enhancement of the adhesive properties, specific capacitance and power characteristics of the electrode. Because the conducting polymer/SWNT composite material, which is believed to act as a polymer binder, an active material for charge storage and a conducting agent, is well distributed on the activated carbon, greatly enhanced adhesion properties, cell capacitance and power characteristics were obtained.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1989년도 춘계학술대회 논문집
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• pp.77-80
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• 1989

The aim of the study is to develope the processing technique of PZT-Polymer piezoelectric composite materials for ultrasonic transducer application such as biomedical probe and hydrophone. Piezoelectric composite of PZT and polymer with 1-3 connectivity patterns have been fabricated by dicing-filling method and extrusion forming method. In this study processing forming method. In the study processing steps by extrusion forming method in the preperation of PZT/polymer piezoelectric composites are described. The PZT powder used in the study is commercial powder which is prepared by mixing PbO, TiO$_2$ and ZrO$_2$. The binder, water and plasticizer are mixed with the PZT powder to form a slip. It is necessary to adjust the viescosity of slip according on the PZT rod diameters to be extruded. The electromechanical properties of the piezoelectric composites are characterized in terms of the thickness resonance mode. The pulse response characteristics by the ultrasonic transducer analyzer and osciloscope are evaluated.

• 공업화학
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• 제7권2호
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• pp.393-400
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• 1996

Seed 유화 중합법과 용매 추출법을 이용하여 전도성 고분자 복합체를 위한 다공성 입자를 제조하였다. 건조된 다공성 입자를 모체 고분자로 사용하여 dopant로 사용하는 $FeCl_3$를 methanol에 녹여 흡수시킨 뒤에 건조시키고, 이를 다시 pyrrole를 녹인 ethyl ether 용액으로 중합하여 용액을 증발시킴으로서 전도성 고분자 복합체를 합성하였다. 이때, 모체 고분자로 사용된 비다공성 입자와 다공성 입자의 전도도를 비교하였다. 실험결과, 전도성 복합체의 전도도는 비다공성 입자보다는 다공성 입자를 사용하여 제조한 복합체가 전도성 중합체가 입자의 표면뿐만 아니라 pore안에서도 용이하게 형성되어 더 우수한 전도도를 나타내었다.

• Macromolecular Research
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• 제12권6호
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• pp.564-572
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• 2004

Modem applications could benefit from multifunctional materials having anisotropic optical, electrical, thermal, or mechanical properties, especially when coupled with locally controlled distribution of the directional response. Such materials are difficult to engineer by conventional methods, but the electric field-aided technology presented herein is able to locally tailor electroactive composites. Applying an electric field to a polymer in its liquid state allows the orientation of chain- or fiber-like inclusions or phases from what was originally an isotropic material. Such composites can be formed from liquid solutions, melts, or mixtures of pre-polymers and cross-linking agents. Upon curing, a 'created composite' results; it consists of these 'pseudofibers' embedded in a matrix. One can also create oriented composites from embedded spheres, flakes, or fiber-like shapes in a liquid plastic. Orientation of the externally applied electric field defines the orientation of the field-aided self-assembled composites. The strength and duration of exposure of the electric field control the degree of anisotropy created. Results of electromechanical testing of these modified materials, which are relevant to sensing and actuation applications, are presented. The materials' micro/nanostructures were analyzed using microscopy and X-ray diffraction techniques.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.91-94
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• 2003

The purpose of this project is to research and development of thin film supercapacitor with conducting polymer composite electrodes and polymer electrolyte which have high energy density for thin film supercapacitor. We investigated cyclic voltammetry and charge/discharge cycling of PFPT-flyash electrodes. The first discharge capacity of PFPT-flyash electrode with 40wt.% flyash was 24F/g, while that of PFPT-VOflyash electrode with 40wt.% VOflyash was 32F/g. The capacitance of PFPT-VOflyash composite film with polymer electrolyte was 32 F/g at 1st and 20th cycle, respectively. The capacitance of PFPT-VOflyash/Li cell with 40 wt% VOflyash was 141 F/g at 8th cycle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1490-1492
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• 2001

Recently polymer composite materials has been replacing the porcelain in suspension insulators as a insulating material. The polymer composite materials are introduced into Korea from the abroad, so there is, actually, no formal standard of assessment Both the porcelain insulator specifications and composite material test specifications are being used at the same time. The aim of this project is to establish a systematic standard suitable to current situations considering the trends of its production within Korea. This would protect the inner-markets against the market-opening and would promote the industrial development within a country.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
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• pp.224-228
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• 2002

In this study, the piezoelectric ceramics PZT powder was synthesized by the Wet-Dry combination method. Flexible 1-3 type composite specimens were fabricated with the piezoceramics PZT filler phase and Eccogel polymer matrix phase. This paper represents the pulse-echo response of the 1-3 type composite transducer to check it out to investigate a basic property regarding a level limit switch. The acoustic impedance of 1-3 type composite was improved than that of single phase PZT ceramics. The pulse-echo response of transducer fabricated with the self-made 1-3 type composites resonator was better than that of the solid PZT transducer.