The microstructural and mechanical properties of Al-Si alloyed powder, prepared by gas atomization fallowed by hot extrusion, were studied by optical and scanning electron microscopies, hardness and wear testing. The gas atomized Al-Si alloy powder exhibited uniformly dispersed Si particles with particle size ranging from 5 to . The hot extruded Al-Si alloy shows the average Si particle size of less than . After heat-treatment, the average particle size was increased from 2 to . Also, mechanical properties of extruded Al-Si alloy powder were analyzed before and after heat-treatment. As expected from the microstructural analysis, the heat-treated samples resulted in a decrease in the hardness and wear resistance due to Si particle growth. The friction coefficient of heat-treated Al-Si alloyed powder showed higher value tough all sliding speed. This behavior would be due to abrasive wear mechanism. As sliding speed increases, friction coefficient and depth and width of wear track increase. No significant changes occurred in the wear track shape with increased sliding speed.

The Ti-Ni alloy nanopowders were synthesized by a levitational gas condensation (LGC) by using a micron powder feeding system and their particulate properties were investigated by x-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) method. The starting Ti and Ni micron powders were incorporated into the micron powder feeding system. An ingot type of the Ti-Ni ahoy was used as a seed material for the levitation and evaporation reactions. The collected powders were finally passivated by oxidation. The x-ray diffraction experiments have shown that the synthesized powders were completely alloyed with Ti and Ni and comprised of two different cubic and monoclinic crystalline phases. The TEM results showed that the produced powders were very fine and uniform with a spherical particle size of 18 to 32nm. The typical thickness of a passivated oxide layer on the particle surface was about 2 to 3 nm. The specific surface area of the Ti-Ni alloy nanopowders was based on BET method.

최근의 물류환경은 유통시장의 개방과 세계시장의 단일화로 국제적인 경쟁환경에 노출되어 글로벌화와 정보화 경쟁이 가속화되고 있으며 국내적으로는 대형 유통업체의 공격적인 마케팅 전개로 중소유통업체의 생존권을 위협하고 있다. 또한 물류부문의 아웃소싱화 추세가 증가하고 있으며 대형소매점 위주의 유통구조재편과 편의점들간의 규모의 경쟁 추구에 따른 지역상권 장악이 가속화되어 중소물류업체들의 경쟁력이 급속히 하락하고 있는 추세이다. 특히 대형할인점 위주의 대형 유통업체가 상당부분의 지역상권을 장악해가고 있지만 중소유통업체들은 여전히 구매력과 판매력이 미흡한 상황이며 유통 물류체계 또한 대기업 위주의 편향적인 구조로 되어 있어 상대적으로 영세하고 정보화가 취약한 중소물류업체들의 공도물류사업을 통한 가격경쟁력 강화 등의 필요성이 제기되고 있으며, 합리적인 유통 물류시스템구축이 필요한 실정이다. 그리고 전국 유통 물류시설의 기능들이 상호 연계되지 못하여 상호 중복되고 본래의 기능을 발휘하지 못하는 등 유통 물류시스템의 정보화, 체계화가 미흡한 상황에서 중소유통 물류공동화의 대안으로서 공동도매물류센터가 필요하며 이를 통해 유통 물류시설간의 전국 네트워크화를 실시하고 공동구매, 공동판매 및 조직화 등을 통해 시너지효과가 발휘될 수 있는 중소물류산업에 대한 활성화 방안의 모색이 절실히 요구되고 있다.

The purpose of this study was to investigate the antioxidative effect and quality characteristics of cookies made with Sea tangle powder(STP). The cookies were at 30℃ for 45 days. The 3% STP had higher pH value compared to the other groups and control. As more STP was added, the L-value and b-value decreased, and the a-value increased for the color values. The results of sensory evaluation and acceptance test showed that the cookies with 3% STP was significantly more preferable in overall acceptability than the others. The acid value, peroxide value, and thiobarbituric acid value were lower in cookies with 3% and 6% STP than in those cookies made 9% STP and the control cookies.

The present study is to analyze the thermoelectric properties of thermoelectric materials fabricated by the mechanical grinding process. The powders were prepared by the combination of mechanical milling and reduction treating methods using simply crushed pre-alloyed powder. The mechanical milling was carried out using the tumbler-ball mill and planetary ball mill. The tumbler-ball milling had an effect on the carrier mobility rather than the carrier concentration, whereas, the latter on the carrier concentration. The specific electric resistivity and Seebeck coefficient decreased with increasing the reduction-heat-treatment time. The thermal conductivity continuously increased with increasing the reduction-heat-treatment time. The figure of merit of the sintered body prepared by the mechanical grinding process showed higher value than one of the sintered body of the simply crushed powder.

It is attempted to develop flame retardant polyurethane coatings, which have received significant attention in recent years. It is the purpose of this study to synthesize new reactive polyurethane coatings containing halogen. Lactone based modified polyester polyols, using trichlorobenzoic acid as chlorine moiety (TBAOs) were synthesized. These polyesters were cured with isophorone diisocyanate (IPDI)-isocyanurate at room temperature (TBAPUs). Physical properties of these flame retardant coatings were similar with those of non-flame retardant coatings. The flammability of coatings was strongly dependent on the chlorine contents. We found that the increasing chlorine contents showed better flame retarding properties and that, however, they also resulted in more smog generation during combustion. The detailed results of flammability test using various methods indicated 24~26% in LOI and 3.7~5.3 cm char length in 45˚ Meckel burner method.

Anti-corrosive coatings for steel structures with an alternative anti-corrosive pigment, polyaniline was prepared and anti-corrosive characteristics of the prepared coatings were investigated. The structure of the polyaniline was identified by using FT-IR, UV/Vis. and TGA analysis, and the anti-corrosive properties were analyzed from the results of the salt spray experiment. We found that the anti-corrosion properties of the prepared coatings varied in accordance with the types of primer coating resins as well as with the existence and nonexistence of the top coating. In this condition, the properties of adhesion, chemical resistance, and water resistance were found to be very satisfactory when using the single-packaged urethane resin as the primer coating resin and the urethane resin as the top coating resin.

본 연구는 불소관능기인 perfluorocyclobutane (PFCB), fluorenyl, sulfonyl계 방향족 화합물을 동시에 포함하는 술폰화된 랜덤 고분자 전해질 막의 제조 및 그 특성에 관한 것이다. 이러한 고분자 전해질 막은 세단계의 합성, 즉 trifluorovinyloxy그룹을 양말단에 포함하는 단량체의 합성, 중부가반응 형태의 열중합, 그리고 chlorosulfonic acid를 이용한 후술폰화를 통하여 얻어졌다. 후술폰화 반응은 고분자 내에 포함된 fluorenyl기의 함량에 따라 일정한 몰비의 술폰화제 비율로 고정하여 진행되었으며, 이에 따라 다양한 이온교환 능력(IEC)을 가지는 고분자를 쉽게 합성할 수 있었다. 제조된 단량체 및 고분자들의 구조와 순도는 각각 FT-IR과 NMR 그리고 질량분석기를 통하여 확인되었다. 술폰화된 fluorenyl기가 많아질수록 술폰화도와 이온교환 능력이 증가하는 것을 확인할 수 있었고 그에 따른 함수율도 역시 증가하는 거동을 보였다. 술폰화된 고분자들의 이온전도도를 측정한 결과 술폰화도가 증가할수록 이온 전도도가 증가하는 것을 관찰할 수 있었다, 이렇게 제조된 전해질막 중 S-1과 S-2의 경우 다양한 온도범위(25sim80℃ 수식 이미지)에서 상용 전해질막인 Nafion-115를 능가하는 우수한 이온전도도를 나타냈다.