Ultra-fine copper powders with particle size about 150 nm were synthesized from copper hydroxide slurry by wet method using hydrazine as reduction agent and several sur factants at below . The particle size distribution and dispersion of synthesized powders as function of temperature, feeding rate of reduction and especially, sur factants were character ized by XRD, BET, PSA and SEM by this process.

Ultrafine copper powder was prepared from slurry with hydrazine, a reductant, under . The influence of various reaction parameters such as temperature, reaction time, molar ratio of , PvP and NaOH to Cu in aqueous solution had been studied on the morphology and powder phase of Cu powders obtained. The production ratio of Cu from CuO was increased with the ratio of and the temperature. When the ratio of was higher than 2.5 and the temperature was higher than , CuO was completely reduced into Cu within 40 min. The crystalline size of Cu obtained became fine as the temperature increase, whereas the aggregation degree of particles was increased with the reaction time. The morphology of Cu powder depended on that of the precursor of CuO and processing conditions. The average particle size was about

Ag powder was prepared from by wet chemical reduction method using various reduction agent system involving , (AgCl) and Ag complex ion aqueous solution. The pure Ag powder could be prepared regardless of reaction system but the particle shape and distribution were affected very much according to the kind of reduction agents and reaction systems. The optimum reaction system for the preparation of the silver powder having the uniform particle shape and size distribution was Ag complex ion aqueous solution-reduction agent system and in particular, and as a reduction agent leaded the more uniform particle shape and size distribution

관광지의 도로, 산책로 등과 같이 중차량이 통과하지 않고 많은 사람들이 통행하는 도로는 큰 내하력을 갖추지 않아도 되며, 인간공학적이고 환경친화적이어야 한다 이를 위하여 최근에 흙을 주재료로 하여 특수한 경화재와의 혼합물을 사용한 도로 포장공법이 개발되어 사용되고 있지만, 역학적인 해석과 설계가 이루어지지 않고 경험적인 방법에 의존하고 있다. 따라서 흙-경화재 혼합물의 기본적인 공학적 특성을 규명할 필요가 있다. 본 연구에서는 흙-경화재 혼합물의 주재료에 대한 혼합비를 달리하는 일련의 배합을 실시하여 공시체를 제작하고, 이에 대하여 재령별로 강도시험을 실시함으로써 혼합비와 재령에 따른 혼합물의 역학적 특성을 규명하였다. 또한 시멘트콘크리트포장에서는 양생하는 과정에서 수화열이 발생할 뿐만 아니라 그 지지기반인 흙과의 온도에 따른 거동의 차이로 인한 공학적 문제들이 야기됨으로, 흙-경화재 혼합물과 흙의 온도 특성을 비교 분석하였다. 본 연구 결과, 혼합물은 시멘트의 증가에 따라 강도가 증가하고, 수화열을 억제하기 위하여 제한된 시멘트량에 대해서는 경화재와 물의 혼합비가 6%~8%일 때 가장 큰 강도를 나타내었다. 또한 혼합물의 강도는 14일까지는 재령에 따라 비교적 급격하게 증가하다가 그 이후에는 증가율이 감소하여 28일 후에는 증가율이 급격히 저하되었다. 그리고 본 연구에서 사용한 시멘트량에 대해서는 수화열이 매우 미미하게 나타났으며, 흙과의 온도 특성이 비슷한 것으로 나타났다. 따라서 본 혼합물은 시멘트 콘크리트보다 내하력에서는 크게 못 미치지만 온도 변화에 따른 공학적 문제들을 개선할 수 있으며, 흙을 주재료로 사용하므로 경하중이나 교통량이 적은 포장도로에서 환경친화적인 포장재료로서 우수하게 사용될 수 있을 것으로 판단된다.

This study was conducted to investigate the properties of wet noodle when different concentrations of Prunus mume juice were added to the wheat flour. The characteristics of wet noodle including cooking properties, color, mechanical texture properties, and sensory quality were determined. The compositions of Prunus mume were 88.19% moisture, 0.45% crude ash, 4.04% citric acid and 0.41% total sugars. The pH of Prunus mume was 2.76. The moisture absorption rate, weight, volume and turbidity of cooked noodles added with Prunus mume juice were lower than reference sample. When the amount of Prunus mume juice increased, the Hunter L(brightness) value, a(redness) value of cooked noodles decreased but b(yellowness) value increased. Instrumental rheological characteristics of wet noodle containing Prunus mume juice were measured with a texture analyzer. The hardness, adhesiveness, cohesiveness, springiness and gumminess of wet noodle with 20% Prunus mume juice were higher than others. However, the hardness of cooked noodle decreased with the increase in the amount of Prunus mume juice into noodle. The adhesiveness, cohesiveness, springiness and gumminess of cooked noodles added with Prunus mume juice were higher than reference sample. The results of sensory evaluation of cooked noodles containing Prunus mume juice indicated that the appearance, color, taste and chewiness of the cooked noodle with 10% Prunus mume juice showed the higher preference than others. Based on cooking properties, rheological and sensory evaluation, addition of 10% Prunus mume juice suggested to be acceptable for processing wet noodle.

The effect of addition with maesil(Prunus mume) juice for extending the shelf-life of wet noodle was investigated by measuring quality changes such as total microbial count and pH. The Prunus mume juice showed antimicrobial activities against Salmonella enteritidis, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Escherichia coli. When the wet noodles containing Prunus mume juice were kept at 4℃ for 20 days, it was showed that the drop of pH was not significantly occurred during the storage. Total microbial counts for control exceeded the initial putrefactive criterion level of 1.0×106 cfu/g at 16 days of storage at 4℃. However, total microbial count of wet noodles with the addition of 10%, 20% and 30% Prunus mume juice were 3.0×102 cfu/g, 3.0×102 cfu/g, and 1.5×102 cfu/g, respectively, and these bacterial counts were still less than the criterion level ever at 20 days of storage. The addition of Prunus mume juice extended the shelf-life of wet noodle appreciably.

It is well known that the porosity and adsorption capacity in a carbon depends on the nature of precursor, pyrolysis and activation conditions and the ash content. The studies on carbon prepared from the dry and wet babbool wood were under taken to ascertain the effect of initial state of precursor on the development of porosity in the resulting activated carbon. The characterization and adsorption studies carried out shows the presence of mainly mesoporosity in the carbon prepared from dry wood while more of microporosity was observed in the activated carbon prepared from wet wood. The results on porosity in both the cases have been compared and correlated with their processing conditions.

용융탄산염 연료전지(MCFC)의 상용화에 있어서 가장 큰 문제점으로 지적되고 있는 분리판 wet-seal부의 내식성 향상을 위해 AISI 316L 스테인레스강에 Ni은 전기도금법으로, Y과 Al은 e-beam PVD법으로 피복하여 Ni/Y/Al충을 형성시켰다. 800˚C 환원분위기에서 5시간의 열처리를 통해 NiAlY 합금층을 얻을 수 있었으며, 그 후 650˚C 용융탄산염내에서 as-received AISI 316L 스테인레스강과 200시간의 침지실험을 퉁해 내식성이 비교.평가되었다. SEM/EDS를 통한 단면 관찰 결과, Y의 첨가에 의해 치밀한 산화막을 형성하여 분리판 wet-seal부의 내식성을 향상시킬 수 있었다.