We report the feasibility of TaC production via self-propagating high temperature synthesis, and the influence of the initial green compact density on the final composite particle size. Experiments are carried out from a minimum pressure of 0.3 MPa, the pressure at which the initial green body becomes self-standing, up to 3 MPa, the point at which no further combustion occurs. The green density of the pellets varies from 29.99% to 42.97%, as compared with the theoretical density. The increase in green density decreases the powder size of TaC, and the smallest particle size is observed with 1.5 MPa, at 10.36 μm. Phase analysis results confirm the presence of the TaC phase only. In the range of 0.3-0.5 MPa, traces of unreacted Ta and C residues are detected. However, results also show the presence of only C residue in the matrix within the pressure range of 0.6-3.0 MPa.

The purpose of this study is to investigate the effect of superheated steam (SHS) treatment on the inactivation of an enzyme involved in the racidity of brown rice as well as the degree of rancidity during storage of brown. Brown rice was treated with SHS at temperatures of 160oC, 200oC, and 240oC, and the result showed that the degree of starch damage was higher in the brown rice treated with SHS at higher temperature. Lipoxygenase was inactivated by treating with SHS for 20 s at 160oC, 15 s at 200oC, or 5 s at 240oC. The acidity and sensory evaluation of the brown rice treated with SHS showed that the acidity was decreased as the SHS treatment increased and SHS temperature became higher. The result of the sensory evaluation showed a similar tendency. These results show that the SHS treatment has potential as a method for improving the brown rice storage quality.

우리나라의 공동주택은 ‘프랑스･미국･일본’을 거쳐 우리나라에 유입되었으며, 본격적으로 자리잡기 시작한 것은 1977년 12월 31일 주택건설촉진법이 제정되면서 부터라고 할 수 있다. 현재의 공동주택은 외관의 화려함이나 편리성 측면에서 좋은 호응을 얻고는 있으나, 집의 본질인 ‘거주자의 건강하고 쾌적한 삶’에 있어서는 오히려 퇴보 되었다고 할 수 있으며, 이 는 과거의 한옥이 자연에 순응하는 생활방식과 사용재료가 천연재료였다는 점에서 현재의 공동주택과 차이가 있다. 현재 우리나라 공동주택의 특징으로는 단지의 대형화･평면구성의 고정화･실내구성의 화려 함･마감자재의 합성제품화 등이 있으며, 관리상의 특징으로는 입주자대표회의제도와 주택 관리사제도를 두고 있다는 점이다. 공동주택의 실내유해환경과 관련하여 국가의 책무로 볼 수 있는 점은 헌법 제35조‘국민은 누구나 건강하고 쾌적한 상태에서 살아갈 권리를 보장한다’에 근거한 각종 관련법이 있으 며, 이를 구체적으로 실천하는 대표적인 법으로는 주택법이 있다. 공동주택의 증가추세와 국민1인당 의료비 지출간에 관련성이 있다는 점에서 공동주택의 실 내유해환경의 문제가 시사하는 바는 크다고 할 수 있다. 독일의 실존주의 철학자 하이데거는 ‘인간은 주거하기로부터 실존의 의미를 갖는다’라고 한 바 있다. 이에 비추어 현재의 공동주택은 동시에 많은 사람이동시에 거주하기를 하고 있다는 점에서 치열한 실존 현장이라고 하겠다. 현재 우리나라의 공동주택의 관리제도에 있어서 환경법에서는 100세대 이상의 신축공동 주택에 대하여 실내 공기 질 점검제도를 두고 있고, 주택법은 엘리베이터가 설치되는 150 세대이상 또는 300세대 이상의 공동주택에 대하여 입주자대표회의 구성 및 주택관리사에 의한 위탁관리규정을 두고 있음에도 불구하고 공동주택의 실내유해환경문제가 지속적인 사회 문제로 부각되는 것은 제도 및 운영상의 미비점에서 기인한다고 하겠으며, 주요원인 으로는 첫째, 사법상의 집합건물에 관한 법률과 공법상의 주택법에 관한 법률에 의한 관리 운영제도의 미흡, 둘째, 주거환경으로부터 비롯되는 1차 의료영역의 질병예방관리를 관할 하는 보건법과의 연계성 부족, 셋째, 환경법에 서 100세대 이상의 신축공동주택에 대하여 실시하는 점검제도의 형식적인 운영을 들 수 있다. 따라서 본 논문은 우리나라 공동주택이 안고 있는 현행 실내유해환경관리제도의 문제점을 살펴봄으로써 개선방안을 찾는데 그 목적이 있으며, 연구목적을 달성하기 위하여 공동주택 중 ‘다중이용시설 등의 실내공기질 관리법’의 저촉 대상이 되는 100세대 이상의 공동주택 을 대상으로 설문하였고, 주택의 변천과정, 외국주거환경관리사례, 실내유해환경과 거주자 의 건강관련성, 공동주택관리제도 및 관련법에 대하여 살펴보았으며, 부족한 점에 대하여 는 차후 보완연구과제로 남겼다.

Zirconium boride is an artificial or which is rarely found in the nature. ZrB2 is popular in the hard material industry because it has a high melting point, excellent mechanical properties and chemical stability. There are two known methods to synthesize ZrB2. The first involves direct reaction between Zr and B, and the second is by reduction of the metal halogen. However, these two methods are known to be unsuitable for mass production. SHS(Self-propagating High-temperature Synthesis) is an efficient and economic method for synthesizing hard materials because it uses exothermic reactions. In this study, ZrB2 was successfully synthesized by subjecting ZrO2, Mg and B2O3 to SHS. Because of the high combustion temperature and rapid combustion, in conjunction with the stoichiometric ratio of ZrO2, Mg and B2O3; single phase ZrB2 was not synthesized. In order to solve the temperature problem, Mg and NaCl additives were investigated as diluents. From the experiments it was found that both diluents effectively stabilized the reaction and combustion regime. The final product, made under optimum conditions, was single-phase ZrB2 of 0.1-0.9μm particle size.

Due to their unique properties, tungsten borides are good candidates for the industrial applications where certain features such as high hardness, chemical inertness, resistance to high temperatures, thermal shock and corrosion. In this study, conditions were investigated for producing tungsten boride powder from tungsten oxide(WO3) by self-propagating high-temperature synthesis (SHS) followed by HCl leaching techniques. In the first stage of the study, the exothermicity of the WO3-Mg reaction was investigated by computer simulation. Based on the simulation experimental study was conducted and the SHS products consisting of borides and other compounds were obtained starting with different initial molar ratios of WO3, Mg and B2O3. It was found that WO3, Mg and B2O3 reaction system produced high combustion temperature and radical reaction so that diffusion between W and B was not properly occurred. Addition of NaCl and replacement of B2O3 with B successfully solved the diffusion problem. From the optimum condition tungsten boride(W2B and WB) powders which has 0.1~0.9 um particle size were synthesized.

Preparation processing of sintered silicon nitride ceramics was emphatically investigated with Self-Propagating High-Temperature Synthesis (SHS) of silicon nitride prepared by ourselves as raw material. The results indicate that good sinter ability can be obtained with cheaply SHS of silicon nitride preparing silicon nitride materials. The cost of silicon nitride materials will be lowered.

In this study, high purity fine powders were prepared by SHS (Self-propagating High-temperature Synthesis). We would examinate the study of sintering properties and characteristics as a function of temperature with various additives (binder, sintering agent). In separately binder addition, the green and sintered density of specimen were increased as binder content increases. The increased porosity resulted in fine grain size due to the inhibition of grain boundary moving. The and MgO playa role of increasing dielectric constants at room temperature. These values were decreased at curie temperature. In case of , the Curie temperature was decreased. In this study, a high dielectric ceramic capacitor material with temperature stability was synthesized by using various additives

This study for preparation of aluminum nitride (AlN) with high purity was carried out by self-propagating high-temperature synthesis method in two different systems, Al-N and Al-N-AlN, with the change of nitrogen gas pressure and dilution factor. On the occasion of Al-N system, unreacted aluminum was detected in the product in spite of high nitrogen pressure, 10 MPa, This may be caused by obstructing nitrogen gas flow to inner part of molten and agglomerate of aluminum, formed in pre-heating zone. In Al-N-AlN system, AlN with a purity of 95% or ever can be prepared in the condition of f 0.5, PN2 1 MPa, and the purity can be elevated to 98% over in the condition of f = 0.7 and PN2 = 10 MPa