Nb 첨가 Zr합금인 Zr-lNb합금과 Zr-lNb-lSn-0.3Fe함금의 석출물 및 산화 특성에 미치는 마지막 열처리 온도의 영향을 알아보기 위하여 최종 열처리 온도를 450˚C에서 800˚C까지 변화시켜 미세조직 및 산화 특성을 조사하였다. 부식 시험은 400˚C , 수중기 분위기에서 270 일 동안 실시하였으며 X-선 회절법을 이용하여 산화막 결정 구조를 분석하였다. 마지막 열처리 온도가 600˚C 이상일 때 두 합금 모두 β-Zr이 관찰되었으며 모두 재결정 이후 마지막 열처리 온도가 상승할수록 석출물의 면적 분율이 증가하는 경향을 나타내었다. 모든 열처리 온도 구간에서 Zr-lNb합금의 부식 저항성이 Zr-lNb-lSn-0.3Fe 합금에 비해 우수하였으며 두 합금 모두 재결정 이후 부식 저항성이 급격히 나빠졌다. 이는 600˚C 이후 형성된 β-Zr의 영향으로 밝혀졌다.

아크이온 플레이팅 장치를 이용하여 STD61강 기판 위에 이온질화 전처리를 행하거나 하지 않은 후, CrN 박막을 증착하고, 대기중 700~900˚C의 온도에서 40시간동안 이들에 대한 산화거동을 연구하였다. 산화거동은 열중량분석기, X선회절기, EDS, SEM을 이용하여 조사하였다. 증착된 CrN박막은 CrN과 Cr2N의 두 상으로 구성되어 있었다. CrN박막은 보호적 Cr2O3층을 형성하여 기판을 산화로부터 보호하였다. 이온질화처리는 CrN박막의 내산화성에 영향을 주지 않았다.

As already pointed out increasing the concentration of dried insam with gangjung becomes progressing the antioxidant effect: 1. The antioxidant effect of gangjung with undried insam increased than gangjung and above 6.0% of undried insam is same of the storage stability, 6 months 2. The more increased acid value(AV) and the peroxide value(POV) of susam gangjung the longer period of storage, but there was no significient difference with the kinds of adding methods. 3. Sensory evaluation of preference for flavor gangjung with increased according to increasing concentration of undried insam but 6.0% undried insam in maltose was the best among samples.

Spark-Plasma Sintering(SPS) is one of the new sintering methods which takes advantages both inconventional pressure sintering and electric current sintering. It is known that SPS is very effective for the densification of hard-to-sinter materials like refractory metals, intermetallic compounds, glass and ceramics without grain growth. However, a clear explanation for sintering mechanism and an experimental evidence for the formation of weak plasma during SPS are not given yet. In this study, fundamental study on sintering behavior and mechanism of SPS was investiged. For this study, various spherical Fe powders were prepared such as as-received, as-reduced, and as-oxidized and then sintered by SPS facility. In order to confirm the surface cleaning effect during SPS neck region and fracture surface of sintered body was observed and analyzed by SEM/EPMA. Densification behavior was analyzed from the data of deflection along the pressure axis. Some specimens were additionally produced by Hot Pressing and the results were compared with those of SPS.

양극산화법을 이용하여 광촉매 특성을 나타내는 TiO2 피막을 제조하고 염료의 분해반응을 통하여 광분해 효율을 조사하였다 양극산화법에 의해 제조된 산화피막은 모두 광촉매 분해특성이 있었으며 양극산화의 조건에 따라서 TiO2 피막의 성장거동과 피막 형태에 차이가 나타났다. 황산용액에서 양극산화된 TiO2 피막은 불규칙적 인 입자모양으로 anatase와 rutile이 혼합된 조직이었으며, 인산이 첨가된 혼합용액에서 형성된 TiO2는 anatase로 셀 모양의 피막형태로 생성되었다. 광촉매 특성에 적합한 양극산화의 인가 전압은 180V인 것으로 나타났다.

Fe-28%Al(Fe3Al)과 Fe-28%Al-4%Cr(Fe3Al-4Cr) 금속간화합물을 대기중 1073, 1273, 1473k의 온도에서 최고 17일까지 장시간 산화시켰다. Fe3Al-4Cr의 산화저항은 근본적으로 Fe3Al과 거의 비슷하거나, 약간 우수하였다. Fe3Al 위에 형성된 산화물은 거의 순수한 α-AL2O3로만 구성되어 있었으며, Fe3Al-4Cr 위에 형성된 산화물은 약간의 Fe와 Cr 이온이 고용된 α-AL2O3로 구성되어 있었다. 외부산화막을 형성하기 위해 모재원소의 외부확산에 의해 산화물-모재 계면에는 Kirkendall 기공이 존재하였다. Fe3Al(-4Cr) 표면에 형성된 산화막은 1273k가지는 비교적 얇고 치밀하였으나, 1473k에서 산화막의 박리와 함께 상대적으로 큰 무게증가가 발생하였다.

The antioxidant effect and sensory evaluation of various concentration of dried insam on gangjung was investigated for 6 months. The results were as follows: 1. The antioxidant effect of each sample were in the rank order of 0$gt;0.5$gt;1.0$gt;1.5$gt;2.0$gt;2.5% of dried insam at 20℃ by acid and peroxide value but the effect did not increase proportionally with increasing concentration. 2. In 3 months, acid and peroxide values increased slowly showing, but after 3 months, acid and peroxide values increased remarkably. 3. The acid value(AV) and the peroxide value(POV) of dried insam gangjung increased according to storage term but there was no significant difference with the kinds of adding methods of dried insam. 4. Sensory evaluation of preference for flavor, texture, taste and total quality of six samples by multiple paired comparison test indicated that gangjung with 1.5% dried insam in maltose was the best among samples.

This paper describes the mechanical properties and oxidation resistance of carbon fibers with and without additions of boron oxide additives, and describes the changes in the properties resulting from increased heat treatment temperature (HTT) of the fibers. Carbon fibers in this experiment were heat treated up to 2800℃ each with and without boron oxide treated on the surface of fibers. In the case of boron oxide added carbon fibers, they do not show the improvement of tensile strength and modulus compared to those of no treated carbon fibers below 2200℃ since they are doped substitutionally with boron above 2600℃, which accelerate the graphitization of carbon fibers. Boron oxide implanted carbon fibers showed high resistance to oxidation, however, when carbon fibers were heat treated below 2200℃, they showed almost the same trend of air oxidation.

Electrochemical promotion of the reaction rate was investigated for CO oxidation in a solid electrolyte catalytic reactor where a thin film of Pt was deposited on the yttria stabilized zirconia as an electrode as well as a catalyst. It was shown under open circuit condition that potential was a mixed potential of O2exchange reaction and electrochemical reaction induced by CO. The effect of electrochemical modification on the CO oxidation rate was studied at various overpotentials and PCOPO2.

약 90 nm 두께의 비정질 TaSiN박막을 poly-Si and SiO2/Si 기판 위에 rf magnetron sputtering법으로 증착하였다. TaSiN박막은 산소부위기에서 열처리 시 900˚C까지 결정화되지 않는 비정질 상을 보였다. 산소의 확산 깊이는 산소분위기 열처리 온도가 증가함에 따라 증가하였으며 650˚C, 30분 열처리시 Ta23Si29N48의 경우 약 20 nm의 깊이까지 확산되었다. Ta23Si29N48 박막의 증착 후 비저항은 약 1,300μΩ-cm의 값을 보였지만 산소분위기 열처리시 700˚C 이상에서 급격히 증가하였다.

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to NO2 over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

The oxidation of methane was carried out in six different configurations of plasma reactors in order to study the radical reactions inside and outside of the plasma zone and to explore the method to control them. Various radicals and reactive molecules, such as CH, CH2, CH3, H, and O(from O2) were generated in the plasma. A variety of products were produced through many competing reaction pathways. Among them. partial oxidation products were usually not favored, because the intermediates leading to the partial oxidation products could be oxidized further to carbon dioxides easily. It is important to control the free radical reactions in the plasma reactor by controlling the experimental conditions so that the reactions leading to the desired products are the major pathways

The flavin-containing monooxygenases (FMOs) (EC 1.14.13.8) are NADPH-dependent flavoenzymes that catalyze oxidation of soft nucleophilic heteroatom centers in a range of structurally diverse compounds including foods, drugs, pesticides, and other xenobiotics. In humans, FMO1 appears to be the predominant form expressed in human fetal liver. cDNA-expressed human FMO and human liver microsomal FMO have been observed to N- and S-oxygenate nucleophilic nitrogen- and sulfur-containing drugs and chemicals, respectively. In the present study, FMOl can be expressed in the baculovirus expression vector system at level of 2.68 nmol FMO1/㎎ of membrane protein. This isoform was examined for its capacity to metabolize methimazole to its S-oxide using thiocholine assay. Kinetic studies of its S-oxide by recombinant human FMO1 result in K_m of 7.66 μM and V_(max) of 17.79 nmol/min/㎎ protein.

6종류의 조성을 가진 TiAl계 합금, 즉 Ti-(42, 44)Al-2Nb-4V, Ti-(42, 44)Al-4Nb-2V 및 Ti-(42, 44)Al-4Nb-2Cr을 아크용해법으로 제조한 후, 이들의 산화성질을 조사하였다. 700, 800 및 900˚C의 대기 중, 50시간동안의 등온 및 반복 산화실험으로부터, 산화저항은 Ti-(42, 44)Al-2Nb-4V, Ti-(42, 44)Al-4Nb-2V 및 Ti-(42, 44)Al-4Nb-2Cr의 순으로 증가함을 알 수 있었다. 내산화성에서 V은 해로운 원소이고 Cr은 유익한 원소이었다. 산화 중 모든 모재 구성원서는 외부확산하였고 분위기중으로 부터의 산소는 내부확산하는 상호확산이 관찰되었으며, 생성되는 산화물은 최외각 TiO2층, 상부 (TiO2+Al2O3) 혼합층 및 하부 TiO2-잉여층으로 이루어진 3층 산화물구조로 구성되어 있었다.

4NH(sub)3+3O2→2N2+6H2O 의 화학반응식을 가지며 O2 및 H2O를 산화제로 하는 NH3/O2산화의 성장모델을 세웠으며, 그 결과 Fick의 제 1 법칙을 기초로 하는 건식 및 습식 산화메카니즘으로 이해되는 Deal-Grove의 산화막 성장모델과 유사한 결과가 도출되었다. 이 성장모델에 의하면 산화제 O2 및 H2O가 상호보완적으로 산화에 영향을 미치므로 산화온도 뿐 아니라 NH3/O2의 유량비도 산화율을 결정한다. rapid thermal processing(RTP)에 의한 산화막 성장실험으로 본 연구에서 제안하는 성장모델을 확인하였으며, NH3분자의 분해에 의해 발생하는 N 원자의 산화막 내부확산을 secondary ion mass spectroscopy(SIMS)로 확인하였으며, Auger electron spectroscopy (AES) 측정결과 N 원자의 존재는 무시할만한 수준이었다.

The oxidation behavior of the simulated spent fuel of burn up 33 MWD/kgU was investigated to predict that of the spent fuel in the temperature ranges of 400 to and was compared with those of . The forms of uranium oxides after the oxidation were conformed by XRD analyses. The oxidation rate at each the temperature and the activation energy were obtained. After complete oxidation, the simulated spent fuel was converted to and pulverized to powder due to the density difference between the simulated spent fuel and uranium oxides. The activation energies were 85.35 and 30.77kJ/mol in the temperature ranges of 400T()500 and 500T()700, respectively.