• Title/Summary/Keyword: Wet oxidation method

Search Result 59, Processing Time 0.11 seconds

Extraction and Mixing Effects of Grape (Campbell) Seed Oil

  • Kang, Han-Chul;Min, Young-Kyoo;Hwang, Jong-Taek;Kim, Si-Dong;Kim, Tae-Su
    • Journal of Applied Biological Chemistry
    • /
    • v.42 no.4
    • /
    • pp.175-179
    • /
    • 1999
  • Grape seed oil was extracted using different preparatory treatments as follows: (1) grinding, (2) grinding and roasting, (3) grinding and wet- roasting, (4) grinding, roasting, and wet-roasting, and (5) grinding, wet-roasting, and wet-roasting. The highest antioxidant activity was obtained from the sample with the method (2). Initial states of oxidation were similar except method (1) that showed more oxidized state, being P.O.V.8. Acid values were observed in the range from 1.42 to 1.89. The lowest acid value was found as 1.42 in method (1) and those of others were somewhat higher, indicating that heating process of roasting produced some free fatty acids. From the results of sensory evaluation, the best odor and taste were obtained from the methods (2) and (3). Repetitive procedure of wet-roasting, like method 5, caused some loss of flavor components and decrease in the sensory evaluation score. Addition of grape seed oil (method 2) to soybean and perilla oil at the level of 20% retained considerable antioxidant activities as much as 4.3 and 5 times, respectively, than 100% soybean or perilla oil stored for 12 weeks. When soybean or perilla oil was mixed with 20% grape seed oils, P.O.V. decreased to half of that of unmixed oils.

  • PDF

Double Layer (Wet/CVD $SiO_2$)의 Interface Trap Density에 대한 연구

  • Lee, Gyeong-Su;Choe, Seong-Ho;Choe, Byeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.02a
    • /
    • pp.340-340
    • /
    • 2012
  • 최근 MOS 소자들이 게이트 산화막을 Mono-layer가 아닌 Multi-Layer을 사용하는 추세이다. Bulk와 High-k물질간의 Dangling Bond를 줄이기 위해 Passivation 층을 만드는 것을 예로 들 수 있다. 이러한 Double Layer의 쓰임이 많아지면서 계면에서의 Interface State Density의 영향도 커지게 되면서 이를 측정하는 방법에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 $SiO_2$ Double Layer의 Interface State Density를 Conductance Method를 사용하여 구하는 연구를 진행하였다. Wet Oxidation과 Chemical Vapor Deposition (CVD) 공정을 이용하여 $SiO_2$ Double-layer로 증착한 후 Aluminium을 전극으로 하는 MOS-Cap 구조를 만들었다. 마지막 공정은 $450^{\circ}C$에서 30분 동안 Forming-Gas Annealing (FGA) 공정을 진행하였다. LCR meter를 이용하여 high frequency C-V를 측정한 후 North Carolina State University California Virtual Campus (NCSU CVC) 프로그램을 이용하여 Flatband Voltage를 구한 후에 Conductance Method를 측정하여 Dit를 측정하였다. 본 연구 결과 Double layer (Wet/CVD $SiO_2$)에 대해서 Conductance Method를 방법을 이용하여 Dit를 측정하는 것이 유효하다는 것을 확인 할 수 있었다. 본 실험은 앞으로 많이 쓰이고 측정될 Double layer (Wet/CVD $SiO_2$)에 대한 Interface State Density의 측정과 분석에 대한 방향을 제시하는데 도움이 될 것이라 판단된다.

  • PDF

Evaluation Method for Graphene Grain Boundary by UV/ozone-oxidation Chemical-etching Process (UV/ozone 산화처리 및 화학적 식각공정을 적용한 그래핀 Grain Boundary 평가 방법)

  • Kang, Jaewoon;Park, Hongsik
    • Journal of Sensor Science and Technology
    • /
    • v.25 no.4
    • /
    • pp.275-279
    • /
    • 2016
  • Chemical vapor deposited (CVD) polycrystalline graphene is widely used for various sensor application because of its extremely large surface-to-volume ratio. The electrical properties of CVD-graphene is significantly affected by the grain size and boundaries (GGBs), but evaluation of GGB of continuous monolayer graphene is difficult. Although several evaluation methods such as tunneling electron microscopy, confocal Raman, UV/ozone-oxidation are typically used, they still have issues in evaluation efficiency and accuracy. In this paper, we suggest an improved evaluation method for precise and simple GGB evaluation which is based on UV/ozone-oxidation and chemical etching process. Using this method, we could observe clear GGBs of CVD-graphene layers grown by different process conditions and statistically evaluate average grain sizes varying from $1.69{\sim}4.43{\mu}m$. This evaluation method can be used for analyzing the correlation between the electrical properties and grain size of CVD-graphene, which is essential for the development of graphene-based sensor devices.

Experimental study of NOx reduction in marine diesel engines by using wet-type exhaust gas cleaning system (선박용 디젤엔진의 NOx를 저감하기 위한 습식 배기가스 처리기술 적용에 관한 실험적 연구)

  • Ryu, Younghyun;Kim, Taewoo;Kim, Jungsik;Nam, Jeonggil
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.41 no.3
    • /
    • pp.216-221
    • /
    • 2017
  • Diesel engines have the highest brake thermal efficiency among internal combustion engines. Therefore, they are utilized in medium and large transportation vehicles requiring large amounts of power such as heavy trucks, ships, power generation systems, etc. However, diesel engines have a disadvantage of generating large quantities of nitrogen oxides during the combustion process. Therefore, the authors tried to reduce the amount of nitrogen oxides in marine diesel engines using a wet-type exhaust gas cleaning system utilizing the undivided electrolyzed seawater method. In this method, electrolyzed seawater in injected into the harmful gas discharge from the diesel engine using real seawater. The authors investigated the reduction of NO and NOx from the pH value, available chlorine concentration, and the temperature of electrolyzed seawater. The results of this experiment indicated that when the electrolyzed seawater is acidic, the NO oxidation rate in the oxidation tower is higher than that when the electrolyzed seawater has a neutral pH. Likewise, the NO oxidation rate increased with the increase in concentration of chlorine. Further, it was confirmed that the electrolyzed seawater temperature had no effect on the NO oxidation rate. Thus, the NOx exhaust emission value produced by the diesel engine was reduced by means of electrolyzed seawater treatment.

Evaluation of Mechanical Backside Damage of Silicon Wafer by Minority Carrier Recombination Lifetime and Photo-Acoustic Displacement Method

  • Park, Chi-Young;Cho, Sang-Hee
    • Proceedings of the Korea Association of Crystal Growth Conference
    • /
    • 1997.10a
    • /
    • pp.155-159
    • /
    • 1997
  • We investigated the effect of mechanical backside damage in Czochralski silicon wafer. The intensity of mechanical damage were evaluated by minority carrier recombination lifetime by a laser excitation/microwave reflection photoconductance decay method, photo-acoustic displacement method, X-ray section topography, and wet oxidation/preferential etch methods. The data indicate that the higher the mechanical damage intensity, the lower the minority carrier lifetime, and the photoacoustic displacement values are also increased proportionally.

  • PDF

Characterizations of Oxide Film Grown by $NH_3/O_2$ Oxidation Method ($NH_3/O_2$산화법으로 성장한 산화막의 특성평가)

    • Journal of the Korean Vacuum Society
    • /
    • v.7 no.2
    • /
    • pp.82-87
    • /
    • 1998
  • In the oxidation process of the $NH_3/O_2$ oxidation method, adding $NH_3$ gas to $O_2$ gas, the detected outlet gases in the reaction quartz chamber are N2, $O_2$ and $H_2O$ and in addition, a very small quantity of $CO_2$, NO and $NO_2$ are detected. Two kinds of species ($O_2$ and H2O) contribute to oxidation, so the growth rate is determined by oxidation temperature and by also partial pressure of the NH3 and $O_2$ gases. The slop of growth rate is identified to be medial and in parallel between that of the dry and wet oxidation. Auger electron spectroscopy (AES) indicates that $NH_3/O_2$ oxide film has a certain stoichiomerty of $SiO_2$, this oxidation method restrains the generation of defects in the $SiO_2/Si$ interface, minimizing fixed charges. The breakdown voltage of $NH_3/O_2$ oxide film (470$\AA$) is 57.5 volts, and the profile of the C-V curve including flat band voltage (0.29 volts) agree with the ideal curve.

  • PDF

Design of the Dry Powder Device and Slitting Machine Device (탈피복 기계 장치와 건식 분말화 장치 설계)

  • 정재후;윤지섭;김영환;이종열;홍동희
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.10a
    • /
    • pp.630-633
    • /
    • 1997
  • Spent fuel decladding device and dry voloxidizer is to separate the spent pellet from spent fuel rod cut by 250mm and to convert the spent pellet into powder form for reuse and/or disposal of the spent fuel. There are two methods in decladding and voloxidation of spent fuel, that is, wet method with chemical material and dry method with mechanical device. In this study, to examine the fuel rod decladding process and the pellet voloxidation process, the devices for the spent fuel decladding and the pellet voloxidation with dry method are developed. The decladding machine is designed to separate pellets from fuel rod by slitting device. And, the voloxidizer is designed to convert the spent pellet which is ceramic form into powder form by oxidation using the multi step mesh, vibrator, and air in the high temperature environment. The result of this study, such as operation condition et., will be utilized in the design of the machine for demonstration.

  • PDF

Comparison of 2,4,6-tribromophenol removal using in-situ liquid ferrate(VI) and stable ferrate(VI) (원위치 제조 액상 Ferrate(VI)와 안정화 Ferrate(VI)를 이용한 2,4,6-tribromophenol의 제거 비교연구)

  • Laksono, Fajar Budi;Jung, Sun-Young;Kim, Il-Kyu
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.32 no.2
    • /
    • pp.123-130
    • /
    • 2018
  • This paper provided the information related to the removal of 2,4,6-tribromophenol using in-situ and stable liquid ferrates(VI). This research's goal was to observe the differences of oxidation power between in-situ liquid ferrate(VI) and stable liquid ferrate(VI). The in-situ liquid ferrate(VI) ($FeO_4{^{2-}}$) has been successfully produced with the concentration 42,000 ppm (Fe) after 11 minutes of reaction time. The stable liquid ferrate(VI) was also successfully produced following the modification method by Sharma with the produced concentrations 7,000 ppm. The stable liquid ferrate(VI) was stable for 44 days and slightly decreased afterwards. This research has been carried out using 2,4,6-tribromophenol as the representative compound. Both of ferrates(VI) have the highest oxidation capability at the neutral condition. Furthermore, the stable liquid ferrate(VI) has higher oxidation power than the in-situ liquid ferrate(VI).

Development of On-Site Process for Refractory 2,4-Dichlorophenol Treatment (난분해성 2,4-Dichlorophenol 처리를 위한 원위치 처리 프로세스 개발 연구)

  • Park, Kyeong-Deok;Kim, Il-Kyu
    • Journal of Power System Engineering
    • /
    • v.20 no.1
    • /
    • pp.42-49
    • /
    • 2016
  • This study showed that on-site ferrate(VI) solution was synthesized by wet oxidation method and applied aqueous 2,4-dichlorophenol(DCP) solution to evaluate the degradation efficiency. On-site ferrate(VI) solution was synthesized by putting $FeCl_3{\cdot}6H_2O$ in the strong alkali solution with NaClO and NaOH and applied DCP solution directly. DCP solution was extracted by the liquid-liquid method and analyzed by GC-ECD. The factors such as pH, DCP initial concentration, injected ferrate(VI) dosage, temperature were investigated. The optimum pH and temperature conditions of DCP degradation were obtained in neutral condition and $35^{\circ}C$. And the experimental results showed that DCP removal efficiency also increased with the decrease of DCP initial condition and the injected ferrate(VI) dosage.