• Title/Summary/Keyword: Steam oxidation

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Quality Characteristics of Vegetables by Different Steam Treatments (스팀 열처리 방식에 따른 채소류의 품질 특성)

  • Cheigh, Chan-Ick;Lee, Jin-Hee;Chung, Myong-Soo
    • The Korean Journal of Food And Nutrition
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    • v.24 no.3
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    • pp.464-470
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    • 2011
  • Thermally processed vegetables have long been considered to have lower nutritional values compared to fresh produce. This consideration is based on the fact that ascorbic acid(vitamin C) or other thermolabile compounds may lose their activity due to oxidation or by consequence of leaching into the water during home cooking or industrial processing, such as by blanching. In this study, major agricultural products such as carrots, broccoli, and potatoes were exposed to steam treatments of different types. Then, changes in color and levels of ascorbic acid, carotene, and moisture in the fresh and steam processed vegetable samples were measured and evaluated. The results clearly showed that steam-processing using a natural convection type method was superior to the other treatments in terms of quality, including color and nutrient retention, among all the vegetables tested.

Rubber Material Development and Performance Evaluation of Diaphragm Seal for Steam Generator Nozzle Dam

  • Woo, Chang-Su;Song, Chi-Sung;Lee, Han-Chil;Kwon, Jin-Wook
    • Elastomers and Composites
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    • v.55 no.3
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    • pp.222-228
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    • 2020
  • Rubber materials, used in nuclear power plants, need high heat-oxidation resistance to curing or cracking under a heat aging environment. This is because they are applied to environments with high temperature, high humidity, and radiation exposure. Nuclear radiation causes additional hardening or degradation, therefore, rubber materials need radiation resistance that satisfies the general and any accidental conditions produced in the power plant. Therefore, in this study, we developed a rubber material with excellent heat and radiation resistance for the diaphragm seal of a nuclear steam generator nozzle dam. The rubber material greatly improved the reliability of the steam generator nozzle dam. In addition, 30 inch and 42 inch diaphragm seals were manufactured using the developed rubber material. A nozzle dam was installed in a nuclear power plant and tested under the same conditions as a steam generator to evaluate safety and reliability. In the future, the performance and safety of diaphragm seals developed through field tests of nuclear power plants will be evaluated and applied to currently operating and new nuclear power plants.

The effect of Rh/Ce/Zr additives on the redox cycling of iron oxide for hydrogen storage (산화철의 환원-산화 반응을 이용한 수소저장에 미치는 Rh/Ce/Zr의 효과)

  • Lee, Dong-Hee;Cha, Kwang-Seo;Park, Chu-Sik;Kang, Kung-Soo;Kim, Young-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.49-52
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    • 2007
  • We investigated hydrogen storage and production properties using redox system of iron oxide($Fe_{3}O_{4}$ + $4H_{2}$ ${\leftrightarrows}$ 3Fe + $4H_{2}O$) modified with rhodium, ceria and zirconia under atmospheric pressure. Reduction of iron oxide with hydrogen(hydrogen storage) and re-oxidation of reduced iron oxide with steam(hydrogen evolution) was carried out using a temperature programmed reaction(TPR) technique. On the temperature programmed studies, the effects of amounts of cerium and zirconium on the re-oxidation rate of partial reduced iron oxides were increased with increasing metal additives amount, but the rhodium amount showed little effect on the re-oxidation rate. On the thermal studies, the re-oxidation rates were enhanced with increasing temperature(300 $^{\circ}C$ < 350 $^{\circ}C$).

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High-temperature Corrosion by Chlorides in Biomass-fired Plants (바이오매스 발전시 염소가스에 의한 고온부식)

  • Lee, Dong Bok
    • Journal of the Korean institute of surface engineering
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    • v.49 no.1
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    • pp.14-19
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    • 2016
  • Biomass is a renewable and sustainable source of energy used to create electricity or pressurized steam. In biomass-fueled power plants, wood waste or other waste is burned to produce steam that runs a turbine to make electricity, or that provides heat to industries and homes. Biomass power plants, apart from producing energy, help to reduce the $CO_2$ emission. However, the main problem is the high-temperature corrosion due to fuel corrosivity, especially of the straw. This limits both the temperature of the steam and also the effectiveness of the power plant. The corrosion in biomass-fueled plant was described.

A Study on Syngas Production By Noncatalytic Partial Oxidation of Methane (메탄의 무촉매 부분산화를 통한 합성가스 제조 연구)

  • Na, Ik-Hwan;Yang, Dong-Jin;Choi, Sin-Yeong;Chae, Tae-Young;Bang, Byoung-Yeol;Yang, Won
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.4
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    • pp.337-343
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    • 2009
  • Noncatalytic partial oxidation of methane for producing synthesis gas was studied in a lab-scale experimental apparatus. Partial oxidation developed for high-temperature, fuel-rich combustion and it is exothermic process. but Steam reforming and Caron reforming is highly endothermic process to need much energy. Noncatalytic partial oxidation of methane is affected by temperature and equivalent ratio, so we studied effect about composition of synthesis gas at lab scale reactor. We used electronic heater to control the temperature of reactor. The quality of synthesis gas is improved and reduced heat value to require at Noncatalytic partial oxidation because the reacting temperature is lower at oxy condition.

Effects of Steam Sources and Glycerol on the Storage Stability of Fish Oil (탈취공정 중 steam source의 조절과 glycerol 첨가가 어유의 저장안정성에 미치는 영향)

  • Yi, Ock-Sook;Han, Dae-Seok;Cho, Dong-Wuk
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.824-827
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    • 1994
  • Sardine oil was vacuum-steam deodorized at $170^{\circ}C$ with acid (acetic and citric acid) and ethanol solution as steam sources. Glycerol was added to fish oil to remove volatile odorous constituents. The storage stability of deodorized fish oil was determined by totox value, secondary parameter obtained from peroxide and anisidine values. Both deodorization with acetic acid solution and addition of glycerol to the oil resulted in improved storage stability. The totox values of fish oil deodorized with water, glycerol+water and glycerol+acetic acid solution were 936, 611, and 443, respectively after 10 days at $30^{\circ}C$. The result showed that acetic acid seemed to destroy the odorous constituents and glycerol accelerated the removal of odorous constituents, such as amines in fish oil.

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