• 제목/요약/키워드: oxide reduction

검색결과 1,352건 처리시간 0.032초

NMOSFET SOI 소자에서 부분적 게이트 산화막 두께 변화에 의한 돌연 전류 효과 고찰 (A Study on the Current Kink Effect in NMOSFET SOI Device with the Varying Gate Oxide Thickness)

  • 한명석;이충근홍신남
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.545-548
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    • 1998
  • Thin film SOI(Silicon-On-Insulator) devices exhibit floating body effect. In this paper, SOI NMOSFET is proposed to solve this problem. Some part of gate oxide was considered to be 30nm~80nm thicker than the other normal gate oxide and simulated with TSUPREM-4. The I-V characteristics were simulated with 2D MEDICI mesh. Since part of gate oxide has different oxide thickness in proposed device, the gate electric field strength is not the same throught the gate and consequently the reduction of current kink effect is occurred.

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

  • 이동희;차광서;박주식;강경수;김영호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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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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주철분말(鑄鐵粉末)의 소결조직(燒結組織)에 미치는 산화철(酸化鐵) 첨가(添加)의 효과(效果) (The Effect of Fe-Oxide Addition on the Sintered Structure of Cast Iron Power)

  • 김형수;김철범;나형용
    • 한국주조공학회지
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    • 제10권2호
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    • pp.154-161
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    • 1990
  • The microstructures of sintered products of $Fe_2O_3$or $Fe_3O_4$-Oxide added cast iron powder was investigated. And the effects of particle size distribution was investigated too. As the result, the structures of sintered products did not related to the species of Fe-Oxide. Th porosity of sintered products was decreased in size and spherodized with increasing sintering temperature, decreasing Fe-Oxide quantity. Fe-Oxide itself did not hinder sintering of cast iron powder particularly, therefore sintering could be occurred without termination of reduction of it. And the sintered products of finer particle size distribution had finer and more spherodized porosity, and had minimized the deviation of size and shape of porosity.

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제산제 알루미나수화물의 콜로이드성과 제산능 (Collodial Properties and Acid Consuming Capacity of Hydrous Aluminum Oxide Suspension)

  • 이계주;이기명
    • 약학회지
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    • 제35권4호
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    • pp.277-282
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    • 1991
  • Rheological, colloidal and micromeritical properties were followed to investigate aging mechanisms of hydrous aluminum oxide suspension using Zeta-meter systems, BET adsorption apparatus, Master sizer and electronmicroscope. The results indicate that hydrous aluminum oxide suspension revealed plastic flow with thixotropy. The viscosity, thixotropy and yield value were increased with increasing concentration. During aging process, the viscosity and thixotropic index were increased by an addition of glycerin, however, sorbitol stabilized aging process of the suspension being accompanied with growth of particle size and reduction in specific surface area, pore area and pore volume, and consistency. Diminution of adsorptive power of the particles was also protected by addition of sorbitol to hydrous aluminum oxide suspension. From these results, one of aging mechanism of hydrous aluminum oxide suspension assumed growth and/or crystallization of colloidal particles in aqueous suspension.

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고순도 수소 생성을 위한 SIP법에서 첨가제에 따른 환원 특성 (Characteristics of Redox Agent with Additive in Steam-Iron Process for the High Purity Hydrogen Production)

  • 전법주;김선명;박지훈
    • 한국수소및신에너지학회논문집
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    • 제22권3호
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    • pp.340-348
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    • 2011
  • Effects of various inorganic-metal oxide (Zr, Zn, Si, Al and Ca as promoters and stabilizers) additive on the reduction rate of iron oxide and the composition of forming hydrogen using the steam-iron cycle operation was investigated. The reduction rate of redox agent with additive was determined from weight change by TGA. The changes of weight loss and reduction rate according to redox agent with various additive affected the hydrogen purity and cycle stability of the process. The cyclic micro reactor showed that hydrogen purity exceeding 95% could be obtained by the water splitting with Si/Fe, Zn/Fe, Zr/Fe redox agents. The redox agents with these elements had an affect on redox cycle stability as a good stabilizer for forming hydrogen by the steam-iron process.

진동에너지에 의한 산화질소 분자(NO)의 음이온(NO-)으로의 환원반응에 관한 연구 (A Study on the Reduction of Nitric Oxide Molecule (NO) to Nitroxyl Anion (NO-) by Vibrational Energy)

  • 조선욱
    • 대한화학회지
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    • 제46권1호
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    • pp.14-18
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    • 2002
  • 산화질소 분자(NO)가 전자 한 개를 받아 산화질소 음이온$(NO^-)$으로 환원되는 반응의 정도가 진동에너지에 따라 크게 달라질 수 있음을 제시하였다. NO와 $NO^-$의 포텐샬에너지 표면은 진동에너지가 많아짐에 따라 NO 분자가 전자를 받아 $NO^-$음이온으로 바뀔수 있는 에너지적 측면을 가짐을 보여준다. 또한, 진동 파동함수간의 Franck-Condon 인자를 계산하였다. 진동에너지가 많아지면 NO에서 $NO^-$로 바뀔 경로가 더 많이 증가함을 보인다. 이 결과는 NO 분자에게 적절한 빛을 조사시킴으로 $NO^-$이온으로의 환원반응속도를 조절할 수 있음을 의미한다.

비이온계 계면활성제 첨가수에 대한 관내 유동저항 감소 및 열전달 촉진에 관한 연구 (A Study on the Drag Reduction Effect and Heat Transfer Enhancement of Non ionized Surfactant and Water Mixture in a Circular Pipe Flow)

  • 김명준
    • Journal of Advanced Marine Engineering and Technology
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    • 제31권5호
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    • pp.552-557
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    • 2007
  • This paper has dealt with the effect of non ionized surfactant and water mixture on drag reduction and heat transfer enhancement in a circular pipe flow with experimentally. The test section was consisted of stainless steel pipe with inside diameter of 16mm. The wire coil was used to increase heat transfer in a pipe and the on ionized surfactant(Oleyl Dihydroxyethyl Amino Oxide, ODEAO) was used to reduce the drag force of water mixture with surfactant. The main parameters of this experiment were diameter and pitch of wire coil and the ratio of test section length and horizontal wire coil length. In this experiment, the acquired results were 1) Drag reduction effect existed in this ODEAO-water mixture, 2) Friction factor and heat transfer were increased with insertion the heat transfer enhancement coil, 3) With increasing of pitch ratio, heat transfer was decreased, and 4) Heat transfer was decreased by the decreasing of inserting coil diameter.