Open Access. Powered by Scholars. Published by Universities.®

Materials Science and Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Oxidation

Discipline
Institution
Publication Year
Publication
Publication Type

Articles 61 - 72 of 72

Full-Text Articles in Materials Science and Engineering

Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho Jan 2009

Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen is of great interest since the availability of traditional fossil fuels is in decline. Strictly speaking, hydrogen is not a primary source of energy but is an energy carrier, since energy typically must be used from another source (electricity, natural gas, coal, etc.) to produce it. Of hydrogen production techniques, the Sulfur-Iodine thermochemical water splitting process (S-I cycle), which was proposed by General Atomics (GA), is promising with its simplicity and high efficiency. Most of the chemicals are recycled except water. However, the S-I cycle operates in a harsh, corrosive environment in the presence of a mixture of iodine …

Go to article

Effects Of Frequency And Environment On Fatigue Behavior Of An Oxide-Oxide Ceramic Matrix Composite At 1200°C, Griffin Hetrick Jun 2006

Effects Of Frequency And Environment On Fatigue Behavior Of An Oxide-Oxide Ceramic Matrix Composite At 1200°C, Griffin Hetrick

Theses and Dissertations

Advances in aeronautical engineering in the 21st century depend upon materials that can perform well in extreme environments such as high temperatures and oxidizing conditions. Nextel™720/Alumina (N720/A) is an oxide/oxide ceramic matrix composite with a porous alumina matrix that has been identified as a candidate material for such applications. This research investigated the effects of frequency on fatigue response of N720/A at 1200°C in both air and steam environment. Prior investigation of this material by Eber [8] in 2005 studied fatigue behavior at 1200°C in air and in steam environments at the frequency of 1.0 Hz. The current research focused …

Go to article

Polymer-Derived Si-Al-C-N Ceramics:Oxidation, Hot-Corrosion, And Structural Evolution, Yiguang Wang Jan 2006

Polymer-Derived Si-Al-C-N Ceramics:Oxidation, Hot-Corrosion, And Structural Evolution, Yiguang Wang

Electronic Theses and Dissertations

Polymer-derived ceramics are a new class of materials synthesized by thermal decomposition of polymer precursors. Previous studies have shown that the materials exhibit excellent thermo-mechanical properties and can be stable at temperatures up to 2000oC. Furthermore, the novel polymer-to-ceramics process enables the manipulation of the ceramic structures at the atomic/nano level by designing the chemistry of polymer precursors and controlling the pyrolysis conditions, thereby, the properties of ceramics. In this dissertation, oxidation/hot-corrosion behavior and the structural evolution of Si-Al-C-N ceramics have been studied. The structural evolution and crystallization behavior of the SiCN and SiAlCN ceramics are investigated using FT-IR, XRD, …

Go to article

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics - Phase Three, Samir Moujaes, Yitung Chen Aug 2003

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics - Phase Three, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Go to article

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Phase Two, Samir Moujaes, Yitung Chen May 2002

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Phase Two, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Go to article

Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jian-Zhang Zhou, Ling-Ling Wu, Jin Luo, Zhong-Hua Lin May 1999

Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jian-Zhang Zhou, Ling-Ling Wu, Jin Luo, Zhong-Hua Lin

Journal of Electrochemistry

It is shown that calf thymus DNA (CT DNA) can be adsorbed at highly ordered pyrolytic graphite (HOPG) electrode and detected by differential pulse voltammetry (DPV) and electrochemical atomic force microscopy (ECAFM). It is found that controlled potential pre-polarization influences largely the adsorption of dsDNA while it has little influence on ssDNA. It is demonstrated that ECAFM is useful to exploit adsorption of DNA at HOPGE. The pattern of adsorption of DNA at HOPG electrode that fits best with the experimental data is proposed. The results aslo shows that UV/Vis reflection spectroscopy, which has not been used in studying electrochemical …

Go to article

Oxidation Mechanism Of Hypophosphite, Dong-Bai Sun, Ying Jin, Hong-Ying Yu, De-Jun Yang Feb 1999

Oxidation Mechanism Of Hypophosphite, Dong-Bai Sun, Ying Jin, Hong-Ying Yu, De-Jun Yang

Journal of Electrochemistry

There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V (SCE) in Na-hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H2PO2- to H2PO3-, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V (SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H2PO2-, i.e. peak Ⅱ corresponds to the oxidation process of …

Go to article

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi Aug 1995

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi

Journal of Electrochemistry

This paper introduces the method to judge: 1)the possibility of oxidation of themetal hydride electrode in an anode process by cyclic voltammetric curves, 2)the oxidation pattern ofmetal hydride electrode in oxygen atmosphere in various charged states, and 3)the inhibition ofoxidation of hydrogen absorbing alloys by certain surface treatment.

Go to article

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski May 1994

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski

Mechanical Engineering Faculty Research

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, …

Go to article

Determination Of Oxygen Chemical Diffusion Coefficients In Single Crystal Srtio By Capacitance Manometry, D. B. Schwarz, Harlan U. Anderson Jan 1975

Determination Of Oxygen Chemical Diffusion Coefficients In Single Crystal Srtio By Capacitance Manometry, D. B. Schwarz, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The oxidation kinetics of a single crystal of SrTiOs were measured with a tensivolumetric system over the temperature range 700 -975 at 0.03 atm oxygen pressure. The oxidation was found to be oxygen diffusion limited with an activation energy of 14.9 - 1.3 kcal/mole. Combining the kinetic data with relative defect concentration data yielded an activation energy for oxygen self-diffusion of 57 - 16 kcal/mole. The enthalpy of formation of doubly ionized oxygen vacancies was calculated to be 126 - 13 kcal/mol. © 1975, The Electrochemical Society, Inc. All rights reserved.

Go to article

Ferromagnetism In Some Alloys Of The Copper-Manganese-Tin System, Leonard W. Boyd Jr. May 1958

Ferromagnetism In Some Alloys Of The Copper-Manganese-Tin System, Leonard W. Boyd Jr.

Bachelors Theses and Reports, 1928 - 1970

The specific purpose of this investigation is to study the effects of heat treating at various temperatures for different lengths of time, with special attention paid to changes in magnetization. Identical heat-treating conditions were used on several different alloys, the compositions of which are such that some specimens are in the single-phase beta prime and beta regions, whereas others are in two-phase regions. For this investigation, only magnetic measurements will be attempted.

Go to article

The Effect Of The Cu:Fe''' Ratio Upon The Current Efficiency In The Electrolysis Of A Copper Sulfate Solution Containing Iron Sulfate, Joseph Thomas Roy, Francis Carroll Moran Jun 1929

The Effect Of The Cu:Fe''' Ratio Upon The Current Efficiency In The Electrolysis Of A Copper Sulfate Solution Containing Iron Sulfate, Joseph Thomas Roy, Francis Carroll Moran

Bachelors Theses and Reports, 1928 - 1970

It is a well-known fact that, in the electrolysis of a CuSO4 solution containing iron sulfate, using insoluble anodes, with the depletion of copper, the point is finally reached where the current efficiency becomes zero. This decrease in current efficiency is due to the oxidation of the ferrous sulfate to the ferric condition at the anode, by the oxygen liberated. The resulting ferric sulfate diffuses over to the cathode and there dissolves copper from the cathode according to the chemical equation Cu + Fe2 (SO4)3 = CuSO4 + 2FeSO4. This copper, which has …

Go to article

First Prev