Download or read book Formation of Surface Sulfides on Iron Through Reaction with Sulfur written by Larry A. Haas and published by . This book was released on 1974 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Formation of Surface Sulfides on Iron Through Reaction with Sulfur written by L. A. Haas and published by . This book was released on 1974 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Analysis of a Coal Mine Opening in Elastic Multilayered Material written by Fun-Den Wang and published by . This book was released on 1974 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanisms Governing the Growth Reactivity and Stability of Iron Sulfides written by Francis William Herbert and published by . This book was released on 2015 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The kinetics of electrochemical processes in ionic materials are fundamentally governed by dynamic events at the atomic scale, including point defect formation and migration, and molecular interactions at the surface. A corrosion system comprising an iron sulfide film (passive layer) formed on iron or steel in contact with an hydrogen sulfide (H2S)- rich fluid can thus, in principle, be modeled by a series of unit reaction steps that control the rate of degradation under given thermodynamic conditions. This overarching thesis goal necessitates a concerted experimental and computational approach to determine the relevant kinetic parameters such as activation barriers Ea and rate constants v0 for the homogeneous and heterogeneous reactions of interest. These fundamental values can be obtained experimentally via temperature-dependent measurements on pure, model iron sulfide samples. This thesis therefore consists of three case studies on the stable Fe-S phases pyrrhotite (Fe1-xS) and pyrite (FeS2) to identify the elementary corrosion mechanisms and their kinetic parameters. Pyrrhotite is of interest because the off-stoichiometry of this phase leads to relatively rapid bulk processes such as diffusion; pyrite has a comparitively inert bulk but this work showed that it has a chemically labile surface. The first study focuses on two basic, rate-controlling steps in the growth of pyrrhotite: cation diffusion and sulfur exchange at the surface. First, iron self-diffusivity *DFe is determined across the temperature range 170-400 °C through magnetokinetic studies of the diffusion-driven "[lambda]" magnetic transformation, as well as direct tracer diffusion measurements in Fe1-xS crystals using secondary ion mass spectrometry (SIMS). This range encompasses the sponteneous magnetic and structural order-disorder temperature TN = 315 °C in pyrrhotite. The effect of spontaneous magnetization below TN is to increase the Fe vacancy migration energy by a combined 40% increasing Ea for diffusion from 0.83 eV in paramagnetic Fe1-xS to ~1.20 eV in the fully magnetized state. An extrapolation of the Arrhenius law from the paramagnetic regime would therefore overestimate actual diffusivities by up to 102 times at 150 °C. Second, the surface exchange of sulfur from H2S into the solid state in Fe1-xS is measured using electrical conductivity relaxation, yielding Ea = 1.1 eV for sulfur incorporation into pyrrhotite. With their similar thermal dependence, there is no clear temperature crossover from cation diffusion- to surface exchange-limiting regimes, or vice versa. Instead, surface exchange is expected to constrain pyrrhotite growth for films under ~100 [mu]m thickness, beyond which diffusion becomes the rate limiting mechanism, independent of external driving factors such as temperature. The second study explores the role of surface electronic states on the electrochemical reactivity of pyrite. Charge transfer between a solid surface and an adsorbate such as H2S requires the mutual availability of filled/empty electronic states at the same energy level. The semiconducting FeS2(100) surface is predicted to have intrinsic surface states (SS's) from Fe and S dangling bonds, as well as extrinsic SS's related to delocalized defects at the surface, both of which would affect charge transfer characteristics. A novel, broadly-applicable methodology is developed in this thesis to quantify the energy and density of these SS's, based on experimental scanning tunneling microscopy / spectroscopy (STM/STS) in conjunction with first principles tunneling current modeling. As a result, a decreased surface band gap Eg of 0.4 eV, compared to 0.95 eV in bulk pyrite, is measured. The findings highlight the need to differentiate between bulk and surface electronic structure when assessing heterogeneous reactivity, and have implications for the use of FeS2 in potential technological applications, for example as a photovoltaic adsorber. Finally, the dynamics of point defect formation and clustering on FeS2(100) under high-temperature, reducing conditions are investigated to understand the stability of the surface under extreme conditions. Synchrotron x-ray photoelectron spectroscopy (XPS) is used to measure a formation energy [delta]Hf for sulfur vacancies in the topmost atomic layer of 0.1 eV up to approximately 240 °C. Above this temperature, however, point defects are shown to condense into surface pits as measured by scnaning tunneling microscopy (STM). The combined, experimental XPS and STM results are replicated with high precision by a kinetic Monte Carlo (kMC) simulation, developed by Aravind Krishnamoorthy towards his doctoral thesis, of surface degradation on realistic length-and timescales of 10-10 - 10-7 m and up to several hours, respectively. The findings have implications for the initiation of surface breakdown via pitting in ionic passive films, as well as providing a broader understanding of the non-stoichiometry of the pyrite surface. The common thread is a focus on events at the atomic and electronic scale, with an emphasis on point defects. The results thereby facilitate a bottom-up approach to modeling electrochemical processes such as corrosion in Fe-S phases, in which the unit steps are cast into probabilistic simulation tools. While the three studies here comprise only a partial examination of the atomic-scale events regulating the behavior of Fe-S passive layers, this approach makes inroads towards more accurate component lifetime prediction and the design of robust materials for aggressive environments. Moreover, the fundamental surface and bulk physical chemistry of iron sulfides explored in this work has implications beyond corrosion to other uses of these materials, including potential magnetic devices (Fe1-xS) and earth-abundant photovoltaic and photoelectrochemical adsorbers (FeS2).

Download or read book High temperature Metallic Corrosion of Sulfur and Its Compounds written by Z. A. Foroulis and published by . This book was released on 1970 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sulfide to Sulfate Reaction Mechanism written by Edwin Earle Smith and published by . This book was released on 1970 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report of Investigations written by and published by . This book was released on 1973 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chlorination Kinetics of Selected Metal Sulfides written by Arne Landsberg and published by . This book was released on 1975 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics and Mechanisms of the Oxidation of Ferrous Sulfide written by Michael B. Nelson and published by . This book was released on 1978 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analyses of tipple and delivered samples of coal written by and published by . This book was released on 1974 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sulfide and Selenide Based Materials for Emerging Applications written by Goutam Kumar Dalapati and published by Elsevier. This book was released on 2022-06-17 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sulfide and Selenide-Based Materials for Emerging Applications explores a materials and device-based approach to the transition to low-cost sustainable thin film photovoltaic devices and energy storage systems. Part 1 examines recent advances in renewable technologies and materials for sustainable development, as well as photovoltaic energy storage devices. Part 2 discusses thin film solar cells with earth abundant materials, highlighting the power conversion efficiency of the kesterite-based solar cells. Kesterite film technology including different synthesis and doping method designs are also discussed, along with emerging sulfide semiconductors with potential in thin film photovoltaics/flexible devices. In Part 3 sulfur- and selenides-based materials for thermoelectric applications are explored. Part 4 covers chalcogenide semiconductors with applications in electrochemical water splitting for green hydrogen generation and oxygen generation, as well as the latest research on layered 2D transition metal chalcogenides for electrochemical water splitting. To conclude, part 5 discusses recent developments of storage technologies such as Li-S batteries, sulfide-based supercapacitors and metal-ion batteries, and the development of 3D printing sulfides/selenides for energy conversion and storage. This book is a useful resource for those involved in green energy technology and decarbonization and is designed for a broad audience, from students to experienced scientists. - Discusses the emerging sulfide/selenide based thin film absorber materials and their deposition methods - Previews device engineering techniques that have been developed to enhance the power conversion efficiency and lifetime of sulfide/selenide based thin film solar cells - Provides an update on what low cost sulfide/selenide based electro-catalysts have become available and the comparison of their performance vs. noble metal catalysts

Download or read book Oxidation of Sulfide Minerals in Benefication Processes written by A Abramov and published by CRC Press. This book was released on 1998-01-23 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of recent experimental studies and modern theoretical concepts are combined in this volume to provide a comprehensive analysis of sulfide mineral oxidation processes. Introductory chapters discuss the properties of sulfide minerals and various investigative techniques, followed by chapters on oxidation mechanisms and the behavior of minerals under these various oxidizing conditions. This book also demonstrates modern methods of physical-chemical modelling and the regulation and optimization of flotation processes.

Download or read book Proceedings of the Fourth International Symposium on Electrochemistry in Mineral and Metal Processing written by R. Woods and published by The Electrochemical Society. This book was released on 1996 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Ground Water Development written by Roscoe Moss Company and published by John Wiley & Sons. This book was released on 1991-01-16 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: The definitive work on the subject, it offers you comprehensive and accurate coverage of the theory and techniques of ground water development. Provides not only a general overview of the topic with applications but also incorporates sufficient detail to be of use to professionals involved in any phase of ground water. Divided into three parts, the text traces the progression of the study of ground water from its origin through its development and exploitation. Part one deals mainly with the nature of ground water and where it can be found. Part two considers the parameters related to water well design and construction. In part three, there is a thorough review of well and well field operation, including monitoring for environmental protection. Although the focus is on high-capacity ground water producing installations, most of the material is also applicable to lower-yield wells.

Download or read book Proceedings of the Symposium on Corrosion in Fossil Fuel Systems written by I. G. Wright and published by . This book was released on 1983 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Devex Corporation V Houdaille Industries Inc written by and published by . This book was released on 1966 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metal Nanoparticles in Microbiology written by Mahendra Rai and published by Springer Science & Business Media. This book was released on 2011-04-02 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following an introduction to biogenic metal nanoparticles, this book presents how they can be biosynthesized using bacteria, fungi and yeast, as well as their potential applications in biomedicine. It is shown that the synthesis of nanoparticles using microbes is eco-friendly and results in reproducible metal nanoparticles of well-defined sizes, shapes and structures. This biotechnological approach based on the process of biomineralization exploits the effectiveness and flexibility of biological systems. Chapters include practical protocols for microbial synthesis of nanoparticles and microbial screening methods for isolating a specific nanoparticle producer as well as reviews on process optimization, industrial scale production, biomolecule-nanoparticle interactions, magnetosomes, silver nanoparticles and their numerous applications in medicine, and the application of gold nanoparticles in developing sensitive biosensors.