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Chemistry of the Corrosion of Metals in Presence of Molten Vanadium Pentoxide
CHEMISTRY OF THE CORROSION OF METALS IN PRESENCE OF MOLTEN VANADIUM PENTOXIDE THESIS Submitted for the Degree of DOCTOR OF PHILOSOPHY THE UNIVERSITY OF LONDON by KAILATHUVALAPPIL INNIRI VASU February, 1964 Department of Metallurgy, Royal School of Mines, Imperial College, London, S.W.7. The author is grateful to Dr. D. A. Pantony, who supervised this research project, for his constant encouragement, numerous suggestions and stimulating discussions; to his colleagues and the members of the teaching and technical staff of the Department of Metallurgy, Imperial College, for their helpful co—operation; and to the British Petroleum Company Limited for financial assistance. CONTENTS ABSTRACT NOMENCLATURE vi I. INTRODUCTION A. HISTORY 1 B. NATURE OF CORROSION 2 C. ACTIVATION - AND DIFFUSION - CONTROLLED PROCESSES 4 D. RELEVANT PREVIOUS INVESTIGATIONS 6 E. APPROACH TO THE PROBLEM 9 (a) PHYSICAL-CHEMICAL STUDIES ON VANADIC MELTS (1)Dissociation Equilibrium 10 (2)Kinetics of the Oxidation of Vanadium Dioxide 11 (3)Cryoscopy 11 (4)Conductivity of Vanadic Melts 11 (5)Viscosity and Density 12 (b) CORROSION OF METALS IN THE PRESENCE OF MOLTEN VANADIUM PENTOXIDE (1)General Nature 12 (2)In Relation to Gas-Turbine Corrosion 13 (3)A Model for Study 14 (3a) The Corrosion Layer 19 (4)Metal Surface and Corrosion 23 (5)Prevention of Corrosion 23 II. EXPERIMENTAL A. MATERIALS (a)Vanadium Pentoxide 25 (b)Metals 25 (c)Metal Oxides 27 (d)Oxygen, Nitrogen, and Oxygen- Nitrogen Mixtures 28 B. SPECIMENS FOR CORROSION STUDIES 30 C. EXPERIMENTAL PROCEDURE (a)Container -
S42004-019-0231-3.Pdf — Adobe
ARTICLE https://doi.org/10.1038/s42004-019-0231-3 OPEN Niobium pentoxide nanomaterials with distorted structures as efficient acid catalysts Kai Skrodczky1, Margarida M. Antunes2, Xianying Han1, Saveria Santangelo 3, Gudrun Scholz1, Anabela A. Valente 2*, Nicola Pinna 1* & Patrícia A. Russo1* 1234567890():,; Niobium pentoxides are promising acid catalysts for the conversion of biomass into fuels and chemicals. Developing new synthesis routes is essential for designing niobium pentoxide catalysts with improved activity for specific practical processes. Here we show a synthesis approach in acetophenone, which produces nanostructured niobium pentoxides with varying structure and acidity that act as efficient acid catalysts. The oxides have orthorhombic structures with different extents of distortions and coordinatively unsaturated metal atoms. A strong dependence is observed between the type and strength of the acid sites and specific structural motifs. Ultrasmall niobium pentoxide nanoparticles, which have strong Brønsted acidity, as well as Lewis acidity, give product yields of 96% (3 h, 140 °C, 100% conversion), 85% (3 h, 140 °C, 86% conversion), and 100% (3 h, 110 °C, 100% conversion) in the reac- tions of furfuryl alcohol, 5-(hydroxymethyl)furfural, and α-angelica lactone with ethanol, respectively. 1 Institut für Chemie and IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany. 2 Department of Chemistry, CICECO, University of Aveiro, Aveiro, Portugal. 3 Dipartimento di Ingegneria Civile, dell’Energia, dell’Ambiente e dei Materiali (DICEAM), Università “Mediterranea”, Reggio Calabria, Italy. *email: [email protected]; [email protected]; [email protected] COMMUNICATIONS CHEMISTRY | (2019) 2:129 | https://doi.org/10.1038/s42004-019-0231-3 | www.nature.com/commschem 1 ARTICLE COMMUNICATIONS CHEMISTRY | https://doi.org/10.1038/s42004-019-0231-3 iobium pentoxides show high potential as acid catalysts will also allow getting insights into the structure–acidity–activity Nfor the sustainable production of fuels and chemicals from relationships. -
Enrichment Strategies for Phosphoproteomics: State-Of-The-Art
Rev Anal Chem 31 (2012): 29–41 © 2012 by Walter de Gruyter • Berlin • Boston. DOI 10.1515/revac-2011-0025 Enrichment strategies for phosphoproteomics: state-of-the-art Barbora Salovska 1,2, *, Ales Tichy 1,2 , Martina MIP molecularly imprinted polymer Rezacova 1 , Jirina Vavrova 2 and Eva Novotna 2 MOAC metal oxide affi nity chromatography MS mass spectrometry 1 Department of Medical Biochemistry , Faculty of NTA nitriloacetic acid Medicine in Hradec Kralove, Charles University in PTMs post-translational modifi cations Prague, Hradec Kr á lov é , Czech Republic , pS phosphoserine e-mail: [email protected] pT phosphothreonine 2 Department of Radiobiology , Faculty of Military Health pY phosphotyrosine Sciences, University of Defence, Hradec Kralove , RPLC reversed phase liquid chromatography Czech Republic SAX strong anion-exchange chromatography SCX strong cation-exchange chromatography * Corresponding author Introduction Abstract Protein phosphorylation is a key regulator in many biological The human genome involves approximately 30,000 protein- processes, such as homeostasis, cellular signaling and com- coding genes; the human proteome contains several million munication, transcriptional and translational regulation, and different protein effectors. This is due to alternative splic- apoptosis. The defects in this tightly controlled reversible post- ing of genes and post-translational modifi cations (PTMs). translational modifi cation have been described to contribute Several hundred PTMs are currently known, among them to genesis and -
Niobium(V) Oxide Patinal®
Product Information Niobium(V) Oxide Patinal ® GENERAL INFORMATION Niobium pentoxide is especially suited for IAD processes and a suitable alternative to TiO 2 with its high refractive index and low absorption. However the layers may show some absorption when deposited by conventional thermal evaporation. Similar to tantalum pentoxide, niobium pentoxide emits oxygen during melting and evaporation, requiring reactive evaporation. Due to the similarities in the process for those two materials, Nb 2O5 is a close alternative to Ta 2O5 and, in contrary to tantalum, not included on the list of “conflict minerals” mentioned in the Dodd-Franck Wall Street Reform and Consumer Protection Act. AREAS OF APPLICATION • Multi-layer coatings for laser mirrors and beam splitters • Anti-reflection coatings on glass in VIS and NIR THIN FILM PROPERTIES Chemical Formula Nb 2O5 Range of Transparency 380 nm – 7 µm Refractive index at 500 nm • conventional T s = 300 °C / no IAD ~ 2.25 – 2.30 • IAD – Ts = RT ~ 2.30 – 2.35 Thin film stress Compressive The optical properties of the thin film are strongly dependent on the deposition rate, substrate temperature and oxygen partial pressure. Strict control of these parameters allows excellent reproducibility. wavl / nm 375 450 550 700 900 1200 n - IAD 2.495 2.341 2.266 2.220 2.196 2.181 k - IAD 2.5E-03 4.6E-04 2.0E-04 1.1E-04 6.9E-05 4.6E-05 Status: 02 / 2018, Page 1 of 4 EMD Performance Materials* One International Plaza Suite 300 / Philadelphia, PA / 19113 USA +888 367 3275 / [email protected] / patinal.com -
Platinum Group Metals Patent Analysis and Mapping a REVIEW of PATENTING TRENDS and IDENTIFICATION of EMERGING TECHNOLOGIES
DOI: 10.1595/147106708X362735 Platinum Group Metals Patent Analysis and Mapping A REVIEW OF PATENTING TRENDS AND IDENTIFICATION OF EMERGING TECHNOLOGIES By Richard Seymour Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.; E-mail: [email protected] The patent literature contains a wealth of detailed information about existing and new uses for the platinum group metals (pgms). While excellent searching tools have existed for many years for identifying patents relating to specific topics, it is only relatively recently that it has been feasible to map the complete archive of patent literature to identify important trends relating to potential new applications. This paper summarises the results of such an exercise for the pgms carried out in early 2008 and shows that one such ‘hot spot’ relates to organic light emitting diodes (OLEDs). Previous articles in this Journal have described Matthey Technology Centre is Aureka® (a product the importance of patents as a key source of techni- available from Thomson Reuters) (3), which cal and commercial intelligence (1, 2). The use of includes patent data sets from the Patent patent mapping to visualise large sets of patent data Cooperation Treaty (PCT) and European Patent and to identify trends contained within that data has offices, plus a range of national patent collections also been demonstrated (2). The present paper fur- including those of the U.S.A., Japan, the U.K., ther develops these themes by examining the patent France and Germany. With the exception of Japan, literature on pgms published since 1983, in particu- these collections contain full-text patent docu- lar that on the minor metals iridium and ruthenium. -
~Ui&£R5itt! of J\Rij!Oua
Minerals and metals of increasing interest, rare and radioactive minerals Authors Moore, R.T. Rights Arizona Geological Survey. All rights reserved. Download date 06/10/2021 17:57:35 Link to Item http://hdl.handle.net/10150/629904 Vol. XXIV, No.4 October, 1953 ~ui&£r5itt! of J\rij!oua ~ul1etiu ARIZONA BUREAU OF MINES MINERALS AND METALS OF INCREASING INTEREST RARE AND RADIOACTIVE MINERALS By RICHARD T. MOORE ARIZONA BUREAU OF MINES MINERAL TECHNOLOGY SERIES No. 47 BULLETIN No. 163 THIRTY CENTS (Free to Residents of Arizona) PUBLISHED BY ~tti£ll~r5itt! of ~rh!Omt TUCSON, ARIZONA TABLE OF CONTENTS INTRODUCTION 5 Acknowledgments 5 General Features 5 BERYLLIUM 7 General Features 7 Beryllium Minerals 7 Beryl 7 Phenacite 8 Gadolinite 8 Helvite 8 Occurrence 8 Prices and Possible Buyers ,........................................ 8 LITHIUM 9 General Features 9 Lithium Minerals 9 Amblygonite 9 Spodumene 10 Lepidolite 10 Triphylite 10 Zinnwaldite 10 Occurrence 10 Prices and Possible Buyers 10 CESIUM AND RUBIDIUM 11 General Features 11 Cesium and Rubidium Minerals 11 Pollucite ..................•.........................................................................., 11 Occurrence 12 Prices and Producers 12 TITANIUM 12 General Features 12 Titanium Minerals 13 Rutile 13 Ilmenite 13 Sphene 13 Occurrence 13 Prices and Buyers 14 GALLIUM, GERMANIUM, INDIUM, AND THALLIUM 14 General Features 14 Gallium, Germanium, Indium and Thallium Minerals 15 Germanite 15 Lorandite 15 Hutchinsonite : 15 Vrbaite 15 Occurrence 15 Prices and Producers ~ 16 RHENIUM 16 -
INTERVIEW: Swiss Fund CDMR Argues Investment Case for Minor Metals
INTERVIEW: Swiss fund CDMR argues investment case for minor metals LONDON (Metal-Pages) 15-Apr-15. While investment funds speculating in base metals are a fairly routine occurrence, those same funds rarely get involved with minor metals or rare earths. If they do, they tend to hold an equity stake in the mining companies rather than in the actual metal. Over the years some smaller funds and hedge funds have made forays into minor metals but those kind of speculative investors are still few and far between. One of them is the Swiss firm Compagnie des Métaux Rares. It operates a Luxembourg-based fund with a stake in physical minor metals, holding 12 metals in warehouses in Rotterdam. CDMR was set up by Vincent Donnen and Gregoire Teze, two former fund analysts with extensive experience of working in Asia, who took it off the ground with $1mn of their own money and another $4mn raised from their network. Now they are looking to attract a total of $20mn to $25mn into the fund which has been operational since last April. The attraction of minor metals, explains Donnen, stems from the fact that the majority of them are currently undervalued and yet demand from the industries which used them such as electronics, car manufacturing or aircraft building is on the rise. At the same time most of these metals are not produced on their own but rather as a by-product of base and precious metals such as copper, nickel or platinum. Aircraft manufacture, electronics and clean energy will drive minor metal demand Some of Donnen’s top choices include rhenium, a popular metal in aircraft building, rhodium and ruthenium, both used in catalytic converters in cars, tellurium and several metals used in electronics. -
Niobium Pentoxide Based Materials for High Rate Rechargeable Electrochemical Energy Storage Cite This: Mater
Materials Horizons View Article Online REVIEW View Journal | View Issue Niobium pentoxide based materials for high rate rechargeable electrochemical energy storage Cite this: Mater. Horiz., 2021, 8, 1130 Fei Shen,a Zhongti Sun,ab Qinggang He, *c Jingyu Sun, abd Richard B. Kaner *e and Yuanlong Shao*abd The demand for high rate energy storage systems is continuously increasing driven by portable electronics, hybrid/electric vehicles and the need for balancing the smart grid. Accordingly, Nb2O5 based materials have gained great attention because of their fast cation intercalation faradaic charge storage that endows them with high rate energy storage performance. In this review, we describe the crystalline features of the five main phases of Nb2O5 and analyze their specific electrochemical characteristics with an emphasis on the intrinsic ion intercalation pseudocapacitive behavior of T-Nb2O5. The charge Received 14th September 2020, storage mechanisms, electrochemical performance and state-of-the-art characterization techniques for Accepted 9th December 2020 Nb2O5 anodes are summarized. Next, we review recent progress in developing various types of Nb2O5 DOI: 10.1039/d0mh01481h based fast charging electrode materials, including Nb2O5 based mixed metal oxides and composites. Finally, we highlight the major challenges for Nb2O5 based materials in the realm of high rate rechargeable rsc.li/materials-horizons energy storage and provide perspectives for future research. 1. Introduction Due to the increasing demand for rapid charging and high power a College of Energy, Soochow Institute for Energy and Materials InnovationS delivery for portable electronics and electricvehicles,highrate (SIEMIS), Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and energy storage systems (ESSs) that can store/release charge in Wearable Energy Technologies, Soochow University, 215006 Suzhou, P. -
Synthesis, Characterization of Nb2o5\Cdsnanocomposites, And
International Journal of ChemTech Research CODEN (USA): IJCRGG, ISSN: 0974-4290, ISSN(Online):2455-9555 Vol.9, No.10 pp 149-156, 2016 Synthesis, Characterization of Nb2O5\Cds Nanocomposites and Study of High Photo Catalytic Activity of Transition Metal Ion Zena T Omran, and Nada Y Fairooz* Department of Chemistry, College of Science, University of Babylon,Hilla-Iraq Abstract : This work includes the study of preparing the new Nb2O5/CdS coupled photocatalyst was prepare by wet commixing method at different ratios of (0.75:0.25, 0.6:0.4,0.5:0.5, 0.85:0.15,0:1 ,1:0) and calcinations at different temperature 200 0C,500 0C and8000C for4 hours .The prepared powder was characterized by X-ray diffraction, and Fourier Transform Technique (FT-IR).The photocatalytic activity was estimated under mercury high pressure lamp for degradation Co(NO3)2 solution after find the wavelength at λ max510nm . The result showed that (0.85:0.15) percentage at 800 0C has high activity than other ratio at different temperature. After this study some measure such as best of mass for the catalyst, initial of concentration for Co(NO3)2, effect of temperature, effect of PH. Keywords: Co(NO3)2, couple Nb2o5/CdS, Degradation, photocatalytic. Introduction: Niobium pentoxide (Nb2O5) is considered one of the most committed transition metal oxides (TMO) for 1 pseudocapacitive energy storage. Nb2O5 is to a great degreestudied in lithium-ion batteries (LIB) , electrochemical hydrogenation catalysts2.gas sensing3, electrochromic devices4 and solar cells5. Nb2O5 exhibits a different of crystalline allotropes,with orthorhombic (T-Nb2O5), pseudo-hexagonal 6,7 (TT-Nb2O5), tetragonal (M-Nb2O5) and monoclinic(H-Nb2O5) . -
1 Thermodynamic Evaluation of the Propensity of Niobium to Absorb
Thermodynamic Evaluation of the Propensity of Niobium to Absorb Hydrogen During Fabrication of Superconducting Radio Frequency Accelerator Cavities Richard E. Ricker Materials Performance Group Metallurgy Division Materials Science and Engineering Laboratory National Institute of Standards and Technology US Department of Commerce Gaithersburg, MD 20899-8553 ABSTRACT During the fabrication of niobium superconducting radio frequency (SRF) particle accelerator cavities procedures are used that chemically or mechanically remove the passivating surface film of niobium pentoxide (Nb2O5). Removal of this film will expose the underlying niobium metal and allow it to react with the processing environment. If these reactions produce hydrogen at sufficient concentrations and rates, then hydrogen will be absorbed and diffuse into the metal. High hydrogen activities could result in supersaturation and the nucleation of hydride phases. If the metal repassivates at the conclusion of the processing step and the passive film blocks hydrogen egress, then the absorbed hydrogen or hydrides could be retained and alter the performance of the metal during subsequent processing steps or in-service. This report examines the feasibility of this hypothesis by identifying the postulated events, conditions, and reactions and determining if each is consistent with accepted scientific principles, literature, and data. Established precedent for similar events in other systems was found in the scientific literature and thermodynamic analysis found that the postulated reactions were not only energetically favorable, but produced large driving forces. The hydrogen activity or fugacity required for the reactions to be at equilibrium was determined used to indicate the propensity for hydrogen evolution, absorption, and hydride nucleation. The influence of processing conditions and kinetics on the proximity of hydrogen surface coverage to these theoretical values is discussed. -
Formation of Niobium Oxides by Electrolysis from Acidic Aqueous Solutions on Glassy Carbon
Macedonian Journal of Chemistry and Chemical Engineering, Vol. 38, No. 1, pp. 39–48 (2019) MJCCA9 – 767 ISSN 1857-5552 e-ISSN 1857-5625 Received: November 13, 2018 DOI: 10.20450/mjcce.2019.1623 Accepted: February 1, 2019 Original scientific paper FORMATION OF NIOBIUM OXIDES BY ELECTROLYSIS FROM ACIDIC AQUEOUS SOLUTIONS ON GLASSY CARBON Nataša M. Vukićević1*, Vesna S. Cvetković1, Ljiljana S. Jovanović2, Miroslav M. Pavlović1, Jovan N. Jovićević1 1Institute of Chemistry, Technology and Metallurgy, National Institute, Department of Electrochemistry, University of Belgrade, Njegoševa 12, Serbia 2Faculty of Science, Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Trg Dositeja Obradovića 3, Serbia [email protected] In this study niobium oxide films were formed without peroxo-precursors from three different mixed acidic aqueous solutions on glassy carbon. Linear sweep voltammetry and potential step were techniques used for electrochemical experiments. The simultaneous and consecutive electrochemical re- duction of water, nitrate and sulphate ions provided an alkaline environment with oxygen in the near vi- cinity of the working cathode, which in combination with the present niobium ions, produced niobium oxides and/or oxyhydroxides on the glassy carbon substrate. The formed deposits were analyzed using scanning electron microscopy and energy dispersive spectroscopy and appear to consist of NbO, NbO2 and Nb2O5. Both the niobium and acid concentration of the electrolytes used influenced the morphology and particle size of the deposits. The formation of niobium-fluoride and hydrogen-niobiumoxide com- plexes is addressed. Key words: electrochemical deposition; niobium oxides; acidic solution; glassy carbon ФОРМИРАЊЕ НА ФИЛМОВИ ОД ОКСИДИ НА НИОБИУМ СО ЕЛЕКТРОЛИЗА ОД КИСЕЛИ РАСТВОРИ НА СТАКЛЕСТА ГРАФИТНА ЕЛЕКТРОДА Во овој труд е изучувано формирањето на филмови на оксиди од ниобиум што се одвива без пероксидни медијатори од три различни водни раствори со различни рН вредности на стаклеста графитна електрода. -
Minor Metals—Ready for the Circular Economy in Conversation with Derek Raphael, Derek Raphael & Co
ISSN 2056-6735 (Online) Minor Metals—Ready for the Circular Economy In Conversation with Derek Raphael, Derek Raphael & Co. The magazine of the Minor Metals Trade Association 5th Edition 2016/May www.mmta.co.uk 1 We focus on quality Established over 21 years with an unrivalled reputation for supplying pure metals and high temperature super alloys into the aerospace, oil, medical and associated industries Accredited ISO 9001, ISO 14001, BS OHSAS 18001 We buy & sell Specialists in the supply of Mo Ta W Hf Nb All Nickel / Cobalt based alloys Full revert management/processing Shot blast Size reduction/plasma Bar cutting Turnings degreased Suppliers of High Temp Raw Materials & Pure Metals Call us on 01909 569930 Email us at [email protected] Website www.advancedalloys.co.uk 2 Counterparty Insolvency INSIDE THIS ISSUE & Conference Review 2016 4-6 Warehouse Fraud Letter from North America 7 Finishing with a ‘bonus’ Q & A on Brexit and Commodities Minor Metals in the Circular 8-9 Economy MMTA & Holman Fenwick Willan Tea with the MMTA—Derek 10-12 Raphael Breakfast Seminar Liquidmetal (and Terminators) 13-14 Swordmaking 16-17 26th May—8:30-10:30am, London In Brief 18-19 We are very pleased to announce that new MMTA Member, Holman Fenwick Willan is holding a breakfast seminar in partnership with the MMTA at its London office. The MMTA promotes essential elements that add This event is free to attend quality, safety and Draft programme: enjoyment to our lives. Registration & Breakfast The MMTA is the world's leading minor metals industry Session 1: Counterparty Insolvency - a case study on: organisation.