DOCSLIB.ORG

PLATINUM METALS REVIEW a Quarterly Survey of Research on the Platinum Metals and of Developments in Their Application in Industry

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
PLATINUM METALS REVIEW a Quarterly Survey of Research on the Platinum Metals and of Developments in Their Application in Industry E-ISSN 1471–0676 PLATINUM METALS REVIEW A Quarterly Survey of Research on the Platinum Metals and of Developments in their Application in Industry www.platinummetalsreview.com VOL. 50 OCTOBER 2006 NO. 4 Contents High-Temperature Mechanical Properties of the 158 Platinum Group Metals By R. Weiland, D. F. Lupton, B. Fischer, J. Merker, C. Scheckenbach and J. Witte Rhodium and Iridium in Organometallic Catalysis 171 By Robert H. Crabtree CAPoC7: The State of the Art in Automotive 177 Pollution Control Reviewed by Jillian Bailie, Peter Hinde and Valérie Houel The Platinised Platinum Interface Under 180 Cathodic Polarisation By Jacques Simonet SURCAT 2006 Conference 194 Reviewed by S. E. Golunski Reliability of Platinum-Based Thermocouples 197 By Roy Rushforth “Principles of Fuel Cells” 200 Reviewed by Tom R. Ralph 10th Ulm Electrochemical Talks 202 Reviewed by Sarah C. Ball Susan V. Ashton 205 By M. C. F. Steel Abstracts 207 New Patents 211 Indexes to Volume 50 213 Communications should be addressed to: The Editor, Barry W. Copping, Platinum Metals Review, [email protected]; Johnson Matthey Public Limited Company, Orchard Road, Royston, Hertfordshire SG8 5HE DOI: 10.1595/147106706X154198 High-Temperature Mechanical Properties of the Platinum Group Metals PROPERTIES OF PURE IRIDIUM AT HIGH TEMPERATURE By R. Weiland and D. F. Lupton* Engineered Materials Division, W. C. Heraeus GmbH, Hanau, Germany; *E-mail: [email protected] B. Fischer, J. Merker and C. Scheckenbach Department SciTec, Precision-Optics-Materials-Environment, University of Applied Sciences Jena, Germany and J. Witte Melting Technology, SCHOTT Glas, Mainz, Germany In order to provide reliable data on the high-temperature deformation behaviour of iridium, the high-temperature material properties such as stress-rupture strength, high-temperature tensile strength and creep behaviour are determined for pure iridium in the temperature range 1650–2300ºC. Analyses of the stress-rupture curves and the creep behaviour of pure iridium samples at 1650ºC, 1800ºC and 2000ºC imply that the fracture behaviour is controlled by two different fracture mechanisms depending on test conditions, in particular applied load and test temperature. The existence of the different fracture modes is confirmed by SEM examination of the fracture surface of samples ruptured at high temperatures. Anomalies in the creep curves and the results of high-temperature tensile tests indicate that dynamic recrystallisation plays an important role in the high-temperature deformation behaviour of pure iridium. Due to their excellent chemical stability, oxida- A knowledge of the high-temperature proper- tion resistance, and resistance to the action of ties of a material, for instance stress-rupture many molten oxides, the platinum group metals strength and creep behaviour, is crucially impor- (pgms): iridium, platinum and rhodium are widely tant for the design of components used at high used for high-temperature applications involving temperatures. The current investigation is part of simultaneous chemical attack and mechanical load- an extensive test programme focused on the deter- ing (1). Although iridium is more sensitive to mination of the high-temperature mechanical oxidation than platinum or rhodium, it is the most properties of the pgms, such as the stress-rupture chemically resistant of all metals. Its resistance to strength, creep behaviour (3) and elastic properties attack by stable oxide melts is maintained up to (4). In this work new investigations into the high- temperatures above 2000ºC. temperature properties of iridium are presented for The melting point of iridium (2454ºC) (2) and the temperature range between 1650ºC and its high strength even at temperatures above 2300ºC. The results are discussed in conjunction 2000ºC make it a particularly suitable material for with data determined from earlier studies (3). applications under extreme thermal and mechani- cal conditions which preclude the use of platinum Methodology for Stress-Rupture alloys or rhodium. Important applications of iridi- and High-Temperature Tensile Tests um and iridium alloys are as crucibles for pulling The stress-rupture strength and the creep single crystals (e.g. yttrium-aluminium garnet behaviour of pure iridium and iridium alloys were (YAG)) and components for manufacturing and determined with a testing facility developed at the processing high-melting special glasses. University of Applied Sciences Jena. The testing Platinum Metals Rev., 2006, 50, (4), 158–170 158 Fig. 1 Schematic diagram of equip- ment for high-temperature creep measurements device, for the measurement of high-temperature ing technique using a digital pyrometer material properties up to 3000ºC, is shown (INFRATHERM IS10). The infrared pyrometer schematically in Figure 1. It consists of a gas-tight has a small measurement spot (approximately 0.5 specimen chamber which permits investigations mm in diameter). Due to the ohmic heating the either in air or under a protective gas atmosphere. highest temperatures are found in the central part In the case of iridium and iridium alloys, a gas mix- of the sample. This region is therefore scanned ture of argon with 5 vol.% H2 was used to protect continuously by the pyrometer via a tilting mirror. the material from oxidation and thus avoid a By storing the maximum value of emitted radia- reduction in cross-section of the sample due to tion, the maximum temperature at the surface of evaporation of volatile oxides (5, 6). the sample may be determined. This value is used The load can be applied in two different ways. to adjust the heating current via a thyristor regula- For the constant-load stress-rupture experiments tor connected to the primary winding of a 100 the load is applied via a steel pull-rod by means of kVA transformer. The sample, short-circuited calibrated weights. For the high-temperature ten- across the secondary winding of the transformer, is sile tests the specimen chamber is mounted in a heated by alternating current at 50 Hz. Over a zone commercial servomotor-driven test machine and 30 mm in length around the centre of the sample the steel pull-rod is connected to the load cell at the temperature usually does not vary by more the crosshead of the test machine. This allows a than ± 5ºC. Once “necking” occurs in the sample, controlled variation of the applied load. Non-stan- the temperature outside the necking region dard specimens (with typical dimensions of 120 decreases, whereas the temperature within the mm × 4 mm × 1 mm) were used for all measure- necking region remains constant at the intended ments. The samples were laser cut from hot rolled value. The design of the equipment thus guaran- sheet material. The sample orientation was chosen tees uniformity of temperature throughout the parallel to the rolling direction. duration of the test, despite the sample deformation. Direct electrical heating achieves high heating The strain is measured with a non-contacting and cooling rates for the samples. The ohmic heat- video extensometer consisting of a 17 mm charge ing method allows easy access to the sample, and coupled device (CCD) camera with 1280 × 1024 generally straightforward operation. pixel resolution. A special arrangement of telecen- The temperature is measured by a non-contact- tric lenses allows only near-parallel rays to pass the Platinum Metals Rev., 2006, 50, (4) 159 aperture, thus minimising perspective distortions material was then hot rolled at moderate tempera- caused by variations in the distance to the object. ture to 1 mm thick sheet. The iridium sheet was Both the CCD camera and frame grabber are con- finally subjected to a special annealing procedure trolled by “SuperCreep” software, developed at so as to recrystallise the deformed material without the University of Applied Sciences Jena, which significant grain growth. uses digital image analysis. As mentioned above, ohmic heating causes the Scanning Secondary Ion Mass highest temperature to be limited to the central Spectrometry (Scanning SIMS) part of the sample, to which creep deformation is The microanalytical investigations were per- normally also limited. Strain at this part of the formed with a Cameca IMS 4f-E6 scanning sample is determined by “SuperCreep” from con- secondary ion mass spectrometer. Secondary ion tinuous measurements of the distance between mass spectrometry (SIMS) allows the detection of two markers. Suitable markers for high-tempera- very small amounts of impurity elements in the ture tests on sheet materials are made by laser matrix. Since both the species of detectable sec- machining samples of the material with four small ondary ions and their detection limits differ as shoulders (Figure 2). The distance between the between the positive and negative secondary ion two corresponding markers on the same side of spectra, different primary ions were chosen for the the sample is 10 mm. Since the part of the sample excitation of the secondary ions. Oxygen primary between the markers experiences a uniform tem- ions were used for the investigation of the positive perature, the exactness of strain measurements can secondary ion spectrum emitted by the iridium be guaranteed, without their being influenced by samples. The emission of the negative spectrum the temperature gradients near the ends of the was induced by caesium primary ions. It could sample. thus be ensured that all possible impurity elements A detailed description of the testing facility and contained in the iridium samples were detected. the algorithm for strain measurement is given in Metallographically prepared samples were used (7) and (8). for the scanning SIMS investigations. So as to be able to investigate impurity levels both inside the Material Preparation grains and at the grain boundaries, areas of the The iridium raw material was melted inductive- samples containing grain boundaries were chosen. ly at 2550ºC in air in a zirconia crucible. After It should be mentioned that the intensity of the elemental analysis the ingot was forged at temper- emitted secondary ion spectrum is dependent on atures between 1400ºC and 1600ºC.
Load more

Recommended publications
  • Functionalization of Heterocycles: a Metal Catalyzed Approach Via
    FUNCTIONALIZATION OF HETEROCYCLES: A METAL CATALYZED APPROACH VIA ALLYLATION AND C-H ACTIVATION A Dissertation Submitted to the Graduate Faculty of the North Dakota State University of Agriculture and Applied Science By Sandeepreddy Vemula In Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Department: Chemistry and Biochemistry October 2018 Fargo, North Dakota North Dakota State University Graduate School Title FUNCTIONALIZATION OF HETEROCYCLES: A METAL CATALYZED APPROACH VIA ALLYLATION AND C-H ACTIVATION By Sandeepreddy Vemula The Supervisory Committee certifies that this disquisition complies with North Dakota State University’s regulations and meets the accepted standards for the degree of DOCTOR OF PHILOSOPHY SUPERVISORY COMMITTEE: Prof. Gregory R. Cook Chair Prof. Mukund P. Sibi Prof. Pinjing Zhao Prof. Dean Webster Approved: November 16, 2018 Prof. Gregory R. Cook Date Department Chair ABSTRACT The central core of many biologically active natural products and pharmaceuticals contain N-heterocycles, the installation of simple/complex functional groups using C-H/N-H functionalization methodologies has the potential to dramatically increase the efficiency of synthesis with respect to resources, time and overall steps to key intermediate/products. Transition metal-catalyzed functionalization of N-heterocycles proved as a powerful tool for the construction of C-C and C-heteroatom bonds. The work in this dissertation describes the development of palladium catalyzed allylation, and the transition metal catalyzed C-H activation for selective functionalization of electron deficient N-heterocycles. Chapter 1 A thorough study highlighting the important developments made in transition metal catalyzed approaches for C-C and C-X bond forming reactions is discussed with a focus on allylation, directed indole C-2 substitution and vinylic C-H activation.
    [Show full text]
  • Secondary Organic Aerosol from Chlorine-Initiated Oxidation of Isoprene Dongyu S
    Secondary organic aerosol from chlorine-initiated oxidation of isoprene Dongyu S. Wang and Lea Hildebrandt Ruiz McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78756, USA 5 Correspondence to: Lea Hildebrandt Ruiz ([email protected]) Abstract. Recent studies have found concentrations of reactive chlorine species to be higher than expected, suggesting that atmospheric chlorine chemistry is more extensive than previously thought. Chlorine radicals can interact with HOx radicals and nitrogen oxides (NOx) to alter the oxidative capacity of the atmosphere. They are known to rapidly oxidize a wide range of volatile organic compounds (VOC) found in the atmosphere, yet little is known about secondary organic aerosol (SOA) 10 formation from chlorine-initiated photo-oxidation and its atmospheric implications. Environmental chamber experiments were carried out under low-NOx conditions with isoprene and chlorine as primary VOC and oxidant sources. Upon complete isoprene consumption, observed SOA yields ranged from 8 to 36 %, decreasing with extended photo-oxidation and SOA aging. Formation of particulate organochloride was observed. A High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer was used to determine the molecular composition of gas-phase species using iodide-water and hydronium-water 15 cluster ionization. Multi-generational chemistry was observed, including ions consistent with hydroperoxides, chloroalkyl hydroperoxides, isoprene-derived epoxydiol (IEPOX) and hypochlorous acid (HOCl), evident of secondary OH production and resulting chemistry from Cl-initiated reactions. This is the first reported study of SOA formation from chlorine-initiated oxidation of isoprene. Results suggest that tropospheric chlorine chemistry could contribute significantly to organic aerosol loading.
    [Show full text]
  • Use of Chlorofluorocarbons in Hydrology : a Guidebook
    USE OF CHLOROFLUOROCARBONS IN HYDROLOGY A Guidebook USE OF CHLOROFLUOROCARBONS IN HYDROLOGY A GUIDEBOOK 2005 Edition The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GREECE PANAMA ALBANIA GUATEMALA PARAGUAY ALGERIA HAITI PERU ANGOLA HOLY SEE PHILIPPINES ARGENTINA HONDURAS POLAND ARMENIA HUNGARY PORTUGAL AUSTRALIA ICELAND QATAR AUSTRIA INDIA REPUBLIC OF MOLDOVA AZERBAIJAN INDONESIA ROMANIA BANGLADESH IRAN, ISLAMIC REPUBLIC OF RUSSIAN FEDERATION BELARUS IRAQ SAUDI ARABIA BELGIUM IRELAND SENEGAL BENIN ISRAEL SERBIA AND MONTENEGRO BOLIVIA ITALY SEYCHELLES BOSNIA AND HERZEGOVINA JAMAICA SIERRA LEONE BOTSWANA JAPAN BRAZIL JORDAN SINGAPORE BULGARIA KAZAKHSTAN SLOVAKIA BURKINA FASO KENYA SLOVENIA CAMEROON KOREA, REPUBLIC OF SOUTH AFRICA CANADA KUWAIT SPAIN CENTRAL AFRICAN KYRGYZSTAN SRI LANKA REPUBLIC LATVIA SUDAN CHAD LEBANON SWEDEN CHILE LIBERIA SWITZERLAND CHINA LIBYAN ARAB JAMAHIRIYA SYRIAN ARAB REPUBLIC COLOMBIA LIECHTENSTEIN TAJIKISTAN COSTA RICA LITHUANIA THAILAND CÔTE D’IVOIRE LUXEMBOURG THE FORMER YUGOSLAV CROATIA MADAGASCAR REPUBLIC OF MACEDONIA CUBA MALAYSIA TUNISIA CYPRUS MALI TURKEY CZECH REPUBLIC MALTA UGANDA DEMOCRATIC REPUBLIC MARSHALL ISLANDS UKRAINE OF THE CONGO MAURITANIA UNITED ARAB EMIRATES DENMARK MAURITIUS UNITED KINGDOM OF DOMINICAN REPUBLIC MEXICO GREAT BRITAIN AND ECUADOR MONACO NORTHERN IRELAND EGYPT MONGOLIA UNITED REPUBLIC EL SALVADOR MOROCCO ERITREA MYANMAR OF TANZANIA ESTONIA NAMIBIA UNITED STATES OF AMERICA ETHIOPIA NETHERLANDS URUGUAY FINLAND NEW ZEALAND UZBEKISTAN FRANCE NICARAGUA VENEZUELA GABON NIGER VIETNAM GEORGIA NIGERIA YEMEN GERMANY NORWAY ZAMBIA GHANA PAKISTAN ZIMBABWE The Agency’s Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the Agency are situated in Vienna.
    [Show full text]
  • CHAPTER12 Atmospheric Degradation of Halocarbon Substitutes
    CHAPTER12 AtmosphericDegradation of Halocarbon Substitutes Lead Author: R.A. Cox Co-authors: R. Atkinson G.K. Moortgat A.R. Ravishankara H.W. Sidebottom Contributors: G.D. Hayman C. Howard M. Kanakidou S .A. Penkett J. Rodriguez S. Solomon 0. Wild CHAPTER 12 ATMOSPHERIC DEGRADATION OF HALOCARBON SUBSTITUTES Contents SCIENTIFIC SUMMARY ......................................................................................................................................... 12.1 12.1 BACKGROUND ............................................................................................................................................... 12.3 12.2 ATMOSPHERIC LIFETIMES OF HFCS AND HCFCS ................................................................................. 12.3 12.2. 1 Tropospheric Loss Processes .............................................................................................................. 12.3 12.2.2 Stratospheric Loss Processes .............................................................................................................. 12.4 12.3 ATMOSPHERIC LIFETIMES OF OTHER CFC AND HALON SUBSTITUTES ......................................... 12.4 12.4 ATMOSPHERIC DEGRADATION OF SUBSTITUTES ................................................................................ 12.5 12.5 GAS PHASE DEGRADATION CHEMISTRY OF SUBSTITUTES .............................................................. 12.6 12.5.1 Reaction with NO ..............................................................................................................................
    [Show full text]
  • Verification Program Manual and Mexico
    SHARE: Join Our Email List CLIMATE ACTION NEWS December 2020 A note from our President Greetings, The climate community is hopeful and excited for a new era of climate policy, action, and diplomacy. The incoming Administration has already indicated a serious commitment to addressing the climate crisis, with key appointments and statements portending well for the future of U.S. climate action on the federal level. We are excited for the U.S. to not only rejoin the Paris Agreement, but to provide the example, the innovation, and the thought-leadership to achieve GHG reductions at the scale and urgency required. The Reserve is working to support and inform international efforts to scale up, mobilize, and strengthen the effectiveness of voluntary carbon markets across the globe. Even though COP has been postponed this year, experts around the world continue to discuss and deliberate critical issues to help craft key underlying decisions on how markets should function, how to apply usage of carbon offsets, and how to ensure the environmental integrity and financial value of offset projects and credits. In addition to participating in international discussions, the Reserve is working to expand our work in Mexico. We are updating the Mexico Ozone Depleting Substances Protocol to add several halocarbons, which are refrigerants with high global warming potentials. We are also continuing to work with communities and organizations across Mexico with outreach and education on implementing forest carbon projects, as well as drafting agricultural offset protocols for consideration by the Mexican Government. Thank you again for your climate action and leadership throughout the year.
    [Show full text]
  • Research on Ocean Acidification at the University of Malaya
    ADVANCINGResearch SUSTAINABLE on DEVELOPMENTOcean A INcidification LMEs DURING CLIMATE at theCHANGE University of Malaya Emienour Muzalina Mustafa, Choon-Weng Lee & Siew-Moi Phang Institute of Ocean & Earth Sciences, University of Malaya, Kuala Lumpur, Malaysia OCEANS IN A CHANGING CLIMATE OCEAN ↑ CO 2 ACIDIFICATION HUMAN IMPACTS: OCEAN MARINE POLLUTION WARMING BIOTA EUTROPHICATION OVERFISHING OCEAN DE- OXYGENATION Fig. 5. The palaeohistorical record of ocean pH demonstrates that present levels are unseen in the last 20 million years (Turley et al., 2006). Fig. 1. Projected regional changes in ocean chemistry likely to be experienced by particularly vulnerable ecosystems and compared to global-scale surface ocean changes. Global ocean surface averages (bottom) are shown, from left to right: CO2 partial pressure, pH(SWS) and calcite and aragonite saturation. Editorial, Marine Pollution Bulletin 60(2010): 787-792 Fig. 2. Photos of representatives of calcifying groups thought to be vulnerable to ocean acidification from top left to bottom right: pteropod (Jeremy Young, NHM), benthic foraminifer (James Rae, UBristol), coccolithophore (Jeremy Young, NHM), blue mussel (Frédéric Gazeau, Villefranche), sea urchin (Helen Findlay, PML), brittlestar (Sam Dupont, UGothenburg), tropical coral (Malcolm Shick, UMaine), coralline algae (Armin Form, IFM-GEOMAR), cold water coral (Karen Hissmann, IFM-GEOMAR). COMMERCIAL SPECIES IN ASIA THAT MAY BE IMPACTED BY OCEAN ACIDIFICATION Climate change and the oceans – What does the future hold? Jelle Bijma a,⇑, Hans-O. Pörtner a, Chris Yesson b, Alex D. Rogers Marine Pollution Bulletin 74 (2013) 495–505 Atmospheric pCO2 levels (ppmv CO2) that would be required to cause pH changes in Change in diversity as a function of ocean surface waters pH reduction for organisms living near the Ischia CO2 vents.
    [Show full text]
  • The Need for Fast Near-Term Climate Mitigation to Slow Feedbacks and Tipping Points
    The Need for Fast Near-Term Climate Mitigation to Slow Feedbacks and Tipping Points Critical Role of Short-lived Super Climate Pollutants in the Climate Emergency Background Note DRAFT: 27 September 2021 Institute for Governance Center for Human Rights and & Sustainable Development (IGSD) Environment (CHRE/CEDHA) Lead authors Durwood Zaelke, Romina Picolotti, Kristin Campbell, & Gabrielle Dreyfus Contributing authors Trina Thorbjornsen, Laura Bloomer, Blake Hite, Kiran Ghosh, & Daniel Taillant Acknowledgements We thank readers for comments that have allowed us to continue to update and improve this note. About the Institute for Governance & About the Center for Human Rights and Sustainable Development (IGSD) Environment (CHRE/CEDHA) IGSD’s mission is to promote just and Originally founded in 1999 in Argentina, the sustainable societies and to protect the Center for Human Rights and Environment environment by advancing the understanding, (CHRE or CEDHA by its Spanish acronym) development, and implementation of effective aims to build a more harmonious relationship and accountable systems of governance for between the environment and people. Its work sustainable development. centers on promoting greater access to justice and to guarantee human rights for victims of As part of its work, IGSD is pursuing “fast- environmental degradation, or due to the non- action” climate mitigation strategies that will sustainable management of natural resources, result in significant reductions of climate and to prevent future violations. To this end, emissions to limit temperature increase and other CHRE fosters the creation of public policy that climate impacts in the near-term. The focus is on promotes inclusive socially and environmentally strategies to reduce non-CO2 climate pollutants, sustainable development, through community protect sinks, and enhance urban albedo with participation, public interest litigation, smart surfaces, as a complement to cuts in CO2.
    [Show full text]
  • Novel Microbiocides
    (19) TZZ _Z__T (11) EP 2 641 901 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 25.09.2013 Bulletin 2013/39 C07D 215/40 (2006.01) C07D 401/12 (2006.01) A61K 31/4709 (2006.01) A01N 43/42 (2006.01) (21) Application number: 12160780.8 (22) Date of filing: 22.03.2012 (84) Designated Contracting States: (72) Inventor: The designation of the inventor has not AL AT BE BG CH CY CZ DE DK EE ES FI FR GB yet been filed GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (74) Representative: Herrmann, Jörg Designated Extension States: Syngenta Crop Protection BA ME Münchwilen AG Intellectual Property Department (71) Applicant: Syngenta Participations AG Schaffhauserstrasse 4058 Basel (CH) 4332 Stein (CH) (54) Novel microbiocides (57) The invention relates to compounds of formula I wherein R1, R2, X, Y1, Y2, Y3, D1, D2, D3, G1, G2, G3 and p are as defined in the claims. The invention further provides intermediates used in the preparation of these compounds, to compositions which comprise these compounds and to theiruse in agriculture or horticulture for controlling orpreventing infestation of plants by phytopathogenic microorganisms, preferably fungi. EP 2 641 901 A1 Printed by Jouve, 75001 PARIS (FR) EP 2 641 901 A1 Description [0001] The present invention relates to novel microbiocidally active, in particular fungicidally active, cyclic bisoxime derivatives. Itfurther relatesto intermediates used inthe preparationof these compounds, to compositions which comprise 5 these compounds and to their use in agriculture or horticulture for controlling or preventing infestation of plants by phytopathogenic microorganisms, preferably fungi.
    [Show full text]
  • Halocarbon Scenarios, Ozone Depletion Potentials, and Global Warming Potentials
    CHAPTER 8 Halocarbon Scenarios, Ozone Depletion Potentials, and Global Warming Potentials Lead Authors: J.S. Daniel G.J.M. Velders Coauthors: A.R. Douglass P.M.D. Forster D.A. Hauglustaine I.S.A. Isaksen L.J.M. Kuijpers A. McCulloch T.J. Wallington Contributors: P. Ashford S.A. Montzka P.A. Newman D.W. Waugh Final Release: February 2007 From Scientific Assessment of Ozone Depletion: 2006 CHAPTER 8 HALOCARBON SCENARIOS, OZONE DEPLETION POTENTIALS, AND GLOBAL WARMING POTENTIALS Contents SCIENTIFIC SUMMARY . 8.1 8.1 INTRODUCTION . 8.5 8.2 HALOCARBON LIFETIMES, OZONE DEPLETION POTENTIALS, AND GLOBAL WARMING POTENTIALS . 8.5 8.2.1 Introduction . 8.5 8.2.2 Ozone Depletion Potentials . 8.5 8.2.2.1 Atmospheric Lifetimes . 8.6 8.2.2.2 Fractional Release Factors . 8.6 8.2.2.3 Ozone Destruction Effectiveness . 8.7 8.2.2.4 ODP Values . 8.8 8.2.3 Direct Global Warming Potentials . 8.8 8.2.4 Degradation Products and Their Implications for ODPs and GWPs . 8.13 8.3 FUTURE HALOCARBON SOURCE GAS CONCENTRATIONS . .8.13 8.3.1 Introduction . 8.13 8.3.2 Baseline Scenario (A1) . 8.15 8.3.2.1 Emissions . 8.15 8.3.2.2 Mixing Ratios . 8.21 8.3.2.3 Equivalent Effective Stratospheric Chlorine . 8.25 8.3.3 Alternative Projections . 8.28 8.3.3.1 Emissions . 8.28 8.3.3.2 Mixing Ratios . 8.28 8.3.3.3 Equivalent Effective Stratospheric Chlorine . 8.30 8.3.4 Uncertainties in ODS Projections . 8.32 8.4 OTHER PROCESSES RELEVANT TO FUTURE OZONE EVOLUTION .
    [Show full text]
  • An Algorithm to Detect Non-Background Signals in Greenhouse Gas Time Series from European Tall Tower and Mountain Stations
    https://doi.org/10.5194/amt-2021-16 Preprint. Discussion started: 9 March 2021 c Author(s) 2021. CC BY 4.0 License. An algorithm to detect non-background signals in greenhouse gas time series from European tall tower and mountain stations Alex Resovsky1, Michel Ramonet1, Leonard Rivier1, Jerome Tarniewicz1, Philippe Ciais1, Martin 5 Steinbacher2, Ivan Mammarella3, Meelis Mölder4, Michal Heliasz4, Dagmar Kubistin5, Matthias Lindauer5, Jennifer Müller-Williams5, Sebastien Conil6, Richard Engelen7 1Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France 2Empa, Laboratory for Air Pollution/Environmental Technology, CH-8600 Duebendorf, Switzerland 10 3Institute for Atmospheric and Earth System Research/ Physics, University of Helsinki, Helsinki, Finland 4Lund University, 22100 Lund, Sweden 5Deutscher Wetterdienst, Meteorological Observatory Hohenpeissenberg, 82383 Hohenpeissenberg, Germany 6DRD/OPE, Andra, Bure, 55290, France 7European Center for Medium-Range Weather Forecasts, Shinfield Park, Reading, UK 15 Correspondence to: Alex Resovsky ([email protected]) Abstract. We present a statistical framework for near real-time signal processing to identify regional signals in CO2 time series recorded at stations which are normally uninfluenced by local processes. A curve-fitting function is first applied to the de- trended time series to derive a harmonic describing the annual CO2 cycle. We then combine a polynomial fit to the data with a short-term residual filter to estimate the smoothed cycle and define a seasonally-adjusted noise component, equal to two 20 standard deviations of the smoothed cycle about the annual cycle. Spikes in the smoothed daily data which rise above this 2σ threshold are classified as anomalies.
    [Show full text]
  • Ocean Acidification Due to Increasing Atmospheric Carbon Dioxide
    Ocean acidification due to increasing atmospheric carbon dioxide Policy document 12/05 June 2005 ISBN 0 85403 617 2 This report can be found at www.royalsoc.ac.uk ISBN 0 85403 617 2 © The Royal Society 2005 Requests to reproduce all or part of this document should be submitted to: Science Policy Section The Royal Society 6-9 Carlton House Terrace London SW1Y 5AG email [email protected] Copy edited and typeset by The Clyvedon Press Ltd, Cardiff, UK ii | June 2005 | The Royal Society Ocean acidification due to increasing atmospheric carbon dioxide Ocean acidification due to increasing atmospheric carbon dioxide Contents Page Summary vi 1 Introduction 1 1.1 Background to the report 1 1.2 The oceans and carbon dioxide: acidification 1 1.3 Acidification and the surface oceans 2 1.4 Ocean life and acidification 2 1.5 Interaction with the Earth systems 2 1.6 Adaptation to and mitigation of ocean acidification 2 1.7 Artificial deep ocean storage of carbon dioxide 3 1.8 Conduct of the study 3 2 Effects of atmospheric CO2 enhancement on ocean chemistry 5 2.1 Introduction 5 2.2 The impact of increasing CO2 on the chemistry of ocean waters 5 2.2.1 The oceans and the carbon cycle 5 2.2.2 The oceans and carbon dioxide 6 2.2.3 The oceans as a carbonate buffer 6 2.3 Natural variation in pH of the oceans 6 2.4 Factors affecting CO2 uptake by the oceans 7 2.5 How oceans have responded to changes in atmospheric CO2 in the past 7 2.6 Change in ocean chemistry due to increases in atmospheric CO2 from human activities 9 2.6.1 Change to the oceans
    [Show full text]
  • 202 Section: B Course Instructor: Dr BK Singh Study Material (Name of T
    Course Name: Methods in Organic Synthesis Paper Number: 202 Section: B Course Instructor: Dr BK Singh Study Material (Name of Topic/Chapter): Organosilicone Compounds, Preparation and applications in organic synthesis; Application of Pd(0) and Pd(II) Complexes in Organic Synthesis- Stille, Suzuki and Sonogashira Coupling, Heck reaction and Negishi Coupling. Dr. BK SINGH, Department of Chemistry, University of Delhi Applications of Pd(0) and Pd(II) complexes in organic synthesis- Heck, Negishi, Suzuki, Stille and Sonogashira Coupling 2010 Nobel Prize in Chemistry awarded jointly to Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki "for palladium-catalyzed cross couplings in organic synthesis" Dr. BK SINGH, Department of Chemistry, University of Delhi Palladium-catalyzed carbon-carbon bond formation via cross coupling The principle of palladium-catalyzed cross couplings is that two molecules are assembled on the metal via the formation of metal-carbon bonds. In this way the carbon atoms bound to palladium are brought very close to one another. In the next step they couple to one another and this leads to the formation of a new carbon-carbon single bond. There are two types of cross-coupling reactions that have become important in organic synthesis. Both reactions are catalyzed by zero valent Pd and both reactions employ an organohalide RX (or analogous compound) as the electrophilic coupling partner. The nucleophilic coupling partner differs in these two reactions. In the first type it is an olefin whereas in the second type it is an organometallic compound R’’M where, M is typically zinc, boron, or tin. Both reactions begin by generating an organopalladium complex RPdX from the reaction of the organic halide with Pd(0).
    [Show full text]