Science.gov

Sample records for iridium 174

  1. Iridium in natural waters

    SciTech Connect

    Anbar, A.D.; Wasserburg, G.J.; Papanastassiou, D.A.

    1996-09-13

    Iridium, commonly used as a tracer of extraterrestrial material, was measured in rivers, oceans, and an estuarine environment. The concentration of iridium in the oceans ranges from 3.0 ({+-}1.3) x 10{sup 8} to 5.7 ({+-}0.8) x 10{sup 8} atoms per kilogram. Rivers contain from 17.4 ({+-}0.9) x 10{sup 8} to 92.9 ({+-}2.2) x 10{sup 8} atoms per kilogram and supply more dissolved iridium to the oceans than do extraterrestrial sources. In the Baltic Sea, {approximately}75% of riverine iridium is removed from solution. Iron-manganese oxyhydroxides scavenge iridium under oxidizing conditions, but anoxic environments are not a major sink for iridium. The ocean residence time of iridium is between 2 x 10{sup 3} and 2 x 10{sup 4} years. 32 refs., 3 figs., 1 tab.

  2. Processing of Iridium and Iridium Alloys

    SciTech Connect

    Ohriner, Evan Keith

    2008-01-01

    Iridium and its alloys have been considered to be difficult to fabricate due to their high melting temperatures, limited ductility, sensitivity to impurity content, and chemical properties. The variety of processing methods used for iridium and its alloys are reviewed, including purification, melting, forming, joining, and powder metallurgy techniques. Also included are coating and forming by the methods of electroplating, chemical and physical vapor deposition, and melt particle deposition.

  3. Iridium Interfacial Stack (IRIS)

    NASA Technical Reports Server (NTRS)

    Spry, David James (Inventor)

    2015-01-01

    An iridium interfacial stack ("IrIS") and a method for producing the same are provided. The IrIS may include ordered layers of TaSi.sub.2, platinum, iridium, and platinum, and may be placed on top of a titanium layer and a silicon carbide layer. The IrIS may prevent, reduce, or mitigate against diffusion of elements such as oxygen, platinum, and gold through at least some of its layers.

  4. Iridium: failures & successes

    NASA Astrophysics Data System (ADS)

    Christensen, CarissaBryce; Beard, Suzette

    2001-03-01

    This paper will provide an overview of the Iridium business venture in terms of the challenges faced, the successes achieved, and the causes of the ultimate failure of the venture — bankruptcy and system de-orbit. The paper will address technical, business, and policy issues. The intent of the paper is to provide a balanced and accurate overview of the Iridium experience, to aid future decision-making by policy makers, the business community, and technical experts. Key topics will include the history of the program, the objectives and decision-making of Motorola, the market research and analysis conducted, partnering strategies and their impact, consumer equipment availability, and technical issues — target performance, performance achieved, technical accomplishments, and expected and unexpected technical challenges. The paper will use as sources trade media and business articles on the Iridium program, technical papers and conference presentations, Wall Street analyst's reports, and, where possible, interviews with participants and close observers.

  5. Hydridomethyl iridium complex

    SciTech Connect

    Bergman, R.G; Buchanan, J.M.; Stryker, J.M.; Wax, M.J.

    1989-07-18

    This patent describes a hydridomethyl complex of the formula: CpIr(P(R{sub 1}){sub 3})HMe. Cp represents a cyclopentadienyl or alkyl cyclopentadienyl radical; Ir represents an iridium atom; P represents a phosphorus atom; R{sub 1} represents an alkyl group; and Me represents a methyl group.

  6. Luminogenic iridium azide complexes

    PubMed Central

    Ohata, Jun; Vohidov, Farrukh; Aliyan, Amirhossein; Huang, Kewei; Martí, Angel A.

    2015-01-01

    The synthesis and characterization of luminogenic, bioorthogonal iridium probes is described. These probes exhibit long fluorescent lifetimes amenable to time-resolved applications. A simple, modular synthesis via 5-azidophenanthroline allows structural variation and allows optimization of cell labeling. PMID:26325066

  7. Method for refining contaminated iridium

    DOEpatents

    Heshmatpour, B.; Heestand, R.L.

    1982-08-31

    Contaminated iridium is refined by alloying it with an alloying agent selected from the group consisting of manganese and an alloy of manganese and copper, and then dissolving the alloying agent from the formed alloy to provide a purified iridium powder.

  8. Method for refining contaminated iridium

    DOEpatents

    Heshmatpour, Bahman; Heestand, Richard L.

    1983-01-01

    Contaminated iridium is refined by alloying it with an alloying agent selected from the group consisting of manganese and an alloy of manganese and copper, and then dissolving the alloying agent from the formed alloy to provide a purified iridium powder.

  9. Electrochemical deposition of iridium and iridium-nickel-alloys

    NASA Astrophysics Data System (ADS)

    Näther, J.; Köster, F.; Freudenberger, R.; Schöberl, C.; Lampke, T.

    2017-03-01

    To develop durable and reliable electronic contacts, precious metals are still very important for finish plating of contact surfaces. The lesser-known iridium might be an interesting alternative to substitute gold alloys, platinum or rhodium for applications with highest demands to wear and corrosion resistance such as sliding and plug contacts. As matters stand there is no commercial electrolyte for iridium plating. Initial investigation screened the parameter range for different iridium compounds when an iridium layer occurred on the substrates. This approach showed that the oxidation state of iridium is crucial to reach contenting deposits. Best results came from Ir(IV) electrolyte with high bromine concentration coming from the starting compound, while electrolytes made from Ir(III) compounds gave very poor deposits. In subsequent experiments different organic compounds were added to the electrolytes to improve plating efficiency and stability of the solutions. So found electrolytes gave crack-free deposits up to two microns with a micro-hardness of 600 HV. To reduce the iridium content in the layer, iridium-nickel-alloys were investigated, finding that a nickel-content of 10 wt% raised the layer hardness to more than 900 HV.

  10. Iridium at Kilauea

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Trace-element anomalies observed in rocks located stratigraphically at the Cretaceous-Tertiary boundary are considered significant evidence that the boundary is a record of a large meteorite impact (Science, 208, 1095-1108, 1980). In particular, trace metals, including iridium and other members of the platinum metals group, are thought to be enriched in rocks alien to the earth's surface. These elements are indeed enriched in meteorites relative to earth crustal rocks, but new evidence from analyses of the January 1983 eruption of Kilauea suggest that the analogy may be invalid. W.H. Zoller, J.R. Parrington, and J.M. Phelan Kotra reported neutron activation analyses of airborne particulate matter collected at the Mauna Loa Observatory and found “strikingly” large concentrations of iridium in addition to element concentrations expected from volcanic emissions (Science, 222, 1118, 1983). The only other platinum-group trace metal analyzed was gold, which was also found to be anomalously high. They concede that they need more data of other platinum group elements and more data on other volcanos, but the implication is that the Cretacious-Tertiary boundary may well be volcanic, not due to a large meteorite impact.

  11. Iridium Satellite Signal Exploitation

    NASA Astrophysics Data System (ADS)

    McDonough, Peter

    2010-03-01

    The Iridium Satellite constellation is unique to satellite communication networks in that it allows for transmission of data between satellites instead of relying on transmission by the bent pipe methodology. As such, this network is far more secure than other satellite communication networks, and forces interception to occur within the locale of the transmission from modem to satellite or within the locale of the downlink from the satellite other modem. The purpose of this project was to demonstrate the security weaknesses within the Iridium protocol, showing that it was possible to track one of these satellites with a high gain antenna, resulting in the ability to anticipate transmission, to acquire the location of that transmission, and to uncover the content of that transmission. This project was completed as part of the summer student program at the Southwest Research Institute. The presentation will demonstrate the thought process used in chronological order, essentially demonstrating how I achieved the result from my point of view as the summer progressed.

  12. Hydridomethyl iridium complex

    DOEpatents

    Bergman, Robert G.; Buchanan, J. Michael; Stryker, Jeffrey M.; Wax, Michael J.

    1989-01-01

    A process for functionalizing methane comprising: (a) reacting methane with a hydridoalkyl metal complex of the formula: CpIr[P(R.sub.1).sub.3 ]H(R.sub.2) wherein Cp represents a cyclopentadienyl or alkylcyclopentadienyl radical having from 1 to 5 carbon atoms; Ir represents an iridium atom; P represents a phosphorus atom; R.sub.1 represents an alkyl group; R.sub.2 represents an alkyl group having at least two carbon atoms; and H represents a hydrogen atom, in the presence of a liquid alkane R.sub.3 H having at least three carbon atoms to form a hydridomethyl complex of the formula: CpIr[P(R.sub.1).sub.3 ]HMe where Me represents a methyl radical. (b) reacting said hydridomethyl complex with an organic halogenating agent such as a tetrahalomethane or a haloform of the formulas: CX'X"X'"X"" or CHX'X"X'"; wherein X', X", X"', and X"" represent halogens selected from bromine, iodine and chlorine, to halomethyl complex of step (a) having the formula: CpIr[P(R.sub.1).sub.3 ]MeX: (c) reacting said halomethyl complex with a mercuric halide of the formula HgX.sub.2 to form a methyl mercuric halide of the formula HgMeX; and (d) reacting said methyl mercuric halide with a molecular halogen of the formula X.sub.2 to form methyl halide.

  13. Iridium in sea-water.

    PubMed

    Fresco, J; Weiss, H V; Phillips, R B; Askeland, R A

    1985-08-01

    Iridium in sea-water has been measured (after isolation from the saline matrix by reduction with magnesium) by neutron bombardment, radiochemical purification and high-resolution gamma-ray spectroscopy. The concentration obtained in a Pacific coastal water was 1.02 +/- 0.26 x 10(-14) g per g of sea-water. At such extremely low concentrations, seawater is an extremely unlikely source for anomalously high iridium concentrations measured in the Cretaceous-Tertiary boundary layer of deep-sea sediments.

  14. Iridium-Catalyzed Allylic Substitution

    NASA Astrophysics Data System (ADS)

    Hartwig, John F.; Pouy, Mark J.

    Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced cyclometalation at the methyl group of this substituent to generate an iridium metalacycle bound by the COD ligand of the [Ir(COD)Cl]2 precursor and one additional labile dative ligand. Such complexes catalyze the reactions of linear allylic esters with alkylamines, arylamines, phenols, alcohols, imides, carbamates, ammonia, enolates and enolate equivalents, as well as typical stabilized carbon nucleophiles generated from malonates and cyanoesters. Iridium catalysts for enantioselective allylic substitution have also been generated from phosphorus ligands with substituents bound by heteroatoms, and an account of the studies of such systems, along with a description of the development of iridium catalysts is included.

  15. IRIDIUM LINER FOR NASA 5 LBF CLASS MATERIAL TEST CHAMBER IRIDIUM LINER FOR ATLANTIC RESEARCH CORPORA

    NASA Technical Reports Server (NTRS)

    1995-01-01

    IRIDIUM LINER FOR NASA 5 LBF CLASS MATERIAL TEST CHAMBER IRIDIUM LINER FOR ATLANTIC RESEARCH CORPORATION 5 LBF CLASS ROCKET CHAMBER 25 LBF CLASS 75 HFC 25 TAC CERAMIC COMPOSITE ROCKET CHAMBER FROM REFRACTURY COMPOSITES INC. PURCHASE ORDER C-551941-

  16. Iridium material for hydrothermal oxidation environments

    DOEpatents

    Hong, Glenn T.; Zilberstein, Vladimir A.

    1996-01-01

    A process for hydrothermal oxidation of combustible materials in which, during at least a part of the oxidation, corrosive material is present and makes contact with at least a portion of the apparatus over a contact area on the apparatus. At least a portion of the contact surface area comprises iridium, iridium oxide, an iridium alloy, or a base metal overlaid with an iridium coating. Iridium has been found to be highly resistant to environments encountered in the process of hydrothermal oxidation. Such environments typically contain greater than 50 mole percent water, together with oxygen, carbon dioxide, and a wide range of acids, bases and salts. Pressures are typically about 27.5 to about 1000 bar while temperatures range as high as 800.degree. C.

  17. TCP Performance Enhancement Over Iridium

    NASA Technical Reports Server (NTRS)

    Torgerson, Leigh; Hutcherson, Joseph; McKelvey, James

    2007-01-01

    In support of iNET maturation, NASA-JPL has collaborated with NASA-Dryden to develop, test and demonstrate an over-the-horizon vehicle-to-ground networking capability, using Iridium as the vehicle-to-ground communications link for relaying critical vehicle telemetry. To ensure reliability concerns are met, the Space Communications Protocol Standards (SCPS) transport protocol was investigated for its performance characteristics in this environment. In particular, the SCPS-TP software performance was compared to that of the standard Transmission Control Protocol (TCP) over the Internet Protocol (IP). This paper will report on the results of this work.

  18. On the dissolution of iridium by aluminum.

    SciTech Connect

    Hewson, John C.

    2009-08-01

    The potential for liquid aluminum to dissolve an iridium solid is examined. Substantial uncertainties exist in material properties, and the available data for the iridium solubility and iridium diffusivity are discussed. The dissolution rate is expressed in terms of the regression velocity of the solid iridium when exposed to the solvent (aluminum). The temperature has the strongest influence in the dissolution rate. This dependence comes primarily from the solubility of iridium in aluminum and secondarily from the temperature dependence of the diffusion coefficient. This dissolution mass flux is geometry dependent and results are provided for simplified geometries at constant temperatures. For situations where there is negligible convective flow, simple time-dependent diffusion solutions are provided. Correlations for mass transfer are also given for natural convection and forced convection. These estimates suggest that dissolution of iridium can be significant for temperatures well below the melting temperature of iridium, but the uncertainties in actual rates are large because of uncertainties in the physical parameters and in the details of the relevant geometries.

  19. Determining the Altitude of Iridium Flares

    NASA Technical Reports Server (NTRS)

    Foster, James; Owe, Manfred

    1999-01-01

    Iridium flares have nothing to do with the element iridium. Iridium is also the name of a telecommunications company that has been launching satellites into low orbits around the Earth. These satellites are being used for a new type of wireless phone and paging service. Flares have been observed coming from these satellites. These flares have the potential, especially when the full fleet of satellites is in orbit, to disrupt astronomical observations. The paper reviews using simple trigonometry how to calculate the altitude of one of these satellites.

  20. Enantioselective, iridium-catalyzed monoallylation of ammonia.

    PubMed

    Pouy, Mark J; Stanley, Levi M; Hartwig, John F

    2009-08-19

    Highly enantioselective, iridium-catalyzed monoallylations of ammonia are reported. These reactions occur with electron-neutral, -rich, and -poor cinnamyl carbonates, alkyl and trityloxy-substituted allylic carbonates, and dienyl carbonates in moderate to good yields and excellent enantioselectivities. This process is enabled by the use of an iridium catalyst that does not require a Lewis acid for activation and that is stable toward a large excess of ammonia. This selective formation of primary allylic amines allows for one-pot syntheses of heterodiallylamines and allylic amides that are not otherwise accessible via iridium-catalyzed allylic amination without the use of blocking groups and protective group manipulations.

  1. Enantioselective, Iridium-Catalyzed Monoallylation of Ammonia

    PubMed Central

    Pouy, Mark J.; Stanley, Levi M.; Hartwig, John F.

    2009-01-01

    Highly enantioselective, iridium-catalyzed monoallylations of ammonia are reported. These reactions occur with electron-neutral, -rich, and -poor cinnamyl carbonates, alkyl and trityloxy-substituted allylic carbonates, and dienyl carbonates in moderate to good yields and excellent enantioselectivities. This process is enabled by the use of an iridium catalyst that does not require a Lewis acid for activation and that is stable toward a large excess of ammonia. This selective formation of primary allylic amines allows for one-pot syntheses of heterodiallylamines and allylic amides that are not otherwise accessible via iridium-catalyzed allylic amination without the use of blocking groups and protective group manipulations. PMID:19722644

  2. IRIDIUM (R): A Lockheed transition to commercial space

    NASA Technical Reports Server (NTRS)

    Tadano, Thomas N.

    1995-01-01

    At Lockheed Missiles & Space Company, the IRIDIUM commercial space program is dramatically revolutionizing spacecraft development and manufacturing processes to reduce cost while maintaining quality and reliability. This report includes the following sections: an overview of the IRIDIUM system, the Lockheed IRIDIUM project and challenges; cycle-time reduction through production reorganization; and design for manufacturing and quality.

  3. Laser Spectroscopy of Iridium Monochloride

    NASA Astrophysics Data System (ADS)

    Linton, Colan; Adam, Allan G.; Foran, Samantha; Ma, Tongmei; Steimle, Timothy

    2016-06-01

    Iridium monochloride (IrCl) molecules have been produced in the gas phase using laser ablation sources at the University of New Brunswick (UNB) and Arizona State University (ASU). Low resolution laser induced fluorescence (LIF) spectra, obtained at UNB using a pulsed dye laser, showed three bands at 557, 545 and 534 nm which appeared to form an upper state vibrational progression. Dispersed fluorescence (DF) spectra, obtained by exciting each band at its band head frequency, showed a ground state vibrational progression extending from v=0 to 6. High resolution spectra (FWHM=0.006 wn), taken using a cw ring dye laser, showed resolved rotational lines, broadened by unresolved Ir (I=3/2) hyperfine structure, in both the 193Ir35Cl and 191Ir35Cl isotopologues. Vibrational assignments of 0-0, 1-0 and 2-0 for the three bands were determined from the isotope structure and the rotational analysis showed the transition to be ^3Φ_4 - ^3Φ_4, similar to that previously observed in IrF. Higher resolution spectra (FWHM=0.001 wn) of the 1-0 band, obtained at ASU, showed resolved hyperfine structure from which the magnetic and quadrupole hyperfine parameters in the ground and excited states were determined. The interpretation of the hyperfine parameters in terms of the electron configurations will be presented along with a comparison of the properties of IrCl and IrF.

  4. In vitro study of iridium electrodes for neural stimulation.

    PubMed

    Aryan, Naser Pour; Brendler, Christian; Rieger, Viola; Schleehauf, Sebastian; Heusel, Gerhard; Rothermel, Albrecht

    2012-01-01

    Iridium is one of the main electrode materials for applications like neural stimulation. Iridium has a higher charge injection capacity when activated and transformed into AIROF (activated iridium oxide film) using specific electrical signals. Activation is not possible in stimulating devices, if they do not include the necessary circuitry for activation. We introduce a method for iridium electrode activation requiring minimum additional on-chip hardware. In the main part, the lifetime behavior of iridium electrodes is investigated. These results may be interesting for applications not including on-chip activation hardware, and also because activation has drawbacks such as worse mechanical properties and reproducibility of AIROF.

  5. Annealing Increases Stability Of Iridium Thermocouples

    NASA Technical Reports Server (NTRS)

    Germain, Edward F.; Daryabeigi, Kamran; Alderfer, David W.; Wright, Robert E.; Ahmed, Shaffiq

    1989-01-01

    Metallurgical studies carried out on samples of iridium versus iridium/40-percent rhodium thermocouples in condition received from manufacturer. Metallurgical studies included x-ray, macroscopic, resistance, and metallographic studies. Revealed large amount of internal stress caused by cold-working during manufacturing, and large number of segregations and inhomogeneities. Samples annealed in furnace at temperatures from 1,000 to 2,000 degree C for intervals up to 1 h to study effects of heat treatment. Wire annealed by this procedure found to be ductile.

  6. Iridium emissions from Hawaiian volcanoes

    NASA Technical Reports Server (NTRS)

    Finnegan, D. L.; Zoller, W. H.; Miller, T. M.

    1988-01-01

    Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes.

  7. Osmium-191/iridium-191m radionuclide

    DOEpatents

    Knapp, Jr., Furn F.; Butler, Thomas A.; Brihaye, Claude

    1987-01-01

    A generator system to provide iridium-191m for clinical imaging applications comprises an activated carbon adsorbent loaded with a compound containing the parent nuclide, osmium-191. The generator, which has a shelf-life in excess of two weeks and does not require a scavenger column, can be eluted with physiologically compatible saline.

  8. Osmium-191/iridium-191m radionuclide

    DOEpatents

    Knapp, F.F. Jr.; Butler, T.A.; Brihaye, C.

    1985-08-26

    A generator system to provide iridium-191m for clinical imaging applications comprises an activated carbon adsorbent loaded with a compound containing the parent nuclide, osmium-191. The generator, which has a shelf-life in excess of two weeks and does not require a scavenger column, can be eluted with physiologically compatible saline. 4 figs. 3 tabs.

  9. Iridium-Coated Rhenium Combustion Chamber

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Tuffias, Robert H.; Rosenberg, Sanders D.

    1994-01-01

    Iridium-coated rhenium combustion chamber withstands operating temperatures up to 2,200 degrees C. Chamber designed to replace older silicide-coated combustion chamber in small rocket engine. Modified versions of newer chamber could be designed for use on Earth in gas turbines, ramjets, and scramjets.

  10. Iridium-192 Production for Cancer Treatment

    SciTech Connect

    Rostelato, M.E.C.M.; Silva, C.P.G.; Rela, P.R.; Zeituni, C.A.; Lepki, V.; Feher, A.

    2004-10-05

    The purpose of this work is to settle a laboratory for Iridium -192 sources production, that is, to determine a wire activation method and to build a hot cell for the wires manipulation, quality control and packaging. The paper relates, mainly, the wire activation method and its quality control. The wire activation is carried out in our nuclear reactor, IEA- R1m.

  11. 46 CFR 174.300 - Specific applicability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Specific applicability. 174.300 Section 174.300 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Hopper Dredges With Working Freeboard Assignments § 174.300...

  12. 49 CFR 174.24 - Shipping papers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Shipping papers. 174.24 Section 174.24... Requirements § 174.24 Shipping papers. (a) A person may not accept a hazardous material for transportation or transport a hazardous material by rail unless that person receives a shipping paper prepared in...

  13. 19 CFR 122.174 - Operational procedures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Operational procedures. 122.174 Section 122.174 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Air Carrier Smuggling Prevention Program § 122.174 Operational...

  14. 7 CFR 993.174 - Records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Records. 993.174 Section 993.174 Agriculture... Administrative Rules and Regulations Reports and Books and Other Records § 993.174 Records. Each handler shall maintain such records as are necessary to furnish the reports required to be submitted to the Committee...

  15. 7 CFR 993.174 - Records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Records. 993.174 Section 993.174 Agriculture... Administrative Rules and Regulations Reports and Books and Other Records § 993.174 Records. Each handler shall maintain such records as are necessary to furnish the reports required to be submitted to the Committee...

  16. 49 CFR 174.24 - Shipping papers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Shipping papers. 174.24 Section 174.24... Requirements § 174.24 Shipping papers. (a) A person may not accept a hazardous material for transportation or transport a hazardous material by rail unless that person receives a shipping paper prepared in...

  17. 49 CFR 174.24 - Shipping papers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Shipping papers. 174.24 Section 174.24... Requirements § 174.24 Shipping papers. (a) A person may not accept a hazardous material for transportation or transport a hazardous material by rail unless that person receives a shipping paper prepared in...

  18. 49 CFR 174.24 - Shipping papers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Shipping papers. 174.24 Section 174.24... Requirements § 174.24 Shipping papers. (a) A person may not accept a hazardous material for transportation or transport a hazardous material by rail unless that person receives a shipping paper prepared in...

  19. 12 CFR 174.4 - Control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Control. 174.4 Section 174.4 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY ACQUISITION OF CONTROL OF FEDERAL SAVINGS ASSOCIATIONS § 174.4 Control. (a) Conclusive control. (1) An acquiror shall be deemed to have acquired control of...

  20. 12 CFR 174.4 - Control.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Control. 174.4 Section 174.4 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY ACQUISITION OF CONTROL OF FEDERAL SAVINGS ASSOCIATIONS § 174.4 Control. (a) Conclusive control. (1) An acquiror shall be deemed to have acquired control of...

  1. 12 CFR 174.4 - Control.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Control. 174.4 Section 174.4 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY ACQUISITION OF CONTROL OF FEDERAL SAVINGS ASSOCIATIONS § 174.4 Control. (a) Conclusive control. (1) An acquiror shall be deemed to have acquired control of...

  2. 46 CFR 174.250 - Unrestricted service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Unrestricted service. 174.250 Section 174.250 Shipping... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Liftboats § 174.250 Unrestricted service. Each liftboat not limited to restricted service must comply with subpart C of this part in...

  3. 28 CFR 35.174 - Referral.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Referral. 35.174 Section 35.174 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY IN STATE AND LOCAL GOVERNMENT SERVICES Compliance Procedures § 35.174 Referral. If the public entity declines to enter into...

  4. 28 CFR 35.174 - Referral.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Referral. 35.174 Section 35.174 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY IN STATE AND LOCAL GOVERNMENT SERVICES Compliance Procedures § 35.174 Referral. If the public entity declines to enter into...

  5. 28 CFR 35.174 - Referral.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Referral. 35.174 Section 35.174 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY IN STATE AND LOCAL GOVERNMENT SERVICES Compliance Procedures § 35.174 Referral. If the public entity declines to enter into...

  6. 32 CFR 174.5 - Responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Responsibilities. 174.5 Section 174.5 National... BASE CLOSURE COMMUNITIES AND ADDRESSING IMPACTS OF REALIGNMENT Policy § 174.5 Responsibilities. (a) The... implementation and shall monitor compliance with this part. All authorities and responsibilities of the...

  7. 32 CFR 174.5 - Responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Responsibilities. 174.5 Section 174.5 National... BASE CLOSURE COMMUNITIES AND ADDRESSING IMPACTS OF REALIGNMENT Policy § 174.5 Responsibilities. (a) The... implementation and shall monitor compliance with this part. All authorities and responsibilities of the...

  8. 19 CFR 174.32 - Publication.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Publication. 174.32 Section 174.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.32 Publication. Within 120 days after issuing...

  9. 19 CFR 174.32 - Publication.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Publication. 174.32 Section 174.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.32 Publication. Within 90 calendar days...

  10. 19 CFR 174.32 - Publication.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Publication. 174.32 Section 174.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.32 Publication. Within 90 calendar days...

  11. 19 CFR 174.32 - Publication.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Publication. 174.32 Section 174.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.32 Publication. Within 90 calendar days...

  12. 19 CFR 174.32 - Publication.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Publication. 174.32 Section 174.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.32 Publication. Within 90 calendar days...

  13. 46 CFR 174.335 - Watertight doors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Watertight doors. 174.335 Section 174.335 Shipping COAST... SPECIFIC VESSEL TYPES Hopper Dredges With Working Freeboard Assignments Design § 174.335 Watertight doors. (a) Each hopper dredge must have sliding watertight doors (Class 3) approved under § 170.270 of...

  14. 46 CFR 174.335 - Watertight doors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Watertight doors. 174.335 Section 174.335 Shipping COAST... SPECIFIC VESSEL TYPES Hopper Dredges With Working Freeboard Assignments Design § 174.335 Watertight doors. (a) Each hopper dredge must have sliding watertight doors (Class 3) approved under § 170.270 of...

  15. 40 CFR 417.174 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true 417.174 Section 417.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.174...

  16. 40 CFR 417.174 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true 417.174 Section 417.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.174...

  17. 40 CFR 417.174 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true 417.174 Section 417.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.174...

  18. 40 CFR 417.174 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false 417.174 Section 417.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.174...

  19. 40 CFR 417.174 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true 417.174 Section 417.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.174...

  20. 46 CFR 174.360 - Calculations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Calculations. 174.360 Section 174.360 Shipping COAST... SPECIFIC VESSEL TYPES Special Rules Pertaining to Dry Cargo Ships § 174.360 Calculations. Each ship to... II-1, part B-1. Compliance with the applicable requirements must be demonstrated by calculations...

  1. 49 CFR 174.57 - Cleaning cars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Cleaning cars. 174.57 Section 174.57... and Loading Requirements § 174.57 Cleaning cars. All hazardous material which has leaked from a package in any rail car or on other railroad property must be carefully removed....

  2. 49 CFR 174.110 - Car magazine.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if...

  3. 49 CFR 174.110 - Car magazine.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if...

  4. 49 CFR 174.110 - Car magazine.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if...

  5. 49 CFR 174.615 - Cleaning cars.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Cleaning cars. 174.615 Section 174.615... Requirements for Division 6.1 (Poisonous) Materials § 174.615 Cleaning cars. (a) (b) After Division 6.1 (poisonous) materials are unloaded from a rail car, that car must be thoroughly cleaned unless the car...

  6. 49 CFR 174.615 - Cleaning cars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Cleaning cars. 174.615 Section 174.615... Requirements for Division 6.1 (Poisonous) Materials § 174.615 Cleaning cars. (a) [Reserved] (b) After Division 6.1 (poisonous) materials are unloaded from a rail car, that car must be thoroughly cleaned...

  7. 49 CFR 174.57 - Cleaning cars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Cleaning cars. 174.57 Section 174.57... and Loading Requirements § 174.57 Cleaning cars. All hazardous material which has leaked from a package in any rail car or on other railroad property must be carefully removed....

  8. 49 CFR 174.57 - Cleaning cars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Cleaning cars. 174.57 Section 174.57... and Loading Requirements § 174.57 Cleaning cars. All hazardous material which has leaked from a package in any rail car or on other railroad property must be carefully removed....

  9. 49 CFR 174.615 - Cleaning cars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Cleaning cars. 174.615 Section 174.615... Requirements for Division 6.1 (Poisonous) Materials § 174.615 Cleaning cars. (a) (b) After Division 6.1 (poisonous) materials are unloaded from a rail car, that car must be thoroughly cleaned unless the car...

  10. 49 CFR 174.615 - Cleaning cars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Cleaning cars. 174.615 Section 174.615... Requirements for Division 6.1 (Poisonous) Materials § 174.615 Cleaning cars. (a) (b) After Division 6.1 (poisonous) materials are unloaded from a rail car, that car must be thoroughly cleaned unless the car...

  11. 49 CFR 174.57 - Cleaning cars.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Cleaning cars. 174.57 Section 174.57... and Loading Requirements § 174.57 Cleaning cars. All hazardous material which has leaked from a package in any rail car or on other railroad property must be carefully removed....

  12. 49 CFR 174.110 - Car magazine.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if...

  13. 49 CFR 174.57 - Cleaning cars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Cleaning cars. 174.57 Section 174.57... and Loading Requirements § 174.57 Cleaning cars. All hazardous material which has leaked from a package in any rail car or on other railroad property must be carefully removed....

  14. 49 CFR 174.110 - Car magazine.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Car magazine. 174.110 Section 174.110...) Materials § 174.110 Car magazine. When specially authorized by the carrier, Division 1.1 or 1.2 (explosive) materials in quantity not exceeding 68 kg (150 pounds) may be carried in construction or repair cars if...

  15. 49 CFR 174.615 - Cleaning cars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Cleaning cars. 174.615 Section 174.615... Requirements for Division 6.1 (Poisonous) Materials § 174.615 Cleaning cars. (a) (b) After Division 6.1 (poisonous) materials are unloaded from a rail car, that car must be thoroughly cleaned unless the car...

  16. 46 CFR 174.190 - Collision bulkhead.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Collision bulkhead. 174.190 Section 174.190 Shipping... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.190 Collision bulkhead. (a) Each OSV must have a collision bulkhead in compliance with §§ 171.085(c)(1), (d), (e)(2),...

  17. 46 CFR 174.190 - Collision bulkhead.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Collision bulkhead. 174.190 Section 174.190 Shipping... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.190 Collision bulkhead. (a) Each OSV must have a collision bulkhead in compliance with §§ 171.085(c)(1), (d), (e)(2),...

  18. 46 CFR 174.190 - Collision bulkhead.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Collision bulkhead. 174.190 Section 174.190 Shipping... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.190 Collision bulkhead. (a) Each OSV must have a collision bulkhead in compliance with §§ 171.085(c)(1), (d), (e)(2),...

  19. 46 CFR 174.190 - Collision bulkhead.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Collision bulkhead. 174.190 Section 174.190 Shipping... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.190 Collision bulkhead. (a) Each OSV must have a collision bulkhead in compliance with §§ 171.085(c)(1), (d), (e)(2),...

  20. 46 CFR 174.190 - Collision bulkhead.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Collision bulkhead. 174.190 Section 174.190 Shipping... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.190 Collision bulkhead. (a) Each OSV must have a collision bulkhead in compliance with §§ 171.085(c)(1), (d), (e)(2),...

  1. Application of the Iridium Satellite System to Aeronautical Communications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Meza, Mike; Gupta, Om

    2008-01-01

    The next generation air transportation system will require greater air-ground communications capacity to accommodate more air traffic with increased safety and efficiency. Communications will remain primarily terrestrially based, but satellite communications will have an increased role. Inmarsat s aeronautical services have been approved and are in use for aeronautical safety communications provided by geostationary satellites. More recently the approval process for the Iridium low earth orbit constellation is nearing completion. The current Iridium system will be able to provide basic air traffic services communications suitable for oceanic, remote and polar regions. The planned second generation of the Iridium system, called Iridium NEXT, will provide enhanced capabilities and enable a greater role in the future of aeronautical communications. This paper will review the potential role of satellite communications in the future of air transportation, the Iridium approval process and relevant system testing, and the potential role of Iridium NEXT.

  2. Iridium and Radio Astronomy in Europe

    NASA Astrophysics Data System (ADS)

    Cohen, R. J.

    2004-06-01

    An account is given of the coordination of the Iridium mobile satellite system with the radio astronomy service in Europe, from the initial exploratory discussions at Jodrell Bank in 1991 to the signing of the so-called ``Interim Agreement'' in Paris in 1999. The technical issue of unwanted emissions from the Iridium downlink into the frequency band 1610.6-1613.8 MHz was not resolved, so the coordination agreement amounts to time sharing, albeit on more favourable terms for radio astronomy than agreements negotiated elsewhere. The European agreement fully recognizes the heavy use of the frequency band in European radio astronomy, and carries the promise that ``from 1 January 2006, European radioastronomers shall be able to collect measurement data consistent with the recommendation ITU-R RA.769-1.'' Some personal observations on the events are offered.

  3. Iridium-coated rhenium thrusters by CVD

    NASA Technical Reports Server (NTRS)

    Harding, John T.; Kazaroff, John M.; Appel, Marshall A.

    1988-01-01

    Operation of spacecraft thrusters at increased temperature reduces propellant requirements. Inasmuch as propellant comprises the bulk of a satellite's mass, even a small percentage reduction makes possible a significant enhancement of the mission in terms of increased payload. Because of its excellent high temperature strength, rhenium is often the structural material of choice. It can be fabricated into free-standing shapes by chemical vapor deposition (CVD) onto an expendable mandrel. What rhenium lacks is oxidation resistance, but this can be provided by a coating of iridium, also by CVD. This paper describes the process used by Ultramet to fabricate 22-N (5-lbf) and, more recently, 445-N (100-lbf) Ir/Re thrusters; characterizes the CVD-deposited materials; and summarizes the materials effects of firing these thrusters. Optimal propellant mixture ratios can be employed because the materials withstand an oxidizing environment up to the meltimg temperature of iridium, 2400 C (4350 F).

  4. Iridium-coated rhenium thrusters by CVD

    NASA Technical Reports Server (NTRS)

    Harding, J. T.; Kazaroff, J. M.; Appel, M. A.

    1989-01-01

    Operation of spacecraft thrusters at increased temperature reduces propellant requirements. Inasmuch as propellant comprises the bulk of a satellite's mass, even a small percentage reduction makes possible a significant enhancement of the mission in terms of increased payload. Because of its excellent high temperature strength, rhenium is often the structural material of choice. It can be fabricated into free-standing shapes by chemical vapor deposition (CVD) onto an expendable mandrel. What rhenium lacks is oxidation resistance, but this can be provided by a coating of iridium, also by CVD. This paper describes the process used by Ultramet to fabricate 22-N (5-lbf) and, more recently, 445-N (100-lbf) Ir/Re thrusters; characterizes the CVD-deposited materials; and summarizes the materials effects of firing these thrusters. Optimal propellant mixture ratios can be employed because the materials withstand an oxidizing environment up to the melting temperature of iridium, 2400 C (4350 F).

  5. Iridium versus Iridium: Nanocluster and Monometallic Catalysts Carrying the Same Ligand Behave Differently.

    PubMed

    Cano, Israel; Martínez-Prieto, Luis M; Chaudret, Bruno; van Leeuwen, Piet W N M

    2017-01-26

    A specific secondary phosphine oxide (SPO) ligand (tert-butyl(phenyl)phosphine oxide) was employed to generate two iridium catalysts, an Ir-SPO complex and IrNPs (iridium nanoparticles) ligated with SPO ligands, which were compared mutually and with several supported iridium catalysts with the aim to establish the differences in their catalytic properties. The Ir-SPO-based catalysts showed totally different activities and selectivities in the hydrogenation of various substituted aldehydes, in which H2 is likely cleaved by a metal-ligand cooperation, that is, the SPO ligand and a neighboring metal centre operate in tandem to activate the hydrogen molecule. In addition, the supported IrNPs behave very differently from both Ir-SPO catalysts. This study exemplifies perfectly the advantages and disadvantages related to the use of the main types of catalysts, and thus the dissimilarities between them.

  6. The Chemical Vapor Deposition of Iridium.

    DTIC Science & Technology

    1981-07-01

    accepted types are made of porous tungsten impregnated with barium calcium aluminates (Levi, 1955; Brodie and Jenkins, 1956). The emission capability of the...not only does the chemical composition of the pore ends and the bulk material undergo alteration, but the crystal structure of the tungsten (Maloney... hexafluoride to iridium metal or IrF 6 species. In our work, IrF 6 was prepared and stored in fluorine-passivated apparatus, and between runs maintained at

  7. Sputtered iridium oxide for stimulation electrode coatings.

    PubMed

    Mokwa, Wilfried; Wessling, Boerge; Schnakenberg, Uwe

    2007-01-01

    This work deals with the reactive RF-powered sputter deposition of iridium oxide for use as the active stimulation layer in functional medical implants. The oxygen gettered by the growing films is determined by an approach based on generic curves. Films deposited at different stages of oxygen integration show strong differences in electrochemical behaviour, caused by different morphologies. The dependence of electrochemical activity on morphology is further illustrated by RF sputtering onto heated substrates, as well as DC sputtering onto cold substrates.

  8. Benzo annulated cycloheptatriene PCP pincer iridium complexes.

    PubMed

    Leis, Wolfgang; Wernitz, Sophie; Reichart, Benedikt; Ruckerbauer, David; Wielandt, Johannes Wolfram; Mayer, Hermann A

    2014-08-28

    The benzo annulated cycloheptatriene PCP pincer ligand was prepared in five steps. Treatment of with Ir(CO)3Cl gave the meridional cyclometalated chlorohydrido carbonyl iridium complexes which differ in their arrangement of the H, Cl, and CO ligands around iridium. Storing in THF led to isomerization processes. Hydrogen shifts from the sp(3)-CH carbon bound to iridium into the ligand backbone produced the three isomers . Reductive elimination of HCl from these complexes resulted in the square planar Ir(i) carbonyl complexes . Abstraction of the hydrogen from the sp(3)-CH-Ir fragment could be achieved either by treatment of with Ph3CBF4 or by the elimination of H2 which is initiated by CF3SO3H. The mass spectrometric characterisation of using fast atom bombardment reveals a complex fragmentation pattern. These different "fragment" ions were further investigated by electro-spray ionisation (tandem) mass spectrometry in high and low resolution. The identified compounds were attributed to structures by DFT calculations.

  9. 46 CFR 160.174-11 - Performance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Performance. 160.174-11 Section 160.174-11 Shipping...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-11 Performance. (a) Thermal... between −30 °C (−22 °F) and +65 C (149 °F). (d) In water performance. The thermal protective aid must...

  10. 46 CFR 160.174-11 - Performance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Performance. 160.174-11 Section 160.174-11 Shipping...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-11 Performance. (a) Thermal... between −30 °C (−22 °F) and +65 C (149 °F). (d) In water performance. The thermal protective aid must...

  11. Synthesis of benzimidazoles via iridium-catalyzed acceptorless dehydrogenative coupling.

    PubMed

    Sun, Xiang; Lv, Xiao-Hui; Ye, Lin-Miao; Hu, Yu; Chen, Yan-Yan; Zhang, Xue-Jing; Yan, Ming

    2015-07-21

    Iridium-catalyzed acceptorless dehydrogenative coupling of tertiary amines and arylamines has been developed. A number of benzimidazoles were prepared in good yields. An iridium-mediated C-H activation mechanism is suggested. This finding represents a novel strategy for the synthesis of benzimidazoles.

  12. Variation of iridium in a differentiated tholeiitic dolerite

    USGS Publications Warehouse

    Greenland, L.P.

    1971-01-01

    Iridium has been determined in a drill core from the Great Lake (Tasmania) dolerite sheet. Iridium decreases systematically from the mafic dolerites (0.25 ppb) to the granophyres (0.006 ppb). The trend with differentiation closely parallels that of chromium. ?? 1971.

  13. Iridium enrichment in airborne particles from kilauea volcano: january 1983.

    PubMed

    Zoller, W H; Parrington, J R; Kotra, J M

    1983-12-09

    Airborne particulate matter from the January 1983 eruption of Kilauea volcano was inadvertently collected on air filters at Mauna Loa Observatory at a sampling station used to observe particles in global circulation. Analyses of affected samples revealed unusually large concentrations of selenium, arsenic, indium, gold, and sulfur, as expected for volcanic emissions. Strikingly large concentrations of iridium were also observed, the ratio of iridium to aluminum being 17,000 times its value in Hawaiian basalt. Since iridium enrichments have not previously been observed in volcanic emissions, the results for Kilauea suggest that it is part of an unusual volcanic system which may be fed by magma from the mantle. The iridium enrichment appears to be linked with the high fluorine content of the volcanic gases, which suggests that the iridium is released as a volatile IrF(6).

  14. 49 CFR 173.174 - Refrigerating machines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or...

  15. 49 CFR 173.174 - Refrigerating machines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or...

  16. 49 CFR 173.174 - Refrigerating machines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or...

  17. 49 CFR 173.174 - Refrigerating machines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or...

  18. 49 CFR 173.174 - Refrigerating machines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or...

  19. 20 CFR 632.174 - Administrative costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Administrative costs. 632.174 Section 632.174 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR INDIAN AND NATIVE AMERICAN... Administrative costs. Administrative costs for this subpart are limited to and shall not exceed 20 percent of...

  20. 34 CFR 668.174 - Past performance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false Past performance. 668.174 Section 668.174 Education... performance. (a) Past performance of an institution. An institution is not financially responsible if the... pursuant to subpart G or H of this part. (b) Past performance of persons affiliated with an institution....

  1. 34 CFR 668.174 - Past performance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Past performance. 668.174 Section 668.174 Education... performance. (a) Past performance of an institution. An institution is not financially responsible if the... pursuant to subpart G or H of this part. (b) Past performance of persons affiliated with an institution....

  2. 27 CFR 26.174 - Records.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Records. 26.174 Section 26... Eligible Articles From Puerto Rico § 26.174 Records. (a) General. Every person intending to file claim for drawback on eligible articles brought into the United States from Puerto Rico shall keep permanent...

  3. 27 CFR 26.174 - Records.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Records. 26.174 Section 26... Eligible Articles From Puerto Rico § 26.174 Records. (a) General. Every person intending to file claim for drawback on eligible articles brought into the United States from Puerto Rico shall keep permanent...

  4. 27 CFR 26.174 - Records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Records. 26.174 Section 26... Eligible Articles From Puerto Rico § 26.174 Records. (a) General. Every person intending to file claim for drawback on eligible articles brought into the United States from Puerto Rico shall keep permanent...

  5. 13 CFR 120.174 - Earthquake hazards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Earthquake hazards. 120.174... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.174 Earthquake..., the construction must conform with the “National Earthquake Hazards Reduction Program...

  6. 13 CFR 120.174 - Earthquake hazards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Earthquake hazards. 120.174... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.174 Earthquake..., the construction must conform with the “National Earthquake Hazards Reduction Program...

  7. 13 CFR 120.174 - Earthquake hazards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Earthquake hazards. 120.174... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.174 Earthquake..., the construction must conform with the “National Earthquake Hazards Reduction Program...

  8. 13 CFR 120.174 - Earthquake hazards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Earthquake hazards. 120.174... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.174 Earthquake..., the construction must conform with the “National Earthquake Hazards Reduction Program...

  9. 13 CFR 120.174 - Earthquake hazards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Earthquake hazards. 120.174... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.174 Earthquake..., the construction must conform with the “National Earthquake Hazards Reduction Program...

  10. 33 CFR 174.103 - Administration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Administration. 174.103 Section 174.103 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED....103 Administration. The State casualty reporting system must be administered by a State agency...

  11. 33 CFR 174.103 - Administration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Administration. 174.103 Section 174.103 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED....103 Administration. The State casualty reporting system must be administered by a State agency...

  12. 19 CFR 174.0 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Scope. 174.0 Section 174.0 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED... applicable to Canadian and Mexican exporters and producers regarding administrative review and appeal...

  13. 19 CFR 174.0 - Scope.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Scope. 174.0 Section 174.0 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED... applicable to Canadian and Mexican exporters and producers regarding administrative review and appeal...

  14. 19 CFR 174.0 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Scope. 174.0 Section 174.0 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED... applicable to Canadian and Mexican exporters and producers regarding administrative review and appeal...

  15. 19 CFR 174.0 - Scope.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Scope. 174.0 Section 174.0 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED... applicable to Canadian and Mexican exporters and producers regarding administrative review and appeal...

  16. 19 CFR 174.0 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Scope. 174.0 Section 174.0 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED... applicable to Canadian and Mexican exporters and producers regarding administrative review and appeal...

  17. 46 CFR 174.340 - Collision bulkhead.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Collision bulkhead. 174.340 Section 174.340 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Collision bulkhead. Each hopper dredge must have a collision bulkhead that is located not less than...

  18. 46 CFR 174.340 - Collision bulkhead.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Collision bulkhead. 174.340 Section 174.340 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Collision bulkhead. Each hopper dredge must have a collision bulkhead that is located not less than...

  19. 46 CFR 174.340 - Collision bulkhead.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Collision bulkhead. 174.340 Section 174.340 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Collision bulkhead. Each hopper dredge must have a collision bulkhead that is located not less than...

  20. 46 CFR 174.340 - Collision bulkhead.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Collision bulkhead. 174.340 Section 174.340 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Collision bulkhead. Each hopper dredge must have a collision bulkhead that is located not less than...

  1. 46 CFR 174.340 - Collision bulkhead.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Collision bulkhead. 174.340 Section 174.340 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... Collision bulkhead. Each hopper dredge must have a collision bulkhead that is located not less than...

  2. Iridium Interfacial Stack - IrIS

    NASA Technical Reports Server (NTRS)

    Spry, David

    2012-01-01

    Iridium Interfacial Stack (IrIS) is the sputter deposition of high-purity tantalum silicide (TaSi2-400 nm)/platinum (Pt-200 nm)/iridium (Ir-200 nm)/platinum (Pt-200 nm) in an ultra-high vacuum system followed by a 600 C anneal in nitrogen for 30 minutes. IrIS simultaneously acts as both a bond metal and a diffusion barrier. This bondable metallization that also acts as a diffusion barrier can prevent oxygen from air and gold from the wire-bond from infiltrating silicon carbide (SiC) monolithically integrated circuits (ICs) operating above 500 C in air for over 1,000 hours. This TaSi2/Pt/Ir/Pt metallization is easily bonded for electrical connection to off-chip circuitry and does not require extra anneals or masking steps. There are two ways that IrIS can be used in SiC ICs for applications above 500 C: it can be put directly on a SiC ohmic contact metal, such as Ti, or be used as a bond metal residing on top of an interconnect metal. For simplicity, only the use as a bond metal is discussed. The layer thickness ratio of TaSi2 to the first Pt layer deposited thereon should be 2:1. This will allow Si from the TaSi2 to react with the Pt to form Pt2Si during the 600 C anneal carried out after all layers have been deposited. The Ir layer does not readily form a silicide at 600 C, and thereby prevents the Si from migrating into the top-most Pt layer during future anneals and high-temperature IC operation. The second (i.e., top-most) deposited Pt layer needs to be about 200 nm to enable easy wire bonding. The thickness of 200 nm for Ir was chosen for initial experiments; further optimization of the Ir layer thickness may be possible via further experimentation. Ir itself is not easily wire-bonded because of its hardness and much higher melting point than Pt. Below the iridium layer, the TaSi2 and Pt react and form desired Pt2Si during the post-deposition anneal while above the iridium layer remains pure Pt as desired to facilitate easy and strong wire-bonding to the Si

  3. Iridium Film For Charge-Coupled Device

    NASA Technical Reports Server (NTRS)

    Hecht, Michael H.

    1990-01-01

    Usability extended to different environments. Application of thin film of iridium to back surface of back-surface-illuminated charge-coupled device expected to increase and stabilize quantum efficiency at wavelengths less than 4,500 Angstrom. Enhances quantum efficiency according to principle discussed in "Metal Film Increases CCD Output" (NPO-16815). Does not react with hydrogen, so device need not be kept in oxygen: Advantage where high absorption of ultraviolet light by oxygen undesirable; for example, when device used to make astronomical observations from high altitudes.

  4. Iridium/Rhenium Parts For Rocket Engines

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Harding, John T.; Wooten, John R.

    1991-01-01

    Oxidation/corrosion of metals at high temperatures primary life-limiting mechanism of parts in rocket engines. Combination of metals greatly increases operating temperature and longevity of these parts. Consists of two transition-element metals - iridium and rhenium - that melt at extremely high temperatures. Maximum operating temperature increased to 2,200 degrees C from 1,400 degrees C. Increases operating lifetimes of small rocket engines by more than factor of 10. Possible to make hotter-operating, longer-lasting components for turbines and other heat engines.

  5. Diminiode thermionic conversion with 111-iridium electrodes

    NASA Technical Reports Server (NTRS)

    Koeger, E. W.; Bair, V. L.; Morris, J. F.

    1976-01-01

    Preliminary data indicating thermionic-conversion potentialities for a 111-iridium emitter and collector spaced 0.2 mm apart are presented. These results comprise output densities of current and of power as functions of voltage for three sets of emitter, collector, and reservoir temperatures: 1553, 944, 561 K; 1605, 898, 533 K; and 1656, 1028, 586 K. For the 1605 K evaluation, estimates produced work-function values of 2.22 eV for the emitter and 1.63 eV for the collector with a 2.0-eV barrier index (collector work function plus interelectrode voltage drop) corresponding to the maximum output of 5.5 W/sq cm at 0.24 volt. The current, voltage curve for the 1656 K 111-iridium diminiode yields a 6.2 W/sq cm maximum at 0.25 volt and is comparable with the 1700 K envelope for a diode with an etched-rhenium emitter and a 0.025-mm electrode gap made by TECO and evaluated by NASA.

  6. Ab initio phase diagram of iridium

    NASA Astrophysics Data System (ADS)

    Burakovsky, L.; Burakovsky, N.; Cawkwell, M. J.; Preston, D. L.; Errandonea, D.; Simak, S. I.

    2016-09-01

    The phase diagram of iridium is investigated using the Z methodology. The Z methodology is a technique for phase diagram studies that combines the direct Z method for the computation of melting curves and the inverse Z method for the calculation of solid-solid phase boundaries. In the direct Z method, the solid phases along the melting curve are determined by comparing the solid-liquid equilibrium boundaries of candidate crystal structures. The inverse Z method involves quenching the liquid into the most stable solid phase at various temperatures and pressures to locate a solid-solid boundary. Although excellent agreement with the available experimental data (to ≲65 GPa) is found for the equation of state (EOS) of Ir, it is the third-order Birch-Murnaghan EOS with B0'=5 rather than the more widely accepted B0'=4 that describes our ab initio data to higher pressure (P ) . Our results suggest the existence of a random-stacking hexagonal close-packed structure of iridium at high P . We offer an explanation for the 14-layer hexagonal structure observed in experiments by Cerenius and Dubrovinsky.

  7. Iridium wire grid polarizer fabricated using atomic layer deposition.

    PubMed

    Weber, Thomas; Käsebier, Thomas; Szeghalmi, Adriana; Knez, Mato; Kley, Ernst-Bernhard; Tünnermann, Andreas

    2011-10-25

    In this work, an effective multistep process toward fabrication of an iridium wire grid polarizer for UV applications involving a frequency doubling process based on ultrafast electron beam lithography and atomic layer deposition is presented. The choice of iridium as grating material is based on its good optical properties and a superior oxidation resistance. Furthermore, atomic layer deposition of iridium allows a precise adjustment of the structural parameters of the grating much better than other deposition techniques like sputtering for example. At the target wavelength of 250 nm, a transmission of about 45% and an extinction ratio of 87 are achieved.

  8. 46 CFR 174.260 - Freeboard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSEL TYPES Special Rules Pertaining to Liftboats § 174.260 Freeboard. (a) Each liftboat not required to... continuation outwards of the upper surface of the weather deck and the outer surface of the shell....

  9. 46 CFR 174.010 - Specific applicability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Deck Cargo Barges § 174.010 Specific applicability. Each barge that carries cargo above the weather deck must comply with this subpart....

  10. 46 CFR 174.030 - Specific applicability.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.030 Specific applicability. Each mobile offshore drilling unit (MODU) inspected under Subchapter IA of...

  11. 46 CFR 174.030 - Specific applicability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.030 Specific applicability. Each mobile offshore drilling unit (MODU) inspected under Subchapter IA of...

  12. Phase control of iridium and iridium oxide thin films in atomic layer deposition

    SciTech Connect

    Kim, Sung-Wook; Kwon, Se-Hun; Kwak, Dong-Kee; Kang, Sang-Won

    2008-01-15

    The atomic layer deposition of iridium (Ir) and iridium oxide (IrO{sub 2}) films was investigated using an alternating supply of (ethylcyclopentadienyl)(1,5-cyclooctadiene) iridium and oxygen gas at temperatures between 230 and 290 deg. C. The phase transition between Ir and IrO{sub 2} occurred at the critical oxygen partial pressure during the oxygen injection pulse. The oxygen partial pressure was controlled by the O{sub 2}/(Ar+O{sub 2}) ratio or deposition pressures. The resistivity of the deposited Ir and IrO{sub 2} films was about 9 and 120 {mu}{omega} cm, respectively. In addition, the critical oxygen partial pressure for the phase transition between Ir and IrO{sub 2} was increased with increasing the deposition temperature. Thus, the phase of the deposited film, either Ir or IrO{sub 2}, was controlled by the oxygen partial pressure and the deposition temperature. However, the formation of a thin Ir layer was detected between the IrO{sub 2} and SiO{sub 2} substrate. To remove this interfacial layer, the oxygen partial pressure is increased to a severe condition. And the impurity contents were below the detection limit of Auger electron spectroscopy in both Ir and IrO{sub 2} films.

  13. Monoalkylation of acetonitrile by primary alcohols catalyzed by iridium complexes.

    PubMed

    Anxionnat, Bruno; Pardo, Domingo Gomez; Ricci, Gino; Cossy, Janine

    2011-08-05

    The monoalkylation of acetonitrile by primary alcohols was achieved in a one-pot sequence in the presence of iridium catalysts. A diversity of nitriles has been obtained from aryl- and alkyl-methanols in excellent yield.

  14. Acute radiodermatitis from occupational exposure to iridium 192

    SciTech Connect

    Becker, J.; Rosen, T. )

    1989-12-01

    Industrial radiography using the man-made radioisotope iridium 192 is commonplace in the southern states. Despite established procedures and safeguards, accidental exposure may result in typical acute radiodermatitis. We have presented a clinical example of this phenomenon.9 references.

  15. GPS/GNSS Interference from Iridium Data Transmitters

    NASA Astrophysics Data System (ADS)

    Berglund, H. T.; Blume, F.; Estey, L.; White, S.

    2011-12-01

    The Iridium satellite communication system broadcasts in the 1610 to 1626.5 MHz band. The L1 frequencies broadcast by GPS, Galileo and GLONASS satellites are 1575.42 MHz, 1575.42 MHz and 1602 MHz + n × 0.5625 MHz, respectively (each GLONASS satellite uses a unique frequency). The proximity of the Iridium frequency band with the L1 frequencies of the GPS, Galileo and GLONASS systems leaves GNSS receivers susceptible to interference from Iridium data transmissions. Interference from Iridium transmissions can cause cycle slips and loss of lock on the carrier and code phases, thereby degrading the quality of GNSS observations and position estimates. In 2008, UNAVCO staff members observed that the percent of slips vs. the number of observations increased as the distance between a GPS choke ring antenna (TRM29659.00) and an Iridium antenna decreased. From those observations they suggested that Iridium antennas and GPS antennas should be separated by >30 m to minimize cycle slips caused by the interference from Iridium data transmissions. A second test conducted in 2009 using a newer Trimble GNSS choke ring antenna (TRM59800.00) showed similar results to the previous test despite the wider frequency range of the newer antenna. More recent testing conducted to investigate the response of new receiver models to iridium transmissions has shown that many GNSS enabled models, when combined with GNSS enabled antennas, have increased sensitivity to interference when compared to older GPS-only models. The broader frequency spectrum of the Low Noise Amplifiers (LNA) installed in many newer GNSS antennas can increase the impact of near-band RF interference on tracking performance. Our testing has shown that the quality of data collected at sites collocated with iridium communications is highly degraded for antenna separations exceeding 100m. Using older GPS antenna models (e.g. TRM29659.00) with newer GNSS enabled receivers can reduce this effect. To mitigate the effects that

  16. Synthesis and characterization of nitrides of iridium and palladiums

    SciTech Connect

    Crowhurst, Jonathan C.; Goncharov, Alexander F.; Sadigh, B.; Zaug, J.M.; Aberg, D.; Meng, Yue; Prakapenka, Vitali B.

    2008-08-14

    We describe the synthesis of nitrides of iridium and palladium using the laser-heated diamond anvil cell. We have used the in situ techniques of x-ray powder diffraction and Raman scattering to characterize these compounds and have compared our experimental findings where possible to the results of first-principles theoretical calculations. We suggest that palladium nitride is isostructural with pyrite, while iridium nitride has a monoclinic symmetry and is isostructural with baddeleyite.

  17. Iridium{reg_sign} worldwide personal communication system

    SciTech Connect

    Helm, J.

    1997-01-01

    The IRIDIUM system is a personal worldwide communication system designed to support portable, low power subscriber units through the use of a constellation of satellites in low earth polar orbit. The satellites are networked together to form a system which provides continuous line-of-sight communications between the IRIDIUM system and any point within 30 km of the earth{close_quote}s surface. The system architecture and operation are described. {copyright} {ital 1997 American Institute of Physics.}

  18. Laser Induced Fluorescence Spectrum of Iridium Monophosphide

    NASA Astrophysics Data System (ADS)

    Pang, H. F.; Liu, Anwen; Cheung, A. S.-C.

    2009-06-01

    Laser induced fluorescence spectrum of IrP in the spectral region between 380-600 nm has been studied. Reacting laser ablated iridium atoms with 1% PH_3 seeded in argon produced the IrP molecule. A few vibronic transitions have been recorded. Preliminary analysis of the rotational structure indicated that these vibronic bands are with Ω^' = 0 and Ω^'' = 0 and is likely to be ^{1}Σ - X ^{1}Σ transition. Vibrational separation of the excited state is estimated to be about 442 cm^{-1}. The ground state bond length is determined to be 1.766 Å. This work represents the first experimental investigation of the spectra of IrP.

  19. Solventless synthesis of iridium(0) nanoparticles

    NASA Astrophysics Data System (ADS)

    Redón, R.; Ramírez-Crescencio, F.; Fernández-Osorio, A. L.

    2011-11-01

    In this article, we present the results of a solvent-free synthesis of iridium(0) nanoparticles, both water washed and unwashed. IrCl3 and NaBH4, as starting materials, are mixed using an agate mortar and milled for 15 min until a black powder is obtained, which is heated in a nitrogen-controlled atmosphere oven at 200 °C for 2 h. If the product of the reaction is not washed before heating, NaBH4 and IrO2 impurities are observed. On the other hand, if the reaction product is washed before the heating, the obtained powder is free of impurities. We study the effect of the variation in reducing agent concentration and the annealing temperature used after the reaction. In all cases, the calculated particle size is less than 10 nm.

  20. On the Extreme Oxidation States of Iridium.

    PubMed

    Pyykkö, Pekka; Xu, Wen-Hua

    2015-06-22

    It has recently been suggested that the oxidation states of Ir run from the putative -III in the synthesized solid Na3 [Ir(CO)3 ] to the well-documented +IX in the species IrO4 (+) . Furthermore, [Ir(CO)3 ](3-) was identified as an 18-electron species. A closer DFT study now finds support for this picture: The orbitals spanned by the 6s,6p,5d orbitals of the iridium are all occupied. Although some have considerable ligand character, the deviations from 18 e leave the orbital symmetries unchanged. The isoelectronic systems from Os(-IV) to Au(-I) behave similarly, suggesting further possible species. To paraphrase Richard P. Feynmann "there is plenty of room at the bottom".

  1. PURIFICATION OF IRIDIUM BY ELECTRON BEAM MELTING

    SciTech Connect

    Ohriner, Evan Keith

    2008-01-01

    The purification of iridium metal by electron beam melting has been characterized for 48 impurity elements. Chemical analysis was performed by glow discharge mass spectrographic (GDMS) analysis for all elements except carbon, which was analyzed by combustion. The average levels of individual elemental impurities in the starting powder varied from 37 g/g to 0.02 g/g. The impurity elements Li, Na, Mg, P, S, Cl, K, Ca, Mn, Co, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Sb, Te, Ba, Ce, Tl, Pb, and Bi were not detectable following the purification. No significant change in concentration of the elements Ti, V, Zr, Nb, Mo, and Re was found. The elements B, C, Al, Si, Cr, Fe, Ru, Rh, and Pt were partially removed by vaporization during electron beam melting. Langmuir's equation for ideal vaporization into a vacuum was used to calculate for each impurity element the expected ratio of impurity content after melting to that before melting. Equilibrium vapor pressures were calculated using Henry's law, with activity coefficients obtained from published data for the elements Fe, Ti, and Pt. Activity coefficients were estimated from enthalpy data for Al, Si, V, Cr, Mn, Co, Ni, Zr, Nb, Mo, and Hf and an ideal solution model was used for the remaining elements. The melt temperature was determined from measured iridium weight loss. Excellent agreement was found between measured and calculated impurity ratios for all impurity elements. The results are consistent with some localized heating of the melt pool due to rastering of the electron beam, with an average vaporization temperature of 3100 K as compared to a temperature of 2965 K calculated for uniform heating of the melt pool. The results are also consistent with ideal mixing in the melt pool.

  2. 46 CFR 174.090 - Permeability of spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Permeability of spaces. 174.090 Section 174.090 Shipping... Permeability of spaces. When doing the calculations required in § 174.065— (a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and (b) Calculations in which...

  3. 46 CFR 174.090 - Permeability of spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Permeability of spaces. 174.090 Section 174.090 Shipping... Permeability of spaces. When doing the calculations required in § 174.065— (a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and (b) Calculations in which...

  4. 46 CFR 174.090 - Permeability of spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Permeability of spaces. 174.090 Section 174.090 Shipping... Permeability of spaces. When doing the calculations required in § 174.065— (a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and (b) Calculations in which...

  5. 46 CFR 174.090 - Permeability of spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Permeability of spaces. 174.090 Section 174.090 Shipping... Permeability of spaces. When doing the calculations required in § 174.065— (a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and (b) Calculations in which...

  6. 46 CFR 174.090 - Permeability of spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Permeability of spaces. 174.090 Section 174.090 Shipping... Permeability of spaces. When doing the calculations required in § 174.065— (a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and (b) Calculations in which...

  7. DETERMINATION OF HETEROGENEOUS ELECTRON TRANSFER RATE CONSTANTS AT MICROFABRICATED IRIDIUM ELECTRODES. (R825511C022)

    EPA Science Inventory

    There has been an increasing use of both solid metal and microfabricated iridium electrodes as substrates for various types of electroanalysis. However, investigations to determine heterogeneous electron transfer rate constants on iridium, especially at an electron beam evapor...

  8. Iridium complexes demonstrating broadband emission through controlled geometric distortion and applications thereof

    SciTech Connect

    Li, Jian; Turner, Eric

    2016-04-12

    Iridium compounds and their uses are disclosed herein. For example, carbazole containing iridium compounds are disclosed. The compounds are useful in many devices, including, but not limited to, electroluminescent devices.

  9. Highly fluorescent and biocompatible iridium nanoclusters for cellular imaging.

    PubMed

    Vankayala, Raviraj; Gollavelli, Ganesh; Mandal, Badal Kumar

    2013-08-01

    Highly fluorescent iridium nanoclusters were synthesized and investigated its application as a potential intracellular marker. The iridium nanoclusters were prepared with an average size of ~2 nm. Further, these nanoclusters were refluxed with aromatic ligands, such as 2,2'-binaphthol (BINOL) in order to obtain fluorescence properties. The photophysical properties of these bluish-green emitting iridium nanoclusters were well characterized by using UV-Visible, fluorescence and lifetime decay measurements. The emission spectrum for these nanoclusters exhibit three characteristic peaks at 449, 480 and 515 nm. The fluorescence quantum yield of BINOL-Ir NCs were estimated to be 0.36 and the molar extinction co-efficients were in the order of 10(6) M(-1)cm(-1). In vitro cytotoxicity studies in HeLa cells reveal that iridium nanoclusters exhibited good biocompatibility with an IC50 value of ~100 μg/ml and also showed excellent co-localization and distribution throughout the cytoplasm region without entering into the nucleus. This research has opened a new window in developing the iridium nanoparticle based intracellular fluorescent markers and has wide scope to act as biomedical nanocarrier to carry many biological molecules and anticancer drugs.

  10. SO2 adsorption on silica supported iridium

    NASA Astrophysics Data System (ADS)

    Bounechada, Djamela; Anderson, David P.; Skoglundh, Magnus; Carlsson, Per-Anders

    2017-02-01

    The interaction of SO2 with Ir/SiO2 was studied by simultaneous in situ diffuse reflectance infrared Fourier transform spectroscopy and mass spectrometry, exposing the sample to different SO2 concentrations ranging from 10 to 50 ppm in the temperature interval 200-400 °C. Evidences of adsorption of sulfur species in both absence and presence of oxygen are found. For a pre-reduced sample in the absence of oxygen, SO2 disproportionates such that the iridium surface is rapidly saturated with adsorbed S while minor amounts of formed SO3 may adsorb on SiO2. Adding oxygen to the feed leads to the oxidation of sulfide species that either (i) desorb as SO2 and/or SO3, (ii) remain at metal sites in the form of adsorbed SO2, or (iii) spillover to the oxide support and form sulfates (SO42-). Notably, significant formation of sulfates on silica is possible only in the presence of both SO2 and O2, suggesting that SO2 oxidation to SO3 is a necessary first step in the mechanism of formation of sulfates on silica. During the formation of sulfates, a concomitant removal/rearrangement of surface silanol groups is observed. Finally, the interaction of SO2 with Ir/SiO2 depends primarily on the temperature and type of gas components but only to a minor extent on the inlet SO2 concentration.

  11. 32 CFR 174.4 - Policy.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... COMMUNITIES AND ADDRESSING IMPACTS OF REALIGNMENT Policy § 174.4 Policy. It is DoD policy to: (a) Act... circumstances of the surrounding communities does not lend itself to a single universal solution, the Department... address growth. The Department will work with the surrounding community so that the public and...

  12. 46 CFR 160.174-9 - Construction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS... material that meets the thermal insulation requirements in § 160.174-11(a). Each aid must be designed to... single thread lock stitch. (c) Seam strength. Each seam must have a strength of at least 225 Newtons...

  13. 33 CFR 174.103 - Administration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 174.103 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... cause of casualties and accidents reported based on information available and indicates the apparent... problem area in boating safety peculiar to the State is determined, together, with corrective...

  14. 33 CFR 174.103 - Administration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 174.103 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... cause of casualties and accidents reported based on information available and indicates the apparent... problem area in boating safety peculiar to the State is determined, together, with corrective...

  15. 19 CFR 174.1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Customs officers who did not participate directly in the decision which is the subject of the protest. ....S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS General Provisions § 174.1 Definitions. When used in this part, the following term...

  16. 46 CFR 160.174-9 - Construction.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS... material that meets the thermal insulation requirements in § 160.174-11(a). Each aid must be designed to... single thread lock stitch. (c) Seam strength. Each seam must have a strength of at least 225 Newtons...

  17. 40 CFR 80.174 - Addresses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.174 Addresses. (a) The detergent additive sample..., 2565 Plymouth Road, Ann Arbor, Michigan 48105. (b) Other detergent registration and certification data, and certain other information which may be specified in this subpart, shall be sent to:...

  18. 40 CFR 80.174 - Addresses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.174 Addresses. (a) The detergent additive sample..., 2565 Plymouth Road, Ann Arbor, Michigan 48105. (b) Other detergent registration and certification data, and certain other information which may be specified in this subpart, shall be sent to:...

  19. 49 CFR 174.24 - Shipping papers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY RAIL General Operating Requirements § 174.24 Shipping papers. (a) A person may not accept a hazardous material for transportation...

  20. 46 CFR 174.035 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.035 Definitions. (a... IA of this chapter: (1) Column stabilized unit. (2) Mobile offshore drilling unit. (3) Self-elevating... loaded or arranged for drilling, field transit, or ocean transit. (4) Severe storm condition means...

  1. 46 CFR 174.035 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.035 Definitions. (a... IA of this chapter: (1) Column stabilized unit. (2) Mobile offshore drilling unit. (3) Self-elevating... loaded or arranged for drilling, field transit, or ocean transit. (4) Severe storm condition means...

  2. 46 CFR 174.035 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.035 Definitions. (a... IA of this chapter: (1) Column stabilized unit. (2) Mobile offshore drilling unit. (3) Self-elevating... loaded or arranged for drilling, field transit, or ocean transit. (4) Severe storm condition means...

  3. 46 CFR 174.035 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.035 Definitions. (a... IA of this chapter: (1) Column stabilized unit. (2) Mobile offshore drilling unit. (3) Self-elevating... loaded or arranged for drilling, field transit, or ocean transit. (4) Severe storm condition means...

  4. 46 CFR 174.035 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.035 Definitions. (a... IA of this chapter: (1) Column stabilized unit. (2) Mobile offshore drilling unit. (3) Self-elevating... loaded or arranged for drilling, field transit, or ocean transit. (4) Severe storm condition means...

  5. 40 CFR 80.174 - Addresses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.174 Addresses. (a) The detergent additive sample..., 2565 Plymouth Road, Ann Arbor, Michigan 48105. (b) Other detergent registration and certification data, and certain other information which may be specified in this subpart, shall be sent to:...

  6. 40 CFR 80.174 - Addresses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.174 Addresses. (a) The detergent additive sample..., 2565 Plymouth Road, Ann Arbor, Michigan 48105. (b) Other detergent registration and certification data, and certain other information which may be specified in this subpart, shall be sent to:...

  7. Experimental determination of the solubility of iridium in silicate melts: Preliminary results

    NASA Technical Reports Server (NTRS)

    Borisov, Alexander; Dingwell, Donald B.; Oneill, Hugh ST.C.; Palme, Herbert

    1992-01-01

    Little is known of the geochemical behavior of iridium. Normally this element is taken to be chalcophile and/or siderophile so that during planetary differentiation processes, e.g., core formation, iridium is extracted from silicate phases into metallic phases. Experimental determination of the metal/silicate partition coefficient of iridium is difficult simply because it is so large. Also there are no data on the solubility behavior of iridium in silicate melts. With information on the solubility of iridium in silicate melts it is possible, in combination with experimental data for Fe-Ir alloys, to calculate the partition coefficient between a metallic phase and a silicate melt.

  8. Field desorption of Na and Cs from graphene on iridium

    NASA Astrophysics Data System (ADS)

    Bernatskii, D. P.; Pavlov, V. G.

    2015-08-01

    Field electron and desorption microscopy has been used to study specific features of the field desorption of sodium and cesium ions adsorbed on the surface of iridium with graphene. It was found that adsorbed sodium atoms most strongly reduce the work function on graphene islands situated over densely packed faces of iridium. A strong electric field qualitatively similarly affects the sodium and cesium desorption processes from a field emitter to give two desorption phases and has no noticeable effect on the disintegration of the graphene layer.

  9. Corrosion-resistant iridium-platinum anode material for high polarization application in corrosive acids

    SciTech Connect

    Farmer, J.; Summers, L.; Lewis, P.

    1993-09-08

    The present invention relates to highly corrosion resistant components for use in an electrochemical cell. Specifically, these components are resistant to corrosion under very extreme conditions such as exposure to aqua regia in the presence of a constant current density of 100mA/m{sup 2}. The components are comprised of an iridium-platinum alloy that comprises less than 30% iridium. In a preferred embodiment of the present invention, the iridium-platinum alloy comprises 15-20% iridium. In another preferred embodiment of the present invention, the iridium-platinum alloy is deposited on the surface of an electrochemical cell component by magnetron sputtering. The present invention also relates to a method for conducting an electrochemical reaction in the presence of highly corrosive acids under a high degree of polarization wherein the electrochemical cell comprises a component, preferably the anode, containing an iridium-platinum alloy that comprises less than 30% iridium.

  10. Homogeneous and heterogenized iridium water oxidation catalysts

    NASA Astrophysics Data System (ADS)

    Macchioni, Alceo

    2014-10-01

    The development of an efficient catalyst for the oxidative splitting of water into molecular oxygen, protons and electrons is of key importance for producing solar fuels through artificial photosynthesis. We are facing the problem by means of a rational approach aimed at understanding how catalytic performance may be optimized by the knowledge of the reaction mechanism of water oxidation and the fate of the catalytic site under the inevitably harsh oxidative conditions. For the purposes of our study we selected iridium water oxidation catalysts, exhibiting remarkable performance (TOF > 5 s-1 and TON > 20000). In particular, we recently focused our attention on [Cp*Ir(N,O)X] (N,O = 2-pyridincarboxylate; X = Cl or NO3) and [IrCl(Hedta)]Na water oxidation catalysts. The former exhibited a remarkable TOF whereas the latter showed a very high TON. Furthermore, [IrCl(Hedta)]Na was heterogenized onto TiO2 taking advantage of the presence of a dandling -COOH functionality. The heterogenized catalyst maintained approximately the same catalytic activity of the homogeneous analogous with the advantage that could be reused many times. Mechanistic studies were performed in order to shed some light on the rate-determining step and the transformation of catalysts when exposed to "oxidative stress". It was found that the last oxidative step, preceding oxygen liberation, is the rate-determining step when a small excess of sacrificial oxidant is used. In addition, several intermediates of the oxidative transformation of the catalyst were intercepted and characterized by NMR, X-Ray diffractometry and ESI-MS.

  11. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 174.86 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY RAIL Handling of Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.86 Maximum...

  12. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 174.86 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY RAIL Handling of Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.86 Maximum...

  13. Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

    SciTech Connect

    Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.; Pivovar, Bryan S.

    2016-06-02

    Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparative studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. Lastly, they also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.

  14. Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

    DOE PAGES

    Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.; ...

    2016-06-02

    Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparativemore » studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. Lastly, they also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.« less

  15. 49 CFR 174.300 - Special handling requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Special handling requirements. 174.300 Section 174.300 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... Detailed Requirements for Class 3 (Flammable Liquid) Materials § 174.300 Special handling requirements....

  16. 49 CFR 174.300 - Special handling requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Special handling requirements. 174.300 Section 174.300 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... Detailed Requirements for Class 3 (Flammable Liquid) Materials § 174.300 Special handling requirements....

  17. 19 CFR 174.11 - Matters subject to protest.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Matters subject to protest. 174.11 Section 174.11... TREASURY (CONTINUED) PROTESTS Protests § 174.11 Matters subject to protest. The following decisions of CBP... administrative decisions involving the following subject matters are subject to protest: (1) The appraised...

  18. 19 CFR 174.11 - Matters subject to protest.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Matters subject to protest. 174.11 Section 174.11... TREASURY (CONTINUED) PROTESTS Protests § 174.11 Matters subject to protest. The following decisions of CBP... administrative decisions involving the following subject matters are subject to protest: (1) The appraised...

  19. 19 CFR 174.11 - Matters subject to protest.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Matters subject to protest. 174.11 Section 174.11... TREASURY (CONTINUED) PROTESTS Protests § 174.11 Matters subject to protest. The following decisions of CBP... administrative decisions involving the following subject matters are subject to protest: (1) The appraised...

  20. 19 CFR 174.11 - Matters subject to protest.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Matters subject to protest. 174.11 Section 174.11... TREASURY (CONTINUED) PROTESTS Protests § 174.11 Matters subject to protest. The following decisions of CBP... administrative decisions involving the following subject matters are subject to protest: (1) The appraised...

  1. 19 CFR 174.11 - Matters subject to protest.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Matters subject to protest. 174.11 Section 174.11 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) PROTESTS Protests § 174.11 Matters subject to protest. The following decisions of...

  2. 46 CFR 160.174-5 - Independent laboratory.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Independent laboratory. 160.174-5 Section 160.174-5...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-5 Independent laboratory. (a... laboratory accepted by the Coast Guard under subpart 159.010 of this chapter. (b)...

  3. 46 CFR 160.174-5 - Independent laboratory.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Independent laboratory. 160.174-5 Section 160.174-5...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-5 Independent laboratory. (a... laboratory accepted by the Coast Guard under subpart 159.010 of this chapter. (b)...

  4. 46 CFR 160.174-5 - Independent laboratory.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Independent laboratory. 160.174-5 Section 160.174-5...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-5 Independent laboratory. (a... laboratory accepted by the Coast Guard under subpart 159.010 of this chapter. (b)...

  5. 46 CFR 160.174-5 - Independent laboratory.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Independent laboratory. 160.174-5 Section 160.174-5...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-5 Independent laboratory. (a... laboratory accepted by the Coast Guard under subpart 159.010 of this chapter. (b)...

  6. 46 CFR 160.174-5 - Independent laboratory.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Independent laboratory. 160.174-5 Section 160.174-5...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-5 Independent laboratory. (a... laboratory accepted by the Coast Guard under subpart 159.010 of this chapter. (b)...

  7. 10 CFR 72.174 - Quality assurance records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Quality assurance records. 72.174 Section 72.174 Energy... NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C WASTE Quality Assurance § 72.174 Quality assurance records. The licensee, applicant for a license, certificate holder,...

  8. 46 CFR 174.065 - Damage stability requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... simultaneously to— (1) Damage causing flooding described in §§ 174.075 through 174.085; and (2) A wind heeling moment calculated in accordance with § 174.055(b) using a wind velocity of 50 knots (25.8 meters...

  9. 46 CFR 160.174-25 - Production testing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Production testing. 160.174-25 Section 160.174-25...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-25 Production testing. (a) Thermal protective aid production testing is conducted under the procedures in this section and...

  10. 46 CFR 160.174-25 - Production testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Production testing. 160.174-25 Section 160.174-25...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-25 Production testing. (a) Thermal protective aid production testing is conducted under the procedures in this section and...

  11. 33 CFR 167.174 - Off Delaware Bay: Precautionary area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... area. 167.174 Section 167.174 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Separation Schemes and Precautionary Areas Atlantic East Coast § 167.174 Off Delaware Bay: Precautionary area. A precautionary area is established as follows: from 38°42.80′ N, 74°58.90′ W; then northerly by...

  12. 27 CFR 25.174 - Bond not sufficient.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Bond not sufficient. 25.174 Section 25.174 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Tax on Beer Prepayment of Tax § 25.174 Bond not sufficient. When...

  13. 27 CFR 25.174 - Bond not sufficient.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Bond not sufficient. 25.174 Section 25.174 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Prepayment of Tax § 25.174 Bond not sufficient. When...

  14. 27 CFR 25.174 - Bond not sufficient.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Bond not sufficient. 25.174 Section 25.174 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Tax on Beer Prepayment of Tax § 25.174 Bond not sufficient. When...

  15. 27 CFR 25.174 - Bond not sufficient.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Bond not sufficient. 25.174 Section 25.174 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Prepayment of Tax § 25.174 Bond not sufficient. When...

  16. 27 CFR 25.174 - Bond not sufficient.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bond not sufficient. 25.174 Section 25.174 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Prepayment of Tax § 25.174 Bond not sufficient. When...

  17. 49 CFR 174.3 - Unacceptable hazardous materials shipments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Unacceptable hazardous materials shipments. 174.3 Section 174.3 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY RAIL General Requirements § 174.3...

  18. 33 CFR 167.174 - Off Delaware Bay: Precautionary area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... area. 167.174 Section 167.174 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Separation Schemes and Precautionary Areas Atlantic East Coast § 167.174 Off Delaware Bay: Precautionary area. A precautionary area is established as follows: from 38°42.80′ N, 74°58.90′ W; then northerly by...

  19. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Equity and good conscience. 17.4 Section 17.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL OVERPAYMENTS FROM THE FOREIGN SERVICE RETIREMENT AND... PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  20. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Equity and good conscience. 17.4 Section 17.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL OVERPAYMENTS FROM THE FOREIGN SERVICE RETIREMENT AND... PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  1. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Equity and good conscience. 17.4 Section 17.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL OVERPAYMENTS FROM THE FOREIGN SERVICE RETIREMENT AND... PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  2. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Equity and good conscience. 17.4 Section 17.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL OVERPAYMENTS FROM THE FOREIGN SERVICE RETIREMENT AND... PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  3. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Equity and good conscience. 17.4 Section 17.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL OVERPAYMENTS FROM THE FOREIGN SERVICE RETIREMENT AND... PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  4. 33 CFR 174.125 - Coast Guard address.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Coast Guard address. 174.125 Section 174.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY STATE NUMBERING AND CASUALTY REPORTING SYSTEMS State Reports § 174.125 Coast Guard...

  5. 33 CFR 174.125 - Coast Guard address.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Coast Guard address. 174.125 Section 174.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY STATE NUMBERING AND CASUALTY REPORTING SYSTEMS State Reports § 174.125 Coast Guard...

  6. 33 CFR 174.125 - Coast Guard address.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Coast Guard address. 174.125 Section 174.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY STATE NUMBERING AND CASUALTY REPORTING SYSTEMS State Reports § 174.125 Coast Guard...

  7. 33 CFR 174.125 - Coast Guard address.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Coast Guard address. 174.125 Section 174.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY STATE NUMBERING AND CASUALTY REPORTING SYSTEMS State Reports § 174.125 Coast Guard...

  8. 33 CFR 174.125 - Coast Guard address.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Coast Guard address. 174.125 Section 174.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY STATE NUMBERING AND CASUALTY REPORTING SYSTEMS State Reports § 174.125 Coast Guard...

  9. 49 CFR 174.67 - Tank car unloading.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Tank car unloading. 174.67 Section 174.67... and Loading Requirements § 174.67 Tank car unloading. For transloading operations, the following rules... least one wheel to prevent movement in any direction. If multiple tank cars are coupled...

  10. 46 CFR 174.065 - Damage stability requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.065 Damage stability requirements. (a) Each unit must be designed so that, while in each of its normal... simultaneously to— (1) Damage causing flooding described in §§ 174.075 through 174.085; and (2) A wind...

  11. 49 CFR 174.26 - Notice to train crews.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Notice to train crews. 174.26 Section 174.26... Requirements § 174.26 Notice to train crews. (a) The train crew must have a document that reflects the current position in the train of each rail car containing a hazardous material. The train crew must update...

  12. Achieving Zero Stress in Iridium, Chromium, and Nickle Thin Films

    NASA Technical Reports Server (NTRS)

    Broadway, David M.; Weimer, Jeffrey; Gurgew, Danielle; Lis, Tomasz; Ramsey, Brian D.; O'Dell, Stephen L.; Ames, A.; Bruni, R.

    2015-01-01

    We examine a method for achieving zero intrinsic stress in thin films of iridium, chromium, and nickel deposited by magnetron sputter deposition. The examination of the stress in these materials is motivated by efforts to advance the optical performance of light-weight x-ray space telescopes into the regime of sub-arc second resolution that rely on control of the film stress to values within 10-100 MPa. A characteristic feature of the intrinsic stress behavior in chromium and nickel is their sensitivity to the magnitude and sign of the intrinsic stress with argon gas pressure, including the existence of a critical pressure that results in zero film stress. This critical pressure scales linearly with the film's density. While the effect of stress reversal with argon pressure has been previously reported by Hoffman and others for nickel and chromium, we have discovered a similar behavior for iridium. Additionally, we have identified zero stress in iridium shortly after island coalescence. This feature of film growth is used for achieving a total internal stress of -2.89 MPa for a 15.8 nm thick iridium film. The surface roughness of this low-stress film was examined using scanning probe microscopy (SPM) and x-ray reflectivity (XRR) at CuKa and these results presented and discussed.

  13. The Marine Geochemistry of Rhenium, Iridium and Platinum

    DTIC Science & Technology

    1991-09-01

    fields ( Koeberl 1989). Iridium enrichment factors, defined reiaiive to Hawaiian basalt (and relative to Sc) range from 104 to 105. The transport of Ir in...and M. B. McElroy. (1984). "Changes in atmospheric C02: influence of marine biota at high latitudes." J. Geoohys. Res. 89: 4629-4637. Koeberl , C

  14. Electrodeposited iridium oxide for neural stimulation and recording electrodes.

    PubMed

    Meyer, R D; Cogan, S F; Nguyen, T H; Rauh, R D

    2001-03-01

    Iridium oxide films formed by electrodeposition onto noniridium metal substrates are compared with activated iridium oxide films (AIROFs) as a low impedance, high charge capacity coating for neural stimulation and recording electrodes. The electrodeposited iridium oxide films (EIROFs) were deposited on Au, Pt, PtIr, and 316 LVM stainless steel substrates from a solution of IrCl4, oxalic acid, and K2CO3. A deposition protocol involving 50 potential sweeps at 50 mV/s between limits of 0.0 V and 0.55 V (versus Ag AgCl) followed by potential pulsing between the same limits produced adherent films with a charge storage capacity of >25 mC/cm2. Characterization by cyclic voltammetry and impedance spectroscopy revealed no differences in the electrochemical behavior of EIROF on non-Ir substrates and AIROF. The mechanical stability of the oxides was evaluated by ultrasonication in distilled water followed by dehydration and rehydration. Stability under charge injection was evaluated using 200 micros, 5.9 A/cm2 (1.2 mC/cm2) cathodal pulses. Loss of iridium oxide charge capacity was comparable for AIROFs and the EIROFs, ranging from 1% to 8% of the capacity immediately after activation or deposition. The EIROFs were deposited and evaluated on silicon microprobe electrodes and on metallized polyimide electrodes being developed for neural recording and stimulation applications.

  15. Discovery of tantalum, rhenium, osmium, and iridium isotopes

    SciTech Connect

    Robinson, R.; Thoennessen, M.

    2012-09-15

    Currently, thirty-eight tantalum, thirty-eight rhenium, thirty-nine osmium, and thirty-eight iridium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  16. Remote Sensing Missions for Earth Observation on Iridium NEXT

    NASA Astrophysics Data System (ADS)

    Gupta, O. P.

    2009-12-01

    A unique opportunity exists to host up to 66 earth observation sensors on Iridium’s proposed NEXT LEO constellation in a manner that can revolutionize earth observation and weather predictions. A constellation approach to sensing, using the real-time communications backbone of Iridium, will enable unprecedented geospatial and temporal sampling for now-casting of weather on a global basis as well as global climate monitoring. The NEXT constellation, which, like Iridium’s current LEO constellation, is expected to consist of 66 interconnected satellites in 6 near polar orbiting planes, provides a unique platform for hosting a variety of earth observation missions. Several remote sensing missions were recommended by Group on Earth Observations (GEO), NASA, NOAA, and ESA for consideration by Iridium during 2008. These include GPS radio occultation sensors, earth radiation budget measurements, altimetry, ocean and land imaging, and troposphere and stratospheric winds measurements including polar winds measurements. These missions are also considered high priority climate missions by the Decadal Survey. Study teams consisting of Iridium, NASA/JPL and multiple industrial partners of Iridium have conducted detailed studies of these missions for compatibility with NEXT. These studies have established technical feasibility, unique benefits from a constellation approach, and cost effectiveness for these solutions on NEXT.

  17. The Iridium (tm) system: Personal communications anytime, anyplace

    NASA Astrophysics Data System (ADS)

    Hatlelid, John E.; Casey, Larry

    The Iridium system is designed to provide handheld personal communications between diverse locations around the world at any time and without prior knowledge of the location of the personal units. This paper provides an overview of the system, the services it provides, its operation, and an overview of the commercial practices and relatively high volume satellite production techniques which will make the system cost effective. A constellation of 66 satellites will provide an orbiting, spherical-shell, infrastructure for this global calling capability. The satellites act as tall cellular towers and allow convenient operation for portable handheld telephones. The system will provide a full range of services including voice, paging, data, geolocation, and fax capabilities. Motorola is a world leader in the production of high volume, high quality, reliable telecommunications hardware. One of Iridium's goals is to apply these production techniques to high reliability space hardware. Concurrent engineering, high performance work teams, advanced manufacturing technologies, and improved assembly and test methods are some of the techniques that will keep the Iridium system cost effective. Mobile, global, flexible personal communications are coming that will allow anyone to call or receive a call from/to anyplace at anytime. The Iridium system will provide communications where none exist today. This connectivity will allow increased information transfer, open new markets for various business endeavors, and in general increase productivity and development.

  18. Origins of Regioselectivity in Iridium Catalyzed Allylic Substitution.

    PubMed

    Madrahimov, Sherzod T; Li, Qian; Sharma, Ankit; Hartwig, John F

    2015-12-02

    Detailed studies on the origin of the regioselectivity for formation of branched products over linear products have been conducted with complexes containing the achiral triphenylphosphite ligand. The combination of iridium and P(OPh)3 was the first catalytic system shown to give high regioselectivity for the branched product with iridium and among the most selective for forming branched products among any combination of metal and ligand. We have shown the active catalyst to be generated from [Ir(COD)Cl]2 and P(OPh)3 by cyclometalation of the phenyl group on the ligand and have shown such species to be the resting state of the catalyst. A series of allyliridium complexes ligated by the resulting P,C ligand have been generated and shown to be competent intermediates in the catalytic system. We have assessed the potential impact of charge, metal-iridium bond length, and stability of terminal vs internal alkenes generated by attack at the branched and terminal positions of the allyl ligand, respectively. These factors do not distinguish the regioselectivity for attack on allyliridium complexes from that for attack on allylpalladium complexes. Instead, detailed computational studies suggest that a series of weak, attractive, noncovalent interactions, including interactions of H-bond acceptors with a vinyl C-H bond of the alkene ligand, favor formation of the branched product with the iridium catalyst. This conclusion underscores the importance of considering attractive interactions, as well as repulsive steric interactions, when seeking to rationalize selectivities.

  19. Mononuclear iridium dinitrogen complexes bonded to zeolite HY

    SciTech Connect

    Yang, Dong; Chen, Mingyang; Martinez-Macias, Claudia; Dixon, David A.; Gates, Bruce C.

    2014-11-07

    In this study, the adsorption of N2 on structurally well-defined dealuminated HY zeolite-supported iridium diethylene complexes was investigated. Iridium dinitrogen complexes formed when the sample was exposed to N2 in H2 at 298 K, as shown by infrared spectra recorded with isotopically labeled N2. Four supported species formed in various flowing gases: Ir(N2), Ir(N2)(N2), Ir(C2H5)(N2), and Ir(H)(N2). Their interconversions are summarized in a reaction network, showing, for example, that, in the presence of N2, Ir(N2) was the predominant dinitrogen species at temperatures of 273-373 K. Ir(CO)(N2) formed transiently in flowing CO, and in the presence of H2, rather stable iridium hydride complexes formed. Here, four structural models of each iridium complex bonded at the acidic sites of the zeolite were employed in a computational investigation, showing that the calculated vibrational frequencies agree well with experiment when full calculations are done at the level of density functional theory, independent of the size of the model of the zeolite.

  20. Iridium Aluminide Coats For Protection Against Ox idation

    NASA Technical Reports Server (NTRS)

    Kaplan, Richard B.; Tuffias, Robert H.; La Ferla, Raffaele; Jang, Qin

    1996-01-01

    Iridium aluminide coats investigated for use in protecting some metallic substrates against oxidation at high temperatures. Investigation prompted by need for cost-effective anti-oxidation coats for walls of combustion chambers in rocket engines. Also useful in special terrestrial applications like laboratory combustion chambers and some chemical-processing chambers.

  1. Iridium alloy Clad Vent Set manufacturing qualification studies

    NASA Astrophysics Data System (ADS)

    Ulrich, George B.

    Metallurgical qualification studies to demonstrate the manufacturing readiness of the iridium alloy Clad Vent Set (CVS) for the General Purpose Heat Source program at the Oak Ridge Y-12 Plant are described. Microstructural data for various materials/test conditions are presented.

  2. The Iridium (tm) system: Personal communications anytime, anyplace

    NASA Technical Reports Server (NTRS)

    Hatlelid, John E.; Casey, Larry

    1993-01-01

    The Iridium system is designed to provide handheld personal communications between diverse locations around the world at any time and without prior knowledge of the location of the personal units. This paper provides an overview of the system, the services it provides, its operation, and an overview of the commercial practices and relatively high volume satellite production techniques which will make the system cost effective. A constellation of 66 satellites will provide an orbiting, spherical-shell, infrastructure for this global calling capability. The satellites act as tall cellular towers and allow convenient operation for portable handheld telephones. The system will provide a full range of services including voice, paging, data, geolocation, and fax capabilities. Motorola is a world leader in the production of high volume, high quality, reliable telecommunications hardware. One of Iridium's goals is to apply these production techniques to high reliability space hardware. Concurrent engineering, high performance work teams, advanced manufacturing technologies, and improved assembly and test methods are some of the techniques that will keep the Iridium system cost effective. Mobile, global, flexible personal communications are coming that will allow anyone to call or receive a call from/to anyplace at anytime. The Iridium system will provide communications where none exist today. This connectivity will allow increased information transfer, open new markets for various business endeavors, and in general increase productivity and development.

  3. Utilization of Low Bandwidth Iridium Modems for Polar Seismology

    NASA Astrophysics Data System (ADS)

    Parker, T.

    2012-12-01

    Transmission of realtime seismic data is a desirable goal when a rapid response is needed. However, for many science applications sample waveform data, system state of health, and the ability to command and control the seismic station are operationally adequate. Determining the optimal telemetry requirements for a remote polar seismic experiment requires balancing science objective against the expensive, over-subscribed support available in the polar environments? For example there is a significant difference in the resources needed for a permanent "monitoring" effort versus a short-term experiment. We will describe IRIS/PASSCAL's successful approach to utilizing Iridium telemetry for short-term seismic experiments and suggest viable use of an Iridium RUDICs system for higher data-rate, permanent seismic stations such as a monitoring scenario. Most seismic stations are configured to record at a rate that exceeds twice the data rate of a single Iridium Internet modem. The power requirement to run continuous Iridium telemetry better than doubles that of a standalone seismic station. Doubling station power roughly doubles station logistics by requiring an increased number of support flights for installation and service. The tradeoffs between desirable and adequate telemetry requirements and the ramifications these requirements have on support services must be considered for a successful seismic station. We describe two Iridium telemetry systems, developed by the IRIS/PASSCAL Polar Program, for use with seismic stations in Antarctica and the Arctic. The first system uses an inexpensive Iridium 9602 modem based device and short burst data (SBD) transmission to monitor station performance, provide some command and control, and return a small amount of representative seismic data. Power requirements for this SBD system are approximately 10Ah per year for a daily message. The second system uses an Iridium 9522b modem based device the DOD RUDICs system for a 2400 Baud

  4. Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX

    SciTech Connect

    Purwaningsih, Anik

    2014-09-30

    Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.

  5. Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX

    NASA Astrophysics Data System (ADS)

    Purwaningsih, Anik

    2014-09-01

    Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.

  6. 49 CFR 174.112 - Loading Division 1.3 materials and Division 1.2 (explosive) materials (Also see § 174.101).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (explosive) materials (Also see § 174.101). 174.112 Section 174.112 Transportation Other Regulations... Division 1.3 materials and Division 1.2 (explosive) materials (Also see § 174.101). (a) Division 1.3... with spark shields (see § 174.104). Packages of Division 1.3 materials and Division 1.2...

  7. Network flexibility of the IRIDIUM (R) Global Mobile Satellite System

    NASA Technical Reports Server (NTRS)

    Hutcheson, Jonathan; Laurin, Mala

    1995-01-01

    The IRIDIUM system is a global personal communications system supported by a constellation of 66 low earth orbit (LEO) satellites and a collection of earth-based 'gateway' switching installations. Like traditional wireless cellular systems, coverage is achieved by a grid of cells in which bandwidth is reused for spectral efficiency. Unlike any cellular system ever built, the moving cells can be shared by multiple switching facilities. Noteworthy features of the IRIDIUM system include inter-satellite links, a GSM-based telephony architecture, and a geographically controlled system access process. These features, working in concert, permit flexible and reliable administration of the worldwide service area by gateway operators. This paper will explore this unique concept.

  8. Iridium alloy clad vent set manufacturing qualification studies

    NASA Astrophysics Data System (ADS)

    Ulrich, George B.

    1991-01-01

    Qualification studies have been successfully conducted to demonstrate iridium alloy Clad Vent Set (CVS) manufacturing readiness for the General Purpose Heat Source (GPHS) program at the Oak Ridge Y-12 Plant. These studies were joint comparison evaluations of both the Y-12 Plant and EG&G Mound G-MAT) products. Note: EG&G-MAT formerly manufactured the iridium alloy CVS. The comparison evaluations involved work in a number of areas; however, only the CVS cup metallurgical evalution will be presented here. The initial metallurgical comparisons in conjunction with follow-up metallurgical work showed the Y-12 Plant CVS product to be comparable to the fully qualified (for Galileo and Ulysses missions) EG&G-MAT product. This allowed the Y-12 Plant to commence pilot production of CVS components for potential use in the CRAF and CASSINI missions.

  9. Iridium-Catalyzed Asymmetric Hydrogenation of Unsaturated Carboxylic Acids.

    PubMed

    Zhu, Shou-Fei; Zhou, Qi-Lin

    2017-04-04

    Chiral carboxylic acid moieties are widely found in pharmaceuticals, agrochemicals, flavors, fragrances, and health supplements. Although they can be synthesized straightforwardly by transition-metal-catalyzed enantioselective hydrogenation of unsaturated carboxylic acids, because the existing chiral catalysts have various disadvantages, the development of new chiral catalysts with high activity and enantioselectivity is an important, long-standing challenge. Ruthenium complexes with chiral diphosphine ligands and rhodium complexes with chiral monodentate or bidentate phosphorus ligands have been the predominant catalysts for asymmetric hydrogenation of unsaturated acids. However, the efficiency of these catalysts is highly substrate-dependent, and most of the reported catalysts require a high loading, high hydrogen pressure, or long reaction time for satisfactory results. Our recent studies have revealed that chiral iridium complexes with chiral spiro-phosphine-oxazoline ligands and chiral spiro-phosphine-benzylamine ligands exhibit excellent activity and enantioselectivity in the hydrogenation of α,β-unsaturated carboxylic acids, including α,β-disubstituted acrylic acids, trisubstituted acrylic acids, α-substituted acrylic acids, and heterocyclic α,β-unsaturated acids. On the basis of an understanding of the role of the carboxy group in iridium-catalyzed asymmetric hydrogenation reactions, we developed a carboxy-group-directed strategy for asymmetric hydrogenation of olefins. Using this strategy, we hydrogenated several challenging olefin substrates, such as β,γ-unsaturated carboxylic acids, 1,1-diarylethenes, 1,1-dialkylethenes, and 1-alkyl styrenes in high yield and with excellent enantioselectivity. All these iridium-catalyzed asymmetric hydrogenation reactions feature high turnover numbers (up to 10000) and turnover frequencies (up to 6000 h(-1)), excellent enantioselectivities (greater than 95% ee with few exceptions), low hydrogen pressure (<12 atm

  10. Blistering during the atomic layer deposition of iridium

    SciTech Connect

    Genevée, Pascal E-mail: a.szeghalmi@uni-jena.de; Ahiavi, Ernest; Janunts, Norik; Pertsch, Thomas; Kley, Ernst-Bernhard; Szeghalmi, Adriana E-mail: a.szeghalmi@uni-jena.de; Oliva, Maria

    2016-01-15

    The authors report on the formation of blisters during the atomic layer deposition of iridium using iridium acetylacetonate and oxygen precursors. Films deposited on fused silica substrates led to sparsely distributed large blisters while in the case of silicon with native oxide additional small blisters with a high density was observed. It is found that the formation of blisters is favored by a higher deposition temperature and a larger layer thickness. Postdeposition annealing did not have a significant effect on the formation of blisters. Finally, changing purge duration during the film growth allowed us to avoid blistering and evidenced that impurities released from the film in gas phase were responsible for the formation of blisters.

  11. Iridium-Doped Ruthenium Oxide Catalyst for Oxygen Evolution

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Narayan, Sri R.; Billings, Keith J.

    2011-01-01

    NASA requires a durable and efficient catalyst for the electrolysis of water in a polymer-electrolyte-membrane (PEM) cell. Ruthenium oxide in a slightly reduced form is known to be a very efficient catalyst for the anodic oxidation of water to oxygen, but it degrades rapidly, reducing efficiency. To combat this tendency of ruthenium oxide to change oxidation states, it is combined with iridium, which has a tendency to stabilize ruthenium oxide at oxygen evolution potentials. The novel oxygen evolution catalyst was fabricated under flowing argon in order to allow the iridium to preferentially react with oxygen from the ruthenium oxide, and not oxygen from the environment. Nanoparticulate iridium black and anhydrous ruthenium oxide are weighed out and mixed to 5 18 atomic percent. They are then heat treated at 300 C under flowing argon (in order to create an inert environment) for a minimum of 14 hours. This temperature was chosen because it is approximately the creep temperature of ruthenium oxide, and is below the sintering temperature of both materials. In general, the temperature should always be below the sintering temperature of both materials. The iridium- doped ruthenium oxide catalyst is then fabricated into a PEM-based membrane- electrode assembly (MEA), and then mounted into test cells. The result is an electrolyzer system that can sustain electrolysis at twice the current density, and at the same efficiency as commercial catalysts in the range of 100-200 mA/sq cm. At 200 mA/sq cm, this new system operates at an efficiency of 85 percent, which is 2 percent greater than commercially available catalysts. Testing has shown that this material is as stable as commercially available oxygen evolution catalysts. This means that this new catalyst can be used to regenerate fuel cell systems in space, and as a hydrogen generator on Earth.

  12. 46 CFR 174.045 - Intact stability requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... plotted on GRAPH 174.045, define areas that satisfy the equation: Area(A)≥(K)×(Area (B)) where— (1) K=1.4 except that if the unit is a column stabilized unit K=1.3; (2) Area (A) is the area on GRAPH 174.045... downflooding would occur, whichever angle is less; and (3) Area (B) is the area on GRAPH 174.045 under the...

  13. 46 CFR 174.045 - Intact stability requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... plotted on GRAPH 174.045, define areas that satisfy the equation: Area(A)≥(K)×(Area (B)) where— (1) K=1.4 except that if the unit is a column stabilized unit K=1.3; (2) Area (A) is the area on GRAPH 174.045... downflooding would occur, whichever angle is less; and (3) Area (B) is the area on GRAPH 174.045 under the...

  14. 46 CFR 174.045 - Intact stability requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... plotted on GRAPH 174.045, define areas that satisfy the equation: Area(A)≥(K)×(Area (B)) where— (1) K=1.4 except that if the unit is a column stabilized unit K=1.3; (2) Area (A) is the area on GRAPH 174.045... downflooding would occur, whichever angle is less; and (3) Area (B) is the area on GRAPH 174.045 under the...

  15. 46 CFR 174.045 - Intact stability requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... plotted on GRAPH 174.045, define areas that satisfy the equation: Area(A)≥(K)×(Area (B)) where— (1) K=1.4 except that if the unit is a column stabilized unit K=1.3; (2) Area (A) is the area on GRAPH 174.045... downflooding would occur, whichever angle is less; and (3) Area (B) is the area on GRAPH 174.045 under the...

  16. 46 CFR 174.045 - Intact stability requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... plotted on GRAPH 174.045, define areas that satisfy the equation: Area(A)≥(K)×(Area (B)) where— (1) K=1.4 except that if the unit is a column stabilized unit K=1.3; (2) Area (A) is the area on GRAPH 174.045... downflooding would occur, whichever angle is less; and (3) Area (B) is the area on GRAPH 174.045 under the...

  17. Sputtered iridium oxide films (SIROFs) for neural stimulation electrodes

    PubMed Central

    Cogan, Stuart F.; Ehrlich, Julia; Plante, Timothy D.; Smirnov, Anton; Shire, Douglas B.; Gingerich, Marcus; Rizzo, Joseph F.

    2009-01-01

    Sputtered iridium oxide films (SIROFs) deposited by DC reactive sputtering from an iridium metal target have been characterized in vitro for their potential as neural recording and stimulation electrodes. SIROFs were deposited over gold metallization on flexible multielectrode arrays fabricated on thin (15 µm) polyimide substrates. SIROF thickness and electrode areas of 200–1300 nm and 1960–125600 µm2, respectively, were investigated. The charge-injection capacities of the SIROFs were evaluated in an inorganic interstitial fluid model in response to charge-balanced, cathodal-first current pulses. Charge injection capacities were measured as a function of cathodal pulse width (0.2 – 1 ms) and potential bias in the interpulse period (0.0 to 0.7 V vs. Ag|AgCl). Depending on the pulse parameters and electrode area, charge-injection capacities ranged from 1–9 mC/cm2, comparable with activated iridium oxide films (AIROFs) pulsed under similar conditions. Other parameters relevant to the use of SIROF on nerve electrodes, including the thickness dependence of impedance (0.05–105 Hz) and the current necessary to maintain a bias in the interpulse region were also determined. PMID:17271216

  18. Mononuclear iridium dinitrogen complexes bonded to zeolite HY

    DOE PAGES

    Yang, Dong; Chen, Mingyang; Martinez-Macias, Claudia; ...

    2014-11-07

    In this study, the adsorption of N2 on structurally well-defined dealuminated HY zeolite-supported iridium diethylene complexes was investigated. Iridium dinitrogen complexes formed when the sample was exposed to N2 in H2 at 298 K, as shown by infrared spectra recorded with isotopically labeled N2. Four supported species formed in various flowing gases: Ir(N2), Ir(N2)(N2), Ir(C2H5)(N2), and Ir(H)(N2). Their interconversions are summarized in a reaction network, showing, for example, that, in the presence of N2, Ir(N2) was the predominant dinitrogen species at temperatures of 273-373 K. Ir(CO)(N2) formed transiently in flowing CO, and in the presence of H2, rather stable iridiummore » hydride complexes formed. Here, four structural models of each iridium complex bonded at the acidic sites of the zeolite were employed in a computational investigation, showing that the calculated vibrational frequencies agree well with experiment when full calculations are done at the level of density functional theory, independent of the size of the model of the zeolite.« less

  19. Mono- and bis-tolylterpyridine iridium(III) complexes

    SciTech Connect

    Hinkle, Lindsay M.; Young, Jr., Victor G.; Mann, Kent R.

    2012-01-20

    The first structure report of trichlorido[4'-(p-tolyl)-2,2':6',2{double_prime}-terpyridine]iridium(III) dimethyl sulfoxide solvate, [IrCl{sub 3}(C{sub 22}H{sub 17}N{sub 3})] {center_dot} C{sub 2}H{sub 6}OS, (I), is presented, along with a higher-symmetry setting of previously reported bis[4'-(p-tolyl)-2,2':6',2{double_prime}-terpyridine]iridium(III) tris(hexafluoridophosphate) acetonitrile disolvate, [Ir(C{sub 22}H{sub 17}N{sub 3})2](PF{sub 6}){sub 3} {center_dot} 2C{sub 2}H{sub 3}N, (II) [Yoshikawa, Yamabe, Kanehisa, Kai, Takashima & Tsukahara (2007). Eur. J. Inorg. Chem. pp. 1911-1919]. For (I), the data were collected with synchrotron radiation and the dimethyl sulfoxide solvent molecule is disordered over three positions, one of which is an inversion center. The previously reported structure of (II) is presented in the more appropriate C2/c space group. The iridium complex and one PF{sub 6}{sup -} anion lie on twofold axes in this structure, making half of the molecule unique.

  20. Evaluation of Molybdenum as a Surrogate for Iridium in the GPHS Weld Development

    SciTech Connect

    Stine, Andrew Martin; Pierce, Stanley W.; Moniz, Paul F.

    2015-10-17

    The welding equipment used for welding iridium containers (clads) at Los Alamos National Laboratory is twenty five years old and is undergoing an upgrade. With the upgrade, there is a requirement for requalification of the welding process, and the opportunity for process improvement. Testing of the new system and requalification will require several welds on iridium test parts and clads, and any efforts to improve the process will add to the need for iridium parts. The extreme high cost of iridium imposes a severe limitation on the extent of test welding that can be done. The 2 inch diameter, 0.027 inch thick, iridium blank disc that the clad cup is formed from, is useful for initial weld trials, but it costs $5000. The development clad sets needed for final tests and requalification cost $15,000 per set. A solution to iridium cost issue would be to do the majority of the weld development on a less expensive surrogate metal with similar weld characteristics. One such metal is molybdenum. Since its melting index (melting temperature x thermal conductivity) is closest to iridium, welds on molybdenum should be similar in size for a given weld power level. Molybdenum is inexpensive; a single 2 inch molybdenum disc costs only $9. In order to evaluate molybdenum as a surrogate for iridium, GTA welds were first developed to provide full penetration on 0.030 inch thick molybdenum discs at speeds of 20, 25, and 30 inches per minute (ipm). These weld parameters were then repeated on the standard 0.027 inch thick iridium blanks. The top surface and bottom surface (root) width and grain structure of the molybdenum and iridium welds were compared, and similarities were evident between the two metals. Due to material and thickness differences, the iridium welds were approximately 35% wider than the molybdenum welds. A reduction in iridium weld current of 35% produce welds slightly smaller than the molybdenum welds yet showed that current could be scaled according to molybdenum/iridium

  1. Rockot Launch Vehicle Commercial Operations for Grace and Iridium Program

    NASA Astrophysics Data System (ADS)

    Viertel, Y.; Kinnersley, M.; Schumacher, I.

    2002-01-01

    The GRACE mission and the IRIDIUM mission on ROCKOT launch vehicle are presented. Two identical GRACE satellites to measure in tandem the gravitational field of the earth with previously unattainable accuracy - it's called the Gravity Research and Climate Experiment, or and is a joint project of the U.S. space agency, NASA and the German Centre for Aeronautics and Space Flight, DLR. In order to send the GRACE twins into a 500x500 km , 89deg. orbit, the Rockot launch vehicle was selected. A dual launch of two Iridium satellites was scheduled for June 2002 using the ROCKOT launch vehicle from Plesetsk Cosmodrome in Northern Russia. This launch will inject two replacement satellites into a low earth orbit (LEO) to support the maintenance of the Iridium constellation. In September 2001, Eurockot successfully carried out a "Pathfinder Campaign" to simulate the entire Iridium mission cycle at Plesetsk. The campaign comprised the transport of simulators and related equipment to the Russian port-of-entry and launch site and also included the integration and encapsulation of the simulators with the actual Rockot launch vehicle at Eurockot's dedicated launch facilities at Plesetsk Cosmodrome. The pathfinder campaign lasted four weeks and was carried out by a joint team that also included Khrunichev, Russian Space Forces and Eurockot personnel on the contractors' side. The pathfinder mission confirmed the capability of Eurockot Launch Services to perform the Iridium launch on cost and on schedule at Plesetsk following Eurockot's major investment in international standard preparation, integration and launch facilities including customer facilities and a new hotel. In 2003, Eurockot will also launch the Japanese SERVI'S-1 satellite for USEF. The ROCKOT launch vehicle is a 3 stage liquid fuel rocket whose first 2 stages have been adapted from the Russian SS-19. A third stage, called "Breeze", can be repeatedly ignited and is extraordinarily capable of manoeuvre. Rockot can place

  2. Development and Testing of High Surface Area Iridium Anodes for Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Shchetkovskiy, Anatoliy; McKechnie, Timothy; Sadoway, Donald R.; Paramore, James; Melendez, Orlando; Curreri, Peter A.

    2010-01-01

    Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith is an attractive method of processing, because no additional chemical reagents are needed. The electrochemical processing of molten oxides requires high surface area, inert anodes. Such electrodes need to be structurally robust at elevated temperatures (1400-1600?C), be resistant to thermal shock, have good electrical conductivity, be resistant to attack by molten oxide (silicate), be electrochemically stable and support high current density. Iridium with its high melting point, good oxidation resistance, superior high temperature strength and ductility is the most promising candidate for anodes in high temperature electrochemical processes. Several innovative concepts for manufacturing such anodes by electrodeposition of iridium from molten salt electrolyte (EL-Form? process) were evaluated. Iridium electrodeposition to form of complex shape components and coating was investigated. Iridium coated graphite, porous iridium structure and solid iridium anodes were fabricated. Testing of electroformed iridium anodes shows no visible degradation. The result of development, manufacturing and testing of high surface, inert iridium anodes will be presented.

  3. Real-Time Characterization of Formation and Breakup of Iridium Clusters in Highly Dealuminated Zeolite Y

    SciTech Connect

    Uzun, Alper; Gates, Bruce C.

    2009-01-15

    The chemistry of formation of iridium clusters from mononuclear iridium diethylene complexes anchored in dealuminated Y zeolite, and their subsequent breakup -- all including changes in the metal-metal, metal-support, and metal-ligand interactions -- is demonstrated by time-resolved EXAFS, XANES, and IR spectroscopy.

  4. Development and Testing of High Surface Area Iridium Anodes for Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Shchetkovskiy, Anatoliy; McKechnie, Timothy; Sadoway, Donald R.; Paramore, James; Melendez, Orlando; Curreri, Peter A.

    2010-01-01

    Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith is an attractive method of processing, because no additional chemical reagents are needed. The electrochemical processing of molten oxides requires high surface area, inert anodes. Such electrodes need to be structurally robust at elevated temperatures (1400-1600 C), be resistant to thermal shock, have good electrical conductivity, be resistant to attack by molten oxide (silicate), be electrochemically stable and support high current density. Iridium with its high melting point, good oxidation resistance, superior high temperature strength and ductility is the most promising candidate for anodes in high temperature electrochemical processes. Several innovative concepts for manufacturing such anodes by electrodeposition of iridium from molten salt electrolyte (EL-Form process) were evaluated. Iridium electrodeposition to form of complex shape components and coating was investigated. Iridium coated graphite, porous iridium structure and solid iridium anodes were fabricated. Testing of electroformed iridium anodes shows no visible degradation. The result of development, manufacturing and testing of high surface, inert iridium anodes will be presented.

  5. 46 CFR 160.174-3 - Incorporation by reference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus—160.174-17 ASTM C 518-91, Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus—160.174-17 ASTM D 975-98,...

  6. 27 CFR 53.174 - Determination of price readjustments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... paid to a manufacturer's own agents or salesperson for selling the manufacturer's taxable products are... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Determination of price readjustments. 53.174 Section 53.174 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND...

  7. 46 CFR 174.195 - Bulkheads in machinery spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Bulkheads in machinery spaces. 174.195 Section 174.195... in machinery spaces. (a) The bulkhead in each machinery space of each OSV must be watertight to the bulkhead deck. (b) Each penetration of, and each opening in, a bulkhead in a machinery space must— (1)...

  8. 46 CFR 174.195 - Bulkheads in machinery spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Bulkheads in machinery spaces. 174.195 Section 174.195... in machinery spaces. (a) The bulkhead in each machinery space of each OSV must be watertight to the bulkhead deck. (b) Each penetration of, and each opening in, a bulkhead in a machinery space must— (1)...

  9. 46 CFR 174.195 - Bulkheads in machinery spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Bulkheads in machinery spaces. 174.195 Section 174.195... in machinery spaces. (a) The bulkhead in each machinery space of each OSV must be watertight to the bulkhead deck. (b) Each penetration of, and each opening in, a bulkhead in a machinery space must— (1)...

  10. 49 CFR 174.201 - Class 2 (gases) material cylinders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Class 2 (gases) material cylinders. 174.201... RAIL Detailed Requirements for Class 2 (Gases) Materials § 174.201 Class 2 (gases) material cylinders. (a) Except as provided in paragraphs (b) and (c) of this section, cylinders containing Class 2...

  11. 49 CFR 174.201 - Class 2 (gases) material cylinders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Class 2 (gases) material cylinders. 174.201... RAIL Detailed Requirements for Class 2 (Gases) Materials § 174.201 Class 2 (gases) material cylinders. (a) Except as provided in paragraphs (b) and (c) of this section, cylinders containing Class 2...

  12. 49 CFR 174.201 - Class 2 (gases) material cylinders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Class 2 (gases) material cylinders. 174.201... RAIL Detailed Requirements for Class 2 (Gases) Materials § 174.201 Class 2 (gases) material cylinders. (a) Except as provided in paragraphs (b) and (c) of this section, cylinders containing Class 2...

  13. 49 CFR 174.201 - Class 2 (gases) material cylinders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Class 2 (gases) material cylinders. 174.201... RAIL Detailed Requirements for Class 2 (Gases) Materials § 174.201 Class 2 (gases) material cylinders. (a) Except as provided in paragraphs (b) and (c) of this section, cylinders containing Class 2...

  14. 49 CFR 174.201 - Class 2 (gases) material cylinders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Class 2 (gases) material cylinders. 174.201... RAIL Detailed Requirements for Class 2 (Gases) Materials § 174.201 Class 2 (gases) material cylinders. (a) Except as provided in paragraphs (b) and (c) of this section, cylinders containing Class 2...

  15. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. Link to an amendment... antenna structure that requires notice of proposed construction to the Federal Aviation...

  16. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1, 1996, the owner of any proposed or existing antenna structure that requires notice of proposed...

  17. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1, 1996, the owner of any proposed or existing antenna structure that requires notice of proposed...

  18. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1, 1996, the owner of any proposed or existing antenna structure that requires notice of proposed...

  19. 40 CFR 60.174 - Standard for visible emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for visible emissions. 60.174 Section 60.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary...

  20. 40 CFR 60.174 - Standard for visible emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for visible emissions. 60.174 Section 60.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary...

  1. 40 CFR 60.174 - Standard for visible emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for visible emissions. 60.174 Section 60.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary...

  2. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Maximum allowable operating speed. 174.86 Section 174.86 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY...

  3. 46 CFR 174.065 - Damage stability requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Damage stability requirements. (a) Each unit must be designed so that, while in each of its normal... second). (b) Each unit must have a means to close off each pipe, ventilation system, and trunk in each compartment described in § 174.080 or § 174.085 if any portion of the pipe, ventilation system, or trunk...

  4. 46 CFR 174.065 - Damage stability requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Damage stability requirements. (a) Each unit must be designed so that, while in each of its normal... second). (b) Each unit must have a means to close off each pipe, ventilation system, and trunk in each compartment described in § 174.080 or § 174.085 if any portion of the pipe, ventilation system, or trunk...

  5. 42 CFR 84.174 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.174... Air-Purifying Particulate Respirators § 84.174 Respirator containers; minimum requirements. (a) Except..., durable container bearing markings which show the applicant's name, the type of respirator it...

  6. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  7. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  8. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  9. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  10. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  11. 21 CFR 14.174 - Advice and recommendations in writing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Advice and recommendations in writing. 14.174... § 14.174 Advice and recommendations in writing. Advice and recommendations given by a committee on a... of the advice and recommendations of the committee....

  12. 21 CFR 14.174 - Advice and recommendations in writing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Advice and recommendations in writing. 14.174... § 14.174 Advice and recommendations in writing. Advice and recommendations given by a committee on a... of the advice and recommendations of the committee....

  13. 21 CFR 14.174 - Advice and recommendations in writing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Advice and recommendations in writing. 14.174... § 14.174 Advice and recommendations in writing. Advice and recommendations given by a committee on a... of the advice and recommendations of the committee....

  14. 21 CFR 14.174 - Advice and recommendations in writing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Advice and recommendations in writing. 14.174... § 14.174 Advice and recommendations in writing. Advice and recommendations given by a committee on a... of the advice and recommendations of the committee....

  15. 46 CFR 174.215 - Drainage of weather deck.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Drainage of weather deck. 174.215 Section 174.215 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... weather deck. The weather deck must have open rails to allow rapid clearing of water, or must have...

  16. 46 CFR 174.215 - Drainage of weather deck.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Drainage of weather deck. 174.215 Section 174.215 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... weather deck. The weather deck must have open rails to allow rapid clearing of water, or must have...

  17. 46 CFR 174.215 - Drainage of weather deck.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Drainage of weather deck. 174.215 Section 174.215 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... weather deck. The weather deck must have open rails to allow rapid clearing of water, or must have...

  18. 46 CFR 174.215 - Drainage of weather deck.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Drainage of weather deck. 174.215 Section 174.215 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... weather deck. The weather deck must have open rails to allow rapid clearing of water, or must have...

  19. 46 CFR 174.215 - Drainage of weather deck.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Drainage of weather deck. 174.215 Section 174.215 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES... weather deck. The weather deck must have open rails to allow rapid clearing of water, or must have...

  20. 7 CFR 1260.173-1260.174 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false 1260.173-1260.174 Section 1260.173-1260.174 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE BEEF PROMOTION AND RESEARCH...

  1. 21 CFR 14.174 - Advice and recommendations in writing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Advice and recommendations in writing. 14.174... § 14.174 Advice and recommendations in writing. Advice and recommendations given by a committee on a... of the advice and recommendations of the committee....

  2. 46 CFR 174.210 - Watertight doors in watertight bulkheads.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Watertight doors in watertight bulkheads. 174.210... Vessels § 174.210 Watertight doors in watertight bulkheads. (a) This section applies to each vessel with watertight doors in bulkheads made watertight in compliance with this chapter. (b) Except as provided...

  3. 46 CFR 174.210 - Watertight doors in watertight bulkheads.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Watertight doors in watertight bulkheads. 174.210... Vessels § 174.210 Watertight doors in watertight bulkheads. (a) This section applies to each vessel with watertight doors in bulkheads made watertight in compliance with this chapter. (b) Except as provided...

  4. 40 CFR 429.174 - New source performance standards (NSPS).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards (NSPS). 429.174 Section 429.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Wood Furniture...

  5. 40 CFR 429.174 - New source performance standards (NSPS).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards (NSPS). 429.174 Section 429.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Wood Furniture and...

  6. 40 CFR 429.174 - New source performance standards (NSPS).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards (NSPS). 429.174 Section 429.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Wood Furniture...

  7. 46 CFR 174.070 - General damage stability assumptions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false General damage stability assumptions. 174.070 Section 174.070 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  8. 46 CFR 174.075 - Compartments assumed flooded: general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Compartments assumed flooded: general. 174.075 Section 174.075 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  9. 46 CFR 174.085 - Flooding on column stabilized units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Flooding on column stabilized units. 174.085 Section 174.085 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  10. 46 CFR 174.070 - General damage stability assumptions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false General damage stability assumptions. 174.070 Section 174.070 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  11. 46 CFR 174.050 - Stability on bottom.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Stability on bottom. 174.050 Section 174.050 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units §...

  12. 46 CFR 174.075 - Compartments assumed flooded: general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments assumed flooded: general. 174.075 Section 174.075 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore...

  13. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Applicability to EPA proceedings. 17.4... ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to EPA proceedings. The Act applies to an adversary adjudication pending before EPA at any time between October...

  14. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Applicability to EPA proceedings. 17.4... ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to EPA proceedings. The Act applies to an adversary adjudication pending before EPA at any time between October...

  15. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Applicability to EPA proceedings. 17.4... ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to EPA proceedings. The Act applies to an adversary adjudication pending before EPA at any time between October...

  16. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Applicability to EPA proceedings. 17.4... ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to EPA proceedings. The Act applies to an adversary adjudication pending before EPA at any time between October...

  17. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Applicability to EPA proceedings. 17.4... ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to EPA proceedings. The Act applies to an adversary adjudication pending before EPA at any time between October...

  18. 46 CFR 154.174 - Transverse contiguous hull structure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Transverse contiguous hull structure. 154.174 Section... Equipment Hull Structure § 154.174 Transverse contiguous hull structure. (a) The transverse contiguous hull structure of a vessel having cargo containment systems without secondary barriers must meet the standards...

  19. 46 CFR 174.207 - Damaged stability criteria.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this... centerline, at the level of the deepest load waterline. Table 174.207(b)—Permeability of Spaces Spaces and tanks Permeability Storerooms 60 percent. Accommodations 95 percent. Machinery 85 percent. Voids...

  20. 46 CFR 174.207 - Damaged stability criteria.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this... centerline, at the level of the deepest load waterline. Table 174.207(b)—Permeability of Spaces Spaces and tanks Permeability Storerooms 60 percent. Accommodations 95 percent. Machinery 85 percent. Voids...

  1. 40 CFR 429.174 - New source performance standards (NSPS).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). 429.174 Section 429.174 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Wood Furniture and...

  2. 46 CFR 174.315 - Extent and character of damage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... must assume the most disabling side penetration with the damage collision penetration provided by Table 174.315, except that if the most disabling damage collision penetrations would be less than those provided by Table 174.315, the smaller damage collision penetration must be assumed. Table...

  3. 46 CFR 174.315 - Extent and character of damage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... must assume the most disabling side penetration with the damage collision penetration provided by Table 174.315, except that if the most disabling damage collision penetrations would be less than those provided by Table 174.315, the smaller damage collision penetration must be assumed. Table...

  4. 46 CFR 174.315 - Extent and character of damage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... must assume the most disabling side penetration with the damage collision penetration provided by Table 174.315, except that if the most disabling damage collision penetrations would be less than those provided by Table 174.315, the smaller damage collision penetration must be assumed. Table...

  5. 46 CFR 174.315 - Extent and character of damage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... must assume the most disabling side penetration with the damage collision penetration provided by Table 174.315, except that if the most disabling damage collision penetrations would be less than those provided by Table 174.315, the smaller damage collision penetration must be assumed. Table...

  6. 46 CFR 174.315 - Extent and character of damage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... must assume the most disabling side penetration with the damage collision penetration provided by Table 174.315, except that if the most disabling damage collision penetrations would be less than those provided by Table 174.315, the smaller damage collision penetration must be assumed. Table...

  7. 46 CFR 174.195 - Bulkheads in machinery spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Bulkheads in machinery spaces. 174.195 Section 174.195... in machinery spaces. (a) The bulkhead in each machinery space of each OSV must be watertight to the bulkhead deck. (b) Each penetration of, and each opening in, a bulkhead in a machinery space must— (1)...

  8. 46 CFR 174.195 - Bulkheads in machinery spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Bulkheads in machinery spaces. 174.195 Section 174.195... in machinery spaces. (a) The bulkhead in each machinery space of each OSV must be watertight to the bulkhead deck. (b) Each penetration of, and each opening in, a bulkhead in a machinery space must— (1)...

  9. 50 CFR 218.174 - Requirements for monitoring and reporting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... 218.174 Section 218.174 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... monitor HFAS and MFAS respectively at the DBRC Range site. (ii) For specified events, shore-based and vessel surveys shall be used 1 day prior to and 1-2 days post activity. (A) Shore-based Surveys:...

  10. Sensitized near-infrared emission from ytterbium(III) via direct energy transfer from iridium(III) in a heterometallic neutral complex.

    PubMed

    Mehlstäubl, Marita; Kottas, Gregg S; Colella, Silvia; De Cola, Luisa

    2008-05-14

    A tetrametallic iridium-ytterbium complex has been synthesised that shows sensitized near-infrared emission (lambda(max) = 976 nm) upon excitation of the iridium unit in the visible region (400 nm) due to efficient energy transfer from the iridium units to the Yb(III) ion. The iridium phosphorescence is quenched nearly quantitatively while the ytterbium ion emits brightly in the NIR.

  11. Sputtered iridium oxide films (SIROFs) for low-impedance neural stimulation and recording electrodes.

    PubMed

    Cogan, S F; Plante, T D; Ehrlich, J

    2004-01-01

    Iridium oxide films formed by electrochemical activation of iridium metal (AIROF) or by electrochemical deposition (EIROF) are being evaluated as low-impedance charge-injection coatings for neural stimulation and recording. Iridium oxide may also be deposited by reactive sputtering from iridium metal in an oxidizing plasma. The characterization of sputtered iridium oxide films (SIROFs) as coatings for nerve electrodes is reported. SIROFs were characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and potential transient measurements during charge-injection. The surface morphology of the SIROF transitions from smooth to highly nodular with increasing film thickness from 80 nm to 4600 nm. Charge-injection capacities exceed 0.75 mC/cm(2) with 0.75 ms current pulses in thicker films. The SIROF was deposited on both planar and non-planar substrates and photolithographically patterned by lift-off.

  12. Iridium-based double perovskites for efficient water oxidation in acid media

    NASA Astrophysics Data System (ADS)

    Diaz-Morales, Oscar; Raaijman, Stefan; Kortlever, Ruud; Kooyman, Patricia J.; Wezendonk, Tim; Gascon, Jorge; Fu, W. T.; Koper, Marc T. M.

    2016-08-01

    The development of active, cost-effective and stable oxygen-evolving catalysts is one of the major challenges for solar-to-fuel conversion towards sustainable energy generation. Iridium oxide exhibits the best available compromise between catalytic activity and stability in acid media, but it is prohibitively expensive for large-scale applications. Therefore, preparing oxygen-evolving catalysts with lower amounts of the scarce but active and stable iridium is an attractive avenue to overcome this economical constraint. Here we report on a class of oxygen-evolving catalysts based on iridium double perovskites which contain 32 wt% less iridium than IrO2 and yet exhibit a more than threefold higher activity in acid media. According to recently suggested benchmarking criteria, the iridium double perovskites are the most active catalysts for oxygen evolution in acid media reported until now, to the best of our knowledge, and exhibit similar stability to IrO2.

  13. Iridium-based double perovskites for efficient water oxidation in acid media

    PubMed Central

    Diaz-Morales, Oscar; Raaijman, Stefan; Kortlever, Ruud; Kooyman, Patricia J.; Wezendonk, Tim; Gascon, Jorge; Fu, W. T.; Koper, Marc T. M.

    2016-01-01

    The development of active, cost-effective and stable oxygen-evolving catalysts is one of the major challenges for solar-to-fuel conversion towards sustainable energy generation. Iridium oxide exhibits the best available compromise between catalytic activity and stability in acid media, but it is prohibitively expensive for large-scale applications. Therefore, preparing oxygen-evolving catalysts with lower amounts of the scarce but active and stable iridium is an attractive avenue to overcome this economical constraint. Here we report on a class of oxygen-evolving catalysts based on iridium double perovskites which contain 32 wt% less iridium than IrO2 and yet exhibit a more than threefold higher activity in acid media. According to recently suggested benchmarking criteria, the iridium double perovskites are the most active catalysts for oxygen evolution in acid media reported until now, to the best of our knowledge, and exhibit similar stability to IrO2. PMID:27498694

  14. Iridium: Global OTH data communications for high altitude scientific ballooning

    NASA Astrophysics Data System (ADS)

    Denney, A.

    beneficial points provided by the Iridium platform include pure global accessibility (as well as polar), cost effectiveness because it is available as a COTS (Commercially Off The Shelf) technology, reliability in that the equipment must operate in extreme conditions (near space), integration and development time into current systems must be minimized. As a bonus Motorola and NAL Research Corporation are developing SBD (Short Burst Data) into the Iridium network. This may lead the way to a global IP (Internet Protocol) node based ballooning platform. The Iridium satellite data modems employ the Iridium Low-Earth Orbit (LEO) satellite network. The scope of this paper is to introduce an OTH communications alternative, albeit not necessarily a primary one, to existing ballooning platforms using COTS based emerging technologies. Design aspects, characteristics, actual flight testing statistics, principles of the Iridium modems and communication paths are described including payload and support instrumentation interfacing. Not limited to high altitude ballooning, the Iridium communications platform opens a new era in remote commanding and data retrieval.

  15. Bias-enhanced nucleation of diamond on iridium: A comprehensive study of the first stages by sequential surface analysis

    NASA Astrophysics Data System (ADS)

    Chavanne, A.; Arnault, J.-C.; Barjon, J.; Arabski, J.

    2011-03-01

    The chemical evolution of the iridium surface along the successive steps of BEN was investigated using electron spectroscopy techniques (XPS, AES). To this end, a sequential study was carried out in an UHV analysis chamber connected to a MPCVD reactor. First, experimental results were obtained on iridium surfaces exposed to a methane plasma without bias. They show a sp 2 carbon layer formation on iridium, probably due to the segregation during cooling of carbon solubilized at high temperature in iridium. In this scenario, the iridium surface would be uncovered by carbon as BEN starts. Then, the consequences of BEN were observed: (i) formation of a thicker carbon layer at the iridium surface due to carbon segregation and sub-implantation (ii) chemical modification of iridium neighboring within the first nanometers; (iii) diamond nucleation.

  16. Luminescent iridium(III) complexes as novel protein staining agents.

    PubMed

    Jia, Junli; Fei, Hao; Zhou, Ming

    2012-05-01

    This article reports a new class of luminescent metal complexes, biscyclometalated iridium(III) complexes with an ancillary bathophenanthroline disulfonate ligand, for staining protein bands that are separated by electrophoresis. The performances of these novel staining agents have been studied in comparison with tris(bathophenanthroline disulfonate) ruthenium(II) tetrasodium salt (i.e. RuBPS) using a commercially available imaging system. The staining agents showed different limits of detection, linear dynamic ranges, and protein-to-protein variations. The overall performances of all three stains were found to be better than or equivalent to RuBPS under the experimental conditions.

  17. Broadband iridium wire grid polarizer for UV applications.

    PubMed

    Weber, Thomas; Käsebier, Thomas; Kley, Ernst-Bernhard; Tünnermann, Andreas

    2011-02-15

    In this Letter, we present an iridium wire grid polarizer with a large spectral working range from IR down to the UV spectral region. The required grating period of 100 nm for an application below a wavelength of 300 nm was realized using a spatial frequency doubling technique based on ultrafast electron beam writing. The optical performance of the polarizer at a wavelength of 300 nm is a transmittance of almost 60% and an extinction ratio of about 30 (15 dB). Furthermore, the oxidation resistance is discussed.

  18. Determination of iridium in mafic rocks by atomic absorption

    USGS Publications Warehouse

    Grimaldi, F.S.; Schnepfe, M.M.

    1970-01-01

    Iridium is determined in mineralized mafic rocks by atomic absorption after fire-assay concentration into a gold bead. Interelement interferences in the atomic-absorption determination are removed and Ir sensitivity is increased by buffering the solutions with a mixture of copper and sodium sulphates. Substantial amounts of Ag, Al, Au, Bi, Ca, Cd, Co, Cr, Fe, Ho, Hg, K, La, Mg, Mn, Mo, Ni, Pb, Te, Ti, V, Y, Zn and platinum metals can be tolerated in the atomic-absorption determination. The sensitivity and detection limits are 3.2 and 0.25 ppm of Ir, respectively. ?? 1970.

  19. Luminescent cyclometallated iridium(III) complexes having acetylide ligands

    DOEpatents

    Thompson, Mark E.; Bossi, Alberto; Djurovich, Peter Ivan

    2014-09-02

    The present invention relates to phosphorescent (triplet-emitting) organometallic materials. The phosphorescent materials of the present invention comprise Ir(III)cyclometallated alkynyl complexes for use as triplet light-emitting materials. The Ir(III)cyclometallated alkynyl complexes comprise at least one cyclometallating ligand and at least one alkynyl ligand bonded to the iridium. Also provided is an organic light emitting device comprising an anode, a cathode and an emissive layer between the anode and the cathode, wherein the emissive layer comprises a Ir(III)cyclometallated alkynyl complex as a triplet emitting material.

  20. Iridium-catalyzed reductive nitro-Mannich cyclization.

    PubMed

    Gregory, Alex W; Chambers, Alan; Hawkins, Alison; Jakubec, Pavol; Dixon, Darren J

    2015-01-02

    A new chemoselective reductive nitro-Mannich cyclization reaction sequence of nitroalkyl-tethered lactams has been developed. Relying on the rapid and chemoselective iridium(I)-catalyzed reduction of lactams to the corresponding enamine, subsequent nitro-Mannich cyclization of tethered nitroalkyl functionality provides direct access to important alkaloid natural-product-like structures in yields up to 81 % and in diastereoselectivities that are typically good to excellent. An in-depth understanding of the reaction mechanism has been gained through NMR studies and characterization of reaction intermediates. The new methodology has been applied to the total synthesis of (±)-epi-epiquinamide in four steps.

  1. The solubility of hydrogen in rhodium, ruthenium, iridium and nickel.

    NASA Technical Reports Server (NTRS)

    Mclellan, R. B.; Oates, W. A.

    1973-01-01

    The temperature variation of the solubility of hydrogen in rhodium, ruthenium, iridium, and nickel in equilibrium with H2 gas at 1 atm pressure has been measured by a technique involving saturating the solvent metal with hydrogen, quenching, and analyzing in resultant solid solutions. The solubilities determined are small (atom fraction of H is in the range from 0.0005 to 0.00001, and the results are consistent with the simple quasi-regular model for dilute interstitial solid solutions. The relative partial enthalpy and excess entropy of the dissolved hydrogen atoms have been calculated from the solubility data and compared with well-known correlations between these quantities.

  2. Measurements of the hard-x-ray reflectivity of iridium

    SciTech Connect

    Romaine, S.; Bruni, R.; Gorenstein, P.; Zhong, Z

    2007-01-10

    In connection with the design of a hard-x-ray telescope for the Constellation X-Ray Observatory we measured the reflectivity of an iridium-coated zerodur substrate as a function of angle at 55, 60, 70, and 80 keV at the National Synchrotron Light Source of Brookhaven National Laboratory. The optical constants were derived from the reflectivity data. The real component of the index of refraction is in excellent agreement with theoretical values at all four energies. However, the imaginary component, which is related to the mass attenuation coefficient, is 50% to 70% larger at 55, 60, and 70 keV than theoretical values.

  3. Methanol dehydrogenation by iridium N-heterocyclic carbene complexes.

    PubMed

    Campos, Jesús; Sharninghausen, Liam S; Manas, Michael G; Crabtree, Robert H

    2015-06-01

    A series of homogeneous iridium bis(N-heterocyclic carbene) catalysts are active for three transformations involving dehydrogenative methanol activation: acceptorless dehydrogenation, transfer hydrogenation, and amine monoalkylation. The acceptorless dehydrogenation reaction requires base, yielding formate and carbonate, as well as 2-3 equivalents of H2. Of the few homogeneous systems known for this reaction, our catalysts tolerate air and employ simple ligands. Transfer hydrogenation of ketones and imines from methanol is also possible. Finally, N-monomethylation of anilines occurs through a "borrowing hydrogen" reaction. Notably, this reaction is highly selective for the monomethylated product.

  4. 17-4 PH and 15-5 PH

    NASA Technical Reports Server (NTRS)

    Johnson, Howard T.

    1995-01-01

    17-4 PH and 15-5 PH are extremely useful and versatile precipitation-hardening stainless steels. Armco 17-4 PH is well suited for the magnetic particle inspection requirements of Aerospace Material Specification. Armco 15-5 PH and 17-4 PH are produced in billet, plate, bar, and wire. Also, 15-5 PH is able to meet the stringent mechanical properties required in the aerospace and nuclear industries. Both products are easy to heat treat and machine, making them very useful in many applications.

  5. Dynamic high-temperature characterization of an iridium alloy in tension

    SciTech Connect

    Song, Bo; Nelson, Kevin; Jin, Helena; Lipinski, Ronald J.; Bignell, John; Ulrich, G. B.; George, E. P.

    2015-09-01

    Iridium alloys have been utilized as structural materials for certain high-temperature applications, due to their superior strength and ductility at elevated temperatures. The mechanical properties, including failure response at high strain rates and elevated temperatures of the iridium alloys need to be characterized to better understand high-speed impacts at elevated temperatures. A DOP-26 iridium alloy has been dynamically characterized in compression at elevated temperatures with high-temperature Kolsky compression bar techniques. However, the dynamic high-temperature compression tests were not able to provide sufficient dynamic high-temperature failure information of the iridium alloy. In this study, we modified current room-temperature Kolsky tension bar techniques for obtaining dynamic tensile stress-strain curves of the DOP-26 iridium alloy at two different strain rates (~1000 and ~3000 s-1) and temperatures (~750°C and ~1030°C). The effects of strain rate and temperature on the tensile stress-strain response of the iridium alloy were determined. The DOP-26 iridium alloy exhibited high ductility in stress-strain response that strongly depended on both strain rate and temperature.

  6. Analysis and Consequences of the Iridium 33-Cosmos 2251 Collision

    NASA Technical Reports Server (NTRS)

    Anz-Meador, P. D.; Liou, Jer-Chi

    2010-01-01

    The collision of Iridium 33 and Cosmos 2251, on 10 February 2009, was the first known unintentional hypervelocity collision in space of intact satellites. Iridium 33 was an active commercial telecommunications satellite, while Cosmos 2251 was a derelict communication satellite of the Strela-2M class. The collision occurred at a relative velocity of 11.6 km/s at an altitude of approximately 790 km over the Great Siberian Plain and near the northern apex of Cosmos 2251 s orbit. This paper describes the physical and orbital characteristics of the relevant spacecraft classes and reports upon our analysis of the resulting debris clouds size, mass, area-to-mass ratio, and relative velocity/directionality distributions. We compare these distributions to those predicted by the NASA breakup model and notable recent fragmentation events; in particular, we compare the area-to-mass ratio distribution for each spacecraft to that exhibited by the FY-1C debris cloud for the purpose of assessing the relative contribution of modern aerospace materials to debris clouds resulting from energetic collisions. In addition, we examine the long-term consequences of this event for the low Earth orbit (LEO) environment. Finally, we discuss "lessons learned", which may be incorporated into NASA s environmental models.

  7. Analysis of Abrasive Blasting of DOP-26 Iridium Alloy

    SciTech Connect

    Ohriner, Evan Keith; Zhang, Wei; Ulrich, George B

    2012-01-01

    The effects of abrasive blasting on the surface geometry and microstructure of DOP-26 iridium alloy (Ir-0.3% W-0.006% Th 0.005% Al) have been investigated. Abrasive blasting has been used to control emissivity of components operating at elevated temperature. The effects of abrasive blasting conditions on surface morphology were investigated both experimentally and by numerical modeling. The simplified model, based on finite element analysis of a single angular particle impacting on Ir alloy disk, calculates the surface deformation and residual strain distribution. The experimental results and modeling results both indicate that the surface geometry is not sensitive to the abrasive blast process conditions of nozzle pressure and standoff distance considered in this study. On the other hand, the modeling results suggest that the angularity of the abrasive particle has an important role in determining surface geometry, which in turn, affects the emissivity. Abrasive blasting causes localized surface strains and localized recrystallization, but it does not affect grain size following extended exposure at elevated temperature. The dependence of emissivity of the DOP-26 alloy on mean surface slope follows a similar trend to that reported for pure iridium.

  8. Testing of Wrought Iridium/Chemical Vapor Deposition Rhenium Rocket

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.; Schneider, Steven J.

    1996-01-01

    A 22-N class, iridium/rhenium (Ir/Re) rocket chamber, composed of a thick (418 miocrometer) wrought iridium (Ir) liner and a rhenium substrate deposited via chemical vapor deposition, was tested over an extended period on gaseous oxygen/gaseous hydrogen (GO2/GH2) propellants. The test conditions were designed to produce species concentrations similar to those expected in an Earth-storable propellant combustion environment. Temperatures attained in testing were significantly higher than those expected with Earth-storable propellants, both because of the inherently higher combustion temperature of GO2/GH2 propellants and because the exterior surface of the rocket was not treated with a high-emissivity coating that would be applied to flight class rockets. Thus the test conditions were thought to represent a more severe case than for typical operational applications. The chamber successfully completed testing (over 11 hr accumulated in 44 firings), and post-test inspections showed little degradation of the Ir liner. The results indicate that use of a thick, wrought Ir liner is a viable alternative to the Ir coatings currently used for Ir/Re rockets.

  9. Microindentation hardness evaluation of iridium alloy clad vent set cups

    NASA Astrophysics Data System (ADS)

    Ulrich, George B.; DeRoos, Larry F.; Stinnette, Samuel E.

    1993-01-01

    An iridium alloy, DOP-26, is used as cladding for 238PuO2 fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  10. Microindentation hardness evaluation of iridium alloy clad vent set cups

    SciTech Connect

    Ulrich, G.B.; DeRoos, L.F.; Stinnette, S.E. )

    1993-01-15

    An iridium alloy, DOP-26, is used as cladding for [sup 238]PuO[sub 2] fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  11. Microindentation hardness evaluation of iridium alloy clad vent set cups

    SciTech Connect

    Ulrich, G.B.; DeRoos, L.F.; Stinnette, S.E.

    1992-05-15

    An iridium alloy, DOP-26, is used as cladding for {sup 238}PuO{sup 2} fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration`s Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  12. Microindentation hardness evaluation of iridium alloy clad vent set cups

    SciTech Connect

    Ulrich, G.B.; DeRoos, L.F.; Stinnette, S.E.

    1992-05-15

    An iridium alloy, DOP-26, is used as cladding for {sup 238}PuO{sup 2} fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  13. Iridium anomaly in the Cretaceous section of the Eastern Kamchatka

    NASA Astrophysics Data System (ADS)

    Savelyev, Dmitry; Savelyeva, Olga

    2010-05-01

    The origin of iridium anomalies is widely discussed with regard to massive fauna and flora extinction at several geologic boundaries. Two hypotheses are most popular, cosmogenic and volcanogenic. Anomalies of iridium are known at many stratigraphic levels, both at the geologic series borders and within geologic series. Our studies revealed increased content of iridium in a section of Cretaceous oceanic deposits on the Kamchatsky Mys Peninsula (Eastern Kamchatka, Russia). The investigated section (56°03.353´N, 163°00.376´E) includes interbedded jaspers and siliceous limestones overlaying pillow-basalts. These deposits belong to the Smagin Formation of the Albian-Cenomanian age. In the middle and upper parts of the section two beds of black carbonaceous rocks with sapropelic organic matter were observed. Their formation marked likely episodes of oxygen depletion of oceanic intermediate water (oceanic anoxic events). Our geochemical studies revealed an enrichment of the carbonaceous beds in a number of major and trace elements (Al2O3, TiO2, FeO, MgO, K2O, P2O5, Cu, Zn, Ni, Cr, V, Mo, Ba, Y, Zr, Nb, REE, U, Au, Pt etc.) in comparison with associating jaspers and limestones. There are likely different sources which contributed to the enrichment. It is possible however to correlate the excess of Al, Ti, Zr, Nb with volcanogenic admixture, which is absent in limestones and jaspers. A possible source of the volcanogenic material was local volcanism as suggested by the close association of the investigated section with volcanic rocks (basaltic lavas and hyaloclastites). The basalts of the Smagin Formation were previously proposed to originate during Cretaceous activity of the Hawaiian mantle plume (Portnyagin et al., Geology, 2008). Neutron activation analysis indicated increased up to 9 ppb concentration of Ir at the bottom of the lower carbonaceous bed (inorganic part of the sample was analyzed comprising 46% of the bulk rock). In other samples Ir content was below

  14. Phosphorescent Neutral Iridium (III) Complexes for Organic Light-Emitting Diodes.

    PubMed

    Bin Mohd Yusoff, Abd Rashid; Huckaba, Aron J; Nazeeruddin, Mohammad Khaja

    2017-04-01

    The development of transition metal complexes for application in light-emitting devices is currently attracting significant research interest. Among phosphorescent emitters, those involving iridium (III) complexes have proven to be exceedingly useful due to their relatively short triplet lifetime and high phosphorescence quantum yields. The emission wavelength of iridium (III) complexes significantly depends on the ligands, and changing the electronic nature and the position of the ligand substituents can control the properties of the ligands. In this chapter, we discuss recent developments of phosphorescent transition metal complexes for organic light-emitting diode applications focusing solely on the development of iridium metal complexes.

  15. 46 CFR 174.020 - Alternate intact stability criterion.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Deck Cargo Barges § 174.020... 170 of this chapter if it has the following characteristics: (a) The weather deck is watertight....

  16. 49 CFR 174.50 - Nonconforming or leaking packages.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 174.50 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY RAIL... through telephonic or electronic means, with subsequent written confirmation provided within two...

  17. 7 CFR 1.74 - Basis for special working relationships.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Production of Television Films § 1.74 Basis for special working relationships. The Department and its agencies may lend special assistance on television films when it is clearly evident that public...

  18. 7 CFR 1.74 - Basis for special working relationships.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Production of Television Films § 1.74 Basis for special working relationships. The Department and its agencies may lend special assistance on television films when it is clearly evident that public...

  19. 7 CFR 1.74 - Basis for special working relationships.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Production of Television Films § 1.74 Basis for special working relationships. The Department and its agencies may lend special assistance on television films when it is clearly evident that public...

  20. 7 CFR 1.74 - Basis for special working relationships.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Production of Television Films § 1.74 Basis for special working relationships. The Department and its agencies may lend special assistance on television films when it is clearly evident that public...

  1. 7 CFR 1.74 - Basis for special working relationships.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Production of Television Films § 1.74 Basis for special working relationships. The Department and its agencies may lend special assistance on television films when it is clearly evident that public...

  2. 46 CFR 174.040 - Stability requirements: general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.040... draft for navigation, towing, or drilling afloat, or at a temporary draft when changing drafts....

  3. 46 CFR 174.040 - Stability requirements: general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.040... draft for navigation, towing, or drilling afloat, or at a temporary draft when changing drafts....

  4. A preliminary study of factors affecting the calibration stability of the iridium versus iridium-40 percent rhodium thermocouple

    NASA Technical Reports Server (NTRS)

    Ahmed, Shaffiq; Germain, Edward F.; Daryabeigi, Kamran; Alderfer, David W.; Wright, Robert E.

    1987-01-01

    An iridium versus iridium-40% rhodium thermocouple was studied. Problems associated with the use of this thermocouple for high temperature applications (up to 2000 C) were investigated. The metallurgical studies included X-ray, macroscopic, resistance, and metallographic studies. The thermocouples in the as-received condition from the manufacturer revealed large amounts of internal stress caused by cold working during manufacturing. The thermocouples also contained a large amount of inhomogeneities and segregations. No phase transformations were observed in the alloy up to 1100 C. It was found that annealing the thermocouple at 1800 C for two hours, and then at 1400 C for 2 to 3 hours yielded a fine grain structure, relieving some of the strains, and making the wire more ductile. It was also found that the above annealing procedure stabilized the thermal emf behavior of the thermocouple for application below 1800 C (an improvement from + or - 1% to + or - 0.02% within the range of the test parameters used).

  5. Analysis and Implications of the Iridium 33-Cosmos 2251 Collision

    NASA Astrophysics Data System (ADS)

    Kelso, T. S.

    On 2009 February 10, Iridium 33--an operational US communications satellite in low-Earth orbit--was struck and destroyed by Cosmos 2251--a long-defunct Russian communications satellite. This is the first time since the dawn of the Space Age that two satellites have collided in orbit. To better understand the circumstances of this event and the ramifications for avoiding similar events in the future, this paper provides a detailed analysis of the predictions leading up to the collision, using various data sources, and looks in detail at the collision, the evolution of the debris clouds, and the long-term implications for satellite operations. The only publicly available system available to satellite operators for screening for close approaches, SOCRATES, did predict this close approach, but it certainly wasn't the closest approach predicted for the week of February 10. In fact, at the time of the collision, SOCRATES ranked this close approach 152 of the 11,428 within 5 km of any payload. A detailed breakdown is provided to help understand the limitations of screening for close approaches using the two-line orbital element sets. Information is also provided specifically for the Iridium constellation to provide an understanding of how these limitations affect decision making for satellite operators. Post-event analysis using high-accuracy orbital data sources will be presented to show how that information might have been used to prevent this collision, had it been available and used. Analysis of the collision event, along with the distribution of the debris relative to the original orbits, will be presented to help develop an understanding of the geometry of the collision and the near-term evolution of the resulting debris clouds. Additional analysis will be presented to show the long-term evolution of the debris clouds, including orbital lifetimes, and estimate the increased risk for operations conducted by Iridium and other satellite operators in the low-Earth orbit

  6. Iridium-catalyzed hydrogen transfer: synthesis of substituted benzofurans, benzothiophenes, and indoles from benzyl alcohols.

    PubMed

    Anxionnat, Bruno; Gomez Pardo, Domingo; Ricci, Gino; Rossen, Kai; Cossy, Janine

    2013-08-02

    An iridium-catalyzed hydrogen transfer has been developed in the presence of p-benzoquinone, allowing the synthesis of a diversity of substituted benzofurans, benzothiophenes, and indoles from substituted benzylic alcohols.

  7. Synthesis and luminescence properties of iridium(III) azide- and triazole-bisterpyridine complexes.

    PubMed

    Goldstein, Daniel C; Peterson, Joshua R; Cheng, Yuen Yap; Clady, Raphael G C; Schmidt, Timothy W; Thordarson, Pall

    2013-07-26

    We describe here the synthesis of azide-functionalised iridium(III) bisterpyridines using the "chemistry on the complex" strategy. The resulting azide-complexes are then used in the copper(I)-catalysed azide-alkyne Huisgen 1,3-dipolar cycloaddition "click chemistry" reaction to from the corresponding triazole-functionalised iridium(III) bisterpyridines. The photophysical characteristics, including lifetimes, of these compounds were also investigated. Interestingly, oxygen appears to have very little effect on the lifetime of these complexes in aqueous solutions. Unexpectedly, sodium ascorbate acid appears to quench the luminescence of triazole-functionalised iridium(III) bisterpyridines, but this effect can be reversed by the addition of copper(II) sulfate, which is known to oxidize ascorbate under aerobic conditions. The results demonstrate that iridium(III) bisterpyridines can be functionalized for use in "click chemistry" facilitating the use of these photophysically interesting complexes in the modification of polymers or surfaces, to highlight just two possible applications.

  8. Iridium-catalyst-based autonomous bubble-propelled graphene micromotors with ultralow catalyst loading.

    PubMed

    Wang, Hong; Sofer, Zdeněk; Eng, Alex Yong Sheng; Pumera, Martin

    2014-11-10

    A novel concept of an iridium-based bubble-propelled Janus-particle-type graphene micromotor with very high surface area and with very low catalyst loading is described. The low loading of Ir catalyst (0.54 at %) allows for fast motion of graphene microparticles with high surface area of 316.2 m(2)  g(-1). The micromotor was prepared with a simple and scalable method by thermal exfoliation of iridium-doped graphite oxide precursor composite in hydrogen atmosphere. Oxygen bubbles generated from the decomposition of hydrogen peroxide at the iridium catalytic sites provide robust propulsion thrust for the graphene micromotor. The high surface area and low iridium catalyst loading of the bubble-propelled graphene motors offer great possibilities for dramatically enhanced cargo delivery.

  9. Concepts for Cost-Effective Enhanced Cryosat Continuity: Opportunity in the Iridium PRIME Context

    NASA Astrophysics Data System (ADS)

    Le Roy, Y.; Caubet, E.; Silverstrin, P.; Legrand, C.

    2016-08-01

    The Iridium-PRIME offer, recently initiated by the Iridium company, consists in hosting payloads on customized low cost Iridium-NEXT platforms on which the main telecom mission antenna (L-band) is removed. This leaves significant resources in terms of mass, volume and power consumption to host up to three payloads on these customized platforms. The Iridium-PRIME satellites will be inserted in the Iridium-NEXT constellation to take benefit of the low cost operation service (command, control and data telemetry through the life time of the Iridium-PRIME mission). Given the synergy between schedules of the Iridium-PRIME program (launches starting around 2020) and of a possible CryoSat Follow-On (FO) mission (launch around 2022) and the adequacy of the available on-board resources for such a mission, ESA tasked Thales Alenia Space, as responsible for the SIRAL radar instrument of the currently in-orbit CryoSat mission, to study the feasibility of a concept for enhanced continuity of CryoSat on an Iridium- PRIME satellite as potential low-cost fast-track solution. The study aimed to define a cost-effective topographic payload including not only the SIRAL radar but also the necessary sub-systems to retrieve the SIRAL antenna baseline attitude (star trackers) with high accuracy and to perform a Precise Orbit Determination (POD). All these aspects are presented in this paper. In addition, possible evolutions/improvements of the Ku-band radar instrument were analysed and are presented: adding a Ka-band nadir measurement capability and a Ku-band or Ka-band wide swath mode measurement capability. The transmission issue for the SIRAL science data is also discussed in the paper.

  10. Novel Quadrifilar Helix Antenna Combining GNSS, Iridium, and a UHF Communications Monopole

    DTIC Science & Technology

    2012-04-01

    R. J. Davis; “ Ferrite Loaded UHF Sleeve Monopole Integrated with a GPS Patch Antenna for a Handset”. Submitted for publication in “ Microwave and...Novel Quadrifilar Helix Antenna Combining GNSS, Iridium, and a UHF Communications Monopole P. G. Elliot, E. N. Rosario, R. J. Davis The MITRE...Corporation, Bedford, MA 01730 Abstract- A GPS/GNSS/Iridium antenna co-located with a UHF communications monopole on a handset was developed to

  11. Multidirectional Synthesis of Substituted Indazoles via Iridium-Catalyzed C-H Borylation.

    PubMed

    Sadler, Scott A; Hones, Andrew C; Roberts, Bryan; Blakemore, David; Marder, Todd B; Steel, Patrick G

    2015-05-15

    In the absence of a steric directing group, iridium-catalyzed C-H borylation of N-protected indazoles occurs rapidly and selectively at C-3 and the resulting boronate esters can be utilized in a range of downstream conversions. The functional group tolerance of the iridium-catalyzed C-H borylation reaction enables simple and efficient multidirectional syntheses of substituted indazoles to be realized.

  12. Inhibition of Beta-Amyloid Fibrillation by Luminescent Iridium(III) Complex Probes.

    PubMed

    Lu, Lihua; Zhong, Hai-Jing; Wang, Modi; Ho, See-Lok; Li, Hung-Wing; Leung, Chung-Hang; Ma, Dik-Lung

    2015-09-30

    We report herein the application of kinetically inert luminescent iridium(III) complexes as dual inhibitors and probes of beta-amyloid fibrillogenesis. These iridium(III) complexes inhibited Aβ1-40 peptide aggregation in vitro, and protected against Aβ-induced cytotoxicity in neuronal cells. Furthermore, the complexes differentiated between the aggregated and unaggregated forms of Aβ1-40 peptide on the basis of their emission response.

  13. Inhibition of Beta-Amyloid Fibrillation by Luminescent Iridium(III) Complex Probes

    PubMed Central

    Lu, Lihua; Zhong, Hai-Jing; Wang, Modi; Ho, See-Lok; Li, Hung-Wing; Leung, Chung-Hang; Ma, Dik-Lung

    2015-01-01

    We report herein the application of kinetically inert luminescent iridium(III) complexes as dual inhibitors and probes of beta-amyloid fibrillogenesis. These iridium(III) complexes inhibited Aβ1–40 peptide aggregation in vitro, and protected against Aβ-induced cytotoxicity in neuronal cells. Furthermore, the complexes differentiated between the aggregated and unaggregated forms of Aβ1–40 peptide on the basis of their emission response. PMID:26419607

  14. Inhibition of Beta-Amyloid Fibrillation by Luminescent Iridium(III) Complex Probes

    NASA Astrophysics Data System (ADS)

    Lu, Lihua; Zhong, Hai-Jing; Wang, Modi; Ho, See-Lok; Li, Hung-Wing; Leung, Chung-Hang; Ma, Dik-Lung

    2015-09-01

    We report herein the application of kinetically inert luminescent iridium(III) complexes as dual inhibitors and probes of beta-amyloid fibrillogenesis. These iridium(III) complexes inhibited Aβ1-40 peptide aggregation in vitro, and protected against Aβ-induced cytotoxicity in neuronal cells. Furthermore, the complexes differentiated between the aggregated and unaggregated forms of Aβ1-40 peptide on the basis of their emission response.

  15. Iridium-alloy processing experience in FY 1989

    SciTech Connect

    Ohriner, E.K.

    1990-11-01

    Iridium-alloy blanks and foil are produced at the Oak Ridge National Laboratory for use as fuel cladding material in radioisotope thermoelectric generators for space power sources. Until 1984, the material was produced from small 500-g drop castings. A new process has been developed in which consumable electrodes of about 10 kg are arc melted, extruded, and then rolled to produce the sheet products. The work performed during FY 1989 included the arc melting of three electrodes and the extruding and rolling to sheet of three billets. Significant improvements have been made in the extruding and arc-melting processes. Preliminary results show that these improvements have had an important effect in increasing the rate of blank acceptance in nondestructive evaluations. 4 refs., 33 figs., 11 tabs.

  16. Iridium abundance maxima in the Upper Cenomanian extinction interval

    NASA Technical Reports Server (NTRS)

    Orth, C. J.; Attrep, M., Jr.; Mao, X. Y.; Kauffman, E. G.; Diner, R.

    1988-01-01

    Two iridium abundance peaks, both 0.11 ppb (whole-rock basis) over a local background of 0.017 ppb, have been found in Middle Cretaceous marine rocks near Pueblo, Colorado. They occur just below the 92-million-year-old Cenomanian-Turonian (C-T) stage boundary. No other peaks were found in 45 meters of strata (about 2.5 million years of deposition) above and below the boundary interval. The broad lower peak straddles the first in a series of extinctions of benthic and nektonic macrobiota which comprise the C-T extinction event. The sharp upper peak occurs stratigraphically about 1.2 meters above the lower peak. The excess Ir might be from meteoroid impacts.

  17. Comparative modelling of chemical ordering in palladium-iridium nanoalloys

    SciTech Connect

    Davis, Jack B. A.; Johnston, Roy L.; Rubinovich, Leonid; Polak, Micha

    2014-12-14

    Chemical ordering in “magic-number” palladium-iridium nanoalloys has been studied by means of density functional theory (DFT) computations, and compared to those obtained by the Free Energy Concentration Expansion Method (FCEM) using derived coordination dependent bond energy variations (CBEV), and by the Birmingham Cluster Genetic Algorithm using the Gupta potential. Several compositions have been studied for 38- and 79-atom particles as well as the site preference for a single Ir dopant atom in the 201-atom truncated octahedron (TO). The 79- and 38-atom nanoalloy homotops predicted for the TO by the FCEM/CBEV are shown to be, respectively, the global minima and competitive low energy minima. Significant reordering of minima predicted by the Gupta potential is seen after reoptimisation at the DFT level.

  18. Intercalation of graphene on iridium with samarium atoms

    NASA Astrophysics Data System (ADS)

    Afanas'eva, E. Yu.; Rut'kov, E. V.; Gall, N. R.

    2016-07-01

    Intercalation of graphene on Ir (111) with Sm atoms is studied by methods of thermal desorption spectroscopy and thermionic emission. It is shown that adsorption of samarium at T = 300 K on graphene to concentrations of N ≤ 6 × 1014 atoms cm-2 followed by heating of the substrate leads to practically complete escape of adsorbate underneath the graphene layer. At N > 6 × 1014 atoms cm-2 and increasing temperature, a fraction of adsorbate remains on graphene in the form of two-dimensional "gas" and samarium islands and are desorbed in the range of temperatures of 1000-1200 K. Samarium remaining under the graphene is desorbed from the surface in the temperature range 1200-2150 K. Model conceptions for the samarium-graphene-iridium system in a wide temperature range are developed.

  19. Large Deformation Change in Iridium Isotopes from Laser Spectroscopy

    SciTech Connect

    D. Verney; L. Cabaret; J. Crawford; H.T. Duong; J. Genevey; G. Hubert; F. Ibrahim; M. Krieg; F. Le Blanc; J.K.P. Lee; G. Le Scornet; D. Lunney; J. Obert; J. Oms; J. Pinard; J.C. Putaux; B. Roussiere; J. Sauvage; V. Sebastian

    1999-12-31

    Laser spectroscopy measurements have been performed on neutron-deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d{sup 7}6s{sup 2} {sup 4}F{sub 9/2} {yields}5d{sup 7}6s6p {sup 6}F{sub 11/2} have been studied for the {sup 182-189}Ir, {sup 186}Ir{sup m} and {sup 191,193}Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the hyperfine splitting measurements and the changes of the mean square charge radii from the isotope shift measurements. A large deformation change between {sup 187}Ir and {sup 186}Ir and between {sup 186}Ir{sup m} and {sup 186}Ir{sup g} has been observed.

  20. Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods.

    PubMed

    Kalisman, Philip; Nakibli, Yifat; Amirav, Lilac

    2016-02-11

    We demonstrate a procedure for the photochemical oxidative growth of iridium oxide catalysts on the surface of seeded cadmium selenide-cadmium sulfide (CdSe@CdS) nanorod photocatalysts. Seeded rods are grown using a colloidal hot-injection method and then moved to an aqueous medium by ligand exchange. CdSe@CdS nanorods, an iridium precursor and other salts are mixed and illuminated. The deposition process is initiated by absorption of photons by the semiconductor particle, which results with formation of charge carriers that are used to promote redox reactions. To insure photochemical oxidative growth we used an electron scavenger. The photogenerated holes oxidize the iridium precursor, apparently in a mediated oxidative pathway. This results in the growth of high quality crystalline iridium oxide particles, ranging from 0.5 nm to about 3 nm, along the surface of the rod. Iridium oxide grown on CdSe@CdS heterostructures was studied by a variety of characterization methods, in order to evaluate its characteristics and quality. We explored means for control over particle size, crystallinity, deposition location on the CdS rod, and composition. Illumination time and excitation wavelength were found to be key parameters for such control. The influence of different growth conditions and the characterization of these heterostructures are described alongside a detailed description of their synthesis. Of significance is the fact that the addition of iridium oxide afforded the rods astounding photochemical stability under prolonged illumination in pure water (alleviating the requirement for hole scavengers).

  1. Dynamic High-Temperature Characterization of an Iridium Alloy in Compression at High Strain Rates

    SciTech Connect

    Song, Bo; Nelson, Kevin; Lipinski, Ronald J.; Bignell, John L.; Ulrich, G. B.; George, E. P.

    2014-06-01

    Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-temperature high-strain-rate performance are needed for understanding high-speed impacts in severe elevated-temperature environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain-rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. Current high-temperature Kolsky compression bar techniques are not capable of obtaining satisfactory high-temperature high-strain-rate stress-strain response of thin iridium specimens investigated in this study. We analyzed the difficulties encountered in high-temperature Kolsky compression bar testing of thin iridium alloy specimens. Appropriate modifications were made to the current high-temperature Kolsky compression bar technique to obtain reliable compressive stress-strain response of an iridium alloy at high strain rates (300 – 10000 s-1) and temperatures (750°C and 1030°C). Uncertainties in such high-temperature high-strain-rate experiments on thin iridium specimens were also analyzed. The compressive stress-strain response of the iridium alloy showed significant sensitivity to strain rate and temperature.

  2. Iridium NEXT partnership for Earth observation: exploiting global satellite constellations for new remote sensing capabilities

    NASA Astrophysics Data System (ADS)

    Gupta, Om P.

    2008-08-01

    A unique opportunity exists to host up to 66 earth observation sensors on the Iridium NEXT LEO constellation in a manner that can revolutionize earth observation and weather predictions. A constellation approach to sensing, using the real-time communications backbone of Iridium, will enable unprecedented geospatial and temporal sampling for now-casting of weather on a global basis as well as global climate monitoring. The Iridium NEXT constellation, with 66 interconnected satellites in 6 near polar orbiting planes, provides a unique platform for hosting a variety of earth observation missions. The opportunity is proposed as a Public-Private Partnership (PPP) allowing for the sharing of infrastructure by government agencies. This has the potential to augment current and planned climate and weather observation programs in a very cost effective manner not achievable in any other way. Iridium, with the assistance of the Group on Earth Observations (GEO), NASA, NOAA, and ESA, has evaluated a number of sensing missions that would be a good fit to the Iridium NEXT constellation. These include GPS radio occultation sensors, earth radiation budget measurements, radio altimetry, tropospheric and stratospheric winds measurements including polar winds measurements, and atmospheric chemistry. Iridium NEXT launches start in 2013 and constellation operational life will extend beyond 2030. Detailed feasibility studies on specific missions are planned to begin later this year.

  3. Catalytic Transfer of Magnetism using a Neutral Iridium Phenoxide Complex

    PubMed Central

    Ruddlesden, Amy J.; Mewis, Ryan E.; Green, Gary G. R.; Whitwood, Adrian C.; Duckett, Simon B.

    2016-01-01

    A novel neutral iridium carbene complex Ir(κC,O-L1)(COD) (1) [where COD = cyclooctadiene and L1 = 3-(2-methylene-4-nitrophenolate)-1-(2,4,6-trimethylphenyl) imidazolylidene] with a pendant alkoxide ligand has been prepared and characterized. It contains a strong Ir-O bond and X-ray analysis reveals a distorted square planar structure. NMR spectroscopy reveals dynamic solution state behavior commensurate with rapid seven-membered ring flipping. In CD2Cl2 solution, under hydrogen at low temperature, this complex dominates although it exists in equilibrium with a reactive iridium dihydride cyclooctadiene complex. 1 reacts with pyridine and H2 to form neutral Ir(H)2(κC,O-L1)(py)2 which also exists in two conformers that differ according to the orientation of the seven-membered metallocycle and whilst its Ir-O bond remains intact, the complex undergoes both pyridine and H2 exchange. As a consequence, when placed under parahydrogen, efficient polarization transfer catalysis (PTC) is observed via the Signal Amplification By Reversible Exchange (SABRE) approach. Due to the neutral character of this catalyst, good hyperpolarization activity is shown in a wide range of solvents for a number of substrates. These observations reflect a dramatic improvement in solvent tolerance of SABRE over that reported for the best PTC precursor IrCl(IMes)(COD). For THF, the associated 1H NMR signal enhancement for the ortho proton signal of pyridine shows an increase of 600-fold at 298 K. The level of signal enhancement can be increased further through warming or varying the magnetic field experienced by the sample at the point of catalytic magnetization transfer.

  4. New yellow-emitting phosphorescent cyclometalated iridium(III) complex

    NASA Astrophysics Data System (ADS)

    Ivanov, P.; Tomova, R.; Petrova, P.; Stanimirov, S.; Petkov, I.

    2012-12-01

    We have synthesized a new yellow iridium complex Iridium(III) bis[2-phenylbenzothiazolato-N,C2']-(1-phenylicosane-1,3-dionate) (bt)2Ir(bsm), based on the benzothiazole derivative. The synthesized molecule was identified by 1H NMR and elemental analysis. The UV-Visible absorption and photoluminescence (PL) spectra of (bt)Ir2(bsm) in CH2Cl2 solution were found at 273 nm and 559 nm, respectively. The complex was used as a dopant into a hole-transporting layer (HTL) in a multilayered organic light emitting device (OLED) structure: ITO/doped-HTL/EL/ETL/M. ITO was a transparent anode of In2O3:SnO2, M- a metallic Al cathode, HTL- 4,4'-bis(9H-carbazol-9-yl)biphenyl (CBP) incorporated in poly(N-vinylcarbazole) (PVK) matrix, EL- electroluminescent layer of bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum (BAlq) and ETL- electron-transporting layer of tris(8-hydroxyquinolinato)aluminum (Alq3). The electroluminescent (EL) spectra of OLEDs were basically the sum of the emissions of BAlq at 496 nm and the emission of (bt)2Ir(bsm) at 559 nm. With increasing (bt)2Ir(bsm) concentration, the relative electroluminescent intensity of greenish-blue emission (at 496 nm) decreased, while the yellow (at 559 nm) - increased and CIE coordinates of the device shifted from (0.21, 0.33) at 0 wt % to (0.40, 0.48) at 8 wt % of the dopant. It was found that OLED with 0.5 wt % (bt)2Ir(bsm) had the best performance and stable color chromaticity at various voltages.

  5. Iridium-Coated Rhenium Radiation-Cooled Rockets

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.; Biaglow, James A.; Schneider, Steven J.

    1997-01-01

    Radiation-cooled rockets are used for a range of low-thrust propulsion functions, including apogee insertion, attitude control, and repositioning of satellites, reaction control of launch vehicles, and primary propulsion for planetary space- craft. The key to high performance and long lifetimes for radiation-cooled rockets is the chamber temperature capability. The material system that is currently used for radiation-cooled rockets, a niobium alloy (C103) with a fused silica coating, has a maximum operating temperature of 1370 C. Temperature limitations of C103 rockets force the use of fuel film cooling, which degrades rocket performance and, in some cases, imposes a plume contamination issue from unburned fuel. A material system composed of a rhenium (Re) substrate and an iridium (Ir) coating has demonstrated operation at high temperatures (2200 C) and for long lifetimes (hours). The added thermal margin afforded by iridium-coated rhenium (Ir/Re) allows reduction or elimination of fuel film cooling. This, in turn, leads to higher performance and cleaner spacecraft environments. There are ongoing government- and industry-sponsored efforts to develop flight Ir/ Re engines, with the primary focus on 440-N, apogee insertion engines. Complementing these Ir/Re engine development efforts is a program to address specific concerns and fundamental characterization of the Ir/Re material system, including (1) development of Ir/Re rocket fabrication methods, (2) establishment of critical Re mechanical properly data, (3) development of reliable joining methods, and (4) characterization of Ir/Re life-limiting mechanisms.

  6. The Electric Dipole Moment of Iridium Monosilicide, IrSi

    NASA Astrophysics Data System (ADS)

    Le, Anh; Steimle, Timothy C.; Cheng, Lan; Stanton, John F.

    2013-06-01

    The optical spectrum of iridium monosilicide (IrSi) was recently observed using REMPI spectroscopy in the range 17200 to 23850 cm^{-1}. The observation was supported by an ab initio calculation which predicted a X^{2}Δ_{5/2} state. Here, we report on the analysis of the optical Stark effect for the X^{2}Δ_{5/2} and [16.0]1.5 (v=6) states. The (6,0)[16.0]1.5 - X^{2}Δ_{5/2} and the (7,0)[16.0]3.5- X^{2}Δ_{5/2} bands of IrSi have been recorded using high-resolution laser-induced fluorescence spectroscopy. The observed optical Stark shifts for the ^{193}IrSi and ^{191}IrSi isotopologues were analyzed to produce the electric dipole moments of -0.4139(64)D and 0.7821(63)D for the X^{2}Δ_{5/2} and [16.0]1.5 (v=6) states, respectively. The negative sign of electric dipole moment of the X^{2}Δ_{5/2} state is supported by high-level quantum-chemical calculations employing all-electron scalar-relativistic CCSD(T) method augmented with spin-orbit corrections as well as corrections due to full triple excitations. In particular, electron-correlation effects have been shown to be essential in the prediction of the negative sign of the dipole moment. A comparison with other iridium containing molecules will be made. Maria A. Garcia, Carolin Vietz, Fernando Ruipérez, Michael D. Morse, and Ivan Infante, Kimika Fakultatea, Euskal Herriko. J. Chem. Phys., (submitted)

  7. Cytotoxic activity and protein binding through an unusual oxidative mechanism by an iridium(I)-NHC complex.

    PubMed

    Gothe, Y; Marzo, T; Messori, L; Metzler-Nolte, N

    2015-02-21

    A new NHC iridium(I) complex (1) showing significant antiproliferative properties in vitro is described here. Its crystal structure, solution behaviour and interactions with the model proteins cytochrome c (cyt c) and lysozyme were investigated. High resolution ESI-MS measurements suggest that this iridium(i) complex acts as a prodrug and binds cyt c tightly through an unusual "oxidative" mechanism. Eventually, an iridium(III)-NHC fragment is found associated to the protein.

  8. Feasibility Analysis on the Utilization of the Iridium Satellite Communications Network for Resident Space Objects in Low Earth Orbit

    DTIC Science & Technology

    2013-03-21

    turquoise -colored plane (containing Iridium_68) and orange-colored plane (containing Iridium_40) compared to the spacing between the turquoise -colored...plane and the white-colored plane (containing Iridium_11). The turquoise -colored and orange-colored planes can be thought of as planes one and six...United States, the turquoise - colored plane is descending, or transiting north to south, and the orange-colored plane is ascending, or transiting

  9. Evaluation of oxide-coated iridium-rhenium chambers

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.

    1994-01-01

    Iridium-coated rhenium (Ir-Re) provides long life operation of radiation-cooled rockets at temperatures up to 2200 C. Ceramic oxide coatings could be used to increase Ir-Re rocket lifetimes and allow operation in highly oxidizing environments. Ceramic oxide coatings promise to serve as both thermal and diffusion barriers for the iridium layer. Seven ceramic oxide-coated Ir-Re, 22-N rocket chambers were tested with gaseous hydrogen/gaseous oxygen (GHz/G02) propellants. Five chambers had thick (over 10 mils), monolithic coatings of either hafnia (HfO2) or zirconia (ZrO2). Two chambers had coatings with thicknesses less than 5 mils. One of these chambers had a thin-walled coating of ZrO2 infiltrated with sol gel HfO2. The other chamber had a coating composed of an Ir-oxide composite. The purpose of this test program was to assess the ability of the oxide coatings to withstand the thermal shock of combustion initiation, adhere under repeated thermal cycling, and operate in aggressively oxidizing environments. All of the coatings survived the thermal shock of combustion and demonstrated operation at mixture ratios up to 11. Testing the Ir-oxide composite-coated chamber included over 29 min at mixture ratio 16. The thicker walled coatings provided the larger temperature drops across the oxide layer (up to 570 C), but were susceptible to macrocracking and eventual chipping at a stress concentrator. The cracks apparently resealed during firing, under compression of the oxide layer. The thinner walled coatings did not experience the macrocracking and chipping of the chambers that was seen with the thick, monolithic coatings. However, burn-throughs in the throat region did occur in both of the thin-walled chambers at mixture ratios well above stoichiometric. The burn-throughs were probably the result of oxygen diffusion through the oxide coating that allowed the underlying Ir and Re layers to be oxidized. The results of this test program indicated that the thin-walled oxide

  10. 12 CFR 174.7 - Determination by the OCC.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... FEDERAL SAVINGS ASSOCIATIONS § 174.7 Determination by the OCC. (a)(1)-(3) (b)-(c) (d) Notice criteria. In...) Failure to disapprove a notice. If, upon expiration of the 60-day review period of any notice deemed to be... pressure on the savings association to be acquired; or (ii) Failure to furnish a business plan...

  11. 49 CFR 174.200 - Special handling requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Detailed Requirements for Class 2 (Gases) Materials § 174.200 Special handling requirements. (a) Division 2.1 (flammable gas) materials may not be loaded, transported, or stored in a rail car equipped with any type of lighted heater or open-flame device, or in a rail car equipped with any apparatus...

  12. 46 CFR 174.220 - Hatches and coamings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.220 Hatches and coamings. (a) Each hatch exposed to the weather must be watertight, except that the following hatches may... inches) above the weather deck. (2) Each hatch in a cabin top. (b) Each hatch cover must— (1)...

  13. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures. (a) To determine... converter arsenic charging rate as follows: (1) Collect daily grab samples of copper matte and any lead... determine the weight percent of inorganic arsenic contained in each sample. (3) Calculate the...

  14. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures. (a) To determine... converter arsenic charging rate as follows: (1) Collect daily grab samples of copper matte and any lead... determine the weight percent of inorganic arsenic contained in each sample. (3) Calculate the...

  15. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures. (a) To determine... converter arsenic charging rate as follows: (1) Collect daily grab samples of copper matte and any lead... determine the weight percent of inorganic arsenic contained in each sample. (3) Calculate the...

  16. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures. (a) To determine... converter arsenic charging rate as follows: (1) Collect daily grab samples of copper matte and any lead... determine the weight percent of inorganic arsenic contained in each sample. (3) Calculate the...

  17. 40 CFR 61.174 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Arsenic Emissions From Primary Copper Smelters § 61.174 Test methods and procedures. (a) To determine... converter arsenic charging rate as follows: (1) Collect daily grab samples of copper matte and any lead... determine the weight percent of inorganic arsenic contained in each sample. (3) Calculate the...

  18. 17 CFR 256.174 - Miscellaneous current and accrued assets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... COMPANIES, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935 3. Current and Accrued Assets § 256.174 Miscellaneous current and accrued assets. This account shall include the cost of all other current and accrued assets... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Miscellaneous current...

  19. 17 CFR 256.174 - Miscellaneous current and accrued assets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... COMPANIES, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935 3. Current and Accrued Assets § 256.174 Miscellaneous current and accrued assets. This account shall include the cost of all other current and accrued assets... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Miscellaneous current...

  20. 33 CFR 174.123 - Annual report of numbered vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Annual report of numbered vessels... (CONTINUED) BOATING SAFETY STATE NUMBERING AND CASUALTY REPORTING SYSTEMS State Reports § 174.123 Annual report of numbered vessels. Before March 1 of each year, each State that has an approved numbering...

  1. 37 CFR 2.174 - Correction of Office mistake.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Correction of Office mistake..., DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Correction, Disclaimer, Surrender, Etc. § 2.174 Correction of Office mistake. Whenever Office records clearly disclose a material mistake in a...

  2. 37 CFR 2.174 - Correction of Office mistake.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Correction of Office mistake..., DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Correction, Disclaimer, Surrender, Etc. § 2.174 Correction of Office mistake. Whenever Office records clearly disclose a material mistake in a...

  3. 46 CFR 154.174 - Transverse contiguous hull structure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 154.174 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... structure of a vessel having cargo containment systems without secondary barriers must meet the standards of... barriers must be designed for a temperature that is: (1) Colder than the calculated temperature of...

  4. 46 CFR 154.174 - Transverse contiguous hull structure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 154.174 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... structure of a vessel having cargo containment systems without secondary barriers must meet the standards of... barriers must be designed for a temperature that is: (1) Colder than the calculated temperature of...

  5. 46 CFR 154.174 - Transverse contiguous hull structure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 154.174 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS... structure of a vessel having cargo containment systems without secondary barriers must meet the standards of... barriers must be designed for a temperature that is: (1) Colder than the calculated temperature of...

  6. 26 CFR 1.174-4 - Treatment as deferred expenses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the property resulting from the research or experimental expenditures has no determinable useful life. If the property resulting from the expenditures has a determinable useful life, section 174(b) is not... life. Amounts treated as deferred expenses are properly chargeable to capital account for purposes...

  7. 26 CFR 1.174-4 - Treatment as deferred expenses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the property resulting from the research or experimental expenditures has no determinable useful life. If the property resulting from the expenditures has a determinable useful life, section 174(b) is not... life. Amounts treated as deferred expenses are properly chargeable to capital account for purposes...

  8. 49 CFR 174.5 - Carrier's materials and supplies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not required when these materials and supplies are being transported by the carrier who owns them. The requirements of this subchapter do not apply to railway torpedoes or fusees when carried in engines or rail cars. Railway torpedoes must be in closed metal boxes when not in use. [Amdt. 174-26B, 41 FR 57071,...

  9. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Handling of Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.86 Maximum allowable operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in...) for shipments by rail. (b) For trains transporting any loaded, placarded tank cars containing...

  10. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Handling of Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.86 Maximum allowable operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in...) for shipments by rail. (b) For trains transporting any loaded, placarded tank cars containing...

  11. 32 CFR 174.10 - Consideration for economic development conveyances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Consideration for economic development... Property § 174.10 Consideration for economic development conveyances. (a) For conveyances made pursuant to... the date of the initial transfer of property shall be used to support economic redevelopment of,...

  12. 5 CFR 1201.174 - Enforcing the Special Panel decision.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Enforcing the Special Panel decision... Panel § 1201.174 Enforcing the Special Panel decision. The Board, upon receipt of the decision of the Special Panel, will order the agency concerned to take any action appropriate to carry out the decision...

  13. 40 CFR 174.21 - General qualifications for exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... tolerance would otherwise be required for the plant-incorporated protectant. (c) Any inert ingredient that... PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Exemptions § 174.21 General qualifications for exemptions. A plant-incorporated protectant is exempt from the requirements of FIFRA,...

  14. 40 CFR 174.700 - Scope and purpose.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS List of Approved Inert Ingredients § 174.700 Scope and purpose. This subpart lists the inert ingredients that have been exempted from FIFRA and FFDCA section 408 requirements and may be used in a plant-incorporated protectant listed in subpart B of...

  15. 32 CFR 174.9 - Economic development conveyances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 1 2012-07-01 2012-07-01 false Economic development conveyances. 174.9 Section... Economic development conveyances. (a) The Secretary concerned may transfer real property and personal... Economic Development Conveyance (EDC). (b) An LRA is the only entity eligible to receive property under...

  16. 32 CFR 174.9 - Economic development conveyances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 1 2014-07-01 2014-07-01 false Economic development conveyances. 174.9 Section... Economic development conveyances. (a) The Secretary concerned may transfer real property and personal... Economic Development Conveyance (EDC). (b) An LRA is the only entity eligible to receive property under...

  17. 32 CFR 174.10 - Consideration for economic development conveyances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Consideration for economic development... Property § 174.10 Consideration for economic development conveyances. (a) For conveyances made pursuant to... the date of the initial transfer of property shall be used to support economic redevelopment of,...

  18. 174. Photocopy of Photograph (original in Roger Lewis' private collection). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    174. Photocopy of Photograph (original in Roger Lewis' private collection). Photographer and date unknown. SNAKE RIVER BELOW MILNER DAM SITE, TWIN FALLS COUNTY, MILNER, IDAHO; RAPIDS JUST BELOW MILNER TOWNSITE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  19. 46 CFR 174.050 - Stability on bottom.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.050 Stability on bottom. Each bottom bearing unit must be designed so that, while supported on the sea bottom... subjected to the forces of wave and current and to wind blowing at the velocities described in §...

  20. Peptide-functionalized luminescent iridium complexes for lifetime imaging of CXCR4 expression.

    PubMed

    Kuil, Joeri; Steunenberg, Peter; Chin, Patrick T K; Oldenburg, Joppe; Jalink, Kees; Velders, Aldrik H; van Leeuwen, Fijs W B

    2011-08-16

    The chemokine receptor 4 (CXCR4) is over-expressed in 23 types of cancer in which it plays a role in, among others, the metastatic spread. For this reason it is a potential biomarker for the field of diagnostic oncology. The antagonistic Ac-TZ14011 peptide, which binds to CXCR4, has been conjugated to luminescent iridium dyes to allow for CXCR4 visualization. The iridium dyes are cyclometalated octahedral iridium(III) 2-phenylpyridine complexes that can be functionalized with one, two or three targeting Ac-TZ14011 peptides. Confocal microscopy and fluorescence lifetime imaging microscopy (FLIM) showed that the peptide-iridium complex conjugates can be used to visualize CXCR4 expression in tumor cells. The CXCR4 receptor affinity and specific cell binding of the mono-, di- and trimeric peptide derivatives were assessed by using flow cytometry. The three derivatives possessed nanomolar receptor affinity and could distinguish between cell lines with different CXCR4 expression levels. This yields the first example of a neutral iridium(III) complex functionalized with peptides for FLIM-based visualization of a cancer associated membrane receptor.

  1. Electrodeposition of platinum-iridium alloy nanowires for hermetic packaging of microelectronics.

    PubMed

    Petrossians, Artin; Whalen, John J; Weiland, James D; Mansfeld, Florian

    2012-01-01

    An electrodeposition technique was applied for fabrication of dense platinum-iridium alloy nanowires as interconnect structures in hermetic microelectronic packaging to be used in implantable devices. Vertically aligned arrays of platinum-iridium alloy nanowires with controllable length and a diameter of about 200 nm were fabricated using a cyclic potential technique from a novel electrodeposition bath in nanoporous aluminum oxide templates. Ti/Au thin films were sputter deposited on one side of the alumina membranes to form a base material for electrodeposition. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to characterize the morphology and the chemical composition of the nanowires, respectively. SEM micrographs revealed that the electrodeposited nanowires have dense and compact structures. EDS analysis showed a 60:40% platinum-iridium nanowire composition. Deposition rates were estimated by determining nanowire length as a function of deposition time. High Resolution Transmission Electron Microscopy (HRTEM) images revealed that the nanowires have a nanocrystalline structure with grain sizes ranging from 3 nm to 5 nm. Helium leak tests performed using a helium leak detector showed leak rates as low as 1 × 10(-11) mbar L s(-1) indicating that dense nanowires were electrodeposited inside the nanoporous membranes. Comparison of electrical measurements on platinum and platinum-iridium nanowires revealed that platinum-iridium nanowires have improved electrical conductivity.

  2. Luminescent Iridium(III) Complex Labeled DNA for Graphene Oxide-Based Biosensors.

    PubMed

    Zhao, Qingcheng; Zhou, Yuyang; Li, Yingying; Gu, Wei; Zhang, Qi; Liu, Jian

    2016-02-02

    There has been growing interest in utilizing highly photostable iridium(III) complexes as new luminescent probes for biotechnology and life science. Herein, iridium(III) complex with carboxyl group was synthesized and activated with N-hydroxysuccinimide, followed by tagging to the amino terminate of single-stranded DNA (ssDNA). The Ir-ssDNA probe was further combined with graphene oxide (GO) nanosheets to develop a GO-based biosensor for target ssDNA detection. The quenching efficiency of GO, and the photostability of iridium(III) complex and GO-Ir-ssDNA biosensor, were also investigated. On the basis of the high luminescence quenching efficiency of GO toward iridium(III) complex, the GO-Ir-ssDNA biosensor exhibited minimal background signals, while strong emission was observed when Ir-ssDNA desorbed from GO nanosheets and formed a double helix with the specific target, leading to a high signal-to-background ratio. Moreover, it was found that luminescent intensities of iridium(III) complex and GO-Ir-ssDNA biosensor were around 15 and 3 times higher than those of the traditional carboxyl fluorescein (FAM) dye and the GO-FAM-ssDNA biosensor after UV irradiation, respectively. Our study suggested the sensitive and selective Ir-ssDNA probe was suitable for the development of highly photostable GO-based detection platforms, showing promise for application beyond the OLED (organic light emitting diode) area.

  3. Design, analysis, and fabrication of oxide-coated iridium/rhenium combustion chambers

    NASA Technical Reports Server (NTRS)

    Jang, Q.; Tuffias, R. H.; Laferla, R.; Ghoniem, N. M.

    1993-01-01

    Iridium-coated rhenium (Ir/Re) combustion chambers provide high temperature, oxidation-resistant operation for radiation-cooled liquid-fueled rocket engines. A 22-N (5-lb(sub f)) chamber has been operated for 15 hours at 2200 C (4000 F) using nitrogen tetroxide/monomethyl hydrazine (NTO/MMH) propellant, with negligible internal erosion. The oxidation resistance of these chambers could be further increased by the addition of refractory oxide coatings, providing longer life and/or operation in more oxidizing and higher temperature environments. The oxide coatings would serve as a thermal and diffusion barrier for the iridium coating, lowering the temperature of the iridium layer while also preventing the ingress of oxygen and egress of iridium oxides. This would serve to slow the failure mechanisms of Ir/Re chambers, namely the diffusion of rhenium to the inner surface and the oxidation of iridium. Such protection could extend chamber lifetimes by tens or perhaps hundreds of hours, and allow chamber operation on stoichiometric or higher mixture ratio oxygen/hydrogen (O2/H2) propellant. Extensive thermomechanical, thermochemical, and mass transport modeling was performed as a key material/structure design tool. Based on the results of these analyses, several 22-N oxide-coated Ir/Re chambers were fabricated and delivered to NASA Lewis Research Center for hot-fire testing.

  4. Meteoric smoke fallout over the Holocene epoch revealed by iridium and platinum in Greenland ice.

    PubMed

    Gabrielli, Paolo; Barbante, Carlo; Plane, John M C; Varga, Anita; Hong, Sungmin; Cozzi, Giulio; Gaspari, Vania; Planchon, Frédéric A M; Cairns, Warren; Ferrari, Christophe; Crutzen, Paul; Cescon, Paolo; Boutron, Claude F

    2004-12-23

    An iridium anomaly at the Cretaceous/Tertiary boundary layer has been attributed to an extraterrestrial body that struck the Earth some 65 million years ago. It has been suggested that, during this event, the carrier of iridium was probably a micrometre-sized silicate-enclosed aggregate or the nanophase material of the vaporized impactor. But the fate of platinum-group elements (such as iridium) that regularly enter the atmosphere via ablating meteoroids remains largely unknown. Here we report a record of iridium and platinum fluxes on a climatic-cycle timescale, back to 128,000 years ago, from a Greenland ice core. We find that unexpectedly constant fallout of extraterrestrial matter to Greenland occurred during the Holocene, whereas a greatly enhanced input of terrestrial iridium and platinum masked the cosmic flux in the dust-laden atmosphere of the last glacial age. We suggest that nanometre-sized meteoric smoke particles, formed from the recondensation of ablated meteoroids in the atmosphere at altitudes >70 kilometres, are transported into the winter polar vortices by the mesospheric meridional circulation and are preferentially deposited in the polar ice caps. This implies an average global fallout of 14 +/- 5 kilotons per year of meteoric smoke during the Holocene.

  5. Design, analysis, and fabrication of oxide-coated iridium/rhenium combustion chambers

    NASA Astrophysics Data System (ADS)

    Jang, Q.; Tuffias, R. H.; Laferla, R.; Ghoniem, N. M.

    1993-11-01

    Iridium-coated rhenium (Ir/Re) combustion chambers provide high temperature, oxidation-resistant operation for radiation-cooled liquid-fueled rocket engines. A 22-N (5-lb(sub f)) chamber has been operated for 15 hours at 2200 C (4000 F) using nitrogen tetroxide/monomethyl hydrazine (NTO/MMH) propellant, with negligible internal erosion. The oxidation resistance of these chambers could be further increased by the addition of refractory oxide coatings, providing longer life and/or operation in more oxidizing and higher temperature environments. The oxide coatings would serve as a thermal and diffusion barrier for the iridium coating, lowering the temperature of the iridium layer while also preventing the ingress of oxygen and egress of iridium oxides. This would serve to slow the failure mechanisms of Ir/Re chambers, namely the diffusion of rhenium to the inner surface and the oxidation of iridium. Such protection could extend chamber lifetimes by tens or perhaps hundreds of hours, and allow chamber operation on stoichiometric or higher mixture ratio oxygen/hydrogen (O2/H2) propellant. Extensive thermomechanical, thermochemical, and mass transport modeling was performed as a key material/structure design tool. Based on the results of these analyses, several 22-N oxide-coated Ir/Re chambers were fabricated and delivered to NASA Lewis Research Center for hot-fire testing.

  6. Efficient asymmetric transfer hydrogenation of ketones in ethanol with chiral iridium complexes of spiroPAP ligands as catalysts.

    PubMed

    Liu, Wei-Peng; Yuan, Ming-Lei; Yang, Xiao-Hui; Li, Ke; Xie, Jian-Hua; Zhou, Qi-Lin

    2015-04-11

    Highly efficient iridium catalyzed asymmetric transfer hydrogenation of simple ketones with ethanol as a hydrogen donor has been developed. By using chiral spiro iridium catalysts (S)- a series of alkyl aryl ketones were hydrogenated to chiral alcohols with up to 98% ee.

  7. High Strain Rate Tensile Testing of DOP-26 Iridium

    SciTech Connect

    Schneibel, Joachim H; Carmichael Jr, Cecil Albert; George, Easo P

    2007-11-01

    The iridium alloy DOP-26 was developed through the Radioisotope Power Systems Program in the Office of Nuclear Energy of the Department of Energy. It is used for clad vent set cups containing radioactive fuel in radioisotope thermoelectric generator (RTG) heat sources which provide electric power for spacecraft. This report describes mechanical testing results for DOP-26. Specimens were given a vacuum recrystallization anneal of 1 hour at 1375 C and tested in tension in orientations parallel and perpendicular to the rolling direction of the sheet from which they were fabricated. The tests were performed at temperatures ranging from room temperature to 1090 C and strain rates ranging from 1 x 10{sup -3} to 50 s{sup -1}. Room temperature testing was performed in air, while testing at elevated temperatures was performed in a vacuum better than 1 x 10{sup -4} Torr. The yield stress (YS) and the ultimate tensile stress (UTS) decreased with increasing temperature and increased with increasing strain rate. Between 600 and 1090 C, the ductility showed a slight increase with increasing temperature. Within the scatter of the data, the ductility did not depend on the strain rate. The reduction in area (RA), on the other hand, decreased with increasing strain rate. The YS and UTS values did not differ significantly for the longitudinal and transverse specimens. The ductility and RA values of the transverse specimens were marginally lower than those of the longitudinal specimens.

  8. Phosphorescent sensor for phosphorylated peptides based on an iridium complex.

    PubMed

    Kang, Jung Hyun; Kim, Hee Jin; Kwon, Tae-Hyuk; Hong, Jong-In

    2014-07-03

    A bis[(4,6-difluorophenyl)pyridinato-N,C(2')]iridium(III) picolinate (FIrpic) derivative coupled with bis(Zn(2+)-dipicolylamine) (ZnDPA) was developed as a sensor (1) for phosphorylated peptides, which are related to many cellular mechanisms. As a control, a fluorescent sensor (2) based on anthracene coupled to ZnDPA was also prepared. When the total negative charge on the phosphorylated peptides was changed to -2, -4, and -6, the emission intensity of sensor 1 gradually increased by factors of up to 7, 11, and 16, respectively. In contrast, there was little change in the emission intensity of sensor 1 upon the addition of a neutral phosphorylated peptide, non-phosphorylated peptides, or various anions such as CO3(2-), NO3(-), SO4(2-), phosphate, azide, and pyrophosphate. Furthermore, sensor 1 could be used to visually discriminate between phosphorylated peptides and adenosine triphosphate in aqueous solution under a UV-vis lamp, unlike fluorescent sensor 2. This enhanced luminance of phosphorescent sensor 1 upon binding to a phosphorylated peptide is attributed to a reduction in the repulsion between the Zn(2+) ions due to the phenoxy anion, its strong metal-to-ligand charge transfer character, and a reduction in self-quenching.

  9. High-Temperature Oxidation Behavior of Iridium-Rhenium Alloys

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.

    1995-01-01

    The life-limiting mechanism for radiation-cooled rockets made from iridium-coated rhenium (Ir/Re) is the diffusion of Re into the Ir layer and the subsequent oxidation of the resulting Ir-Re alloy from the inner surface. In a previous study, a life model for Ir/Re rockets was developed. It incorporated Ir-Re diffusion and oxidation data to predict chamber lifetimes as a function of temperature and oxygen partial pressure. Oxidation testing at 1540 deg C suggested that a 20-wt percent Re concentration at the inner wall surface should be established as the failure criterion. The present study was performed to better define Ir-oxidation behavior as a function of Re concentration and to supplement the data base for the life model. Samples ranging from pure Ir to Ir-40 wt percent Re (Ir-40Re) were tested at 1500 deg C, in two different oxygen environments. There were indications that the oxidation rate of the Ir-Re alloy increased significantly when it went from a single-phase solid solution to a two-phase mixture, as was suggested in previous work. However, because of testing anomalies in this study, there were not enough dependable oxidation data to definitively raise the Ir/Re rocket failure criterion from 20-wt percent Re to a Re concentration corresponding to entry into the two-phase region.

  10. Iridium profiles and delivery across the Cretaceous/Paleogene boundary

    NASA Astrophysics Data System (ADS)

    Esmeray-Senlet, Selen; Miller, Kenneth G.; Sherrell, Robert M.; Senlet, Turgay; Vellekoop, Johan; Brinkhuis, Henk

    2017-01-01

    We examined iridium (Ir) anomalies at the Cretaceous/Paleogene (K/Pg) boundary in siliciclastic shallow marine cores of the New Jersey Coastal Plain, USA, that were deposited at an intermediate distance (∼2500 km) from the Chicxulub, Mexico crater. Although closely spaced and generally biostratigraphically complete, the cores show heterogeneity in terms of preservation of the ejecta layers, maximum concentration of Ir measured (∼0.1-2.4 ppb), and total thickness of the Ir-enriched interval (11-119 cm). We analyzed the shape of the Ir profiles with a Lagrangian particle-tracking model of sediment mixing. Fits between the mixing model and measured Ir profiles, as well as visible burrows in the cores, show that the shape of the Ir profiles was determined primarily by sediment mixing via bioturbation. In contrast, Tighe Park 1 and Bass River cores show post-depositional remobilization of Ir by geochemical processes. There is a strong inverse relationship between the maximum concentration of Ir measured and the thickness of the sediments over which Ir is spread. We show that the depth-integrated Ir inventory is similar in the majority of the cores, indicating that the total Ir delivery at time of the K/Pg event was spatially homogeneous over this region. Though delivered through a near-instantaneous source, stratospheric dispersal, and settling, our study shows that non-uniform Ir profiles develop due to changes in the regional delivery and post-depositional modification by bioturbation and geochemical processes.

  11. Earth's Radiation Imbalance from a Constellation of 66 Iridium Satellites

    NASA Astrophysics Data System (ADS)

    Chiu, J. C.; Wiscombe, W. J.

    2012-04-01

    The Earth Radiation Imbalance (ERI) at the top of the atmosphere is the primary driving force for climate change. If ERI is not zero, then Earth's temperature, both oceanic and atmospheric, will change gradually over time, tending toward a new steady state. The best estimates of current ERI from climate models range from 0.4 to 0.9 W/m2 (the imbalance being caused mainly by increasing CO2), but current satellite systems do not have the accuracy to measure ERI to even one significant digit. In this paper, we will describe a proposed constellation of 66 Earth radiation budget instruments, to be hosted on Iridium satellites. This system represents a quantum leap over current systems in several ways, in particular in providing ERI to at least one significant digit, thus enabling a crucial test of climate models. Because of its 24/7 coverage, the system will also provide ERI at three-hourly time scales without requiring extrapolations from narrowband geostationary instruments. This would allow studies of ERI's response to fast-evolving phenomena like dust storms and hurricanes. This offers a new, synoptic view of Earth radiation budget that will transform it from a monthly average into a dynamical variable alongside standard meteorological variables like temperature and pressure.

  12. Mono- and dinuclear cationic iridium(III) complexes bearing a 2,5-dipyridylpyrazine (2,5-dpp) ligand.

    PubMed

    Donato, Loïc; McCusker, Catherine E; Castellano, Felix N; Zysman-Colman, Eli

    2013-08-05

    The synthesis, X-ray structures, photophysical, and electrochemical characterization of mono- (1) and dinuclear (2) cationic iridium(III) complexes bearing a 2,5-dipyridylpyrazine (2,5-dpp) ancillary ligand are reported. Upon the complexation of a first equivalent of iridium, the photoluminescence shifts markedly into the deep red (λem = 710 nm, ΦPL = 0.9%) compared to other cationic iridium complexes such as [Ir(ppy)2(bpy)]PF6. With the coordination of a second equivalent of iridium, room temperature luminescence is completely quenched. Both 1 and 2 are luminescent at low temperatures but with distinct excited state decay kinetics; the emission of 2 is significantly red-shifted compared to 1. Emission both at 298 and 77 K results from a mixed charge-transfer state. Density functional theory (DFT) calculations and electrochemical behavior point to an electronic communication between the two iridium complexes.

  13. Reforming catalyst of separate platinum-containing and iridium-containing particles

    SciTech Connect

    Schoennagel, H.J.

    1981-04-21

    Catalyst compositions are provided comprising a refractory support, about 0.1 to about 2 percent by weight of platinum, about 0.1 to about 2 percent by weight of iridium and about 0.1 to about 5 weight percent of halogen where the platinum and iridium are contained on separate particles of said support. The relative weight ratio of the particles containing platinum and those containing iridium is between about 10:1 to about 1:10. The compositions are useful as hydrocarbon conversion catalysts and are especially applicable for use in catalyzing the reforming of naphtha petroleum fractions. There is also disclosed a reforming process conducted in the presence of hydrogen, under reforming conditions, in the presence of the above catalyst.

  14. Properties of mixed molybdenum oxide iridium oxide thin films synthesized by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Patil, P. S.; Kawar, R. K.; Sadale, S. B.; Inamdar, A. I.; Deshmukh, H. P.

    2006-09-01

    Molybdenum-doped iridium oxide thin films have been deposited onto corning glass- and fluorine-doped tin oxide coated corning glass substrates at 350 °C by using a pneumatic spray pyrolysis technique. An aqueous solution of 0.01 M ammonium molybdate was mixed with 0.01 M iridium trichloride solution in different volume proportions and the resultant solution was used as a precursor solution for spraying. The as-deposited samples were annealed at 600 °C in air medium for 1 h. The structural, electrical and optical properties of as-deposited and annealed Mo-doped iridium oxide were studied and values of room temperature electrical resistivity, and thermoelectric power were estimated. The as-deposited samples with 2% Mo doping exhibit more pronounced electrochromism than other samples, including pristine Ir oxide.

  15. Activation of C-H bonds in nitrones leads to iridium hydrides with antitumor activity.

    PubMed

    Song, Xiaoda; Qian, Yong; Ben, Rong; Lu, Xiang; Zhu, Hai-Liang; Chao, Hui; Zhao, Jing

    2013-08-22

    We report the design and synthesis of a series of new cyclometalated iridium hydrides derived from the C-H bond activation of aromatic nitrones and the biological evaluation of these iridium hydrides as antitumor agents. The nitrone ligands are based on the structure of a popular antioxidant, α-phenyl-N-tert-butylnitrone (PBN). Compared to cisplatin, the iridium hydrides exhibit excellent antitumor activity on HepG2 cells. The metal-coordinated compound with the most potent anticancer activity, 2f, was selected for further analysis because of its ability to induce apoptosis and interact with DNA. During in vitro studies and in vivo efficacy analysis with tumor xenograft models in Institute of Cancer Research (ICR) mice, complex 2f exhibited antitumor activity that was markedly superior to that of cisplatin. Our results suggest, for the first time, that metal hydrides could be a new type of metal-based antitumor agent.

  16. Identification of an iridium(III) complex with anti-bacterial and anti-cancer activity.

    PubMed

    Lu, Lihua; Liu, Li-juan; Chao, Wei-chieh; Zhong, Hai-Jing; Wang, Modi; Chen, Xiu-Ping; Lu, Jin-Jian; Li, Ruei-nian; Ma, Dik-Lung; Leung, Chung-Hang

    2015-09-29

    Group 9 transition metal complexes have been widely explored as therapeutic agents due to their unique geometry, their propensity to undergo ligand exchanges with biomolecules and their diverse steric and electronic properties. These metal complexes can offer distinct modes of action in living organisms compared to carbon-based molecules. In this study, we investigated the antimicrobial and anti-proliferative abilities of a series of cyclometallated iridium(III) complexes. The iridium(III) complex 1 inhibited the growth of S. aureus with MIC and MBC values of 3.60 and 7.19 μM, respectively, indicating its potent bactericidal activity. Moreover, complex 1 also exhibited cytotoxicity against a number of cancer cell lines, with particular potency against ovarian, cervical and melanoma cells. This cyclometallated iridium(III) complex is the first example of a substitutionally-inert, Group 9 organometallic compound utilized as a direct and selective inhibitor of S. aureus.

  17. Heterogeneous Catalysis for Water Oxidation by an Iridium Complex Immobilized on Bipyridine-Periodic Mesoporous Organosilica.

    PubMed

    Liu, Xiao; Maegawa, Yoshifumi; Goto, Yasutomo; Hara, Kenji; Inagaki, Shinji

    2016-07-04

    Heterogenization of metal-complex catalysts for water oxidation without loss of their catalytic activity is important for the development of devices simulating photosynthesis. In this study, efficient heterogeneous iridium complexes for water oxidation were prepared using bipyridine-bridged periodic mesoporous organosilica (BPy-PMO) as a solid chelating ligand. The BPy-PMO-based iridium catalysts (Ir-BPy-PMO) were prepared by postsynthetic metalation of BPy-PMO and characterized through physicochemical analyses. The Ir-BPy-PMOs showed high catalytic activity for water oxidation. The turnover frequency (TOF) values for Ir-BPy-PMOs were one order of magnitude higher than those of conventional heterogeneous iridium catalysts. The reusability and stability of Ir-BPy-PMO were also examined, and detailed characterization was conducted using powder X-ray diffraction, nitrogen adsorption, (13) C DD MAS NMR spectroscopy, TEM, and XAFS methods.

  18. Preparation of iridium targets by electrodeposition for neutron capture cross section measurements

    DOE PAGES

    Bond, Evelyn M.; Moody, W. Allen; Arnold, Charles; ...

    2016-03-01

    Here, the preparation of 191Ir and 193Ir electrodeposits for neutron capture cross-section measurements at the detector for advanced neutron capture experiments located at the at Los Alamos Neutron Science Center is described. The electrodeposition of iridium in the desired thickness of 0.4–1 mg/cm2 is challenging. Better yields and thicknesses were obtained using electrodeposition from isopropyl alcohol solutions than from ammonium sulfate solutions. 191Ir and 193Ir targets were initially prepared using the standard single-sided electrodeposition cell. Iridium electrodepositions using a double-sided electrodeposition cell were developed and were optimized, resulting in thick, uniform iridium deposits. LA UR 15-22475.

  19. Preparation of iridium targets by electrodeposition for neutron capture cross section measurements

    SciTech Connect

    Bond, Evelyn M.; Moody, W. Allen; Arnold, Charles; Bredeweg, Todd A.; Jandel, Marian; Rusev, Gencho Y.

    2016-03-01

    Here, the preparation of 191Ir and 193Ir electrodeposits for neutron capture cross-section measurements at the detector for advanced neutron capture experiments located at the at Los Alamos Neutron Science Center is described. The electrodeposition of iridium in the desired thickness of 0.4–1 mg/cm2 is challenging. Better yields and thicknesses were obtained using electrodeposition from isopropyl alcohol solutions than from ammonium sulfate solutions. 191Ir and 193Ir targets were initially prepared using the standard single-sided electrodeposition cell. Iridium electrodepositions using a double-sided electrodeposition cell were developed and were optimized, resulting in thick, uniform iridium deposits. LA UR 15-22475.

  20. Identification of an iridium(III) complex with anti-bacterial and anti-cancer activity

    PubMed Central

    Lu, Lihua; Liu, Li-Juan; Chao, Wei-chieh; Zhong, Hai-Jing; Wang, Modi; Chen, Xiu-Ping; Lu, Jin-Jian; Li, Ruei-nian; Ma, Dik-Lung; Leung, Chung-Hang

    2015-01-01

    Group 9 transition metal complexes have been widely explored as therapeutic agents due to their unique geometry, their propensity to undergo ligand exchanges with biomolecules and their diverse steric and electronic properties. These metal complexes can offer distinct modes of action in living organisms compared to carbon-based molecules. In this study, we investigated the antimicrobial and anti-proliferative abilities of a series of cyclometallated iridium(III) complexes. The iridium(III) complex 1 inhibited the growth of S. aureus with MIC and MBC values of 3.60 and 7.19 μM, respectively, indicating its potent bactericidal activity. Moreover, complex 1 also exhibited cytotoxicity against a number of cancer cell lines, with particular potency against ovarian, cervical and melanoma cells. This cyclometallated iridium(III) complex is the first example of a substitutionally-inert, Group 9 organometallic compound utilized as a direct and selective inhibitor of S. aureus. PMID:26416333

  1. Oxygen atom transfer to a half-sandwich iridium complex: clean oxidation yielding a molecular product.

    PubMed

    Turlington, Christopher R; White, Peter S; Brookhart, Maurice; Templeton, Joseph L

    2014-03-12

    The oxidation of [Ir(Cp*)(phpy)(NCAr(F))][B(Ar(F))4] (1; Cp* = η(5)-pentamethylcyclopentadienyl, phpy = 2-phenylene-κC(1')-pyridine-κN, NCAr(F) = 3,5-bis(trifluoromethyl)benzonitrile, B(Ar(F))4 = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) with the oxygen atom transfer (OAT) reagent 2-tert-butylsulfonyliodosobenzene (sPhIO) yielded a single, molecular product at -40 °C. New Ir(Cp*) complexes with bidentate ligands derived by oxidation of phpy were synthesized to model possible products resulting from oxygen atom insertion into the iridium-carbon and/or iridium-nitrogen bonds of phpy. These new ligands were either cleaved from iridium by water or formed unreactive, phenoxide-bridged iridium dimers. The reactivity of these molecules suggested possible decomposition pathways of Ir(Cp*)-based water oxidation catalysts with bidentate ligands that are susceptible to oxidation. Monitoring the [Ir(Cp*)(phpy)(NCAr(F))](+) oxidation reaction by low-temperature NMR techniques revealed that the reaction involved two separate OAT events. An intermediate was detected, synthesized independently with trapping ligands, and characterized. The first oxidation step involves direct attack of the sPhIO oxidant on the carbon of the coordinated nitrile ligand. Oxygen atom transfer to carbon, followed by insertion into the iridium-carbon bond of phpy, formed a coordinated organic amide. A second oxygen atom transfer generated an unidentified iridium species (the "oxidized complex"). In the presence of triphenylphosphine, the "oxidized complex" proved capable of transferring one oxygen atom to phosphine, generating phosphine oxide and forming an Ir-PPh3 adduct in 92% yield. The final Ir-PPh3 product was fully characterized.

  2. 46 CFR 174.100 - Appliances for watertight and weathertight integrity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... through 174.085; and (2) A wind heeling moment calculated in accordance with § 174.055 using a wind... met. In either case, control systems for watertight doors must have power supplies, power...

  3. 46 CFR 174.100 - Appliances for watertight and weathertight integrity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... through 174.085; and (2) A wind heeling moment calculated in accordance with § 174.055 using a wind... met. In either case, control systems for watertight doors must have power supplies, power...

  4. 46 CFR 174.100 - Appliances for watertight and weathertight integrity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... through 174.085; and (2) A wind heeling moment calculated in accordance with § 174.055 using a wind... met. In either case, control systems for watertight doors must have power supplies, power...

  5. Thermocouples of molybdenum and iridium alloys for more stable vacuum-high temperature performance

    NASA Technical Reports Server (NTRS)

    Morris, J. F. (Inventor)

    1978-01-01

    Thermocouples providing stability and performance reliability in systems involving high temperatures and vacuums by employing a bimetallic thermocouple sensor are described. Each metal of the sensor is selected from a group of metals comprising molybdenum and iridium and alloys containing only those two metals. The molybdenum, iridium thermocouple sensor alloys provide bare metal thermocouple sensors having advantageous vapor pressure compatibility and performance characteristics. The compatibility and physical characteristics of the thermocouple sensor alloys result in improved emf, temperature properties and thermocouple hot junction performance.

  6. Selective DNA purine base photooxidation by bis-terdentate iridium(III) polypyridyl and cyclometalated complexes.

    PubMed

    Jacques, Alexandre; Kirsch-De Mesmaeker, Andrée; Elias, Benjamin

    2014-02-03

    Two bis-terdentate iridium(III) complexes with polypyridyl and cyclometalated ligands have been prepared and characterized. Their spectroscopic and electrochemical properties have been studied, and a photophysical scheme addressing their properties is proposed. Different types of excited states have been considered to account for the deactivation processes in each complex. Interestingly, in the presence of mono- or polynucleotides, a photoinduced electron-transfer process from a DNA purine base (i.e., guanine or adenine) to the excited complex is shown through luminescence quenching experiments. For the first time, this work reports evidence for selective DNA purine bases oxidation by excited iridium(III) bis-terdentate complexes.

  7. An Iridium(III) Complex Inhibits JMJD2 Activities and Acts as a Potential Epigenetic Modulator.

    PubMed

    Liu, Li-Juan; Lu, Lihua; Zhong, Hai-Jing; He, Bingyong; Kwong, Daniel W J; Ma, Dik-Lung; Leung, Chung-Hang

    2015-08-27

    A novel iridium(III) complex was synthesized and evaluated for its ability to target JMJD2 enzymatic activity. The iridium(III) complex 1 can inhibit JMJD2 activity and was selective for JMJD2 activity over JARID, JMJD3, and HDAC activities. Moreover, 1 suppressed the trimethylation of the p21 promoter on H3K9me3 and interrupted the JMJD2D-H3K9me3 interactions in human cells, suggesting that it could act as an epigenetic modulator. To our knowledge, 1 represents the first metal-based JMJD2 inhibitor reported in the literature.

  8. New Iridium Complex Coordinated with Tetrathiafulvalene Substituted Triazole-pyridine Ligand: Synthesis, Photophysical and Electrochemical Properties.

    PubMed

    Niu, Zhi-Gang; Xie, Hui; He, Li-Rong; Li, Kai-Xiu; Xia, Qing; Wu, Dong-Min; Li, Gao-Nan

    2016-01-01

    A new iridium(III) complex based on the triazole-pyridine ligand with tetrathiafulvalene unit, [Ir(ppy)2(L)]PF6 (1), has been synthesized and structurally characterized. The absorption spectra, luminescent spectra and electrochemical behaviors of L and 1 have been investigated. Complex 1 is found to be emissive at room temperature with maxima at 481 and 510 nm. The broad and structured emission bands are suggested a mixing of 3LC (3π-π*) and 3CT (3MLCT) excited states. The influence of iridium ion coordination on the redox properties of the TTF has also been investigated by cyclic voltammetry.

  9. High-strain-rate, high-temperature biaxial testing of DOP-26 iridium

    SciTech Connect

    George, T.G.

    1988-05-01

    High-strain-rate biaxial punch tests were performed on DOP-26 (Ir-0.3 wt.% tungsten) iridium-alloy disc given annealing and aging heat treatments. Test temperatures ranged between 600 and 1440/degree/C, and punch velocity was held constant at 45 m/s. Three types of samples were evaluated: Z-batch old-process discs, B-batch old-process discs, and B-batch new-process discs. The results indicate that batch-to-batch variations in ductility are significant and that new-process iridium is slightly more ductile than old-process material. 12 refs., 43 figs., 26 tabs.

  10. Hot Ductility of the 17-4 PH Stainless Steels

    NASA Astrophysics Data System (ADS)

    Herrera Lara, V.; Guerra Fuentes, L.; Covarrubias Alvarado, O.; Salinas Rodriguez, A.; Garcia Sanchez, E.

    2016-03-01

    The mechanisms of loss of hot ductility and the mechanical behavior of 17-4 PH alloys were investigated using hot tensile testing at temperatures between 700 and 1100 °C and strain rates of 10-4, 10-2, and 10-1 s-1. Scanning electron microscopy was used in conjunction with the results of the tensile tests to find the temperature region of loss of ductility and correlate it with cracking observed during processing by hot upsetting prior to ring rolling. It is reported that 17-4 PH alloys lose ductility in a temperature range around 900 °C near to the duplex austenite + ferrite phase field. Furthermore, it is found that niobium carbides precipitated at austenite/ferrite interfaces and grain boundaries have a pronounced effect on the mechanical behavior of the alloy during high-temperature deformation.

  11. New Outburst of Centaur Comet (60558) 174P/Echeclus

    NASA Astrophysics Data System (ADS)

    Choi, Young-Jun; Ishiguro, Masateru; Moon, Hong-Kyu

    2015-03-01

    We report observations of new outburst of Centaur (60558) 174P/Echeclus, using Suprime-Cam of Subaru tele-scope. The outburst was detected by Jager on May 30, 2011 (Jaeger et al., 2011). We made several follow-up observations for this outburst with 1m telescope at Mt. Lemon Optical Astronomy Observatory located in US and 60cm telescope at Sobaeksan Optical Astronomy Observatory in Korea. The very first presence of coma around (60558) 2000 EC98 has been detected by Choi and Weissman (2006) on 2005 December 30.50 UT with the Palomar 5m telescope. Soon after, the object was given the periodic comet designa-tion 174P/Echeclus. We will present the characterstics and discuss the reason of this recursive outburst.

  12. 46 CFR 174.080 - Flooding on self-elevating and surface type units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Flooding on self-elevating and surface type units. 174.080 Section 174.080 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Mobile Offshore Drilling Units § 174.080 Flooding...

  13. 49 CFR 174.700 - Special handling requirements for Class 7 (radioactive) materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (radioactive) materials. 174.700 Section 174.700 Transportation Other Regulations Relating to Transportation... REGULATIONS CARRIAGE BY RAIL Detailed Requirements for Class 7 (Radioactive) Materials § 174.700 Special handling requirements for Class 7 (radioactive) materials. (a) Each rail shipment of low specific...

  14. 48 CFR 217.174 - Multiyear contracts that employ economic order quantity procurement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... employ economic order quantity procurement. 217.174 Section 217.174 Federal Acquisition Regulations... TYPES SPECIAL CONTRACTING METHODS Mulityear Contracting 217.174 Multiyear contracts that employ economic... defense committees at least 30 days before awarding— (1) A multiyear contract providing for economic...

  15. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... SPECIAL CONTRACTING METHODS Mulityear Contracting 217.174 Multiyear contracts for electricity from... not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  16. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... SPECIAL CONTRACTING METHODS Mulityear Contracting 217.174 Multiyear contracts for electricity from... not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  17. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... SPECIAL CONTRACTING METHODS Mulityear Contracting 217.174 Multiyear contracts for electricity from... not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  18. 48 CFR 217.174 - Multiyear contracts for electricity from renewable energy sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electricity from renewable energy sources. 217.174 Section 217.174 Federal Acquisition Regulations System... SPECIAL CONTRACTING METHODS Mulityear Contracting 217.174 Multiyear contracts for electricity from... not to exceed 10 years for the purchase of electricity from sources of renewable energy, as that...

  19. 21 CFR 174.5 - General provisions applicable to indirect food additives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... additives. 174.5 Section 174.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: GENERAL § 174.5 General provisions applicable to indirect food additives. (a) Regulations prescribing conditions...

  20. 21 CFR 174.5 - General provisions applicable to indirect food additives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... additives. 174.5 Section 174.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: GENERAL § 174.5 General provisions applicable to indirect food additives. (a) Regulations prescribing conditions under which food additive substances may...

  1. 21 CFR 174.5 - General provisions applicable to indirect food additives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... additives. 174.5 Section 174.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: GENERAL § 174.5 General provisions applicable to indirect food additives. (a) Regulations prescribing conditions...

  2. 21 CFR 174.5 - General provisions applicable to indirect food additives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... additives. 174.5 Section 174.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: GENERAL § 174.5 General provisions applicable to indirect food additives. (a) Regulations prescribing conditions...

  3. 21 CFR 174.5 - General provisions applicable to indirect food additives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... additives. 174.5 Section 174.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: GENERAL § 174.5 General provisions applicable to indirect food additives. (a) Regulations prescribing conditions...

  4. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, the reporting authority receiving the report must forward a paper or electronic copy...

  5. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, the reporting authority receiving the report must forward a paper or electronic copy...

  6. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, each State that has an approved numbering system must forward a copy of that report to...

  7. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, each State that has an approved numbering system must forward a copy of that report to...

  8. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, the reporting authority receiving the report must forward a paper or electronic copy...

  9. 42 CFR 413.174 - Prospective rates for hospital-based and independent ESRD facilities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... independent ESRD facilities. 413.174 Section 413.174 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... NURSING FACILITIES Payment for End-Stage Renal Disease (ESRD) Services and Organ Procurement Costs § 413.174 Prospective rates for hospital-based and independent ESRD facilities. Link to an...

  10. 49 CFR 174.715 - Cleanliness of transport vehicles after use.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Cleanliness of transport vehicles after use. 174.715 Section 174.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... RAIL Detailed Requirements for Class 7 (Radioactive) Materials § 174.715 Cleanliness of...

  11. 49 CFR 174.715 - Cleanliness of transport vehicles after use.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Cleanliness of transport vehicles after use. 174.715 Section 174.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... RAIL Detailed Requirements for Class 7 (Radioactive) Materials § 174.715 Cleanliness of...

  12. 49 CFR 174.715 - Cleanliness of transport vehicles after use.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Cleanliness of transport vehicles after use. 174.715 Section 174.715 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... RAIL Detailed Requirements for Class 7 (Radioactive) Materials § 174.715 Cleanliness of...

  13. 30 CFR 250.174 - When may the Regional Supervisor grant or direct an SOP?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... direct an SOP? 250.174 Section 250.174 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... Suspensions § 250.174 When may the Regional Supervisor grant or direct an SOP? The Regional Supervisor may grant or direct an SOP when the suspension is in the National interest, and it is necessary because...

  14. 30 CFR 250.174 - When may the Regional Supervisor grant or direct an SOP?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... direct an SOP? 250.174 Section 250.174 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... Suspensions § 250.174 When may the Regional Supervisor grant or direct an SOP? The Regional Supervisor may grant or direct an SOP when the suspension is in the National interest, and it is necessary because...

  15. 30 CFR 250.174 - When may the Regional Supervisor grant or direct an SOP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... direct an SOP? 250.174 Section 250.174 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION... CONTINENTAL SHELF General Suspensions § 250.174 When may the Regional Supervisor grant or direct an SOP? The Regional Supervisor may grant or direct an SOP when the suspension is in the national interest, and it...

  16. 30 CFR 250.174 - When may the Regional Supervisor grant or direct an SOP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... direct an SOP? 250.174 Section 250.174 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE... § 250.174 When may the Regional Supervisor grant or direct an SOP? The Regional Supervisor may grant or direct an SOP when the suspension is in the national interest, and it is necessary because the...

  17. 30 CFR 250.174 - When may the Regional Supervisor grant or direct an SOP?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... direct an SOP? 250.174 Section 250.174 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT... Suspensions § 250.174 When may the Regional Supervisor grant or direct an SOP? The Regional Supervisor may grant or direct an SOP when the suspension is in the National interest, and it is necessary because...

  18. 46 CFR 174.200 - Damaged stability in machinery spaces for all OSVs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Damaged stability in machinery spaces for all OSVs. 174.200 Section 174.200 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.200 Damaged stability...

  19. 27 CFR 41.174 - Disposition of tobacco products and cigarette papers and tubes, and schedule.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... products and cigarette papers and tubes, and schedule. 41.174 Section 41.174 Alcohol, Tobacco Products and... IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Claims Tobacco Products and Cigarette Papers and Tubes Withdrawn from the Market § 41.174 Disposition of tobacco products and...

  20. 27 CFR 41.174 - Disposition of tobacco products and cigarette papers and tubes, and schedule.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... products and cigarette papers and tubes, and schedule. 41.174 Section 41.174 Alcohol, Tobacco Products and... IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Claims Tobacco Products and Cigarette Papers and Tubes Withdrawn from the Market § 41.174 Disposition of tobacco products and...

  1. 27 CFR 41.174 - Disposition of tobacco products and cigarette papers and tubes, and schedule.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... products and cigarette papers and tubes, and schedule. 41.174 Section 41.174 Alcohol, Tobacco Products and... IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Claims Tobacco Products and Cigarette Papers and Tubes Withdrawn from the Market § 41.174 Disposition of tobacco products and...

  2. 27 CFR 41.174 - Disposition of tobacco products and cigarette papers and tubes, and schedule.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... products and cigarette papers and tubes, and schedule. 41.174 Section 41.174 Alcohol, Tobacco Products and... IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Claims Tobacco Products and Cigarette Papers and Tubes Withdrawn from the Market § 41.174 Disposition of tobacco products and...

  3. 27 CFR 41.174 - Disposition of tobacco products and cigarette papers and tubes, and schedule.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... products and cigarette papers and tubes, and schedule. 41.174 Section 41.174 Alcohol, Tobacco Products and... IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Claims Tobacco Products and Cigarette Papers and Tubes Withdrawn from the Market § 41.174 Disposition of tobacco products and...

  4. 46 CFR 174.100 - Appliances for watertight and weathertight integrity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Offshore Drilling Units § 174.100 Appliances for watertight and weathertight integrity. (a) Appliances to... station. (2) Each closing appliance must remain watertight under the design water pressure of the... through 174.085; and (2) A wind heeling moment calculated in accordance with § 174.055 using a...

  5. Dynamic High-Temperature Tensile Characterization of an Iridium Alloy with Kolsky Tension Bar Techniques

    SciTech Connect

    Song, Bo; Nelson, Kevin; Lipinski, Ronald; Bignell, John; Ulrich, G. B.; George, Easo P.

    2015-05-29

    In this study, conventional Kolsky tension bar techniques were modified to characterize an iridium alloy in tension at elevated strain rates and temperatures. The specimen was heated to elevated temperatures with an induction coil heater before dynamic loading; whereas, a cooling system was applied to keep the bars at room temperature during heating. A preload system was developed to generate a small pretension load in the bar system during heating in order to compensate for the effect of thermal expansion generated in the high-temperature tensile specimen. A laser system was applied to directly measure the displacements at both ends of the tensile specimen in order to calculate the strain in the specimen. A pair of high-sensitivity semiconductor strain gages was used to measure the weak transmitted force due to the low flow stress in the thin specimen at elevated temperatures. The dynamic high-temperature tensile stress–strain curves of a DOP-26 iridium alloy were experimentally obtained at two different strain rates (~1000 and 3000 s-1) and temperatures (~750 and 1030°C). The effects of strain rate and temperature on the tensile stress–strain response of the iridium alloy were determined. Finally, the iridium alloy exhibited high ductility in stress–strain response that strongly depended on strain-rate and temperature.

  6. Dynamic High-Temperature Tensile Characterization of an Iridium Alloy with Kolsky Tension Bar Techniques

    DOE PAGES

    Song, Bo; Nelson, Kevin; Lipinski, Ronald; ...

    2015-05-29

    In this study, conventional Kolsky tension bar techniques were modified to characterize an iridium alloy in tension at elevated strain rates and temperatures. The specimen was heated to elevated temperatures with an induction coil heater before dynamic loading; whereas, a cooling system was applied to keep the bars at room temperature during heating. A preload system was developed to generate a small pretension load in the bar system during heating in order to compensate for the effect of thermal expansion generated in the high-temperature tensile specimen. A laser system was applied to directly measure the displacements at both ends ofmore » the tensile specimen in order to calculate the strain in the specimen. A pair of high-sensitivity semiconductor strain gages was used to measure the weak transmitted force due to the low flow stress in the thin specimen at elevated temperatures. The dynamic high-temperature tensile stress–strain curves of a DOP-26 iridium alloy were experimentally obtained at two different strain rates (~1000 and 3000 s-1) and temperatures (~750 and 1030°C). The effects of strain rate and temperature on the tensile stress–strain response of the iridium alloy were determined. Finally, the iridium alloy exhibited high ductility in stress–strain response that strongly depended on strain-rate and temperature.« less

  7. Optimization and electrochemical characterization of RF-sputtered iridium oxide microelectrodes for electrical stimulation

    NASA Astrophysics Data System (ADS)

    Kang, Xiaoyang; Liu, Jingquan; Tian, Hongchang; Yang, Bin; NuLi, Yanna; Yang, Chunsheng

    2014-02-01

    A reactively sputtered iridium oxide (IrOx) thin film has been developed as electrochemical modification material for microelectrodes to obtain high stability and charge storage capacity (CSC) in functional electrical stimulation. The effect of the oxygen flow and oxygen to argon ratio during sputtering process on the microstructure and electrochemical properties of the IrOx film is characterized. After optimization, the activated IrOx microelectrode shows the highest CSC of 36.15 mC cm-2 at oxygen flow of 25 sccm and oxygen to argon ratio of (2.5:1). Because the deposition process of the reactively sputtered iridium oxide is an exothermic reaction, it is difficult to form film patterning by the lift-off process. The lift-off process was focused on the partially carbonized photoresist (PR) and normal PR. The higher of the carbonization degree of PR reaches, the longer the immersion duration. However, the patterning process of the iridium oxide film becomes feasible when the sputtering pressure is increasing. The experimental results show that the iridium oxide films forms the pattern with the lowest duration of ultrasonic agitation when the deposition pressure is 4.2 Pa and pressure ratio between O2 and Ar pressure is 3:4.

  8. Acylsilanes in Iridium-Catalyzed Directed Amidation Reactions and Formation of Heterocycles via Siloxycarbenes.

    PubMed

    Becker, Peter; Pirwerdjan, Ramona; Bolm, Carsten

    2015-12-14

    Exposing ortho-amido aroylsilanes to visible light or heat leads to cyclization reactions that provide N-heterocyclic compounds via siloxycarbenes as key intermediates. The previously unreported starting materials have been prepared by directed amidations of aromatic acylsilanes in the presence of an iridium catalyst followed by N-alkylation.

  9. Single orientation graphene synthesized on iridium thin films grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Dangwal Pandey, A.; Krausert, K.; Franz, D.; Grânäs, E.; Shayduk, R.; Müller, P.; Keller, T. F.; Noei, H.; Vonk, V.; Stierle, A.

    2016-08-01

    Heteroepitaxial iridium thin films were deposited on (0001) sapphire substrates by means of molecular beam epitaxy, and subsequently, one monolayer of graphene was synthesized by chemical vapor deposition. The influence of the growth parameters on the quality of the Ir films, as well as of graphene, was investigated systematically by means of low energy electron diffraction, x-ray reflectivity, x-ray diffraction, Auger electron spectroscopy, scanning electron microscopy, and atomic force microscopy. Our study reveals (111) oriented iridium films with high crystalline quality and extremely low surface roughness, on which the formation of large-area epitaxial graphene is achieved. The presence of defects, like dislocations, twins, and 30° rotated domains in the iridium films is also discussed. The coverage of graphene was found to be influenced by the presence of 30° rotated domains in the Ir films. Low iridium deposition rates suppress these rotated domains and an almost complete coverage of graphene was obtained. This synthesis route yields inexpensive, air-stable, and large-area graphene with a well-defined orientation, making it accessible to a wider community of researchers for numerous experiments or applications, including those which use destructive analysis techniques or irreversible processes. Moreover, this approach can be used to tune the structural quality of graphene, allowing a systematic study of the influence of defects in various processes like intercalation below graphene.

  10. Total Synthesis of Cryptocaryol A by Enantioselective Iridium-Catalyzed Alcohol C-H Allylation.

    PubMed

    Perez, Felix; Waldeck, Andrew R; Krische, Michael J

    2016-04-11

    The polyketide natural product cryptocaryol A is prepared in 8 steps via iridium catalyzed enantioselective diol double C-H allylation, which directly generates an acetate-based triketide stereodiad. In 4 previously reported total syntheses, 17-28 steps were required.

  11. Catalytic cleavage of ether C-O bonds by pincer iridium complexes.

    PubMed

    Haibach, Michael C; Lease, Nicholas; Goldman, Alan S

    2014-09-15

    The development of efficient catalytic methods to cleave the relatively unreactive C-O bonds of ethers remains an important challenge in catalysis. Building on our group's recent work, we report the dehydroaryloxylation of aryl alkyl ethers using pincer iridium catalysts. This method represents a rare fully atom-economical method for ether C-O bond cleavage.

  12. Comparative assessment of iridium oxide and platinum alloy wires using an in vitro glial scar assay.

    PubMed

    Ereifej, Evon S; Khan, Saida; Newaz, Golam; Zhang, Jinsheng; Auner, Gregory W; VandeVord, Pamela J

    2013-12-01

    The long-term effect of chronically implanted electrodes is the formation of a glial scar. Therefore, it is imperative to assess the biocompatibility of materials before employing them in neural electrode fabrication. Platinum alloy and iridium oxide have been identified as good candidates as neural electrode biomaterials due to their mechanical and electrical properties, however, effect of glial scar formation for these two materials is lacking. In this study, we applied a glial scarring assay to observe the cellular reactivity to platinum alloy and iridium oxide wires in order to assess the biocompatibility based on previously defined characteristics. Through real-time PCR, immunostaining and imaging techniques, we will advance the understanding of the biocompatibility of these materials. Results of this study demonstrate iridium oxide wires exhibited a more significant reactive response as compared to platinum alloy wires. Cells cultured with platinum alloy wires had less GFAP gene expression, lower average GFAP intensity, and smaller glial scar thickness. Collectively, these results indicated that platinum alloy wires were more biocompatible than the iridium oxide wires.

  13. Iridium-catalyzed regio- and enantioselective allylic substitution of silyl dienolates derived from dioxinones.

    PubMed

    Chen, Ming; Hartwig, John F

    2014-11-03

    Reported herein is the iridium-catalyzed regio- and enantioselective allylic substitution reactions of unstabilized silyl dienolates derived from dioxinones. Asymmetric allylic substitution of a variety of allylic trichloroethyl carbonates with these silyl dienolates gave γ-allylated products selectively in 60-84% yield and 90-98% ee.

  14. Synthesis and luminescence properties of iridium complexes chelated with coumarin ligands.

    PubMed

    Park, Hye Rim; Kim, Bo Young; Kim, Young Kwan; Ha, Yunkyoung

    2013-05-01

    According to a recent report, the organic light-emitting diodes (OLEDs) using the iridium complexes of coumarin derivatives as emissive dopants are highly efficient and stable. Unlike the other Ir(III) phopsphorescent dopants, these coumarin-based Ir(III) complexes can effectively trap and transport electrons in the emissive layer. We have prepared a series of phosphorescent cyclometalated Ir(III) complexes containing 3-(2-pyridinyl)coumarin (pc) as an ancillary ligand. The new heteroleptic iridium complexes, Ir(C--N)2(pc) (CAN = 2-(2,4-difluorophenyl)pyridine (F2-ppy), 2-phenylpyridine (ppy) and 2-phenylquinoline (pq)) were characterized by 1H NMR and mass spectrometer. As main ligands, F2-ppy, ppy and pq were employed, which should have the drastically different ligand molecular orbital energy levels. The iridium complexes showed various emission ranges from 560 to 610 nm, depending upon the relative energy levels of their main and ancillary ligands. The photoabsorption, photoluminescence and electroluminescence of the complexes were studied. We also investigated the electrochemical properties of the iridium complexes to compare the HOMO and LUMO energy levels of these phosphorescent materials.

  15. Theoretical study of structure, stability, and the hydrolysis reactions of small iridium oxide nanoclusters.

    PubMed

    Zhou, Xin; Yang, Jingxiu; Li, Can

    2012-10-11

    The geometric structures and relative stabilities of small iridium oxide nanoclusters, Ir(m)O(n) (m = 1-5 and n = 1-2m), have been systematically investigated using density functional theory (DFT) calculations at the B3LYP level. Our results show that the lowest-energy structures of these clusters can be obtained by the sequential oxidation of small "core" iridium clusters. The iridium-monoxide-like clusters have relatively higher stability because of their relatively high binding energy and second difference in energies. On the basis of the optimized lowest-energy structures of neutral and cationic (IrO(2))(n) (n = 1-5), DFT has been used to study the hydrolysis reaction of these clusters with water molecules. The calculated results show that the addition of water molecules to the cationic species is much easier than the neutral ones. The overall hydrolysis reaction energies are more exothermic for the cationic clusters than for the neutral clusters. Our calculations indicate that H(2)O can be more easily split on the cationic iridium oxide clusters than on the neutral clusters.

  16. A pH Sensor Based on a Stainless Steel Electrode Electrodeposited with Iridium Oxide

    ERIC Educational Resources Information Center

    Martinez, C. C. M.; Madrid, R. E.; Felice, C. J.

    2009-01-01

    A simple procedure to make an iridium oxide (IrO[subscript 2]) electrodeposited pH sensor, that can be used in a chemical, biomedical, or materials laboratory, is presented here. Some exercises, based on this sensor, that can be used to teach important concepts in the field of biomedical, biochemical, tissue, or materials engineering, are also…

  17. Iridium-catalyzed selective α-alkylation of unactivated amides with primary alcohols.

    PubMed

    Guo, Le; Liu, Yinghua; Yao, Wubing; Leng, Xuebing; Huang, Zheng

    2013-03-01

    The first α-alkylation of unactivated amides with primary alcohols is described. An effective and robust iridium pincer complex has been developed for selective α-alkylation of tertiary and secondary acetamides involving a "borrowing hydrogen" methodology. The method is compatible with alcohols bearing various functional groups. This presents a convenient and environmentally benign protocol for α-alkylation of amides.

  18. A monolith immobilised iridium Cp* catalyst for hydrogen transfer reactions under flow conditions.

    PubMed

    Rojo, Maria Victoria; Guetzoyan, Lucie; Baxendale, Ian R

    2015-02-14

    An immobilised iridium hydrogen transfer catalyst has been developed for use in flow based processing by incorporation of a ligand into a porous polymeric monolithic flow reactor. The monolithic construct has been used for several redox reductions demonstrating excellent recyclability, good turnover numbers and high chemical stability giving negligible metal leaching over extended periods of use.

  19. The growth of graphite phase on an iridium field electron emitter

    NASA Astrophysics Data System (ADS)

    Bernatskii, D. P.; Pavlov, V. G.

    2016-06-01

    The growth of graphite on the surface of an iridium tip in pyrolysis of benzene to give a ribbed crystal has been found by the methods of field electron and desorption microscopy. The formation of a graphite crystal results in the electric field factor increasing. The adsorption of alkali metals on the surface of graphite is accompanied by the intercalation effect.

  20. Grazing incidence X-ray reflectivity of gold and iridium coated flat mirrors

    NASA Astrophysics Data System (ADS)

    Aschenbach, Bernd; Braeuninger, Heinrich; Burkert, Wolfgang

    In the context of developing high reflectivity coatings for X-ray telescopes highly polished Zerodur and BK-7 glass flats have been coated with either gold or iridium. Grazing incidence reflectivity measurements at various X-ray energies are reported and compared with standard theory prediction.

  1. High temperature reactive ion etching of iridium thin films with aluminum mask in CF4/O2/Ar plasma

    NASA Astrophysics Data System (ADS)

    Yeh, Chia-Pin; Lisker, Marco; Kalkofen, Bodo; Burte, Edmund P.

    2016-08-01

    Reactive ion etching (RIE) technology for iridium with CF4/O2/Ar gas mixtures and aluminum mask at high temperatures up to 350 °C was developed. The influence of various process parameters such as gas mixing ratio and substrate temperature on the etch rate was studied in order to find optimal process conditions. The surface of the samples after etching was found to be clean under SEM inspection. It was also shown that the etch rate of iridium could be enhanced at higher process temperature and, at the same time, very high etching selectivity between aluminum etching mask and iridium could be achieved.

  2. Testing and evaluation of oxide-coated iridium/rhenium chambers

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.

    1993-01-01

    Iridium-coated rhenium provides long life operation of radiation-cooled rockets at temperatures up to 2200 C. Ceramic oxide coatings could be used to increase iridium/rhenium rocket lifetimes and allow operation in highly oxidizing environments. Ceramic oxide coatings promise to serve as both thermal and diffusion barriers for the iridium layer. Seven ceramic oxide-coated iridium/rhenium, 22 N rocket chambers were tested on gaseous hydrogen/gaseous oxygen propellants. Five chambers had thick (over 10 mils), monolithic coatings of either hafnia or zirconia. Two chambers had coatings with thicknesses less than 5 mils. One of these chambers had a thin-walled coating of zirconia infiltrated with sol gel hafnia. The other chamber had a coating composed of an iridium/oxide composite. The purpose of this test program was to assess the ability of the oxide coatings to withstand the thermal shock of combustion initiation, adhere under repeated thermal cycling, and operate in aggressively oxidizing environments. All of the coatings survived the thermal shock of combustion and demonstrated operation at mixture ratios up to 11. The iridium/oxide composite coated chamber included testing for over 29 minutes at mixture ratio 16. The thicker-walled coatings provided the larger temperature drops across the oxide layer (up to 570 C), but were susceptible to macrocracking and eventual chipping at a stress concentrator. The cracks apparently resealed during firing, under compression of the oxide layer. The thinner-walled coatings did not experience the macrocracking and chipping of the chambers seen with the thick, monolithic coatings. However, burnthroughs in the throat region did occur in both of the thin-walled chambers at mixture ratios well above stochiometric. The burn-throughs were probably the result of oxygen-diffusion through the oxide coating that allowed the underlying iridium and rhenium layers to be oxidized. The results of this test program indicated that the thin

  3. Chlorido-containing ruthenium(II) and iridium(III) complexes as antimicrobial agents.

    PubMed

    Pandrala, Mallesh; Li, Fangfei; Feterl, Marshall; Mulyana, Yanyan; Warner, Jeffrey M; Wallace, Lynne; Keene, F Richard; Collins, J Grant

    2013-04-07

    A series of polypyridyl-ruthenium(II) and -iridium(III) complexes that contain labile chlorido ligands, [{M(tpy)Cl}(2){μ-bb(n)}](2/4+) {Cl-Mbb(n); where M = Ru or Ir; tpy = 2,2':6',2''-terpyridine; and bb(n) = bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane (n = 7, 12 or 16)} have been synthesised and their potential as antimicrobial agents examined. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the series of metal complexes against four strains of bacteria - Gram positive Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), and Gram negative Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) - have been determined. All the ruthenium complexes were highly active and bactericidal. In particular, the Cl-Rubb(12) complex showed excellent activity against all bacterial cell lines with MIC values of 1 μg mL(-1) against the Gram positive bacteria and 2 and 8 μg mL(-1) against E. coli and P. aeruginosa, respectively. The corresponding iridium(III) complexes also showed significant antimicrobial activity in terms of MIC values; however and surprisingly, the iridium complexes were bacteriostatic rather than bactericidal. The inert iridium(III) complex, [{Ir(phen)(2)}(2){μ-bb(12)}](6+) {where phen = 1,10-phenanthroline) exhibited no antimicrobial activity, suggesting that it could not cross the bacterial membrane. The mononuclear model complex, [Ir(tpy)(Me(2)bpy)Cl]Cl(2) (where Me(2)bpy = 4,4'-dimethyl-2,2'-bipyridine), was found to aquate very rapidly, with the pK(a) of the iridium-bound water in the corresponding aqua complex determined to be 6.0. This suggests the dinuclear complexes [Ir(tpy)Cl}(2){μ-bb(n)}](4+) aquate and deprotonate rapidly and enter the bacterial cells as 4+ charged hydroxo species.

  4. Water reduction systems associated with homoleptic cyclometalated iridium complexes of various 2-phenylpyridines.

    PubMed

    Yuan, Yong-Jun; Yu, Zhen-Tao; Cai, Jian-Guang; Zheng, Chao; Huang, Wei; Zou, Zhi-Gang

    2013-08-01

    The photoreduction of water to hydrogen represents a promising method for generating sustainable clean fuel. The molecular processes of this photoreduction require an effective light absorber, such as the ruthenium polybipyridine complex, to collect and convert the solar energy into a usable chemical form. In the search for a highly active and stable photosensitizer (PS), iridium complexes are attractive because of their desirable photophysical characteristics. Herein, a series of homoleptic tris-cyclometalated iridium complexes, based on different 2-phenylpyridine ligands, were utilized as PSs in photocatalytic systems for hydrogen production with [Rh(dtb-bpy)3 ](PF6 )3 (dtb-bpy=4,4'-di-tert-butyl-2,2'-dipyridyl) serving as the water reduction catalyst (WRC) and triethanolamine (TEOA) as the electron donor. The photophysical and electrochemical properties of these complexes were systematically investigated. The excited state of neutral iridium complexes (PS*) could not be quenched by using TEOA as an electron donor, but they could be quenched by using [Rh(dtb-bpy)3 ](PF6 )3 as an electron acceptor, indicating that the PS* quenching pathway in catalytic reactions was most likely an oxidative quenching process. A set of long-lived and highly active systems for hydrogen evolution were obtained in Ir(III) -Rh(III) -TEOA systems. These systems maintained their activity for more than 72 h with visible-light irradiation, and the total turnover number was up to 3040. Comparative studies indicated that the photocatalytic performance of these homoleptic tris-cyclometalated iridium compounds was superior to that of the cationic iridium complex [Ir(ppy)2 (bpy)](PF6 ) (ppy=2-phenylpyridine, bpy=2,2'-dipyridyl) (4), which was used as a reference. The significant increase in the photocatalytic efficiencies was in part attributed to the higher photostability of the neutral Ir(III) complexes. This assumption was supported by their different coordination modes, photophysical, and

  5. Iridium and Spherules in Late Eocene Impact Deposits

    NASA Technical Reports Server (NTRS)

    Kyte, F. T.; Liu, S.

    2002-01-01

    We have been independently examining the Ir (FTK) and spherule (SL) contents of recently discovered late Eocene impact deposits from the south Atlantic and western Indian oceans. These include ODP Sites 1090 [14,15], 709 [lo], and 699 [Liu in prep.]. Iridium abundances at these sites are within the typical range reported for late Eocene deposits, with peak concentrations between 100 and 1000 pg/g. In Table 1 we present estimated net Ir fluences (in ng Ir/cm ) for these and nine other sites. Although there are fewer sites than the K/T boundary, the average of 9 ng Ir/cm2 is probably a good estimate of the late Eocene global flux. This is enough Ir for a 6 km comet (assuming 250 ng/g Ir, p=1.5), is sufficient to produce the Popigai or Chesapeake Bay structures, and is 16% of the flux estimated for the K/T boundary (55 ng/cm2 [ 161). Figure 1 shows the relative abundances of Ir, glassy microtektites and cpx-bearing spherules in sediments from Sites 699 and 1090, which are separated by only 3100 km. Although these two sites have similar Ir anomalies, the abundances of spherules are quite different. Site 1090 has well-defined peaks for both types of spherules, with a peak of 562 cpx spheruledg, while Site 699 contains only a few glassy microtektites and no cpx spherules. While the different abundances of spherules may reflect a heterogeneous distribution of spherules on the Earth s surface, an equally likely cause of this difference may be differential preservation of spherules in the sediment. recovered are only a trace residue of the initial impact deposit. Earlier work found 0.22 ng/g Ir in glassy microtektites from Site 689 [17], an insufficient concentration to support 0.16 ng/g in the bulk sediment at this site. We measured 15 ng/g Ir in a group of 95 cpx spherules from Site 1090 with sizes from 63 to -200 pm, a set typical of the size distribution at this site. Although this is a significant concentration it also cannot support the Ir peak. We presently lack

  6. Testing of electroformed deposited iridium/powder metallurgy rhenium rockets

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.; Dickerson, Robert

    1996-01-01

    High-temperature, oxidation-resistant chamber materials offer the thermal margin for high performance and extended lifetimes for radiation-cooled rockets. Rhenium (Re) coated with iridium (Ir) allow hours of operation at 2200 C on Earth-storable propellants. One process for manufacturing Ir/Re rocket chambers is the fabrication of Re substrates by powder metallurgy (PM) and the application of Ir coatings by using electroformed deposition (ED). ED Ir coatings, however, have been found to be porous and poorly adherent. The integrity of ED Ir coatings could be improved by densification after the electroforming process. This report summarizes the testing of two 22-N, ED Ir/PM Re rocket chambers that were subjected to post-deposition treatments in an effort to densify the Ir coating. One chamber was vacuum annealed, while the other chamber was subjected to hot isostatic pressure (HIP). The chambers were tested on gaseous oxygen/gaseous hydrogen propellants, at mixture ratios that simulated the oxidizing environments of Earth-storable propellants. ne annealed ED Ir/PM Re chamber was tested for a total of 24 firings and 4.58 hr at a mixture ratio of 4.2. After only 9 firings, the annealed ED Ir coating began to blister and spall upstream of the throat. The blistering and spalling were similar to what had been experienced with unannealed, as-deposited ED Ir coatings. The HIP ED Ir/PM Re chamber was tested for a total of 91 firings and 11.45 hr at mixture ratios of 3.2 and 4.2. The HIP ED Ir coating remained adherent to the Re substrate throughout testing; there were no visible signs of coating degradation. Metallography revealed, however, thinning of the HIP Ir coating and occasional pores in the Re layer upstream of the throat. Pinholes in the Ir coating may have provided a path for oxidation of the Re substrate at these locations. The HIP ED Ir coating proved to be more effective than vacuum annealed and as-deposited ED Ir. Further densification is still required to

  7. Functional relationship between bacteriophages G4 and phi X174.

    PubMed Central

    Borrias, W E; Hagenaar, M; Van Den Brekel, R; Kühlemeijer, C; Weisbeek, P J

    1979-01-01

    Mutants of bacteriophage G4 were isolated and characterized, and their mutations were mapped. They constitute six different genes, namely, A, B, E, F, G, and H. The functional relationship with bacteriophage phi X174 was determined by complementation experiments using amber mutants of phi X and amber mutants of G4. Bacteriophage phi X was able to use the products of G4 genes E, F, G, and H. In bacteriophage G4, however, only the phi X gene H product was functional. Images PMID:480475

  8. Green chemiluminescence from a bis-cyclometalated iridium(III) complex with an ancillary bathophenanthroline disulfonate ligand.

    PubMed

    Zammit, Elizabeth M; Barnett, Neil W; Henderson, Luke C; Dyson, Gail A; Zhou, Ming; Francis, Paul S

    2011-08-07

    The reaction of a fluorinated iridium complex with cerium(IV) and organic reducing agents generates an intense emission with a significant hypsochromic shift compared to contemporary chemically-initiated luminescence from metal complexes.

  9. Determination of surface coverage of catalysts: Temperature programmed experiments on platinum and iridium sponge catalysts after low temperature ammonia oxidation

    SciTech Connect

    Broek, A.C.M. van den; Grondelle, J. van; Santen, R.A. van

    1999-07-25

    The activity of iridium and platinum sponge catalysts was studied in the low temperature gas phase oxidation of ammonia with oxygen. Under the reaction conditions used, iridium was found to be more active and more selective to nitrogen than platinum. Furthermore it was established from activity measurements that both catalysts lose activity as a function of time on stream due to inhibition of the surface by reaction intermediates. The used catalysts were studied by XPS and temperature programmed techniques. It was found that the surface of the catalysts had a high coverage of NH and OH and some additional NH{sub 2}. It seems most likely that the reaction mechanism proceeds through a stepwise dehydrogenation of the ammonia molecule. It appears that the last dehydrogenation step (NH by OH to N and water) is the rate determining step. The high selectivity of iridium to nitrogen can be explained by the higher activity of iridium in dissociating NO.

  10. Highly active iridium/iridium-tin/tin oxide heterogeneous nanoparticles as alternative electrocatalysts for the ethanol oxidation reaction.

    PubMed

    Du, Wenxin; Wang, Qi; Saxner, David; Deskins, N Aaron; Su, Dong; Krzanowski, James E; Frenkel, Anatoly I; Teng, Xiaowei

    2011-09-28

    Ethanol is a promising fuel for low-temperature direct fuel cell reactions due to its low toxicity, ease of storage and transportation, high-energy density, and availability from biomass. However, the implementation of ethanol fuel cell technology has been hindered by the lack of low-cost, highly active anode catalysts. In this paper, we have studied Iridium (Ir)-based binary catalysts as low-cost alternative electrocatalysts replacing platinum (Pt)-based catalysts for the direct ethanol fuel cell (DEFC) reaction. We report the synthesis of carbon supported Ir(71)Sn(29) catalysts with an average diameter of 2.7 ± 0.6 nm through a "surfactant-free" wet chemistry approach. The complementary characterization techniques, including aberration-corrected scanning transmission electron microscopy equipped with electron energy loss spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy, are used to identify the "real" heterogeneous structure of Ir(71)Sn(29)/C particles as Ir/Ir-Sn/SnO(2), which consists of an Ir-rich core and an Ir-Sn alloy shell with SnO(2) present on the surface. The Ir(71)Sn(29)/C heterogeneous catalyst exhibited high electrochemical activity toward the ethanol oxidation reaction compared to the commercial Pt/C (ETEK), PtRu/C (Johnson Matthey) as well as PtSn/C catalysts. Electrochemical measurements and density functional theory calculations demonstrate that the superior electro-activity is directly related to the high degree of Ir-Sn alloy formation as well as the existence of nonalloyed SnO(2) on surface. Our cross-disciplinary work, from novel "surfactant-free" synthesis of Ir-Sn catalysts, theoretical simulations, and catalytic measurements to the characterizations of "real" heterogeneous nanostructures, will not only highlight the intriguing structure-property correlations in nanosized catalysts but also have a transformative impact on the commercialization of DEFC technology by replacing Pt with low

  11. The CXC-chemokine, H174: expression in the central nervous system.

    PubMed

    Luo, Y; Kim, R; Gabuzda, D; Mi, S; Collins-Racie, L A; Lu, Z; Jacobs, K A; Dorf, M E

    1998-12-01

    H174 is a new member of the CXC-chemokine family. A cDNA probe containing the entire H174 coding region recognized a predominant inducible transcript of approximately 1.5 kb expressed in interferon (IFN) activated astrocytoma and monocytic cell lines. H174 message can be induced following IFN-alpha, IFN-beta, or IFN-gamma stimulation. H174 message was also detected in IFN treated cultures of primary human astrocytes, but was absent in unstimulated astrocytes. H174, like IP10 and Mig, lacks the ELR sequence associated with the neutrophil specificity characteristic of most CXC-chemokines. Preliminary experiments suggest H174, IP10 and Mig are independently regulated. Recombinant H174 is a weak chemoattractant for monocyte-like cells. H174 can also stimulate calcium flux responses. The data support the classification of H174 as a member of a subfamily of interferon-gamma inducible non-ELR CXC-chemokines. Brain tissues were obtained at autopsy from one patient with AIDS dementia, one patient with multiple sclerosis, and two normal control patients. H174 and Mig were detected by RT-PCR in brain tissue cDNA derived from the patients with pathological conditions associated with activated astrocytes but not in cDNA from control specimens.

  12. Chiral N-heterocyclic carbene/pyridine ligands for the iridium-catalyzed asymmetric hydrogenation of olefins.

    PubMed

    Schumacher, Andreas; Bernasconi, Maurizio; Pfaltz, Andreas

    2013-07-15

    Swapping N,P for C,N: Iridium complexes of bidentate pyridine-based C,N ligands with an N-heterocylic carbene (NHC) unit proved to be efficient and highly enantioselective hydrogenation catalysts. As a result of the lower acidity of iridium hydride intermediates produced from NHC-based complexes, these catalysts are much better suited than analogous N,P-ligand complexes for the hydrogenation of acid-sensitive substrates.

  13. An Aldol Reaction-Based Iridium(III) Chemosensor for the Visualization of Proline in Living Cells

    NASA Astrophysics Data System (ADS)

    Liu, Jin-Biao; Liu, Li-Juan; Dong, Zhen-Zhen; Yang, Guan-Jun; Leung, Chung-Hang; Ma, Dik-Lung

    2016-11-01

    A long-lived aldol reaction-based iridium(III) chemosensor [Ir(ppy)2(5-CHOphen)]PF6 (1, where ppy = 2-phenylpyridine and 5-CHOphen = 1,10-phenanthroline-5-carbaldehyde) for proline detection has been synthesized. The iridium(III) complex 1, incorporating an aldehyde group in N^N donor ligand, can take part in aldol reaction with acetone mediated by proline. The transformation of the sp2-hybridized carbonyl group into a sp3-hybridized alcohol group influences the metal-to-ligand charge-transfer (MLCT) state of the iridium(III) complex, resulting in a change in luminescence in response to proline. The interaction of the iridium(III) complex 1 with proline was investigated by 1H NMR, HRMS and emission titration experiments. Upon the addition of proline to a solution of iridium(III) complex 1, a maximum 8-fold luminescence enhancement was observed. The luminescence signal of iridium(III) complex 1 could be recognized in strongly fluorescent media using time-resolved emission spectroscopy (TRES). The detection of proline in living cells was also demonstrated.

  14. An Analysis of the FY-1C, Iridium 33, and Cosmos 2251 Fragments

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.

    2014-01-01

    The beginning of the year 2013 marks the sixth anniversary of the destruction of the Fengyun-1C (FY-1C) weather satellite as the result of an anti-satellite test conducted by China in January 2007 and the fourth anniversary of the accidental collision between Cosmos 2251 and the operational Iridium 33 in February 2009. These two events represent the worst satellite breakups in history. A total of 5579 fragments have been cataloged by the U.S. Space Surveillance Network (SSN), and almost 5000 of them were still in orbit in January 2013. In addition to these cataloged objects, hundreds of thousands (or more) of fragments down to the millimeter size regime were also generated during the breakups. These fragments are too small to be tracked by the SSN, but are large enough to be a safety concern for human space activities and robotic missions in low Earth orbit (LEO, the region below 2000 km altitude). Like their cataloged siblings, many of them remain in orbit today. These two breakup events dramatically changed the landscape of the orbital debris environment in LEO. The spatial density of the cataloged population in January 2013 is shown as the top blue curve. The combined FY-1C, Iridium 33, and Cosmos 2251 fragments (black curve) account for about 50 percent of the cataloged population below an altitude of 1000 km. They are also responsible for the concentrations at 770 km and 850 km, altitudes at which the collisions occurred. The effects of the FY-1C, Iridium 33, and Cosmos 2251 fragments will continue to be felt for decades to come. For example, approximately half of the generated FY-1C fragments will remain in orbit 20 years from now. In general, the Iridium 33 and Cosmos 2251 fragments will decay faster than the FY-1C fragments because of their lower altitudes. Of the Iridium 33 and Cosmos 2251 fragments, the former have much shorter orbital lifetimes than the latter, because lightweight composite materials were heavily used in the construction of the Iridium

  15. Cloned bacteriophage phi X174 DNA sequence interferes with synthesis of the complementary strand of infecting bacteriophage phi X174.

    PubMed Central

    van der Avoort, H G; van Arkel, G A; Weisbeek, P J

    1982-01-01

    The insertion of a particular phi X DNA sequence in the plasmid pACYC177 strongly decreased the capacity of Escherichia coli cells containing such a plasmid to propagate bacteriophage phi X174. The smallest DNA sequence tested that showed the effect was the HindII fragment R4. This fragment does not code for a complete protein. It contains the sequence specifying the C-terminal part of the gene H protein and the N-terminal part of the gene A protein, as well as the noncoding region between these genes. Analysis of cells that contain plasmids with the "reduction sequence" showed that (i) the adsorption of the phages to the host cells is normal, (ii) in a single infection cycle much less phage is formed, (iii) only 10% of the infecting viral single-stranded DNA is converted to double-stranded replicative-form DNA, and (iv) less progeny replicative form DNA is synthesized. The reduction process is phi X174 specific, since the growth of the related G4 and St-1 phages was not affected in these cells. The effect of the recombinant plasmids on infecting phage DNA shows similarity to the process of superinfection exclusion. Images PMID:6211550

  16. Excimer laser deinsulation of Parylene-C on iridium for use in an activated iridium oxide film-coated Utah electrode array.

    PubMed

    Yoo, Je-Min; Negi, Sandeep; Tathireddy, Prashant; Solzbacher, Florian; Song, Jong-In; Rieth, Loren W

    2013-04-30

    Implantable microelectrodes provide a measure to electrically stimulate neurons in the brain and spinal cord and record their electrophysiological activity. A material with a high charge capacity such as activated or sputter-deposited iridium oxide film (AIROF or SIROF) is used as an interface. The Utah electrode array (UEA) uses SIROF for its interface material with neural tissue and oxygen plasma etching (OPE) with an aluminium foil mask to expose the active area, where the interface between the electrode and neural tissue is formed. However, deinsulation of Parylene-C using OPE has limitations, including the lack of uniformity in the exposed area and reproducibility. While the deinsulation of Parylene-C using an excimer laser is proven to be an alternative for overcoming the limitations, the iridium oxide (IrOx) suffers from fracture when high laser fluence (>1000 mJ/cm2) is used. Iridium (Ir), which has a much higher fracture resistance than IrOx, can be deposited before excimer laser deinsulation and then the exposed Ir film area can be activated by electrochemical treatment to acquire the AIROF. Characterisation of the laser-ablated Ir film and AIROF by surface analysis (X-ray photoelectron spectroscopy, scanning electron microscope, and atomic force microscope) and electrochemical analysis (electrochemical impedance spectroscopy, and cyclic voltammetry) shows that the damage on the Ir film induced by laser irradiation is significantly less than that on SIROF, and the AIROF has a high charge storage capacity. The results show the potential of the laser deinsulation technique for use in high performance AIROF-coated UEA fabrication.

  17. Preliminary design studies for an iridium rod target at the BNL-AGS

    SciTech Connect

    Ludewig, H.; Hastings, J.; Montanez, P.; Todosow, M.

    1998-12-31

    The BNL-AGS is an intense source of 24 GeV protons. It is proposed to explore the potential to use these protons as the driver for a Pulsed Spallation Neutron Source target. The proposed target design is based on an edge cooled iridium rod concept--similar to the anti-proton production target which operated reliably at CERN under similar conditions. Lead, lead fluoride, and beryllium are investigated as possible reflector materials, and ambient temperature light water and 80 K light water ice are proposed as initial moderator materials. Both moderators are decoupled by cadmium containing moderator chamber walls. The small size of the target has the advantage that the moderators can be placed close to the target (resulting in a bright source), and since a large fraction of the radioactive inventory is contained in the iridium rod, removal and disposition of this inventory should be relatively simple and inexpensive.

  18. First Applications of DoD Iridium RUDICS in the NSF Polar Programs

    NASA Astrophysics Data System (ADS)

    Valentic, T.; Stehle, R.

    2008-12-01

    We will present the first deployment and application of the new Iridium RUDICS service to remote instrumentation projects within the National Science Foundation's polar programs. The rise of automated observing networks has increased the demand for real-time connectivity to remote instruments, not only for immediate access to data, but to also interrogate health and status. Communicating with field sites in the polar regions is complicated by the remoteness from existing infrastructure, low temperatures and limited connection options. Sites located above 78° latitude are not able to see geostationary satellites, leaving the Iridium constellation as the only one that provide a direct connection. Some others, such as Orbcomm, only provide a store-and-forward service. Iridium is often used as a dial up modem to establish a PPP connection to the Internet with data files transferred via FTP. On low-bandwidth, high-latency networks like Iridium (2400bps with ping times of seconds), this approach is time consuming and inefficient. The dial up time alone takes upwards of a minute, and standard TCP/IP and FTP protocols are hampered by the long latencies. Minimizing transmission time is important for reducing battery usage and connection costs. The new Iridium RUDICS service can be used for more efficient transfers. RUDICS is an acronym for "Router-based Unstructured Digital Inter-working Connectivity Solution" and provides a direct connection between an instrument in the field and a server on the Internet. After dialing into the Iridium gateway, a socket connection is opened to a registered port on a user's server. Bytes sent to or from the modem appear at the server's socket. The connection time is reduced to about 10 seconds because the modem training and PPP negotiation stages are eliminated. The remote device does not need to have a full TCP/IP stack, allowing smaller instruments such as data loggers to directly handle the data transmission. Alternative protocols can

  19. Iridium-catalyzed H/D exchange: ligand complexes with improved efficiency and scope.

    PubMed

    Parmentier, Michael; Hartung, Thomas; Pfaltz, Andreas; Muri, Dieter

    2014-09-01

    Hydrogen isotope exchange (HIE) is one of the most attractive tools for the introduction of deuterium or tritium to an organic compound. Herein, iridium complexes with N,P-ligands, highly active catalysts for asymmetric double bond reductions, have been tested for their HIE capabilities. Electron-rich ligands, containing dicyclohexylphosphines or phosphinites, have been identified as excellent ligands for efficient deuterium incorporation. Substrates with strong directing groups, that is, pyridines, ketones, and amides, as well as weak ligating units, such as, nitro, sulfones, and sulfonamides, could be labeled efficiently. With the addition of tris(pentafluorophenyl) borane to the reaction mixture, also highly deactivating nitrile substituents were well tolerated in the reaction. Based on the excellent results obtained with the chiral ThrePhox ligand, a structurally simpler, achiral ligand was developed. The iridium complex containing this ligand, proved to be a powerful catalyst for HIE reactions.

  20. The treatment of malignant diseases in Romania using stainless steel encapsulated iridium-192 sources

    NASA Astrophysics Data System (ADS)

    Stanef, I.; Matache, G.; Ciocǎltei, V.; Gheorghiev, G.

    1994-01-01

    Iridium-192 sources supplied by the Institute for Nuclear Physics and Engineering have been used in Romanian radiotherapy clinics since 1980. The source assembly is sealed in a protective stainless steel sheath which satisfies the requirements of international standards. Since this sheath acts as a filter to change the characteristic spectrum it has been necessary to determine experimentally an accurate value of the specific gamma-ray constant. Some clinical aspects of the complex treatment of carcinomas with iridium-192 are reviewed. Results of the calculation of the dose distribution around single and multiple sources are given for different applications in the treatment of carcinomas of the vaginal and uterine cervix, oral cavity, rectum and vagina.