Science.gov

Sample records for niobium 88

  1. Process for recovering niobium from uranium-niobium alloys

    DOEpatents

    Wallace, Steven A.; Creech, Edward T.; Northcutt, Walter G.

    1983-01-01

    Niobium is recovered from scrap uranium-niobium alloy by melting the scrap with tin, solidifying the billet thus formed, heating the billet to combine niobium with tin therein, placing the billet in hydrochloric acid to dissolve the uranium and leave an insoluble residue of niobium stannide, then separating the niobium stannide from the acid.

  2. Passivated niobium cavities

    SciTech Connect

    Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

    2006-12-19

    A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

  3. Process for recovering niobium from uranium-niobium alloys

    DOEpatents

    Wallace, S.A.; Creech, E.T.; Northcutt, W.G.

    1982-09-27

    Niobium is recovered from scrap uranium-niobium alloy by melting the scrap with tin, solidifying the billet thus formed, heating the billet to combine niobium with tin therein, placing the billet in hydrochloric acid to dissolve the uranium and form a precipitate of niobium stannide, then separating the precipitate from the acid.

  4. Melting And Purification Of Niobium

    SciTech Connect

    Salles Moura, Hernane R.; Moura, Lourenco de

    2007-08-09

    The aspects involved in the purification of niobium in Electron Beam Furnaces will be outlined and correlated with practical experience accumulated over 17 years of continuously producing high purity niobium metal and niobium-zirconium ingots at CBMM, meeting the needs for a wide range of uses. This paper also reports some comments regarding raw material requirements, the experience on cold hearth operation melting niobium and the production of large grains niobium ingots by CBMM with some comments of their main characteristics.

  5. Melting And Purification Of Niobium

    NASA Astrophysics Data System (ADS)

    Moura, Hernane R. Salles; de Moura, Lourenço

    2007-08-01

    The aspects involved in the purification of niobium in Electron Beam Furnaces will be outlined and correlated with practical experience accumulated over 17 years of continuously producing high purity niobium metal and niobium-zirconium ingots at CBMM, meeting the needs for a wide range of uses. This paper also reports some comments regarding raw material requirements, the experience on cold hearth operation melting niobium and the production of large grains niobium ingots by CBMM with some comments of their main characteristics.

  6. Introduction to Ingot Niobium

    SciTech Connect

    Myneni, Ganapati Rao; Hutton, Andrew

    2011-03-31

    Superconducting radiofrequency (SRF) technology using niobium accelerating cavities was first applied at large scale in the recirculating electron linear accelerator CEBAF--the Continuous Electron Beam Accelerator Facility in Newport News, Virginia, USA, at what is now called Thomas Jefferson National Accelerator Facility, or Jefferson Lab. Building on the high quality factors and peak magnetic fields found in low residual resistivity ratio (low-RRR) solid niobium in the 1970s, Jefferson Lab has reintroduced ingot niobium technology. High tantalum content in ingot niobium is not expected to negatively impact cavity performance, but will reduce the cost of accelerator structures considerably. Optimized low-cost CW linear accelerators built with ingot niobium will show the way for future R and D and industrial applications. This paper portrays the Jefferson Lab SRF context, reviews the early history of ingot niobium technology from over a third of a century ago, explains the technical advantages of that technology's recent reintroduction, and presents the outlook for further development.

  7. Introduction to Ingot Niobium

    SciTech Connect

    Ganapati Rao Mynen, Andrew Hutton

    2011-03-01

    Superconducting radiofrequency (SRF) technology using niobium accelerating cavities was first applied at large scale in the recirculating electron linear accelerator CEBAF—the Continuous Electron Beam Accelerator Facility in Newport News, Virginia, USA, at what is now called Thomas Jefferson National Accelerator Facility, or Jefferson Lab. Building on the high quality factors and peak magnetic fields found in low residual resistivity ratio (low-RRR) solid niobium in the 1970s, Jefferson Lab has reintroduced ingot niobium technology. High tantalum content in ingot niobium is not expected to negatively impact cavity performance, but will reduce the cost of accelerator structures considerably. Optimized low-cost CW linear accelerators built with ingot niobium will show the way for future R&D and industrial applications. This paper portrays the Jefferson Lab SRF context, reviews the early history of ingot niobium technology from over a third of a century ago, explains the technical advantages of that technology's recent reintroduction, and presents the outlook for further development.

  8. One hundred angstrom niobium wire

    NASA Technical Reports Server (NTRS)

    Cline, H. E.; Rose, R. M.; Wulff, J.

    1968-01-01

    Composite of fine niobium wires in copper is used to study the size and proximity effects of a superconductor in a normal matrix. The niobium rod was drawn to a 100 angstrom diameter wire on a copper tubing.

  9. Proton in SRF Niobium

    SciTech Connect

    Wallace, John Paul

    2011-03-31

    Hydrogen is a difficult impurity to physically deal with in superconducting radio frequency (SRF) niobium, therefore, its properties in the metals should be well understood to allow the metal's superconducting properties to be optimized for minimum loss in the construction of resonant accelerator cavities. It is known that hydrogen is a paramagnetic impurity in niobium from NMR studies. This paramagnetism and its effect on superconducting properties are important to understand. To that end analytical induction measurements aimed at isolating the magnetic properties of hydrogen in SRF niobium are introduced along with optical reflection spectroscopy which is also sensitive to the presence of hydrogen. From the variety, magnitude and rapid kinetics found in the optical and magnetic properties of niobium contaminated with hydrogen forced a search for an atomic model. This yielded quantum mechanical description that correctly generates the activation energy for diffusion of the proton and its isotopes not only in niobium but the remaining metals for which data is available. This interpretation provides a frame work for understanding the individual and collective behavior of protons in metals.

  10. METHOD OF PRODUCING NIOBIUM METAL

    DOEpatents

    Wilhelm, H.A.; Stevens, E.R.

    1960-05-24

    A process is given for preparing ductile niobium metal by the reduction of niobium pentoxide with carbon. The invention resides in the addition, to the reaction mass, of from 0.05 to 0.4 atom of titanium (in the form of metallic titanium, titanium carbide, and/or titanium oxide) per one mole of niobium pentoxide. The mixture is heated under subatmospheric pressure to above 1300 deg C but below the melting point of niobium, and the carbon- and oxygen-free niobium sponge obtained is cooled under reduced pressure.

  11. Method of surface preparation of niobium

    DOEpatents

    Srinivasan-Rao, Triveni; Schill, John F.

    2003-01-01

    The present invention is for a method of preparing a surface of niobium. The preparation method includes polishing, cleaning, baking and irradiating the niobium surface whereby the resulting niobium surface has a high quantum efficiency.

  12. Niobium and niobium nitride contacts on semiconducting material

    SciTech Connect

    Cukauskas, E.; Carter, W.; Pond, J.; Newman, H.

    1989-06-30

    This invention related generally to a metallization layer of niobium or niobium nitride on a semiconductor in an integrated-circuit structure, which can function from the superconducting-temperature regime to above room temperature. Niobium or niobium nitride is deposited onto a heated gallium arsenide substrate. This metallization will maintain chemical stability after high-temperature post processing. These materials provide a low-resistivity metallization suitable for Schottky contacts used over a wide operating temperature range and are superconducting at low temperatures.

  13. Vapor deposition of hardened niobium

    DOEpatents

    Blocher, Jr., John M.; Veigel, Neil D.; Landrigan, Richard B.

    1983-04-19

    A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

  14. Large grain cavities from pure niobium ingot

    SciTech Connect

    Myneni, Ganapati Rao; Kneisel, Peter; Cameiro, Tadeu

    2012-03-06

    Niobium cavities are fabricated by the drawing and ironing of as cast niobium ingot slices rather than from cold rolled niobium sheet. This method results in the production of niobium cavities having a minimum of grain boundaries at a significantly reduced cost as compared to the production of such structures from cold rolled sheet.

  15. NIOBIUM-TANTALUM SEPARATION

    DOEpatents

    Wilhelm, H.A.; Foos, R.A.

    1959-01-27

    The usual method for the separation of tantalum and niobium consists of a selective solvent extraction from an aqueous hydrofluoric acid solution of the metals. A difficulty encountered in this process is the fact that the corrosion problems associated with hydrofluoric acid are serious. It has been found that the corrosion caused by the hydrofluoric acid may be substantially reduced by adding to the acidic solution an amine, such as phenyl diethanolamine or aniline, and adjusting pH value to between 4 and 6.

  16. Niobium Production at Tokyo Denkai

    SciTech Connect

    Umezawa, Hiroaki

    2011-03-31

    In recent years, single-crystal/large-grain niobium has received much attention. It has the following advantages: rolling-annealing is unnecessary, and superconducting cavities made from large-grain niobium discs may not require electropolishing. However, to obtain a large-grain disc, an ingot must be sliced using a saw and finished smooth by using a lathe. Slicing a disc takes several hours and produces niobium shavings. KEK, Tokyo Denkai, and TKX Corporation have developed a new niobium ingot slicing technique, and Tokyo Denkai has installed the slicing machine. This study describes the new ingot slicing technology, which ensures state-of-the-art productivity for the superconducting radio frequency (SRF) cavity material industry.

  17. Mechanical properties of niobium radio-frequency cavities

    DOE PAGESBeta

    Ciovati, Gianluigi; Dhakal, Pashupati; Matalevich, Joseph R.; Myneni, Ganapati Rao; Schmidt, A.; Iversen, J.; Matheisen, A.; Singer, W.

    2015-07-02

    Radio-frequency cavities made of bulk niobium are one of the components used in modern particle accelerators. The mechanical stability is an important aspect of cavity design, which typically relies on finite-element analysis simulations using material properties from tensile tests on sample. This contribution presents the results of strain and resonant frequency measurements as a function of a uniform pressure up to 722 kPa, applied to single-cell niobium cavities with different crystallographic structure, purity and treatments. In addition, burst tests of high-purity multi-cell cavities with different crystallographic structure have been conducted up to the tensile strength of the material. Finite-element analysismore » of the single-cell cavity geometry is in good agreement with the observed behavior in the elastic regime assuming a Young's modulus value of 88.5 GPa and a Poisson's ratio of 0.4, regardless of crystallographic structure, purity or treatment. However, the measured yield strength and tensile strength depend on crystallographic structure, material purity and treatment. In particular, the results from this study show that the mechanical properties of niobium cavities with large crystals are comparable to those of cavities made of fine-grain niobium.« less

  18. Mechanical properties of niobium radio-frequency cavities

    SciTech Connect

    Ciovati, Gianluigi; Dhakal, Pashupati; Matalevich, Joseph R.; Myneni, Ganapati Rao; Schmidt, A.; Iversen, J.; Matheisen, A.; Singer, W.

    2015-07-02

    Radio-frequency cavities made of bulk niobium are one of the components used in modern particle accelerators. The mechanical stability is an important aspect of cavity design, which typically relies on finite-element analysis simulations using material properties from tensile tests on sample. This contribution presents the results of strain and resonant frequency measurements as a function of a uniform pressure up to 722 kPa, applied to single-cell niobium cavities with different crystallographic structure, purity and treatments. In addition, burst tests of high-purity multi-cell cavities with different crystallographic structure have been conducted up to the tensile strength of the material. Finite-element analysis of the single-cell cavity geometry is in good agreement with the observed behavior in the elastic regime assuming a Young's modulus value of 88.5 GPa and a Poisson's ratio of 0.4, regardless of crystallographic structure, purity or treatment. However, the measured yield strength and tensile strength depend on crystallographic structure, material purity and treatment. In particular, the results from this study show that the mechanical properties of niobium cavities with large crystals are comparable to those of cavities made of fine-grain niobium.

  19. METHOD FOR COATING GRAPHITE WITH NIOBIUM CARBIDE

    DOEpatents

    Kane, J.S.; Carpenter, J.H.; Krikorian, O.H.

    1962-01-16

    A method is given for coating graphite with a hard, tenacious layer of niobium carbide up to 30 mils or more thick. The method makes use of the discovery that niobium metal, if degassed and heated rapidly below the carburization temperature in contact with graphite, spreads, wets, and penetrates the graphite without carburization. The method includes the obvious steps of physically contacting niobium powders or other physical forms of niobium with graphite, degassing the assembly below the niobium melting point, e.g., 1400 deg C, heating to about 2200 to 2400 deg C within about 15 minutes while outgassing at a high volume throughput, and thereafter carburizing the niobium. (AEC)

  20. Niobium and tantalum: indispensable twins

    USGS Publications Warehouse

    Schulz, Klaus; Papp, John

    2014-01-01

    Niobium and tantalum are transition metals almost always paired together in nature. These “twins” are difficult to separate because of their shared physical and chemical properties. In 1801, English chemist Charles Hatchett uncovered an unknown element in a mineral sample of columbite; John Winthrop found the sample in a Massachusetts mine and sent it to the British Museum in London in 1734. The name columbium, which Hatchet named the new element, came from the poetic name for North America—Columbia—and was used interchangeably for niobium until 1949, when the name niobium became official. Swedish scientist Anders Ekberg discovered tantalum in 1802, but it was confused with niobium, because of their twinned properties, until 1864, when it was recognized as a separate element. Niobium is a lustrous, gray, ductile metal with a high melting point, relatively low density, and superconductor properties. Tantalum is a dark blue-gray, dense, ductile, very hard, and easily fabricated metal. It is highly conductive to heat and electricity and renowned for its resistance to acidic corrosion. These special properties determine their primary uses and make niobium and tantalum indispensable.

  1. Niobium - Proceedings of the international symposium

    SciTech Connect

    Stuart, H.

    1984-01-01

    This book presents the papers given at a symposium on niobium. Topics considered at the symposium included niobium mining, ore processing, uses, fabrication, microstructure, mechanical properties, physical properties, corrosion, physical radiation effects, and marketing.

  2. Preparation of cubic niobium pyrophosphate containing Nb(IV) and topatactic extraction of phosphorus atoms

    SciTech Connect

    Fukuoka, Hiroshi; Imoto, Hideo; Saito, Taro

    1995-10-01

    A reduced phase of niobium pyrophosphate containing Nb{sup 4+} has been prepared from the reaction of Nb{sup 6}Cl{sub 14}{center_dot}8H{sub 2}O and phosphoric acid. The X-ray powder diffraction and electron diffraction studies have shown that the compound belongs to the Pa3 space group and has the ZrP{sub 2}O{sub 7} structure with a cubic superstructure (a{prime} = 3a{sub 0}). Magnetic susceptibility was measured for two samples, and the mean oxidation numbers of niobium in them are deduced to by + 4.66 and +4.88. The cell constants of these samples are a = 8.0830(4) and 8.0705(2) {angstrom}, respectively. As the mean oxidation number of niobium increases, the color of the compound varies from brown to gray. When the compound is heated in oxygen, it changes into the known white niobium pyrophosphate, in which all niobium is in the +5 oxidation state. Rietveld refinements indicate that niobium pyrophosphates have defects in the phosphorus sites. The topotactic extraction of the phosphorus atoms in the reaction with oxygen was confirmed by the analysis of phosphorus oxide generated during the reaction.

  3. Spectrophotometric determination of niobium and its application to niobium-stabilized stainless steel.

    PubMed

    Dutta, R K; Banerjee, S

    1974-10-01

    A spectrophotometric method is described for the determination of niobium by means of its reaction with tannin and thioglycollic acid. The yellow-orange colour developed with the reagent mixture at pH 4 is measured at 410-420 nm and obeys Beer's law between 0.5 and 10 ppm niobium. The method is suitable for the determination of niobium in niobium-stabilized stainless steel and other types of steels containing niobium, but a prior separation of niobium is necessary. Titanium interferes even in traces. PMID:18961571

  4. Dissipative hydride precipitates in superconducting niobium cavities

    SciTech Connect

    Romanenko, A.; Cooley, L.D.; Ciovati, G.; Wu, G.; /Argonne

    2011-10-01

    We report the first direct observation of the microstructural features exhibiting RF losses at high surface magnetic fields of above 100 mT in field emission free superconducting niobium cavities. The lossy areas were identified by advanced thermometry. Surface investigations using different techniques were carried out on cutout samples from lossy areas and showed the presence of dendritic niobium hydrides. This finding has possible implications to the mechanisms of RF losses in superconducting niobium at all field levels.

  5. Niobium content of soils from West Africa

    USGS Publications Warehouse

    Grimaldi, F.S.; Berger, I.A.

    1961-01-01

    Analysis of twenty lateritic soil samples from West Africa has shown them to contain an average 24 p.p.m. of niobium; four similar samples taken from within a few miles from a niobium deposit contain from 79 to 87 p.p.m. niobium. It has been shown that as the aluminum content of the soils increases, the following depletion sequence is obtained: Si > Nb > Al = Fe The data indicate that, in general, high enrichments of niobium are not to be expected in lateritic soils. ?? 1961.

  6. Process for alloying uranium and niobium

    DOEpatents

    Holcombe, Cressie E.; Northcutt, Jr., Walter G.; Masters, David R.; Chapman, Lloyd R.

    1991-01-01

    Alloys such as U-6Nb are prepared by forming a stacked sandwich array of uraniun sheets and niobium powder disposed in layers between the sheets, heating the array in a vacuum induction melting furnace to a temperature such as to melt the uranium, holding the resulting mixture at a temperature above the melting point of uranium until the niobium dissolves in the uranium, and casting the uranium-niobium solution. Compositional uniformity in the alloy product is enabled by use of the sandwich structure of uranium sheets and niobium powder.

  7. STS-88 Crew Portrait

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Five NASA astronauts and a Russian cosmonaut assigned to the STS-88 mission pose for a crew portrait. Seated in front (left to right) are mission specialists Sergei K. Krikalev, representing the Russian Space Agency (RSA), and astronaut Nancy J. Currie. In the rear from the left, are astronauts Jerry L. Ross, mission specialist; Robert D. Cabana, mission commander; Frederick W. 'Rick' Sturckow, pilot; and James H. Newman, mission specialist. The STS-88 mission launched aboard the Space Shuttle Endeavor on December 4, 1998 at 2:35 a.m. (CST) to deliver the Unity Node to the International Space Station (ISS).

  8. Purification of Niobium by Electron Beam Melting

    NASA Astrophysics Data System (ADS)

    Sankar, M.; Mirji, K. V.; Prasad, V. V. Satya; Baligidad, R. G.; Gokhale, A. A.

    2016-06-01

    Pure niobium metal, produced by alumino-thermic reduction of niobium oxide, contains various impurities which need to be reduced to acceptable levels to obtain aerospace grade purity. In the present work, an attempt has been made to refine niobium metals by electron beam drip melting technique to achieve purity confirming to the ASTM standard. Input power to the electron gun and melt rate were varied to observe their combined effect on extend of refining and loss of niobium. Electron beam (EB) melting is shown to reduce alkali metals, trace elements and interstitial impurities well below the specified limits. The reduction in the impurities during EB melting is attributed to evaporation and degassing due to the combined effect of high vacuum and high melt surface temperature. The % removal of interstitial impurities is essentially a function of melt rate and input power. As the melt rate decreases or input power increases, the impurity levels in the solidified niobium ingot decrease. The EB refining process is also accompanied by considerable amount of niobium loss, which is attributed to evaporation of pure niobium and niobium sub-oxide. Like other impurities, Nb loss increases with decreasing melt rate or increase in input power.

  9. Free energy of hydration of niobium oxide

    SciTech Connect

    Plodinec, M.J.

    1996-08-21

    Some of the glasses being formulated by SRTC researchers contain niobium oxide. In this report, the free energy of hydration of the oxide is calculated from the free energies of formation of the oxide, the hydroxide, and water. This value can be used in calculations of the free energy of hydration of glasses containing niobium.

  10. Method of nitriding niobium to form a superconducting surface

    DOEpatents

    Kelley, Michael J.; Klopf, John Michael; Singaravelu, Senthilaraja

    2014-08-19

    A method of forming a delta niobium nitride .delta.-NbN layer on the surface of a niobium object including cleaning the surface of the niobium object; providing a treatment chamber; placing the niobium object in the treatment chamber; evacuating the chamber; passing pure nitrogen into the treatment chamber; focusing a laser spot on the niobium object; delivering laser fluences at the laser spot until the surface of the niobium object reaches above its boiling temperature; and rastering the laser spot over the surface of the niobium object.

  11. Method for etching thin films of niobium and niobium-containing compounds for preparing superconductive circuits

    DOEpatents

    Kampwirth, Robert T.; Schuller, Ivan K.; Falco, Charles M.

    1981-01-01

    An improved method of preparing thin film superconducting electrical circuits of niobium or niobium compounds in which a thin film of the niobium or niobium compound is applied to a nonconductive substrate, and covered with a layer of photosensitive material. The sensitive material is in turn covered with a circuit pattern exposed and developed to form a mask of the circuit in photoresistive material on the surface of the film. The unmasked excess niobium film is removed by contacting the substrate with an aqueous etching solution of nitric acid, sulfuric acid and hydrogen fluoride, which will rapidly etch the niobium compound without undercutting the photoresist. A modification of the etching solution will permit thin films to be lifted from the substrate without further etching.

  12. Buffered Electrochemical Polishing of Niobium

    SciTech Connect

    Gianluigi Ciovati; Tian, Hui; Corcoran, Sean

    2011-03-01

    The standard preparation of superconducting radio-frequency (SRF) cavities made of pure niobium include the removal of a 'damaged' surface layer, by buffered chemical polishing (BCP) or electropolishing (EP), after the cavities are formed. The performance of the cavities is characterized by a sharp degradation of the quality factor when the surface magnetic field exceeds about 90 mT, a phenomenon referred to as 'Q-drop.' In cavities made of polycrystalline fine grain (ASTM 5) niobium, the Q-drop can be significantly reduced by a low-temperature (? 120 °C) 'in-situ' baking of the cavity if the chemical treatment was EP rather than BCP. As part of the effort to understand this phenomenon, we investigated the effect of introducing a polarization potential during buffered chemical polishing, creating a process which is between the standard BCP and EP. While preliminary results on the application of this process to Nb cavities have been previously reported, in this contribution we focus on the characterization of this novel electrochemical process by measuring polarization curves, etching rates, surface finish, electrochemical impedance and the effects of temperature and electrolyte composition. In particular, it is shown that the anodic potential of Nb during BCP reduces the etching rate and improves the surface finish.

  13. A Terminally Bound Niobium Methylidyne.

    PubMed

    Kurogi, Takashi; Carroll, Patrick J; Mindiola, Daniel J

    2016-04-01

    Complex (PNP)Nb(CH3)2(OAr) (PNP = N[2-P(i)Pr2-4-methylphenyl]2(-), Ar = 2,6-(i)Pr2C6H3), prepared from treatment of (PNP)NbCl3 with NaOAr followed by 2 equiv of H3CMgCl, can be oxidized with [FeCp2][OTf] to afford (PNP)Nb(CH3)2(OAr)(OTf). While photolysis of the latter resulted in formation of a rare example of a niobium methylidene, (PNP)Nb═CH2(OAr)(OTf), treatment of the dimethyl triflate precursor with the ylide H2CPPh3 produced the mononuclear group 5 methylidyne complex, (PNP)Nb≡CH(OAr). Adding a Brønsted base to (PNP)Nb═CH2(OAr)(OTf) also resulted in formation of the methylidyne. Solid-state structural analysis confirms both methylidene and methylidyne moieties to be terminal, having very short Nb-C distances of 1.963(2) and 1.820(2) Å, respectively. It is also shown that methylidyne for nitride cross-metathesis between (PNP)Nb≡CH(OAr) and NCR (R = tert-butyl or 1-adamantyl) results in formation of a neutral and mononuclear niobium nitride, (PNP)Nb≡N(OAr), along with the terminal alkyne HC≡CR. PMID:26977892

  14. Fatigue of niobium. Technical progress report

    SciTech Connect

    Stoloff, N. S.

    1980-01-31

    Tests to determine the effects of frequency, test temperature, and hydrogen content on the fatigue life and crack propagation behavior of polycrystalline niobium are described. Unalloyed niobium is nearly insensitive to test frequency at 25/sup 0/C, while hydrided alloys exhibit a strong frequency effect. Increasing test temperature decreases fatigue life, consistent with decreasing tensile strength. A brief survey of irradiation effects on fatigue of refractory metal alloys suggests that fatigue resistance of irradiated niobium should increase in proportion to effects on strength.

  15. Degreasing and cleaning superconducting RF Niobium cavities

    SciTech Connect

    Rauchmiller, Michael; Kellett, Ron; /Fermilab

    2011-09-01

    The purpose and scope of this report is to detail the steps necessary for degreasing and cleaning of superconducting RF Niobium cavities in the A0 clean room. It lists the required equipment and the cleaning procedure.

  16. Mineral Resource of the Month: Niobium

    USGS Publications Warehouse

    Papp, John F.

    2014-01-01

    Niobium, also called columbium, is a transition metal with a very high melting point. It is in greatest demand in industrialized countries, like the United States, because of its defense-related uses in the aerospace, energy and transportation industries. Niobium is used mostly to make high-strength, low-alloy (HSLA) steel and stainless steel. HSLA steels are used in large-diameter pipes for oil and natural gas pipelines and automobile wheels.

  17. Mineral resource of the month: niobium (columbium)

    USGS Publications Warehouse

    Papp, John F.

    2007-01-01

    It’s not just diamonds associated with conflict in Africa. Coltan, short for columbite-tantalite (a blend of niobium — also called columbium — and tantalum minerals), is linked with the recent conflicts in the Congo that involved several African countries. The metallic ore, which is processed to separate out niobium and the very valuable tantalum (see Geotimes, August 2004), is believed to be smuggled out and sold to help finance the armed conflicts.

  18. Investigation of proton induced reactions on niobium at low and medium energies

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Hermanne, A.; Corniani, E.; Takács, S.; Tárkányi, F.; Csikai, J.; Shubin, Yu. N.

    2009-10-01

    Niobium is a metal with important technological applications: use as alloying element to increase strength of super alloys, as thin layer for tribological applications, as superconductive material, in high temperature engineering systems, etc. In the frame of a systematic study of activation cross-sections of charged particle induced reactions on structural materials proton induced excitation functions on Nb targets were determined with the aim of applications in accelerator and reactor technology and for thin layer activation (TLA). The charged particle activation cross-sections on this element are also important for yield calculation of medical isotope production ( 88,89Zr, 86,87,88Y) and for dose estimation in PET targetry. As niobium is a monoisotopic element it is an ideal target material to test nuclear reaction theories. We present here the experimental excitation functions of 93Nb(p,x) 90,93mMo, 92m,91m,90Nb, 88,89Zr and 88Y in the energy range 0-37 MeV. The results were compared with the theoretical cross-sections calculated by means of the code ALICE-IPPE, EMPIRE-3, TALYS and with the literature data. The theory reproduces the shape of the measured results well and magnitude is also acceptable. Thick target yields calculated from our fitted cross-section give reliable estimations for production of medically relevant radioisotopes and for dose estimation in accelerator technology.

  19. 40 CFR 721.10602 - Lead niobium titanium zirconium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Lead niobium titanium zirconium oxide... Specific Chemical Substances § 721.10602 Lead niobium titanium zirconium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lead niobium...

  20. 40 CFR 721.10602 - Lead niobium titanium zirconium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Lead niobium titanium zirconium oxide... Specific Chemical Substances § 721.10602 Lead niobium titanium zirconium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lead niobium...

  1. Niobium based coatings for dental implants

    NASA Astrophysics Data System (ADS)

    Ramírez, G.; Rodil, S. E.; Arzate, H.; Muhl, S.; Olaya, J. J.

    2011-01-01

    Niobium based thin films were deposited on stainless steel (SS) substrates to evaluate them as possible biocompatible surfaces that might improve the biocompatibility and extend the life time of stainless steel dental implants. Niobium nitride and niobium oxide thin films were deposited by reactive unbalanced magnetron sputtering under standard deposition conditions without substrate bias or heating. The biocompatibility of the surfaces was evaluated by testing the cellular adhesion and viability/proliferation of human cementoblasts during different culture times, up to 7 days. The response of the films was compared to the bare substrate and pieces of Ti6Al4V; the most commonly used implant material for orthopedics and osteo-synthesis applications. The physicochemical properties of the films were evaluated by different means; X-ray diffraction, Rutherford backscattering spectroscopy and contact angle measurements. The results suggested that the niobium oxide films were amorphous and of stoichiometric Nb2O5 (a-Nb2O5), while the niobium nitride films were crystalline in the FCC phase (c-NbN) and were also stoichiometric with an Nb to N ratio of one. The biological evaluation showed that the biocompatibility of the SS could be improved by any of the two films, but neither was better than the Ti6Al4V alloy. On the other hand, comparing the two films, the c-NbN seemed to be a better surface than the oxide in terms of the adhesion and proliferation of human cemetoblasts.

  2. Radioactivity analysis in niobium activation foils

    SciTech Connect

    Mueller, G.E.

    1995-06-01

    The motivation for this study was to measure and analyze the activity of six (6) niobium (Nb) foils (the x-rays from an internal transition in Nb-93m) and apply this information with previously obtained activation foil data. The niobium data was used to determine the epithermal to MeV range for the neutron spectrum and fluence. The foil activation data was re-evaluated in a spectrum analysis code (STAY`SL) to provide new estimates of the exposure at the Los Alamos Spallation Radiation Effect Facility (LASREF). The activity of the niobium foils was measured and analyzed at the University of Missouri-Columbia (UMC) under the direction of Professor William Miller. The spectrum analysis was performed at the University of Missouri-Rolla (UMR) by Professor Gary Mueller.

  3. Recovery of niobium from irradiated targets

    DOEpatents

    Phillips, Dennis R.; Jamriska, Sr., David J.; Hamilton, Virginia T.

    1994-01-01

    A process for selective separation of niobium from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected form the group consisting of molybdenum, biobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the cationic resin; adjusting the pH of the second ion-containing solution to within a range of from about 5.0 to about 6.0; contacting the pH adjusting second ion-containing solution with a dextran-based material for a time to selectively separate niobium from the solution and recovering the niobium from the dextran-based material.

  4. Production of High Purity Niobium Ingots at CBMM

    NASA Astrophysics Data System (ADS)

    de Moura, Lourenço; de Faria Sousa, Clovis Antonio; Cruz, Edmundo Burgos

    2011-03-01

    CBMM is a fully integrated company, from the mine to the end line of the production chain, supplying different niobium products to the world market: ferroniobium, nickelniobium, niobium pentoxide and high purity metallic niobium. This high purity metallic niobium has long been known to exhibit superconductivity below 9.25 Kelvin. This characteristic has the potential to bring technological benefits for many different areas such as medicine, computing and environment. This paper presents the raw material requirements as well as CBMM experience on producing high purity niobium ingots. The results prove that CBMM material can be the best solution for special applications such as low cost superconductive radiofrequency cavities.

  5. Production of High Purity Niobium Ingots at CBMM

    SciTech Connect

    Moura, Lourenco de; Faria Sousa, Clovis Antonio de; Burgos Cruz, Edmundo

    2011-03-31

    CBMM is a fully integrated company, from the mine to the end line of the production chain, supplying different niobium products to the world market: ferroniobium, nickelniobium, niobium pentoxide and high purity metallic niobium. This high purity metallic niobium has long been known to exhibit superconductivity below 9.25 Kelvin. This characteristic has the potential to bring technological benefits for many different areas such as medicine, computing and environment. This paper presents the raw material requirements as well as CBMM experience on producing high purity niobium ingots. The results prove that CBMM material can be the best solution for special applications such as low cost superconductive radiofrequency cavities.

  6. Residual charge of niobium spheres

    SciTech Connect

    Phillips, J.D.

    1984-01-01

    In 1964, Gell-Mann and Zweig hypothesized that the particles inside nuclei are composed of quarks with electric charges of {plus minus} 1/3 e and {plus minus} 1/2 e. Since then, many searches have been made for stable fractional charges. The experiment described in a Millikan-type electrometer with a sample 10{sup 7} times heavier. A 0.28 mm diameter superconducting niobium ball is levitated magnetically between capacitor plates. The ball oscillates vertically on this magnetic spring and an electric field is applied at the oscillation frequency. The rate of change of the ball's oscillation amplitude is proportional to the force exerted on the ball by the electric field. The force on the ball is measured as a function of its position between the capacitor plates to discriminate against the background force due to the patch effect field gradient of the plates. There is one other background effect, due to the tilting of the ball's magnetic moment, which has sometimes manifested itself as a drift or occasionally as an offset in the measured force. An analysis presented in this thesis explains a mechanism for this effect and shows that we can eliminate it in our next run by spinning the ball about the vertical axis. The results are strong evidence for the existence of stable fractional charges of {plus minus} 1/3 e in matter. Out of 58 measurements on 20 balls, 9 have yielded results near - 1/3 e, 34 near 0, 13 near + 1/3e, one of the 0.19 e, and one of 0.44 e. Out of 38 repeat measurements, there have been 12 residual charge changes, 5 near - 1/3e and 7 near + 1/3 e.

  7. Crystallization of niobium germanosilicate glasses

    SciTech Connect

    Santos, Rodrigo; Wondraczek, Lothar

    2010-01-15

    Niobium germanosilicate glasses are potential candidates for the fabrication of transparent glass ceramics with interesting non-linear optical properties. A series of glasses in the (Ge,Si)O{sub 2}-Nb{sub 2}O{sub 5}-K{sub 2}O system were prepared by melting and casting and their characteristic temperatures were determined by differential thermal analysis. Progressive replacement of GeO{sub 2} by SiO{sub 2} improved the thermal stability of the glasses. Depending on the composition and the crystallization heat-treatment, different nanocrystalline phases-KNbSi{sub 2}O{sub 7}, K{sub 3}Nb{sub 3}Si{sub 2}O{sub 13} and K{sub 3.8}Nb{sub 5}Ge{sub 3}O{sub 20.4} could be obtained. The identification and characterization of these phases were performed by X-ray diffraction and Raman spectroscopy. The 40 GeO{sub 2}-10 SiO{sub 2}-25 Nb{sub 2}O{sub 5}-25 K{sub 2}O (mol%) composition presented the higher ability for volume crystallization and its nucleation temperature was determined by the Marotta's method. An activation energy for crystal growth of {approx}529 kJ/mol and a nucleation rate of 9.7x10{sup 18} m{sup -3} s{sup -1} was obtained, for this composition. Transparent glass ceramics with a crystalline volume fraction of {approx}57% were obtained after a 2 h heat-treatment at the nucleation temperature, with crystallite sizes of {approx}20 nm as determined by transmission electron microscopy. - Abstract: TEM image and XRD pattern of the glass ceramic produced (circles indicate nanocrystals).

  8. Developing of superconducting niobium cavities for accelerators

    NASA Astrophysics Data System (ADS)

    Pobol, I. L.; Yurevich, S. V.

    2015-11-01

    The results of a study of structure and mechanical properties of welding joints, superconducting characteristics of the material after joining of welded components of superconducting radio frequency cavities are presented. The paper also describes the results of testing of the RF 1.3 GHz single-cell niobium cavity manufactured in the PTI NAS Belarus.

  9. RF Sputtering of Gold Contacts On Niobium

    NASA Technical Reports Server (NTRS)

    Barr, D. W.

    1983-01-01

    Reliable gold contacts are deposited on niobium by combination of RF sputtering and photolithography. Process results in structures having gold only where desired for electrical contact. Contacts are stable under repeated cycling from room temperature to 4.2 K and show room-temperature contact resistance as much as 40 percent below indium contacts made by thermalcompression bonding.

  10. A spiraled niobium tin superconductive ribbon

    NASA Technical Reports Server (NTRS)

    Coles, W. D.

    1973-01-01

    Copper film is vapor-deposited on clean ribbon and sprayed with photosensitive etch-resistant material. Photographic film masks are placed on ribbon and exposed to ultraviolet light. Etchant removes copper and exposure to oxidizing atmosphere forms niobium oxide. Photosensitive material is removed and ribbon is immersed in molten temperatures.

  11. PROCESS OF COATING GRAPHITE WITH NIOBIUM-TITANIUM CARBIDE

    DOEpatents

    Halden, F.A.; Smiley, W.D.; Hruz, F.M.

    1961-07-01

    A process of coating graphite with niobium - titanium carbide is described. It is found that the addition of more than ten percent by weight of titanium to niobium results in much greater wetting of the graphite by the niobium and a much more adherent coating. The preferred embodiment comprises contacting the graphite with a powdered alloy or mixture, degassing simultaneously the powder and the graphite, and then heating them to a high temperature to cause melting, wetting, spreading, and carburization of the niobium-titanium powder.

  12. Nitrogen doping study in ingot niobium cavities

    SciTech Connect

    Dhakal, Pashupati; Ciovati, Gianluigi; Kneisel, Peter; Myneni, Ganapati Rao; Makita, Junki

    2015-09-01

    Thermal diffusion of nitrogen in niobium superconducting radio frequency cavities at temperature ~800 °C has resulted in the increase in quality factor with a low-field Q-rise extending to Bp > 90 mT. However, the maximum accelerating gradient of these doped cavities often deteriorates below the values achieved by standard treatments prior to doping. Here, we present the results of the measurements on ingot niobium cavities doped with nitrogen at 800 °C. The rf measurements were carried out after the successive electropolishing to remove small amount of material from the inner surface layer. The result showed higher breakdown field with lower quality factor as material removal increases.

  13. Field Emission Measurements from Niobium Electrodes

    SciTech Connect

    M. BastaniNejad, P.A. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, R. Mammei, M. Poelker

    2011-03-01

    Increasing the operating voltage of a DC high voltage photogun serves to minimize space charge induced emittance growth and thereby preserve electron beam brightness, however, field emission from the photogun cathode electrode can pose significant problems: constant low level field emission degrades vacuum via electron stimulated desorption which in turn reduces photocathode yield through chemical poisoning and/or ion bombardment and high levels of field emission can damage the ceramic insulator. Niobium electrodes (single crystal, large grain and fine grain) were characterized using a DC high voltage field emission test stand at maximum voltage -225kV and electric field gradient > 10MV/m. Niobium electrodes appear to be superior to diamond-paste polished stainless steel electrodes.

  14. Microstructures in rapidly solidified niobium aluminides

    NASA Technical Reports Server (NTRS)

    Hebsur, Mohan G.; Locci, Ivan E.

    1988-01-01

    The microstructures of niobium aluminides produced by chill block melt spinning were compared to those of niobium aluminides produced by conventional casting. The rapidly solidified alloys were rapidly solidified by melt spinning in an argon atmosphere, and the melt-spun ribbons were examined by optical, X-ray, and TEM techniques. Microstructures were found to range from single-phase for Nb-75 at. pct Al (NbAl3) to two phase for Nb-46 at. pct Al (NbAl3 + Nb2Al). It was found that the melt spinning of Nb-aluminides produced finer grained microstructures than those produced in induction-melted ingots or in powders produced by the rotating electrode process. Ternary additions such as Cr, Ti, and Si tended to form intermetallic phases along the grain boundaries.

  15. Microwave mixing with niobium variable thickness bridges

    NASA Technical Reports Server (NTRS)

    Wang, L.-K.; Callegari, A.; Deaver, B. S., Jr.

    1977-01-01

    Niobium thin-film bridges 300-A thick, 1-micron wide, and 0.5-micron long joining two bulk films 5000-A thick and having normal resistance of the order of 1 ohm have been fabricated and used for microwave mixing at 10 GHz. They exhibit Josephson, bolometric, and multiple-flux-flow mixing and have useful response at 100-200 GHz. The data show in a direct way limitations imposed by flux flow and heating.

  16. Mechanical properties of carbon-implanted niobium

    SciTech Connect

    Zinkle, S.J. ); Huang, J.S. )

    1990-01-01

    Polycrystalline niobium specimens were implanted with either 200 keV carbon ions or a combination of 50, 100, and 200 keV carbon ions to peak concentrations of 0.6 to 50 at. {percent}. Microindentation techniques were used to measure the hardness and elastic modulus of the implanted layer. Both the hardness (H) and modulus (E) showed dramatic increases due to the carbon implantation. The measured peak hardness and modulus following uniform implantation with 16 at. {percent} C were 15{times} and 3{times} that of niobium, respectively, which is comparable to the literature values for NbC. The peak hardness and modulus for the implanted specimens were observed at an indent depth of {approximately}40 nm, which is about one-eighth of the depth of the implanted carbon layer. The decrease in the indentation mechanical properties at deeper indent depths is due to the interaction of long-ranging strain fields underneath the indenter with the niobium substrate. 17 refs., 6 figs.

  17. ROUGHNESS ANALYSIS OF VARIOUSLY POLISHED NIOBIUM SURFACES

    SciTech Connect

    Ribeill, G.; Reece, C.

    2008-01-01

    Niobium superconducting radio frequency (SRF) cavities have gained widespread use in accelerator systems. It has been shown that surface roughness is a determining factor in the cavities’ effi ciency and maximum accelerating potential achievable through this technology. Irregularities in the surface can lead to spot heating, undesirable local electrical fi eld enhancement and electron multipacting. Surface quality is typically ensured through the use of acid etching in a Buffered Chemical Polish (BCP) bath and electropolishing (EP). In this study, the effects of these techniques on surface morphology have been investigated in depth. The surface of niobium samples polished using different combinations of these techniques has been characterized through atomic force microscopy (AFM) and stylus profi lometry across a range of length scales. The surface morphology was analyzed using spectral techniques to determine roughness and characteristic dimensions. Experimentation has shown that this method is a valuable tool that provides quantitative information about surface roughness at different length scales. It has demonstrated that light BCP pretreatment and lower electrolyte temperature favors a smoother electropolish. These results will allow for the design of a superior polishing process for niobium SRF cavities and therefore increased accelerator operating effi ciency and power.

  18. Creep behavior of tungsten/niobium and tungsten/niobium-1 percent zirconium composites

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Titran, R. H.

    1988-01-01

    A study was conducted to determine the feasibility of using tungsten fiber reinforced niobium or niobium-1 percent zirconium matrix composites to meet the anticipated increased temperature and creep resistance requirements imposed by advanced space power systems. The results obtained on the short time tensile properties indicated that W/Nb composites showed significant improvements in high temperature strength and offer significant mass reductions for high temperature space power systems. The prime material requirement for space power systems applications is long time creep resistance. A study was conducted to determine the effect of high temperature exposure on the properties of these composites, with emphasis upon their creep behavior at elevated temperatures.

  19. Study of proton induced reactions on niobium targets up to 70 MeV

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Takács, S.; Tárkányi, F.; Baba, M.; Corniani, E.; Shubin, Yu. N.

    2008-12-01

    Niobium is a metal with important technological applications: use as alloying element to increase strength of super alloys, as thin layer for tribological applications, as superconductive material, in high temperature engineering systems, etc. In the frame of a systematic study of activation cross-sections of charged particle induced reactions on structural materials proton induced excitation functions on Nb targets were determined with the aim of applications in accelerator and reactor technology and for thin layer activation (TLA). The charged particle activation cross-sections on this element are also important for yield calculation of medical isotope production ( 88,89Zr, 86,87,88Y) and for dose estimation in PET targetry. As Niobium is a monoisotopic element it is an ideal target material to test nuclear reaction theories. We present here the integral excitation functions of 93Nb(p,x) 90,93mMo, 92m,91m,90Nb, 86,88,89Zr, 86,87mg,88Y and 85Sr in the energy range 30-70 MeV, some measured for the first time at this energy range. The results were compared with the theoretical cross-sections calculated by means of the code ALICE-IPPE and with the literature data. The calculations have been carried out without any parameter adjustment. The theory reproduces the shape of the measured results well and magnitude is also acceptable. Thick target yields calculated from our fitted cross-section give reliable estimations for production of medically relevant radioisotopes and for dose estimation in accelerator technology.

  20. Extraction spectrophotometric determination of niobium in rocks with sulfochlorophenol S

    USGS Publications Warehouse

    Childress, A.E.; Greenland, L.P.

    1980-01-01

    After acid decomposition and potassium pyrosulfate fusion, niobium (1-26 ppm) is separated from interfering elements by extraction into methyl isobutyl ketone from 6 M H2SO4-2 M HF and back-extracted into water. The niobium-sulfochloro-phenol S complex is extracted into amyl alcohol. ?? 1980.

  1. Niobium oxide compositions and methods for using same

    DOEpatents

    Goodenough, John B; Han, Jian-Tao

    2014-02-11

    The disclosure relates a niobium oxide useful in anodes of secondary lithium ion batteries. Such niobium oxide has formula Li.sub.xM.sub.1-yNb.sub.yNb.sub.2O.sub.7, wherein 0.ltoreq.x.ltoreq.3, 0.ltoreq.y.ltoreq.1, and M represents Ti or Zr. The niobium oxide may be in the form of particles, which may be carbon coated. The disclosure also relates to an electrode composition containing at least one or more niobium oxides of formula Li.sub.xM.sub.1-yNb.sub.yNb.sub.2O.sub.7. The disclosure further relates to electrodes, such as anodes, and batteries containing at least one or more niobium oxides of formula Li.sub.xM.sub.1-yNb.sub.yNb.sub.2O.sub.7. Furthermore, the disclosure relates to methods of forming the above.

  2. Superconducting structure with layers of niobium nitride and aluminum nitride

    DOEpatents

    Murduck, James M.; Lepetre, Yves J.; Schuller, Ivan K.; Ketterson, John B.

    1989-01-01

    A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources.

  3. Superconducting structure with layers of niobium nitride and aluminum nitride

    DOEpatents

    Murduck, J.M.; Lepetre, Y.J.; Schuller, I.K.; Ketterson, J.B.

    1989-07-04

    A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources. 8 figs.

  4. The Manufacturing of Niobium Powder by Hunter Process

    NASA Astrophysics Data System (ADS)

    Yoon, Jae-Sik

    Niobium powder was fabricated by metallothermic reduction process using K2NbF7 as the raw material, KCl and KF as the diluents and Na as the reducing agent. The apparatus for the experiment was designed and built specifically for the present study. Varying properties of niobium powder depending on reaction temperature and excess of reducing agent were analyzed. The niobium particle size increased significantly as the reduction temperature increased from 993 to 1093 K. The particle size was fairly uniform at a given reaction temperature, varying from 0.2 μ m to 50 nm depending on the reaction temperature. The yield of niobium powder increased from 58 to 83% with an increase in reaction temperature. The average particle size of niobium powder was improved from 70 nm to 0.2 μ m with the increase in the amount of Na excess. In addition, the yield rate of Nb powder was 82% in the 5% excess sodium.

  5. Niobium matrix composites for high temperature turbine blades, phase 2

    NASA Technical Reports Server (NTRS)

    Heng, Sangvavann; Laferla, Raffaele; Tuffias, Robert H.

    1991-01-01

    This program demonstrated the feasibility of fabricating fiber-reinforced MMC (niobium matrix) turbine blades to net shape by chemical vapor infiltration (CVI). A controllable, repeatable niobium infiltration process was developed, and the kinetics of both deposition and infiltration were studied. Several continuous refractory fibers (Nicalon, Nextel 440, FP-Al2O3, HPZ, and tungsten mesh) were investigated as potential reinforcements for strengthening niobium. Thermodynamic and experimental evaluation indicated FP-Al2O3 and tungsten to be the most chemically compatible with niobium, while Nicalon, FP-Al2O3, and tungsten were found to be best with regard to reinforcing capability. Finally, a protective coating for iridium was found to provide substantial oxidation protection to the niobium blade matrix.

  6. Observations of flux motion in niobium films

    SciTech Connect

    Xiao, Y.M.; Keiser, G.M. . W.W. Hansen Labs. of Physics)

    1991-03-01

    In this paper magnetic field trapped in a superconducting sphere is examined at temperatures from 4.6 K to 5.5 K The sphere is the rotor of a precision gyroscope, and is made of fused quartz and coated with a sputtered niobium film. The rotor diameter is 3.8 centimeters. The film thickness is 2.5 micrometers. The tests are carried out at ambient magnetic field of about 1 milligauss. Unexpected instability of the trapped field is observed. The experimental results and possible explanations are presented.

  7. Laser polishing of niobium for SRF applications

    SciTech Connect

    Zhao, Liang; Klopf, J. Michael; Reece, Charles E.; Kelley, Michael

    2013-09-01

    Smooth interior surfaces are desired for niobium SRF cavities, now obtained by buffered chemical polish (BCP) and/or electropolish (EP). Laser polishing is a potential alternative, having advantages of speed, freedom from chemistry and in-process inspection. Here we show that laser polishing can produce smooth topography with Power Spectral Density (PSD) measurements similar to that obtained by EP. We studied the influence of the laser power density and laser beam raster rate on the surface topography. These two factors need to be combined carefully to smooth the surface without damaging it. Computational modeling was used to simulate the surface temperature and explain the mechanism of laser polishing.

  8. Germanium-overcoated niobium Dayem bridges

    NASA Technical Reports Server (NTRS)

    Holdeman, L. B.; Peters, P. N.

    1976-01-01

    Overcoating constriction microbridges with semiconducting germanium provides additional thermal conductivity at liquid-helium temperatures to reduce the effects of self-heating in these Josephson junctions. Microwave-induced steps were observed in the I-V characteristics of an overcoated Dayem bridge fabricated in a 15-nm-thick niobium film; at least 20 steps could be counted at 4.2 K. No steps were observed in the I-V characteristics of the bridge prior to overcoating. In addition, the germanium overcoat can protect against electrical disturbances at room temperature.

  9. STS-88 Day 06 Highlights

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On this sixth day of the STS-88 mission, the flight crew, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, James H. Newman, Jerry L. Ross, and Sergei Krikalev are awakened by Dwight Yokum's "Streets of Bakersfield," requested by the wife of Pilot Rick Sturckow, a California native. Cabana and Sturckow fire Endeavour's primary reaction control jets to raise the altitude of the International Space Station by about 5-1/2 statute miles. Later on Cabana, Sturckow and Currie are interviewed by the ABC News/Discovery Channel and MSNBC.

  10. STS-88 Day 01 Highlights

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On this first day of the STS-88 mission, the flight crew, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, James H. Newman, Jerry L. Ross, and Sergei Krikalev can be seen performing pre-launch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew is readied in the "white room" for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters.

  11. SEPARATION OF URANIUM FROM ZIRCONIUM AND NIOBIUM BY SOLVENT EXTRACTION

    DOEpatents

    Voiland, E.E.

    1958-05-01

    A process for separation of the uranium from zirconium and/or niobium values contained in 3 to 7M aqueous nitric acid solutions is described. This is accomplished by adding phosphoric acid anions to the nitric acid solution containing the uranium, zirconium, and/or niobium in an amount sufficient to make the solution 0.05 to 0.2M in phosphate ion and contacting the solution with an organic water-immiscible solvent such as MEK, whereby the uranyl values are taken up by the extract phase while the zirconium and niobium preferentially remain in the aqueous raffinate.

  12. Research & Development on Superconducting Niobium Materials via Magnetic Measurements

    SciTech Connect

    S. B. Roy, V. C. Sahni, and G. R. Myneni

    2011-03-01

    We present a study of superconducting properties of both large grain (1 mm average grain size) and small grain (50 micron average grain size) Niobium materials containing varying amounts of Tantalum impurities that have been used in the fabrication of high accelerating gradient superconducting radio frequency cavities. We found that a buffered chemical polishing of these Niobium samples causes a distinct reduction in the superconducting parameters like TC, wt- ppm to 1300 wt-ppm. Implications of these results on the performance of niobium superconducting radio frequency cavities are discussed, especially the anomalous high field RF losses that have been reported in the literature.

  13. Creep behavior of tungsten/niobium and tungsten/niobium-1 percent zirconium composites

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Titran, Robert H.

    1988-01-01

    The creep behavior and microstructural stability of tungsten fiber reinforced niobium and niobium 1 percent zirconium was determined at 1400 and 1500 K in order to assess the potential of this material for use in advanced space power systems. The creep behavior of the composite materials could be described by a power law creep equation. A linear relationship was found to exist between the minimum creep rate of the composite and the inverse of the composite creep rupture life. The composite materials had an order of magnitude increase in stress to achieve 1 percent creep strain and in rupture strength at test temperatures of 1400 and 1500 K compared to unreinforced material. The composite materials were also stronger than the unreinforced materials by an order of magnitude when density was taken into consideration. Results obtained on the creep behavior and microstructural stability of the composites show significant potential improvement in high temperature properties and mass reduction for space power system components.

  14. Synthesis of piezoelectric and bioactive NaNbO3 from metallic niobium and niobium oxide.

    PubMed

    Prado da Silva, Marcelo Henrique; da Rocha, Daniel Navarro; de Andrade Gobbo, Luciano; Dos Santos Azevedo, Luciana Maria; Louro, Luís Henrique Leme; Machado Costa, Andréa; Brant de Campos, José

    2016-07-01

    NaNbO3 was synthesized by two different routes, one using metallic niobium powder, and another using niobium oxide (Nb2 O5 ) powder. In both routes an aqueous sodium hydroxide solution was used to hydrothermally treating the powders. In the first approach, the solution concentrations were 3M, 1M, and 0.5M. The second route used solution concentrations of 10M and 12.5M. After the hydrothermal treatments, the powders were heat treated in order to synthesize NaNbO3 . The products were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and X-ray diffraction (XRD) with Rietveld refinement. The phases were identified by means of X-ray diffraction (XRD) with Rietveld refinement. It was observed that the molar concentrations of the solutions had opposing effects for each route. An antiferroelectric phase was found in both routes. In the niobium metallic route, a ferroelectric phase was also synthesized. This study proves that piezoelectric NaNbO3 can be obtained after alkali treatment of both Nb and Nb2 O5. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 979-985, 2016.

  15. Synthesis of piezoelectric and bioactive NaNbO3 from metallic niobium and niobium oxide.

    PubMed

    Prado da Silva, Marcelo Henrique; da Rocha, Daniel Navarro; de Andrade Gobbo, Luciano; Dos Santos Azevedo, Luciana Maria; Louro, Luís Henrique Leme; Machado Costa, Andréa; Brant de Campos, José

    2016-07-01

    NaNbO3 was synthesized by two different routes, one using metallic niobium powder, and another using niobium oxide (Nb2 O5 ) powder. In both routes an aqueous sodium hydroxide solution was used to hydrothermally treating the powders. In the first approach, the solution concentrations were 3M, 1M, and 0.5M. The second route used solution concentrations of 10M and 12.5M. After the hydrothermal treatments, the powders were heat treated in order to synthesize NaNbO3 . The products were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and X-ray diffraction (XRD) with Rietveld refinement. The phases were identified by means of X-ray diffraction (XRD) with Rietveld refinement. It was observed that the molar concentrations of the solutions had opposing effects for each route. An antiferroelectric phase was found in both routes. In the niobium metallic route, a ferroelectric phase was also synthesized. This study proves that piezoelectric NaNbO3 can be obtained after alkali treatment of both Nb and Nb2 O5. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 979-985, 2016. PMID:25980635

  16. STS-88 Day 03 Highlights

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On this third day of the STS-88 mission, the flight crew, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, James H. Newman, Jerry L. Ross, and Sergei Krikalev check out the various tools they will use during the three scheduled spacewalks to be conducted later in the flight. They then begin an early set-up of the Shuttle's airlock in preparation for that first spacewalk. Newman and Russian cosmonaut Sergei Krikalev take part in an on-line interview by the New York Times. Currie is seen placing Unity just inches above the extended outer ring on Endeavour's docking mechanism, enabling Commander Bob Cabana to fire downward maneuvering jets to lock the shuttle's docking system to one of two Pressurized Mating Adapters (PMA's) attached to Unity.

  17. STS-88 Day 04 Highlights

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On this forth day of the STS-88 mission, the flight crew, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, James H. Newman, Jerry L. Ross, and Sergei are awakened to the sounds of "Somewhere Over the Rainbow," requested by Commander Bob Cabana's daughter, Sarah. With the three-story-high Unity connecting module latched upright in the shuttle's payload bay, Cabana takes manual control of the shuttle as it moves to within about a half-mile of Zarya. Cabana and Sturckow execute a sequence of maneuvers that will bring Endeavour directly above the module. Currie uses the robotic arm to capture the module. She then positions Zarya above Unity's docking mechanism.

  18. Diffusion of hydrogen, deuterium, and tritium in niobium

    SciTech Connect

    Matusiewicz, Gerald Robert

    1981-01-01

    The diffusion of hydrogen in niobium was investigated over the temperature range 148 to 500 degrees Kelvin, using measurements of the elastic after effect caused by long range diffusion (the Gorsky Effect). Relaxation curves for pure annealed niobium were generally not of the single exponential form expected from the Gorsky Effect theory, but were described well by a sum of two exponential curves with different amplitudes and relaxation times. The effects of oxygen and nitrogen interstitials on the diffusion were studied and were not in agreement with conventional trapping models. Deuterium and tritium diffusion in niobium were also studied, and a non-classical isotope effect was observed. Hydrogen diffusion coefficients in several Nb-Ta alloys were measured, and the diffusivity in all these alloys exhibited a non-Arrhenius temperature dependence. Experimental results were compared to several models for diffusion and trapping. A model is presented which can account for the form of the relaxation curves observed in pure, annealed niobium.

  19. Studies of Niobium Thin Film Produced by Energetic Vacuum Deposition

    SciTech Connect

    Genfa Wu; Anne-Marie Valente; H. Phillips; Haipeng Wang; Andy Wu; T. J. Renk; P Provencio

    2004-05-01

    An energetic vacuum deposition system has been used to study deposition energy effects on the properties of niobium thin films on copper and sapphire substrates. The absence of working gas avoids the gaseous inclusions commonly seen with sputtering deposition. A biased substrate holder controls the deposition energy. Transition temperature and residual resistivity ratio of the niobium thin films at several deposition energies are obtained together with surface morphology and crystal orientation measurements by AFM inspection, XRD and TEM analysis. The results show that niobium thin films on sapphire substrate exhibit the best cryogenic properties at deposition energy around 123 eV. The TEM analysis revealed that epitaxial growth of film was evident when deposition energy reaches 163 eV for sapphire substrate. Similarly, niobium thin film on copper substrate shows that film grows more oriented with higher deposition energy and grain size reaches the scale of the film thickness at the deposition energy around 153 eV.

  20. Electroplating and stripping copper on molybdenum and niobium

    NASA Technical Reports Server (NTRS)

    Power, J. L.

    1978-01-01

    Molybdenum and niobium are often electroplated and subsequently stripped of copper. Since general standard plating techniques produce poor quality coatings, general procedures have been optimized and specified to give good results.

  1. Effects of Impurities on Alumina-Niobium InterfacialMicrostructures

    SciTech Connect

    McKeown, Joseph T.; Sugar, Joshua D.; Gronsky, Ronald; Glaeser,Andreas M.

    2005-06-20

    Optical microscopy, scanning electron microscopy, and transmission electron microscopy were employed to examine the interfacial microstructural effects of impurities in alumina substrates used to fabricate alumina-niobium interfaces via liquid-film-assisted joining. Three types of alumina were used: undoped high-purity single-crystal sapphire; a high-purity, high-strength polycrystalline alumina; and a lower-purity, lower-strength polycrystalline alumina. Interfaces formed between niobium and both the sapphire and high-purity polycrystalline alumina were free of detectable levels of impurities. In the lower-purity alumina, niobium silicides were observed at the alumina-niobium interface and on alumina grain boundaries near the interface. These silicides formed in small-grained regions of the alumina and were found to grow from the interface into the alumina along grain boundaries. Smaller silicide precipitates found on grain boundaries are believed to form upon cooling from the bonding temperature.

  2. Parameter Optimization for Laser Polishing of Niobium for SRF Applications

    SciTech Connect

    Zhao, Liang; Klopf, John Michael; Reece, Charles E.; Kelley, Michael J.

    2013-06-01

    Surface smoothness is critical to the performance of SRF cavities. As laser technology has been widely applied to metal machining and surface treatment, we are encouraged to use it on niobium as an alternative to the traditional wet polishing process where aggressive chemicals are involved. In this study, we describe progress toward smoothing by optimizing laser parameters on BCP treated niobium surfaces. Results shows that microsmoothing of the surface without ablation is achievable.

  3. International strategic minerals inventory summary report; niobium (columbium) and tantalum

    USGS Publications Warehouse

    Crockett, R.N.; Sutphin, D.M.

    1993-01-01

    Major world resources of niobium and tantalum are described in this summary report of information in the International Strategic Minerals Inventory (ISMI). ISMI is a cooperative data-collection effort of earth-science and mineral-resource agencies in Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, the United Kingdom, and the United States of America. Part I of this report presents an overview of the resources and potential supply of niobium and tantalum based on inventory information; Part II contains tables of both geologic and mineral-resource information and includes production data collected by ISMI participants. Niobium is used principally as an alloying element in special steels and superalloys, and tantalum is used mainly in electronics. Minerals in the columbite-tantalite series are principal ore minerals of niobium and tantalum. Pyrochlore is a principal source of niobium. These minerals are found in carbonatite, certain rocks in alkaline igneous complexes, pegmatite, and placer deposits. ISMI estimates show that there are over 7 million metric tons of niobium and almost 0.5 million metric tons of tantalum in known deposits, outside of China and the former Soviet Union, for which reliable estimates have been made. Brazilian deposits, followed by Canadian deposits, contain by far the largest source of niobium. Tantalum production is spread widely among several countries, and Brazil and Canada are the most significant of these producers. Brazil's position is further strengthened by potential byproduct columbite from tin mining. Present economically exploitable resources of niobium appear to be sufficient for the near future, but Brazil will continue to be the predominant world supplier of ferrocolumbium. Tantalum, a byproduct of tin production, has been captive to the fluctuations of that market, but resources in pegmatite in Canada and Australia make it likely that future increases in the present modest demand will be met.

  4. Characterization of electron beam melted uranium - 6% niobium ingots

    SciTech Connect

    McKoon, R.H.

    1997-10-31

    A study was undertaken at Lawrence Livermore National Laboratory to characterize uranium, 6{percent} niobium ingots produced via electron beam melting,hearth refining and continuous casting and to compare this material with conventional VIM/skull melt /VAR material. Samples of both the ingot and feed material were analyzed for niobium, trace metallic elements, carbon, oxygen and nitrogen. Ingot samples were also inspected metallographically and via microprobe analysis.

  5. Tuning of superconducting niobium nitride terahertz metamaterials.

    PubMed

    Wu, Jingbo; Jin, Biaobing; Xue, Yuhua; Zhang, Caihong; Dai, Hao; Zhang, Labao; Cao, Chunhai; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2011-06-20

    Superconducting planar terahertz (THz) metamaterials (MMs), with unit cells of different sizes, are fabricated on 200 nm-thick niobium nitride (NbN) films deposited on MgO substrates. They are characterized using THz time domain spectroscopy over a temperature range from 8.1 K to 300 K, crossing the critical temperature of NbN films. As the gap frequency (f(g) = 2Δ0/h, where Δ0 is the energy gap at 0 K and h is the Plank constant) of NbN is 1.18 THz, the experimentally observed THz spectra span a frequency range from below f(g) to above it. We have found that, as the resonance frequency approaches f(g), the relative tuning range of MMs is quite wide (30%). We attribute this observation to the large change of kinetic inductance of superconducting film.

  6. A bulk niobium superconducting quarter wave resonator

    SciTech Connect

    Ben-Zvi, I. ); Chiaveri, E. ); Elkonin, B.V. ); Facco, A.; Sokolowski, J.S. . Lab. Nazionale di Legnaro)

    1990-01-01

    A bath-cooled all-niobium 160 MHz quarter wave resonator prototype was constructed and tested. The objective of this research has been the development of a high performance accelerating element with {beta}{sub opt} {approx equal} 0.11 for the ALPI linac at the Laboratori Nazionali di Legnaro. The design of this resonator was based upon a previous 150 MHz model, with minor changes due to the different frequency and to modified welding procedure. An accelerating field of 5 MV/m was achieved at a power dissipation of 10 W and the low power Q was 2.4 {times} 10{sup 8}. The resonator could dissipate 70 W of power without thermal breakdown. 16 refs., 2 figs., 1 tab.

  7. Enhanced characterization of niobium surface topography

    NASA Astrophysics Data System (ADS)

    Xu, Chen; Tian, Hui; Reece, Charles E.; Kelley, Michael J.

    2011-12-01

    Surface topography characterization is a continuing issue for the superconducting radio frequency (SRF) particle accelerator community. Efforts are under way to both improve surface topography and its characterization and analysis using various techniques. In measurement of topography, power spectral density (PSD) is a promising method to quantify typical surface parameters and develop scale-specific interpretations. PSD can also be used to indicate how the process modifies topography at different scales. However, generating an accurate and meaningful topographic PSD of an SRF surface requires careful analysis and optimization. In this report, niobium surfaces with different process histories are sampled with atomic force microscopy and stylus profilometry and analyzed to trace topography evolution at different scales. An optimized PSD analysis protocol to serve SRF needs is presented.

  8. Determination of niobium in the parts per million range in rocks

    USGS Publications Warehouse

    Grimaldi, F.S.

    1960-01-01

    A modified niobium thiocyanate spectrophotometric procedure relatively insensitive to titanium interference is presented. Elements such as tungsten, molybdenum, vanadium, and rhenium, which seriously interfere in the spectrophotometric determination of niobium, are separated by simple sodium hydroxide fusion and leach; iron and magnesium are used as carriers for the niobium. Tolerance limits are given for 28 elements in the spectrophotometric method. Specific application is made to the determination of niobium in the parts per million range in rocks. The granite G-1 contains 0.0022% niobium and the diabase W-1 0.00096% niobium.

  9. Niobium (columbium) and tantalum resources of Brazil

    USGS Publications Warehouse

    White, Max Gregg

    1975-01-01

    Most of the niobium resources of Brazil occur as pyrochlore in carbonatites within syenitic intrusives of Late Cretaceous to early Tertiary age in western Minas Gerais and southeastern Goils. Minor amounts of it are produced together with tantalum from columbite-tantalite concentrates from pegmatites and placers adjacent to them, in the Sao Joao del Rei district in south-central Minas Gerais. All the niobium and tantalum produced in Brazil is exported. The only pyrochlore mined is from the Barreiro carbonatite deposit near Araxa in Minas Gerais where concentrates and ferroniobium are produced. Exploration work for pyrochlore and other mineral resources are being undertaken on other carbonatites, particularly at Catalao I in southeast Goias and at Tapira and Serra Negra in western Minas Gerais. Annual production and export from the Barreiro deposit are about 8,000 metric tons of pyrochlore concentrate containing about 60 percent Nb205 and about 2,700 metric tons of ferroniobium with 63 percent Nb2O5. The annual production capacity of the Barreiro plant is 18,000 tons of concentrate and 4,000 tons of ferroniobium. Ore reserves of the Barreiro deposit in all categories are 380 million tons with percent Nb2O5. Annual production of tantalite-columbite from the Sao Joao del Rei district, most of which is exported to the United States, is about 290 tons, of which about 79 percent is tantalite and about percent is columbite. Reserves of tantalite-columbite in the Sao Joao del Rei district are about 43,000 tons of proved and 73,000 tons of probable ore.

  10. Recent developments in high purity niobium metal production at CBMM

    SciTech Connect

    Abdo, Gustavo Giovanni Ribeiro Sousa, Clovis Antonio de Faria Guimarães, Rogério Contato Ribas, Rogério Marques Vieira, Alaércio Salvador Martins Menezes, Andréia Duarte Fridman, Daniel Pallos Cruz, Edmundo Burgos

    2015-12-04

    CBMM is a global supplier of high quality niobium products including pure niobium, the focus of this paper. CBMM’s position has been consolidated over three decades of producing high purity niobium metal ingots. The company supplies, among other products, commercial and reactor grade niobium ingots. One of the main uses of CBMM’s ingots is for the manufacture of particle accelerators (superconducting radio frequency – SRF – cavities), where the purity and homogeneity of niobium metal is essentially important for good performance. CBMM constantly strives to improve process controls and product quality, and is currently implementing innovations in production, research and development to further improve ingot quality. The main aim is to reduce the content of interstitial elements, such as nitrogen (N), oxygen (O), carbon (C), and hydrogen (H), starting with the raw materials through the final step of ingot production. CBMM held the first trial to produce the world’s largest-diameter niobium ingot (as cast 535 mm). The results of this initial trial presented very low levels of interstitial impurities (N, O, C, H), allowing the achievement of residual resistivity ratio (RRR) values very close to 300 in a six-melt process in an electron beam furnace. These values were reached with 850 ppm of tantalum. SRF cavities will be produced with this material in order to study the effect of low impurities and high RRR on the Q factor and accelerating gradient.

  11. Titanium-niobium, a new finishing wire alloy.

    PubMed

    Dalstra, M; Denes, G; Melsen, B

    2000-02-01

    The mechanical properties of the newly introduced titanium-niobium finishing wires were investigated. Both in bending and torsional loading mode, the stiffness, yield point, post-yield behavior, and springback of titanium-niobium wires were experimentally determined and compared to those of equally sized stainless steel wires. The experimentally obtained values were also validated with theoretical values from engineering formulas of cantilever deformations. The ratios for these parameters for the two materials proved to be different in bending and torsion. The stiffness of titanium-niobium in bending is roughly half of that of stainless steel, whereas in torsion it is roughly one-third. These characteristics enable the clinician to use titanium-niobium for creative bends without the excessive force levels of steel wires. The springback of titanium-niobium in bending is 14% lower than that of steel, whereas in torsion it is about the same or even slightly higher than that of steel, thus making it possible to utilize the wire for even major third-order corrections. Finally, the weldability of titanium-niobium wires was found to be good, so it is possible to weld wires of different dimensions together for the generation of differentiated force systems. PMID:11168279

  12. Recent developments in high purity niobium metal production at CBMM

    NASA Astrophysics Data System (ADS)

    Abdo, Gustavo Giovanni Ribeiro; Sousa, Clovis Antonio de Faria; Guimarães, Rogério Contato; Ribas, Rogério Marques; Vieira, Alaércio Salvador Martins; Menezes, Andréia Duarte; Fridman, Daniel Pallos; Cruz, Edmundo Burgos

    2015-12-01

    CBMM is a global supplier of high quality niobium products including pure niobium, the focus of this paper. CBMM's position has been consolidated over three decades of producing high purity niobium metal ingots. The company supplies, among other products, commercial and reactor grade niobium ingots. One of the main uses of CBMM's ingots is for the manufacture of particle accelerators (superconducting radio frequency - SRF - cavities), where the purity and homogeneity of niobium metal is essentially important for good performance. CBMM constantly strives to improve process controls and product quality, and is currently implementing innovations in production, research and development to further improve ingot quality. The main aim is to reduce the content of interstitial elements, such as nitrogen (N), oxygen (O), carbon (C), and hydrogen (H), starting with the raw materials through the final step of ingot production. CBMM held the first trial to produce the world's largest-diameter niobium ingot (as cast 535 mm). The results of this initial trial presented very low levels of interstitial impurities (N, O, C, H), allowing the achievement of residual resistivity ratio (RRR) values very close to 300 in a six-melt process in an electron beam furnace. These values were reached with 850 ppm of tantalum. SRF cavities will be produced with this material in order to study the effect of low impurities and high RRR on the Q factor and accelerating gradient.

  13. Field determination of microgram quantities of niobium in rocks

    USGS Publications Warehouse

    Ward, F.N.; Marranzino, A.P.

    1955-01-01

    A rapid, simple, and moderately accurate method was needed for the determination of traces of niobium in rocks. The method developed is based on the reaction of niobium(V) with thiocyanate ion in a 4M hydrochloric acid and 0.5M tartaric acid medium, after which the complex is extracted with ethyl ether. The proposed procedure is applicable to rocks containing from 50 to 2000 p.p.m. of niobium, and, with modifications, can be used on rocks containing larger amounts. Five determinations on two rocks containing 100 p.p.m. or less of niobium agree within 5 p.p.m. of the mean, and the confidence limits at the 95% level are, respectively, ??6 and ??4 p.p.m. The addition of acetone to the ether extract of the niobium thiocyanate inhibits the polymerization of the thiocyanate ion and stabilizes the solution for at least 20 hours. The proposed procedure permits the determination of 20 ?? of niobium in the presence of 1000 ?? of iron, titanium, or uranium; 500 ?? of vanadium; or 100 ?? of tungsten or molybdenum or both.

  14. Thermal transport properties of niobium and some niobium base alloys from 80 to 1600/sup 0/K

    SciTech Connect

    Moore, J.P.; Graves, R.S.; Williams, R.K.

    1980-01-01

    The electrical resistivities and absolute Seebeck coefficients of 99.8 at. % niobium with a RRR of 36, Nb-4.8 at. % W, Nb-5 at. % Mo, Nb-10 at. % Mo, and Nb-2.4 at. % Mo-2.4 at. % Zr were measured from 80 to 1600/sup 0/K, and the thermal conductivities of the niobium and Nb-5 at. % W were measured from 80 to 1300/sup 0/K. A technique is described for measuring the electrical resistivity and Seebeck coefficient of a specimen during radial heat flow measurements of the thermal conductivity. The transport property results, which had uncertainties of +-0.4%for electrical resistivity and +-1.4% for thermal conductivity, showed the influence of tungsten and molybdenum solutes on the transport properties of niobium and were used to obtain the electronic Lorenz function of pure niobium, which was found to approach the Sommerfeld value at high temperatures.

  15. WSR-88D Cell Trends

    NASA Technical Reports Server (NTRS)

    Wheeler, Mark M.

    1998-01-01

    This report documents the Applied Meteorology Unit's evaluation of the Cell Trends display as a tool for radar operators to use in their evaluation of storm cell strength. The objective of the evaluation is to assess the utility of the WSR-88D graphical Cell Trends display for local radar cell interpretation in support of the 45th Weather Squadron (45 WS), Spaceflight Meteorology Group (SMG), and National Weather Service (NWS) Melbourne (MLB) operational requirements. The analysis procedure was to identify each cell and track the maximum reflectivity, height of maximum reflectivity, storm top, storm base, hail and severe hail probability, cell-based Vertically Integrated Liquid (VIL) and core aspect ratio using WATADS Build 9.0 cell trends information. One problem noted in the analysis phase was that the Storm Cell Identification and Tracking (SCIT) algorithm had a difficult time tracking the small cells associated with the Florida weather regimes. The analysis indicated numerous occasions when a cell track would end or an existing cell would be give a new ID in the middle of its life cycle. This investigation has found that most cells, which produce hail or microburst events, have discernable Cell Trends signatures. Forecasters should monitor the PUP's Cell Trends display for cells that show rapid (1 scan) changes in both the heights of maximum reflectivity and cell-based VIEL. It is important to note that this a very limited data set (four case days). Fifty-two storm cells were analyzed during those four days. The above mentioned t=ds, increase in the two cell attributes for hail events and decrease in the two cell attributes for wind events were noted in most of the cells. The probability of detection was 88% for both events. The False Alarm Rate (FAR) was a 36% for hail events and a respectable 25% for microburst events. In addition the Heidke Skill Score (HSS) is 0.65 for hail events and 0.67 for microburst events. For random forecast the HSS is 0 and that a

  16. STS-88 Day 11 Highlights

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On this eleventh day of the STS-88 mission, the flight crew, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, James H. Newman, Jerry L. Ross, and Sergei Krikalev are awakened with the song "Goodnight, Sweetheart, Goodnight". Pilot Rick Sturckow undocks Endeavour from the station and backs the shuttle away to a distance of 450 feet above the station before beginning a nose-forward fly-around. Later Cabana, Sturckow and Ross deploy the SAC-A satellite from Endeavour's payload bay. SAC-A is a small, self-contained, non-recoverable satellite built by the Argentinean National Commission of Space Activities. The cube-shaped, 590-pound satellite will test and characterize the performance of new equipment and technologies that may be used in future scientific or operational missions. The payload includes a differential global positioning system, a magnetometer, silicon solar cells, a charge-coupled device Earth camera and a whale tracker experiment.

  17. STS-88 Post Flight Presentation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The flight crew of the STS-88 mission, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, Jerry L. Ross, James H. Newman, and Sergei K. Krikalev, present a video mission over-view of their space flight. Images include prelaunch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the "white room" for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters. Once the seven-day mission begins, the astronauts comment on the mating of the U.S.-built Node 1 station element to the Functional Energy Block (FGB) which was already in orbit, and two EVAs that were planned to connect power and data transmission cables between the Node and the FGB. The crew can also be seen conducting a series of rendezvous maneuvers similar to those conducted on other Shuttle missions to reach the orbiting FGB.

  18. 32 CFR 88.6 - Information requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Information requirements. 88.6 Section 88.6 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN TRANSITION ASSISTANCE FOR MILITARY PERSONNEL § 88.6 Information requirements. The quarterly...

  19. 29 CFR 1918.88 - Log operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Log operations. 1918.88 Section 1918.88 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.88 Log operations. (a) Working in holds. When loading logs into the holds of vessels and using dumper devices to roll logs into the...

  20. 42 CFR 430.88 - Evidence.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Evidence. 430.88 Section 430.88 Public Health... Plans and Practice to Federal Requirements § 430.88 Evidence. (a) Evidentiary purpose. The hearing is directed to receiving factual evidence and expert opinion testimony related to the issues involved in...

  1. 42 CFR 430.88 - Evidence.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Evidence. 430.88 Section 430.88 Public Health... Plans and Practice to Federal Requirements § 430.88 Evidence. (a) Evidentiary purpose. The hearing is directed to receiving factual evidence and expert opinion testimony related to the issues involved in...

  2. 42 CFR 430.88 - Evidence.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Evidence. 430.88 Section 430.88 Public Health... Plans and Practice to Federal Requirements § 430.88 Evidence. (a) Evidentiary purpose. The hearing is directed to receiving factual evidence and expert opinion testimony related to the issues involved in...

  3. 42 CFR 430.88 - Evidence.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Evidence. 430.88 Section 430.88 Public Health... Plans and Practice to Federal Requirements § 430.88 Evidence. (a) Evidentiary purpose. The hearing is directed to receiving factual evidence and expert opinion testimony related to the issues involved in...

  4. 40 CFR 98.88 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Definitions. 98.88 Section 98.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.88 Definitions. All terms used in this subpart have the...

  5. 21 CFR 500.88 - Regulatory method.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Regulatory method. 500.88 Section 500.88 Food and... § 500.88 Regulatory method. (a) The sponsor shall submit for evaluation and validation a regulatory method developed to monitor compliance with FDA's operational definition of no residue. (b)...

  6. 34 CFR 668.88 - Hearing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false Hearing. 668.88 Section 668.88 Education Regulations of... Proceedings § 668.88 Hearing. (a) A hearing is an orderly presentation of arguments and evidence conducted by a hearing official. (b) If the hearing official, the designated department official who brought...

  7. 34 CFR 668.88 - Hearing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Hearing. 668.88 Section 668.88 Education Regulations of... Proceedings § 668.88 Hearing. (a) A hearing is an orderly presentation of arguments and evidence conducted by a hearing official. (b) If the hearing official, the designated department official who brought...

  8. 9 CFR 88.2 - General information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false General information. 88.2 Section 88.2... EQUINES FOR SLAUGHTER § 88.2 General information. (a) State governments may enact and enforce regulations... transported the equines information regarding the business of that individual or other entity. When...

  9. 32 CFR 88.5 - Responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Responsibilities. 88.5 Section 88.5 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN TRANSITION ASSISTANCE FOR MILITARY PERSONNEL § 88.5 Responsibilities. (a) The Assistant Secretary of...

  10. 32 CFR 88.5 - Responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Responsibilities. 88.5 Section 88.5 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN TRANSITION ASSISTANCE FOR MILITARY PERSONNEL § 88.5 Responsibilities. (a) The Assistant Secretary of...

  11. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  12. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  13. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  14. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  15. 9 CFR 381.88 - Parasites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites,...

  16. 7 CFR 3570.88 - Management assistance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Management assistance. 3570.88 Section 3570.88 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE COMMUNITY PROGRAMS Community Facilities Grant Program § 3570.88 Management assistance....

  17. 7 CFR 3570.88 - Management assistance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Management assistance. 3570.88 Section 3570.88 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE COMMUNITY PROGRAMS Community Facilities Grant Program § 3570.88 Management assistance....

  18. 7 CFR 3570.88 - Management assistance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Management assistance. 3570.88 Section 3570.88 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE COMMUNITY PROGRAMS Community Facilities Grant Program § 3570.88 Management assistance....

  19. 34 CFR 361.88 - Reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION STATE VOCATIONAL REHABILITATION SERVICES PROGRAM Evaluation Standards and Performance Indicators § 361.88 Reporting requirements. (a) The Secretary requires that each... 34 Education 2 2014-07-01 2013-07-01 true Reporting requirements. 361.88 Section 361.88...

  20. 49 CFR 393.88 - Television receivers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Television receivers. 393.88 Section 393.88... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.88 Television receivers. Any motor vehicle equipped with a television viewer, screen or other means of visually receiving a...

  1. 36 CFR 251.88 - Filing procedures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Filing procedures. 251.88 Section 251.88 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Appeal of Decisions Relating to Occupancy and Use of National Forest System Lands § 251.88...

  2. 40 CFR 98.88 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Definitions. 98.88 Section 98.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.88 Definitions. All terms used in this subpart have the...

  3. 7 CFR 1780.88 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true 1780.88 Section 1780.88 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE (CONTINUED) WATER... Documents for Public Body Applicants § 1780.88...

  4. 49 CFR 393.88 - Television receivers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Television receivers. 393.88 Section 393.88... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.88 Television receivers. Any motor vehicle equipped with a television viewer, screen or other means of visually receiving a...

  5. 49 CFR 393.88 - Television receivers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Television receivers. 393.88 Section 393.88... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.88 Television receivers. Any motor vehicle equipped with a television viewer, screen or other means of visually receiving a...

  6. 49 CFR 393.88 - Television receivers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Television receivers. 393.88 Section 393.88... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.88 Television receivers. Any motor vehicle equipped with a television viewer, screen or other means of visually receiving a...

  7. 49 CFR 393.88 - Television receivers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Television receivers. 393.88 Section 393.88... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.88 Television receivers. Any motor vehicle equipped with a television viewer, screen or other means of visually receiving a...

  8. 40 CFR 88.201-94 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Scope. 88.201-94 Section 88.201-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program § 88.201-94 Scope. Applicability. The requirements of this...

  9. 45 CFR 96.88 - Administrative costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Administrative costs. 96.88 Section 96.88 Public... Assistance Program § 96.88 Administrative costs. (a) Costs of planning and administration. Any expenditure... be included in determining administrative costs subject to the statutory limitation on...

  10. 50 CFR 260.88 - Political activity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 11 2012-10-01 2012-10-01 false Political activity. 260.88 Section 260.88... Products for Human Consumption Miscellaneous § 260.88 Political activity. All inspectors and licensed... part in political management or in political campaigns. Political activities in city, county, State,...

  11. 50 CFR 260.88 - Political activity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Political activity. 260.88 Section 260.88... Products for Human Consumption Miscellaneous § 260.88 Political activity. All inspectors and licensed... part in political management or in political campaigns. Political activities in city, county, State,...

  12. 50 CFR 260.88 - Political activity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Political activity. 260.88 Section 260.88... Products for Human Consumption Miscellaneous § 260.88 Political activity. All inspectors and licensed... part in political management or in political campaigns. Political activities in city, county, State,...

  13. 50 CFR 260.88 - Political activity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 11 2014-10-01 2014-10-01 false Political activity. 260.88 Section 260.88... Products for Human Consumption Miscellaneous § 260.88 Political activity. All inspectors and licensed... part in political management or in political campaigns. Political activities in city, county, State,...

  14. 50 CFR 260.88 - Political activity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Political activity. 260.88 Section 260.88... Products for Human Consumption Miscellaneous § 260.88 Political activity. All inspectors and licensed... part in political management or in political campaigns. Political activities in city, county, State,...

  15. 19 CFR 141.88 - Computed value.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Computed value. 141.88 Section 141.88 Customs... (CONTINUED) ENTRY OF MERCHANDISE Invoices § 141.88 Computed value. When the port director determines that information as to computed value is necessary in the appraisement of any class or kind of merchandise,...

  16. 40 CFR 88.309 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false 88.309 Section 88.309 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program § 88.309...

  17. 19 CFR 141.88 - Computed value.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Computed value. 141.88 Section 141.88 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY OF MERCHANDISE Invoices § 141.88 Computed value. When the port director determines...

  18. 21 CFR 500.88 - Regulatory method.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Regulatory method. 500.88 Section 500.88 Food and... § 500.88 Regulatory method. (a) The sponsor shall submit for evaluation and validation a regulatory method developed to monitor compliance with FDA's operational definition of no residue. (b)...

  19. 38 CFR 4.88 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false 4.88 Section 4.88 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings Infectious Diseases, Immune Disorders and Nutritional Deficiencies § 4.88...

  20. 38 CFR 4.88 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false 4.88 Section 4.88 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings Infectious Diseases, Immune Disorders and Nutritional Deficiencies § 4.88...

  1. 38 CFR 4.88 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false 4.88 Section 4.88 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings Infectious Diseases, Immune Disorders and Nutritional Deficiencies § 4.88...

  2. 38 CFR 4.88 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false 4.88 Section 4.88 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings Infectious Diseases, Immune Disorders and Nutritional Deficiencies § 4.88...

  3. 38 CFR 4.88 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false 4.88 Section 4.88 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings Infectious Diseases, Immune Disorders and Nutritional Deficiencies § 4.88...

  4. 40 CFR 763.88 - Assessment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Assessment. 763.88 Section 763.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT ASBESTOS Asbestos-Containing Materials in Schools § 763.88 Assessment. (a)(1) For each inspection and...

  5. 40 CFR 763.88 - Assessment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Assessment. 763.88 Section 763.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT ASBESTOS Asbestos-Containing Materials in Schools § 763.88 Assessment. (a)(1) For each inspection and...

  6. Physical and Mechanical Properties of Niobium for SRF Science and Technology

    SciTech Connect

    Ganapati Rao Myneni

    2006-10-31

    Optimized mechanical and physical properties of high purity niobium are crucial for obtaining high performance SRF particle beam accelerator structures consistently. This paper summarizes these important material properties for both high purity polycrystalline and single crystal niobium.

  7. Elucidating the Band Gap of Niobium Dioxide

    NASA Astrophysics Data System (ADS)

    O'Hara, Andrew; Vigil-Fowler, Derek; Louie, Steven G.; Demkov, Alexander A.

    2015-03-01

    Like VO2, niobium dioxide (NbO2) belongs to the family of transition metal oxides with a temperature-driven metal-to-insulator transition. However, NbO2 has received considerably less attention, and several open questions about the material remain. One such question, of both practical and fundamental importance, is the nature and size of the band gap in the low-temperature, distorted rutile phase with a range reported for the gap of 0.5 eV to 1.2 eV. In this work, we investigate the low-temperature phase, utilizing several methodologies - density functional theory within the standard local density approximation (LDA), LDA +U, hybrid functional, and the GW approximation, to better understand the physics of the band gap in NbO2. Comparisons of the calculations are made to recent experimental work on NbO2 utilizing photoemission spectroscopy and ellipsometry. This work is supported by DOE under the SciDAC program, the NSF, and SRC.

  8. Density Prediction of Uranium-6 Niobium Ingots

    SciTech Connect

    D.F.Teter; P.K. Tubesing; D.J.Thoma; E.J.Peterson

    2003-04-15

    The densities of uranium-6 niobium (U-Nb) alloys have been compiled from a variety of literature sources such as Y-12 and Rocky Flats datasheets. We also took advantage of the 42 well-pedigreed, homogeneous baseline U-Nb alloys produced under the Enhanced Surveillance Program for density measurements. Even though U-Nb alloys undergo two-phase transitions as the Nb content varies from 0 wt. % to 8 wt %, the theoretical and measured densities vary linearly with Nb content. Therefore, the effect of Nb content on the density was modeled with a linear regression. From this linear regression, a homogeneous ingot of U-6 wt.% Nb would have a density of 17.382 {+-} 0.040 g/cc (95% CI). However, ingots produced at Y-12 are not homogeneous with respect to the Nb content. Therefore, using the 95% confidence intervals, the density of a Y-12 produced ingot would vary from 17.310 {+-} 0.043 g/cc at the center to 17.432 {+-} 0.039 g/cc at the edge. Ingots with larger Nb inhomogeneities will also have larger variances in the density.

  9. SRF niobium characterization using SIMS and FIB-TEM

    NASA Astrophysics Data System (ADS)

    Stevie, F. A.

    2015-12-01

    Our understanding of superconducting radio frequency (SRF) accelerator cavities has been improved by elemental analysis at high depth resolution and by high magnification microscopy. This paper summarizes the technique development and the results obtained on poly-crystalline, large grain, and single crystal SRF niobium. Focused ion beam made possible sample preparation using transmission electron microscopy and the images obtained showed a very uniform oxide layer for all samples analyzed. Secondary ion mass spectrometry indicated the presence of a high concentration of hydrogen and the hydrogen content exhibited a relationship with improvement in performance. Depth profiles of carbon, nitrogen, and oxygen did not show major differences with heat treatment. Niobium oxide less than 10 nm thick was shown to be an effective hydrogen barrier. Niobium with titanium contamination showed unexpected performance improvement.

  10. SRF niobium characterization using SIMS and FIB-TEM

    SciTech Connect

    Stevie, F. A.

    2015-12-04

    Our understanding of superconducting radio frequency (SRF) accelerator cavities has been improved by elemental analysis at high depth resolution and by high magnification microscopy. This paper summarizes the technique development and the results obtained on poly-crystalline, large grain, and single crystal SRF niobium. Focused ion beam made possible sample preparation using transmission electron microscopy and the images obtained showed a very uniform oxide layer for all samples analyzed. Secondary ion mass spectrometry indicated the presence of a high concentration of hydrogen and the hydrogen content exhibited a relationship with improvement in performance. Depth profiles of carbon, nitrogen, and oxygen did not show major differences with heat treatment. Niobium oxide less than 10 nm thick was shown to be an effective hydrogen barrier. Niobium with titanium contamination showed unexpected performance improvement.

  11. Superconducting DC and RF Properties of Ingot Niobium

    SciTech Connect

    Pashupati Dhakal, Gianluigi Ciovati, Peter Kneisel, Ganapati Rao Myneni

    2011-07-01

    The thermal conductivity, DC magnetization and penetration depth of large-grain niobium hollow cylindrical rods fabricated from ingots, manufactured by CBMM subjected to chemical and heat treatment were measured. The results confirm the influence of chemical and heat-treatment processes on the superconducting properties, with no significant dependence on the impurity concentrations in the original ingots. Furthermore, RF properties, such as the surface resistance and quench field of the niobium rods were measured using a TE{sub 011} cavity. The hollow niobium rod is the center conductor of this cavity, converting it to a coaxial cavity. The quench field is limited by the critical heat flux through the rods' cooling channel.

  12. Precipitation of hydrides in high purity niobium after different treatments

    SciTech Connect

    Barkov, F.; Romanenko, A.; Trenikhina, Y.; Grassellino, A.

    2013-01-01

    Precipitation of lossy non-superconducting niobium hydrides represents a known problem for high purity niobium in superconducting applications. Using cryogenic optical and laser confocal scanning microscopy we have directly observed surface precipitation and evolution of niobium hydrides in samples after different treatments used for superconducting RF cavities for particle acceleration. Precipitation is shown to occur throughout the sample volume, and the growth of hydrides is well described by the fast diffusion-controlled process in which almost all hydrogen is precipitated at $T=140$~K within $\\sim30$~min. 120$^{\\circ}$C baking and mechanical deformation are found to affect hydride precipitation through their influence on the number of nucleation and trapping centers.

  13. Interfacial fracture toughness of alumina/niobium systems

    SciTech Connect

    Stout, M.G. ); O'Dowd, N.P.; Shih, C.F. . Div. of Engineering)

    1991-01-01

    The interfacial fracture toughness of an alumina/niobium composite has been measured as a function of phase angle. The interface was formed by solid-state bonding bulk Coor's AD-999 fine-grain alumina with a commercial purity niobium at 1600{degrees}C for 0.5 hr under a pressure of 10.5 MPa. The alumina/niobium system has a number of features which makes it ideal for an investigation of interfacial fracture toughness. From HREM data we estimate that the width of the interface is no more than 10 atomic planes. Furthermore the thermal expansion coefficients of the two materials differ by less than 5% so residual stresses due to the bonding process are small. Using symmetric and asymmetric four point bend specimens we have measured the fracture toughness of homogenous alumina and that of the alumina/niobium bimaterial in combinations of in-plane shear and tension. The fracture toughness of the homogenous alumina is relatively insensitive to the loading phase. The measured fracture toughness K{sub c} of the interface, however, depended strongly on phase angle. We were unable to obtain valid alumina/niobium interfacial toughness data at negative phase angles as the fracture initiates in the alumina and not at the interface. In symmetric bending at a phase angle {approx}5{degrees}, we measured a nominal interface toughness of 4.0 MPa{radical}m, comparable to the homogeneous alumina. We found that the toughness increased with loading phase angle to a value of K{sub c} {approx} 9 MPa{radical}m at a phase between 25{degrees} and 40{degrees}. Preliminary calculations and experiments suggest that this effect is due to an asymmetric stress distribution, with respect to the interface, and plastic deformation in the niobium. 12 refs., 9 figs., 1 tab.

  14. Study of AC/RF properties of SRF ingot niobium

    SciTech Connect

    Dhakal, Pashupati; Tsindlekht, Menachem I; Genkin, Valery M; Ciovati, Gianluigi; Myneni, Ganapati Rao

    2013-09-01

    In an attempt to correlate the performance of superconducting radiofrequency cavities made of niobium with the superconducting properties, we present the results of the magnetization and ac susceptibility of the niobium used in the superconducting radiofrequency cavity fabrication. The samples were subjected to buffer chemical polishing (BCP) surface and high temperature heat treatments, typically applied to the cavities fabrications. The analysis of the results show the different surface and bulk ac conductivity for the samples subjected to BCP and heat treatment. Furthermore, the RF surface impedance is measured on the sample using a TE011 microwave cavity for a comparison to the low frequency measurements.

  15. America's Overview of Superconducting Science and Technology of Ingot Niobium

    SciTech Connect

    Gianluigi Ciovati, Peter Kneisel, Ganapati Myneni

    2011-03-01

    This contribution will present an overview of the results from R&D programs in the USA over the past four years towards the development of ingot Niobium as a viable alternative material to fabricate SRF cavities for particle accelerators. Activities at several laboratories and universities include fabrication, surface treatment and RF testing of single- and multi-cell cavities and studies of the thermal, mechanical and superconducting properties of samples from ingots of different purity. Possible advantages of ingot niobium over standard fine-grain (ASTM 6) are discussed and a streamlined treatment procedure to fully exploit those advantages is proposed.

  16. Niobium-Matrix-Composite High-Temperature Turbine Blades

    NASA Technical Reports Server (NTRS)

    Kaplan, Richard B.; Tuffias, Robert H.; La Ferla, Raffaele; Heng, Sangvavann; Harding, John T.

    1995-01-01

    High-temperture composite-material turbine blades comprising mainly niobium matrices reinforced with refractory-material fibers being developed. Of refractory fibrous materials investigated, FP-AL(2)0(3), tungsten, and polymer-based SiC fibers most promising. Blade of this type hollow and formed in nearly net shape by wrapping mesh of reinforcing refractory fibers around molybdenum mandrel, then using thermal-gradient chemical-vapor infiltration (CVI) to fill interstices with niobium. CVI process controllable and repeatable, and kinetics of both deposition and infiltration well understood.

  17. Effect of Surface Flow on Topography in Niobium Electropolishing

    SciTech Connect

    M.J. Kelley, C.E. Reece, L. Zhao

    2011-03-01

    Electropolishing (EP) is reliably delivering improved performance of multi-celled niobium SRF accelerator cavities, attributed to the smoother surface obtained. This superior leveling is a consequence of an etchant concentration gradient layer that arises in the HF-H2SO4 electrolyte adjacent to the niobium surface during polishing. Electrolyte circulation raises the prospect that fluid flow adjacent to the surface might affect the diffusion layer and impair EP performance. In this study, preliminary bench-top experiments with a moving electrode apparatus were conducted. We find that flow conditions approximating cavity EP show no effects attributable to depletion layer disruption.

  18. PROCESS OF PRODUCING A NIOBIUM-TIN COMPOUND

    DOEpatents

    Zegler, S.T.; Darby, J.B. Jr.

    1963-04-01

    This patent deals with a process of preparing pure Nb/sub 3/Sn. The process comprises heating powders of niobium and excess tin to 900 to 1000 deg C, whereby niobium reacts with the molten tin under the formation of Nb/sub 3/Sn; cooling and powdering the product and immersing the powder in concentrated hydrochloric acid for removal of excessive tin; separating the Nb/sub 3/Sn, rinsing and drying it and sintering it in an inert atmosphere at 900 to 1300 deg C. (AEC)

  19. 7 CFR 984.88 - Agents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Agents. 984.88 Section 984.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order...

  20. 7 CFR 984.88 - Agents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Agents. 984.88 Section 984.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order...

  1. 7 CFR 984.88 - Agents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Agents. 984.88 Section 984.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order...

  2. 7 CFR 984.88 - Agents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Agents. 984.88 Section 984.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order...

  3. 7 CFR 984.88 - Agents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Agents. 984.88 Section 984.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order...

  4. 7 CFR 982.88 - Amendments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Amendments. 982.88 Section 982.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON...

  5. 7 CFR 982.88 - Amendments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Amendments. 982.88 Section 982.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON...

  6. 7 CFR 982.88 - Amendments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Amendments. 982.88 Section 982.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON...

  7. 7 CFR 982.88 - Amendments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Amendments. 982.88 Section 982.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON...

  8. 7 CFR 982.88 - Amendments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Amendments. 982.88 Section 982.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON...

  9. 38 CFR 8.8 - Health requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Health requirements. 8.8... INSURANCE Reinstatement § 8.8 Health requirements. National Service life insurance on any plan may be... month for which the unpaid premium was due, provided the applicant be in as good health on the date...

  10. 38 CFR 8.8 - Health requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Health requirements. 8.8... INSURANCE Reinstatement § 8.8 Health requirements. National Service life insurance on any plan may be... month for which the unpaid premium was due, provided the applicant be in as good health on the date...

  11. 38 CFR 8.8 - Health requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Health requirements. 8.8... INSURANCE Reinstatement § 8.8 Health requirements. National Service life insurance on any plan may be... month for which the unpaid premium was due, provided the applicant be in as good health on the date...

  12. 38 CFR 8.8 - Health requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Health requirements. 8.8... INSURANCE Reinstatement § 8.8 Health requirements. National Service life insurance on any plan may be... month for which the unpaid premium was due, provided the applicant be in as good health on the date...

  13. 38 CFR 8.8 - Health requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Health requirements. 8.8... INSURANCE Reinstatement § 8.8 Health requirements. National Service life insurance on any plan may be... month for which the unpaid premium was due, provided the applicant be in as good health on the date...

  14. 21 CFR 808.88 - Pennsylvania.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pennsylvania. 808.88 Section 808.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific...

  15. 21 CFR 808.88 - Pennsylvania.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pennsylvania. 808.88 Section 808.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific...

  16. 21 CFR 808.88 - Pennsylvania.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pennsylvania. 808.88 Section 808.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific...

  17. 21 CFR 808.88 - Pennsylvania.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pennsylvania. 808.88 Section 808.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific...

  18. 21 CFR 808.88 - Pennsylvania.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pennsylvania. 808.88 Section 808.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EXEMPTIONS FROM FEDERAL PREEMPTION OF STATE AND LOCAL MEDICAL DEVICE REQUIREMENTS Listing of Specific...

  19. 40 CFR 88.302-94 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... circumstances garaged at personal residence means a vehicle that, when it is not in use, is normally parked at...) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program § 88.302-94 Definitions. The definitions in § 88.302-93 and 40 CFR part 86 also apply to this part. All terms used in this part, but not defined in this...

  20. 49 CFR 230.88 - Throttles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Throttles. 230.88 Section 230.88 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Throttles...

  1. 45 CFR 96.88 - Administrative costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Administrative costs. 96.88 Section 96.88 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION BLOCK GRANTS Low-income Home Energy... planning and administering the low-income home energy assistance program shall be 20 percent of...

  2. 34 CFR 361.88 - Reporting requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Reporting requirements. 361.88 Section 361.88 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION STATE VOCATIONAL REHABILITATION SERVICES PROGRAM Evaluation Standards and Performance Indicators...

  3. 34 CFR 361.88 - Reporting requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Reporting requirements. 361.88 Section 361.88 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION STATE VOCATIONAL REHABILITATION SERVICES PROGRAM...

  4. 40 CFR 88.302-94 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 CFR part 86 also apply to this part. All terms used in this part, but not defined in this section or in § 88.302-93 and 40 CFR part 86 shall have the meaning assigned to them in the Clean Air Act.../engine conversion configuration pursuant to the requirements of 40 CFR part 86 and this part 88....

  5. 24 CFR 200.88 - Late charge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Late charge. 200.88 Section 200.88 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN...

  6. 32 CFR 88.4 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Special Separation Benefit Programs as defined in § 88.3 (c). (d) Service members from one Service shall... ASSISTANCE FOR MILITARY PERSONNEL § 88.4 Policy. It is DoD policy that: (a) Transition assistance programs... programs be designed to complete the military personnel “life cycle.” This cycle begins with the...

  7. 32 CFR 88.4 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Special Separation Benefit Programs as defined in § 88.3 (c). (d) Service members from one Service shall... ASSISTANCE FOR MILITARY PERSONNEL § 88.4 Policy. It is DoD policy that: (a) Transition assistance programs... programs be designed to complete the military personnel “life cycle.” This cycle begins with the...

  8. 32 CFR 88.4 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Special Separation Benefit Programs as defined in § 88.3 (c). (d) Service members from one Service shall... ASSISTANCE FOR MILITARY PERSONNEL § 88.4 Policy. It is DoD policy that: (a) Transition assistance programs... programs be designed to complete the military personnel “life cycle.” This cycle begins with the...

  9. 42 CFR 88.1 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Definitions. 88.1 Section 88.1 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND... Conditions (4) Cancers: This list includes those individual cancer types specified in Table 1,...

  10. 7 CFR 966.88 - Agents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Agents. 966.88 Section 966.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order...

  11. 7 CFR 966.88 - Agents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Agents. 966.88 Section 966.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order...

  12. 7 CFR 966.88 - Agents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Agents. 966.88 Section 966.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order...

  13. 7 CFR 966.88 - Agents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Agents. 966.88 Section 966.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order...

  14. 7 CFR 966.88 - Agents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Agents. 966.88 Section 966.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Order...

  15. Solvent extraction-absorptiometric determination of niobium in steels with bromopyrogallol red.

    PubMed

    Ramakrishna, T V; Rahim, S A; West, T S

    1969-07-01

    A simple and rapid method is described for the determination of niobium in steel with Bromopyrogallol Red. After dissolution of the sample, niobium is extracted along with iron from concentrated hydrochloric acid into isopentyl acetate. Niobium and iron are stripped into an aqueous solution containing sodium acetate, and EDTA, ammonium chloride, tartaric acid, and Bromopyrogallol Red are added to complex the niobium. The niobium-Bromopyro-gallol Red complex along with excess of reagent is extracted into isopentyl acetate containing di-n-octylmethylamine, and measured at 610 nm. The molar absorptivity is 2.50 x 10(4) and Beer's law is obeyed up to 27 mug of niobium. The method is free from interferences and can be applied to the analysis of samples containing as little as 0.01 % niobium. PMID:18960586

  16. Variation of Mechanical Properties of High RRR And Reactor Grade Niobium With Heat Treatments

    SciTech Connect

    Ganapati Myneni; H. Umezawa

    2003-06-01

    Superconducting rf cavities used as accelerating structures in particle accelerators are made from high purity niobium with residual resistance ratios greater than 250. Reactor grade niobium is also used to make wave-guide and/or end group components for these accelerating structures. The major impurities in this type of niobium are interstitially dissolved gases such as hydrogen, nitrogen, and oxygen in addition to carbon. After fabricating the niobium accelerating structures, they are subjected to heat treatments for several hours in vacuum at temperatures of up to 900 C for degassing hydrogen or up to 1400 C for improving the thermal conductivity of niobium considerably. These heat treatments are affecting the mechanical properties of niobium drastically. In this paper the variation of the mechanical properties of high purity and reactor grade niobium with heat treatments in a vacuum of {approx} 10{sup -6} Torr and temperatures from 600 C to 1250 C for periods of 10 to 6 hours are presented.

  17. Measurements of Modulus of Elasticity and Thermal Contraction of Epoxy Impregnated Niobium-Tin and Niobium-Titanium Composites

    SciTech Connect

    Chow, K.P.; Millos, G.A.

    1998-09-01

    In the high field magnet program at Lawrence Berkeley National Laboratory, accelerator magnet prototypes are designed with epoxy impregnated niobium-tin and niobium-titanium superconductor. Accurate mechanical property values are essential for magnet mechanical design and prediction of conductor performance. Two key mean property values are measured on coil samples: modulus of elasticity (Young's modulus) and mean thermal contraction. Measurements are made in compression and are conducted in three orthogonal directions. Modulus of elasticity measurements are currently conducted at room temperature and the mean thermal contraction is measured from room temperature to liquid nitrogen temperature. Room temperature values are compared with values estimated using the individual coil components.

  18. Stress dependent oxidation of sputtered niobium and effects on superconductivity

    SciTech Connect

    David Henry, M. Wolfley, Steve; Monson, Todd; Clark, Blythe G.; Shaner, Eric; Jarecki, Robert

    2014-02-28

    We report on the suppression of room temperature oxidation of DC sputtered niobium films and the effects upon the superconductive transition temperature, T{sub c}. Niobium was sputter-deposited on silicon dioxide coated 150 mm wafers and permitted to oxidize at room temperature and pressure for up to two years. Resistivity and stress measurements indicate that tensile films greater than 400 MPa resist bulk oxidation with measurements using transmission electron microscope, electron dispersive X-ray spectroscopy, x-ray photoelectric spectroscopy, and secondary ion mass spectrometry confirming this result. Although a surface oxide, Nb{sub 2}O{sub 5}, consumed the top 6–10 nm, we measure less than 1 at. % oxygen and nitrogen in the bulk of the films after the oxidation period. T{sub c} measurements using a SQUID magnetometer indicate that the tensile films maintained a T{sub c} approaching the dirty superconductive limit of 8.4 K after two years of oxidation while maintaining room temperature sheet resistance. This work demonstrates that control over niobium film stress during deposition can prevent bulk oxidation by limiting the vertical grain boundaries ability to oxidize, prolonging the superconductive properties of sputtered niobium when exposed to atmosphere.

  19. High-Temperature Creep Behavior Of Fiber-Reinforced Niobium

    NASA Technical Reports Server (NTRS)

    Petrasek, Donald W.; Titran, Robert H.

    1990-01-01

    Study conducted to determine feasibility of using composite materials in advanced space power systems, described in 22-page report. Tungsten fibers reduce creep and mass in advanced power systems. Reinforcing niobium alloys with tungsten fibers increases their resistances to creep by factors of as much as 10.

  20. Superconducting niobium thin film slow-wave structures

    NASA Technical Reports Server (NTRS)

    Bautista, J. J.; Petty, S. M.; Allen, L. H.; Beasley, M. R.; Hammond, R. H.

    1983-01-01

    A superconducting comb structure as a slow-wave element in a traveling-wave maser will significantly improve maser noise temperature and gain by reducing the insertion loss. The results of the insertion loss measurements of superconducting niobium slow-wave structures subjected to maser operating conditions at X-Band frequencies are presented.

  1. Stress dependent oxidation of sputtered niobium and effects on superconductivity

    NASA Astrophysics Data System (ADS)

    David Henry, M.; Wolfley, Steve; Monson, Todd; Clark, Blythe G.; Shaner, Eric; Jarecki, Robert

    2014-02-01

    We report on the suppression of room temperature oxidation of DC sputtered niobium films and the effects upon the superconductive transition temperature, Tc. Niobium was sputter-deposited on silicon dioxide coated 150 mm wafers and permitted to oxidize at room temperature and pressure for up to two years. Resistivity and stress measurements indicate that tensile films greater than 400 MPa resist bulk oxidation with measurements using transmission electron microscope, electron dispersive X-ray spectroscopy, x-ray photoelectric spectroscopy, and secondary ion mass spectrometry confirming this result. Although a surface oxide, Nb2O5, consumed the top 6-10 nm, we measure less than 1 at. % oxygen and nitrogen in the bulk of the films after the oxidation period. Tc measurements using a SQUID magnetometer indicate that the tensile films maintained a Tc approaching the dirty superconductive limit of 8.4 K after two years of oxidation while maintaining room temperature sheet resistance. This work demonstrates that control over niobium film stress during deposition can prevent bulk oxidation by limiting the vertical grain boundaries ability to oxidize, prolonging the superconductive properties of sputtered niobium when exposed to atmosphere.

  2. Influence of pressure on the Fermi surface of niobium

    NASA Astrophysics Data System (ADS)

    Anderson, J. R.; Papaconstantopoulos, D. A.; Schirber, J. E.

    1981-12-01

    The effects of pressure on selected de Haas - van Alphen frequencies in niobium have been measured. The frequency shifts, including a relatively large negative shift for the jungle-gym arms, can be explained by a model which uses a Slater-Koster interpolation of augmented-plane-wave Xα bands which had been calculated for two lattice spacings.

  3. Oxidation Behavior of Binary Niobium Alloys

    NASA Technical Reports Server (NTRS)

    Barrett, Charles A.; Corey, James L.

    1960-01-01

    This investigation concludes a study to determine the effects of up to 25 atomic percent of 55 alloying additions on the oxidation characteristics of niobium. The alloys were evaluated by oxidizing in an air atmosphere for 4 hours at 1000 C and 2 hours at 1200 C. Titanium and chromium improved oxidation resistance at both evaluation conditions. Vanadium and aluminum improved oxidation resistance at 1000 C, even though the V scale tended to liquefy and the Al specimens became brittle and the scale powdery. Copper, cobalt, iron, and iridium improved oxidation resistance at 1200 C. Other investigations report tungsten and molybdenum are protective up to about 1000 C, and tantalum at 1100 C. The most important factor influencing the rate of oxidation was the ion size of the alloy additions. Ions slightly smaller than the Nb(5+) ion are soluble in the oxide lattice and tend to lower the compressive stresses in the bulk scale that lead to cracking. The solubility of the alloying addition also depends on the valence to some extent. All of the elements mentioned that improve the oxidation resistance of Nb fit this size criterion with the possible exception of Al, whose extremely small size in large concentrations would probably lead to the formation of a powdery scale. Maintenance of a crack-free bulk scale for as long as possible may contribute to the formation of a dark subscale that ultimately is rate- controlling in the oxidation process. The platinum-group metals, especially Ir, appear to protect by entrapment of the finely dispersed alloying element by the incoming Nb2O5 metal-oxide interface. This inert metallic Ir when alloyed in a sufficient amount with Yb appears to give a ductile phase dispersed in the brittle oxide. This scale would then flow more easily to relieve the large compressive stresses to delay cracking. Complex oxide formation (which both Ti and Zr tend to initiate) and valence effects, which probably change the vacancy concentration in the scale

  4. Noburnium: Systems design of niobium superalloys

    NASA Astrophysics Data System (ADS)

    Misra, Abhijeet

    2005-11-01

    A systems-based approach, integrating quantum mechanical calculations with efficient experimentation, was employed to design niobium-based superalloys. The microstructural concept of gamma-gamma' nickel-based superalloys was adopted, where, the coherent gamma ' aluminides act both as the strengthening phase and a source of aluminum for Al2O3 passivation. Building on previous research, the selected bcc-type ordered aluminide was L2 1 structured Pd2HfAl phase. Comprehensive phase relations were measured on Nb-Pd-Hf-Al prototype alloys, and key tie-tetrahedra were identified. Aluminide precipitation in a bcc matrix was demonstrated in designed Nb+Pd2HfAl alloys. Thermodynamic databases were developed by integrating first-principles calculations with measured phase relations. Atomic volume models were developed for the bcc matrix and the Pd2HfAl phase and matrix elements which would reduce lattice misfit were identified. An experimental 2-phase alloy demonstrated a misfit of 3%. A modified Wagner's model was used to predict the required transient properties to form external Al2O3. The principal oxidation design goal was to decrease the oxygen permeability ( NSOx DO ) divided by the aluminum diffusivity (DAl) by 5 orders of magnitude. A multicomponent mobility database was developed to predict the diffusivities. Guided by first-principles calculations the effect of alloying elements on the oxygen diffusivity in Nb was measured, and the mobility database was experimentally validated. Based on the mobility database, it was found that increasing Al solubility in the bcc matrix greatly increased Al diffusivity. Alloying elements were identified that would increase Al solubility in the bcc matrix. Prototype alloys were prepared and the best oxidation performance was exhibited by a bcc+Nb2Al Nb-Hf-Al alloy, which exhibited parabolic oxidation behavior at 1300°C. The alloy was shown to have achieved the required 5 orders of magnitude reduction in the design parameter. The

  5. First-principles calculations of niobium hydride formation in superconducting radio-frequency cavities

    SciTech Connect

    Ford, Denise C.; Cooley, Lance D.; Seidman, David N.

    2013-09-01

    Niobium hydride is suspected to be a major contributor to degradation of the quality factor of niobium superconducting radio-frequency (SRF) cavities. In this study, we connect the fundamental properties of hydrogen in niobium to SRF cavity performance and processing. We modeled several of the niobium hydride phases relevant to SRF cavities and present their thermodynamic, electronic, and geometric properties determined from calculations based on density-functional theory. We find that the absorption of hydrogen from the gas phase into niobium is exothermic and hydrogen becomes somewhat anionic. The absorption of hydrogen by niobium lattice vacancies is strongly preferred over absorption into interstitial sites. A single vacancy can accommodate six hydrogen atoms in the symmetrically equivalent lowest-energy sites and additional hydrogen in the nearby interstitial sites affected by the strain field: this indicates that a vacancy can serve as a nucleation center for hydride phase formation. Small hydride precipitates may then occur near lattice vacancies upon cooling. Vacancy clusters and extended defects should also be enriched in hydrogen, potentially resulting in extended hydride phase regions upon cooling. We also assess the phase changes in the niobium-hydrogen system based on charge transfer between niobium and hydrogen, the strain field associated with interstitial hydrogen, and the geometry of the hydride phases. The results of this study stress the importance of not only the hydrogen content in niobium, but also the recovery state of niobium for the performance of SRF cavities.

  6. 45 CFR 88.3 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES FUNDS DO NOT SUPPORT COERCIVE OR DISCRIMINATORY POLICIES OR PRACTICES § 88.3 Applicability. (a..., teaching hospital, or program for the training of health care professionals or health care workers...

  7. 40 CFR 88.303-93 - Abbreviations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program § 88.303-93 Abbreviations. The abbreviations in subpart A of this part and in 40 CFR part 86 apply to this subpart. The abbreviations in this section apply...

  8. 32 CFR 644.88 - Other acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... District Engineer, pursuant to 43 CFR part 295, as soon as a real estate directive is issued. (i) If use... HANDBOOK Acquisition Acquisition by Purchase, Donation, and Transfer § 644.88 Other acquisition....

  9. 19 CFR 141.88 - Computed value.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) ENTRY OF MERCHANDISE Invoices § 141.88 Computed value. When the port director determines that... shall so notify the importer, and thereafter invoices of such merchandise shall contain a...

  10. 19 CFR 141.88 - Computed value.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) ENTRY OF MERCHANDISE Invoices § 141.88 Computed value. When the port director determines that... shall so notify the importer, and thereafter invoices of such merchandise shall contain a...

  11. 19 CFR 141.88 - Computed value.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) ENTRY OF MERCHANDISE Invoices § 141.88 Computed value. When the port director determines that... shall so notify the importer, and thereafter invoices of such merchandise shall contain a...

  12. Two myeloid differentiation factor 88 (MyD88) isoforms identified in ducks.

    PubMed

    Cheng, Yuqiang; Wang, Hengan; Yan, Yaxian; Ding, Chan; Sun, Jianhe

    2015-10-01

    MyD88 is an adaptor protein involved in the interleukin-1 receptor-induced and Toll-like receptor (TLR)-induced activation of nuclear factor-κB (NF-κB). In this study, we identified two isoforms of MyD88 gene, designated DuMyD88-X1 and DuMyD88-X2, from duck cells. Both variants were determined to have a death domain at the N-terminal and a Toll/IL-1R (TIR) domain at the C-terminal; however, the TIR domain of DuMyD88-X2 was incomplete and was 81 amino acids shorter than DuMyD88-X1. Quantitative real-time reverse transcription PCR revealed broad expression of both MyD88s. During Newcastle disease virus (NDV) challenge experiments, expression of the two genes increased significantly, with DuMyD88-X1 having a larger amplitude and longer duration. Overexpression of DuMyD88-X1 and DuMyD88-X2 induced the activation of NF-κB and IL-6 in vitro, suggesting that DuMyD88-X1 and DuMyD88-X2 may be important in the innate immune response. The results verify the existence of a MyD88-dependent signaling pathway in ducks and contribute to understanding the potential role of MyD88s in the innate immune response.

  13. Method for etching thin films of niboium and niobium-containing compounds for preparing superconductive circuits

    DOEpatents

    Kampwirth, R.T.; Schuller, I.K.; Falco, C.M.

    1979-11-23

    An improved method of preparing thin film superconducting electrical circuits of niobium or niobium compounds is provided in which a thin film of the niobium or niobium compound is applied to a nonconductive substrate and covered with a layer of photosensitive material. The sensitive material is in turn covered with a circuit pattern exposed and developed to form a mask of the circuit in photoresistive material on the surface of the film. The unmasked excess niobium film is removed by contacting the substrate with an aqueous etching solution of nitric acid, sulfuric acid, and hydrogen fluoride, which will rapidly etch the niobium compound without undercutting the photoresist. A modification of the etching solution will permit thin films to be lifted from the substrate without further etching.

  14. Niobium tetrahalide complexes with neutral diphosphine ligands.

    PubMed

    Benjamin, Sophie L; Chang, Yao-Pang; Hector, Andrew L; Jura, Marek; Levason, William; Reid, Gillian; Stenning, Gavin

    2016-05-10

    The reactions of NbCl4 with diphosphine ligands o-C6H4(PMe2)2, Me2PCH2CH2PMe2 or Et2PCH2CH2PEt2 in a 1 : 2 molar ratio in MeCN solution produced eight-coordinate [NbCl4(diphosphine)2]. [NbBr4(diphosphine)2] (diphosphine = o-C6H4(PMe2)2 or Me2PCH2CH2PMe2) were made similarly from NbBr4. X-ray crystal structures show that [NbCl4{o-C6H4(PMe2)2}2] has a dodecahedral geometry, but the complexes with dimethylene-backboned diphosphines are distorted square antiprisms. The Nb-P distances and niobium tetrabromide, conveniently made from NbCl4 and BBr3, is a chain polymer with edge-linked NbBr6 octahedra and alternating long and short Nb-Nb distances, the latter ascribed to Nb-Nb bonds. PMID:27094082

  15. Cytotoxic, hematologic and histologic effects of niobium pentoxide in Swiss mice.

    PubMed

    Dsouki, Nuha Ahmad; de Lima, Maurício Pereira; Corazzini, Roseli; Gáscon, Thaís Moura; Azzalis, Ligia Ajaime; Junqueira, Virgínia Berlanga Campos; Feder, David; Fonseca, Fernando Luiz Affonso

    2014-05-01

    The use of metal devices in medical application is increasing but it remains incompletely understood the physiological effects of component degradation. Niobium (Nb) alloys have already been investigated in the 1980's and recent studies demonstrated the potential of Nb as an implant material. The purpose of this study was to determine cytotoxic, hematologic and histologic effects of niobium in Swiss mice. Animals were treated with a single dose of 3 % niobium oxide (Nb2O5) diluted in PBS, i.p. Cytotoxic assay, hematologic and histologic evaluation were done 3, 7 and 12 days after niobium treatment. Data have shown increased number of cells after niobium treatment, but there was no difference in cell viability. Furthermore, it was not observed hematological modification 3, 7 or 12 days after niobium treatment. Despite the fact that animals treated with niobium for 3 and 7 days showed mild degeneration in hepatocytes, mice kept alive for 12 days showed liver cells regeneration. Our results suggested that niobium cytotoxicity was not progressive because 12 days after treatment there was an evident liver regeneration. Data obtained indicated that niobium may be promising alternatives to biomedical applications.

  16. Determination of niobium in rocks by an isotope dilution spectrophotometric method

    USGS Publications Warehouse

    Greenland, L.P.; Campbell, E.Y.

    1970-01-01

    Rocks and minerals are fused with sodium peroxide in the presence of carrierfree 95Nb. The fusion cake is leached with water and the precipitate dissolved in hydrofluoric-sulfuric acid mixture. Niobium is extracted into methyl isobutyl ketone and further purified by ion exchange. The amount of niobium is determined spectrophotometrically with 4-(2-pyridylazo)-resorcinol, and the chemical yield of the separations determined by counting 95Nb. This procedure is faster and less sensitive to interferences than previously proposed methods for determining niobium in rocks.The high purity of the separated niobium makes the method applicable to nearly all matrices. ?? 1970.

  17. Microstructure, oxidation behavior and mechanical behavior of lens deposited niobium-titanium-silicon and niobium-titanium-silicon based alloys

    NASA Astrophysics Data System (ADS)

    Dehoff, Ryan Richard

    With current high temperature structural materials such as nickel based superalloys being pushed to the limits of suitable operating conditions, there comes a need for replacement materials with even higher temperature capabilities. Niobium silicon based systems have been shown to have superior density normalized strength at elevated temperatures when compared to currently used alloys. The drawbacks associated with the niobium silicon system are due to catastrophic oxidation behavior at elevated temperatures. Alloying addition have been shown to increase the oxidation resistance near suitable levels, but also decrease the high temperature strength and increases creep rates when compared to the binary alloy system. The microstructure of the material is similar to metal matrix composites in which high melting temperature silicides are dispersed in a niobium based matrix phase. The silicides produce high temperature strength while the niobium based matrix increases the room temperature properties such as fracture toughness. The bulk of the research has been conducted on directionally solidified material which has a coarse microstructure due to the slow cooling rates associated with the processing condition. The current research uses a powder metallurgy process termed Laser Engineered Net Shaping, or LENS, to produce material with a significantly refined microstructure due to fast cooling rates associated with the laser process. Several compositions of alloys were examined and the ideal processing parameters were determined for each alloy. The resulting microstructures show a refinement of the microstructure as expected with a fine scale distribution of Nb5Si3 and Nb3Si dispersed in a niobium based matrix phase. The high temperature oxidation behavior of the LENS deposited alloys was comparable to alloys produced using other techniques. A non protective oxide scale formed on samples exposed for only 0.5 hours but was not protective and showed large amounts of

  18. Quantitative microscopy characterization of hydrous niobium phosphate into bleached cellulose.

    PubMed

    Cruz, T G; Pereira, P H F; Silva, M L C P; Cioffi, M O H; Voorwald, H J C

    2010-07-01

    In this research the spatial distribution characterization of niobium phosphate into bleached cellulose was carried out combining processing and images analysis obtained by SEM and statistical methodologies. The objective is to investigate the deposit composition and phosphate morphology by using complementary analytical techniques. Based on the proposed methodology, parameters of niobium phosphate agglomerates (size and shape) and fiber morphology were evaluated depending on gray-levels (average luminance and fiber type): fiber characteristics (morphology) were measured. For the test method proposed, a specific region of cellulose/NbOPO(4) x nH(2)O composite was analyzed. This method involves area fraction measuring with a conditional probabilistic analysis. The analyzed fields were divided in different ways, called 'Scanning' and as a result, in quantitative terms, the phosphate deposition was described as spatial distribution homogeneous or inhomogeneous. The quantitative microscopy as a non-destructive testing provides relevant information when it is combined with statistic analysis.

  19. A Single Crystal Niobium RF Cavity of the TESLA Shape

    SciTech Connect

    W. Singer; X. Singer; P. Kneisel

    2007-09-01

    A fabrication method for single crystal niobium cavities of the TESLA shape was proposed on the basis of metallographic investigations and electron beam welding tests on niobium single crystals. These tests showed that a cavity can be produced without grain boundaries even in the welding area. An appropriate annealing allows the outgassing of hydrogen and stress relaxation of the material without destruction of the single crystal. A prototype single crystal single cell cavity was built. An accelerating gradient of 37.5 MV/m was reached after approximately 110 mu-m of Buffered Chanical Polishing (BCP) and in situ baking at 120°C for 6 hrs with a quality factor exceeding 2x1010 at 1.8 K. The developed fabrication method can be extended to fabrication of multi cell cavities.

  20. A Single Crystal Niobium RF Cavity of the TESLA Shape

    SciTech Connect

    Singer, W.; Singer, X.; Kneisel, P.

    2007-08-09

    A fabrication method for single crystal niobium cavities of the TESLA shape was proposed on the basis of metallographic investigations and electron beam welding tests on niobium single crystals. These tests showed that a cavity can be produced without grain boundaries even in the welding area. An appropriate annealing allows the outgassing of hydrogen and stress relaxation of the material without destruction of the single crystal. A prototype single crystal single cell cavity was build. An accelerating gradient of 37.5 MV/m was reached after approximately 110 {mu}m of Buffered Chemical Polishing (BCP) and in situ baking at 120 deg. C for 6 hrs with a quality factor exceeding 2x1010 at 1.8 K. The developed fabrication method can be extended to fabrication of multi cell cavities.

  1. Niobium Uptake and Release by Bacterial Ferric Ion Binding Protein

    PubMed Central

    Shi, Yanbo; Harvey, Ian; Campopiano, Dominic; Sadler, Peter J.

    2010-01-01

    Ferric ion binding proteins (Fbps) transport FeIII across the periplasm and are vital for the virulence of many Gram negative bacteria. Iron(III) is tightly bound in a hinged binding cleft with octahedral coordination geometry involving binding to protein side chains (including tyrosinate residues) together with a synergistic anion such as phosphate. Niobium compounds are of interest for their potential biological activity, which has been little explored. We have studied the binding of cyclopentadienyl and nitrilotriacetato NbV complexes to the Fbp from Neisseria gonorrhoeae by UV-vis spectroscopy, chromatography, ICP-OES, mass spectrometry, and Nb K-edge X-ray absorption spectroscopy. These data suggest that NbV binds strongly to Fbp and that a dinuclear NbV centre can be readily accommodated in the interdomain binding cleft. The possibility of designing niobium-based antibiotics which block iron uptake by pathogenic bacteria is discussed. PMID:20445753

  2. The ``Q disease'' in Superconducting Niobium RF Cavities

    NASA Astrophysics Data System (ADS)

    Knobloch, J.

    2003-07-01

    Superconducting niobium cavities can achieve quality (Q0) factors of 1010-1011, more than six orders of magnitude higher than conventional copper cavities. However, to maintain this performance at high accelerating gradient (20 MV/m) the radio-frequency (rf) surface must be damage and dust free. Cavity preparation techniques therefore routinely include a chemical etch or electropolishing. Under certain conditions, these (and other) treatments can contaminate the niobium with hydrogen. Hydrides may then form when the cavity is cooled through 150 K, even if only a few atomic percent hydrogen are present. If hydrides are formed, the cavity quality can degrade substantially (Q disease). A rapid cooldown often inhibits the hydride formation. Other "cures" include degassing cavities at 900 °C to eliminate the hydrogen. A historical review of the Q disease is provided here, with the emphasis being placed on its discovery, symptoms, mechanism, and cures.

  3. Formation and Redox Interconversion of Niobium Methylidene and Methylidyne Complexes.

    PubMed

    Searles, Keith; Smith, Kyle T; Kurogi, Takashi; Chen, Chun-Hsing; Carroll, Patrick J; Mindiola, Daniel J

    2016-06-01

    The niobium methylidene [{(Ar'O)2 Nb}2 (μ2 -Cl)2 (μ2 -CH2 )] (2) can be cleanly prepared via thermolysis or photolysis of [(Ar'O)2 Nb(CH3 )2 Cl] (1) (OAr'=2,6-bis(diphenylmethyl)-4-tert-butylphenoxide). Reduction of 2 with two equivalents of KC8 results in formation of the first niobium methylidyne [K][{(Ar'O)2 Nb}2 (μ2 -CH)(μ2 -H)(μ2 -Cl)] (3) via a binuclear α-hydrogen elimination. Oxidation of 3 with two equiv of ClCPh3 reforms 2. In addition to solid state X-ray analysis, all these complexes were elucidated via multinuclear NMR experiments and isotopic labelling studies, including a crossover experiment, support the notion for a radical mechanism as well as a binuclear α-hydrogen abstraction pathway being operative in the formation of 2 from 1. PMID:27110689

  4. Temperature dependence of penetration depth in thin film niobium

    NASA Technical Reports Server (NTRS)

    More, N.; Muhlfelder, B.; Lockhart, J.

    1989-01-01

    A novel technique is presented which should allow precise determination of the temperature dependence of the inductance, and hence of the penetration depth, of superconducting niobium thin-film structures. Four niobium thin-film stripline inductors are arranged in a bridge configuration, and inductance differences are measured using a potentiometric technique with a SQUID (superconducting quantum interference device) as the null detector. Numerical simulations of the stripline inductances are presented which allow the performance of the measurement technique to be evaluated. The prediction of the two-fluid model for the penetration-depth temperature dependence is given for reduced temperatures of 0.3 to 0.9. The experimental apparatus and its resolution and accuracy are discussed.

  5. Creep behavior of tungsten fiber reinforced niobium metal matrix composites

    NASA Technical Reports Server (NTRS)

    Grobstein, T. L.

    1989-01-01

    Tungsten fiber reinforced niobium metal matrix composites were evaluated for use in space nuclear power conversion systems. The composite panels were fabricated using the arc-spray monotape technique at the NASA Lewis Research Center. The creep behavior of W/Nb composite material was determined at 1400 and 1500 K in vacuum over a wide range of applied loads. The time to reach 1 percent strain, the time to rupture, and the minimum creep rate were measured. The W/Nb composites exceeded the properties of monolithic niobium alloys significantly even when compared on a strength to density basis. The effect of fiber orientation on the creep strength also was evaluated. Kirkendall void formation was observed at the fiber/matrix interface; the void distribution differed depending on the fiber orientation relative to the stress axis. A relationship was found between the fiber orientation and the creep strength.

  6. Creep behavior of tungsten fiber reinforced niobium metal matrix composites

    NASA Technical Reports Server (NTRS)

    Grobstein, Toni L.

    1992-01-01

    Tungsten fiber reinforced niobium metal matrix composites were evaluated for use in space nuclear power conversion systems. The composite panels were fabricated using the arc-spray monotape technique at the NASA Lewis Research Center. The creep behavior of W/Nb composite material was determined at 1400 and 1500 K in vacuum over a wide range of applied loads. The time to reach 1 percent strain, the time to rupture, and the minimum creep rate were measured. The W/Nb composites exceeded the properties of monolithic niobium alloys significantly even when compared creep strength also was evaluated. Kirkendall void formation was observed at the fiber/matrix interface; the void distribution differed depending the fiber orientation relative to the stress axis. A relationship was found between the fiber orientation and the creep strength.

  7. Structural behaviour of niobium oxynitride under high pressure

    SciTech Connect

    Sharma, Bharat Bhooshan Poswal, H. K. Pandey, K. K. Sharma, Surinder M.; Yakhmi, J. V.; Ohashi, Y.; Kikkawa, S.

    2014-04-24

    High pressure investigation of niobium oxynitrides (NbN{sub 0.98}O{sub 0.02}) employing synchrotron based angle dispersive x-ray diffraction experiments was carried out in very fine pressure steps using membrane driven diamond anvil cell. Ambient cubic phase was found to be stable up to ∼18 GPa. At further high pressure cubic phase showed rhombohedral distortion.

  8. Mechanical Properties of High Purity Niobium - Novel Measurements

    SciTech Connect

    Ganapati Myneni

    2003-09-01

    One of the procedures to improve the performance of superconducting niobium cavities is a heat treatment for several hours in an ultrahigh vacuum at temperatures between 800C and 1400C for hydrogen degassing or post-purification, respectively. However, it was recently observed with Spallation Neutron Source Project (SNS) prototype cavities, that a heat treatment at 800 C for even 1 hour degraded the mechanical properties of RRR niobium, in particular the yield strength. This lower strength resulted in cavity deformations during handling thus affecting both their resonant frequency and field profile. In addition to lowering the yield strength, it was observed in some lots of material that the Young's modulus was also apparently reduced by a factor of 2 as a result of the hydrogen outgassing at 800 C. Surprisingly, material received at other national laboratories exhibited similar anomalous behavior even without any heat treatments in vacuum. Based on these observations a multi-institutional collaborative basic research activity on high RRR niobium (determination of Nb yield strength as a function of grain size, work hardening, chemical composition, and heat treatment temperature) has been initiated by JLAB to gain a better understanding of the material properties affecting the mechanical behavior In this contribution, a brief review of the measurements at JLAB, at the Materials Science and Engineering Department of the University of Virginia, at the Analytical Chemistry and Metallurgy Divisions of the National Institute of Standard and Technology, Gaithersburg and in the Department of Physics, SUNY, Albany are presented. The measurements include yield strength, hardness, ultrasonic velocity, crystallographic structure, microstructure, determination of interstitial contents using internal friction; particular emphasis is placed on determining the hydrogen concentration in the niobium via Cold Neutron Prompt Gamma-Ray Activation Analysis and Neutron Incoherent

  9. Synthesis and photocatalytic activity of electrospun niobium oxide nanofibers

    SciTech Connect

    Qi, Shishun; Zuo, Ruzhong; Liu, Yi; Wang, Yu

    2013-03-15

    Graphical abstract: Different morphologies are obtained for the electrospun niobium oxide nanofibers with different phase structures. The nanofibers of the two phase structures present different band gap value and the light absorption. Hexagonal phase nanofibers show better photocatalytic activity compared with the orthorhombic nanofibers. Highlights: ► Niobium oxide nanofibers of two phase structures were fabricated by electrospinning. ► Photocatalytic properties of the niobium oxide nanofibers were first explored. ► Nanofibers of different phase structures showed different photocatalytic activities. ► Reasons for the differences in the photocatalysis were carefully discussed. - Abstract: Niobium oxide (Nb{sub 2}O{sub 5}) nanofibers have been synthesized by sol–gel based electrospinning technique. Pure hexagonal phase (H-Nb{sub 2}O{sub 5}) and orthorhombic phase (O-Nb{sub 2}O{sub 5}) nanofibers were obtained by thermally annealing the electrospun Nb{sub 2}O{sub 5}/polyvinylpyrrolidone composite fibers in air at 500 °C and 700 °C, respectively. The fibers were characterized using the X-ray diffraction, scanning electron microscopy, specific surface area analyzer and UV–vis diffuse reflectance spectroscopy. Photocatalytic activities of the obtained nanofibers were evaluated depending on the degradation of methyl orange. The results indicate that the heat-treatment temperature, the crystalline structure and the morphology affected the physical and chemical properties of the as-prepared Nb{sub 2}O{sub 5} nanofibers. The H-Nb{sub 2}O{sub 5} nanofibers obtained at lower temperature showed better potential for the application as a promising photocatalyst.

  10. Development of a Niobium Bellow for Beamline Connections

    SciTech Connect

    Larry Turlington; John Brawley; Robert Manus; Stephen Manning; Samuel Morgan; Gary Slack; Peter Kneisel

    2003-09-01

    Superconducting cavities in an accelerator assembly are usually connected at the beampipes by stainless steel bellows. They operate at an intermediate temperature, compensating for alignment tolerances on the cavity beamlines and for thermal contraction during cooldown to cryogenic temperatures. This transition from one cavity to the next in a cavity string is typically of the order of 3/2 wavelength along with approximately half a wavelength taken up by the bellows. If one could incorporate a niobium bellows in the beam pipe, this distance could be reduced by half a wave length. In the case of a big accelerator such as TESLA the overall cavity length for the accelerator could be reduced by roughly 10% or 2000 m. In terms of cost savings this would amount to several million dollars. Based on this estimate we have begun to develop a niobium bellows to be used on a 2.75 inch diameter beamline. It is made from 0.3 mm thick niobium sheet, rolled into a tube and secured by a longitudinal full penetration electron beam weld; the weld is made with a high speed a narrow, focused beam reducing the heat affected zone, thus limiting the grain growth, which could affect the formability. Subsequently, two convolutions have been pressed into this tube in a 2-stage process, using an external die and a polyurethane internal expander. Niobium cuffs and flanges were electron beam welded to the formed bellows, which facilitated leak testing and allowed some measurements of compression/expansion and bending. In this contribution the fabrication process and the subsequent mechanical and vacuum tests with the bellows will be described.

  11. Deposition of aluminide and silicide based protective coatings on niobium

    NASA Astrophysics Data System (ADS)

    Majumdar, S.; Arya, A.; Sharma, I. G.; Suri, A. K.; Banerjee, S.

    2010-11-01

    We compare aluminide and alumino-silicide composite coatings on niobium using halide activated pack cementation (HAPC) technique for improving its oxidation resistance. The coated samples are characterized by SEM, EDS, EPMA and hardness measurements. We observe formation of NbAl3 in aluminide coating of Nb, though the alumino-silicide coating leads to formation primarily of NbSi2 in the inner layer and a ternary compound of Nb-Si-Al in the outer layer, as reported earlier (Majumdar et al. [11]). Formation of niobium silicide is preferred over niobium aluminide during alumino-silicide coating experiments, indicating Si is more strongly bonded to Nb than Al, although equivalent quantities of aluminium and silicon powders were used in the pack chemistry. We also employ first-principles density functional pseudopotential-based calculations to calculate the relative stability of these intermediate phases and the adhesion strength of the Al/Nb and Si/Nb interfaces. NbSi2 exhibits much stronger covalent character as compared to NbAl3. The ideal work of adhesion for the relaxed Al/Nb and Si/Nb interfaces are calculated to be 3226 mJ/m2 and 3545 mJ/m2, respectively, indicating stronger Nb-Si bonding across the interface.

  12. Pressure dependence of prototype structures of metastable niobium oxides

    NASA Astrophysics Data System (ADS)

    Obara, Kozo

    1993-03-01

    Faculty of Engineering, Kagoshima University, Korimoto, 1-21-40, Kagoshima 890, Japan Pressure dependences of prototypes of nonstoichiometric metastable niobium oxides formed by a magnetron sputtering system were investigated. The morphology of derived crystals depended strongly on the argon pressure. At argon pressure PAr< 0.2 Torr, thin microcrystals with five types of superlattice structures were derived. Observed lattice constants were transformed into one another by simple lattice deformations within 1% error. All types of superlattice structures were related to the cubic lattice a0 = 3.22 Å. At PAr > 0.3 Torr, metastable niobium oxide super-fine particles with a cubic lattice constant a = 3.44 Å were obtained. Unique relationships between lattice constants were found on the oxidized niobium super-fine particles, NbO and NbO2 formed above 0.3 Torr within 0.5% error. In this case, the lattice structure with a = 3.44 ,Å (BCC) is related to all structures. These lattices a0 = 3.22 ,Å and a = 3.44 Å seem to be the prototypes at PAr ≤ 0.2 Torr and PAr ≥ 0.3 Tort, respectively. These structural changes due to pressure difference depend on the density and the enthalpy of vacancies in as-grown crystals. The density of vacancies is related to the condensation rate of the crystals.

  13. Effect of low temperature baking on niobium cavities

    SciTech Connect

    Peter Kneisel; Ganapati Myneni; William Lanford; Gianluigi Ciovati

    2003-09-01

    A low temperature (100 C-150 C) ''in situ'' baking under ultra-high vacuum has been successfully applied as final preparation of niobium RF cavities by several laboratories over the last few years. The benefits reported consist mainly of an improvement of the cavity quality factor and a recovery from the so-called ''Q-drop'' without field emission at high field. A series of experiments with a CEBAF single cell cavity have been carried out at Jefferson Lab to carefully investigate the effect of baking at progressively higher temperatures for a fixed time on all the relevant material parameters. Measurements of the cavity quality factor in the temperature range 1.37K-280K and resonant frequency shift between 6K-9.3K provide information about the surface resistance, energy gap, penetration depth and mean free path. The experimental data have been analyzed with the complete BCS theory of superconductivity using a modified version of the computer code originally written by J. Halbritter [1] . Small niobium samples inserted in the cavity during its surface preparation were analyzed with respect to their hydrogen content with a Nuclear Reaction Analysis (NRA). The single cell cavity has been tested at three different temperatures before and after baking to gain some insight on thermal conductivity and Kapitza resistance and the data are compared with different models. This paper describes the results from these experiments and comments on the existing models to explain the effect of baking on the performance of niobium RF cavities.

  14. Field dependent surface resistance of niobium on copper cavities

    NASA Astrophysics Data System (ADS)

    Junginger, T.

    2015-07-01

    The surface resistance RS of superconducting cavities prepared by sputter coating a niobium film on a copper substrate increases significantly stronger with the applied rf field compared to cavities of bulk material. A possible cause is that the thermal boundary resistance between the copper substrate and the niobium film induces heating of the inner cavity wall, resulting in a higher RS. Introducing helium gas in the cavity, and measuring its pressure as a function of applied field allowed to conclude that the inner surface of the cavity is heated up by less than 120 mK when RS increases with Eacc by 100 n Ω . This is more than one order of magnitude less than what one would expect from global heating. Additionally, the effects of cooldown speed and low temperature baking have been investigated in the framework of these experiments. It is shown that for the current state of the art niobium on copper cavities there is only a detrimental effect of low temperature baking. A fast cooldown results in a lowered RS.

  15. Semimicrodetermination of combined tantalum and niobium with selenous acid

    USGS Publications Warehouse

    Grimaldi, F.S.; Schnepfe, M.

    1959-01-01

    Tantalum and niobium are separated and determined gravimetrically by precipitation with selenous acid from highly acidic solutions in the absence of complexing agents. Hydrogen peroxide is used in the preparation of the solution and later catalytically destroyed during digestion of the precipitate. From 0.2 to 30 mg., separately or in mixtures, of niobium or tantalum pentoxide can be separated from mixtures containing 100 mg. each of the oxides of scandium, yttrium, cerium, vanadium, molybdenum, iron, aluminum, tin, lead, and bismuth with a single precipitation; and from 30 mg. of titanium dioxide, and 50 mg. each of the oxides of antimony and thorium, when present separately, with three precipitations. At least 50 mg. of uranium(VI) oxide can be separated with a single precipitation when present alone; otherwise, three precipitations may be needed. Zirconium does not interfere when the tantalum and niobium contents of the sample are small, but in general, zirconium as well as tungsten interfere. The method is applied to the determination of the earth acids in tantaloniobate ores.

  16. 40 CFR 763.88 - Assessment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Asbestos-Containing Materials in Schools § 763.88 Assessment. (a)(1) For each inspection and reinspection... ACBM in the school building. (2) Each accredited inspector providing a written assessment shall sign... management plan within 30 days of the assessment. (b) The inspector shall classify and give reasons in...

  17. 32 CFR 88.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... outlined in Department of Defense Directive 1332.30. 2 2 Copies may be obtained, at cost, from the National... well as the officer's service, as outlined in Department of Defense Directive 1332.30. (3) In the case... of Defense Directive 1332.14. 3 3 See footnote 2 to section 88.3(a)(1). (4) In the case of a...

  18. 15 CFR 8.8 - Complaints.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and Foreign Trade Office of the Secretary of Commerce NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF COMMERCE-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 General Compliance § 8.8 Complaints. (a) Filing complaints. Any person who believes himself or any specific class...

  19. 16 CFR 1.88 - Implementing procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... environmental impact statement is developed to assure timely consideration of environmental factors. (d) The... consideration of environmental factors. (e) Parties seeking information or status reports on environmental... PROCEDURES Procedures for Implementation of the National Environmental Policy Act of 1969 § 1.88...

  20. 27 CFR 9.88 - Pacheco Pass.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.88 Pacheco Pass. (a) Name. The name of the viticultural area described in this section is “Pacheco Pass.” (b) Approved maps. The appropriate maps for determining the boundaries of Pacheco Pass viticultural area...

  1. 27 CFR 9.88 - Pacheco Pass.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.88 Pacheco Pass. (a) Name. The name of the viticultural area described in this section is “Pacheco Pass.” (b) Approved maps. The appropriate maps for determining the boundaries of Pacheco Pass viticultural area...

  2. 27 CFR 9.88 - Pacheco Pass.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.88 Pacheco Pass. (a) Name. The name of the viticultural area described in this section is “Pacheco Pass.” (b) Approved maps. The appropriate maps for determining the boundaries of Pacheco Pass viticultural area...

  3. 27 CFR 9.88 - Pacheco Pass.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.88 Pacheco Pass. (a) Name. The name of the viticultural area described in this section is “Pacheco Pass.” (b) Approved maps. The appropriate maps for determining the boundaries of Pacheco Pass viticultural area...

  4. 27 CFR 9.88 - Pacheco Pass.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.88 Pacheco Pass. (a) Name. The name of the viticultural area described in this section is “Pacheco Pass.” (b) Approved maps. The appropriate maps for determining the boundaries of Pacheco Pass viticultural area...

  5. 40 CFR 88.302-94 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 CFR part 86 also apply to this part. All terms used in this part, but not defined in this section or in § 88.302-93 and 40 CFR part 86 shall have the meaning assigned to them in the Clean Air Act... covered fleet operator. Any vehicle that is under normal operations garaged at home at night but that...

  6. 40 CFR 88.302-94 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 CFR part 86 also apply to this part. All terms used in this part, but not defined in this section or in § 88.302-93 and 40 CFR part 86 shall have the meaning assigned to them in the Clean Air Act... covered fleet operator. Any vehicle that is under normal operations garaged at home at night but that...

  7. 40 CFR 88.302-94 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 CFR part 86 also apply to this part. All terms used in this part, but not defined in this section or in § 88.302-93 and 40 CFR part 86 shall have the meaning assigned to them in the Clean Air Act... covered fleet operator. Any vehicle that is under normal operations garaged at home at night but that...

  8. 9 CFR 88.2 - General information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... EQUINES FOR SLAUGHTER § 88.2 General information. (a) State governments may enact and enforce regulations... whether an individual or other entity found to transport equines for slaughter is subject to the... transported the equines information regarding the business of that individual or other entity. When...

  9. 9 CFR 88.2 - General information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... EQUINES FOR SLAUGHTER § 88.2 General information. (a) State governments may enact and enforce regulations... whether an individual or other entity found to transport equines to a slaughtering facility is subject to... who transported the equines information regarding the business of that individual or other...

  10. 9 CFR 88.2 - General information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... EQUINES FOR SLAUGHTER § 88.2 General information. (a) State governments may enact and enforce regulations... whether an individual or other entity found to transport equines for slaughter is subject to the... transported the equines information regarding the business of that individual or other entity. When...

  11. 34 CFR 361.88 - Reporting requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... compliance with the evaluation standards and performance indicators and include in this report the following... REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION STATE VOCATIONAL REHABILITATION SERVICES PROGRAM Evaluation Standards and Performance Indicators § 361.88 Reporting requirements. (a) The Secretary requires that...

  12. 9 CFR 88.1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE... SLAUGHTER § 88.1 Definitions. The following definitions apply to this part: APHIS. The Animal and Plant... incidental to his or her principal activity of production agriculture (production of food or fiber)....

  13. 32 CFR 552.88 - Responsibilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Fort Lewis Land Use Policy § 552.88 Responsibilities... of Ft. Lewis Land Use Policy and area access procedures, and provide periodic updates through media. Act as interface, when necessary, to resolve community relations issues related to land...

  14. 32 CFR 552.88 - Responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Fort Lewis Land Use Policy § 552.88 Responsibilities... of Ft. Lewis Land Use Policy and area access procedures, and provide periodic updates through media. Act as interface, when necessary, to resolve community relations issues related to land...

  15. 32 CFR 552.88 - Responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Fort Lewis Land Use Policy § 552.88 Responsibilities... of Ft. Lewis Land Use Policy and area access procedures, and provide periodic updates through media. Act as interface, when necessary, to resolve community relations issues related to land...

  16. 32 CFR 552.88 - Responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Fort Lewis Land Use Policy § 552.88 Responsibilities... of Ft. Lewis Land Use Policy and area access procedures, and provide periodic updates through media. Act as interface, when necessary, to resolve community relations issues related to land...

  17. 32 CFR 552.88 - Responsibilities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Fort Lewis Land Use Policy § 552.88 Responsibilities... of Ft. Lewis Land Use Policy and area access procedures, and provide periodic updates through media. Act as interface, when necessary, to resolve community relations issues related to land...

  18. 29 CFR 1915.88 - Sanitation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT General Working Conditions § 1915.88...) Potable water. (1) The employer shall provide potable water for all employee health and personal needs...

  19. 1987-88 Statewide Computer Survey Report.

    ERIC Educational Resources Information Center

    South Carolina Educational Television Network Columbia.

    This fifth annual survey of computers and their use in South Carolina schools covers the 1978-88 school years. A questionnaire inventoried computer equipment and software, and dealt with such issues as instructional and administrative uses of computers, and availability of funding. The forms were distributed to all South Carolina public school…

  20. 40 CFR 88.302-93 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program § 88.302-93 Definitions. The definitions in 40 CFR part 86... which they are designed to operate. Partially-Covered Fleet pertains to a vehicle fleet in a covered area which contains both covered fleet vehicles and non-covered fleet vehicles, i.e., exempt...

  1. 32 CFR 88.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 102-484; continued use of military family housing as described in section 502 (a)(1) of Public Law 101... Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN TRANSITION ASSISTANCE FOR MILITARY PERSONNEL § 88.3 Definitions. (a) Involuntary separation. A member of the...

  2. 32 CFR 88.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 102-484; continued use of military family housing as described in section 502 (a)(1) of Public Law 101... Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN TRANSITION ASSISTANCE FOR MILITARY PERSONNEL § 88.3 Definitions. (a) Involuntary separation. A member of the...

  3. 36 CFR 223.88 - Bidding methods.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Bidding methods. 223.88... methods. (a) Competitive sales of National Forest timber shall be offered through either sealed or oral auction bidding. The method chosen for each sale will: (1) Insure open and fair competition, (2)...

  4. Process for the generation of .alpha., .beta.-unsaturated carboxylic acids and esters using niobium catalyst

    DOEpatents

    Gogate, Makarand Ratnakav; Spivey, James Jerome; Zoeller, Joseph Robert

    1999-01-01

    A process using a niobium catalyst includes the step of reacting an ester or carboxylic acid with oxygen and an alcohol in the presence a niobium catalyst to respectively produce an .alpha.,.beta.-unsaturated ester or carboxylic acid. Methanol may be used as the alcohol, and the ester or carboxylic acid may be passed over the niobium catalyst in a vapor stream containing oxygen and methanol. Alternatively, the process using a niobium catalyst may involve the step of reacting an ester and oxygen in the presence the niobium catalyst to produce an .alpha.,.beta.-unsaturated carboxylic acid. In this case the ester may be a methyl ester. In either case, niobium oxide may be used as the niobium catalyst with the niobium oxide being present on a support. The support may be an oxide selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide and mixtures thereof. The catalyst may be formed by reacting niobium fluoride with the oxide serving as the support. The niobium catalyst may contain elemental niobium within the range of 1 wt % to 70 wt %, and more preferably within the range of 10 wt % to 30 wt %. The process may be operated at a temperature from 150 to 450.degree. C. and preferably from 250 to 350.degree. C. The process may be operated at a pressure from 0.1 to 15 atm. absolute and preferably from 0.5-5 atm. absolute. The flow rate of reactants may be from 10 to 10,000 L/kg.sub.(cat) /h, and preferably from 100 to 1,000 L/kg.sub.(cat) /h.

  5. Identification of Transmembrane Protein 88 (TMEM88) as a Dishevelled-binding Protein*

    PubMed Central

    Lee, Ho-Jin; Finkelstein, David; Li, Xiaofeng; Wu, Dianqing; Shi, De-Li; Zheng, Jie J.

    2010-01-01

    Wnt signaling pathways are involved in embryonic development and adult tissue maintenance and have been implicated in tumorigenesis. Dishevelled (Dvl/Dsh) protein is one of key components in Wnt signaling and plays essential roles in regulating these pathways through protein-protein interactions. Identifying and characterizing Dvl-binding proteins are key steps toward understanding biological functions. Given that the tripeptide VWV (Val-Trp-Val) binds to the PDZ domain of Dvl, we searched publically available databases to identify proteins containing the VWV motif at the C terminus that could be novel Dvl-binding partners. On the basis of the cellular localization and expression patterns of the candidates, we selected for further study the TMEM88 (target protein transmembrane 88), a two-transmembrane-type protein. The interaction between the PDZ domain of Dvl and the C-terminal tail of TMEM88 was confirmed by using NMR and fluorescence spectroscopy. Furthermore, in HEK293 cells, TMEM88 attenuated the Wnt/β-catenin signaling induced by Wnt-1 ligand in a dose-dependent manner, and TMEM88 knockdown by RNAi increased Wnt activity. In Xenopus, TMEM88 protein is sublocalized at the cell membrane and inhibits Wnt signaling induced by Xdsh but not β-catenin. In addition, TMEM88 protein inhibits the formation of a secondary axis normally induced by Xdsh. The findings suggest that TMEM88 plays a role in regulating Wnt signaling. Indeed, analysis of microarray data revealed that the expression of the Tmem88 gene was strongly correlated with that of Wnt signaling-related genes in embryonic mouse intestines. Together, we propose that TMEM88 associates with Dvl proteins and regulates Wnt signaling in a context-dependent manner. PMID:21044957

  6. Measuring and modeling oxygen diffusion in niobium-vanadium and niobium-palladium alloys

    NASA Astrophysics Data System (ADS)

    Hennessey, Theresa P.

    Niobium alloys are under consideration for high-temperature aerospace applications, but they have poor oxidation resistance and need high-temperature coatings for protection in severe environments. Our approach to creating an oxidation-resistant Nb alloy is to identify substitutional solute elements that lower the diffusivity of oxygen in Nb. In theory, this will induce a transition from internal to external oxidation and promote the formation of a desirable, protective oxide scale. The objective of this particular project is to compare the oxygen diffusivity in Nb alloys that contain either trap or repulsive sites. In Nb, oxygen atoms diffuse via an interstitial mechanism, and they can interact with substitutional solute atoms in different ways. The interstitial sites adjacent to a substitutional atom constitute a "zone of influence". If the sites in this zone have a lower energy than the normal sites, they are called "trap" sites. If these sites have a higher energy, they are called "repulsive" sites. Oxygen diffusion is inhibited in both cases: trap sites hold the oxygen and keep it from diffusing further, while repulsive sites block the path of the oxygen. Two new mathematical models for interstitial diffusion in these systems were derived from probability and statistical thermodynamic theory. The models were verified using a new random-walk computer simulation of oxygen diffusion through Nb alloys. These models were also tested experimentally by measuring oxygen diffusivity in Nb-V and Nb-Pd alloys. These results showed that V atoms create trap sites for oxygen atoms, confirming previous work. However, there was not enough data to prove definitively that Pd atoms create repulsive sites, as expected by theory.

  7. Large Grain Niobium Cavity R&D in Asia and the Future

    SciTech Connect

    Saito, K; Furuta, F; Saeki, T; Inoue, H; Shim, J; Ahn, J; Kim, E S; Xu, Q; Zong, Z; Gao, J; Kneisel, P; Myneni, G R

    2007-09-01

    The status of the large grain niobium cavity R&D in Asia and the future scope are presented. Recently KEK has received CBMM and NingXia large grain niobium sheets through collaborations. KEK has fabricated 1.3 GHz single cell cavities using these materials and measured the cavity performance. Those results are presented in this paper.

  8. Nuclear Data Sheets for A = 88

    SciTech Connect

    McCutchan, E.A.; Sonzogni, A.A.

    2014-01-15

    The experimental results from the various reaction and radioactive decay studies leading to nuclides in the A=88 mass chain have been reviewed. Nuclides ranging from Ge (Z=32) to Ru (Z=44) are included. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given. This work supersedes the previous evaluation of the data on these nuclides (G. Mukherjee, A.A. Sonzogni – Nucl.Data Sheets 105, 419 (2005))

  9. FIFRA-88, GLP, and QA: pesticide registration.

    PubMed

    Sterner, R T; Fagerstone, K A

    1997-01-01

    The 1988 amendment to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA-88) has decreased the number of pesticide registrations in the United States. Subsequent implementation of the U.S. Environmental Protection Agency (EPA) Good Laboratory Practice (GLP) and quality assurance (QA) standards has increased costs of maintaining these registrations. The U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) maintains approximately 30 Section 3 (federal) or Section 24c (state) vertebrate pesticide registrations for the Wildlife Services (WS) program to control wild mammals and birds that damage crops, impact endangered species, or pose human health risks. Under FIFRA-88, APHIS summarized, performed, and submitted or gained waivers for > 500 studies requested by the U.S. EPA to assess potential hazards/effects of these pesticides. A summary of FIFRA-88 milestones for registration of 3-chloro-p-toluidine hydrochloride (CPTH), the active ingredient (AI) in a "low-volume, minor-use" avicide (DRC-1339, Starlicide), is used to illustrate GLP/QA/animal welfare issues involved in this process. Trends in the development of new pesticides and veterinary drugs are compared to provide some perspectives on future career paths for QA professionals.

  10. Qualification of niobium materials for superconducting radio frequency cavity applications: View of a condensed matter physicist

    SciTech Connect

    Roy, S. B.; Myneni, G. R.

    2015-12-04

    We address the issue of qualifications of the niobium materials to be used for superconducting radio frequency (SCRF) cavity fabrications, from the point of view of a condensed matter physicist/materials scientist. We focus on the particular materials properties of niobium required for the functioning a SCRF cavity, and how to optimize the same properties for the best SCRF cavity performance in a reproducible manner. In this way the niobium materials will not necessarily be characterized by their purity alone, but in terms of those materials properties, which will define the limit of the SCRF cavity performance and also other related material properties, which will help to sustain this best SCRF cavity performance. Furthermore we point out the need of standardization of the post fabrication processing of the niobium-SCRF cavities, which does not impair the optimized superconducting and thermal properties of the starting niobium-materials required for the reproducible performance of the SCRF cavities according to the design values.

  11. Influence of niobium on the beginning of the plastic flow of material during cold deformation.

    PubMed

    Rešković, Stoja; Jandrlić, Ivan

    2013-01-01

    Investigations were conducted on low-carbon steel and the steel with same chemical composition with addition of microalloying element niobium. While tensile testing was carried out, the thermographic measurement was tacking place simultaneously. A specific behavior of niobium microalloyed steel was noticed. Test results have shown that, in the elastic deformation region, thermoelastic effect occurs, which is more pronounced in niobium microalloyed steel. Start of plastic flow in steel which is not microalloyed with niobium begins later in comparison to the microalloyed steel, and it is conducted so that, at the point of maximum stress, deformation zone is formed within which stresses grow. In steel microalloyed with niobium after proportionality limit, comes the occurrence of the localized increase in temperature and the occurrence of Lüders band, which propagate along the sample forming a deformation zone.

  12. Influence of niobium on the beginning of the plastic flow of material during cold deformation.

    PubMed

    Rešković, Stoja; Jandrlić, Ivan

    2013-01-01

    Investigations were conducted on low-carbon steel and the steel with same chemical composition with addition of microalloying element niobium. While tensile testing was carried out, the thermographic measurement was tacking place simultaneously. A specific behavior of niobium microalloyed steel was noticed. Test results have shown that, in the elastic deformation region, thermoelastic effect occurs, which is more pronounced in niobium microalloyed steel. Start of plastic flow in steel which is not microalloyed with niobium begins later in comparison to the microalloyed steel, and it is conducted so that, at the point of maximum stress, deformation zone is formed within which stresses grow. In steel microalloyed with niobium after proportionality limit, comes the occurrence of the localized increase in temperature and the occurrence of Lüders band, which propagate along the sample forming a deformation zone. PMID:24453896

  13. Columbium (niobium) recycling in the United States in 1998

    USGS Publications Warehouse

    Cunningham, Larry D.

    2001-01-01

    This report describes the flow of columbium in the United States in 1998 with emphasis on the extent to which columbium (niobium) was recycled/reused. Columbium was mostly recycled from products of columbium-bearing steels and superalloys; little was recovered from products specifically for their columbium content. In 1998, about 1,800 metric tons of columbium was recycled/reused, with about 55% derived from old scrap. The columbium recycling rate was calculated to be 22%, and columbium scrap recycling efficiency, 50%.

  14. Monolithic gyroidal mesoporous mixed titanium-niobium nitrides.

    PubMed

    Robbins, Spencer W; Sai, Hiroaki; DiSalvo, Francis J; Gruner, Sol M; Wiesner, Ulrich

    2014-08-26

    Mesoporous transition metal nitrides are interesting materials for energy conversion and storage applications due to their conductivity and durability. We present ordered mixed titanium-niobium (8:2, 1:1) nitrides with gyroidal network structures synthesized from triblock terpolymer structure-directed mixed oxides. The materials retain both macroscopic integrity and mesoscale ordering despite heat treatment up to 600 °C, without a rigid carbon framework as a support. Furthermore, the gyroidal lattice parameters were varied by changing polymer molar mass. This synthesis strategy may prove useful in generating a variety of monolithic ordered mesoporous mixed oxides and nitrides for electrode and catalyst materials.

  15. Molecular beam epitaxy growth of monolayer niobium diselenide flakes

    NASA Astrophysics Data System (ADS)

    Hotta, Takato; Tokuda, Takuto; Zhao, Sihan; Watanabe, Kenji; Taniguchi, Takashi; Shinohara, Hisanori; Kitaura, Ryo

    2016-09-01

    Monolayer niobium diselenide (NbSe2) is prepared through molecular beam epitaxy with hexagonal boron nitride (hBN) as substrates. Atomic force microscopy and the Raman spectroscopy have shown that the monolayer NbSe2 grown on the hBN possesses triangular or truncated triangular shape whose lateral size amounts up to several hundreds of nanometers. We have found that the precisely controlled supply rate and ultraflat surface of hBN plays an important role in the growth of the monolayer NbSe2.

  16. Monolithic Gyroidal Mesoporous Mixed Titanium–Niobium Nitrides

    PubMed Central

    2015-01-01

    Mesoporous transition metal nitrides are interesting materials for energy conversion and storage applications due to their conductivity and durability. We present ordered mixed titanium–niobium (8:2, 1:1) nitrides with gyroidal network structures synthesized from triblock terpolymer structure-directed mixed oxides. The materials retain both macroscopic integrity and mesoscale ordering despite heat treatment up to 600 °C, without a rigid carbon framework as a support. Furthermore, the gyroidal lattice parameters were varied by changing polymer molar mass. This synthesis strategy may prove useful in generating a variety of monolithic ordered mesoporous mixed oxides and nitrides for electrode and catalyst materials. PMID:25122534

  17. Native niobium in the regolith from the Mare Crisium

    NASA Astrophysics Data System (ADS)

    Mokhov, A. V.; Gornostaeva, T. A.; Kartashov, P. M.; Bogatikov, O. A.

    2016-08-01

    A new mineral phase was discovered in the course of studies at the Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (IGEM) of fine-grained fractions of the lunar regolith delivered to the Earth by the Luna 16, Luna 20, and Luna 24 automatic stations. The grain of native niobium was identified in the regolith sample from the Mare Crisium. Presumably, this phase was formed during the fractioning process in a gas-plasma cloud under an impact event on the Moon.

  18. Cathodic arc grown niobium films for RF superconducting cavity applications

    NASA Astrophysics Data System (ADS)

    Catani, L.; Cianchi, A.; Lorkiewicz, J.; Tazzari, S.; Langner, J.; Strzyzewski, P.; Sadowski, M.; Andreone, A.; Cifariello, G.; Di Gennaro, E.; Lamura, G.; Russo, R.

    2006-07-01

    Experimental results on the characterization of the linear and non-linear microwave properties of niobium film produced by UHV cathodic arc deposition are presented. Surface impedance Zs as a function of RF field and intermodulation distortion (IMD) measurement have been carried out by using a dielectrically loaded resonant cavity operating at 7 GHz. The experimental data show that these samples have a lower level of intrinsic non-linearities at low temperature and low circulating power in comparison with Nb samples grown by sputtering. These results make UHV cathodic arc deposition a promising technique for the improvement of RF superconducting cavities for particle accelerators.

  19. Electrochemical behavior of niobium triselenide cathode in lithium secondary cells

    NASA Technical Reports Server (NTRS)

    Ratnakumar, B. V.; Di Stefano, S.; Bankston, C. P.

    1988-01-01

    Niobium triselenide cathodes in Li ambient-temperature rechargeable batteries for space applications undergo a topotactic reaction, with three equivalents of Li at high positive potential furnishing high energy density. It also yields good electronic conductivity, a long life cycle, and high diffusivity for Li. An attempt is presently made to characterize the intercalation mechanism between Li and NbSe3 by means of an ac impedance study conducted at various charge stages in the process of SbSe3 reduction. An effort is also made to predict the charge state of NbSe3 nondestructively, on the basis of the impedance parameters.

  20. The Meteoritical Bulletin, No. 88, 2004 July

    USGS Publications Warehouse

    Russell, S.S.; Folco, L.; Grady, M.M.; Zolensky, M.E.; Jones, R.; Righter, K.; Zipfel, J.; Grossman, J.N.

    2004-01-01

    The Meteoritical Bulletin No. 88 lists information for 1610 newly classified meteorites, comprising 753 from Antarctica, 302 from Africa, 505 from Asia (495 of which are from Oman), 40 from North America, 5 from South America, 4 from Europe, and 1 of unknown origin. Information is provided for 9 falls (Alby sur Che??ran, Al Zarnkh, Devgaon, Kamioka, Kendrapara, Maromandia, New Orleans, Sivas, and Villalbeto de la Pen??a). Noteworthy specimens include a eucrite fall (Alby sur Che??ran), 6 martian meteorites, 13 lunar meteorites, and 12 irons including one weighing 3 metric ions (Dronino). ?? Meteoritical Society, 2004.

  1. WSR-88D observations of volcanic ash

    USGS Publications Warehouse

    Wood, J.; Scott, C.; Schneider, D.

    2007-01-01

    Conclusions that may impact operations are summarized below: ??? Current VCPs may not be optimal for the scharacterization of volcanic events. Therefore, the development of a new VCP that combines the enhanced low level elevation density and increased temporal resolution of VCP 12 with the enhanced sensitivity of VCP 31. ??? Given currently available scan strategies, this preliminary investigation would suggest that it is advisable to use VCP 12 during the initial explosive phase of an eruptive event. Once the maximum reflectivity has dropped below 30 dBZ, VCP 31 should be used. ??? This study clearly indicates that WSR-88D Level II data offers many advantages over Level III data currently available in Alaska. The ability to access this data would open up greater opportunities for research. Given the proximity of WSR-88D platforms to active volcanoes in Alaska, as well as in the western Lower 48 states and Hawaii, radar data will likely play a major operational role when volcanic eruptions again pose a threat to life and property. The utilization of this tool to its maximum capability is vital.

  2. An evolutionary yield function based on Barlat 2000 yield function for the superconducting niobium sheet

    SciTech Connect

    Darbandi, Payam; Pourboghrat, Farhang

    2011-08-22

    Superconducting radio frequency (SRF) niobium cavities are widely used in high-energy physics to accelerate particle beams in particle accelerators. The performance of SRF cavities is affected by the microstructure and purity of the niobium sheet, surface quality, geometry, etc. Following optimum strain paths in the forming of these cavities can significantly control these parameters. To select these strain paths, however, information about the mechanical behavior, microstructure, and formability of the niobium sheet is required. In this study the Barlat 2000 yield function has been used as a yield function for high purity niobium. Results from this study showed that, due to intrinsic behavior, it is necessary to evolve the anisotropic coefficients of Barlat's yield function in order to properly model the plastic behavior of the niobium sheet. The accuracy of the newly developed evolutionary yield function was verified by applying it to the modeling of the hydrostatic bulging of the niobium sheet. Also, in a separate attempt crystal plasticity finite element method was use to model the behavior of the polycrystalline niobium sheet with a particular initial texture.

  3. Effects of helium on the mechanical properties and microstructure of niobium

    NASA Astrophysics Data System (ADS)

    Barmore, W. L.; Raymond, E. L.; Echer, C. J.; Vandervoort, R. R.

    1980-02-01

    Mechanical property specimens of niobium (Cb) were doped with helium by the tritium trick to concentrations as high as 500 appm. The tritium decays by the reaction3H →3He + β - at a rate that produces about 7 appm per day in the host microstructure. Tensile properties were measured from room temperature to 800°C, and creep properties from 700 to 1000°C at stresses from 45 to 75 MPa. Transmission electron microscopy was used to study the microstructure of the helium doped specimens, and the observations were correlated with the mechanical property results. The results of this investigation showed that niobium has a high tolerance to helium trapped in the microstructure. The tensile and creep strengths of niobium increased as helium concentration increased. The ductility decreased significantly as the helium concentration increased, but niobium retained substantial ductility even at a high helium concentration of 500 appm. This amount of helium would be generated by (n,α) reactions in the microstructure of a niobium first wall after a 20 y exposure in a D-T fusion reactor. Thus, niobium and niobium alloys are potential candidates for high temperature structural materials in D-T fusion reactors.

  4. Localized magnetism on the surface of niobium: experiments and theory

    NASA Astrophysics Data System (ADS)

    Proslier, Thomas; Zasadzinski, John; Ciovati, Gianluigi; Pellin, Mike

    2011-03-01

    The presence of magnetic impurities in native niobium oxides have been confirmed by Point contact spectroscopy (PCT), SQUID magnetometry and Electron paramagnetic resonance (EPR). All niobium (Nb) samples displayed a small impurity contribution to the magnetic susceptibility at low temperatures which exhibited Curie-Weiss behavior, indicative of weakly coupled localized paramagnetic moments. By examining Nb samples with widely varying surface-to-volume ratios it was found that the impurity contribution is correlated with surface area. Tunneling measurements which use the native oxide layers as barriers exhibit a zero-bias conductance peak which splits in a magnetic field > 4 T , consistentwiththeAppelbaummodelforspinfliptunneling . ViewedtogethertheexperimentsstronglysuggestthatthenativeoxidesofNbareintrinsicallydefective , andconsistentlyexhibitlocalizedparamagneticmomentscausedbyoxygenvacanciesinNb 2 O 5 . Thecomputationofthesurfaceimpedance (R S) in presence of magnetic impurities in the Shiba approximation reveals the saturation at low temperature of Rs, suggesting that magnetic impurities are responsible for the so-called residual resistance. Work supported by DOE-HEP office, under contract No. DE-AC02-06CH11357.

  5. Joining of alumina via copper/niobium/copper interlayers

    SciTech Connect

    Marks, Robert A.; Chapman, Daniel R.; Danielson, David T.; Glaeser, Andreas M.

    2000-03-15

    Alumina has been joined at 1150 degrees C and 1400 degrees C using multilayer copper/niobium/copper interlayers. Four-point bend strengths are sensitive to processing temperature, bonding pressure, and furnace environment (ambient oxygen partial pressure). Under optimum conditions, joints with reproducibly high room temperature strengths (approximately equal 240 plus/minus 20 MPa) can be produced; most failures occur within the ceramic. Joints made with sapphire show that during bonding an initially continuous copper film undergoes a morphological instability, resulting in the formation of isolated copper-rich droplets/particles at the sapphire/interlayer interface, and extensive regions of direct bonding between sapphire and niobium. For optimized alumina bonds, bend tests at 800 degrees C-1100 degrees C indicate significant strength is retained; even at the highest test temperature, ceramic failure is observed. Post-bonding anneals at 1000 degrees C in vacuum or in gettered argon were used to assess joint stability and to probe the effect of ambient oxygen partial pressure on joint characteristics. Annealing in vacuum for up to 200 h causes no significant decrease in room temperature bend strength or change in fracture path. With increasing anneal time in a lower oxygen partial pressure environment, the fracture strength decreases only slightly, but the fracture path shifts from the ceramic to the interface.

  6. Plasma Treatment of Single-Cell Niobium SRF Cavities

    SciTech Connect

    J. Upadhyay, M. Nikolić, S. Popović, L. Vušković, H.L. Phillips, A-M. Valente-Feliciano

    2011-03-01

    Superconducting radio frequency cavities of bulk Niobium are integral components of particle accelerators based on superconducting technology. Wet chemical processing is the commonly used procedure for impurities and surface defects removal and surface roughness improvement , both required to improve the RF performance of the cavity. We are studying plasma etching as an alternate technique to process these cavities. The uniformity of the plasma sheath at the inner wall of the cavity is one prerequisite for its uniform etching. We are developing electro-optic diagnostic techniques to assess the plasma uniformity. Multiple electro-optical probes are placed at different locations of the single cell cavity to diagnose the electrical and optical properties of the plasma. The electrical parameters are required to understand the kinetic nature of the plasma and the optical emission spectroscopy provides the spatial distribution of radicals in the plasma. The spatial variation of the plasma parameters inside the cavity and their effect on the etching of niobium samples placed at different locations in the cavity will be presented.

  7. Silicidation of Niobium Deposited on Silicon by Physical Vapor Deposition

    SciTech Connect

    Coumba Ndoye, Kandabara Tapily, Marius Orlowski, Helmut Baumgart, Diefeng Gu

    2011-07-01

    Niobium was deposited by physical vapor deposition (PVD) using e-beam evaporation on bare (100) silicon substrates and SiO2 surfaces. The formation of niobium silicide was investigated by annealing PVD Nb films in the temperatures range 400–1000°C. At all elevated annealing temperatures the resistivity of Nb silicide is substantially higher than that of Nb. The Nb silicidation as a function of temperature has been investigated and different NbXSiy compounds have been characterized. It has been observed that the annealing of the Nb film on Si is accompanied by a strong volume expansion of about 2.5 of the resulting reacted film. The films' structural properties were studied using X-Ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM), which was not previously presented in the context of the extant NbSi literature. The X-Ray diffraction characterization of the Nb on Si sample annealed at 1000°C, showed the presence of hexagonal Nb5Si3 phases, with a dominant peak at the (200) plane, and NbSi2 phases. Fractal dimension calculations indicate a distinct transition from Stranski-Krastanov to Volmer-Weber film growth for NbSi formation at the annealing temperature of 600°C and above.

  8. Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

    NASA Technical Reports Server (NTRS)

    Roth, R. S.; Brower, W. S.; Parker, H. S.; Minor, D. B.; Waring, J. L.

    1975-01-01

    The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases.

  9. Preliminary Experience with ''In-Site'' Baking of Niobium Cavities

    SciTech Connect

    P. Kneisel

    2000-01-01

    In a series of experiments several single cell and multi-cell niobium cavities made from reactor grade and high RRR niobium (frequencies were 700 MHz, 1300 MHz and 1497 MHz) have been baked--after initial testing--in-situ around 145 C for up to 90 hours prior to being recooled. Surprisingly, all cavities showed significant improvements in Q-values between 4.2 and 1.6K. The BCS surface resistance was lowered by nearly a factor of two. This cannot be explained by solely a reduction of dielectric losses caused by adsorbates at the surface or by a decrease of the mean free path due to possibly diffusion of oxygen into the surface layer. In several experiments also the high field behavior of the cavity improved after the in-situ baking procedure. The observed effect opens the possibility for the CEBAF upgrade cavities, which in turn will permit to run the cavities at higher gradients if field emission loading can be prevented. Utilizing this effect can possibly translate into sizeable cost savings since fewer modules are needed for the upgrade program.

  10. Ultrasonic Velocity and Texture of High RRR Niobium

    SciTech Connect

    S. R. Agnew; F. Zeng; G.R. Myneni

    2003-06-01

    Conventional assessments of the mechanical properties of rolled high RRR niobium plate material via tensile testing have revealed an unusually low apparent Young's moduli and yield strength in some annealed samples. These observations motivated a series of measurements of ultrasonic velocity, a dynamic assessment of the elastic moduli. In fact, the dynamic modulus is within the range of normal for all samples tested. However, there is a trend of increasing shear velocities for shear waves propagating through the sheet thickness and polarized in the sheet transverse direction. Careful analyses of the crystallographic texture using SEM-based electron backscattered diffraction (EBSD) have revealed a subtle, but systematic change in the texture, which can explain the trend. It is further important to note that the change in texture is not observable from surface measurements using x-ray diffraction, but requires sectioning of the samples. Thus, measurements of ultrasonic velocity represent a non-destructive evaluation tool which is extremely sensitive to subtle changes in the texture of high RRR niobium. Finally, there are material lot variations, which are currently attributed to the effects of impurities, such as Ta and H.

  11. Influence of electropolishing and anodic oxidation on morphology, chemical composition and corrosion resistance of niobium.

    PubMed

    Sowa, Maciej; Greń, Katarzyna; Kukharenko, Andrey I; Korotin, Danila M; Michalska, Joanna; Szyk-Warszyńska, Lilianna; Mosiałek, Michał; Zak, Jerzy; Pamuła, Elżbieta; Kurmaev, Ernst Z; Cholakh, Seif O; Simka, Wojciech

    2014-09-01

    The work presents results of the studies performed on electropolishing of pure niobium in a bath that contained: sulphuric acid, hydrofluoric acid, ethylene glycol and acetanilide. After the electropolishing, the specimens were subjected to anodic passivation in a 1moldm(-3) phosphoric acid solution at various voltages. The surface morphology, thickness, roughness and chemical composition of the resulting oxide layers were analysed. Thusly prepared niobium samples were additionally investigated in terms of their corrosion resistance in Ringer's solution. The electropolished niobium surface was determined to be smooth and lustrous. The anodisation led to the growth of barrier-like oxide layers, which were enriched in phosphorus species.

  12. Redistribution of components in the niobium-silicon system under high-temperature proton irradiation

    SciTech Connect

    Afonin, N. N.; Logacheva, V. A. Khoviv, A. M.

    2011-12-15

    The redistribution of components in the niobium-silicon system during magnetron-assisted sputtering of niobium, vacuum annealing, and high-temperature proton irradiation is studied. It is established that, during magnetron-assisted sputtering followed by vacuum annealing, silicon penetrates through the metal film to the outer boundary of the film. Under high-temperature proton irradiation, the suppression of the diffusion of niobium into silicon is observed. This effect is attributed to the high concentration of radiation vacancies in the region of the Nb/Si interphase boundary.

  13. Influence of electropolishing and anodic oxidation on morphology, chemical composition and corrosion resistance of niobium.

    PubMed

    Sowa, Maciej; Greń, Katarzyna; Kukharenko, Andrey I; Korotin, Danila M; Michalska, Joanna; Szyk-Warszyńska, Lilianna; Mosiałek, Michał; Zak, Jerzy; Pamuła, Elżbieta; Kurmaev, Ernst Z; Cholakh, Seif O; Simka, Wojciech

    2014-09-01

    The work presents results of the studies performed on electropolishing of pure niobium in a bath that contained: sulphuric acid, hydrofluoric acid, ethylene glycol and acetanilide. After the electropolishing, the specimens were subjected to anodic passivation in a 1moldm(-3) phosphoric acid solution at various voltages. The surface morphology, thickness, roughness and chemical composition of the resulting oxide layers were analysed. Thusly prepared niobium samples were additionally investigated in terms of their corrosion resistance in Ringer's solution. The electropolished niobium surface was determined to be smooth and lustrous. The anodisation led to the growth of barrier-like oxide layers, which were enriched in phosphorus species. PMID:25063150

  14. Secondary laser cooling of strontium-88 atoms

    SciTech Connect

    Strelkin, S. A.; Khabarova, K. Yu. Galyshev, A. A.; Berdasov, O. I.; Gribov, A. Yu.; Kolachevsky, N. N.; Slyusarev, S. N.

    2015-07-15

    The secondary laser cooling of a cloud of strontium-88 atoms on the {sup 1}S{sub 0}–{sup 3}P{sub 1} (689 nm) intercombination transition captured into a magneto-optical trap has been demonstrated. We describe in detail the recapture of atoms from the primary trap operating on the strong {sup 1}S{sub 0}–{sup 1}P{sub 1} (461 nm) transition and determine the recapture coefficient κ, the number of atoms, and their temperature in the secondary trap as a function of experimental parameters. A temperature of 2 µK has been reached in the secondary trap at the recapture coefficient κ = 6%, which confirms the secondary cooling efficiency and is sufficient to perform metrological measurements of the {sup 1}S{sub 0}–{sup 3}P{sub 1} (698 nm) clock transition in an optical lattice.

  15. W88 integrated circuit shelf life program

    SciTech Connect

    Soden, J.M.; Anderson, R.E.

    1998-01-01

    The W88 Integrated Circuit Shelf Life Program was created to monitor the long term performance, reliability characteristics, and technological status of representative WR ICs manufactured by the Allied Signal Albuquerque Microelectronics Operation (AMO) and by Harris Semiconductor Custom Integrated Circuits Division. Six types of ICs were used. A total of 272 ICs entered two storage temperature environments. Electrical testing and destructive physical analysis were completed in 1995. During each year of the program, the ICs were electrically tested and samples were selected for destructive physical analysis (DPA). ICs that failed electrical tests or DPA criteria were analyzed. Fifteen electrical failures occurred, with two dominant failure modes: electrical overstress (EOS) damage involving the production test programs and electrostatic discharge (ESD) damage during analysis. Because of the extensive handling required during multi-year programs like this, it is not unusual for EOS and ESD failures to occur even though handling and testing precautions are taken. The clustering of the electrical test failures in a small subset of the test operations supports the conclusion that the test operation itself was responsible for many of the failures and is suspected to be responsible for the others. Analysis of the electrical data for the good ICs found no significant degradation trends caused by the storage environments. Forty-six ICs were selected for DPA with findings primarily in two areas: wire bonding and die processing. The wire bonding and die processing findings are not surprising since these technology conditions had been documented during manufacturing and were determined to present acceptable risk. The current reliability assessment of the W88 stockpile assemblies employing these and related ICs is reinforced by the results of this shelf life program. Data from this program will aid future investigation of 4/3 micron or MNOS IC technology failure modes.

  16. High-Performance Supercapacitors from Niobium Nanowire Yarns.

    PubMed

    Mirvakili, Seyed M; Mirvakili, Mehr Negar; Englezos, Peter; Madden, John D W; Hunter, Ian W

    2015-07-01

    The large-ion-accessible surface area of carbon nanotubes (CNTs) and graphene sheets formed as yarns, forests, and films enables miniature high-performance supercapacitors with power densities exceeding those of electrolytics while achieving energy densities equaling those of batteries. Capacitance and energy density can be enhanced by depositing highly pseudocapacitive materials such as conductive polymers on them. Yarns formed from carbon nanotubes are proposed for use in wearable supercapacitors. In this work, we show that high power, energy density, and capacitance in yarn form are not unique to carbon materials, and we introduce niobium nanowires as an alternative. These yarns show higher capacitance and energy per volume and are stronger and 100 times more conductive than similarly spun carbon multiwalled nanotube (MWNT) and graphene yarns. The long niobium nanowires, formed by repeated extrusion and drawing, achieve device volumetric peak power and energy densities of 55 MW·m(-3) (55 W·cm(-3)) and 25 MJ·m(-3) (7 mWh·cm(-3)), 2 and 5 times higher than that for state-of-the-art CNT yarns, respectively. The capacitance per volume of Nb nanowire yarn is lower than the 158 MF·m(-3) (158 F·cm(-3)) reported for carbon-based materials such as reduced graphene oxide (RGO) and CNT wet-spun yarns, but the peak power and energy densities are 200 and 2 times higher, respectively. Achieving high power in long yarns is made possible by the high conductivity of the metal, and achievement of high energy density is possible thanks to the high internal surface area. No additional metal backing is needed, unlike for CNT yarns and supercapacitors in general, saving substantial space. As the yarn is infiltrated with pseudocapacitive materials such as poly(3,4-ethylenedioxythiophene) (PEDOT), the energy density is further increased to 10 MJ·m(-3) (2.8 mWh·cm(-3)). Similar to CNT yarns, niobium nanowire yarns are highly flexible and show potential for weaving into textiles

  17. High-Performance Supercapacitors from Niobium Nanowire Yarns.

    PubMed

    Mirvakili, Seyed M; Mirvakili, Mehr Negar; Englezos, Peter; Madden, John D W; Hunter, Ian W

    2015-07-01

    The large-ion-accessible surface area of carbon nanotubes (CNTs) and graphene sheets formed as yarns, forests, and films enables miniature high-performance supercapacitors with power densities exceeding those of electrolytics while achieving energy densities equaling those of batteries. Capacitance and energy density can be enhanced by depositing highly pseudocapacitive materials such as conductive polymers on them. Yarns formed from carbon nanotubes are proposed for use in wearable supercapacitors. In this work, we show that high power, energy density, and capacitance in yarn form are not unique to carbon materials, and we introduce niobium nanowires as an alternative. These yarns show higher capacitance and energy per volume and are stronger and 100 times more conductive than similarly spun carbon multiwalled nanotube (MWNT) and graphene yarns. The long niobium nanowires, formed by repeated extrusion and drawing, achieve device volumetric peak power and energy densities of 55 MW·m(-3) (55 W·cm(-3)) and 25 MJ·m(-3) (7 mWh·cm(-3)), 2 and 5 times higher than that for state-of-the-art CNT yarns, respectively. The capacitance per volume of Nb nanowire yarn is lower than the 158 MF·m(-3) (158 F·cm(-3)) reported for carbon-based materials such as reduced graphene oxide (RGO) and CNT wet-spun yarns, but the peak power and energy densities are 200 and 2 times higher, respectively. Achieving high power in long yarns is made possible by the high conductivity of the metal, and achievement of high energy density is possible thanks to the high internal surface area. No additional metal backing is needed, unlike for CNT yarns and supercapacitors in general, saving substantial space. As the yarn is infiltrated with pseudocapacitive materials such as poly(3,4-ethylenedioxythiophene) (PEDOT), the energy density is further increased to 10 MJ·m(-3) (2.8 mWh·cm(-3)). Similar to CNT yarns, niobium nanowire yarns are highly flexible and show potential for weaving into textiles

  18. Iron-niobium-aluminum alloy having high-temperature corrosion resistance

    DOEpatents

    Hsu, Huey S.

    1988-04-14

    An alloy for use in high temperature sulfur and oxygen containing environments, having aluminum for oxygen resistance, niobium for sulfur resistance and the balance iron, is discussed. 4 figs., 2 tabs.

  19. Review of R&D at DESY on ingot niobium for accelerators

    SciTech Connect

    Navitski, Aliaksandr Sekutowicz, Jacek Singer, Waldemar Singer, Xenia

    2015-12-04

    An R&D program at DESY exploring the potential of the production of 1.3 GHz TESLA shape cavities from large grain or ingot niobium material has been carried out as a feasibility study for using ingot niobium material for the European X-ray Free-Electron Laser project. The most important issues like feasibility of the fabrication of niobium discs from ingots, material properties, cavity fabrication, treatment, and finally the cryogenic radiofrequency (RF) performance of the cavity in the accelerator modules are presented and discussed. At least 25% higher intrinsic quality factor comparing to conventional fine-grain niobium and high accelerating gradient of up to 45 MV/m have been demonstrated during the cryogenic RF tests both in the vertical cryostats and in a completely assembled accelerating cryo-module.

  20. Reclamation of niobium compounds from ionic liquid electrochemical polishing of superconducting radio frequency cavities

    SciTech Connect

    Wixtrom, Alex I.; Buhler, Jessica E.; Reece, Charles E.; Abdel-Fattah, Tarek M.

    2013-06-01

    Recent research has shown that choline chloride (vitamin B4)-based solutions can be used as a greener alternative to acid-based electrochemical polishing solutions. This study demonstrated a successful method for electrochemical deposition of niobium compounds onto the surface of copper substrates using a novel choline chloride-based ionic liquid. Niobium ions present in the ionic liquid solution were dissolved into the solution prior to deposition via electrochemical polishing of solid niobium. A black coating was clearly visible on the surface of the Cu following deposition. This coating was analyzed using scanning electron microscopy (SEM), electron dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and X-ray fluorescence spectroscopy (XRF). This ionic liquid-based electrochemical deposition method effectively recycles previously dissolved niobium from electrochemical polishing of superconducting radio frequency (SRF) cavities.

  1. Process for separation of zirconium-88, rubidium-83 and yttrium-88

    DOEpatents

    Heaton, Richard C.; Jamriska, Sr., David J.; Taylor, Wayne A.

    1994-01-01

    A process for selective separation of strontium-82 and strontium-85 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, passing the first ion-containing solution through a first cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in the first ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, contacting the first resin with an acid solution capable of stripping adsorbed ions from the first cationic exchange resin whereby the adsorbed ions are removed from the first resin to form a second ion-containing solution, evaporating the second ion-containing solution for time sufficient to remove substantially all of the acid and water from the second ion-containing solution whereby a residue remains, dissolving the residue from the evaporated second-ion containing solution in a dilute acid to form a third ion-containing solution, said third ion-containing solution having an acid molarity adapted to permit said ions to be adsorbed by a cationic exchange resin, passing the third ion-containing solution through a second cationic resin whereby the ions are adsorbed by the second resin, contacting the second resin with a dilute sulfuric acid solution whereby the adsorbed ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, and zirconium are selectively removed from the second resin, and contacting the second resin with a dilute acid solution whereby the adsorbed strontium ions are selectively removed. Zirconium, rubidium, and yttrium radioisotopes can also be recovered with additional steps.

  2. High performance superconducting radio frequency ingot niobium technology for continuous wave applications

    SciTech Connect

    Dhakal, Pashupati Ciovati, Gianluigi Myneni, Ganapati R.

    2015-12-04

    Future continuous wave (CW) accelerators require the superconducting radio frequency cavities with high quality factor and medium accelerating gradients (≤20 MV/m). Ingot niobium cavities with medium purity fulfill the specifications of both accelerating gradient and high quality factor with simple processing techniques and potential reduction in cost. This contribution reviews the current superconducting radiofrequency research and development and outlines the potential benefits of using ingot niobium technology for CW applications.

  3. Hardness behavior of binary and ternary niobium alloys at 77 and 300 K

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.; Witzke, W. R.

    1974-01-01

    The effects of alloy additions of zirconium, hafnium, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, and iridium on the hardness of niobium was determined. Both binary and ternary alloys were investigated by means of hardness tests at 77 K and 300 K. Results showed that atomic size misfit plays a dominant role in controlling hardness of binary niobium alloys. Alloy softening, which occurred at dilute solute additions, is most likely due to an extrinsic mechanism involving interaction between solute elements and interstitial impurities.

  4. Quench-age method for the fabrication of niobium-aluminum superconductors

    DOEpatents

    Pickus, Milton R.; Ciardella, Robert L.

    1978-01-01

    A flexible Nb.sub.3 Al superconducting wire is fabricated from a niobium-aluminum composite wire by heating to form a solid solution which is retained at room temperature as a metastable solid solution by quenching. The metastable solid solution is then transformed to the stable superconducting A-15 phase by low temperature aging. The transformation induced by aging can be controlled to yield either a multifilamentary or a solid A-15 core surrounded by ductile niobium.

  5. Niobium quarter-wave cavity for the New Delhi booster linac

    SciTech Connect

    Shepard, K.W.; Roy, A.; Potukuchi, P.N.

    1997-09-01

    This paper reports the completion of development of a 97 Mhz niobium coaxial quarter-wave cavity to be used in a booster linac for the New Delhi 16UD pellatron electrostatic accelerator. A prototype cavity, which incorporates a niobium-bellows tuning device, has been completed and operated at 4.2 K at accelerating gradients above 4 MV/m for extended periods of time.

  6. Synthesis, characterization, and catalytic application of ordered mesoporous carbon–niobium oxide composites

    SciTech Connect

    Gao, Juan-Li; Gao, Shuang; Liu, Chun-Ling; Liu, Zhao-Tie; Dong, Wen-Sheng

    2014-11-15

    Graphical abstract: The ordered mesoporous carbon–niobium oxide composites have been synthesized by a multi-component co-assembly method associated with a carbonization process. - Highlights: • Ordered mesoporous carbon–niobium oxide composites were synthesized. • The content of Nb{sub 2}O{sub 5} in the composites could be tuned from 38 to 75%. • Niobium species were highly dispersed in amorphous carbon framework walls. • The composites exhibited good catalytic performance in the dehydration of fructose. - Abstract: Ordered mesoporous carbon–niobium oxide composites have been synthesized by a multi-component co-assembly method associated with a carbonization process using phenolic resol as carbon source, niobium chloride as precursor and amphiphilic triblock copolymer Pluronic F127 as template. The resulting materials were characterized using a combination of techniques including differential scanning calorimetry–thermogravimetric analysis, N{sub 2} physical adsorption, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results show that with increasing the content of Nb{sub 2}O{sub 5} from 38 to 75% the specific surface area decreases from 306.4 to 124.5 m{sup 2} g{sup −1}, while the ordered mesoporous structure is remained. Niobium species is well dispersed in the amorphous carbon framework. The mesoporous carbon–niobium oxide composites exhibit high catalytic activity in the dehydration of fructose to 5-hydroxymethylfurfural. A 100% conversion of fructose and a 76.5% selectivity of 5-hydroxymethylfurfural were obtained over the carbon–niobium oxide composite containing 75% Nb{sub 2}O{sub 5} under the investigated reaction conditions.

  7. Room-temperature dislocation climb in copper-niobium interfaces

    SciTech Connect

    Wang, Jian; Hoagland, Richard G; Hirth, John P; Misra, Amit

    2008-01-01

    Using atomistic simulations, we show that dislocations climb efficiently in metallic copper-niobium interfaces through absorption and emission of vacancies in the dislocation core, as well as an associated counter diffusion of Cu atoms in the interfacial plane. The high efficiency of dislocation climb in the interface is ascribed to the high vacancy concentration of 0.05 in the interfacial plane, the low formation energy of 0.12 e V with respect to removal or insertion of Cu atoms, as well as the low kinetic barrier of 0.10 eV for vacancy migration in the interfacial Cu plane. Dislocation climb in the interface facilitates reactions of interfacial dislocations, and enables interfaces to be in the equilibrium state with respect to concentrations ofpoint defects.

  8. Temperature Mapping of Nitrogen-doped Niobium Superconducting Radiofrequency Cavities

    SciTech Connect

    Makita, Junki; Ciovati, Gianluigi; Dhakal, Pashupati

    2015-09-01

    It was recently shown that diffusing nitrogen on the inner surface of superconducting radiofrequency (SRF) cavities at high temperature can improve the quality factor of the niobium cavity. However, a reduction of the quench field is also typically found. To better understand the location of rf losses and quench, we used a thermometry system to map the temperature of the outer surface of ingot Nb cavities after nitrogen doping and electropolishing. Surface temperature of the cavities was recorded while increasing the rf power and also during the quenching. The results of thermal mapping showed no precursor heating on the cavities and quenching to be ignited near the equator where the surface magnetic field is maximum. Hot-spots at the equator area during multipacting were also detected by thermal mapping.

  9. Low-loss terahertz metamaterial from superconducting niobium nitride films.

    PubMed

    Zhang, C H; Wu, J B; Jin, B B; Ji, Z M; Kang, L; Xu, W W; Chen, J; Tonouchi, M; Wu, P H

    2012-01-01

    This paper reports a type of low Ohmic loss terahertz (THz) metamaterials made from low-temperature superconducting niobium nitride (NbN) films. Its resonance properties are studied by THz time domain spectroscopy. Our experiments show that its unloaded quality factor reaches as high as 178 at 8 K with the resonance frequency at around 0.58 THz, which is about 24 times that of gold metamaterial at the same temperature. The unloaded quality factor keeps at a high level, above 90, even when the resonance frequency increases to 1.02 THz, which is close to the gap frequency of NbN film. All these experimental observations fit well into the framework of Bardeen-Copper-Schrieffer theory and equivalent circuit model. These new metamaterials offer an efficient way to the design and implementation of high performance THz electronic devices.

  10. SIMS analysis of high-performance accelerator niobium

    SciTech Connect

    Maheshwari, P.; Stevie, F. A.; Myneni, Ganapati Rao; Rigsbee, J, M.; Dhakal, Pashupati; Ciovati, Gianluigi; Griffis, D. P.

    2014-11-01

    Niobium is used to fabricate superconducting radio frequency accelerator modules because of its high critical temperature, high critical magnetic field, and easy formability. Recent experiments have shown a very significant improvement in performance (over 100%) after a high-temperature bake at 1400 degrees C for 3h. SIMS analysis of this material showed the oxygen profile was significantly deeper than the native oxide with a shape that is indicative of diffusion. Positive secondary ion mass spectra showed the presence of Ti with a depth profile similar to that of O. It is suspected that Ti is associated with the performance improvement. The source of Ti contamination in the anneal furnace has been identified, and a new furnace was constructed without Ti. Initial results from the new furnace do not show the yield improvement. Further analyses should determine the relationship of Ti to cavity performance.

  11. Characterization on RF magnetron sputtered niobium pentoxide thin films

    SciTech Connect

    Usha, N.; Sivakumar, R.; Sanjeeviraja, C.

    2014-10-15

    Niobium pentoxide (Nb{sub 2}O{sub 5}) thin films with amorphous nature were deposited on microscopic glass substrates at 100°C by rf magnetron sputtering technique. The effect of rf power on the structural, morphological, optical, and vibrational properties of Nb{sub 2}O{sub 5} films have been investigated. Optical study shows the maximum average transmittance of about 87% and the optical energy band gap (indirect allowed) changes between 3.70 eV and 3.47 eV. AFM result indicates the smooth surface nature of the samples. Photoluminescence measurement showed the better optical quality of the deposited films. Raman spectra show the LO-TO splitting of Nb-O stretching of Nb{sub 2}O{sub 5} films.

  12. Unanticipated results in the uranium niobium alloy system

    SciTech Connect

    Cooley, J. C.; Hults, W. L.; Dauelsberg, L. B.; Thoma, D. J.; Peterson, E. J.; Teter, D. F.; Smith, J. L.; Kelly, A. M.; Lashley, J. C.

    2002-01-01

    The uranium niobium binary alloy system exhibits a rich collection of phenomena for study. The composition range from 0 wt.% Nb to 10 wt.% Nb exhibits multiple crystallographic phases with interesting properties such as superconductivity, charge density waves and shape memory effects. We have measured the resistivity and heat capacity as a function of temperature from 2 to 325K in the above composition range in an effort to map out the phase boundaries of interest. Surprisingly the temperature dependence of the resistivity transitions from metallic (decreasing with decreasing temperature) to nonmetallic (increasing with decreasing temperature). It is not clear if the nonmetallic resistivity is caused by strongly correlated electronic effects or is the result of some other effect such as disorder driven scattering.

  13. Secondary electron emission from plasma processed accelerating cavity grade niobium

    NASA Astrophysics Data System (ADS)

    Basovic, Milos

    by different techniques. Specifically, this work provides the results of SEY from the plasma cleaned cavity grade niobium (Nb) samples. Pure niobium is currently the material of choice for the fabrication of Superconducting Radio Frequency (SRF) cavities. The effect of plasma processing with two different gases will be examined in two groups of samples. The first group of samples is made from cavity grade niobium. The second group of samples is made from the same material, but include a welded joint made by electron beam welding, since in niobium SRF cavities the peak electric and magnetic field are seen in close proximity to the welded joints. Both groups of samples will be exposed to nitrogen (N2) and a mixture of argon with oxygen (Ar/O2) plasma. It is the goal of this research to determine the SEY on these two groups of samples before and after plasma processing as a function of the energy of primary electrons. The SEY as a function of the angle of incidence of the primary electrons is tested on the samples treated with Ar/O2 plasma.

  14. Diffusion and segregation of niobium in fcc-nickel.

    PubMed

    Connétable, Damien; Ter-Ovanessian, Benoît; Andrieu, Éric

    2012-03-01

    Niobium is one of the major alloying elements, among the refractory elements, contributing to the strengthening of superalloys. Consequently, data about its behavior and its migration mechanism in fcc-Ni are essential knowledge to understand and control the strengthening in such alloys. We present in this work Nb interactions, solubility and diffusion in Ni performed by using the GGA approximation of the density functional theory. The substituted site is found to be the most favorable configuration in comparison to the tetrahedral and octahedral sites. The effect of temperature on solubility is discussed taking into account the thermal expansion of the lattice parameter and the vibrational contribution. Its diffusion mechanism is also discussed and compared to the literature. We finally discuss the segregation of Nb atoms on a Σ(5)-(012) symmetric tilt grain boundary.

  15. Thermodynamic Evaluation of Hydrogen Absorption by Niobium During SRF Fabrication

    SciTech Connect

    R.E. Ricker, G.R. Myneni

    2011-03-01

    The properties and performance of the ultra high purity Nb used to fabricate superconducting radio frequency (SRF) particle accelerator cavities have been found to vary with processing conditions. One hypothesis for these variations is that hydrogen, absorbed during processing, is responsible for this behavior. The key assumption behind this hypothesis is that niobium can absorb hydrogen from one or more of the processing environments. This paper reviews work examining the validity of this assumption. It was determined that Nb will spontaneously react with water producing adsorbed atomic hydrogen that is readily absorbed into the metal. The passivating oxide film normally prevents this reaction, but this film is frequently removed during processing and it is attacked by the fluoride ion used in the polishing solutions for SRF cavities. However, during electropolishing that cathodic reduction of hydrogen is transferred to the auxiliary electrode and this should suppress hydrogen absorption.

  16. Thermodynamic Evaluation of Hydrogen Absorption by Niobium During SRF Fabrication

    SciTech Connect

    Ricker, R. E.; Myneni, G. R.

    2011-03-31

    The properties and performance of the ultra high purity Nb used to fabricate superconducting radio frequency (SRF) particle accelerator cavities have been found to vary with processing conditions. One hypothesis for these variations is that hydrogen, absorbed during processing, is responsible for this behavior. The key assumption behind this hypothesis is that niobium can absorb hydrogen from one or more of the processing environments. This paper reviews work examining the validity of this assumption. It was determined that Nb will spontaneously react with water producing adsorbed atomic hydrogen that is readily absorbed into the metal. The passivating oxide film normally prevents this reaction, but this film is frequently removed during processing and it is attacked by the fluoride ion used in the polishing solutions for SRF cavities. However, during electropolishing that cathodic reduction of hydrogen is transferred to the auxiliary electrode and this should suppress hydrogen absorption.

  17. Method of manufacturing a niobium-aluminum-germanium superconductive material

    DOEpatents

    Wang, John L.; Pickus, Milton R.; Douglas, Kent E.

    1980-01-01

    A method for manufacturing flexible Nb.sub.3 (Al,Ge) multifilamentary superconductive material in which a sintered porous niobium compact is infiltrated with an aluminum-germanium alloy and thereafter deformed and heat treated in a series of steps at different successively higher temperatures preferably below 1000.degree. C. to produce filaments composed of Nb.sub.3 (Al,G3) within the compact. By avoiding temperatures in excess of 1000.degree. C. during the heat treatment, cladding material such as copper can be applied to facilitate a deformation step preceding the heat treatment and can remain in place through the heat treatment to also serve as a temperature stabilizer for supeconductive material produced. Further, these lower heat treatment temperatures favor formation of filaments with reduced grain size and, hence with more grain boundaries which in turn increase the current-carrying capacity of the superconductive material.

  18. Synthesis and characterization of superconducting nanocrystalline niobium nitride.

    PubMed

    Shi, Liang; Gu, Yunle; Chen, Luyang; Yang, Zeheng; Ma, Jianhua; Qian, Yitai

    2005-02-01

    Nanocrystalline niobium nitride (NbN0.9) was successfully synthesized at 600 degrees C through a solid-state reaction. The synthesis was carried out in an autoclave by using NbCl5 and NaN3 as the reactants. The X-ray powder diffraction pattern indicates the formation of cubic NbN0.9. Transmission electron microscopy images show that typical NbN0.9 crystallites are composed of uniform particles with an average size of about 30 nm and nanorod crystallites with a typical size of about 40 x 2500 nm. Magnetic measurements exhibited that a superconducting transition occurred at 15.4 K for the NbN0.9 product. PMID:15853151

  19. Quantum Phase Slips in 6 mm Long Niobium Nanowire.

    PubMed

    Zhao, Weiwei; Liu, Xin; Chan, M H W

    2016-02-10

    Transport measurements were made to study the superconducting transition of four 6 mm long niobium nanowires with different cross-sectional dimensions. A low-temperature residual resistance tail measured with an excitation current of 5 nA is found in the thinnest wire down to 50 mK or 7.7% of Tc of Nb. The functional form of the residual resistance is consistent with quantum phase slip (QPS) processes. Resistance measured at high bias excitation current switches among many discrete values that are well below the normal state resistance. These discrete resistance values as a function of temperature fall into several parallel curves all showing QPS-like decay in the low temperature limit similar to that found at low current. The coexistence of QPS-like resistance tails and resistance jumps found in the same wire unifies results from previous experiments where these two distinct sets of evidence for QPS are exclusive of each other. PMID:26788964

  20. High-gradient, pulsed operation of superconducting niobium cavities

    SciTech Connect

    Campisi, I.E.; Farkas, Z.D.

    1984-02-01

    Tests performed on several Niobium TM/sub 010/ cavities at frequencies of about 2856 MHz using a high-power, pulsed method indicate that, at the end of the charging pulse, peak surface magnetic fields of up to approx. 1300 Oe, corresponding to a peak surface electric field of approx. 68 MV/m, can be reached at 4.2/sup 0/K without appreciable average losses. Further studies of the properties of superconductors under pulsed operation might shed light on fundamental properties of rf superconductivity, as well as lead to the possibility of applying the pulse method to the operation of high-gradient linear colliders. 7 references, 30 figures, 2 tables.

  1. Performance of Large grain and Single Crystal Niobium Cavities

    SciTech Connect

    Kneisel, Peter; Ciovati, Gianluigi; Sekutowicz, Jacek

    2006-07-01

    We have fabricated and tested several single and one multi-cell cavity made from large grain niobium of four different ingots. Two cavities at a frequency of ~ 2.2 GHz were made from single crystal sheets. Large grain material was used for four single cell cavities of the HG â and OC shapes, a 7-cell cavity of the HG â shape â all resonating at 1500 MHz â and an ILC_LL single cell cavity at 1300 MHz. We began to explore also different chemical polishing baths such as a 1:1:1 and a 1:1:2 buffered solution and explored the change of cavity performance as a function of material removal. The results from these preliminary investigations are reported in this contribution.

  2. Fabricating niobium test loops for the SP-100 space reactor

    NASA Technical Reports Server (NTRS)

    Bryhan, Anthony J.; Chan, Ricky C.

    1993-01-01

    This article describes the successful fabrication, operation, and evaluation of a series of niobium-alloy (Nb-1 Zr and PWC-11) thermal convection loops designed to contain and circulate molten lithium at 1,350 K. These loops were used to establish the fabrication variables of significance for a nuclear power supply for space. Approximately 200 weldments were evaluated for their tendency to be attacked by lithium as a function of varying atmospheric contamination. No attack occurred for any weldment free of contamination, with or without heat treatment, and no welds accidentally deviated from purity. The threshold oxygen content for weldment attack was determined to be 170-200 ppm. Attack varied directly with weldment oxygen and nitrogen contents.

  3. [Thyroid nodule. Study of 88 cases].

    PubMed

    González Treviño, O; Bolaños Gil, F; Lerman Garber, I; García-Rubí, E; Maisterrena Fernández, J A

    1993-01-01

    We present a prospective study of 88 patients with thyroid nodules seen in our institution in 1985-86 and the results of a 5 year follow up. The algorithm for resolution among different therapeutic options was established in regard to the clinical characteristics, imaging and particularly the histopathologic studies. Their age ranged from 18 to 79 years; 94% of the patients were females. Most of the nodules were solid (69%) and measured 1-4 cm in diameter. The image of 62% of the thyroid scans was of a non-functioning nodule and 13% were hyperfunctioning. In 80% the ultrasonographic pattern was solid or mixed. Surgery was undertaken in 19 patients (21%). In 58%, a diagnosis of malignancy was established. The biopsy (aspiration and tru-cut) suggested the presence of the malignant tumors when taken together in 90% of the cases. Hormonal treatment was given to 62 patients; in 40-45% of them there was a significant reduction in the size of the nodule. Aspiration and sclerosis of cystic nodules were performed in 19 patients with significant shrinkage in 82%. Radioactive iodine was used in 11 patients. Our algorithm reduces costs and precludes unnecessary morbidity in patients with thyroid nodules.

  4. 14 CFR 33.88 - Engine overtemperature test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine overtemperature test. 33.88 Section 33.88 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.88 Engine...

  5. 7 CFR 8.8 - Use by public informational services.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Use by public informational services. 8.8 Section 8.8 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.8 Use by public informational services. (a) In any advertisement, display, exhibit, visual and audio-visual material, news...

  6. 7 CFR 8.8 - Use by public informational services.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Use by public informational services. 8.8 Section 8.8 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.8 Use by public informational services. (a) In any advertisement, display, exhibit, visual and audio-visual material, news...

  7. 28 CFR 2.88 - Confidentiality of parole records.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Confidentiality of parole records. 2.88 Section 2.88 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT... Parolees § 2.88 Confidentiality of parole records. (a) Consistent with the Privacy Act of 1974 (5...

  8. 28 CFR 2.88 - Confidentiality of parole records.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Confidentiality of parole records. 2.88 Section 2.88 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT... Parolees § 2.88 Confidentiality of parole records. (a) Consistent with the Privacy Act of 1974 (5...

  9. 28 CFR 2.88 - Confidentiality of parole records.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Confidentiality of parole records. 2.88 Section 2.88 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT... Parolees § 2.88 Confidentiality of parole records. (a) Consistent with the Privacy Act of 1974 (5...

  10. 28 CFR 2.88 - Confidentiality of parole records.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Confidentiality of parole records. 2.88 Section 2.88 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT... Parolees § 2.88 Confidentiality of parole records. (a) Consistent with the Privacy Act of 1974 (5...

  11. 28 CFR 2.88 - Confidentiality of parole records.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Confidentiality of parole records. 2.88 Section 2.88 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT... Parolees § 2.88 Confidentiality of parole records. (a) Consistent with the Privacy Act of 1974 (5...

  12. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate oral suspension. 520.88c Section 520.88c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension....

  13. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88d Amoxicillin trihydrate soluble powder....

  14. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  15. 21 CFR 520.88 - Amoxicillin oral dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin oral dosage forms. 520.88 Section 520.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88 Amoxicillin...

  16. 21 CFR 520.88 - Amoxicillin oral dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin oral dosage forms. 520.88 Section 520.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88 Amoxicillin...

  17. 21 CFR 520.88 - Amoxicillin oral dosage forms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin oral dosage forms. 520.88 Section 520.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88 Amoxicillin...

  18. 21 CFR 520.88 - Amoxicillin oral dosage forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin oral dosage forms. 520.88 Section 520.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88 Amoxicillin...

  19. 21 CFR 520.88 - Amoxicillin oral dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin oral dosage forms. 520.88 Section 520.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88 Amoxicillin...

  20. 40 CFR 87.83-87.88 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false 87.83-87.88 Section 87.83-87.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) Definitions. Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) §§ 87.83-87.88...

  1. 7 CFR 989.88 - Duration of immunities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Duration of immunities. 989.88 Section 989.88... GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this amended...

  2. 7 CFR 989.88 - Duration of immunities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Duration of immunities. 989.88 Section 989.88... GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this amended...

  3. 7 CFR 981.88 - Duration of immunities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Duration of immunities. 981.88 Section 981.88... Regulating Handling Miscellaneous Provisions § 981.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this subpart shall cease upon its termination except...

  4. 7 CFR 981.88 - Duration of immunities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Duration of immunities. 981.88 Section 981.88... Regulating Handling Miscellaneous Provisions § 981.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this subpart shall cease upon its termination except...

  5. 7 CFR 981.88 - Duration of immunities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Duration of immunities. 981.88 Section 981.88... Regulating Handling Miscellaneous Provisions § 981.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this subpart shall cease upon its termination except...

  6. 7 CFR 989.88 - Duration of immunities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Duration of immunities. 989.88 Section 989.88... GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this amended...

  7. 7 CFR 989.88 - Duration of immunities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Duration of immunities. 989.88 Section 989.88... GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this amended...

  8. 7 CFR 981.88 - Duration of immunities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Duration of immunities. 981.88 Section 981.88... Regulating Handling Miscellaneous Provisions § 981.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this subpart shall cease upon its termination except...

  9. 7 CFR 981.88 - Duration of immunities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Duration of immunities. 981.88 Section 981.88... Regulating Handling Miscellaneous Provisions § 981.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this subpart shall cease upon its termination except...

  10. 7 CFR 989.88 - Duration of immunities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Duration of immunities. 989.88 Section 989.88... GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of this amended...

  11. 42 CFR 88.14 - Standard for determining medical necessity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Standard for determining medical necessity. 88.14 Section 88.14 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES WORLD TRADE CENTER HEALTH PROGRAM § 88.14 Standard...

  12. 42 CFR 88.14 - Standard for determining medical necessity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Standard for determining medical necessity. 88.14 Section 88.14 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES WORLD TRADE CENTER HEALTH PROGRAM § 88.14 Standard...

  13. 42 CFR 88.14 - Standard for determining medical necessity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Standard for determining medical necessity. 88.14 Section 88.14 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES WORLD TRADE CENTER HEALTH PROGRAM § 88.14 Standard...

  14. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpt. B, Tables Tables to Subpart B of Part 88...

  15. 7 CFR 800.88 - Loss of identity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 7 2013-01-01 2013-01-01 false Loss of identity. 800.88 Section 800.88 Agriculture... Methods and Procedures § 800.88 Loss of identity. (a) Lots. Except as noted in paragraph (d) of this... personnel performing a reinspection, appeal inspection, or Board appeal inspection service, the identity...

  16. 42 CFR 88.3 - Eligibility-currently identified responders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Eligibility-currently identified responders. 88.3 Section 88.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES WORLD TRADE CENTER HEALTH PROGRAM § 88.3...

  17. 42 CFR 88.3 - Eligibility-currently identified responders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Eligibility-currently identified responders. 88.3 Section 88.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES WORLD TRADE CENTER HEALTH PROGRAM § 88.3...

  18. 42 CFR 88.3 - Eligibility-currently identified responders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Eligibility-currently identified responders. 88.3 Section 88.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES WORLD TRADE CENTER HEALTH PROGRAM § 88.3...

  19. 7 CFR 800.88 - Loss of identity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Loss of identity. 800.88 Section 800.88 Agriculture... Methods and Procedures § 800.88 Loss of identity. (a) Lots. Except as noted in paragraph (d) of this... personnel performing a reinspection, appeal inspection, or Board appeal inspection service, the identity...

  20. 42 CFR 32.88 - Examinations and treatment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Examinations and treatment. 32.88 Section 32.88... Hansen's Disease § 32.88 Examinations and treatment. Patients will be provided necessary clinical examinations which may be required for the diagnosis of primary or secondary conditions, and such treatment...

  1. 42 CFR 32.88 - Examinations and treatment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Examinations and treatment. 32.88 Section 32.88... Hansen's Disease § 32.88 Examinations and treatment. Patients will be provided necessary clinical examinations which may be required for the diagnosis of primary or secondary conditions, and such treatment...

  2. 42 CFR 32.88 - Examinations and treatment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Examinations and treatment. 32.88 Section 32.88... Hansen's Disease § 32.88 Examinations and treatment. Patients will be provided necessary clinical examinations which may be required for the diagnosis of primary or secondary conditions, and such treatment...

  3. 40 CFR 86.603-88 - Test orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Test orders. 86.603-88 Section 86.603-88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Auditing of New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Vehicles § 86.603-88 Test orders....

  4. 40 CFR 86.603-88 - Test orders.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Test orders. 86.603-88 Section 86.603-88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Auditing of New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Vehicles § 86.603-88 Test orders....

  5. 40 CFR 8.8 - Comprehensive environmental evaluation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Comprehensive environmental evaluation. 8.8 Section 8.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL IMPACT ASSESSMENT OF NONGOVERNMENTAL ACTIVITIES IN ANTARCTICA § 8.8 Comprehensive...

  6. 40 CFR 144.88 - What are the additional requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...? 144.88 Section 144.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) UNDERGROUND INJECTION CONTROL PROGRAM Requirements for Owners and Operators of Class V Injection Wells § 144.88 What are the additional requirements? The additional requirements are specified...

  7. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  8. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  9. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  10. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  11. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  12. 33 CFR 88.05 - Copy of rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Copy of rules. 88.05 Section 88... RULES ANNEX V: PILOT RULES § 88.05 Copy of rules. The operator of each self-propelled vessel 12 meters or more in length shall carry on board and maintain for ready reference a copy of the...

  13. 28 CFR 115.88 - Data review for corrective action.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Data review for corrective action. 115.88 Section 115.88 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PRISON RAPE ELIMINATION ACT NATIONAL STANDARDS Standards for Adult Prisons and Jails Data Collection and Review § 115.88 Data...

  14. 28 CFR 115.88 - Data review for corrective action.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Data review for corrective action. 115.88 Section 115.88 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PRISON RAPE ELIMINATION ACT NATIONAL STANDARDS Standards for Adult Prisons and Jails Data Collection and Review § 115.88 Data...

  15. 28 CFR 115.88 - Data review for corrective action.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Data review for corrective action. 115.88 Section 115.88 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PRISON RAPE ELIMINATION ACT NATIONAL STANDARDS Standards for Adult Prisons and Jails Data Collection and Review § 115.88 Data...

  16. 40 CFR 8.8 - Comprehensive environmental evaluation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Comprehensive environmental evaluation. 8.8 Section 8.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL IMPACT ASSESSMENT OF NONGOVERNMENTAL ACTIVITIES IN ANTARCTICA § 8.8 Comprehensive...

  17. 40 CFR 8.8 - Comprehensive environmental evaluation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Comprehensive environmental evaluation. 8.8 Section 8.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL IMPACT ASSESSMENT OF NONGOVERNMENTAL ACTIVITIES IN ANTARCTICA § 8.8 Comprehensive...

  18. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  19. 10 CFR 110.88 - Authority of the Secretary.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Authority of the Secretary. 110.88 Section 110.88 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) EXPORT AND IMPORT OF NUCLEAR EQUIPMENT AND MATERIAL Public Participation Procedures Concerning License Applications § 110.88 Authority of the Secretary. The Secretary...

  20. Niobium Oxide-Metal Based Seals for High Temperature Applications

    SciTech Connect

    Ivar Reimanis

    2006-08-14

    The present final report describes technical progress made in regards to evaluating niobium oxide/alumina as a high temperature seal material. Fabrication and characterization of specimens comprising niobium oxide and alumina composites of various compositions was performed. The goal was to identify regions where a glass formed. There were no experimental conditions where a glassy phase was unequivocally identified. However, the results led to the formation of an interesting class of fibrous composites which may have applications where high compliance and high toughness are needed. It is clear that vapor phase sintering is an active mass transport mechanism in Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} composites (Figure 1), and it may be possible to design porous materials by utilizing vapor phase sintering. The compositions evaluated in the present work are 52, 60, 73, 82 and 95 mol. % Nb{sub 2}O{sub 5} with the remainder Al{sub 2}O{sub 3}. These were chosen so that some eutectic composition was present during cooling, in an attempt to encourage glass formation. However, the presence of large, elongated crystals, both in the slow cool and the quench experiments indicates that the driving force for crystallization is very high. Several joints were formed between high purity alumina with two compositions (60 and 82 mol. %) forming the joint. These were created by grinding and polishing alumina surfaces and stacking them end-to-end with the powdered Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} material in between. Joining was accomplished in air at temperatures between 1400 C and 1450 C. The joints failed during subsequent machining for strength bars, indicating low strength. It may be possible to use the compositions evaluated here as a joint material, but it seems unlikely that a glassy phase could be produced while joining.

  1. Niobium oxide-polydimethylsiloxane hybrid composite coatings for tuning primary fibroblast functions.

    PubMed

    Young, Matthew D; Tran, Nhiem; Tran, Phong A; Jarrell, John D; Hayda, Roman A; Born, Chistopher T

    2014-05-01

    This study evaluates the potential of niobium oxide-polydimethylsiloxane (PDMS) composites for tuning cellular response of fibroblasts, a key cell type of soft tissue/implant interfaces. In this study, various hybrid coatings of niobium oxide and PDMS with different niobium oxide concentrations were synthesized and characterized using scanning electron microscopy, X-ray photoelectron spectrometry (XPS), and contact angle goniometry. The coatings were then applied to 96-well plates, on which primary fibroblasts were seeded. Fibroblast viability, proliferation, and morphology were assessed after 1, 2, and 3 days of incubation using WST-1 and calcein AM assays along with fluorescent microscopy. The results showed that the prepared coatings had distinct surface features with submicron spherical composites covered in a polymeric layer. The water contact angle measurement demonstrated that the hybrid surfaces were much more hydrophobic than the original pure niobium oxide and PDMS. The combination of surface roughness and chemistry resulted in a biphasic cellular response with maximum fibroblast density on substrate with 40 wt % of niobium oxide. The results of the current study indicate that by adjusting the concentration of niobium oxide in the coating, a desirable cell response can be achieved to improve tissue/implant interfaces.

  2. Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities

    DOE PAGESBeta

    Kneisel, P.; Ciovati, G.; Dhakal, P.; Saito, K.; Singer, W.; Singer, X.; Myneni, G. R.

    2014-12-01

    As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. The large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities mademore » from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of Eacc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.« less

  3. Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities

    SciTech Connect

    Kneisel, P.; Ciovati, G.; Dhakal, P.; Saito, K.; Singer, W.; Singer, X.; Myneni, G. R.

    2014-12-01

    As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. The large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities made from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of Eacc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.

  4. Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities

    NASA Astrophysics Data System (ADS)

    Kneisel, P.; Ciovati, G.; Dhakal, P.; Saito, K.; Singer, W.; Singer, X.; Myneni, G. R.

    2015-02-01

    As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. Large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities made from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of Eacc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.

  5. Electrochemical Deposition of Niobium onto the Surface of Copper Using a Novel Choline Chloride-Based Ionic Liquid

    SciTech Connect

    Wixtroma, Alex I.; Buhlera, Jessica E.; Reece, Charles E.; Abdel-Fattah, Tarek M.

    2013-06-01

    Recent research has shown that choline chloride-based solutions can be used to replace acid-based electrochemical polishing solutions. In this study niobium metal was successfully deposited on the surface of copper substrate via electrochemical deposition using a novel choline chloride-based ionic liquid. The niobium metal used for deposition on the Cu had been dissolved in the solution from electrochemical polishing of a solid niobium piece prior to the deposition. The visible coating on the surface of the Cu was analyzed using scanning electron microscopy (SEM) and electron dispersive x-ray spectroscopy (EDX). This deposition method effectively recycles previously dissolved niobium from electrochemical polishing.

  6. Theoretical study of the ground-state structures and properties of niobium hydrides under pressure

    NASA Astrophysics Data System (ADS)

    Gao, Guoying; Hoffmann, Roald; Ashcroft, N. W.; Liu, Hanyu; Bergara, Aitor; Ma, Yanming

    2013-11-01

    As part of a search for enhanced superconductivity, we explore theoretically the ground-state structures and properties of some hydrides of niobium over a range of pressures and particularly those with significant hydrogen content. A primary motivation originates with the observation that under normal conditions niobium is the element with the highest superconducting transition temperature (Tc), and moreover some of its compounds are metals again with very high Tc's. Accordingly, combinations of niobium with hydrogen, with its high dynamic energy scale, are also of considerable interest. This is reinforced further by the suggestion that close to its insulator-metal transition, hydrogen may be induced to enter the metallic state somewhat prematurely by the addition of a relatively small concentration of a suitable transition metal. Here, the methods used correctly reproduce some ground-state structures of niobium hydrides at even higher concentrations of niobium. Interestingly, the particular stoichiometries represented by NbH4 and NbH6 are stabilized at fairly low pressures when proton zero-point energies are included. While no paired H2 units are found in any of the hydrides we have studied up to 400 GPa, we do find complex and interesting networks of hydrogens around the niobiums in high-pressure NbH6. The Nb-Nb separations in NbHn are consistently larger than those found in Nb metal at the respective pressures. The structures found in the ground states of the high hydrides, many of them metallic, suggest that the coordination number of hydrogens around each niobium atom grows approximately as 4n in NbHn (n = 1-4), and is as high as 20 in NbH6. NbH4 is found to be a plausible candidate to become a superconductor at high pressure, with an estimated Tc ˜ 38 K at 300 GPa.

  7. Planktic foraminifer census data from Northwind Ridge cores PI-88-AP P3, PI-88-AR P7 and PI-88-AR P9, Arctic Ocean

    USGS Publications Warehouse

    Foley, Kevin M.; Poore, Richard Z.

    1993-01-01

    The U.S. Geological Survey recovered 9 piston cores from the Northwind Ridge in the Canada Basin of the Arctic Ocean from a cruise of the USCGC Polar Star during 1988. Preliminary analysis of the cores suggests sediments deposited on Northwind Ridge preserve a detailed record of glacial and interglacial cycles for the last few hundred-thousand to one million years. This report includes quantitative data on foraminifers and selected sediment size-fraction data in 98 samples from Northwind Ridge core PI-88AR P3, 51 samples from core PI-88-AR P7 and 117 samples from core PI-88-AR P9.

  8. Co-precipitation of copper and niobium carbide in a low carbon steel

    NASA Astrophysics Data System (ADS)

    Gagliano, Michael Scott

    Co-precipitation of niobium carbide and body-centered cubic (BCC) copper in ferrite was investigated as a high strength, low carbon, chromium-free alternative to conventional high performance structural steels that rely on a tempered martensitic microstructure. Theoretical nucleation and growth rate models for BCC copper and niobium carbide were constructed using calculated thermodynamic driving forces in conjunction with classical theories for the homogeneous nucleation and subsequent growth of coherent, spherical precipitates. The maximum calculated nucleation and growth rates for niobium carbide were found to be 1.0 x 106 nuclei/cm3s at 666°C and 1.0 nm/s at 836°C, respectively, for an austenitizing temperature of 1170°C. For BCC copper in ferrite, the maximum calculated nucleation and growth rates were determined to be 8.0 x 1015 nuclei/cm 3s at 612°C and 0.038 nm/s at 682°C, respectively, for all austenitizing temperatures. Three-dimensional atom probe (3DAP) microscopy revealed the presence of nano-scale BCC copper clusters in approximately the same number density predicted by the theoretical nucleation model. Using an experimentally determined "effective" activation energy for copper in iron, the normalized theoretical nucleation rate curve compared very well with the normalized hardness response after 5 minutes of aging and effectively described the experimental short-time aging behavior of a low carbon, niobium bearing steel. The size and morphological evolution as well as the growth and coarsening behavior of copper precipitates were investigated through conventional TEM during isothermal direct aging at 550°C for a niobium and niobium-free steel. Although niobium carbide precipitation was not characterized, niobium additions provided increased hardness upon direct aging and showed a much higher resistance to overaging, than a niobium-free steel, for long isothermal aging times. In both steels for aging times up to five hours, both 9R type and BCC

  9. Surface analyses of electropolished niobium samples for superconducting radio frequency cavity

    SciTech Connect

    Tyagi, P. V.; Nishiwaki, M.; Saeki, T.; Sawabe, M.; Hayano, H.; Noguchi, T.; Kato, S.

    2010-07-15

    The performance of superconducting radio frequency niobium cavities is sometimes limited by contaminations present on the cavity surface. In the recent years extensive research has been done to enhance the cavity performance by applying improved surface treatments such as mechanical grinding, electropolishing (EP), chemical polishing, tumbling, etc., followed by various rinsing methods such as ultrasonic pure water rinse, alcoholic rinse, high pressure water rinse, hydrogen per oxide rinse, etc. Although good cavity performance has been obtained lately by various post-EP cleaning methods, the detailed nature about the surface contaminants is still not fully characterized. Further efforts in this area are desired. Prior x-ray photoelectron spectroscopy (XPS) analyses of EPed niobium samples treated with fresh EP acid, demonstrated that the surfaces were covered mainly with the niobium oxide (Nb{sub 2}O{sub 5}) along with carbon, in addition a small quantity of sulfur and fluorine were also found in secondary ion mass spectroscopy (SIMS) analysis. In this article, the authors present the analyses of surface contaminations for a series of EPed niobium samples located at various positions of a single cell niobium cavity followed by ultrapure water rinsing as well as our endeavor to understand the aging effect of EP acid solution in terms of contaminations presence at the inner surface of the cavity with the help of surface analytical tools such as XPS, SIMS, and scanning electron microscope at KEK.

  10. Evaluation of Niobium as Candidate Electrode Material for DC High Voltage Photoelectron Guns

    NASA Technical Reports Server (NTRS)

    BastaniNejad, M.; Mohamed, Abdullah; Elmustafa, A. A.; Adderley, P.; Clark, J.; Covert, S.; Hansknecht, J.; Hernandez-Garcia, C.; Poelker, M.; Mammei, R.; Surles-Law, K.; Williams, P.

    2012-01-01

    The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirror-like finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field emission from electrodes (stainless steel and/or niobium) could be significantly reduced and sometimes completely eliminated, by introducing krypton gas into the vacuum chamber while the electrode was biased at high voltage. Of all the electrodes tested, a large-grain niobium electrode performed the best, exhibiting no measurable field emission (< 10 pA) at 225 kV with 20 mm cathode/anode gap, corresponding to a field strength of 18:7 MV/m.

  11. Effect of niobium on the structure and photoactivity of anatase (TiO2) nanoparticles.

    PubMed

    Hirano, Masanori; Matsushima, Kazumasa

    2006-03-01

    Anatase-type TiO2 nanoparticles doped with 0-30 mol% niobium were directly formed from precursor solutions of TiOSO4 and NbCl5 under mild hydrothermal conditions at 120-180 degrees C for 5 h using the hydrolysis of urea. When the niobium content increased from 0 to 30 mol%, the crystallite size of anatase increased from 8.5 to 19 nm. The band gap of anatase was slightly decreased by making solid solutions with niobium. Their photocatalytic activity and adsorptivity were evaluated separately by the measurement of the concentration of methylene blue (MB) remained in the solution after maintained in the dark or under UV-light irradiation. To form anatase-type solid solutions by doping 5-15 mol% niobium into TiO2 was effective for improvement of the photoactivity of TiO2. The photocatalytic activity (the photooxidation rate) and the adsorption amount of MB for the sample containing 15 mol% niobium became more than approximately nine times and six times as much as those of the hydrothermal anatase-type pure TiO2, respectively.

  12. TEM and SIMS Analysis of (100), (110), and (111) Single Crystal Niobium

    SciTech Connect

    Batchelor, A. D.; Stevie, F. A.; Leonard, D. N.; Russell, P. E.; Griffis, D. P.; Myneni, G. R.

    2007-08-09

    Single crystal niobium specimens of (100), (110) and (111) crystal orientations have been analyzed using TEM and SIMS. The TEM specimens were prepared using Focused Ion Beam (FIB) and show niobium oxide thicknesses ranging from 4.9 to 8.3 nm for the three specimens after buffer chemical polishing. The oxide layers appear uniform and no significant sub-oxide region was noted. SIMS analysis was made for all three orientations on hydrogen, carbon, and oxygen before and after heat treatments at 90, 600, and 1250 deg. C. Hydrogen is at a high level between the oxide layer and niobium, but at a relatively low level in the oxide. No high oxygen concentration region was noted in the niobium below the oxide. C contamination on the surface is detected mainly at the surface. Analysis after heat treatments showed some decrease in hydrogen after the 600 deg. C heat treatment, and significant oxidation of the niobium after the 1250 deg. C heat treatment.

  13. Single Crystal and Large Grain Niobium Research at Michigan State University

    SciTech Connect

    Compton, Chris; Aizaz, Ahmad; Baars, Derek; Bieler, Tom; Bierwagen, John; Bricker, Steve; Grimm, Terry; Hartung, Walter; Jiang, Hairong; Johnson, Matt; Popielarski, John; Saxton, Laura; Antoine, Claire; Wagner, Bob; Kneisel, Peter

    2007-09-01

    As Superconducting Radio Frequency (SRF) technology is used in more accelerator designs, research has focused on increasing the efficiency of these accelerators by pushing gradients and investigating cast reduction options. Today, most SRF structures are fabricated from high purity niobium. Over years of research, a material specification has been derived that defines a uniaxial, fine gain structure for SRF cavity fabrication. Most recently a push has been made to investigate the merits of using single or large grain niobium as a possible alternative to fine grain niobium. Michigan State University (MSU), in collaboration with Fermi National Accelerator Laboratory (FNAL) and Thomas Jefferson National Accelerator Facility (JLAB), is researching large grain niobium via cavity fabrication processes end testing, as well as exploring materials science issues associated with recrystallization and heat transfer. Single-cell 1.3 GHz (Beta=0.081) cavities made from both fine end large grain niobium were compared both in terms of fabrication procedures and performance. Two 7-cell cavities are currently being fabricated.

  14. Structure, texture, and properties of superconductive electrolytic niobium coatings on nickel and copper substrates

    NASA Astrophysics Data System (ADS)

    Kolosov, V. N.; Shevyrev, A. A.

    2015-05-01

    Structure, texture, chemical purity, and other characteristics of superconductive niobium coatings prepared via electrochemical deposition onto nickel and copper substrates in (LiF + NaF + KF)eut + 5 wt % K2NbF7 molten salt are studied. It is shown that, when depositing the coatings onto nickel, the intermediate layer of Ni3Nb and NiNb intermetallides is formed at the substrate-coating interface, which inhibits the diffusion of nickel in niobium. The nickel concentration in niobium coatings above this layer is (2-7) × 10-2 wt %. In coatings deposited onto the copper substrate the copper content does not exceed 1.5 × 10-4 wt %, and from the viewpoint of the amount of impurities, niobium is considered as a high purity metal. The dynamics of structure modifications in niobium coatings and changes in microdeformations and dislocation density in the deposited metal are explored depending on the current density at the cathode.

  15. First-Principles Study of Carbon and Vacancy Structures in Niobium

    DOE PAGESBeta

    Ford, Denise C.; Zapol, Peter; Cooley, Lance D.

    2015-04-03

    The interstitial chemical impurities hydrogen, oxygen, nitrogen, and carbon are important for niobium metal production, and particularly for the optimization of niobium SRF technology. These atoms are present in refined sheets and can be absorbed into niobium during processing treatments, resulting in changes to the residual resistance and the performance of SRF cavities. A first-principles approach is taken to study the properties of carbon in niobium, and the results are compared and contrasted with the properties of the other interstitial impurities. The results indicate that C will likely form precipitates or atmospheres around defects rather than strongly bound complexes withmore » other impurities. Based on the analysis of carbon and hydrogen near niobium lattice vacancies and small vacancy chains and clusters, the formation of extended carbon chains and hydrocarbons is not likely to occur. Association of carbon with hydrogen atoms can, however, occur through the strain fields created by interstitial binding of the impurity atoms. In conclusion, calculated electronic densities of states indicate that interstitial C may have a similar effect as interstitial O on the superconducting transition temperature of Nb.« less

  16. Effect of niobium on the structure and photoactivity of anatase (TiO2) nanoparticles.

    PubMed

    Hirano, Masanori; Matsushima, Kazumasa

    2006-03-01

    Anatase-type TiO2 nanoparticles doped with 0-30 mol% niobium were directly formed from precursor solutions of TiOSO4 and NbCl5 under mild hydrothermal conditions at 120-180 degrees C for 5 h using the hydrolysis of urea. When the niobium content increased from 0 to 30 mol%, the crystallite size of anatase increased from 8.5 to 19 nm. The band gap of anatase was slightly decreased by making solid solutions with niobium. Their photocatalytic activity and adsorptivity were evaluated separately by the measurement of the concentration of methylene blue (MB) remained in the solution after maintained in the dark or under UV-light irradiation. To form anatase-type solid solutions by doping 5-15 mol% niobium into TiO2 was effective for improvement of the photoactivity of TiO2. The photocatalytic activity (the photooxidation rate) and the adsorption amount of MB for the sample containing 15 mol% niobium became more than approximately nine times and six times as much as those of the hydrothermal anatase-type pure TiO2, respectively. PMID:16573134

  17. First-Principles Study of Carbon and Vacancy Structures in Niobium

    SciTech Connect

    Ford, Denise C.; Zapol, Peter; Cooley, Lance D.

    2015-04-03

    The interstitial chemical impurities hydrogen, oxygen, nitrogen, and carbon are important for niobium metal production, and particularly for the optimization of niobium SRF technology. These atoms are present in refined sheets and can be absorbed into niobium during processing treatments, resulting in changes to the residual resistance and the performance of SRF cavities. A first-principles approach is taken to study the properties of carbon in niobium, and the results are compared and contrasted with the properties of the other interstitial impurities. The results indicate that C will likely form precipitates or atmospheres around defects rather than strongly bound complexes with other impurities. Based on the analysis of carbon and hydrogen near niobium lattice vacancies and small vacancy chains and clusters, the formation of extended carbon chains and hydrocarbons is not likely to occur. Association of carbon with hydrogen atoms can, however, occur through the strain fields created by interstitial binding of the impurity atoms. In conclusion, calculated electronic densities of states indicate that interstitial C may have a similar effect as interstitial O on the superconducting transition temperature of Nb.

  18. Optoelectronic properties of valence-state-controlled amorphous niobium oxide

    NASA Astrophysics Data System (ADS)

    Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

    2016-06-01

    In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

  19. High upper critical field in disordered niobium nitride superconductor

    SciTech Connect

    Baskaran, R. Thanikai Arasu, A. V.; Amaladass, E. P.; Janawadkar, M. P.

    2014-10-28

    Superconducting Niobium Nitride thin films have been deposited on glass, aluminum nitride buffered glass, and oxidized silicon substrates by reactive DC magnetron sputtering at ambient substrate temperatures. The crystal structure of these thin films has been determined to be cubic fcc B1 structure by Glancing Incidence X-Ray Diffraction analysis. The superconducting transition temperatures of the thin films were measured to be greater than 11.6 K with a maximum of 13.4 K. The negative temperature coefficient of resistance observed in these thin films indicates the presence of disorder. Magneto-resistance measurements have been carried out on these thin films patterned into standard four probe geometry upto a maximum magnetic field of 12 T for two films and upto 15 T for the other two films. The dependence of transition temperature on the applied field is analyzed to estimate the upper critical field. The upper critical field for most of the films was estimated to exceed 35 T, while one of the most disordered films had an estimated upper critical field greater than 70 T.

  20. Surface characterization of niobium for superconducting RF cavities

    NASA Astrophysics Data System (ADS)

    Cao, Chaoyue

    Surface characterization techniques including point contact tunneling (PCT) spectroscopy and Raman spectroscopy have been employed to study the surface of niobium (Nb) superconducting radio frequency (SRF) cavities. PCT spectroscopy provides a direct means of measuring the surface superconductivity, which is closely correlated with the cavity's performance characterized by the quality factor Q. Cavities with remarkably high Q show near ideal tunneling spectra with sharp coherent peaks and low zero bias conductance, consistent with the Bardeen-Cooper-Schrieffer (BCS) density of stats (DOS), and bulk gap parameter, Delta = 1.55-1.6 meV. Cavities with Q-drop often exhibit strong non-uniform heating during RF operations, with high loss regions identified as hot spots. PCT spectra on hot spots reveal suppressed superconductivity, broadened DOS and Kondo tunneling, consistent with magnetic impurities on the surface. Raman spectra on hot spots indicate the presence of various impurities on the surface including amorphous carbon, C-H chain compounds and NbC, providing insights into the formation of hot spots. The origin of the impurities is unclear at present but it is suggested that particular processing steps in SRF cavity fabrication may be responsible.

  1. Pulsed laser deposition of niobium nitride thin films

    SciTech Connect

    Farha, Ashraf Hassan Elsayed-Ali, Hani E.; Ufuktepe, Yüksel; Myneni, Ganapati

    2015-12-04

    Niobium nitride (NbN{sub x}) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbN{sub x} films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ∼40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbN{sub x} films from mixed β-Nb{sub 2}N and cubic δ-NbN phases to single hexagonal β-Nb{sub 2}N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbN{sub x} deposited on Si(100) were also investigated. The NbN{sub x} films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbN{sub x} film morphology and phase.

  2. Niobium resonator development for high-brightness ion beam acceleration

    SciTech Connect

    Delayen, J.R.; Bohn, C.L.; Roche, C.T.

    1990-01-01

    Two niobium resonant cavities for high-brightness ion beam acceleration have been constructed and tested. The first was based on a coaxial quarter-wave geometry and was optimized for phase velocity {beta}{sub o} = 0.15. This cavity, which resonates at 400 MHz in the fundamental mode, operated at an average (wall-to-wall) accelerating gradient of 12.9 MV/m under continuous-wave (cw) fields. At this gradient, a cavity Q of 1.4 {times} 10{sup 8} was measured. The second was based on a coaxial half-wave geometry and was optimized for {beta}{sub o} = 0.12. This cavity, which resonates at 355 MHz in the fundamental mode, operated at an average accelerating gradient of 18.0 MV/m under cw fields. This is the highest average accelerating gradient achieved to date in low-velocity structures designed for cw operation. At this gradient, a cavity Q of 1.2 {times} 10{sup 8} was measured.

  3. Superconducting RF materials other than bulk niobium: a review

    NASA Astrophysics Data System (ADS)

    Valente-Feliciano, Anne-Marie

    2016-11-01

    For the past five decades, bulk niobium (Nb) has been the material of choice for superconducting RF (SRF) cavity applications. Alternatives such as Nb thin films and other higher-T c materials, mainly Nb compounds and A15 compounds, have been investigated with moderate effort in the past. In recent years, RF cavity performance has approached the theoretical limit for bulk Nb. For further improvement of RF cavity performance for future accelerator projects, research interest is renewed towards alternatives to bulk Nb. Institutions around the world are now investing renewed efforts in the investigation of Nb thin films and superconductors with higher transition temperature T c for application to SRF cavities. This paper gives an overview of the results obtained so far and challenges encountered for Nb films as well as other materials, such as Nb compounds, A15 compounds, MgB2, and oxypnictides, for SRF cavity applications. An interesting alternative using a superconductor-insulator-superconductor multilayer approach has been recently proposed to delay the vortex penetration in Nb surfaces. This could potentially lead to further improvement in RF cavities performance using the benefit of the higher critical field H c of higher-T c superconductors without being limited with their lower H c1.

  4. L -shell resonant transfer and excitation in niobium ions

    SciTech Connect

    Badnell, N.R. )

    1990-07-01

    We have calculated {ital L}-shell cross sections for the process of resonant transfer excitation followed by x-ray stabilization (RTEX) in collisions of Nb{sup {ital q}+} ions ({ital q}=28--32) with H{sub 2}. The {ital LMn} plateau cross section is nearly constant ((4.5--5.2){times}10{sup {minus}20} cm{sup 2}) for {ital q}=29--32 and is consistent with the results of the recent experiment by Bernstein {ital et} {ital al}. (Phys. Rev. A 40, 4085 (1989)) for {ital q}=31 and 32, but our results for {ital q}=28--30 are substantially larger than experiment. For Ne-like niobium ({ital q}=31), the inclusion of RTEX contributions from higher transitions ({ital LNn}, {ital LOn}, etc.) leads to good agreement with the experiment by Bernstein {ital et} {ital al}. in the high-energy tail. This implies that only a small contribution is possible from the uncorrelated transfer excitation process.

  5. Fastest Electropolishing Technique on Niobium for Particle Accelerators

    SciTech Connect

    A.T. Wu, S. Jin, R.A. Rimmer, X.Y. Lu, K. Zhao

    2011-09-01

    Field emission on the inner surfaces of niobium (Nb) superconducting radio frequency (SRF) cavities is still one of the major obstacles for reaching high accelerating gradients for SRF community. Our previous experimental results [1] seemed to imply that the threshold of field emission was related to the thickness of Nb surface oxide layers. In this contribution, a more detailed study on the influences of the surface oxide layers on the field emission on Nb surfaces will be reported. By anodization technique, the thickness of the surface pentoxide layer was artificially fabricated from 3nm up to 460nm. A home-made scanning field emission microscope (SFEM) was employed to perform the scans on the surfaces. Emitters were characterized using a scanning electron microscope together with an energy dispersive x-ray analyzer. The experimental results could be understood by a simple model calculation based on classic electromagnetic theory as shown in Ref.1. Possibly implications for Nb SRF cavity applications from this study will be discussed.

  6. Tunneling study of SRF cavity-grade niobium.

    SciTech Connect

    Proslier, T.; Zasadzinski, J.; Cooley, L.; Pellin, M.; Norem, J.; Elam, J.; Antonine, C. Z.; Rimmer, R.; Kneisel, P.; Illinois Inst. of Tech.; FNL; Thomas Jefferson Lab.; CEA-Saclay

    2009-06-01

    Niobium, with its very high H{sub C1}, has been used in superconducting radio frequency (SRF) cavities for accelerator systems for 40 years with continual improvement. The quality factor of cavities (Q) is governed by the surface impedance R{sub BCS}, which depends on the quasiparticle gap, delta, and the superfluid density. Both of these parameters are seriously affected by surface imperfections (metallic phases, dissolved oxygen, magnetic impurities). Loss mechanism and surface treatments of Nb cavities found to improve the Q factor are still unsolved mysteries. We present here an overview of the capabilities of the point contact tunneling spectroscopy and Atomic layer deposition methods and how they can help understanding the High field Q-drop and the mild baking effect. Tunneling spectroscopy was performed on Nb pieces from the same processed material used to fabricate SRF cavities. Air exposed, electropolished Nb exhibited a surface superconducting gap Delta = 1.55 meV, characteristic of clean, bulk Nb, however the tunneling density of states (DOS) was broadened significantly. Nb pieces treated with the same mild baking used to improve the Q-slope in SRF cavities revealed a much sharper DOS. Good fits to the DOS are obtained using Shiba theory suggesting that magnetic scattering of quasiparticles is the origin of the degraded surface superconductivity and the Q-slope problem of Nb SRF cavities.

  7. Austenite recrystallization and carbonitride precipitation in niobium microalloyed steels

    SciTech Connect

    Speer, J.G.; Hansen, S.S. )

    1989-01-01

    The response of austenite to thermomechanical treatment is investigated in two series of niobium microalloyed steels. Optical and electron metallographic techniques were used to follow the austenite recystallizaiton and carbonitride precipitation reactions in these steels. The first series of steels contained a constant level of 0.05Nb, with carbon levels varying from 0.008 to 0.25 pct. It was found that a lower carbon concentration results in faster austenite recrystallization due to a smaller carbonitride supersaturation which leads to a reduced precipitate nucleation rate. The second series of steels was designed with a constant carbonitride supersaturation by simultaneously varying the Nb and C concentrations while maintaining a constant solubility product. In these steels, the recrystallization kinetics increase as the volume fraction of Nb(C,N) is reduced and/or as the precipitate coarsening rate is increased. The volume fraction of carbonitrides increases as the Nb:(C + 12/14 N) ratio approaches the stoichiometric ratio of approximately 8:1. An experiment to determine whether Nb atoms dissolved in the austenite could exert a significant solute-drag effect on the recrystallization reaction indicated that 0.20Nb in solution could reduce the rate of recrystallization compared to a Nb-free C-Mn steel.

  8. Characterization of precipitates in a niobium-zirconium-carbon alloy

    NASA Technical Reports Server (NTRS)

    Grobstein, T. L.; Titran, R. H.

    1986-01-01

    A niobium alloy with 1 percent zirconium and 0.063 percent carbon by weight was investigated in the as-rolled and annealed conditions, and after high-temperature (1350 and 1400 K) exposure with and without an applied stress. In the as-rolled and annealed conditions, large metastable carbides were observed in addition to a regular distribution of small particles. During the high-temperature exposure, the majority of the large carbides were dissolved and a more stable carbide phase formed. This finely dispersed phase had a composition determined to be approximately 70 percent ZrC and approximately 30 percent NbC and showed some evidence of an orientation relationship with the matrix. The precipitates appeared to coarsen slightly after approximately 5000 hr exposure in the presence of an applied stress resulted in a decrease in the size and in the interparticle spacing of the stable precipitates. However, the composition of the precipitate phase and its ability to pin dislocations were not affected by the temperature or stress conditions.

  9. Investigation of solution-processed bismuth-niobium-oxide films

    SciTech Connect

    Inoue, Satoshi; Ariga, Tomoki; Matsumoto, Shin; Onoue, Masatoshi; Miyasako, Takaaki; Tokumitsu, Eisuke; Shimoda, Tatsuya; Chinone, Norimichi; Cho, Yasuo

    2014-10-21

    The characteristics of bismuth-niobium-oxide (BNO) films prepared using a solution process were investigated. The BNO film annealed at 550°C involving three phases: an amorphous phase, Bi₃NbO₇ fluorite microcrystals, and Nb-rich cubic pyrochlore microcrystals. The cubic pyrochlore structure, which was the main phase in this film, has not previously been reported in BNO films. The relative dielectric constant of the BNO film was approximately 140, which is much higher than that of a corresponding film prepared using a conventional vacuum sputtering process. Notably, the cubic pyrochlore microcrystals disappeared with increasing annealing temperature and were replaced with triclinic β-BiNbO₄ crystals at 590°C. The relative dielectric constant also decreased with increasing annealing temperature. Therefore, the high relative dielectric constant of the BNO film annealed at 550°C is thought to result from the BNO cubic pyrochlore structure. In addition, the BNO films annealed at 500°C contained approximately 6.5 atm.% carbon, which was lost at approximately 550°C. This result suggests that the carbon in the BNO film played an important role in the formation of the cubic pyrochlore structure.

  10. Optimization of chemical etching process in niobium cavities

    SciTech Connect

    Tajima, T.; Trabia, M.; Culbreth, W.; Subramanian, S.

    2004-01-01

    Superconducting niobium cavities are important components of linear accelerators. Buffered chemical polishing (BCP) on the inner surface of the cavity is a standard procedure to improve its performance. The quality of BCP, however, has not been optimized well in terms of the uniformity of surface smoothness. A finite element computational fluid dynamics (CFD) model was developed to simulate the chemical etching process inside the cavity. The analysis confirmed the observation of other researchers that the iris section of the cavity received more etching than the equator regions due to higher flow rate. The baffle, which directs flow towards the walls of the cavity, was redesigned using optimization techniques. The redesigned baffle significantly improves the performance of the etching process. To verify these results an experimental setup for flow visualization was created. The setup consists of a high speed, high resolution CCD camera. The camera is positioned by a computer-controlled traversing mechanism. A dye injecting arrangement is used for tracking the fluid path. Experimental results are in general agreement with CFD and optimization results.

  11. Hydrometallurgical Separation of Niobium and Tantalum: A Fundamental Approach

    NASA Astrophysics Data System (ADS)

    Nete, Motlalepula; Purcell, Walter; Nel, Johann T.

    2016-02-01

    A mixture of pure Ta2O5 and Nb2O5 was dissolved using two different fluxes, namely NH4F·HF and Na2HPO4/NaH2PO4·H2O. Selective precipitation and ion exchange were used as separation techniques. Selective precipitation using p-phenylediamine in a fluoride matrix resulted in the isolation of 73(3)% tantalum accompanied by 23(5)% niobium. A separation factor of 11(4) was obtained. A single solvent extraction step using methyl-isobutyl ketone at a 4 M H2SO4 yielded excellent Ta and Nb separation in the fluoride solution with 80% of the Ta and only 2% Nb recovered in the organic layer. A two-step extraction recovered 100% Ta at 0.5-4 M H2SO4 with a separation factor of ~2000. A study of the extraction mechanism indicated that the stability of the protonated compounds such as H2TaF7/H2NbOF5 is in the extraction and separation determining steps in this process. A K' (double de-protonated constant) of approximately 0.2 was calculated for H2TaF7. Only 91.7% Nb and 73.4% Ta were recovered from anion separation using strong Amberlite resin and 96.1% Nb and 52.3% using the weak Dowex Marathon resin from fluoride dissolution.

  12. Radiation damage and nanocrystal formation in uranium-niobium titanates

    NASA Astrophysics Data System (ADS)

    Lian, J.; Wang, S. X.; Wang, L. M.; Ewing, R. C.

    2001-07-01

    Two uranium-niobium titanates, U 2.25Nb 1.90Ti 0.32O 9.8 and Nb 2.75U 1.20Ti 0.36O 10, formed during the synthesis of brannnerite (UTi 2O 6), a minor phase in titanate-based ceramics investigated for plutonium immobilization. These uranium titanates were subjected to 800 keV Kr 2+ irradiation from 30 to 973 K. The critical amorphization dose of the U-rich and Nb-rich titanates at room temperature were 4.72×10 17 and 5×10 17 ions/ m2, respectively. At elevated temperature, the critical amorphization dose increases due to dynamic thermal annealing. The critical amorphization temperature for both Nb-rich and U-rich titanates is ˜933 K under a 800 keV Kr 2+ irradiation. Above the critical amorphization temperature, nanocrystals with an average size of ˜15 nm were observed. The formation of nanocrystals is due to epitaxial recrystallization. At higher temperatures, an ion irradiation-induced nucleation-growth mechanism also contributes to the formation of nanocrystals.

  13. Biomimetic novel nanoporous niobium oxide coating for orthopaedic applications

    NASA Astrophysics Data System (ADS)

    Pauline, S. Anne; Rajendran, N.

    2014-01-01

    Niobium oxide was synthesized by sol-gel methodology and a crystalline, nanoporous and adherent coating of Nb2O5 was deposited on 316L SS using the spin coating technique and heat treatment. The synthesis conditions were optimized to obtain a nanoporous morphology. The coating was characterized using attenuated total reflectance-Infrared spectroscopy (ATR-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and the formation of crystalline Nb2O5 coating with nanoporous morphology was confirmed. Mechanical studies confirmed that the coating has excellent adherence to the substrate and the hardness value of the coating was excellent. Contact angle analysis showed increased hydrophilicity for the coated substrate. In vitro bioactivity test confirmed that the Nb2O5 coating with nanoporous morphology facilitated the growth of hydroxyapatite (HAp). This was further confirmed by the solution analysis test where increased uptake of calcium and phosphorous ions from simulated body fluid (SBF) was observed. Electrochemical evaluation of the coating confirmed that the crystalline coating is insulative and protective in nature and offered excellent corrosion protection to 316L SS. Thus, this study confirmed that the nanoporous crystalline Nb2O5 coating conferred bioactivity and enhanced corrosion resistance on 316L SS.

  14. The activation energy for creep of columbium /niobium/.

    NASA Technical Reports Server (NTRS)

    Klein, M. J.; Gulden, M. E.

    1973-01-01

    The activation energy for creep of nominally pure columbium (niobium) was determined in the temperature range from 0.4 to 0.75 T sub M by measuring strain rate changes induced by temperature shifts at constant stress. A peak in the activation energy vs temperature curve was found with a maximum value of 160 kcal/mole. A pretest heat treatment of 3000 F for 30 min resulted in even higher values of activation energy (greater than 600 kcal/mole) in this temperature range. The activation energy for the heat-treated columbium (Nb) could not be determined near 0.5 T sub M because of unusual creep curves involving negligible steady-state creep rates and failure at less than 5% creep strain. It is suggested that the anomalous activation energy values and the unusual creep behavior in this temperature range are caused by dynamic strain aging involving substitutional atom impurities and that this type of strain aging may be in part responsible for the scatter in previously reported values of activation energy for creep of columbium (Nb) near 0.5 T sub M.

  15. Optoelectronic properties of valence-state-controlled amorphous niobium oxide.

    PubMed

    Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

    2016-06-29

    In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications. PMID:27168317

  16. Pulsed laser deposition of niobium nitride thin films

    NASA Astrophysics Data System (ADS)

    Farha, Ashraf Hassan; Ufuktepe, Yüksel; Myneni, Ganapati; Elsayed-Ali, Hani E.

    2015-12-01

    Niobium nitride (NbNx) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbNx films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ˜40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbNx films from mixed β-Nb2N and cubic δ-NbN phases to single hexagonal β-Nb2N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbNx deposited on Si(100) were also investigated. The NbNx films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbNx film morphology and phase.

  17. Advance in Vertical Buffered Electropolishing on Niobium for Particle Accelerators*

    SciTech Connect

    A.T. Wu, S. Jin, J.D. Mammosser, C.E. Reece, R.A. Rimmer,L. Lin, X.Y. Lu, K. Zhao

    2011-09-01

    Niobium (Nb) is the most popular material that has been employed for making superconducting radio frequency (SRF) cavities to be used in various particle accelerators over the last couple of decades. One of the most important steps in fabricating Nb SRF cavities is the final chemical removal of 150 {mu}m of Nb from the inner surfaces of the SRF cavities. This is usually done by either buffered chemical polishing (BCP) or electropolishing (EP). Recently a new Nb surface treatment technique called buffered electropolishing (BEP) has been developed at Jefferson Lab. It has been demonstrated that BEP can produce the smoothest surface finish on Nb ever reported in the literature while realizing a Nb removal rate as high as 10 {mu}m/min that is more than 25 and 5 times quicker than those of EP and BCP(112) respectively. In this contribution, recent advance in optimizing and understanding BEP treatment technique is reviewed. Latest results from RF measurements on BEP treated Nb single cell cavities by our unique vertical polishing system will be reported.

  18. Why There Are 88 Keys on the Piano: "88 Logic-The Mackay Method for Piano." Volume 1

    ERIC Educational Resources Information Center

    Mackay, Stephen R.

    2005-01-01

    Background: After trying to define the reason why the piano ended up with 88 keys, I found patterns to explain ways of playing the piano with an 8:8 ratio which gives purpose to why the piano has 88 keys on it. Purpose: The first purpose is to enable piano teachers and music students to benefit from understanding how to play piano and be…

  19. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bag test. 84.88 Section 84.88 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained...

  20. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing bag test. 84.88 Section 84.88 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained...

  1. 33 CFR 88.15 - Lights on dredge pipelines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lights on dredge pipelines. 88.15... NAVIGATION RULES ANNEX V: PILOT RULES § 88.15 Lights on dredge pipelines. Dredge pipelines that are floating... than 10 meters apart where the pipeline crosses a navigable channel. Where the pipeline does not...

  2. 33 CFR 88.15 - Lights on dredge pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lights on dredge pipelines. 88.15... NAVIGATION RULES ANNEX V: PILOT RULES § 88.15 Lights on dredge pipelines. Dredge pipelines that are floating... than 10 meters apart where the pipeline crosses a navigable channel. Where the pipeline does not...

  3. 33 CFR 88.15 - Lights on dredge pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lights on dredge pipelines. 88.15... NAVIGATION RULES ANNEX V: PILOT RULES § 88.15 Lights on dredge pipelines. Dredge pipelines that are floating... than 10 meters apart where the pipeline crosses a navigable channel. Where the pipeline does not...

  4. 7 CFR 983.88 - Suspension or termination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Suspension or termination. 983.88 Section 983.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  5. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains amoxicillin trihydrate equivalent to...

  6. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains amoxicillin trihydrate equivalent to...

  7. 21 CFR 312.88 - Safeguards for patient safety.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Safeguards for patient safety. 312.88 Section 312... Severely-debilitating Illnesses § 312.88 Safeguards for patient safety. All of the safeguards incorporated within parts 50, 56, 312, 314, and 600 of this chapter designed to ensure the safety of clinical...

  8. 28 CFR 8.8 - Advertisement and declaration of forfeiture.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... forfeiture. 8.8 Section 8.8 Judicial Administration DEPARTMENT OF JUSTICE FBI FORFEITURE AUTHORITY FOR... (FBI) within 20 days from the date of the first publication of the notice a claim to such property and... judicial district in which the property was seized. If a claim is not made within the time period, the...

  9. 28 CFR 8.8 - Advertisement and declaration of forfeiture.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... forfeiture. 8.8 Section 8.8 Judicial Administration DEPARTMENT OF JUSTICE FBI FORFEITURE AUTHORITY FOR... (FBI) within 20 days from the date of the first publication of the notice a claim to such property and... judicial district in which the property was seized. If a claim is not made within the time period, the...

  10. 28 CFR 8.8 - Advertisement and declaration of forfeiture.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... forfeiture. 8.8 Section 8.8 Judicial Administration DEPARTMENT OF JUSTICE FBI FORFEITURE AUTHORITY FOR... (FBI) within 20 days from the date of the first publication of the notice a claim to such property and... judicial district in which the property was seized. If a claim is not made within the time period, the...

  11. 40 CFR 790.88 - Denial of exemption application.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Denial of exemption application. 790.88 Section 790.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC... has not received an adequate study plan for the test for which exemption is sought; or (5) The...

  12. 48 CFR 852.236-88 - Contract changes-supplement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Contract changes-supplement. 852.236-88 Section 852.236-88 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  13. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2013-01-01 2012-01-01 true Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  14. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2014-01-01 2014-01-01 false Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  15. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2011-01-01 2011-01-01 false Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  16. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2012-01-01 2012-01-01 false Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  17. 40 CFR 600.113-88 - Fuel economy calculations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Fuel economy calculations. 600.113-88... FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1978 and Later Model Year Automobiles-Test Procedures § 600.113-88 Fuel economy calculations....

  18. 33 CFR 88.13 - Lights on moored barges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on moored barges. 88.13... NAVIGATION RULES ANNEX V: PILOT RULES § 88.13 Lights on moored barges. (a) The following barges shall display at night and if practicable in periods of restricted visibility the lights described in paragraph...

  19. 33 CFR 88.13 - Lights on moored barges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on moored barges. 88.13... NAVIGATION RULES ANNEX V: PILOT RULES § 88.13 Lights on moored barges. (a) The following barges shall display at night and if practicable in periods of restricted visibility the lights described in paragraph...

  20. 25 CFR 88.1 - Employment of attorneys.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Indian Affairs and the Department of the Interior is subject to the requirements of 43 CFR 1.1 through 1... 25 Indians 1 2010-04-01 2010-04-01 false Employment of attorneys. 88.1 Section 88.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT RECOGNITION OF ATTORNEYS AND...

  1. 32 CFR 776.88 - Report to licensing authorities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Report to licensing authorities. 776.88 Section... Complaint Processing Procedures § 776.88 Report to licensing authorities. Upon determination by JAG that a... report that fact to the Federal, State, or local bar or other licensing authority of the covered...

  2. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin trihydrate oral suspension. 520.88c... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension. (a) Specifications. Each 0.8-milliliter dose contains amoxicillin...

  3. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate oral suspension. 520.88c... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension. (a) Specifications. Each 0.8-milliliter dose contains amoxicillin...

  4. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate oral suspension. 520.88c... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension. (a) Specifications. Each 0.8-milliliter dose contains amoxicillin...

  5. 40 CFR 87.83-87.88 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false 87.83-87.88 Section 87.83-87.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft...

  6. 14 CFR 34.83-34.88 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false 34.83-34.88 Section 34.83-34.88 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine...

  7. 14 CFR 34.83-34.88 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false 34.83-34.88 Section 34.83-34.88 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Test Procedures for Engine...

  8. 40 CFR 87.83-87.88 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false 87.83-87.88 Section 87.83-87.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft...

  9. 27 CFR 6.88 - Equipment and supplies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Equipment and supplies. 6.88 Section 6.88 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... material), dispensing accessories, carbon dioxide (and other gasses used in dispensing equipment) or...

  10. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  11. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  12. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  13. 40 CFR 282.88 - Pennsylvania State-Administered Program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... program that make it more stringent, in accordance with section 9004 of RCRA, 42 U.S.C. 6991c, and 40 CFR... Program. 282.88 Section 282.88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) APPROVED UNDERGROUND STORAGE TANK PROGRAMS Approved State Programs §...

  14. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of...

  15. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpt. B, Tables Tables to Subpart B of Part...

  16. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of...

  17. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpt. B, Tables Tables to Subpart B of Part...

  18. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of...

  19. 33 CFR 88.11 - Law enforcement vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Law enforcement vessels. 88.11... NAVIGATION RULES ANNEX V: PILOT RULES § 88.11 Law enforcement vessels. (a) Law enforcement vessels may display a flashing blue light when engaged in direct law enforcement or public safety activities....

  20. 40 CFR 745.88 - Recognized test kits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Recognized test kits. 745.88 Section... Renovation § 745.88 Recognized test kits. (a) Effective June 23, 2008, EPA recognizes the test kits that have... publicizes its recognition of the first test kit that meets both the negative response and positive...

  1. 9 CFR 88.6 - Violations and penalties.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Violations and penalties. 88.6 Section 88.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS...

  2. 10 CFR 51.88 - Proposals for legislation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Proposals for legislation. 51.88 Section 51.88 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND RELATED REGULATORY FUNCTIONS National Environmental Policy Act-Regulations Implementing Section...

  3. 40 CFR 86.603-88 - Test orders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Test orders. 86.603-88 Section 86.603... New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Vehicles § 86.603-88 Test orders. (a) The Administrator will require any testing under this subpart by means of a test order addressed to the...

  4. 40 CFR 86.603-88 - Test orders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Test orders. 86.603-88 Section 86.603... Auditing of New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Vehicles § 86.603-88 Test orders. (a) The Administrator will require any testing under this subpart by means of a test order addressed...

  5. 27 CFR 6.88 - Equipment and supplies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Equipment and supplies. 6.88 Section 6.88 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... material), dispensing accessories, carbon dioxide (and other gasses used in dispensing equipment) or...

  6. 27 CFR 6.88 - Equipment and supplies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Equipment and supplies. 6.88 Section 6.88 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... material), dispensing accessories, carbon dioxide (and other gasses used in dispensing equipment) or...

  7. 27 CFR 6.88 - Equipment and supplies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Equipment and supplies. 6.88 Section 6.88 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... material), dispensing accessories, carbon dioxide (and other gasses used in dispensing equipment) or...

  8. 27 CFR 6.88 - Equipment and supplies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Equipment and supplies. 6.88 Section 6.88 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... material), dispensing accessories, carbon dioxide (and other gasses used in dispensing equipment) or...

  9. 40 CFR Appendix - Tables to Subpart C of Part 88

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Tables to Subpart C of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program Incentives for the purchase of Inherently Low-Emission Vehicles. Pt. 88, Subpt. C, Tables Tables to Subpart C of...

  10. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpart B, Tables Tables to Subpart B of Part...

  11. 40 CFR Appendix - Tables to Subpart B of Part 88

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Tables to Subpart B of Part 88 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES California Pilot Test Program State opt-in for the California Pilot Test Program. Pt. 88, Subpart B, Tables Tables to Subpart B of Part...

  12. 27 CFR 479.88 - Special (occupational) taxpayers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Special (occupational) taxpayers. 479.88 Section 479.88 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE...

  13. 27 CFR 479.88 - Special (occupational) taxpayers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Special (occupational) taxpayers. 479.88 Section 479.88 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE...

  14. 27 CFR 479.88 - Special (occupational) taxpayers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Special (occupational) taxpayers. 479.88 Section 479.88 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE...

  15. 27 CFR 479.88 - Special (occupational) taxpayers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Special (occupational) taxpayers. 479.88 Section 479.88 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE...

  16. Project 88: Parent Participation in the Elementary School.

    ERIC Educational Resources Information Center

    Elliott, David L.

    The program described in this paper illustrates the extension of teaching to parents and older children. Project 88, so-called because of the 88 children who were involved during the first year of the program in 1969, is a parent participation program that included a kindergarten, a first grade, and an interage 4-5-6 combination at the Castro…

  17. 21 CFR 312.88 - Safeguards for patient safety.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Safeguards for patient safety. 312.88 Section 312.88 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... application (§ 314.50 of this chapter), and postmarketing adverse reaction reporting (§ 314.80 of this chapter)....

  18. 33 CFR 88.13 - Lights on moored barges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lights on moored barges. 88.13... NAVIGATION RULES ANNEX V: PILOT RULES § 88.13 Lights on moored barges. (a) The following barges shall display at night and if practicable in periods of restricted visibility the lights described in paragraph...

  19. 33 CFR 88.13 - Lights on moored barges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lights on moored barges. 88.13... NAVIGATION RULES ANNEX V: PILOT RULES § 88.13 Lights on moored barges. (a) The following barges shall display at night and if practicable in periods of restricted visibility the lights described in paragraph...

  20. 33 CFR 88.13 - Lights on moored barges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lights on moored barges. 88.13... NAVIGATION RULES ANNEX V: PILOT RULES § 88.13 Lights on moored barges. (a) The following barges shall display at night and if practicable in periods of restricted visibility the lights described in paragraph...

  1. 36 CFR 8.8 - Filing of labor agreements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Filing of labor agreements. 8.8 Section 8.8 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... agreements. Within 60 days after the effective date of the regulations in this part (January 1,...

  2. 36 CFR 8.8 - Filing of labor agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Filing of labor agreements. 8.8 Section 8.8 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... agreements. Within 60 days after the effective date of the regulations in this part (January 1,...

  3. 42 CFR 88.15 - Appeals regarding treatment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Appeals regarding treatment. 88.15 Section 88.15... treatment. (a) Individuals may appeal the following decisions made by the WTC Program Administrator: not to... associated with a WTC-related health condition; or not to authorize treatment due to a determination by...

  4. 42 CFR 88.15 - Appeals regarding treatment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Appeals regarding treatment. 88.15 Section 88.15... treatment. (a) Individuals may appeal the following decisions made by the WTC Program Administrator: not to... associated with a WTC-related health condition; or not to authorize treatment due to a determination by...

  5. 42 CFR 88.15 - Appeals regarding treatment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Appeals regarding treatment. 88.15 Section 88.15... treatment. (a) Individuals may appeal the following decisions made by the WTC Program Administrator: not to... associated with a WTC-related health condition; or not to authorize treatment due to a determination by...

  6. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  7. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  8. 33 CFR 88.15 - Lights on dredge pipelines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and course. (b) Two red lights at each end of the pipeline, including the ends in a channel where the... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on dredge pipelines. 88.15... NAVIGATION RULES ANNEX V: PILOT RULES § 88.15 Lights on dredge pipelines. Dredge pipelines that are...

  9. 33 CFR 88.15 - Lights on dredge pipelines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and course. (b) Two red lights at each end of the pipeline, including the ends in a channel where the... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on dredge pipelines. 88.15... NAVIGATION RULES ANNEX V: PILOT RULES § 88.15 Lights on dredge pipelines. Dredge pipelines that are...

  10. 18 CFR 401.88 - Findings, report and Commission review.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Findings, report and Commission review. 401.88 Section 401.88 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Administrative and Other Hearings §...

  11. 45 CFR 88.5 - Written certification of compliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... such at the Department's discretion. I further certify that, except as provided in 45 CFR 88.5(e), the... under this instrument, and will require, except as provided in 45 CFR 88.5(e), such sub-recipient to... for, abortion. _ subject any institutional or individual health care entity to discrimination on...

  12. 7 CFR 983.88 - Suspension or termination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Suspension or termination. 983.88 Section 983.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  13. 7 CFR 983.88 - Suspension or termination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Suspension or termination. 983.88 Section 983.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  14. 7 CFR 983.88 - Suspension or termination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Suspension or termination. 983.88 Section 983.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  15. 7 CFR 983.88 - Suspension or termination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Suspension or termination. 983.88 Section 983.88 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  16. 7 CFR 2.88 - Assistant Secretary for Civil Rights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Assistant Secretary for Civil Rights. 2.88 Section 2... Administration § 2.88 Assistant Secretary for Civil Rights. (a) Delegations. Pursuant to § 2.24(a)(1), and with... authority are made by the Assistant Secretary for Administration to the Assistant Secretary for Civil...

  17. 7 CFR 2.88 - Assistant Secretary for Civil Rights.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Assistant Secretary for Civil Rights. 2.88 Section 2... Administration § 2.88 Assistant Secretary for Civil Rights. (a) Delegations. Pursuant to § 2.24(a)(1), and with... authority are made by the Assistant Secretary for Administration to the Assistant Secretary for Civil...

  18. Effect of hydrocarbons on the morphology of synthesized niobium carbide nanoparticles.

    PubMed

    Grove, David E; Gupta, Ujjwal; Castleman, A W

    2010-11-01

    Niobium carbide nanoparticles were synthesized by flowing methane, ethylene, or acetylene gas through a plasma generated from an arc discharge between two niobium electrodes. Varying methane, ethylene, and acetylene concentrations were employed in the studies to investigate their effects on niobium carbide nanoparticle morphology. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and selected area diffraction pattern (SADP) were used to investigate the synthesized NbC nanoparticles, whereupon it was found that these nanoparticles adopt cubic morphology with methane gas, a mixture of cubes and cuboctahedron morphology with ethylene gas, and solely a cuboctahedron morphology with acetylene gas. The change in particle morphology might be attributed to either the ethylene and acetylene free radicals or the increase in carbon concentration effecting the relative growth rates of the {111} and {100} facets on a NbC seed crystal.

  19. Superconducting Niobium-Titanium: Enabler for Affordable MRI and the Search for the Higgs Boson

    NASA Astrophysics Data System (ADS)

    Berlincourt, T. G.

    2016-01-01

    In 1961, Bell Telephone Laboratories researchers startled the world of physics by reporting that, at temperatures near absolute zero, a superconducting niobium-tin compound could support enormous electric current densities without resistance in the presence of very high magnetic fields. Suddenly, it became possible to fabricate supermagnets that generate high magnetic fields with unprecedented efficiency and economy. Scientists raced to find additional such materials and also to account theoretically for their behavior. Disregarded early on as unpromising, niobium-titanium alloys eventually emerged from among thousands of superconductors to become the most widely used, finding application in many thousands of MRI medical imaging systems and in huge particle accelerator magnets. In 1962, at Atomics International, experiments that revealed the supermagnet promise of niobium-titanium alloys also made essential contributions to the confirmation of the initially overlooked superconductivity theories of Soviet scientists Ginzburg, Landau, Abrikosov, and Gor'kov as the appropriate framework for understanding the physics of high magnetic field superconductivity.

  20. CRADA 2009S001: Investigation of the Supercondcuting RF Properties of Large Grain Ingot Niobium

    SciTech Connect

    Grimm, Terry; Hollister, Jerry L.; Kolka, Ahren; Myneni, Ganapati Rao

    2012-12-18

    This CRADA intended to explore the properties of large grain ingot niobium by fabricating four single cell TESLA shaped accelerating cavities. Once the cavities were fabricated, SRF performance would be measured. Niowave received four discs of large grain ingot niobium from JLAB in February 2009. Niowave cut samples from each disc and tested the RRR. After the RRR was measured with disappointing results, the project lost interest. A no cost extension was signed in July 2009 to allow progress until June 2010, but ultimately no further work was accomplished by either party. No firm conclusions were drawn, as further investigations were not made. Large grain ingot niobium has shown real potential for high accelerating gradient superconducting cavities. However, this particular CRADA did not gather enough data to reach any conclusions in this regard.