Respiration of metal (hydr)oxides by Shewanella and Geobacter: a key role for multihaem c-type cytochromes

PubMed Central

Shi, Liang; Squier, Thomas C; Zachara, John M; Fredrickson, James K

2007-01-01

Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer electrons from the inner membrane quinone/quinol pool through the periplasm to the outer membrane. The type II secretion system of S. oneidensis MR-1 has been implicated in the reduction of metal (hydr)oxides, most likely by translocating decahaem c-Cyts MtrC and OmcA across outer membrane to the surface of bacterial cells where they form a protein complex. The extracellular MtrC and OmcA can directly reduce solid metal (hydr)oxides. Likewise, outer membrane multihaem c-Cyts OmcE and OmcS of G. sulfurreducens are suggested to transfer electrons from outer membrane to type IV pili that are hypothesized to relay the electrons to solid metal (hydr)oxides. Thus, multihaem c-Cyts play critical roles in S. oneidensis MR-1- and G. sulfurreducens-mediated dissimilatory reduction of solid metal (hydr)oxides by facilitating ET across the bacterial cell envelope. PMID:17581116

Portable heatable container

NASA Technical Reports Server (NTRS)

Yang, L. C. (Inventor)

1980-01-01

A container is provided which can be designed to heat its outer surface to sterilize it, or to heat its inner surface and any contents therewithin. In a container that self sterilizes its outer surface, the container includes a combustible layer of thermite-type pyrotechnic material which can be ignited to generate considerable heat, and a thin casing around the combustible layer which is of highly thermally conductive materials such as aluminum which can be heated to a high temperature by the ignited combustible layer. A buffer layer which may be of metal, lies within the combustible layer, and a layer of insulation such as Teflon lies within the buffer layer to insulate the contents of the container from the heat.

Method of making a sodium sulfur battery

DOEpatents

Elkins, P. E.

1981-09-22

A method of making a portion of a sodium sulfur battery is disclosed. The battery portion made is a portion of the container which defines the volume for the cathodic reactant materials which are sulfur and sodium polysulfide materials. The container portion is defined by an outer metal casing with a graphite liner contained therein, the graphite liner having a coating on its internal diameter for sealing off the porosity thereof. The steel outer container and graphite pipe are united by a method which insures that at the operating temperature of the battery, relatively low electrical resistance exists between the two materials because they are in intimate contact with one another. 3 figs.

Portable heatable container

NASA Astrophysics Data System (ADS)

Yang, L. C.

1980-03-01

A container is provided which can be designed to heat its outer surface to sterilize it, or to heat its inner surface and any contents therewithin. In a container that self sterilizes its outer surface, the container includes a combustible layer of thermite-type pyrotechnic material which can be ignited to generate considerable heat, and a thin casing around the combustible layer which is of highly thermally conductive materials such as aluminum which can be heated to a high temperature by the ignited combustible layer. A buffer layer which may be of metal, lies within the combustible layer, and a layer of insulation such as Teflon lies within the buffer layer to insulate the contents of the container from the heat.

Freeform Deposition Method for Coolant Channel Closeout

NASA Technical Reports Server (NTRS)

Gradl, Paul R. (Inventor); Reynolds, David Christopher (Inventor); Walker, Bryant H. (Inventor)

2017-01-01

A method is provided for fabricating a coolant channel closeout jacket on a structure having coolant channels formed in an outer surface thereof. A line of tangency relative to the outer surface is defined for each point on the outer surface. Linear rows of a metal feedstock are directed towards and deposited on the outer surface of the structure as a beam of weld energy is directed to the metal feedstock so-deposited. A first angle between the metal feedstock so-directed and the line of tangency is maintained in a range of 20-90.degree.. The beam is directed towards a portion of the linear rows such that less than 30% of the cross-sectional area of the beam impinges on a currently-deposited one of the linear rows. A second angle between the beam and the line of tangency is maintained in a range of 5-65 degrees.

Load-resistant coaxial transmission line

DOEpatents

Hall, David R.; Fox, Joe

2006-01-03

A transmission line for downhole tools that make up all or part of a tool string for drilling and production of oil, gas, and geothermal wells that can withstand the dynamic gravitational forces and other accelerations associated with downhole excavations. The transmission line has a metal tube, or outer conductor, that houses a coaxial wire inner conductor. A non-metallic dielectric material is interposed between the inner and outer conductors. The outer and inner conductors and the dielectric are sufficiently compressed together so that independent motion between them is abated. Compression of the components of the transmission line may be achieved by drawing the transmission through one or more dies in order to draw down the outer conductor onto the dielectric, or by expanding the inner conductor against the dielectric using a mandrel or hydraulic pressure. Non-metallic bead segments may be used in aid of the compression necessary to resist the dynamic forces and accelerations of drilling.

SUPPORTING AND HEAT INSULATING MEANS

DOEpatents

Birmingham, B.W.; Brown, H.; Scott, R.B.; Vander-arend, P.C.

1959-01-27

A method is described for simultaneously supporting inner and outer members spaced from each other and heat insulating them from each other comprising an inner and outer member together defining an annular cavity. Each member carries a shoulder projecting towards the other member. A stack of annular metal plates in the cavity is held between the shoulder of the outer member and the shoulder of the inner member. The edges of the metal plate forming the stack are exposed to the cavity and to evacuation conditions which may exist within thc cavity. The stack of metal plates acts to both support one of the members with respect to the other and as a heat insulator.

Laser pumping of thyristors for fast high current rise-times

DOEpatents

Glidden, Steven C.; Sanders, Howard D.

2013-06-11

An optically triggered semiconductor switch includes an anode metallization layer; a cathode metallization layer; a semiconductor between the anode metallization layer and the cathode metallization layer and a photon source. The semiconductor includes at least four layers of alternating doping in the form P-N-P-N, in which an outer layer adjacent to the anode metallization layer forms an anode and an outer layer adjacent the cathode metallization layer forms a cathode and in which the anode metallization layer has a window pattern of optically transparent material exposing the anode layer to light. The photon source emits light having a wavelength, with the light from the photon source being configured to match the window pattern of the anode metallization layer.

LC and ferromagnetic resonance in soft/hard magnetic microwires

NASA Astrophysics Data System (ADS)

Tian, Bin; Vazquez, Manuel

2015-12-01

The magnetic behavior of soft/hard biphase microwires is introduced here. The microwires consist of a Co59.1Fe14.8Si10.2B15.9 soft magnetic nucleus and a Co90Ni10 hard outer shell separated by an intermediate insulating Pyrex glass microtube. By comparing the resistance spectrums of welding the ends of metallic core (CC) or welding the metallic core and outer shell (CS) to the connector, it is found that one of the two peaks in the resistance spectrum is because the LC resonance depends on the inductor and capacitors in which one is the capacitor between the metallic core and outer shell, and the other is between the outer shell and connector. Correspondingly, another peak is for the ferromagnetic resonance of metallic core. After changing the capacitance of the capacitors, the frequency of LC resonance moves to high frequency band, and furthermore, the peak of LC resonance in the resistance spectrum disappeared. These magnetostatically coupled biphase systems are thought to be of large potential interest as sensing elements in sensor devices.

Method for manufacturing magnetohydrodynamic electrodes

DOEpatents

Killpatrick, D.H.; Thresh, H.R.

1980-06-24

A method of manufacturing electrodes for use in a magnetohydrodynamic (MHD) generator is described comprising the steps of preparing a billet having a core of a first metal, a tubular sleeve of a second metal, and an outer sheath of an extrusile metal; evacuating the space between the parts of the assembled billet; extruding the billet; and removing the outer jacket. The extruded bar may be made into electrodes by cutting and bending to the shape required for an MHD channel frame. The method forms a bond between the first metal of the core and the second metal of the sleeve strong enough to withstand a hot and corrosive environment.

System for rapid biohydrogen phenotypic screening of microorganisms using a chemochromic sensor

DOEpatents

Seibert, Michael; Benson, David K.; Flynn, Timothy Michael

2002-01-01

Provided is a system for identifying a hydrogen gas producing organism. The system includes a sensor film having a first layer comprising a transition metal oxide or oxysalt and a second layer comprising a hydrogen-dissociative catalyst metal, the first and second layers having an inner and an outer surface wherein the inner surface of the second layer is deposited on the outer surface of the first layer, and a substrate adjacent to the outer surface of the second layer, the organism isolated on the substrate.

Method and apparatus for rapid biohydrogen phenotypic screening of microorganisms using a chemochromic sensor

DOEpatents

Seibert, Michael; Benson, David K.; Flynn, Timothy Michael

2001-01-01

The invention provides an assay system for identifying a hydrogen-gas-producing organism, including a sensor film having a first layer comprising a transition metal oxide or oxysalt and a second layer comprising hydrogen-dissociative catalyst metal, the first and second layers having an inner and an outer surface wherein the inner surface of the second layer is deposited on the outer surface of the first layer, and a substrate disposed proximally to the outer surface of the second layer, the organism being isolated on the substrate.

Carbon-enhanced metal-poor stars: CEMP-s and CEMP-no subclasses in the halo system of the Milky Way

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carollo, Daniela; Freeman, Ken; Beers, Timothy C.

2014-06-20

We explore the kinematics and orbital properties of a sample of 323 very metal-poor stars in the halo system of the Milky Way, selected from the high-resolution spectroscopic follow-up studies of Aoki et al. and Yong et al. The combined sample contains a significant fraction of carbon-enhanced metal-poor (CEMP) stars (22% or 29%, depending on whether a strict or relaxed criterion is applied for this definition). Barium abundances (or upper limits) are available for the great majority of the CEMP stars, allowing for their separation into the CEMP-s and CEMP-no subclasses. A new method to assign membership to the inner-more » and outer-halo populations of the Milky Way is developed, making use of the integrals of motion, and applied to determine the relative fractions of CEMP stars in these two subclasses for each halo component. Although limited by small-number statistics, the data suggest that the inner halo of the Milky Way exhibits a somewhat higher relative number of CEMP-s stars than CEMP-no stars (57% versus 43%), while the outer halo possesses a clearly higher fraction of CEMP-no stars than CEMP-s stars (70% versus 30%). Although larger samples of CEMP stars with known Ba abundances are required, this result suggests that the dominant progenitors of CEMP stars in the two halo components were different; massive stars for the outer halo, and intermediate-mass stars in the case of the inner halo.« less

Radiation and phase change of lithium fluoride in an annulus

NASA Technical Reports Server (NTRS)

Lund, Kurt O.

1993-01-01

A one-dimensional thermal model is developed to evaluate the effect of radiation on the phase change of lithium-fluoride (LiF) in an annular canister under gravitational and microgravitational conditions. Specified heat flux at the outer wall of the canister models focused solar flux; adiabatic and convective conditions are considered for the inner wall. A two-band radiation model is used for the combined-mode heat transfer within the canister, and LiF optical properties relate metal surface properties in vacuum to those in LiF. For axial gravitational conditions, the liquid LiF remains in contact with the two bounding walls, whereas a void gap is used at the outer wall to model possible microgravitational conditions. For the adiabatic cases, exact integrals are obtained for the time required for complete melting of the LiF. Melting was found to occur primarily from the outer wall in the 1-g model, whereas it occurred primarily from the inner wall in the mu-g model. For the convective cases, partially melted steady-state conditions and fully melted conditions are determined to depend on the source flux level, with radiation extending the melting times.

46 CFR 42.13-15 - Definitions of terms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... line of the frame in a vessel with a metal shell and to the outer surface of the hull in a vessel with... vessel with a metal shell, and is the volume of displacement to the outer surface of the hull in a vessel... between the machinery space and peak bulkheads and continuous athwartships. When this lower deck is...

46 CFR 42.13-15 - Definitions of terms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... line of the frame in a vessel with a metal shell and to the outer surface of the hull in a vessel with... vessel with a metal shell, and is the volume of displacement to the outer surface of the hull in a vessel... between the machinery space and peak bulkheads and continuous athwartships. When this lower deck is...

Power inverters

DOEpatents

Miller, David H [Redondo Beach, CA; Korich, Mark D [Chino Hills, CA; Smith, Gregory S [Woodland Hills, CA

2011-11-15

Power inverters include a frame and a power module. The frame has a sidewall including an opening and defining a fluid passageway. The power module is coupled to the frame over the opening and includes a substrate, die, and an encasement. The substrate includes a first side, a second side, a center, an outer periphery, and an outer edge, and the first side of the substrate comprises a first outer layer including a metal material. The die are positioned in the substrate center and are coupled to the substrate first side. The encasement is molded over the outer periphery on the substrate first side, the substrate second side, and the substrate outer edge and around the die. The encasement, coupled to the substrate, forms a seal with the metal material. The second side of the substrate is positioned to directly contact a fluid flowing through the fluid passageway.

Pal 12 - A metal-rich globular cluster in the outer halo

NASA Technical Reports Server (NTRS)

Cohen, J. G.; Frogel, J. A.; Persson, S. E.; Zinn, R.

1980-01-01

New optical and infrared observations of several stars in the distant globular cluster Pal 12 show that they have CO strengths and heavy element abundances only slightly less than in M 71, one of the more metal-rich globular clusters. Pal 12 thus has a metal abundance near the high end of the range over which globular clusters exist and lies in the outer galactic halo. Its red horizontal branch is not anomalous in view of the abundance that has been found.

A sheet metal forming simulation of automotive outer panels considering the behavior of air in die cavity

NASA Astrophysics Data System (ADS)

Choi, Kwang Yong; Kim, Yun Chang; Choi, Hee Kwan; Kang, Chul Ho; Kim, Heon Young

2013-12-01

During a sheet metal forming process of automotive outer panels, the air trapped between a blank sheet and a die tool can become highly compressed, ultimately influencing the blank deformation and the press force. To prevent this problem, vent holes are drilled into die tools and needs several tens to hundreds according to the model size. The design and the drilling of vent holes are based on expert's experience and try-out result and thus the process can be one of reasons increasing development cycle. Therefore the study on the size, the number, and the position of vent holes is demanded for reducing development cycle, but there is no simulation technology for analyzing forming defects, making numerical sheet metal forming process simulations that incorporate the fluid dynamics of air. This study presents a sheet metal forming simulation of automotive outer panels (a roof and a body side outer) that simultaneously simulates the behavior of air in a die cavity. Through CAE results, the effect of air behavior and vent holes to blank deformation was analyzed. For this study, the commercial software PAM-STAMP{trade mark, serif} and PAM-SAFE{trade mark, serif} was used.

Method for manufacturing magnetohydrodynamic electrodes

DOEpatents

Killpatrick, Don H.; Thresh, Henry R.

1982-01-01

A method of manufacturing electrodes for use in a magnetohydrodynamic (MHD) generator comprising the steps of preparing a billet having a core 10 of a first metal, a tubular sleeve 12 of a second metal, and an outer sheath 14, 16, 18 of an extrusile metal; evacuating the space between the parts of the assembled billet; extruding the billet; and removing the outer jacket 14. The extruded bar may be made into electrodes by cutting and bending to the shape required for an MDH channel frame. The method forms a bond between the first metal of the core 10 and the second metal of the sleeve 12 strong enough to withstand a hot and corrosive environment.

Electronic transport properties of inner and outer shells in near ohmic-contacted double-walled carbon nanotube transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yuchun; Zhou, Liyan; Zhao, Shangqian

2014-06-14

We investigate electronic transport properties of field-effect transistors based on double-walled carbon nanotubes, of which inner shells are metallic and outer shells are semiconducting. When both shells are turned on, electron-phonon scattering is found to be the dominant phenomenon. On the other hand, when outer semiconducting shells are turned off, a zero-bias anomaly emerges in the dependence of differential conductance on the bias voltage, which is characterized according to the Tomonaga-Luttinger liquid model describing tunneling into one-dimensional materials. We attribute these behaviors to different contact conditions for outer and inner shells of the double-walled carbon nanotubes. A simple model combiningmore » Luttinger liquid model for inner metallic shells and electron-phonon scattering in outer semiconducting shells is given here to explain our transport data at different temperatures.« less

Structured copolymers and their use as absorbents, gels and carriers of metal ions

DOEpatents

Hedstrand, David M.; Helmer, Bradley J.; Tomalia, Donald A.

1996-01-01

Dense star polymers or dendrimers having a highly branched interior structure capable of associating or chelating with metal ions are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell. The modified dendrimers are useful for dispersing metal ions in a non-aqueous polymer matrix. Also dense star polymers or dendrimers having a highly branched hydrophilic interior structure are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, which modified polymers are useful as gels and surfactants.

Structured copolymers and their use as absorbents, gels and carriers of metal ions

DOEpatents

Hedstrand, D.M.; Helmer, B.J.; Tomalia, D.A.

1996-10-01

Dense star polymers or dendrimers having a highly branched interior structure capable of associating or chelating with metal ions are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell. The modified dendrimers are useful for dispersing metal ions in a non-aqueous polymer matrix. Also dense star polymers or dendrimers having a highly branched hydrophilic interior structure are modified by capping with a hydrophobic group capable of providing a hydrophobic outer shell, which modified polymers are useful as gels and surfactants.

High pressure mechanical seal

NASA Technical Reports Server (NTRS)

Babel, Henry W. (Inventor); Anderson, Raymond H. (Inventor)

1996-01-01

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After compression, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as measured using the Helium leak test.

Ceramic-metal composite article and joining method

DOEpatents

Kang, Shinhoo; Selverian, John H.; Kim, Hans J.; Dunn, Edmund M.; Kim, Kyung S.

1992-01-01

A ceramic-metal article including a ceramic rod, a metal rod, and a braze joining the ceramic and metal rods at a braze area of a coaxial bore in the metal rod. The bore gradually decreases in diameter, having an inward seat area sized for close sliding fit about the ceramic, a larger brazing area near the joint end, and a void area intermediate the braze and seat areas. The ceramic is seated without brazing in the bore seat area. The side wall between the brazing area and the metal outer surface is about 0.030-0.080 inch. The braze includes an inner braze layer, an outer braze layer, and an interlayer about 0.030-0.090 inch thick. A shoulder between the brazing and void areas supports the interlayer during bonding while preventing bonding between the void area and the ceramic member, leaving a void space between the void area and the ceramic member. A venting orifice extends generally radially through the metal member from the outer surface to the void space. The braze layers are palladium, platinum, gold, silver, copper, nickel, indium, chromium, molybdenum, niobium, iron, aluminum, or alloys thereof. Preferred is a gold-palladium-nickel brazing alloy. The interlayer is nickel, molybdenum, copper, tantalum, tungsten, niobium, aluminum, cobalt, iron, or an alloy thereof.

Ceramic-metal composite article and joining method

DOEpatents

Kang, S.; Selverian, J.H.; Kim, H.J.; Dunn, E.M.; Kim, K.S.

1992-04-28

A ceramic-metal article including a ceramic rod, a metal rod, and a braze joining the ceramic and metal rods at a braze area of a coaxial bore in the metal rod is described. The bore gradually decreases in diameter, having an inward seat area sized for close sliding fit about the ceramic, a larger brazing area near the joint end, and a void area intermediate the braze and seat areas. The ceramic is seated without brazing in the bore seat area. The side wall between the brazing area and the metal outer surface is about 0.030-0.080 inch. The braze includes an inner braze layer, an outer braze layer, and an interlayer about 0.030-0.090 inch thick. A shoulder between the brazing and void areas supports the interlayer during bonding while preventing bonding between the void area and the ceramic member, leaving a void space between the void area and the ceramic member. A venting orifice extends generally radially through the metal member from the outer surface to the void space. The braze layers are palladium, platinum, gold, silver, copper, nickel, indium, chromium, molybdenum, niobium, iron, aluminum, or alloys thereof. Preferred is a gold-palladium-nickel brazing alloy. The interlayer is nickel, molybdenum, copper, tantalum, tungsten, niobium, aluminum, cobalt, iron, or an alloy thereof. 4 figs.

Expanded nickel screen electrical connection supports for solid oxide fuel cells

DOEpatents

Draper, Robert; Antol, Ronald F.; Zafred, Paolo R.

2002-01-01

A solid oxide fuel assembly is made, wherein rows (14, 24) of fuel cells (16, 18, 20, 26, 28, 30), each having an outer interconnection (36) and an outer electrode (32), are disposed next to each other with corrugated, electrically conducting expanded metal mesh (22) between each row of cells, the corrugated mesh (22) having top crown portions (40) and bottom shoulder portions (42), where the top crown portion (40) contacts outer interconnections (36) of the fuel cells (16, 18, 20) in a first row (14), and the bottom shoulder portions (42) contacts outer electrodes (32) of the fuel cells in a second row (24), said mesh electrically connecting each row of fuel cells, and where there are no metal felt connections between any fuel cells.

AGARD Corrosion Handbook. Volume 1. Aircraft Corrosion: Causes and Case Histories

DTIC Science & Technology

1985-07-01

Anodic coatings can be formed in chromic acid, sulphuric acid, phosphoric acid or oxalic acid solutions. Chromic acid anodizing is widely used with...and consists of a thin non-porous barrier layer next to the metal with a porous outer layer that can be sealed by hydrothermal treatment in steam...anaerobic) or an oxidative (aerobic) mechanism. Various organic acids such as citric acid, oxalic acid, gluconic acid, dodecanoic acid, etc., which may be

Heat pump water heater and method of making the same

DOEpatents

Mei, Viung C.; Tomlinson, John J.; Chen, Fang C.

2001-01-01

An improved heat pump water heater wherein the condenser assembly of the heat pump is inserted into the water tank through an existing opening in the top of the tank, the assembly comprising a tube-in-a-tube construction with an elongated cylindrical outer body heat exchanger having a closed bottom with the superheated refrigerant that exits the compressor of the heat pump entering the top of the outer body. As the refrigerant condenses along the interior surface of the outer body, the heat from the refrigerant is transferred to the water through the outer body. The refrigerant then enters the bottom of an inner body coaxially disposed within the outer body and exits the top of the inner body into the refrigerant conduit leading into the expansion device of the heat pump. The outer body, in a second embodiment of the invention, acts not only as a heat exchanger but also as the sacrificial anode in the water tank by being constructed of a metal which is more likely to corrode than the metal of the tank.

Producing thin film photovoltaic modules with high integrity interconnects and dual layer contacts

DOEpatents

Jansen, Kai W.; Maley, Nagi

2000-01-01

High performance photovoltaic modules are produced with improved interconnects by a special process. Advantageously, the photovoltaic modules have a dual layer back (rear) contact and a front contact with at least one layer. The front contact and the inner layer of the back contact can comprise a transparent conductive oxide. The outer layer of the back contact can comprise a metal or metal oxide. The front contact can also have a dielectric layer. In one form, the dual layer back contact comprises a zinc oxide inner layer and an aluminum outer layer and the front contact comprises a tin oxide inner layer and a silicon dioxide dielectric outer layer. One or more amorphous silicon-containing thin film semiconductors can be deposited between the front and back contacts. The contacts can be positioned between a substrate and an optional superstrate. During production, the transparent conductive oxide layer of the front contact is scribed by a laser, then the amorphous silicon-containing semiconductors and inner layer of the dual layer back contact are simultaneously scribed and trenched (drilled) by the laser and the trench is subsequently filled with the same metal as the outer layer of the dual layer back contact to provide a superb mechanical and electrical interconnect between the front contact and the outer layer of the dual layer back contact. The outer layer of the dual layer back contact can then be scribed by the laser. For enhanced environmental protection, the photovoltaic modules can be encapsulated.

Producing thin film photovoltaic modules with high integrity interconnects and dual layer contacts

DOEpatents

Jansen, Kai W.; Maley, Nagi

2001-01-01

High performance photovoltaic modules are produced with improved interconnects by a special process. Advantageously, the photovoltaic modules have a dual layer back (rear) contact and a front contact with at least one layer. The front contact and the inner layer of the back contact can comprise a transparent conductive oxide. The outer layer of the back contact can comprise a metal or metal oxide. The front contact can also have a dielectric layer. In one form, the dual layer back contact comprises a zinc oxide inner layer and an aluminum outer layer and the front contact comprises a tin oxide inner layer and a silicon dioxide dielectric outer layer. One or more amorphous silicon-containing thin film semiconductors can be deposited between the front and back contacts. The contacts can be positioned between a substrate and an optional superstrate. During production, the transparent conductive oxide layer of the front contact is scribed by a laser, then the amorphous silicon-containing semiconductors and inner layer of the dual layer back contact are simultaneously scribed and trenched (drilled) by the laser and the trench is subsequently filled with the same metal as the outer layer of the dual layer back contact to provide a superb mechanical and electrical interconnect between the front contact and the outer layer of the dual layer back contact. The outer layer of the dual layer back contact can then be scribed by the laser. For enhanced environmental protection, the photovoltaic modules can be encapsulated.

Heavy metals in bark of Pinus massoniana (Lamb.) as an indicator of atmospheric deposition near a smeltery at Qujiang, China.

PubMed

Kuang, Yuan Wen; Zhou, Guo Yi; Da Wen, Zhi; Liu, Shi Zhong

2007-06-01

Rapid urbanization and the expansion of industrial activities in the past several decades have led to large increases in emissions of pollutants in the Pearl River Delta of south China. Recent reports have suggested that industrial emission is a major factor contributing to the damages in current natural ecosystem in the Delta area. Tree barks have been used successfully to monitor the levels of atmospheric metal deposition in many areas, but rarely in China. This study aimed at determining whether atmospheric heavy metal deposition from a Pb-Zn smeltery at Qujiang, Guangdong province, could be accurately reflected both in the inner bark and the outer bark of Masson pine (Pinus massoniana L.). The impact of the emission from smeltery on the soils beneath the trees and the relationships of the concentrations between the soils and the barks were also analyzed. Barks around the bole of Pinus massoniana from a pine forest near a Pb-Zn smeltery at Qujiang and a reference forest at Dinghushan natural reserve were sampled with a stainless knife at an average height of 1.5 m above the ground. Mosses and lichens on the surface barks were cleaned prior to sampling. The samples were carefully divided into the inner bark (living part) and the outer bark (dead part) in the laboratory, and dried and ground, respectively. After being dry-ashed, the powder of the barks was dissolved in HNO3. The solutions were analyzed for iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni) and cobalt (Co) by inductively coupled plasmas emission spectrometry (ICP, PS-1000AT, USA) and Cadmium (Cd) and lead (Pb) by graphite furnace atomic absorption spectrometry (GFAAS, ZEENIT 60, Germany). Surface soils (0-10 cm) beneath the sample trees were also collected and analyzed for the selected metals. Concentrations of the selected metals in soils at Qujiang were far above their environmental background values in the area, except for Fe and Mn, whilst at Dinghushan, they were far below their background values, except for Cd and Co. Levels of the metals, in particular Pb and Zn, in the soils beneath the sample trees at Qujiang were higher than those at Dinghushan with statistical significance. The result suggested that the pine forest soils at Qujiang had a great input of heavy metals from wet and dry atmospheric deposition, with the Pb-Zn smeltery most probably being the source. Levels of Cu, Fe, Mn, Zn, Ni and Pb at Qujiang, both in the inner and the outer bark, were statistically higher than those at Dinghushan. Higher concentrations of Pb, Fe, Zn and Cu may come from the stem-flow of elements leached from the canopy, soil splash on the 1.5 m height and sorption of metals in the mosses and lichens growing on the bark, which were direct or indirect results from the atmospheric deposition. Levels of heavy metals in the outer barks were associated well with the metal concentrations in the soil, reflecting the close relationships between the metal atmospheric deposition and their accumulation in the outer bark of Masson pine. The significant (p<0.01) correlations of Fe-Cu, Fe-Cr, Fe-Pb, Fe-Ni, Pb-Ni, and Pb-Zn in the outer barks at Qujiang again suggested a common source for the metals. The correlation only occurred between Pb and Ni, Cd and Co in the outer barks at Dinghushan, which suggested that those metals must possibly have other uncommon sources. Atmospheric deposition of the selected metals was great at Qujiang, based on the levels in the bark of Pinus massoniana and on the concentrations in the soils beneath the trees compared with that at Dinghushan. Bark of Pinus massoniana, especially the outer bark, was an indicator of metal loading at least at the time of sampling. The results from this study and the techniques employed constituted a new contribution to the development of biogeochemical methods for environmental monitoring particularly in areas with high frequency of pollution in China. The method would be of value for follow up studies aimed at the assessment of industrial pollution in other areas similar with the Pearl River Delta.

Patterned structures of graphene and graphitic carbon and methods for their manufacture

DOEpatents

Polsky, Ronen; Xiao, Xiaoyin; Burckel, David Bruce; Wheeler, David R.; Brozik, Susan M.; Beechem, Thomas Edwin

2017-01-03

A patterned graphene or graphitic body is produced by providing a three-dimensionally patterned carbonaceous body; coating the body with a catalytic metal whereby is formed a coating having an inner surface proximal the body and an outer surface distal the body; and annealing the coated body under time and temperature conditions effective to form a graphene or graphitic layer on the outer surface of the catalytic metal coating.

Patterned structures of graphene and graphitic carbon and methods for their manufacture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polsky, Ronen; Xiao, Xiaoyin; Burckel, David Bruce

A patterned graphene or graphitic body is produced by providing a three-dimensionally patterned carbonaceous body; coating the body with a catalytic metal whereby is formed a coating having an inner surface proximal the body and an outer surface distal the body; and annealing the coated body under time and temperature conditions effective to form a graphene or graphitic layer on the outer surface of the catalytic metal coating.

Combination nickel foam expanded nickel screen electrical connection supports for solid oxide fuel cells

DOEpatents

Draper, Robert; Prevish, Thomas; Bronson, Angela; George, Raymond A.

2007-01-02

A solid oxide fuel assembly is made, wherein rows (14, 25) of fuel cells (17, 19, 21, 27, 29, 31), each having an outer interconnection (20) and an outer electrode (32), are disposed next to each other with corrugated, electrically conducting expanded metal mesh member (22) between each row of cells, the corrugated mesh (22) having top crown portions and bottom portions, where the top crown portion (40) have a top bonded open cell nickel foam (51) which contacts outer interconnections (20) of the fuel cells, said mesh and nickel foam electrically connecting each row of fuel cells, and where there are no more metal felt connections between any fuel cells.

Distribution and risk assessment of trace metals in sediments from Yangtze River estuary and Hangzhou Bay, China.

PubMed

Li, Feipeng; Mao, Lingchen; Jia, Yubao; Gu, Zhujun; Shi, Weiling; Chen, Ling; Ye, Hua

2018-01-01

The Yangtze River estuary (YRE) and Hangzhou Bay (HZB) is of environmental significance because of the negative impact from industrial activities and rapid development of aquaculture on the south bank of HZB (SHZB) in recent years. This study investigated the distribution and risk assessments of trace metals (Cr, Cu, Zn, Hg, Pb, and Cd) accumulated in surface sediments by sampling in YRE, outer and south HZB. Copper and Zn concentration (avg. 35.4 and 98.7 mg kg -1 , respectively) in surface sediments were generally higher than the background suggesting a widespread of Cu and Zn in the coastal area of Yangtze River Delta. High concentrations of Cu (~ 42 mg kg -1 ), Zn (~ 111 mg kg -1 ), Cd (~ 0.27 mg kg -1 ), and Hg (~ 0.047 mg kg -1 ) were found in inner estuary of YRE and decreased offshore as a result of terrestrial input and dilution effect of total metal contents by "cleaner" sediments from the adjacent sea. In outer HZB, accumulation of terrestrial derived metal has taken place near the Zhoushan Islands. Increase in sediment metal concentration from the west (inner) to the east (outer) of SHZB gave rise to the input of fine-grained sediments contaminated with metals from outer bay. According the results from geoaccumulation index, nearly 75% of samples from YRE were moderately polluted (1.0 < I geo  < 2.0) by Cd. Cadmium and Hg contributed for 80~90% to the potential ecological risk index in the YRE and HZB, with ~ 72% sites in HZB under moderate risk (150 ≤ RI < 300) especially near Zhoushan Islands.

High pressure mechanical seal

NASA Technical Reports Server (NTRS)

Babel, Henry W. (Inventor); Fuson, Phillip L. (Inventor); Chickles, Colin D. (Inventor); Jones, Cherie A. (Inventor); Anderson, Raymond H. (Inventor)

1995-01-01

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting, prior to swaging the fitting onto the tube. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, nickel, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After swaging, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as meaured using the Helium leak test.

Cooking utensil with improved heat retention

DOEpatents

Potter, Thomas F.; Benson, David K.; Burch, Steven D.

1997-01-01

A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber therebetween. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food.

Cooking utensil with improved heat retention

DOEpatents

Potter, T.F.; Benson, D.K.; Burch, S.D.

1997-07-01

A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber there between. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food. 26 figs.

Tubular screen electrical connection support for solid oxide fuel cells

DOEpatents

Tomlins, Gregory W.; Jaszcar, Michael P.

2002-01-01

A solid oxide fuel assembly is made of fuel cells (16, 16', 18, 24, 24', 26), each having an outer interconnection layer (36) and an outer electrode (28), which are disposed next to each other with rolled, porous, hollow, electrically conducting metal mesh conductors (20, 20') between the fuel cells, connecting the fuel cells at least in series along columns (15, 15') and where there are no metal felt connections between any fuel cells.

First-second shell interactions in metal binding sites in proteins: a PDB survey and DFT/CDM calculations.

PubMed

Dudev, Todor; Lin, Yen-lin; Dudev, Minko; Lim, Carmay

2003-03-12

The role of the second shell in the process of metal binding and selectivity in metalloproteins has been elucidated by combining Protein Data Bank (PDB) surveys of Mg, Mn, Ca, and Zn binding sites with density functional theory/continuum dielectric methods (DFT/CDM). Peptide backbone groups were found to be the most common second-shell ligand in Mg, Mn, Ca, and Zn binding sites, followed (in decreasing order) by Asp/Glu, Lys/Arg, Asn/Gln, and Ser/Thr side chains. Aromatic oxygen- or nitrogen-containing side chains (Tyr, His, and Trp) and sulfur-containing side chains (Cys and Met) are seldom found in the second coordination layer. The backbone and Asn/Gln side chain are ubiquitous in the metal second coordination layer as their carbonyl oxygen and amide hydrogen can act as a hydrogen-bond acceptor and donor, respectively, and can therefore partner practically every first-shell ligand. The second most common outer-shell ligand, Asp/Glu, predominantly hydrogen bonds to a metal-bound water or Zn-bound histidine and polarizes the H-O or H-N bond. In certain cases, a second-shell Asp/Glu could affect the protonation state of the metal ligand. It could also energetically stabilize a positively charged metal complex more than a neutral ligand such as the backbone and Asn/Gln side chain. As for the first shell, the second shell is predicted to contribute to the metal selectivity of the binding site by discriminating between metal cations of different ionic radii and coordination geometries. The first-shell-second-shell interaction energies decay rapidly with increasing solvent exposure of the metal binding site. They are less favorable but are of the same order of magnitude as compared to the respective metal-first-shell interaction energies. Altogether, the results indicate that the structure and properties of the second shell are dictated by those of the first layer. The outer shell is apparently designed to stabilize/protect the inner-shell and complement/enhance its properties.

Detection of MgCn in IRC + 10216: A new metal-bearing free radical

NASA Technical Reports Server (NTRS)

Ziurys, L. M.; Apponi, A. J.; Guelin, M.; Cernicharo, J.

1995-01-01

A new metal-containing molecule, MgCN, has been detected toward the late-type star IRC + 10216, using the NRAO 12 m and IRAM 30 m telescopes. The N = 11 approaches 10, 10 approaches 9, and 9 approaches 8 transtions of this species which has a (sup 2)Sigma(sup +) ground state, have been observed in the outer envelope of this object at 3 mm. For the N = 11 approaches 10 transitions, the two spin-rotation components are clearly resolved and conclusively identify this new radical. These measurements imply a column of density for MgCN of N(sub tot) approximately 10(exp 12)/sq cm in the outer shell, which corresponds to a fractional abundance of f approximately 7x10(exp -10). This molecule, the metastable isomer of MgNC, is the third metal-bearing species thus far identified in the outer shell of IRC + 10216, and its detection implies a ratio of MgNC/MgCN approximately 22/1. MgCN may be formed through a reaction scheme involving magnesium and HNC or CN, both prominent outer shell molecules, or through synthesis on grains.

Normal Mode Derived Models of the Physical Properties of Earth's Outer Core

NASA Astrophysics Data System (ADS)

Irving, J. C. E.; Cottaar, S.; Lekic, V.; Wu, W.

2017-12-01

Earth's outer core, the largest reservoir of metal in our planet, is comprised of an iron alloy of an uncertain composition. Its dynamical behaviour is responsible for the generation of Earth's magnetic field, with convection driven both by thermal and chemical buoyancy fluxes. Existing models of the seismic velocity and density of the outer core exhibit some variation, and there are only a small number of models which aim to represent the outer core's density.It is therefore important that we develop a better understanding of the physical properties of the outer core. Though most of the outer core is likely to be well mixed, it is possible that the uppermost outer core is stably stratified: it may be enriched in light elements released during the growth of the solid, iron enriched, inner core; by elements dissolved from the mantle into the outer core; or by exsolution of compounds previously dissolved in the liquid metal which will eventually be swept into the mantle. The stratified layer may host MAC or Rossby waves and it could impede communication between the chemically differentiated mantle and outer core, including screening out some of the geodynamo's signal. We use normal mode center frequencies to estimate the physical properties of the outer core in a Bayesian framework. We estimate the mineral physical parameters needed to best produce velocity and density models of the outer core which are consistent with the normal mode observations. We require that our models satisfy realistic physical constraints. We create models of the outer core with and without a distinct uppermost layer and assess the importance of this region.Our normal mode-derived models are compared with observations of body waves which travel through the outer core. In particular, we consider SmKS waves which are especially sensitive to the uppermost outer core and are therefore an important way to understand the robustness of our models.

Lid design for low level waste container

DOEpatents

Holbrook, R.H.; Keener, W.E.

1995-02-28

A container for low level waste includes a shell and a lid. The lid has a frame to which a planar member is welded. The lid frame includes a rectangular outer portion made of square metal tubing, a longitudinal beam extending between axial ends of the rectangular outer portion, and a transverse beam extending between opposite lateral sides of the rectangular outer portion. Two pairs of diagonal braces extend between the longitudinal beam and the four corners of the rectangular outer portion of the frame. 6 figs.

Liquid metal reactor air cooling baffle

DOEpatents

Hunsbedt, Anstein

1994-01-01

A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat.

Liquid metal reactor air cooling baffle

DOEpatents

Hunsbedt, A.

1994-08-16

A baffle is provided between a relatively hot containment vessel and a relatively cold silo for enhancing air cooling performance. The baffle includes a perforate inner wall positionable outside the containment vessel to define an inner flow riser therebetween, and an imperforate outer wall positionable outside the inner wall to define an outer flow riser therebetween. Apertures in the inner wall allow thermal radiation to pass laterally therethrough to the outer wall, with cooling air flowing upwardly through the inner and outer risers for removing heat. 3 figs.

Lid design for low level waste container

DOEpatents

Holbrook, Richard H.; Keener, Wendell E.

1995-01-01

A container for low level waste includes a shell and a lid. The lid has a frame to which a planar member is welded. The lid frame includes a rectangular outer portion made of square metal tubing, a longitudinal beam extending between axial ends of the rectangular outer portion, and a transverse beam extending between opposite lateral sides of the rectangular outer portion. Two pairs of diagonal braces extend between the longitudinal beam and the four corners of the rectangular outer portion of the frame.

High-pressure metallization of FeO and implications for the earth's core

NASA Technical Reports Server (NTRS)

Knittle, Elise; Jeanloz, Raymond

1986-01-01

The phase diagram of FeO has been experimentally determined to pressures of 155 GPa and temperatures of 4000 K using shock-wave and diamond-cell techniques. A metallic phase of FeO is observed at pressures greater than 70 GPa and temperatures exceeding 1000 K. The metallization of FeO at high pressures implies that oxygen can be present as the light alloying element of the earth's outer core, in accord with the geochemical predictions of Ringwood (1977 and 1979). The high pressures necessary for this metallization suggest that the core has acquired its composition well after the initial stages of the earth's accretion. Direct experimental observations at elevated pressures and temperatures indicate that core-forming alloy can react chemically with oxides such as those forming the mantle. The core and mantle may never have reached complete chemical equilibrium, however. If this is the case, the core-mantle boundary is likely to be a zone of active chemical reactions.

Finite-Difference Solutions of the Alternate Turbopump Development High-Pressure Oxidizer Turbopump Pump-End Ball-Bearing Cavity Flows

NASA Technical Reports Server (NTRS)

Benjamin, Theodore G.; Garcia, Roberto; Mcconnaughey, Paul K.; Wang, Ten-See; Vu, Bruce T.; Dakhoul, Youssef

1993-01-01

These analyses were undertaken to aid in the understanding of flow phenomena in the Alternate Turbopump Development (ATD) High-pressure Oxidizer Turbopump (HPOTP) Pump-end ball bearing (PEBB) cavities and their roles in turbopump vibration initiation and bearing distress. This effort was being performed to provide timely support to the program in a decision as to whether or not the program should be continued. In the first case, it was determined that a change in bearing through flow had no significant effect on axial preload. This was a follow-on to a previous study which had resulted in a redesign of the bearing exit cavity which virtually eliminated bearing axial loading. In the second case, a three-dimensional analysis of the inner-race-guided cage configuration was performed so as to determine the pressure distribution on the outer race when the shaft is 0.0002 inches off-center. The results indicate that there is virtually no circumferential pressure difference caused by the offset to contribute to bearing tilt. In the third case, axisymmetric analyses were performed on an outer-race guided cage configuration to determine the magnitude of tangential flow entering the bearing. The removed-shoulder case was analyzed as was the static diverter case. A third analysis where the preload spring was shielded by a sheet of metal for the baseline case was also performed. It was determined that the swirl entering the bearing was acceptable and the project decided to use the outer-race-guided cage configuration. In the fourth case, more bearing configurations were analyzed. These analyses included thermal modeling so as to determine the added benefit of injecting colder fluid directly onto the bearing inner-race contact area. The results of these analyses contributed to a programmatic decision to include coolant injection in the design.

Experiments pertaining to the formation and equilibration of planetary cores

NASA Technical Reports Server (NTRS)

Jeanloz, Raymond; Knittle, Elise; Williams, Quentin

1987-01-01

The phase diagram of FeO was experimentally determined to pressures of 155 GPa and temperatures of 4000 K using shock wave and diamond-cell techniques. Researchers discovered a metallic phase of FeO at pressures greater than 70 GPa and temperatures exceeding 1000 K. The metallization of FeO at high pressures implies that oxygen can be present as the light alloying element of the Earth's outer core, in accord with the geochemical predictions of Ringwood. The high pressures necessry for this metallization suggest that the core has acquired its composition well after the initial stages of the Earth's accretion. The core forming alloy can react chemically with oxides such as those forming the mantle. The core and mantle may never have reached complete chemical equilibrium, however. If this is the case, the core-mantle boundary is likely to be a zone of active chemical reactions.

Universal fuel basket for use with an improved oxide reduction vessel and electrorefiner vessel

DOEpatents

Herrmann, Steven D.; Mariani, Robert D.

2002-01-01

A basket, for use in the reduction of UO.sub.2 to uranium metal and in the electrorefining of uranium metal, having a continuous annulus between inner and outer perforated cylindrical walls, with a screen adjacent to each wall. A substantially solid bottom and top plate enclose the continuous annulus defining a fuel bed. A plurality of scrapers are mounted adjacent to the outer wall extending longitudinally thereof, and there is a mechanism enabling the basket to be transported remotely.

NUCLEAR REACTOR

DOEpatents

Young, G.

1963-01-01

This patent covers a power-producing nuclear reactor in which fuel rods of slightly enriched U are moderated by heavy water and cooled by liquid metal. The fuel rods arranged parallel to one another in a circle are contained in a large outer closed-end conduit that extends into a tank containing the heavy water. Liquid metal is introduced into the large conduit by a small inner conduit that extends within the circle of fuel rods to a point near the lower closed end of the outer conduit. (AEC) Production Reactors

Fabrication of Spherical Reflectors in Outer Space

NASA Technical Reports Server (NTRS)

Wang, Yu; Dooley, Jennifer; Dragovan, Mark; Serivens, Wally

2005-01-01

A process is proposed for fabrication of lightweight spherical reflectors in outer space for telescopes, radio antennas, and light collectors that would be operated there. The process would obviate the relatively massive substrates and frames needed to support such reflectors in normal Earth gravitation. According to the proposal, fabrication of a reflector would begin with blowing of a bubble to the specified reflector radius. Taking advantage of the outer-space vacuum as a suitable environment for evaporative deposition of metal, a metal-evaporation source would be turned on and moved around the bubble to deposit a reflective metal film over the specified reflector area to a thickness of several microns. Then the source would be moved and aimed to deposit more metal around the edge of the reflector area, increasing the thickness there to approximately equal to 100 micron to form a frame. Then the bubble would be deflated and peeled off the metal, leaving a thin-film spherical mirror having an integral frame. The mirror would then be mounted for use. The feasibility of this technology has been proved by fabricating a prototype at JPL. As shown in the figure, a 2-in. (.5-cm) diameter hemispherical prototype reflector was made from a polymer bubble coated with silver, forming a very smooth surface.

The Potential and Equipotentiality of Spacecraft

NASA Astrophysics Data System (ADS)

Afonin, V. V.

2004-01-01

The problem of maintenance of the equipotentiality of spacecraft surfaces is considered. The method under examination is the use of the ``conductive thermal-vacuum multilayer blanket'' (CMLB), whose outer surface represents a fabric woven of threads of glass fiber type with interwoven metal threads. The process of spacecraft potential formation and methods of the potential calculation are described, and the results of such a calculation for the illuminated and shadowed parts of spacecraft surfaces in some characteristic near-Earth plasma environments are presented. The CMLB model is described, and the potential distribution near the CMLB surface is calculated. The conclusion was drawn that the conductive thermal-vacuum multilayer blanket used in some cases on Russian spacecraft does not ensure the equipotentiality of spacecraft surfaces, and in the case of using CMLB, the differential spacecraft charging in outer regions of the Earth's magnetosphere may reach a dangerous level for onboard electronic systems. In spite of the fact that CMLB guards against large-scale powerful discharges, one cannot exclude discharges completely, what may result in broadband noise enhancement and cause onboard systems failures.

A novel metal flow imaging using electrical capacitance tomography

NASA Astrophysics Data System (ADS)

Wondrak, Thomas; Soleimani, Manuchehr

2017-06-01

The measurement of gas-liquid metal two phase flow is a challenging task due to the opaqueness and the high temperatures. For instance, during continuous casting of steel the distribution of argon gas and liquid steel in the submerged entry nozzle is of high interest, since it influences the quality of the produced steel. In this paper we present the results of a feasibility study for applying the electrical capacitance tomography (ECT) to detect the outer surface of a liquid metal stream. The results of this study are the basis for the development of a new contactless sensor which should be able to detect the outer shape of a liquid metal jet using ECT and the bubbles inside the jet at the same time with mutual inductance tomography.

Mass Producing Targets for Nuclear Fusion

NASA Technical Reports Server (NTRS)

Wang, T. G.; Elleman, D. D.; Kendall, J. M.

1983-01-01

Metal-encapsulating technique advances prospects of controlling nuclear fusion. Prefilled fusion targets form at nozzle as molten metal such as tin flows through outer channel and pressurized deuterium/tritium gas flows through inner channel. Molten metal completely encloses gas charge as it drops off nozzle.

A design study of hydrazine and biowaste resistojets

NASA Technical Reports Server (NTRS)

Page, R. J.; Stoner, W. A.; Barker, L.

1986-01-01

A generalized modeling program was adapted in BASIC on a personal computer to compare the performance of four types of biowaste resistojets and two types of hydrazine augmenters. Analyzed biowaste design types were: (1) an electrically conductive ceramic heater-exchanger of zirconia; (2) a truss heater of platinum in cross flow; (3) an immersed bicoiled tubular heater-exchanger; and (4) a nonexposed, refractory metal, radiant heater in a central cavity within a heat exchanger case. Concepts 2 and 3 are designed to have an efficient, stainless steel outer pressure case. The hydrazine design types are: (5) an immersed bicoil heater exchanger and (6) a nonexposed radiant heater now with a refractory metal case. The ceramic biowaste resistojet has the highest specific impulse growth potential at 2000 K of 192.5 (CO2) and 269 s (H2O). The bicoil produces the highest augmenter temperature of 1994 K for a 2073 K heater giving 317 s at .73 overall efficiency. Detailed temperature profiles of each of the designs are shown. The scaled layout drawings of each are presented with recommended materials and fabrication methods.

Europa's differentiated internal structure: inferences from four Galileo encounters.

PubMed

Anderson, J D; Schubert, G; Jacobson, R A; Lau, E L; Moore, W B; Sjogren, W L

1998-09-25

Radio Doppler data from four encounters of the Galileo spacecraft with the jovian moon Europa have been used to refine models of Europa's interior. Europa is most likely differentiated into a metallic core surrounded by a rock mantle and a water ice-liquid outer shell, but the data cannot eliminate the possibility of a uniform mixture of dense silicate and metal beneath the water ice-liquid shell. The size of a metallic core is uncertain because of its unknown composition, but it could be as large as about 50 percent of Europa's radius. The thickness of Europa's outer shell of water ice-liquid must lie in the range of about 80 to 170 kilometers.

The mechanism of enantioselective ketone reduction with Noyori and Noyori–Ikariya bifunctional catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dub, Pavel A.; Gordon, John C.

2016-03-21

The catalytic hydrogenation of prochiral ketones with second and third-row transition metal complexes bearing chelating chiral ligands containing at least one N–H functionality has achieved unparalleled performance, delivering, in the best cases, chiral alcohols with up to 99.9% ee using extremely small catalyst loadings (~10 -5 mol%). Hence the efficacy of this reaction has closely approached that of natural enzymatic systems and the reaction itself has become one of the most efficient artificial catalytic reactions developed to date. This paper describes the current level of understanding of the mechanism of enantioselective hydrogenation and transfer hydrogenation of aromatic ketones with pioneeringmore » prototypes of bifunctional catalysts, the Noyori and Noyori–Ikariya complexes. Finally, analysis presented herein expands the concept of “metal–ligand cooperation”, redefines the term “cooperative ligand” and introduces “H –/H + outer-sphere hydrogenation” as a novel paradigm in outer-sphere hydrogenation.« less

Integrated Light Chemical Abundance Analyses of 7 M31 Outer Halo Globular Clusters from the Pan-Andromeda Archaeological Survey

NASA Astrophysics Data System (ADS)

Sakari, Charli; Venn, Kim; Mackey, Dougal; Shetrone, Matthew D.; Dotter, Aaron L.; Wallerstein, George

2015-01-01

Detailed chemical abundances of globular clusters provide insight into the formation and evolution of galaxies and their globular cluster systems. This talk presents detailed chemical abundances for seven M31 outer halo globular clusters (with projected radii greater than 30 kpc), as derived from high resolution integrated light spectra. Five of these clusters were recently discovered in the Pan-Andromeda Archaeological Survey (PAndAS). The integrated abundances show that 4 of these clusters are metal-poor ([Fe/H] < -1.5) while the other 3 are more metal-rich. The most metal-poor globular clusters are α-enhanced, though 3 of the 4 are possibly less α-enhanced than MW stars (at the 1σ level). Other chemical abundance ratios ([Ba/Eu], [Eu/Ca], and [Ni/Fe]) are consistent with origins in low mass dwarf galaxies (similar to Fornax). The most metal-rich cluster ([Fe/H] ~ -1) stands out as being chemically distinct from Milky Way field stars of the same metallicity---its chemical abundance ratios agree best with the stars and clusters in the Large Magellanic Cloud (LMC) and the Sagittarius dwarf spheroidal (Sgr) than with the Milky Way field stars. The other metal-rich clusters, H10 and H23, look similar to the LMC and Milky Way field stars in all abundance ratios. These results indicate that M31's outer halo is being at least partially built up by the accretion of dwarf satellites, in agreement with previous observations.

Reoxidation of estuarine sediments during simulated resuspension events: Effects on nutrient and trace metal mobilisation

NASA Astrophysics Data System (ADS)

Vidal-Durà, Andrea; Burke, Ian T.; Stewart, Douglas I.; Mortimer, Robert J. G.

2018-07-01

Estuarine environments are considered to be nutrient buffer systems as they regulate the delivery of nutrients from rivers to the ocean. In the Humber Estuary (UK) seawater and freshwater mixing during tidal cycles leads to the mobilisation of oxic surface sediments (0-1 cm). However, less frequent seasonal events can also mobilise anoxic subsurface (5-10 cm) sediments, which may have further implications for the estuarine geochemistry. A series of batch experiments were carried out on surface and subsurface sediments taken from along the salinity gradient of the Humber Estuary. The aim was to investigate the geochemical processes driving major element (N, Fe, S, and Mn) redox cycling and trace metal behaviour during simulated resuspension events. The magnitude of major nutrient and metal release was significantly greater during the resuspension of outer estuarine sediments rather than from inner estuarine sediments. When comparing resuspension of surface versus subsurface sediment, only the outer estuary experiments showed significant differences in major nutrient behaviour with sediment depth. In general, any ammonium, manganese and trace metals (Cu and Zn) released during the resuspension experiments were rapidly removed from solution as new sorption sites (i.e. Fe/Mn oxyhydroxides) formed. Therefore Humber estuary sediments showed a scavenging capacity for these dissolved species and hence may act as an ultimate sink for these elements. Due to the larger aerial extent of the outer estuary intertidal mudflats in comparison with the inner estuary area, the mobilisation of the outer estuary sediments (more reducing and richer in sulphides and iron) may have a greater impact on the transport and cycling of nutrients and trace metals. Climate change-associated sea level rise combined with an increasing frequency of major storm events in temperate zones, which are more likely to mobilise deeper sediment regions, will impact the nutrient and metal inputs to the coastal waters, and therefore enhance the likelihood of eutrophication in this environment.

Study of the welding gas influence on a controlled short-arc GMAW process by optical emission spectroscopy

NASA Astrophysics Data System (ADS)

Wilhelm, G.; Gött, G.; Schöpp, H.; Uhrlandt, D.

2010-11-01

The controlled short-arc processes, variants of the gas metal arc welding (GMAW) process, which have recently been developed, are used to reduce the heat input into the workpiece. Such a process with a wire feeding speed which varies periodically, using a steel wire and a steel workpiece to produce bead-on-plate welds has been investigated. As welding gases CO2 and a mixture of Ar and O2 have been used. Depending on the gas, the properties of the plasma change, and as a consequence the weldseams themselves also differ distinctly. Optical emission spectroscopy has been applied to analyse the plasma. The radial profiles of the emission coefficients of an iron line and an argon line or an atomic oxygen line, respectively, have been determined. These profiles indicate the establishment of a metal vapour arc core which has a broader profile under CO2 but is more focused in the centre for argon. The measured iron line emission was near to its norm maximum in the case of CO2. From this fact, temperatures around 8000 K and a metal vapour molar fraction above 75% in the arc centre could be roughly estimated for this case. Estimations of the electrical conductivity and the arc field indicate that the current path must include not only the metal vapour arc core but also outer hot regions dominated by welding gas properties in the case of argon.

Solvent extraction: the coordination chemistry behind extractive metallurgy.

PubMed

Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B

2014-01-07

The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents.

Outer-Sphere Direction in Iridium C-H Borylation

PubMed Central

Roosen, Philipp C.; Kallepalli, Venkata A.; Chattopadhyay, Buddhadeb; Singleton, Daniel A.; Maleczka, Robert E.; Smith, Milton R.

2013-01-01

The NHBoc group affords ortho selective C–H borylations in arenes and alkenes. Experimental and computational studies support an outer sphere mechanism where the N–H proton hydrogen bonds to a boryl ligand oxygen. The regioselectivities are unique and complement those of directed ortho metalations. PMID:22703452

Static current-voltage characteristics for radio-frequency induction discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budyansky, A.; Zykov, A.

1995-12-31

The aim of this work was to obtain experimentally such characteristic of Radio-Frequency Induction Discharge (RFID) that can play the role of its current-voltage characteristic (CVC) and to explain the nature of current and voltage jumps arising in RF coils at exciting of discharge. Experiments were made in quartz 5.5, 11, 20 cm diam tubes with outer RF coil at pressures 10--100 mTorr, at frequency 13.56 MHz and discharge power to 500 W. In case of outer coil as analogue of discharge voltage it`s convenient to use the value of the RF voltage U{sub R}, induced around outer perimeter ofmore » discharge tube. It is evident that current and voltage jumps arising at exciting of discharge are due to low output resistance of standard generators and negative slope of initial part of CVC. Three sets of such dependencies for different pressures were obtained for each diameter of tubes. The influence of different metal electrodes placed into discharge volume on CVC`s shape has been studied also. Experimental results can explain the behavior of HFI discharge as a load of RF generator and give data for calculation of RF circuit.« less

Theory of nanotube faraday cage

NASA Astrophysics Data System (ADS)

Roxana Margine, Elena; Nisoli, Cristiano; Kolmogorov, Aleksey; Crespi, Vincent H.

2003-03-01

Charge transfer between dopants and double-wall carbon nanotubes is examined theoretically. We model the system as a triple cylindrical capacitor with the dopants forming a shell around the outer wall of the nanotube. The total energy of the system contains three terms: the band structure energies of the inner and outer tube, calculated in a tight-binding model with rigid bands, and the electrostatic energy of the tri-layer distribution. Even for metallic inner and outer tube walls, wherein the diameter dependence of the bandgap does not favor the outer wall, nearly all of the dopant charge resides on the outer layer, a nanometer-scale Faraday cage. The calculated charge distribution is in agreement with recent experimental measurements.

Prospective of employing high porosity open-cell metal foams in passive cryogenic radiators for space applications

NASA Astrophysics Data System (ADS)

Tisha, Dixit; Indranil, Ghosh

2017-02-01

Passive cryogenic radiators work on the principle of dissipating heat to the outer space purely by radiation. High porosity open-cell metal foams are a relatively new class of extended surfaces. These possess the advantages of high surface area density and low weight, characteristics which the space industry looks for. In case of radiative heat transfer, the porous nature of metal foams permits a deeper penetration of the incident radiation. Consequently, the heat transfer area participating in radiative heat exchange increases thereby enhancing the heat transfer rate. However, effective heat conduction in between the foam struts reduces as a result of the void spaces. These two conflicting phenomenon for radiation heat transfer in metal foams have been studied in this work. Similar to the foam conduction-convection heat transfer analysis, a conduction-radiation heat transfer model has been developed for metal foams in analogy with the conventional solid fin theory. Metal foams have been theoretically represented as simple cubic structures. A comparison of the radiative heat transfer through metal foams and solid fins attached to a surface having constant temperature has been presented. Effect of changes in foam characteristic properties such as porosity and pore density have also been studied.

Fuel cell assembly fluid flow plate having conductive fibers and rigidizing material therein

DOEpatents

Walsh, Michael M.

2000-01-01

A fluid flow plate is preferably formed with three initial sections, for instance, two layers of conductive (e.g., metal) fibers and a barrier material (e.g., metal foil) which is interposed between the two layers. For example, sintering of these three sections can provide electrical path(s) between outer faces of the two layers. Then, the sintered sections can be, for instance, placed in a mold for forming of flow channel(s) into one or more of the outer faces. Next, rigidizing material (e.g., resin) can be injected into the mold, for example, to fill and/or seal space(s) about a conductive matrix of the electrical path(s). Preferably, abrading of surface(s) of the outer face(s) serves to expose electrical contact(s) to the electrical path(s).

Trends in Ionization Energy of Transition-Metal Elements

ERIC Educational Resources Information Center

Matsumoto, Paul S.

2005-01-01

A rationale for the difference in the periodic trends in the ionization energy of the transition-metal elements versus the main-group elements is presented. The difference is that in the transition-metal elements, the electrons enter an inner-shell electron orbital, while in the main-group elements, the electrons enter an outer-shell electron…

Kinetic Assessment of Golf Shoe Outer Sole Design Features

PubMed Central

Smith, Neal A.; Dyson, Rosemary J.

2009-01-01

This study assessed human kinetics in relation to golf shoe outer sole design features during the golf swing using a driver club by measuring both within the shoe, and beneath the shoe at the natural grass interface. Three different shoes were assessed: metal 7- spike shoe, alternative 7-spike shoe, and a flat soled shoe. In-shoe plantar pressure data were recorded using Footscan RS International pressure insoles and sampling at 500 Hz. Simultaneously ground reaction force at the shoe outer sole was measured using 2 natural grass covered Kistler force platforms and 1000 Hz data acquisition. Video recording of the 18 right-handed golfers at 200 Hz was undertaken while the golfer performed 5 golf shots with his own driver in each type of shoe. Front foot (nearest to shot direction) maximum vertical force and torque were greater than at the back foot, and there was no significant difference related to the shoe type. Wearing the metal spike shoe when using a driver was associated with more torque generation at the back foot (p < 0. 05) than when the flat soled shoe was worn. Within shoe regional pressures differed significantly with golf shoe outer sole design features (p < 0.05). Comparison of the metal spike and alternative spike shoe results provided indications of the quality of regional traction on the outer sole. Potential golf shoe outer sole design features and traction were presented in relation to phases of the golf swing movement. Application of two kinetic measurement methods identified that moderated (adapted) muscular control of foot and body movement may be induced by golf shoe outer sole design features. Ground reaction force measures inform comparisons of overall shoe functional performance, and insole pressure measurements inform comparisons of the underfoot conditions induced by specific regions of the golf shoe outer sole. Key points Assessments of within golf shoe pressures and beneath shoe forces at the natural grass interface were conducted during golf shots with a driver. Application of two kinetic measurement methods simultaneously identified that moderated (adapted) muscular control of the foot and body movement may be induced by golf shoe outer sole localised design features. Ground force measures inform overall shoe kinetic functional performance. Insole pressure measurement informs of underfoot conditions induced by localised specific regions of the golf outer sole. Significant differences in ground-shoe torque generation and insole regional pressures were identified when different golf shoes were worn. PMID:24149603

Personal exposure to pesticide among workers engaged in pesticide container recycling operations.

PubMed

Guidotti, T L; Yoshida, K; Clough, V

1994-12-01

Pesticide container handling operations in western Canada were examined to determine the exposure of workers to residual pesticide in sorting, metal-container crushing, metal-container shredding, plastic-container shredding, metal washing, and metal melting. Environmental exposure monitoring and biological monitoring were applied, including measurement of pesticide deposition density on outer clothing (test coveralls and other protective wear), deposition on fabric and gauze patches under the outer clothing, inhalation of airborne pesticide residues, dislodgement of pesticide residues by hand washing, and pre- and postexposure urinary excretion of pesticide (2,4-D). Exposure levels were highly variable; some variability was accounted for by work practices or lapses in protection. The highest levels of exposure were observed for metal washing, metal crushing, and metal shredding; sorting and plastic shredding were intermediate, and metal melting was associated with very little exposure. Urinary 2,4-D excretion, as an indicator of internal dose, correlated most closely with exposure by the inhalation route, and both were highest for metal washing and shredding. Deposition of pesticide on garments was highest for metal crushing. Melting of washed metal does not appear to present a significant hazard of exposure. Recommendations are proposed for the protection of workers emphasizing health and safety guidelines, worker education, personal hygiene, exposure and health monitoring, and record-keeping, and specific recommendations for each process. These recommendations apply to all pesticide container recycling operations except melting of washed metal containers.

Mechanism of Cd2+-coordination during Slow Inactivation in Potassium Channels

PubMed Central

Raghuraman, H.; Cordero-Morales, Julio F.; Jogini, Vishwanath; Pan, Albert C.; Kollewe, Astrid; Roux, Benoît; Perozo, Eduardo

2013-01-01

Summary In K+ channels, rearrangements of the pore outer-vestibule have been associated with C-type inactivation gating. Paradoxically, the crystal structure of Open/C-type inactivated KcsA suggest these movements to be modest in magnitude. Here, we show that under physiological conditions, the KcsA outer-vestibule undergoes relatively large dynamic rearrangements upon inactivation. External Cd2+ enhances the rate of C-type inactivation in an outer-vestibule cysteine mutant (Y82C) via metal-bridge formation. This effect is not present in a non-inactivating mutant (E71A/Y82C). Tandem dimer and tandem tetramer constructs of equivalent cysteine mutants in KcsA and Shaker K+ channels demonstrate that these Cd2+ metal bridges are formed only between adjacent subunits. This is well supported by molecular dynamics simulations. Based on the crystal structure of Cd2+-bound Y82C-KcsA in the closed state, together with EPR distance measurements in the KcsA outer-vestibule, we suggest that subunits must dynamically come in close proximity as the channels undergo inactivation. PMID:22771214

Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemke, R. W., E-mail: rwlemke@sandia.gov; Dolan, D. H.; Dalton, D. G.

We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as itmore » implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ∼1000 GPa is achieved in all cases. These experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.« less

Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemke, R. W.; Dolan, D. H.; Dalton, D. G.

We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as itmore » implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ~1000 GPa is achieved in all cases. Lastly, these experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.« less

Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

DOE PAGES

Lemke, R. W.; Dolan, D. H.; Dalton, D. G.; ...

2016-01-07

We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as itmore » implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ~1000 GPa is achieved in all cases. Lastly, these experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.« less

Capacitors Would Help Protect Against Hypervelocity Impacts

NASA Technical Reports Server (NTRS)

Edwards, David; Hubbs, Whitney; Hovater, Mary

2007-01-01

A proposal investigates alternatives to the present bumper method of protecting spacecraft against impacts of meteoroids and orbital debris. The proposed method is based on a British high-voltage-capacitance technique for protecting armored vehicles against shaped-charge warheads. A shield, according to the proposal, would include a bare metal outer layer separated by a gap from an inner metal layer covered with an electrically insulating material. The metal layers would constitute electrodes of a capacitor. A bias potential would be applied between the metal layers. A particle impinging at hypervelocity on the outer metal layer would break apart into a debris cloud that would penetrate the electrical insulation on the inner metal layer. The cloud would form a path along which electric current could flow between the metal layers, thereby causing the capacitor to discharge. With proper design, the discharge current would be large enough to vaporize the particles in the debris cloud to prevent penetration of the spacecraft. The shield design can be mass optimized to be competitive with existing bumper designs. Parametric studies were proposed to determine optimum correction between bias voltage, impacting particle velocity, gap space, and insulating material required to prevent spacecraft penetration.

Cooling of Gas Turbines I - Effects of Addition of Fins to Blade Tips and Rotor, Admission of Cooling Air Through Part of Nozzles, and Change in Thermal Conductivity of Turbine Components

NASA Technical Reports Server (NTRS)

Brown, Byron

1947-01-01

An analysis was developed for calculating the radial temperature distribution in a gas turbine with only the temperatures of the gas and the cooling air and the surface heat-transfer coefficient known. This analysis was applied to determine the temperatures of a complete wheel of a conventional single-stage impulse exhaust-gas turbine. The temperatures were first calculated for the case of the turbine operating at design conditions of speed, gas flow, etc. and with only the customary cooling arising from exposure of the outer blade flange and one face of the rotor to the air. Calculations were next made for the case of fins applied to the outer blade flange and the rotor. Finally the effects of using part of the nozzles (from 0 to 40 percent) for supplying cooling air and the effects of varying the metal thermal conductivity from 12 to 260 Btu per hour per foot per degree Farenheit on the wheel temperatures were determined. The gas temperatures at the nozzle box used in the calculations ranged from 1600F to 2000F. The results showed that if more than a few hundred degrees of cooling of turbine blades are required other means than indirect cooling with fins on the rotor and outer blade flange would be necessary. The amount of cooling indicated for the type of finning used could produce some improvement in efficiency and a large increase in durability of the wheel. The results also showed that if a large difference is to exist between the effective temperature of the exhaust gas and that of the blade material, as must be the case with present turbine materials and the high exhaust-gas temperatures desired (2000F and above), two alternatives are suggested: (a) If metal with a thermal conductivity comparable with copper is used, then the blade temperature can be reduced by strong cooling at both the blade tip and root. The center of the blade will be less than 2000F hotter than the ends; (b) With low conductivity materials some method of direct cooling other than partial admission of cooling air is essential. From this study, it can be deduced that indirect cooling of turbine blades will not make possible large increases in gas temperature.

Tunable multiwalled nanotube resonator

DOEpatents

Jensen, Kenneth J; Girit, Caglar O; Mickelson, William E; Zettl, Alexander K; Grossman, Jeffrey C

2013-11-05

A tunable nanoscale resonator has potential applications in precise mass, force, position, and frequency measurement. One embodiment of this device consists of a specially prepared multiwalled carbon nanotube (MWNT) suspended between a metal electrode and a mobile, piezoelectrically controlled contact. By harnessing a unique telescoping ability of MWNTs, one may controllably slide an inner nanotube core from its outer nanotube casing, effectively changing its length and thereby changing the tuning of its resonance frequency. Resonant energy transfer may be used with a nanoresonator to detect molecules at a specific target oscillation frequency, without the use of a chemical label, to provide label-free chemical species detection.

Tunable multiwalled nanotube resonator

DOEpatents

Zettl, Alex K [Kensington, CA; Jensen, Kenneth J [Berkeley, CA; Girit, Caglar [Albany, CA; Mickelson, William E [San Francisco, CA; Grossman, Jeffrey C [Berkeley, CA

2011-03-29

A tunable nanoscale resonator has potential applications in precise mass, force, position, and frequency measurement. One embodiment of this device consists of a specially prepared multiwalled carbon nanotube (MWNT) suspended between a metal electrode and a mobile, piezoelectrically controlled contact. By harnessing a unique telescoping ability of MWNTs, one may controllably slide an inner nanotube core from its outer nanotube casing, effectively changing its length and thereby changing the tuning of its resonance frequency. Resonant energy transfer may be used with a nanoresonator to detect molecules at a specific target oscillation frequency, without the use of a chemical label, to provide label-free chemical species detection.

Quantitative diagnostics of multilayered composite structures with ultrasonic guided waves

NASA Astrophysics Data System (ADS)

Bunget, Gheorghe; Friedersdorf, Fritz; Na, Jeong K.

2015-03-01

The main objective of the current work is to develop a practical nondestructive inspection methodology for a highly sound absorbing composite structural system consisting of polymeric and metallic materials. Due to constraints in geometrical shapes and thicknesses of the composite system used in this work, ultrasonic guided wave approach has been chosen. Since the polymer coatings have high damping properties, less energy is dissipated into the adjacent media in the presence of interface delaminations. Experimental measurements performed on a targeted composite system, whether it has an aluminum, carbon-fiber-composite, or steel outer casing, show promising results.

Research on wire rope stress distribution of WR-CVT

NASA Astrophysics Data System (ADS)

Zhang, Wu; Guo, Wei; Zhang, Chuanwei; Lu, Zhengxiong; Xu, Xiaobin

2017-10-01

A wire rope continuously variable transmissions (WR-CVT) has been introduced in the paper, in view of its less research, this paper mainly studied the stress distribution of 6×7+IWS bending wire rope. The results shown that the wire stress is layered distribution in each section, the stress at the outer strand center wire and outer strand side wire was the greatest, the stress value of the outer strand side wire and metal block circular notch is second. As the transmission ratio decreases, the wire stress decreases, which is related to the pulley working radius increases. Compared with the section A1, the stress value on the section A2 is smaller, mainly because the section A2 is not in contact with the metal block or the contact pressure is small. This study provides a basis for the study of fatigue and wears failure of WR-CVT components.

Inner and Outer Coordination Shells of Mg(2+) in CorA Selectivity Filter from Molecular Dynamics Simulations.

PubMed

Kitjaruwankul, Sunan; Wapeesittipan, Pattama; Boonamnaj, Panisak; Sompornpisut, Pornthep

2016-01-28

Structural data of CorA Mg(2+) channels show that the five Gly-Met-Asn (GMN) motifs at the periplasmic loop of the pentamer structure form a molecular scaffold serving as a selectivity filter. Unfortunately, knowledge about the cation selectivity of Mg(2+) channels remains limited. Since Mg(2+) in aqueous solution has a strong first hydration shell and apparent second hydration sphere, the coordination structure of Mg(2+) in a CorA selectivity filter is expected to be different from that in bulk water. Hence, this study investigated the hydration structure and ligand coordination of Mg(2+) in a selectivity filter of CorA using molecular dynamics (MD) simulations. The simulations reveal that the inner-shell structure of Mg(2+) in the filter is not significantly different from that in aqueous solution. The major difference is the characteristic structural features of the outer shell. The GMN residues engage indirectly in the interactions with the metal ion as ligands in the second shell of Mg(2+). Loss of hydrogen bonds between inner- and outer-shell waters observed from Mg(2+) in bulk water is mostly compensated by interactions between waters in the first solvation shell and the GMN motif. Some water molecules in the second shell remain in the selectivity filter and become less mobile to support the metal binding. Removal of Mg(2+) from the divalent cation sensor sites of the protein had an impact on the structure and metal binding of the filter. From the results, it can be concluded that the GMN motif enhances the affinity of the metal binding site in the CorA selectivity filter by acting as an outer coordination ligand.

Star Surface Polluted by Planetary Debris

NASA Astrophysics Data System (ADS)

2007-07-01

Looking at the chemical composition of stars that host planets, astronomers have found that while dwarf stars often show iron enrichment on their surface, giant stars do not. The astronomers think that the planetary debris falling onto the outer layer of the star produces a detectable effect in a dwarf star, but this pollution is diluted by the giant star and mixed into its interior. "It is a little bit like a Tiramisu or a Capuccino," says Luca Pasquini from ESO, lead-author of the paper reporting the results. "There is cocoa powder only on the top!' ESO PR Photo 29/07 ESO PR Photo 29/07 The Structure of Stars Just a few years after the discovery of the first exoplanet it became evident that planets are preferentially found around stars that are enriched in iron. Planet-hosting stars are on average almost twice as rich in metals than their counterparts with no planetary system. The immediate question is whether this richness in metals enhances planet formation, or whether it is caused by the presence of planets. The classic chicken and egg problem. In the first case, the stars would be metal-rich down to their centre. In the second case, debris from the planetary system would have polluted the star and only the external layers would be affected by this pollution. When observing stars and taking spectra, astronomers indeed only see the outer layers and can't make sure the whole star has the same composition. When planetary debris fall onto a star, the material will stay in the outer parts, polluting it and leaving traces in the spectra taken. A team of astronomers has decided to tackle this question by looking at a different kind of stars: red giants. These are stars that, as will the Sun in several billion years, have exhausted the hydrogen in their core. As a result, they have puffed up, becoming much larger and cooler. Looking at the distribution of metals in fourteen planet-hosting giants, the astronomers found that their distribution was rather different from normal planet-hosting stars. "We find that evolved stars are not enriched in metals, even when hosting planets," says Pasquini. "Thus, the anomalies found in planet-hosting stars seem to disappear when they get older and puff up!" Looking at the various options, the astronomers conclude that the most likely explanation lies in the difference in the structure between red giants and solar-like stars: the size of the convective zone, the region where all the gas is completely mixed. In the Sun, this convective zone comprises only 2% of the star's mass. But in red giants, the convective zone is huge, encompassing 35 times more mass. The polluting material would thus be 35 times more diluted in a red giant than in a solar-like star. "Although the interpretation of the data is not straightforward, the simplest explanation is that solar-like stars appear metal-rich because of the pollution of their atmospheres," says co-author Artie Hatzes, Director of the Thüringer Landessternwarte Tautenburg (Germany) where some of the data were obtained. When the star was still surrounded by a proto-planetary disc, material enriched in more heavy elements would fall onto the star, thereby polluting its surface. The metal excess produced by this pollution, while visible in the thin atmospheres of solar-like stars, is completely diluted in the extended, massive atmospheres of the giants.

Positive contact, self retaining bearing seals

DOEpatents

Johnson, Bruce H.; Larsen, Lawrence E.; Welch, Edmund F.

1992-05-05

An ultra-low friction bearing including an inner race, an outer race, bearing elements engaged between the inner and outer races and a seal between the inner and outer races is disclosed. The seal includes first and second sealing washers. The first washer has an outer diameter greater than an inner diameter of the outer race and an inner diameter greater than the outer diameter of the inner race. The second washer has an inner diameter less than the outer diameter of the inner race and an outer diameter less than the inner diameter of the outer race. The first washer slidably engages the outer race, the second washer slidably engages the inner race and the washers overlap and slidably engage one another. One of the washers snap fits into its respective inner or outer race while the other washer engages a stepped surface of the other of the inner and outer races. The grooved and stepped surface are offset from one another in a longitudinal direction of the races such that the washers are conically loaded thus providing a seal between the inner and outer races sufficient to prevent lubricant and contaminating particles from passing therethrough. The washers are made from a non-metallic semi-flexible low-modulus material.

Composition Formulas of Inorganic Compounds in Terms of Cluster Plus Glue Atom Model.

PubMed

Ma, Yanping; Dong, Dandan; Wu, Aimin; Dong, Chuang

2018-01-16

The present paper attempts to identify the molecule-like structural units in inorganic compounds, by applying the so-called "cluster plus glue atom model". This model, originating from metallic glasses and quasi-crystals, describes any structure in terms of a nearest-neighbor cluster and a few outer-shell glue atoms, expressed in the cluster formula [cluster](glue atoms). Similar to the case for normal molecules where the charge transfer occurs within the molecule to meet the commonly known octet electron rule, the octet state is reached after matching the nearest-neighbor cluster with certain outer-shell glue atoms. These kinds of structural units contain information on local atomic configuration, chemical composition, and electron numbers, just as for normal molecules. It is shown that the formulas of typical inorganic compounds, such as fluorides, oxides, and nitrides, satisfy a similar octet electron rule, with the total number of valence electrons per unit formula being multiples of eight.

Terahertz plasmon and surface-plasmon modes in hollow nanospheres

PubMed Central

2012-01-01

We present a theoretical study of the electronic subband structure and collective electronic excitation associated with plasmon and surface plasmon modes in metal-based hollow nanosphere. The dependence of the electronic subband energy on the sample parameters of the hollow nanosphere is examined. We find that the subband states with different quantum numbers l degenerate roughly when the outer radius of the sphere is r2 ≥ 100 nm. In this case, the energy spectrum of a sphere is mainly determined by quantum number n. Moreover, the plasmon and surface plasmon excitations can be achieved mainly via inter-subband transitions from occupied subbands to unoccupied subbands. We examine the dependence of the plasmon and surface-plasmon frequencies on the shell thickness d and the outer radius r2 of the sphere using the standard random-phase approximation. We find that when a four-state model is employed for calculations, four branches of the plasmon and surface plasmon oscillations with terahertz frequencies can be observed, respectively. PMID:23092121

Control of electronic properties of 2D carbides (MXenes) by manipulating their transition metal layers

DOE PAGES

Anasori, Babak; Shi, Chenyang; Moon, Eun Ju; ...

2016-02-24

In this paper, a transition from metallic to semiconducting-like behavior has been demonstrated in two-dimensional (2D) transition metal carbides by replacing titanium with molybdenum in the outer transition metal (M) layers of M 3C 2 and M 4C 3 MXenes. The MXene structure consists of n + 1 layers of near-close packed M layers with C or N occupying the octahedral site between them in an [MX] nM arrangement. Recently, two new families of ordered 2D double transition metal carbides MXenes were discovered, M' 2M"C 2 and M' 2M" 2C 3 – where M' and M" are two different earlymore » transition metals, such as Mo, Cr, Ta, Nb, V, and Ti. The M' atoms only occupy the outer layers and the M" atoms fill the middle layers. In other words, M' atomic layers sandwich the middle M"–C layers. Using X-ray atomic pair distribution function (PDF) analysis on Mo 2TiC 2 and Mo 2Ti 2C 3 MXenes, we present the first quantitative analysis of structures of these novel materials and experimentally confirm that Mo atoms are in the outer layers of the [MC] nM structures. The electronic properties of these Mo-containing MXenes are compared with their Ti 3C 2 counterparts, and are found to be no longer metallic-like conductors; instead the resistance increases mildly with decreasing temperatures. Density functional theory (DFT) calculations suggest that OH terminated Mo–Ti MXenes are semiconductors with narrow band gaps. Measurements of the temperature dependencies of conductivities and magnetoresistances have confirmed that Mo 2TiC 2T x exhibits semiconductor-like transport behavior, while Ti 3C 2T x is a metal. Finally, this finding opens new avenues for the control of the electronic and optical applications of MXenes and for exploring new applications, in which semiconducting properties are required.« less

System protection from atmospheric electricity for aerostats with conducting tethers

NASA Astrophysics Data System (ADS)

Wheeler, M. S.; Beach, G. R.; Jakubowski, P. R.; Fisher, F. A.

1988-04-01

Aerostat power tethers have demonstrated survival of lightning strikes, but they usually have to be reterminated or replaced afterward. Two requirements are given for the prevention of lightning damage to the tether to about 100 kA: installation of a metal-to-metal contact on the outer tether surface to ground the tether at the base flying sheave at typical flying positions; and installation of a shielding band within the outer tether jacket with a weight of about 0.05 lb/ft for a half-inch tether. This determination was made in part by high current tests and in part by electrical modeling.

A description on plasma background effect in growth rate of THz waves in a metallic cylindrical waveguide, including a dielectric tube and two current sources

NASA Astrophysics Data System (ADS)

Hajijamali-Arani, Z.; Jazi, B.

2018-04-01

The propagation of slow waves in a dielectric tube surrounded by a long cylindrical metallic waveguide is investigated. The dielectric tube located in a background region of plasma under two different states A and B. In the A-state the dielectric tube hollow filled with the plasma and in the B-state the outer surface of dielectric tube has been covered by the plasma layer. There are two relativistic electron beams with opposite velocities injected in the waveguide as the energy sources. Using the fluid theory for the plasmas, the Cherenkov instability in the mentioned waveguide will be analyzed. The dispersion relations of E-mode waves for the states A, B have been obtained. The time growth rate of surface waves are compared with each other for two cases A and B. The effect of plasma region on time growth rate of the waves, will be investigated. In all cases it will be shown, while an electron beam is responsible for instability, another electron beam plays a stabilizing role.

Metal tube reducer is inexpensive and simple to operate

NASA Technical Reports Server (NTRS)

Mayfield, R. M.

1967-01-01

Low-cost metal tube reducer accepts tubing up to 1 inch outer diameter and can reduce this diameter to less than 1/2 inch with controlled wall thickness. This device can reduce all of the tube without waste. It produces extremely good surface finishes.

Characterization of the Alumina Scale formed on Coated and Uncoated Doped Superalloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unocic, Kinga A; Parish, Chad M; Pint, Bruce A

2011-01-01

To investigate the mechanisms by which Y and La dopants affect the oxidation behavior of Ni base single crystal superalloys, the oxide scales formed on two variants of a commercial X4 alloy, each with and without a MCrAlYHfSi coating were characterized. The alloy systems were oxidized for 100h at 1100 C and then examined using analytical transmission electron microscopy. Without a coating, a duplex scale was formed on the superalloy surface comprised of an outer Ni rich spinel type layer and an inner columnar Al2O3 layer. In this case, Hf and Ti were found segregated to the alumina grain boundariesmore » in the outer part of the scale on both alloys but only Hf was detected near the metal alumina interface. There was no evidence of Ta, Y or La segregation to the scale grain boundaries after this exposure. The scale formed on the alloys with the thermally sprayed coating was primarily alumina, and Y and Hf segregated to the alumina grain boundaries for both alloys. There was evidence of Ti rich oxides in the outer part of the scale indicating that Ti had diffused through the coating into the thermally grown oxide but La was not found.« less

THE VELOCITY DISTRIBUTION OF NEARBY STARS FROM HIPPARCOS DATA. II. THE NATURE OF THE LOW-VELOCITY MOVING GROUPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bovy, Jo; Hogg, David W., E-mail: jo.bovy@nyu.ed

2010-07-10

The velocity distribution of nearby stars ({approx}<100 pc) contains many overdensities or 'moving groups', clumps of comoving stars, that are inconsistent with the standard assumption of an axisymmetric, time-independent, and steady-state Galaxy. We study the age and metallicity properties of the low-velocity moving groups based on the reconstruction of the local velocity distribution in Paper I of this series. We perform stringent, conservative hypothesis testing to establish for each of these moving groups whether it could conceivably consist of a coeval population of stars. We conclude that they do not: the moving groups are neither trivially associated with their eponymousmore » open clusters nor with any other inhomogeneous star formation event. Concerning a possible dynamical origin of the moving groups, we test whether any of the moving groups has a higher or lower metallicity than the background population of thin disk stars, as would generically be the case if the moving groups are associated with resonances of the bar or spiral structure. We find clear evidence that the Hyades moving group has higher than average metallicity and weak evidence that the Sirius moving group has lower than average metallicity, which could indicate that these two groups are related to the inner Lindblad resonance of the spiral structure. Further, we find weak evidence that the Hercules moving group has higher than average metallicity, as would be the case if it is associated with the bar's outer Lindblad resonance. The Pleiades moving group shows no clear metallicity anomaly, arguing against a common dynamical origin for the Hyades and Pleiades groups. Overall, however, the moving groups are barely distinguishable from the background population of stars, raising the likelihood that the moving groups are associated with transient perturbations.« less

Microminiature coaxial cable and methods manufacture

DOEpatents

Bongianni, Wayne L.

1986-01-01

A coaxial cable is provided having a ribbon inner conductor surrounded by a dielectric and a circumferential conductor. The coaxial cable may be microminiature comprising a very thin ribbon strip conductor from between 5 to 15 .mu.m thick and from 150 to 200 .mu.m wide, having a surrounding foamed dielectric or parylene applied thereon by a vapor plasma process and an outer conductor of an adhering high conductivity metal vacuum deposited on the dielectric. Alternately the foam dielectric embodiment may have a contiguous parylene coating applied adjacent the inner conductor or the outer conductor or both. Also, the cable may be fabricated by forming a thin ribbon of strip conductive material into an inner conductor, applying thereabout a dielectric by spraying on a solution of polystyrene and polyethylene and then vacuum depositing and adhering high conductivity metal about the dielectric. The cable strength may be increased by adding glass microfilament fibers or glass microballoons to the solution of polystyrene and polyethylene. Further, the outer conductive layer may be applied by electroless deposition in an aqueous solution rather than by vacuum deposition. A thin coating of parylene is preferably applied to the outer conductor to prevent its oxidation and inhibit mechanical abrasion.

Microminiature coaxial cable and method of manufacture

DOEpatents

Bongianni, W.L.

1989-03-28

A coaxial cable is provided having a ribbon inner conductor surrounded by a dielectric and a circumferential conductor. The coaxial cable may be microminiature comprising a very thin ribbon strip conductor from between 5 to 15 [mu]m thick and from 150 to 200 [mu]m wide, having a surrounding foamed dielectric or parylene applied thereon by a vapor plasma process and an outer conductor of an adhering high conductivity metal vacuum deposited on the dielectric. Alternately, the foam dielectric embodiment may have a contiguous parylene coating applied adjacent the inner conductor or the outer conductor or both. Also, the cable may be fabricated by forming a thin ribbon of strip conductive material into an inner conductor, applying thereabout a dielectric by spraying on a solution of polystyrene and polyethylene and then vacuum depositing and adhering high conductivity metal about the dielectric. The cable strength may be increased by adding glass microfilament fibers or glass microspheres to the solution of polystyrene and polyethylene. Further, the outer conductive layer may be applied by electroless deposition in an aqueous solution rather than by vacuum deposition. A thin coating of parylene is preferably applied to the outer conductor to prevent its oxidation and inhibit mechanical abrasion. 2 figs.

Microminiature coaxial cable and method of manufacture

DOEpatents

Bongianni, Wayne L.

1989-01-01

A coaxial cable is provided having a ribbon inner conductor surrounded by a dielectric and a circumferential conductor. The coaxial cable may be microminiature comprising a very thin ribbon strip conductor from between 5 to 15 .mu.m thick and from 150 to 200 .mu.m wide, having a surrounding foamed dielectric or parylene applied thereon by a vapor plasma process and an outer conductor of an adhering high conductivity metal vacuum deposited on the dielectric. Alternately, the foam dielectric embodiment may have a contiguous parylene coating applied adjacent the inner conductor or the outer conductor or both. Also, the cable may be fabricated by forming a thin ribbon of strip conductive material into an inner conductor, applying thereabout a dielectric by spraying on a solution of polystyrene and polyethylene and then vacuum depositing and adhering high conductivity metal about the dielectric. The cable strength may be increased by adding glass microfilament fibers or glass microspheres to the solution of polystyrene and polyethylene. Further, the outer conductive layer may be applied by electroless deposition in an aqueous solution rather than by vacuum deposition. A thin coating of parylene is preferably applied to the outer conductor to prevent its oxidation and inhibit mechanical abrasion.

Microminiature coaxial cable and methods of manufacture

DOEpatents

Bongianni, W.L.

1983-12-29

A coaxial cable is provided having a ribbon inner conductor surrounded by a dielectric and a circumferential conductor. The coaxial cable may be microminiature comprising a very thin ribbon strip conductor from between 5 to 15 ..mu..m thick and from 150 to 200 ..mu..m wide, having a surrounding foamed dielectric or parylene applied thereon by a vapor plasma process and an outer conductor of an adhering high conductivity metal vacuum deposited on the dieleectric. Alternately the foam dielectric embodiment may have a contiguous parylene coating applied adjacent the inner conductor or the outer conductor or both. Also, the cable may be fabricated by forming a thin ribbon of strip conductive material into an inner conductor, applying thereabout a dielectric by spraying on a solution of polystyrene and polyethylene and then vacuum depositing and adhering high conductivity metal about the dielectric. The cable strength may be increased by adding glass microfilament fibers or glass microballoons to the solution of polystyrene and polyethylene. Further, the outer conductive layer may be applied by electroless deposition in an aqueous solution rather than by vacuum deposition. A thin coating of parylene is preferably applied to the outer conductor to prevent its oxidation and inhibit mechanical abrasion.

Microminiature coaxial cable and methods manufacture

DOEpatents

Bongianni, W.L.

1986-04-08

A coaxial cable is provided having a ribbon inner conductor surrounded by a dielectric and a circumferential conductor. The coaxial cable may be microminiature comprising a very thin ribbon strip conductor from between 5 to 15 [mu]m thick and from 150 to 200 [mu]m wide, having a surrounding foamed dielectric or parylene applied thereon by a vapor plasma process and an outer conductor of an adhering high conductivity metal vacuum deposited on the dielectric. Alternately the foam dielectric embodiment may have a contiguous parylene coating applied adjacent the inner conductor or the outer conductor or both. Also, the cable may be fabricated by forming a thin ribbon of strip conductive material into an inner conductor, applying thereabout a dielectric by spraying on a solution of polystyrene and polyethylene and then vacuum depositing and adhering high conductivity metal about the dielectric. The cable strength may be increased by adding glass microfilament fibers or glass microballoons to the solution of polystyrene and polyethylene. Further, the outer conductive layer may be applied by electroless deposition in an aqueous solution rather than by vacuum deposition. A thin coating of parylene is preferably applied to the outer conductor to prevent its oxidation and inhibit mechanical abrasion. 2 figs.

Investigation into Cause of High Temperature Failure of Boiler Superheater Tube

NASA Astrophysics Data System (ADS)

Ghosh, D.; Ray, S.; Roy, H.; Shukla, A. K.

2015-04-01

The failure of the boiler tubes occur due to various reasons like creep, fatigue, corrosion and erosion. This paper highlights a case study of typical premature failure of a final superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement, chemical analysis, oxide scale thickness measurement, microstructural examination are conducted as part of the investigations. Apart from these investigations, sulfur print, Energy Dispersive spectroscopy (EDS) and X ray diffraction analysis (XRD) are also conducted to ascertain the probable cause of failure of final super heater tube. Finally it has been concluded that the premature failure of the super heater tube can be attributed to the combination of localized high tube metal temperature and loss of metal from the outer surface due to high temperature corrosion. The corrective actions have also been suggested to avoid this type of failure in near future.

Interlayer exchange coupling in complex magnetic multilayers

NASA Astrophysics Data System (ADS)

Xiang-dong, Zhang; Lie-ming, Li; Bo-zang, Li; Fu-cho, Pu

1998-07-01

We extend the hole confinement model of Edwards et al. to the problem of two kinds of complex magnetic sandwich structures. One is the magnetic sandwich covered on both sides by nonmagnetic films (case 1) and the other is that covered by magnetic films (case 2). The interlayer exchange coupling and the angular dependence of coupling energy in the two cases are investigated systematically. For case 1, our results show that the magnetic and outer nonmagnetic films influence significantly the oscillation behavior of exchange coupling and the appearance of noncollinear exchange coupling is very sensitive to the thickness of magnetic and outer nonmagnetic layers. Our results also show that the nonoscillatory component of the coupling generally varies with the thickness of magnetic (outer nonmagnetic) films and the results in the case where the thickness of both magnetic (outer nonmagnetic) films vary simultaneously are significantly different from that in the case where the thickness of one of the two magnetic (outer nonmagnetic) films is fixed while the other is varied, which is qualitatively in agreement with the experimental measurements. For case 2, the exponential dependence of exchange coupling on the thickness of the intermagnetic layer has been obtained, similar to the Parkin's experimental results for giant magnetoresistance.

Wüstite in the fusion crust of Almahata Sitta sulfide-metal assemblage MS-166: Evidence for oxygen in metallic melts

NASA Astrophysics Data System (ADS)

Horstmann, Marian; Humayun, Munir; Harries, Dennis; Langenhorst, Falko; Chabot, Nancy L.; Bischoff, Addi; Zolensky, Michael E.

2013-05-01

Meteorite fusion crusts form during the passage of a meteoroid through the Earth's atmosphere and are highly oxidized intergrowths as documented by the presence of e.g., oxides. The porous and irregular fusion crust surrounding the Almahata Sitta sulfide-metal assemblage MS-166 was found highly enriched in wüstite (Fe1-xO). Frictional heating of the outer portions of the assemblage caused partial melting of predominantly the Fe-sulfide and minor amounts of the outer Ni-rich portions of the originally zoned metal in MS-166. Along with melting significant amounts of oxygen were incorporated into the molten fusion crust and mainly FeS was oxidized and desulfurized to form wüstite. Considerable amounts of FeS were lost due to ablation, whereas the cores of the large metal grains appear largely unmelted leaving behind metal grains and surrounding wüstite-rich material (matte). Metal grains along with the surrounding matte typically form an often highly porous framework of globules interconnected with the matte. Although textures and chemical composition suggest that melting of Fe,Ni metal occurred only partially (Ni-rich rims), there is a trace elemental imprint of siderophile element partitioning influenced by oxygen in the metallic melt as indicated by the behavior of W and Ga, the two elements significantly affected by oxygen in a metallic melt. It is remarkable that MS-166 survived the atmospheric passage as troilite inclusions in iron meteorites are preferentially destroyed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anasori, Babak; Shi, Chenyang; Moon, Eun Ju

In this paper, a transition from metallic to semiconducting-like behavior has been demonstrated in two-dimensional (2D) transition metal carbides by replacing titanium with molybdenum in the outer transition metal (M) layers of M 3C 2 and M 4C 3 MXenes. The MXene structure consists of n + 1 layers of near-close packed M layers with C or N occupying the octahedral site between them in an [MX] nM arrangement. Recently, two new families of ordered 2D double transition metal carbides MXenes were discovered, M' 2M"C 2 and M' 2M" 2C 3 – where M' and M" are two different earlymore » transition metals, such as Mo, Cr, Ta, Nb, V, and Ti. The M' atoms only occupy the outer layers and the M" atoms fill the middle layers. In other words, M' atomic layers sandwich the middle M"–C layers. Using X-ray atomic pair distribution function (PDF) analysis on Mo 2TiC 2 and Mo 2Ti 2C 3 MXenes, we present the first quantitative analysis of structures of these novel materials and experimentally confirm that Mo atoms are in the outer layers of the [MC] nM structures. The electronic properties of these Mo-containing MXenes are compared with their Ti 3C 2 counterparts, and are found to be no longer metallic-like conductors; instead the resistance increases mildly with decreasing temperatures. Density functional theory (DFT) calculations suggest that OH terminated Mo–Ti MXenes are semiconductors with narrow band gaps. Measurements of the temperature dependencies of conductivities and magnetoresistances have confirmed that Mo 2TiC 2T x exhibits semiconductor-like transport behavior, while Ti 3C 2T x is a metal. Finally, this finding opens new avenues for the control of the electronic and optical applications of MXenes and for exploring new applications, in which semiconducting properties are required.« less

A model for osmium isotopic evolution of metallic solids at the core-mantle boundary

NASA Astrophysics Data System (ADS)

Humayun, Munir

2011-03-01

Some plumes are thought to originate at the core-mantle boundary, but geochemical evidence of core-mantle interaction is limited to Os isotopes in samples from Hawaii, Gorgona (89 Ma), and Kostomuksha (2.7 Ga). The Os isotopes have been explained by physical entrainment of Earth's liquid outer core into mantle plumes. This model has come into conflict with geophysical estimates of the timing of core formation, high-pressure experimental determinations of the solid metal-liquid metal partition coefficients (D), and the absence of expected 182W anomalies. A new model is proposed where metallic liquid from the outer core is partially trapped in a compacting cumulate pile of Fe-rich nonmetallic precipitates (FeO, FeS, Fe3Si, etc.) at the top of the core and undergoes fractional crystallization precipitating solid metal grains, followed by expulsion of the residual metallic liquid back to the outer core. The Os isotopic composition of the solids and liquids in the cumulate pile is modeled as a function of the residual liquid remaining and the emplacement age using 1 bar D values, with variable amounts of oxygen (0-10 wt %) as the light element. The precipitated solids evolve Os isotope compositions that match the trends for Hawaii (at an emplacement age of 3.5-4.5 Ga; 5%-10% oxygen) and Gorgona (emplacement age < 1.5 Ga; 0%-5% oxygen). The Fe-rich matrix of the cumulate pile dilutes the precipitated solid metal decoupling the Fe/Mn ratio from Os and W isotopes. The advantages to using precipitated solid metal as the Os host include a lower platinum group element and Ni content to the mantle source region relative to excess iron, miniscule anomalies in 182W (<0.1 ɛ), and no effects for Pb isotopes, etc. A gradual thermomechanical erosion of the cumulate pile results in incorporation of this material into the base of the mantle, where mantle plumes subsequently entrain it. Fractional crystallization of metallic liquids within the CMB provides a consistent explanation of both Os isotope correlations, Os-W isotope systematics, and Fe/Mn evidence for core-mantle interaction over the entire Hawaiian source.

Metal concentrations in surface sediments of Boston Harbor: Changes with time

USGS Publications Warehouse

Bothner, Michael H.; Buchholtz ten Brink, Marilyn R.; Manheim, F.T.

1998-01-01

The concentrations of metals in surface sediments of Boston Harbor have decreased during the period 1977–1993. This conclusion is supported by analysis of: (1) surface sediments collected at monitoring stations in the outer harbor between 1977 and 1993; (2) metal concentration profiles in sediment cores from depositional areas of the harbor; and (3) historical data from a contaminated-sediment database, which includes information on metal and organic contaminants and sediment texture. The background and matrix-corrected concentrations of lead (Pb) measured in the surficial layer (0–2 cm) of cores decreased by an average of 46%±12% among four locations in the outer harbor during the 16 y period. Chromium (Cr), copper (Cu), mercury (Hg), silver (Ag), and zinc (Zn) exhibited similar trends. Results from our sediment sampling are supported by historical data that were compiled from diverse sources into a regional sediment database. This sediment database contains approximately 3000 samples; of these, about 460 samples were collected and analyzed for Cu, Hg, or Zn and many other sediment parameters in Boston Harbor surface sediments between 1971–1993. The database indicates that the concentrations of these three metals also decreased with time in Boston’s Inner Harbor. The decreases in metal concentrations that are observed in more recent years parallel a general decrease in the flux of metals to the harbor, implemented by: (1) ending the sewage sludge discharge to the Harbor in December, 1991; (2) greater source reduction (e.g. recovery of silver from photographic processing) and closing or moving of industries; (3) improvements in wastewater handling and sewage treatment; and (4) diminishing use of lead in gasoline beginning about 1973. Despite the general decrease in metal concentrations in Boston Harbor surface sediments, the concentrations of Ag and Hg measured at some outer harbor stations in 1993 were still at, or above, the level associated with frequent adverse effects to marine organisms (guidelines are: Ag 3.7 μg g−1, Hg 1.17 μg g−1, from Long et al., 1995). Concentrations of the other metals listed were in the range considered to occasionally induce adverse biological effects.

Metal-Matrix Composite Parts With Metal Inserts

NASA Technical Reports Server (NTRS)

Majkowski, T.; Kashalikar, U.

1995-01-01

Developmental fabrication process produces metal-matrix composite (MMC) parts with integral metal inserts. With inserts, MMC parts readily joined to similar parts by use of brazing, welding, or mechanical fasteners. Process conceived to make strong, lightweight components of structures erected in outer space. Also useful on Earth, in such automotive parts as rocker arms, cylinder liners, and pistons. Potential industrial applications include parts subjected to high stresses at high temperatures, as in power-generation, mining, and oil-drilling equipment.

GEC Ferranti piezo vibratory gyroscope

NASA Technical Reports Server (NTRS)

Nuttall, J. D.

1993-01-01

Prototypes of a piezo-electric vibratory angular rate transducer (gyroscope) (PVG) have been constructed and evaluated. The construction is on the lines suggested by Burdess. The sensitive element is a cylinder of radially poled piezo-electric ceramic. The cylinder is metallized inside and out, and the outer metallization is divided into eight electrodes. The metallization on the inside is earthed. A phase locked loop, using pairs of the electrodes, causes the cylinder to vibrate in one of its two fundamental, degenerate modes. In the presence of rotation, some of the vibration is coupled into the outer mode. This can be detected, or suppressed with a closed-up technique and provides a measure of rotation rate. The gyroscope provides a number of advantages over rotating mass and optical instruments: low size and mass, lower power consumption, potentially high reliability, potentially good dormancy, low cost and high maximum rate.

The controlled deposition of metal oxides onto carbon nanotubes by atomic layer deposition: examples and a case study on the application of V2O4 coated nanotubes in gas sensing.

PubMed

Willinger, Marc-Georg; Neri, Giovanni; Bonavita, Anna; Micali, Giuseppe; Rauwel, Erwan; Herntrich, Tobias; Pinna, Nicola

2009-05-21

A new atomic layer deposition (ALD) process was applied for the uniform coating of carbon nanotubes with a number of transition-metal oxide thin films (vanadium, titanium, and hafnium oxide). The presented approach is adapted from non-aqueous sol-gel chemistry and utilizes metal alkoxides and carboxylic acids as precursors. It allows the coating of the inner and outer surface of the tubes with a highly conformal film of controllable thickness and hence, the production of high surface area hybrid materials. The morphology and the chemical composition as well as the high purity of the films are evidenced through a combination of electron microscopic and electron-energy-loss spectrometric techniques. Furthermore, in order to highlight a possible application of the obtained hybrids, the electrical and sensing properties of resistive gas sensors based on hybrid vanadium oxide-coated carbon nanotubes (V2O4-CNTs) are reported and the effect of thermal treatment on the gas sensing properties is studied.

Implementation of an Outer Can Welding System for Savannah River Site FB-Line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howard, S.R.

2003-03-27

This paper details three phases of testing to confirm use of a Gas Tungsten Arc (GTA) system for closure welding the 3013 outer container used for stabilization/storage of plutonium metals and oxides. The outer container/lid closure joint was originally designed for laser welding, but for this application, the gas tungsten arc (GTA) welding process has been adapted. The testing progressed in three phases: (1) system checkout to evaluate system components for operational readiness, (2) troubleshooting to evaluate high weld failure rates and develop corrective techniques, and (3) pre-installation acceptance testing.

Hydrolytic conversion of a metal-organic polyhedron into a metal-organic framework.

PubMed

Mallick, Arijit; Garai, Bikash; Díaz, David Díaz; Banerjee, Rahul

2013-12-16

Twist and release: The metal-organic polyhedron 1 synthesized from 5-(prop-2-ynyloxy)isophthalic acid and Cu(NO3 )2 ⋅ 3 H2 O has a hydrophobic outer surface and a hydrophilic inner core. In an aqueous medium, the resulting polarity gradient led to the transformation of 1 into the 2D metal-organic framework 2. This unique phenomenon enabled the gradual release of entrapped drug molecules. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PROCESS FOR PRODUCING JACKETED BODIES

DOEpatents

Saller, H.A.

1958-01-21

A method is given for enclosing a metallic core within an outer protective jacket, such as in the production of fuel elements for neutronic reactors. The method comprises the steps of inserting the body of a first metal into an aperture in a frame of a second metal, placing a sheet of the second metal on each of opposite sides of the assembled body and frame, and bonding the sheets to the body and the frame and the body and the frame to one another.

COAXIAL TUBE COUPLING

DOEpatents

Niemoth, H.R.

1963-02-26

BS>This patent shows a device for quickly coupling coaxial tubes in metal-to-metal fashion, so as to be suitable for use in a nuclear reactor. A threaded coliar urges a tapered metal extension on the outer coaxial tube into a tapered seat in the device and simultaneously exerts pressure through a coaxial helical spring so that a similar extension on the inner tube seats in a similar seat near the other end. (AEC)

FUEL ELEMENTS FOR THERMAL-FISSION NUCLEAR REACTORS

DOEpatents

Flint, O.

1961-01-10

Fuel elements for thermal-fission nuclear reactors are described. The fuel element is comprised of a core of alumina, a film of a metal of the class consisting of copper, silver, and nickel on the outer face of the core, and a coating of an oxide of a metal isotope of the class consisting of Un/sup 235/, U/ sup 233/, and Pu/sup 239/ on the metal f ilm.

Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms for organometallic complexes

NASA Astrophysics Data System (ADS)

Our studies of reactions of metal carbonyl cations and anions have shown that metal carbonyl cations can catalyze CO exchange reactions on metal carbonyl anions. This result provides further evidence for a mechanism involving attack of the metal carbonyl anion on a carbon of the metal carbonyl cation in CO(exp 2+) transfer reactions. Reaction of metal carbonyl anions with metal carbonyl halides is a common approach to formation of metal-metal bonds. We have begun to use kinetic data and product analysis to understand the formation of homobimetallic versus heterobimetallic products in such reactions. Initial data indicate a nucleophilic attack, possibly through a ring-slippage mechanism.

Inner- and outer-wall sorting of double-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Li, Han; Gordeev, Georgy; Wasserroth, Sören; Chakravadhanula, Venkata Sai Kiran; Neelakandhan, Shyam Kumar Chethala; Hennrich, Frank; Jorio, Ado; Reich, Stephanie; Krupke, Ralph; Flavel, Benjamin Scott

2017-12-01

Double-walled carbon nanotubes (DWCNTs) consist of two coaxially aligned single-walled carbon nanotubes (SWCNTs), and previous sorting methods only achieved outer-wall electronic-type selectivity. Here, a separation technique capable of sorting DWCNTs by semiconducting (S) or metallic (M) inner- and outer-wall electronic type is presented. Electronic coupling between the inner and outer wall is used to alter the surfactant coating around each of the DWCNT types, and aqueous gel permeation is used to separate them. Aqueous methods are used to remove SWCNT species from the raw material and prepare enriched DWCNT fractions. The enriched DWCNT fractions are then transferred into either chlorobenzene or toluene using the copolymer PFO-BPy to yield the four inner@outer combinations of M@M, M@S, S@M and S@S. The high purity of the resulting fractions is verified by absorption measurements, transmission electron microscopy, atomic force microscopy, resonance Raman mapping and high-density field-effect transistor devices.

Multilayer Article Characterized by Low Coefficient of Thermal Expansion Outer Layer

NASA Technical Reports Server (NTRS)

Lee, Kang N. (Inventor)

2004-01-01

A multilayer article comprises a substrate comprising a ceramic or a silicon-containing metal alloy. The ceramic is a Si-containing ceramic or an oxide ceramic with or without silicon. An outer layer overlies the substrate and at least one intermediate layer is located between the outer layer and thc substrate. An optional bond layer is disposed between thc 1 least one intermediate layer and thc substrate. The at least one intermediate layer may comprise an optional chemical barrier layer adjacent the outer layer, a mullite-containing layer and an optional chemical barrier layer adjacent to the bond layer or substrate. The outer layer comprises a compound having a low coefficient of thermal expansion selected from one of the following systems: rare earth (RE) silicates; at least one of hafnia and hafnia-containing composite oxides; zirconia-containing composite oxides and combinations thereof.

Inner- and outer-wall sorting of double-walled carbon nanotubes.

PubMed

Li, Han; Gordeev, Georgy; Wasserroth, Sören; Chakravadhanula, Venkata Sai Kiran; Neelakandhan, Shyam Kumar Chethala; Hennrich, Frank; Jorio, Ado; Reich, Stephanie; Krupke, Ralph; Flavel, Benjamin Scott

2017-12-01

Double-walled carbon nanotubes (DWCNTs) consist of two coaxially aligned single-walled carbon nanotubes (SWCNTs), and previous sorting methods only achieved outer-wall electronic-type selectivity. Here, a separation technique capable of sorting DWCNTs by semiconducting (S) or metallic (M) inner- and outer-wall electronic type is presented. Electronic coupling between the inner and outer wall is used to alter the surfactant coating around each of the DWCNT types, and aqueous gel permeation is used to separate them. Aqueous methods are used to remove SWCNT species from the raw material and prepare enriched DWCNT fractions. The enriched DWCNT fractions are then transferred into either chlorobenzene or toluene using the copolymer PFO-BPy to yield the four inner@outer combinations of M@M, M@S, S@M and S@S. The high purity of the resulting fractions is verified by absorption measurements, transmission electron microscopy, atomic force microscopy, resonance Raman mapping and high-density field-effect transistor devices.

Core Formation Process and Light Elements in the Planetary Core

NASA Astrophysics Data System (ADS)

Ohtani, E.; Sakairi, T.; Watanabe, K.; Kamada, S.; Sakamaki, T.; Hirao, N.

2015-12-01

Si, O, and S are major candidates for light elements in the planetary core. In the early stage of the planetary formation, the core formation started by percolation of the metallic liquid though silicate matrix because Fe-S-O and Fe-S-Si eutectic temperatures are significantly lower than the solidus of the silicates. Therefore, in the early stage of accretion of the planets, the eutectic liquid with S enrichment was formed and separated into the core by percolation. The major light element in the core at this stage will be sulfur. The internal pressure and temperature increased with the growth of the planets, and the metal component depleted in S was molten. The metallic melt contained both Si and O at high pressure in the deep magma ocean in the later stage. Thus, the core contains S, Si, and O in this stage of core formation. Partitioning experiments between solid and liquid metals indicate that S is partitioned into the liquid metal, whereas O is weakly into the liquid. Partitioning of Si changes with the metallic iron phases, i.e., fcc iron-alloy coexisting with the metallic liquid below 30 GPa is depleted in Si. Whereas hcp-Fe alloy above 30 GPa coexisting with the liquid favors Si. This contrast of Si partitioning provides remarkable difference in compositions of the solid inner core and liquid outer core among different terrestrial planets. Our melting experiments of the Fe-S-Si and Fe-O-S systems at high pressure indicate the core-adiabats in small planets, Mercury and Mars, are greater than the slope of the solidus and liquidus curves of these systems. Thus, in these planets, the core crystallized at the top of the liquid core and 'snowing core' formation occurred during crystallization. The solid inner core is depleted in both Si and S whereas the liquid outer core is relatively enriched in Si and S in these planets. On the other hand, the core adiabats in large planets, Earth and Venus, are smaller than the solidus and liquidus curves of the systems. The inner core of these planets crystallized at the center of the core and it has the relatively Si rich inner core and the S enriched outer core. Based on melting and solid-liquid partitioning, the equation of state, and sound velocity of iron-light element alloys, we examined the plausible distribution of light elements in the liquid outer and solid inner cores of the terrestrial planets.

High thermal conductivity connector having high electrical isolation

DOEpatents

Nieman, Ralph C.; Gonczy, John D.; Nicol, Thomas H.

1995-01-01

A method and article for providing a low-thermal-resistance, high-electrical-isolation heat intercept connection. The connection method involves clamping, by thermal interference fit, an electrically isolating cylinder between an outer metallic ring and an inner metallic disk. The connection provides durable coupling of a heat sink and a heat source.

Handbook of Oceanographic Winch, Wire, and Cable Technology.

DTIC Science & Technology

1982-10-18

Strength Members (Figure 2-3), involve a center arrangement of electrical conductors Tone, coax, tristed, pair, triad, etc.) with the braided metal or...8217. .. . . . .-.. . . . . .. - . . . C. Robert Shaw, Chief Engineer Union Metal Manufacturing...2-4 1.1 COINCIDENCE............................ 2-4 *1 .2 CEN4TER STRENGTH MEMBER.................. 2-4 *1.3 BRAIDED OUTER STRENGTH MIBER

Multilayer article having stabilized zirconia outer layer and chemical barrier layer

NASA Technical Reports Server (NTRS)

Bansal, Narottam P. (Inventor); Lee, Kang N. (Inventor)

2004-01-01

A multilayer article includes a substrate that includes at least one of a ceramic compound and a Si-containing metal alloy. An outer layer includes stabilized zirconia. Intermediate layers are located between the outer layer and the substrate and include a mullite-containing layer and a chemical barrier layer. The mullite-containing layer includes 1) mullite or 2) mullite and an alkaline earth metal aluminosilicate. The chemical barrier layer is located between the mullite-containing layer and the outer layer. The chemical barrier layer includes at least one of mullite, hafnia, hafnium silicate and rare earth silicate (e.g., at least one of RE.sub.2 SiO.sub.5 and RE.sub.2 Si.sub.2 O.sub.7 where RE is Sc or Yb). The multilayer article is characterized by the combination of the chemical barrier layer and by its lack of a layer consisting essentially of barium strontium aluminosilicate between the mullite-containing layer and the chemical barrier layer. Such a barium strontium aluminosilicate layer may undesirably lead to the formation of a low melting glass or unnecessarily increase the layer thickness with concomitant reduced durability of the multilayer article. In particular, the chemical barrier layer may include at least one of hafnia, hafnium silicate and rare earth silicate.

Spectral models for early time SN 2011fe observations

NASA Astrophysics Data System (ADS)

Baron, E.; Hoeflich, P.; Friesen, Brian; Sullivan, M.; Hsiao, E.; Ellis, R. S.; Gal-Yam, A.; Howell, D. A.; Nugent, P. E.; Dominguez, I.; Krisciunas, K.; Phillips, M. M.; Suntzeff, N.; Wang, L.; Thomas, R. C.

2015-12-01

We use observed UV through near-IR spectra to examine whether SN 2011fe can be understood in the framework of Branch-normal Type Ia supernovae (SNe Ia) and to examine its individual peculiarities. As a benchmark, we use a delayed-detonation model with a progenitor metallicity of Z⊙/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011fe resembles closely that of a delayed-detonation model with a transition density that has been fit to other Branch-normal SNe Ia. At early times, the model photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011fe has a lower specific energy in the outer ≈0.1 M⊙ than does the model. We discuss several explanations for the discrepancies. Finally, we examine variations in both the spectral energy distribution and in the colours due to variations in the progenitor metallicity, which suggests that colours are only weak indicators for the progenitor metallicity, in the particular explosion model that we have studied. We do find that the flux in the U band is significantly higher at maximum light in the solar metallicity model than in the lower metallicity model and the lower metallicity model much better matches the observed spectrum.

Speciation dynamics of metals in dispersion of nanoparticles with discrete distribution of charged binding sites.

PubMed

Polyakov, Pavel D; Duval, Jérôme F L

2014-02-07

We report a comprehensive theory to evaluate the kinetics of complex formation between metal ions and charged spherical nanoparticles. The latter consist of an ion-impermeable core surrounded by a soft shell layer characterized by a discrete axisymmetric 2D distribution of charged sites that bind metal ions. The theory explicitly integrates the conductive diffusion of metal ions from bulk solution toward the respective locations of the reactive sites within the particle shell volume. The kinetic constant k for outer-sphere nanoparticle-metal association is obtained from the sum of the contributions stemming from all reactive sites, each evaluated from the corresponding incoming flux of metal ions derived from steady-state Poisson-Nernst-Planck equations. Illustrations are provided to capture the basic intertwined impacts of particle size, overall particle charge, spatial heterogeneity in site distribution, type of particle (hard, core-shell or porous) and concentration of the background electrolyte on k. As a limit, k converges with predictions from previously reported analytical expressions derived for porous particles with low and high charge density, cases that correspond to coulombic and mean-field (smeared-out) electrostatic treatments, respectively. The conditions underlying the applicability of these latter approaches are rigorously identified in terms of (i) the extent of overlap between electric double layers around charged neighbouring sites, and (ii) the magnitude of the intraparticulate metal concentration gradient. For the first time, the proposed theory integrates the differentiated impact of the local potential around the charged binding sites amidst the overall particle field, together with that of the so-far discarded intraparticulate flux of metal ions.

Low heat-leak cryogenic envelope

DOEpatents

DeHaan, James R.

1976-10-19

A plurality of cryogenic envelope sections are joined together to form a power transmission line. Each of the sections is comprised of inner and outer tubes having multilayer metalized plastic spirally wrapped within a vacuum chamber formed between the inner and outer tubes. A refrigeration tube traverses the vacuum chamber, but exits one section and enters another through thermal standoffs for reducing heat-leak from the outer tube to the refrigeration tube. The refrigeration tube passes through a spirally wrapped shield within each section's vacuum chamber in a manner so that the refrigeration tube is in close thermal contact with the shield, but is nevertheless slideable with respect thereto.

VERY METAL-POOR STARS IN THE OUTER GALACTIC BULGE FOUND BY THE APOGEE SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia Perez, Ana E.; Majewski, Steven R.; Hearty, Fred R.

2013-04-10

Despite its importance for understanding the nature of early stellar generations and for constraining Galactic bulge formation models, at present little is known about the metal-poor stellar content of the central Milky Way. This is a consequence of the great distances involved and intervening dust obscuration, which challenge optical studies. However, the Apache Point Observatory Galactic Evolution Experiment (APOGEE), a wide-area, multifiber, high-resolution spectroscopic survey within Sloan Digital Sky Survey III, is exploring the chemistry of all Galactic stellar populations at infrared wavelengths, with particular emphasis on the disk and the bulge. An automated spectral analysis of data on 2403more » giant stars in 12 fields in the bulge obtained during APOGEE commissioning yielded five stars with low metallicity ([Fe/H] {<=} -1.7), including two that are very metal-poor [Fe/H] {approx} -2.1 by bulge standards. Luminosity-based distance estimates place the 5 stars within the outer bulge, where 1246 of the other analyzed stars may reside. A manual reanalysis of the spectra verifies the low metallicities, and finds these stars to be enhanced in the {alpha}-elements O, Mg, and Si without significant {alpha}-pattern differences with other local halo or metal-weak thick-disk stars of similar metallicity, or even with other more metal-rich bulge stars. While neither the kinematics nor chemistry of these stars can yet definitively determine which, if any, are truly bulge members, rather than denizens of other populations co-located with the bulge, the newly identified stars reveal that the chemistry of metal-poor stars in the central Galaxy resembles that of metal-weak thick-disk stars at similar metallicity.« less

Reusable Metallic Thermal Protection Systems Development

NASA Technical Reports Server (NTRS)

Blosser, Max L.; Martin, Carl J.; Daryabeigi, Kamran; Poteet, Carl C.

1998-01-01

Metallic thermal protection systems (TPS) are being developed to help meet the ambitious goals of future reusable launch vehicles. Recent metallic TPS development efforts at NASA Langley Research Center are described. Foil-gage metallic honeycomb coupons, representative of the outer surface of metallic TPS were subjected to low speed impact, hypervelocity impact, rain erosion, and subsequent arcjet exposure. TPS panels were subjected to thermal vacuum, acoustic, and hot gas flow testing. Results of the coupon and panel tests are presented. Experimental and analytical tools are being developed to characterize and improve internal insulations. Masses of metallic TPS and advanced ceramic tile and blanket TPS concepts are compared for a wide range of parameters.

High-efficiency solar cells fabricated by vacuum MO-CVD

NASA Technical Reports Server (NTRS)

Fraas, L. M.; Cape, J. A.; Partain, L. D.; Mcleod, P. S.

1984-01-01

High-efficiency, monolithic, two-color, three-terminal solar cells were fabricated by a novel growth technique, vacuum metal-organic chemical vapor deposition. The technique uses the expensive metal alkyls efficiently and toxic gases sparingly. The fact that the outer chamber is constructed of nonbreakable stainless steel is an attractive safety feature associated with this deposition system.

Shewanella oneidensis MR-1 nanowires are outer membrane and periplasmic extensions of the extracellular electron transport components

PubMed Central

Pirbadian, Sahand; Barchinger, Sarah E.; Leung, Kar Man; Byun, Hye Suk; Jangir, Yamini; Bouhenni, Rachida A.; Reed, Samantha B.; Romine, Margaret F.; Saffarini, Daad A.; Shi, Liang; Gorby, Yuri A.; Golbeck, John H.; El-Naggar, Mohamed Y.

2014-01-01

Bacterial nanowires offer an extracellular electron transport (EET) pathway for linking the respiratory chain of bacteria to external surfaces, including oxidized metals in the environment and engineered electrodes in renewable energy devices. Despite the global, environmental, and technological consequences of this biotic–abiotic interaction, the composition, physiological relevance, and electron transport mechanisms of bacterial nanowires remain unclear. We report, to our knowledge, the first in vivo observations of the formation and respiratory impact of nanowires in the model metal-reducing microbe Shewanella oneidensis MR-1. Live fluorescence measurements, immunolabeling, and quantitative gene expression analysis point to S. oneidensis MR-1 nanowires as extensions of the outer membrane and periplasm that include the multiheme cytochromes responsible for EET, rather than pilin-based structures as previously thought. These membrane extensions are associated with outer membrane vesicles, structures ubiquitous in Gram-negative bacteria, and are consistent with bacterial nanowires that mediate long-range EET by the previously proposed multistep redox hopping mechanism. Redox-functionalized membrane and vesicular extensions may represent a general microbial strategy for electron transport and energy distribution. PMID:25143589

Shewanella oneidensis MR-1 nanowires are outer membrane and periplasmic extensions of the extracellular electron transport components.

PubMed

Pirbadian, Sahand; Barchinger, Sarah E; Leung, Kar Man; Byun, Hye Suk; Jangir, Yamini; Bouhenni, Rachida A; Reed, Samantha B; Romine, Margaret F; Saffarini, Daad A; Shi, Liang; Gorby, Yuri A; Golbeck, John H; El-Naggar, Mohamed Y

2014-09-02

Bacterial nanowires offer an extracellular electron transport (EET) pathway for linking the respiratory chain of bacteria to external surfaces, including oxidized metals in the environment and engineered electrodes in renewable energy devices. Despite the global, environmental, and technological consequences of this biotic-abiotic interaction, the composition, physiological relevance, and electron transport mechanisms of bacterial nanowires remain unclear. We report, to our knowledge, the first in vivo observations of the formation and respiratory impact of nanowires in the model metal-reducing microbe Shewanella oneidensis MR-1. Live fluorescence measurements, immunolabeling, and quantitative gene expression analysis point to S. oneidensis MR-1 nanowires as extensions of the outer membrane and periplasm that include the multiheme cytochromes responsible for EET, rather than pilin-based structures as previously thought. These membrane extensions are associated with outer membrane vesicles, structures ubiquitous in Gram-negative bacteria, and are consistent with bacterial nanowires that mediate long-range EET by the previously proposed multistep redox hopping mechanism. Redox-functionalized membrane and vesicular extensions may represent a general microbial strategy for electron transport and energy distribution.

Electrochemical cell having cylindrical electrode elements

DOEpatents

Nelson, Paul A.; Shimotake, Hiroshi

1982-01-01

A secondary, high temperature electrochemical cell especially adapted for lithium alloy negative electrodes, transition metal chalcogenide positive electrodes and alkali metal halide or alkaline earth metal halide electrolyte is disclosed. The cell is held within an elongated cylindrical container in which one of the active materials is filled around the outside surfaces of a plurality of perforate tubular current collectors along the length of the container. Each of the current collector tubes contain a concentric tubular layer of electrically insulative ceramic as an interelectrode separator. The active material of opposite polarity in elongated pin shape is positioned longitudinally within the separator layer. A second electrically conductive tube with perforate walls can be swagged or otherwise bonded to the outer surface of the pin as a current collector and the electrically insulative ceramic layer can be coated or otherwise layered onto the outer surface of this second current collector. Alternatively, the central pin electrode can include an axial core as a current collector.

Ceramic tile expansion engine housing

DOEpatents

Myers, Blake

1995-01-01

An expandable ceramic tile housing for a high temperature engine is disclosed wherein each tile is independently supported in place in an interlocking matrix by retention mechanisms which mechanically couple the individual ceramic tiles to an outer metal support housing while maintaining thermal isolation of the metal housing from the ceramic tiles. The ceramic tiles are formed with either an octagonal front face portion and a square shank portion or a square front face portion with an octagonal shank portion. The length of the sides of the octagonal front face portion on one tile is equal to the length of the sides of the square front face portion of adjoining tiles to permit formation of an interlocking matrix. Fibrous ceramic sealing material may be placed between radial and tangential facing surfaces of adjacent tiles to limit radial gas flow therebetween. Labyrinth-sealed pressure-controlled compartments may be established between the tile housing and the outer metal support housing to control radial gas flow.

Ceramic tile expansion engine housing

DOEpatents

Myers, B.

1995-04-11

An expandable ceramic tile housing for a high temperature engine is disclosed wherein each tile is independently supported in place in an interlocking matrix by retention mechanisms which mechanically couple the individual ceramic tiles to an outer metal support housing while maintaining thermal isolation of the metal housing from the ceramic tiles. The ceramic tiles are formed with either an octagonal front face portion and a square shank portion or a square front face portion with an octagonal shank portion. The length of the sides of the octagonal front face portion on one tile is equal to the length of the sides of the square front face portion of adjoining tiles to permit formation of an interlocking matrix. Fibrous ceramic sealing material may be placed between radial and tangential facing surfaces of adjacent tiles to limit radial gas flow there between. Labyrinth-sealed pressure-controlled compartments may be established between the tile housing and the outer metal support housing to control radial gas flow. 8 figures.

An Isotopic Exchange Kinetic Model to Assess the Speciation of Metal Available Pool in Soil: The Case of Nickel.

PubMed

Zelano, I O; Sivry, Y; Quantin, C; Gélabert, A; Maury, A; Phalyvong, K; Benedetti, M F

2016-12-06

In this study an innovative approach is proposed to predict the relative contribution of each mineral phase to the total metal availability in soils, which, in other words, could be called the available metal fractionation. Through the use of isotopic exchange kinetics (IEK) performed on typical Ni bearing phases (i.e., two types of serpentines, chlorite, smectite, goethite, and hematite) the isotopic exchange and metal-solid interaction processes are connected, considering both the thermodynamic and kinetic aspects. Results of Ni IEK experiments on mineral phases are fitted with a pseudo-first order kinetic model. For each Ni bearing phase, this allows to (i) determine the number and size of exchangeable pools (E Ni(i) ), (ii) assess their corresponding kinetic constants (k (i) ), and (iii) discuss the mechanism of Ni isotopic exchange at mineral surfaces. It is shown that all the phases investigated, with the only exception of hematite, present at least two distinct reactive pools with significantly different k (i) values. Results suggest also that metal involved in outer-sphere complexes would display isotopic exchange between 100 and 1000 times faster than metal involved in inner-sphere complexes, and that the presence of high and low affinity sites may influence the rate of isotopic exchange up to 1 order of magnitude. Moreover, the method developed represents a tool to predict and estimate Ni mobility and availability in natural soil samples on the basis of soil mineral composition, providing information barely obtained with other techniques.

49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

Code of Federal Regulations, 2014 CFR

2014-10-01

... fiberboard boxes with inside metal cans containing not over one pound each, or inside metal cans with a... packaged as follows in metal boxes (4A, 4B or 4N) or wooden boxes (4C1, 4C2, 4D or 4F) with inner glass... mm (0.5 inch) of absorbent material. Total amount of liquid in the outer box must not exceed 11 kg...

49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

Code of Federal Regulations, 2013 CFR

2013-10-01

... fiberboard boxes with inside metal cans containing not over one pound each, or inside metal cans with a... packaged as follows in metal boxes (4A, 4B or 4N) or wooden boxes (4C1, 4C2, 4D or 4F) with inner glass... mm (0.5 inch) of absorbent material. Total amount of liquid in the outer box must not exceed 11 kg...

Ultra-Wide-Field Fundus Autofluorescence and Spectral-Domain Optical Coherence Tomography Findings in Syphilitic Outer Retinitis.

PubMed

Saleh, Mohamed G A; Campbell, John Peter; Yang, Paul; Lin, Phoebe

2017-03-01

To determine the ultra-wide-field fundus autofluorescence (UWFFAF) and optical coherence tomography (OCT) features of syphilitic outer retinopathy (SOR). Retrospective chart review. Three patients with SOR were investigated. Treatment with parenteral penicillin led to improvement of outer retinopathy, visual acuity, and symptoms. UWFFAF showed speckled hyperautofluorescence, hypoautofluorescence, and normal autofluorescence, similar to what has been described as a trizonal pattern in acute zonal occult outer retinopathy (AZOOR) in the chronic case of SOR, but with hyperautofluorescent areas in the two acute cases. OCT showed disruption of the photoreceptor outer segment ellipsoid zone and external limiting membrane, which improved after penicillin treatment, and corresponded to normalization of the hyperautofluorescent areas on UWFFAF. There was irregularity and nodular thickening of retinal pigment epithelium on OCT in areas of mottled hyperautofluorescence. SOR can present similarly to AZOOR on UWFFAF and should be highly suspected in cases presenting like AZOOR. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:208-215. ]. Copyright 2017, SLACK Incorporated.

NO.sub.x catalyst and method of suppressing sulfate formation in an exhaust purification system

DOEpatents

Balmer-Millar, Mari Lou [Chillicothe, IL; Park, Paul W [Peoria, IL; Panov, Alexander G [Peoria, IL

2007-06-26

The activity and durability of a zeolite lean-burn NOx catalyst can be increased by loading metal cations on the outer surface of the zeolite. However, the metal loadings can also oxidize sulfur dioxide to cause sulfate formation in the exhaust. The present invention is a method of suppressing sulfate formation in an exhaust purification system including a NO.sub.x catalyst. The NO.sub.x catalyst includes a zeolite loaded with at least one metal. The metal is selected from among an alkali metal, an alkaline earth metal, a lanthanide metal, a noble metal, and a transition metal. In order to suppress sulfate formation, at least a portion of the loaded metal is complexed with at least one of sulfate, phosphate, and carbonate.

NO.sub.x catalyst and method of suppressing sulfate formation in an exhaust purification system

DOEpatents

Balmer-Millar, Mari Lou; Park, Paul W.; Panov, Alexander G.

2006-08-22

The activity and durability of a zeolite lean-bum NOx catalyst can be increased by loading metal cations on the outer surface of the zeolite. However, the metal loadings can also oxidize sulfur dioxide to cause sulfate formation in the exhaust. The present invention is a method of suppressing sulfate formation in an exhaust purification system including a NO.sub.x catalyst. The NO.sub.x catalyst includes a zeolite loaded with at least one metal. The metal is selected from among an alkali metal, an alkaline earth metal, a lanthanide metal, a noble metal, and a transition metal. In order to suppress sulfate formation, at least a portion of the loaded metal is complexed with at least one of sulfate, phosphate, and carbonate.

Degradation of Hubble Space Telescope Metallized Teflon(trademark) FEP Thermal Control Materials

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.; Townsend, Jacqueline A.; Yoshikawa, Yukio; Castro, J. David; Triolo, Jack J.; Peters, Wanda C.

1998-01-01

The mechanical and optical properties of the metallized Teflon Fluorinated Ethylene Propylene (FEP) thermal control materials on the Hubble Space Telescope (HST) have degraded over the seven years the telescope has been in orbit. Astronaut observations and photographic documentation from the Second Servicing Mission revealed severe cracks of the multi-layer insulation (MLI) blanket outer layer in many locations around the telescope, particularly on solar facing surfaces. Two samples, the outer Teflon FEP MLI layer and radiator surfaces, were characterized post- mission through exhaustive mechanical, thermal, chemical, and optical testing. The observed damage to the thermal control materials, the sample retrieval and handling, and the significant changes to the radiator surfaces of HST will be discussed. Each of these issues is addressed with respect to current and future mission requirements.

EXHIBIT - SPACESUITS

NASA Image and Video Library

1982-02-08

S82-26645 (March 1982) --- Spacesuit inner gloves consist of pressure bladders covered by Beta Cloth. EVA outer gloves are made of Beta Cloth, Mylar and a metallic mesh hand area. The thumb and fingertips of the glove are molded of silicone rubber to permit a degree of sensitivity. The inner gloves attach to the suit by pressure sealing rings, similar to these used in helmet-to-suit connections. The outer gloves served as a cover to protect from micrometeorites, abrasions and heat.

Coated woven materials and method of preparation

DOEpatents

McCreary, W.J.; Carroll, D.W.

Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is by coating with materials, with metals or with pyrolytic carbon. Materials are deposited in Chemical Vapor Deposition (CND) reactions using a fluidized bed so that the porosity of the woven materials is retained and the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

Modeling of laser welding of steel and titanium plates with a composite insert

NASA Astrophysics Data System (ADS)

Isaev, V. I.; Cherepanov, A. N.; Shapeev, V. P.

2017-10-01

A 3D model of laser welding proposed before by the authors was extended to the case of welding of metallic plates made of dissimilar materials with a composite multilayer intermediate insert. The model simulates heat transfer in the welded plates and takes into account phase transitions. It was proposed to select the composition of several metals and dimensions of the insert to avoid the formation of brittle intermetallic phases in the weld joint negatively affecting its strength properties. The model accounts for key physical phenomena occurring during the complex process of laser welding. It is capable to calculate temperature regimes at each point of the plates. The model can be used to select the welding parameters reducing the risk of formation of intermetallic plates. It can forecast the dimensions and crystalline structure of the solidified melt. Based on the proposed model a numerical algorithm was constructed. Simulations were carried out for the welding of titanium and steel plates with a composite insert comprising four different metals: copper and niobium (intermediate plates) with steel and titanium (outer plates). The insert is produced by explosion welding. Temperature fields and the processes of melting, evaporation, and solidification were studied.

SQUID sensor application for small metallic particle detection

NASA Astrophysics Data System (ADS)

Tanaka, Saburo; Hatsukade, Yoshimi; Ohtani, Takeyoshi; Suzuki, Shuichi

2009-04-01

High-Tc superconducting quantum interference device (SQUID) is an ultra-sensitive magnetic sensor. Since the performance of the SQUID is improved and stabilized, now it is ready for application. One strong candidate for application is a detection system of magnetic foreign matters in industrial products or beverages. There is a possibility that ultra-small metallic foreign matter has been accidentally mixed with industrial products such as lithium ion batteries. If this happens, the manufacturer of the product suffers a great loss recalling products. The outer dimension of metallic particles less than 100 μm cannot be detected by an X-ray imaging, which is commonly used for the inspection. Ionization of the material is also a big issue for beverages in the case of the X-ray imaging. Therefore a highly sensitive and safety detection system for small foreign matters is required. We developed detection systems based on high-Tc SQUID with a high-performance magnetic shield. We could successfully measure small iron particles of 100 μm on a belt conveyer and stainless steel balls of 300 μm in water. These detection levels were hard to be achieved by a conventional X-ray detection or other methods.

CHEMODYNAMIC EVOLUTION OF DWARF GALAXIES IN TIDAL FIELDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williamson, David; Martel, Hugo; Romeo, Alessandro B., E-mail: david-john.williamson.1@ulaval.ca

The mass–metallicity relation shows that the galaxies with the lowest mass have the lowest metallicities. As most dwarf galaxies are in group environments, interaction effects such as tides could contribute to this trend. We perform a series of smoothed particle hydrodynamics simulations of dwarf galaxies in external tidal fields to examine the effects of tides on their metallicities and metallicity gradients. In our simulated galaxies, gravitational instabilities drive gas inwards and produce centralized star formation and a significant metallicity gradient. Strong tides can contribute to these instabilities, but their primary effect is to strip the outer low-metallicity gas, producing amore » truncated gas disk with a large metallicity. This suggests that the effect of tides on the mass–metallicity relation is to move dwarf galaxies to higher metallicities.« less

Thermal reactor for afterburning automotive internal combustion engine exhaust gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masaki, K.; Nagaishi, H.

1974-08-08

A thermal reactor for burning unburned components in exhaust gases of an internal combustion engine before emission to the atmosphere is described. An outer casing has an exhaust gas inlet connected to the exhaust ports, and an inner casing divides the reactor into an outer chamber and an inner chamber. The inner casing has an inlet from the outer chamber, an outlet to the atmosphere, and perforations opening to the outer chamber. An oxidation catalyst in the inner chamber promotes oxidation of the unburned components in the exhaust gases to generate oxidation reaction heat. A first secondary air injection nozzlemore » in the inner chamber between the oxidation catalyst and the outlet and a second secondary air injection nozzle in a portion upstream of the oxidation catalyst inject secondary air into oxidation catalyst.« less

Open cycle ocean thermal energy conversion system

DOEpatents

Wittig, J. Michael

1980-01-01

An improved open cycle ocean thermal energy conversion system including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flowpath and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support therefor and impart a desired flow direction to the steam.

Metallicity and Kinematics of M31's Outer Stellar Halo from a Keck Spectroscopic Survey

NASA Astrophysics Data System (ADS)

Reitzel, David B.; Guhathakurta, Puragra

2002-07-01

We present first results from a spectroscopic survey designed to examine the metallicity and kinematics of individual red giant branch stars in the outer halo of the Andromeda spiral galaxy (M31). This study is based on multislit spectroscopy with the Keck II 10 m telescope and Low Resolution Imaging Spectrograph of the Ca II near-infrared triplet in 99 M31 halo candidates in a field at R=19 kpc on the southeast minor axis with brightnesses from 20~2 dex range over which the abundance measurement methods are calibrated. The mean/median metallicity of the M31 halo is about <[Fe/H]>=-1.9 to -1.1 dex (depending on the details of metallicity calibration and sample selection) and possibly higher: the high-metallicity end of the distribution is poorly constrained by our data since the selection function for the secure M31 sample excludes over 80% of the giants in solar/supersolar metallicity range. Possible reasons are explored for the apparent discrepancy between the mean [Fe/H] found in our spectroscopic survey (corrected for metallicity selection bias) and the slightly higher mean values found in earlier photometric studies. Field halo red giants in M31 appear to be somewhat more metal-rich on average than their Milky Way counterparts. The M31 halo [Fe/H] distribution is comparable to that of M31 globular clusters, Galactic globular clusters, and Local Group dwarf satellite galaxies. The data in this 19 kpc outer halo field are broadly consistent with a scenario in which the halo is built from the accretion of small stellar subsystems. There are four stars in the secure M31 sample that have particularly strong Ca II lines, indicating solar metallicity, at a common velocity of ~-340 km s-1 close to the galaxy's systemic velocity, similar to what might be expected for M31 disk giants on the minor axis. An extrapolation of the inner disk brightness profile, however, falls far short of accounting for these four stars-the disk would instead have to be very large (Rdisk>~80 kpc) and/or warped. More likely, these four stars represent a metal-rich debris trail from a past accretion event in the halo. Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Production Engineering Measure for Improved Reliability of Metallized Polycarbonate and Metallized Polysulfone Capacitors

DTIC Science & Technology

1976-02-01

N N N-~~ ~ - N N N X N N N N N 41 1 x N NNNWNNn Nxx xx 0 0 N N N N N N x N NX x N N z ~ ~ ~ ~ x x e x2d NNx CNNx xwNm N NNNNNNNNNNNNNNN - N x xNxx xN...to prevent grounding to the outer metal tube. These sections are then assembled into electro-tinned brass LUbes. The com :.-ession glass end seals are

Hybrid Gear

NASA Technical Reports Server (NTRS)

Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

2016-01-01

A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

Duration of the Early Galactic Formation Epoch: HST Photometry for Red-Horizontal Branch Clusters in the Outer Halo

NASA Astrophysics Data System (ADS)

Hesser, J. E.; Stetson, P. B.; McClure, R. D.; van den Bergh, S.; Bolte, M.; Harris, W. E.; van den Berg, D. A.; Bell, R. A.; Fahlman, G. G.; Richer, H. B.; Bond, H. E.

1997-12-01

Last year we presented evidence from HST photometry of the low-metallicity cluster NGC 2419 (M_V = -9.5, R_⊙ ~ 90 kpc, [Fe/H] = -2.2) that globular cluster formation began at essentially the same time throughout a region of the Galactic halo now almost 200 kpc in diameter (Harris et al. 1997 AJ 114, 1030). We now turn to the time spread of halo formation, with the ultimate aim of addressing the relative roles of mergers over the first 4 or more Gyrs (Searle & Zinn 1978, ApJ, 225, 357; Lee, Demarque & Zinn 1994 ApJ, 423, 248) versus models favoring a rapid collapse (Eggen, Lynden-Bell & Sandage 1962, ApJ, 236, 748; Stetson, VandenBerg & Bolte 1996, PASP, 108, 560), or some combination of those and other processes. We provide the first reliable measurements from the giant branch through the main-sequence turnoffs of red-horizontal-branch clusters in the outer halo, which are frequently postulated to be younger than most other globular clusters. From WFPC2 F555W (`V') and F814W (`I') photometry for Pal 3 (M_V = -5.2, R_⊙ ~ 87 kpc), Pal 4 (M_V = -5.8, R_⊙ ~ 98 kpc), and Eridanus (M_V = -4.8, R_⊙ ~ 78 kpc), all with [Fe/H] ~ -1.5, we estimate their relative ages by making differential comparisons among them and with respect to inner-halo objects of, presumably, comparable chemical compositions. It seems likely at this stage of our analysis that (a) the three clusters are the same age to our measurement precision of ~ 1 Gyr, and, (b) the CMDs of all three outer halo clusters differ from those of M 3 and M 5 (our template clusters of similar metallicity), in the sense that the outer halo clusters are younger by ~ 3 Gyr, or they are ~ 0.5 dex more metal-rich than currently thought. Large uncertainties in chemical compositions (He, [alpha /Fe], [CNO/Fe]) for outer halo and template clusters alike mask the true interpretation.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites.

PubMed

Van Kooten, Elishevah M M E; Wielandt, Daniel; Schiller, Martin; Nagashima, Kazuhide; Thomen, Aurélien; Larsen, Kirsten K; Olsen, Mia B; Nordlund, Åke; Krot, Alexander N; Bizzarro, Martin

2016-02-23

The short-lived (26)Al radionuclide is thought to have been admixed into the initially (26)Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent (54)Cr and (26)Mg*, the decay product of (26)Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling (26)Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived (26)Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a (26)Mg*-depleted and (54)Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived (26)Al. The (26)Mg* and (54)Cr compositions of bulk metal-rich chondrites require significant amounts (25-50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites

PubMed Central

Van Kooten, Elishevah M. M. E.; Wielandt, Daniel; Schiller, Martin; Nagashima, Kazuhide; Thomen, Aurélien; Olsen, Mia B.; Nordlund, Åke; Krot, Alexander N.; Bizzarro, Martin

2016-01-01

The short-lived 26Al radionuclide is thought to have been admixed into the initially 26Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent 54Cr and 26Mg*, the decay product of 26Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling 26Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived 26Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a 26Mg*-depleted and 54Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived 26Al. The 26Mg* and 54Cr compositions of bulk metal-rich chondrites require significant amounts (25–50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants. PMID:26858438

Planet population synthesis driven by pebble accretion in cluster environments

NASA Astrophysics Data System (ADS)

Ndugu, N.; Bitsch, B.; Jurua, E.

2018-02-01

The evolution of protoplanetary discs embedded in stellar clusters depends on the age and the stellar density in which they are embedded. Stellar clusters of young age and high stellar surface density destroy protoplanetary discs by external photoevaporation and stellar encounters. Here, we consider the effect of background heating from newly formed stellar clusters on the structure of protoplanetary discs and how it affects the formation of planets in these discs. Our planet formation model is built on the core accretion scenario, where we take the reduction of the core growth time-scale due to pebble accretion into account. We synthesize planet populations that we compare to observations obtained by radial velocity measurements. The giant planets in our simulations migrate over large distances due to the fast type-II migration regime induced by a high disc viscosity (α = 5.4 × 10-3). Cold Jupiters (rp > 1 au) originate preferably from the outer disc, due to the large-scale planetary migration, while hot Jupiters (rp < 0.1 au) preferably form in the inner disc. We find that the formation of gas giants via pebble accretion is in agreement with the metallicity correlation, meaning that more gas giants are formed at larger metallicity. However, our synthetic population of isolated stars host a significant amount of giant planets even at low metallicity, in contradiction to observations where giant planets are preferably found around high metallicity stars, indicating that pebble accretion is very efficient in the standard pebble accretion framework. On the other hand, discs around stars embedded in cluster environments hardly form any giant planets at low metallicity in agreement with observations, where these changes originate from the increased temperature in the outer parts of the disc, which prolongs the core accretion time-scale of the planet. We therefore conclude that the outer disc structure and the planet's formation location determines the giant planet occurrence rate and the formation efficiency of cold and hot Jupiters.

Quartz antenna with hollow conductor

DOEpatents

Leung, Ka-Ngo; Benabou, Elie

2002-01-01

A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.

Chemically Doped Double-Walled Carbon Nanotubes: Cylindrical Molecular Capacitors

NASA Astrophysics Data System (ADS)

Chen, Gugang; Bandow, S.; Margine, E. R.; Nisoli, C.; Kolmogorov, A. N.; Crespi, Vincent H.; Gupta, R.; Sumanasekera, G. U.; Iijima, S.; Eklund, P. C.

2003-06-01

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

Chemically doped double-walled carbon nanotubes: cylindrical molecular capacitors.

PubMed

Chen, Gugang; Bandow, S; Margine, E R; Nisoli, C; Kolmogorov, A N; Crespi, Vincent H; Gupta, R; Sumanasekera, G U; Iijima, S; Eklund, P C

2003-06-27

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

[Stress analysis on the acetabular side of bipolar hemiarthroplasty by the two-dimensional finite element method incorporating the boundary friction layer].

PubMed

Ichihashi, K; Imura, S; Oomori, H; Gesso, H

1994-11-01

We compared the biomechanical characteristics of bipolar and unipolar hemiarthroplasty on the proximal migration of the outer head by determining the von Mises stress distribution and acetabular (outer head) displacement with clinical assessment of hemiarthroplasty in 75 patients. This analysis used the two-dimensional finite element method, which incorporated boundary friction layers on both the inner and outer bearings of the prosthesis. Acetabular reaming increased stress within the pelvic bone and migration of the outer head. A combination of the acetabular reaming and bone transplantation increased the stress within the pelvic bone and grafted bone, and caused outer head migration. These findings were supported by clinical results. Although the bipolar endoprosthesis was biomechanically superior to the unipolar endoprosthesis, migration of the outer head still occurred. The bipolar endoprosthesis appeared to be indicated in cases of a femoral neck fracture or of avascular necrosis in the femoral head, but its use in cases of osteoarthritis in the hip required caution.

Turbine nozzle positioning system

DOEpatents

Norton, Paul F.; Shaffer, James E.

1996-01-30

A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The nozzle guide vane assembly includes an outer shroud having a mounting leg with an opening defined therein, a tip shoe ring having a mounting member with an opening defined therein, a nozzle support ring having a plurality of holes therein and a pin positioned in the corresponding opening in the outer shroud, opening in the tip shoe ring and the hole in the nozzle support ring. A rolling joint is provided between metallic components of the gas turbine engine and the nozzle guide vane assembly. The nozzle guide vane assembly is positioned radially about a central axis of the gas turbine engine and axially aligned with a combustor of the gas turbine engine.

Turbine nozzle positioning system

DOEpatents

Norton, P.F.; Shaffer, J.E.

1996-01-30

A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The nozzle guide vane assembly includes an outer shroud having a mounting leg with an opening defined therein, a tip shoe ring having a mounting member with an opening defined therein, a nozzle support ring having a plurality of holes therein and a pin positioned in the corresponding opening in the outer shroud, opening in the tip shoe ring and the hole in the nozzle support ring. A rolling joint is provided between metallic components of the gas turbine engine and the nozzle guide vane assembly. The nozzle guide vane assembly is positioned radially about a central axis of the gas turbine engine and axially aligned with a combustor of the gas turbine engine. 9 figs.

Cell and current collector felt arrangement for solid oxide electrochemical cell combinations

DOEpatents

Reichner, Philip

1988-01-01

A solid electrolyte electrochemical cell combination 1 is made, comprising an annular, axially elongated, inner electrode 2 containing at least one interior gas feed conduit 3; annular solid electrolyte segments 4 around and covering portions of the inner electrode; annular outer electrode segments 6 around and covering portions of the electrolyte segments; electronically conducting, non-porous, interconnection material 5 disposed between electrolyte segments and in contact with the inner electrode, and electronically conducting, porous, metal fiber current collector felts 7 disposed on top of the non-porous interconnect material and outer electrode segments, where both the non-porous interconnect material and the porous metal felts are disposed circumferentially about the cell, transversely to the axial length of the cell and the inner electrode is continuous for the entire axial length of the cell combination.

Element of an inductive coupler

DOEpatents

Hall, David R.; Fox, Joe

2006-08-15

An element for an inductive coupler in a downhole component comprises magnetically conductive material, which is disposed in a recess in annular housing. The magnetically conductive material forms a generally circular trough. The circular trough comprises an outer generally U-shaped surface, an inner generally U-shaped surface, and two generally planar surfaces joining the inner and outer surfaces. The element further comprises pressure relief grooves in at least one of the surfaces of the circular trough. The pressure relief grooves may be scored lines. Preferably the pressure relief grooves are parallel to the magnetic field generated by the magnetically conductive material. The magnetically conductive material is selected from the group consisting of soft iron, ferrite, a nickel iron alloy, a silicon iron alloy, a cobalt iron alloy, and a mu-metal. Preferably, the annular housing is a metal ring.

Spectral Models of Kuiper Belt Objects and Centaurs

NASA Technical Reports Server (NTRS)

Cruikshank, Dale; Ore, Christina M. Dalle

2003-01-01

We present models of the spectral reflectances of groups of outer Solar System objects defined primarily by their colors in the spectral region 0.4 -1.2 microns, and which have geometric albedo 0.04 at wavelength 0.55 microns. Our models of the groups with the strongest reflectance gradients (reddest colors) use combinations of organic tholins. We test the hypothesis that metal-reddened igneous rock-forming minerals contribute to the red colors of Centaurs and KBOs by using the space-weathered lunar soil as one of the components of our models. We find that our models can admit the presence of moderate amounts of space-weathered (metal-reddened) minerals, but that they do not require this material to achieve the red colors of the reddest outer Solar System bodies. Our models with organic tholins are consistent with the results of other investigators.

Chemistry of the Triangulum-Andromeda Overdensity as Seen by APOGEE

NASA Astrophysics Data System (ADS)

Rochford Hayes, Christian; Majewski, Steven R.; Hasselquist, Sten; Beaton, Rachael; Cunha, Katia M. L.; Smith, Verne V.; Price-Whelan, Adrian M.; APOGEE Team

2018-06-01

The nature of the Triangulum-Andromeda (TriAnd) system has been debated since the discovery of this distant, low-latitude Milky Way (MW) overdensity more than a decade ago. Explanations for its origin are either as a halo substructure from the disruption of a dwarf galaxy or a distant extension of the Galactic disk. We test these hypotheses using chemical abundances of a dozen TriAnd members from the Sloan Digital Sky Survey’s 14th Data Release of Apache Point Observatory Galactic Evolution Experiment (APOGEE) data to compare to APOGEE abundances of stars with similar metallicity from both the Sagittarius (Sgr) dSph, and the outer MW disk. We find that TriAnd stars are chemically distinct from Sgr across a variety of elements, (C+N), Mg, K, Ca, Mn, and Ni, with a separation in [X/Fe] of about 0.1 to 0.4 dex depending on the element. Instead, the TriAnd stars, with a median metallicity of about -0.8, exhibit chemical abundance ratios similar to those of the lowest metallicity ([Fe/H] ~ -0.7) stars in the outer Galactic disk, and are consistent with expectations of extrapolated chemical gradients in the outer disk of the MW. These results suggest that TriAnd is associated with the MW disk, and, therefore, that the disk extends to this overdensity - i.e., past a Galactocentric radius of 24 kpc - albeit vertically perturbed about 7 kpc below the nominal disk midplane in this region of the Galaxy.

Radioisotopic heat source

DOEpatents

Sayell, E.H.

1973-10-23

A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

Alkali metal protective garment and composite material

DOEpatents

Ballif, III, John L.; Yuan, Wei W.

1980-01-01

A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

Boiler Stack Gas Heat Recovery

DTIC Science & Technology

1987-09-01

flue gas environ- ment. Conventional finned metal (aluminum, copper, stainless steel) tubes should not be used unless controls maintain the outer metal...xý Table 5. Summary of Actual Applications of Fiberglass Reinforced Plastic (FRP) in Corrosive Flue Gas Desulfurization Service Equipment Corrosive...process-steam/water heating. The procedure for estimating the energy potential of a given flue - gas stream is explained in detail with sample plots

Metallic Induction Reaction Engine.

DTIC Science & Technology

1984-12-28

FODA CLAIJ TY Figure 2: Experimental Setup 2 A EML Research Metallic Induction Reaction Engine page 3 Figure 3: Aluminum Reaction Mass Ring in Flight...reaction mass materials. Furthur analysis performed with the *] numerical model indicates that there exists a back EMF saturation effect which inhibits the...instrumentation difficulties, a detailed analysis of it’s performance has not been established. r Outer Coil Projectile- Coil Inner Coil Figure 4

Nose-only exposure system

DOEpatents

Cannon, William C.; Bass, Edward W.; Decker, Jr., John R.

1988-01-01

An exposure system for supplying a gaseous material, i.e. an aerosol, gas or a vapor, directly to the noses of experimental animals includes concentric vertical inner and outer manifolds. The outer manifold connects with the necks of a large number of bottles in which the animals are confined with their noses adjacent the bottle necks. Readily detachable small tubes communicate with the inner manifold and extend to the necks of the bottles. The upper end of the outer manifold and the lower end of the inner manifold are closed. Gaseous material is supplied to the upper end of the inner manifold, flows through the small tubes to points adjacent the noses of the individual animals, then is drawn out through the bottom of the outer manifold. The bottles are readily removable and the device can be disassembled, e.g., for cleaning, by removing the bottles, removing the small tubes, and lifting the inner manifold from the outer manifold. The bottles are supported by engagement of their necks with the outer manifold supplemented, if additional support is required, by individual wire cradles. The outer ends of the bottles are closed by plugs, through which pass metal tubes which receive the tails of the animals (usually rodents) and which serve to dissipate body heat. The entire device is mounted for rotation on turntable bearings.

Study on the resistance mechanism via outer membrane protein OprD2 and metal β-lactamase expression in the cell wall of Pseudomonas aeruginosa.

PubMed

Cai, Shuangqi; Chen, Yiqiang; Song, Dezhi; Kong, Jinliang; Wu, Yanbin; Lu, Huasong

2016-11-01

The aim of the present study was to evaluate the imipenem-resistant mechanism via the outer membrane protein (OMP) OprD2 and metal β-lactamase expression in the cell wall of Pseudomonas aeruginosa . The Pseudomonas aeruginosa was clinically separated and validated by VITEK-2 full-automatic bacteria analyzer. Drug resistance, sensitive antibiotics and minimum inhibitory concentration (MIC) were tested using the drug sensitivity analysis system. The phenotype positive strains of MBL genes were screened using the Kirby-Bauer diffusion method by adding metal ion-chelating agent EDTA on the imipenem susceptibility paper. IMP-1, VIM-1 and SPM metaloenzyme genes were tested by polymerase chain reaction (PCR)-telomeric repeat amplification protocol (TRAP). The OMP OprD2 genes were tested by PCR-TRAP, and the protein expression was tested using western blot analysis. The location of OMP OprD2 was confirmed using the sodium salicylate inhibition test. The results showed that 80 portions (40%) of MBL-positive strains were screened out of 200 specimens. Imipenem-resistant Pseudomonas aeruginosa (IRPA) and MIC values were significantly higher than quality control bacteria and control bacteria (P<0.05). A total of 35 cases with IMP-1 positive, 20 with VIM-1 positive, 16 with SPM positive, 5 with 2 positive genes and 4 with 3 positive genes were screened among MBL positive strains. A total of 150 portions (75%) of OprD2 deficiencies were screened from 200 specimens. The standard strains and sensitive strains showed OprD2 protein bands at 45 kDa while no OprD2 protein bands appeared in OprD2 deficiency strains. It was in accordance with gene detection. In conclusion, OMP OprD2 deficiency and MBL phenotype positivity may be important mechanisms of IRPA.

Spectral models for early time SN 2011fe observations

DOE PAGES

Baron, E.; Hoeflich, P.; Friesen, Brian; ...

2015-10-13

We use observed UV through near-IR spectra to examine whether SN 2011fe can be understood in the framework of Branch-normal Type Ia supernovae (SNe Ia) and to examine its individual peculiarities. As a benchmark, we use a delayed-detonationmodel with a progenitormetallicity of Z ⊙/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011fe resembles closely that of a delayed-detonation model withmore » a transition density that has been fit to other Branch-normal SNe Ia. At early times, the model photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011fe has a lower specific energy in the outer ≈0.1 M ⊙ than does the model. We discuss several explanations for the discrepancies. Lastly, we examine variations in both the spectral energy distribution and in the colours due to variations in the progenitor metallicity, which suggests that colours are only weak indicators for the progenitor metallicity, in the particular explosion model that we have studied. Here we do find that the flux in the U band is significantly higher at maximum light in the solar metallicity model than in the lower metallicity model and the lower metallicity model much better matches the observed spectrum.« less

Evidence of cross-cutting and redox reaction in Khatyrka meteorite reveals metallic-Al minerals formed in outer space.

PubMed

Lin, Chaney; Hollister, Lincoln S; MacPherson, Glenn J; Bindi, Luca; Ma, Chi; Andronicos, Christopher L; Steinhardt, Paul J

2017-05-09

We report on a fragment of the quasicrystal-bearing CV3 carbonaceous chondrite Khatyrka recovered from fine-grained, clay-rich sediments in the Koryak Mountains, Chukotka (Russia). We show higher melting-point silicate glass cross-cutting lower melting-point Al-Cu-Fe alloys, as well as unambiguous evidence of a reduction-oxidation reaction history between Al-Cu-Fe alloys and silicate melt. The redox reactions involve reduction of FeO and SiO 2 to Fe and Fe-Si metal, and oxidation of metallic Al to Al 2 O 3 , occurring where silicate melt was in contact with Al-Cu-Fe alloys. In the reaction zone, there are metallic Fe and Fe-Si beads, aluminous spinel rinds on the Al-Cu-Fe alloys, and Al 2 O 3 enrichment in the silicate melt surrounding the alloys. From this and other evidence, we demonstrate that Khatyrka must have experienced at least two distinct events: first, an event as early as 4.564 Ga in which the first Al-Cu-Fe alloys formed; and, second, a more recent impact-induced shock in space that led to transformations of and reactions between the alloys and the meteorite matrix. The new evidence firmly establishes that the Al-Cu-Fe alloys (including quasicrystals) formed in outer space in a complex, multi-stage process.

Polarization of IRON-REGULATED TRANSPORTER 1 (IRT1) to the plant-soil interface plays crucial role in metal homeostasis.

PubMed

Barberon, Marie; Dubeaux, Guillaume; Kolb, Cornelia; Isono, Erika; Zelazny, Enric; Vert, Grégory

2014-06-03

In plants, the controlled absorption of soil nutrients by root epidermal cells is critical for growth and development. IRON-REGULATED TRANSPORTER 1 (IRT1) is the main root transporter taking up iron from the soil and is also the main entry route in plants for potentially toxic metals such as manganese, zinc, cobalt, and cadmium. Previous work demonstrated that the IRT1 protein localizes to early endosomes/trans-Golgi network (EE/TGN) and is constitutively endocytosed through a monoubiquitin- and clathrin-dependent mechanism. Here, we show that the availability of secondary non-iron metal substrates of IRT1 (Zn, Mn, and Co) controls the localization of IRT1 between the outer polar domain of the plasma membrane and EE/TGN in root epidermal cells. We also identify FYVE1, a phosphatidylinositol-3-phosphate-binding protein recruited to late endosomes, as an important regulator of IRT1-dependent metal transport and metal homeostasis in plants. FYVE1 controls IRT1 recycling to the plasma membrane and impacts the polar delivery of this transporter to the outer plasma membrane domain. This work establishes a functional link between the dynamics and the lateral polarity of IRT1 and the transport of its substrates, and identifies a molecular mechanism driving polar localization of a cell surface protein in plants.

Segmented lasing tube for high temperature laser assembly

DOEpatents

Sawicki, Richard H.; Alger, Terry W.; Finucane, Raymond G.; Hall, Jerome P.

1996-01-01

A high temperature laser assembly capable of withstanding operating temperatures in excess of 1500.degree. C. is described comprising a segmented cylindrical ceramic lasing tube having a plurality of cylindrical ceramic lasing tube segments of the same inner and outer diameters non-rigidly joined together in axial alignment; insulation of uniform thickness surround the walls of the ceramic lasing tube; a ceramic casing, preferably of quartz, surrounding the insulation; and a fluid cooled metal jacket surrounds the ceramic casing. In a preferred embodiment, the inner surface of each of the ceramic lasing tube segments are provided with a pair of oppositely spaced grooves in the wall thereof parallel to the center axis of the segmented cylindrical ceramic lasing tube, and both of the grooves and the center axis of the segmented cylindrical ceramic lasing tube lie in a common plane, with the grooves in each ceramic lasing tube segment in circumferential alignment with the grooves in the adjoining ceramic lasing tube segments; and one or more ceramic plates, all lying in a common plane to one another and with the central axis of the segmented ceramic lasing tube, are received in the grooves to provide additional wall area in the segmented ceramic lasing tube for collision and return to ground state of metastable metal atoms within the segmented ceramic lasing tube.

Electrical Investigation of Metal-Olivine Systems and Application to the Deep Interior of Mercury

NASA Astrophysics Data System (ADS)

Zhang, Zhou; Pommier, Anne

2017-12-01

We report electrical conductivity measurements on metal-olivine systems at about 5 and 6 GPa and up to 1,675°C in order to investigate the electrical properties of core-mantle boundary (CMB) systems. Electrical experiments were conducted in the multianvil apparatus using the impedance spectroscopy technique. The samples are composed of one metal layer (Fe, FeS, FeSi2, or Fe-Ni-S-Si) and one polycrystalline olivine layer, with the metal:olivine ratio ranging from 1:0.7 to 1:9.2. For all samples, we observe that the bulk electrical conductivity increases with temperature from 10-2.5 to 101.8 S/m, which is higher than the conductivity of polycrystalline olivine but lower than the conductivity of the pure metal phase at similar conditions. In some experiments, a conductivity jump is observed at the temperature corresponding to the melting temperature of the metallic phase. Both the metal:olivine ratio and the metal phase geometry control the electrical conductivity of the two-layer samples. By combining electrical results, textural analyses of the samples, and previous studies of the structure and composition of Mercury's interior, we propose an electrical profile of the deep interior of the planet that accounts for a layered CMB-outer core structure. The electrical model agrees with existing conductivity estimates of Mercury's lower mantle and CMB using magnetic observations and thermodynamic calculations, and thus, supports the hypothesis of a layered CMB-outermost core structure in the present-day interior of Mercury. We propose that the layered CMB-outer core structure is possibly electrically insulating, which may influence the planet's structure and cooling history.

Major substructure in the M31 outer halo: the South-West Cloud

NASA Astrophysics Data System (ADS)

Bate, N. F.; Conn, A. R.; McMonigal, B.; Lewis, G. F.; Martin, N. F.; McConnachie, A. W.; Veljanoski, J.; Mackey, A. D.; Ferguson, A. M. N.; Ibata, R. A.; Irwin, M. J.; Fardal, M.; Huxor, A. P.; Babul, A.

2014-02-01

We undertake the first detailed analysis of the stellar population and spatial properties of a diffuse substructure in the outer halo of M31. The South-West Cloud lies at a projected distance of ˜100 kpc from the centre of M31 and extends for at least ˜50 kpc in projection. We use Pan-Andromeda Archaeological Survey photometry of red giant branch stars to determine a distance to the South-West Cloud of 793^{+45}_{-45} kpc. The metallicity of the cloud is found to be [Fe/H] = -1.3 ± 0.1. This is consistent with the coincident globular clusters PAndAS-7 and PAndAS-8, which have metallicities determined using an independent technique of [Fe/H] = -1.35 ± 0.15. We measure a brightness for the Cloud of MV = -12.1 mag; this is ˜75 per cent of the luminosity implied by the luminosity-metallicity relation. Under the assumption that the South-West Cloud is the visible remnant of an accreted dwarf satellite, this suggests that the progenitor object was amongst M31's brightest dwarf galaxies prior to disruption.

Contamination control device

DOEpatents

Clark, Robert M.; Cronin, John C.

1977-01-01

A contamination control device for use in a gas-insulated transmission bus consisting of a cylindrical center conductor coaxially mounted within a grounded cylindrical enclosure. The contamination control device is electrically connected to the interior surface of the grounded outer shell and positioned along an axial line at the lowest vertical position thereon. The contamination control device comprises an elongated metallic member having a generally curved cross-section in a first plane perpendicular to the axis of the bus and having an arcuate cross-section in a second plane lying along the axis of the bus. Each opposed end of the metallic member and its opposing sides are tapered to form a pair of generally converging and downward sloping surfaces to trap randomly moving conductive particles in the relatively field-free region between the metallic member and the interior surface of the grounded outer shell. The device may have projecting legs to enable the device to be spot welded to the interior of the grounded housing. The control device provides a high capture probability and prevents subsequent release of the charged particles after the capture thereof.

A Tandem Catalyst with Multiple Metal Oxide Interfaces Produced by Atomic Layer Deposition.

PubMed

Ge, Huibin; Zhang, Bin; Gu, Xiaomin; Liang, Haojie; Yang, Huimin; Gao, Zhe; Wang, Jianguo; Qin, Yong

2016-06-13

Ideal heterogeneous tandem catalysts necessitate the rational design and integration of collaborative active sites. Herein, we report on the synthesis of a new tandem catalyst with multiple metal-oxide interfaces based on a tube-in-tube nanostructure using template-assisted atomic layer deposition, in which Ni nanoparticles are supported on the outer surface of the inner Al2 O3 nanotube (Ni/Al2 O3 interface) and Pt nanoparticles are attached to the inner surface of the outer TiO2 nanotube (Pt/TiO2 interface). The tandem catalyst shows remarkably high catalytic efficiency in nitrobenzene hydrogenation over Pt/TiO2 interface with hydrogen formed in situ by the decomposition of hydrazine hydrate over Ni/Al2 O3 interface. This can be ascribed to the synergy effect of the two interfaces and the confined nanospace favoring the instant transfer of intermediates. The tube-in-tube tandem catalyst with multiple metal-oxide interfaces represents a new concept for the design of highly efficient and multifunctional nanocatalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Asymmetric metal-insulator-metal (MIM) structure formed by pulsed Nd:YAG laser deposition with titanium nitride (TiN) and aluminum nitride (AlN)

NASA Astrophysics Data System (ADS)

Oshikane, Yasushi

2017-08-01

A novel nanostructured end cap for a truncated conical apex of optical fiber has been studied experimental and numerically. The peculiar cap is composed of asymmetric metal-insulator-metal (MIM) structure coupled with subwavelength holes. The MIM structure may act as reflective band cut filter or generator of surface plasmon polariton (SPP). And nano holes in the thicker metal layer could extract the SPP from the MIM structure and lead it to outer surface of the metal layer. For the purpose, the author has started to create the asymmetric MIM structure with TiN and AlN by pulsed laser deposition (PLD). The resultant structure was diagnosed by spectroscopic analyses.

Nanoantenna couplers for metal-insulator-metal waveguide interconnects

NASA Astrophysics Data System (ADS)

Onbasli, M. Cengiz; Okyay, Ali K.

2010-08-01

State-of-the-art copper interconnects suffer from increasing spatial power dissipation due to chip downscaling and RC delays reducing operation bandwidth. Wide bandwidth, minimized Ohmic loss, deep sub-wavelength confinement and high integration density are key features that make metal-insulator-metal waveguides (MIM) utilizing plasmonic modes attractive for applications in on-chip optical signal processing. Size-mismatch between two fundamental components (micron-size fibers and a few hundred nanometers wide waveguides) demands compact coupling methods for implementation of large scale on-chip optoelectronic device integration. Existing solutions use waveguide tapering, which requires more than 4λ-long taper distances. We demonstrate that nanoantennas can be integrated with MIM for enhancing coupling into MIM plasmonic modes. Two-dimensional finite-difference time domain simulations of antennawaveguide structures for TE and TM incident plane waves ranging from λ = 1300 to 1600 nm were done. The same MIM (100-nm-wide Ag/100-nm-wide SiO2/100-nm-wide Ag) was used for each case, while antenna dimensions were systematically varied. For nanoantennas disconnected from the MIM; field is strongly confined inside MIM-antenna gap region due to Fabry-Perot resonances. Major fraction of incident energy was not transferred into plasmonic modes. When the nanoantennas are connected to the MIM, stronger coupling is observed and E-field intensity at outer end of core is enhanced more than 70 times.

Chemical Cartography. I. A Carbonicity Map of the Galactic Halo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Young Sun; Kim, Young Kwang; Beers, Timothy C.

We present the first map of carbonicity, [C/Fe], for the halo system of the Milky Way, based on a sample of over 100,000 main-sequence turnoff stars with available spectroscopy from the Sloan Digital Sky Survey. This map, which explores distances up to 15 kpc from the Sun, reveals clear evidence for the dual nature of the Galactic halo, based on the spatial distribution of stellar carbonicity. The metallicity distribution functions of stars in the inner- and outer-halo regions of the carbonicity map reproduce those previously argued to arise from contributions of the inner- and outer-halo populations, with peaks at [Fe/H]more » = −1.5 and −2.2, respectively. From consideration of the absolute carbon abundances for our sample, A (C), we also confirm that the carbon-enhanced metal-poor (CEMP) stars in the outer-halo region exhibit a higher frequency of CEMP-no stars (those with no overabundances of heavy neutron-capture elements) than of CEMP- s stars (those with strong overabundances of elements associated with the s -process), whereas the stars in the inner-halo region exhibit a higher frequency of CEMP- s stars. We argue that the contrast in the behavior of the CEMP-no and CEMP- s fractions in these regions arises from differences in the mass distributions of the mini-halos from which the stars of the inner- and outer-halo populations formed, which gives rise in turn to the observed dichotomy of the Galactic halo.« less

Assessment of marine pollution in Izmir Bay: nutrient, heavy metal and total hydrocarbon concentrations.

PubMed

Kucuksezgin, F; Kontas, A; Altay, O; Uluturhan, E; Darilmaz, E

2006-01-01

Izmir Bay (western Turkey) is one of the great natural bays of the Mediterranean. Izmir is an important industrial and commercial centre and a cultural focal point. The main industries in the region include food processing, oil, soap and paint production, chemical industries, paper and pulp factories, textile industries and metal processing. The mean concentrations showed ranges of 0.01-0.19 and 0.01-10 microM for phosphate, 0.10-1.8 and 0.12-27 microM for nitrate+nitrite, and 0.30-5.8 and 0.43-39 microM for silicate in the outer and middle-inner bays, respectively. The TNO(x)/PO(4) ratio is significantly lower than the Redfield's ratio and nitrogen is the limiting element in the middle-inner bays. Diatoms and dinoflagellates were observed all year around in the bay and are normally nitrogen limited. Metal concentrations ranged between Hg: 0.05-1.3, Cd: 0.005-0.82, Pb: 14-113 and Cr: 29-316 microg g(-1) in the sediments. The results showed significant enrichments during sampling periods from Inner Bay. Outer and middle bays show low levels of heavy metal enrichments except estuary of Gediz River. The concentrations of Hg, Cd and Pb in the outer bay were generally similar to the background levels from the Mediterranean. The levels gradually decreased over the sampling period. Total hydrocarbons concentrations range from 427 to 7800 ng g(-1) of sediments. The highest total hydrocarbon levels were found in the inner bay due to the anthropogenic activities, mainly combustion processes of traffic and industrial activities. The concentrations of heavy metals found in fish varied for Hg: 4.5-520, Cd: 0.10-10 and Pb: 0.10-491 microg kg(-1) in Izmir Bay. There was no significant seasonal variation in metal concentrations. An increase in Hg concentration with increasing length was noted for Mullus barbatus. A person can consume more than 2, 133 and 20 meals per week of fish in human diet would represent the tolerable weekly intake of mercury, cadmium and lead, respectively, in Izmir Bay. Heavy metal levels were lower than the results in fish tissues reported from polluted areas of the Mediterranean Sea.

CORROSION RESISTANT JACKETED METAL BODY

DOEpatents

Brugmann, E.W.

1958-08-26

Jacketed metal bodies of the type used as fuel elements for nuclear reactors, which contain an internal elongated body of fissionable material jacketed in a corrosion resistant metal are described. The ends of the internal bodies are provided with screw threads having a tapered outer end. The jacket material overlaps the ends and extends into the tapered section of the screw threaded opening. Screw caps with a mating tapered section are screwed into the ends of the body to compress the jacket material in the tapered sections to provtde an effective seal against corrosive gases and liquids.

Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study

PubMed Central

Li, Xiong; Li, Hang; Yang, Gang

2015-01-01

Defect sites exist abundantly in minerals and play a crucial role for a variety of important processes. Here molecular dynamics simulations are used to comprehensively investigate the adsorption behaviors, stabilities and mechanisms of metal ions on defective minerals, considering different ionic concentrations, defect sizes and contents. Outer-sphere adsorbed Pb2+ ions predominate for all models (regular and defective), while inner-sphere Na+ ions, which exist sporadically only at concentrated solutions for regular models, govern the adsorption for all defective models. Adsorption quantities and stabilities of metal ions on kaolinite are fundamentally promoted by defect sites, thus explaining the experimental observations. Defect sites improve the stabilities of both inner- and outer-sphere adsorption, and (quasi) inner-sphere Pb2+ ions emerge only at defect sites that reinforce the interactions. Adsorption configurations are greatly altered by defect sites but respond weakly by changing defect sizes or contents. Both adsorption quantities and stabilities are enhanced by increasing defect sizes or contents, while ionic concentrations mainly affect adsorption quantities. We also find that adsorption of metal ions and anions can be promoted by each other and proceeds in a collaborative mechanism. Results thus obtained are beneficial to comprehend related processes for all types of minerals. PMID:26403873

Displacements of Metallic Thermal Protection System Panels During Reentry

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Blosser, Max L.; Wurster, Kathryn E.

2006-01-01

Bowing of metallic thermal protection systems for reentry of a previously proposed single-stage-to-orbit reusable launch vehicle was studied. The outer layer of current metallic thermal protection system concepts typically consists of a honeycomb panel made of a high temperature nickel alloy. During portions of reentry when the thermal protection system is exposed to rapidly varying heating rates, a significant temperature gradient develops across the honeycomb panel thickness, resulting in bowing of the honeycomb panel. The deformations of the honeycomb panel increase the roughness of the outer mold line of the vehicle, which could possibly result in premature boundary layer transition, resulting in significantly higher downstream heating rates. The aerothermal loads and parameters for three locations on the centerline of the windward side of this vehicle were calculated using an engineering code. The transient temperature distributions through a metallic thermal protection system were obtained using 1-D finite volume thermal analysis, and the resulting displacements of the thermal protection system were calculated. The maximum deflection of the thermal protection system throughout the reentry trajectory was 6.4 mm. The maximum ratio of deflection to boundary layer thickness was 0.032. Based on previously developed distributed roughness correlations, it was concluded that these defections will not result in tripping the hypersonic boundary layer.

Real-time eye lens dose monitoring during cerebral angiography procedures.

PubMed

Safari, M J; Wong, J H D; Kadir, K A A; Thorpe, N K; Cutajar, D L; Petasecca, M; Lerch, M L F; Rosenfeld, A B; Ng, K H

2016-01-01

To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures. Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures. The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R(2)) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AKL: 0.93, AKF: 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions. The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose. Real-time patient dose monitoring helps interventionalists to monitor doses. Strong correlation was observed between kerma-area-product and measured eye doses. Radiation dose at left outer canthus was higher than at left eyelid.

Numerical investigation of a tunable band-pass plasmonic filter with a hollow-core ring resonator

NASA Astrophysics Data System (ADS)

Setayesh, Amir; Mirnaziry, S. Reza; Sadegh Abrishamian, Mohammad

2011-03-01

In this study, a compact nanoscale plasmonic filter which consists of two metal-insulator-metal (MIM) waveguides coupled to each other by a rectangular ring resonator is presented and investigated numerically. The propagating modes of surface plasmon polaritons (SPPs) are studied in this structure. By replacing a portion of the ring core with air, while the outer dimensions of the structure are kept constant, we illustrate the possibility of the redshift of resonant wavelengths in order to tune the resonance modes. This feature is useful for integrated circuits in which we have limitations on the outer dimensions of the filter structure and it is not possible to enlarge the dimension of the ring resonator to reach longer resonant wavelengths. The corresponding results are illustrated by the 2D finite-difference time-domain (FDTD) method. The proposed structure has potential applications in plasmonic integrated circuits and can be simply fabricated.

Vanadium(V) Reduction by Shewanella oneidensis MR-1 Requires Menaquinone and Cytochromes from the Cytoplasmic and Outer Membranes

PubMed Central

Myers, Judith M.; Antholine, William E.; Myers, Charles R.

2004-01-01

The metal-reducing bacterium Shewanella oneidensis MR-1 displays remarkable anaerobic respiratory plasticity, which is reflected in the extensive number of electron transport components encoded in its genome. In these studies, several cell components required for the reduction of vanadium(V) were determined. V(V) reduction is mediated by an electron transport chain which includes cytoplasmic membrane components (menaquinone and the tetraheme cytochrome CymA) and the outer membrane (OM) cytochrome OmcB. A partial role for the OM cytochrome OmcA was evident. Electron spin resonance spectroscopy demonstrated that V(V) was reduced to V(IV). V(V) reduction did not support anaerobic growth. This is the first report delineating specific electron transport components that are required for V(V) reduction and of a role for OM cytochromes in the reduction of a soluble metal species. PMID:15006760

Progress Toward Fabrication of Machined Metal Shells for the First Double-Shell Implosions at the National Ignition Facility

DOE PAGES

Cardenas, Tana; Schmidt, Derek W.; Loomis, Eric N.; ...

2018-01-25

The double-shell platform fielded at the National Ignition Facility requires developments in new machining techniques and robotic assembly stations to meet the experimental specifications. Current double-shell target designs use a dense high-Z inner shell, a foam cushion, and a low-Z outer shell. The design requires that the inner shell be gas filled using a fill tube. This tube impacts the entire machining and assembly design. Other intermediate physics designs have to be fielded to answer physics questions and advance the technology to be able to fabricate the full point design in the near future. One of these intermediate designs ismore » a mid-Z imaging design. The methods of designing, fabricating, and characterizing each of the major components of an imaging double shell are discussed with an emphasis on the fabrication of the machined outer metal shell.« less

Progress Toward Fabrication of Machined Metal Shells for the First Double-Shell Implosions at the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cardenas, Tana; Schmidt, Derek W.; Loomis, Eric N.

The double-shell platform fielded at the National Ignition Facility requires developments in new machining techniques and robotic assembly stations to meet the experimental specifications. Current double-shell target designs use a dense high-Z inner shell, a foam cushion, and a low-Z outer shell. The design requires that the inner shell be gas filled using a fill tube. This tube impacts the entire machining and assembly design. Other intermediate physics designs have to be fielded to answer physics questions and advance the technology to be able to fabricate the full point design in the near future. One of these intermediate designs ismore » a mid-Z imaging design. The methods of designing, fabricating, and characterizing each of the major components of an imaging double shell are discussed with an emphasis on the fabrication of the machined outer metal shell.« less

VizieR Online Data Catalog: Habitable zone code (Valle+, 2014)

NASA Astrophysics Data System (ADS)

Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G.; Degl'Innocenti, S.

2014-06-01

A C computation code that provide in output the distance dm (i for which the duration of habitability is longest, the corresponding duration tm (in Gyr), the width W (in AU) of the zone for which the habitability lasts tm/2, the inner (Ri) and outer (Ro) boundaries of the 4Gyr continuously habitable zone. The code read the input file HZ-input.dat, containing in each row the mass of the host star (range: 0.70-1.10M⊙), its metallicity (either Z (range: 0.005-0.004) or [Fe/H]), the helium-to-metal enrichment ratio (range: 1-3, standard value = 2), the equilibrium temperature for habitable zone outer boundary computation (range: 169-203K) and the planet Bond Albedo (range: 0.0-1.0, Earth = 0.3). The output is printed on-screen. Compilation: just use your favorite C compiler: gcc hz.c -lm -o HZ (2 data files).

Metal halide arc discharge lamp having short arc length

NASA Technical Reports Server (NTRS)

Muzeroll, Martin E. (Inventor)

1994-01-01

A metal halide arc discharge lamp includes a sealed light-transmissive outer jacket, a light-transmissive shroud located within the outer jacket and an arc tube assembly located within the shroud. The arc tube assembly includes an arc tube, electrodes mounted within the arc tube and a fill material for supporting an arc discharge. The electrodes have a spacing such that an electric field in a range of about 60 to 95 volts per centimeter is established between the electrodes. The diameter of the arc tube and the spacing of the electrodes are selected to provide an arc having an arc diameter to arc length ratio in a range of about 1.6 to 1.8. The fill material includes mercury, sodium iodide, scandium tri-iodide and a rare gas, and may include lithium iodide. The lamp exhibits a high color rendering index, high lumen output and high color temperature.

Determination of the thermal stress wave propagation in orthotropic hollow cylinder based on classical theory of thermoelasticity

NASA Astrophysics Data System (ADS)

Shahani, Amir Reza; Sharifi Torki, Hamid

2018-01-01

The thermoelasticity problem in a thick-walled orthotropic hollow cylinder is solved analytically using finite Hankel transform and Laplace transform. Time-dependent thermal and mechanical boundary conditions are applied on the inner and the outer surfaces of the cylinder. For solving the energy equation, the temperature itself is considered as boundary condition to be applied on both the inner and the outer surfaces of the orthotropic cylinder. Two different cases are assumed for solving the equation of motion: traction-traction problem (tractions are prescribed on both the inner and the outer surfaces) and traction-displacement (traction is prescribed on the inner surface and displacement is prescribed on the outer surface of the hollow orthotropic cylinder). Due to considering uncoupled theory, after obtaining temperature distribution, the dynamical structural problem is solved and closed-form relations are derived for radial displacement, radial and hoop stress. As a case study, exponentially decaying temperature with respect to time is prescribed on the inner surface of the cylinder and the temperature of the outer surface is considered to be zero. Owing to solving dynamical problem, the stress wave propagation and its reflections were observed after plotting the results in both cases.

Coated woven materials and method of preparation

DOEpatents

McCreary, William J.; Carroll, David W.

1981-01-01

Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is the following: Woven materials are coated with materials, for example with metals or with pyrolytic carbon, which materials are deposited in Chemical Vapor Deposition (CVD) reactions using a fluidized bed so that the porosity of the woven material is retained and so that the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

Double interconnection fuel cell array

DOEpatents

Draper, R.; Zymboly, G.E.

1993-12-28

A fuel cell array is made, containing number of tubular, elongated fuel cells which are placed next to each other in rows (A, B, C, D), where each cell contains inner electrodes and outer electrodes, with solid electrolyte between the electrodes, where the electrolyte and outer electrode are discontinuous, having two portions, and providing at least two opposed discontinuities which contain at least two oppositely opposed interconnections contacting the inner electrode, each cell having only three metallic felt electrical connectors which contact surrounding cells, where each row is electrically connected to the other. 5 figures.

Exploring the molecular mechanisms of electron shuttling across the microbe/metal space

PubMed Central

Paquete, Catarina M.; Fonseca, Bruno M.; Cruz, Davide R.; Pereira, Tiago M.; Pacheco, Isabel; Soares, Cláudio M.; Louro, Ricardo O.

2014-01-01

Dissimilatory metal reducing organisms play key roles in the biogeochemical cycle of metals as well as in the durability of submerged and buried metallic structures. The molecular mechanisms that support electron transfer across the microbe-metal interface in these organisms remain poorly explored. It is known that outer membrane proteins, in particular multiheme cytochromes, are essential for this type of metabolism, being responsible for direct and indirect, via electron shuttles, interaction with the insoluble electron acceptors. Soluble electron shuttles such as flavins, phenazines, and humic acids are known to enhance extracellular electron transfer. In this work, this phenomenon was explored. All known outer membrane decaheme cytochromes from Shewanella oneidensis MR-1 with known metal terminal reductase activity and a undecaheme cytochrome from Shewanella sp. HRCR-6 were expressed and purified. Their interactions with soluble electron shuttles were studied using stopped-flow kinetics, NMR spectroscopy, and molecular simulations. The results show that despite the structural similarities, expected from the available structural data and sequence homology, the detailed characteristics of their interactions with soluble electron shuttles are different. MtrC and OmcA appear to interact with a variety of different electron shuttles in the close vicinity of some of their hemes, and with affinities that are biologically relevant for the concentrations typical found in the medium for this type of compounds. All data support a view of a distant interaction between the hemes of MtrF and the electron shuttles. For UndA a clear structural characterization was achieved for the interaction with AQDS a humic acid analog. These results provide guidance for future work of the manipulation of these proteins toward modulation of their role in metal attachment and reduction. PMID:25018753

SDSS IV MaNGA - metallicity and nitrogen abundance gradients in local galaxies

NASA Astrophysics Data System (ADS)

Belfiore, Francesco; Maiolino, Roberto; Tremonti, Christy; Sánchez, Sebastian F.; Bundy, Kevin; Bershady, Matthew; Westfall, Kyle; Lin, Lihwai; Drory, Niv; Boquien, Médéric; Thomas, Daniel; Brinkmann, Jonathan

2017-07-01

We study the gas phase metallicity (O/H) and nitrogen abundance gradients traced by star-forming regions in a representative sample of 550 nearby galaxies in the stellar mass range 109-1011.5 M⊙ with resolved spectroscopic data from the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory survey. Using strong-line ratio diagnostics (R23 and O3N2 for metallicity and N2O2 for N/O) and referencing to the effective (half-light) radius (Re), we find that the metallicity gradient steepens with stellar mass, lying roughly flat among galaxies with log (M⋆/M⊙) = 9.0 but exhibiting slopes as steep as -0.14 dex R_e^{-1} at log (M⋆/M⊙) = 10.5 (using R23, but equivalent results are obtained using O3N2). At higher masses, these slopes remain typical in the outer regions of our sample (R > 1.5Re), but a flattening is observed in the central regions (R < 1Re). In the outer regions (R > 2.0Re), we detect a mild flattening of the metallicity gradient in stacked profiles, although with low significance. The N/O ratio gradient provides complementary constraints on the average chemical enrichment history. Unlike the oxygen abundance, the average N/O profiles do not flatten out in the central regions of massive galaxies. The metallicity and N/O profiles both depart significantly from an exponential form, suggesting a disconnect between chemical enrichment and stellar mass surface density on local scales. In the context of inside-out growth of discs, our findings suggest that central regions of massive galaxies today have evolved to an equilibrium metallicity, while the nitrogen abundance continues to increase as a consequence of delayed secondary nucleosynthetic production.

Disk-like Chemistry of the Triangulum-Andromeda Overdensity as Seen by APOGEE

NASA Astrophysics Data System (ADS)

Hayes, Christian R.; Majewski, Steven R.; Hasselquist, Sten; Beaton, Rachael L.; Cunha, Katia; Smith, Verne V.; Price-Whelan, Adrian M.; Anguiano, Borja; Beers, Timothy C.; Carrera, Ricardo; Fernández-Trincado, J. G.; Frinchaboy, Peter M.; García-Hernández, D. A.; Lane, Richard R.; Nidever, David L.; Nitschelm, Christian; Roman-Lopes, Alexandre; Zamora, Olga

2018-05-01

The nature of the Triangulum-Andromeda (TriAnd) system has been debated since the discovery of this distant, low-latitude Milky Way (MW) overdensity more than a decade ago. Explanations for its origin are either as a halo substructure from the disruption of a dwarf galaxy, or a distant extension of the Galactic disk. We test these hypotheses using the chemical abundances of a dozen TriAnd members from the Sloan Digital Sky Survey-IV’s (SDSS-IV’s) 14th Data Release (DR14) of Apache Point Observatory Galactic Evolution Experiment (APOGEE) data to compare to APOGEE abundances of stars with similar metallicity from both the Sagittarius (Sgr) dSph and the outer MW disk. We find that TriAnd stars are chemically distinct from Sgr across a variety of elements, (C+N), Mg, K, Ca, Mn, and Ni, with a separation in [X/Fe] of about 0.1 to 0.4 dex depending on the element. Instead, the TriAnd stars, with a median metallicity of about ‑0.8, exhibit chemical abundance ratios similar to those of the lowest metallicity ([Fe/H] ∼ ‑0.7) stars in the outer Galactic disk, and are consistent with expectations of extrapolated chemical gradients in the outer disk of the MW. These results suggest that TriAnd is associated with the MW disk, and, therefore, that the disk extends to this overdensity—i.e., past a Galactocentric radius of 24 kpc—albeit vertically perturbed about 7 kpc below the nominal disk midplane in this region of the Galaxy.

Multimodal imaging in a case of bilateral outer retinitis associated with mumps infection.

PubMed

Kahloun, Rim; Ben Amor, Hager; Ksiaa, Imen; Zina, Sourour; Jelliti, Bechir; Ben Yahia, Salim; Khairallah, Moncef

2018-02-01

To report the results of multimodal imaging of acute outer retinitis associated to mumps infection. A patient with mumps-associated outer retinitis evaluated by color fundus photography, spectral domain optical coherence tomography (SD-OCT), optical coherence tomography angiography, fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography (ICGA). We report a case of a 12-year-old boy who developed bilateral outer retinitis related to mumps. Ophthalmoscopy showed confluent areas of outer retinitis involving the posterior pole and the periphery with a centrifugal gyrate pattern. SD-OCT revealed a marked disorganization of the outer retinal layers with multiple highly reflective spicules. FA shows diffuse late hyperfluorescence with optic disk staining. ICGA shows macular and peripheral hyperfluorescent lesions with a geographical pattern in the late phases. The patient was treated with acyclovir and oral prednisone. Four weeks after presentation visual acuity remained unchanged, and retinal changes seen at the acute phase had resolved leading to extensive retinal atrophy and optic disk pallor. SD-OCT showed atrophy of the retinal pigment epithelial and outer retinal layers. FAF revealed scattered hyperautofluorescent lesions. Electrophysiology showed generalized retinal dysfunction. Mumps infection should be considered in the differential diagnosis of bilateral necrotizing outer retinitis in children and young adults. A multimodal imaging approach may help distinguish mumps-associated retinitis from other causes of viral retinitis and facilitate appropriate management.

Formation of metal clusters in halloysite clay nanotubes

NASA Astrophysics Data System (ADS)

Vinokurov, Vladimir A.; Stavitskaya, Anna V.; Chudakov, Yaroslav A.; Ivanov, Evgenii V.; Shrestha, Lok Kumar; Ariga, Katsuhiko; Darrat, Yusuf A.; Lvov, Yuri M.

2017-12-01

We developed ceramic core-shell materials based on abundant halloysite clay nanotubes with enhanced heavy metal ions loading through Schiff base binding. These clay tubes are formed by rolling alumosilicate sheets and have diameter of c.50 nm, a lumen of 15 nm and length 1 μm. This allowed for synthesis of metal nanoparticles at the selected position: (1) on the outer surface seeding 3-5 nm metal particles on the tubes; (2) inside the tube's central lumen resulting in 10-12 nm diameter metal cores shelled with ceramic wall; and (3) smaller metal nanoparticles intercalated in the tube's wall allowing up to 9 wt% of Ru, and Ag loading. These composite materials have high surface area providing a good support for catalytic nanoparticles, and can also be used for sorption of metal ions from aqueous solutions.

Formation of metal clusters in halloysite clay nanotubes.

PubMed

Vinokurov, Vladimir A; Stavitskaya, Anna V; Chudakov, Yaroslav A; Ivanov, Evgenii V; Shrestha, Lok Kumar; Ariga, Katsuhiko; Darrat, Yusuf A; Lvov, Yuri M

2017-01-01

We developed ceramic core-shell materials based on abundant halloysite clay nanotubes with enhanced heavy metal ions loading through Schiff base binding. These clay tubes are formed by rolling alumosilicate sheets and have diameter of c .50 nm, a lumen of 15 nm and length ~1 μm. This allowed for synthesis of metal nanoparticles at the selected position: (1) on the outer surface seeding 3-5 nm metal particles on the tubes; (2) inside the tube's central lumen resulting in 10-12 nm diameter metal cores shelled with ceramic wall; and (3) smaller metal nanoparticles intercalated in the tube's wall allowing up to 9 wt% of Ru, and Ag loading. These composite materials have high surface area providing a good support for catalytic nanoparticles, and can also be used for sorption of metal ions from aqueous solutions.

Active Metal Brazing and Characterization of Brazed Joints in Titanium to Carbon-Carbon Composites

NASA Technical Reports Server (NTRS)

Singh, M.; Shpargel, T. P.; Morscher, G. N.; Asthana, R.

2006-01-01

The Ti-metal/C-C composite joints were formed by reactive brazing with three commercial brazes, namely, Cu-ABA, TiCuNi, and TiCuSiI. The joint microstructures were examined using optical microscopy and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). The results of the microstructure analysis indicate solute redistribution across the joint and possible metallurgical bond formation via interdiffusion, which led to good wetting and spreading. A tube-on-plate tensile test was used to evaluate joint strength of Ti-tube/ C-C composite joints. The load-carrying ability was greatest for the Cu-ABA braze joint structures. This system appeared to have the best braze spreading which resulted in a larger braze/C-C composite bonded area compared to the other two braze materials. Also, joint loadcarrying ability was found to be higher for joint structures where the fiber tows in the outer ply of the C-C composite were aligned perpendicular to the tube axis when compared to the case where fiber tows were aligned parallel to the tube axis.

Electromagnetic valve for controlling the flow of molten, magnetic material

DOEpatents

Richter, T.

1998-06-16

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.

Electromagnetic valve for controlling the flow of molten, magnetic material

DOEpatents

Richter, Tomas

1998-01-01

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.

Osmium-187 enrichment in some plumes: Evidence for core-mantle interaction?

USGS Publications Warehouse

Walker, R.J.; Morgan, J.W.; Horan, M.F.

1995-01-01

Calculations with data for asteroidal cores indicate that Earth's outer core may have a rhenium/osmium ratio at least 20 percent greater than that of the chondritic upper mantle, potentially leading to an outer core with an osmium-187/osmium-188 ratio at least 8 percent greater than that of chondrites. Because of the much greater abundance of osmium in the outer core relative to the mantle, even a small addition of metal to a plume ascending from the D??? layer would transfer the enriched isotopic signature to the mixture. Sources of certain plume-derived systems seem to have osmium-187/osmium-188 ratios 5 to 20 percent greater than that for chondrites, consistent with the ascent of a plume from the core-mantle boundary.

Manufacture of annular cermet articles

DOEpatents

Forsberg, Charles W.; Sikka, Vinod K.

2004-11-02

A method to produce annular-shaped, metal-clad cermet components directly produces the form and avoids multiple fabrication steps such as rolling and welding. The method includes the steps of: providing an annular hollow form with inner and outer side walls; filling the form with a particulate mixture of ceramic and metal; closing, evacuating, and hermetically sealing the form; heating the form to an appropriate temperature; and applying force to consolidate the particulate mixture into solid cermet.

Kepler's mathematization of Cosmology

NASA Astrophysics Data System (ADS)

Field, Judith V.

The paper concerns with mathematical knowledge of Johannes Kepler. A part of the paper describes the mathematical education of Kepler which includes the Euclidean geometry and texts by Ptolemy. The first He knew from the Proclus' Commentary which was published in 1533. The author is pointing out that Kepler's epistemology was close to Plato's. The "polyhedral archetype" is discussed in detail. The greatest error was in the case of Mercury (~20%) Kepler's reaction was otherwise absolutely what one would exopect of a theoretician in the twentieth century: he suggested that better observations would imoprouve matter. The author make an analogy with modern discussions on metal abundances in the outer layers of old stars. The author is mentioning also that the Kepler's version of Copernicus' system is noticeably different from Copernicus' original one, including important improvements.

Transition from the adiabatic to the sudden limit in core-level photoemission: A model study of a localized system

NASA Astrophysics Data System (ADS)

Lee, J. D.; Gunnarsson, O.; Hedin, L.

1999-09-01

We consider core electron photoemission in a localized system, where there is a charge transfer excitation. Examples are transition metal and rare earth compounds, chemisorption systems, and high-Tc compounds. The system is modeled by three electron levels, one core level, and two outer levels. In the initital state the core level and one outer level is filled (a spinless two-electron problem). This model system is embedded in a solid state environment, and the implications of our model system results for solid state photoemission are discussed. When the core hole is created, the more localized outer level (d) is pulled below the less localized level (L). The spectrum has a leading peak corresponding to a charge transfer between L and d (``shakedown''), and a satellite corresponding to no charge transfer. The model has a Coulomb interaction between these levels and the continuum states into which the core electron is emitted. The model is simple enough to allow an exact numerical solution, and with a separable potential an analytic solution. Analytic results are also obtained in lowest order perturbation theory, and in the high-energy limit of the semiclassical approximation. We calculate the ratio r(ω) between the weights of the satellite and the main peak as a function of the photon energy ω. The transition from the adiabatic to the sudden limit is found to take place for quite small kinetic energies of the photoelectron. For such small energies, the variation of the dipole matrix elements is substantial and described by the energy scale E~d. Without the coupling to the photoelectron, the corresponding ratio r0(ω) shows a smooth turn-on of the satellite intensity, due to the turn on of the dipole matrix element. The characteristic energy scales are E~d and the satellite excitation energy δE. When the interaction potential with the continuum states is introduced an energy scale E~s=1/(2R~2s) enters, where R~s is a length scale of the interaction (scattering) potential. At threshold there is typically a (weak) constructive interference between intrinsic and extrinsic contributions, and the ratio r(ω)/r0(ω) is larger than its limiting value for large ω. The interference becomes small or weakly destructive for photoelectron energies of the order E~s. For larger photoelectron energies r(ω)/r0(ω) therefore typically has a weak undershoot. If this undershoot is neglected, r(ω)/r0(ω) reaches its limiting value on the energy scale E~s for the parameter range considered here. In a ``shake-up'' scenario, where the two outer levels do not cross as the core hole is created, we instead find that r(ω)/r0(ω) is typically reduced for small ω by interference effects, as in the case of plasmon excitation. Even for this shake-down case, however, the results are very different from those for a simple metal, where plasmons dominate the picture. In particular, the adiabatic to sudden transition takes place at much lower energies in the case of a localized excitation. The reasons for the differences are briefly discussed.

Long-lived thermal control materials for high temperature and deep space applications

NASA Technical Reports Server (NTRS)

Whitt, Robin; O'Donnell, Tim

1988-01-01

Considerable effort has been put into developing thermal-control materials for the Galileo space-craft. This paper presents a summary of these findings to date with emphasis on requirements, testing and results for the post-Challenger Galileo mission. Polyimide film (Kapton), due to its inherent stability in vacuum, UV, and radiation environments, combined with good mechanical properties over a large temperature range, has been the preferred substrate for spacecraft thermal control materials. Composite outer layers, using Kapton substrates, can be fabricated to meet the requirements of severe space environments. Included in the processing of Kapton-based composite outer layers can be the deposition of metal oxide, metallic and/or polymeric thin-film coatings to provide desirable electrical, optical and thermo-optical properties. In addition, reinforcement of Kapton substrates with fabrics and films is done to improve mechanical properties. Also these substrates can be filled with varying amounts of carbon to achieve particular electrical properties. The investigation and material development reported on here has led to improved thermo-gravimetric stability, surface conductivity, RF transparency, radiation and UV stability, flammability and handle-ability of outer layer thermal control materials for deep space and near-sun spacecraft. Designing, testing, and qualifying composite thermal-control film materials to meet the requirements of the Galileo spacecraft is the scope of this paper.

Chemical Abundances of Seven Outer Halo M31 Globular Clusters from the Pan-Andromeda Archaeological Survey

NASA Astrophysics Data System (ADS)

Sakari, Charli M.

2017-03-01

Observations of stellar streams in M31's outer halo suggest that M31 is actively accreting several dwarf galaxies and their globular clusters (GCs). Detailed abundances can chemically link clusters to their birth environments, establishing whether or not a GC has been accreted from a satellite dwarf galaxy. This talk presents the detailed chemical abundances of seven M31 outer halo GCs (with projected distances from M31 greater than 30 kpc), as derived from high-resolution integrated-light spectra taken with the Hobby Eberly Telescope. Five of these clusters were recently discovered in the Pan-Andromeda Archaeological Survey (PAndAS)-this talk presents the first determinations of integrated Fe, Na, Mg, Ca, Ti, Ni, Ba, and Eu abundances for these clusters. Four of the target clusters (PA06, PA53, PA54, and PA56) are metal-poor ([Fe/H] < -1.5), α-enhanced (though they are possibly less alpha-enhanced than Milky Way stars at the 1 sigma level), and show signs of star-to-star Na and Mg variations. The other three GCs (H10, H23, and PA17) are more metal-rich, with metallicities ranging from [Fe/H] = -1.4 to -0.9. While H23 is chemically similar to Milky Way field stars, Milky Way GCs, and other M31 clusters, H10 and PA17 have moderately-low [Ca/Fe], compared to Milky Way field stars and clusters. Additionally, PA17's high [Mg/Ca] and [Ba/Eu] ratios are distinct from Milky Way stars, and are in better agreement with the stars and clusters in the Large Magellanic Cloud (LMC). None of the clusters studied here can be conclusively linked to any of the identified streams from PAndAS; however, based on their locations, kinematics, metallicities, and detailed abundances, the most metal-rich PAndAS clusters H23 and PA17 may be associated with the progenitor of the Giant Stellar Stream, H10 may be associated with the SW Cloud, and PA53 and PA56 may be associated with the Eastern Cloud.

Adsorption mechanisms of selenium oxyanions at the aluminum oxide/water interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peak, Derek

2008-06-09

Sorption processes at the mineral/water interface typically control the mobility and bioaccessibility of many inorganic contaminants such as oxyanions. Selenium is an important micronutrient for human and animal health, but at elevated concentrations selenium toxicity is a concern. The objective of this study was to determine the bonding mechanisms of selenate (SeO{sub 4}{sup 2-}) and selenite (SeO{sub 3}{sup 2-}) on hydrous aluminum oxide (HAO) over a wide range of reaction pH using extended X-ray absorption fine structure (EXAFS) spectroscopy. Additionally, selenate adsorption on corundum ({alpha}-Al{sub 2}O{sub 3}) was studied to determine if adsorption mechanisms change as the aluminum oxide surfacemore » structure changes. The overall findings were that selenite forms a mixture of outer-sphere and inner-sphere bidentate-binuclear (corner-sharing) surface complexes on HAO, selenate forms primarily outer-sphere surface complexes on HAO, and on corundum selenate forms outer-sphere surface complexes at pH 3.5 but inner-sphere monodentate surface complexes at pH 4.5 and above. It is possible that the lack of inner-sphere complex formation at pH 3.5 is caused by changes in the corundum surface at low pH or secondary precipitate formation. The results are consistent with a structure-based reactivity for metal oxides, wherein hydrous metal oxides form outer-sphere complexes with sulfate and selenate, but inner-sphere monodentate surface complexes are formed between sulfate and selenate and {alpha}-Me{sub 2}O{sub 3}.« less

Ceramic gas turbine shroud

DOEpatents

Shi, Jun; Green, Kevin E.

2014-07-22

An example gas turbine engine shroud includes a first annular ceramic wall having an inner side for resisting high temperature turbine engine gasses and an outer side with a plurality of radial slots. A second annular metallic wall is positioned radially outwardly of and enclosing the first annular ceramic wall and has a plurality of tabs in communication with the slot of the first annular ceramic wall. The tabs of the second annular metallic wall and slots of the first annular ceramic wall are in communication such that the first annular ceramic wall and second annular metallic wall are affixed.

Bidirectional chaos communication between two outer semiconductor lasers coupled mutually with a central semiconductor laser.

PubMed

Li, Ping; Wu, Jia-Gui; Wu, Zheng-Mao; Lin, Xiao-Dong; Deng, Dao; Liu, Yu-Ran; Xia, Guang-Qiong

2011-11-21

Based on a linear chain composed of a central semiconductor laser and two outer semiconductor lasers, chaos synchronization and bidirectional communication between two outer lasers have been investigated under the case that the central laser and the two outer lasers are coupled mutually, whereas there exists no coupling between the two outer lasers. The simulation results show that high-quality and stable isochronal synchronization between the two outer lasers can be achieved, while the cross-correlation coefficients between the two outer lasers and the central laser are very low under proper operation condition. Based on the high performance chaos synchronization between the two outer lasers, message bidirectional transmissions of bit rates up to 20 Gbit/s can be realized through adopting a novel decoding scheme which is different from that based on chaos pass filtering effect. Furthermore, the security of bidirectional communication is also analyzed. © 2011 Optical Society of America

Mapping photometric metallicities in the Galactic halo using broadband photometry

NASA Astrophysics Data System (ADS)

Hebenstreit, Samuel David; Nidever, David L.; Munn, Jeffrey A.; Majewski, Steven R.

2018-06-01

An important objective of modern Astrophysics is to trace the history of galaxies and the dynamics of their formations. The outer regions of the Milky Way, including the Galactic halo, could potentially elucidate the evolutionary history of our galaxy. In this study, we make use of extensive DDO51 photometry combined with SDSS broadband photometry to select giant stars reaching to 90 kpc. Photometric metallicities, calibrated by overlapping spectroscopic data (SDSS, APOGEE and LAMOST), and distances are calculated for all giant stars. Using these metallicities and distances, we construct metallicity distribution functions (MDFs) from these stars. We study the MDFs for information pertaining to the accretion history of the Milky Way.

Analysis of stress-strain state of support ring of vertical steel tank RVS-20000

NASA Astrophysics Data System (ADS)

Chepur, P. V.; Tarasenko, A. A.; Gruchenkova, A. A.

2018-05-01

The refined finite element model of the joint of a fixed roof with a support ring for a large-size vertical steel tank RVS-20000 is executed. It considers the real geometry of metal shell plates - in accordance with the TP-704-1-60 design, geometric and physical nonlinearity, and features of the non-axisymmetric design loading scheme of the structure. Dependences of the SSS parameters of the support joint design on the size of the subsidence zone of the outer contour of the RVS-20000 bottom are obtained. It is established that at the value of subsidence zone coefficient n ≤ 1, a region of critical values occurs, exceeding which leads to the appearance of unacceptable plastic deformations of metal structures. The authors performed interpretation of the postprocessing of the finite element analysis, as a result of which the dependences of the parameters of the stress-strain state on the value of the zone of warping were obtained. The graphs of the dependence of the values of strains and stresses of the metal structure of the support ring on the size of the subsidence zone along the arc of the outer contour of the bottom are presented.

Leaf seal for inner and outer casings of a turbine

DOEpatents

Schroder, Mark Stewart; Leach, David

2002-01-01

A plurality of arcuate, circumferentially extending leaf seal segments form an annular seal spanning between annular sealing surfaces of inner and outer casings of a turbine. The ends of the adjoining seal segments have circumferential gaps to enable circumferential expansion and contraction of the segments. The end of a first segment includes a tab projecting into a recess of a second end of a second segment. Edges of the tab seal against the sealing surfaces of the inner and outer casings have a narrow clearance with opposed edges of the recess. An overlying cover plate spans the joint. Leakage flow is maintained at a minimum because of the reduced gap between the radially spaced edges of the tab and recess, while the seal segments retain the capacity to expand and contract circumferentially.

Transport comparison of multiwall carbon nanotubes by contacting outer shell and all shells.

PubMed

Luo, Qiang; Cui, A-Juan; Zhang, Yi-Guang; Lu, Chao; Jin, Ai-Zi; Yang, Hai-Fang; Gu, Chang-Zhi

2010-11-01

Carbon nanotubes, particularly multiwall carbon nanotubes (MWCNTs) can serve as interconnects in nanoelectronic devices and integrated circuits because of their extremely large current-carrying capacity. Many experimental results about the transport properties of individual MWCNTs by contacting outer shell or all shells have been reported. In this work, a compatible method with integrated circuit manufacturing process was presented to compare the transport property of an individual multiwall carbon nanotube (MWCNT) by contacting outer shell only and all shells successively. First of the Ti/Au electrodes contacting outer shell only were fabricated onto the nanotube through the sequence of electron beam lithography (EBL) patterning, metal deposition and lift-off process. After the characterization of its transport property, focused ion beam (FIB) was used to drill holes through the same nanotube at the as-deposited electrodes. Then new contact to the holes and electrodes were made by ion-induced deposition of tungsten from W(CO)6 precursor gas. The transport results indicated that the new contact to all shells can clear up the intershell resistance and the electrical conductance of the tube can be improved about 8 times compared to that of by contacting outer shell only.

Promoter Effects of Alkali Metal Cations on the Electrochemical Reduction of Carbon Dioxide

DOE PAGES

Resasco, Joaquin; Chen, Leanne D.; Clark, Ezra; ...

2017-07-24

The electrochemical reduction of CO 2 is known to be influenced by the identity of the alkali metal cation in the electrolyte; however, a satisfactory explanation for this phenomenon has not been developed. Here we present the results of experimental and theoretical studies aimed at elucidating the effects of electrolyte cation size on the intrinsic activity and selectivity of metal catalysts for the reduction of CO 2. Experiments were conducted under conditions where the influence of electrolyte polarization is minimal in order to show that cation size affects the intrinsic rates of formation of certain reaction products, most notably formore » HCOO –, C 2H 4, and C 2H 5OH over Cu(100)- and Cu(111)-oriented thin films, and for CO and HCOO– over polycrystalline Ag and Sn. Interpretation of the findings for CO 2 reduction was informed by studies of the reduction of glyoxal and CO, key intermediates along the reaction pathway to final products. Density functional theory calculations show that the alkali metal cations influence the distribution of products formed as a consequence of electrostatic interactions between solvated cations present at the outer Helmholtz plane and adsorbed species having large dipole moments. As a result, the observed trends in activity with cation size are attributed to an increase in the concentration of cations at the outer Helmholtz plane with increasing cation size.« less

Radial Velocity and Metallicity Determinations for Remote Globular Clusters in M31 and M33

NASA Astrophysics Data System (ADS)

Ferguson, Annette; Barmby, Pauline; Cote, Pat; Harris, Bill; Huxor, Avon; Mackey, Dougal; Puzia, Thomas

2009-08-01

We propose to determine radial velocities and metallicities for a sample of ~ 20 remote globular clusters (GCs) which we have discovered in the outer halos of the Local Group galaxies M31 and M33. Most of these objects have been uncovered in the course of the PAndAs survey, an international collaboration which is using CFHT/MegaPrime to map more than 300 square degrees in the g and i bands around M31 and M33. The target clusters, all of which have been identified from high- quality imaging (typically ≲ 0.8'' seeing), lie at projected radii of up to 130 kpc from M31 and 30 kpc from M33 and thus lie significantly beyond all previously-known GCs in these systems. Rather intriguingly, many of the new discoveries exhibit either possible associations with halo tidal streams, or show unusual spatial anisotropies with respect to their host galaxy. Velocity and metallicity data for these objects will provide a detailed characterization of the ensemble properties of the outer halo GC populations, and, through the search for kinematic and metallicity correlations within groups of GCs, help determine what fraction of these objects can be attributed to either late or ongoing accretion events. Ultimately, these data will also provide a basis for improved dynamical mass estimates of both galaxies.

Promoter Effects of Alkali Metal Cations on the Electrochemical Reduction of Carbon Dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Resasco, Joaquin; Chen, Leanne D.; Clark, Ezra

The electrochemical reduction of CO 2 is known to be influenced by the identity of the alkali metal cation in the electrolyte; however, a satisfactory explanation for this phenomenon has not been developed. Here we present the results of experimental and theoretical studies aimed at elucidating the effects of electrolyte cation size on the intrinsic activity and selectivity of metal catalysts for the reduction of CO 2. Experiments were conducted under conditions where the influence of electrolyte polarization is minimal in order to show that cation size affects the intrinsic rates of formation of certain reaction products, most notably formore » HCOO –, C 2H 4, and C 2H 5OH over Cu(100)- and Cu(111)-oriented thin films, and for CO and HCOO– over polycrystalline Ag and Sn. Interpretation of the findings for CO 2 reduction was informed by studies of the reduction of glyoxal and CO, key intermediates along the reaction pathway to final products. Density functional theory calculations show that the alkali metal cations influence the distribution of products formed as a consequence of electrostatic interactions between solvated cations present at the outer Helmholtz plane and adsorbed species having large dipole moments. As a result, the observed trends in activity with cation size are attributed to an increase in the concentration of cations at the outer Helmholtz plane with increasing cation size.« less

Formation of metal clusters in halloysite clay nanotubes

DOE PAGES

Vinokurov, Vladimir A.; Stavitskaya, Anna V.; Chudakov, Yaroslav A.; ...

2017-02-16

We developed ceramic core-shell materials based on abundant halloysite clay nanotubes with enhanced heavy metal ions loading through Schiff base binding. These clay tubes are formed by rolling alumosilicate sheets and have diameter of c.50 nm, a lumen of 15 nm and length ~1 μm. This allowed for synthesis of metal nanoparticles at the selected position: (1) on the outer surface seeding 3-5 nm metal particles on the tubes; (2) inside the tube’s central lumen resulting in 10-12 nm diameter metal cores shelled with ceramic wall; and (3) smaller metal nanoparticles intercalated in the tube’s wall allowing up to 9more » wt% of Ru, and Ag loading. These composite materials have high surface area providing a good support for catalytic nanoparticles, and can also be used for sorption of metal ions from aqueous solutions.« less

Formation of metal clusters in halloysite clay nanotubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vinokurov, Vladimir A.; Stavitskaya, Anna V.; Chudakov, Yaroslav A.

We developed ceramic core-shell materials based on abundant halloysite clay nanotubes with enhanced heavy metal ions loading through Schiff base binding. These clay tubes are formed by rolling alumosilicate sheets and have diameter of c.50 nm, a lumen of 15 nm and length ~1 μm. This allowed for synthesis of metal nanoparticles at the selected position: (1) on the outer surface seeding 3-5 nm metal particles on the tubes; (2) inside the tube’s central lumen resulting in 10-12 nm diameter metal cores shelled with ceramic wall; and (3) smaller metal nanoparticles intercalated in the tube’s wall allowing up to 9more » wt% of Ru, and Ag loading. These composite materials have high surface area providing a good support for catalytic nanoparticles, and can also be used for sorption of metal ions from aqueous solutions.« less

Formation of metal clusters in halloysite clay nanotubes

PubMed Central

Vinokurov, Vladimir A.; Stavitskaya, Anna V.; Chudakov, Yaroslav A.; Ivanov, Evgenii V.; Shrestha, Lok Kumar; Ariga, Katsuhiko; Darrat, Yusuf A.; Lvov, Yuri M.

2017-01-01

Abstract We developed ceramic core-shell materials based on abundant halloysite clay nanotubes with enhanced heavy metal ions loading through Schiff base binding. These clay tubes are formed by rolling alumosilicate sheets and have diameter of c.50 nm, a lumen of 15 nm and length ~1 μm. This allowed for synthesis of metal nanoparticles at the selected position: (1) on the outer surface seeding 3–5 nm metal particles on the tubes; (2) inside the tube’s central lumen resulting in 10–12 nm diameter metal cores shelled with ceramic wall; and (3) smaller metal nanoparticles intercalated in the tube’s wall allowing up to 9 wt% of Ru, and Ag loading. These composite materials have high surface area providing a good support for catalytic nanoparticles, and can also be used for sorption of metal ions from aqueous solutions. PMID:28458738

Si-depleted outer core inferred from sound velocity measurements of liquid Fe-Si alloys

NASA Astrophysics Data System (ADS)

Nakajima, Y.; Imada, S.; Hirose, K.; Kuwayama, Y.; Sinmyo, R.; Tateno, S.; Ozawa, H.; Tsutsui, S.; Uchiyama, H.; Baron, A. Q. R.

2016-12-01

Recent core formation models [1,2] suggested that a large amount of Si could have been incorporated into the core forming metals in the early stage of the Earth. These studies gave estimates for the Si content in the core, from 2 to 9 wt.%. In order to constrain the Si content of the outer core, we have determined the sound wave velocity of liquid Fe-Si alloys under high pressures and high temperatures. Starting materials of Fe-Si alloys with 6.5 and 9 wt.% Si were melted in a laser-heated diamond-anvil cell. The longitudinal acoustic phonon excitation of a liquid metal was measured up to 52 GPa and 3200 K by using high resolution inelastic X-ray scattering spectroscopy at beamline BL35XU [3] of the SPring-8 synchrotron facility. Our results show that silicon significantly increases the P-wave velocity of liquid Fe. Seismological observation shows that the P-wave velocity in the outer core is 3-4% faster than in pure iron. Comparing the present results with seismological observations, the silicon content of the outer core should be limited to be <2 wt.%, significantly lower than previous estimates based on the element partitioning between core forming mental and silicate magma ocean during core formation processes. This indicates that the present-day core is depleted in Si relative to the ancient core just after core formation, which agrees with the recent proposal [4] that the Si content in the outer core has been diminished by SiO2 crystallization through the core cooling history. [1] Rubie et al. (2011) Earth Planet. Sci. Lett. 301, 31-42. [2] Siebert et al. (2013) Science 339, 1194-1197. [3] Baron et al. (2000) J. Phys. Chem. Solids 61, 461-465 [4] Hirose et al. (2015) Abstract presented at AGU Fall Meeting 2015.

Outer planet probe navigation. [considering Pioneer space missions

NASA Technical Reports Server (NTRS)

Friedman, L.

1974-01-01

A series of navigation studies in conjunction with outer planet Pioneer missions are reformed to determine navigation requirements and measurement systems in order to target probes. Some particular cases are established where optical navigation is important and some cases where radio alone navigation is suffucient. Considered are a direct Saturn mission, a Saturn Uranus mission, a Jupiter Uranus mission, and a Titan probe mission.

Oligo-m-phenyleneoxalamide copper(II) mesocates as electro-switchable ferromagnetic metal-organic wires.

PubMed

Pardo, Emilio; Ferrando-Soria, Jesús; Dul, Marie-Claire; Lescouëzec, Rodrigue; Journaux, Yves; Ruiz-García, Rafael; Cano, Joan; Julve, Miguel; Lloret, Francesc; Cañadillas-Delgado, Laura; Pasán, Jorge; Ruiz-Pérez, Catalina

2010-11-15

Double-stranded copper(II) string complexes of varying nuclearity, from di- to tetranuclear species, have been prepared by the Cu(II)-mediated self-assembly of a novel family of linear homo- and heteropolytopic ligands that contain two outer oxamato and either zero (1 b), one (2 b), or two (3 b) inner oxamidato donor groups separated by rigid 2-methyl-1,3-phenylene spacers. The X-ray crystal structures of these Cu(II) (n) complexes (n=2 (1 d), 3 (2 d), and 4 (3 d)) show a linear array of metal atoms with an overall twisted coordination geometry for both the outer CuN(2)O(2) and inner CuN(4) chromophores. Two such nonplanar all-syn bridging ligands 1 b-3 b in an anti arrangement clamp around the metal centers with alternating M and P helical chiralities to afford an overall double meso-helicate-type architecture for 1 d-3 d. Variable-temperature (2.0-300 K) magnetic susceptibility and variable-field (0-5.0 T) magnetization measurements for 1 d-3 d show the occurrence of S=nS(Cu) (n=2-4) high-spin ground states that arise from the moderate ferromagnetic coupling between the unpaired electrons of the linearly disposed Cu(II) ions (S(Cu)=1/2) through the two anti m-phenylenediamidate-type bridges (J values in the range of +15.0 to 16.8 cm(-1)). Density functional theory (DFT) calculations for 1 d-3 d evidence a sign alternation of the spin density in the meta-substituted phenylene spacers in agreement with a spin polarization exchange mechanism along the linear metal array with overall intermetallic distances between terminal metal centers in the range of 0.7-2.2 nm. Cyclic voltammetry (CV) and rotating-disk electrode (RDE) electrochemical measurements for 1 d-3 d show several reversible or quasireversible one- or two-electron steps that involve the consecutive metal-centered oxidation of the inner and outer Cu(II) ions (S(Cu)=1/2) to diamagnetic Cu(III) ones (S(Cu)=0) at relatively low formal potentials (E values in the range of +0.14 to 0.25 V and of +0.43 to 0.67 V vs. SCE, respectively). Further developments may be envisaged for this family of oligo-m-phenyleneoxalamide copper(II) double mesocates as electroswitchable ferromagnetic 'metal-organic wires' (MOWs) on the basis of their unique ferromagnetic and multicenter redox behaviors.

Fiber glass prevents cracking of polyurethane foam insulation on cryogenic vessels

NASA Technical Reports Server (NTRS)

Forge, D. A.

1968-01-01

Fiber glass material, placed between polyurethane foam insulation and the outer surfaces of cryogenic vessels, retains its resilience at cryogenic temperatures and provides an expansion layer between the metal surfaces and the polyurethane foam, preventing cracking of the latter.

Multilayer Composite Pressure Vessels

NASA Technical Reports Server (NTRS)

DeLay, Tom

2005-01-01

A method has been devised to enable the fabrication of lightweight pressure vessels from multilayer composite materials. This method is related to, but not the same as, the method described in gMaking a Metal- Lined Composite-Overwrapped Pressure Vessel h (MFS-31814), NASA Tech Briefs, Vol. 29, No. 3 (March 2005), page 59. The method is flexible in that it poses no major impediment to changes in tank design and is applicable to a wide range of tank sizes. The figure depicts a finished tank fabricated by this method, showing layers added at various stages of the fabrication process. In the first step of the process, a mandrel that defines the size and shape of the interior of the tank is machined from a polyurethane foam or other suitable lightweight tooling material. The mandrel is outfitted with metallic end fittings on a shaft. Each end fitting includes an outer flange that has a small step to accommodate a thin layer of graphite/epoxy or other suitable composite material. The outer surface of the mandrel (but not the fittings) is covered with a suitable release material. The composite material is filament- wound so as to cover the entire surface of the mandrel from the step on one end fitting to the step on the other end fitting. The composite material is then cured in place. The entire workpiece is cut in half in a plane perpendicular to the axis of symmetry at its mid-length point, yielding two composite-material half shells, each containing half of the foam mandrel. The halves of the mandrel are removed from within the composite shells, then the shells are reassembled and bonded together with a belly band of cured composite material. The resulting composite shell becomes a mandrel for the subsequent steps of the fabrication process and remains inside the final tank. The outer surface of the composite shell is covered with a layer of material designed to be impermeable by the pressurized fluid to be contained in the tank. A second step on the outer flange of each end fitting accommodates this layer. Depending on the application, this layer could be, for example, a layer of rubber, a polymer film, or an electrodeposited layer of metal. If the fluid to be contained in the tank is a gas, then the best permeation barrier is electrodeposited metal (typically copper or nickel), which can be effective at a thickness of as little as 0.005 in (.0.13 mm). The electrodeposited metal becomes molecularly bonded to the second step on each metallic end fitting. The permeation-barrier layer is covered with many layers of filament-wound composite material, which could be the same as, or different from, the composite material of the inner shell. Finally, the filament-wound composite material is cured in an ov

Controlled modulation of hard and soft X-ray induced tunneling currents utilizing coaxial metal-insulator-metal probe tips

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cummings, Marvin; Shirato, Nozomi; Kersell, Heath

Here, the effect of a local external electric field on the barrier potential of a tunneling gap is studied utilizing an emerging technique, synchrotron x-ray scanning tunneling microscopy. Here, we demonstrate that the shape of the potential barrier in the tunneling gap can be altered by a localized external electric field, generated by voltages placed on the metallic outer shield of a nanofabricated coaxial metal-insulator-metal tip, resulting in a controlled linear modulation of the tunneling current. Experiments at hard and soft x-ray synchrotron beamlines reveal that both the chemical contrast and magnetic contrast signals measured by the tip can bemore » drastically enhanced, resulting in improved local detection of chemistry and magnetization at the surface.« less

Controlled modulation of hard and soft X-ray induced tunneling currents utilizing coaxial metal-insulator-metal probe tips

DOE PAGES

Cummings, Marvin; Shirato, Nozomi; Kersell, Heath; ...

2017-01-05

Here, the effect of a local external electric field on the barrier potential of a tunneling gap is studied utilizing an emerging technique, synchrotron x-ray scanning tunneling microscopy. Here, we demonstrate that the shape of the potential barrier in the tunneling gap can be altered by a localized external electric field, generated by voltages placed on the metallic outer shield of a nanofabricated coaxial metal-insulator-metal tip, resulting in a controlled linear modulation of the tunneling current. Experiments at hard and soft x-ray synchrotron beamlines reveal that both the chemical contrast and magnetic contrast signals measured by the tip can bemore » drastically enhanced, resulting in improved local detection of chemistry and magnetization at the surface.« less

Diaphragm flange and method for lowering particle beam impedance at connected beam tubes of a particle accelerator

DOEpatents

Biallas, George Herman

2017-07-04

A diaphragm flange for connecting the tubes in a particle accelerator while minimizing beamline impedance. The diaphragm flange includes an outer flange and a thin diaphragm integral with the outer flange. Bolt holes in the outer flange provide a means for bolting the diaphragm flange to an adjacent flange or beam tube having a mating bolt-hole pattern. The diaphragm flange includes a first surface for connection to the tube of a particle accelerator beamline and a second surface for connection to a CF flange. The second surface includes a recessed surface therein and a knife-edge on the recessed surface. The diaphragm includes a thickness that enables flexing of the integral diaphragm during assembly of beamline components. The knife-edge enables compression of a soft metal gasket to provide a leak-tight seal.

Cured composite materials for reactive metal battery electrolytes

DOEpatents

Harrup, Mason K.; Stewart, Frederick F.; Peterson, Eric S.

2006-03-07

A solid molecular composite polymer-based electrolyte is made for batteries, wherein silicate compositing produces a electrolytic polymer with a semi-rigid silicate condensate framework, and then mechanical-stabilization by radiation of the outer surface of the composited material is done to form a durable and non-tacky texture on the electrolyte. The preferred ultraviolet radiation produces this desirable outer surface by creating a thin, shallow skin of crosslinked polymer on the composite material. Preferably, a short-duration of low-medium range ultraviolet radiation is used to crosslink the polymers only a short distance into the polymer, so that the properties of the bulk of the polymer and the bulk of the molecular composite material remain unchanged, but the tough and stable skin formed on the outer surface lends durability and processability to the entire composite material product.

Radiation Hydrodynamics Simulations of Photoevaporation of Protoplanetary Disks by Ultraviolet Radiation: Metallicity Dependence

NASA Astrophysics Data System (ADS)

Nakatani, Riouhei; Hosokawa, Takashi; Yoshida, Naoki; Nomura, Hideko; Kuiper, Rolf

2018-04-01

Protoplanetary disks are thought to have lifetimes of several million yr in the solar neighborhood, but recent observations suggest that the disk lifetimes are shorter in a low-metallicity environment. We perform a suite of radiation hydrodynamics simulations of photoevaporating protoplanetary disks to study their long-term evolution of ∼10,000 yr and the metallicity dependence of mass-loss rates. Our simulations follow hydrodynamics, extreme and far-ultraviolet (FUV) radiative transfer, and nonequilibrium chemistry in a self-consistent manner. Dust-grain temperatures are also calculated consistently by solving the radiative transfer of the stellar irradiation and grain (re-)emission. We vary the disk metallicity over a wide range of {10}-4 {Z}ȯ ≤slant Z≤slant 10 {Z}ȯ . The photoevaporation rate is lower with higher metallicity in the range of {10}-1 {Z}ȯ ≲ Z≲ 10 {Z}ȯ , because dust shielding effectively prevents FUV photons from penetrating and heating the dense regions of the disk. The photoevaporation rate sharply declines at even lower metallicities in {10}-2 {Z}ȯ ≲ Z≲ {10}-1 {Z}ȯ , because FUV photoelectric heating becomes less effective than dust–gas collisional cooling. The temperature in the neutral region decreases, and photoevaporative flows are excited only in an outer region of the disk. At {10}-4 {Z}ȯ ≤slant Z≲ {10}-2 {Z}ȯ , H I photoionization heating acts as a dominant gas heating process and drives photoevaporative flows with a roughly constant rate. The typical disk lifetime is shorter at Z = 0.3 {Z}ȯ than at Z={Z}ȯ , being consistent with recent observations of the extreme outer galaxy.

Computer simulation of uranyl uptake by the rough lipopolysaccharide membrane of Pseudomonas aeruginosa.

PubMed

Lins, Roberto D; Vorpagel, Erich R; Guglielmi, Matteo; Straatsma, T P

2008-01-01

Heavy metal environmental contaminants cannot be destroyed but require containment, preferably in concentrated form, in a solid or immobile form for recycling or final disposal. Microorganisms are able to take up and deposit high levels of contaminant metals, including radioactive metals such as uranium and plutonium, into their cell wall. Consequently, these microbial systems are of great interest as the basis for potential environmental bioremediation technologies. The outer membranes of Gram-negative microbes are highly nonsymmetric and exhibit a significant electrostatic potential gradient across the membrane. This gradient has a significant effect on the uptake and transport of charged and dipolar compounds. However, the effectiveness of microbial systems for environmental remediation will depend strongly on specific properties that determine the uptake of targeted contaminants by a particular cell wall. To aid in the design of microbial remediation technologies, knowledge of the factors that determine the affinity of a particular bacterial outer membrane for the most common ionic species found in contaminated soils and groundwater is of great importance. Using our previously developed model for the lipopolysaccharide (LPS) membrane of Pseudomonas aeruginosa, this work presents the potentials of mean force as the estimate of the free energy profile for uptake of sodium, calcium, chloride, uranyl ions, and a water molecule by the bacterial LPS membrane. A compatible classical parameter set for uranyl has been developed and validated. Results show that the uptake of uranyl is energetically a favorable process relative to the other ions studied. At neutral pH, this nuclide is shown to be retained on the surface of the LPS membrane through chelation with the carboxyl and hydroxyl groups located in the outer core.

Heat shield manifold system for a midframe case of a gas turbine engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayer, Clinton A.; Eng, Jesse; Schopf, Cheryl A.

A heat shield manifold system for an inner casing between a compressor and turbine assembly is disclosed. The heat shield manifold system protects the outer case from high temperature compressor discharge air, thereby enabling the outer case extending between a compressor and a turbine assembly to be formed from less expensive materials than otherwise would be required. In addition, the heat shield manifold system may be configured such that compressor bleed air is passed from the compressor into the heat shield manifold system without passing through a conventional flange to flange joint that is susceptible to leakage.

Spatiotemporal exposome dynamics of soil lead and children's blood lead pre- and ten years post-Hurricane Katrina: Lead and other metals on public and private properties in the city of New Orleans, Louisiana, U.S.A.

PubMed

Mielke, Howard W; Gonzales, Christopher R; Powell, Eric T; Mielke, Paul W

2017-05-01

Anthropogenic re-distribution of lead (Pb) principally through its use in gasoline additives and lead-based paints have transformed the urban exposome. This unique study tracks urban-scale soil Pb (SPb) and blood Pb (BPb) responses of children living in public and private communities in New Orleans before and ten years after Hurricane Katrina (29 August 2005). To compare and evaluate associations of pre- and ten years post-Katrina SPb and children's BPb on public and private residential census tracts in the core and outer areas of New Orleans, and to examine correlations between SPb and nine other soil metals. The Louisiana Healthy Housing and Childhood Lead Poisoning Prevention Program BPb (µg/dL) data from pre- (2000-2005) and post-Katrina (2010-2015) for ≤6-year-old children. Data from public and adjacent private residential census tracts within core and outer areas are stratified from a database that includes 916 and 922 SPb and 13,379 and 4830 BPb results, respectively, from pre- and post-Katrina New Orleans. Statistical analyses utilize Multi-Response Permutation Procedure and Spearman's Rho Correlation. Pre- to Post-Katrina median SPb decreases in public and private core census tracts were from 285 to 55mg/kg and 710-291mg/kg, respectively. In public and private outer census tracts the median SPb decreased from 109 to 56mg/kg and 88-55mg/kg. Children's BPb percent ≥5µg/dL on public and private core areas pre-Katrina was 63.2% and 67.5%, and declined post-Katrina to 7.6% and 20.2%, respectively. BPb decreases also occurred in outer areas. Soil Pb is strongly correlated with other metals. Post-Katrina re-building of public housing plus landscaping amends the exposome and reduces children's BPb. Most importantly, Hurricane Katrina revealed that decreasing the toxicants in the soil exposome is an effective intervention for decreasing children's BPb. Copyright © 2017 Elsevier Inc. All rights reserved.

33 CFR 142.36 - Protective clothing.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.36 Protective clothing. Personnel in areas where there are flying particles, molten metal, radiant energy, heavy... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Protective clothing. 142.36...

33 CFR 142.36 - Protective clothing.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.36 Protective clothing. Personnel in areas where there are flying particles, molten metal, radiant energy, heavy... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Protective clothing. 142.36...

Method for shearing spent nuclear fuel assemblies

DOEpatents

Weil, Bradley S.; Watson, Clyde D.

1977-01-01

A method is disclosed for shearing spent nuclear fuel assemblies of the type wherein a plurality of long metal tubes packed with ceramic fuel are supported in a spaced apart relationship within an outer metal shell or shroud which provides structural support to the assembly. Spent nuclear fuel assemblies are first compacted in a stepwise manner between specially designed gag-compactors and then sheared into short segments amenable to chemical processing by shear blades contoured to mate with the compacted surface of the fuel assembly.

Ionic polymer-metal composite actuators based on triple-layered polyelectrolytes composed of individually functionalized layers.

PubMed

Lee, Jang-Woo; Yoo, Young-Tai; Lee, Jae Yeol

2014-01-22

Ionic polymer-metal composite (IPMC) actuators based on two types of triple-layered Nafion composite membranes were prepared via consecutive solution recasting and electroless plating methods. The triple-layered membranes are composed of a Nafion layer containing an amphiphilic organic molecule (10-camphorsulfonic acid; CSA) in the middle section (for fast and large ion conduction) and two Nafion/modified inorganic composite layers in the outer sections (for large accumulation/retention of mobile ions). For construction of the two types of IPMCs, sulfonated montmorillonite (MMT) and polypyrrole (PPy)-coated alumina fillers were incorporated into the outer layers. Both the triple-layered IPMCs exhibited 42% higher tip displacements at the maximum deflections with a negligible back-relaxation, 50-74% higher blocking forces, and more rapid responses under 3 V dc, compared with conventional single-layered Nafion-IPMCs. Improvements in cyclic displacement under a rectangular voltage input of 3 V at 1 Hz were also made in the triple-layered configurations. Compared with single-layered IPMCs consisting of the identical compositions with the respective outer composite layers, the bending rates and energy efficiencies of both the triple-layered IPMCs were significantly higher, although the blocking forces were a bit lower. These remarkable improvements were attributed to higher capacitances and Young's moduli as well as a more efficient transport of mobile ions and water through the middle layer (Nafion/CSA) and a larger accumulation/retention of the mobile species in the outer functionalized inorganic composite layers. Especially, the triple-layered IPMC with the PPy-modified alumina registered the best actuation performance among all the samples, including a viable actuation even at a low voltage of 1.5 V due to involving efficient redox reactions of PPy with the aid of hygroscopic alumina.

Error Control Coding Techniques for Space and Satellite Communications

NASA Technical Reports Server (NTRS)

Lin, Shu

2000-01-01

This paper presents a concatenated turbo coding system in which a Reed-Solomom outer code is concatenated with a binary turbo inner code. In the proposed system, the outer code decoder and the inner turbo code decoder interact to achieve both good bit error and frame error performances. The outer code decoder helps the inner turbo code decoder to terminate its decoding iteration while the inner turbo code decoder provides soft-output information to the outer code decoder to carry out a reliability-based soft-decision decoding. In the case that the outer code decoding fails, the outer code decoder instructs the inner code decoder to continue its decoding iterations until the outer code decoding is successful or a preset maximum number of decoding iterations is reached. This interaction between outer and inner code decoders reduces decoding delay. Also presented in the paper are an effective criterion for stopping the iteration process of the inner code decoder and a new reliability-based decoding algorithm for nonbinary codes.

An Interactive Concatenated Turbo Coding System

NASA Technical Reports Server (NTRS)

Liu, Ye; Tang, Heng; Lin, Shu; Fossorier, Marc

1999-01-01

This paper presents a concatenated turbo coding system in which a Reed-Solomon outer code is concatenated with a binary turbo inner code. In the proposed system, the outer code decoder and the inner turbo code decoder interact to achieve both good bit error and frame error performances. The outer code decoder helps the inner turbo code decoder to terminate its decoding iteration while the inner turbo code decoder provides soft-output information to the outer code decoder to carry out a reliability-based soft- decision decoding. In the case that the outer code decoding fails, the outer code decoder instructs the inner code decoder to continue its decoding iterations until the outer code decoding is successful or a preset maximum number of decoding iterations is reached. This interaction between outer and inner code decoders reduces decoding delay. Also presented in the paper are an effective criterion for stopping the iteration process of the inner code decoder and a new reliability-based decoding algorithm for nonbinary codes.

OUTER LOOP LANDFILL CASE STUDY

EPA Science Inventory

This presentation will describe the interim data reaulting from a CRADA between USEPA and Waste Management, Inc. at the outer Loop Landfill Bioreactor research project located in Louisville, KY. Recently updated data will be presented covering landfill solids, gas being collecte...

Globally Convergent Methods for Solving Coefficient Inverse Problems for Time Dependent Maxwell Equations

DTIC Science & Technology

2014-08-19

geode (heterogeneous): Rock two spherical layers and air inside 13 Blind A piece of rock Rock 14 Blind A plastic bottle filled with coffee grounds... Coffee grounds 15 Blind A ceramic mug Ceramic 16 Blind A cylinder and a block at 3 cm separation Metal/Metal 17 Blind An aluminum can and a block Metal...2.5 cm 1.0 1.52 1.31 (outer) (two layers) 1.25 (inner) 1.28 (average) 13 Rock 2.0 cm 2.3 cm 1.0 1.34 1.34 14 Coffee grounds 2.0 cm 2.5 cm 1.0 1.46

High-performance, lightweight coaxial cable from carbon nanotube conductors.

PubMed

Jarosz, Paul R; Shaukat, Aalyia; Schauerman, Christopher M; Cress, Cory D; Kladitis, Paul E; Ridgley, Richard D; Landi, Brian J

2012-02-01

Coaxial cables have been constructed with carbon nanotube (CNT) materials serving as both the inner and outer conductors. Treatment of the CNT outer and inner conductors with KAuBr(4) was found to significantly reduce the attenuation of these cables, which demonstrates that chemical agents can be used to improve power transmission through CNT networks at high frequencies (150 kHz-3 GHz). For cables constructed with a KAuBr(4)-treated CNT outer conductor, power attenuation per length approaches parity with cables constructed from metallic conductors at significantly lower weight per length (i.e., 7.1 g/m for CNT designs compared to 38.8 g/m for an RG-58 design). A relationship between the thickness of the CNT outer conductor and the cable attenuation was observed and used to estimate the effective skin depth at high frequency. These results establish reliable, reproducible methods for the construction of coaxial cables from CNT materials that can facilitate further investigation of their performance in high-frequency transmission structures, and highlight a specific opportunity for significant reduction in coaxial cable mass.

Adsorption of lead on multi-walled carbon nanotubes with different outer diameters and oxygen contents: kinetics, isotherms and thermodynamics.

PubMed

Yu, Fei; Wu, Yanqing; Ma, Jie; Zhang, Chi

2013-01-01

The effects of different outer diameters and surface oxygen contents on the adsorption of heavy metals onto six types of multi-walled carbon nanotubes (MWCNTs) were investigated in an aqueous solution and lead was chosen as a model metal ion. The results indicated that the percentage removal and adsorption capacity of lead remarkably increased with decreasing outer diameter due to larger specific surface area (SSA). The SSA-normalized maximum adsorption capacity (qmSSA) and SSA-normalized adsorption coefficient (Kd/SSA) were strongly positively correlated with surface oxygen content, implying that lead adsorption onto MWCNTs significantly increases with the rise of oxygen content and decreases with decreasing SSA. The calculated thermodynamic parameters indicated that adsorption of lead on MWCNTs was endothermic and spontaneous. When the oxygen content of MWCNTs increased from 2.0% to 5.9%, the standard free energy (deltaG0) became more negative, which implied that the oxygenated functional groups increased the adsorption affinity of MWCNTs for lead. Through calculation of enthalpy (deltaH0), deltaG0 and free energy of adsorption (Ea), lead adsorption onto MWCNTs was recognized as a chemisorption process. The chemical interaction between lead and the phenolic groups of MWCNTs could be one of the main adsorption mechanisms due to highly positive correlations between the phenolic groups and Kd/SSA or qm/SSA.

Evolution of Optical Binary Fraction in Sparse Stellar Systems

NASA Astrophysics Data System (ADS)

Li, Zhongmu; Mao, Caiyan

2018-05-01

This work studies the evolution of the fraction of optical binary stars (OBF; not including components such as neutron stars and black holes), which is caused by stellar evolution, and the contributions of various binaries to OBF via the stellar population synthesis technique. It is shown that OBF decreases from 1 to about 0.81 for stellar populations with the Salpeter initial mass function (IMF), and to about 0.85 for the case of the Kroupa IMF, on a timescale of 15 Gyr. This result depends on metallicity, slightly. The contributions of binaries varying with mass ratio, orbital period, separation, spectral types of primary and secondary, contact degree, and pair type to OBF are calculated for stellar populations with different ages and metallicities. The contribution of different kinds of binaries to OBF depends on age and metallicity. The results can be used for estimating the global OBF of star clusters or galaxies from the fraction of a kind of binary. It is also helpful for estimating the primordial and future binary fractions of sparse stellar systems from the present observations. Our results are suitable for studying field stars, open clusters, and the outer part of globular clusters, because the OBF of such objects is affected by dynamical processes, relatively slightly, but they can also be used for giving some limits for other populations.

IODIDE AEROSOL SORBENTS FOR MERCURY CAPTURE IN COMBUSTION EXHAUSTS

EPA Science Inventory

Several sorbent processes are being studied for their feasibility for mercury capture. Mercury is different from the other heavy metals as it is not as chemically reactive (due to a filled outer electronic shell), thus making it difficult for sorbents to chemically trap it (a). ...

CMC vane assembly apparatus and method

DOEpatents

Schiavo, Anthony L; Gonzalez, Malberto F; Huang, Kuangwei; Radonovich, David C

2012-10-23

A metal vane core or strut (64) is formed integrally with an outer backing plate (40). An inner backing plate (38) is formed separately. A spring (74) with holes (75) is installed in a peripheral spring chamber (76) on the strut. Inner and outer CMC shroud covers (46, 48) are formed, cured, then attached to facing surfaces of the inner and outer backing plates (38, 40). A CMC vane airfoil (22) is formed, cured, and slid over the strut (64). The spring (74) urges continuous contact between the strut (64) and airfoil (66), eliminating vibrations while allowing differential expansion. The inner end (88) of the strut is fastened to the inner backing plate (38). A cooling channel (68) in the strut is connected by holes (69) along the leading edge of the strut to peripheral cooling paths (70, 71) around the strut. Coolant flows through and around the strut, including through the spring holes.

Protective coating for ceramic materials

NASA Technical Reports Server (NTRS)

Kourtides, Demetrius A. (Inventor); Churchward, Rex A. (Inventor); Lowe, David M. (Inventor)

1994-01-01

A protective coating for ceramic materials such as those made of silicon carbide, aluminum oxide, zirconium oxide, aluminoborosilicate and silicon dioxide, and a thermal control structure comprising a ceramic material having coated thereon the protective coating. The protective coating contains, in admixture, silicon dioxide powder, colloidal silicon dioxide, water, and one or more emittance agents selected from silicon tetraboride, silicon hexaboride, silicon carbide, molybdenum disilicide, tungsten disilicide and zirconium diboride. In another aspect, the protective coating is coated on a flexible ceramic fabric which is the outer cover of a composite insulation. In yet another aspect, a metallic foil is bonded to the outer surface of a ceramic fabric outer cover of a composite insulation via the protective coating. A primary application of this invention is as a protective coating for ceramic materials used in a heat shield for space vehicles subjected to very high aero-convective heating environments.

Catalyst cartridge for carbon dioxide reduction unit

NASA Technical Reports Server (NTRS)

Holmes, R. F. (Inventor)

1973-01-01

A catalyst cartridge, for use in a carbon dioxide reducing apparatus in a life support system for space vehicles, is described. The catalyst cartridge includes an inner perforated metal wall, an outer perforated wall space outwardly from the inner wall, a base plate closing one end of the cartridge, and a cover plate closing the other end of the cartridge. The cover plate has a central aperture through which a supply line with a heater feeds a gaseous reaction mixture comprising hydrogen and carbon dioxide at a temperature from about 1000 to about 1400 F. The outer surfaces of the internal wall and the inner surfaces of the outer wall are lined with a ceramic fiber batting material of sufficient thickness to prevent carbon formed in the reaction from passing through it. The portion of the surfaces of the base and cover plates defined within the inner and outer walls are also lined with ceramic batting. The heated reaction mixture passes outwardly through the inner perforated wall and ceramic batting and over the catalyst. The solid carbon product formes is retained within the enclosure containing the catalyst. The solid carbon product formed is retained within the enclosure containing the catalyst. The water vapor and unreacted carbon dioxide and any intermediate products pass through the perforations of the outer wall.

Nanostructured high-energy cathode materials for advanced lithium batteries

NASA Astrophysics Data System (ADS)

Sun, Yang-Kook; Chen, Zonghai; Noh, Hyung-Joo; Lee, Dong-Ju; Jung, Hun-Gi; Ren, Yang; Wang, Steve; Yoon, Chong Seung; Myung, Seung-Taek; Amine, Khalil

2012-11-01

Nickel-rich layered lithium transition-metal oxides, LiNi1-xMxO2 (M = transition metal), have been under intense investigation as high-energy cathode materials for rechargeable lithium batteries because of their high specific capacity and relatively low cost. However, the commercial deployment of nickel-rich oxides has been severely hindered by their intrinsic poor thermal stability at the fully charged state and insufficient cycle life, especially at elevated temperatures. Here, we report a nickel-rich lithium transition-metal oxide with a very high capacity (215 mA h g-1), where the nickel concentration decreases linearly whereas the manganese concentration increases linearly from the centre to the outer layer of each particle. Using this nano-functional full-gradient approach, we are able to harness the high energy density of the nickel-rich core and the high thermal stability and long life of the manganese-rich outer layers. Moreover, the micrometre-size secondary particles of this cathode material are composed of aligned needle-like nanosize primary particles, resulting in a high rate capability. The experimental results suggest that this nano-functional full-gradient cathode material is promising for applications that require high energy, long calendar life and excellent abuse tolerance such as electric vehicles.

Nanostructured high-energy cathode materials for advanced lithium batteries.

PubMed

Sun, Yang-Kook; Chen, Zonghai; Noh, Hyung-Joo; Lee, Dong-Ju; Jung, Hun-Gi; Ren, Yang; Wang, Steve; Yoon, Chong Seung; Myung, Seung-Taek; Amine, Khalil

2012-11-01

Nickel-rich layered lithium transition-metal oxides, LiNi(1-x)M(x)O(2) (M = transition metal), have been under intense investigation as high-energy cathode materials for rechargeable lithium batteries because of their high specific capacity and relatively low cost. However, the commercial deployment of nickel-rich oxides has been severely hindered by their intrinsic poor thermal stability at the fully charged state and insufficient cycle life, especially at elevated temperatures. Here, we report a nickel-rich lithium transition-metal oxide with a very high capacity (215 mA h g(-1)), where the nickel concentration decreases linearly whereas the manganese concentration increases linearly from the centre to the outer layer of each particle. Using this nano-functional full-gradient approach, we are able to harness the high energy density of the nickel-rich core and the high thermal stability and long life of the manganese-rich outer layers. Moreover, the micrometre-size secondary particles of this cathode material are composed of aligned needle-like nanosize primary particles, resulting in a high rate capability. The experimental results suggest that this nano-functional full-gradient cathode material is promising for applications that require high energy, long calendar life and excellent abuse tolerance such as electric vehicles.

Functionally graded alumina-based thin film systems

DOEpatents

Moore, John J.; Zhong, Dalong

2006-08-29

The present invention provides coating systems that minimize thermal and residual stresses to create a fatigue- and soldering-resistant coating for aluminum die casting dies. The coating systems include at least three layers. The outer layer is an alumina- or boro-carbide-based outer layer that has superior non-wettability characteristics with molten aluminum coupled with oxidation and wear resistance. A functionally-graded intermediate layer or "interlayer" enhances the erosive wear, toughness, and corrosion resistance of the die. A thin adhesion layer of reactive metal is used between the die substrate and the interlayer to increase adhesion of the coating system to the die surface.

Double interconnection fuel cell array

DOEpatents

Draper, Robert; Zymboly, Gregory E.

1993-01-01

A fuel cell array (10) is made, containing number of tubular, elongated fuel cells (12) which are placed next to each other in rows (A, B, C, D), where each cell contains inner electrodes (14) and outer electrodes (18 and 18'), with solid electrolyte (16 and 16') between the electrodes, where the electrolyte and outer electrode are discontinuous, having two portions, and providing at least two opposed discontinuities which contain at least two oppositely opposed interconnections (20 and 20') contacting the inner electrode (14), each cell (12) having only three metallic felt electrical connectors (22) which contact surrounding cells, where each row is electrically connected to the other.

30 CFR 250.1405 - When is a case file developed?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 250.1405 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf (OCS) Civil... Officer may administer oaths and issue subpoenas requiring witnesses to attend meetings, submit...

46 CFR 69.65 - Calculation of volumes.

Code of Federal Regulations, 2013 CFR

2013-10-01

... accepted naval architectural practices for the spaces concerned. (b) The volume of the hull below the upper... boundary plating, in vessels constructed of metal; and (2) To the outer surface of the shell or to the... cargo space, measurements must be taken without consideration for insulation, sparring, or ceiling...

46 CFR 69.65 - Calculation of volumes.

Code of Federal Regulations, 2014 CFR

2014-10-01

... accepted naval architectural practices for the spaces concerned. (b) The volume of the hull below the upper... boundary plating, in vessels constructed of metal; and (2) To the outer surface of the shell or to the... cargo space, measurements must be taken without consideration for insulation, sparring, or ceiling...

46 CFR 69.65 - Calculation of volumes.

Code of Federal Regulations, 2012 CFR

2012-10-01

... accepted naval architectural practices for the spaces concerned. (b) The volume of the hull below the upper... boundary plating, in vessels constructed of metal; and (2) To the outer surface of the shell or to the... cargo space, measurements must be taken without consideration for insulation, sparring, or ceiling...

LEACHATE RECIRCULATION, METHANOGENS AND METAL CONCENTRATIONS IN BIOREACTOR LANDFILLS

EPA Science Inventory

The idea of operating landfills as bioreactors has received a lot of attention owing to many of the economic and waste treatment benefits. Portions of the Outer Loop landfill in Louisville, KY, owned and operated by WMI, Inc., are currently being used to test two different decom...

Formation of Planetary Populations I: Metallicity & Envelope Opacity Effects

NASA Astrophysics Data System (ADS)

Alessi, Matthew; Pudritz, Ralph E.

2018-05-01

We present a comprehensive body of simulations of the formation of exoplanetary populations that incorporate the role of planet traps in slowing planetary migration. The traps we include in our model are the water ice line, the disk heat transition, and the dead zone outer edge. We reduce our model parameter set to two physical parameters: the opacity of the accreting planetary atmospheres (κenv) and a measure of the efficiency of planetary accretion after gap opening (fmax). We perform planet population synthesis calculations based on the initial observed distributions of host star and disk properties - their disk masses, lifetimes, and stellar metallicities. We find the frequency of giant planet formation scales with disk metallicity, in agreement with the observed Jovian planet frequency-metallicity relation. We consider both X-ray and cosmic ray disk ionization models, whose differing ionization rates lead to different dead zone trap locations. In both cases, Jovian planets form in our model out to 2-3 AU, with a distribution at smaller radii dependent on the disk ionization source and the setting of envelope opacity. We find that low values of κenv (0.001-0.002 cm2 g-1) and X-ray disk ionization are necessary to obtain a separation between hot Jupiters near 0.1 AU, and warm Jupiters outside 0.6 AU, a feature present in the data. Our model also produces a large number of super Earths, but the majority are outside of 2 AU. As our model assumes a constant dust to gas ratio, we suggest that radial dust evolution must be taken into account to reproduce the observed super Earth population.

Progressive outer retinal necrosis associated with occlusive vasculitis in acquired immunodeficiency syndrome.

PubMed

Tseng, Chien-Chi; Chen, San-Ni; Hwang, Jiunn-Feng; Lin, Chun-Ju; Chen, Huan-Sheng

2015-05-01

A 45-year-old man, a case of acquired immunodeficiency syndrome, received a highly active antiretroviral therapy at the outpatient service for 4 years without regular follow-up. He experienced progressively blurred vision for 6 months and a cutaneous zoster on his back 3 months ago. He was diagnosed with progressive outer retinal necrosis by polymerase chain reaction-restriction fragment length polymorphism using an aqueous humor sample, which revealed an existence of varicella zoster virus. He was given a combination of systemic, intravitreal antiviral and a highly active antiretroviral therapy. Occlusive vasculitis, an unusual finding for progressive outer retinal necrosis, developed in both eyes 1 week after the secondary intravitreal injection. Unfortunately, his vision deteriorated to no light perception in both eyes within 2 weeks. Progressive outer retinal necrosis is characterized clinically as showing minimal or no inflammation in the aqueous and vitreous humors, absence of retinal vasculitis, and patches of yellowish spots located deep in the retina. Physicians should pay attention to this rare case of progressive outer retinal necrosis associated occlusive vasculitis with very poor prognosis in spite of aggressive treatment. Copyright © 2015. Published by Elsevier B.V.

Response of Metal Core Piezoelectric Fibers to Unsteady Airflows

NASA Astrophysics Data System (ADS)

Qiu, J. H.; Ji, H. L.; Zhu, K. J.; Park, M. J.

In the previous study, possible applications of metal core piezoelectric fibers with a diameter of 200 to 250 µm as bionic airflow sensors mimicking the flow sensitive receptor hairs of crickets have been proposed. This study aims to investigate the dynamic responses of the metal core piezoelectric fibers to unsteady airflow. The metal core piezoelectric fiber is half coated on the outer surface and is used in the bending mode. Wind tunnel tests were carried out and the output voltage of the fiber under the excitation of the unsteady aerodynamic force during flow acceleration and deceleration was measured when the wind tunnel was suddenly closed or opened by a shutter. The relationship between the maximum voltage and the steady-state velocity and that between the voltage and the acceleration of flow were also obtained.

Flexible Polymer/Metal/Polymer and Polymer/Metal/Inorganic Trilayer Transparent Conducting Thin Film Heaters with Highly Hydrophobic Surface.

PubMed

Kang, Tae-Woon; Kim, Sung Hyun; Kim, Cheol Hwan; Lee, Sang-Mok; Kim, Han-Ki; Park, Jae Seong; Lee, Jae Heung; Yang, Yong Suk; Lee, Sang-Jin

2017-09-27

Polymer/metal/polymer and polymer/metal/inorganic trilayer-structured transparent electrodes with fluorocarbon plasma polymer thin film heaters have been proposed. The polymer/metal/polymer and polymer/metal/inorganic transparent conducting thin films fabricated on a large-area flexible polymer substrate using a continuous roll-to-roll sputtering process show excellent electrical properties and visible-light transmittance. They also exhibit water-repelling surfaces to prevent wetting and to remove contamination. In addition, the adoption of a fluorocarbon/metal/fluorocarbon film permits an outer bending radius as small as 3 mm. These films have a sheet resistance of less than 5 Ω sq -1 , sufficient to drive light-emitting diode circuits. The thin film heater with the fluorocarbon/Ag/SiN x structure exhibits excellent heating characteristics, with a temperature reaching 180 °C under the driving voltage of 13 V. Therefore, the proposed polymer/metal/polymer and polymer/metal/inorganic transparent conducting electrodes using polymer thin films can be applied in flexible and rollable displays as well as automobile window heaters and other devices.

Specific features of implosion of metallized fiber arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitrofanov, K. N., E-mail: mitrofan@triniti.ru; Aleksandrov, V. V.; Gritsuk, A. N.

2017-02-15

Implosion of metallized fiber arrays was studied experimentally at the Angara-5-1 facility. The use of such arrays makes it possible to investigate the production and implosion dynamics of plasmas of various metals (such as tin, indium, and bismuth) that were previously unavailable for such studies. The plasma production rates m-dot (in μg/(cm{sup 2} ns)) for different metals were determined and quantitatively compared. Varying the thickness of the metal layer deposited on kapron fibers (the total linear mass of the metal coating being maintained at the level of 220 μg/cm), the current and velocity of the plasma precursor were studied asmore » functions of the thickness of the metal coating. The strong difference in the rates of plasma production from the metal coating and kapron fibers results in the redistribution of the discharge current between the Z-pinch and the trailing fiber plasma. The outer boundary of the plasma produced from the metal coating is found to be stable against instabilities typical of the final stage of implosion of conventional wire arrays.« less

Response dynamics of bluff-body stabilized conical premixed turbulent flames with spatial mixture gradients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaudhuri, Swetaprovo; Cetegen, Baki M.

2009-03-15

Response of bluff-body stabilized conical turbulent premixed flames was experimentally studied for a range of excitation frequencies (10-400 Hz), mean flow velocities (5, 10 and 15 m/s) and three different spatial mixture distributions (uniform, inner and outer enrichment). Upstream excitation was provided by a loudspeaker producing velocity oscillation amplitudes of about 8% of the mean flow velocity. Flame response was detected by a photomultiplier observing the CH{sup *} emission from the flame. The studied turbulent flames exhibited transfer function characteristics of a low-pass filter with a cutoff Strouhal number between 0.08 and 0.12. The amplification factors at low frequencies rangedmore » from 2 to 20 and generally increased for mean flow velocities from 5 to 15 m/s. The highest levels of amplification were found for the outer mixture enrichment followed in decreasing order by uniform and inner mixture gradient cases. The high levels of flame response for the outer enrichment case were attributed to the enhanced flame-vortex interaction in outer jet shear layer. At high excitation levels (u{sup '}/U{sub m}{approx}0.3) for U{sub m}=5 m/ s where non-linear flame response is expected, the flame exhibited a reduced amplitude response in the frequency range between 40 and 100 Hz for the uniform and outer equivalence ratio gradient cases and no discernible effect for the inner equivalence ratio gradient. In all cases, transfer function phase was found to vary linearly with excitation frequency. Finally, a relationship between the amplitude characteristics of the bluff-body wake transfer function and flame blowoff equivalence ratio was presented. (author)« less

Statistical mechanics of light elements at high pressure. IV - A model free energy for the metallic phase. [for Jovian type planet interiors

NASA Technical Reports Server (NTRS)

Dewitt, H. E.; Hubbard, W. B.

1976-01-01

A large quantity of data on the thermodynamic properties of hydrogen-helium metallic liquids have been obtained in extended computer calculations in which a Monte Carlo code essentially identical to that described by Hubbard (1972) was used. A model free energy for metallic hydrogen with a relatively small mass fraction of helium is discussed, taking into account the definition of variables, a procedure for choosing the free energy, values for the fitting parameters, and the evaluation of the entropy constants. Possibilities concerning a use of the obtained data in studies of the interiors of the outer planets are briefly considered.

Magnetohydrodynamic electrode

DOEpatents

Marchant, David D.; Killpatrick, Don H.

1978-01-01

An electrode capable of withstanding high temperatures and suitable for use as a current collector in the channel of a magnetohydrodynamic (MHD) generator consists of a sintered powdered metal base portion, the upper surface of the base being coated with a first layer of nickel aluminide, an intermediate layer of a mixture of nickel aluminide - refractory ceramic on the first layer and a third or outer layer of a refractory ceramic material on the intermediate layer. The sintered powdered metal base resists spalling by the ceramic coatings and permits greater electrode compliance to thermal shock. The density of the powdered metal base can be varied to allow optimization of the thermal conductivity of the electrode and prevent excess heat loss from the channel.

Composite pipe to metal joint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leslie, James C.; Leslie, II, James C.; Heard, James

A method for making a metal to composite tube joint including selecting an elongated interior fitting constructed with an exterior barrel, reduced in exterior diameter to form a distally facing annular shoulder and then projecting still further distally to form an interior sleeve having a radially outwardly facing bonding surface. Selecting an elongated metal outer sleeve formed proximally with a collar constructed for receipt over the barrel and increased in interior diameter and projecting distally to form an exterior sleeve having a radially inwardly facing bonding surface cooperating with the first bonding surface to form an annulus receiving an extremitymore » of a composite tube and a bond bonding the extremity of the tube to the bonding surfaces.« less

Spectral domain optical coherence tomography imaging in optic disk pit associated with outer retinal dehiscence

PubMed Central

Wong, Chee Wai; Wong, Doric; Mathur, Ranjana

2014-01-01

A 37-year-old Bangladeshi male presented with an inferotemporal optic disk pit and serous macular detachment in the left eye. Imaging with spectral domain optical coherence tomography (OCT) revealed a multilayer macular schisis pattern with a small subfoveal outer retinal dehiscence. This case illustrates a rare phenotype of optic disk maculopathy with macular schisis and a small outer retinal layer dehiscence. Spectral domain OCT was a useful adjunct in delineating the retinal layers in optic disk pit maculopathy, and revealed a small area of outer retinal layer dehiscence that could only have been detected on high-resolution OCT. PMID:25349471

Analysis of Eddy Current Capabilities for the Detection of Outer Diameter Stress Corrosion Cracking in Small Bore Metallic Structures

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Williams, Phillip; Simpson, John

2007-01-01

The use of eddy current techniques for the detection of outer diameter damage in tubing and many complex aerospace structures often requires the use of an inner diameter probe due to a lack of access to the outside of the part. In small bore structures the probe size and orientation are constrained by the inner diameter of the part, complicating the optimization of the inspection technique. Detection of flaws through a significant remaining wall thickness becomes limited not only by the standard depth of penetration, but also geometrical aspects of the probe. Recently, an orthogonal eddy current probe was developed for detection of such flaws in Space Shuttle Primary Reaction Control System (PRCS) Thrusters. In this case, the detection of deeply buried stress corrosion cracking by an inner diameter eddy current probe was sought. Probe optimization was performed based upon the limiting spatial dimensions, flaw orientation, and required detection sensitivity. Analysis of the probe/flaw interaction was performed through the use of finite and boundary element modeling techniques. Experimental data for the flaw detection capabilities, including a probability of detection study, will be presented along with the simulation data. The results of this work have led to the successful deployment of an inspection system for the detection of stress corrosion cracking in Space Shuttle Primary Reaction Control System (PRCS) Thrusters.

Cytomegalovirus implicated in a case of progressive outer retinal necrosis (PORN).

PubMed

Sfeir, Maroun

2015-08-01

Progressive outer retinal necrosis, also known as PORN, has been described as a variant of necrotizing herpetic retinopathy, occurring particularly in patients with acquired immune deficiency syndrome (AIDS). Although the etiologic organism has been reported to be Varicella-zoster virus, cytomegalovirus (CMV) can be an etiologic agent. Our case illustrates the occurrence of two opportunistic infections: PORN associated with CMV and Mycobacterium avium intracellulare duodenitis in a patient with uncontrolled HIV infection. Copyright © 2015 Elsevier B.V. All rights reserved.

Relationship between macular ganglion cell complex thickness and macular outer retinal thickness: a spectral-domain optical coherence tomography study.

PubMed

Kita, Yoshiyuki; Kita, Ritsuko; Takeyama, Asuka; Anraku, Ayako; Tomita, Goji; Goldberg, Ivan

2013-01-01

To assess the relationship between macular ganglion cell complex and macular outer retinal thicknesses. Case-control study. Forty-two normal eyes and 91 eyes with primary open-angle glaucoma were studied. Spectral-domain optical coherence tomography (RTVue-100) was used to measure the macular ganglion cell complex and macular outer retinal thickness. Ganglion cell complex to outer retinal thickness ratio was also calculated. The relationships between the ganglion cell complex and outer retinal thicknesses and between the ganglion cell complex to outer retinal thickness ratio and outer retinal thickness were evaluated. There was a positive correlation between ganglion cell complex and outer retinal thicknesses in the normal group and the glaucoma group (r = 0.53, P < 0.001 and r = 0.42, P < 0.001, respectively). In that respect, there was no correlation between ganglion cell complex to outer retinal thickness ratio and outer retinal thickness in the both groups (r = -0.07, P = 0.657, and r = 0.04, P = 0.677, respectively). The ganglion cell complex to outer retinal thickness ratio was 55.65% in the normal group, 45.07% in the glaucoma group. This difference was statistically significant. The ganglion cell complex thickness may be affected by outer retinal thickness, and there is individual variation in the outer retinal thickness. Therefore, when determining the ganglion cell complex, it seems necessary to consider the outer retinal thickness as well. We propose the ratio as a suitable parameter to account for individual variations in outer retinal thickness. © 2013 The Authors. Clinical and Experimental Ophthalmology © 2013 Royal Australian and New Zealand College of Ophthalmologists.

Backscattering from frost on icy satellites in the outer solar system

NASA Technical Reports Server (NTRS)

Verbiscer, Anne; Helfenstein, Paul; Veverka, Joseph

1990-01-01

Two extreme models are presented of how frost and ice might be intermixed on a typical satellite surface: areal and intimate mixing. Applying such models to selected representative satellite data, it is found that the frost component of the surfaces of these outer satellites must itself be backscattering, unlike its terrestrial counterpart. The difference may arise because frost particles can have much more complex internal textures under the low-temperature and low-gravity conditions of the outer satellites than is the case on earth.

Torsional Oscillations of the Earths's Core

NASA Technical Reports Server (NTRS)

Hide, Raymond; Boggs, Dale H.; Dickey, Jean O.

1997-01-01

Torsional oscillations of the Earth's liquid metallic outer core are investigated by diving the core into twenty imaginary e1qui-volume annuli coaxial with the axis of ratation of the Earth and determining temproal fluctuations in the axial component of angular memonetum of each annulus under the assumption of iso-rotation on cylindrical surfaces.

Improving Metallic Thermal Protection System Hypervelocity Impact Resistance Through Design of Experiments Approach

NASA Technical Reports Server (NTRS)

Poteet, Carl C.; Blosser, Max L.

2001-01-01

A design of experiments approach has been implemented using computational hypervelocity impact simulations to determine the most effective place to add mass to an existing metallic Thermal Protection System (TPS) to improve hypervelocity impact protection. Simulations were performed using axisymmetric models in CTH, a shock-physics code developed by Sandia National Laboratories, and validated by comparison with existing test data. The axisymmetric models were then used in a statistical sensitivity analysis to determine the influence of five design parameters on degree of hypervelocity particle dispersion. Several damage metrics were identified and evaluated. Damage metrics related to the extent of substructure damage were seen to produce misleading results, however damage metrics related to the degree of dispersion of the hypervelocity particle produced results that corresponded to physical intuition. Based on analysis of variance results it was concluded that the most effective way to increase hypervelocity impact resistance is to increase the thickness of the outer foil layer. Increasing the spacing between the outer surface and the substructure is also very effective at increasing dispersion.

Extrusion of metal oxide superconducting wire, tube or ribbon

DOEpatents

Dusek, Joseph T.

1993-10-05

A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

Extrusion of metal oxide superconducting wire, tube or ribbon

DOEpatents

Dusek, Joseph T.

1993-01-01

A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

Core-protective half-metallicity in trilayer graphene nanoribbons

NASA Astrophysics Data System (ADS)

Jeon, Gi Wan; Lee, Kyu Won; Lee, Cheol Eui

2017-07-01

Half-metals, playing an important role in spintronics, can be described as materials that enable fully spin-polarized electrical current. Taking place in graphene-based materials, half-metallicity has been shown in zigzag-edged graphene nanoribbons (ZGNRs) under an electric field. Localized electron states on the edge carbons are a key to enabling half-metallicity in ZGNRs. Thus, modification of the localized electron states is instrumental to the carbon-based spintronics. Our simple model shows that in a trilayer ZGNRs (triZGNRs) only the middle layer may become half-metallic leaving the outer layers insulating in an electric field, as confirmed by our density functional theory (DFT) calculations. Due to the different circumstances of the edge carbons, the electron energies at the edge carbons are different near the Fermi level, leading to a layer-selective half-metallicity. We believe that triZGNRs can be the tiniest electric cable (nanocable) form and can open a route to graphene-based spintronics applications.

General and programmable synthesis of hybrid liposome/metal nanoparticles

PubMed Central

Lee, Jin-Ho; Shin, Yonghee; Lee, Wooju; Whang, Keumrai; Kim, Dongchoul; Lee, Luke P.; Choi, Jeong-Woo; Kang, Taewook

2016-01-01

Hybrid liposome/metal nanoparticles are promising candidate materials for biomedical applications. However, the poor selectivity and low yield of the desired hybrid during synthesis pose a challenge. We designed a programmable liposome by selective encoding of a reducing agent, which allows self-crystallization of metal nanoparticles within the liposome to produce stable liposome/metal nanoparticles alone. We synthesized seven types of liposome/monometallic and more complex liposome/bimetallic hybrids. The resulting nanoparticles are tunable in size and metal composition, and their surface plasmon resonance bands are controllable in visible and near infrared. Owing to outer lipid bilayer, our liposome/Au nanoparticle shows better colloidal stability in biologically relevant solutions as well as higher endocytosis efficiency than gold nanoparticles without the liposome. We used this hybrid in intracellular imaging of living cells via surface-enhanced Raman spectroscopy, taking advantage of its improved physicochemical properties. We believe that our method greatly increases the utility of metal nanoparticles in in vivo applications. PMID:28028544

General and programmable synthesis of hybrid liposome/metal nanoparticles.

PubMed

Lee, Jin-Ho; Shin, Yonghee; Lee, Wooju; Whang, Keumrai; Kim, Dongchoul; Lee, Luke P; Choi, Jeong-Woo; Kang, Taewook

2016-12-01

Hybrid liposome/metal nanoparticles are promising candidate materials for biomedical applications. However, the poor selectivity and low yield of the desired hybrid during synthesis pose a challenge. We designed a programmable liposome by selective encoding of a reducing agent, which allows self-crystallization of metal nanoparticles within the liposome to produce stable liposome/metal nanoparticles alone. We synthesized seven types of liposome/monometallic and more complex liposome/bimetallic hybrids. The resulting nanoparticles are tunable in size and metal composition, and their surface plasmon resonance bands are controllable in visible and near infrared. Owing to outer lipid bilayer, our liposome/Au nanoparticle shows better colloidal stability in biologically relevant solutions as well as higher endocytosis efficiency than gold nanoparticles without the liposome. We used this hybrid in intracellular imaging of living cells via surface-enhanced Raman spectroscopy, taking advantage of its improved physicochemical properties. We believe that our method greatly increases the utility of metal nanoparticles in in vivo applications.

What shapes stellar metallicity gradients of massive galaxies at large radii?

NASA Astrophysics Data System (ADS)

Hirschmann, Michaela

2017-03-01

We investigate the differential impact of physical mechanisms, mergers and internal energetic phenomena, on the evolution of stellar metallicity gradients in massive, present-day galaxies employing sets of high-resolution, cosmological zoom simulations. We demonstrate that negative metallicity gradients at large radii (>2Reff) originate from the accretion of metal-poor stellar systems. At larger radii, galaxies become typically more dominated by stars accreted from satellite galaxies in major and minor mergers. However, only strong galactic, stellar-driven winds can sufficiently reduce the metallicity content of the accreted stars to realistically steepen the outer metallicity gradients in agreement with observations. In contrast, the gradients of the models without winds are inconsistent with observations. Moreover, we discuss the impact of additional AGN feedback. This analysis greatly highlights the importance of both energetic processes and merger events for stellar population properties of massive galaxies at large radii. Our results are expected to significantly contribute to the interpretation of current and up-coming IFU surveys (e.g. MaNGA, CALIFA).

Electrodes for microfluidic applications

DOEpatents

Crocker, Robert W [Fremont, CA; Harnett, Cindy K [Livermore, CA; Rognlien, Judith L [Livermore, CA

2006-08-22

An electrode device for high pressure applications. These electrodes, designed to withstand pressure of greater than 10,000 psi, are adapted for use in microfluidic devices that employ electrokinetic or electrophoretic flow. The electrode is composed, generally, of an outer electrically insulating tubular body having a porous ceramic frit material disposed in one end of the outer body. The pores of the porous ceramic material are filled with an ion conductive polymer resin. A conductive material situated on the upper surface of the porous ceramic frit material and, thus isolated from direct contact with the electrolyte, forms a gas diffusion electrode. A metal current collector, in contact with the gas diffusion electrode, provides connection to a voltage source.

Dielectric supported radio-frequency cavities

DOEpatents

Yu, David U. L.; Lee, Terry G.

2000-01-01

A device which improves the electrical and thermomechanical performance of an RF cavity, for example, in a disk-loaded accelerating structure. A washer made of polycrystalline diamond is brazed in the middle to a copper disk washer and at the outer edge to the plane wave transformer tank wall, thus dissipating heat from the copper disk to the outer tank wall while at the same time providing strong mechanical support to the metal disk. The washer structure eliminates the longitudinal connecting rods and cooling channels used in the currently available cavities, and as a result minimizes problems such as shunt impedance degradation and field distortion in the plane wave transformer, and mechanical deflection and uneven cooling of the disk assembly.

METAL-RICH PLANETARY NEBULAE IN THE OUTER REACHES OF M31

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balick, B.; Kwitter, K. B.; Corradi, R. L. M.

2013-09-01

Spectroscopic data of two relatively [O III]-luminous planetary nebulae (PNe) have been obtained with the 10.4 m Gran Telescopio Canarias. M174 and M2496 are each {approx}1 Degree-Sign from the center of M31 along opposite sides of its minor axis. The ensemble of these 2 distant PNe plus 16 similarly luminous outer-disk PNe published previously by Kwitter et al. forms a homogeneous group in luminosity, metal content, progenitor mass, age, and kinematics. The main factual findings of our work are (1) O/H (and other low-mass {alpha} elements and their ratios to O) is uniformly solar-like in all 18 PNe ((12 +more » log(O/H)) = 8.62 {+-} 0.14); (2) the general sky distribution and kinematics of the ensemble much more closely resemble the rotation pattern of the classical disk of M31 than its halo or bulge; (3) the O/H gradient is surprisingly flat beyond R{sub g} {approx} 20 kpc. The PNe are too metal-rich to be bona fide members of M31's disk or halo, and (4) the abundance patterns of the sample are distinct from those in the spiral galaxies M33, M81, and NGC 300. Using standard PN age diagnostic methods, we suggest that all of the PNe formed {approx}2 Gyr ago in a starburst of metal-rich interstellar medium that followed an M31-M33 encounter about 3 Gyr ago. We review supporting evidence from stellar studies. Other more prosaic explanations, such as dwarf galaxy assimilation, are unlikely.« less

Transition duct system with metal liners for delivering hot-temperature gases in a combustion turbine engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiebe, David J.

A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include a straight path segment (26) and an arcuate connecting segment (36). A respective straight metal liner (92) and an arcuate metal liner (94) may be each inwardly disposed onto a metal outer shell (38) along the straight path segment and the arcuate connecting segment (36) of the exit piece. Structural arrangements are provided to securely attach the respective liners in the presence of substantialmore » flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liners can be readily removed and replaced as needed.« less

HST Multi Layer Insulation Failure Review Board Findings

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline; Hansen, Patricia

1998-01-01

The mechanical and optical properties of the thermal control materials on the Hubble Space Telescope (HST) have degraded over the nearly seven years the telescope has been in orbit. Astronaut observations and photographs from the Second Servicing Mission (SM2) revealed large cracks in the metallized Teflon fluorinated ethylene propylene (FEP), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. Also, the absorptance of the bonded metallized Teflon FEP radiator surfaces of the telescope has increased over time. A Failure Review Board was established to determine the damage mechanism and to identify a replacement material. Samples of the top layer of the MLI and radiator material were retrieved during SM2, and a thorough investigation into the degradation followed in order to determine the primary cause of the damage. Mapping of the cracks on HST and the ground testing showed that thermal cycling with deep-layer damage from electron and proton radiation are necessary to cause the observed embrittlement. Further, strong evidence was found indicating that chain scission (reduced molecular weight) is the dominant form of damage to the metallized Teflon FEP. Given the damage to the outer layer of the multi-layer insulation (MLI) that was apparent during the second servicing mission (SM2), the decision was made to replace the outer layer during subsequent servicing missions. The replacement material had to meet the stringent thermal requirements of the spacecraft and maintain structural integrity for at least ten years. Ten candidate materials were exposed to simulated orbital environments and a replacement material was selected. This presentation will summarize the FRB results, in particular, the analysis of the retrieved specimens, the results of the simulated environmental exposures, and the selection of the replacement material. The NASA Space Environments and Effects community needs to hear these results because they reveal that Teflon (FEP) films should not be used in LEO as routinely as they are today.

Inner and outer star forming regions over the disks of spiral galaxies. I. Sample characterization

NASA Astrophysics Data System (ADS)

Rodríguez-Baras, M.; Díaz, A. I.; Rosales-Ortega, F. F.; Sánchez, S. F.

2018-01-01

Context. The knowledge of abundance distributions is central to understanding the formation and evolution of galaxies. Most of the relations employed for the derivation of gas abundances have so far been derived from observations of outer disk H ii regions, despite the known differences between inner and outer regions. Aims: Using integral field spectroscopy (IFS) observations we aim to perform a systematic study and comparison of two inner and outer H ii regions samples. The spatial resolution of the IFS, the number of objects and the homogeneity and coherence of the observations allow a complete characterization of the main observational properties and differences of the regions. Methods: We analyzed a sample of 725 inner H ii regions and a sample of 671 outer H ii regions, all of them detected and extracted from the observations of a sample of 263 nearby, isolated, spiral galaxies observed by the CALIFA survey. Results: We find that inner H ii regions show smaller equivalent widths, greater extinction and luminosities, along with greater values of [N ii] λ6583/Hα and [O ii] λ3727/[O iii] λ5007 emission-line ratios, indicating higher metallicities and lower ionization parameters. Inner regions have also redder colors and higher photometric and ionizing masses, although MionMphot is slighty higher for the outer regions. Conclusions: This work shows important observational differences between inner and outer H ii regions in star forming galaxies not previously studied in detail. These differences indicate that inner regions have more evolved stellar populations and are in a later evolution state with respect to outer regions, which goes in line with the inside-out galaxy formation paradigm. Table 4 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A102

Physical properties of star clusters in the outer LMC as observed by the DES

DOE PAGES

Pieres, A.; Santiago, B.; Balbinot, E.; ...

2016-05-26

The Large Magellanic Cloud (LMC) harbors a rich and diverse system of star clusters, whose ages, chemical abundances, and positions provide information about the LMC history of star formation. We use Science Verification imaging data from the Dark Energy Survey to increase the census of known star clusters in the outer LMC and to derive physical parameters for a large sample of such objects using a spatially and photometrically homogeneous data set. Our sample contains 255 visually identified cluster candidates, of which 109 were not listed in any previous catalog. We quantify the crowding effect for the stellar sample producedmore » by the DES Data Management pipeline and conclude that the stellar completeness is < 10% inside typical LMC cluster cores. We therefore develop a pipeline to sample and measure stellar magnitudes and positions around the cluster candidates using DAOPHOT. We also implement a maximum-likelihood method to fit individual density profiles and colour-magnitude diagrams. For 117 (from a total of 255) of the cluster candidates (28 uncatalogued clusters), we obtain reliable ages, metallicities, distance moduli and structural parameters, confirming their nature as physical systems. The distribution of cluster metallicities shows a radial dependence, with no clusters more metal-rich than [Fe/H] ~ -0.7 beyond 8 kpc from the LMC center. Furthermore, the age distribution has two peaks at ≃ 1.2 Gyr and ≃ 2.7 Gyr.« less

Mineral and heavy metal contents of the outer and inner tissues of commonly used fruits.

PubMed

Özcan, Mehmet Musa; Harmankaya, Mustafa; Gezgin, Sait

2012-01-01

The rate of heavy metal pollution in some minor fruit samples growing at roadsides in Turkey were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The mineral contents of samples were found to be different depending on the several parts Citrus fruits. The highest minor and heavy metal levels for Citrus fruits were determined between 17.24 and 45.30 mg/kg boron, 2.08 and 15.05 mg/kg copper, 1.01 and 16.00 mg/kg iron and 2.35 and 9.87 mg/kg zinc. Boron content ranged from 16.54 mg/kg (Deveci pear inner pulp) to 89.89 mg/kg (Arjantin apple outer skin). The level of Fe ranged from 1.49 mg/kg (quince pulp) to 25.05 mg/kg (Ankara pear pulp). Cu content of fruits ranged between 2.52 mg/kg (Fuji apple skin) and 25.93 mg/kg quince skin). Zn content was found between 0.46 mg/kg (Golden apple pulp) and 14.34 mg/kg (quince skin). P contents ranged from 651 mg/kg (Golden apple pulp) to 1269 mg/kg (quince skin). Na was found between 500 mg/kg (Fuji apple skin) and 907 mg/kg (Arjantin apple skin).

Physical properties of star clusters in the outer LMC as observed by the DES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pieres, A.; Santiago, B.; Balbinot, E.

The Large Magellanic Cloud (LMC) harbors a rich and diverse system of star clusters, whose ages, chemical abundances, and positions provide information about the LMC history of star formation. We use Science Verification imaging data from the Dark Energy Survey to increase the census of known star clusters in the outer LMC and to derive physical parameters for a large sample of such objects using a spatially and photometrically homogeneous data set. Our sample contains 255 visually identified cluster candidates, of which 109 were not listed in any previous catalog. We quantify the crowding effect for the stellar sample producedmore » by the DES Data Management pipeline and conclude that the stellar completeness is < 10% inside typical LMC cluster cores. We therefore develop a pipeline to sample and measure stellar magnitudes and positions around the cluster candidates using DAOPHOT. We also implement a maximum-likelihood method to fit individual density profiles and colour-magnitude diagrams. For 117 (from a total of 255) of the cluster candidates (28 uncatalogued clusters), we obtain reliable ages, metallicities, distance moduli and structural parameters, confirming their nature as physical systems. The distribution of cluster metallicities shows a radial dependence, with no clusters more metal-rich than [Fe/H] ~ -0.7 beyond 8 kpc from the LMC center. Furthermore, the age distribution has two peaks at ≃ 1.2 Gyr and ≃ 2.7 Gyr.« less

Mussel Shell Evaluation as Bioindicator For Heavy Metals

NASA Astrophysics Data System (ADS)

Andrello, Avacir Casanova; Lopes, Fábio; Galvão, Tiago Dutra

2010-05-01

Recently, in Brazil, it has appeared a new and unusual "plague" in lazer and commercial fishing. It is caused by the parasitic larval phase of certain native bivalve mollusks of fresh water known as "Naiades" and its involves the presence of big bivalve of fresh water, mainly Anodontites trapesialis, in the tanks and dams of the fish creation. These bivalve mollusks belong to the Unionoida Order, Mycetopodidae Family. The objective of the present work was to analyze the shells of these mollusks to verify the possibility of use as bioindicators for heavy metals in freshwater. The mollusks shells were collected in a commercial fishing at Londrina-PR. A qualitative analysis was made to determine the chemical composition of the shells and verify a possible correlation with existent heavy metals in the aquatic environment. In the inner part of the shells were identified the elements Ca, P, Fe, Mn and Sr and in the outer part were identified Ca, P, Fe, Mn, Sr and Cu. The Ca ratio of the outer part by inner part of the analyzed shells is around of 1, as expected, because Ca is the main compound of mollusks shells. The ratio of P, Fe, Mn, and Sr to the Ca were constant in all analyzed shells, being close to 0.015. The ratio Cu/Ca varied among the shells, showing that this mollusk is sensitive to concentration of this element in the aquatic environment.

Targeted Protein Degradation of Outer Membrane Decaheme Cytochrome MtrC Metal Reductase in Shewanella oneidensis MR-1 Measured Using Biarsenical Probe CrAsH-EDT2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Yijia; Chen, Baowei; Shi, Liang

2011-10-14

Development of efficient microbial biofuel cells requires an ability to exploit interfacial electron transfer reactions to external electron acceptors, such as metal oxides; such reactions occur in the facultative anaerobic gram-negative bacterium Shewanella oneidensis MR-1 through the catalytic activity of the outer membrane decaheme c-type cytochrome MtrC. Central to the utility of this pathway to synthetic biology is an understanding of cellular mechanisms that maintain optimal MtrC function, cellular localization, and renewal by degradation and resynthesis. In order to monitor trafficking to the outer membrane, and the environmental sensitivity of MtrC, we have engineered a tetracysteine tag (i.e., CCPGCC) atmore » its C-terminus that permits labeling by the cell impermeable biarsenical fluorophore, carboxy-FlAsH (CrAsH) of MtrC at the surface of living Shewanella oneidensis MR-1 cells. In comparison, the cell permeable reagent FlAsH permits labeling of the entire population of MtrC, including proteolytic fragments resulting from incorrect maturation. We demonstrate specific labeling by CrAsH of engineered MtrC which is dependent on the presence of a functional type-2 secretion system (T2S), as evidenced by T2S system gspD or gspG deletion mutants which are incapable of CrAsH labeling. Under these latter conditions, MtrC undergoes proteolytic degradation to form a large 35-38 kDa fragment; this degradation product is also resolved during normal turnover of the CrAsH-labeled MtrC protein. No MtrC protein is released into the medium during turnover, suggesting the presence of cellular turnover systems involving MtrC reuptake and degradation. The mature MtrC localized on the outer membrane is a long-lived protein, with a turnover rate of 0.043 hr-1 that is insensitive to O2 concentration. Maturation of MtrC is relatively inefficient, with substantial rates of turnover of the immature protein prior to export to the outer membrane (i.e., 0.028 hr-1) that are consistent with the inherent complexity associated with correct heme insertion and acylation of MtrC that occurs in the periplasm prior to its targeting to the outer membrane. These latter results suggest that MtrC protein trafficking to the outer membrane and its subsequent degradation are tightly regulated, which is consistent with cellular processing pathways that target MtrC to extracellular structures and their possible role in promoting electron transfer from Shewanella to extracellular acceptors.« less

Method of making a composite tube to metal joint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leslie, James C.; Leslie, II, James C.; Heard, James

A method for making a metal to composite tube joint including selecting an elongated interior fitting constructed with an exterior barrel, reduced in exterior diameter to form a distally facing annular shoulder and then projecting still further distally to form an interior sleeve having a radially outwardly facing bonding surface. Selecting an elongated metal outer sleeve formed proximally with a collar constructed for receipt over the barrel and increased in interior diameter and projecting distally to form an exterior sleeve having a radially inwardly facing bonding surface cooperating with the first bonding surface to form an annulus receiving an extremitymore » of a composite tube and a bond bonding the extremity of the tube to the bonding surfaces.« less

Europa's differentiated internal structure: inferences from two Galileo encounters.

PubMed

Anderson, J D; Lau, E L; Sjogren, W L; Schubert, G; Moore, W B

1997-05-23

Doppler data generated with the Galileo spacecraft's radio carrier wave during two Europa encounters on 19 December 1996 (E4) and 20 February 1997 (E6) were used to measure Europa's external gravitational field. The measurements indicate that Europa has a predominantly water ice-liquid outer shell about 100 to 200 kilometers thick and a deep interior with a density in excess of about 4000 kilograms per cubic meter. The deep interior could be a mixture of metal and rock or it could consist of a metal core with a radius about 40 percent of Europa's radius surrounded by a rock mantle with a density of 3000 to 3500 kilograms per cubic meter. The metallic core is favored if Europa has a magnetic field.

Rapid-quench axially staged combustor

DOEpatents

Feitelberg, Alan S.; Schmidt, Mark Christopher; Goebel, Steven George

1999-01-01

A combustor cooperating with a compressor in driving a gas turbine includes a cylindrical outer combustor casing. A combustion liner, having an upstream rich section, a quench section and a downstream lean section, is disposed within the outer combustor casing defining a combustion chamber having at least a core quench region and an outer quench region. A first plurality of quench holes are disposed within the liner at the quench section having a first diameter to provide cooling jet penetration to the core region of the quench section of the combustion chamber. A second plurality of quench holes are disposed within the liner at the quench section having a second diameter to provide cooling jet penetration to the outer region of the quench section of the combustion chamber. In an alternative embodiment, the combustion chamber quench section further includes at least one middle region and at least a third plurality of quench holes disposed within the liner at the quench section having a third diameter to provide cooling jet penetration to at least one middle region of the quench section of the combustion chamber.

Genomic analyses of bacterial porin-cytochrome gene clusters

DOE PAGES

Shi, Liang; Fredrickson, James K.; Zachara, John M.

2014-11-26

In this study, the porin-cytochrome (Pcc) protein complex is responsible for trans-outer membrane electron transfer during extracellular reduction of Fe(III) by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens PCA. The identified and characterized Pcc complex of G. sulfurreducens PCA consists of a porin-like outer-membrane protein, a periplasmic 8-heme c type cytochrome (c-Cyt) and an outer-membrane 12-heme c-Cyt, and the genes encoding the Pcc proteins are clustered in the same regions of genome (i.e., the pcc gene clusters) of G. sulfurreducens PCA. A survey of additionally microbial genomes has identified the pcc gene clusters in all sequenced Geobacter spp. and other bacteriamore » from six different phyla, including Anaeromyxobacter dehalogenans 2CP-1, A. dehalogenans 2CP-C, Anaeromyxobacter sp. K, Candidatus Kuenenia stuttgartiensis, Denitrovibrio acetiphilus DSM 12809, Desulfurispirillum indicum S5, Desulfurivibrio alkaliphilus AHT2, Desulfurobacterium thermolithotrophum DSM 11699, Desulfuromonas acetoxidans DSM 684, Ignavibacterium album JCM 16511, and Thermovibrio ammonificans HB-1. The numbers of genes in the pcc gene clusters vary, ranging from two to nine. Similar to the metal-reducing (Mtr) gene clusters of other Fe(III)-reducing bacteria, such as Shewanella spp., additional genes that encode putative c-Cyts with predicted cellular localizations at the cytoplasmic membrane, periplasm and outer membrane often associate with the pcc gene clusters. This suggests that the Pcc-associated c-Cyts may be part of the pathways for extracellular electron transfer reactions. The presence of pcc gene clusters in the microorganisms that do not reduce solid-phase Fe(III) and Mn(IV) oxides, such as D. alkaliphilus AHT2 and I. album JCM 16511, also suggests that some of the pcc gene clusters may be involved in extracellular electron transfer reactions with the substrates other than Fe(III) and Mn(IV) oxides.« less

Electronic stopping in oxides beyond Bragg additivity

NASA Astrophysics Data System (ADS)

Sigmund, P.; Schinner, A.

2018-01-01

We present stopping cross sections calculated by our PASS code for several ions in metal oxides and SiO2 over a wide energy range. Input takes into account changes in the valence structure by assigning two additional electrons to the 2p shell of oxygen and removing the appropriate number of electrons from the outer shells of the metal atom. Results are compared with tabulated experimental values and with two versions of Bragg's additivity rule. Calculated stopping cross sections are applied in testing a recently-proposed scaling rule, which relates the stopping cross section to the number of oxygen atoms per molecule.

Phase transitions, interparticle correlations, and elementary processes in dense plasmas

NASA Astrophysics Data System (ADS)

Ichimaru, Setsuo

2017-12-01

Astrophysical dense plasmas are those we find in the interiors, surfaces, and outer envelopes of stellar objects such as neutron stars, white dwarfs, the Sun, and giant planets. Condensed plasmas in the laboratory settings include those in ultrahigh-pressure metal-physics experiments undertaken for realization of metallic hydrogen. We review basic physics issues studied in the past 60 some years on the phase transitions, the interparticle correlations, and the elementary processes in dense plasmas, through survey on scattering of electromagnetic waves, equations of state, phase diagrams, transport processes, stellar and planetary magnetisms, and thermo- and pycnonuclear reactions.

Electrolytic cell with reference electrode

DOEpatents

Kessie, Robert W.

1989-01-01

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane.

Reference electrode for electrolytic cell

DOEpatents

Kessie, R.W.

1988-07-28

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane. 4 figs.

Miniature electrical connector

DOEpatents

Casper, Robert F.

1976-01-01

A miniature coaxial cable electrical connector includes an annular compressible gasket in a receptacle member, the gasket having a generally triangular cross section resiliently engaging and encircling a conically tapered outer surface of a plug member to create an elongated current leakage path at their interface; means for preventing rotation of the plug relative to the receptacle; a metal sleeve forming a portion of the receptacle and encircling the plug member when interconnected; and a split ring in the plug having outwardly and rearwardly projecting fingers spaced from and encircling a portion of a coaxial cable and engageable with the metal sleeve to interlock the receptacle and plug.

Floquet Topological Insulators in Uranium Compounds

NASA Astrophysics Data System (ADS)

Pi, Shu-Ting; Savrasov, Sergey

2014-03-01

A major issue regarding the Uranium based nuclear fuels is to conduct the heat from the core area to its outer area. Unfortunately, those materials are notorious for their extremely low thermal conductivity due to the phonon-dominated-heat-transport properties in insulating states. Although metallic Uranium compounds are helpful in increasing the thermal conductivity, their low melting point still make those efforts in vain. In this report, we will figure out potential Uranium based Floquet topological insulators where the insulating bulk states accompanied with metallic surface states is achieved by applying periodic electrical fields which makes the coexistence of both benefits possible.

Induction of low-level hydrogen peroxide generation by unbleached cotton nonwovens as potential or wound healing applications

USDA-ARS?s Scientific Manuscript database

Greige cotton is an intact plant fiber. The cuticle and primary cell wall near the outer surface of the cotton fiber contains pectin, peroxidases, superoxide dismutase (SOD), and trace metals, which are associated with hydrogen peroxide (H2O2) generation during cotton fiber development. The compon...

Thermionic energy converters

DOEpatents

Monroe, Jr., James E.

1977-08-09

A thermionic device for converting nuclear energy into electrical energy comprising a tubular anode spaced from and surrounding a cylindrical cathode, the cathode having an outer emitting surface of ruthenium, and nuclear fuel on the inner cylindrical surface. The nuclear fuel is a ceramic composition of fissionable material in a metal matrix. An axial void is provided to collect and contain fission product gases.

Electron transport through rectifying self-assembled monolayer diodes on silicon: Fermi-level pinning at the molecule-metal interface.

PubMed

Lenfant, S; Guerin, D; Tran Van, F; Chevrot, C; Palacin, S; Bourgoin, J P; Bouloussa, O; Rondelez, F; Vuillaume, D

2006-07-20

We report the synthesis and characterization of molecular rectifying diodes on silicon using sequential grafting of self-assembled monolayers of alkyl chains bearing a pi group at their outer end (Si/sigma-pi/metal junctions). We investigate the structure-performance relationships of these molecular devices, and we examine the extent to which the nature of the pi end group (change in the energy position of their molecular orbitals) drives the properties of these molecular diodes. Self-assembled monolayers of alkyl chains (different chain lengths from 6 to 15 methylene groups) functionalized by phenyl, anthracene, pyrene, ethylene dioxythiophene, ethylene dioxyphenyl, thiophene, terthiophene, and quaterthiophene were synthesized and characterized by contact angle measurements, ellipsometry, Fourier transform infrared spectroscopy, and atomic force microscopy. We demonstrate that reasonably well-packed monolayers are obtained in all cases. Their electrical properties were assessed by dc current-voltage characteristics and high-frequency (1-MHz) capacitance measurements. For all of the pi groups investigated here, we observed rectification behavior. These results extend our preliminary work using phenyl and thiophene groups (Lenfant et al., Nano Lett. 2003, 3, 741). The experimental current-voltage curves were analyzed with a simple analytical model, from which we extracted the energy position of the molecular orbital of the pi group in resonance with the Fermi energy of the electrodes. We report experimental studies of the band lineup in these silicon/alkyl pi-conjugated molecule/metal junctions. We conclude that Fermi-level pinning at the pi group/metal interface is mainly responsible for the observed absence of a dependence of the rectification effect on the nature of the pi groups, even though the groups examined were selected to have significant variations in their electronic molecular orbitals.

The effects of nickel and sulphur on the core-mantle partitioning of oxygen in Earth and Mars

NASA Astrophysics Data System (ADS)

Tsuno, Kyusei; Frost, Daniel J.; Rubie, David C.

2011-03-01

Constraints on the partitioning of oxygen between silicates, oxides, and metallic liquids are important for determining the amount of oxygen that may have entered the cores of terrestrial planets and to identify likely reactions at the core-mantle boundary. Several previous studies have examined oxygen partitioning between liquid Fe metal and ferropericlase, however, the cores of terrestrial planets also contain nickel and most likely sulphur. We have performed experiments to examine the effects of both nickel and sulphur on the partitioning of oxygen between ferropericlase and liquid Fe alloy up to pressures of 24.5 GPa in the temperature range 2430-2750 K using a multianvil press. The results show that at a fixed oxygen fugacity the proportion of oxygen that partitions into liquid metal will decrease by approximately 1-2 mol% on the addition of 10-20 mol% nickel to the liquid. The addition of around 30 mol% sulphur will, on the other hand, increase the metal oxygen content by approximately 10 mol%. Experiments to examine the combined effects of both nickel and sulphur, show a decrease in the effect of nickel on oxygen partitioning as the sulphur content of the metal increases. We expand an existing thermodynamic model for the partitioning of oxygen at high pressures and temperatures to include the effects of nickel and sulphur by fitting these experimental data, with further constraints provided by existing phase equilibria studies at similar conditions in the Fe-S and Fe-O-S systems. Plausible terrestrial core sulphur contents have little effect on oxygen partitioning. When our model is extrapolated to conditions of the present day terrestrial core-mantle boundary, the presence of nickel is found to lower the oxygen content of the outer core that is in equilibrium with the expected mantle ferropericlase FeO content, by approximately 1 weight %, in comparison to nickel free calculations. In agreement with nickel-free experiments, this implies that the Earth's outer core is undersaturated in oxygen with respect to plausible mantle FeO contents, which will result in either the depletion of FeO from the base of the mantle or cause the development of an outer core layer that is enriched in oxygen. The oxygen content of the more sulphur-rich Martian core would be in the range 2-4 wt.% if it is in equilibrium with the FeO-rich Martian mantle.

FmvB: A Francisella tularensis Magnesium-Responsive Outer Membrane Protein that Plays a Role in Virulence

PubMed Central

Wu, Xiaojun; Ren, Guoping; Gunning, William T.; Weaver, David A.; Kalinoski, Andrea L.; Khuder, Sadik A.; Huntley, Jason F.

2016-01-01

Francisella tularensis is the causative agent of the lethal disease tularemia. Despite decades of research, little is understood about why F. tularensis is so virulent. Bacterial outer membrane proteins (OMPs) are involved in various virulence processes, including protein secretion, host cell attachment, and intracellular survival. Many pathogenic bacteria require metals for intracellular survival and OMPs often play important roles in metal uptake. Previous studies identified three F. tularensis OMPs that play roles in iron acquisition. In this study, we examined two previously uncharacterized proteins, FTT0267 (named fmvA, for Francisella metal and virulence) and FTT0602c (fmvB), which are homologs of the previously studied F. tularensis iron acquisition genes and are predicted OMPs. To study the potential roles of FmvA and FmvB in metal acquisition and virulence, we first examined fmvA and fmvB expression following pulmonary infection of mice, finding that fmvB was upregulated up to 5-fold during F. tularensis infection of mice. Despite sequence homology to previously-characterized iron-acquisition genes, FmvA and FmvB do not appear to be involved iron uptake, as neither fmvA nor fmvB were upregulated in iron-limiting media and neither ΔfmvA nor ΔfmvB exhibited growth defects in iron limitation. However, when other metals were examined in this study, magnesium-limitation significantly induced fmvB expression, ΔfmvB was found to express significantly higher levels of lipopolysaccharide (LPS) in magnesium-limiting medium, and increased numbers of surface protrusions were observed on ΔfmvB in magnesium-limiting medium, compared to wild-type F. tularensis grown in magnesium-limiting medium. RNA sequencing analysis of ΔfmvB revealed the potential mechanism for increased LPS expression, as LPS synthesis genes kdtA and wbtA were significantly upregulated in ΔfmvB, compared with wild-type F. tularensis. To provide further evidence for the potential role of FmvB in magnesium uptake, we demonstrated that FmvB was outer membrane-localized. Finally, ΔfmvB was found to be attenuated in mice and cytokine analyses revealed that ΔfmvB-infected mice produced lower levels of pro-inflammatory cytokines, including GM-CSF, IL-3, and IL-10, compared with mice infected with wild-type F. tularensis. Taken together, although the function of FmvA remains unknown, FmvB appears to play a role in magnesium uptake and F. tularensis virulence. These results may provide new insights into the importance of magnesium for intracellular pathogens. PMID:27513341

Models of metal binding structures in fulvic acid from the Suwannee River, Georgia

USGS Publications Warehouse

Leenheer, J.A.; Brown, G.K.; MacCarthy, P.; Cabaniss, S.E.

1998-01-01

Fulvic acid, isolated from the Suwannee River, Georgia, was assessed for its ability to bind Ca2+, Cd2+, Cu2+, Ni2+, and Zn2+ ions at pH 6 before and after extensive fractionation that was designed to reveal the nature of metal binding functional groups. The binding constant for Ca2+ ion had the greatest increase of all the ions in a metal binding fraction that was selected for intensive characterization for the purpose of building quantitative average model structures. The 'metal binding' fraction was characterized by quantitative 13C NMR, 1H NMR, and FT-1R spectrometry and elemental, titrimetric, and molecular weight determinations. The characterization data revealed that carboxyl groups were clustered in short- chain aliphatic dibasic acid structures. The Ca2+ binding data suggested that ether-substituted oxysuccinic acid structures are good models for the metal binding sites at pH 6. Structural models were derived based upon oxidation and photolytic rearrangements of cutin, lignin, and tannin precursors. These structural models rich in substituted dibasic acid structures revealed polydentate binding sites with the potential for both inner-sphere and outer-sphere type binding. The majority of the fulvic acid molecule was involved with metal binding rather than a small substructural unit.Fulvic acid, isolated from the Suwannee River, Georgia, was assessed for its ability to bind Ca2+, Cd2+, Cu2+, Ni2+, and Zn2+ ions at pH 6 before and after extensive fractionation that was designed to reveal the nature of metal binding functional groups. The binding constant for Ca2+ ion had the greatest increase of all the ions in a metal binding fraction that was selected for intensive characterization for the purpose of building quantitative average model structures. The `metal binding' fraction was characterized by quantitative 13C NMR, 1H NMR, and FT-IR spectrometry and elemental, titrimetric, and molecular weight determinations. The characterization data revealed that carboxyl groups were clustered in short-chain aliphatic dibasic acid structures. The Ca2+ binding data suggested that ether-substituted oxysuccinic acid structures are good models for the metal binding sites at pH 6. Structural models were derived based upon oxidation and photolytic rearrangements of cutin, lignin, and tannin precursors. These structural models rich in substituted dibasic acid structures revealed polydentate binding sites with the potential for both inner-sphere and outer-sphere type binding. The majority of the fulvic acid molecule was involved with metal binding rather than a small substructural unit.

Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator

NASA Technical Reports Server (NTRS)

Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

2014-01-01

A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

Macrocyclic Receptor for Precious Gold, Platinum, or Palladium Coordination Complexes.

PubMed

Liu, Wenqi; Oliver, Allen G; Smith, Bradley D

2018-06-06

Two macrocyclic tetralactam receptors are shown to selectively encapsulate anionic, square-planar chloride and bromide coordination complexes of gold(III), platinum(II), and palladium(II). Both receptors have a preorganized structure that is complementary to its precious metal guest. The receptors do not directly ligate the guest metal center but instead provide an array of arene π-electron donors that interact with the electropositive metal and hydrogen-bond donors that interact with the outer electronegative ligands. This unique mode of supramolecular recognition is illustrated by six X-ray crystal structures showing receptor encapsulation of AuCl 4 - , AuBr 4 - , PtCl 4 -2 , or Pd 2 Cl 6 -2 . In organic solution, the 1:1 association constants correlate with specific supramolecular features identified in the solid state. Technical applications using these receptors are envisioned in a wide range of fields that involve precious metals, including mining, recycling, catalysis, nanoscience, and medicine.

RTAPS (Research and Technology for Aerospace Propulsion Systems): Simulation of Structural Loads within a Hybrid Gear Resulting From Loading at the Gear Teeth

NASA Technical Reports Server (NTRS)

Naffin, Richard K.; Ulun, Umut; Garmel, Charles D.; McManus, Nika; Hu, Zhenning; Ohlerking, Westin B.; Myers, David E.

2017-01-01

This report investigates the practical usage of hybrid structures for rotorcraft gearing. The primary driver for utilizing hybrid structures for rotorcraft gearing is to reduce the drive system weight. The hybrid structure concept featured in this study for rotorcraft gearing consists of a metallic gear tooth-rim, a web section manufactured from composite materials, and a metallic hub. The metallic gear tooth-rim is manufactured from conventional gear steel alloys, such as AISI 9310. The gear tooth-rim attaches to the outer diameter of the web section made from composite materials. The inner diameter of the composite web can then attach to a metallic hub, completing the assembly. It is assumed that areas of the shafting or hub where rolling element bearings may ride must remain as gear steel alloys for this study.

Effective modern methods of protecting metal road structures from corrosion

NASA Astrophysics Data System (ADS)

Panteleeva, Margarita

2017-10-01

In the article the ways of protection of barrier road constructions from various external influences which cause development of irreversible corrosion processes are considered. The author studied modern methods of action on metal for corrosion protection and chose the most effective of them: a method of directly affecting the metal structures themselves. This method was studied in more detail in the framework of the experiment. As a result, the article describes the experiment of using a three-layer polymer coating, which includes a thermally activated primer, an elastomeric thermoplastic layer with a spatial structure, and a strong outer polyolefin layer. As a result of the experiment, the ratios of the ingredients for obtaining samples of the treated metal having the best parameters of corrosion resistance, elasticity, and strength were revealed. The author constructed a regression equation describing the main properties of the protective polymer coating using the simplex-lattice planning method in the composition-property diagrams.

METAL RESISTIVITY MEASURING DEVICE

DOEpatents

Renken, J. Jr.; Myers, R.G.

1960-12-20

An eddy current device is offered for detecting discontinuities in metal samples. Alternate short and long duration pulses are inductively applied to a metal sample via the outer coil of a probe. The long pulses give a resultant signal from the metal sample responsive to probe-tosample spacing and discontinuities within the sample and the shont pulses give a resultant signal responsive only to probe -to-sample spacing. The inner coil of the probe detects the two resultant signals and transmits them to a separation network where the two signals are separated. The two separated signals are then transmitted to a compensation network where the detected signals due to the short pulses are used to compensate for variations due to probe-to-sample spacing contained in the detected signals from the long pulses. Thus, a resultant signal is obtained responsive to discontinuities within the sample and independent of probe-to- sample spacing.

Metal Resistivity Measuring Device

DOEpatents

Renken, Jr, C. J.; Myers, R. G.

1960-12-20

An eddy current device is designed for detecting discontinuities in metal samples. Alternate short and long duration pulses are inductively applied to a metal sample via the outer coil of a probe. The lorg pulses give a resultant signal from the metal sample responsive to probe-tosample spacing and discontinuities with the sample, and the short pulses give a resultant signal responsive only to probe-to-sample spacing. The inner coil of the probe detects the two resultant signals and transmits them to a separation network where the two signals are separated. The two separated signals are then transmitted to a compensation network where the detected signals due to the short pulses are used to compensate for variations due to probeto-sample spacing contained in the detected signals from the long pulses. Thus a resultant signal is obtained responsive to discontinuities within the sample and independent of probe-to- sample spacing.

Study on the adsorption of bacteria in ceramsite and their synergetic effect on adsorption of heavy metals.

PubMed

Qiu, Shan; Ma, Fang; Huang, Xu; Xu, Shanwen

2014-01-01

In this paper, heavy metal adsorption by ceramsite with or without Bacillus subtilis (B. subtilis) immobilization was studied, and the synergetic effect of ceramsite and bacteria was discussed in detail. To investigate the roles of the micro-pore structure of ceramsite and bacteria in removing heavy metals, the amount of bacteria immobilized on the ceramsite was determined and the effect of pH was evaluated. It was found that the immobilization of B. subtilis on the ceramsite was attributed to the electrostatic attraction and covalent bond. The scanning electron microscopy results revealed that, with the presence of ceramsite, there was the conglutination of B. subtilis cells due to the cell outer membrane dissolving. In addition, the B. subtilis immobilized ceramsite showed a different adsorption capacity for different heavy metals, with the adsorption capacity ranking of La(3+) > Cu(2+) > Mg(2+) > Na(+).

Long-life mission reliability for outer planet atmospheric entry probes

NASA Technical Reports Server (NTRS)

Mccall, M. T.; Rouch, L.; Maycock, J. N.

1976-01-01

The results of a literature analysis on the effects of prolonged exposure to deep space environment on the properties of outer planet atmospheric entry probe components are presented. Materials considered included elastomers and plastics, pyrotechnic devices, thermal control components, metal springs and electronic components. The rates of degradation of each component were determined and extrapolation techniques were used to predict the effects of exposure for up to eight years to deep space. Pyrotechnic devices were aged under accelerated conditions to an equivalent of eight years in space and functionally tested. Results of the literature analysis of the selected components and testing of the devices indicated that no severe degradation should be expected during an eight year space mission.

Enlargement of halloysite clay nanotube lumen by selective etching of aluminum oxide.

PubMed

Abdullayev, Elshad; Joshi, Anupam; Wei, Wenbo; Zhao, Yafei; Lvov, Yuri

2012-08-28

Halloysite clay tubes have 50 nm diameter and chemically different inner and outer walls (inner surface of aluminum oxide and outer surface of silica). Due to this different chemistry, the selective etching of alumina from inside the tube was realized, while preserving their external diameter (lumen diameter changed from 15 to 25 nm). This increases 2-3 times the tube lumen capacity for loading and further sustained release of active chemical agents such as metals, corrosion inhibitors, and drugs. In particular, halloysite loading efficiency for the benzotriazole increased 4 times by selective etching of 60% alumina within the tubes' lumens. Specific surface area of the tubes increased over 6 times, from 40 to 250 m(2)/g, upon acid treatment.

Electric discharge for treatment of trace contaminants

NASA Technical Reports Server (NTRS)

Flamm, D. L.; Wydeven, T. J. (Inventor)

1978-01-01

A radio frequency glow discharge reactor is described for removing trace oxidizable contaminants from an oxygen bearing atmosphere. The reaction chamber is defined by an inner metal electrode facing a dielectric backed by an outer conductive electrode. In one embodiment, a conductive liquid forms the conductor of an outer electrode and cools the dielectric. A resonator coupled to a variable radio frequency source generates the high voltages for creating a glow discharge in the chamber at a predetermined pressure whereby the trace contaminants are oxidized into a few simple non-toxic products that may be easily recovered. The corresponding process for removal of trace contaminants from an oxygen-bearing atmosphere with high efficiency independent of the concentration level is also disclosed.

Holocene facies analysis of the sedimentary record with anthropogenic impacts in the Ria de Vigo (NW Spain)

NASA Astrophysics Data System (ADS)

Rubio, B.; Garcia-Gil, S.; Vilas, F.; Garcia, A.

2004-05-01

The Ria de Vigo constitutes the southernmost ria of the Rias Bajas. The reconnaisance studies of this ria indicate a heterogeneous distribution of both terrigenous and carbonate sediments with a major axial deposit of cohesive sediments. These fine sediments are relatively rich in organic matter, particularly in the inner part of the ria. This is the result of a progressive change in hydrodynamic conditions along the ria. The outer parts are affected by severe storms in winter and by upwelling processes in summer, whilst the inner parts have an estuarine character throughout the year. The upwelling produces a marked increase in the biological productivity in the Ria and, consequently, these sediments have typically very high contents of organic matter. In recent years, increasing interest has been shown in the levels of heavy metals in sediments of the Galician Rias. Particularly, some of these studies showed a higher concentration of heavy metals in the muddiest surficial sediments in the Ria de Vigo. However, and despite of the important human and industrial settlement in the Galician rias, knowledge about the evolution of historical contamination along the Holocene sedimentary record is scarce. In order to ascertain this evolution have been selected 8 gravity corer located along the axial part of the ria. This evaluation was focused on the muddy sediments of the axial part of the ria due to the dependence of metal levels on grain size, resulting from the association of metals with the finer particles, as it has been demonstrated by previous studies in the ria. On these sediments, the combination of geochemical, mineralogical and sedimentological data, facies interpretations (obtained from x-ray radiography), and their integration with high resolution seismic data (Uniboom and 3.5 Khz subbottom profiler) have allowed to establish the evolution of certain heavy metals (Zn, Cu and Pb) along the Holocene recent sedimentary record in the Ria de Vigo. Sediments in the outer ria are comprised by muddy sands showing a very slight enrichment in certain heavy metals in the upper sediments. Contrary to facies in the outer ria sediments, facies in the inner ria comprises finer organic-rich sediments. These are related to the presence of biodeposits produced by mussel rafts and to a higher anthropogenic influence due to industrial activity. Both influences are notably reflected in the Cu, Zn and Pb vertical profiles, increasing markedly the levels of these metals in the uppermost 0.15 m of sediments. Diagenetic recycling may contribute to the enhancement of trace metal concentrations in the upper sediments of inner cores and also this is related to a higher content of organic carbon in these sediments. Results obtained in this ria constitutes a good reference to study other rias and coastal areas of the Iberian Atlantic margin. This work was funded by projects REN2003-02822 MAR, REN2003-03233 MAR, VEM2003-20093-C03-03 of the Spanish MCYT and PGDIT03RMA30101PR of the Galician Government (XUGA). Contribution No 302 XM2 group.

Can direct extracellular electron transfer occur in the absence of outer membrane cytochromes in Desulfovibrio vulgaris?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elias, Dwayne A; Zane, Mr. Grant M.; Auer, Dr. Manfred

2010-01-01

Extracellular electron transfer has been investigated over several decades via forms of soluble electron transfer proteins that are exported for extracellular reoxidation. More recently, several organisms have been shown to reduce extracellular metals via the direct transfer of electron through appendages; also known as nanowires. They have been reported most predominantly in Shewanella and Geobacter. While the relevancy and composition of these structures in each genus has been debated, both possess outer membrane cytochrome complexes that could theoretically come into direct contact with solid phase oxidized metals. Members of the genus Desulfovibrio apparently have no such cytochromes although similar appendagesmore » are present, are electrically conductive, and are different from flagella. Upon U(VI)-reduction, the structures in Desulfovibrio become coated with U(IV). Deletion of flagellar genes did not alter soluble or amorphous Fe(III) or U(VI) reduction, or appendage appearance. Removal of the chromosomal pilA gene hampered amorphous Fe(III)-reduction by ca. 25%, but cells lacking the native plasmid, pDV1, reduced soluble Fe(III) and U(VI) at ca. 50% of the wild type rate while amorphous Fe(III)-reduction slowed to ca. 20% of the wild type rate. Appendages were present in all deletions as well as pDV1, except pilA. Gene complementation restored all activities and morphologies to wild type levels. This suggests that pilA encodes the structural component, whereas genes within pDV1 may provide the reactive members. How such appendages function without outer membrane cytochromes is under investigation.« less

High Levels of Sediment Contamination Have Little Influence on Estuarine Beach Fish Communities

PubMed Central

McKinley, Andrew C.; Dafforn, Katherine A.; Taylor, Matthew D.; Johnston, Emma L.

2011-01-01

While contaminants are predicted to have measurable impacts on fish assemblages, studies have rarely assessed this potential in the context of natural variability in physico-chemical conditions within and between estuaries. We investigated links between the distribution of sediment contamination (metals and PAHs), physico-chemical variables (pH, salinity, temperature, turbidity) and beach fish assemblages in estuarine environments. Fish communities were sampled using a beach seine within the inner and outer zones of six estuaries that were either heavily modified or relatively unmodified by urbanization and industrial activity. All sampling was replicated over two years with two periods sampled each year. Shannon diversity, biomass and abundance were all significantly higher in the inner zone of estuaries while fish were larger on average in the outer zone. Strong differences in community composition were also detected between the inner and outer zones. Few differences were detected between fish assemblages in heavily modified versus relatively unmodified estuaries despite high concentrations of sediment contaminants in the inner zones of modified estuaries that exceeded recognized sediment quality guidelines. Trends in species distributions, community composition, abundance, Shannon diversity, and average fish weight were strongly correlated to physico-chemical variables and showed a weaker relationship to sediment metal contamination. Sediment PAH concentrations were not significantly related to the fish assemblage. These findings suggest that variation in some physico-chemical factors (salinity, temperature, pH) or variables that co-vary with these factors (e.g., wave activity or grain size) have a much greater influence on this fish assemblage than anthropogenic stressors such as contamination. PMID:22039470

Explosion Welding for Hermetic Containerization

NASA Technical Reports Server (NTRS)

Dolgin, Benjamin; Sanok, Joseph

2003-01-01

A container designed for storing samples of hazardous material features a double wall, part of which is sacrificed during an explosion-welding process in which the container is sealed and transferred to a clean environment. The major advantage of this container sealing process is that once the samples have been sealed inside, the outer wall of what remains of the container is a clean surface that has not come into contact with the environment from which the samples were taken. Thus, there is no need to devise a decontamination process capable of mitigating all hazards that might be posed by unanticipated radioactive, chemical, and/or biological contamination of the outside of the container. The container sealing method was originally intended to be used to return samples from Mars to Earth, but it could also be used to store samples of hazardous materials, without the need to decontaminate its outer surface. The process stages are shown. In its initial double-wall form, the volume between the walls is isolated from the environment; in other words, the outer wall (which is later sacrificed) initially serves to protect the inner container from contamination. The sample is placed inside the container through an opening at one end, then the container is placed into a transfer dock/lid. The surfaces that will be welded together under the explosive have been coated with a soft metallic sacrificial layer. During the explosion, the sacrificial layer is ejected, and the container walls are welded together, creating a strong metallic seal. The inner container is released during the same event and enters the clean environment.

The Electronic Structure of Transition Metal Coated Fullerenes

NASA Astrophysics Data System (ADS)

Patton, David C.; Pederson, Mark R.; Kaxiras, Efthimios

1998-03-01

Clusters composed of fullerene molecules with an outer shell of transition metal atoms in the composition C_60M_62 (M being a transition metal) have been produced with laser vaporisation techniques(F. Tast, N. Malinowski, S. Frank, M. Heinebrodt, I.M.L. Billas, and T. P. Martin, Z. Phys D 40), 351 (1997).. We have studied several of these very large systems with a parallel version of the all-electron NRLMOL cluster code. Optimized geometries of the metal encased fullerenes C_60Ti_62 and C_60V_62 are presented along with their HOMO-LUMO gaps, electron affinities, ionization energies, and cohesive energies. We compare the stability of these clusters to relaxed met-car structures (e.g. Ti_8C_12) and to relaxed rocksalt metal-carbide fragments (TiC)n with n=8 and 32. In addition to metal-coated fullerenes we consider the possibility of a trilayered structure consisting of a small shell of metal atoms enclosed by a metal coated fullerene. The nature of bonding in these systems is analyzed by studying the electronic charge distributions.

Contributions from inner and outer shell electron energies to reaction heats for C/sub 1/, C/sub 2/, and C/sub 3/ hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, P.; Bock, C.W.; Trachtman, M.

1979-04-01

The expectation energy values E/sub k/, V/sub ee/, V/sub nn/, V/sub en/, and E/sub T/ have been calculated for H/sub 2/ and the C/sub 1/, C/sub 2/, and C/sub 3/ hydrocarbons using a (9,5) basis set and the experimental geometries. Treating the theoretical reaction heat, ..delta..E/sub T/, as the resultant of the nuclear repulsion term, ..delta..V/sub nn/, and the net electron energy term, ..delta..E/sub elec/ = ..delta..E/sub k/ + ..delta..V/sub ee/ + ..delta..V/sub en/, the contribution of inner and outer shell electron energies to ..delta..E/sub elec/, and hence to ..delta..E/sub T/, has been calculated for a large number of hydrocarbonmore » reactions by evaluating the Coulson--Neilson energies eta/sub i/, where eta/sub i/ = E/sub elec/. For the vast majority of reactions, 67/84, the change in inner shell electron energy, (..delta sigma..eta/sub i/)/sub inner/, accounts for more than 10% of ..delta..E/sub elec/, in many cases being as high as 20-35%. Furthermore, in addition to these cases in which the change in inner shell electron energy serves to augment (significantly) the change in outer shell electron energy, there are other cases in which the change in inner shell electron energy either exceeds in magnitude the change in outer shell energy, or is even opposite in sign, indicative of inner and outer shell electrons acting contrariwise. Inner shell electron energies contribute to the reaction heats because they are structure dependent, like the more familiar orbital energies epsilon, but the dependence is of a different kind.« less

Nano-G research laboratory for a spacecraft

NASA Technical Reports Server (NTRS)

Vonbun, Friedrich O. (Inventor); Garriott, Owen K. (Inventor)

1991-01-01

An acceleration free research laboratory is provided that is confined within a satellite but free of any physical engagement with the walls of the satellite, wherein the laboratory has adequate power, heating, cooling, and communications services to conduct basic research and development. An inner part containing the laboratory is positioned at the center-of-mass of a satellite within the satellite's outer shell. The satellite is then positioned such that its main axes are in a position parallel to its flight velocity vector or in the direction of the residual acceleration vector. When the satellite is in its desired orbit, the inner part is set free so as to follow that orbit without contacting the inside walls of the outer shell. Sensing means detect the position of the inner part with respect to the outer shell, and activate control rockets to move the outer shell; thereby, the inner part is repositioned such that it is correctly positioned at the center-of-mass of the satellite. As a consequence, all disturbing forces, such as drag forces, act on the outer shell, and the inner part containing the laboratory is shielded and is affected only by gravitational forces. Power is supplied to the inner part and to the laboratory by a balanced microwave/laser link which creates the kind of environment necessary for basic research to study critical phenomena such as the Lambda transition in helium and crystal growth, and to perform special metals and alloys research, etc.

Alterations of the outer retina in non-arteritic anterior ischaemic optic neuropathy detected using spectral-domain optical coherence tomography.

PubMed

Ackermann, Philipp; Brachert, Maike; Albrecht, Philipp; Ringelstein, Marius; Finis, David; Geerling, Gerd; Aktas, Orhan; Guthoff, Rainer

2017-07-01

A characteristic disease pattern may be reflected by retinal layer thickness changes in non-arteritic anterior ischaemic optic neuropathy measured using spectraldomain optical coherence tomography. Retinal layer segmentation is enabled by advanced software. In this study, retinal layer thicknesses in acute and chronic non-arteritic anterior ischaemic optic neuropathy were compared. A single-centre cross-sectional analysis was used. A total of 27 patients (20 age-matched healthy eyes) were included: 14 with acute (<7 days) and 13 patients with chronic non-arteritic anterior ischaemic optic neuropathy. Macular volume and 12° peripapillary ring optical coherence tomography scans were used. The peripapillary thicknesses of the following layers were determined by manual segmentation: retinal nerve fibres, ganglion cells + inner plexiform layer, inner nuclear layer + outer plexiform layer, outer nuclear layer + inner segments of the photoreceptors and outer segments of the photoreceptors to Bruch's membrane. Macular retinal layer thicknesses were automatically determined in volume cubes centred on the fovea. Peripapillary retinal swelling in acute nonarteritic anterior ischaemic optic neuropathy was attributable to retinal nerve fibre layer, ganglion cell layer/inner plexiform layer and outer nuclear layer/segments of the photoreceptors thickening. In chronic cases, peripapillary retinal nerve fibre layer, macular ganglion cell layer and inner plexiform layer thinning were observed. In acute non-arteritic anterior ischaemic optic neuropathy, the inner and outer peripapillary retinal layers are affected by thickness changes. In chronic cases, atrophy of the ganglion cells and their axons and dendrites is evident by inner retinal layer thinning. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

Outer layer effects in wind-farm boundary layers: Coriolis forces and boundary layer height

NASA Astrophysics Data System (ADS)

Allaerts, Dries; Meyers, Johan

2015-11-01

In LES studies of wind-farm boundary layers, scale separation between the inner and outer region of the atmospheric boundary layer (ABL) is frequently assumed, i.e., wind turbines are presumed to fall within the inner layer and are not affected by outer layer effects. However, modern wind turbine and wind farm design tends towards larger rotor diameters and farm sizes, which means that outer layer effects will become more important. In a prior study, it was already shown for fully-developed wind farms that the ABL height influences the power performance. In this study, we use the in-house LES code SP-Wind to investigate the importance of outer layer effects on wind-farm boundary layers. In a suite of LES cases, the ABL height is varied by imposing a capping inversion with varying inversion strengths. Results indicate the growth of an internal boundary layer (IBL), which is limited in cases with low inversion layers. We further find that flow deceleration combined with Coriolis effects causes a change in wind direction throughout the farm. This effect increases with decreasing boundary layer height, and can result in considerable turbine wake deflection near the end of the farm. The authors are supported by the ERC (ActiveWindFarms, grant no: 306471). Computations were performed on VSC infrastructiure (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government-department EWI.

Anisotropic metal growth on phospholipid nanodiscs via lipid bilayer expansion

PubMed Central

Oertel, Jana; Keller, Adrian; Prinz, Julia; Schreiber, Benjamin; Hübner, René; Kerbusch, Jochen; Bald, Ilko; Fahmy, Karim

2016-01-01

Self-assembling biomolecules provide attractive templates for the preparation of metallic nanostructures. However, the intuitive transfer of the “outer shape” of the assembled macromolecules to the final metallic particle depends on the intermolecular forces among the biomolecules which compete with interactions between template molecules and the metal during metallization. The shape of the bio-template may thus be more dynamic than generally assumed. Here, we have studied the metallization of phospholipid nanodiscs which are discoidal particles of ~10 nm diameter containing a lipid bilayer ~5 nm thick. Using negatively charged lipids, electrostatic adsorption of amine-coated Au nanoparticles was achieved and followed by electroless gold deposition. Whereas Au nanoparticle adsorption preserves the shape of the bio-template, metallization proceeds via invasion of Au into the hydrophobic core of the nanodisc. Thereby, the lipidic phase induces a lateral growth that increases the diameter but not the original thickness of the template. Infrared spectroscopy reveals lipid expansion and suggests the existence of internal gaps in the metallized nanodiscs, which is confirmed by surface-enhanced Raman scattering from the encapsulated lipids. Interference of metallic growth with non-covalent interactions can thus become itself a shape-determining factor in the metallization of particularly soft and structurally anisotropic biomaterials. PMID:27216789

[Bilateral acute retinal necrosis in a patient with acquired immunodeficiency syndrome].

PubMed

Menerath, J M; Gerard, M; Laurichesse, H; Goldschmidt, P; Peigue-Lafeuille, H; Rozenberg, F; Beytout, J

1995-01-01

A case of bilateral progressive outer retinal necrosis occurred after herpes zoster ophthalmicus in a patient with acquired immunodeficiency syndrome. This case does not correspond to the classical picture of progressive outer retinal necrosis. The disease led to blindness despite intravenous therapy with acyclovir and foscarnet. PCR could not identify any virus in the aqueous humour, but VZV is evidenced in cerebrospinal fluid. Acute retinal necrosis is now clearly defined by the American Uveitis Society, which should allow to determine its incidence and risk factors. Herpes zoster usually precedes the acute outer retinal necrosis. The infectious theory (VZV, HSV, CMV) widely prevails over the immune theory. We prefer the virus genome identification in the aqueous humor or in the vitreous by PCR to confirm diagnosis rather than the specific antibody titration. Therapy consists in acyclovir, foscarnet and ganciclovir. But whatever the treatment, the visual prognosis is poor.

Control of fluorescence in quantum emitter and metallic nanoshell hybrids for medical applications

NASA Astrophysics Data System (ADS)

Singh, Mahi R.; Guo, Jiaohan; J. Cid, José M.; De Hoyos Martinez, Jesús E.

2017-03-01

We study the light emission from a quantum emitter and double metallic nanoshell hybrid systems. Quantum emitters act as local sources which transmit their light efficiently due to a double nanoshell near field. The double nanoshell consists of a dielectric core and two outer nanoshells. The first nanoshell is made of a metal, and the second spacer nanoshell is made of a dielectric material or human serum albumin. We have calculated the fluorescence emission for a quantum emitter-double nanoshell hybrid when it is injected in an animal or a human body. Surface plasmon polariton resonances in the double nanoshell are calculated using Maxwell's equations in the quasi-static approximation, and the fluorescence emission is evaluated using the density matrix method in the presence of dipole-dipole interactions. We have compared our theory with two fluorescence experiments in hybrid systems in which the quantum emitter is Indocyanine Green or infrared fluorescent molecules. The outer spacer nanoshell of double metallic nanoshells consists of silica and human serum albumin with variable thicknesses. Our theory explains the enhancement of fluorescence spectra in both experiments. We find that the thickness of the spacer nanoshell layer increases the enhancement when the fluorescence decreases. The enhancement of the fluorescence depends on the type of quantum emitter, spacer layer, and double nanoshell. We also found that the peak of the fluorescence spectrum can be shifted by changing the shape and the size of the nanoshell. The fluorescence spectra can be switched from one peak to two peaks by removing the degeneracy of excitonic states in the quantum emitter. Hence, using these properties, one can use these hybrids as sensing and switching devices for applications in medicine.

c-Type Cytochrome-Dependent Formation of U(IV) Nanoparticles by Shewanella oneidensis

PubMed Central

Marshall, Matthew J; Dohnalkova, Alice C; Kennedy, David W; Shi, Liang; Wang, Zheming; Boyanov, Maxim I; Lai, Barry; Kemner, Kenneth M; McLean, Jeffrey S; Reed, Samantha B; Culley, David E; Bailey, Vanessa L; Simonson, Cody J; Saffarini, Daad A; Romine, Margaret F; Zachara, John M

2006-01-01

Modern approaches for bioremediation of radionuclide contaminated environments are based on the ability of microorganisms to effectively catalyze changes in the oxidation states of metals that in turn influence their solubility. Although microbial metal reduction has been identified as an effective means for immobilizing highly-soluble uranium(VI) complexes in situ, the biomolecular mechanisms of U(VI) reduction are not well understood. Here, we show that c-type cytochromes of a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, are essential for the reduction of U(VI) and formation of extracelluar UO 2 nanoparticles. In particular, the outer membrane (OM) decaheme cytochrome MtrC (metal reduction), previously implicated in Mn(IV) and Fe(III) reduction, directly transferred electrons to U(VI). Additionally, deletions of mtrC and/or omcA significantly affected the in vivo U(VI) reduction rate relative to wild-type MR-1. Similar to the wild-type, the mutants accumulated UO 2 nanoparticles extracellularly to high densities in association with an extracellular polymeric substance (EPS). In wild-type cells, this UO 2-EPS matrix exhibited glycocalyx-like properties and contained multiple elements of the OM, polysaccharide, and heme-containing proteins. Using a novel combination of methods including synchrotron-based X-ray fluorescence microscopy and high-resolution immune-electron microscopy, we demonstrate a close association of the extracellular UO 2 nanoparticles with MtrC and OmcA (outer membrane cytochrome). This is the first study to our knowledge to directly localize the OM-associated cytochromes with EPS, which contains biogenic UO 2 nanoparticles. In the environment, such association of UO 2 nanoparticles with biopolymers may exert a strong influence on subsequent behavior including susceptibility to oxidation by O 2 or transport in soils and sediments. PMID:16875436

Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Praphairaksit, Narong

2000-09-12

An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at ~70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W withmore » an outer gas flow rate of ~4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression of signal for even the most troublesome combination of light analyte and heavy matrix elements can be attenuated from 90-99% to only 2-10% for 2 mM matrix solutions with an ultrasonic nebulizer. The supplemental electron current can be adjusted to ''titrate'' out the matrix effects as desired.« less

Debris-less method and apparatus for forming apertures in hollow metallic articles

DOEpatents

Jordan, C.L.; Chodelka, E.J.

1980-06-24

This invention is a method for forming an aperture in a wall of a hollow metallic article without introducing metallic debris therein. In a typical operation, an annular groove is formed in an exterior portion of the wall. The groove defines an annular wall segment, and the bottom of the groove is shaped to slope downwardly away from the segment to form a tapered annular web which connects the segment to the wall. Any suitable coupling is attached to the outer face of the segment, as by welding. Pull then is applied to the coupling to effect circumferential breakage of the web, thus forming a removable single-piece wall fragment consisting of the web and segment. The fragment and the coupling member attached thereto then are removed from the wall.

Metal Accumulation and Vanadium-Induced Multidrug Resistance by Environmental Isolates of Escherichia hermannii and Enterobacter cloacae

PubMed Central

Hernández, Alicia; Mellado, Rafael P.; Martínez, José L.

1998-01-01

Contaminated soils from an oil refinery were screened for the presence of microorganisms capable of accumulating either nickel, vanadium, or both metals. Three strains of bacteria that belonged to the family Enterobacteriaceae were selected. Two of them were Escherichia hermannii strains, and outer membrane profile (OMP) analysis showed that they were similar to a strain of clinical origin; the other one was an Enterobacter cloacae strain that differed from clinical isolates. The selected bacteria accumulated both nickel and vanadium. Growth in the presence of vanadium induced multidrug resistance phenotypes in E. hermannii and E. cloacae. Incubation with this metal changed the OMP profile of E. hermannii but did not produce variations in the expression of the major OMPs of E. cloacae. PMID:9797283

High temperature thrust chamber for spacecraft

NASA Technical Reports Server (NTRS)

Chazen, Melvin L. (Inventor); Mueller, Thomas J. (Inventor); Kruse, William D. (Inventor)

1998-01-01

A high temperature thrust chamber for spacecraft (20) is provided herein. The high temperature thrust chamber comprises a hollow body member (12) having an outer surface and an internal surface (16) defining the high temperature chamber (10). The body member (12) is made substantially of rhenium. An alloy (18) consisting of iridium and at least alloying metal selected of the group consisting of rhodium, platinum and palladium is deposited on at least a portion of the internal surface (16) of the body member (12). The iridium and the alloying metal are electrodeposited onto the body member (12). A HIP cycle is performed upon the body member (12) to cause the coating of iridium and the alloying metal to form the alloy (18) which protects the body member (12) from oxidation.

The Influence of Heat Flux Boundary Heterogeneity on Heat Transport in Earth's Core

NASA Astrophysics Data System (ADS)

Davies, C. J.; Mound, J. E.

2017-12-01

Rotating convection in planetary systems can be subjected to large lateral variations in heat flux from above; for example, due to the interaction between the metallic cores of terrestrial planets and their overlying silicate mantles. The boundary anomalies can significantly reorganise the pattern of convection and influence global diagnostics such as the Nusselt number. We have conducted a suite of numerical simulations of rotating convection in a spherical shell geometry comparing convection with homogeneous boundary conditions to that with two patterns of heat flux variation at the outer boundary: one hemispheric pattern, and one derived from seismic tomographic imaging of Earth's lower mantle. We consider Ekman numbers down to 10-6 and flux-based Rayleigh numbers up to 800 times critical. The heterogeneous boundary conditions tend to increase the Nusselt number relative to the equivalent homogeneous case by altering both the flow and temperature fields, particularly near the top of the convecting region. The enhancement in Nusselt number tends to increase as the amplitude and wavelength of the boundary heterogeneity is increased and as the system becomes more supercritical. In our suite of models, the increase in Nusselt number can be as large as 25%. The slope of the Nusselt-Rayleigh scaling also changes when boundary heterogeneity is included, which has implications when extrapolating to planetary conditions. Additionally, regions of effective thermal stratification can develop when strongly heterogeneous heat flux conditions are applied at the outer boundary.

Integrated light chemical tagging analyses of seven M31 outer halo globular clusters from the Pan-Andromeda Archaeological Survey

NASA Astrophysics Data System (ADS)

Sakari, Charli M.; Venn, Kim A.; Mackey, Dougal; Shetrone, Matthew D.; Dotter, Aaron; Ferguson, Annette M. N.; Huxor, Avon

2015-04-01

Detailed chemical abundances are presented for seven M31 outer halo globular clusters (with projected distances from M31 greater than 30 kpc), as derived from high-resolution integrated light spectra taken with the Hobby-Eberly Telescope. Five of these clusters were recently discovered in the Pan-Andromeda Archaeological Survey (PAndAS) - this paper presents the first determinations of integrated Fe, Na, Mg, Ca, Ti, Ni, Ba, and Eu abundances for these clusters. Four of the target clusters (PA06, PA53, PA54, and PA56) are metal poor ([Fe/H] < -1.5), α-enhanced (though they are possibly less α-enhanced than Milky Way stars at the 1σ level), and show signs of star-to-star Na and Mg variations. The other three globular clusters (H10, H23, and PA17) are more metal rich, with metallicities ranging from [Fe/H] = -1.4 to -0.9. While H23 is chemically similar to Milky Way field stars, Milky Way globular clusters, and other M31 clusters, H10 and PA17, have moderately low [Ca/Fe], compared to Milky Way field stars and clusters. Additionally, PA17's high [Mg/Ca] and [Ba/Eu] ratios are distinct from Milky Way stars, and are in better agreement with the stars and clusters in the Large Magellanic Cloud. None of the clusters studied here can be conclusively linked to any of the identified streams from PAndAS; however, based on their locations, kinematics, metallicities, and detailed abundances, the most metal-rich PAndAS clusters H23 and PA17 may be associated with the progenitor of the Giant Stellar Stream, H10 may be associated with the SW cloud, and PA53 and PA56 may be associated with the eastern cloud.

Physiological and molecular genetic evaluation of the dechlorination agent, pyridine-2,6-bis(monothiocarboxylic acid) (PDTC) as a secondary siderophore of Pseudomonas.

PubMed

Lewis, Thomas A; Leach, Lynne; Morales, Sergio; Austin, Paula R; Hartwell, Hadley J; Kaplan, Benjamin; Forker, Cynthia; Meyer, Jean-Marie

2004-02-01

The bacterial metabolite and transition metal chelator pyridine-2,6-dithiocarboxylic acid (PDTC), promotes a novel and effective means of dechlorination of the toxic and carcinogenic pollutant, carbon tetrachloride. Pyridine-2,6-dithiocarboxylic acid has been presumed to act as a siderophore in the Pseudomonas strains known to produce it. To explore further the physiological function of PDTC production, we have examined its regulation, the phenotype of PDTC-negative (pdt) mutants, and envelope proteins associated with PDTC in P. putida strain DSM 3601. Aspects of the regulation of PDTC production and outer membrane protein composition were consistent with siderophore function. Pyridine-2,6-dithiocarboxylic acid production was coordinated with production of the well-characterized siderophore pyoverdine; exogenously added pyoverdine led to decreased PDTC production, and added PDTC led to decreased pyoverdine production. Positive regulation of a chromosomal pdtI-xylE transcriptional fusion, and of a 66 kDa outer membrane protein (IROMP), was seen in response to exogenous PDTC. Tests with transition metal chelators indicated that PDTC could provide a benefit under conditions of metal limitation; the loss of PDTC biosynthetic capacity caused by a pdtI transposon insertion resulted in increased sensitivity to 1,10-phenanthroline, a chelator that has high affinity for a range of divalent transition metals (e.g. Fe(2+), Cu(2+), Zn(2+)). Exogenously added PDTC could also suppress a phenotype of pyoverdine-negative (Pvd-) mutants, that of sensitivity to EDDHA, a chelator with higher affinity and specificity for Fe(3+). Measurement of 59Fe incorporation showed uptake from 59Fe:PDTC by DSM 3601 grown in low-iron medium, but not by cells grown in high iron medium, or by the pdtI mutant, which did not show expression of the 66 kDa envelope protein. These data verified a siderophore function for PDTC, and have implicated it in the uptake of transition metals in addition to iron.

Strain-tolerant ceramic coated seal

DOEpatents

Schienle, James L.; Strangman, Thomas E.

1994-01-01

A metallic regenerator seal is provided having multi-layer coating comprising a NiCrAlY bond layer, a yttria stabilized zirconia (YSZ) intermediate layer, and a ceramic high temperature solid lubricant surface layer comprising zinc oxide, calcium fluoride, and tin oxide. An array of discontinuous grooves is laser machined into the outer surface of the solid lubricant surface layer making the coating strain tolerant.

Layered method of electrode for solid oxide electrochemical cells

DOEpatents

Jensen, Russell R.

1991-07-30

A process for fabricating a fuel electrode comprising: slurry dipping to form layers which are structurally graded from all or mostly all stabilized zirconia at a first layer, to an outer most layer of substantially all metal powder, such an nickel. Higher performaance fuel electrodes may be achieved if sinter active stabilized zirconia doped for electronic conductivity is used.

Mount assembly for porous transition panel at annular combustor outlet

NASA Technical Reports Server (NTRS)

Sweeney, Ralph B. (Inventor); Verdouw, Albert J. (Inventor)

1980-01-01

A gas turbine engine combustor assembly of annular configuration has outer and inner walls made up of a plurality of axially extending multi-layered porous metal panels joined together at butt joints therebetween and each outer and inner wall including a transition panel of porous metal defining a combustor assembly outlet supported by a combustor mount assembly including a stiffener ring having a side undercut thereon fit over a transition panel end face; and wherein an annular weld joins the ring to the end face to transmit exhaust heat from the end face to the stiffener ring for dissipation from the combustor; a combustor pilot member is located in axially spaced, surrounding relationship to the end face and connector means support the stiffener ring in free floating relationship with the pilot member to compensate for both radial and axial thermal expansion of the transition panel; and said connector means includes a radial gap for maintaining a controlled flow of coolant from outside of the transition panel into cooling relationship with the stiffener ring and said weld to further cool the end face against excessive heat build-up therein during flow of hot gas exhaust through said outlet.

Characterization of a Messer – The late-Medieval single-edged sword of Central Europe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fajfar, Peter; Medved, Jožef; Klančnik, Grega

2013-12-15

Metallurgical characterization of a sword blade fragments dating from the second half of the 15th century found in central Slovenia was performed in order to determine its chemical composition, microstructure, microhardness, and to obtain insight into the methods of manufacture of a late-medieval Messer sword. As the artefact was broken, examinations were limited to six very small fragments that were allowed to be removed from the cutting edge, core and the back of the blade. Light optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence spectrometry, differential scanning calorimetry, thermodynamics approach and Vickers micro-hardness tests weremore » employed to analyze the microstructure and mechanical properties. The results show that the sword was manufactured from a single wrought iron billet. The surface of the sword was carburized. No evidence of quenching was found. The ferritic microstructure is concentrated in the core, and the pearlitic in the outer layer of the blade. All metal fragments contained non-metallic inclusions that were derived mostly from slag and some from hammer scale. - Highlights: • A metallurgical characterization of a medieval sword blade has been performed. • The carbon content decreased from the surface to the core of the blade. • The dominant microstructure in the outer layer is pearlite and in the core is ferrite. • The presence of lump shaped and elongated non-metallic inclusions was observed. • The sword was manufactured from a single wrought iron billet.« less

The merger remnant NGC 3610 and its globular cluster system: a large-scale study

NASA Astrophysics Data System (ADS)

Bassino, Lilia P.; Caso, Juan P.

2017-04-01

We present a photometric study of the prototype merger remnant NGC 3610 and its globular cluster (GC) system, based on new Gemini/GMOS and Advanced Camera for Surveys/Hubble Space Telescope archival images. Thanks to the large field of view of our GMOS data, larger than previous studies, we are able to detect a 'classical' bimodal GC colour distribution, corresponding to metal-poor and metal-rich GCs, at intermediate radii and a small subsample of likely young clusters of intermediate colours, mainly located in the outskirts. The extent of the whole GC system is settled as about 40 kpc. The GC population is quite poor, about 500 ± 110 members that corresponds to a low total specific frequency SN ˜ 0.8. The effective radii of a cluster sample are determined, including those of two spectroscopically confirmed young and metal-rich clusters, that are in the limit between GC and UCD sizes and brightness. The large-scale galaxy surface-brightness profile can be decomposed as an inner embedded disc and an outer spheroid, determining for both larger extents than earlier research (10 and 30 kpc, respectively). We detect boxy isophotes, expected in merger remnants, and show a wealth of fine-structure in the surface-brightness distribution with unprecedented detail, coincident with the outer spheroid. The lack of symmetry in the galaxy colour map adds a new piece of evidence to the recent merger scenario of NGC 3610.

Progressive outer retinal necrosis: a missed diagnosis and a blind, young woman.

PubMed

Parekh, Parth; Oldfield, Edward C; Marik, Paul E

2013-04-22

We present a 33-year-old woman with a history significant for HIV/AIDS (CD4 count of 17) and diabetes mellitus who was diagnosed as having progressive outer retinal necrosis (PORN) after presenting with peripheral vision loss. This case provided a diagnostic challenge and demonstrates the devastating effects of a misdiagnosis as it pertains to PORN.

Progressive outer retinal necrosis: a missed diagnosis and a blind, young woman

PubMed Central

Parekh, Parth; Oldfield, Edward C; Marik, Paul E

2013-01-01

We present a 33-year-old woman with a history significant for HIV/AIDS (CD4 count of 17) and diabetes mellitus who was diagnosed as having progressive outer retinal necrosis (PORN) after presenting with peripheral vision loss. This case provided a diagnostic challenge and demonstrates the devastating effects of a misdiagnosis as it pertains to PORN. PMID:23608868

APT Blanket Thermal Analyses of Top Horizontal Row 1 Modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shadday, M.A.

1999-09-20

The Accelerator Production of Tritium (APT) cavity flood system (CFS) is designed to be the primary safeguard for the integrity of the blanket modules during loss of coolant accidents (LOCAs). For certain large break LOCAs the CFS also provides backup for the residual heat removal systems (RHRs) in cooling the target assemblies. In the unlikely event that the internal flow passages in a blanket module or target assembly dryout, decay heat in the metal structures will be dissipated to the CFS through the module or assembly walls (i.e., rung outer walls). The target assemblies consist of tungsten targets encased inmore » steel conduits, and they can safely sustain high metal temperatures. Under internally dry conditions, the cavity flood fluid will cool the target assemblies with vigorous nucleate boiling on the external surfaces. However, the metal structures in the blanket modules consist of lead cladded in aluminum, and they have a long-term exposure temperature limit currently set to 150 degrees C. Simultaneous LOCAs in both the target and blanket heat removal systems (HRS) could result in dryout of the target ladders, as well as the horizontal blanket modules above the target. The cavity flood coolant would boil on the outside surfaces of the target ladder rungs, and the resultant steam could reduce the effectiveness of convection heat transfer from the blanket modules to the cavity flood coolant. A two-part analysis was conducted to ascertain if the cavity flood system can adequately cool the blanket modules above the targets, even when boiling is occurring on the outer surfaces of the target ladder rungs. The first part of the analysis was to model transient thermal conduction in the front top horizontal row 1 module (i.e. top horizontal modules nearest the incoming beam), while varying parametrically the convection heat transfer coefficient (htc) for the external surfaces exposed to the cavity flood flow. This part of the analysis demonstrated that the module could adequately conduct heat to the outer module surfaces, given reasonable values for the convection heat transfer coefficients. The second part of the analysis consisted of two-phase flow modeling of the natural circulation of the cavity flood fluid past the top modules. Slots in the top shield allow the cavity flood fluid to circulate. The required width for these slots, to prevent steam from backing up and blanketing the outer surfaces of the top modules, was determined.« less

The close binary frequency of Wolf-Rayet stars as a function of metallicity in M31 and M33

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neugent, Kathryn F.; Massey, Philip, E-mail: kneugent@lowell.edu, E-mail: phil.massey@lowell.edu

Massive star evolutionary models generally predict the correct ratio of WC-type and WN-type Wolf-Rayet stars at low metallicities, but underestimate the ratio at higher (solar and above) metallicities. One possible explanation for this failure is perhaps single-star models are not sufficient and Roche-lobe overflow in close binaries is necessary to produce the 'extra' WC stars at higher metallicities. However, this would require the frequency of close massive binaries to be metallicity dependent. Here we test this hypothesis by searching for close Wolf-Rayet binaries in the high metallicity environments of M31 and the center of M33 as well as in themore » lower metallicity environments of the middle and outer regions of M33. After identifying ∼100 Wolf-Rayet binaries based on radial velocity variations, we conclude that the close binary frequency of Wolf-Rayets is not metallicity dependent and thus other factors must be responsible for the overabundance of WC stars at high metallicities. However, our initial identifications and observations of these close binaries have already been put to good use as we are currently observing additional epochs for eventual orbit and mass determinations.« less

Accretion of low-metallicity gas by the Milky Way.

PubMed

Wakker, B P; Howk, J C; Savage, B D; van Woerden, H; Tufte, S L; Schwarz, U J; Benjamin, R; Reynolds, R J; Peletier, R F; Kalberla, P M

1999-11-25

Models of the chemical evolution of the Milky Way suggest that the observed abundances of elements heavier than helium ('metals') require a continuous infall of gas with metallicity (metal abundance) about 0.1 times the solar value. An infall rate integrated over the entire disk of the Milky Way of approximately 1 solar mass per year can solve the 'G-dwarf problem'--the observational fact that the metallicities of most long-lived stars near the Sun lie in a relatively narrow range. This infall dilutes the enrichment arising from the production of heavy elements in stars, and thereby prevents the metallicity of the interstellar medium from increasing steadily with time. However, in other spiral galaxies, the low-metallicity gas needed to provide this infall has been observed only in associated dwarf galaxies and in the extreme outer disk of the Milky Way. In the distant Universe, low-metallicity hydrogen clouds (known as 'damped Ly alpha absorbers') are sometimes seen near galaxies. Here we report a metallicity of 0.09 times solar for a massive cloud that is falling into the disk of the Milky Way. The mass flow associated with this cloud represents an infall per unit area of about the theoretically expected rate, and approximately 0.1-0.2 times the amount required for the whole Galaxy.

Electrode for electrochemical cell

DOEpatents

Kaun, T.D.; Nelson, P.A.; Miller, W.E.

1980-05-09

An electrode structure for a secondary electrochemical cell includes an outer enclosure defining a compartment containing electrochemical active material. The enclosure includes a rigid electrically conductive metal sheet with perforated openings over major side surfaces. The enclosure can be assembled as first and second trays each with a rigid sheet of perforated electrically conductive metal at major side surfaces and normally extending flanges at parametric margins. The trays can be pressed together with moldable active material between the two to form an expandable electrode. A plurality of positive and negative electrodes thus formed are arranged in an alternating array with porous frangible interelectrode separators within the housing of the secondary electrochemical cell.

Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines

NASA Technical Reports Server (NTRS)

Amos, D. J.

1977-01-01

An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

Electrode for electrochemical cell

DOEpatents

Kaun, Thomas D.; Nelson, Paul A.; Miller, William E.

1981-01-01

An electrode structure for a secondary electrochemical cell includes an outer enclosure defining a compartment containing electrochemical active material. The enclosure includes a rigid electrically conductive metal sheet with perforated openings over major side surfaces. The enclosure can be assembled as first and second trays each with a rigid sheet of perforated electrically conductive metal at major side surfaces and normally extending flanges at parametric margins. The trays can be pressed together with moldable active material between the two to form an expandable electrode. A plurality of positive and negative electrodes thus formed are arranged in an alternating array with porous frangible interelectrode separators within the housing of the secondary electrochemical cell.

Coalescence growth mechanism of ultrafine metal particles

NASA Astrophysics Data System (ADS)

Kasukabe, S.

1990-01-01

Ultrafine particles produced by a gas-evaporation technique show clear-cut crystal habits. The convection of an inert gas makes distinct growth zones in a metal smoke. The coalescence stages of hexagonal plates and multiply twinned particles are observed in the outer zone of a smoke. A model of the coalescence growth of particles with different crystal habits is proposed. Size distributions can be calculated by counting the ratio of the number of collisions by using the effective cross section of collisions and the existence probability of the volume of a particle. This simulation model makes clear the effect on the growth rate of coalescence growth derived from crystal habit.

Overlay metallic-cermet alloy coating systems

NASA Technical Reports Server (NTRS)

Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

1984-01-01

A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

A gaseous metal disk around a white dwarf.

PubMed

Gänsicke, B T; Marsh, T R; Southworth, J; Rebassa-Mansergas, A

2006-12-22

The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines constrains the outer disk radius to just 1.2 solar radii. The likely origin of the disk is a tidally disrupted asteroid, which has been destabilized from its initial orbit at a distance of more than 1000 solar radii by the interaction with a relatively massive planetesimal object or a planet. The white dwarf mass of 0.77 solar mass implies that planetary systems may form around high-mass stars.

The nature of the pressure-induced metallization of FeO and its implications to the core-mantle boundary

USGS Publications Warehouse

Sherman, David M.

1989-01-01

The pressure and temperature-induced metallization of FeO discovered by Knittle et al (1986) is here argued to result from a Mott transition associated with increased Fe(3d)-Fe(3d) orbital overlap at high pressures. Consequently, it is here argued that a lower mantle containing only these phases should be electrically insulating. Finally, the formation of itinerant d-electrons in FeO may be a necessary, if not sufficient, condition for the apparent alloying of FeO with Fe. Such alloying may allow oxygen to be incorporated into the outer core. -from Author

Hybrid Composite Cryogenic Tank Structure

NASA Technical Reports Server (NTRS)

DeLay, Thomas

2011-01-01

A hybrid lightweight composite tank has been created using specially designed materials and manufacturing processes. The tank is produced by using a hybrid structure consisting of at least two reinforced composite material systems. The inner composite layer comprises a distinct fiber and resin matrix suitable for cryogenic use that is a braided-sleeve (and/or a filamentwound layer) aramid fiber preform that is placed on a removable mandrel (outfitted with metallic end fittings) and is infused (vacuum-assisted resin transfer molded) with a polyurethane resin matrix with a high ductility at low temperatures. This inner layer is allowed to cure and is encapsulated with a filamentwound outer composite layer of a distinct fiber resin system. Both inner and outer layer are in intimate contact, and can also be cured at the same time. The outer layer is a material that performs well for low temperature pressure vessels, and it can rely on the inner layer to act as a liner to contain the fluids. The outer layer can be a variety of materials, but the best embodiment may be the use of a continuous tow of carbon fiber (T-1000 carbon, or others), or other high-strength fibers combined with a high ductility epoxy resin matrix, or a polyurethane matrix, which performs well at low temperatures. After curing, the mandrel can be removed from the outer layer. While the hybrid structure is not limited to two particular materials, a preferred version of the tank has been demonstrated on an actual test tank article cycled at high pressures with liquid nitrogen and liquid hydrogen, and the best version is an inner layer of PBO (poly-pphenylenebenzobisoxazole) fibers with a polyurethane matrix and an outer layer of T-1000 carbon with a high elongation epoxy matrix suitable for cryogenic temperatures. A polyurethane matrix has also been used for the outer layer. The construction method is ideal because the fiber and resin of the inner layer has a high strain to failure at cryogenic temperatures, and will not crack or produce leaks. The outer layer serves as more of a high-performance structural unit for the inner layer, and can handle external environments.

Chemical Compositions of Kinematically Selected Outer Halo Stars

NASA Astrophysics Data System (ADS)

Zhang, Lan; Ishigaki, Miho; Aoki, Wako; Zhao, Gang; Chiba, Masashi

2009-12-01

Chemical abundances of 26 metal-poor dwarfs and giants are determined from high-resolution and high signal-to-noise ratio spectra obtained with the Subaru/High Dispersion Spectrograph. The sample is selected so that most of the objects have outer-halo kinematics. Self-consistent atmospheric parameters were determined by an iterative procedure based on spectroscopic analysis. Abundances of 13 elements, including α-elements (Mg, Si, Ca, Ti), odd-Z light elements (Na, Sc), iron-peak elements (Cr, Mn, Fe, Ni, Zn), and neutron-capture elements (Y, Ba), are determined by two independent data reduction and local thermodynamic equillibrium analysis procedures, confirming the consistency of the stellar parameters and abundances results. We find a decreasing trend of [α/Fe] with increasing [Fe/H] for the range of -3.5< [Fe/H] <-1, as found by Stephens & Boesgaard. [Zn/Fe] values of most objects in our sample are slightly lower than the bulk of halo stars previously studied. These results are discussed as possible chemical properties of the outer halo in the Galaxy. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Iron-magnesium alloy in the Earth's Core

NASA Astrophysics Data System (ADS)

Dubrovinskaia, N.; Dubrovinsky, L.; Abrikosov, I.

2005-12-01

Composition of the Earth's outer core is a geochemical parameter crucial for understanding the evolution and current dynamics of our planet. Since it was recognized that the liquid metallic outer core is about 10% less dense than pure iron, different elements lighter than iron, including Si, S, O, C, and H, were proposed as major or at least significantly abundant in Earth's core. However, combination of experimental results with theoretical and geochemical considerations shows that it is unlikely that any one of these elements can account for the density deficit on its own. In series of experiments in a multianvil apparatus and in electrically- and laser-heated diamond anvil cells, we demonstrate that high pressure promotes solubility of magnesium in iron and at megabar pressure range more than 10 at% of Mg can dissolve in Fe. At pressures above 95 to 100 GPa, molten iron reacts with periclase MgO forming an iron-magnesium alloy and iron oxide. Our observations suggest that magnesium can be an important light element in Earth's outer core, but it cannot account for the seismologically determined density deficit on its own.

Capacitively coupled pickup in MCP-based photodetectors using a conductive metallic anode

NASA Astrophysics Data System (ADS)

Angelico, E.; Seiss, T.; Adams, B.; Elagin, A.; Frisch, H.; Spieglan, E.

2017-02-01

We have designed and tested a robust 20×20 cm2 thin metal film internal anode capacitively coupled to an external array of signal pads or micro-strips for use in fast microchannel plate photodetectors. The internal anode, in this case a 10 nm-thick NiCr film deposited on a 96% pure Al2O3 3 mm-thick ceramic plate and connected to HV ground, provides the return path for the electron cascade charge. The multi-channel pickup array consists of a printed-circuit card or glass plate with metal signal pickups on one side and the signal ground plane on the other. The pickup can be put in close proximity to the bottom outer surface of the sealed photodetector, with no electrical connections through the photodetector hermetic vacuum package other than a single ground connection to the internal anode. Two pickup patterns were tested using a small commercial MCP-PMT as the signal source: 1) parallel 50 Ω 25-cm-long micro-strips with an analog bandwidth of 1.5 GHz, and 2) a 20×20 cm2 array of 2-dimensional square 'pads' with sides of 1.27 cm or 2.54 cm. The rise-time of the fast input pulse is maintained for both pickup patterns. For the pad pattern, we observe 80% of the directly coupled amplitude. For the strip pattern we measure 34% of the directly coupled amplitude on the central strip of a broadened signal. The physical decoupling of the photodetector from the pickup pattern allows easy customization for different applications while maintaining high analog bandwidth.

Evolution of Warped Accretion Disks in Active Galactic Nuclei. I. Roles of Feeding at the Outer Boundaries

NASA Astrophysics Data System (ADS)

Li, Yan-Rong; Wang, Jian-Min; Cheng, Cheng; Qiu, Jie

2013-02-01

We investigate the alignment processes of spinning black holes and their surrounding warped accretion disks in a frame of two different types of feeding at the outer boundaries. We consider (1) fixed flows in which gas is continually fed with a preferred angular momentum, and (2) free flows in which there is no gas supply and the disks diffuse freely at their outer edges. As expected, we find that for the cases of fixed flows the black hole disk systems always align on timescales of several 106 yr, irrespective of the initial inclinations. If the initial inclination angles are larger than π/2, the black hole accretion transits from retrograde to prograde fashion, and the accreted mass onto the black holes during these two phases is comparable. On the other hand, for the cases of free flows, both alignments and anti-alignments can occur, depending on the initial inclinations and the ratios of the angular momentum of the disks to that of the black holes. In such cases, the disks will be consumed within timescales of 106 yr by black holes accreting at the Eddington limit. We propose that there is a close connection between the black hole spin and the lifetime for which the feeding persists, which determines the observable episodic lifetimes of active galactic nuclei. We conclude that careful inclusion of the disk feeding at the outer boundaries is crucial for modeling the evolution of the black hole spin.

Investigation of linearity of the ITER outer vessel steady-state magnetic field sensors at high temperature

NASA Astrophysics Data System (ADS)

Entler, S.; Duran, I.; Kocan, M.; Vayakis, G.

2017-07-01

Three vacuum vessel sectors in ITER will be instrumented by the outer vessel steady-state magnetic field sensors. Each sensor unit features a pair of metallic Hall sensors with a sensing layer made of bismuth to measure tangential and normal components of the local magnetic field. The influence of temperature and magnetic field on the Hall coefficient was tested for the temperature range from 25 to 250 oC and the magnetic field range from 0 to 0.5 T. A fit of the Hall coefficient normalized temperature function independent of magnetic field was found, and a model of the Hall coefficient functional dependence at a wide range of temperature and magnetic field was built with the purpose to simplify the calibration procedure.

The morphology of the ridge belts on Venus

NASA Astrophysics Data System (ADS)

Kriuchkov, V. P.

1990-06-01

The length and spacing of linear features were measured for ridge and groove belts, for the outer mountain zones of the Lakshmi planum, and for the outer ridge zones of coronal structures. The distributions of these parameters show small but significant differences in most of the cases. The ridges are assumed to result from deformations. Deformed-layer thickness were estimated for various types of linear subdivisions.

CORNER OF SUBPILE ROOM: NORTH AND EAST SIDES. STEEL OUTER ...

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

CORNER OF SUBPILE ROOM: NORTH AND EAST SIDES. STEEL OUTER SHELL HAS BEEN AFFIXED. SIGN SAYS "HERRICK IRON WORKS STEEL, OAKLAND, CALIFORNIA." NOTE CONDUIT FOR FUTURE INSTRUMENTATION. TOP OF STEEL CASE WILL BE LEVEL WITH BASEMENT CEILING. CAMERA FACES SOUTHEAST. INL NEGATIVE NO. 734. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

30 CFR 250.421 - What are the casing and cementing requirements by type of casing string?

Code of Federal Regulations, 2010 CFR

2010-07-01

... hazards, and water depthsSet casing immediately before drilling into formations known to contain oil or..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.421 What are the casing and cementing...

Carbon nanotube wires and cables: Near-term applications and future perspectives

NASA Astrophysics Data System (ADS)

Jarosz, Paul; Schauerman, Christopher; Alvarenga, Jack; Moses, Brian; Mastrangelo, Thomas; Raffaelle, Ryne; Ridgley, Richard; Landi, Brian

2011-11-01

Wires and cables are essential to modern society, and opportunities exist to develop new materials with reduced resistance, mass, and/or susceptibility to fatigue. This article describes how carbon nanotubes (CNTs) offer opportunities for integration into wires and cables for both power and data transmission due to their unique physical and electronic properties. Macroscopic CNT wires and ribbons are presently shown as viable replacements for metallic conductors in lab-scale demonstrations of coaxial, USB, and Ethernet cables. In certain applications, such as the outer conductor of a coaxial cable, CNT materials may be positioned to displace metals to achieve substantial benefits (e.g. reduction in cable mass per unit length (mass/length) up to 50% in some cases). Bulk CNT materials possess several unique properties which may offer advantages over metallic conductors, such as flexure tolerance and environmental stability. Specifically, CNT wires were observed to withstand greater than 200,000 bending cycles without increasing resistivity. Additionally, CNT wires exhibit no increase in resistivity after 80 days in a corrosive environment (1 M HCl), and little change in resistivity with temperature (<1% from 170-330 K). This performance is superior to conventional metal wires and truly novel for a wiring material. However, for CNTs to serve as a full replacement for metals, the electrical conductivity of CNT materials must be improved. Recently, the conductivity of a CNT wire prepared through simultaneous densification and doping has exceeded 1.3 × 106 S/m. This level of conductivity brings CNTs closer to copper (5.8 × 107 S/m) and competitive with some metals (e.g. gold) on a mass-normalized basis. Developments in manipulation of CNT materials (e.g. type enrichment, doping, alignment, and densification) have shown progress towards this goal. In parallel with efforts to improve bulk conductivity, integration of CNT materials into cabling architectures will require development in electrical contacting. Several methods for contacting bulk CNT materials to metals are demonstrated, including mechanical crimping and ultrasonic bonding, along with a method for reducing contact resistance by tailoring the CNT-metal interface via electroless plating. Collectively, these results summarize recent progress in CNT wiring technologies and illustrate that nanoscale conductors may become a disruptive technology in cabling designs.

Carbon nanotube wires and cables: near-term applications and future perspectives.

PubMed

Jarosz, Paul; Schauerman, Christopher; Alvarenga, Jack; Moses, Brian; Mastrangelo, Thomas; Raffaelle, Ryne; Ridgley, Richard; Landi, Brian

2011-11-01

Wires and cables are essential to modern society, and opportunities exist to develop new materials with reduced resistance, mass, and/or susceptibility to fatigue. This article describes how carbon nanotubes (CNTs) offer opportunities for integration into wires and cables for both power and data transmission due to their unique physical and electronic properties. Macroscopic CNT wires and ribbons are presently shown as viable replacements for metallic conductors in lab-scale demonstrations of coaxial, USB, and Ethernet cables. In certain applications, such as the outer conductor of a coaxial cable, CNT materials may be positioned to displace metals to achieve substantial benefits (e.g. reduction in cable mass per unit length (mass/length) up to 50% in some cases). Bulk CNT materials possess several unique properties which may offer advantages over metallic conductors, such as flexure tolerance and environmental stability. Specifically, CNT wires were observed to withstand greater than 200,000 bending cycles without increasing resistivity. Additionally, CNT wires exhibit no increase in resistivity after 80 days in a corrosive environment (1 M HCl), and little change in resistivity with temperature (<1% from 170-330 K). This performance is superior to conventional metal wires and truly novel for a wiring material. However, for CNTs to serve as a full replacement for metals, the electrical conductivity of CNT materials must be improved. Recently, the conductivity of a CNT wire prepared through simultaneous densification and doping has exceeded 1.3 × 10(6) S/m. This level of conductivity brings CNTs closer to copper (5.8 × 10(7) S/m) and competitive with some metals (e.g. gold) on a mass-normalized basis. Developments in manipulation of CNT materials (e.g. type enrichment, doping, alignment, and densification) have shown progress towards this goal. In parallel with efforts to improve bulk conductivity, integration of CNT materials into cabling architectures will require development in electrical contacting. Several methods for contacting bulk CNT materials to metals are demonstrated, including mechanical crimping and ultrasonic bonding, along with a method for reducing contact resistance by tailoring the CNT-metal interface via electroless plating. Collectively, these results summarize recent progress in CNT wiring technologies and illustrate that nanoscale conductors may become a disruptive technology in cabling designs.

Demonstration Of A Nanomaterial-Modified Primer For Use In Corrosion-Inhibiting Coating Systems

DTIC Science & Technology

2011-11-01

abrasive blasting or other means. This report documents the materials and methodologies used for testing and application of the new coating systems on the...method with improved corrosion resistant coatings will provide the DoD with a means to cost effectively rehabilitate the outer metal surfaces of...contained with environmental controls in place. ........................................ 9 Figure 6. Abrasive blast-cleaned tank surface

Surface Structure Formation in Direct Chill (DC) Casting of Al Alloys

NASA Astrophysics Data System (ADS)

Bayat, Nazlin; Carlberg, Torbjörn

2014-05-01

The aim of this study is to increase the understanding of the surface zone formation during direct chill (DC) casting of aluminum billets produced by the air slip technology. The depth of the shell zone, with compositions deviating from the bulk, is of large importance for the subsequent extrusion productivity and quality of final products. The surface microstructures of 6060 and 6005 aluminum alloys in three different surface appearances—defect free, wavy surface, and spot defects—were studied. The surface microstructures and outer appearance, segregation depth, and phase formation were investigated for the mentioned cases. The results were discussed and explained based on the exudation of liquid metal through the mushy zone and the fact that the exudated liquid is contained within a surface oxide skin. Outward solidification in the surface layer was quantitatively analyzed, and the oxide skin movements explained meniscus line formation. Phases forming at different positions in the segregation zone were analyzed and coupled to a cellular solidification in the exudated layer.

Ultem((R))/ZIF-8 mixed matrix hollow fiber membranes for CO2/N-2 separations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Y; Johnson, JR; Karvan, O

2012-05-15

Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem((R)) 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13 wt% (17more » vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO2/N-2 gas pairs was observed for both pure gas and mixed gas feeds. (C) 2012 Elsevier B.V. All rights reserved.« less

Chemical Abundances of Planetary Nebulae in the Substructures of M31. II. The Extended Sample and a Comparison Study with the Outer-disk Group

NASA Astrophysics Data System (ADS)

Fang, Xuan; García-Benito, Rubén; Guerrero, Martín A.; Zhang, Yong; Liu, Xiaowei; Morisset, Christophe; Karakas, Amanda I.; Miller Bertolami, Marcelo M.; Yuan, Haibo; Cabrera-Lavers, Antonio

2018-01-01

We report deep spectroscopy of 10 planetary nebulae (PNe) in the Andromeda Galaxy (M31) using the 10.4 m Gran Telescopio Canarias (GTC). Our targets reside in different regions of M31, including halo streams and the dwarf satellite M32, and kinematically deviate from the extended disk. The temperature-sensitive [O III] λ4363 line is observed in all PNe. For four PNe, the GTC spectra extend beyond 1 μm, enabling the explicit detection of the [S III] λ6312 and λλ9069, 9531 lines and thus determination of the [S III] temperature. Abundance ratios are derived and generally consistent with AGB model predictions. Our PNe probably all evolved from low-mass (<2 M ⊙) stars, as analyzed with the most up-to-date post-AGB evolutionary models, and their main-sequence ages are mostly ∼2–5 Gyr. Compared to the underlying, smooth, metal-poor halo of M31, our targets are uniformly metal rich ([O/H] ≳ ‑0.4), and seem to resemble the younger population in the stream. We thus speculate that our halo PNe formed in the Giant Stream’s progenitor through extended star formation. Alternatively, they might have formed from the same metal-rich gas as did the outer-disk PNe but were displaced into their present locations as a result of galactic interactions. These interpretations are, although speculative, qualitatively in line with the current picture, as inferred from previous wide-field photometric surveys, that M31's halo is the result of complex interactions and merger processes. The behavior of the N/O of the combined sample of the outer-disk and our halo/substructure PNe signifies that hot bottom burning might actually occur at <3 M ⊙ but careful assessment is needed. Based on observations made with the Gran Telescopio Canarias, installed at the Spanish Observatorio del Roque de los Muchachos of Instituto de Astrofísica de Canarias, in the island of La Palma. The observations presented in this paper are associated with GTC programs #GTC66-16A and #GTC25-16B.

Ag@ZnO core-shell nanoparticles study by first principle: The structural, magnetic and optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Hai-Xia; Wang, Xiao-Xu; Beijing Computing Center, Beijing 100094

Ag@ZnO core-shell nanoparticles of around 72 atoms have been investigated by the density functional theory, revealing proving for the first time that the core-shell structure exhibits a shrinkage phenomenon from outer shell in agreement with the other studies in literatures. Our calculations predict that the Ag@ZnO core-shell structure is a ferromagnetic spin polarized state, and the magnetism mainly stems from the spin splitting of 2p electrons of O atoms. In addition, the total and partial DOS of Ag@ZnO indicate that the nanostructure is a half-metallic nanoparticle and has the characters of the p-type semiconductor. Furthermore, the optical properties calculations showmore » that the absorption edge of Ag@ZnO have a red shift and good photocatalysis compare to that of the bulk ZnO. These results of the Ag@ZnO core-shell structure obtain a well agreement with the experimental measurement. - Graphical abstract: Geometric structure of (a) Ag@ZnO core-shell nanostructure; (b) the core of Ag; (c) the shell of ZnO The core-shell nanoparticle Ag@ZnO contains Ag inner core of radius of 4 Å and ZnO outer shell with thickness of 2 Å. Ag@ZnO core-shell nanoparticles of around 72 atoms have been proved for the first time that the core-shell structure exhibit a shrinkage phenomenon from outer shell. Our calculations predict that the Ag@ZnO core-shell structure is a half-metallic nanoparticle and has the characters of the p-type semiconductor. The absorption edge of Ag@ZnO have a red shift and get good photo-catalysis compare to that of the bulk ZnO.« less

30 CFR 250.420 - What well casing and cementing requirements must I meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.420 What well casing and cementing... thereof. (2) The casing design must include safety measures that ensure well control during drilling and...

30 CFR 250.420 - What well casing and cementing requirements must I meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.420 What well casing and cementing... casing design must include safety measures that ensure well control during drilling and safe operations...

30 CFR 250.420 - What well casing and cementing requirements must I meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.420 What well casing and cementing... thereof. (2) The casing design must include safety measures that ensure well control during drilling and...

Transient spectral domain optical coherence tomography findings in classic MEWDS: a case report.

PubMed

Lavigne, Luciana Castro; Isaac, David Leonardo Cruvinel; Duarte Júnior, José Osório; Avila, Marcos Pereira de

2014-01-01

The purpose of this study was to describe a patient with multiple evanescent white dot syndrome (MEWDS) who presented with classic retinal findings and transient changes in outer retinal anatomy. A 20-year-old man presented with mild blurred vision in the left eye, reporting flu-like symptoms 1 week before the visual symptoms started. Fundus examination of the left eye revealed foveal granularity and multiple scattered spots deep to the retina in the posterior pole. Fluorescein angiography and indocyanine green angiography showed typical MEWDS findings. Spectral Domain Optical Coherence Tomography has shown transient changes in outer retinal anatomy with disappearance of inner segment-outer segment junction and mild attenuation of external limiting membrane. Six months later, Spectral Domain Optical Coherence Tomography has shown complete resolution with recovery of normal outer retinal aspect.

Correlation between spectral-domain OCT findings and visual acuity in X-linked retinoschisis.

PubMed

Yang, Hyun Seung; Lee, Jung Bok; Yoon, Young Hee; Lee, Joo Yong

2014-05-08

To investigate the tomographic characteristics of the outer retina and choroid and their relationship with visual acuity in X-linked juvenile retinoschisis (XLRS) patients using spectral-domain optical coherence tomography (SD-OCT). In this retrospective, observational, case-control study, we analyzed 20 eyes of 10 patients with XLRS using SD-OCT. The clinical and tomographic features of the outer retina, including the external limiting membrane (ELM), inner segment/outer segment (IS/OS) junction, cone cell outer segment tips (COST) line, photoreceptor outer segment (PROS) length, and choroid, were evaluated. As controls, 40 age-, sex-, and refraction-matched healthy eyes (1:2 matched) were randomly selected and imaged in parallel. The most prevalent area of abnormality in the outer retina layer of our patients was the outer plexiform layer (OPL; 60% of all affected eyes) and COST line (75% of all affected eyes). On average, the subfoveal choroid and PROS lengths were 35 μm thicker and 19 μm thinner, respectively, in XLRS patients (P = 0.084 and P < 0.001, respectively). A dominant IS/OS junction, COST line defects, and PROS length were related to patient best-corrected visual acuity (BCVA; P = 0.029, P = 0.001, and P < 0.001, respectively) by univariate analysis. Cone cell outer segment tips line defect and PROS length were the only factors related to BCVA in multivariate analysis (P = 0.028 and 0.003, respectively). Outer plexiform layer and photoreceptor microstructure defects are frequent in XLRS patients. Cone cell outer segment tips line defects and shortened PROS lengths as well as other photoreceptor microstructure defects may be closely related to poor vision in XLRS.

Weak variations of Lipschitz graphs and stability of phase boundaries

NASA Astrophysics Data System (ADS)

Grabovsky, Yury; Kucher, Vladislav A.; Truskinovsky, Lev

2011-03-01

In the case of Lipschitz extremals of vectorial variational problems, an important class of strong variations originates from smooth deformations of the corresponding non-smooth graphs. These seemingly singular variations, which can be viewed as combinations of weak inner and outer variations, produce directions of differentiability of the functional and lead to singularity-centered necessary conditions on strong local minima: an equality, arising from stationarity, and an inequality, implying configurational stability of the singularity set. To illustrate the underlying coupling between inner and outer variations, we study in detail the case of smooth surfaces of gradient discontinuity representing, for instance, martensitic phase boundaries in non-linear elasticity.

Composite Pulse Tube

NASA Technical Reports Server (NTRS)

Martin, Jerry L.; Cloyd, Jason H.

2007-01-01

A modification of the design of the pulse tube in a pulse-tube cryocooler reduces axial thermal conductance while preserving radial thermal conductance. It is desirable to minimize axial thermal conductance in the pulse-tube wall to minimize leakage of heat between the warm and cold ends of the pulse tube. At the same time, it is desirable to maximize radial thermal conductance at the cold end of the pulse tube to ensure adequate thermal contact between (1) a heat exchanger in the form of a stack of copper screens inside the pulse tube at the cold end and (2) the remainder of the cold tip, which is the object to which the heat load is applied and from which heat must be removed. The modified design yields a low-heat-leak pulse tube that can be easily integrated with a cold tip. A typical pulse tube of prior design is either a thin-walled metal tube or a metal tube with a nonmetallic lining. It is desirable that the outer surface of a pulse tube be cylindrical (in contradistinction to tapered) to simplify the design of a regenerator that is also part of the cryocooler. Under some conditions, it is desirable to taper the inner surface of the pulse tube to reduce acoustic streaming. The combination of a cylindrical outer surface and a tapered inner surface can lead to unacceptably large axial conduction if the pulse tube is made entirely of metal. Making the pulse-tube wall of a nonmetallic, lowthermal- conductivity material would not solve the problem because the wall would not afford the needed thermal contact for the stack of screens in the cold end. The modified design calls for fabricating the pulse tube in two parts: a longer, nonmetallic part that is tapered on the inside and cylindrical on the outside and a shorter, metallic part that is cylindrical on both the inside and the outside. The nonmetallic part can be made from G-10 fiberglass-reinforced epoxy or other low-thermal-conductivity, cryogenically compatible material. The metallic part must have high thermal conductivity in the cryogenic temperature range and would typically be made of pure copper to satisfy this requirement. The metallic part is bonded to the nonmetallic part with epoxy. Copper screens are inserted in the metallic part to form the cold-end heat exchanger, then the assembled pulse tube is inserted in the cold tip.

30 CFR 250.426 - What are the recordkeeping requirements for casing and liner pressure tests?

Code of Federal Regulations, 2011 CFR

2011-07-01

... MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements...

186Os- 187Os systematics of Gorgona Island komatiites: implications for early growth of the inner core

NASA Astrophysics Data System (ADS)

Brandon, Alan D.; Walker, Richard J.; Puchtel, Igor S.; Becker, Harry; Humayun, Munir; Revillon, Sidonie

2003-02-01

The presence of coupled enrichments in 186Os/ 188Os and 187Os/ 188Os in some mantle-derived materials reflects long-term elevation of Pt/Os and Re/Os relative to the primitive upper mantle. New Os data for the 89 Ma Gorgona Island, Colombia komatiites indicate that these lavas are also variably enriched in 186Os and 187Os, with 186Os/ 188Os ranging between 0.1198397±22 and 0.1198470±38, and with γOs correspondingly ranging from +0.15 to +4.4. These data define a linear trend that converges with the previously reported linear trend generated from data for modern Hawaiian picritic lavas and a sample from the ca. 251 Ma Siberian plume, to a common component with a 186Os/ 188Os of approximately 0.119870 and γOs of +17.5. The convergence of these data to this Os isotopic composition may imply a single ubiquitous source in the Earth's interior that mixes with a variety of different mantle compositions distinguished by variations in γOs. The 187Os- and 186Os-enriched component may have been generated via early crystallization of the solid inner core and consequent increases in Pt/Os and Re/Os in the liquid outer core, with time leading to suprachondritic 186Os/ 188Os and γOs in the outer core. The presence of Os from the outer core in certain portions of the mantle would require a mechanism that could transfer Os from the outer core to the lower mantle, and thence to the surface. If this is the process that generated the isotopic enrichments in the mantle sources of these plume-derived systems, then the current understanding of solid metal-liquid metal partitioning of Pt, Re and Os requires that crystallization of the inner core began prior to 3.5 Ga. Thus, the Os isotopic data reported here provide a new source of data to better constrain the timing of inner core formation, complementing magnetic field paleo-intensity measurements as data sources that constrain models based on secular cooling of the Earth.

The imprint of satellite accretion on the chemical and dynamical properties of disc galaxies

NASA Astrophysics Data System (ADS)

Ruiz-Lara, T.; Few, C. G.; Gibson, B. K.; Pérez, I.; Florido, E.; Minchev, I.; Sánchez-Blázquez, P.

2016-02-01

Aims: We study the effects of the cosmological assembly history on the chemical and dynamical properties of the discs of spiral galaxies as a function of radius. Methods: We made use of the simulated Milky Way mass, fully-cosmological discs from Ramses Disc Environment Study (RaDES). We analysed their assembly history by examining the proximity of satellites to the galactic disc, instead of their merger trees, to better gauge which satellites impact the disc. We presented stellar age and metallicity profiles, age-metallicity relation (AMR), age-velocity dispersion relation (AVR), and stellar age distribution (SAD) in several radial bins for the simulated galaxies. Results: Assembly histories can be divided into three different stages: I) a merger dominated phase, when a large number of mergers with mass ratios of ~1:1 take place (lasting ~3.2 ± 0.4 Gyr on average); II) a quieter phase, when ~1:10 mergers take place (lasting ~4.4 ± 2.0 Gyr); and III) a secular phase where the few mergers that take place have mass ratios below 1:100, which do not affect the disc properties (lasting ~5.5 ± 2.0 Gyr). The first two phases are able to kinematically heat the disc and produce a disc that is chemically mixed over its entire radial extension. Phase 2 ends with a final merger event (at time tjump) marking the onset of important radial differences in the AMR, AVR, and SAD. Conclusions: Inverted AMR trends in the outer parts of discs, for stars younger than tjump, are found as the combined effect of radial motions and star formation in satellites temporarily located in these outer parts. U-shaped stellar age profiles change to an old plateau (~10 Gyr) in the outer discs for the entire RaDES sample. This shape is a consequence of inside-out growth of the disc, radial motions of disc stars (inwards and outwards), and the accretion of old stars from satellites. We see comparable age profiles even when ignoring the influence of stellar migration due to the presence of early in situ star formation in the outer regions of the galaxy.

Developmental patterning of sub-epidermal cells in the outer integument of Arabidopsis seeds

PubMed Central

Fiume, Elisa; Coen, Olivier; Xu, Wenjia; Lepiniec, Loïc

2017-01-01

The seed, the reproductive unit of angiosperms, is generally protected by the seed coat. The seed coat is made of one or two integuments, each comprising two epidermal cells layers and, in some cases, extra sub-epidermal cell layers. The thickness of the seed-coat affects several aspects of seed biology such as dormancy, germination and mortality. In Arabidopsis, the inner integument displays one or two sub-epidermal cell layers that originate from periclinal cell divisions of the innermost epidermal cell layer. By contrast, the outer integument was considered to be two-cell layered. Here, we show that sub-epidermal chalazal cells grow in between the epidermal outer integument cell layers to create an incomplete three-cell layered outer integument. We found that the MADS box transcription factor TRANSPARENT TESTA 16 represses growth of the chalaza and formation of sub-epidermal outer integument cells. Finally, we demonstrate that sub-epidermal cells of the outer and inner integument respond differently to the repressive mechanism mediated by FERTILIZATION INDEPENDENT SEED Polycomb group proteins and to fertilization signals. Our data suggest that integument cell origin rather than sub-epidermal cell position underlies different responses to fertilization. PMID:29141031

Effects of Constituents and Lay-up Configuration on Drop-Weight Tests of Fiber-Metal Laminates

NASA Astrophysics Data System (ADS)

Liu, Yanxiong; Liaw, Benjamin

2010-02-01

Impact responses and damage of various fiber-metal laminates were studied using a drop-weight instrument with the post-impact damage characteristics being evaluated through ultrasonic and mechanical sectioning techniques. The first severe failure induced by the low-velocity drop-weight impact occurred as delamination between the aluminum and fiber-epoxy layers at the non-impact side. It was followed by a visible shear crack in the outer aluminum layer on the non-impact face. Through-thickness shear cracks in the aluminum sheets and severe damage in the fiber laminated layers (including delamination between adjacent fiber-epoxy laminae with different fiber orientations) developed under higher energy impacts. The impact properties of fiber-metal laminates varied with different constituent materials and fiber orientations. Since it was punched through easily, the aramid-fiber reinforced fiber-metal laminates (ARALL) offered poorer impact resistance than the glass-fiber reinforced fiber-metal laminates (GLARE). Tougher and more ductile aluminum alloys improved the impact resistance. GLARE made of cross-ply prepregs provided better impact resistance than GLARE with unidirectional plies.

Mechanical Fracturing of Core-Shell Undercooled Metal Particles for Heat-Free Soldering.

PubMed

Çınar, Simge; Tevis, Ian D; Chen, Jiahao; Thuo, Martin

2016-02-23

Phase-change materials, such as meta-stable undercooled (supercooled) liquids, have been widely recognized as a suitable route for complex fabrication and engineering. Despite comprehensive studies on the undercooling phenomenon, little progress has been made in the use of undercooled metals, primarily due to low yields and poor stability. This paper reports the use of an extension of droplet emulsion technique (SLICE) to produce undercooled core-shell particles of structure; metal/oxide shell-acetate ('/' = physisorbed, '-' = chemisorbed), from molten Field's metal (Bi-In-Sn) and Bi-Sn alloys. These particles exhibit stability against solidification at ambient conditions. Besides synthesis, we report the use of these undercooled metal, liquid core-shell, particles for heat free joining and manufacturing at ambient conditions. Our approach incorporates gentle etching and/or fracturing of outer oxide-acetate layers through mechanical stressing or shearing, thus initiating a cascade entailing fluid flow with concomitant deformation, combination/alloying, shaping, and solidification. This simple and low cost technique for soldering and fabrication enables formation of complex shapes and joining at the meso- and micro-scale at ambient conditions without heat or electricity.

Self-Assembly of Porphyrin J-Aggregates

NASA Astrophysics Data System (ADS)

Snitka, Valentinas; Rackaitis, Mindaugas; Navickaite, Gintare

2006-03-01

The porphyrin nanotubes were built by ionic self-assembly of two oppositely charged porphyrins in aqueous solution. The porphyrins in the acid aqueous solution self-assemble into J-aggregates, wheels or other structures. The electrostatic forces between these porphyrin blocks contribute to the formation of porphyrin aggregates in the form of nanotubes, enhance the structural stability of these nanostructures. The nanotubes were composed mixing aqueous solutions of the two porphyrins - anionic Meso-tetra(4- sulfonatophrnyl)porhine dihydrochloride (TPPS4) and cationic Meso-tetra(4-pyridyl)porphine (T4MPyP). The porphyrin nanotubes obtained are hollow structures with the length of 300 nm and diameter 50 nm. Photocatalytic porphyrins are used to reduce metal complexes from aqueous solution and to control the deposition of Au from AuHCl4 and Au nanoparticles colloid solutions onto porphyrin nanotubes. Porphyrin nanotubes are shown to reduce metal complexes and deposit the metal selectively onto the inner or outer surface of the tubes, leading to nanotube-metal composite structures.

Analysis of ablation debris from natural and artificial iron meteorites

NASA Technical Reports Server (NTRS)

Blanchard, M. B.; Davis, A. S.

1977-01-01

Artificial ablation studies were performed on iron and nickel-iron samples using an arc-heated plasma of ionized air. Experiment conditions simulated a meteoroid traveling about 12 km/sec at an altitude of 70 km. The artificially produced fusion crusts and ablation debris show features very similar to natural fusion crusts of the iron meteorites Boguslavka, Norfork, and N'Kandhla and to magnetic spherules recovered from Mn nodules. X-ray diffraction, electron microprobe, optical, and scanning electron microscope analyses reveal that important mineralogical, elemental, and textural changes occur during ablation. Some metal is melted and ablated. The outer margin of the melted rind is oxidized and recrystallizes as a discontinuous crust of magnetite and wustite. Adjacent to the oxidized metallic ablation zone is an unoxidized metallic ablation zone in which structures such as Widmannstatten bands are obliterated as the metal is transformed to unequilibrated alpha 2 nickel-iron. Volatile elements are vaporized and less volatile elements undergo fractionation.

ChAT-like immunoreactivity of olivocochlear fibres on rat outer hair cells during the postnatal development.

PubMed

Roth, B; Dannhof, B; Bruns, V

1991-01-01

Several studies present a great deal of information about putative efferent neurotransmitters and their distribution in the adult and developing cochlea. Anatomical mapping of outer hair cell efferent fibres during ontogeny is still not available. Using quantitative electron microscopy in combination with immunocytochemistry, the distribution of ChAT-like immunoreactivity in the developing rat was investigated. Adult-like immunoreactivity in the whole cochlea is first observed in 30-day-old rats. We localized the adult-like immunoreactivity in all efferent fibres and synapses of the outer hair cells along the entire cochlear duct. An adult-like reaction in the whole cochlea could be observed on the 25th day after birth in two out of three cases. On the 20th postnatal day, no adult-like ChAT immunoreactivity was found, with the exception of one case where labelling was seen in the basal region only. The adult-like ChAT immunoreactivity on the 30th day, 2-3 weeks after the onset of hearing, is the latest maturation of all features of the organ of Corti so far investigated. Synaptogenesis of the outer hair cell efferents reaches an adult-like appearance already on the 16th day after birth.

Predicting the Presence of Companions for Stripped-envelope Supernovae: The Case of the Broad-lined Type Ic SN 2002ap

NASA Astrophysics Data System (ADS)

Zapartas, E.; de Mink, S. E.; Van Dyk, S. D.; Fox, O. D.; Smith, N.; Bostroem, K. A.; de Koter, A.; Filippenko, A. V.; Izzard, R. G.; Kelly, P. L.; Neijssel, C. J.; Renzo, M.; Ryder, S.

2017-06-01

Many young, massive stars are found in close binaries. Using population synthesis simulations we predict the likelihood of a companion star being present when these massive stars end their lives as core-collapse supernovae (SNe). We focus on stripped-envelope SNe, whose progenitors have lost their outer hydrogen and possibly helium layers before explosion. We use these results to interpret new Hubble Space Telescope observations of the site of the broad-lined Type Ic SN 2002ap, 14 years post-explosion. For a subsolar metallicity consistent with SN 2002ap, we expect a main-sequence (MS) companion present in about two thirds of all stripped-envelope SNe and a compact companion (likely a stripped helium star or a white dwarf/neutron star/black hole) in about 5% of cases. About a quarter of progenitors are single at explosion (originating from initially single stars, mergers, or disrupted systems). All of the latter scenarios require a massive progenitor, inconsistent with earlier studies of SN 2002ap. Our new, deeper upper limits exclude the presence of an MS companion star >8-10 {M}⊙ , ruling out about 40% of all stripped-envelope SN channels. The most likely scenario for SN 2002ap includes nonconservative binary interaction of a primary star initially ≲ 23 {M}⊙ . Although unlikely (<1% of the scenarios), we also discuss the possibility of an exotic reverse merger channel for broad-lined Type Ic events. Finally, we explore how our results depend on the metallicity and the model assumptions and discuss how additional searches for companions can constrain the physics that govern the evolution of SN progenitors.

Open cycle ocean thermal energy conversion steam control and bypass system

DOEpatents

Wittig, J. Michael; Jennings, Stephen J.

1980-01-01

Two sets of hinged control doors for regulating motive steam flow from an evaporator to a condenser alternatively through a set of turbine blades in a steam bypass around the turbine blades. The evaporator has a toroidal shaped casing situated about the turbine's vertical axis of rotation and an outlet opening therein for discharging motive steam into an annular steam flow path defined between the turbine's radially inner and outer casing structures. The turbine blades extend across the steam flow path intermediate the evaporator and condenser. The first set of control doors is arranged to prevent steam access to the upstream side of the turbine blades and the second set of control doors acts as a bypass around the blades so as to maintain equilibrium between the evaporator and condenser during non-rotation of the turbine. The first set of control doors preferably extend, when closed, between the evaporator casing and the turbine's outer casing and, when open, extend away from the axis of rotation. The second set of control doors preferably constitute a portion of the turbine's outer casing downstream from the blades when closed and extend, when open, toward the axis of rotation. The first and second sets of control doors are normally held in the open and closed positions respectively by locking pins which may be retracted upon detecting an abnormal operating condition respectively to permit their closing and opening and provide steam flow from the evaporator to the condenser.

30 CFR 75.701 - Grounding metallic frames, casings, and other enclosures of electric equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding metallic frames, casings, and other... Grounding § 75.701 Grounding metallic frames, casings, and other enclosures of electric equipment. [Statutory Provisions] Metallic frames, casings, and other enclosures of electric equipment that can become...

The Fossil Record of Two-phase Galaxy Assembly: Kinematics and Metallicities in the Nearest S0 Galaxy

NASA Astrophysics Data System (ADS)

Arnold, Jacob A.; Romanowsky, Aaron J.; Brodie, Jean P.; Chomiuk, Laura; Spitler, Lee R.; Strader, Jay; Benson, Andrew J.; Forbes, Duncan A.

2011-08-01

We present a global analysis of kinematics and metallicity in the nearest S0 galaxy, NGC 3115, along with implications for its assembly history. The data include high-quality wide-field imaging from Suprime-Cam on the Subaru telescope, and multi-slit spectra of the field stars and globular clusters (GCs) obtained using Keck-DEIMOS/LRIS and Magellan-IMACS. Within two effective radii, the bulge (as traced by the stars and metal-rich GCs) is flattened and rotates rapidly (v/σ >~ 1.5). At larger radii, the rotation declines dramatically to v/σ ~ 0.7, but remains well aligned with the inner regions. The radial decrease in characteristic metallicity of both the metal-rich and metal-poor GC subpopulations produces strong gradients with power-law slopes of -0.17 ± 0.04 and -0.38 ± 0.06 dex dex-1, respectively. We argue that this pattern is not naturally explained by a binary major merger, but instead by a two-phase assembly process where the inner regions have formed in an early violent, dissipative phase, followed by the protracted growth of the outer parts via minor mergers with typical mass ratios of ~15-20:1.

Observational evidence of competing source, loss, and transport processes for relativistic electrons in Earth's outer radiation belt

NASA Astrophysics Data System (ADS)

Turner, Drew; Mann, Ian; Usanova, Maria; Rodriguez, Juan; Henderson, Mike; Angelopoulos, Vassilis; Morley, Steven; Claudepierre, Seth; Li, Wen; Kellerman, Adam; Boyd, Alexander; Kim, Kyung-Chan

Earth’s outer electron radiation belt is a region of extreme variability, with relativistic electron intensities changing by orders of magnitude over time scales ranging from minutes to years. Extreme variations of outer belt electrons ultimately result from the relative impacts of various competing source (and acceleration), loss, and transport processes. Most of these processes involve wave-particle interactions between outer belt electrons and different types of plasma waves in the inner magnetosphere, and in turn, the activity of these waves depends on different solar wind and magnetospheric driving conditions and thus can vary drastically from event to event. Using multipoint analysis with data from NASA’s Van Allen Probes, THEMIS, and SAMPEX missions, NOAA’s GOES and POES constellations, and ground-based observatories, we present results from case studies revealing how different source/acceleration and loss mechanisms compete during active periods to result in drastically different distributions of outer belt electrons. By using a combination of low-Earth orbiting and high-altitude-equatorial orbiting satellites, we briefly review how it is possible to get a much more complete picture of certain wave activity and electron losses over the full range of MLTs and L-shells throughout the radiation belt. We then show example cases highlighting the importance of particular mechanisms, including: substorm injections and whistler-mode chorus waves for the source and acceleration of relativistic electrons; magnetopause shadowing and wave-particle interactions with EMIC waves for sudden losses; and ULF wave activity for driving radial transport, a process which is important for redistributing relativistic electrons, contributing both to acceleration and loss processes. We show how relativistic electron enhancement events involve local acceleration that is consistent with wave-particle interactions between a seed population of 10s to 100s of keV electrons, with a source in the plasma sheet, and chorus waves. We show how sudden losses during outer belt dropout events are dominated at higher L-shells (L>~4) by magnetopause shadowing and outward radial transport, which is effective over the full ranges of energy and equatorial pitch angle of outer belt electrons, but at lower L-shells near the plasmapause, energy and pitch angle dependent losses can also occur and are consistent with rapid scattering by interactions between relativistic electrons and EMIC waves. We show cases demonstrating how these different processes occur simultaneously during active periods, with relative effects that vary as a function of L-shell and electron energy and pitch angle. Ultimately, our results highlight the complexity of competing source/acceleration, loss, and transport processes in Earth’s outer radiation belt and the necessity of using multipoint observations to disambiguate between them for future studies.

Dynamic changes in the distribution of minerals in relation to phytic acid accumulation during rice seed development.

PubMed

Iwai, Toru; Takahashi, Michiko; Oda, Koshiro; Terada, Yasuko; Yoshida, Kaoru T

2012-12-01

Phytic acid (inositol hexakisphosphate [InsP(6)]) is the storage compound of phosphorus in seeds. As phytic acid binds strongly to metallic cations, it also acts as a storage compound of metals. To understand the mechanisms underlying metal accumulation and localization in relation to phytic acid storage, we applied synchrotron-based x-ray microfluorescence imaging analysis to characterize the simultaneous subcellular distribution of some mineral elements (phosphorus, calcium, potassium, iron, zinc, and copper) in immature and mature rice (Oryza sativa) seeds. This fine-imaging method can reveal whether these elements colocalize. We also determined their accumulation patterns and the changes in phosphate and InsP(6) contents during seed development. While the InsP(6) content in the outer parts of seeds rapidly increased during seed development, the phosphate contents of both the outer and inner parts of seeds remained low. Phosphorus, calcium, potassium, and iron were most abundant in the aleurone layer, and they colocalized throughout seed development. Zinc was broadly distributed from the aleurone layer to the inner endosperm. Copper localized outside the aleurone layer and did not colocalize with phosphorus. From these results, we suggest that phosphorus translocated from source organs was immediately converted to InsP(6) and accumulated in aleurone layer cells and that calcium, potassium, and iron accumulated as phytic acid salt (phytate) in the aleurone layer, whereas zinc bound loosely to InsP(6) and accumulated not only in phytate but also in another storage form. Copper accumulated in the endosperm and may exhibit a storage form other than phytate.

Electrochemical Measurement of Electron Transfer Kinetics by Shewanella oneidensis MR-1*

PubMed Central

Baron, Daniel; LaBelle, Edward; Coursolle, Dan; Gralnick, Jeffrey A.; Bond, Daniel R.

2009-01-01

Shewanella oneidensis strain MR-1 can respire using carbon electrodes and metal oxyhydroxides as electron acceptors, requiring mechanisms for transferring electrons from the cell interior to surfaces located beyond the cell. Although purified outer membrane cytochromes will reduce both electrodes and metals, S. oneidensis also secretes flavins, which accelerate electron transfer to metals and electrodes. We developed techniques for detecting direct electron transfer by intact cells, using turnover and single turnover voltammetry. Metabolically active cells attached to graphite electrodes produced thin (submonolayer) films that demonstrated both catalytic and reversible electron transfer in the presence and absence of flavins. In the absence of soluble flavins, electron transfer occurred in a broad potential window centered at ∼0 V (versus standard hydrogen electrode), and was altered in single (ΔomcA, ΔmtrC) and double deletion (ΔomcA/ΔmtrC) mutants of outer membrane cytochromes. The addition of soluble flavins at physiological concentrations significantly accelerated electron transfer and allowed catalytic electron transfer to occur at lower applied potentials (−0.2 V). Scan rate analysis indicated that rate constants for direct electron transfer were slower than those reported for pure cytochromes (∼1 s−1). These observations indicated that anodic current in the higher (>0 V) window is due to activation of a direct transfer mechanism, whereas electron transfer at lower potentials is enabled by flavins. The electrochemical dissection of these activities in living cells into two systems with characteristic midpoint potentials and kinetic behaviors explains prior observations and demonstrates the complementary nature of S. oneidensis electron transfer strategies. PMID:19661057

Deep-Earth Equilibration between Molten Iron and Solid Silicates

NASA Astrophysics Data System (ADS)

Brennan, M.; Zurkowski, C. C.; Chidester, B.; Campbell, A.

2017-12-01

Elemental partitioning between iron-rich metals and silicate minerals influences the properties of Earth's deep interior, and is ultimately responsible for the nature of the core-mantle boundary. These interactions between molten iron and solid silicates were influential during planetary accretion, and persist today between the mantle and liquid outer core. Here we report the results of diamond anvil cell experiments at lower mantle conditions (40 GPa, >2500 K) aimed at examining systems containing a mixture of metals (iron or Fe-16Si alloy) and silicates (peridotite). The experiments were conducted at pressure-temperature conditions above the metallic liquidus but below the silicate solidus, and the recovered samples were analyzed by FIB/SEM with EDS to record the compositions of the coexisting phases. Each sample formed a three-phase equilibrium between bridgmanite, Fe-rich metallic melt, and an oxide. In one experiment, using pure Fe, the quenched metal contained 6 weight percent O, and the coexisting oxide was ferropericlase. The second experiment, using Fe-Si alloy, was highly reducing; its metal contained 10 wt% Si, and the coexisting mineral was stishovite. The distinct mineralogies of the two experiments derived from their different starting metals. These results imply that metallic composition is an important factor in determining the products of mixed phase iron-silicate reactions. The properties of deep-Earth interfaces such as the core-mantle boundary could be strongly affected by their metallic components.

Anisotropic Coulomb Explosion of CO Ligands in Group 6 Metal Hexacarbonyls: Cr(CO)6, Mo(CO)6, W(CO)6.

PubMed

Tanaka, Hiroki; Nakashima, Nobuaki; Yatsuhashi, Tomoyuki

2016-09-08

Multiple ionization and subsequent Coulomb explosion have been studied for many organic molecules and their clusters; however, the metal complexes, particularly the large Coulombic interactions expected between a metal and its ligands, have not yet been explored. In this study, the angular distribution of CO(+), oxygen, and carbon ions ejected from metal hexacarbonyls (M(CO)6, M: Cr, Mo, W) having Oh symmetry by Coulomb explosion in femtosecond laser fields (>1 × 10(14) W cm(-2)) is investigated. The emissions of oxygen ions are well-explained in terms of the geometric alignment along a line inclined 45° relative to the CO-M-CO axis in a M(CO)4 plane. Unlike the explosion behavior of the oxygen ions located on the outer part of the molecule, the explosion behavior of the carbon ions was affected by the laser intensity, kinetic energy, and metal. This finding that the emission trends of carbon sandwiched between oxygen and metal atoms were the opposite of those for oxygen was explained by the obstruction by oxygen, the deformation of structure in bending coordinates, and the strong interaction with charged metal. The anisotropic Coulomb explosion of metal complexes reflecting their structural symmetry and central metal charge is a promising candidate for use in the investigation of large Coulombic interactions at the molecular level.

30 CFR 250.426 - What are the recordkeeping requirements for casing and liner pressure tests?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.426 What are the recordkeeping...

Development and evaluation of thin semi-rigid cables for superconducting detectors

NASA Astrophysics Data System (ADS)

Kasai, Soichi; Kushino, Akihiro

2015-03-01

We are developing semi-rigid cables for accurate readout of superconducting radiation/particle detectors and other low temperature experiments. The center conductor with a diameter of 0.86 mm is separated with seamless metal outer conductor by dielectric material, polytetrafluoroethylene. We used various metal materials with low thermal conductivity for the electrical conductors such as stainless-steel, cupro-nickel, brass, beryllium-copper, phosphor-bronze, niobium-titanium, and niobium. In addition to the conventional semi-rigid cables, low-pass-filter-type cables were manufactured and evaluated to cut the high frequency noise into superconducting detectors. We measured their low thermal conductance and attenuation property up to 10GHz below the liquid helium temperature.

Development of semi-rigid cables for low temperature superconducting detectors

NASA Astrophysics Data System (ADS)

Kushino, Akihiro; Kasai, Soichi

We are developing semi-rigid cables for accurate readout of superconducting radiation/particle detectors and other low temperature experiments. The center conductor with a diameter of 0.86 mm is separated with seamless metal outer conductor by dielectric material, polytetrafluoroethylene. We used various metal materials with low thermal conductivity for the electrical conductors such as stainless-steel, cupro-nickel, brass, beryllium-copper, phosphor-bronze, niobium-titanium, and niobium. In addition to the conventional semi-rigid cables, low-pass-filter type cables were manufactured and evaluated to cut the high frequency noise into superconducting detectors. We measured their low thermal conductance and attenuation property up to 10 GHz below the liquid helium temperature.

A polymer driveshaft for use in orbital and rotational atherectomy

NASA Astrophysics Data System (ADS)

Grothe, Preston Lee

Driveshafts used in atherectomy medical devices are often comprised of coiled or braided metal wires. These constructions are designed to tolerate delivery through tortuous vessels and can endure high speed rotation used during activation of the atherectomy treatment. This research investigated polymer driveshaft designs, which were comprised of polymer inner and outer layers, and coiled or braided stainless steel wires. The polymer driveshaft materials included polyimide, nylon 12, and polytetrafluoroethylene (PTFE). Mechanical testing of polymer driveshafts was conducted to determine material response in bending, tension, compression, and torsion. The polymer driveshaft test results were then compared with current coiled metal wire driveshaft constructions. The investigation identified polymer driveshaft options that could feasibly work in an atherectomy application.

Performance of PTFE-lined composite journal bearings

NASA Technical Reports Server (NTRS)

Sliney, H. E.; Williams, F. J.

1982-01-01

Plain cylindrical journal bearings consisting of aramid fiber reinforced epoxy outer shells and glass fiber reinforced PTFE lubricating liners were evaluated. All materials in these bearings are electrically nonconductive; thus eliminating the problem of galvanic corrosion sometimes encountered with metal bearings installed in dissimilar metal mountings. Friction and wear characteristics were determined for loads, temperatures, and oscillating conditions that are typical of current airframe bearing applications. Friction and wear characteristics were found to be compatible with most airframe bearing requirements from -23 C to 121 C. Contamination with MIL H-5606 hydraulic fluid increased wear of the PTFE liners at 121 C, but did not affect the structural integrity of the aramid/epoxy composite.

Coating with overlay metallic-cermet alloy systems

NASA Technical Reports Server (NTRS)

Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

1984-01-01

A base layer of an oxide dispersed, metallic alloy (cermet) is arc plasma sprayed onto a substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use. A top layer of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then arc plasma sprayed onto the base layer. A heat treatment is used to improve the bonding. The base layer serves as an inhibitor to interdiffusion between the protective top layer and the substrate. Otherwise, the 10 protective top layer would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

Ceramic Cerami Turbine Nozzle

DOEpatents

Boyd, Gary L.

1997-04-01

A turbine nozzle vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes an outer shroud and an inner shroud having a plurality of horizontally segmented vanes therebetween being positioned by a connecting member positioning segmented vanes in functional relationship one to another. The turbine nozzle vane assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the other component.

Heat transfer in a rotating cavity with a stationary stepped casing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirzaee, I.; Quinn, P.; Wilson, M.

1999-04-01

In the system considered here, corotating turbine disks are cooled by air supplied at the periphery of the system. The system comprises two corotating disks, connected by a rotating cylindrical hub and shrouded by a stepped, stationary cylindrical outer casing. Cooling air enters the system through holes in the periphery of one disk, and leaves through the clearances between the outer casing and the disks. The paper describes a combined computational and experimental study of the heat transfer in the above-described system. In the experiments, one rotating disk is heated, the hub and outer casing are insulated, and the othermore » disk is quasi-adiabatic. Thermocouples and fluxmeters attached to the heated disc enable the Nusselt numbers, Nu, to be determined for a wide range of rotational speeds and coolant flow rates. Computations are carried out using an axisymmetric elliptic solver incorporating the Launder-Sharma low-Reynolds-number {kappa}-{epsilon} turbulence model. The flow structure is shown to be complex and depends strongly on the so-called turbulent flow parameter, {lambda}{sub T}, which incorporates both rotational speed and flow rate. For a given value of {lambda}{sub T}, the computations show that Nu increases as Re{sub {phi}}, the rotational Reynolds number, increases. Despite the complexity of the flow, the agreement between the computed and measured Nusselt numbers is reasonably good.« less

49 CFR 173.194 - Gas identification sets.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 4A, 4B or 4N metal boxes or 4C1, 4C2, 4D or 4F wooden boxes. Not more than 100 mL (3.4 fluid ounces) or 100 g (3.5 ounces) of poisonous materials may be packed in one outer box. (2) If the poisonous... fiberboard box. No more than four boxes, well-cushioned, may in turn be placed in a steel cylinder. The...

49 CFR 173.194 - Gas identification sets.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 4A, 4B or 4N metal boxes or 4C1, 4C2, 4D or 4F wooden boxes. Not more than 100 mL (3.4 fluid ounces) or 100 g (3.5 ounces) of poisonous materials may be packed in one outer box. (2) If the poisonous... fiberboard box. No more than four boxes, well-cushioned, may in turn be placed in a steel cylinder. The...

175Hp contrarotating homopolar motor design report

NASA Astrophysics Data System (ADS)

Cannell, Michael J.; Drake, John L.; McConnell, Richard A.; Martino, William R.

1994-06-01

A normally conducting contrarotating homopolar motor has been designed and constructed. The reaction torque, in the outer rotor, from the inner rotor is utilized to produce true contrarotation. The machine utilizes liquid cooled conductors, high performance liquid metal current collectors, and ferrous conductors in the active region. The basic machine output is 175 hp at + or - 1,200 rpm with an input of 4 volts and 35,000 amps.

DebriSat Laboratory Analyses

DTIC Science & Technology

2015-01-05

droplets. Fluorine from Teflon wire insulation was also common in the SEM stub and witness plates deposits. Nano droplets of metallic materials...and Debris-LV debris. Aluminum was from the Al honeycomb, nadir and zenith panels, structural core and COPV liner. Aluminum oxide particles were...three pieces: Outer Nylon shell (sabot) with 2 part hollow aluminum insert. • ~600 grams, 8.6 cm diameter X 10.3 cm long – size of a soup can

Dynamic Response and Optimal Design of Curved Metallic Sandwich Panels under Blast Loading

PubMed Central

Yang, Shu; Han, Shou-Hong; Lu, Zhen-Hua

2014-01-01

It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a “soft” outer face and a “hard” inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances. PMID:25126606

Dynamic response and optimal design of curved metallic sandwich panels under blast loading.

PubMed

Qi, Chang; Yang, Shu; Yang, Li-Jun; Han, Shou-Hong; Lu, Zhen-Hua

2014-01-01

It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a "soft" outer face and a "hard" inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances.

Fine structural features of nanoscale zero-valent iron characterized by spherical aberration corrected scanning transmission electron microscopy (Cs-STEM).

PubMed

Liu, Airong; Zhang, Wei-xian

2014-09-21

An angstrom-resolution physical model of nanoscale zero-valent iron (nZVI) is generated with a combination of spherical aberration corrected scanning transmission electron microscopy (Cs-STEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDS) and electron energy-loss spectroscopy (EELS) on the Fe L-edge. Bright-field (BF), high-angle annular dark-field (HAADF) and secondary electron (SE) imaging of nZVI acquired by a Hitachi HD-2700 STEM show near atomic resolution images and detailed morphological and structural information of nZVI. The STEM-EDS technique confirms that the fresh nZVI comprises of a metallic iron core encapsulated with a thin layer of iron oxides or oxyhydroxides. SAED patterns of the Fe core suggest the polycrystalline structure in the metallic core and amorphous nature of the oxide layer. Furthermore, Fe L-edge of EELS shows varied structural features from the innermost Fe core to the outer oxide shell. A qualitative analysis of the Fe L(2,3) edge fine structures reveals that the shell of nZVI consists of a mixed Fe(II)/Fe(III) phase close to the Fe (0) interface and a predominantly Fe(III) at the outer surface of nZVI.

Metal-on-Metal Hip Retrieval Analysis: A Case Report

PubMed Central

Pace, Thomas B.; Rusaw, Kara A.; Minette, Lawrence J.; Shirley, Brayton R.; Snider, Rebecca G.; DesJardins, John D.

2013-01-01

This is a case report involving a single case with severe bone and soft tissue destruction in a young male patient with a 10-year-metal on-metal total hip arthroplasty. Following complete aseptic erosion of the affected hip greater trochanter and abductor muscles, the hip was revised for recurrent instability. Histological examination of the patient's periprosthetic tissues, serological studies, and review of recent medical reports of similar cases were used to support an explanation of the destructive process and better contribute to our understanding of human reaction to metal debris in some patients following metal-on-metal hip arthroplasty. PMID:23840999

Degradation of Teflon(trademark) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline; Powers, Charles; Viens, Michael; Ayres-Treusdell, Mary; Munoz, Bruno

1999-01-01

During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon(trademark) FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon(trademark) FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon(trademark) FEP.

Degradation of Teflon(tm) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline A.; Powers, Charles E.; Viens, Michael J.; Ayres-Treusdell, Mary T.; Munoz, Bruno

1998-01-01

During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon' FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon FEP.

Degradation of Teflon(tm) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline A.; Powers, Charles E.; Viens, Michael J.; Ayres-Treusdell, Mary T.; Munoz, Bruno F.

1998-01-01

During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon' FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon(registered trademark) FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon(registered trademark) FEP.

Degradation of Teflon(tm) FEP Following Charged Particle Radiation and Rapid Thermal Cycling

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline; Powers, Charles; Viens, Michael; Ayres-Treusdell, Mary; Munoz, Bruno

1998-01-01

During the Second Servicing Mission (SM2) of the Hubble Space Telescope (HST) severe degradation was observed on the outer layer of the thermal control blankets. Astronaut observations and photographs revealed large cracks in the metallized Teflon(R) FEP (fluorinated ethylene propylene), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. In an effort to understand what elements of the space environment might cause such damage, pristine Teflon(R) FEP was tested for durability to radiation and thermal cycling. Specimens were subjected to electron and proton fluences comparable to those experienced by HST and were subsequently thermal cycled in a custom-built rapid thermal cycle chamber. Tensile tests of the specimens showed that radiation followed by thermal cycling significantly reduced the ultimate strength and elongation of Teflon(R) FEP.

Improving stamping simulation accuracy by accounting for realistic friction and lubrication conditions: Application to the door-outer of the Mercedes-Benz C-class Coupé

NASA Astrophysics Data System (ADS)

Hol, J.; Wiebenga, J. H.; Stock, J.; Wied, J.; Wiegand, K.; Carleer, B.

2016-08-01

In the stamping of automotive parts, friction and lubrication play a key role in achieving high quality products. In the development process of new automotive parts, it is therefore crucial to accurately account for these effects in sheet metal forming simulations. Only then, one can obtain reliable and realistic simulation results that correspond to the actual try-out and mass production conditions. In this work, the TriboForm software is used to accurately account for tribology-, friction-, and lubrication conditions in stamping simulations. The enhanced stamping simulations are applied and validated for the door-outer of the Mercedes- Benz C-Class Coupe. The project results demonstrate the improved prediction accuracy of stamping simulations with respect to both part quality and actual stamping process conditions.

A charging model for three-axis stabilized spacecraft

NASA Technical Reports Server (NTRS)

Massaro, M. J.; Green, T.; Ling, D.

1977-01-01

A charging model was developed for geosynchronous, three-axis stabilized spacecraft when under the influence of a geomagnetic substorm. The differential charging potentials between the thermally coated or blanketed outer surfaces and metallic structure of a spacecraft were determined when the spacecraft was immersed in a dense plasma cloud of energetic particles. The spacecraft-to-environment interaction was determined by representing the charged particle environment by equivalent current source forcing functions and by representing the spacecraft by its electrically equivalent circuit with respect to the plasma charging phenomenon. The charging model included a sun/earth/spacecraft orbit model that simulated the sum illumination conditions of the spacecraft outer surfaces throughout the orbital flight on a diurnal as well as a seasonal basis. Transient and steady-state numerical results for a three-axis stabilized spacecraft are presented.

Composite drill pipe and method for forming same

DOEpatents

Leslie, James C; Leslie, II, James C; Heard, James; Truong, Liem; Josephson, Marvin

2014-04-15

Metal inner and outer fittings configured, the inner fitting configured proximally with an external flange and projecting distally to form a cylindrical barrel and stepped down-in-diameter to form an abutment shoulder and then projecting further distally to form a radially inwardly angled and distally extending tapered inner sleeve. An outer sleeve defining a torque tube is configured with a cylindrical collar to fit over the barrel and is formed to be stepped up in diameter in alignment with the first abutment shoulder to then project distally forming a radially outwardly tapered and distally extending bonding surface to cooperate with the inner sleeve to cooperate with the inner sleeve in forming a annular diverging bonding cavity to receive the extremity of a composite pipe to abut against the abutment shoulders and to be bonded to the respective bonding surfaces by a bond.

A numerical study of active structural acoustic control in a stiffened, double wall cylinder

NASA Technical Reports Server (NTRS)

Grosveld, Ferdinand W.; Coats, T. J.; Lester, H. C.; Silcox, R. J.

1994-01-01

It is demonstrated that active structural acoustic control of complex structural/acoustic coupling can be numerically modeled using finite element and boundary element techniques in conjunction with an optimization procedure to calculate control force amplitudes. Appreciable noise reduction is obtained when the structure is excited at a structural resonance of the outer shell or an acoustic resonance of the inner cavity. Adding ring stiffeners as a connection between the inner and outer shells provides an additional structural transmission path to the interior cavity and coupled the modal behavior of the inner and outer shells. For the case of excitation at the structural resonance of the unstiffened outer shell, adding the stiffeners raises the structural resonance frequencies. The effectiveness of the control forces is reduced due to the off resonance structural response. For excitation at an acoustic cavity resonance, the controller effectiveness is enhanced.

Shape, zonal winds and gravitational field of Jupiter: a fully self-consistent, multi-layered model

NASA Astrophysics Data System (ADS)

Schubert, Gerald; Kong, Dali; Zhang, Keke

2016-10-01

We construct a three-dimensional, finite-element, fully self-consistent, multi-layered,non-spheroidal model of Jupiter consisting of an inner core, a metallic electrically conducting dynamo region and an outer molecular electrically insulating envelope. We assume that the Jovian zonal winds are on cylinders parallel to the rotation axis but, due to the effect of magnetic braking, are confined within the outer molecular envelope. Two related calculations are carried out. The first provides an accurate description of the shape and internal density profile of Jupiter; the effect of rotational distortion is not treated as a small perturbation on a spherically symmetric state. This calculation determines the density, size and shape of the inner core, the irregular shape of the 1-bar pressure level, and the internal structure of Jupiter; the full effect of rotational distortion, without the influence of the zonal winds, is accounted for. Our multi-layered model is able to produce the known mass, the known equatorial and polar radii, and the known zonal gravitational coefficient J2 of Jupiter within their error bars; it also yields the coefficients J4 and J6 within about 5% accuracy, and the core equatorial radius 0.09RJ containing 3.73 Earth masses.The second calculation determines the variation of the gravitational field caused solely by the effect of the zonal winds on the rotationally distorted non-spheroidal Jupiter. Four different cases, ranging from a deep wind profile to a very shallow profile, are considered and implications for accurate interpretation of the zonal gravitational coefficients expected from the Juno mission are discussed.

In vitro assembly of the outer core of the lipopolysaccharide from Escherichia coli K-12 and Salmonella typhimurium.

PubMed

Qian, Jinghua; Garrett, Teresa A; Raetz, Christian R H

2014-03-04

There are five distinct core structures in the lipopolysaccharides of Escherichia coli and at least two in Salmonella isolates, which vary principally in the outer core oligosaccharide. Six outer core glycosyltransferases, E. coli K-12 WaaG, WaaB, and WaaO and Salmonella typhimurium WaaI, WaaJ, and WaaK, were cloned, overexpressed, and purified. A novel substrate for WaaG was isolated from ΔwaaG E. coli overexpressing the lipid A phosphatase lpxE and the lipid A late acyltransferase lpxM. The action of lpxE and lpxM in the ΔwaaG background yielded heptose2-1-dephospho Kdo2-lipid A, a 1-dephosphorylated hexa-acylated lipid A with the inner core sugars that is easily isolated by organic extraction. Using this structurally defined acceptor and commercially available sugar nucleotides, each outer core glycosyltransferases was assayed in vitro. We show that WaaG and WaaB add a glucose and galactose sequentially to heptose2-1-dephospho Kdo2-lipid A. E. coli K-12 WaaO and S. typhimurium WaaI add a galactose to the WaaG/WaaB product but can also add a galactose to the WaaG product directly without the branched core sugar added by WaaB. Both WaaI and WaaO require divalent metal ions for optimal activity; however, WaaO, unlike WaaI, can add several glucose residues to its lipid acceptor. Using the product of WaaG, WaaB, and WaaI, we show that S. typhimurium WaaJ and WaaK transfer a glucose and N-acetylglucosamine, respectively, to yield the full outer core. This is the first demonstration of the in vitro assembly of the outer core of the lipopolysaccharide using defined lipid A-oligosaccharide acceptors and sugar donors.

In Vitro Assembly of the Outer Core of the Lipopolysaccharide from Escherichia coli K-12 and Salmonella typhimurium

PubMed Central

2015-01-01

There are five distinct core structures in the lipopolysaccharides of Escherichia coli and at least two in Salmonella isolates, which vary principally in the outer core oligosaccharide. Six outer core glycosyltransferases, E. coli K-12 WaaG, WaaB, and WaaO and Salmonella typhimurium WaaI, WaaJ, and WaaK, were cloned, overexpressed, and purified. A novel substrate for WaaG was isolated from ΔwaaG E. coli overexpressing the lipid A phosphatase lpxE and the lipid A late acyltransferase lpxM. The action of lpxE and lpxM in the ΔwaaG background yielded heptose2-1-dephospho Kdo2-lipid A, a 1-dephosphorylated hexa-acylated lipid A with the inner core sugars that is easily isolated by organic extraction. Using this structurally defined acceptor and commercially available sugar nucleotides, each outer core glycosyltransferases was assayed in vitro. We show that WaaG and WaaB add a glucose and galactose sequentially to heptose2-1-dephospho Kdo2-lipid A. E. coli K-12 WaaO and S. typhimurium WaaI add a galactose to the WaaG/WaaB product but can also add a galactose to the WaaG product directly without the branched core sugar added by WaaB. Both WaaI and WaaO require divalent metal ions for optimal activity; however, WaaO, unlike WaaI, can add several glucose residues to its lipid acceptor. Using the product of WaaG, WaaB, and WaaI, we show that S. typhimurium WaaJ and WaaK transfer a glucose and N-acetylglucosamine, respectively, to yield the full outer core. This is the first demonstration of the in vitro assembly of the outer core of the lipopolysaccharide using defined lipid A-oligosaccharide acceptors and sugar donors. PMID:24479701

Concentric wrench for blind access opening in a turbine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laurer, Kurt Neal; Drlik, Gary Joseph; Gibler, Edward Eugene

The concentric wrench includes an outer tube having flats at one end and a gripping surface at an opposite end. An inner tube has interior flats at one end and a gripping surface at its opposite end. With the inner and outer tubes disposed about a pressure transmitting conduit, the tubes may be inserted into a blind access opening in the outer turbine casing to engage the flats of the tubes against hex nuts of an internal fitting. By relatively rotating the tubes using the externally exposed gripping surfaces, the threaded connection between the parts of the fitting bearing themore » respective hex nuts can be tightened or loosened.« less

THE EFFECTS OF EPISODIC STAR FORMATION ON THE FUV-NUV COLORS OF STAR FORMING REGIONS IN OUTER DISKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, Kate L.; Van Zee, Liese; Dowell, Jayce D., E-mail: barneskl@astro.indiana.edu, E-mail: vanzee@astro.indiana.edu, E-mail: jdowell@unm.edu

2013-09-20

We run stellar population synthesis models to examine the effects of a recently episodic star formation history (SFH) on UV and Hα colors of star forming regions. Specifically, the SFHs we use are an episodic sampling of an exponentially declining star formation rate (SFR; τ model) and are intended to simulate the SFHs in the outer disks of spiral galaxies. To enable comparison between our models and observational studies of star forming regions in outer disks, we include in our models sensitivity limits that are based on recent deep UV and Hα observations in the literature. We find significant dispersionmore » in the FUV-NUV colors of simulated star forming regions with frequencies of star formation episodes of 1 × 10{sup –8} to 4 × 10{sup –9} yr{sup –1}. The dispersion in UV colors is similar to that found in the outer disk of nearby spiral galaxies. As expected, we also find large variations in L{sub H{sub α}}/L{sub FUV}. We interpret our models within the context of inside-out disk growth, and find that a radially increasing τ and decreasing metallicity with an increasing radius will only produce modest FUV-NUV color gradients, which are significantly smaller than what is found for some nearby spiral galaxies. However, including moderate extinction gradients with our models can better match the observations with steeper UV color gradients. We estimate that the SFR at which the number of stars emitting FUV light becomes stochastic is ∼2 × 10{sup –6} M{sub ☉} yr{sup –1}, which is substantially lower than the SFR of many star forming regions in outer disks. Therefore, we conclude that stochasticity in the upper end of the initial mass function is not likely to be the dominant cause of dispersion in the FUV-NUV colors of star forming regions in outer disks. Finally, we note that if outer disks have had an episodic SFH similar to that used in this study, this should be taken into account when estimating gas depletion timescales and modeling chemical evolution of spiral galaxies.« less

High-Speed Ultra-High-Resolution Optical Coherence Tomography Findings in Hydroxychloroquine Retinopathy

PubMed Central

Rodriguez-Padilla, Julio A.; Hedges, Thomas R.; Monson, Bryan; Srinivasan, Vivek; Wojtkowski, Maciej; Reichel, Elias; Duker, Jay S.; Schuman, Joel S.; Fujimoto, James G.

2007-01-01

Objectives To compare structural changes in the retina seen on high-speed ultra–high-resolution optical coherence tomography (hsUHR-OCT) with multifocal electroretinography (mfERG) and automated visual fields in patients receiving hydroxychloroquine. Methods Fifteen patients receiving hydroxychloroquine were evaluated clinically with hsUHR-OCT, mfERG, and automated visual fields. Six age-matched subjects were imaged with hsUHR-OCT and served as controls. Results Distinctive discontinuity of the perifoveal photoreceptor inner segment/outer segment junction and thinning of the outer nuclear layer were seen with hsUHR-OCT in patients with mild retinal toxic effects. Progression to complete loss of the inner segment/outer segment junction and hyperscattering at the outer segment level were seen in more advanced cases. The mfERG abnormalities correlated with the hsUHR-OCT findings. Asymptomatic patients had normal hsUHR-OCT and mfERG results. Conclusion Distinctive abnormalities in the perifoveal photoreceptor inner segment/outer segment junction were seen on hsUHR-OCT in patients receiving hydroxychloroquine who also were symptomatic and had abnormalities on automated visual fields and mfERG. PMID:17562988

30 CFR 250.426 - What are the recordkeeping requirements for casing and liner pressure tests?

Code of Federal Regulations, 2013 CFR

2013-07-01

... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.426 What are the...

30 CFR 250.426 - What are the recordkeeping requirements for casing and liner pressure tests?

Code of Federal Regulations, 2014 CFR

2014-07-01

... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.426 What are the...

30 CFR 250.426 - What are the recordkeeping requirements for casing and liner pressure tests?

Code of Federal Regulations, 2012 CFR

2012-07-01

... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.426 What are the...

Thermally stable nanoparticles on supports

DOEpatents

Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

2012-11-13

An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

Shields for Enhanced Protection Against High-Speed Debris

NASA Technical Reports Server (NTRS)

Christiansen, Eric L.; Kerr, Justin H.

2003-01-01

A report describes improvements over the conventional Whipple shield (two thin, spaced aluminum walls) for protecting spacecraft against high-speed impacts of orbiting debris. The debris in question arise mainly from breakup of older spacecraft. The improved shields include exterior bumper layers composed of hybrid fabrics woven from combinations of ceramic fibers and high-density metallic wires or, alternatively, completely metallic outer layers composed of high-strength steel or copper wires. These shields are designed to be light in weight, yet capable of protecting against orbital debris with mass densities up to about 9 g/cm3, without generating damaging secondary debris particles. As yet another design option, improved shields can include sparsely distributed wires made of shape-memory metals that can be thermally activated from compact storage containers to form shields of predetermined shape upon arrival in orbit. The improved shields could also be used to augment shields installed previously.

Shields for Enhanced Protection Against High-Speed Debris

NASA Technical Reports Server (NTRS)

Christiansen, Eric L.; Kerr, Justin H.

2003-01-01

A report describes improvements over the conventional Whipple shield (two thin, spaced aluminum walls) for protecting spacecraft against high-speed impacts of orbiting debris. The debris in question arises mainly from breakup of older spacecraft. The improved shields include exterior "bumper" layers composed of hybrid fabrics woven from combinations of ceramic fibers and high-density metallic wires or, alternatively, completely metallic outer layers composed of high-strength steel or copper wires. These shields are designed to be light in weight, yet capable of protecting against orbital debris with mass densities up to about 9 g/cubic cm, without generating damaging secondary debris particles. As yet another design option, improved shields can include sparsely distributed wires made of shape memory metals that can be thermally activated from compact storage containers to form shields of predetermined shape upon arrival in orbit. The improved shields could also be used to augment shields installed previously.

Cell and method for electrolysis of water and anode

NASA Technical Reports Server (NTRS)

Aylward, J. R. (Inventor)

1981-01-01

An electrolytic cell for converting water vapor to oxygen and hydrogen include an anode comprising a foraminous conductive metal substrate with a 65-85 weight percent iridium oxide coating and 15-35 weight percent of a high temperature resin binder. A matrix member contains an electrolyte to which a cathode substantially inert. The foraminous metal member is most desirably expanded tantalum mesh, and the cell desirably includes reservoir elements of porous sintered metal in contact with the anode to receive and discharge electrolyte to the matrix member as required. Upon entry of a water vapor containing airstream into contact with the outer surface of the anode and thence into contact with iridium oxide coating, the water vapor is electrolytically converted to hydrogen ions and oxygen with the hydrogen ions migrating through the matrix to the cathode and the oxygen gas produced at the anode to enrich the air stream passing by the anode.

Hybrid plasmonic waveguide-assisted Metal–Insulator–Metal ring resonator for refractive index sensing

NASA Astrophysics Data System (ADS)

Butt, M. A.; Khonina, S. N.; Kazanskiy, N. L.

2018-05-01

A highly sensitive refractive index sensor based on an integrated hybrid plasmonic waveguide (HPWG) and a Metal-Insulator-Metal (M-I-M) micro-ring resonator is presented. In our design, there are two slot-waveguide-based micro-rings that encircle a gold disc. The outer slot WG is formed by the combination of Silicon-Air-Gold ring and the inner slot-waveguide is formed by Gold ring-Air-Gold disc. The slot-waveguide rings provide an interaction length sufficient to accumulate a detectable wavelength shift. The transmission spectrum and electric field distribution of this sensor structure are simulated using Finite Element Method (FEM). The sensitivity of this micro-ring resonator is achieved at 800 nm/RIU which is about six times higher than that of the conventional Si ring with the same geometry. Our proposed sensor design has a potential to find further applications in biomedical science and nano-photonic circuits.

Method for forming thermally stable nanoparticles on supports

DOEpatents

Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

2013-08-20

An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

Design and evaluation of thin metal surface insulation for hypersonic flight

NASA Technical Reports Server (NTRS)

Miller, R. C.; Petach, A. M.

1976-01-01

An all-metal insulation was studied as a thermal protection system for hypersonic vehicles. Key program goals included fabricating the insulation in thin packages which are optimized for high temperature insulation of an actively cooled aluminum structure, and the use of state-of-the-art alloys. The insulation was fabricated from 300 series stainless steel in thicknesses of 0.8 to 12 mm. The outer, 0.127 mm thick, skin was textured to accommodate thermal expansion and oxidized to increase emittance. The thin insulating package was achieved using an insulation concept consisting of foil radiation shields spaced within the package, and conical foil supports to carry loads from the skin and maintain package dimensions. Samples of the metal-insulation were tested to evaluate thermal insulation capability, rain and sand erosion resistance, high temperature oxidation resistance, applied load capability, and high temperature emittance.

Atomic scale characterization and surface chemistry of metal modified titanate nanotubes and nanowires

NASA Astrophysics Data System (ADS)

Kukovecz, Ákos; Kordás, Krisztián; Kiss, János; Kónya, Zoltán

2016-10-01

Titanates are salts of polytitanic acid that can be synthesized as nanostructures in a great variety concerning crystallinity, morphology, size, metal content and surface chemistry. Titanate nanotubes (open-ended hollow cylinders measuring up to 200 nm in length and 15 nm in outer diameter) and nanowires (solid, elongated rectangular blocks with length up to 1500 nm and 30-60 nm diameter) are the most widespread representatives of the titanate nanomaterial family. This review covers the properties and applications of these two materials from the surface science point of view. Dielectric, vibrational, electron and X-ray spectroscopic results are comprehensively discussed first, then surface modification methods including covalent functionalization, ion exchange and metal loading are covered. The versatile surface chemistry of one-dimensional titanates renders them excellent candidates for heterogeneous catalytic, photocatalytic, photovoltaic and energy storage applications, therefore, these fields are also reviewed.

Fabrication of Nanopipette Arrays for Biosensing

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya (Inventor)

2015-01-01

Method for providing a nanopipette array for biosensing applications. A thin substrate of anodizable metal ("AN-metal," such as Al, Mg, Zn, Ti, Ta and/or Nb) is anodized at temperature T=20-200.degree. C., chemical bath pH=4-6 and electrical potential 1-300 Volts, to produce an array of anodized nanopipette channels, having diameters 10-50 nm, with oxidized channel surfaces of thickness 5-20 nm. A portion of exposed non-oxidized AN-metal between adjacent nanopipette channels, of length 1-5 .mu.m, is etched away, exposing inner and outer surfaces of a nanopipette channel. A probe molecule, is deposited on one or both surfaces to provide biosensing capability for K(.gtoreq.1) target molecules. Target molecule presence, in an above-threshold concentration, in a fluid passed through or adjacent to a nanopipette channel, produces characteristic detection signals associated with the probe molecule site.

Small-Scale Metal Tanks for High Pressure Storage of Fluids

NASA Technical Reports Server (NTRS)

London, Adam (Inventor)

2016-01-01

Small scale metal tanks for high-pressure storage of fluids having tank factors of more than 5000 meters and volumes of ten cubic inches or less featuring arrays of interconnected internal chambers having at least inner walls thinner than gage limitations allow. The chambers may be arranged as multiple internal independent vessels. Walls of chambers that are also portions of external tank walls may be arcuate on the internal and/or external surfaces, including domed. The tanks may be shaped adaptively and/or conformally to an application, including, for example, having one or more flat outer walls and/or having an annular shape. The tanks may have dual-purpose inlet/outlet conduits of may have separate inlet and outlet conduits. The tanks are made by fusion bonding etched metal foil layers patterned from slices of a CAD model of the tank. The fusion bonded foil stack may be further machined.

Fine metal dust particles on the wall probes from JET-ILW

NASA Astrophysics Data System (ADS)

Fortuna-Zaleśna, E.; Grzonka, J.; Moon, Sunwoo; Rubel, M.; Petersson, P.; Widdowson, A.; Contributors, JET

2017-12-01

Collection and ex situ studies of dust generated in controlled fusion devices during plasma operation are regularly carried out after experimental campaigns. Herewith results of the dust survey performed in JET after the second phase of operation with the metal ITER-like wall (2013-2014) are presented. For the first-time-ever particles deposited on silicon plates acting as dust collectors installed in the inner and outer divertor have been examined. The emphasis is on analysing metal particles (Be and W) with the aim to determine their composition, size and surface topography. The most important is the identification of beryllium dust in the form of droplets (both splashes and spherical particles), flakes of co-deposits and small fragments of Be tiles. Tungsten and nickel rich (from Inconel) particles are also identified. Nitrogen from plasma edge cooling has been detected in all types of particles. They are categorized and the origin of various constituents is discussed.

Photocathode device that replenishes photoemissive coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moody, Nathan A.; Lizon, David C.

2016-06-14

A photocathode device may replenish its photoemissive coating to replace coating material that desorbs/evaporates during photoemission. A linear actuator system may regulate the release of a replenishment material vapor, such as an alkali metal, from a chamber inside the photocathode device to a porous cathode substrate. The replenishment material deposits on the inner surface of a porous membrane and effuses through the membrane to the outer surface, where it replenishes the photoemissive coating. The rate of replenishment of the photoemissive coating may be adjusted using the linear actuator system to regulate performance of the photocathode device during photoemission. Alternatively, themore » linear actuator system may adjust a plasma discharge gap between a cartridge containing replenishment material and a metal grid. A potential is applied between the cartridge and the grid, resulting in ejection of metal ions from the cartridge that similarly replenish the photoemissive coating.« less

The metal content of molybdenum-mineralizing fluids

NASA Astrophysics Data System (ADS)

Lerchbaumer, L.; Audétat, A.

2012-04-01

Molybdenum can be found in porphyry-type systems as well as in hydrothermal veins and breccias associated with granite systems. Up to now our knowledge on the metal content of fluids forming molybdenum ore deposits has been very limited. The only data available so far are from the porphyry Mo deposit at Questa, New Mexico, and from the Cave Peak porphyry Mo-Nb deposit in Texas. We have studied early, intermediate-density fluid inclusions in quartz crystals from miarolitic cavities in the Drammen and Glitrevann granites (Norway) and the Treasure Mountain Dome (Colorado/USA) to obtain more information about the bulk composition of magmatic-hydrothermal fluids exsolved from these plutons. The Treasure Mountain Dome contains weak Mo mineralization and is an apophysis of the Alma Batholith that produced also the famous Climax and Henderson porphyry Mo deposits; the Glitrevann granite hosts a sub-economic Mo stockwork, and the Drammen Granite contains numerous vein-type Mo mineralizations. As a preliminary result, based on analyses of fluid inclusions using optical microscopy, microthermometry, Raman spectroscopy, and LA-ICP-MS we conclude that the primordial fluid of the Drammen granite was of high acidity and carried certain amounts of metals at conditions of 650°C and 1.3-1.5 kbar. The total elemental budget is: 3 wt% Na, 1.8 wt% K, 0.5 wt% S, 0.4 wt% Fe, 0.3 wt% Cu, 0.2 wt% Mn, 40 ppm Mo, 800 ppm Zn, 600 ppm Rb, 300 ppm Cs, 180 ppm Pb, 150 ppm As, 40 ppm W, 15 ppm Bi, and minor amounts of Ag, Sn, and Ce. Striking is the fact, that all the metal concentrations show little variability except the one of Cu. In view of recent studies (Lerchbaumer & Audétat, 2011) showing that the Cu-values in quartz-hosted fluid inclusions are not always representative of the primary fluid and in fact can be too high, we want to check if this could be the case for the Cu-values measured in the samples from Norway and Colorado. The alteration of the original Cu-concentrations stems from post-entrapment diffusion of Cu+ through the host quartz into the fluid inclusions. The trigger for this process is the changing pH of the outer fluid due to rock-buffered cooling: As this fluid gets more and more basic, the increasing concentration gradient promotes the loss of H+ from existing fluid inclusions and the corresponding uptake of Cu+. In order to experimentally reconstruct this process we will put a well characterized trail of fluid inclusions from the Drammen granite into a gold capsule together with its original, acidic fluid (known from analyses mentioned above) and subject it to its forming conditions in rapid quench autoclaves. In the case of fluid inclusions with a diffusively altered elemental composition, the pH-difference between the fluid inclusions and the outer fluid would reverse the diffusion process and would lead to quite diminished concentrations of Cu after the run. Such a result would finally indicate that these Mo-mineralizing fluids hardly transported any Cu. Lerchbaumer L. & Audétat A. (2011): Preferential partitioning of copper into the vapor phase: An artifact? Mineralogical Magazine 75 (3), 1302.

Progressive outer retinal necrosis presenting as cherry red spot.

PubMed

Yiu, Glenn; Young, Lucy H

2012-10-01

To report a case of progressive outer retinal necrosis (PORN) presenting as a cherry red spot. Case report. A 53-year-old woman with recently diagnosed HIV and varicella-zoster virus (VZV) aseptic meningitis developed rapid sequential vision loss in both eyes over 2 months. Her exam showed a "cherry red spot" in both maculae with peripheral atrophy and pigmentary changes, consistent with PORN. Due to her late presentation and the rapid progression of her condition, she quickly developed end-stage vision loss in both eyes. PORN should be considered within the differential diagnosis of a "cherry red spot." Immune-deficient patients with a history of herpetic infection who present with visual loss warrant prompt ophthalmological evaluation.

Spectral domain optical coherence tomography findings in tamoxifen retinopathy--a case report.

PubMed

Nair, Sandhya Narayanan; Anantharaman, Giridhar; Gopalakrishnan, Mahesh; Vyas, Jyothiprakash

2013-01-01

To report spectral domain optical coherence tomography findings in a case of typical tamoxifen retinopathy. In this observational case report, a patient with tamoxifen retinopathy was imaged with spectral domain optical coherence tomography and fundus auto fluorescence. Spectral domain optical coherence tomography showed numerous hyperreflective spots within the retina, mainly in the inner retinal layers in both the eyes. The external limiting membrane, the Inner Segment-Outer Segment junction, and the photoreceptors were not discernable at the fovea in the right eye. In the left eye, there was foveal atrophy with total loss of photoreceptors. The autofluorescent images showed macular hypofluorescence with foveal hyperfluorescence. Spectral domain optical coherence tomography demonstrated abnormalities in the outer retinal layers in tamoxifen retinopathy. There were also characteristic alterations in the autofluorescence pattern at the macula in tamoxifen retinopathy.

30 CFR 250.423 - What are the requirements for pressure testing casing?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.423 What are the requirements for... of casing. You may not resume drilling or other down-hole operations until you obtain a satisfactory...

30 CFR 250.423 - What are the requirements for pressure testing casing?

Code of Federal Regulations, 2014 CFR

2014-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.423 What are the requirements for... of casing. You may not resume drilling or other down-hole operations until you obtain a satisfactory...

30 CFR 250.423 - What are the requirements for pressure testing casing?

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.423 What are the... for each string of casing. You may not resume drilling or other down-hole operations until you obtain...

30 CFR 250.423 - What are the requirements for pressure testing casing?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.423 What are the requirements for... of casing. You may not resume drilling or other down-hole operations until you obtain a satisfactory...

30 CFR 285.111 - When and how does MMS charge me processing fees on a case-by-case basis?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When and how does MMS charge me processing fees on a case-by-case basis? 285.111 Section 285.111 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER...

30 CFR 250.525 - What do I submit if my casing diagnostic test requires action?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What do I submit if my casing diagnostic test... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations Casing Pressure Management § 250.525 What do I submit if my casing diagnostic test...

Testing the Presence of Multiple Photometric Components in Nearby Early-type Galaxies using SDSS

NASA Astrophysics Data System (ADS)

Oh, Semyeong; Greene, Jenny E.; Lackner, Claire N.

2017-02-01

We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are ˜3 and ˜15 kpc. The inner component lies on the mass-size relation of ETGs at z ˜ 0.25-0.75, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between single- and double-component ETGs, with double-component galaxies being younger and more metal-rich. The fraction of double-component ETGs increases with increasing σ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.

New insights into hydrosilylation of unsaturated carbon-heteroatom (C═O, C═N) bonds by rhenium(V)-dioxo complexes.

PubMed

Huang, Liangfang; Wang, Wenmin; Wei, Xiaoqin; Wei, Haiyan

2015-04-23

The hydrosilylation of unsaturated carbon-heteroatom (C═O, C═N) bonds catalyzed by high-valent rhenium(V)-dioxo complex ReO2I(PPh3)2 (1) were studied computationally to determine the underlying mechanism. Our calculations revealed that the ionic outer-sphere pathway in which the organic substrate attacks the Si center in an η(1)-silane rhenium adduct to prompt the heterolytic cleavage of the Si-H bond is the most energetically favorable process for rhenium(V)-dioxo complex 1 catalyzed hydrosilylation of imines. The activation energy of the turnover-limiting step was calculated to be 22.8 kcal/mol with phenylmethanimine. This value is energetically more favorable than the [2 + 2] addition pathway by as much as 10.0 kcal/mol. Moreover, the ionic outer-sphere pathway competes with the [2 + 2] addition mechanism for rhenium(V)-dioxo complex 1 catalyzing the hydrosilylation of carbonyl compounds. Furthermore, the electron-donating group on the organic substrates would induce a better activity favoring the ionic outer-sphere mechanistic pathway. These findings highlight the unique features of high-valent transition-metal complexes as Lewis acids in activating the Si-H bond and catalyzing the reduction reactions.

Nickel-metal hydride battery development. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-06-01

Rechargeable batteries are used as the power source for a broad range of portable equipment. Key battery selection criteria typically are weight, volume, first cost, life cycle cost, and environmental impact. Rechargeable batteries are favored from a life cycle cost and environmental impact standpoint over primary batteries. The nickel-metal hydride (Ni-MH) battery system has emerged as the battery of choice for many applications based on its superior characteristics when judged on the above criteria against other battery types. In most cases commercial Ni-MH batteries are constructed with coiled electrodes in cylindrical metal containers. Electro Energy, Inc. (EEI) has been developingmore » a novel flat bipolar configuration of the Ni-MH system that offers weight, volume, and cost advantages when compared to cylindrical cells. The unique bipolar approach consists of fabricating individual flat wafer cells in conductive, carbon-filled, plastic face plates. The individual cells contain a nonconductive plastic border which is heat sealed around the perimeter to make a totally sealed unit cell. Multi-cell batteries are fabricated by stacking the individual wafer cells in such a way that the positive face of one cell contacts the negative face of the adjacent cell. The stack is then contained in an outer housing with end contacts. The purpose of this program was to develop, evaluate, and demonstrate the capabilities of the EEI Ni-MH battery system for consumer applications. The work was directed at the development and evaluation of the compact bipolar construction for its potential advantages of high power and energy density. Experimental investigations were performed on various nickel electrode types, hydride electrode formulations, and alternate separator materials. Studies were also directed at evaluating various oxygen recombination techniques for low pressure operation during charge and overcharge.« less

Bioinspired systems for metal-ion sensing: new emissive peptide probes based on benzo[d]oxazole derivatives and their gold and silica nanoparticles.

PubMed

Oliveira, Elisabete; Genovese, Damiano; Juris, Riccardo; Zaccheroni, Nelsi; Capelo, José Luis; Raposo, M Manuela M; Costa, Susana P G; Prodi, Luca; Lodeiro, Carlos

2011-09-19

Seven new bioinspired chemosensors (2-4 and 7-10) based on fluorescent peptides were synthesized and characterized by elemental analysis, (1)H and (13)C NMR, melting point, matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and IR and UV-vis absorption and emission spectroscopy. The interaction with transition- and post-transition-metal ions (Cu(2+), Ni(2+), Ag(+), Zn(2+), Cd(2+), Hg(2+), Pb(2+), and Fe(3+)) has been explored by absorption and fluorescence emission spectroscopy and MALDI-TOF-MS. The reported fluorescent peptide systems, introducing biological molecules in the skeleton of the probes, enhance their sensitivity and confer them strong potential for applications in biological fields. Gold and silica nanoparticles functionalized with these peptides were also obtained. All nanoparticles were characterized by dynamic light scattering, transmission electron microscopy, and UV-vis absorption and fluorescence spectroscopy. Stable gold nanoparticles (diameter 2-10 nm) bearing ligands 1 and 4 were obtained by common reductive synthesis. Commercial silica nanoparticles were decorated at their surface using compounds 8-10, linked through a silane spacer. The same chemosensors were also taken into aqueous solutions through their dispersion in the outer layer of silica core/poly(ethylene glycol) shell nanoparticles. In both cases, these complex nanoarchitectures behaved as new sensitive materials for Ag(+) and Hg(2+) in water. The possibility of using these species in this solvent is particularly valuable because the impact on human health of heavy- and transition-metal-ion pollution is very severe, and all analytical and diagnostics investigations involve a water environment.

On the violence of thermal explosion in solid explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chidester, S.K.; Tarver, C.M.; Green, L.G.

Heavily confined cylinders of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and triaminotrinitrobenzene (TATB) were heated at rates varying from 2 C/min to 3.3 C/h. Fourteen of the cylinders were hollow, and inner metallic liners with small heaters attached were used to produce uniform temperatures just prior to explosion. A complex thermocouple pattern was used to measure the temperature history throughout the charge and to determine the approximate location where the runaway exothermic reaction first occurred. The violence of the resulting explosion was measured using velocity pin arrays placed inside and outside of the metal confinement cylinders, flash x-rays, overpressure gauges, and fragment collection techniques.more » Five cylinders were intentionally detonated for violence comparisons. The measured temperature histories, times to explosion, and the locations of first reaction agreed closely with those calculated by a two-dimensional heat transfer code using multistep chemical decomposition models. The acceleration of the confining metal cylinders by the explosion process was accurately simulated using a two-dimensional pressure dependent deflagration reactive flow hydrodynamic mode. The most violent HMX thermal explosions gradually accelerated their outer cases to velocities approaching those of intentional detonations approximately 120 {micro}m after the onset of explosion. The measured inner cylinder collapse velocities from thermal explosions were considerably lower than those produced by detonations. In contrast to the HMX thermal reactions, no violent thermal explosions were produced by the TATB-based explosive LX-17. A heavily confined, slowly heated LX-17 test produced sufficient pressure to cause a 0.1 cm bend in a 2 cm thick steel plate.« less

Direct laser metal sintering as a new approach to fabrication of an isoelastic functionally graded material for manufacture of porous titanium dental implants.

PubMed

Traini, T; Mangano, C; Sammons, R L; Mangano, F; Macchi, A; Piattelli, A

2008-11-01

This work focuses on a titanium alloy implants incorporating a gradient of porosity, from the inner core to the outer surface, obtained by laser sintering of metal powder. Surface appearance, microstructure, composition, mechanical properties and fractography were evaluated. All the specimens were prepared by a selective laser sintering procedure using a Ti-6Al-4V alloy powder with a particle size of 1-10 microm. The morphological and chemical analyses were performed by SEM and energy dispersive X-ray spectroscopy. The flexure strength was determined by a three-point bend test using a universal testing machine. The surface roughness was investigated using a confocal scanning laser microscope. The surface roughness variation was statistically evaluated by use of a Chi square test. A p value of <0.05 was considered statistically significant. The original surface microstructure consisted of roughly spherical particles, diameter range 5-50 microm. After exposure to hydrofluoric acid some of these were removed and the microsphere diameter then ranged from 5.1 microm to 26.8 microm. Following an organic acid treatment, particles were replaced by grooves 14.6-152.5 microm in width and 21.4-102.4 microm depth. The metal core consisted of columnar beta grains with alpha and beta laths within the grains. The alloy was composed of 90.08% Ti, 5.67% Al and 4.25% V. The Young's modulus of the inner core material was 104+/-7.7 GPa; while that of the outer porous material was 77+/-3.5 GPa. The fracture face showed a dimpled appearance typical of ductile fracture. In conclusion, laser metal sintering proved to be an efficient means of construction of dental implants with a functionally graded material which is better adapted to the elastic properties of the bone. Such implants should minimize stress shielding effects and improve long-term performance.

CONSTRAINTS ON THE FORMATION OF THE GALACTIC BULGE FROM Na, Al, AND HEAVY-ELEMENT ABUNDANCES IN PLAUT's FIELD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Christian I.; Rich, R. Michael; Kobayashi, Chiaki

2012-04-20

We report chemical abundances of Na, Al, Zr, La, Nd, and Eu for 39 red giant branch (RGB) stars and 23 potential inner disk red clump stars located in Plaut's low-extinction window. We also measure lithium for a super Li-rich RGB star. The abundances were determined by spectrum synthesis of high-resolution (R Almost-Equal-To 25,000), high signal-to-noise (S/N {approx} 50-100 pixel{sup -1}) spectra obtained with the Blanco 4 m telescope and Hydra multifiber spectrograph. For the bulge RGB stars, we find a general increase in the [Na/Fe] and [Na/Al] ratios with increasing metallicity, and a similar decrease in [La/Fe] and [Nd/Fe].more » Additionally, the [Al/Fe] and [Eu/Fe] abundance trends almost identically follow those of the {alpha}-elements, and the [Zr/Fe] ratios exhibit relatively little change with [Fe/H]. The consistently low [La/Eu] ratios of the RGB stars indicate that at least a majority of bulge stars formed rapidly ({approx}<1 Gyr) and before the main s-process could become a significant pollution source. In contrast, we find that the potential inner disk clump stars exhibit abundance patterns more similar to those of the thin and thick disks. Comparisons between the abundance trends at different bulge locations suggest that the inner and outer bulges formed on similar timescales. However, we find evidence of some abundance differences between the most metal-poor and metal-rich stars in various bulge fields. The data also indicate that the halo may have had a more significant impact on the outer bulge initial composition than the inner bulge composition. The [Na/Fe], and to a lesser extent [La/Fe], abundances further indicate that the metal-poor bulge, at least at {approx}1 kpc from the Galactic center, and thick disk may not share an identical chemistry.« less

Effects of Complex Interplanetary Structures on the Dynamics of the Earth's Outer Radiation Belt During the 16-30 September 2014 Period: II) Corotating Solar Wind Stream

NASA Astrophysics Data System (ADS)

Souza, V. M. C. E. S.; Da Silva, L. A.; Sibeck, D. G.; Alves, L. R.; Jauer, P. R.; Dias Silveira, M. V.; Medeiros, C.; Marchezi, J.; Rockenbach, M.; Baker, D. N.; Kletzing, C.; Kanekal, S. G.; Georgiou, M.; Mendes, O., Jr.; Dal Lago, A.; Vieira, L. E. A.

2015-12-01

We present a case study describing the dynamics of the outer radiation belt for two different solar wind conditions. First, we discuss a dropout of outer belt energetic electron fluxes corresponding to the arrival of an interplanetary coronal mass ejection (ICME) followed by a corotating stream in September 2014. Second, we discuss the reformation of the outer radiation belt that began on September 22nd. We find that the arrival of the ICME and the corotating interaction region that preceded the stream cause a long-duration (many day) dropout of high-energy electrons. The recovery in radiation belt fluxes only begins when the high-speed stream begins to develop IMF Bz fluctuations and auroral activity resumes. Furthermore, during periods in which several consecutive solar wind structures appear, the first structure primes the outer radiation belt prior to the interaction of the subsequent solar wind structures with the magnetosphere. Consequently, the evolution of the outer radiation belt through the solar cycle is significantly affected by the dominant structure of each phase of the cycle. We use energetic electron and magnetic field observations provided by the Van Allen Probes, THEMIS, and GOES missions.

Pseudomonas fluorescens' view of the periodic table.

PubMed

Workentine, Matthew L; Harrison, Joe J; Stenroos, Pernilla U; Ceri, Howard; Turner, Raymond J

2008-01-01

Growth in a biofilm modulates microbial metal susceptibility, sometimes increasing the ability of microorganisms to withstand toxic metal species by several orders of magnitude. In this study, a high-throughput metal toxicity screen was initiated with the aim of correlating biological toxicity data in planktonic and biofilm cells to the physiochemical properties of metal ions. To this end, Pseudomonas fluorescens ATCC 13525 was grown in the Calgary Biofilm Device (CBD) and biofilms and planktonic cells of this microorganism were exposed to gradient arrays of different metal ions. These arrays included 44 different metals with representative compounds that spanned every group of the periodic table (except for the halogens and noble gases). The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum biofilm eradication concentration (MBEC) values were obtained after exposing the biofilms to metal ions for 4 h. Using these values, metal ion toxicity was correlated to the following ion-specific physicochemical parameters: standard reduction-oxidation potential, electronegativity, the solubility product of the corresponding metal-sulfide complex, the Pearson softness index, electron density and the covalent index. When the ions were grouped according to outer shell electron structure, we found that heavy metal ions gave the strongest correlations to these parameters and were more toxic on average than the other classes of the ions. Correlations were different for biofilms than for planktonic cells, indicating that chemical mechanisms of metal ion toxicity differ between the two modes of growth. We suggest that biofilms can specifically counter the toxic effects of certain physicochemical parameters, which may contribute to the increased ability of biofilms to withstand metal toxicity.

Glove and gown effects on intraoperative bacterial contamination.

PubMed

Ward, William G; Cooper, Joshua M; Lippert, Dylan; Kablawi, Rawan O; Neiberg, Rebecca H; Sherertz, Robert J

2014-03-01

Experiments were performed to determine the risk of bacterial contamination associated with changing outer gloves and using disposable spunlace paper versus reusable cloth gowns. Despite decades of research, there remains a lack of consensus regarding certain aspects of optimal aseptic technique including outer glove exchange while double-gloving and surgical gown type selection. In an initial glove study, 102 surgical team members were randomized to exchange or retain outer gloves 1 hour into clean orthopedic procedures; cultures were obtained 15 minutes later from the palm of the surgeon's dominant gloved hand and from the surgical gown sleeve. Surgical gown type selection was recorded. A laboratory strike-through study investigating bacterial transmission through cloth and paper gowns was performed with coagulase-negative staphylococci. In a follow-up glove study, 251 surgical team members, all wearing paper gowns, were randomized as in the first glove study. Glove study 1 revealed 4-fold higher levels of baseline bacterial contamination (31% vs 7%) on the sleeve of surgical team members wearing cloth gowns than those using paper gowns [odds ratio (95% confidence interval): 4.64 (1.72-12.53); P = 0.0016]. The bacterial strike-through study revealed that 26 of 27 cloth gowns allowed bacterial transmission through the material compared with 0 of 27 paper gowns (P < 0.001). In glove study 2, surgeons retaining outer gloves 1 hour into the case had a subsequent positive glove contamination rate of 23% compared with 13% among surgeons exchanging their original outer glove [odds ratio (95% confidence interval): 1.97 (1.02-3.80); P = 0.0419]. Paper gowns demonstrated less bacterial transmission in the laboratory and lower rates of contamination in the operating room. Disposable paper gowns are recommended for all surgical cases, especially those involving implants, because of the heightened risk of infection. Outer glove exchange just before handling implant materials is also recommended to minimize intraoperative contamination.

Outer edges of debris discs. How sharp is sharp?

NASA Astrophysics Data System (ADS)

Thébault, P.; Wu, Y.

2008-04-01

Context: Rings or annulus-like features have been observed in most imaged debris discs. Outside the main ring, while some systems (e.g., β Pictoris and AU Mic) exhibit smooth surface brightness profiles (SB) that fall off roughly as ~r-3.5, others (e.g. HR 4796A and HD 139664) display large drops in luminosity at the ring's outer edge and steeper radial luminosity profiles. Aims: We seek to understand this diversity of outer edge profiles under the “natural” collisional evolution of the system, without invoking external agents such as planets or gas. Methods: We use a multi-annulus statistical code to follow the evolution of a collisional population, ranging in size from dust grains to planetesimals and initially confined within a belt (the “birth ring”). The crucial effect of radiation pressure on the dynamics and spatial distribution of the smallest grains is taken into account. We explore the dependence of the resulting disc surface brightness profile on various parameters. Results: The disc typically evolves toward a “standard” steady state, where the radial surface brightness profile smoothly decreases with radius as r-3.5 outside the birth ring. This confirms and extends the semi-analytical study of Strubbe & Chiang (2006, ApJ, 648, 652) and provides a firm basis for interpreting observed discs. Deviations from this typical profile, in the form of a sharp outer edge and a steeper fall-off, occur for two “extreme” cases: 1) when the birth ring is so massive that it becomes radially optically thick for the smallest grains. However, the required disc mass is probably too high here to be realistic; 2) when the dynamical excitation of the dust-producing planetesimals is so low (< e> and < i> ≤ 0.01) that the smallest grains, which otherwise dominate the optical depth of the system, are preferentially depleted. This low-excitation case, although possibly not generic, cannot be ruled out by observations for most systems, . Conclusions: Our “standard” profile provides a satisfactory explanation for a large group of debris discs that show smooth outer edges and SB ∝ r-3.5. Systems with sharper outer edges, barring other confining agents, could still be explained by “natural” collisional evolution if their dynamical excitation is very low. We show that such a dynamically-cold case provides a satisfactory fit to the specific HR4796A ring.

MELTING AND PURIFICATION OF URANIUM

DOEpatents

Spedding, F.H.; Gray, C.F.

1958-09-16

A process is described for treating uranium ingots having inner metal portions and an outer oxide skin. The method consists in partially supporting such an ingot on the surface of a grid or pierced plate. A sufficient weight of uranium is provided so that when the mass becomes molten, the oxide skin bursts at the unsupported portions of its bottom surface, allowing molten urantum to flow through the burst skin and into a container provided below.

Combining Sequential Extractions and X-ray Absorption Spectroscopy for Quantitative and Qualitative Zinc Speciation in Soil

NASA Astrophysics Data System (ADS)

Bauer, Tatiana; Minkina, Tatiana; Batukaev, Abdulmalik; Nevidomskaya, Dina; Burachevskaya, Marina; Tsitsuashvili, Viktoriya; Urazgildieva, Kamilya

2017-04-01

The combined use of X-ray absorption spectrometry and extractive fractionation is an effective approach for studying the interaction of metal ions with soil compounds and identifying the phases-carriers of metals in soil and their stable fixation. These studies were carried out using the technique of X-ray absorption spectroscopy and chemical extractive fractionation. In a model experiment the samples taken in Calcic Chernozem were artificially contaminated with higher portion of Zn(NO3)2 (2000 mg/kg). The metal were incubated in soil samples for 2 year. The samples of soil mineral and organic phases (calcite, kaolinite, bentonite, humic acids) were saturated with Zn2+ from a solution of nitrate salts of metal. The total content of Zn in soil and soil various phases was determined using the X-ray fluorescence method. Extended X-ray absorption fine structure (EXAFS) Zn was measured at the Structural Materials Science beamline of the Kurchatov Center for Synchrotron Radiation. Sequential fractionation of Zn in soil conducted by Tessier method (Tessier et al., 1979) which determining 5 fractions of metals in soil: exchangeable, bound to Fe-Mn oxide, bound to carbonate, bound to the organic matter, and bound to silicate (residual). This methodology has so far more than 4000 citations (Web of Science), which demonstrates the popularity of this approach. Much Zn compounds are contained in uncontaminated soils in stable primary and secondary silicates inherited from the parental rocks (67% of the total concentrations in all fractions), which is a regional trait of soils in the fore-Caucasian plain. Extracted fractionation of metal compounds in soil samples, artificially contaminated with Zn salts, indicates the priority holding of Zn2+ ions by silicates, carbonates and Fe-Mn oxides. The Zn content significantly increases in the exchangeable fraction. Atomic structure study of the soil various phases saturated with Zn2+ ion by using (XANES) X-ray absorption spectroscopy allowed the determination of mechanism of metal ions interaction with soil phases and the resulting types of chemical bonds. Interaction with soil components modifies the electron structure of the metal ions themselves. The soil contamination with Zn is accompanied by decreasing the stable connection between metal and soil components. Interacting with humic acids in chernozem, the Zn2+ ion is coordinated by functional groups and ligands and forms unstable outer-sphere complexes. Zinc included into octahedral structures of layered minerals and hydro(oxides) can be inner-and outer-sphere adsorbed. The Zn2+ ions enable to replace Ca2+ ions in octahedral positions being coordinated with carbonate ions as ligands, thus forming absorbed complexes at the surface of mineral calcite. This work was supported by grant of the Russian Scientific Foundation № 16-14-10217.

Increasing the efficiency of designing hemming processes by using an element-based metamodel approach

NASA Astrophysics Data System (ADS)

Kaiser, C.; Roll, K.; Volk, W.

2017-09-01

In the automotive industry, the manufacturing of automotive outer panels requires hemming processes in which two sheet metal parts are joined together by bending the flange of the outer part over the inner part. Because of decreasing development times and the steadily growing number of vehicle derivatives, an efficient digital product and process validation is necessary. Commonly used simulations, which are based on the finite element method, demand significant modelling effort, which results in disadvantages especially in the early product development phase. To increase the efficiency of designing hemming processes this paper presents a hemming-specific metamodel approach. The approach includes a part analysis in which the outline of the automotive outer panels is initially split into individual segments. By doing a para-metrization of each of the segments and assigning basic geometric shapes, the outline of the part is approximated. Based on this, the hemming parameters such as flange length, roll-in, wrinkling and plastic strains are calculated for each of the geometric basic shapes by performing a meta-model-based segmental product validation. The metamodel is based on an element similar formulation that includes a reference dataset of various geometric basic shapes. A random automotive outer panel can now be analysed and optimized based on the hemming-specific database. By implementing this approach into a planning system, an efficient optimization of designing hemming processes will be enabled. Furthermore, valuable time and cost benefits can be realized in a vehicle’s development process.

STAR FORMATION HISTORY OF THE MILKY WAY HALO TRACED BY THE OOSTERHOFF DICHOTOMY AMONG GLOBULAR CLUSTERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jang, Sohee; Lee, Young-Wook, E-mail: ywlee2@yonsei.ac.kr

2015-06-22

In our recent investigation of the Oosterhoff dichotomy in the multiple population paradigm, we have suggested that the RR Lyrae variables in the globular clusters (GCs) of Oosterhoff groups I, II, and III are produced mostly by first, second, and third generation stars (G1, G2, and G3), respectively. Here we show, for the first time, that the observed dichotomies in the inner and outer halo GCs can be naturally reproduced when these models are extended to all metallicity regimes, while maintaining reasonable agreements in the horizontal-branch type versus [Fe/H] correlations. In order to achieve this, however, specific star formation historiesmore » are required for the inner and outer halos. In the inner halo GCs, the star formation commenced and ceased earlier with a relatively short formation timescale between the subpopulations (∼0.5 Gyr), while in the outer halo, the formation of G1 was delayed by ∼0.8 Gyr with a more extended timescale between G1 and G2 (∼1.4 Gyr). This is consistent with the dual origin of the Milky Way halo. Despite the difference in detail, our models show that the Oosterhoff period groups observed in both outer and inner halo GCs are all manifestations of the “population-shift” effect within the instability strip, for which the origin can be traced back to the two or three discrete episodes of star formation in GCs.« less

Behaviour of wrapped cold-formed steel columns under different loading conditions

NASA Astrophysics Data System (ADS)

Baabu, B. Hari; Sreenath, S.

2017-07-01

The use of Cold Formed Steel (CFS) sections as structural members is widely accepted because of its light nature. However, the load carrying capacity of these sections will be less compared to hot rolled sections. This study is meant to analyze the possibility of strengthening cold formed members by wrapping it with Glass Fiber Reinforced Polymer (GFRP) laminates. Light gauge steel columns of cross sectional dimensions 100mm x 50mm x 3.15mm were taken for this study. The effective length of the section is about 750mm. A total of 8 specimens including the control specimen is tested under axial and eccentric loading. The columns were tested keeping both ends hinged. For both loading cases the buckling behaviour, ultimate load carrying capacity and load-deflection characteristics of the CFS columns were analyzed. The GFRP laminates were wrapped on columns in three different ways such that wrapping the outer surface of web and flange throughout the length of specimen, wrapping the outer surface of web alone throughout the length of specimen and wrapping the outer surface of web and flange for the upper half length of the specimen where the buckling is expected. For both loading cases, the results indicated that the column with wrapping at the outer surface of web and flange throughout the length of specimen provides better strength for it.

Coexistence and limiting similarity of consumer species competing for a linear array of resources.

PubMed

Abrams, Peter A; Rueffler, Claus

2009-03-01

Consumer-resource systems with linear arrays of substitutable resources form the conceptual basis of much of present-day competition theory. However, most analyses of the limiting similarity of competitors have only employed consumer-resource models as a justification for using the Lotka-Volterra competition equations to represent the interaction. Unfortunately, Lotka-Volterra models cannot reflect resource exclusion via apparent competition and are poor approximations of systems with nonlogistic resource growth. We use consumer-resource models to examine the impact of exclusion of biotic resources or depletion of abiotic resources on the ability of three consumer species to coexist along a one-dimensional resource axis. For a wide range of consumer-resource models, coexistence conditions can become more restrictive with increasing niche separation of the two outer species. This occurs when the outer species are highly efficient; in this case they cause extinction or severe depletion of intermediate resources when their own niches have an intermediate level of separation. In many cases coexistence of an intermediate consumer species is prohibited when niche separation of the two outer species is moderately large, but not when it is small. Coexistence may be most likely when the intermediate species is closer to one of the two outer species, contrary to previous theory. These results suggest that competition may lead to uneven spacing of utilization curves. The implications and range of applicability of the models are discussed.

Effects of semi-floating ring bearing outer clearance on the subsynchronous oscillation of turbocharger rotor

NASA Astrophysics Data System (ADS)

Liang, Feng; Zhou, Ming; Xu, Quanyong

2016-09-01

Semi-floating ring bearing(SFRB) is developed to control the vibration of turbocharger rotor. The outer clearance of SFRB affects the magnitude and frequency of nonlinear whirl motion, which is significant for the design of turbocharger. In order to explore the effects of outer clearance, a transient finite element analysis program for rotor and oil film bearing is built and validated by a published experimental case. The nonlinear dynamic behaviors of rotor-SFRB system are simulated. According to the simulation results, two representative subsynchronous oscillations excited by the two bearings respectively are discovered. As the outer clearance of SFRB increases from 24 μm to 60 μm, the low-frequency subsynchronous oscillation experiences three steps, including a strong start, a gradual recession and a combination with the other one. At the same time, the high-frequency subsynchronous oscillation starts to appear gradually, then strengthens, and finally combines. If gravity and unbalance are neglected, the combination will start starts from high rotor speed and extents to low rotor speed, just like a "zipper". It is found from the quantitative analysis that when the outer clearance increases, the vibration amplitude experiences large value firstly, then reduction, and suddenly increasing after combination. A useful design principle of SFRB outer clearance for minimum vibration amplitude is proposed: the outer clearance value should be chosen to keep the frequency of two subsynchronous oscillations clearly separated and their amplitudes close.

30 CFR 250.421 - What are the casing and cementing requirements by type of casing string?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.421 What... drilling into formations known to contain oil or gas. If you encounter oil or gas or unexpected formation...

30 CFR 250.421 - What are the casing and cementing requirements by type of casing string?

Code of Federal Regulations, 2012 CFR

2012-07-01

... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.421 What are the... Cementing requirements (a) Drive or Structural Set by driving, jetting, or drilling to the minimum depth as...

30 CFR 250.421 - What are the casing and cementing requirements by type of casing string?

Code of Federal Regulations, 2013 CFR

2013-07-01

... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.421 What are the... Cementing requirements (a) Drive or Structural Set by driving, jetting, or drilling to the minimum depth as...

30 CFR 250.421 - What are the casing and cementing requirements by type of casing string?

Code of Federal Regulations, 2014 CFR

2014-07-01

... ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Casing and Cementing Requirements § 250.421 What are the... Cementing requirements (a) Drive or Structural Set by driving, jetting, or drilling to the minimum depth as...

30 CFR 250.520 - When do I have to perform a casing diagnostic test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... test? 250.520 Section 250.520 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations Casing Pressure Management § 250.520 When do I have to perform a casing diagnostic test? (a) You...

A seismologically consistent compositional model of Earth's core.

PubMed

Badro, James; Côté, Alexander S; Brodholt, John P

2014-05-27

Earth's core is less dense than iron, and therefore it must contain "light elements," such as S, Si, O, or C. We use ab initio molecular dynamics to calculate the density and bulk sound velocity in liquid metal alloys at the pressure and temperature conditions of Earth's outer core. We compare the velocity and density for any composition in the (Fe-Ni, C, O, Si, S) system to radial seismological models and find a range of compositional models that fit the seismological data. We find no oxygen-free composition that fits the seismological data, and therefore our results indicate that oxygen is always required in the outer core. An oxygen-rich core is a strong indication of high-pressure and high-temperature conditions of core differentiation in a deep magma ocean with an FeO concentration (oxygen fugacity) higher than that of the present-day mantle.

Affinity purification of bacterial outer membrane vesicles (OMVs) utilizing a His-tag mutant.

PubMed

Alves, Nathan J; Turner, Kendrick B; DiVito, Kyle A; Daniele, Michael A; Walper, Scott A

To facilitate the rapid purification of bacterial outer membrane vesicles (OMVs), we developed two plasmid constructs that utilize a truncated, transmembrane protein to present an exterior histidine repeat sequence. We chose OmpA, a highly abundant porin protein, as the protein scaffold and utilized the lac promoter to allow for inducible control of the epitope-presenting construct. OMVs containing mutant OmpA-His6 were purified directly from Escherichia coli culture media on an immobilized metal affinity chromatography (IMAC) Ni-NTA resin. This enabling technology can be combined with other molecular tools directed at OMV packaging to facilitate the separation of modified/cargo-loaded OMV from their wt counterparts. In addition to numerous applications in the pharmaceutical and environmental remediation industries, this technology can be utilized to enhance basic research capabilities in the area of elucidating endogenous OMV function. Published by Elsevier Masson SAS.

Solar energy apparatus with apertured shield

NASA Technical Reports Server (NTRS)

Collings, Roger J. (Inventor); Bannon, David G. (Inventor)

1989-01-01

A protective apertured shield for use about an inlet to a solar apparatus which includesd a cavity receiver for absorbing concentrated solar energy. A rigid support truss assembly is fixed to the periphery of the inlet and projects radially inwardly therefrom to define a generally central aperture area through which solar radiation can pass into the cavity receiver. A non-structural, laminated blanket is spread over the rigid support truss in such a manner as to define an outer surface area and an inner surface area diverging radially outwardly from the central aperture area toward the periphery of the inlet. The outer surface area faces away from the inlet and the inner surface area faces toward the cavity receiver. The laminated blanket includes at least one layer of material, such as ceramic fiber fabric, having high infra-red emittance and low solar absorption properties, and another layer, such as metallic foil, of low infra-red emittance properties.

A seismologically consistent compositional model of Earth’s core

PubMed Central

Badro, James; Côté, Alexander S.; Brodholt, John P.

2014-01-01

Earth’s core is less dense than iron, and therefore it must contain “light elements,” such as S, Si, O, or C. We use ab initio molecular dynamics to calculate the density and bulk sound velocity in liquid metal alloys at the pressure and temperature conditions of Earth's outer core. We compare the velocity and density for any composition in the (Fe–Ni, C, O, Si, S) system to radial seismological models and find a range of compositional models that fit the seismological data. We find no oxygen-free composition that fits the seismological data, and therefore our results indicate that oxygen is always required in the outer core. An oxygen-rich core is a strong indication of high-pressure and high-temperature conditions of core differentiation in a deep magma ocean with an FeO concentration (oxygen fugacity) higher than that of the present-day mantle. PMID:24821817

Biogenesis of the mitochondrial TOM complex: Mim1 promotes insertion and assembly of signal-anchored receptors.

PubMed

Becker, Thomas; Pfannschmidt, Sylvia; Guiard, Bernard; Stojanovski, Diana; Milenkovic, Dusanka; Kutik, Stephan; Pfanner, Nikolaus; Meisinger, Chris; Wiedemann, Nils

2008-01-04

The translocase of the outer membrane (TOM complex) is the central entry gate for nuclear-encoded mitochondrial precursor proteins. All Tom proteins are also encoded by nuclear genes and synthesized as precursors in the cytosol. The channel-forming beta-barrel protein Tom40 is targeted to mitochondria via Tom receptors and inserted into the outer membrane by the sorting and assembly machinery (SAM complex). A further outer membrane protein, Mim1, plays a less defined role in assembly of Tom40 into the TOM complex. The three receptors Tom20, Tom22, and Tom70 are anchored in the outer membrane by a single transmembrane alpha-helix, located at the N terminus in the case of Tom20 and Tom70 (signal-anchored) or in the C-terminal portion in the case of Tom22 (tail-anchored). Insertion of the precursor of Tom22 into the outer membrane requires pre-existing Tom receptors while the import pathway of the precursors of Tom20 and Tom70 is only poorly understood. We report that Mim1 is required for efficient membrane insertion and assembly of Tom20 and Tom70, but not Tom22. We show that Mim1 associates with SAM(core) components to a large SAM complex, explaining its role in late steps of the assembly pathway of Tom40. We conclude that Mim1 is not only required for biogenesis of the beta-barrel protein Tom40 but also for membrane insertion and assembly of signal-anchored Tom receptors. Thus, Mim1 plays an important role in the efficient assembly of the mitochondrial TOM complex.

Mechanical Fracturing of Core-Shell Undercooled Metal Particles for Heat-Free Soldering

PubMed Central

Çınar, Simge; Tevis, Ian D.; Chen, Jiahao; Thuo, Martin

2016-01-01

Phase-change materials, such as meta-stable undercooled (supercooled) liquids, have been widely recognized as a suitable route for complex fabrication and engineering. Despite comprehensive studies on the undercooling phenomenon, little progress has been made in the use of undercooled metals, primarily due to low yields and poor stability. This paper reports the use of an extension of droplet emulsion technique (SLICE) to produce undercooled core-shell particles of structure; metal/oxide shell-acetate (‘/’ = physisorbed, ‘-’ = chemisorbed), from molten Field’s metal (Bi-In-Sn) and Bi-Sn alloys. These particles exhibit stability against solidification at ambient conditions. Besides synthesis, we report the use of these undercooled metal, liquid core-shell, particles for heat free joining and manufacturing at ambient conditions. Our approach incorporates gentle etching and/or fracturing of outer oxide-acetate layers through mechanical stressing or shearing, thus initiating a cascade entailing fluid flow with concomitant deformation, combination/alloying, shaping, and solidification. This simple and low cost technique for soldering and fabrication enables formation of complex shapes and joining at the meso- and micro-scale at ambient conditions without heat or electricity. PMID:26902483

Thermal sprayed composite melt containment tubular component and method of making same

DOEpatents

Besser, Matthew F.; Terpstra, Robert L.; Sordelet, Daniel J.; Anderson, Iver E.

2002-03-19

A tubular thermal sprayed melt containment component for transient containment of molten metal or alloy wherein the tubular member includes a thermal sprayed inner melt-contacting layer for contacting molten metal or alloy to be processed, a thermal sprayed heat-generating layer deposited on the inner layer, and an optional thermal sprayed outer thermal insulating layer. The thermal sprayed heat-generating layer is inductively heated as a susceptor of an induction field or electrical resistively heated by passing electrical current therethrough. The tubular thermal sprayed melt containment component can comprise an elongated melt pour tube of a gas atomization apparatus where the melt pour tube supplies molten material from a crucible to an underlying melt atomization nozzle.

Temperature distributions and thermal stresses in a graded zirconia/metal gas path seal system for aircraft gas turbine engines

NASA Technical Reports Server (NTRS)

Taylor, C. M.; Bill, R. C.

1978-01-01

A ceramic/metallic aircraft gas turbine outer gas path seal designed for improved engine performance was studied. Transient temperature and stress profiles in a test seal geometry were determined by numerical analysis. During a simulated engine deceleration cycle from sea-level takeoff to idle conditions, the maximum seal temperature occurred below the seal surface, therefore the top layer of the seal was probably subjected to tensile stresses exceeding the modulus of rupture. In the stress analysis both two- and three-dimensional finite element computer programs were used. Predicted trends of the simpler and more easily usable two-dimensional element programs were borne out by the three-dimensional finite element program results.

Radial elemental and phase separation in Ni-Mn-Ga glass-coated microwires

NASA Astrophysics Data System (ADS)

Shevyrtalov, S.; Zhukov, A.; Medvedeva, S.; Lyatun, I.; Zhukova, V.; Rodionova, V.

2018-05-01

In this manuscript, radial elemental and phase separation in Ni-Mn-Ga glass-coated microwires with high excess Ni as a result of high-temperature annealing was observed. Partial manganese evaporation from the outer part of the metallic nucleus and glass melting results in the formation of manganese oxide at the surface. The lack of manganese due to its evaporation induces Ni3Ga formation in the intermediate part, while in the middle part of the metallic nucleus, the residual L21 phase with an average chemical composition of Ni60Mn9Ga31 remains. The layered structure exhibits soft ferromagnetic behavior below 270 K. The results were discussed taking into account the chemical composition, arising internal stresses, recrystallization, and atomic ordering.