Science.gov

Sample records for hard outer shell

  1. Unemployment: Hard-Core or Hard-Shell?

    ERIC Educational Resources Information Center

    Lauer, Robert H.

    1972-01-01

    The term hard-core'' makes the unemployed culpable; the term hard shell'' shifts the burden to the employer, and the evidence from the suburban plant indicates that a substantial part of the problem must lie there. (DM)

  2. The hard sphere view of the outer core

    NASA Astrophysics Data System (ADS)

    Helffrich, George

    2015-12-01

    The hard sphere model for liquids attempts to capture the physical behavior of a real liquid in a simple conceptual model: a fluid of fixed size spheres that only interact repulsively when they come into contact. Is the model good enough to use for modeling internal planetary structure? To answer this question, I survey variants of hard sphere liquid theory by applying them to the Earth's outer core to determine which of them explains wavespeeds in the outer core best. The variants explored here are the Carnahan-Starling hard sphere model, the Mansoori-Canfield extension to hard sphere mixtures, the transition metal hard sphere liquid, and the Lennard-Jones hard sphere liquid with attractive forces. With an empirical addition of a temperature dependence to the liquid's hard sphere diameter, all of the variants explored can replicate wavespeeds in most of the radius range of the outer core. The hard sphere model for liquid transition metals explains the wavespeed best because it yields a mean liquid atomic weight of 48.8 g mo l -1 at 10 wt% light element abundance in the core which is in good cosmochemical agreement with core light element models. Other variants also fit core wavespeeds but require implausibly low liquid mean atomic weight implying excessive incorporation of hydrogen or helium in the core. Applied to the detailed wavespeed structure of the Earth's outermost outer core, the model suggests that the mean atomic weight could be reduced by up to 1.74% or the temperature could be increased by up to 400 K relative to an adiabatic profile, or there could be 8% fewer valence electrons in the liquid.

  3. Apparatus and methods for installing, removing and adjusting an inner turbine shell section relative to an outer turbine shell section

    DOEpatents

    Leach, David (Niskayuna, NY); Bergendahl, Peter Allen (Scotia, NY); Waldo, Stuart Forrest (Salem, NC); Smith, Robert Leroy (Milford, OH); Phelps, Robert Kim (Milford, OH)

    2001-01-01

    A turbine includes upper and lower inner shell sections mounting the nozzles and shrouds and which inner shell is supported by pins secured to a surrounding outer shell. To disassemble the turbine for access to the inner shell sections and rotor, an alignment fixture is secured to the lower outer shell section and has pins engaging the inner shell section. To disassemble the turbine, the inner shell weight is transferred to the lower outer shell section via the alignment fixture and cradle pins. Roller assemblies are inserted through access openings vacated by support pins to permit rotation of the lower inner shell section out of and into the lower outer shell section during disassembly and assembly. The alignment fixture includes adjusting rods for adjusting the inner shell axially, vertically, laterally and about a lateral axis. A roller over-cage is provided to rotate the inner shell and a dummy shell to facilitate assembly and disassembly in the field.

  4. Influence of the inner shell electrons on photoionization of outer shells

    NASA Astrophysics Data System (ADS)

    Amusia, Miron; Chernysheva, Larissa V.; Drukarev, Evgenii G.

    2015-11-01

    We investigate the role of virtual excitations of inner shells on the cross section of the outer shell photoionization. The calculations are performed in the frames of the Random Phase Approximation and of its generalized versions GRPAE and GRPAE II, which takes into account variation of the atomic field due to creation of holes in the inner shells and due to their Auger decay, respectively. We employ both analytic approximations and numeric computations. We present the numerical results for the cross sections of photoionization of 3 p electrons in Ar and 4 d-electrons in Pd near the inner shells thresholds. We focus on the cross-section outside the inner shell discrete excitation region. The effect proved itself to be noticeable.

  5. Elasticity of Interfacial Rafts of Hard Particles with Soft Shells

    E-print Network

    Sebastian Knoche; Jan Kierfeld

    2015-05-10

    We study an elasticity model for compressed protein monolayers or particle rafts at a liquid interface. Based on the microscopic view of hard-core particles with soft shells, a bead-spring model is formulated and analyzed in terms of continuum elasticity theory. The theory can be applied, for example, to hydrophobin-coated air-water interfaces or, more generally, to liquid interfaces coated with an adsorbed monolayer of interacting hard-core particles. We derive constitutive relations for such particle rafts and describe the buckling of compressed planar liquid interfaces as well as their apparent Poisson ratio. We also use the constitutive relations to obtain shape equations for pendant or buoyant capsules attached to a capillary, and to compute deflated shapes of such capsules. A comparison with capsules obeying the usual Hookean elasticity (without hard cores) reveals that the hard cores trigger capsule wrinkling. Furthermore, it is shown that a shape analysis of deflated capsules with hard-core/soft-shell elasticity gives apparent elastic moduli which can be much higher than the original values if Hookean elasticity is assumed.

  6. Elasticity of interfacial rafts of hard particles with soft shells.

    PubMed

    Knoche, Sebastian; Kierfeld, Jan

    2015-05-19

    We study an elasticity model for compressed protein monolayers or particle rafts at a liquid interface. Based on the microscopic view of hard-core particles with soft shells, a bead-spring model is formulated and analyzed in terms of continuum elasticity theory. The theory can be applied, for example, to hydrophobin-coated air-water interfaces or, more generally, to liquid interfaces coated with an adsorbed monolayer of interacting hard-core particles. We derive constitutive relations for such particle rafts and describe the buckling of compressed planar liquid interfaces as well as their apparent Poisson ratio. We also use the constitutive relations to obtain shape equations for pendant or buoyant capsules attached to a capillary, and to compute deflated shapes of such capsules. A comparison with capsules obeying the usual Hookean elasticity (without hard cores) reveals that the hard cores trigger capsule wrinkling. Furthermore, it is shown that a shape analysis of deflated capsules with hard-core/soft-shell elasticity gives apparent elastic moduli which can be much higher than the original values if Hookean elasticity is assumed. PMID:25901364

  7. DETECTING THE RAPIDLY EXPANDING OUTER SHELL OF THE CRAB NEBULA: WHERE TO LOOK

    SciTech Connect

    Wang Xiang; Ferland, G. J.; Baldwin, J. A.; Loh, E. D.; Richardson, C. T.

    2013-09-10

    We present a range of steady-state photoionization simulations, corresponding to different assumed shell geometries and compositions, of the unseen postulated rapidly expanding outer shell to the Crab Nebula. The properties of the shell are constrained by the mass that must lie within it, and by limits to the intensities of hydrogen recombination lines. In all cases the photoionization models predict very strong emissions from high ionization lines that will not be emitted by the Crab's filaments, alleviating problems with detecting these lines in the presence of light scattered from brighter parts of the Crab. The near-NIR [Ne VI] {lambda}7.652 {mu}m line is a particularly good case; it should be dramatically brighter than the optical lines commonly used in searches. The C IV {lambda}1549 doublet is predicted to be the strongest absorption line from the shell, which is in agreement with Hubble Space Telescope observations. We show that the cooling timescale for the outer shell is much longer than the age of the Crab, due to the low density. This means that the temperature of the shell will actually ''remember'' its initial conditions. However, the recombination time is much shorter than the age of the Crab, so the predicted level of ionization should approximate the real ionization. In any case, it is clear that IR observations present the best opportunity to detect the outer shell and so guide future models that will constrain early events in the original explosion.

  8. 77 FR 27054 - Notice of Approval of Clean Air Act Outer Continental Shelf Permits Issued to Shell Offshore, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ... AGENCY Notice of Approval of Clean Air Act Outer Continental Shelf Permits Issued to Shell Offshore, Inc... Title V air quality operating permit to Shell Offshore, Inc. (``Shell'') for operation of the Kulluk... final permit decision on the OCS permit for Shell's operation of the Kulluk drilling unit in...

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

    SciTech Connect

    Zhang, Yuchun; Zhou, Liyan; Zhao, Shangqian; Wang, Wenlong; Liang, Wenjie; Wang, Enge

    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 combining 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.

  10. Correlation of HI shells and CO clumps in the outer Milky Way

    E-print Network

    Ehlerova, Sona

    2015-01-01

    HI shells, which may be formed by the activity of young and massive stars, or connected to energy released by interactions of high-velocity clouds with the galactic disk, may be partly responsible both for the destruction of CO clouds and for the creation of others. It is not known which effect prevails. We study the relation between HI shells and CO in the outer parts of the Milky Way, using HI and CO surveys and a catalogue of previously identified HI shells. For each individual location, the distance to the nearest HI shell is calculated and it is specified whether it lies in the interior of an HI shell, in its walls, or outside an HI shell. The method takes into account irregular shapes of HI shells. We find a lack of CO clouds in the interiors of HI shells and their increased occurrence in walls. Properties of clouds differ for different environments: interiors of HI shells, their walls, and unperturbed medium. CO clouds found in the interiors of HI shells are those that survived and were robbed of their...

  11. 77 FR 3771 - Notice of Issuance of Final Outer Continental Shelf Air Permit for Shell Offshore, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... From the Federal Register Online via the Government Printing Office ENVIRONMENTAL PROTECTION AGENCY Notice of Issuance of Final Outer Continental Shelf Air Permit for Shell Offshore, Inc. AGENCY... on November 30, 2011, EPA issued a final Outer Continental Shelf (OCS) air permit for Shell...

  12. Driven self-assembly of hard nanoplates on soft elastic shells

    NASA Astrophysics Data System (ADS)

    Zhang, Yao-Yang; Hua, Yun-Feng; Deng, Zhen-Yu

    2015-11-01

    The driven self-assembly behaviors of hard nanoplates on soft elastic shells are investigated by using molecular dynamics (MD) simulation method, and the driven self-assembly structures of adsorbed hard nanoplates depend on the shape of hard nanoplates and the bending energy of soft elastic shells. Three main structures for adsorbed hard nanoplates, including the ordered aggregation structures of hard nanoplates for elastic shells with a moderate bending energy, the collapsed structures for elastic shells with a low bending energy, and the disordered aggregation structures for hard shells, are observed. The self-assembly process of adsorbed hard nanoplates is driven by the surface tension of the elastic shell, and the shape of driven self-assembly structures is determined on the basis of the minimization of the second moment of mass distribution. Meanwhile, the deformations of elastic shells can be controlled by the number of adsorbed rods as well as the length of adsorbed rods. This investigation can help us understand the complexity of the driven self-assembly of hard nanoplates on elastic shells. Project supported by the National Natural Science Foundation of China (Grant No. 21174131).

  13. Applications of exchange coupled bi-magnetic hard/soft and soft/hard magnetic core/shell nanoparticles

    NASA Astrophysics Data System (ADS)

    López-Ortega, Alberto; Estrader, Marta; Salazar-Alvarez, German; Roca, Alejando G.; Nogués, Josep

    2015-02-01

    The applications of exchange coupled bi-magnetic hard/soft and soft/hard ferromagnetic core/shell nanoparticles are reviewed. After a brief description of the main synthesis approaches and the core/shell structural-morphological characterization, the basic static and dynamic magnetic properties are presented. Five different types of prospective applications, based on diverse patents and research articles, are described: permanent magnets, recording media, microwave absorption, biomedical applications and other applications. Both the advantages of the core/shell morphology and some of the remaining challenges are discussed.

  14. Ultrastructural characteristics of ostrich eggshell: outer shell membrane and the calcified layers.

    PubMed

    Richards, P D; Richards, P A; Lee, M E

    2000-06-01

    The ultrastructure of the eggshell of the domestic hen has been well researched and structural studies of other avian species, such as the ostrich, often base their interpretation of egg shell structure on that of the chicken. In the ostrich, lowered hatchability and hatching trauma may be due to shell ultrastructural abnormalities. In the present study the ultrastructure of the calcified portion, and the outer shell membrane (OSM), of domesticated ostrich eggshells was investigated using standard electron microscopic techniques. Transmission and scanning electron microscopy studies demonstrated intimate contact between cup-shaped structures present on the OSM and the mammillary layer of the calcified portion of the shell. The initial calcium carbonate growth of the calcified shell was of a dendritic nature with nucleation sites on the surface of the cup's contents. The dendritic growth gave way to a more randomly-orientated, smaller crystallite growth structure, which changed in form as it neared the vertical crystal layer (VCL). The VCL is described as being both amorphous and 'crumbly' depending on the plane of fracture. These observations suggest that firstly, initial calcification is contained within the cups and is then directed outwards to form the shell and that secondly, the VCL may contain an evolutionary, calcified cuticular layer. These observations serve as a baseline for studies investigating the effect of shell structure and strength on hatchling trauma and the influence of maternal diet. PMID:11030359

  15. Strong exchange coupling in conventional and inverse ferrimagnetic hard/soft and soft/hard core/shell heterostructured nanoparticles

    NASA Astrophysics Data System (ADS)

    Nogues, Josep

    2013-03-01

    Bi-magnetic core/shell nanoparticles are becoming increasingly appealing for diverse fields such as for permanent magnets, microawave absortion, biomedical applications, sensing applications, or future magnetic recording media. Ferrromagnetic (FM)/ antiferromagnetic (AFM) core/shell nanoparticles (or inverted AFM/FM) have been extensively studied. However, exchange coupled hard/soft, or inverse soft/hard, core/shell nanoparticles have been far less investigated. Interestingly, most bi-magnetic core/shell systems are derived by simple partial oxidation of the core, e.g., Co/CoO (FM/AFM) or FePt/Fe3O4 (hard/soft) and only few studies of heterostructured (where core and shell are formed by different magnetic ions) can be found in the literature. We have investigated conventional hard/soft and inverted soft/hard core/shell hetroestructured nanoparticles based on magnetically soft iron oxide (Fe3O4) and magnetically hard manganese oxide (Mn3O4) . The core/shell samples were synthesized by seeded growth using either Fe3O4 or Mn3O4 nanoparticles as seeds. Subsequently, thin layers of the complementary material were grown by thermal decomposition of the corresponding metallorganic precursors. The structure characterization (X-ray diffraction and electron diffraction) confirms the presence of cubic (Fe3O4) and tetragonal (Mn3O4) phases both at the bulk and local levels. In addition, high resolution transmission electron microscopy (HR-TEM) with electron energy loss spectroscopy (EELS) mapping confirms the core/shell structure of the nanopartciles. Magnetic characterization and element-selective hysteresis loops obtained by x-ray magnetic circular dichroism (XMCD) reveal a strong exchange coupling between the core and the shell which results in homogeneous loops with moderate coercivity. Moreover, the magnetic properties can be tuned by controlling the core diameter or shell thickness. However, the results depend only weakly on the hard/soft or inverse soft/hard morphology. In collaboration with A. Lopez-Ortega, M. Estrader, G. Salazar-Alvarez, S. Estrade, F. Peiro, I.V. Golossvsky, M. Vasilakaki, K.N. Trohidou, R.K. Dumas, D.J. Keavney, M. Laver, K. Krycka, J. Borchers, M. Varela, S. Suriñach, M.D. Baro, J. Sort

  16. 77 FR 27054 - Notice of Approval of Clean Air Act Outer Continental Shelf Permits Issued to Shell Offshore, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ...Notice of Approval of Clean Air Act Outer Continental Shelf Permits Issued to Shell Offshore...decision granting a Clean Air Act Outer Continental Shelf (OCS) permit to construct and...The Inupiat Community of the Arctic Slope; (2) Resisting Environmental...

  17. 77 FR 7148 - Notice of Approval of Clean Air Act Outer Continental Shelf Permits Issued to Shell Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-10

    ...Notice of Approval of Clean Air Act Outer Continental Shelf Permits Issued to Shell Gulf of...decisions granting Clean Air Act Outer Continental Shelf (OCS) permit applications, one...The Inupiat Community of the Arctic Slope (ICAS); \\1\\ (2) The Native...

  18. ANNUAL BAND DEPOSITION WITHIN SHELLS OF THE HARD CLAM,

    E-print Network

    lines deposited in shells ofbivalve molluscs, for example, finds powerful application in the fields deposition in bivalve molluscs may vary with environment on several scales: 1) over a broad geographic scale

  19. Mutation of outer-shell residues modulates metal ion co-ordination strength in a metalloenzyme.

    PubMed

    Foo, Jee-Loon; Jackson, Colin J; Carr, Paul D; Kim, Hye-Kyung; Schenk, Gerhard; Gahan, Lawrence R; Ollis, David L

    2010-07-15

    The metal ion co-ordination sites of many metalloproteins have been characterized by a variety of spectroscopic techniques and small-molecule model systems, revealing many important insights into the structural determinants of metal ion co-ordination. However, our understanding of this fundamentally and practically important phenomenon remains frustratingly simplistic; in many proteins it is essentially impossible to predict metal ion specificity and the effects of remote 'outer-shell' residues on metal ion co-ordination strength are also poorly defined. This is exemplified by our inability to explain why metalloenzymes with identical metal ion co-ordination spheres, such as the closely related orthologues of bacterial PTE (phosphotriesterase) from Agrobacterium radiobacter and Pseudomonas diminuta, display different metal ion specificity and co-ordination strength. In the present study, we present a series of PTE variants that all possess identical metal ion co-ordination spheres, yet display large differences in their metal ion co-ordination strength. Using measurement of the rates of metal ion dissociation from the active site alongside analysis of structural data obtained through X-ray crystallography, we show that 'outer-shell' residues provide essential support for the metal ion ligands, in effect buttressing them in their optimal orientation. Remote mutations appear to modulate metal ion interactions by increasing or decreasing the stabilizing effects of these networks. The present study therefore provides a description of how the greater protein fold can be modified to 'tune' the strength of metal ion co-ordination and metal ion specificity, as well as reinforcing the concept of proteins as ensembles of conformational states with unique structures and biochemical properties. PMID:20459397

  20. The original kinematic plate tectonic model proposed that the outer shell (lithosphere) of the Earth is divided into a small

    E-print Network

    Sandwell, David T.

    The original kinematic plate tectonic model proposed that the outer shell (lithosphere driver of plate tectonics and mantle convection, but much of the energy dissipation may be in this part rele- vant to plate tectonics. Here we have compiled a series of global maps that help to confirm

  1. Triple assembly of ZnO, large-scale hollow spherical shells with flower-like species consisting of rods grown on the outer surfaces of shells

    SciTech Connect

    Shang Yazhuo; Hu Jun; Liu Honglai; Hu Ying

    2010-03-15

    Novel large-scale hollow ZnO spherical shells were synthesized by ionic liquids assisted hydrothermal oxidization of pure zinc powder without any catalyst at a relatively low temperature of 160 deg. C. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM) patterns show that the shells are composed of ZnO and the structure of the shells is very unique. Textured flower-like ZnO consisting of ZnO rods is grown on the outer surfaces of shells forming a triple assembly. Room-temperature photoluminescence spectra of the oxidized material show a sharp peak at 379 nm and a wider broad peak centered at 498 nm. The possible growth mechanism of the triple assembly of ZnO is discussed in detail. - Graphical abstract: A proposed growth mechanism of large scale hollow ZnO. Bubbles provide the aggregation center for ionic liquids that leads to the formation of hollow Zn particle-dotted shells, buoyancy promotes shells to go upward, the breach occurs when shells are subjected to overpressure.

  2. Outer Electrospun Polycaprolactone Shell Induces Massive Foreign Body Reaction and Impairs Axonal Regeneration through 3D Multichannel Chitosan Nerve Guides

    PubMed Central

    Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit

    2014-01-01

    We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10?mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts. PMID:24818158

  3. Equatorial symmetry of Boussinesq convective solutions in a rotating spherical shell allowing rotation of the inner and outer spheres

    SciTech Connect

    Kimura, Keiji; Takehiro, Shin-ichi; Yamada, Michio

    2014-08-15

    We investigate properties of convective solutions of the Boussinesq thermal convection in a moderately rotating spherical shell allowing the respective rotation of the inner and outer spheres due to the viscous torque of the fluid. The ratio of the inner and outer radii of the spheres, the Prandtl number, and the Taylor number are fixed to 0.4, 1, and 500{sup 2}, respectively. The Rayleigh number is varied from 2.6 × 10{sup 4} to 3.4 × 10{sup 4}. In this parameter range, the behaviours of obtained asymptotic convective solutions are almost similar to those in the system whose inner and outer spheres are restricted to rotate with the same constant angular velocity, although the difference is found in the transition process to chaotic solutions. The convective solution changes from an equatorially symmetric quasi-periodic one to an equatorially symmetric chaotic one, and further to an equatorially asymmetric chaotic one, as the Rayleigh number is increased. This is in contrast to the transition in the system whose inner and outer spheres are assumed to rotate with the same constant angular velocity, where the convective solution changes from an equatorially symmetric quasi-periodic one, to an equatorially asymmetric quasi-periodic one, and to equatorially asymmetric chaotic one. The inner sphere rotates in the retrograde direction on average in the parameter range; however, it sometimes undergoes the prograde rotation when the convective solution becomes chaotic.

  4. Percolative properties of hard oblate ellipsoids of revolution with a soft shell

    NASA Astrophysics Data System (ADS)

    Ambrosetti, Gianluca; Johner, Niklaus; Grimaldi, Claudio; Danani, Andrea; Ryser, Peter

    2008-12-01

    We present an in-depth analysis of the geometrical percolation behavior in the continuum of random assemblies of hard oblate ellipsoids of revolution. Simulations were carried out by considering a broad range of aspect ratios, from spheres up to aspect-ratio-100 platelike objects, and with various limiting two-particle interaction distances, from 0.05 times the major axis up to 4.0 times the major axis. We confirm the widely reported trend of a consistent lowering of the hard particle critical volume fraction with increase of the aspect ratio. Moreover, by assimilating the limiting interaction distance to a shell of constant thickness surrounding the ellipsoids, we propose a simple relation based on the total excluded volume of these objects which allows us to estimate the critical concentration from a quantity that is quasi-invariant over a large spectrum of limiting interaction distances. Excluded volume and volume quantities are derived explicitly.

  5. Collision safety of a hard-shell low-mass vehicle.

    PubMed

    Kaeser, R; Walz, F H; Brunner, A

    1994-06-01

    Low-mass vehicles and in particular low-mass electric vehicles as produced today in very small quantities are in general not designed for crashworthiness in collisions. Particular problems of compact low-mass cars are: reduced length of the car front, low mass compared to other vehicles, and heavy batteries in the case of an electric car. With the intention of studying design improvements, three frontal crash tests were run last year: the first one with a commercial, lightweight electric car; the second with a reinforced version of the same car; and the last one with a car based on a different structural design with a "hard-shell" car body. Crash tests showed that the latter solution made better use of the small zone available for continuous energy absorption. The paper discusses further the problem of frontal collisions between vehicles of different weight and, in particular, the side collision. A side-collision test was run with the hard-shell vehicle following the ECE lateral-impact test procedure at 50 km/h and led to results for the EuroSID1-dummy well below current injury tolerance criteria. PMID:8011053

  6. Semi-wild chimpanzees open hard-shelled fruits differently across communities.

    PubMed

    Rawlings, Bruce; Davila-Ross, Marina; Boysen, Sarah T

    2014-07-01

    Researchers investigating the evolutionary roots of human culture have turned to comparing behaviours across nonhuman primate communities, with tool-based foraging in particular receiving much attention. This study examined whether natural extractive foraging behaviours other than tool selection differed across nonhuman primate colonies that had the same foods available. Specifically, the behaviours applied to open the hard-shelled fruits of Strychnos spp. were examined in three socially separate, semi-wild colonies of chimpanzees (Pan troglodytes) that lived under shared ecological conditions at Chimfunshi Wildlife Orphanage, and were comparable in their genetic makeup. The chimpanzees (N=56) consistently applied six techniques to open these fruits. GLMM results revealed differences in the number of combined technique types to open fruits across the colonies. They also showed colony differences in the application of three specific techniques. Two techniques (full biting and fruit cracking) were entirely absent in some colonies. This study provides empirical evidence that natural hard-shelled fruit-opening behaviours are distinct across chimpanzee colonies, differences that most likely have not resulted from ecological and genetic reasons. PMID:24337784

  7. Some Investigations on Hardness of Investment Casting Process After Advancements in Shell Moulding for Reduction in Cycle Time

    NASA Astrophysics Data System (ADS)

    Singh, R.; Mahajan, V.

    2014-07-01

    In the present work surface hardness investigations have been made on acrylonitrile butadiene styrene (ABS) pattern based investment castings after advancements in shell moulding for replication of biomedical implants. For the present study, a hip joint, made of ABS material, was fabricated as a master pattern by fused deposition modelling (FDM). After preparation of master pattern, mold was prepared by deposition of primary (1°), secondary (2°) and tertiary (3°) coatings with the addition of nylon fibre (1-2 cm in length of 1.5D). This study outlines the surface hardness mechanism for cast component prepared from ABS master pattern after advancement in shell moulding. The results of study highlight that during shell production, fibre modified shells have a much reduced drain time. Further the results are supported by cooling rate and micro structure analysis of casting.

  8. Environmental salinity modulates the effects of elevated CO2 levels on juvenile hard-shell clams, Mercenaria mercenaria.

    PubMed

    Dickinson, Gary H; Matoo, Omera B; Tourek, Robert T; Sokolova, Inna M; Beniash, Elia

    2013-07-15

    Ocean acidification due to increasing atmospheric CO2 concentrations results in a decrease in seawater pH and shifts in the carbonate chemistry that can negatively affect marine organisms. Marine bivalves such as the hard-shell clam, Mercenaria mercenaria, serve as ecosystem engineers in estuaries and coastal zones of the western Atlantic and, as for many marine calcifiers, are sensitive to the impacts of ocean acidification. In estuaries, the effects of ocean acidification can be exacerbated by low buffering capacity of brackish waters, acidic inputs from freshwaters and land, and/or the negative effects of salinity on the physiology of organisms. We determined the interactive effects of 21 weeks of exposure to different levels of CO2 (~395, 800 and 1500 ?atm corresponding to pH of 8.2, 8.1 and 7.7, respectively) and salinity (32 versus 16) on biomineralization, shell properties and energy metabolism of juvenile hard-shell clams. Low salinity had profound effects on survival, energy metabolism and biomineralization of hard-shell clams and modulated their responses to elevated PCO2. Negative effects of low salinity in juvenile clams were mostly due to the strongly elevated basal energy demand, indicating energy deficiency, that led to reduced growth, elevated mortality and impaired shell maintenance (evidenced by the extensive damage to the periostracum). The effects of elevated PCO2 on physiology and biomineralization of hard-shell clams were more complex. Elevated PCO2 (~800-1500 ?atm) had no significant effects on standard metabolic rates (indicative of the basal energy demand), but affected growth and shell mechanical properties in juvenile clams. Moderate hypercapnia (~800 ?atm PCO2) increased shell and tissue growth and reduced mortality of juvenile clams in high salinity exposures; however, these effects were abolished under the low salinity conditions or at high PCO2 (~1500 ?atm). Mechanical properties of the shell (measured as microhardness and fracture toughness of the shells) were negatively affected by elevated CO2 alone or in combination with low salinity, which may have important implications for protection against predators or environmental stressors. Our data indicate that environmental salinity can strongly modulate responses to ocean acidification in hard-shell clams and thus should be taken into account when predicting the effects of ocean acidification on estuarine bivalves. PMID:23531824

  9. Flexural models of trench/outer rise topography of coronae on Venus with axisymmetric spherical shell elastic plates

    NASA Technical Reports Server (NTRS)

    Moore, W.; Schubert, Gerald; Sandwell, David T.

    1992-01-01

    Magellan altimetry has revealed that many coronae on Venus have trenches or moats around their peripheries and rises outboard of the trenches. This trench/outer rise topographic signature is generally associated with the tectonic annulus of the corona. Sandwell and Schubert have interpreted the trench/outer rise topography and the associated tectonic annulus around coronae to be the result of elastic bending of the Venus lithosphere (though the tectonic structures are consequences of inelastic deformation of the lithosphere). They used two-dimensional elastic plate flexure theory to fit topographic profiles across a number of large coronae and inferred elastic lithosphere thicknesses between about 15 and 40 km, similar to inferred values of elastic thickness for the Earth's lithosphere at subduction zones around the Pacific Ocean. Here, we report the results of using axisymmetric elastic flexure theory for the deformation of thin spherical shell plates to interpret the trench/outer rise topography of the large coronae modeled by Sandwell and Schubert and of coronae as small as 250 km in diameter. In the case of a corona only a few hundred kilometers in diameter, the model accounts for the small planform radius of the moat and the nonradial orientation of altimetric traces across the corona. By fitting the flexural topography of coronae we determine the elastic thickness and loading necessary to account for the observed flexure. We calculate the associated bending moment and determine whether the corona interior topographic load can provide the required moment. We also calculate surface stresses and compare the stress distribution with the location of annular tectonic features.

  10. Excitation and ionization of outer shells in Rb by electron impact

    NASA Astrophysics Data System (ADS)

    Roman, V.; Kupliauskien?, A.; Borovik, A.

    2015-10-01

    The relativistic distorted-wave and binary-encounter-dipole approximations were employed for calculating the electron-impact single ionization cross sections of the 5s, 4p6, 4s2, 3d10 shells and 4p6 excitation cross section for Rb atom taking into account both configuration interaction and relativistic effects. The capabilities of the most used theoretical approaches in describing the single ionization of Rb atom were considered by comparing the present and other available calculated data with the experimental total ionization and total direct single ionization cross sections over the electron-impact energy range from the 5s threshold to 600 eV. The best agreement within experimental uncertainty was obtained by using the non-relativistic binary-encounter-dipole approximation included in the LANL Atomic Physics Codes package. At present none of the used approximations (plane-wave Born or relativistic distorted wave) can satisfactorily describe the experimental excitation-autoionization cross section in rubidium because the efficient formation of the 4p6 core-excited negative-ion rubidium states at near-threshold impact energies is ignored in calculations.

  11. A DETAILED KINEMATIC MAP OF CASSIOPEIA A'S OPTICAL MAIN SHELL AND OUTER HIGH-VELOCITY EJECTA

    SciTech Connect

    Milisavljevic, Dan; Fesen, Robert A.

    2013-08-01

    We present three-dimensional (3D) kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm that the bulk of Cas A's optically bright ejecta populate a torus-like geometry tilted approximately 30 Degree-Sign with respect to the plane of the sky with a -4000 to +6000 km s{sup -1} radial velocity asymmetry. Near-tangent viewing angle effects and an inhomogeneous surrounding circumstellar material/interstellar medium environment suggest that this geometry and velocity asymmetry may not be faithfully representative of the remnant's true 3D structure or the kinematic properties of the original explosion. The majority of the optical ejecta are arranged in several well-defined and nearly circular ring-like structures with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). These ejecta rings appear to be a common phenomenon of young core-collapse remnants and may be associated with post-explosion input of energy from plumes of radioactive {sup 56}Ni-rich ejecta that rise, expand, and compress non-radioactive material. Our optical survey encompasses Cas A's faint outlying ejecta knots and exceptionally high-velocity NE and SW streams of S-rich debris often referred to as ''jets''. These outer knots, which exhibit a chemical make-up suggestive of an origin deep within the progenitor star, appear to be arranged in opposing and wide-angle outflows with opening half-angles of Almost-Equal-To 40 Degree-Sign.

  12. A Detailed Kinematic Map of Cassiopeia A's Optical Main Shell and Outer High-velocity Ejecta

    NASA Astrophysics Data System (ADS)

    Milisavljevic, Dan; Fesen, Robert A.

    2013-08-01

    We present three-dimensional (3D) kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm that the bulk of Cas A's optically bright ejecta populate a torus-like geometry tilted approximately 30° with respect to the plane of the sky with a -4000 to +6000 km s-1 radial velocity asymmetry. Near-tangent viewing angle effects and an inhomogeneous surrounding circumstellar material/interstellar medium environment suggest that this geometry and velocity asymmetry may not be faithfully representative of the remnant's true 3D structure or the kinematic properties of the original explosion. The majority of the optical ejecta are arranged in several well-defined and nearly circular ring-like structures with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). These ejecta rings appear to be a common phenomenon of young core-collapse remnants and may be associated with post-explosion input of energy from plumes of radioactive 56Ni-rich ejecta that rise, expand, and compress non-radioactive material. Our optical survey encompasses Cas A's faint outlying ejecta knots and exceptionally high-velocity NE and SW streams of S-rich debris often referred to as "jets." These outer knots, which exhibit a chemical make-up suggestive of an origin deep within the progenitor star, appear to be arranged in opposing and wide-angle outflows with opening half-angles of ?40°.

  13. Vibration of a single microcapsule with a hard plastic shell in an acoustic standing wave field.

    PubMed

    Koyama, Daisuke; Kotera, Hironori; Kitazawa, Natsuko; Yoshida, Kenji; Nakamura, Kentaro; Watanabe, Yoshiaki

    2011-04-01

    Observation techniques for measuring the small vibration of a single microcapsule of tens of nanometers in an acoustic standing wave field are discussed. First, simultaneous optical observation of a microbubble vibration by two methods is investigated, using a high-speed video camera, which permits two-dimensional observation of the bubble vibration, and a laser Doppler vibrometer (LDV), which can observe small bubble vibration amplitudes at high frequency. Bubbles of tens of micrometers size were trapped at the antinode of an acoustic standing wave generated in an observational cell. Bubble vibration at 27 kHz could be observed and the experimental results for the two methods showed good agreement. The radial vibration of microcapsules with a hard plastic shell was observed using the LDV and the measurement of the capsule vibration with radial oscillation amplitude of tens of nanometers was successful. The acoustic radiation force acting on microcapsules in the acoustic standing wave was measured from the trapped position of the standing wave and the radial oscillation amplitude of the capsules was estimated from the theoretical equation of the acoustic radiation force, giving results in good agreement with the LDV measurements. The radial oscillation amplitude of a capsule was found to be proportional to the amplitude of the driving sound pressure. A larger expansion ratio was observed for capsules closer to the resonance condition under the same driving sound pressure and frequency. PMID:21507751

  14. Images of Soft-bodied Animals with External Hard Shell: 3D Visualization of the Embedded Soft Tissue

    SciTech Connect

    Rao, Donepudi V.; Akatsuka, Takao; Tromba, Giuliana

    2004-05-12

    Images of soft-bodied animals (snails) of various types with external hard shell are obtained for 25, 27 and 29 keV synchrotron X-rays. The SYRMEP facility at Elettra,Trieste, Italy and the associated detection system has been used for the image acquisition. The interior properties of the embedded soft tissue are analysed utilizing the software. From the reconstructed images, the soft tissue distribution, void spaces associated with the soft tissue and external hard shell are identified. 3D images are reconstructed at these energies and optimum energy is chosen based on the quality of the image for further analysis. The optimum energy allowed us to visualize the visibility of low absorbing details and interior microstructure of the embedded soft tissue.

  15. Migration of Salmonella Enteritidis PT 30 through almond hulls and shells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of Salmonella to migrate from an external aqueous environment through the almond hull and shell, and to colonize the kernel, was evaluated in two ways. First, the outer surface of shell halves from five varieties of almonds that differed in shell hardness were placed in contact with a s...

  16. Influence of capsule shell composition on the performance indicators of hypromellose capsule in comparison to hard gelatin capsules.

    PubMed

    Al-Tabakha, Moawia M; Arida, Adi Issam; Fahelelbom, Khairi M S; Sadek, Bassem; Saeed, Dima Ahmed; Abu Jarad, Rami A; Jawadi, Jeevani

    2015-01-01

    The purpose of this study was to assess the in vitro performances of "vegetable" capsules in comparison to hard gelatin capsules in terms of shell weight variation, reaction to different humidity conditions, resistance to stress in the absence of moisture, powder leakage, disintegration and dissolution. Two types of capsules made of HPMC produced with (Capsule 2) or without (Capsule 3) a gelling agent and hard gelatin capsules (Capsule 1) were assessed. Shell weight variability was relatively low for all tested capsules shells. Although Capsule 1 had the highest moisture content under different humidity conditions, all capsule types were unable to protect the encapsulated hygroscopic polyvinylpyrrolidone (PVP) powder from surrounding humidity. The initial disintegration for all Capsule 1 occurred within 3?min, but for other types of capsules within 6?min (n?=?18). Dissolution of acetaminophen was better when the deionized water (DIW) temperature increased from 32 to 42?°C in case of Capsule 1, but the effect of temperature was not significant for the other types of capsules. Acetaminphen dissolution from Capsule 1 was the fastest (i.e. >90% in 10?min) and independent of the media pH or contents unlike Capsule 2 which was influenced by the pH and dissolution medium contents. It is feasible to use hypromellose capsules shells with or without gelling agent for new lines of pharmaceutical products, however, there is a window for capsule shells manufacturing companies to improve the dissolution of their hypromellose capsules to match the conventional gelatin capsule shells and eventually replace them. PMID:25586554

  17. The influence of pellet shape and film coating on the filling of pellets into hard shell capsules.

    PubMed

    Chopra, Ranjana; Podczeck, Fridrun; Newton, J Michael; Alderborn, Göran

    2002-05-01

    Pellets of different shape, varying from spherical to cylindrical, were filled into hard shell capsules. When no film coat was applied, the pellets had not to be perfectly spherical in order to be filled reproducibly. An aspect ratio of 1.2 or less appeared to be the threshold value. However, pronounced surface roughness hindered the filling process, and hence it appears necessary to monitor this parameter. After coating of the pellets with an ethylcellulose film, none of the batches could be filled to an acceptable standard, because electrostatic loading led to a blockage of the filling mechanism. However, the addition of 1% talcum powder was sufficient to remove all charges, and again filling became a function of the pellet shape, confirming the threshold aspect ratio value of 1.2. PMID:11976021

  18. Stratigraphy and paleoenvironments of the Shell 410-1 well, Georges Bank Basin, US North Atlantic outer continental shelf

    USGS Publications Warehouse

    Poppe, L.J.; Poag, C.W.; Swift, B.A.

    1995-01-01

    The Shell 410-1 well is the most downdip (seaward) hydrocarbon exploratory well in the Georges Bank Basin. It was drilled to a total depth of 4745 m RKB, and penetrated a section composed of Middle Jurassic to Quaternary sedimentary rocks. The lithostratigraphy of the section is described. The strata penetrated by the Shell 410-1 well are more marine than rocks at the updip (landward) COST G-1, Exxon 975-1, COST G-2, and Conoco 145-1 well sites. Limestones and calcareous mudstones dominate at the Shell 410-1 site. Dolomite and anhydrite are much more abundant in the Bajocian-Callovian strata of the Shell 410-1 well, which is evidence that the carbonate-bank palaeoenvironments recorded in the Iroquois and Abenaki Formations were more restricted (less marine) here than 47 km to the west-northwest at the Mobil 312-1 well site near the edge of the Jurassic carbonate platform. -from Authors

  19. AxBAx-type block-graft polymers with soft methacrylate middle segments and hard styrene outer grafts: synthesis, morphology, and mechanical properties.

    PubMed

    Miura, Yu; Kaneko, Takeshi; Satoh, Kotaro; Kamigaito, Masami; Jinnai, Hiroshi; Okamoto, Yoshio

    2007-05-01

    Novel copolymers with controlled architectures can function as new building blocks for well-defined nanostructures on the basis of microphase separation, unlike conventional ABA triblock copolymers. A series of well-defined A(x)BA(x)-type block-graft copolymers consisting of soft middle segments (dodecyl methacrylate (DMA)) and hard outer graft chains (styrene (St)) were synthesized by ruthenium-catalyzed living radical block and graft polymerization. NMR spectroscopy and size-exclusion chromatography combined with multiangle laser light scattering confirmed the well-defined structure of the A(x)BA(x) block-graft copolymers with backbones and graft chains of controlled lengths. Transmission electron microscopy and transmission electron microtomography revealed a series of morphologies for the copolymers. Morphological changes were observed from PSt "honeycomb" cylinders to lamellae and poly(DMA) cylinders with increasing PSt-graft content, whereby the phase diagram was shifted significantly to lower volume fractions of the larger-number component (St) relative to those of the corresponding ABA triblock copolymers. More specifically, poly(DMA) cylinders were observed even before the St content reached 50 wt %. The A(x)BA(x) and ABA copolymers with 17-30 wt % of St exhibited characteristics of a thermoplastic elastomer with tensile strengths of 1-6 MPa and elongations at break of 70-300 %. These mechanical properties can be related well to the microphase structures of the A(x)BA(x) and ABA copolymers. PMID:17455174

  20. 7 CFR 51.2289 - Shell.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Shelled English Walnuts (Juglans Regia) Definitions § 51.2289 Shell. Shell means the outer shell and/or the woody partition from...

  1. 7 CFR 51.2289 - Shell.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Shelled English Walnuts (Juglans Regia) Definitions § 51.2289 Shell. Shell means the outer shell and/or the woody partition from...

  2. 7 CFR 51.2289 - Shell.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Shelled English Walnuts (Juglans Regia) Definitions § 51.2289 Shell. Shell means the outer shell and/or the woody partition from...

  3. 7 CFR 51.2289 - Shell.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Shelled English Walnuts (Juglans Regia) Definitions § 51.2289 Shell. Shell means the outer shell and/or the woody...

  4. 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.

  5. Discrimination of the hard keratins animal horn and chelonian shell using attenuated total reflection-infrared spectroscopy.

    PubMed

    Biscardi, Brianna; Welsh, Wendy; Kennedy, Anthony

    2012-05-01

    The ability to discriminate between objects manufactured from animal horn and chelonian (turtle, tortoise, or terrapin) shell is important from a cultural and archeological perspective such that it may allow conservators to determine the appropriate treatment and long-term care solution. It would also aid curators in identifying and cataloging items manufactured from these materials. Discrimination and classification is also a valuable tool for those involved in tracking the illegal trade in restricted materials of this nature. Attenuated total reflection infrared (ATR-IR) spectroscopy, using a single reflection diamond internal reflection element (IRE), coupled with discrimination analysis was used to analyze a total of thirty-nine samples (29 calibration samples, 10 validation samples). A discrimination analysis model was constructed using Mahalanobis distances to classify spectra into one of two classes. The model was then subsequently used to successfully classify all validation samples and correctly identify them as animal horn or chelonian shell based on second-derivative spectra of the amide I and II regions. This technique requires minimal to no sample preparation and may be used to nondestructively identify very small samples successfully without performing detailed secondary structural curve-fitting routines. This model should be a valuable resource to museums, conservators, and wildlife management programs for rapidly and reliably discriminating between animal horn and chelonian shell. PMID:22524968

  6. Ocean acidification alters the material properties of Mytilus edulis shells.

    PubMed

    Fitzer, Susan C; Zhu, Wenzhong; Tanner, K Elizabeth; Phoenix, Vernon R; Kamenos, Nicholas A; Cusack, Maggie

    2015-02-01

    Ocean acidification (OA) and the resultant changing carbonate saturation states is threatening the formation of calcium carbonate shells and exoskeletons of marine organisms. The production of biominerals in such organisms relies on the availability of carbonate and the ability of the organism to biomineralize in changing environments. To understand how biomineralizers will respond to OA the common blue mussel, Mytilus edulis, was cultured at projected levels of pCO2 (380, 550, 750, 1000 µatm) and increased temperatures (ambient, ambient plus 2°C). Nanoindentation (a single mussel shell) and microhardness testing were used to assess the material properties of the shells. Young's modulus (E), hardness (H) and toughness (KIC) were measured in mussel shells grown in multiple stressor conditions. OA caused mussels to produce shell calcite that is stiffer (higher modulus of elasticity) and harder than shells grown in control conditions. The outer shell (calcite) is more brittle in OA conditions while the inner shell (aragonite) is softer and less stiff in shells grown under OA conditions. Combining increasing ocean pCO2 and temperatures as projected for future global ocean appears to reduce the impact of increasing pCO2 on the material properties of the mussel shell. OA may cause changes in shell material properties that could prove problematic under predation scenarios for the mussels; however, this may be partially mitigated by increasing temperature. PMID:25540244

  7. Hard sphere packings within cylinders

    E-print Network

    Lin Fu; William Steinhardt; Hao Zhao; Joshua E. S. Socolar; Patrick Charbonneau

    2015-11-26

    The packing of hard spheres (HS) of diameter $\\sigma$ in a cylinder has been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest packings of HS under this type of confinement, however, grows increasingly complex with the cylinder diameter, $D$. Little is thus known about the densest achievable packings for $D>2.873\\sigma$. In this work, we extend the identification of the packings up to $D=4.00\\sigma$ by adapting Torquato-Jiao's adaptive-shrinking-cell formulation and sequential-linear-programming (SLP) technique. We identify 17 new structures, almost all of them chiral. Beyond $D\\approx2.85\\sigma$, most of the structures consist of an outer shell and an inner core that compete for being close packed. In some cases, the shell adopts its own maximum density configuration, and the stacking of core spheres within it is quasiperiodic. In other cases, an interplay between the two components is observed, which may result in simple periodic structures. In yet other cases, the very distinction between core and shell vanishes, resulting in more exotic packing geometries, including some that are three-dimensional extensions of structures obtained from packing hard disks in a circle.

  8. Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles

    PubMed Central

    Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

    2015-01-01

    Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials. PMID:26522701

  9. Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles.

    PubMed

    Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

    2015-01-01

    Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials. PMID:26522701

  10. Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles

    NASA Astrophysics Data System (ADS)

    Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

    2015-11-01

    Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials.

  11. Micromechanical properties and structural characterization of modern inarticulated brachiopod shells

    NASA Astrophysics Data System (ADS)

    Merkel, C.; Griesshaber, E.; Kelm, K.; Neuser, R.; Jordan, G.; Logan, A.; Mader, W.; Schmahl, W. W.

    2007-06-01

    We investigated micromechanical properties and ultrastructure of the shells of the modern brachiopod species Lingula anatina, Discinisca laevis, and Discradisca stella with scanning electron microscopy (SEM, EDX), transmission electron microscopy (TEM) and Vickers microhardness indentation analyses. The shells are composed of two distinct layers, an outer primary layer and an inner secondary layer. Except for the primary layer in Lingula anatina, which is composed entirely of organic matter, all other shell layers are laminated organic/inorganic composites. The organic matter is built of chitin fibers, which provide the matrix for the incorporation of calcium phosphate. Amorphous calcium phosphate in the outer, primary layer and crystalline apatite is deposited into the inner, secondary layer of the shell. Apatite crystallite sizes in the umbonal region of the shell are about 50 × 50 nm, while within the valves crystallite sizes are significantly smaller, averanging 10 × 25 nm. There is great variation in hardness values between shell layers and between the investigated brachiopod species. The microhardness of the investigated shells is significantly lower than that of inorganic hydroxyapatite. This is caused by the predominantly organic material component that in these shells is either developed as purely organic layers or as an organic fibrous matrix reinforced by crystallites. Our results show that this particular fiber composite material is very efficient for the protection and the support of the soft animal tissue. It lowers the probability of crack formation and effectively impedes crack propagation perpendicular to the shell by crack-deviation mechanisms. The high degree of mechanical stability and toughness is achieved by two design features. First, there is the fiber composite material which overcomes some detrimental and enhances some advantageous properties of the single constituents, that is the softness and flexibility of chitin and the hardness and brittleness of apatite. Second, there is a hierarchical structuring from the nanometer to a micrometer level. We could identify at least seven levels of hierarchy within the shells.

  12. Thermally activated coercivity in core-shell permanent magnets

    NASA Astrophysics Data System (ADS)

    Bance, S.; Fischbacher, J.; Schrefl, T.

    2015-05-01

    Finite element micromagnetic simulations are used to compute the temperature-dependent hysteresis properties of Nd2Fe14B permanent magnets in order to assess the influence of a hard (Dy,Nd)2Fe14B shell. The simulations show that the 4 nm thick shell cancels out the reduction in coercivity from an outer defect layer, which is known to exist at the grain boundaries in NdFeB permanent magnets. Activation volumes are computed and shown to depend on the structure's configuration as well as the temperature.

  13. Lipid Extract from Hard-Shelled Mussel (Mytilus coruscus) Improves Clinical Conditions of Patients with Rheumatoid Arthritis: A Randomized Controlled Trial

    PubMed Central

    Fu, Yuanqing; Li, Guipu; Zhang, Xinhua; Xing, Gengyan; Hu, Xiaojie; Yang, Lifeng; Li, Duo

    2015-01-01

    Studies have suggested a lipid extract from hard-shelled mussel (Mytilus coruscus) (HMLE) possessed strong anti-inflammatory activity in arthritis model of rats. This study investigated whether HMLE could improve clinical conditions of rheumatoid arthritis patients. Fifty rheumatoid arthritis patients (28–75 years) were randomly assigned to receive HMLE capsules or receive placebo capsules for 6 months. Forty-two subjects and 50 subjects were included in per-protocol and intention-to-treat analysis, respectively. Significant differences in changes on disease activity score (DAS28) and clinical disease activity index (CDAI) after 6-month intervention (p < 0.01) were observed in both analyses with more evident efficacy shown in per-protocol population (?DAS28 = 0.47; ?CDAI = 4.17), which favored the benefits of the HMLE group. TNF-? (tumor necrosis factor ?), interleukin (IL)-1? and PGE2 (prostaglandin E2) but not IL-6, were significantly decreased in both groups, and the decrements were much larger in the HMLE group for TNF-? and PGE2 after 6 months from baseline (p < 0.05). IL-10 was significantly increased in both groups and the change was much more evident in the HMLE group (p < 0.05). In conclusion, HMLE exhibited benefits for the clinical conditions of rheumatoid patients in relation to improvement in the balance between pro- and anti-inflammatory factors, which indicated its potential to serve as adjunctive treatment for rheumatoid arthritis. (ClinicalTrials.gov NCT02173587). PMID:25602164

  14. Material with core-shell structure

    DOEpatents

    Luhrs, Claudia (Rio Rancho, NM); Richard, Monique N. (Ann Arbor, MI); Dehne, Aaron (Maumee, OH); Phillips, Jonathan (Rio Rancho, NM); Stamm, Kimber L. (Ann Arbor, MI); Fanson, Paul T. (Brighton, MI)

    2011-11-15

    Disclosed is a material having a composite particle, the composite particle including an outer shell and a core. The core is made from a lithium alloying material and the outer shell has an inner volume that is greater in size than the core of the lithium alloying material. In some instances, the outer mean diameter of the outer shell is less than 500 nanometers and the core occupies between 5 and 99% of the inner volume. In addition, the outer shell can have an average wall thickness of less than 100 nanometers.

  15. Outer-shell photodetachment of the metastable Be{sup -} 1s{sup 2}2s2p{sup 2} {sup 4}P{sup e} state

    SciTech Connect

    Sanz-Vicario, Jose Luis; Lindroth, Eva

    2003-07-01

    We report calculated photodetachment cross sections from the metastable Be{sup -} 1s{sup 2}2s2p{sup 2} {sup 4}P{sup e} state in the photon energy range 0-10 eV. Outer-shell photodetachment takes place in this energy range, which includes the double-ionization threshold Be{sup +}({sup 2}S{sup e}) at {approx}7 eV as well as doubly excited thresholds of the residual atom up to the Be(1s{sup 2}2p4f) threshold at {approx}10 eV. Therefore, triply excited states of Be{sup -} are reached within the selected photon energy. We have implemented the complex scaled configuration interaction method along with a model potential for the 1s{sup 2} core to uncover the first series of Be{sup -} {sup 4}L{sup o} resonant states. In this work, four {sup 4}P{sup o}, seven {sup 4}D{sup o}, and two {sup 4}S{sup o} resonances are reported and we compare our cross section with other previous theoretical calculations, that reported none or, at most, two resonances.

  16. The ultrastructure of shelled and unshelled cashew nuts.

    PubMed

    Muniz, Celli R; Freire, Francisco C O; Soares, Arlete Aparecida; Cooke, Peter H; Guedes, Maria I F

    2013-01-01

    Cashew nuts have many attributes, including sensory, nutritional and health appeal, which contribute to their worldwide acceptance. We demonstrate details of the microstructure of shelled and unshelled cashew kernels with regard to pericarp and cotyledon organization. This study also provides evidence of the colonization of these kernels by filamentous fungi. Nuts were examined by scanning electron and confocal scanning laser microscopy. Staining with acridine orange was performed. A tight lignified palisade layer adjacent to the exocarp surface explains the hardness of the shell's pericarp. The mesocarp contains large secretory cavities that confer a spongy property to this tissue. Papillose cells, which are responsible for secreting CNSL (cashew nutshell liquid), were observed to cover the inner wall of these cavities. Lipid components are readily released from the parenchyma and appear as oil droplets. The outer surface of the shelled samples exhibited a dense Aspergillus infestation. PMID:24045033

  17. 46 CFR 154.170 - Outer hull steel plating.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Outer hull steel plating. 154.170 Section 154.170... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of...

  18. 46 CFR 154.170 - Outer hull steel plating.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Outer hull steel plating. 154.170 Section 154.170... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of...

  19. 46 CFR 154.170 - Outer hull steel plating.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Outer hull steel plating. 154.170 Section 154.170... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of...

  20. 46 CFR 154.170 - Outer hull steel plating.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Outer hull steel plating. 154.170 Section 154.170... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of...

  1. 46 CFR 154.170 - Outer hull steel plating.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Outer hull steel plating. 154.170 Section 154.170... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of...

  2. Thick-shell nanocrystal quantum dots

    DOEpatents

    Hollingsworth, Jennifer A. (Los Alamos, NM); Chen, Yongfen (Eugene, OR); Klimov, Victor I. (Los Alamos, NM); Htoon, Han (Los Alamos, NM); Vela, Javier (Los Alamos, NM)

    2011-05-03

    Colloidal nanocrystal quantum dots comprising an inner core having an average diameter of at least 1.5 nm and an outer shell, where said outer shell comprises multiple monolayers, wherein at least 30% of the quantum dots have an on-time fraction of 0.80 or greater under continuous excitation conditions for a period of time of at least 10 minutes.

  3. Removable inner turbine shell with bucket tip clearance control

    DOEpatents

    Sexton, Brendan F. (Clifton Park, NY); Knuijt, Hans M. (Niskayuna, NY); Eldrid, Sacheverel Q. (Saratoga Springs, NY); Myers, Albert (Amsterdam, NY); Coneybeer, Kyle E. (Schenectady, NY); Johnson, David Martin (Ballston Lake, NY); Kellock, Iain R. (Clifton Park, NY)

    2000-01-01

    A turbine includes a plurality of inner shell sections mounting first and second stage nozzle and shroud portions. The inner shell sections are pinned to an outer containment shell formed of sections to preclude circumferential movement of the inner shell relative to the outer shell and enable thermal expansion and contraction of the inner shell relative to the outer shell. Positive bucket tip clearance control is afforded by passing a thermal medium about the inner shell in heat transfer relation with the shrouds about the first and second stage bucket tips, the thermal medium being provided from a source of heating/cooling fluid independent of the turbine. Access is provided to the rotor and turbine buckets by removing the outer and inner shell sections.

  4. Optimum rotationally symmetric shells for flywheel rotors

    DOEpatents

    Blake, Henry W. (Oak Ridge, TN)

    2000-01-01

    A flywheel rim support formed from two shell halves. Each of the shell halves has a disc connected to the central shaft. A first shell element connects to the disc at an interface. A second shell element connects to the first shell element. The second shell element has a plurality of meridional slits. A cylindrical shell element connects to the second shell element. The cylindrical shell element connects to the inner surface of the flywheel rim. A flywheel rim support having a disc connected an outer diameter of a shaft. Two optimally shaped shell elements connect to the optimally shaped disc at an interface. The interface defines a discontinuity in a meridional slope of said support. A cylindrical shell element connects to the two shell elements. The cylindrical shell element has an outer surface for connecting to the inner surface of the flywheel rim. A flywheel rim casing includes an annular shell connected to the central shaft. The annular shell connects to the flywheel rim. A composite shell surrounds the shaft, annular shell and flywheel rim.

  5. Bio-relevant dissolution testing of hard capsules prepared from different shell materials using the dynamic open flow through test apparatus.

    PubMed

    Garbacz, Grzegorz; Cadé, Dominique; Benameur, Hassan; Weitschies, Werner

    2014-06-16

    Current compendial dissolution and disintegrating testing is unable to mimic physiological conditions affecting gastric drug release from immediate release dosage forms. In order to obtain more realistic data, a novel test setup was developed that we term a 'dynamic open flow through test apparatus'. It is based on the previously described dissolution stress test device and attempts to simulate the intra-gastric dissolution conditions pertinent to immediate release dosage forms administered under fasting conditions with respect to flow rates, intra-gastric temperature profiles and gastric motility. The concept of the dynamic open flow through test apparatus has been tested using five different types of hard capsules: conventional hard gelatin capsules (HGC), three hypromellose based capsules (Vcaps, Vcaps Plus and DRcaps) and pullulan based capsules (Plantcaps). These were of different sizes but all contained 100mg caffeine in each formulation, adjusted to avoid buoyancy by addition of excipient. When the capsules were stressed in the apparatus under the dynamic flow conditions applying mild pressure simulating gastric motility, release from release from Vcaps Plus, Vcaps and Plantcaps capsules was very well comparable to HGC. Capsules are usually swallowed with cold water and the temperature dependency of release from gelatin was noted as a significant factor, since heat exchange in the stomach is slow. PMID:24021609

  6. Shell and coil heat exchanger

    SciTech Connect

    Dempsey, J.C.

    1993-07-20

    A heat exchanger is described comprising: a shell having: a tubular outer wall having a first and second end, a tubular inner wall having a first and second end coaxial with the outer wall, and first and second end plates attached to the first and second ends of the outer and inner walls to form an enclosed tubular shell cavity there between having a first and second end; means for admitting a first fluid into the shell cavity; means for removing the first fluid from the shell cavity; a spiral coil of tubing having a first and second end sealingly exiting through the shell cavity wall for carrying a second fluid there between, the spiral coil lying within the shell cavity and having a plurality of spiral windings formed about the axis thereof, the spiral coil sized to fit between the inner and outer shell wall with limited radial clearance to allow limited axial flow of the first fluid, the winding axially spaced from one another to define a spiral flow path there between for the first fluid, the radial clearance and axial spacing relatively sized to induce the first fluid to travel in a substantially spiral motion to enhance the heat transfer between the first and second fluids; an auxiliary coil of tubing having a first and second end sealing extending through the shell cavity for carrying a third fluid there between, the auxiliary coil lying within the shell cavity and having a plurality of windings formed about the axis thereof and axially spaced apart from the spiral coil, for transferring heat between the first and third fluids; and a divider plate dividing the shell cavity into two coaxial cylindrical regions, a primary region in which lies the spiral coil and an auxiliary region in which lies the auxiliary coil, and means to admit and means to remove a fourth fluid from the auxiliary region.

  7. Method to produce large, uniform hollow spherical shells

    DOEpatents

    Hendricks, Charles D. (Livermore, CA)

    1985-01-01

    Large, uniform hollow spherical shells are produced by forming uniform size drops of heat decomposable or vaporizable material, evaporating the drops to form dried particles, coating the dried particles with a layer of shell forming material, and heating the composite particles to melt the outer layer and decompose or vaporize the inner particle to form an expanding inner gas bubble which expands the outer layer. By cycling the temperature and pressure on the hollow shells, spherical shells with uniform walls are produced.

  8. G359.97-0.038: A Hard X-Ray Filament Associated with a Supernova Shell-Molecular Cloud Interaction

    NASA Astrophysics Data System (ADS)

    Nynka, Melania; Hailey, Charles J.; Zhang, Shuo; Morris, Mark M.; Zhao, Jun-Hui; Goss, Miller; Bauer, Franz E.; Boggs, Stephen E.; Craig, William W.; Christensen, Finn E.; Gotthelf, Eric V.; Harrison, Fiona A.; Mori, Kaya; Perez, Kerstin M.; Stern, Daniel; Zhang, William W.

    2015-02-01

    We present the first high-energy X-ray (>10 keV) observations of the non-thermal filament G359.97-0.038 using the Nuclear Spectroscopic Telescope Array (NuSTAR). This filament is one of approximately 20 X-ray filaments of unknown origin located in the central 20 pc region in the Galactic Center near Sgr A*. Its NuSTAR and Chandra broadband spectrum is characterized by a single power law with ? = 1.3 ± 0.3 that extends from 2 to 50 keV, with an unabsorbed luminosity of 1.3 × 1033 erg s-1 (d/8 kpc)2 in the 2-8 keV band. Despite possessing a cometary X-ray morphology that is typical of a pulsar wind nebula (PWN) in high-resolution Chandra imaging, our spatially resolved Chandra spectral analysis found no significant spectral softening along the filament as would be expected from particle synchrotron cooling. Coincident radio emission is detected using the Very Large Array at 5.5 and 8.3 GHz. We examine and subsequently discard a PWN or magnetic flux tube as the origin of G359.97-0.038. We use broadband spectral characteristics and a morphological analysis to show that G359.97-0.038 is likely an interaction site between the shell of Sgr A East and an adjacent molecular cloud. This is supported by CS molecular line spectroscopy and the presence of an OH maser.

  9. 75 FR 54369 - BOEMRE Information Collection Activity: 1010-NEW, Upcoming Projects Considering the Use of Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-07

    ...Considering the Use of Outer Continental Shelf Sand, Gravel, and Shell Resources for Coastal...respondents will submit to BOEMRE to obtain OCS sand, gravel, and shell resources for use...information and procedures for obtaining sand, gravel, and shell resources can be...

  10. 76 FR 3152 - Agency Information Collection Activity: 1010-NEW, Upcoming Projects Considering the Use of Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ...Use of Outer Continental Shelf (OCS) Sand, Gravel, and Shell Resources for Coastal...respondents will submit to BOEMRE to obtain OCS sand, gravel, and shell resources for use...Information and procedures for obtaining sand, gravel, and shell resources can be...

  11. Sound Transmission through Two Concentric Cylindrical Sandwich Shells

    NASA Technical Reports Server (NTRS)

    Tang, Yvette Y.; Silcox, Richard J.; Robinson, Jay H.

    1996-01-01

    This paper solves the problem of sound transmission through a system of two infinite concentric cylindrical sandwich shells. The shells are surrounded by external and internal fluid media and there is fluid (air) in the annular space between them. An oblique plane sound wave is incident upon the surface of the outer shell. A uniform flow is moving with a constant velocity in the external fluid medium. Classical thin shell theory is applied to the inner shell and first-order shear deformation theory is applied to the outer shell. A closed form for transmission loss is derived based on modal analysis. Investigations have been made for the impedance of both shells and the transmission loss through the shells from the exterior into the interior. Results are compared for double sandwich shells and single sandwich shells. This study shows that: (1) the impedance of the inner shell is much smaller than that of the outer shell so that the transmission loss is almost the same in both the annular space and the interior cavity of the shells; (2) the two concentric sandwich shells can produce an appreciable increase of transmission loss over single sandwich shells especially in the high frequency range; and (3) design guidelines may be derived with respect to the noise reduction requirement and the pressure in the annular space at a mid-frequency range.

  12. Validity of Thin Shell Models

    NASA Astrophysics Data System (ADS)

    Gao, Sijie

    The purpose of this paper is to test the validity of the thin shell formalism. Firstly, we construct a dust thick shell collapsing to a Schwarzschild black hole. From this exact solution, we show that the two sides of the shell satisfy different equations of motion. Moreover, we show that the inner side and the outer side always cross each other right after the formation of the thin shell, causing a breakdown of the model. Secondly, we establish a class of wormholes with non-zero thickness and extremal Reissner-Nordström exterior. In the thin shell limit, we find that the surface stress-energy tensor contains the contribution of electromagnetic field, which contradicts the assumption in previous literature.

  13. The Outer Limits: English.

    ERIC Educational Resources Information Center

    Tyler, Barbara R.; Biesekerski, Joan

    The Quinmester course "The Outer Limits" involves an exploration of unknown worlds, mental and physical, through fiction and nonfiction. Its purpose is to focus attention on the ongoing conquest of the frontiers of the mind, the physical world, and outer space. The subject matter includes identification and investigation of unknown worlds in the…

  14. Method of fabricating nested shells and resulting product

    DOEpatents

    Henderson, Timothy M. (Ann Arbor, MI); Kool, Lawrence B. (Ann Arbor, MI)

    1982-01-01

    A multiple shell structure and a method of manufacturing such structure wherein a hollow glass microsphere is surface treated in an organosilane solution so as to render the shell outer surface hydrophobic. The surface treated glass shell is then suspended in the oil phase of an oil-aqueous phase dispersion. The oil phase includes an organic film-forming monomer, a polymerization initiator and a blowing agent. A polymeric film forms at each phase boundary of the dispersion and is then expanded in a blowing operation so as to form an outer homogeneously integral monocellular substantially spherical thermoplastic shell encapsulating an inner glass shell of lesser diameter.

  15. Active control of radiated noise from a cylindrical shell using external piezoelectric panels

    E-print Network

    Song, Kyungyeol, 1972-

    2002-01-01

    Control architectures and methodologies are developed for the reduction of radiated noise from a thick-walled cylindrical shell using external piezoelectric panels. The proposed approach is to cover the shell's outer surface ...

  16. Outer planet satellites

    SciTech Connect

    Schenk, P.M. )

    1991-01-01

    Recent findings on the outer-planet satellites are presented, with special consideration given to data on the rheologic properties of ice on icy satellites, the satellite surfaces and exogenic processes, cratering on dead cratered satellites, volcanism, and the interiors of outer-planet satellites. Particular attention is given to the state of Titan's surface and the properties of Triton, Pluto, and Charon. 210 refs.

  17. Turbine blade with spar and shell

    DOEpatents

    Davies, Daniel O. (Palm City, FL); Peterson, Ross H. (Loxahatchee, FL)

    2012-04-24

    A turbine blade with a spar and shell construction in which the spar and the shell are both secured within two platform halves. The spar and the shell each include outward extending ledges on the bottom ends that fit within grooves formed on the inner sides of the platform halves to secure the spar and the shell against radial movement when the two platform halves are joined. The shell is also secured to the spar by hooks extending from the shell that slide into grooves formed on the outer surface of the spar. The hooks form a serpentine flow cooling passage between the shell and the spar. The spar includes cooling holes on the lower end in the leading edge region to discharge cooling air supplied through the platform root and into the leading edge cooling channel.

  18. Saturn's outer magnetosphere

    NASA Technical Reports Server (NTRS)

    Schardt, A. W.; Behannon, K. W.; Carbary, J. F.; Eviatar, A.; Lepping, R. P.; Siscoe, G. L.

    1983-01-01

    Similarities between the Saturnian and terrestrial outer magnetosphere are examined. Saturn, like Earth, has a fully developed magnetic tail, 80 to 100 RS in diameter. One major difference between the two outer magnetospheres is the hydrogen and nitrogen torus produced by Titan. This plasma is, in general, convected in the corotation direction at nearly the rigid corotation speed. Energies of magnetospheric particles extend to above 500 keV. In contrast, interplanetary protons and ions above 2 MeV have free access to the outer magnetosphere to distances well below the Stormer cutoff. This access presumably occurs through the magnetotail. In addition to the H+, H2+, and H3+ ions primarily of local origin, energetic He, C, N, and O ions are found with solar composition. Their flux can be substantially enhanced over that of interplanetary ions at energies of 0.2 to 0.4 MeV/nuc.

  19. Ionic bonding of lanthanides, as influenced by d- and f-atomic orbitals, by core-shells and by relativity.

    PubMed

    Ji, Wen-Xin; Xu, Wei; Schwarz, W H Eugen; Wang, Shu-Guang

    2015-03-15

    Lanthanide trihalide molecules LnX3 (X = F, Cl, Br, I) were quantum chemically investigated, in particular detail for Ln = Lu (lutetium). We applied density functional theory (DFT) at the nonrelativistic and scalar and SO-coupled relativistic levels, and also the ab initio coupled cluster approach. The chemically active electron shells of the lanthanide atoms comprise the 5d and 6s (and 6p) valence atomic orbitals (AO) and also the filled inner 4f semivalence and outer 5p semicore shells. Four different frozen-core approximations for Lu were compared: the (1s(2) -4d(10) ) [Pd] medium core, the [Pd+5s(2) 5p(6) = Xe] and [Pd+4f(14) ] large cores, and the [Pd+4f(14) +5s(2) 5p(6) ] very large core. The errors of Lu?X bonding are more serious on freezing the 5p(6) shell than the 4f(14) shell, more serious upon core-freezing than on the effective-core-potential approximation. The Ln?X distances correlate linearly with the AO radii of the ionic outer shells, Ln(3+) -5p(6) and X(-) -np(6) , characteristic for dominantly ionic Ln(3+) -X(-) binding. The heavier halogen atoms also bind covalently with the Ln-5d shell. Scalar relativistic effects contract and destabilize the Lu?X bonds, spin orbit coupling hardly affects the geometries but the bond energies, owing to SO effects in the free atoms. The relativistic changes of bond energy BE, bond length Re , bond force k, and bond stretching frequency vs do not follow the simple rules of Badger and Gordy (Re ?BE?k?vs ). The so-called degeneracy-driven covalence, meaning strong mixing of accidentally near-degenerate, nearly nonoverlapping AOs without BE contribution is critically discussed. PMID:25565146

  20. 75 FR 3915 - Environmental Documents Prepared in Support of Sand and Gravel Activities on the Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ...Environmental Documents Prepared in Support of Sand and Gravel Activities on the Outer Continental...prepared and/or adopted by the MMS for three sand and gravel activities proposed on the Outer...noncompetitive basis, the rights to OCS sand, gravel, or shell resources for...

  1. Influence of the commensal gastropod Crepidula plana on shell choice by the marine hermit crab Pagurus longicarpus, with an assessment of the

    E-print Network

    the slipper snail Crepidula convexa is often found living on the outer surface of empty periwinkle shells choice Hermit crabs are notoriously choosy about the gastropod shells they live in. Many periwinkle shell inside the periwinkle shell. This study examined how the presence of C. plana affected shell

  2. Outer Solar System Exploration

    E-print Network

    Rathbun, Julie A.

    are similar to Uranus and Neptune #12;Oh the Places we'll Go · The outer solar system is target-rich. We'd like to learn more about volcanoes on Io, storms on Titan, the rings around Uranus and whether Ariel ocean and how to access it in the future ­ Uranus orbiter, to study an ice giant in our own solar system

  3. Snail Shell

    USGS Multimedia Gallery

    Plant seems to be a Heliotropum sp. Huge snail shells litter the wetland around Asuncion Bay. Near 25°15’49’’S, 57°37’47’’W. La plantita detrás del caracol parece ser un Heliotropium sp., Boraginaceae....

  4. Photoionization of the outer electrons in noble gas endohedral atoms

    SciTech Connect

    Amusia, M. Ya. Baltenkov, A. S.; Chernysheva, L. V.

    2008-08-15

    We suggest a prominent modification of the outer shell photoionization cross section in noble gas (NG) endohedral atoms NG-C{sub n} under the action of the electron shell of fullerene C{sub n}. This shell leads to two important effects: a strong enhancement of the cross section due to fullerene shell polarization under the action of the incoming electromagnetic wave and to prominent oscillation of this cross section due to the reflection of a photoelectron from the NG by the fullerene shell. Both factors lead to powerful maxima in the outer shell ionization cross sections of NG-C{sub n}, which we call giant endohedral resonances. The oscillator strength reaches a very large value in the atomic scale, 25. We consider atoms of all noble gases except He. The polarization of the fullerene shell is expressed in terms of the total photoabsorption cross section of the fullerene. The photoelectron reflection is taken into account in the framework of the so-called bubble potential, which is a spherical {delta}-type potential. It is assumed in the derivations that the NG is centrally located in the fullerene. It is also assumed, in accordance with the existing experimental data, that the fullerene radius R{sub C} is much larger than the atomic radius r{sub A} and the thickness {delta}{sub C} of the fullerene shell. As was demonstrated recently, these assumptions allow us to represent the NG-C{sub n} photoionization cross section as a product of the NG cross section and two well-defined calculated factors.

  5. The ultimate step towards a tailored engineering of core@shell and core@shell@shell nanoparticles.

    PubMed

    Llamosa, D; Ruano, M; Martínez, L; Mayoral, A; Roman, E; García-Hernández, M; Huttel, Y

    2014-11-21

    Complex core@shell and core@shell@shell nanoparticles are systems that combine the functionalities of the inner core and outer shell materials together with new physico-chemical properties originated by their low (nano) dimensionality. Such nanoparticles are of prime importance in the fast growing field of nanotechnology as building blocks for more sophisticated systems and a plethora of applications. Here, it is shown that although conceptually simple a modified gas aggregation approach allows the one-step generation of well-controlled complex nanoparticles. In particular, it is demonstrated that the atoms of the core and the shell of the nanoparticles can be easily inverted, avoiding intrinsic constraints of chemical methods. PMID:25180699

  6. Outer Solar System Nomenclature

    NASA Technical Reports Server (NTRS)

    Owen, Tobias C.

    1998-01-01

    The Principal Investigator's responsibilities on this grant fell into two categories according to his participation. In the nomenclature work of the International Astronomical Union (IAU). Owen is chair of the Task Group for the Outer Solar System. He is also a member of the IAU's Working Group on Planetary and Satellite Nomenclature (WGPSN) which is composed of the chairs of the several Task Groups plus the presidents of two IAU Commissions and several outside consultants. The WGPSN is presided over by its President, Professor Kaare Aksnes from the Rosseland Institute for Theoretical Astrophysics in Oslo, Norway.

  7. Probabilistic Dynamic Buckling of Smart Composite Shells

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Abumeri, Galib H.

    2007-01-01

    A computational simulation method is presented to evaluate the deterministic and nondeterministic dynamic buckling of smart composite shells. The combined use of intraply hybrid composite mechanics, finite element computer codes, and probabilistic analysis enable the effective assessment of the dynamic buckling load of smart composite shells. A universal plot is generated to estimate the dynamic buckling load of composite shells at various load rates and probabilities. The shell structure is also evaluated with smart fibers embedded in the plies right next to the outer plies. The results show that, on the average, the use of smart fibers improved the shell buckling resistance by about 10% at different probabilities and delayed the buckling occurrence time. The probabilistic sensitivities results indicate that uncertainties in the fiber volume ratio and ply thickness have major effects on the buckling load while uncertainties in the electric field strength and smart material volume fraction have moderate effects. For the specific shell considered in this evaluation, the use of smart composite material is not recommended because the shell buckling resistance can be improved by simply re-arranging the orientation of the outer plies, as shown in the dynamic buckling analysis results presented in this report.

  8. Probabilistic Dynamic Buckling of Smart Composite Shells

    NASA Technical Reports Server (NTRS)

    Abumeri, Galib H.; Chamis, Christos C.

    2003-01-01

    A computational simulation method is presented to evaluate the deterministic and nondeterministic dynamic buckling of smart composite shells. The combined use of composite mechanics, finite element computer codes, and probabilistic analysis enable the effective assessment of the dynamic buckling load of smart composite shells. A universal plot is generated to estimate the dynamic buckling load of composite shells at various load rates and probabilities. The shell structure is also evaluated with smart fibers embedded in the plies right below the outer plies. The results show that, on the average, the use of smart fibers improved the shell buckling resistance by about 10 percent at different probabilities and delayed the buckling occurrence time. The probabilistic sensitivities results indicate that uncertainties in the fiber volume ratio and ply thickness have major effects on the buckling load while uncertainties in the electric field strength and smart material volume fraction have moderate effects. For the specific shell considered in this evaluation, the use of smart composite material is not recommended because the shell buckling resistance can be improved by simply re-arranging the orientation of the outer plies, as shown in the dynamic buckling analysis results presented in this report.

  9. Shell-in-Shell TiO2 hollow microspheres and optimized application in light-trapping perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Sun, Hongxia; Ruan, Peng; Bao, Zhongqiu; Chen, Lei; Zhou, Xingfu

    2015-02-01

    The shell-in-shell structured TiO2 hollow microspheres with enhanced light scattering ability were synthesized via a facile one step hydrothermal process. The diameter of the microsphere is about 1.5 ?m, the core of the unique shell-in-shell structure is composed of TiO2 nanoparticles with a diameter of about 15 nm, while the shell is constructed with ?50 nm TiO2 nanocubes. The hollow space between the outer shell and the inner shell is about 230 nm. The formation mechanism of the unique shell-in-shell structure is interpreted. The design and the optimized application of shell-in-shell structured TiO2 hollow microspheres in the light-trapping perovskite solar cells are also investigated. Owing to the light scattering properties of the shell-in-shell structure of the hollow microsphere, the optimized photoelectrode exhibits an enhanced photoelectric conversion efficiency of 4.29% using perovskite CH3NH3PbI3 as the sensitizer. The shell-in-shell hollow TiO2 microsphere shows a 21.2% increase in conversion efficiency when compared with P25 nanoparticels photoanode. The conversion efficiency enhancement is mainly attributed to the increase of short-current density induced by the light scattering effect.

  10. Energetic particle drift motions in the outer dayside magnetosphere

    SciTech Connect

    Buck, R.M.

    1987-12-01

    Models of the geomagnetic field predict that within a distance of approximately one earth radius inside the dayside magnetopause, magnetic fields produced by the Chapman-Ferraro magnetopause currents create high-latitude minimum-B ''pockets'' in the geomagnetic field. Drift-shell branching caused by the minimum-B pockets is analyzed and interpreted in terms of an adiabatic shell branching and rejoining process. We examine the shell-branching process for a static field in detail, using the Choe-Beard 1974 magnetospheric magnetic field model. We find that shell branching annd rejoining conserves the particle mirror field B/sub M/, the fieldline integral invariant I, and the directional electron flux j. We determine the spatial extent of the stable trapping regions for the Choe-Beard model. We develop an adiabatic branching map methodology which completely identifies and describes the location of shell-branching points and the adiabatic trajectories of particles on branched shells, for any model field. We employ the map to develop synthetic pitch angle distributions near the dayside magnetopause by adiabatically transforming observed midnight distributions to the dayside. We find that outer dayside lines contain particles moving on branched and unbranched shells, giving rise to distinctive pitch angle distribution features. We find a good correlation between the pitch angles which mark the transition from branched to unbranched shells in the model, and the distinctive features of the OGO-5 distributions. In the morning sector, we observe large flux changes at critical pitch angles which correspond to B-pocket edges in the model. Measurements on inbound passes in the afternoon sector show first the adiabatic particle shadow, then the arrival of fluxes on rejoined shells, then fluxes on unbranced shells - in accord with model predictions. 204 refs., 138 figs., 2 tabs.

  11. 77 FR 802 - Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... by the Gulf of Mexico Outer Continental Shelf (OCS) Region AGENCY: Bureau of Ocean Energy Management... Continental Shelf. Shell Offshore Inc., Located in the Central 9/30/2011 Exploration Plan, SEA R-5275. Gulf...

  12. Saturn's outer satellite - Phoebe

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Voyager 2 took these images of Saturn's outer satellite Phoebe, on Sept. 4, 1981, from 2.2 million kilometers (1.36 million miles)away. This pair shows two different hemispheres of the satellite. The left image shows a bright mountain on the upper right edge reflecting the light of the setting sun. This mountain is possibly the central peak of a large impact crater taking up most of the upper right quadrant of Phoebe in this view. The right images shows a hemisphere with an intrinsically bright spot in the top portion of the image as well as the ridges appearing bright in the sunset light of the lower right. These images were processed by the Multimission Image Processing Laboratory of the Jet Propulsion Laboratory. The Jet Propulsion Laboratory manages the Voyager Project for NASA's Office of Space Science and Applications.

  13. 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

  14. Strategy for outer planets exploration

    NASA Technical Reports Server (NTRS)

    1975-01-01

    NASA's Planetary Programs Office formed a number of scientific working groups to study in depth the potential scientific return from the various candidate missions to the outer solar system. The results of these working group studies were brought together in a series of symposia to evaluate the potential outer planet missions and to discuss strategies for exploration of the outer solar system that were consistent with fiscal constraints and with anticipated spacecraft and launch vehicle capabilities. A logical, scientifically sound, and cost effective approach to exploration of the outer solar system is presented.

  15. Vibration of Shells

    NASA Technical Reports Server (NTRS)

    Leissa, A. W.

    1973-01-01

    The vibrational characteristics and mechanical properties of shell structures are discussed. The subjects presented are: (1) fundamental equations of thin shell theory, (2) characteristics of thin circular cylindrical shells, (3) complicating effects in circular cylindrical shells, (4) noncircular cylindrical shell properties, (5) characteristics of spherical shells, and (6) solution of three-dimensional equations of motion for cylinders.

  16. Building Atoms Shell by Shell.

    ERIC Educational Resources Information Center

    Sussman, Beverly

    1993-01-01

    Describes an atom-building activity where students construct three-dimensional models of atoms using a styrofoam ball as the nucleus and pom-poms, gum drops, minimarshmallows, or other small items of two different colors to represent protons and neutrons attached. Rings of various sizes with pom-poms attached represent electron shells and…

  17. Method to produce large, uniform hollow spherical shells

    DOEpatents

    Hendricks, C.D.

    1983-09-26

    The invention is a method to produce large uniform hollow spherical shells by (1) forming uniform size drops of heat decomposable or vaporizable material, (2) evaporating the drops to form dried particles, (3) coating the dried particles with a layer of shell forming material and (4) heating the composite particles to melt the outer layer and to decompose or vaporize the inner particle to form an expanding inner gas bubble. The expanding gas bubble forms the molten outer layer into a shell of relatively large diameter. By cycling the temperature and pressure on the molten shell, nonuniformities in wall thickness can be reduced. The method of the invention is utilized to produce large uniform spherical shells, in the millimeter to centimeter diameter size range, from a variety of materials and of high quality, including sphericity, concentricity and surface smoothness, for use as laser fusion or other inertial confinement fusion targets as well as other applications.

  18. The outer solar system

    NASA Astrophysics Data System (ADS)

    Morrison, D.; Cruikshank, D. P.

    The nature and discovery of the objects of the solar system lying beyond the orbit of Saturn are reviewed. The discoveries of Uranus by Herschel in 1781, Neptune by Adams and Leverrier in 1845 and 1846, respectively, and Pluto by Tombaugh in 1930 are related, and the orbital prediction methods used in the last two cases are noted. The physical properties of the gas giant planets Uranus and Neptune, which both have diameters of 50,000 Km and atmospheres composed of hydrogen, helium and methane and differ from Jupiter and Saturn in size and composition, are discussed in detail. The smaller icy bodies of the outer solar system are then examined, including Pluto, its satellite Charon, the Uranian satellites Titania, Oberon, Ariel, Umbirel and Miranda, the Neptunian satellites Triton and Neried and the asteroids 944 Hidalgo and 2060 Chiron. Voyager 1 observations of the system of satellites of Saturn, which icy bodies are similar in size to Charon, Chiron and the Uranian satellites, are then discussed, and dramatic differences between satellites of the same size and mass are pointed out

  19. Shell worlds

    NASA Astrophysics Data System (ADS)

    Roy, Kenneth I.; Kennedy, Robert G., III; Fields, David E.

    2013-02-01

    The traditional concept of terraforming assumes ready availability of candidate planets with acceptable qualities: orbiting a star in its "Goldilocks zone", liquid water, enough mass, years longer than days, magnetic field, etc. But even stipulating affordable interstellar travel, we still might never find a good candidate elsewhere. Whatever we found likely would require centuries of heavy terraforming, just as Mars or Venus would here. Our increasing appreciation of the ubiquity of life suggests that any terra nova would already possess it. We would then face the dilemma of introducing alien life forms (us, our microbes) into another living world. Instead, we propose a novel method to create habitable environments for humanity by enclosing airless, sterile, otherwise useless planets, moons, and even large asteroids within engineered shells, which avoids the conundrum. These shells are subject to two opposing internal stresses: compression due to the primary's gravity, and tension from atmospheric pressure contained inside. By careful design, these two cancel each other resulting in zero net shell stress. Beneath the shell an Earth-like environment could be created similar in almost all respects to that of Home, except for gravity, regardless of the distance to the sun or other star. Englobing a small planet, moon, or even a dwarf planet like Ceres, would require astronomical amounts of material (quadrillions of tons) and energy, plus a great deal of time. It would be a quantum leap in difficulty over building Dyson Dots or industrializing our solar system, perhaps comparable to a mission across interstellar space with a living crew within their lifetime. But when accomplished, these constructs would be complete (albeit small) worlds, not merely large habitats. They could be stable across historic timescales, possibly geologic. Each would contain a full, self-sustaining ecology, which might evolve in curious directions over time. This has interesting implications for SETI as well.

  20. Waste Package Outer Barrier Stress Due to Thermal Expansion with Various Barrier Gap Sizes

    SciTech Connect

    M. M. Lewis

    2001-11-27

    The objective of this activity is to determine the tangential stresses of the outer shell, due to uneven thermal expansion of the inner and outer shells of the current waste package (WP) designs. Based on the results of the calculation ''Waste Package Barrier Stresses Due to Thermal Expansion'', CAL-EBS-ME-000008 (ref. 10), only tangential stresses are considered for this calculation. The tangential stresses are significantly larger than the radial stresses associated with thermal expansion, and at the WP outer surface the radial stresses are equal to zero. The scope of this activity is limited to determining the tangential stresses the waste package outer shell is subject to due to the interference fit, produced by having two different shell coefficients of thermal expansions. The inner shell has a greater coefficient of thermal expansion than the outer shell, producing a pressure between the two shells. This calculation is associated with Waste Package Project. The calculations are performed for the 21-PWR (pressurized water reactor), 44-BWR (boiling water reactor), 24-BWR, 12-PWR Long, 5 DHLW/DOE SNF - Short (defense high-level waste/Department of Energy spent nuclear fuel), 2-MCO/2-DHLW (multi-canister overpack), and Naval SNF Long WP designs. The information provided by the sketches attached to this calculation is that of the potential design for the types of WPs considered in this calculation. This calculation is performed in accordance with the ''Technical Work Plan for: Waste Package Design Description for SR (Ref.7). The calculation is documented, reviewed, and approved in accordance with AP-3.12Q, Calculations (Ref.1).

  1. Turbine airfoil with outer wall thickness indicators

    DOEpatents

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  2. The 4 K outer cryostat for the CUORE experiment: construction and quality control

    E-print Network

    F. Alessandria; M. Biassoni; G. Ceruti; A. Chiarini; M. Clemenza; O. Cremonesi; V. Datskov; S. Dossena; M. Faverzani; E. Ferri; A. Nucciotti; M. Perego; E. Previtali; M. Sisti; L. Taffarello; F. Terranova

    2013-06-06

    The external shell of the CUORE cryostat is a large cryogen-free system designed to host the dilution refrigerator and the bolometers of the CUORE experiment in a low radioactivity environment. The three vessels that form the outer shell were produced and delivered to the Gran Sasso underground Laboratories in July 2012. In this paper, we describe the production techniques and the validation tests done at the production site in 2012.

  3. Separating in shell pistachio nuts from kernels using impact vibration analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A sorting system has been developed for the separation of small in-shell pistachio nuts from kernels without shells on the basis of vibrations generated when moving samples strike a steel plate. Impacts between the steel plate and the hard shells, as measured using an accelerometer attached to the...

  4. Thermoelectric Outer Planets Spacecraft (TOPS)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The research and advanced development work is reported on a ballistic-mode, outer planet spacecraft using radioisotope thermoelectric generator (RTG) power. The Thermoelectric Outer Planet Spacecraft (TOPS) project was established to provide the advanced systems technology that would allow the realistic estimates of performance, cost, reliability, and scheduling that are required for an actual flight mission. A system design of the complete RTG-powered outer planet spacecraft was made; major technical innovations of certain hardware elements were designed, developed, and tested; and reliability and quality assurance concepts were developed for long-life requirements. At the conclusion of its active phase, the TOPS Project reached its principal objectives: a development and experience base was established for project definition, and for estimating cost, performance, and reliability; an understanding of system and subsystem capabilities for successful outer planets missions was achieved. The system design answered long-life requirements with massive redundancy, controlled by on-board analysis of spacecraft performance data.

  5. Outer pseudoring in the galaxy

    NASA Astrophysics Data System (ADS)

    Mel'Nik, A. M.

    2006-01-01

    The kinematics of the Sagittarius (R = 5.7 kpc),Carina (R = 6.5 kpc), Cygnus (R = 6.8 kpc), and Perseus (R = 8.2 kpc) arms suggests the existence of two spiral patterns in the Galaxy that rotate with different speeds. The inner spiral pattern that is represented by the Sagittarius arm rotates with the speed of the bar, b = 60 ± 5 km s-1 kpc-1, while the outer spiral pattern that includes the Carina, Cygnus, and Perseus arms rotates with a lower speed, s = 12 22 km s-1 kpc-1.The existence of an outer slow tightly wound spiral pattern and an inner fast spiral pattern can be explained by numerically simulating the dynamics of outer pseudorings. The outer Lindblad resonance of the bar must be located between the Sagittarius and Carina arms. The Cygnus arm appears as a connecting link between the fast and slow spiral patterns.

  6. Role of reactant transport in determining the properties of NIF shells made by interfacial polycondensation

    SciTech Connect

    Hamilton, K.E.; Letts, S.A.; Buckley, S.R.; Fearon, E.M.; Wilemski, G.; Cook, R.C.; Schroen-Carey, D.

    1997-03-01

    Polymer shells up to 2 mm in diameter were prepared using an interfacial polycondensation / cross-linking reaction occurring at the surface of an oil drop. The oil phase is comprised of a solution (20 wt% or less) of isophthaloyl dichloride (IPC) dissolved in an organic solvent. An interfacial reaction is initiated when the IPC-loaded oil drop is submerged in an aqueous solution of poly(p-vinylphenol) (PVP), a poly(electrolyte) at elevated pH. Composition, structure, and surface finish for fully-formed dry shells were assessed using a number of techniques including scanning electron microscopy (SEM), atomic force microscopy (AFM), fourier-transform infrared spectroscopy (FTIR), pyrolysis-gas chromatography (GC) mass spectroscopy (MS), microhardness measurements, gas permeability, and solvent permeability measurements. From deposition rate data, a reaction mechanism and key reaction parameters were identified. The deposition rate of shell membrane material was found to be a diffusion limited reaction of IPC through the forming membrane to the exterior shell interface (which is believed to be the reaction front). The final thickness of the film deposited at the interface and the rate of deposition were found to be strong functions of the IPC concentration and oil phase solvent. Films made with diethyl phthalate (DEP) were thinner and harder than films made using 1,6-dichlorohexane (DCH) as a solvent. Differences in solubility of the forming membrane in DCH and DEP appear to be able to account for the differences in deposition rate and the hardness (related to cross-linking density). The deposition can be thought of as a phase separation which is affected by both the poly(electrolyte) / ionomer transition and the amount of cross-linking. Finally, it was found that the choice of oil phase solvent profoundly affects the evolution of the outer surface roughness.

  7. FIRST 100 T NON-DESTRUCTIVE MAGNET OUTER COIL SET

    SciTech Connect

    J. BACON; A. BACA; ET AL

    1999-09-01

    The controlled power outer coil set of the first 100 T non-destructive (100 T ND) magnet is described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND controlled power outer coil set consists of seven nested, mechanically independent externally reinforced coils. These coils, in combination, will produce a 47 T platform field in a 225-mm diameter bore. Using inertial energy storage a synchronous motor/generator provides ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. Each coil consists of a multi-layer winding of high strength conductor supported by an external high strength stainless steel shell. Coils with the highest magnetic loads will utilize a reinforcing shell fabricated from highly cold worked 301 stainless steel strip. The autofrettage conditioning method will be used to pre-stress the coils and thereby limit conductor and reinforcement strains to the elastic range. The purpose of pre-stressing the coils is to attain a design life of 10,000 full field pulses. The operation and conditioning of the coil set will be described along with special features of its design, magnetic and structural analyses and construction.

  8. BOOKSHELF Hard Disk Drive

    E-print Network

    Benmei, Chen

    » BOOKSHELF Hard Disk Drive Servo Systems, 2nd edition by B.M. CHEN, T.H. LEE, K. PENG, and V- widths ever higher as higher frequency disturbances become relevant. THE BOOK Hard Disk Drive Servo I of Hard Disk Drive Servo Systems briefly discusses the history of hard drive control and the disk

  9. Acoustic vibrations in nanosized gold-shell particles

    NASA Astrophysics Data System (ADS)

    Shan, X.; Zhang, X.; Mazurenko, D. A.; van Blaaderen, A.; Dijkhuis, J. I.; Hudert, F.; Dekorsy, T.

    2007-12-01

    We demonstrate and discuss acoustic vibrations in spherical shell particles. The particles consist of 38-nm-thick gold shells, sandwiched between an inner silica core of 456 nm in diameter and an outer silica shell of 10 nm in thickness. Employing standard and asynchronous optical sampling (ASOPS) ultrafast pump-probe experiments, we excite acoustic vibrations of the shells and detect the oscillations via modulations of the optical reflectivity. Two kinds of vibrations were excited and observed. One oscillation with 400 ps period corresponds to the prediction of Lamb theory for breathing modes of free thin gold shells. The other oscillation with 25ps-period corresponds to resonant longitudinal thickness vibrations of the gold shells. At later times, echoes appear corresponding to the travel time through the silica core.

  10. Origin of Outer Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J.; Lindstrom, David (Technical Monitor)

    2005-01-01

    Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; ( 2 ) determining the size distributions or luminosity function of the individual populations or the Kuiper belt as a whole; (3) determining the inclinations distributions of these populations; (4) establishing the radial extent of the Kuiper belt; ( 5 ) measuring and relating the physical properties of different types of KBOs to those of other solar system bodies; and, (6) completing our systematic inventory of the satellites of the outer planets.

  11. Magnetosphere of the outer planets

    NASA Technical Reports Server (NTRS)

    Kennel, C. F.

    1972-01-01

    Scaling laws for possible outer planet magnetospheres are derived. These suggest that convection and its associated auroral effects will play a relatively smaller role than at earth, and that there is a possibility that they could have significant radiation belts of energetic trapped particles.

  12. 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...

  13. Hard thermal effective action in QCD through the thermal operator

    E-print Network

    Ashok Das; J. Frenkel

    2007-06-01

    Through the application of the thermal operator to the zero temperature retarded Green's functions, we derive in a simple way the well known hard thermal effective action in QCD. By relating these functions to forward scattering amplitudes for on-shell particles, this derivation also clarifies the origin of important properties of the hard thermal effective action, such as the manifest Lorentz and gauge invariance of its integrand.

  14. Strategy for exploration of the outer planets: 1986-1996

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Over the past decade COMPLEX has published three strategy reports which, taken together, encompass the entire planetary system and recommend a coherent program of planetary exploration. The highest priority for outer planet exploration during the next decade is intensive study of Saturn (the planet, satellites, rings, and magnetosphere) as a system. The Committee additionally recommends that NASA engage in the following supporting activities: increased support of laboratory and theoretical studies; pursuit of earth-based and earth-orbital observations; commitment to continued operation of productive spacecraft; implementation of the instrument development plan as appropriate for the outer solar system; studies of deep atmospheric probes; development of penetrators or other hard landers; development of radiation-hardened spacecraft; and development of low-thrust propulsion systems. Longer-term objectives include exploration and intensive study of: the Uranus and Neptune systems; planetology of the Galilean satellites and Titan; and the inner Jovian system.

  15. Rockwell Hardness Measurement of

    E-print Network

    Colton, Jonathan S.

    960-5 Rockwell Hardness Measurement of Metallic Materials Samuel R. Low NISTrecommended p r a c t i c e g u i d e Special Publication 960-5 #12;i Rockwell Hardness Measurement of Metallic Materials: (202) 512­2250 Mail: Stop SSOP, Washington, DC 20402-0001 #12;N FOREWORD The Rockwell hardness test

  16. Wear of hard materials by hard particles

    SciTech Connect

    Hawk, Jeffrey A.

    2003-10-01

    Hard materials, such as WC-Co, boron carbide, titanium diboride and composite carbide made up of Mo2C and WC, have been tested in abrasion and erosion conditions. These hard materials showed negligible wear in abrasion against SiC particles and erosion using Al2O3 particles. The WC-Co materials have the highest wear rate of these hard materials and a very different material removal mechanism. Wear mechanisms for these materials were different for each material with the overall wear rate controlled by binder composition and content and material grain size.

  17. Turbine airfoil with a compliant outer wall

    DOEpatents

    Campbell, Christian X. (Oviedo, FL); Morrison, Jay A. (Oviedo, FL)

    2012-04-03

    A turbine airfoil usable in a turbine engine with a cooling system and a compliant dual wall configuration configured to enable thermal expansion between inner and outer layers while eliminating stress formation in the outer layer is disclosed. The compliant dual wall configuration may be formed a dual wall formed from inner and outer layers separated by a support structure. The outer layer may be a compliant layer configured such that the outer layer may thermally expand and thereby reduce the stress within the outer layer. The outer layer may be formed from a nonplanar surface configured to thermally expand. In another embodiment, the outer layer may be planar and include a plurality of slots enabling unrestricted thermal expansion in a direction aligned with the outer layer.

  18. 76 FR 54787 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY... revised North American Datum of 1927 (NAD 27) Outer Continental Shelf Official Protraction Diagram,...

  19. 76 FR 2919 - Outer Continental Shelf Official Protraction Diagram and Supplemental Official Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagram and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY: Bureau of Ocean... American Datum of 1983 (NAD 83) Outer Continental Shelf Official Protraction Diagram and...

  20. 76 FR 54787 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ...of 1927 (NAD 27) Outer Continental Shelf Official Protraction...Supplemental Official Outer Continental Shelf Block Diagrams...following NAD 27-based Outer Continental Shelf (OCS) Official Protraction...the past errors are: (1) Movement of the Submerged Lands...

  1. Endoliths in Lithophaga lithophaga shells--Variation in intensity of infestation and species occurrence.

    PubMed

    Peharda, Melita; Calcinai, Barbara; Puljas, Sanja; Golubi?, Stjepko; Arapov, Jasna; Thébault, Julien

    2015-07-01

    Pronounced differences with respect to the extent of infestation and the degree of Lithophaga lithophaga shell damage inflicted by euendolithic taxa at two sites in the Adriatic Sea representing different productivity conditions, are described. Shells collected from the eastern part of Kaštela Bay, which is characterized by higher primary productivity, have significantly more shell damage then the shell collected from a site on the outer coast of the island of ?iovo exposed to the oligotrophic Adriatic Sea. The presence of endoliths and their perforations were detected in different layers of the shell, including solidly mineralized parts of the skeleton and within the organic lamellae incorporated into the shell. Phototrophic endoliths were not observed in the specimens. The most serious damage to L. lithophaga shells was the boring clionaid sponge Pione vastifica, which was more common in shells collected from Kaštela. PMID:25982321

  2. Wireless Transfer of Electricity in Outer Space

    E-print Network

    Alexander Bolonkin

    2008-05-07

    Author offers conclusions from his research of a revolutionary new idea - transferring electric energy in the hard vacuum of outer space wirelessly, using a plasma power cord as an electric cable (wire). He shows that a certain minimal electric currency creates a compressed force that supports the plasma cable in the compacted form. A large energy can be transferred hundreds of millions of kilometers by this method. The required mass of the plasma cable is only hundreds of grams. He computed the macroprojects: transference of hundreds kilowatts of energy to Earth Space Station, transferring energy to the Moon or back, transferring energy to a spaceship at distance 100 million of kilometers, the transfer energy to Mars when one is located at opposed side of the distant Sun, transfer colossal energy from one of Earth's continents to another continent (for example, between Europe-USA) wirelessly-using Earth ionosphere as cable, using Earth as gigantic storage of electric energy, using the plasma ring as huge MagSail for moving of spaceships. He also demonstrates that electric currency in a plasma cord can accelerate or brake spacecraft and space apparatus.

  3. Hierarchical nanosheet-constructed yolk–shell TiO? porous microspheres for lithium batteries with high capacity, superior rate and long cycle capability

    E-print Network

    Jin, Jun; Huang, Shao-Zhuan; Li, Yu; Tian, He; Wang, Hong-En; Yu, Yong; Chen, Li-Hua; Hasan, Tawfique; Su, Bao-Lian

    2015-06-26

    . Such a yolk–shell structure with a highly porous shell and dense mesoporous core is quite advantageous as an anode material for lithium ion batteries (LIBs). The outer, 2D nanosheet-based porous (15 nm) shell and the nanocrystal-based inner mesoporous (3...

  4. New polymer target-shell properties and characterizations. Appendix A

    SciTech Connect

    Honig, A.; Wei, X.; Fan, Q.; Alexander, N.; Palmer, N.

    1993-12-31

    A method for characterizing ICF target shells is presented, based on measurement of the gas released from a single shell into a small volume. It utilizes cryogenic permeation systems developed in connection with our work on ICF targets containing nuclear spin-polarized deuterium. Permeation rates for polystyrene and parylene-coated-polystyrene shells are measured at temperatures from 350K down to 180K. Burst or implosion pressure can be determined over a full temperature range down to 20K. Shell temperature is calculated from its gas leakage rate, calibrated by permeation measurements over the temperature range. Lag of shell temperature compared with sample-chamber temperature during warming of the latter is attributed to the weakness of the thermal link provided by both radiative heat transfer and free molecular conduction with small accommodation coefficients for helium and deuterium gas at the structure to which the shell is conductively linked, or at the surface of a conductively isolated shell. Quantification of this lag can provide a measure of atomic scale roughness of the shell outer surface. Also presented are reversible pre-rupture leakage phenomena for polystyrene and parylene-coated-polystyrene shells.

  5. New polymer target-shell properties and characterizations

    NASA Astrophysics Data System (ADS)

    Honig, A.; Wei, X.; Fan, Q.; Alexander, N.; Palmer, N.

    A method for characterizing ICF target shells is presented, based on measurement of the gas released from a single shell into a small volume. It utilizes cryogenic permeation systems developed in connection with our work on ICF targets containing nuclear spin-polarized deuterium. Permeation rates for polystyrene and parylene-coated-polystyrene shells are measured at temperatures from 350K down to 180K. Burst or implosion pressure can be determined over a full temperature range down to 20K. Shell temperature is calculated from its gas leakage rate, calibrated by permeation measurements over the temperature range. Lag of shell temperature compared with sample-chamber temperature during warming of the latter is attributed to the weakness of the thermal link provided by both radiative heat transfer and free molecular conduction with small accommodation coefficients for helium and deuterium gas at the structure to which the shell is conductively linked, or at the surface of a conductively isolated shell. Quantification of this lag can provide a measure of atomic scale roughness of the shell outer surface. Also presented are reversible pre-rupture leakage phenomena for polystyrene and parylene-coated-polystyrene shells.

  6. Physics of the outer heliosphere

    SciTech Connect

    Gazis, P.R. )

    1991-01-01

    Major advances in the physics of the outer heliosphere are reviewed for the 1987-1990 time frame. Emphasis is placed on five broad topics: the detailed structure of the solar wind at large heliocentric distances, the global structure of the interplanetary field, latidudinal variations and meridional flows, radial and temporal variations, and the interaction of the solar wind with the local interstellar medium. 122 refs.

  7. Hollow Pollen Shells to Enhance Drug Delivery

    PubMed Central

    Diego-Taboada, Alberto; Beckett, Stephen T.; Atkin, Stephen L.; Mackenzie, Grahame

    2014-01-01

    Pollen grain and spore shells are natural microcapsules designed to protect the genetic material of the plant from external damage. The shell is made up of two layers, the inner layer (intine), made largely of cellulose, and the outer layer (exine), composed mainly of sporopollenin. The relative proportion of each varies according to the plant species. The structure of sporopollenin has not been fully characterised but different studies suggest the presence of conjugated phenols, which provide antioxidant properties to the microcapsule and UV (ultraviolet) protection to the material inside it. These microcapsule shells have many advantageous properties, such as homogeneity in size, resilience to both alkalis and acids, and the ability to withstand temperatures up to 250 °C. These hollow microcapsules have the ability to encapsulate and release actives in a controlled manner. Their mucoadhesion to intestinal tissues may contribute to the extended contact of the sporopollenin with the intestinal mucosa leading to an increased efficiency of delivery of nutraceuticals and drugs. The hollow microcapsules can be filled with a solution of the active or active in a liquid form by simply mixing both together, and in some cases operating a vacuum. The active payload can be released in the human body depending on pressure on the microcapsule, solubility and/or pH factors. Active release can be controlled by adding a coating on the shell, or co-encapsulation with the active inside the shell. PMID:24638098

  8. Breakup of shells under explosion and impact

    NASA Astrophysics Data System (ADS)

    Wittel, F. K.; Kun, F.; Herrmann, H. J.; Kröplin, B. H.

    2005-01-01

    A theoretical and experimental study of the fragmentation of closed thin shells made of a disordered brittle material is presented. Experiments were performed on eggshells under two different loading conditions: fragmentation due to an impact with a hard wall and explosion by a combustion mixture giving rise to power law fragment size distributions. For the theoretical investigations a three-dimensional discrete element model of shells is constructed. Molecular dynamics simulations of the two loading cases resulted in power law fragment mass distributions in satisfactory agreement with experiments. Based on large scale simulations we give evidence that power law distributions arise due to an underlying phase transition which proved to be abrupt and continuous for explosion and impact, respectively. Our results demonstrate that the fragmentation of closed shells defines a universality class, different from that of two- and three-dimensional bulk systems.

  9. Geometrical interpretation for the outer SU(3) outer multiplicity label

    NASA Technical Reports Server (NTRS)

    Draayer, Jerry P.; Troltenier, D.

    1995-01-01

    A geometrical interpretation for the outer multiplicity rho that occurs in a reduction of the product of two SU(3) representations, (lambda(sub pi), mu(sub pi)) x (lambda(sub nu), mu(sub nu)) approaches sigma(sub rho)(lambda, mu)(sub rho), is introduced. This coupling of proton (pi) and neutron (nu) representations arises, for example, in both boson and fermion descriptions of heavy deformed nuclei. Attributing a geometry to the coupling raises the possibility of introducing a simple interaction that provides a physically meaningful way for distinguishing multiple occurrences of (lambda, mu) values that can arise in such products.

  10. Obstruction Sets for Outer-Cylindrical Graphs

    E-print Network

    Archdeacon, Dan

    Obstruction Sets for Outer-Cylindrical Graphs Dan Archdeacon Dept. of Math. and Stat. University is outer-cylindrical if it embeds in the sphere so that there are two distinct faces whose boundaries together contain all the ver- tices. The class of outer-cylindrical graphs is closed under minors. We give

  11. Simulating Hard Rigid Bodies

    E-print Network

    De Michele, Cristiano

    2009-01-01

    Several physical systems in condensed matter have been modeled approximating their constituent particles as hard objects. In fact, the hard spheres model has been one of the cornerstones of the computational and theoretical description in condensed matter. The next level of description is to consider particles as rigid objects of generic shape enriching enormously the possible phenomenology. This kind of modeling will be interesting in all the situations in which steric effect plays a relevant role. These include biology, soft matter, granular material and molecular systems. Nevertheless, except for the case of hard spheres systems, there are no general recipes for event-driven Molecular Dynamics simulations of hard rigid bodies. Two similar algorithms for calculating the distance between two convex hard rigid bodies and the contact time of two colliding hard rigid bodies solving non-linear set of equations will be described. Building on these two methods, an event-driven molecular dynamics algorithm for simu...

  12. Convection electric field effects on outer radiation belt electron precipitation

    NASA Technical Reports Server (NTRS)

    Gelpi, C.; Benbrook, J. R.; Sheldon, W. R.

    1986-01-01

    A model is presented for the possible diurnal modulation of outer radiation belt electron precipitation by considering the effect of the convection electric field on geomagnetically trapped electrons. The modulation flux is the flux due to electrons in the drift loss cone, i.e., those which drift into the bounce loss cone. The electron flux in the drift loss cone is related to the time allowable for diffusion from the stably trapped population to the drift loss cone for precipitation at a specific geographic location. This time, which is termed the maximum L-shell lifetime, is obtained by computing electron trajectories, using a realistic magnetic field model and a simple model for the electric field. The maximum L-shell lifetimes are taken to be the times between successive entries into the bounce loss cone. Conservation of the first two adiabatic invariants, as electrons are slowly energized by the convection electric field, leads to variations in pitch angle, maximum L-shell lifetimes, and, consequently, to changes in the electron flux in the drift loss cone. These results are compared with observations of precipitating electrons made with sounding rocket payloads.

  13. Magnetospheres of the outer planets

    SciTech Connect

    Cheng, A.F.

    1986-12-01

    The magnetospheres of the outer planets have been shown by Voyager explorations to strongly interact with the surfaces and atmospheres of their planetary satellites and rings. In the cases of Jupiter, Saturn and Uranus, the processes of charged particle sputtering, neutral gas cloud formation, and rapid plasma injection from the ionization of the neutral clouds, have important implications both for the magnetospheres as a whole and for the surfaces and atmospheres of their satellites. The general methodology employed in these researches has involved comparisons of the planetary magnetospheres in order to identify common physical processes. 16 references.

  14. Global storm time depletion of the outer electron belt

    NASA Astrophysics Data System (ADS)

    Ukhorskiy, A. Y.; Sitnov, M. I.; Millan, R. M.; Kress, B. T.; Fennell, J. F.; Claudepierre, S. G.; Barnes, R. J.

    2015-04-01

    The outer radiation belt consists of relativistic (>0.5 MeV) electrons trapped on closed trajectories around Earth where the magnetic field is nearly dipolar. During increased geomagnetic activity, electron intensities in the belt can vary by orders of magnitude at different spatial and temporal scales. The main phase of geomagnetic storms often produces deep depletions of electron intensities over broad regions of the outer belt. Previous studies identified three possible processes that can contribute to the main-phase depletions: adiabatic inflation of electron drift orbits caused by the ring current growth, electron loss into the atmosphere, and electron escape through the magnetopause boundary. In this paper we investigate the relative importance of the adiabatic effect and magnetopause loss to the rapid depletion of the outer belt observed at the Van Allen Probes spacecraft during the main phase of 17 March 2013 storm. The intensities of >1 MeV electrons were depleted by more than an order of magnitude over the entire radial extent of the belt in less than 6 h after the sudden storm commencement. For the analysis we used three-dimensional test particle simulations of global evolution of the outer belt in the Tsyganenko-Sitnov (TS07D) magnetic field model with an inductive electric field. Comparison of the simulation results with electron measurements from the Magnetic Electron Ion Spectrometer experiment shows that magnetopause loss accounts for most of the observed depletion at L>5, while at lower L shells the depletion is adiabatic. Both magnetopause loss and the adiabatic effect are controlled by the change in global configuration of the magnetic field due to storm time development of the ring current; a simulation of electron evolution without a ring current produces a much weaker depletion.

  15. Galactic Center Shells and a Recurrent Starburst Model

    NASA Astrophysics Data System (ADS)

    Sofue, Yoshiaki

    2003-04-01

    By applying filtering techniques to remove straight filaments in the 20-cm VLA radio image of the Galactic Center Arc region, we have shown that numerous concentric radio shells of radii 5 to 20pc are surrounding the Pistol and Sickle region, which we call Galactic Center Shells (GCS).Each shell has thermal energy of the order of1049-50erg.Several CO-line shells are associated, whose kinetic energies are of the order of 1049-50erg. Summing up the energies of recognized GCSs, the total energy amounts to ˜ 1051erg.The GCSs show an excellent correlation with the FIR shells observed at 16-26?m with the MSX.We propose a model in which GCSs were produced by recurrent and/or intermittent starbursts in the Pistol area during the last million years.The most recent burst occurred some 105 years ago, producing an inner round-shaped shell (GCS I);earlier ones a million years ago produced outer shells (GCS II and III), which a re more deformed by interactions with the surrounding ISM and Sgr A halo.We argue that recurrent starbursts had also occurred in the past, which produced larger scale hyper-shell structures as well.A burst some million years ago produced the Galactic Center Lobe, and a much stronger one 15 million years ago produced the North Polar Spur.

  16. Yolk/shell nanoparticles: classifications, synthesis, properties, and applications.

    PubMed

    Purbia, Rahul; Paria, Santanu

    2015-12-21

    Core/shell nanoparticles were first reported in the early 1990s with a simple spherical core and shell structure, but the area is gradually diversifying in multiple directions such as different shapes, multishells, yolk/shell etc., because of the development of different new properties of the materials, which are useful for several advanced applications. Among different sub-areas of core/shell nanoparticles, yolk/shell nanoparticles (YS NPs) have drawn significant attention in recent years because of their unique properties such as low density, large surface area, ease of interior core functionalization, a good molecular loading capacity in the void space, tunable interstitial void space, and a hollow outer shell. The YS NPs have better properties over simple core/shell or hollow NPs in various fields including biomedical, catalysis, sensors, lithium batteries, adsorbents, DSSCs, microwave absorbers etc., mainly because of the presence of free void space, porous hollow shell, and free core surface. This review presents an extensive classification of YS NPs based on their structures and types of materials, along with synthesis strategies, properties, and applications with which one would be able to draw a complete picture of this area. PMID:26567966

  17. Exchange coupled SrFe12O19/Fe-Co core/shell particles with different shell thickness

    NASA Astrophysics Data System (ADS)

    Xu, Xia; Hong, Yang-Ki; Park, Jihoon; Lee, Woncheol; Lane, Alan M.

    2015-10-01

    SrFe12O19/Fe-Co core/shell particles with different shell thickness were synthesized by polyol reduction of Fe and Co ions at 180°C with SrFe12O19 particles dispersed in solvent. The core/shell structure is formed by magnetic self-assembly due to the remanent magnetization of SrFe12O19 particles. Within a limited concentration range, the shell thickness could be controlled by regulating the concentration of Fe and Co ions. Core/shell structured SrFe12O19/Fe-Co particles showed more effective exchange coupling effects between hard and soft phases than physically mixed SrFe12O19 and Fe-Co particles.

  18. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  19. Hardness Tester for Polyur

    NASA Technical Reports Server (NTRS)

    Hauser, D. L.; Buras, D. F.; Corbin, J. M.

    1987-01-01

    Rubber-hardness tester modified for use on rigid polyurethane foam. Provides objective basis for evaluation of improvements in foam manufacturing and inspection. Typical acceptance criterion requires minimum hardness reading of 80 on modified tester. With adequate correlation tests, modified tester used to measure indirectly tensile and compressive strengths of foam.

  20. Non-uniform thickness in Europa's icy shell: implications for astrobiology mission design

    NASA Astrophysics Data System (ADS)

    Fairén, A.; Amils, R.

    The exploration of Europa's subsurface ocean is hardly constrained by the presence of an outer ice shell of unknown thickness: a somewhat thin crust would allow easier access to the ocean below. Current estimates for the thickness of Europa's icy surface range from a few km [1] to a few tens of km [2], the shell overlying a liquid water ocean up to 150 km thick [3,4,5]. The surface is believed to be young (mean age of 30-80 Myr [6]) and geologically active [7,8,9], as it is sparsely cratered. Here we report geological evidence indicating that the thickness of Europa's ice crust is actually a complex combination of thicker and thinner areas, highlighting the implications of such structure in the future exploration of the inner ocean. Detailed geologic mapping of impact craters, palimpsests and chaotic terrains distribution on Europa's surface, offers an initial approach to a comprehensive description of the thickness variation in the ice shell. Our analysis is based in: (1) Crater distribution, morphology, diameter and depth. Seminal work by Schenk [2] of transitions in crater shape/diameter suggested enhanced structural collapse of craters with diameter >27-33 km, that will consequently form multiring basins, due to weaker ice or a global ocean at depths >19-25 km. This being true, strictly can only be interpreted regionally: multiring basins indicate regions where the ice shell is thick; in those regions where the icy surface is thin, a bolide impact will breach the ice and leave neither crater nor multiring basin behind, but probably Ganymede's type palimpsests. (2) Palimpsest-type features distribution, indicating regions where the ice shell is too thin to support crater formation after big bolide impacts. In Ganymede, palimpsests are circular, low albedo and relief features formerly formed by impacts [10,11]. (3) Chaotic terrain distribution, considering features tens to hundreds of km across, that may be the evidence for very thin ice areas (from ˜ 2 km to zero shell thickness [12]) with liquid water at shallow depths [5], allowing for bolide penetration, diapirism and the extrusion of water to the surface. The heterogeneity in shell's thickness may be originated in spatial variations in tidal heating [13] and/or warm water upwellings from the silicate interior capable of melt-through the ice from below [12,14]. This thickness heterogeneity can be embedded in a general equatorward thickening trending, due to tidal dissipation and surface temperature variations [15]. A major constraint must be addressed at this point: the dynamism of ductile ice near the base of the shell may drive to decay in lateral thickness contrasts. But this effect has been examined both assuming ice as a Newtonian [16,17,18] and a non-Newtonian material [19], broadly reaching to similar conclusions: global shell thickness variations may survive for up to 100 Myr. In addition, lateral pressure gradients may not decay if they comprise only shallow depths [19]. Therefore, our results point to a dynamic non-uniform Europa's icy shell, displaying some regional and temporal heterogeneity in thickness. As thin/thick ice distribution is as time dependent as the surface ice features are (both are reshaped in periods ˜ 100 Myr), the analysis performed here offers an estimation of the current thickness distribution in the ice shell, estimation that cannot be extrapolated to ancient (e.g., >100 Myr) times. The astrobiological potential the shell and ocean below possess is highlighted by these results: a somewhere thin outer crust allows the possibility for some exogenous materials delivered by asteroids and comets to reach the inner liquid water ocean by breaching the brittle lithosphere [20], and so join to those generated in the interior of Europa via volcanic and hydrothermal activity [21]. In addition, pressure gradients driving the ductile ice at the base of the shell to flow laterally may help to redistribute such materials among the inner ice shell and/or ocean through time. Our results have a direct deal with the investigation of Eur

  1. The hard metal diseases

    SciTech Connect

    Cugell, D.W. )

    1992-06-01

    Hard metal is a mixture of tungsten carbide and cobalt, to which small amounts of other metals may be added. It is widely used for industrial purposes whenever extreme hardness and high temperature resistance are needed, such as for cutting tools, oil well drilling bits, and jet engine exhaust ports. Cobalt is the component of hard metal that can be a health hazard. Respiratory diseases occur in workers exposed to cobalt--either in the production of hard metal, from machining hard metal parts, or from other sources. Adverse pulmonary reactions include asthma, hypersensitivity pneumonitis, and interstitial fibrosis. A peculiar, almost unique form of lung fibrosis, giant cell interstitial pneumonia, is closely linked with cobalt exposure.66 references.

  2. Double Gas Puff Z-Pinch with Axial Magnetic Field for K-Shell Radiation Production

    NASA Astrophysics Data System (ADS)

    Shishlov, Alexander V.; Baksht, Rina B.; Chaikovsky, Stanislav A.; Labetsky, Aleksey Yu.; Oreshkin, Vladimir I.; Rousskikh, Alexander G.; Fedunin, Anatoly V.

    2002-12-01

    A double gas puff with a solid fill inner shell and an annular outer shell with axial magnetic field is proposed as a possible load configuration for a plasma radiation source for K-shell radiation production of high-Z materials. This load configuration is investigated in the experiments with neon gas puffs on the IMRI-5 generator (400 kA, 430 ns) and with argon gas puffs on the GIT-12 generator (2.5 MA, 300 ns). Influence of the axial magnetic field on z-pinch stabilization and K-shell radiation yield is studied.

  3. L shell distribution of energetic electrons at Saturn

    NASA Astrophysics Data System (ADS)

    Carbary, J. F.; Mitchell, D. G.; Krupp, N.; Krimigis, S. M.

    2009-09-01

    Energetic electron fluxes (110-485 keV) observed by the MIMI/LEMMS instrument on the Cassini mission to Saturn were averaged into azimuthal bins and L shell bins for the period from day 150 2004 to day 366 2008. In local time, the electrons fluxes maximize on the night side between the Mimas and Rhea L shells and have a minimum near noon. This local time behavior may be a result of nightside injection combined with subcorotational drift in a nondipolar field. In SLS longitude, the electrons are smoothly distributed, showing no signs of spiral patterns on this multiyear timescale. The lower energy electrons (110-365 keV) form an inner belt near the Mimas L shell and an outer belt between the Dione and Rhea L shells.

  4. Outer planet entry nonequilibrium heating

    NASA Technical Reports Server (NTRS)

    Leibowitz, L. P.; Kuo, T. J.

    1975-01-01

    An analytical tool has been developed which enables the impact of nonequilibrium effects on outer planet entry heating to be estimated. The analysis combines recent shock tube experiments, flow field calculations, and planetary entry trajectory analysis. The thickness of the nonequilibrium layer and its variation around the entry body have been correlated by a reaction flow parameter over a wide range of entry conditions. The influence of nonequilibrium effects on heating during entry into Saturn and Jupiter model atmospheres has been studied and the effect of vehicle size and ballistic coefficient determined. A nonequilibrium layer of significant thickness was found to exist during portions of entry into Saturn and Jupiter warm atmospheres. However, the nonequilibrium layer was found to be thin during the peak heating portions of the trajectory and resulted in reductions in total probe heating of less than 15 per cent.

  5. Aft outer rim seal arrangement

    DOEpatents

    Lee, Ching-Pang; Tham, Kok-Mun; Schroeder, Eric; Meeroff, Jamie; Miller, Jr., Samuel R; Marra, John J; Campbell, Christian X

    2015-04-28

    An outer rim seal arrangement (10), including: an annular rim (70) centered about a longitudinal axis (30) of a rotor disc (31), extending fore and having a fore-end (72), an outward-facing surface (74), and an inward-facing surface (76); a lower angel wing (62) extending aft from a base of a turbine blade (22) and having an aft end (64) disposed radially inward of the rim inward-facing surface to define a lower angel wing seal gap (80); an upper angel wing (66) extending aft from the turbine blade base and having an aft end (68) disposed radially outward of the rim outward-facing surface to define a upper angel wing seal gap (80, 82); and guide vanes (100) disposed on the rim inward-facing surface in the lower angel wing seal gap. Pumping fins (102) may be disposed on the upper angel wing seal aft end in the upper angel wing seal gap.

  6. Outer Appearances Can Be Deceiving

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graph shows the chemical composition of the rock at Gusev Crater dubbed 'Mazatzal' after it was brushed and ground by the Mars Exploration Rover Spirit's rock abrasion tool. The data, taken by the rover's alpha particle X-ray spectrometer over the last few sols, show that the amount of chlorine and sulfur tri-oxide in Mazatzal first increased after brushing, then diminished after grinding. The interior of the rock appears to have the same chemical make-up as other volcanic or basalt rocks studied in the Gusev Crater area ('Adirondack' and 'Humphrey'). Its outer coating or rind, on the other hand, appears to be of a different constitution. Scientists are still puzzling out the implications of these data.

    The larger symbols on the graph represent inferred rock compositions, while the smaller symbols are actual data points. Observations were made at the target dubbed 'New York' on Mazatzal.

  7. Chemistry of the outer planets

    NASA Technical Reports Server (NTRS)

    Scattergood, Thomas W.

    1992-01-01

    Various aspects were studied of past or present chemistry in the atmospheres of the outer planets and their satellites using lab simulations. Three areas were studied: (1) organic chemistry induced by kinetically hot hydrogen atoms in the region of Jupiter's atmosphere containing the ammonia cirrus clouds; (2) the conversion of NH3 into N2 by plasmas associated with entry of meteors and other objects into the atmosphere of early Titan; and (3) the synthesis of simple hydrocarbons and HCN by lightning in mixtures containing N2, CH4, and NH3 representing the atmospheres of Titan and the outer planets. The results showed that: (1) hot H2 atoms formed from the photodissociation of NH3 in Jupiter's atmosphere could account for some of the atmospheric chemistry in the ammonia cirrus cloud region; (2) the thermalization of hot H2 atoms in atmospheres predominated by molecular H is not as rapid as predicted by elastic collision theory; (3) the net quantum loss of NH3 in the presence of a 200 fold excess of H2 is 0.02, much higher than was expected from the amount of H2 present; (4) the conversion of NH3 into N2 in plasmas associated with infalling meteors is very efficient and rapid, and could account for most of the N2 present on Titan; (5) the yields of C2H2 and HCN from lightning induced chemistry in mixtures of CH4 and N2 is consistent with quenched thermodynamic models of the discharge core; and (6) photolysis induced by the UV light emitted by the gases in the hot plasmas may account for some, if not most, of the excess production of C2H6 and the more complex hydrocarbons.

  8. Off-Shell Tachyons

    E-print Network

    Yi-Lei Tang

    2015-01-30

    The idea that the new particles invented in some models beyond the standard model can appear only inside the loops is attractive. In this paper, we fill these loops with off-shell tachyons, leading to a solution of the zero results of the loop diagrams involving the off-shell non-tachyonic particles. We also calculate the Passarino-Veltman $A_0^o$ and $B_0^o$ of the off-shell tachyons.

  9. Off-Shell Tachyons

    E-print Network

    Tang, Yi-Lei

    2015-01-01

    The idea that the new particles invented in some models beyond the standard model can appear only inside the loops is attractive. In this paper, we fill these loops with off-shell tachyons, leading to a solution of the zero results of the loop diagrams involving the off-shell non-tachyonic particles. We also calculate the Passarino-Veltman $A_0^o$ and $B_0^o$ of the off-shell tachyons.

  10. Effect of milling time and CNT concentration on hardness of CNT/Al{sub 2024} composites produced by mechanical alloying

    SciTech Connect

    Perez-Bustamante, R.; Perez-Bustamante, F.; Estrada-Guel, I.; Licea-Jimenez, L.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2013-01-15

    Carbon nanotube/2024 aluminum alloy (CNT/Al{sub 2024}) composites were fabricated with a combination of mechanical alloying (MA) and powder metallurgy routes. Composites were microstructurally and mechanically evaluated at sintering condition. A homogeneous dispersion of CNTs in the Al matrix was observed by a field emission scanning electron microscopy. High-resolution transmission electron microscopy confirmed not only the presence of well dispersed CNTs but also needle-like shape aluminum carbide (Al{sub 4}C{sub 3}) crystals in the Al matrix. The formation of Al{sub 4}C{sub 3} was suggested as the interaction between the outer shells of CNTs and the Al matrix during MA process in which crystallization took place after the sintering process. The mechanical behavior of composites was evaluated by Vickers microhardness measurements indicating a significant improvement in hardness as function of the CNT content. This improvement was associated to a homogeneous dispersion of CNTs and the presence of Al{sub 4}C{sub 3} in the aluminum alloy matrix. - Highlights: Black-Right-Pointing-Pointer The 2024 aluminum alloy was reinforced by CNTs by mechanical alloying process. Black-Right-Pointing-Pointer Composites were microstructural and mechanically evaluated after sintering condition. Black-Right-Pointing-Pointer The greater the CNT concentration, the greater the hardness of the composites. Black-Right-Pointing-Pointer Higher hardness in composites is achieved at 20 h of milling. Black-Right-Pointing-Pointer The formation of Al{sub 4}C{sub 3} does not present a direct relationship with the milling time.

  11. Outer trapped surfaces are dense near MOTSs

    NASA Astrophysics Data System (ADS)

    Chru?ciel, Piotr T.; Galloway, Gregory J.

    2014-02-01

    We show that any vacuum initial data set containing a marginally outer trapped surface S and satisfying a ‘no KIDs’ condition can be perturbed near S so that S becomes strictly outer trapped in the new vacuum initial data set. This, together with the results in Eichmair et al (2012), gives a precise sense in which generic initial data containing marginally outer trapped surfaces lead to geodesically incomplete spacetimes.

  12. The Development of Hard-X-Ray Optics at MSFC

    NASA Technical Reports Server (NTRS)

    Ramsey, Brian D.; Elsner, R. F.; Engelhaupt, D. E.; Kolodziejczak, J. J.; ODell, S. L.; Speegle, C. O.; Weisskopf, M. C.; Six, Frank (Technical Monitor)

    2002-01-01

    We are fabricating optics for the hard-x-ray region using electroless nickel replication. The attraction of this process, which has been widely used elsewhere, is that the resulting full shell optics are inherently table and thus can have very good angular resolution. The challenge with this process is to develop lightweight optics (nickel has a relatively high density of 8.9 g / cu cm), and to keep down the costs of mandrel fabrication. We accomplished the former through the development of high-strength nickel alloys that permit very thin shells without fabrication- and handling-induced deformations. For the latter, we have utilized inexpensive grinding and diamond turning to figure the mandrels and then purpose-built polishing machines to finish the surface. In-house plating tanks and a simple water-bath separation system complete the process. To date we have built shells ranging in size from 5 cm diameter to 50 cm, and with thickness down to 100 micron. For our HERO (high energy replicated optics) balloon program, we are fabricating over 200 iridium-coated shells, 250 microns thick, for hard-x-ray imaging up to 75 keV. Early test results on these have indicated half-power-diameters of 15 arcsec. The status of these and other hard-x-ray optics will be reviewed.

  13. Imperfection Insensitive Thin Shells

    NASA Astrophysics Data System (ADS)

    Ning, Xin

    The buckling of axially compressed cylindrical shells and externally pressurized spherical shells is extremely sensitive to even very small geometric imperfections. In practice this issue is addressed by either using overly conservative knockdown factors, while keeping perfect axial or spherical symmetry, or adding closely and equally spaced stiffeners on shell surface. The influence of imperfection-sensitivity is mitigated, but the shells designed from these approaches are either too heavy or very expensive and are still sensitive to imperfections. Despite their drawbacks, these approaches have been used for more than half a century. This thesis proposes a novel method to design imperfection-insensitive cylindrical shells subject to axial compression. Instead of following the classical paths, focused on axially symmetric or high-order rotationally symmetric cross-sections, the method in this thesis adopts optimal symmetry-breaking wavy cross-sections (wavy shells). The avoidance of imperfection sensitivity is achieved by searching with an evolutionary algorithm for smooth cross-sectional shapes that maximize the minimum among the buckling loads of geometrically perfect and imperfect wavy shells. It is found that the shells designed through this approach can achieve higher critical stresses and knockdown factors than any previously known monocoque cylindrical shells. It is also found that these shells have superior mass efficiency to almost all previously reported stiffened shells. Experimental studies on a design of composite wavy shell obtained through the proposed method are presented in this thesis. A method of making composite wavy shells and a photogrametry technique of measuring full-field geometric imperfections have been developed. Numerical predictions based on the measured geometric imperfections match remarkably well with the experiments. Experimental results confirm that the wavy shells are not sensitive to imperfections and can carry axial compression with superior mass efficiency. An efficient computational method for the buckling analysis of corrugated and stiffened cylindrical shells subject to axial compression has been developed in this thesis. This method modifies the traditional Bloch wave method based on the stiffness matrix method of rotationally periodic structures. A highly efficient algorithm has been developed to implement the modified Bloch wave method. This method is applied in buckling analyses of a series of corrugated composite cylindrical shells and a large-scale orthogonally stiffened aluminum cylindrical shell. Numerical examples show that the modified Bloch wave method can achieve very high accuracy and require much less computational time than linear and nonlinear analyses of detailed full finite element models. This thesis presents parametric studies on a series of externally pressurized pseudo-spherical shells, i.e., polyhedral shells, including icosahedron, geodesic shells, and triambic icosahedra. Several optimization methods have been developed to further improve the performance of pseudo-spherical shells under external pressure. It has been shown that the buckling pressures of the shell designs obtained from the optimizations are much higher than the spherical shells and not sensitive to imperfections.

  14. Study on the fragmentation of shells

    E-print Network

    Falk K. Wittel; Ferenc Kun; Hans J. Herrmann; Bernd H. Kröplin

    2015-09-03

    Fragmentation can be observed in nature and in everyday life on a wide range of length scales and for all kinds of technical applications. Most studies on dynamic failure focus on the behaviour of bulk systems in one, two and three dimensions under impact and explosive loading, showing universal power law behaviour of fragment size distribution. However, hardly any studies have been devoted to fragmentation of shells. We present a detailed experimental and theoretical study on the fragmentation of closed thin shells of various materials, due to an excess load inside the system and impact with a hard wall. Characteristic fragmentation mechanisms are identified by means of a high speed camera and fragment shapes and mass distributions are evaluated. Theoretical rationalisation is given by means of stochastic break-up models and large-scale discrete element simulations with spherical shell systems under different extreme loading situations. By this we ex-plain fragment shapes and distributions and prove a power law for the fragment mass distribution. Satisfactory agreement between experimental findings and nu-merical predictions of the exponents of the power laws for the fragment shapes is obtained.

  15. Simplified nonlinear outer hair cell models

    NASA Astrophysics Data System (ADS)

    Deo, Niranjan; Grosh, Karl

    2005-04-01

    We present a consistent second-order expansion of nonlinear constitutive theories for outer hair cells. For a particular theory, we will test the validity of such a model for small variations in voltage and strain about the resting state of outer hair cells. An analysis of the various terms in the simplified nonlinear model and their relevance to outer hair cell mechanics are presented. Results show that the second-order expansion is adequate for modeling outer hair cell mechanics in a global model of the cochlea. Model predictions agree with the notion that voltage nonlinearities are the dominant ones at low sound levels in vivo. .

  16. Shell Cracking Strength in Almond (Prunus dulcis [Mill.] D.A. Webb.)and its implication in uses as a value-added product.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers are currently developing new uses for almond shells, an abundant agricultural by-product. While almond varieties are classified by processing facilities as being either hard or soft shelled, shell morphological characteristics and compositional components contribute to the variability p...

  17. The triple-shell structure and collimated outflows of the planetary nebula NGC 6891

    E-print Network

    M. A. Guerrero; L. F. Miranda; A. Manchado; R. Vazquez

    1999-10-21

    Narrow-band H$\\alpha$ and [N {\\sc ii}] images and high-dispersion spatially-resolved echelle spectroscopy of the planetary nebula NGC 6891 are presented. These observations show a great wealth of structures. The bright central nebula is surrounded by an attached shell and a detached outer halo. Both the inner and intermediate shells can be described as ellipsoids with similar major to minor axial ratios, but different spatial orientations. The kinematical ages of the intermediate shell and halo are 4,800 and 28,000 years, respectively. The inter-shell time lapse is in good agreement with the evolutionary inter-pulse time lapse. A highly collimated outflow is observed to protrude from the tips of the major axis of the inner nebula and impact on the outer edge of the intermediate shell. Kinematics and excitation of this outflow provide conclusive evidence that it is deflected during the interaction with the outer edge of the intermediate shell. At the same time, both the kinematics and the morphology of the intermediate shell appear to be affected by this interaction.

  18. Thermodynamics of rotating thin shells in the BTZ spacetime

    NASA Astrophysics Data System (ADS)

    Lemos, José P. S.; Lopes, Francisco J.; Minamitsuji, Masato; Rocha, Jorge V.

    2015-09-01

    We investigate the thermodynamic equilibrium states of a rotating thin shell, i.e., a ring, in a (2 +1 )-dimensional spacetime with a negative cosmological constant. The inner and outer regions with respect to the shell are given by the vacuum anti-de Sitter and the rotating Bañados-Teitelbom-Zanelli spacetimes, respectively. The first law of thermodynamics on the thin shell, together with three equations of state for the pressure, the local inverse temperature and the thermodynamic angular velocity of the shell, yields the entropy of the shell, which is shown to depend only on its gravitational radii. When the shell is pushed to its own gravitational radius and its temperature is taken to be the Hawking temperature of the corresponding black hole, the entropy of the shell coincides with the Bekenstein-Hawking entropy. In addition, we consider simple ansätze for the equations of state, as well as a power-law equation of state where the entropy and the thermodynamic stability conditions can be examined analytically.

  19. Shell width Three bumps

    E-print Network

    Shell width Three bumps Five spines Female (left) and male (right) green crab shell undersides crab male/female: Washington Dept. of Fish & Wildlife. Green crab photo: Fisheries and Oceans, Canada. Larval green crabs can also spread from one invaded area to another in ocean currents. Scientists

  20. Unloading Empty Shells 

    E-print Network

    Unknown

    2011-09-05

    cembroides Zucc belongs to this category and is the species used in this study. The seeds of this species form an important part in the diet for humans. Most pine seeds are presently shelled by hand. Mechanical. shelling has been attempted, but the shelters...

  1. Replicated Nickel Optics for the Hard-X-Ray Region

    NASA Technical Reports Server (NTRS)

    Ramsey, Brian

    2005-01-01

    Replicated nickel optics has been used extensively in x-ray astronomy, most notable for the XMM/Newton mission. Thc combination of relative ease of fabrication and the inherent stability of full shell optics, make them FIJI attractive approach for medium-resolution, high-throughput applications. MSFC has been developing these optics for use in the hard-x-ray region. Efforts at improving the resolution of these, particularly the very-thin shells required to meet thc weight budget of future missions, will be described together with the prospects for significant improvements down to the 5-arcsec level.

  2. Chemical Component and Proteomic Study of the Amphibalanus (= Balanus) amphitrite Shell

    PubMed Central

    Zhang, Gen; He, Li-sheng; Wong, Yue-Him; Xu, Ying; Zhang, Yu; Qian, Pei-yuan

    2015-01-01

    As typical biofoulers, barnacles possess hard shells and cause serious biofouling problems. In this study, we analyzed the protein component of the barnacle Amphibalanus (= Balanus) amphitrite shell using gel-based proteomics. The results revealed 52 proteins in the A. Amphitrite shell. Among them, 40 proteins were categorized into 11 functional groups based on KOG database, and the remaining 12 proteins were unknown. Besides the known proteins in barnacle shell (SIPC, carbonic anhydrase and acidic acid matrix protein), we also identified chorion peroxidase, C-type lectin-like domains, serine proteases and proteinase inhibitor proteins in the A. Amphitrite shell. The sequences of these proteins were characterized and their potential functions were discussed. Histology and DAPI staining revealed living cells in the shell, which might secrete the shell proteins identified in this study. PMID:26222041

  3. Meteorology of the outer planets

    NASA Astrophysics Data System (ADS)

    Hunt, G. E.

    The meteorologies of the giant outer planets are discussed in order to provide insight into the fundamental problems of atmospheric physics. Observations of large-scale cloud structures have shown Jupiter to be dominated by alternating cloud bands separated by jet streams, and Saturn to have a similar banded structure, but with a marked hemispherical asymmetry in clarity due to an atmospheric haze layer. The weather systems of Jupiter and Saturn are driven not solely by differential solar heating, but by strong internal heat sources and rotation as well, and little if any pole to equator energy transfer is present at the level of the visible clouds, differences in the zonal velocities of Jupiter and Saturn may be explained by the greater importance of internal heating on Saturn, and its lower gravity. Unlike the other major planets, Uranus does not appear to possess an internal heat source, and has a large inclination of its axis of rotation and a rapid rotation rate, so that only weak atmospheric motions are anticipated. Rapid changes in the reflectance of Neptune may be indicative of large-scale variations in cloud structure.

  4. 76 FR 63654 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... Bureau of Ocean Energy Management Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY: Bureau of Ocean Energy Management (BOEM), Interior. ACTION: Availability of revised North American Datum of 1927 (NAD 27) Outer Continental...

  5. Cohesive Elements for Shells

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Camanho, Pedro P.; Turon, Albert

    2007-01-01

    A cohesive element for shell analysis is presented. The element can be used to simulate the initiation and growth of delaminations between stacked, non-coincident layers of shell elements. The procedure to construct the element accounts for the thickness offset by applying the kinematic relations of shell deformation to transform the stiffness and internal force of a zero-thickness cohesive element such that interfacial continuity between the layers is enforced. The procedure is demonstrated by simulating the response and failure of the Mixed Mode Bending test and a skin-stiffener debond specimen. In addition, it is shown that stacks of shell elements can be used to create effective models to predict the inplane and delamination failure modes of thick components. The results indicate that simple shell models can retain many of the necessary predictive attributes of much more complex 3D models while providing the computational efficiency that is necessary for design.

  6. Radio Wave Emission from the Outer Planets

    E-print Network

    Meyer-Vernet, Nicole

    Radio Wave Emission from the Outer Planets P. Zarka LESIA, Observatoire de Paris, Meudon #12;All outer planets) produce intense nonthermal radio emissions potentially interesting remote sensing tool of magnetospheric plasma(s) we can "see" magnetospheres directly, but do we understand what we see ? #12;"Radio

  7. Elbow and knee joint for hard space suits

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.

    1986-01-01

    An elbow or knee joint for a hard space suit or similar usage is formed of three serially connected rigid sections which have truncated spherical configurations. The ends of each section form solid geometric angles, and the sections are interconnected by hermetically sealed ball bearings. The outer two sections are fixed together for rotation in a direction opposite to rotation of the center section. A preferred means to make the outer sections track each other in rotation comprises a rotatable continuous bead chain which engages sockets circumferentially spaced on the facing sides of the outer races of the bearings. The joint has a single pivot point and the bearing axes are always contained in a single plane for any articulation of the joint. Thus flexure of the joint simulates the coplanar flexure of the knee or elbow and is not susceptible to lockup.

  8. Outer Sphere Adsorption of Pb(II)EDTA on Goethite

    SciTech Connect

    Bargar, John R

    1999-07-16

    FTIR and EXAFS spectroscopic measurements were performed on Pb(II)EDTA adsorbed on goethite as functions of pH (4-6), Pb(II)EDTA concentration (0.11 {micro}M - 72 {micro}M), and ionic strength (16 {micro}M - 0.5M). FTIR measurements show no evidence for carboxylate-Fe(III) bonding or protonation of EDTA at Pb:EDTA = 1:1. Both FTIR and EXAFS measurements suggest that EDTA acts as a hexadentate ligand, with all four of its carboxylate and both amine groups bonded to Pb(II). No evidence was observed for inner-sphere Pb(II)-goethite bonding at Pb:EDTA = 1:1. Hence, the adsorbed complexes should have composition Pb(II)EDTA{sup 2{minus}}. Since substantial uptake of PbEDTA(II){sup 2{minus}} occurred in the samples, we infer that Pb(II)EDTA{sup 2{minus}} adsorbed as outer-sphere complexes and/or as complexes that lose part of their solvation shells and hydrogen bond directly to goethite surface sites. We propose the term ''hydration-sphere'' for the latter type of complexes because they should occupy space in the primary hydration spheres of goethite surface functional groups, and to distinguish this mode of sorption from common structural definitions of inner- and outer-sphere complexes. The similarity of Pb(II) uptake isotherms to those of other divalent metal ions complexed by EDTA suggests that they too adsorb by these mechanisms. The lack of evidence for inner-sphere EDTA-Fe(III) bonding suggests that previously proposed metal-ligand - promoted dissolution mechanisms should be modified, specifically to account for the presence of outer-sphere precursor species.

  9. SAXS Analysis of Shell Formation During Nanocapsule Synthesis via Inverse Miniemulsion Periphery RAFT Polymerization.

    PubMed

    Utama, Robert H; Dulle, Martin; Förster, Stephan; Stenzel, Martina H; Zetterlund, Per B

    2015-07-01

    Currently available methods for synthesis of polymeric nanocapsules only offer limited control over the shell thickness, even though it is an important parameter for various applications. Furthermore, suitable methods to critically measure this parameter in a facile way are still nonexistent. Here, lab-scale small-angle X-ray scattering (SAXS) is utilized to in situ measure the evolution of shell thickness during nanocapsule synthesis via inverse miniemulsion periphery reversible addition-fragmentation chain transfer (RAFT) polymerization (IMEPP). The measured shell thickness is consistent with estimates from the commonly used transmission electron microscopy (TEM) technique. Moreover, the individual thicknesses of two concentric shells comprising different polymeric materials (the outer shell formed via IMEPP chain extension of the inner shell) can be determined, thus further demonstrating the versatility of this approach. PMID:25882373

  10. Production of Polymer Core-Shell Colloids with High Uniformity via Coaxial Electrospray

    NASA Astrophysics Data System (ADS)

    Hwang, Yoon Kyun; Jeong, Unyong

    2008-03-01

    Although nanofibers fabricated by electrospinning have been attracting wide interest, the production of colloids by electrospraying has not much studied so far. We have developed a simple method for the production of core-shell colloids with high uniformity by means of the coaxial electrospray. Contrary to usual coaxial setup, the inner nozzle was set to touch the inside wall of the outer nozzle for reproducible production. A polymer solution for the core was introduced through the outer nozzle and another solution for the shell was provided through the inner nozzle. The structure of the colloids was dependent on the polymer concentration, relative feed ratio between the polymer solutions. Especially, core-shell structured colloids are our primary interest due to their promising uses in drug-delivery systems, cosmetics, and food industries. This talk will present the production of core-shell colloids consisting of two polymer components.

  11. Autoprogrammed synthesis of triple-layered Au@Pd@Pt core-shell nanoparticles consisting of a Au@Pd bimetallic core and nanoporous Pt shell.

    PubMed

    Wang, Liang; Yamauchi, Yusuke

    2010-10-01

    Here we report an autoprogrammed synthesis of unique Au@Pd@Pt triple-layered core-shell structured nanoparticles consisting of a Au core, Pd inner layer, and nanoporous Pt outer shell. The proposed synthesis rationally utilizes the temporal separations of the depositions of Au, Pd, and Pt which affords spontaneously step-by-step formation of triple-layered core-shell colloids. The proposed one-step method is unique in its simplicity and is a significant finding for the facile creation of multilayered nanoarchitectures with designed compositions and desired functions. PMID:20831169

  12. Magnetic nanohybrids loaded with bimetal core-shell-shell nanorods for bacteria capture, separation, and near-infrared photothermal treatment.

    PubMed

    Hu, Bo; Wang, Ning; Han, Lu; Chen, Ming-Li; Wang, Jian-Hua

    2015-04-20

    A novel antimicrobial nanohybrid based on near-infrared (NIR) photothermal conversion is designed for bacteria capture, separation, and sterilization (killing). Positively charged magnetic reduced graphene oxide with modification by polyethylenimine (rGO-Fe3 O4 -PEI) is prepared and then loaded with core-shell-shell Au-Ag-Au nanorods to construct the nanohybrid rGO-Fe3 O4 -Au-Ag-Au. NIR laser irradiation melts the outer Au shell and exposes the inner Ag shell, which facilitates controlled release of the silver shell. The nanohybrids combine physical photothermal sterilization as a result of the outer Au shell with the antibacterial effect of the inner Ag shell. In addition, the nanohybrid exhibits high heat conductivity because of the rGO and rapid magnetic-separation capability that is attributable to Fe3 O4 . The nanohybrid provides a significant improvement of bactericidal efficiency with respect to bare Au-Ag-Au nanorods and facilitates the isolation of bacteria from sample matrixes. A concentration of 25 ?g mL(-1) of nanohybrid causes 100 % capture and separation of Escherichia coli O157:H7 (1×10(8) cfu mL(-1) ) from an aqueous medium in 10 min. In addition, it causes a 22 °C temperature rise for the surrounding solution under NIR irradiation (785 nm, 50 mW cm(-2) ) for 10 min. With magnetic separation, 30 ?g mL(-1) of nanohybrid results in a 100 % killing rate for E. coli O157:H7 cells. The facile bacteria separation and photothermal sterilization is potentially feasible for environmental and/or clinical treatment. PMID:25754902

  13. Autoimmunity and the outer retina.

    PubMed

    Rahi, A H; Addison, D J

    1983-01-01

    Structurally and therefore antigenically the retina is a complex tissue. Since it develops as an extension from the neural tube it shares with the brain several cell membranes and cytoplasm associated antigens including those present in neurofilaments of the various neurones and the glial filaments of the astrocytes. The advent of monoclonal antibodies has helped to dissect, in detail, the antigenic makeup of the retina. Nervous system antigens (NS-3, 4 and 7) are generously represented in the retina. At least in the chick eye there seems to be a concentration gradient of retinal antigens along a dorsoventral axis which is believed to provide means by which neurones of developing retinal signal and receive the positional information necessary for the formation of specific synapses. It now seems certain that organ-specific antigens are presented not only in the photoreceptors and the retinal pigment epithelium but also in the retinal ganglion cells and the astrocytes. Photoreceptor outer-segment contains soluble antigens which when injected in rats, rabbits, guinea-pigs or monkeys produce varying degrees of intraocular inflammation leading to uveitis, retinal detachment, photoreceptor degeneration and occasionally retinal vasculitis. Both cell-mediated and humoral immunity to photoreceptor antigen has been demonstrated in various types of uveitis (including toxoplasmosis and sarcoidosis), pars planitis, vitriitis, Behçets disease, sympathetic ophthalmitis, Vogt-Koyanagi-Harada syndrome, birdshot retinopathy, retinitis pigmentosa and retinal vasculitis. Retinal autoimmunity is also found in retinal detachment and diabetic retinopathy, particularly after Argon laser photocoagulation. Antibodies to retinal antigens are also found in patients with systemic lupus erythematosus and other systemic immune disorders without ocular involvement. The precise pathogenetic role of retinal autoimmunity in eye disease is therefore uncertain. It may simply represent an epiphenomenon which develops afer retinal damage due to physical, micro-organismal or immunological insult. Alternatively it is possible that although autoimmunity does not initiate ocular inflammation it perpetuates and maintains the inflammatory state and produces further damage to ocular tissues. PMID:6611615

  14. Bacterial Diversity and Abundance in Shell Biofilms from the Freshwater Snail Pleurocera canaliculatum (Cerithioidea: Pleuroceridae).

    PubMed

    Minton, Russell L; Creech, Clinton C; Jackson, Debra W

    2015-01-01

    Mollusk shells provide a hard substrate for aquatic biofilm colonization. While most work has focused on bivalve shells and grazing, little work has focused on gastropod shells and the microbes growing on them. We sampled biofilms from 14 Pleuroceracanaliculatum and analyzed them using a metagenomic approach. Microbial diversity varied between individuals, and rarefaction suggested that 63 snails would need to be sampled to capture all of the estimated genus-level diversity. Cyanobacteria and species of Novosphingobium and Methylosoma were the most abundant taxa across all shells. PMID:26373180

  15. Hard superconducting nitrides

    PubMed Central

    Chen, Xiao-Jia; Struzhkin, Viktor V.; Wu, Zhigang; Somayazulu, Maddury; Qian, Jiang; Kung, Simon; Christensen, Axel Nørlund; Zhao, Yusheng; Cohen, Ronald E.; Mao, Ho-kwang; Hemley, Russell J.

    2005-01-01

    Detailed study of the equation of state, elasticity, and hardness of selected superconducting transition-metal nitrides reveals interesting correlations among their physical properties. Both the bulk modulus and Vickers hardness are found to decrease with increasing zero-pressure volume in NbN, HfN, and ZrN. The computed elastic constants from first principles satisfy c11 > c12 > c44 for NbN, but c11 > c44 > c12 for HfN and ZrN, which are in good agreement with the neutron scattering data. The cubic ?-NbN superconducting phase possesses a bulk modulus of 348 GPa, comparable to that of cubic boron nitride, and a Vickers hardness of 20 GPa, which is close to sapphire. Theoretical calculations for NbN show that all elastic moduli increase monotonically with increasing pressure. These results suggest technological applications of such materials in extreme environments. PMID:15728352

  16. Hard superconducting nitrides.

    PubMed

    Chen, Xiao-Jia; Struzhkin, Viktor V; Wu, Zhigang; Somayazulu, Maddury; Qian, Jiang; Kung, Simon; Christensen, Axel Nørlund; Zhao, Yusheng; Cohen, Ronald E; Mao, Ho-kwang; Hemley, Russell J

    2005-03-01

    Detailed study of the equation of state, elasticity, and hardness of selected superconducting transition-metal nitrides reveals interesting correlations among their physical properties. Both the bulk modulus and Vickers hardness are found to decrease with increasing zero-pressure volume in NbN, HfN, and ZrN. The computed elastic constants from first principles satisfy c11 > c12 > c44 for NbN, but c11 > c44 > c12 for HfN and ZrN, which are in good agreement with the neutron scattering data. The cubic delta-NbN superconducting phase possesses a bulk modulus of 348 GPa, comparable to that of cubic boron nitride, and a Vickers hardness of 20 GPa, which is close to sapphire. Theoretical calculations for NbN show that all elastic moduli increase monotonically with increasing pressure. These results suggest technological applications of such materials in extreme environments. PMID:15728352

  17. Inferring the State of Tidally-heated Satellite Ice Shells from Global Shape Measurements

    NASA Astrophysics Data System (ADS)

    Nimmo, F.; Thomas, P. C.; Pappalardo, R. T.; Moore, W. B.

    2006-12-01

    Several icy satellites of the outer solar system, notably Europa and Enceladus, are sufficiently tidally heated that they likely possess ice shells overlying oceans. Because tidal heating varies spatially [1], variations in ice shell thickness are likely to occur [2]. Lateral variations in shell thickness will in turn give rise to global topographic variations. The amplitude of this long-wavelength topography is potentially comparable to shape variations due to tidal and rotational stresses [3]. Thus, careful measurement of satellite shapes from limb profiles may be used to infer the nature of shell thickness variations, and thus the state of the ice shell. We demonstrate that limb profiles of Europa give no evidence for lateral shell thickness variations, in contrast to theoretical predictions [2] for a conductive ice shell above liquid water. There are two possible explanations: 1) the ice shell is sufficiently thick (> ~10 km) that lateral shell flow has smoothed out any variations; 2) the shell is heated mainly from below, resulting in a uniform, thin (~3 km) shell. Based on local topography from limb profiles and stereo topography [4] we favour the former explanation: a constant shell thickness rules out isostatic support, and the thin shell model is unable to flexurally support topography with amplitudes of ~1 km. Given sufficiently good limb profiles, a similar analysis may be carried out for Enceladus. Lateral variations in ice shell thickness also affect the tendency of a satellite to reorient itself [5]; thus, reorientation of Enceladus [6] may provide another constraint on the nature of the ice shell there. [1] G. Tobie et al., Icarus 177, 534-549, 2005. [2] Ojakangas and Stevenson, Icarus 81, 220-241, 1989 [3] Murray and Dermott, Solar System Dynamics, 2000 [4] Prockter and Schenk, Icarus 177, 305-326, 2005. [5] Ojakangas and Stevenson, Icarus 81, 242-270, 1989 [6] Nimmo and Pappalardo, Nature 441, 614-616, 2006.

  18. Incorporation of squalene into rod outer segments

    SciTech Connect

    Keller, R.K.; Fliesler, S.J. )

    1990-08-15

    We have reported previously that squalene is the major radiolabeled nonsaponifiable lipid product derived from ({sup 3}H)acetate in short term incubations of frog retinas. In the present study, we demonstrate that newly synthesized squalene is incorporated into rod outer segments under similar in vitro conditions. We show further that squalene is an endogenous constituent of frog rod outer segment membranes; its concentration is approximately 9.5 nmol/mumol of phospholipid or about 9% of the level of cholesterol. Pulse-chase experiments with radiolabeled precursors revealed no metabolism of outer segment squalene to sterols in up to 20 h of chase. Taken together with our previous absolute rate studies, these results suggest that most, if not all, of the squalene synthesized by the frog retina is transported to rod outer segments. Synthesis of protein is not required for squalene transport since puromycin had no effect on squalene incorporation into outer segments. Conversely, inhibition of isoprenoid synthesis with mevinolin had no effect on the incorporation of opsin into the outer segment. These latter results support the conclusion that the de novo synthesis and subsequent intracellular trafficking of opsin and isoprenoid lipids destined for the outer segment occur via independent mechanisms.

  19. Dynamics of a suspension of interacting yolk-shell particles

    SciTech Connect

    Chen, Wei-Ren; Sanchez-Diaz, Luis E

    2014-01-01

    In this work we study the self-diusion properties of a liquid of hollow spherical particles (shells) bearing a smaller solid sphere in their interior (yolks). We model this system using purely repulsive hard-body interactions between all (shell and yolk) particles, but assume the presence of a background ideal solvent such that all the particles execute free Brownian motion between collisions, characterized by short-time self-diusion coecients D0 s for the shells and D0 y for the yolks. Using a softened version of these interparticle potentials we perform Brownian dynamics simulations to determine the mean squared displacement and intermediate scattering function of the yolk-shell complex. These results can be understood in terms of a set of eective Langevin equations for the N interacting shell particles, pre-averaged over the yolks' degrees of freedom, from which an approximate self-consistent description of the simulated self-diusion properties can be derived. Here we compare the theoretical and simulated results between them, and with the results for the same system in the absence of yolks. We nd that the yolks, which have no eect on the shell-shell static structure, in uence the dynamic properties in a predictable manner, fully captured by the theory.

  20. Depletion of the Outer Asteroid Belt

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi; Malhotra, Renu

    1997-01-01

    During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.

  1. Outer planets and icy satellites

    NASA Technical Reports Server (NTRS)

    Drobyshevski, E. M.

    1991-01-01

    The resources offered by the outer bodies in the Solar System, starting with the main belt asteroids and Jovian System, are not only larger and more diverse but may even be easier to reach than, say, those of Mars. The use of their material, including water and organic matter, depends exclusively on the general strategy of exploration of the Solar System. Of major interest in this respect are the large ice satellites - Titan, Ganymede, and Callisto. Motion through the planetary magnetospheres excites in their ice envelopes megampere currents which, in the presence of rocky, etc., inclusions with electronic conduction should lead to the bulk electrolysis of ice and accumulation in it of 2H2 + O2 in the form of a solid solution. With the concentration of 2H2 + O2 reaching about 15 wt. percent, the solution becomes capable of detonation by a strong meteoritic impact. An explosion of Ganymede's ice envelope about 0.5 By ago could account for the formation of the Trojans and irregular satellites, all known differences between Ganymede and Callisto, and many other things. The explosion of a small icy planet with M approx less than 0.5 Moon created the asteroid belt. Two to three explosions occurred on Io, and two on Europa. The specific features of the longperiod comets close to Saturn's orbit permit dating Titan's envelope explosion as 10,000 yr ago, which produced its thick atmosphere, young Saturn's rings, as well as a reservoir of ice fragments saturated by 2H2 + O2, i.e., cometary nuclei between the orbits of Jupiter and Saturn. Thus these nuclei should contain, besides organic matter, also 2H2 + O2, which could be used for their transportation as well as for fuel for spaceships. Ices of such composition can reside deep inside Deimos, the Trojans, C-asteroids, etc. The danger of a future explosion of Callisto's electrolyzed ices, which would result in a catastrophic bombardment of the Earth by comets, may be high enough to warrant a revision of the priorities and strategy of space exploration.

  2. Hollow spherical shell manufacture

    DOEpatents

    O'Holleran, Thomas P. (Belleville, MI)

    1991-01-01

    A process for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry.

  3. Elastic Platonic Shells

    NASA Astrophysics Data System (ADS)

    Yong, Ee Hou; Nelson, David R.; Mahadevan, L.

    2013-10-01

    On microscopic scales, the crystallinity of flexible tethered or cross-linked membranes determines their mechanical response. We show that by controlling the type, number, and distribution of defects on a spherical elastic shell, it is possible to direct the morphology of these structures. Our numerical simulations show that by deflating a crystalline shell with defects, we can create elastic shell analogs of the classical platonic solids. These morphologies arise via a sharp buckling transition from the sphere which is strongly hysteretic in loading or unloading. We construct a minimal Landau theory for the transition using quadratic and cubic invariants of the spherical harmonic modes. Our approach suggests methods to engineer shape into soft spherical shells using a frozen defect topology.

  4. Hollow spherical shell manufacture

    DOEpatents

    O'Holleran, T.P.

    1991-11-26

    A process is disclosed for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry. 3 figures.

  5. Improved Method of Design for Folding Inflatable Shells

    NASA Technical Reports Server (NTRS)

    Johnson, Christopher J.

    2009-01-01

    An improved method of designing complexly shaped inflatable shells to be assembled from gores was conceived for original application to the inflatable outer shell of a developmental habitable spacecraft module having a cylindrical mid-length section with toroidal end caps. The method is also applicable to inflatable shells of various shapes for terrestrial use. The method addresses problems associated with the assembly, folding, transport, and deployment of inflatable shells that may comprise multiple layers and have complex shapes that can include such doubly curved surfaces as toroids and spheres. One particularly difficult problem is that of mathematically defining fold lines on a gore pattern in a double- curvature region. Moreover, because the fold lines in a double-curvature region tend to be curved, there is a practical problem of how to implement the folds. Another problem is that of modifying the basic gore shapes and sizes for the various layers so that when they are folded as part of the integral structure, they do not mechanically interfere with each other at the fold lines. Heretofore, it has been a common practice to design an inflatable shell to be assembled in the deployed configuration, without regard for the need to fold it into compact form. Typically, the result has been that folding has been a difficult, time-consuming process resulting in a An improved method of designing complexly shaped inflatable shells to be assembled from gores was conceived for original application to the inflatable outer shell of a developmental habitable spacecraft module having a cylindrical mid-length section with toroidal end caps. The method is also applicable to inflatable shells of various shapes for terrestrial use. The method addresses problems associated with the assembly, folding, transport, and deployment of inflatable shells that may comprise multiple layers and have complex shapes that can include such doubly curved surfaces as toroids and spheres. One particularly difficult problem is that of mathematically defining fold lines on a gore pattern in a double- curvature region. Moreover, because the fold lines in a double-curvature region tend to be curved, there is a practical problem of how to implement the folds. Another problem is that of modifying the basic gore shapes and sizes for the various layers so that when they are folded as part of the integral structure, they do not mechanically interfere with each other at the fold lines. Heretofore, it has been a common practice to design an inflatable shell to be assembled in the deployed configuration, without regard for the need to fold it into compact form. Typically, the result has been that folding has been a difficult, time-consuming process resulting in a

  6. Running in Hard Times

    ERIC Educational Resources Information Center

    Berry, John N., III

    2009-01-01

    Roberta Stevens and Kent Oliver are campaigning hard for the presidency of the American Library Association (ALA). Stevens is outreach projects and partnerships officer at the Library of Congress. Oliver is executive director of the Stark County District Library in Canton, Ohio. They have debated, discussed, and posted web sites, Facebook pages,…

  7. Work Hard. Be Nice

    ERIC Educational Resources Information Center

    Mathews, Jay

    2009-01-01

    In 1994, fresh from a two-year stint with Teach for America, Mike Feinberg and Dave Levin inaugurated the Knowledge Is Power Program (KIPP) in Houston with an enrollment of 49 5th graders. By this Fall, 75 KIPP schools will be up and running, setting children from poor and minority families on a path to college through a combination of hard work,…

  8. CSI: Hard Drive

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2008-01-01

    Acting on information from students who reported seeing a classmate looking at inappropriate material on a school computer, school officials used forensics software to plunge the depths of the PC's hard drive, searching for evidence of improper activity. Images were found in a deleted Internet Explorer cache as well as deleted file space.…

  9. Soft Skills, Hard Science

    E-print Network

    Wu, Mingshen

    , and Persons with Disabilities) 6 6 #12;how to help? What factors cause students with disabilities to be less with disabilities, 680 employers who have hired in STEM areas Students rated themselves on various skills, EmployersSoft Skills, Hard Science: A Program to Improve Job Placement of STEM Graduates with Disabilities

  10. Shells and Patterns

    ERIC Educational Resources Information Center

    Sutley, Jane

    2009-01-01

    "Shells and Patterns" was a project the author felt would easily put smiles on the faces of her fifth-graders, and teach them about unity and the use of watercolor pencils as well. It was thrilling to see the excitement in her students as they made their line drawings of shells come to life. For the most part, they quickly got the hang of…

  11. Shape transformation of bimetallic Au–Pd core–shell nanocubes to multilayered Au–Pd–Au core–shell hexagonal platelets

    DOE PAGESBeta

    Bhattarai, Nabraj; Prozorov, Tanya

    2015-11-05

    Transformation of metallic or bimetallic (BM) nanoparticles (NPs) from one shape to another desired shape is of importance to nanoscience and nanotechnology, where new morphologies of NPs lead to enhancement of their exploitable properties. In this report, we present the shape transformation of Au octahedral NPs to Au–Pd core–shell nanocubes, followed by their transformation to nanostars and finally to multilayered Au–Pd–Au core–shell hexagonal platelets in the presence of T30 DNA. The weaker binding affinity of T30 DNA directs the growth to favor the formation of lower energy {111} facets, changing the morphology from nanocubes to nanostar. The nanostars, exhibiting unusualmore »intermediate morphologies, are comprised two sets of shell layers and have Au core, Pd intermediate shell, and Au outer shell. Similarly, the hexagonal platelets, which also have Au core and inner Pd shell, are encased in an external gold shell. As a result, the formation of multilayered Au–Pd–Au core–shell hexagonal platelets from Au–Pd core–shell nanocubes via the multilayered nanostars is monitored using scanning/transmission electron microscopy analysis.« less

  12. Shape transformation of bimetallic Au–Pd core–shell nanocubes to multilayered Au–Pd–Au core–shell hexagonal platelets

    SciTech Connect

    Bhattarai, Nabraj; Prozorov, Tanya

    2015-11-05

    Transformation of metallic or bimetallic (BM) nanoparticles (NPs) from one shape to another desired shape is of importance to nanoscience and nanotechnology, where new morphologies of NPs lead to enhancement of their exploitable properties. In this report, we present the shape transformation of Au octahedral NPs to Au–Pd core–shell nanocubes, followed by their transformation to nanostars and finally to multilayered Au–Pd–Au core–shell hexagonal platelets in the presence of T30 DNA. The weaker binding affinity of T30 DNA directs the growth to favor the formation of lower energy {111} facets, changing the morphology from nanocubes to nanostar. The nanostars, exhibiting unusual intermediate morphologies, are comprised two sets of shell layers and have Au core, Pd intermediate shell, and Au outer shell. Similarly, the hexagonal platelets, which also have Au core and inner Pd shell, are encased in an external gold shell. As a result, the formation of multilayered Au–Pd–Au core–shell hexagonal platelets from Au–Pd core–shell nanocubes via the multilayered nanostars is monitored using scanning/transmission electron microscopy analysis.

  13. Stress Focusing in Creased Shells

    NASA Astrophysics Data System (ADS)

    Selden, Sarah; Evans, Arthur; Bende, Nakul; Hayward, Ryan; Santangelo, Christian

    2015-03-01

    Upon indentation, thin shells react by localizing strain energy in polygonal structures as opposed to a uniform axisymmetric distribution. While the formation of these localized structures are well-characterized for perfect shells, the introduction of a crease fundamentally changes the nature of the shell deformation. We perform finite element simulations, in tandem with experiments to explore the effect of a creased shell on the energy landscape. We find that the crease induces a new symmetry-breaking localization that does not appear in perfect shells, and we explore the deformation characteristics of the creased shell over a wide range of crease sizes, shell thickness, and crease orientations.

  14. Outer planet probe engineering model structural tests

    NASA Technical Reports Server (NTRS)

    Smittkamp, J. A.; Gustin, W. H.; Griffin, M. W.

    1977-01-01

    A series of proof of concept structural tests was performed on an engineering model of the Outer Planets Atmospheric Entry Probe. The tests consisted of pyrotechnic shock, dynamic and static loadings. The tests partially verified the structural concept.

  15. 75 FR 61512 - Outer Continental Shelf Official Protraction Diagrams

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official... Outer Continental Shelf Official Protraction Diagrams (OPDs) located within Atlantic Ocean areas, with... informational purposes only. Outer Continental Shelf Official Protraction Diagrams in the North Atlantic,...

  16. The outer solar system - Perspectives for exobiology

    NASA Technical Reports Server (NTRS)

    Owen, T.

    1974-01-01

    An attempt is made to summarize the current knowledge about the composition and structures of outer planet atmospheres with special emphasis on Jupiter, Saturn, and Titan. The nature of the substances which are responsible for the yellow coloration observed on both Jupiter and Saturn is discussed. The analysis of planetary conditions conducted shows that the outer solar system offers a variety of environments in which natural experiments in prebiotic organic synthesis must be taking place at the present time.

  17. Effects of alga polysaccharide capsule shells on in-vivo bioavailability and disintegration

    NASA Astrophysics Data System (ADS)

    Li, Ting; Guo, Shuju; Ma, Lin; Yuan, Yi; Han, Lijun

    2012-01-01

    Gelatin has been used in hard capsule shells for more than a century, and some shortcomings have appeared, such as high moisture content and risk of transmitting diseases of animal origin to people. Based on available studies regarding gelatin and vegetable shells, we developed a new type of algal polysaccharide capsule (APPC) shells. To test whether our products can replace commercial gelatin shells, we measured in-vivo plasma concentration of 12 selected volunteers with a model drug, ibuprofen, using high performance liquid chromatography (HPLC), by calculating the relative bioavailability of APPC and Qualicaps® referenced to gelatin capsules and assessing bioequivalence of the three types of shells, and calculated pharmacokinetic parameters with the software DAS 2.0 (China). The results show that APPC shells possess bioequivalence with Qualicaps® and gelatin shells. Moreover, the disintegration behavior of four types of shells (APPC, Vegcaps®, Qualicaps® and gelatin shells) with the content of lactose and radioactive element (99mTc) was observed via gamma-scintigraphic images. The bioavailability and gamma-scintigraphic studies showed that APPC was not statistically different from other vegetable and gelatin capsule shells with respect to in-vivo behavior. Hence, it can be concluded that APPCs are exchangeable with other vegetable and gelatin shells.

  18. Au@carbon yolk-shell nanostructures via one-step core-shell-shell template.

    PubMed

    Liu, Rui; Qu, Fengli; Guo, Yunlong; Yao, Nan; Priestley, Rodney D

    2014-01-14

    A facile one-step Stöber route to synthesize high-quality core-shell-shell templates is reported for the fabrication of Au@carbon yolk-shell nanostructures. The converted Au@carbon yolk-shell nanostructures exhibited high catalytic performance as illustrated by the reduction reaction of o-nitrophenol. PMID:24266025

  19. Examining dropouts of Earth's outer radiation belt electrons using multipoint observations of particles and waves

    NASA Astrophysics Data System (ADS)

    Turner, D. L.; Huang, C.; Rodriguez, J. V.; Hartinger, M.; Usanova, M.; Angelopoulos, V.; Shprits, Y.; Bortnik, J.

    2012-12-01

    One of the most drastic events that occur in Earth's outer radiation belt is the sudden depletion of relativistic electron flux, known as a flux dropout. Dropouts are characterized by electron fluxes dropping by up to several orders of magnitude over a broad range of energies, L-shells, and equatorial pitch angles in only a few hours. Here, we provide preliminary results of an ongoing statistical study of outer belt dropout events using multipoint observations. For all of the events, we examine the MLT at which the dropout is first observed, the ranges of L-shells and equatorial pitch angles affected, and how long the loss persists for various electron energies (~30 keV to >1 MeV). To examine the role of magnetopause shadowing and subsequent outward radial transport, we compare the evolution of electron fluxes and phase space density in adiabatic coordinates measured near the magnetic equator by THEMIS to precipitating fluxes observed at low-Earth orbit by the NOAA-POES spacecraft. We show that most often, the flux of electrons precipitating into the atmosphere is insufficient to explain the observed non-adiabatic loss of electrons throughout the belt, particularly at L-shells greater than ~5. Furthermore, characteristics of the dropout as observed by THEMIS and GOES are examined, and they reveal that the dropouts often start at higher L-shells and propagate inward. The important role of ULF waves in breaking the third adiabatic invariant, allowing for radial transport across drift shells, is also presented using wave data from THEMIS and GOES. Finally, we also examine the role of electron precipitation by EMIC waves during dropout events by comparing observed EMIC wave activity and range with the evolution of electron radial and pitch-angle distributions from THEMIS and precipitating electrons from NOAA-POES.

  20. The Impact of Ceramic Shell Strength on Hot Tearing during Investment Casting

    SciTech Connect

    Norouzi, Saeid; Farhangi, Hassan

    2011-01-17

    The effect of ceramic shell strength on hot tearing susceptibility during solidification was inspected practicing investment casting of the cobalt-base superalloy samples with the same casting conditions, but different ceramic shell systems. Results showed that the lower the ceramic shell strength upon using polymer additives, the lower the hindered contraction rate, and the lower the hindered contraction rate, the smaller the hot tearing tendency. Optical microscopy and electron microscopy scanning revealed that the hot tear propagated along the last solidified interdendritic phase, and that the hot tear surface had two major modes: (1) the ductile region in the outer layer; and (2) the inner region of liquid embrittlement.

  1. The Impact of Ceramic Shell Strength on Hot Tearing during Investment Casting

    NASA Astrophysics Data System (ADS)

    Norouzi, Saeid; Farhangi, Hassan

    2011-01-01

    The effect of ceramic shell strength on hot tearing susceptibility during solidification was inspected practicing investment casting of the cobalt-base superalloy samples with the same casting conditions, but different ceramic shell systems. Results showed that the lower the ceramic shell strength upon using polymer additives, the lower the hindered contraction rate, and the lower the hindered contraction rate, the smaller the hot tearing tendency. Optical microscopy and electron microscopy scanning revealed that the hot tear propagated along the last solidified interdendritic phase, and that the hot tear surface had two major modes: 1) the ductile region in the outer layer; and 2) the inner region of liquid embrittlement.

  2. Hard Copy Market Overview

    NASA Astrophysics Data System (ADS)

    Testan, Peter R.

    1987-04-01

    A number of Color Hard Copy (CHC) market drivers are currently indicating strong growth in the use of CHC technologies for the business graphics marketplace. These market drivers relate to product, software, color monitors and color copiers. The use of color in business graphics allows more information to be relayed than is normally the case in a monochrome format. The communicative powers of full-color computer generated output in the business graphics application area will continue to induce end users to desire and require color in their future applications. A number of color hard copy technologies will be utilized in the presentation graphics arena. Thermal transfer, ink jet, photographic and electrophotographic technologies are all expected to be utilized in the business graphics presentation application area in the future. Since the end of 1984, the availability of color application software packages has grown significantly. Sales revenue generated by business graphics software is expected to grow at a compound annual growth rate of just over 40 percent to 1990. Increased availability of packages to allow the integration of text and graphics is expected. Currently, the latest versions of page description languages such as Postscript, Interpress and DDL all support color output. The use of color monitors will also drive the demand for color hard copy in the business graphics market place. The availability of higher resolution screens is allowing color monitors to be easily used for both text and graphics applications in the office environment. During 1987, the sales of color monitors are expected to surpass the sales of monochrome monitors. Another major color hard copy market driver will be the color copier. In order to take advantage of the communications power of computer generated color output, multiple copies are required for distribution. Product introductions of a new generation of color copiers is now underway with additional introductions expected during 1987. The color hard copy market continues to be in a state of constant change, typical of any immature market. However, much of the change is positive. During 1985, the color hard copy market generated 1.2 billion. By 1990, total market revenue is expected to exceed 5.5 billion. The business graphics CHC application area is expected to grow at a compound annual growth rate greater than 40 percent to 1990.

  3. Deformation of an elastic shell with variable thickness: a comparison of different methods

    NASA Astrophysics Data System (ADS)

    Kalousová, K.; Sou?ek, O.; ?adek, O.

    2012-08-01

    Deformation of the outermost parts of single-plate planetary bodies is often modelled in terms of the response of a spherical elastic shell to surface or basal loading. As the thickness of such elastic lithosphere is usually much smaller than the radius of the body, the deformation is commonly approximated by that obtained for a thin elastic shell of uniform thickness. The main advantage of the thin shell approximation is its simplicity—the solution can be expressed analytically if the thickness of the shell is uniform, but even in the case of a thin shell of variable thickness, when the problem must be solved numerically, the computational costs are much lower than in a fully 3-D case. Here we analyse the error of the thin shell approximation by comparing it with the solution obtained for a shell of finite thickness using finite element methods. Special attention is paid to a shell of variable thickness and, in general, to the effect of elastic thickness variations on local deformation. For a shell of uniform thickness with the outer radius corresponding to Mars, we find that the error in radial displacement at low harmonic degrees (?? 20) does not exceed 5 per cent for small shell thicknesses (d? 50 km) and 10 per cent for thick shells (d˜ 250 km). Similar accuracy is also found for a shell of variable thickness if the thin shell approximation is used. Our numerical tests indicate that local deformation of a shell is mostly sensitive to the average thickness of the shell in the near zone while the effect of thickness variations in the far zone can be neglected in the first approximation. Consequently, the extremely simple thin shell method, designed for shells of uniform thickness, can be effectively used to obtain a reasonably accurate estimate of deflection even in the case of a shell with varying thickness. Finally, we investigate the deformation of an elastic lithosphere due to viscous flow beneath the shell, and we propose an extension of the concept, recently developed to correct dynamic topography for the effect of an elastic lithosphere, to the case of a shell of variable thickness.

  4. Experimental shellside flow visualization in a shell and tube heat exchanger 

    E-print Network

    Fischer, Matthew Winslow

    1998-01-01

    information in the shellside flow. A scale-model shell and tube heat exchanger with an outer diameter of 30.5 cm and a length of 61 cm was designed and constructed out of acrylic. Water was utilized as the working fluid and flowrates ranging from 0.32 to 2...

  5. SUPER HARD SURFACED POLYMERS

    SciTech Connect

    Mansur, Louis K; Bhattacharya, R; Blau, Peter Julian; Clemons, Art; Eberle, Cliff; Evans, H B; Janke, Christopher James; Jolly, Brian C; Lee, E H; Leonard, Keith J; Trejo, Rosa M; Rivard, John D

    2010-01-01

    High energy ion beam surface treatments were applied to a selected group of polymers. Of the six materials in the present study, four were thermoplastics (polycarbonate, polyethylene, polyethylene terephthalate, and polystyrene) and two were thermosets (epoxy and polyimide). The particular epoxy evaluated in this work is one of the resins used in formulating fiber reinforced composites for military helicopter blades. Measures of mechanical properties of the near surface regions were obtained by nanoindentation hardness and pin on disk wear. Attempts were also made to measure erosion resistance by particle impact. All materials were hardness tested. Pristine materials were very soft, having values in the range of approximately 0.1 to 0.5 GPa. Ion beam treatment increased hardness by up to 50 times compared to untreated materials. For reference, all materials were hardened to values higher than those typical of stainless steels. Wear tests were carried out on three of the materials, PET, PI and epoxy. On the ion beam treated epoxy no wear could be detected, whereas the untreated material showed significant wear.

  6. Interactive design of large end rings on stiffened conical shells using composites

    NASA Technical Reports Server (NTRS)

    Davis, R. C.; Cooper, P. A.

    1974-01-01

    Design study methods and results for a composite reinforced base ring for the conical aeroshell structure of the planetary lander vehicle for Project Viking, an unmanned mission to Mars, are presented. The aeroshell is a ring and stringer-stiffened conical shell structure having a half angle of 70 degrees with a large base ring mounted at the outer edge of the cone and a large pay-load ring in the interior with many smaller rings spaced along the inside shell surface. The purpose of the structure is to develop the aerodynamic drag required to decelerate the lander in the Mars atmosphere to facilitiate a soft landing. The design of a shell structure of this complexity requires the use of the latest technology available in a large general-purpose shell buckling program. The large general-purpose non-linear shell buckling program (BOSOR 2) which was used for this purpose is described.

  7. Materials science Nanotubes get hard

    E-print Network

    Downs, Robert T.

    Materials science Nanotubes get hard under pressure Proc. Natl Acad. Sci. USA doi:10.1073/pnas something so hard that it cracked the diamond teeth of the apparatus. But they hadn't simply turned-pressure phase of carbon, with a density, hardness and bulk modulus (the inverse of compressibility) at least

  8. Hard-pan soils - Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hard pans, hard layers, or compacted horizons, either surface or subsurface, are universal problems that limit crop production. Hard layers can be caused by traffic or soil genetic properties that result in horizons with high density or cemented soil particles; these horizons have elevated penetrati...

  9. Tailored core-shell-shell nanostructures: sandwiching gold nanoparticles between silica cores and tunable silica shells.

    PubMed

    Shi, Yan-Li; Asefa, Tewodros

    2007-08-28

    Size tunable and structure tailored core-shell-shell nanospheres containing silica cores, gold nanoparticle shells, and controlled thicknesses of smooth, corrugated, or porous silica shells over the gold nanoparticles have been synthesized. The synthesis involved the deposition of gold nanoparticles on silica cores, followed by sol-gel processing of tetraethoxysilane (TEOS) or sodium silicate to form dense or porous silica shells, respectively, over the gold nanoparticles. The structures and sizes of the resulting core-shell-shell nanospheres were found to heavily depend on the sizes of the core nanoparticles, the relative population of the gold nanoparticles on each core, and the concentration of TEOS. While a higher TEOS concentration resulted in thicker and more uniform silica shells around individual larger silica cores (approximately > or =250 nm in diameter), the same TEOS concentration resulted in aggregated and twin core-shell-shell nanostructures for smaller silica cores (approximately < or =110 nm in diameter). The thinner silica shells were synthesized by using a lower TEOS concentration. By using sodium silicate (Ung et al. J. Phys. Chem. B 1999, 103, 6770), the porous silica shells were synthesized. Controlled chemical etching of the core-shell-shell nanoparticles with an aqueous KCN solution resulted in corrugated silica shells around the gold nanoparticles or corrugated silica nanospheres with few or no gold nanoparticles. This has allowed synthesis of new types of core-shell-shell nanoparticles with tailored corrugated shells. The nanoporous silica shells provided accessible structures to the embedded metal nanoparticles as observed from the electrochemical response of the gold nanoparticles. PMID:17661498

  10. 7 CFR 984.10 - Shelled walnuts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA ...Shelled walnuts. Shelled walnuts means walnut kernels after the shells are...

  11. Spontaneous Regeneration of Human Photoreceptor Outer Segments

    PubMed Central

    Horton, Jonathan C.; Parker, Alicia B.; Botelho, James V.; Duncan, Jacque L.

    2015-01-01

    Photoreceptors are damaged in many common eye diseases, such as macular degeneration, retinal detachment, and retinitis pigmentosa. The development of methods to promote the repair or replacement of affected photoreceptors is a major goal of vision research. In this context, it would be useful to know whether photoreceptors are capable of undergoing some degree of spontaneous regeneration after injury. We report a subject who lost retinal function in a wide zone around the optic disc, giving rise to massive enlargement of the physiological blind spot. Imaging with an adaptive optics scanning laser ophthalmoscope (AOSLO) showed depletion of cone outer segments in the affected retina. A year later visual function had improved, with shrinkage of the enlarged blind spot. AOSLO imaging showed repopulation of cone outer segments, although their density remained below normal. There was a one-to-one match between sites of formerly missing outer segments and new outer segments that had appeared over the course of the year’s recovery. This correspondence provided direct morphological evidence that damaged cones are capable, under some circumstances, of generating new outer segments. PMID:26213154

  12. Oyster shell conveyor used to lift shells from the dock ...

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

    Oyster shell conveyor used to lift shells from the dock into the receiving room housed in the 1965 concrete block addition. - J.C. Lore Oyster House, 14430 Solomons Island Road, Solomons, Calvert County, MD

  13. HI shells in the Leiden/Argentina/Bonn HI survey

    NASA Astrophysics Data System (ADS)

    Ehlerová, S.; Palouš, J.

    2013-02-01

    Aims: We analyse the all-sky Leiden/Argentina/Bonn HI survey, where we identify shells belonging to the Milky Way. Methods: We used an identification method based on the search of continuous regions of a low brightness temperature that are compatible with given properties of HI shells. Results: We found 333 shells in the whole Galaxy. The size distribution of shells in the outer Galaxy is fitted by a power law with the coefficient of 2.6 corresponding to the index 1.8 in the distribution of energy sources. Their surface density decreases exponentially with a scale length of 2.8 kpc. The surface density of shells with radii ?100 pc in the solar neighbourhood is ~4 kpc-2 and the 2D porosity is ~0.7. Tables A.1 and A.2 are only available in electronic form 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/550/A23

  14. Baseline Microstructural Characterization of Outer 3013 Containers

    SciTech Connect

    Zapp, Phillip E.; Dunn, Kerry A

    2005-07-31

    Three DOE Standard 3013 outer storage containers were examined to characterize the microstructure of the type 316L stainless steel material of construction. Two of the containers were closure-welded yielding production-quality outer 3013 containers; the third examined container was not closed. Optical metallography and Knoop microhardness measurements were performed to establish a baseline characterization that will support future destructive examinations of 3013 outer containers in the storage inventory. Metallography revealed the microstructural features typical of this austenitic stainless steel as it is formed and welded. The grains were equiaxed with evident annealing twins. Flow lines were prominent in the forming directions of the cylindrical body and flat lids and bottom caps. No adverse indications were seen. Microhardness values, although widely varying, were consistent with annealed austenitic stainless steel. The data gathered as part of this characterization will be used as a baseline for the destructive examination of 3013 containers removed from the storage inventory.

  15. Shock interactions in the outer heliosphere

    NASA Technical Reports Server (NTRS)

    Whang, Y. C.

    1991-01-01

    The results of recent simulations of the nonlinear evolution of the solar wind structures are reviewed, emphasizing theoretical development and the shock interactions model (SIM). Models which calculate jumps in flow properties across shocks without using exact Rankine-Hugoniot relations and models which do use them are addressed. The development of a computer code and some basic applications to the SIM are considered. Simulation results for the formation and propagation of forward-reverse shock pairs and the collision and merging of shocks are shown. Two studies which used the SIM to simulate nonlinear evolution of large-scale solar wind structures in the outer heliosphere are examined, and the SIM is then applied to study the heating of the solar wind in the outer heliosphere. The results support the hypothesis that shocks are mainly responsible for the heating of the solar wind plasma in the outer heliosphere at least up to 30 AU.

  16. MHD processes in the outer heliosphere

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.

    1984-01-01

    The magnetic field measurements from Voyager and the magnetohydrodynamic (MHD) processes in the outer heliosphere are reviewed. A bibliography of the experimental and theoretical work concerning magnetic fields and plasmas observed in the outer heliosphere is given. Emphasis in this review is on basic concepts and dynamical processes involving the magnetic field. The theory that serves to explain and unify the interplanetary magnetic field and plasma observations is magnetohydrodynamics. Basic physical processes and observations that relate directly to solutions of the MHD equations are emphasized, but obtaining solutions of this complex system of equations involves various assumptions and approximations. The spatial and temporal complexity of the outer heliosphere and some approaches for dealing with this complexity are discussed.

  17. Origin of the Outer Solar System

    NASA Technical Reports Server (NTRS)

    Holman, Matthew J. (Principal Investigator); Boyce, Joseph (Technical Monitor)

    2003-01-01

    Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; (2) determining the size distributions or luminosity function of the individual populations or the Kuiper belt as a whole; (3) determining the inclinations distributions of these populations; (4) establishing the radial extent of the Kuiper belt; (5) measuring and relating the physical properties of different types of KBOs to those of other solar system bodies; and, (6) completing our systematic inventory of the satellites of the outer planets.

  18. Ptolemy's treatment of the outer planets

    NASA Astrophysics Data System (ADS)

    Duke, Dennis

    2005-01-01

    The purpose of this paper is to investigate whether for the outer planets Ptolemy followed his otherwise consistent custom of describing a scenario that did not happen as he says, or whether, at least for the outer planets, he left us a more accurate rendition of events. The detailed reconstructions of Ptolemy's calculations that follow show that, at least in the Almagest, Ptolemy is a writer with consistent habits when it comes to observations. We begin by reviewing, with minimal editorial comment, Ptolemy's calculations for each planet.

  19. Is the outer Solar System chaotic?

    E-print Network

    Wayne B. Hayes

    2007-02-07

    The existence of chaos in the system of Jovian planets has been in question for the past 15 years. Various investigators have found Lyapunov times ranging from about 5 millions years upwards to infinity, with no clear reason for the discrepancy. In this paper, we resolve the issue. The position of the outer planets is known to only a few parts in 10 million. We show that, within that observational uncertainty, there exist Lyapunov timescales in the full range listed above. Thus, the ``true'' Lyapunov timescale of the outer Solar System cannot be resolved using current observations.

  20. Hard metal composition

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM)

    1986-01-01

    A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 weight percent boron carbide and the remainder a metal mixture comprising from 70 to 90 percent tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 to 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

  1. Hard metal composition

    DOEpatents

    Sheinberg, H.

    1983-07-26

    A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 wt % boron carbide and the remainder a metal mixture comprising from 70 to 90% tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 and 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

  2. Hard physics in PHENIX

    E-print Network

    D. Peressounko; for the PHENIX collaboration

    2005-12-08

    We review recent results on hard observables in p+p, d+A and A+A collisions obtained by the PHENIX experiment. Emphasis is put on those measurements that provide insight into the properties of hot QCD media expected to be created in nucleus-nucleus collisions at RHIC energies. Direct photon spectra, jet properties and heavy quarks production measured in p+p and d+Au collisions are compared to the same observables extracted in heavy ion collisions to find modifications due to the presence of hot QCD matter.

  3. Shell Higher Olefins Process.

    ERIC Educational Resources Information Center

    Lutz, E. F.

    1986-01-01

    Shows how olefin isomerization and the exotic olefin metathesis reaction can be harnessed in industrial processes. Indicates that the Shell Higher Olefins Process makes use of organometallic catalysts to manufacture alpha-olefins and internal carbon-11 through carbon-14 alkenes in a flexible fashion that can be adjusted to market needs. (JN)

  4. Shell Creek Summers

    ERIC Educational Resources Information Center

    Seier, Mark; Goedeken, Suzy

    2005-01-01

    In 2002 Shell Creek Watershed Improvement Group turned to the Newman Grove Public Schools' science department to help educate the public on water quality in the watershed and to establish a monitoring system that would be used to improve surface and groundwater quality in the creek's watershed. Nebraska Department of Environmental Quality provided…

  5. Prevention of the Outer Space Weaponization

    NASA Astrophysics Data System (ADS)

    Zhukov, Gennady P.

    2002-01-01

    9 states. The satellites of various functions (early warning, communication, data acquisition, reconnaissance and navigation) were actively used and continue to be used with the purposes of raising efficiency of ground armed forces, especially in fight against international terrorism. At the same time such satellites are not a weapon in the sense of that word since they do not create the threats of armed attack in outer space or from outer space. Moreover, they promote maintaining of stability in the international relations. For this reason the reconnaissance and data acquisition satellites used for the verification of observance by States of the arms limitation agreements are under international protection as national technical means of the control. Similar protection is enjoyed by the early warning satellites. With the help of space communication facilities the more reliable operative connection of the statesmen is organized in the strained situations. By this way the probability of making of the incorrect retaliatory decisions in critical political situations is reduced. At the same time it's necessary to take into consideration that the activities of such satellite systems are tightly connected with ground armed forces of the states. the earth, what from the point of view of international law may be qualified as establishing a partial demilitarization regime in outer space. After the prohibition of anti-satellite weapons (ASAT) and anti-satellite (ASAT) weapons it will be possible to speak about establishing of an international legal regime of complete demilitarization in outer space eliminating any kinds of weapon from outer space. in a peaceful time. weaponization.The main task of this paper is to analyze and to discuss the present binding regime of the outer space deweaponization and particular measures on consolidation and strengthening of this regime. agreements of the Russian Federation and the USA into multilateral Treaties. Such "immunity" would cover all operating space objects, irrespective of their military or civil designation. This approach is quite justified taking into consideration that military sattelites enhanced international peace and security and had broad advantages, such as treaty compliance and monitoring, the global positioning system, counter-terrorism and sanctions enforcement. Many examples of the last years demonstrate the tendency of engagement of military satellites into commercial space services. transparency on the pre-launch stage of space activity, including satellite inspection before ignition. Objects Flight Path Tracking. implemantation of a non-use of force and threat of force - a fundamental principle of modern international law. This implies the application of the menshened principle of international law by means of a treaty to the outer space activities with reference to the actions made in outer space, or directed from outer space against targets on the Earth as well as directed from the Earth against objects moving in outer space. to the possibility of conclusion in future of a multilateral arrangement on the prohibition of the space-based ABM. Accordingly, it is discussed the problem of an efficient international control over the prohibition of placement of the above mentioned weapons into outer space. to the challenges of the new millennium. 8

  6. First Images from HERO: A Hard-X-Ray Focusing Telescope

    NASA Technical Reports Server (NTRS)

    Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Benson, Carl M.; Dietz, Kurtis L.; Elsner, Ronald F.; Engelhaupt, Darell E.; Ghosh, Kajal K.; Kolodziejczak, Jeffery J.; ODell, Stephen L.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    We are developing a balloon-borne hard-x-ray telescope that utilizes grazing incidence optics. Termed HERO, for High-Energy Replicated Optics, the instrument will provide unprecented sensitivity in the hard-x-ray region and will achieve milliCrab-level sensitivity in a typical 3-hour balloon-flight observation and 50 microCrab sensitivity on ultra-long-duration flights. A recent proof-of-concept flight, featuring a small number of mirror shells captured the first focused hard-x-ray images of galactic x-ray sources. Full details of the payload, its expected future performance and its recent measurements are provided.

  7. Rollable Thin-Shell Nanolaminate Mirrors

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Lih, Shyh-Shiuh; Barbee, Troy, Jr.

    2003-01-01

    A class of lightweight, deployable, thin-shell, curved mirrors with built-in precise-shape-control actuators is being developed for high-resolution scientific imaging. This technology incorporates a combination of advanced design concepts in actuation and membrane optics that, heretofore, have been considered as separate innovations. These mirrors are conceived to be stowed compactly in a launch shroud and transported aboard spacecraft, then deployed in outer space to required precise shapes at much larger dimensions (diameters of the order of meters or tens of meters). A typical shell rollable mirror structure would include: (1) a flexible single- or multiple-layer face sheet that would include an integrated reflective surface layer that would constitute the mirror; (2) structural supports in the form of stiffeners made of a shape-memory alloy (SMA); and (3) piezoelectric actuators. The actuators, together with an electronic control subsystem, would implement a concept of hierarchical distributed control, in which (1) the SMA actuators would be used for global shape control and would generate the large deformations needed for the deployment process and (2) the piezoelectric actuators would generate smaller deformations and would be used primarily to effect fine local control of the shape of the mirror.

  8. Natural melting within a spherical shell

    NASA Technical Reports Server (NTRS)

    Bahrami, Parviz A.

    1990-01-01

    Fundamental heat transfer experiments were performed on the melting of a phase change medium in a spherical shell. Free expansion of the medium into a void space within the sphere was permitted. A step function temperature jump on the outer shell wall was imposed and the timewise evolution of the melting process and the position of the solid-liquid interface was photographically recorded. Numerical integration of the interface position data yielded information about the melted mass and the energy of melting. It was found that the rate of melting and the heat transfer were significantly affected by the movement of the solid medium to the base of the sphere due to gravity. The energy transfer associated with melting was substantially higher than that predicted by the conduction model. Furthermore, the radio of the measured values of sensible energy in the liquid melt to the energy of melting were nearly proportional to the Stefan number. The experimental results are in agreement with a theory set forth in an earlier paper.

  9. Ground Based Studies of the Outer Planets

    NASA Technical Reports Server (NTRS)

    Trafton, Laurence M.

    2005-01-01

    This report covers progress to date under this grant on our continuing program to conduct ground based studies of the outer solar system planets and satellites, with emphasis on spectroscopy and atmospheric phenomena. The research continues under our new PAST grant, NNG04G131G beginning 5/1/2004. The original period of performance of the subject grant was 3/1/2001 to 2/28/2004, but was extended one year at no cost. Although there is some overlap in the scientific projects conducted during the extended year with those of the new grant, this report is confined to the portion of the work funded under NAG5-10435. The primary goals for this grant period were a comparative study of outer planet thermospheres/ionospheres near solar maximum, extended to the mid-IR, and the investigation of molecular dimers in outer solar system atmospheres. This project supports NASA's planned space missions, Jupiter Polar Orbiter, outer Planet Microprobes, and the recent Cassini flyby of Jupiter. It also supports the OSS strategic plan themes, The Exploration of the Solar System and The Sun-Earth Connection/ Understanding comparative planetary space environments.

  10. THE ORBITS OF THE OUTER URANIAN SATELLITES

    SciTech Connect

    Brozovic, M.; Jacobson, R. A.

    2009-04-15

    We report on the numerically integrated orbits for the nine outer Uranian satellites. The orbits are calculated based on fits to the astrometric observations for the period from 1984 to 2006. The results include the state vectors, post-fit residuals, and mean orbital elements. We also assess the accuracy of the orbital fits and discuss the need for future measurements.

  11. Scientific Goals for Exploration of the Outer

    E-print Network

    Rathbun, Julie A.

    Giant Planets Jupiter and Saturn Uranus and Neptune Giant Planet Magnetospheres Rings Moons Pristine that appears to involve (a) migration of the outer two giant planets, Uranus and Neptune, from somewhere closer with ocean worlds including Europa, Ganymede, Callisto, Enceladus, Titan and Triton. Uranus and Neptune

  12. The magnetospheres of the outer planets

    SciTech Connect

    Mcnutt, R.L., Jr. )

    1991-01-01

    Research on the magnetospheres of all of the outer planets including Jupiter, Uranus, Neptune, and Pluto is reviewed for the 1987-1990 time period. Particular attention is given to magnetospheric structure, plasma transport, Jovian aurora, Io and the plasma torus, Titan and its magnetospheric interactions, rings and dusty plasmas, magnetospheric convection, and satellite interactions.

  13. The processing of materials in outer space

    NASA Technical Reports Server (NTRS)

    Gelles, S. H.; Colling, E. W.

    1977-01-01

    Zero-gravity environment may lead to fabrication of new and improved materials. According to comprehensive study of application of this promising technology to superconducting and electrical contact materials, outer space processing could improve microstructure and homogeneity of many single and multicomponent systems formed from solidification of fluid phases. New structures that are impossible to form terrestrially may also be accessible in space environment.

  14. Protein composition of Rhodopseudomonas sphaeroides outer membrane.

    PubMed Central

    Baumgardner, D; Deal, C; Kaplan, S

    1980-01-01

    The outer membrane polypeptide profile of Rhodopseudmonas sphaeroides was characterized. Solubilization of the outer membrane at 75 or 100 degrees C as opposed to room temperature resulted in the dissociation of 75-, 72-, and 68-kilodalton (kdal) polypeptide aggregates into 29-, 26.5-, and 21.5-kdal polypeptides, respectively, and a shared 47-kdal subunit. Similarly, an 88.5-kdal polypeptide dissociates into a 45-kdal monomeric form, and the electrophoretic mobility of a 58.5-kdal polypeptide was altered to 83 kdal.Lysozyme treatment of outer membrane fractions altered the 21.5-kdal polypeptide mobility to 23 kdal. The presence of lipid in both the 47-kdal polypeptide and an 8- to 10-kdal polypeptide was demonstrated by lipid staining and [14C]acetate incorporation. The lipid component of the 47-kdal polypeptide was neither lipopolysaccharide nor phospholipid. The 8- to 10-kdal polypeptide may be the equivalent of the Braun lipoprotein. Outer membrane fractions isolated from R. sphaeroides-specific phage RS1-resistant mutants were deficient in several of the high-molecular-weight aggregates involving the 47-kdal polypeptide. Images PMID:6967483

  15. Outer membrane protein profiles of Yersinia ruckeri.

    PubMed

    Davies, R L

    1991-01-01

    The outer membrane protein (OMP) profiles of 135 isolates of Yersinia ruckeri, obtained from nine European countries (100 isolates), North America (23 isolates), Australia (six isolates) and South Africa (two isolates), and including four reference strains, were examined by SDS-PAGE. Outer membranes were isolated by selective solubilisation of the cytoplasmic membrane with 0.5% (w/v) sodium N-lauroyl sarcosinate (Sarkosyl). Outer membrane proteins were stable after in vitro passage and there was no variation in OMP profiles due to colony selection. With the exception of a 39.5 kDa peptidoglycan-associated protein there was also no variation at different stages of the growth cycle. The 39.5 kDa protein was not produced during logarithmic growth phase but increased in abundance as the stationary phase progressed. Interstrain variation occurred in the possession of a 36.5 or 38 kDa heat-modifiable protein and in the possession of peptidoglycan-associated proteins in the molecular weight range 36.5 to 40.5 kDa. Based on variation of these proteins five OMP-types, designated OMP-types 1-5, were identified among the 135 isolates examined. Outer membrane protein analysis was demonstrated to be useful in epidemiological studies of Y. ruckeri. PMID:2024435

  16. BIOREACTOR DESIGN - OUTER LOOP LANDFILL, LOUISVILLE, KY

    EPA Science Inventory

    Bioreactor field demonstration projects are underway at the Outer Loop Landfill in Louisville, KY, USA. The research effort is a cooperative research effort between US EPA and Waste Management Inc. Two primary kinds of municipal waste bioreactors are under study at this site. ...

  17. Understanding the Outer Planets and Planetary Atmospheres

    E-print Network

    Mojzsis, Stephen J.

    · Bizarre chemistry of Titan's atmosphere · Charging of dust grains on the surface of the Moon Planetary and Earth's atmosphere. The gas giants--Mars, Venus, Pluto, and various moons and comets-- all haveUnderstanding the Outer Planets and Planetary Atmospheres Planetary science focuses on many aspects

  18. Thickness Constraints on the Icy Shells of the Galilean Satellites from a Comparison of Crater Shapes

    NASA Technical Reports Server (NTRS)

    Schenk, Paul M.

    2002-01-01

    A thin outer ice shell on Jupiter's large moon Europa would imply easy exchange between the surface and any organic or biotic material in its putative subsurface ocean. The thickness of the outer ice shell is poorly constrained, however, with model-dependent estimates ranging from a few kilometers of depths of impact craters on Europa, Ganymede and Callisto that reveal two anomalous transitions in crater shape with diameter. The first transition is probably related to temperature-dependent ductility of the crust at shallow depths (7-8 km on Europa). The second transition is attributed to the influence of subsurface oceans on all three satellites, which constrains Europa's icy shell to be at least 19 km thick. The icy lithospheres of Ganymede and Callisto are equally ice-rich, but Europa's icy shell has a thermal structure about 0.25-0.5 times the thickness of Ganymede's or Callisto's shells, depending on epoch. The appearances of the craters on Europa are inconsistent with thin-ice-shell models and indicate that exchange of oceanic and surface material could be difficult.

  19. Mineralogy of shells from two freshwater snails Belgrandiella fontinalis and B kuesteri.

    PubMed

    Medakovi?, Davorin; Slapnik, Rajko; Popovi?, Stanko; Grzeta, Biserka

    2003-01-01

    X-ray powder diffraction (XRD) was used to study the mineral composition of shells of snails Belgrandiella fontinalis and Belgrandiella kuesteri collected from three freshwater springs in northeastern Slovenia. The fractions of aragonite, calcite, dolomite and quartz in particular shells were determined. The analysed shells consisted of two or more distinct inorganic layers. The outer shell layer for both species and all sampling localities contained aragonite. The outer layer of B. fontinalis collected at one locality, also contained a small fraction of calcite ( approximately 1 molar%) besides the dominant aragonite. Calcite was identified in the inner layer(s) of both species (2 to 3 molar%), while quartz was found only in B. kuesteri (5-7 molar%). However, both species sampled at one locality showed the presence of dolomite (approx. 20 molar%) in the inner layer(s). The presence of dolomite in the shells of adult gastropods and even molluscs is unusual. A possible formation mechanism and specific ecological factor that could influence the precipitation of dolomite in the shells of different Belgrandiella species is discussed. PMID:12507615

  20. Outer-shell excitation mechanisms and static-mode laser-fluorescence spectroscopy of sputtered atoms

    SciTech Connect

    Gruen, D.M.; Pellin, M.J.; Young, C.E.; Mendelsohn, M.H.; DeWald, A.B.

    1982-01-01

    A review of the literature on atoms sputtered in electronically excited states is given together with a discussion of various mechanisms that have been proposed to account for the observations. The major observational features that have emerged from the older studies may be summarized as follows: (1) the kinetic energies of neutral atoms in highly excited electronic states are 1-2 orders of magnitude greater than E/sub b/, the surface binding energy; (2) relative yields show approximately exponential dependence on excitation energy with characteristic temperatures measured in thousands of degrees; (43) absolute yields are lower by 2-3 orders of magnitude than secondary ion yields which themselves are usually very small compared to total sputtering yields. In many cases, excited-state yields increase 1-2 orders of magnitude as a result of surface oxidation. 83 references.

  1. Grinding tool for making hemispherical bores in hard materials

    DOEpatents

    Duran, E.L.

    1985-04-03

    A grinding tool for forming hemispherical bores in hard materials such as boron carbide. The tool comprises a hemicircular grinding bit, formed of a metal bond diamond matrix, which is mounted transversely on one end of a tubular tool shaft. The bit includes a spherically curved outer edge surface which is the active grinding surface of the tool. Two coolant fluid ports on opposite sides of the bit enable introduction of coolant fluid through the bore of the tool shaft so as to be emitted adjacent the opposite sides of the grinding bit, thereby providing optimum cooling of both the workpiece and the bit.

  2. Exciting Hard Spheres

    E-print Network

    T. Antal; P. L. Krapivsky; S. Redner

    2008-05-25

    We investigate the collision cascade that is generated by a single moving incident particle on a static hard-sphere gas. We argue that the number of moving particles at time t grows as t^{xi} and the number collisions up to time t grows as t^{eta}, with xi=2d/(d+2) and eta=2(d+1)/(d+2) and d the spatial dimension. These growth laws are the same as those from a hydrodynamic theory for the shock wave emanating from an explosion. Our predictions are verified by molecular dynamics simulations in d=1 and 2. For a particle incident on a static gas in a half-space, the resulting backsplatter ultimately contains almost all the initial energy.

  3. Bioluminescent signals spatially amplified by wavelength-specific diffusion through the shell of a marine snail

    PubMed Central

    Deheyn, Dimitri D.; Wilson, Nerida G.

    2011-01-01

    Some living organisms produce visible light (bioluminescence) for intra- or interspecific visual communication. Here, we describe a remarkable bioluminescent adaptation in the marine snail Hinea brasiliana. This species produces a luminous display in response to mechanical stimulation caused by encounters with other motile organisms. The light is produced from discrete areas on the snail's body beneath the snail's shell, and must thus overcome this structural barrier to be viewed by an external receiver. The diffusion and transmission efficiency of the shell is greater than a commercial diffuser reference material. Most strikingly, the shell, although opaque and pigmented, selectively diffuses the blue-green wavelength of the species bioluminescence. This diffusion generates a luminous display that is enlarged relative to the original light source. This unusual shell thus allows spatially amplified outward transmission of light communication signals from the snail, while allowing the animal to remain safely inside its hard protective shell. PMID:21159673

  4. Shoulder and hip joints for hard space suits and the like

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.

    1986-01-01

    For use in hard space suits and the like, a joint between the torso covering and the upper arm covering (i.e., shoulder) or between the torso covering and upper leg covering (i.e., hip) is disclosed. Each joint has an outer covering and a inner covering. The outer covering has plural perferably truncated toroidal sections decreasing in size proceeding outwardly. In one embodiment at each joint there are two bearings, the first larger than the second. The outer race of the larger bearing is attached to the outer edge of the smaller end of each section and the inner race of the larger bearing is attached to the end wall. The inner race of the smaller bearing is attached to the end wall. The outer race of the smaller bearing is attached to the larger end of the next section. Each bearing hask appropriate seals. Between each section is a rubber ring for the comfort of the wearer. Such rubber rings have radial flanges attached to the inner races of two adjacent bearings. Matching semicircular grooves are formed in the abutting overlapping surfaces. Bellows-like inner walls are also provided for each section fixed at one end to an inner cylindrical flange and, at the opposite end, to an end wall. Each outer section may rotate 360 deg relative to the next outer section, whereas the bellows sections do not rotate, but rather expand or contract locally as the rigid sections rotate relative to each other.

  5. Shell midden sclerochronology

    NASA Astrophysics Data System (ADS)

    Andrus, C. Fred T.

    2011-10-01

    Sclerochronological analysis of shell midden faunal remains offers a unique opportunity to study climate and environmental change in relation to human activity. Middens exist near most aquatic habitats almost worldwide for much of the late Pleistocene and Holocene. They afford good preservation of accretionary calcium carbonate remains, such as mollusk shells and fish otoliths, in comparatively well-dated contexts. As such, midden samples are a source of sequential proxy records of past climate and environmental conditions and may provide detailed pictures of human-environment interaction. However midden samples present several challenges to the development and application of sclerochronological proxies, including unique taphonomic concerns. Here these challenges are outlined within descriptions of the major applications of midden sclerochronology; archeological concerns including season of capture, reconstructing the history of anthropogenic environmental impacts, and paleoclimate/environment proxy reconstructions.

  6. 76 FR 63654 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ...Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental...Official Protraction Diagram (OPD), Lease Maps, and Supplemental Official OCS Block Diagrams...OCS Official Protraction Diagram, Lease Maps, and Supplemental Official OCS Shelf...

  7. Drift shells and aurora computed using the O8 magnetic field model for Neptune

    NASA Technical Reports Server (NTRS)

    Paranicas, C.; Cheng, A. F.

    1994-01-01

    Charged particle drift shells are calculated using the O8 magnetic field model for Neptune. Inner drift shell morphologies differ significantly from dipolar drift shells for the parts of drift shells inward of r = 2 R(sub N). Outer drift shells (L approx. greater than 10), when traced down to Neptune's surface following magnetic field lines, are simple closed loops around magnetic poles. Inner drift shells (L approx. less than 4), on the other hand, when traced to the surface, are also single loops but stretched in a previously unknown way: sometimes with a cusp and sometimes into two joined loops. Inner drift shell footprints on R = 1 provide the basis for identifying precipitation L shells, interpreting observed aurora, and predicting additional emissions on that part of Neptune's surface unobserved by the Ultraviolet Spectrometer (UVS). Precipitation in a global magnetic anomaly, `ordinary' auroral precipitation near the south magnetic pole, and precipitation from field lines with no magnetic field minimum above Neptune's exobase collectively appear to account for all of the observed auroral emission regions at Neptune. To the extent that aurora can be understood in this model, it is suggested O8 may be reasonably accurate.

  8. Design and synthesis of highly luminescent near-infrared-emitting water-soluble CdTe/CdSe/ZnS core/shell/shell quantum dots.

    PubMed

    Zhang, Wenjin; Chen, Guanjiao; Wang, Jian; Ye, Bang-Ce; Zhong, Xinhua

    2009-10-19

    Applications of water-dispersible near-infrared (NIR)-emitting quantum dots (QDs) have been hampered by their instability and low photoluminescence (PL) efficiencies. In this paper, water-soluble highly luminescent NIR-emitting QDs were developed through constructing CdTe/CdSe/ZnS core/shell/shell nanostructure. The CdTe/CdSe type-II structure yields the QDs with NIR emission. By varying the size of CdTe cores and the thickness of the CdSe shell, the emission wavelength of the obtained nanostructure can span from 540 to 825 nm. In addition, the passivation of the ZnS shell with a substantially wide bandgap confines the excitons within the CdTe/CdSe interface and isolates them from the solution environment and consequently improves the stability of the nanostructure, especially in aqueous media. An effective shell-coating route was developed for the preparation of CdTe/CdSe core/shell nanostructures by selecting capping reagents with a strong coordinating capacity and adopting a low temperature for shell deposition. An additional ZnS shell was deposited around the outer layer of CdTe/CdSe QDs to form the core/shell/shell nanostructure through the decomposition of single molecular precursor zinc diethyldithiocarbamate in the crude CdTe/CdSe reaction solution. The water solubilization of the initially oil-soluble CdTe/CdSe/ZnS QDs was achieved through ligand replacement by 3-mercaptopropionic acid. The as-prepared water-soluble CdTe/CdSe/ZnS QDs possess PL quantum yields as high as 84% in aqueous media, which is one of the best results for the luminescent semiconductor nanocrystals. PMID:19772326

  9. Myxobacteria produce outer membrane-enclosed tubes in unstructured environments.

    PubMed

    Wei, Xueming; Vassallo, Christopher N; Pathak, Darshankumar T; Wall, Daniel

    2014-05-01

    Myxobacteria are social microbes that exhibit complex multicellular behaviors. By use of fluorescent reporters, we show that Myxococcus xanthus isolates produce long narrow filaments that are enclosed by the outer membrane (OM) and contain proteins. We show that these OM tube (OMT) structures are produced at surprisingly high levels when cells are placed in liquid medium or buffer without agitation. OMTs can be long and easily exceed multiple cell lengths. When viewed by transmission electron microscopy, their morphology varies between tubes and chain-like structures. Intermediate-like structures are also found, suggesting that OMTs may transition between these two morphotypes. In support of this, video epifluorescence microscopy found that OMTs in solution dynamically twist and jiggle. On hard surfaces, myxobacteria glide, and upon cell-cell contact, they can efficiently exchange their OM proteins and lipids by a TraAB-dependent mechanism. Although the structure of OMTs hints at a possible role as conduits for exchange, evidence is presented to the contrary. For example, abundant OMT production occurs in traA or traB mutants and when cells are grown in liquid medium, yet transfer cannot occur under these conditions. Thus, genetic and environmental conditions that promote OMT production are incongruent with OM exchange. PMID:24391054

  10. Fluid instabilities of a uniformly imploding ablatively driven shell

    NASA Astrophysics Data System (ADS)

    Book, D. L.; Bernstein, I. B.

    1980-06-01

    The linear stability of a uniformly imploding shell, modelled as an ideal polytropic fluid was investigated. Two types of unstable modes were found: incompressible irrotational perturbations localized at the outer surface which are ascribed to Rayleigh-Taylor instability, and compressible modes associated with convective instability. Kidder's result for the Rayleigh-Taylor modes (1976) holds independently of the form of the shell density profile; by means of a variational principle it is shown that the criterion for convective instability is the existence of a region of 'super-adiabaticity'. Analytic solutions for spatial and temporal dependence of the perturbations are presented, and the results applied to pellets imploded by the action of a laser or a charged-particle beam.

  11. High energy-resolution electron energy-loss spectroscopy study of the dielectric properties of multi-shell nanoparticles.

    PubMed

    Nakahigashi, Naoyuki; Sato, Yohei; Terauchi, Masami; Uehara, Masato

    2014-11-01

    Nanoparticles, which have multi-shell structure, are expected to be stable and high efficient for the light-emitting devices. The efficiency of luminescence is considered to be affected by the multi-shell structure. In order to understand the mechanism of high efficiency luminescence, it is necessary to evaluate the multi-shell structure and dielectric properties from each particle. High energy-resolution electron energy-loss spectroscopy (HR-EELS) based on TEM is a powerful tool for this purpose. By comparing between the experimental and the simulated results, it is possible to evaluate the effect of the size and physical property of each shell material on the dielectric properties of multi-shell nanoparticles. In this study, simulations of EELS spectra of multi-shell nanoparticle (core: CdSe, inner shell: CdS, outer shell: ZnS) and mono-shell nanoparticle (core: CdSe, shell: CdS) were conducted by the dielectric continuum theory[1].Figure 1 shows calculated EELS spectra of multi and mono shell nanoparticles. The spectra are calculated from dielectric functions of single CdSe, CdS and ZnS crystals, which were experimentally derived from HR-EELS spectra by using Kramers-Kronig analysis. The radius of 6.9 nm for the nanoparticle in the simulation corresponds to the average size of actual synthesized nanoparticles. Energy positions of arrows in the inset correspond to band gap energies of CdSe, CdS and ZnS[2]. In the spectrum of multi-shell nanoparticle, the intensity corresponding to interband transition near band gap of CdSe is suppressed comparing with that of the mono shell nanoparticle. This result indicates that ZnS outer shell affects the intensity profile of EELS spectrum near band gap. This effect should be sensitive for the thickness of the shells. Thus, there is a possibility that the effect of size and thickness of each core and shell on dielectric properties of multi-shell nanoparticles could be evaluated by using HR-EELS technique.jmicro;63/suppl_1/i18/DFU039F1F1DFU039F1Fig. 1.Calculated EELS spectra. PMID:25359810

  12. Outer crust of nonaccreting cold neutron stars

    NASA Astrophysics Data System (ADS)

    Rüster, Stefan B.; Hempel, Matthias; Schaffner-Bielich, Jürgen

    2006-03-01

    The properties of the outer crust of nonaccreting cold neutron stars are studied by using modern nuclear data and theoretical mass tables, updating in particular the classic work of Baym, Pethick, and Sutherland. Experimental data from the atomic mass table from Audi, Wapstra, and Thibault of 2003 are used and a thorough comparison of many modern theoretical nuclear models, both relativistic and nonrelativistic, is performed for the first time. In addition, the influences of pairing and deformation are investigated. State-of-the-art theoretical nuclear mass tables are compared to check their differences concerning the neutron drip line, magic neutron numbers, the equation of state, and the sequence of neutron-rich nuclei up to the drip line in the outer crust of nonaccreting cold neutron stars.

  13. Irradiation chemistry in the outer solar system

    NASA Astrophysics Data System (ADS)

    Brown, Michael E.

    2014-11-01

    The dark, reddish tinged surfaces of icy bodies in the outer solar are usually attributed to the long term irradiation of simple hydrocarbons such as methane leading to the loss of hydrogen and the production of long carbon chains. While methane is stable and detected on the most massive bodies in the Kuiper belt, evidence of active irradiation chemistry is scant except for the presence of ethane on methane-rich Makemake and possible detections of ethane on more methane-poor Pluto and Quaoar. We have obtained deep high signal-to-noise spectra of Makemake from 1.5 to 2.5 microns in an attempt to trace the radiation chemistry in the outer solar system beyond the initial ethane formation. We present the first astrophysical detections of solid ethylene, acetylene, and possibly propane -- all expected products of the continued irradiation of methane, and use these species to map the chemical pathway from methane to long-chain hydrocarbons.

  14. Boundary layers of the earth's outer magnetosphere

    NASA Technical Reports Server (NTRS)

    Eastman, T. E.; Frank, L. A.

    1984-01-01

    The magnetospheric boundary layer and the plasma-sheet boundary layer are the primary boundary layers of the earth's outer magnetosphere. Recent satellite observations indicate that they provide for more than 50 percent of the plasma and energy transport in the outer magnetosphere although they constitute less than 5 percent by volume. Relative to the energy density in the source regions, plasma in the magnetospheric boundary layer is predominantly deenergized whereas plasma in the plasma-sheet boundary layer has been accelerated. The reconnection hypothesis continues to provide a useful framework for comparing data sampled in the highly dynamic magnetospheric environment. Observations of 'flux transfer events' and other detailed features near the boundaries have been recently interpreted in terms of nonsteady-state reconnection. Alternative hypotheses are also being investigated. More work needs to be done, both in theory and observation, to determine whether reconnection actually occurs in the magnetosphere and, if so, whether it is important for overall magnetospheric dynamics.

  15. Controllable fabrication and magnetic properties of double-shell cobalt oxides hollow particles

    PubMed Central

    Zhang, Dan; Zhu, Jianyu; Zhang, Ning; Liu, Tao; Chen, Limiao; Liu, Xiaohe; Ma, Renzhi; Zhang, Haitao; Qiu, Guanzhou

    2015-01-01

    Double-shell cobalt monoxide (CoO) hollow particles were successfully synthesized by a facile and effective one-pot solution-based synthetic route. The inner architecture and outer structure of the double-shell CoO hollow particles could be readily created through controlling experimental parameters. A possible formation mechanism was proposed based on the experimental results. The current synthetic strategy has good prospects for the future production of other transition-metal oxides particles with hollow interior. Furthermore, double-shell cobalt oxide (Co3O4) hollow particles could also be obtained through calcinating corresponding CoO hollow particles. The magnetic measurements revealed double-shell CoO and Co3O4 hollow particles exhibit ferromagnetic and antiferromagnetic behaviour, respectively. PMID:25736824

  16. Influence of interface stabilisers and surrounding aqueous phases on nematic liquid crystal shells.

    PubMed

    Noh, JungHyun; Reguengo De Sousa, Kevin; Lagerwall, Jan P F

    2015-12-23

    We investigate the nematic-isotropic (N-I) transition in shells of the liquid crystal 5CB, surrounded by aqueous phases that conventionally are considered to be immiscible with 5CB. The aqueous phases contain either sodium dodecyl sulfate (SDS) or polyvinyl alcohol (PVA) as stabiliser, the former additionally promoting homeotropic director alignment. For all shell configurations we find a depression of the clearing point compared to pure 5CB, indicating that a non-negligible fraction of the constituents of the surrounding phases enter the shell, predominantly water. In hybrid-aligned shells, with planar outer and homeotropic inner boundary (or vice versa), the N-I transition splits into two steps, with a consequent three-step textural transformation. We explain this as a result of the order-enhancing effect of a monolayer of radially aligned SDS molecules adsorbed at the homeotropic interface. PMID:26512764

  17. A photometric survey of outer belt asteroids

    NASA Technical Reports Server (NTRS)

    Dimartino, M.; Gonano-Beurer, M.; Mottola, Stefano; Neukum, G.

    1992-01-01

    Since 1989, we have been conducting a research program devoted to the study of the Trojans and outer belt asteroids (Hilda and Cybele groups), in order to characterize their rotational properties and shapes. As an outcome of several observational campaigns, we determined rotational periods and lightcurve amplitudes for 23 distant asteroids, using both CCD and photoelectric photometry. In this paper, we compare the rotational properties of main belt asteroids and Trojans, based on the preliminary results of this survey.

  18. Planetary magnetism in the outer solar system.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.

    1973-01-01

    A brief review of the salient considerations which apply to the existence of magnetic fields in connection with planetary and subplanetary objects in the outer solar system is given. Consideration is given to internal dynamo fields, fields which might originate from interaction with the solar wind or magnetospheres (externally driven dynamos) and lastly fossil magnetic fields such as have been discovered on the moon. Where possible, connection is made between magnetism, means of detection, and internal body properties.

  19. Stratigraphic evolution of Blake Outer Ridge

    SciTech Connect

    Markl, R.G.; Bryan, G.M.

    1983-04-01

    Multichannel seismic data from a reconnaissance survey of the Blake Outer Ridge reveal the seismic stratigraphy down to oceanic basement, as well as intracrustal and mantle reflections. The depositional history of the outer ridge can now be subdivided into four principal phases, based on seismic stratigraphic style: (1) Jurassic-Early Cretaceous sedimentation which filled in basement irregularities and leveled the sea floor by horizon ..beta.. (Barremian) time, (2) Early Cretaceous-Late Cretaceous deposition of a seaward-thinning wedge typical of Atlantic-type margins; its deeply eroded surface is probably equivalent to the Late Cretaceous-Miocene hiatus reflected by horizon A'', (3) earlies Miocene current-controlled deposits preferentially deposited along the axis of the incipient Blake Outer Ridge; these prograding strata, which thin and dip downridge and laterally away from the ridge axis, are attributed to the interaction of the Florida Current and Western Boundary Undercurrent, and (4) continuing early Miocene preferential deposition on the ridge axis and sculpting by the Western Boundary Undercurrent; this phase is characterized by strata thinning and dipping upridge and toward the ridge axis. The reversal of dip is explained to a first approximation by a steady-state contour-current model in which the current position is progressively shifted by the deposition. Five angular unconformities and associated bathymetric terraces west of the ridge crest are mapped using all Lamont-Doherty seismic data and interpreted as having formed penecontemporaneously during phase four. The areal extent of the gas hydrate (clathrate) horizon is also delineated; it is continuous across the northern Blake Outer Ridge, and the multichannel seismic data presented here show it to extend onto the shallow Blake Plateau as well.

  20. Measuring the Hardness of Minerals

    ERIC Educational Resources Information Center

    Bushby, Jessica

    2005-01-01

    The author discusses Moh's hardness scale, a comparative scale for minerals, whereby the softest mineral (talc) is placed at 1 and the hardest mineral (diamond) is placed at 10, with all other minerals ordered in between, according to their hardness. Development history of the scale is outlined, as well as a description of how the scale is used…

  1. CLOSURE WELD DEVELOPMENT FOR 3013 OUTER CONTAINERS

    SciTech Connect

    Daugherty, W.; Howard, S.; Peterson, K.; Stokes, M.

    2009-11-10

    Excess plutonium materials in the DOE complex are packaged and stored in accordance with DOE-STD-3013. This standard specifies requirements for the stabilization of such materials and subsequent packaging in dual nested seal-welded containers. Austenitic stainless steels have been selected for container fabrication. The inner 3013 container provides contamination control while the outer 3013 container is the primary containment vessel and is the focus of this paper. Each packaging site chose a process for seal welding the outer 3013 containers in accordance with its needs and expertise. The two processes chosen for weld closure were laser beam welding (LBW) and gas tungsten arc welding (GTAW). Following development efforts, each system was qualified in accordance with DOE-STD-3013 prior to production use. The 3013 outer container closure weld joint was designed to accommodate the characteristics of a laser weld. This aspect of the joint design necessitated some innovative process and equipment considerations in the application of the GTAW process. Details of the weld requirements and the development processes are presented and several potential enhancements for the GTAW system are described.

  2. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  3. Overview - Hard Rock Penetration

    SciTech Connect

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  4. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  5. STELLAR POPULATIONS IN THE OUTER HALO OF THE MASSIVE ELLIPTICAL M49

    SciTech Connect

    Mihos, J. Christopher; Harding, Paul; Rudick, Craig S.; Feldmeier, John J. E-mail: paul.harding@case.edu E-mail: jjfeldmeier@ysu.edu

    2013-02-20

    We use deep surface photometry of the giant elliptical M49 (NGC 4472), obtained as part of our survey for diffuse light in the Virgo Cluster, to study the stellar populations in its outer halo. Our data trace M49's stellar halo out to {approx}100 kpc (7r{sub e}), where we find that the shallow color gradient seen in the inner regions becomes dramatically steeper. The outer regions of the galaxy are quite blue (B - V {approx} 0.7); if this is purely a metallicity effect, it argues for extremely metal-poor stellar populations with [Fe/H] < -1. We also find that the extended accretion shells around M49 are distinctly redder than the galaxy's surrounding halo, suggesting that we are likely witnessing the buildup of both the stellar mass and metallicity in M49's outer halo due to late time accretion. While such growth of galaxy halos is predicted by models of hierarchical accretion, this growth is thought to be driven by more massive accretion events which have correspondingly higher mean metallicity than inferred for M49's halo. Thus the extremely metal-poor nature of M49's extended halo provides some tension against current models for elliptical galaxy formation.

  6. Beta Backscatter Measures the Hardness of Rubber

    NASA Technical Reports Server (NTRS)

    Morrissey, E. T.; Roje, F. N.

    1986-01-01

    Nondestructive testing method determines hardness, on Shore scale, of room-temperature-vulcanizing silicone rubber. Measures backscattered beta particles; backscattered radiation count directly proportional to Shore hardness. Test set calibrated with specimen, Shore hardness known from mechanical durometer test. Specimen of unknown hardness tested, and radiation count recorded. Count compared with known sample to find Shore hardness of unknown.

  7. Hardness Amplification Proofs Require Majority Ronen Shaltiel

    E-print Network

    Viola, Emanuele

    Hardness Amplification Proofs Require Majority Ronen Shaltiel Emanuele Viola April 28, 2010 Abstract Hardness amplification is the fundamental task of converting a -hard function f : {0, 1}n {0, 1} into a (1/2 - )-hard function Amp(f), where f is -hard if small circuits fail to compute f on at least

  8. Hardness-based plasticity and fracture model for quench-hardenable boron steel (22MnB5)

    SciTech Connect

    Greve, L. Medricky, M. Andres, M.; Eller, T. K.

    2013-12-16

    A comprehensive strain hardening and fracture characterization of different grades of boron steel blanks has been performed, providing the foundation for the implementation into the modular material model (MMM) framework developed by Volkswagen Group Research for an explicit crash code. Due to the introduction of hardness-based interpolation rules for the characterized main grades, the hardening and fracture behavior is solely described by the underlying Vickers hardness. In other words, knowledge of the hardness distribution within a hot-formed component is enough to set up the newly developed computational model. The hardness distribution can be easily introduced via an experimentally measured hardness curve or via hardness mapping from a corresponding hot-forming simulation. For industrial application using rather coarse and computationally inexpensive shell element meshes, the user material model has been extended by a necking/post-necking model with reduced mesh-dependency as an additional failure mode. The present paper mainly addresses the necking/post-necking model.

  9. 49 CFR 195.9 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  10. 49 CFR 195.9 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  11. 49 CFR 192.10 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Outer continental shelf pipelines. 192.10 Section... shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf (as defined in the Outer Continental Shelf Lands Act; 43 U.S.C. 1331) must identify on all their respective pipelines...

  12. 49 CFR 192.10 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Outer continental shelf pipelines. 192.10 Section... shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf (as defined in the Outer Continental Shelf Lands Act; 43 U.S.C. 1331) must identify on all their respective pipelines...

  13. 49 CFR 192.10 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Outer continental shelf pipelines. 192.10 Section... shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf (as defined in the Outer Continental Shelf Lands Act; 43 U.S.C. 1331) must identify on all their respective pipelines...

  14. 49 CFR 195.9 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  15. 49 CFR 195.9 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  16. 49 CFR 195.9 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Outer continental shelf pipelines. 195.9 Section... HAZARDOUS LIQUIDS BY PIPELINE General § 195.9 Outer continental shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf must identify on all their respective pipelines the specific...

  17. 49 CFR 192.10 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Outer continental shelf pipelines. 192.10 Section... shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf (as defined in the Outer Continental Shelf Lands Act; 43 U.S.C. 1331) must identify on all their respective pipelines...

  18. 49 CFR 192.10 - Outer continental shelf pipelines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Outer continental shelf pipelines. 192.10 Section... shelf pipelines. Operators of transportation pipelines on the Outer Continental Shelf (as defined in the Outer Continental Shelf Lands Act; 43 U.S.C. 1331) must identify on all their respective pipelines...

  19. Relation between outer and luminal diameter in cannulated arteries

    E-print Network

    Mecham, Robert

    Relation between outer and luminal diameter in cannulated arteries GILLES FAURY,1 GAIL M. MAHER,2. Rela- tion between outer and luminal diameter in cannulated arteries. Am. J. Physiol. 277 (Heart Circ area (WCSA) in cannulated arteries is nearly con- stant, allowing IDs to be calculated from outer

  20. 38 CFR 38.629 - Outer Burial Receptacle Allowance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Outer Burial Receptacle Allowance. 38.629 Section 38.629 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) NATIONAL CEMETERIES OF THE DEPARTMENT OF VETERANS AFFAIRS § 38.629 Outer Burial Receptacle Allowance. (a) Definitions—Outer...

  1. An Outer Bound for the Vector Gaussian CEO Problem

    E-print Network

    Ulukus, Sennur

    An Outer Bound for the Vector Gaussian CEO Problem Ersen Ekrem Sennur Ulukus Department@umd.edu Abstract--We study the vector Gaussian CEO problem, and provide an outer bound for its rate-distortion region is strictly contained in our outer bound. I. INTRODUCTION We study the vector Gaussian CEO problem

  2. 33 CFR 117.323 - Outer Clam Bay

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Outer Clam Bay 117.323 Section 117.323 Navigation and...Requirements Florida § 117.323 Outer Clam Bay The drawspan of the Outer Clam Bay Boardwalk Drawbridge shall open on signal if...

  3. Scientific Goals for Exploration of the Outer Solar System

    E-print Network

    Rathbun, Julie A.

    Scientific Goals for Exploration of the Outer Solar System Explore Diverse Worlds How did the outer planets mold the solar system and create habitable worlds? OPAG Report DRAFT 27 March 2015 #12;2 Outline the science objectives for exploration of the outer solar system. It is consistent with Visions and Voyages

  4. The structure of circumstellar shells

    NASA Technical Reports Server (NTRS)

    Fix, John D.

    1993-01-01

    This document provides a report on research activities carried out with the support of NASA grant NAG 5-1174, the Structure of Circumstellar Shells, funded under the Astrophysics Data Program. The research carried out with the support of this grant is a study of the properties of circumstellar dust shells for which spectra are available through IRAS low resolution spectrometry (LRS). This research consisted of the development and application of models of axisymmetric circumstellar shells and a preliminary survey of the applicability of neural nets for analysis of the IRAS LRS spectra of circumstellar dust shells.

  5. Peaceful Use of Outer Space: principles of Japanese Policies on Utilization and Activities in Outer space

    NASA Astrophysics Data System (ADS)

    Kosuge, Toshio

    2002-01-01

    " P e aceful use of outer space of outer space.....Principles of exploitation of outer space was passed in the Japanese Diet. It clearly mentioned that any activity of launching space object into outer space and developing launching rocket should be exclusively for peaceful purpose. NASDA was also established based upon the same principles of the public law. Japanese interpretation of Space Treaty and other related international agreements has been more strict on peaceful use of outer space, like non-military use rather than non-aggressive, because of influence of Japanese Constitution. Treaty and other agreements is analyzed through rapid development of its space activities, technologies and international cooperation with other space powers. Through more than thirty years experiences in space activities in public and private sectors, Japanese domestic laws and policies have not been changed in relation with basic principles. and laws relating to space activities in order to develop new space law and more international cooperation for space utilization rather than military use in new century.

  6. Formaldehyde in the far outer galaxy: constraining the outer boundary of the galactic habitable zone.

    PubMed

    Blair, Samantha K; Magnani, Loris; Brand, Jan; Wouterloot, Jan G A

    2008-02-01

    We present results from an initial survey of the 2(12)-1(11) transition of formaldehyde (H2CO) at 140.8 GHz in giant molecular clouds in the far outer Galaxy (RG >or= 16 kpc). Formaldehyde is a key prebiotic molecule that likely plays an important role in the development of amino acids. Determining the outermost extent of the H2CO distribution can constrain the outer limit of the Galactic Habitable Zone, the region where conditions for the formation of life are thought to be most favorable. We surveyed 69 molecular clouds in the outer Galaxy, ranging from 12 to 23.5 kpc in galactocentric radius. Formaldehyde emission at 140.8 GHz was detected in 65% of the clouds. The H2CO spectral line was detected in 26 of the clouds with RG > 16 kpc (detection rate of 59%), including 6 clouds with RG > 20 kpc (detection rate of 55%). Formaldehyde is readily found in the far outer Galaxy-even beyond the edge of the old stellar disk. Determining the relatively widespread distribution of H2CO in the far outer Galaxy is a first step in establishing how favorable an environment this vast region of the Galaxy may be toward the formation of life. PMID:18266563

  7. The jump-off velocity of an impulsively loaded spherical shell

    SciTech Connect

    Chabaud, Brandon M.; Brock, Jerry S.

    2012-04-13

    We consider a constant temperature spherical shell of isotropic, homogeneous, linearly elastic material with density {rho} and Lame coefficients {lambda} and {mu}. The inner and outer radii of the shell are r{sub i} and r{sub o}, respectively. We assume that the inside of the shell is a void. On the outside of the shell, we apply a uniform, time-varying pressure p(t). We also assume that the shell is initially at rest. We want to compute the jump-off time and velocity of the pressure wave, which are the first time after t = 0 at which the pressure wave from the outer surface reaches the inner surface. This analysis computes the jump-off velocity and time for both compressible and incompressible materials. This differs substantially from [3], where only incompressible materials are considered. We will consider the behavior of an impulsively loaded, exponentially decaying pressure wave p(t) = P{sub 0{sup e}}{sup -{alpha}t}, where {alpha} {ge} 0. We notice that a constant pressure wave P(t) = P{sub 0} is a special case ({alpha} = 0) of a decaying pressure wave. Both of these boundary conditions are considered in [3].

  8. Hardness variability in commercial technologies

    SciTech Connect

    Shaneyfelt, M.R.; Winokur, P.S.; Meisenheimer, T.L.; Sexton, F.W.; Roeske, S.B.; Knoll, M.G.

    1994-12-01

    The radiation hardness of commercial Floating Gate 256K E{sup 2}PROMs from a single diffusion lot was observed to vary between 5 to 25 krad(Si) when irradiated at a low dose rate of 64 mrad(Si)/s. Additional variations in E{sup 2}PROM hardness were found to depend on bias condition and failure mode (i.e., inability to read or write the memory), as well as the foundry at which the part was manufactured. This variability is related to system requirements, and it is shown that hardness level and variability affect the allowable mode of operation for E{sup 2}PROMs in space applications. The radiation hardness of commercial 1-Mbit CMOS SRAMs from Micron, Hitachi, and Sony irradiated at 147 rad(Si)/s was approximately 12, 13, and 19 krad(Si), respectively. These failure levels appear to be related to increases in leakage current during irradiation. Hardness of SRAMs from each manufacturer varied by less than 20%, but differences between manufacturers are significant. The Qualified Manufacturer`s List approach to radiation hardness assurance is suggested as a way to reduce variability and to improve the hardness level of commercial technologies.

  9. 7 CFR 51.2002 - Split shell.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Split shell. 51.2002 Section 51.2002 Agriculture Regulations of the Department of Agriculture...Grades of Filberts in the Shell 1 Definitions § 51.2002 Split shell. Split shell means a shell...

  10. 7 CFR 51.2002 - Split shell.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Split shell. 51.2002 Section 51.2002 Agriculture Regulations of the Department of Agriculture...Grades of Filberts in the Shell 1 Definitions § 51.2002 Split shell. Split shell means a shell...

  11. 7 CFR 51.2002 - Split shell.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Split shell. 51.2002 Section 51.2002 Agriculture Regulations of the Department of Agriculture...Grades of Filberts in the Shell 1 Definitions § 51.2002 Split shell. Split shell means a shell...

  12. 7 CFR 51.2002 - Split shell.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Split shell. 51.2002 Section 51.2002 Agriculture Regulations of the Department of Agriculture...Grades of Filberts in the Shell 1 Definitions § 51.2002 Split shell. Split shell means a shell...

  13. 7 CFR 51.2002 - Split shell.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Split shell. 51.2002 Section 51.2002 Agriculture Regulations of the Department of Agriculture...Grades of Filberts in the Shell 1 Definitions § 51.2002 Split shell. Split shell means a shell...

  14. Automated shell theory for rotating structures (ASTROS)

    NASA Technical Reports Server (NTRS)

    Foster, B. J.; Thomas, J. M.

    1971-01-01

    A computer program for analyzing axisymmetric shells with inertial forces caused by rotation about the shell axis is developed by revising the STARS II shell program. The basic capabilities of the STARS II shell program, such as the treatment of the branched shells, stiffened wall construction, and thermal gradients, are retained.

  15. Off-Shell Supersymmetry

    E-print Network

    Chiu Man Ho; Nobuchika Okada

    2015-11-23

    Supersymmetry does not dictate the way we should quantize the fields in the supermultiplets, and so we have the freedom to quantize the Standard Model (SM) particles and their superpartners differently. We propose a generalized quantization scheme under which a particle can only appear off-shell, while its contributions to quantum corrections are exactly the same as those in the usual quantum field theory. We apply this quantization scheme solely to the sparticles in the $R$-parity preserving Minimal Supersymmetric Standard Model (MSSM). Thus sparticles can only appear off-shell. They could be light but would completely escape the direct detection at any experiments such as the LHC. However, our theory still retains the same desirable features of the usual MSSM at the quantum level. For instance, the gauge hierarchy problem is solved and the three MSSM gauge couplings are unified in the usual way. Although direct detection of sparticles is impossible, their existence can be revealed by precise measurements of some observables (such as the running QCD coupling) that may receive quantum corrections from them and have sizable deviations from the SM predictions. Also the experimental constraints from the indirect sparticle search are still applicable.

  16. Off-shell supersymmetry

    NASA Astrophysics Data System (ADS)

    Ho, Chiu Man; Okada, Nobuchika

    2015-11-01

    Supersymmetry does not dictate the way we should quantize the fields in the supermultiplets, and so we have the freedom to quantize the Standard Model (SM) particles and their superpartners differently. We propose a generalized quantization scheme under which a particle can only appear off-shell, while its contributions to quantum corrections are exactly the same as those in the usual quantum field theory. We apply this quantization scheme solely to the sparticles in the R-parity preserving Minimal Supersymmetric Standard Model (MSSM). Thus, sparticles can only appear off-shell. They could be light but would completely escape the direct detection at any experiments such as the LHC. However, our theory still retains the same desirable features of the usual MSSM at the quantum level. For instance, the gauge hierarchy problem is solved and the three MSSM gauge couplings are unified in the usual way. Although direct detection of sparticles is impossible, their existence can be revealed by precise measurements of some observables (such as the running QCD coupling) that may receive quantum corrections from them and have sizable deviations from the SM predictions. Also, the experimental constraints from the indirect sparticle search are still applicable.

  17. Discovery of Molecular Gas Shells around the Unusual Galaxy Centaurus A

    NASA Astrophysics Data System (ADS)

    2000-03-01

    Recent observations by an international team of astronomers [1] with the 15-metre Swedish-ESO Submillimetre Telescope at the La Silla observatory (Chile) have shown that the unusual, nearby galaxy Centaurus A is surrounded by shells in which carbon monoxide molecules are present. These new exciting results are the first of their kind. In addition to the intrinsic scientific value of this discovery, it also provides an instructive example of what will become possible for more distant galaxies with the projected Atacama Large Millimeter Array (ALMA) , now in the planning phase. Ellipticals and spirals Galaxies come in different shapes. Some of these take the form of more or less perfect spirals, some have the form of ellipsoids and still others have an irregular appearance. One of the major differences between elliptical and spiral galaxies is that the former do not possess extensive gaseous discs in which young stars can be formed. This is despite the fact that most elliptical galaxies are probably formed by the merger of two or more spiral galaxies. However, during such a process most of the gas in the spirals is either quickly turned into stars by massive bursts of star formation or is completely lost into the surrounding space. Shells around elliptical galaxies Most galaxies are members of groups. Once they have been formed, massive elliptical galaxies in these often behave like "cannibals" by swallowing one or more smaller companion galaxies. Some vestiges of such an event may remain visible for a certain time after the merger, normally in the form of weak structures in the otherwise smooth light distribution over the elliptical galaxy. These structures resemble the ripples or waves that develop on the water surface when you throw a small stone into a calm pond. While long-exposure photos show them as faint "rings" around the galaxy, they are in fact the projected images of three-dimensional structures and are often referred to as shells . By means of photometric and spectrographic studies of their light, it has been known since the early 1980's that such shells are made up of stars. It appears that they are quite common - about half of the nearby large elliptical galaxies have been found to be surrounded by stellar shells. More recently, in 1994, atomic hydrogen gas was discovered to be associated with some of the stellar shells. This discovery was a bit of a surprise, because the current theory predicts that when two galaxies merge, their gas and stars will behave very differently. While the individual stars hardly ever hit each other, the interstellar gas clouds collide violently. They will lose all their energy and the gas will fall towards the common centre where it is soon consumed in vigorous bursts of star formation. Why would there then be hydrogen gas in the outer shells of some elliptical galaxies? A possible origin of gaseous shells The astronomer team, headed by Vassilis Charmandaris [1] decided to look into this serious discrepancy between theory and observations. They believed that a possible explanation might be that this diffuse atomic gas is located, not in vast, very dilute clouds, but rather in smaller, much denser molecular clouds , such as these are known in our own galaxy, the Milky Way. Due to their relative compactness (more than 1000 molecules/cm 3 , i.e,. at least 100 times more than that of larger diffuse clouds), molecular clouds would behave more like the stars during the galaxy collision event. Indeed, realistic calculations showed that the dynamical behavior of such dense clouds would be intermediate between the stars and the diffuse hydrogen gas. Thus, while most of the gas would still end up in the centre of the remaining galaxy after a merger, a larger fraction of it would be able to survive at large distances from the nucleus. This would then be the origin of the observed hydrogen shells. During the merger, gas that originates from regions in the outskirts of the "cannibalized" galaxy - and farther out than most of the stars - would be liberated earlier

  18. Lunar and Planetary Science XXXV: Outer Solar System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session 'Outer Solar System" inlcuded:Monte Carlo Modeling of [O I] 630 nm Auroral Emission on Io; The Detection of Iron Sulfide on Io; Io and Loki in 2003 as Seen from the Infrared Telescope Facility Using Mutual Satellite and Jupiter Occultations; Mapping of the Zamama-Thor Region of Io; First Solar System Results of the Spitzer Space Telescope; Mapping the Surface of Pluto with the Hubble Space Telescope; Experimental Study on Fischer-Tropsch Catalysis in the Circum-Saturnian Subnebula; New High-Pressure Phases of Ammonia Dihydrate; Gas Hydrate Stability at Low Temperatures and High Pressures with Applications to Mars and Europa; Laboratory UV Photolysis of Planetary Ice Analogs Containing H2O + CO2 (1:1); The OH Stretch Infrared Band of Water Ice and Its Temperature and Radiation Dependence; Band Position Variations in Reflectance Spectra of the Jovian Satellite Ganymede; Comparison of Porosity and Radar Models for Europa s Near Surface; Combined Effects of Diurnal and Nonsynchronous Surface Stresses on Europa; Europa s Northern Trailing Hemisphere: Lineament Stratigraphic Framework; Europa at the Highest Resolution: Implications for Surface Processes and Landing Sites; Comparison of Methods to Determine Furrow System Centers on Ganymede and Callisto; Resurfacing of Ganymede by Liquid-Water Volcanism; Layered Ejecta Craters on Ganymede: Comparisons with Martian Analogs; Evaluation of the Possible Presence of CO2-Clathrates in Europa s Icy Shell or Seafloor; Geosciences at Jupiter s Icy Moons: The Midas Touch; Planetary Remote Sensing Science Enabled by MIDAS (Multiple Instrument Distributed Aperture Sensor); and In Situ Surveying of Saturn s Rings.

  19. Biomineralisation in Mollusc shells

    NASA Astrophysics Data System (ADS)

    Dauphin, Y.; Cuif, J. P.; Salomé, M.; Williams, C. T.

    2009-04-01

    The main components of Mollusc shells are carbonate minerals: calcite and aragonite. ACC is present in larval stages. Calcite and aragonite can be secreted simultaneously by the mantle. Despite the small number of varieties, the arrangement of the mineral components is diverse, and dependant upon the taxonomy. They are also associated with organic components much more diverse, the diversity of which reflects the large taxonomic diversity. From TGA analyses, the organic content (water included) is high (>5% in some layers). The biomineralisation process is not a passive precipitation process, but is strongly controlled by the organism. The biological-genetic control is shown by the constancy of the arrangement of the layers, the mineralogy and the microstructure in a given species. Microstructural units (i.e. tablets, prisms etc.) have shapes that do not occur in non-biogenic counterparts. Nacreous tablets, for example, are flattened on their crystallographic c axis, which is normally the axis of maximum growth rate for non-biogenic aragonite. Morever, their inner structure is species-specific: the arrangements of nacreous tablets in Gastropoda - Cephalopoda, and in Bivalvia differ, and the inner arrangement of the nacreous tablets is different in ectocochlear and endocochlear Cephalopoda. The organic-mineral ratios also differ in the various layers of a shell. Differences in chemical composition also demonstrates the biological-genetic control: for example, aragonite has a low Sr content unknown in non-biogenic samples; two aragonitic layers in a shell have different Sr and Mg contents, S is higher in calcitic layers. Decalcification releases soluble (SOM) and insoluble (IOM) organic components. Insoluble components form the main part of the intercrystalline membranes, and contain proteins, polysaccharides and lipids. Soluble phases are present within the crystals and the intercrystalline membranes. These phases are composed of more or less glycosylated proteins and polysaccharides, with a large range of molecular weights. Proteins are rich in acidic aminoacids (aspartic and glutamic acids). Sugars are usually sulphated, and very acidic. Several hundreds of proteins and sugars are present in the SOM. The compositions of IOM and SOM are characteristic for each layer present in a shell. Topographical relationships of mineral and organic components are visible at different scales of observation. SEM images of etched surfaces display the growth line rhythmicity and concordance between adjacent microstructural units. EPMA maps show similar chemical growth lines in various structures. Whatever the taxa, the average thickness of growth lines is about 2-3 µm, indicating an inner biological rhythm, not dependant on the environmental conditions. Such growth lines are observed in deep sea molluscs at depth where diurnal changes in light and temperature are absent. However, the role of the environment is shown by larger periodicities. Sulphur deserves a special interest, because it is associated with the organic matrices. Electrophoretic data have shown that acidic sulphated sugars are abundant in some layers. XANES analyses confirm these results. New microscopic techniques allow us to obtain images at a submicrometer scale. AFM images show that all the microstructural units (i.e. tablets, prisms etc.), calcite or aragonite, are composed of small sub-spherical granules with a diameter typically of about 50 nm. These granules are surrounded by a thin cortex (about 8 nm) of organic and/or amorphous material, and are organo-composite material as shown by phase images. They do not have crystalline shapes, despite the fact that the units they build are often monocrystalline. Molecular biology and genetic studies confirm that the control of the biomineralisation process is exerted at the scale of the whole organism: the expression of genes encoding major shell matrix proteins clearly indicates a regular separation of calcite and aragonite secretory activity. The main control on the structural and compositional features of mollusc she

  20. The structural, compositional and mechanical features of the calcite shell of the barnacle Tetraclita rufotincta.

    PubMed

    Astachov, Liliana; Nevo, Zvi; Brosh, Tamar; Vago, Razi

    2011-09-01

    The microstructure and chemical composition of the calcite shell of the sea barnacle Tetraclita rufotincta (Pilsbry, 1916) were investigated using microscopic and analytical methods. The barnacle shell was separated mechanically into its three substructural units: outer, interior, and inner layers. The organic matrices of these structural parts were further separated into soluble and insoluble constituents and their characteristic functional groups were studied by FTIR. Investigation of the mechanical properties of the interior mass of the shell reveals remarkable viscoelastic behavior. In general, the mechanical behavior of the shell is a function of its geometry as well as of the material, of which it is constructed. In the case of T. rufotincta, as calcite is a brittle material, the elastic behavior of the shell is apparently related to its micro- and macroarchitecture. The latter enables the shell to fulfill its primary function which is to protect the organism from a hostile environment and enables its survival. Our detailed identification of the similarities and differences between the various structural components of the shell in regard to the composition and properties of the organic component will hopefully throw light on the role of organic matrices in biomineralization processes. PMID:21549194

  1. Spectral sensitization with dyes of core-silver halide shell microsystems

    NASA Astrophysics Data System (ADS)

    Tyurin, A. V.; Zhukov, S. A.; Churashov, V. P.

    2015-09-01

    We have studied spectral sensitization with anionic dyes of core-silver halide shell microsystems cores of which can be either nonsilver or silver halide compounds. Conditions under which dye sensitizers, being adsorbed on cores, remain under silver halide shells after their growing are considered. Comparison of results of sensitometric and low-temperature ( T = 77 K) luminescent measurements have shown that these conditions are determined by the charge state of cations of microsystem cores. If the shell contains the same univalent component in its composition as the core does, as in the case in which the core is a silver halide compound, the anionic dye is displaced to the outer surface of the shell. If the core contains a divalent cationic component, as in the case in which the core is a nonsilver compound, the dye remains under the silver halide shell; i.e., it is overgrown by the shell. We have shown that the charge state of core cations affects the character of the core interaction with anionic dyes, which ensures differences in the spectral sensitization of core-silver halide shell microsystems, as well as differences in the dye photoexcitation relaxation in them.

  2. Production of K-shell radiation using double gas puffs with stabilizing axial magnetic field

    NASA Astrophysics Data System (ADS)

    Oreshkin, V. I.; Baksht, R. B.; Chaikovsky, S. A.

    2000-10-01

    Use of z-pinch implosions for producing K-shell radiation on the generators with a slow current rise rate requires large initial radii of the imploding shells. However, implosions of z-pinches with large initial radii are very unstable, and such loads could only be used if additional measures are taken to stabilize the implosions. This paper presents the results of 1D RMHD simulation of double gas puff implosion with stabilizing axial magnetic field. The simulations were carried out for the conditions of two different generators: IMRI-5 generator, peak current up to 0.5 MA, current rise time 500 ns, Ne gas puff; and GIT-12 generator, peak current up to 2.5 MA, current rise time 300 ns, Ar gas puff. The optimal load parameters with respect to K-shell yield were determined: masses and initial radii of the shells, mass ratio and radius ratio of inner and outer shells. The K-shell emission was shown to take place in the inner shell, which is compressed and heated by work of the ponderomotive forces.

  3. Hi shells, supershells, shell-like objects, and ''worms''

    SciTech Connect

    Heiles, C.

    1984-08-01

    We present photographic representations of the combination of two Hi surveys, so as to eliminate the survey boundaries at Vertical BarbVertical Bar = 10/sup 0/. We also present high-contrast photographs for particular velocities to exhibit weak Hi features. All of these photographs were used to prepare a new list of Hi shells, supershells, and shell-like objects. We discuss the structure of three shell-like objects that are associated with high-velocity gas, and with gas at all velocities that is associated with radio continuum loops I, II, and III. We use spatial filtering to find wiggly gas filaments: ''worms'': crawling away from the galactic plane in the inner Galaxy. The ''worms'' are probably parts of shells that are open at the top; such shells should be good sources of hot gas for the galactic halo.

  4. The Young Outer Disk of M83

    NASA Astrophysics Data System (ADS)

    Davidge, T. J.

    2010-08-01

    Deep near-infrared images recorded with NICI on Gemini South are used to investigate the evolved stellar content in the outer southeast quadrant of the spiral galaxy M83. A diffuse population of asymptotic giant branch (AGB) stars is detected, indicating that there are stars outside of the previously identified young and intermediate age star clusters in the outer disk. The brightest AGB stars have M K >= -8, and the AGB luminosity function (LF) is well matched by model LFs that assume ages <=1 Gyr. The specific star formation rate (SFR) during the past few Gyr estimated from AGB star counts is consistent with that computed from mid-infrared observations of star clusters at similar radii, and it is concluded that the disruption timescale for star clusters in the outer disk is Lt1 Gyr. The LF and specific frequency of AGB stars vary with galactocentric radius, in a manner that is indicative of lower luminosity-weighted ages at larger radii. Modest numbers of red supergiants are also found, indicating that there has been star formation during the past 100 Myr, while the ratio of C stars to M giants is consistent with that expected for a solar metallicity system that has experienced a constant SFR for the past few Gyr. The results drawn from the properties of resolved AGB stars are broadly consistent with those deduced from integrated light observations in the UV. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a co-operative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council of Canada (Canada), CONICYT (Chile), the Australian Research Council (Australia), the Ministerio da Ciencia e Technologia (Brazil), and the Ministerio de Ciencia, Tecnologia e Innovacion Productiva (Argentina).

  5. Gas hydrates of outer continental margins

    SciTech Connect

    Kvenvolden, K.A. )

    1990-05-01

    Gas hydrates are crystalline substances in which a rigid framework of water molecules traps molecules of gas, mainly methane. Gas-hydrate deposits are common in continental margin sediment in all major oceans at water depths greater than about 300 m. Thirty-three localities with evidence for gas-hydrate occurrence have been described worldwide. The presence of these gas hydrates has been inferred mainly from anomalous lacoustic reflectors seen on marine seismic records. Naturally occurring marine gas hydrates have been sampled and analyzed at about tensites in several regions including continental slope and rise sediment of the eastern Pacific Ocean and the Gulf of Mexico. Except for some Gulf of Mexico gas hydrate occurrences, the analyzed gas hydrates are composed almost exclusively of microbial methane. Evidence for the microbial origin of methane in gas hydrates includes (1) the inverse relation between methane occurence and sulfate concentration in the sediment, (2) the subparallel depth trends in carbon isotopic compositions of methane and bicarbonate in the interstitial water, and (3) the general range of {sup 13}C depletion ({delta}{sub PDB}{sup 13}C = {minus}90 to {minus}60 {per thousand}) in the methane. Analyses of gas hydrates from the Peruvian outer continental margin in particular illustrate this evidence for microbially generated methane. The total amount of methane in gas hydrates of continental margins is not known, but estimates of about 10{sup 16} m{sup 3} seem reasonable. Although this amount of methane is large, it is not yet clear whether methane hydrates of outer continental margins will ever be a significant energy resource; however, these gas hydrates will probably constitute a drilling hazard when outer continental margins are explored in the future.

  6. Aqueous synthesis of glutathione-capped CdTe/CdS/ZnS and CdTe/CdSe/ZnS core/shell/shell nanocrystal heterostructures.

    PubMed

    Samanta, Anirban; Deng, Zhengtao; Liu, Yan

    2012-05-29

    Here we demonstrate the aqueous synthesis of colloidal nanocrystal heterostructures consisting of the CdTe core encapsulated by CdS/ZnS or CdSe/ZnS shells using glutathione (GSH), a tripeptide, as the capping ligand. The inner CdTe/CdS and CdTe/CdSe heterostructures have type-I, quasi-type-II, or type-II band offsets depending on the core size and shell thickness, and the outer CdS/ZnS and CdSe/ZnS structures have type-I band offsets. The emission maxima of the assembled heterostructures were found to be dependent on the CdTe core size, with a wider range of spectral tunability observed for the smaller cores. Because of encapsulation effects, the formation of successive shells resulted in a considerable increase in the photoluminescence quantum yield; however, identifying optimal shell thicknesses was required to achieve the maximum quantum yield. Photoluminescence lifetime measurements revealed that the decrease in the quantum yield of thick-shell nanocrystals was caused by a substantial decrease in the radiative rate constant. By tuning the diameter of the core and the thickness of each shell, a broad range of high quantum yield (up to 45%) nanocrystal heterostructures with emission ranging from visible to NIR wavelengths (500-730 nm) were obtained. This versatile route to engineering the optical properties of nanocrystal heterostructures will provide new opportunities for applications in bioimaging and biolabeling. PMID:22551311

  7. Eccentric features in Saturn's outer C ring

    SciTech Connect

    Porco, C.C.; Nicholson, P.D.

    1987-11-01

    The present search for possible eccentric and inclined features in the outer C ring of Saturn measured all sharp-edged feature radii in Voyager C ring data. The Maxwell ringlet and two other narrow ringlets, 1.470R(s) and 1.495R(s) are found to be eccentric; the latter is best fitted by a model describing a freely precessing Keplerian ellipse, while the former is not conclusively fitted by either a resonant forcing or a free precession model. These two eccentric ringlets are compared with the Titan and Maxwell ringlets. 51 references.

  8. Dark matter in the outer solar system

    NASA Technical Reports Server (NTRS)

    Owen, T.; Cruikshank, D.; De Bergh, C.; Geballe, T.

    1994-01-01

    There are now a large number of small bodies in the outer solar system that are known to be covered with dark material. Attempts to identify that material have been thwarted by the absence of discrete absorption features in the reflection spectra of these planetesimals. An absorption at 2.2 micrometers that appeared to be present in several objects has not been confirmed by new observations. Three absorptions in the spectrum of the unusually red planetesimal 5145 Pholus are well-established, but their identity remains a mystery.

  9. Accretion in the Early Outer Solar System

    E-print Network

    Scott J. Kenyon; Jane X. Luu

    1999-06-08

    We describe calculations of the evolution of an ensemble of small planetesimals in the outer solar system. In a solar nebula with a mass of several times the Minimum Mass Solar Nebula, objects with radii of 100-1000 km can form on timescales of 10-100 Myr. Model luminosity functions derived from these calculations agree with current observations of bodies beyond the orbit of Neptune (Kuiper Belt objects). New surveys with current and planned instruments can place better constraints on the mass and dynamics of the solar nebula by measuring the luminosity function at red magnitudes of 28 or larger.

  10. Atmospheric entry probes for outer planet exploration. Outer planet entry probe technical summary

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The use of unmanned space probes for investigating the conditions existing on and around the outer planets of the solar system is discussed. The subjects included in the report are: (1) the design of a common entry probe for outer planet missions, (2) the significant trades related to the development of a common probe design, (3) the impact of bus selection on probe design, (4) the impact of probe requirements on bus modifications, and (5) the key technology elements recommended for advanced development. Drawings and illustrations of typical probes are included to show the components and systems used in the space probes.

  11. Velocity moments in the outer nightside magnetodisk of Saturn

    NASA Astrophysics Data System (ADS)

    Nemeth, Z.; Szego, K.; Foldy, L.; Kivelson, M. G.; Jia, X.; Ramer, K. M.; Cowley, S. W. H.; Provan, G.; Thomsen, M.

    2013-09-01

    Saturn has a huge rotating magnetosphere, fields and particles exhibit rotational periodicities in all plasma parameters, the periods depend on epoch, elevation, etc. The rotating plasma forms a magnetodisk in the vicinity of the equatorial plane. Studies by Andrews et al. [2012] and Provan et al. [2012] have shown that magnetic field modulation in the northern and southern lobe have distinct and different periods (the well known northern and southern periods), whereas in the magnetodisk both periods are present and changing smoothly with the distance from the equatorial plane; near the current sheet the magnetic field exhibits dual periodicities, roughly of equal amplitudes. The disk has a complex shape depending on local time, seasons of Saturn, and external forces (SW), and it is tilted, possibly due to currents. The non-rigid rotation of the tilted disk imitates flapping, that is a periodic vertical motion in the outer magnetosphere for an observer such as Cassini. Wherever the central line intersects the radial component of the magnetic field, the radial component is about zero, and the ion densities reach their peak values [Szego et al., 2011]. The results of recent numerical simulations [Jia and Kivelson, 2012] show that in the magnetodisk of Saturn fluctuating magnetic field perturbations are accompanied by other oscillatory phenomena. They investigated the magnetotail response for a dual periodicity driver in the case when the solar wind flow was perpendicular to the rotation axis. It was demonstrated that the components of the flow velocity extracted at different radial distances plotted versus time exhibit periodic modulation. We have investigated periodicities in the azimuthal and latitudinal component of the flow velocities using the numerical ion moments derived from the measurements of Cassini Plasma Spectrometer [Thomsen et al, 2010]. Ramer et al. [2012] investigated these periodicities in the inner magnetosphere near the equatorial plane. We have found that the azimuthal velocities show oscillatory behavior in the outer magnetosphere. It was found that the dense plasma near the magnetic equator rotates around the planet at high speed, while the dilute plasma of higher latitudes of the north and south hemispheres is rotating significantly slower. This observed latitudinal gradient in the azimuthal speed as a function of the distance from the equatorial plane can be a direct consequence of the sub-corotation of the plasma in the outer magnetosphere; highest speeds occurring on field lines at lowest latitudes mapping the rapidly rotating inner regions of the plasmasheet, and the speed falling as one approaches the lobe, where the field lines are connected to far away strongly subcorotating plasma. This suggests a picture of the magnetodisk, in which each L-shell rotates more or less rigidly, but the rotation speed is decreasing with L increasing. The dayside magnetodisk structure differs in many respects from the properties observed nightside. We shall point out some of these differences.

  12. Foam shell cryogenic ICF target

    DOEpatents

    Darling, Dale H. (Pleasanton, CA)

    1987-01-01

    A uniform cryogenic layer of DT fuel is maintained in a fusion target having a low density, small pore size, low Z rigid foam shell saturated with liquid DT fuel. Capillary action prevents gravitational slumping of the fuel layer. The saturated shell may be cooled to produce a solid fuel layer.

  13. Shell Observations of Classical Novae

    NASA Astrophysics Data System (ADS)

    Esenoglu, H. H.; Saygac, A. T.

    2014-12-01

    We present shell observations of some classical novae from the Turkish National Observatory. We reobserved them to image their faint shells a long time after their outbursts. We revise the old findings with the new data and we call attention to narrow band pass observations.

  14. 7 CFR 983.29 - Shelled pistachios.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Shelled pistachios. 983.29 Section 983.29 Agriculture...Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND... Definitions § 983.29 Shelled pistachios. Shelled pistachios means...

  15. 7 CFR 983.29 - Shelled pistachios.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Shelled pistachios. 983.29 Section 983.29 Agriculture...Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND... Definitions § 983.29 Shelled pistachios. Shelled pistachios means...

  16. 7 CFR 983.29 - Shelled pistachios.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Shelled pistachios. 983.29 Section 983.29 Agriculture...NUTS), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND... Definitions § 983.29 Shelled pistachios. Shelled pistachios means...

  17. 7 CFR 983.29 - Shelled pistachios.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Shelled pistachios. 983.29 Section 983.29 Agriculture...NUTS), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND... Definitions § 983.29 Shelled pistachios. Shelled pistachios means...

  18. Recent progress in the ground calibration of the ASTRO-H Hard X-ray telescope (HXT-2)

    NASA Astrophysics Data System (ADS)

    Mori, Hideyuki; Kuroda, Yuji; Miyazawa, Takuya; Awaki, Hisamitsu; Babazaki, Yasunori; Furuzawa, Akihiro; Hibino, Tatsuya; Iizuka, Ryo; Ishibashi, Kazunori; Iwase, Toshihiro; Kunieda, Hideyo; Kurihara, Daichi; Matsumoto, Hironori; Miyata, Yusuke; Saji, Shigetaka; Sugita, Satoshi; Suzuki, Yoshio; Tachibana, Sasagu; Tamura, Keisuke; Tawara, Yuzuru; Uesugi, Kentaro

    2014-07-01

    The 6th Japanese X-ray satellite, ASTRO-H, equips two Hard X-ray Telescopes (HXTs) to perform imaging spectroscopy up to 70 keV. The 2nd flight module (HXT-2) had been completed in July, 2013. After some environmental tests were passed, the X-ray performance of the HXT-2 was measured at the SPring-8 BL20B2, 3rd generation synchrotron facility. The angular resolution defined with a Half Power Diameter (HPD) was 1:'9 at 30 keV and 1:'8 at 50 keV. This small energy dependence is considered to be caused by the difference in image quality of each foil; the inner mirror shells have better quality than outer ones. The effective area was found to be 178 cm2 at 30 keV and 82 cm2 at 50 keV, both of which exceed the requirement. Furthermore, the detailed energy dependence of the effective area was examined for a limited aperture in the 30{70 keV band with a pitch of 1 keV. We also measured the off-axis dependence of the effective area at 50 keV, and then determined the optical axis. The field of view of the HXT-2 was found to be 5:'6 (FWHM of the vignetting function), consistent with the simulation. In this paper, we also report the detailed analysis of the ground calibration data, which will be used for image reconstruction by a ray-tracing simulator.

  19. Shell tile thermal protection system

    NASA Technical Reports Server (NTRS)

    Macconochie, I. O.; Lawson, A. G.; Kelly, H. N. (inventors)

    1984-01-01

    A reusable, externally applied thermal protection system for use on aerospace vehicles subject to high thermal and mechanical stresses utilizes a shell tile structure which effectively separates its primary functions as an insulator and load absorber. The tile consists of structurally strong upper and lower metallic shells manufactured from materials meeting the thermal and structural requirements incident to tile placement on the spacecraft. A lightweight, high temperature package of insulation is utilized in the upper shell while a lightweight, low temperature insulation is utilized in the lower shell. Assembly of the tile which is facilitated by a self-locking mechanism, may occur subsequent to installation of the lower shell on the spacecraft structural skin.

  20. Circumstellar Disks and Outer Planet Formation

    E-print Network

    A. Lecavelier Des Etangs

    1998-06-16

    The dust disk around Beta Pic must be produced by collision or by evaporation of orbiting Kuiper belt-like objects. Here we present the Orbiting-Evaporating-Bodies scenario in which the disk is a gigantic multi-cometary tail supplied by slowly evaporating bodies like Chiron. If dust is produced by evaporation, a planet with an eccentric orbit can explain the observed asymmetry of the disk, because the periastron distribution of the parent bodies are then expected to be non-axisymmetric. We investigate the consequence for the Kuiper belt-like objects of the formation and the migration of an outer planet like Neptune in Fernandez's scheme (1982). We find that bodies trapped in resonance with a migrating planet can significantly evaporate, producing a Beta Pic-like disk with similar characteristics like opening angle and asymmetry. We thus show that the Beta Pic disk can be a transient phenomenon. The circumstellar disks around main sequence stars can be the signature of the present formation and migration of outer planets.

  1. Future exploration of the outer solar system

    NASA Astrophysics Data System (ADS)

    Johnson, T.

    Exploration of the outer solar system is constrained by vast distances, consequent communications and light time limitations, power, and long flight times. Early reconnaissance missions (Pioneer 10 and 11, Voyager 1 and 2) employed relatively fast trajectories resulting in very fast fly-bys. The next generation of exploration (Galileo and Cassini) has been characterized by spacecraft with large propellant systems and relatively slow (gravity assist) trajectories needed energetically to achieve orbit around Jupiter and Saturn. All of these spacecraft utilized radioisotope thermoelectric generators for reliable, but modest power. Future exploration priorities require highly capable spacecraft systems that go into orbit around the primary planet and then perform multiple tasks (e.g. orbiting individual moons and delivering surface and atmospheric scientific probes). To achieve major scientific advances will require significant increases in communication rates, improved instrumentation and high power available for experiments. Fission-powered nuclear electric propulsion is being studied to meet these requirements. A Jupiter Icy Moons Orbiter is proposed as the first of this class of new, highly capable missions. The paper will review the scientific rationale for the JIMO mission and prospects for applying these techniques to exploration of Saturn and the other outer planets.

  2. The Utility of Outer Planet Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hill, Steven M.

    2015-05-01

    Amateur astronomers can now routinely record disk integrated spectra of the outer planets at moderate to high spectral and temporal resolution. Initial studies of the application of small telescope spectroscopy to the outer planets (including Titan) were published in the early 2000's. This paper seeks to revisit these capabilities in conjunction with advances in understanding the target atmospheres, available low-cost instrumentation, and current observational needs within the research community. First, observations and data reduction are presented. Second, the basic capability of small-scope planetary spectroscopy is re-validated and spectra of Jupiter, Saturn, Titan, Uranus and Neptune are compared to professional spectra at similar resolutions. Third, effective line-of-sight methane number density, etaN(CH4), is retrieved using best fits to integrated band strengths for both classical single reflecting layer models and classical homogeneous scattering models. The observations and methane number densities obtained lie within the scatter seen in published literature. Fourth, the challenges to making highly repeatable, well calibrated observations are examined. This is done in the context of monitoring for transient changes in band strengths, e.g., as result of longitudinal variations clouds, hazes and/or surface albedo. Jupiter provides an easy, high signal-to-noise test case where the detectability of Great Red Spot transits is evaluated. In conclusion, we summarize the results, make recommendations for extending this work and suggest a campaign that could be carried out immediately by appropriately equipped amateurs.

  3. OSSOS: The Outer Solar System Origins Survey

    NASA Astrophysics Data System (ADS)

    Gladman, Brett; Bannister, Michele; Kavelaars, Jj; Petit, Jean-Marc; Gwyn, Stephen; Chen, Ying-Tung

    2014-11-01

    We present the first detection set from the Outer Solar System Origins Survey (OSSOS) which is a mammoth 560-hour CFHT Large Program over 4 years (finishing January 2017). This is likely to be the largest Kuiper Belt survey before LSST comes on line (in terms of the number of precise transneptunian object (TNO) orbits it provides).OSSOS studies gradually-slewing 21-square degree blocks of sky that are repeatedly imaged in many dark runs over two semesters. This strategy is designed to detect and track TNOs in order to provide extremely high-quality orbits in a short amount of time; in 16-18 month arcs we are obtaining fractional semimajor axis uncertainties in the range 0.01-0.1% and accuracies in the libration amplitudes of resonant objects better than 10 degrees, due to mean astrometric residuals routinely being of order 50-100 milliarcseconds.This talk will present the survey design and full detection sample for objects observed in the first half of 2013 and 2014. We will report how adding these detections to those from the Canada-France Ecliptic Plane Survey (CFEPS) modifies conclusions about the orbital and size distribution of main classical Kuiper Belt, as well as other non-resonant sub-populations. In particular, because OSSOS is sensitive to, and has detected objects, from 8 AU to beyond 60 AU, we will report on how the combined distance and magnitude distribution impact dicsussions of the absolute magnitude distribution of outer Solar System objects.

  4. Composite shell spacecraft seat

    NASA Technical Reports Server (NTRS)

    Barackman, Victor J. (Inventor); Pulley, John K. (Inventor); Simon, Xavier D. (Inventor); McKee, Sandra D. (Inventor)

    2008-01-01

    A two-part seat (10) providing full body support that is specific for each crew member (30) on an individual basis. The two-part construction for the seat (10) can accommodate many sizes and shapes for crewmembers (30) because it is reconfigurable and therefore reusable for subsequent flights. The first component of the two-part seat construction is a composite shell (12) that surrounds the crewmember's entire body and is generically fitted to their general size in height and weight. The second component of the two-part seat (10) is a cushion (20) that conforms exactly to the specific crewmember's entire body and gives total body support in more complex environment.

  5. 76 FR 54787 - Outer Continental Shelf Official Protraction Diagram, Lease Maps, and Supplemental Official Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... LA1 (West Cameron Area)--7/01/2011. LA12 (Sabine Pass Area)--7/01/2011. Supplemental Official Outer... Located Within Lease Map LA1 (West Cameron Area) Date/Block Number 7/01/2011: 53. Supplemental Official... http://www.boemre.gov/homepg/pubinfo/MapsandSpatialData.html . Dated: July 5, 2011. Robert P....

  6. Isolation of the outer membrane and characterization of the major outer membrane protein from Spirochaeta aurantia.

    PubMed Central

    Kropinski, A M; Parr, T R; Angus, B L; Hancock, R E; Ghiorse, W C; Greenberg, E P

    1987-01-01

    The outer membrane of Spirochaeta aurantia was isolated after cells were extracted with sodium lauryl sarcosinate and was subsequently purified by differential centrifugation and KBr isopycnic gradient centrifugation. The purified outer membrane was obtained in the form of carotenoid-containing vesicles. Four protein species with apparent molecular weights of 26,000 (26K), 36.5K, 41K, and 48.5K were readily observed as components of the vesicles. The 36.5K protein was the major polypeptide and constituted approximately 90% of the outer membrane protein observed on sodium dodecyl sulfate-polyacrylamide gels. Under mild denaturing conditions the 36.5K major protein exhibited an apparent molecular weight of approximately 90,000. This, together with the results of protein cross-linking studies, indicates that the 36.5K polypeptide has an oligomeric conformation in the native state. Reconstitution of solubilized S. aurantia outer membrane into lipid bilayer membranes revealed the presence of a porin, presumably the 36.5K protein, with an estimated channel diameter of 2.3 nm based on the measured single channel conductance of 7.7 nS in 1 M KCl. Images PMID:3025168

  7. Magnetically self-assembled SrFe12O19/Fe-Co core/shell particles

    SciTech Connect

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-02-15

    Epitaxial growth to synthesize core/shell-structured materials is limited because large lattice mismatches are common between materials. Magnetically hard/soft, core/shell-structured materials can be potentially used for rare-earth free permanent magnets, but their synthesis presents a challenge. We report a wet chemistry method to synthesize core/shell structured particles consisting of a magnetically hard SrFe12O19 core and a soft Fe-Co shell, with a lattice mismatch of similar to 100%, which cannot be achieved by conventional epitaxial growth or other alternative methods. When decreasing the size of the magnetically soft Fe-Co nanoclusters to below 5 nm, we show that they can be magnetically attracted by the hard SrFe12O19 to form core/shell structured particles. An AC demagnetization experiment demonstrates the formation mechanism of the core/shell particles, and their magnetic hysteresis loop shows potential for use as rare-earth free permanent magnets. Published by Elsevier B.V.

  8. Turbulent 3D MHD dynamo model in spherical shells: Regular oscillations of the dipolar field

    E-print Network

    Simitev, R D; Kosovichev, A G

    2011-01-01

    We report the results of three-dimensional numerical simulations of convection-driven dynamos in relatively thin rotating spherical shells that show a transition from an strong non-oscillatory dipolar magnetic field to a weaker regularly oscillating dipolar field. The transition is induced primarily by the effects a stress-free boundary condition. The variation of the inner to outer radius ratio is found to have a less important effect.

  9. Resonant scattering of outer zone relativistic electrons by multiband EMIC waves and resultant electron loss time scales

    NASA Astrophysics Data System (ADS)

    Ni, Binbin; Cao, Xing; Zou, Zhengyang; Zhou, Chen; Gu, Xudong; Bortnik, Jacob; Zhang, Jichun; Fu, Song; Zhao, Zhengyu; Shi, Run; Xie, Lun

    2015-09-01

    To improve our understanding of the role of electromagnetic ion cyclotron (EMIC) waves in radiation belt electron dynamics, we perform a comprehensive analysis of EMIC wave-induced resonant scattering of outer zone relativistic (>0.5 MeV) electrons and resultant electron loss time scales with respect to EMIC wave band, L shell, and wave normal angle model. The results demonstrate that while H+-band EMIC waves dominate the scattering losses of ~1-4 MeV outer zone relativistic electrons, it is He+-band and O+-band waves that prevail over the pitch angle diffusion of ultrarelativistic electrons at higher energies. Given the wave amplitude, EMIC waves at higher L shells tend to resonantly interact with a larger population of outer zone relativistic electrons and drive their pitch angle scattering more efficiently. Obliquity of EMIC waves can reduce the efficiency of wave-induced relativistic electron pitch angle scattering. Compared to the frequently adopted parallel or quasi-parallel model, use of the latitudinally varying wave normal angle model produces the largest decrease in H+-band EMIC wave scattering rates at pitch angles < ~40° for electrons > ~5 MeV. At a representative nominal amplitude of 1 nT, EMIC wave scattering produces the equilibrium state (i.e., the lowest normal mode under which electrons at the same energy but different pitch angles decay exponentially on the same time scale) of outer belt relativistic electrons within several to tens of minutes and the following exponential decay extending to higher pitch angles on time scales from <1 min to ~1 h. The electron loss cone can be either empty as a result of the weak diffusion or heavily/fully filled due to approaching the strong diffusion limit, while the trapped electron population at high pitch angles close to 90° remains intact because of no resonant scattering. In this manner, EMIC wave scattering has the potential to deepen the anisotropic distribution of outer zone relativistic electrons by reshaping their pitch angle profiles to "top-hat." Overall, H+-band and He+-band EMIC waves are most efficient in producing the pitch angle scattering loss of relativistic electrons at ~1-2 MeV. In contrast, the presence of O+-band EMIC waves, while at a smaller occurrence rate, can dominate the scattering loss of 5-10 MeV electrons in the entire region of the outer zone, which should be considered in future modeling of the outer zone relativistic electron dynamics.

  10. Oceans, Ice Shells, and Life on Europa

    NASA Technical Reports Server (NTRS)

    Schenk, Paul

    2002-01-01

    The four large satellites of Jupiter are famous for their planet-like diversity and complexity, but none more so than ice-covered Europa. Since the provocative Voyager images of Europa in 1979, evidence has been mounting that a vast liquid water ocean may lurk beneath the moon's icy surface. Europa has since been the target of increasing and sometimes reckless speculation regarding the possibility that giant squid and other creatures may be swimming its purported cold, dark ocean. No wonder Europa tops everyone's list for future exploration in the outer solar system (after the very first reconnaissance of Pluto and the Kuiper belt, of course). Europa may be the smallest of the Galilean moons (so-called because they were discovered by Galileo Galilei in the early 17th century) but more than makes up for its diminutive size with a crazed, alien landscape. The surface is covered with ridges hundreds of meters high, domes tens of kilometers across, and large areas of broken and disrupted crust called chaos. Some of the geologic features seen on Europa resemble ice rafts floating in polar seas here on Earth-reinforcing the idea that an ice shell is floating over an ocean on this Moon-size satellite. However, such features do not prove that an ocean exists or ever did. Warm ice is unusually soft and will flow under its own weight. If the ice shell is thick enough, the warm bottom of the shell will flow, as do terrestrial glaciers. This could produce all the observed surface features on Europa through a variety of processes, the most important of which is convection. (Convection is the vertical overturn of a layer due to heating or density differences-think of porridge or sauce boiling on the stove.) Rising blobs from the base of the crust would then create the oval domes dotting Europa's surface. The strongest evidence for a hidden ocean beneath Europa's surface comes from the Galileo spacecraft's onboard magnetometer, which detected fluctuations in Jupiter's magnetic field consistent with a conductor inside Europa. The most likely conductor: a somewhat salty ocean.

  11. Core-shell-shell and hollow double-shell microgels with advanced temperature responsiveness.

    PubMed

    Dubbert, Janine; Nothdurft, Katja; Karg, Matthias; Richtering, Walter

    2015-01-01

    Unique doubly temperature-responsive hollow microgels are presented. These consist of two concentric thermoresponsive polymer shells made of poly(N-isopropylacrylamide) (PNIPAM) and poly(N-isopropylmethacrylamide) (PNIPMAM), respectively. The hollow particles are derived from silica-PNIPAM-PNIPMAM core-shell-shell (CSS) particles by dissolution of the silica core. Light scattering measurements reveal the twofold volume phase transition behavior that occur in the PNIPAM and PNIPMAM regions of the CSS and the respective hollow particles. In the presence of the silica core, i.e., in case of the CSS particles, the swelling of the inner shell is tremendously restricted by the core. However, after the core is dissolved, the transition of the inner shell from the swollen to the collapsed state is highly pronounced. This versatile approach allows preparing hollow particles with individually tunable properties on the particle inside and outside for various applications as multifunctional smart materials. PMID:25354836

  12. THE OUTER DISKS OF DWARF IRREGULAR GALAXIES

    SciTech Connect

    Hunter, Deidre A.; Massey, Philip; Wilsey, Nick; Riabokin, Malanka; Elmegreen, Bruce G.; Oh, Se-Heon; Anderson, Ed; Nordgren, Tyler E. E-mail: phil.massey@lowell.edu E-mail: riabokin@msu.edu E-mail: seheon-oh@ast.uct.ac.za E-mail: tyler_nordgren@redlands.edu

    2011-10-15

    In order to explore the properties of extreme outer stellar disks, we obtained ultra-deep V and GALEX ultraviolet (UV) images of four dwarf irregular galaxies and one blue compact dwarf galaxy, and ultra-deep B images of three of these. Our V-band surface photometry extends to 29.5 mag arcsec{sup -2}. We convert the FUV and V-band photometry, along with H{alpha} photometry obtained in a larger survey, into radial star formation rate profiles that are sensitive to timescales from 10 Myr to the lifetime of the galaxy. We also obtained H I-line emission data and compare the stellar distributions, surface brightness profiles, and star formation rate profiles to H I-line emission maps, gas surface density profiles, and gas kinematics. Our data lead us to two general observations. First, the exponential disks in these irregular galaxies are extraordinarily regular. We observe that the stellar disks continue to decline exponentially as far as our measurements extend. In spite of lumpiness in the distribution of young stars and H I distributions and kinematics that have significant unordered motions, sporadic processes that have built the disks-star formation, radial movement of stars, and perhaps even perturbations from the outside-have, nevertheless, conspired to produce standard disk profiles. Second, there is a remarkable continuity of star formation throughout these disks over time. In four out of five of our galaxies the star formation rate in the outer disk measured from the FUV tracks that determined from the V-band, to within factors of five, requiring star formation at a fairly steady rate over the galaxy's lifetime. Yet, the H I surface density profiles generally decline with radius more shallowly than the stellar light, and the gas is marginally gravitationally stable against collapse into clouds. Outer stellar disks are challenging our concepts of star formation and disk growth and provide a critical environment in which to understand processes that mold galaxy disks.

  13. Glass shell manufacturing in space

    NASA Technical Reports Server (NTRS)

    Downs, R. L.; Ebner, M. A.; Nolen, R. L., Jr.

    1981-01-01

    Highly-uniform, hollow glass spheres (shells), which are used for inertial confinement fusion targets, were formed from metal-organic gel powder feedstock in a vertical furnace. As a result of the rapid pyrolysis caused by the furnace, the gel is transformed to a shell in five distinct stages: (a) surface closure of the porous gel; (b) generation of a closed-cell foam structure in the gel; (c) spheridization of the gel and further expansion of the foam; (d) coalescence of the closed-cell foam to a single-void shell; and (e) fining of the glass shell. The heat transfer from the furnace to the falling gel particle was modeled to determine the effective heating rate of the gel. The model predicts the temperature history for a particle as a function of mass, dimensions, specific heat, and absorptance as well as furnace temperature profile and thermal conductivity of the furnace gas. A model was developed that predicts the gravity-induced degradation of shell concentricity in falling molten shells as a function of shell characteristics and time.

  14. Crack problems in cylindrical and spherical shells

    NASA Technical Reports Server (NTRS)

    Erdogan, F.

    1976-01-01

    Standard plate or shell theories were used as a starting point to study the fracture problems in thin-walled cylindrical and spherical shells, assuming that the plane of the crack is perpendicular to the surface of the sheet. Since recent studies have shown that local shell curvatures may have a rather considerable effect on the stress intensity factor, the crack problem was considered in conjunction with a shell rather than a plate theory. The material was assumed to be isotropic and homogeneous, so that approximate solutions may be obtained by approximating the local shell crack geometry with an ideal shell which has a solution, namely a spherical shell with a meridional crack, a cylindrical shell with a circumferential crack, or a cylindrical shell with an axial crack. A method of solution for the specially orthotropic shells containing a crack was described; symmetric and skew-symmetric problems are considered in cylindrical shells with an axial crack.

  15. Spitzer/Infrared Array Camera near-infrared features in the outer parts of S4G galaxies

    NASA Astrophysics Data System (ADS)

    Laine, Seppo; Knapen, Johan H.; Muñoz-Mateos, Juan-Carlos; Kim, Taehyun; Comerón, Sébastien; Martig, Marie; Holwerda, Benne W.; Athanassoula, E.; Bosma, Albert; Johansson, Peter H.; Erroz-Ferrer, Santiago; Gadotti, Dimitri A.; de Paz, Armando Gil; Hinz, Joannah; Laine, Jarkko; Laurikainen, Eija; Menéndez-Delmestre, Karín; Mizusawa, Trisha; Regan, Michael W.; Salo, Heikki; Sheth, Kartik; Seibert, Mark; Buta, Ronald J.; Cisternas, Mauricio; Elmegreen, Bruce G.; Elmegreen, Debra M.; Ho, Luis C.; Madore, Barry F.; Zaritsky, Dennis

    2014-11-01

    We present a catalogue and images of visually detected features, such as asymmetries, extensions, warps, shells, tidal tails, polar rings, and obvious signs of mergers or interactions, in the faint outer regions (at and outside of R25) of nearby galaxies. This catalogue can be used in future quantitative studies that examine galaxy evolution due to internal and external factors. We are able to reliably detect outer region features down to a brightness level of 0.03 MJy sr-1 pixel-1 at 3.6 ?m in the Spitzer Survey of Stellar Structure in Galaxies (S4G). We also tabulate companion galaxies. We find asymmetries in the outer isophotes in 22 ± 1 per cent of the sample. The asymmetry fraction does not correlate with galaxy classification as an interacting galaxy or merger remnant, or with the presence of companions. We also compare the detected features to similar features in galaxies taken from cosmological zoom re-simulations. The simulated images have a higher fraction (33 per cent) of outer disc asymmetries, which may be due to selection effects and an uncertain star formation threshold in the models. The asymmetries may have either an internal (e.g. lopsidedness due to dark halo asymmetry) or external origin.

  16. HR Del REMNANT ANATOMY USING TWO-DIMENSIONAL SPECTRAL DATA AND THREE-DIMENSIONAL PHOTOIONIZATION SHELL MODELS

    SciTech Connect

    Moraes, Manoel; Diaz, Marcos E-mail: marcos@astro.iag.usp.br

    2009-12-15

    The HR Del nova remnant was observed with the IFU-GMOS at Gemini North. The spatially resolved spectral data cube was used in the kinematic, morphological, and abundance analysis of the ejecta. The line maps show a very clumpy shell with two main symmetric structures. The first one is the outer part of the shell seen in H{alpha}, which forms two rings projected in the sky plane. These ring structures correspond to a closed hourglass shape, first proposed by Harman and O'Brien. The equatorial emission enhancement is caused by the superimposed hourglass structures in the line of sight. The second structure seen only in the [O III] and [N II] maps is located along the polar directions inside the hourglass structure. Abundance gradients between the polar caps and equatorial region were not found. However, the outer part of the shell seems to be less abundant in oxygen and nitrogen than the inner regions. Detailed 2.5-dimensional photoionization modeling of the three-dimensional shell was performed using the mass distribution inferred from the observations and the presence of mass clumps. The resulting model grids are used to constrain the physical properties of the shell as well as the central ionizing source. A sequence of three-dimensional clumpy models including a disk-shaped ionization source is able to reproduce the ionization gradients between polar and equatorial regions of the shell. Differences between shell axial ratios in different lines can also be explained by aspherical illumination. A total shell mass of 9 x 10{sup -4} M {sub sun} is derived from these models. We estimate that 50%-70% of the shell mass is contained in neutral clumps with density contrast up to a factor of 30.

  17. Core-shell-shell nanorods for controlled release of silver that can serve as a nanoheater for photothermal treatment on bacteria.

    PubMed

    Hu, Bo; Wang, Ning; Han, Lu; Chen, Ming-Li; Wang, Jian-Hua

    2015-01-01

    A novel bactericidal material comprising rod-shaped core-shell-shell Au-Ag-Au nanorods is constructed as a nanoheater in the near-infrared (NIR) region. The outer Au shell melts under laser irradiation and results in exposure of the inner Ag shell, facilitating the controlled release of the antibacterial Ag shell/layer or Ag(+). This results in the Au-Ag-Au nanorods having a favorable bactericidal ability as it combines the features of physical photothermal ablation sterilization of the outer Au shell and the antibacterial effect of the inner Ag shell or Ag(+) to the surrounding bacteria. The sterilizing ability of Au-Ag-Au nanorods is investigated with Escherichia coli O157:H7 as a model bacterial strain. Under low-power NIR laser irradiation (785 nm, 50 mW cm(-2)), the Au-Ag-Au nanoheater exhibits a higher photothermal conversion efficiency (with a solution temperature of 44°C) with respect to that for the Au-Ag nanorods (39°C). Meanwhile, a much improved stability with respect to Au-Ag nanorods is observed, i.e., 16 successive days of monitoring reveal virtually no change in the ultraviolet-visible spectrum of Au-Ag-Au nanorods, while a significant drop in absorption along with a 92 nm red shift of Localized Surface Plasmon Resonance is recorded for the Au-Ag nanorods. This brings an increasing bactericidal efficiency and long-term stability for the Au-Ag-Au nanorods. At a dosage of 10 ?g ml(-1), a killing rate of 100% is reached for the E. coli O157:H7 cells under 20 min of irradiation. The use of Au-Ag-Au nanorods avoids the abuse of broad-spectrum antibiotics and reduces the damage of tissues by alleviating the toxicity of silver under controlled release and by the use of low-power laser irradiation. These features could make the bimetallic core-shell-shell nanorods a favorable nanoheater for in vivo biomedical applications. PMID:25219350

  18. The progressive outer retinal necrosis syndrome.

    PubMed

    Holland, G N

    1994-01-01

    The progressive outer retinal necrosis (PORN) syndrome is a recently described clinical variant of necrotizing herpetic retinopathy in patients with the acquired immunodeficiency syndrome (AIDS). It is caused by varicellazoster virus infection of the retina. Its course and clinical features distinguish it from the acute retinal necrosis syndrome and CMV retinopathy. Early disease is characterized by multifocal deep retinal opacification. Lesions rapidly coalesce and progress to total retinal necrosis over a short period of time. Despite aggressive therapy with intravenous antivirial drugs, prognosis is poor; disease progression and/or recurrence is common, and the majority of patients develop no light perception vision. Total retinal detachments are common. Prophylaxis against retinal detachment using laser retinopexy has not been useful in most cases. PORN syndrome is an uncommon, but devastating complication of AIDS. PMID:7852023

  19. Organic Matter in the Outer Solar System

    NASA Technical Reports Server (NTRS)

    Cruiskshank, Dale P.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Many solid bodies in the outer Solar System are covered with ices of various compositions, including water, carbon dioxide, methane, nitrogen, and other molecules that are solid at the low temperatures that prevail there. These ices have all been detected by remote sensing observations made with telescopes on Earth, or more recently, spacecraft in orbit (notably Galileo at Jupiter). The data also reveal other solid materials that could be minerals or complex carbon-bearing organic molecules. A study in progress using large ground-based telescopes to acquire infrared spectroscopic data, and laboratory results on the optical properties of complex organic matter, seeks to identify the non-icy materials on several satellites of Saturn, Uranus, and Neptune. The work on the satellites of Saturn is in part preparatory to the Cassini spacecraft investigation of the Saturn system, which will begin in 2004 and extend for four years.

  20. In Outer Space without a Space Suit?

    E-print Network

    Alexander Bolonkin

    2008-06-24

    The author proposes and investigates his old idea - a living human in space without the encumbrance of a complex space suit. Only in this condition can biological humanity seriously attempt to colonize space because all planets of Solar system (except the Earth) do not have suitable atmospheres. Aside from the issue of temperature, a suitable partial pressure of oxygen is lacking. In this case the main problem is how to satiate human blood with oxygen and delete carbonic acid gas (carbon dioxide). The proposed system would enable a person to function in outer space without a space suit and, for a long time, without food. That is useful also in the Earth for sustaining working men in an otherwise deadly atmosphere laden with lethal particulates (in case of nuclear, chemical or biological war), in underground confined spaces without fresh air, under water or a top high mountains above a height that can sustain respiration.

  1. Outer Hair Cell Electromotility in vivo

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Sripriya; Nuttall, Alfred L.

    2011-11-01

    The effectiveness of outer hair cell (OHC) electro-motility in vivo has been challenged by the expected low-pass filtering of the transmembrane potential due to the cell's own capacitance. The OHC electromotility is characterized here by an electromechanical ratio defined as the ratio of the OHC contraction to the transmembrane potential. This ratio has been measured in isolated cells to be approximately 26 nm/mV. We estimate the OHC electromechanical ratio in vivo from the recently measured displacements of the reticular lamina and the basilar membrane near the 19 kHz characteristic frequency in the basal region of guinea pig cochlea. Our analysis strongly suggests OHC electromotility process is effective for cochlear amplification in vivo at least around the characteristic frequency of the basal location in spite of the low-pass filtering.

  2. Hard Homogeneous Spaces JeanMarc Couveignes

    E-print Network

    International Association for Cryptologic Research (IACR)

    Hard Homogeneous Spaces Jean­Marc Couveignes August 24, 2006 Abstract This note was written in 1997 be, I will publish an updated version later. We introduce the notion of hard homogeneous space (HHS logarithm problem have a counterpart for any hard homogeneous space. Indeed, the notion of hard homogeneous

  3. Hard Homogeneous Spaces Jean-Marc Couveignes

    E-print Network

    International Association for Cryptologic Research (IACR)

    Hard Homogeneous Spaces Jean-Marc Couveignes August 24, 2006 Abstract This note was written in 1997 be, I will publish an updated version later. We introduce the notion of hard homogeneous space (HHS logarithm problem have a counterpart for any hard homogeneous space. Indeed, the notion of hard homogeneous

  4. The Complexity of Hardness Amplification and Derandomization

    E-print Network

    Viola, Emanuele

    The Complexity of Hardness Amplification and Derandomization A thesis presented by Emanuele Viola Emanuele Viola The Complexity of Hardness Amplification and Derandomization Abstract This thesis studies of hardness amplification and deran- domization. Hardness amplification is the task of taking a function

  5. MicroShell Minimalist Shell for Xilinx Microprocessors

    NASA Technical Reports Server (NTRS)

    Werne, Thomas A.

    2011-01-01

    MicroShell is a lightweight shell environment for engineers and software developers working with embedded microprocessors in Xilinx FPGAs. (MicroShell has also been successfully ported to run on ARM Cortex-M1 microprocessors in Actel ProASIC3 FPGAs, but without project-integration support.) Micro Shell decreases the time spent performing initial tests of field-programmable gate array (FPGA) designs, simplifies running customizable one-time-only experiments, and provides a familiar-feeling command-line interface. The program comes with a collection of useful functions and enables the designer to add an unlimited number of custom commands, which are callable from the command-line. The commands are parameterizable (using the C-based command-line parameter idiom), so the designer can use one function to exercise hardware with different values. Also, since many hardware peripherals instantiated in FPGAs have reasonably simple register-mapped I/O interfaces, the engineer can edit and view hardware parameter settings at any time without stopping the processor. MicroShell comes with a set of support scripts that interface seamlessly with Xilinx's EDK tool. Adding an instance of MicroShell to a project is as simple as marking a check box in a library configuration dialog box and specifying a software project directory. The support scripts then examine the hardware design, build design-specific functions, conditionally include processor-specific functions, and complete the compilation process. For code-size constrained designs, most of the stock functionality can be excluded from the compiled library. When all of the configurable options are removed from the binary, MicroShell has an unoptimized memory footprint of about 4.8 kB and a size-optimized footprint of about 2.3 kB. Since MicroShell allows unfettered access to all processor-accessible memory locations, it is possible to perform live patching on a running system. This can be useful, for instance, if a bug is discovered in a routine but the system cannot be rebooted: Shell allows a skilled operator to directly edit the binary executable in memory. With some forethought, MicroShell code can be located in a different memory location from custom code, permitting the custom functionality to be overwritten at any time without stopping the controlling shell.

  6. Impulsive ion acceleration in earth's outer magnetosphere

    SciTech Connect

    Baker, D.N.; Belian, R.D.

    1985-01-01

    Considerable observational evidence is found that ions are accelerated to high energies in the outer magnetosphere during geomagnetic disturbances. The acceleration often appears to be quite impulsive causing temporally brief (10's of seconds), very intense bursts of ions in the distant plasma sheet as well as in the near-tail region. These ion bursts extend in energy from 10's of keV to over 1 MeV and are closely associated with substorm expansive phase onsets. Although the very energetic ions are not of dominant importance for magnetotail plasma dynamics, they serve as an important tracer population. Their absolute intensity and brief temporal appearance bespeaks a strong and rapid acceleration process in the near-tail, very probably involving large induced electric fields substantially greater than those associated with cross-tail potential drops. Subsequent to their impulsive acceleration, these ions are injected into the outer trapping regions forming ion ''drift echo'' events, as well as streaming tailward away from their acceleration site in the near-earth plasma sheet. Most auroral ion acceleration processes occur (or are greatly enhanced) during the time that these global magnetospheric events are occurring in the magnetotail. A qualitative model relating energetic ion populations to near-tail magnetic reconnection at substorm onset followed by global redistribution is quite successful in explaining the primary observational features. Recent measurements of the elemental composition and charge-states have proven valuable for showing the source (solar wind or ionosphere) of the original plasma population from which the ions were accelerated.

  7. Outer Planet Mission Studies Neptune Aerocapture

    NASA Technical Reports Server (NTRS)

    Wercinski, Paul F.; Langhoff, Steven R. (Technical Monitor)

    1997-01-01

    Current and previous studies of orbiter missions to the outer planets have clearly identified high-energy aerocapture as a critical and enabling technology. Aerocapture involves the use of aerodynamic lift to fly a trajectory through a planet's atmosphere to sufficiently decelerate an entry vehicle to capture into planetary orbit. In the past, numerous studies of different configurations of lifting entry vehicles were studied for various planetary orbiter missions which identified aerocapture as a feasible concept yet complex and technically challenging. In order to determine the feasibility of high-speed aerocapture at the outer planets, an accurate trajectory simulation of the flight vehicle is the critical first step in the proposed research. Vehicle response to aerodynamic loading must be predicted accurately in the trajectory simulations. For several Neptune orbiter missions currently under study at the Jet Propulsion Laboratory (JPL), entry velocities relative to the rotating atmosphere ranging from 25 to 30 km/sec, are to be expected. Preliminary trajectory analysis has identified the various flow regimes the entry vehicle is expected to fly in the 8 1% H2 and 19% He atmosphere of Neptune. The size and mass of the vehicle are also determined by the launch vehicle constraints and orbiter spacecraft requirements. For a given baseline arrival conditions of an inertial entry velocity of 28 km/sec and an entry mass of 400 kg, a medium lift (L/D = 1), axisymmetric biconic shaped vehicle was selected in order to satisfy entry corridor width requirements expected for Neptune aerocapture. The analysis summarized in this study indicates that a biconic entry vehicle is a feasible concept for a Neptune aerocapture orbiter mission. The preliminary entry trajectory simulations has demonstrated adequate entry corridor control authority. Furthermore, estimates of the stagnation point heating environment has enabled the preliminary selection of candidate lightweight ceramic TPS materials.

  8. FBL Outer Can Welder Acquisition Software

    Energy Science and Technology Software Center (ESTSC)

    2004-01-16

    The Outer Can Welder Data Acquisition Software (OCWDAS) was originally developed by SRTC for use at Hanford to assist in the storage of their excess plutonium in the DOE standard 3013 containers until it can be properly dispositioned using one of the approved DOE methods. After Hanford OCWDAS software was the starting point for the new version developed for FB-Line. New graphical display formats and features were added to this software to make it moremore »robust and operator friendly. Several hardware changes were also made at this time and the software was modified to accommodate these as well. During the welding process, critical weld parameters such as weld current and voltage, can give valuable information about the weld. In the past, weld data from the TIG welding process, such as the bagless transfer system in FB-Line, has been monitored using strip chart recorders. The data from the weld process, recorded on the strip chart recorder traces, are reviewed to analyze the weld. The OCWDAS improves this technology by digitizing the weld data which allows for automation of the analysis process. The OCWDAS performs the necessary functions to perform the data acquisition functions during the 3013 Outer Can Welding Process. It is important to monitor the critical weld parameters, current and voltage, during a weld as they can be used to set acceptance criteria for weld acceptance. The software monitors and records the weld current, voltage, and RPM data. It also records the absolute position of the weld head during the weld process from a quadrature encoder. Digital handshaking between the AMI Welding unit and the OCWDAS ensure that both systems are operational and ready prior to the weld initiation taking place.« less

  9. FBL Outer Can Welder Acquisition Software

    SciTech Connect

    2004-01-16

    The Outer Can Welder Data Acquisition Software (OCWDAS) was originally developed by SRTC for use at Hanford to assist in the storage of their excess plutonium in the DOE standard 3013 containers until it can be properly dispositioned using one of the approved DOE methods. After Hanford OCWDAS software was the starting point for the new version developed for FB-Line. New graphical display formats and features were added to this software to make it more robust and operator friendly. Several hardware changes were also made at this time and the software was modified to accommodate these as well. During the welding process, critical weld parameters such as weld current and voltage, can give valuable information about the weld. In the past, weld data from the TIG welding process, such as the bagless transfer system in FB-Line, has been monitored using strip chart recorders. The data from the weld process, recorded on the strip chart recorder traces, are reviewed to analyze the weld. The OCWDAS improves this technology by digitizing the weld data which allows for automation of the analysis process. The OCWDAS performs the necessary functions to perform the data acquisition functions during the 3013 Outer Can Welding Process. It is important to monitor the critical weld parameters, current and voltage, during a weld as they can be used to set acceptance criteria for weld acceptance. The software monitors and records the weld current, voltage, and RPM data. It also records the absolute position of the weld head during the weld process from a quadrature encoder. Digital handshaking between the AMI Welding unit and the OCWDAS ensure that both systems are operational and ready prior to the weld initiation taking place.

  10. Lateral interactions in the outer retina

    PubMed Central

    Thoreson, Wallace B.; Mangel, Stuart C.

    2012-01-01

    Lateral interactions in the outer retina, particularly negative feedback from horizontal cells to cones and direct feed-forward input from horizontal cells to bipolar cells, play a number of important roles in early visual processing, such as generating center-surround receptive fields that enhance spatial discrimination. These circuits may also contribute to post-receptoral light adaptation and the generation of color opponency. In this review, we examine the contributions of horizontal cell feedback and feed-forward pathways to early visual processing. We begin by reviewing the properties of bipolar cell receptive fields, especially with respect to modulation of the bipolar receptive field surround by the ambient light level and to the contribution of horizontal cells to the surround. We then review evidence for and against three proposed mechanisms for negative feedback from horizontal cells to cones: 1) GABA release by horizontal cells, 2) ephaptic modulation of the cone pedicle membrane potential generated by currents flowing through hemigap junctions in horizontal cell dendrites, and 3) modulation of cone calcium currents (ICa) by changes in synaptic cleft proton levels. We also consider evidence for the presence of direct horizontal cell feed-forward input to bipolar cells and discuss a possible role for GABA at this synapse. We summarize proposed functions of horizontal cell feedback and feed-forward pathways. Finally, we examine the mechanisms and functions of two other forms of lateral interaction in the outer retina: negative feedback from horizontal cells to rods and positive feedback from horizontal cells to cones. PMID:22580106

  11. Nuclear Electric Propulsion for Outer Space Missions

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    2003-01-01

    Today we know of 66 moons in our very own Solar System, and many of these have atmospheres and oceans. In addition, the Hubble (optical) Space Telescope has helped us to discover a total of 100 extra-solar planets, i.e., planets going around other suns, including several solar systems. The Chandra (X-ray) Space Telescope has helped us to discover 33 Black Holes. There are some extremely fascinating things out there in our Universe to explore. In order to travel greater distances into our Universe, and to reach planetary bodies in our Solar System in much less time, new and innovative space propulsion systems must be developed. To this end NASA has created the Prometheus Program. When one considers space missions to the outer edges of our Solar System and far beyond, our Sun cannot be relied on to produce the required spacecraft (s/c) power. Solar energy diminishes as the square of the distance from the Sun. At Mars it is only 43% of that at Earth. At Jupiter, it falls off to only 3.6% of Earth's. By the time we get out to Pluto, solar energy is only .066% what it is on Earth. Therefore, beyond the orbit of Mars, it is not practical to depend on solar power for a s/c. However, the farther out we go the more power we need to heat the s/c and to transmit data back to Earth over the long distances. On Earth, knowledge is power. In the outer Solar System, power is knowledge. It is important that the public be made aware of the tremendous space benefits offered by Nuclear Electric Propulsion (NEP) and the minimal risk it poses to our environment. This paper presents an overview of the reasons for NEP systems, along with their basic components including the reactor, power conversion units (both static and dynamic), electric thrusters, and the launch safety of the NEP system.

  12. Comparative study of shell swab and shell crush methods for the recovery of Salmonella from shell eggs.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swabbing (SW) is the standard methodology for the recovery of resident microorganisms from shell eggs in Japan. A comparative study of shell swab (SW) and a shell crush (CR) technique was performed to recover the laboratory-inoculated Salmonella from shell eggs. It was found that the recovery of ...

  13. Shell`s new business segment sparks pipeline construction

    SciTech Connect

    Tubb, M.

    1996-08-01

    Shell Oil Co., the largest producer in the Gulf of Mexico is taking the next step to market its expertise and infrastructure with a new organization called Shell Midstream Enterprises (SME). SME`s primary customers will be Gulf of Mexico and Gulf Coast producers who can tie in to Shell`s infrastructure rather than building their own. And, the company has planned for the growth of this new business by building additional capacity into its systems to meet industry needs. This includes, among other things, production handling on offshore platforms, oil and gas gathering and transportation, natural gas processing and fractionation, natural gas liquids supply and transportation, crude oil trading, telecommunications and property transaction capabilities. The pipeline segment is of course a big piece of that. Shell`s existing pipeline assets associated with the new business include: Seven natural gas gathering systems which include about 65 miles of pipe that currently transport 230 MMcf/d of natural gas through these systems, and more than 1,000 miles of off-shore related crude oil pipelines with capacity of about 1 million barrels daily. This paper discusses these facilities.

  14. Corrugated outer sheath gas-insulated transmission line

    DOEpatents

    Kemeny, George A. (Pittsburgh, PA); Cookson, Alan H. (Churchill Boro, PA)

    1981-01-01

    A gas-insulated transmission line includes two transmission line sections each of which are formed of a corrugated outer housing enclosing an inner high-voltage conductor disposed therein, with insulating support means supporting the inner conductor within the outer housing and an insulating gas providing electrical insulation therebetween. The outer housings in each section have smooth end sections at the longitudinal ends thereof which are joined together by joining means which provide for a sealing fixed joint.

  15. Insulative laser shell coupler

    DOEpatents

    Arnold, Phillip A. (Livermore, CA); Anderson, Andrew T. (Livermore, CA); Alger, Terry W. (Tracy, CA)

    1994-01-01

    A segmented coaxial laser shell assembly having at least two water jacket sections, two pairs of interconnection half rings, a dialectric break ring, and a pair of threaded ring sections. Each water jacket section with an inner tubular section that defines an inner laser cavity with water paths adjacent to at least a portion of the exterior of the inner tubular section, and mating faces at the end of the water jacket section through which the inner laser cavity opens and which defines at least one water port therethrough in communication with the water jackets. The water paths also define in their external surface a circumferential notch set back from and in close proximity to the mating face. The dielectric break ring has selected thickness and is placed between, and in coaxial alignment with, the mating faces of two of the adjacent water jacket sections. The break ring also defines an inner laser cavity of the same size and shape as the inner laser cavity of the water jacket sections and at least one water passage through the break ring to communicate with at least one water port through the mating faces of the water jacket sections.

  16. Insulative laser shell coupler

    DOEpatents

    Arnold, P.A.; Anderson, A.T.; Alger, T.W.

    1994-09-20

    A segmented coaxial laser shell assembly having at least two water jacket sections, two pairs of interconnection half rings, a dielectric break ring, and a pair of threaded ring sections is disclosed. Each water jacket section with an inner tubular section that defines an inner laser cavity with water paths adjacent to at least a portion of the exterior of the inner tubular section, and mating faces at the end of the water jacket section through which the inner laser cavity opens and which defines at least one water port therethrough in communication with the water jackets. The water paths also define in their external surface a circumferential notch set back from and in close proximity to the mating face. The dielectric break ring has selected thickness and is placed between, and in coaxial alignment with, the mating faces of two of the adjacent water jacket sections. The break ring also defines an inner laser cavity of the same size and shape as the inner laser cavity of the water jacket sections and at least one water passage through the break ring to communicate with at least one water port through the mating faces of the water jacket sections. 4 figs.

  17. Biogenesis of outer membranes in Gram-negative bacteria.

    PubMed

    Tokuda, Hajime

    2009-03-23

    The outer membrane, an essential organelle of Gram-negative bacteria, is composed of four major components: lipopolysaccharide, phospholipids, beta-barrel proteins, and lipoproteins. The mechanisms underlying the transport of these components to outer membranes are currently under extensive examination. Among them, the sorting of lipoproteins to the outer membrane of Escherichia coli has been clarified in detail. The Lol system, composed of five proteins, catalyzes outer membrane sorting of lipoproteins. Various Lpt proteins have recently been identified as factors involved in the transport of lipopolysaccharide to the outer membrane, although the mechanism remains largely unknown. Proteins with alpha-helical membrane spanning segments are found in the inner membrane, whereas amphipathic beta-barrel proteins span the outer membrane. These beta-barrel proteins are inserted into the outer membranes through a central core protein BamA (YaeT) with the help of four outer membrane lipoproteins. In contrast, little is known about how phospholipids are transported to the outer membrane. PMID:19270402

  18. An Outer Bound for the Vector Gaussian CEO Problem

    E-print Network

    Ekrem, Ersen

    2012-01-01

    We study the vector Gaussian CEO problem, where there are an arbitrary number of agents each having a noisy observation of a vector Gaussian source. The goal of the agents is to describe the source to a central unit, which wants to reconstruct the source within a given distortion. The rate-distortion region of the vector Gaussian CEO problem is unknown in general. Here, we provide an outer bound for the rate-distortion region of the vector Gaussian CEO problem. We obtain our outer bound by evaluating an outer bound for the multi-terminal source coding problem by means of a technique relying on the de Bruijn identity and the properties of the Fisher information. Next, we show that our outer bound strictly improves upon the existing outer bounds for all system parameters. We show this strict improvement by providing a specific example, and showing that there exists a gap between our outer bound and the existing outer bounds. Although our outer bound improves upon the existing outer bounds, we show that our oute...

  19. 75 FR 1076 - Outer Continental Shelf Civil Penalties

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-08

    ...OF THE INTERIOR Minerals Management Service Outer Continental Shelf Civil Penalties AGENCY: Minerals Management Service (MMS), Interior. ACTION: Notice summarizing review of the maximum daily civil penalty...

  20. Shells in the C2 coma of Comet P/Halley

    NASA Technical Reports Server (NTRS)

    Schulz, Rita; A'Hearn, Michael F.

    1995-01-01

    We reanalyzed the CN images of Comet P/Halley, in which jets have been discovered for the first time, in search of shell structures. Shells were actually detected at the outer edges of the frames on those dates for which shells with radii small enough to be covered by the limited field of view of the CCD were predicted. The C2 images of the same data set were subjected to an analogous investigation which led to the discovery of shell structures in C2 as well. The morphology of the CN and the C2 shells is essentially equal on the same observational date. They have the same radii and show almost identical asymmetries which suggests that CN and C2 in the shells originate from the same general source. The comparison of the jets in both species before and after a two-dimensional continuum subtraction supports this supposition. The similar morphology of the jets indicates that both species are produced from the same bulk of precursor material which has been ejected in the form of jets from the same active area. However, similarly located and oriented jets in CN and C2 do not show similar relative intensities in most cases. These differences in the intensity distribution imply that the production rates of CN and C2 follow different laws.

  1. Hard diffraction -- 20 years later

    E-print Network

    Gunnar Ingelman

    2005-12-12

    The idea of diffractive processes with a hard scale involved, to resolve the underlying parton dynamics, was published 1985 and experimentally verified 1988. Today hard diffraction is an active research field with high-quality data and new theoretical models. The trend from Regge-based pomeron models to QCD-based parton level models has given insights on QCD dynamics involving perturbative gluon exchange mechanisms, including the predicted BFKL-dynamics, as well as novel ideas on non-perturbative colour fields and their interactions. Extrapolations to the LHC include the interesting possibility of diffractive Higgs production.

  2. Magnetic levitation for hard superconductors

    SciTech Connect

    Kordyuk, A.A.

    1998-01-01

    An approach for calculating the interaction between a hard superconductor and a permanent magnet in the field-cooled case is proposed. The exact solutions were obtained for the point magnetic dipole over a flat ideally hard superconductor. We have shown that such an approach is adaptable to a wide practical range of melt-textured high-temperature superconductors{close_quote} systems with magnetic levitation. In this case, the energy losses can be calculated from the alternating magnetic field distribution on the superconducting sample surface. {copyright} {ital 1998 American Institute of Physics.}

  3. Nuclear Shell Structure Evolution Theory

    E-print Network

    Zhengda Wang; Xiaobin Wang; Xiaodong Zhang; Xiaochun Wang

    2012-02-29

    The Self-similar-structure shell model (SSM) comes from the evolution of the conventional shell model (SM) and keeps the energy level of SM single particle harmonic oscillation motion. In SM, single particle motion is the positive harmonic oscillation and in SSM, the single particle motion is the negative harmonic oscillation. In this paper a nuclear evolution equation (NEE) is proposed. NEE describes the nuclear evolution process from gas state to liquid state and reveals the relations among SM, SSM and liquid drop model (DM). Based upon SSM and NEE theory, we propose the solution to long-standing problem of nuclear shell model single particle spin-orbit interaction energy . We demonstrate that the single particle motion in normal nuclear ground state is the negative harmonic oscillation of SSM[1][2][3][4] Key words: negative harmonic oscillation, nuclear evolution equation, self-similar shell model

  4. Simulating the Outer Radiation Belt During the Rising Phase of Solar Cycle 24

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Glocer, Alex; Zheng, Qiuhua; Chen, Sheng-Hsien; Kanekal, Shri; Nagai, Tsungunobu; Albert, Jay

    2011-01-01

    After prolonged period of solar minimum, there has been an increase in solar activity and its terrestrial consequences. We are in the midst of the rising phase of solar cycle 24, which began in January 2008. During the initial portion of the cycle, moderate geomagnetic storms occurred follow the 27 day solar rotation. Most of the storms were accompanied by increases in electron fluxes in the outer radiation belt. These enhancements were often preceded with rapid dropout at high L shells. We seek to understand the similarities and differences in radiation belt behavior during the active times observed during the of this solar cycle. This study includes extensive data and simulations our Radiation Belt Environment Model. We identify the processes, transport and wave-particle interactions, that are responsible for the flux dropout and the enhancement and recovery.

  5. Mobile hard substrata - An additional biodiversity source in a high latitude shallow subtidal system

    NASA Astrophysics Data System (ADS)

    Balazy, Piotr; Kuklinski, Piotr

    2013-03-01

    This study demonstrates the importance of a hard mobile substratum (hermit crab shells) for Arctic biodiversity. Based on previous observations from other geographic regions we hypothesized that this niche at high latitudes would support a higher biodiversity of epifauna than might be predicted from similar substrata. We test whether the hermit crab epifauna is specific to that substratum providing unique biodiversity components to the local community. From four study sites in Isfjorden (78°N), West Spitsbergen and two study sites in Northern Norway (69°N) we collected approximately 50 each of hermit crabs, gastropods and pebbles, of visually similar surface area using SCUBA diving. Hermit crab shells were colonized by a larger number of epifaunal species than either gastropods or pebbles, even when they were of a larger size. Among 87 taxa found on all the three substrata, 22 occurred only on hermit crab shells. Except for two study sites hermit crab shells also supported more individuals. This study shows that the contribution of shells carried by hermit crabs to high-latitude, shallow-subtidal diversity is higher than might be predicted by their surface area alone and that hermit crabs modify, maintain and create a unique habitat. This is the result of a number of factors interacting positively on the presence of epifauna including shell surface heterogeneity and the complex influence of the crab host.

  6. The Digital Library Shell Yael Dubinsky

    E-print Network

    Yehudai, Amiram

    The Digital Library Shell Yael Dubinsky University of Rome "La Sapienza" Department of Computer Libraries The Digital Library (DL) Shell The project of development the DL shell Demonstration Summary and future work #12;3 Agenda Digital Libraries The Digital Library (DL) Shell The project of development

  7. Subsurface oceans and deep interiors of medium-sized outer planet satellites and large trans-neptunian objects

    NASA Astrophysics Data System (ADS)

    Hussmann, Hauke; Sohl, Frank; Spohn, Tilman

    2006-11-01

    The detection of induced magnetic fields in the vicinity of the jovian satellites Europa, Ganymede, and Callisto is one of the most surprising findings of the Galileo mission to Jupiter. The observed magnetic signature cannot be generated in solid ice or in silicate rock. It rather suggests the existence of electrically conducting reservoirs of liquid water beneath the satellites' outermost icy shells that may contain even more water than all terrestrial oceans combined. The maintenance of liquid water layers is closely related to the internal structure, composition, and thermal state of the corresponding satellite interior. In this study we investigate the possibility of subsurface oceans in the medium-sized icy satellites and the largest trans-neptunian objects (TNO's). Controlling parameters for subsurface ocean formation are the radiogenic heating rate of the silicate component and the effectiveness of the heat transfer to the surface. Furthermore, the melting temperature of ice will be significantly reduced by small amounts of salts and/or incorporated volatiles such as methane and ammonia that are highly abundant in the outer Solar System. Based on the assumption that the satellites are differentiated and using an equilibrium condition between the heat production rate in the rocky cores and the heat loss through the ice shell, we find that subsurface oceans are possible on Rhea, Titania, Oberon, Triton, and Pluto and on the largest TNO's 2003 UB 313, Sedna, and 2004 DW. Subsurface oceans can even exist if only small amounts of ammonia are available. The liquid subsurface reservoirs are located deeply underneath an ice-I shell of more than 100 km thickness. However, they may be indirectly detectable by their interaction with the surrounding magnetic fields and charged particles and by the magnitude of a satellite's response to tides exerted by the primary. The latter is strongly dependent on the occurrence of a subsurface ocean which provides greater flexibility to a satellite's rigid outer ice shell.

  8. The Electron Shell and Alpha Decay in Super-Heavy Nuclei

    NASA Astrophysics Data System (ADS)

    Igashov, S. Yu.; Tchuvil'Sky, Yu. M.

    2015-11-01

    The influence of the electron shell on the characteristics of the alpha decay of the 294118 isotope, as an example of a super-heavy atom, is studied theoretically. The calculation is based on direct solution of the Schrödinger equation. The rigorous quantum-mechanical approach being developed makes possible the outer boundary condition of the alpha-particle diverging wave to be taken into account properly. The effect under discussion depends on the behavior of the function of electron density both in the classically-forbidden and the classically-allowed areas of alpha-particle motion. A principally new effect - increasing of the decay rate originated by the part of electron shell located in the classically-allowed area - is revealed in the chosen example. The influence of relativistic properties of inner electrons, scenario of penetration of the alpha-particle through the atomic shell and finite size of nucleus are also studied.

  9. Dynamic indentation hardness of materials

    NASA Astrophysics Data System (ADS)

    Koeppel, Brian James

    Indentation hardness is one of the simplest and most commonly used measures for quickly characterizing material response under static loads. Hardness may mean resistance to cutting to a machinist, resistance to wear to a tribologist, or a measure of flow stress to a design engineer. In this simple technique, a predetermined force is applied to an indenter for 5-30 seconds causing it to penetrate a specimen. By measuring the load and the indentation size, a hardness value is determined. However, the rate of deformation during indenter penetration is of the order of 10sp{-4}\\ ssp{-1}. In most practical applications, such as high speed machining or impact, material deforms at strain rates in excess of 10sp3{-}10sp5\\ ssp{-1}. At such high rates, it is well established that the plastic behavior of materials is considerably different from their static counterpart. For example, materials exhibit an increase in their yield stress, flow stress, fracture stress, and fracture toughness at high strain rates. Hence, the use of static hardness as an indicator of material response under dynamic loads may not be appropriate. Accordingly, a simple dynamic indentation hardness tester is developed for characterizing materials at strain rates similar to those encountered in realistic situations. The experimental technique uses elastic stress wave propagation phenomena in a slender rod. The technique is designed to deliver a single indentation load of 100-200 mus duration. Similar to static measurements, the dynamic hardness is determined from the measured load and indentation size. Hardness measurements on a range of metals have revealed that the dynamic hardness is consistently greater than the static hardness. The increase in hardness is strongly dependent on the crystal structure of the material. The observed trends in hardness are also found to be consistent with the yield and flow stresses of these materials under uniaxial compression. Therefore, it is suggested that the current technique can be used to assess the rate sensitive nature of engineering materials. To further characterize the plastic strains within the indentation volume, static microhardness measurements were also performed within this region. The contours of microhardness indicated that the plastic zone beneath the indenter is typically smaller under dynamic conditions compared to static loading for rate sensitive materials. To assess the influence of the elastic modulus, yield stress, and work hardening coefficient on the induced plastic volume, finite element simulations were performed using the explicit finite element code LS-DYNA3D. The parametric study revealed that the yield stress has the most significant influence on the size and shape of the plastic zone. The above microstructural and numerical results can be used as guidelines for proper selection and design of engineering materials in applications involving high strain rate loading. Moreover, the contours of microhardness variation can be used to verify the suitability of analytical models developed for characterizing the deformation behavior of engineering materials under complex three dimensional loads.

  10. Tectonics of the Outer Planet Satellites

    NASA Technical Reports Server (NTRS)

    McKinnon, W. B.; Collins, G. C.; Moore, J. M.; Nimmo, F.; Pappalardo, R. T.; Prockter, L. M.; Schenk, P. M.

    2010-01-01

    Tectonic features on the satellites of the outer planets range from the familiar, such as clearly recognizable graben on many satellites, to the bizarre, such as the ubiquitous double ridges on Europa, the twisting sets of ridges on Triton, or the isolated giant mountains rising from Io's surface. All of the large and middle-sized outer planet satellites except Io are dominated by water ice near their surfaces. Though ice is a brittle material at the cold temperatures found in the outer solar system, the amount of energy it takes to bring it close to its melting point is lower than for a rocky body. Therefore, some unique features of icy satellite tectonics may be influenced by a near-surface ductile layer beneath the brittle surface material, and several of the icy satellites may possess subsurface oceans. Sources of stress to drive tectonism are commonly dominated by the tides that deform these satellites as they orbit their primary giant planets. On several satellites, the observed tectonic features may be the result of changes in their tidal figures, or motions of their solid surfaces with respect to their tidal figures. Other driving mechanisms for tectonics include volume changes due to ice or water phase changes in the interior, thermoelastic stress, deformation of the surface above rising diapirs of warm ice, and motion of subsurface material toward large impact basins as they fill in and relax. Most satellites exhibit evidence for extensional deformation, and some exhibit strike-slip faulting, whereas contractional tectonism appears to be rare. Io s surface is unique, exhibiting huge isolated mountains that may be blocks of crust tilting and foundering into the rapidly emptying interior as the surface is constantly buried by deposits from hyperactive volcanoes. Of the satellites, diminutive Enceladus is spectacularly active; its south polar terrain is a site of young tectonism, copious heat flow, and tall plumes venting into space. Europa's surface is pervasively tectonized, covered with a diverse array of exotic and incompletely understood tectonic features. The paucity of impact craters on Europa suggests that its tectonic activity is ongoing. Geysers on Triton show that some degree of current activity, while tectonic features that cross sparsely cratered terrain indicate that it may also be tectonically active. Ganymede and Miranda both exhibit ancient terrains that have been pulled apart by normal faulting. On Ganymede these faults form a global network, while they are confined to regional provinces on Miranda. Ariel, Dione, Tethys, Rhea, and Titania all have systems of normal faults cutting across their surfaces, though the rifting is less pronounced than it is on Ganymede and Miranda. Iapetus exhibits a giant equatorial ridge that has defied simple explanation. The rest of the large and middle-sized satellites show very little evidence for tectonic features on their surfaces, though the exploration of Titan's surface has just begun.

  11. Highly-resolved 2D HYDRA simulations of Double-Shell Ignition Designs

    SciTech Connect

    Milovich, J L; Amendt, P; Hamza, A; Marinak, M; Robey, H

    2006-06-30

    Double-shell (DS) targets (Amendt, P. A. et al., 2002) offer a complementary approach to the cryogenic baseline design (Lindl, J. et al., 2004) for achieving ignition on the National Ignition Facility (NIF). Among the expected benefits are the ease of room temperature preparation and fielding, the potential for lower laser backscatter and the reduced need for careful shock timing. These benefits are offset, however, by demanding fabrication tolerances, e.g., shell concentricity and shell surface smoothness. In particular, the latter is of paramount importance since DS targets are susceptible to the growth of interface perturbations from impulsive and time-dependent accelerations. Previous work (Milovich, J. L. et al., 2004) has indicated that the growth of perturbations on the outer surface of the inner shell is potentially disruptive. To control this instability new designs have been proposed requiring bimetallic inner shells and material-matching mid-Z nanoporous foam. The challenges in manufacturing such exotic foams have led to a further evaluation of the densities and pore sizes needed to reduce the seeding of perturbations on the outer surface of the inner shell, thereby guiding the ongoing material science research efforts. Highly-resolved 2D simulations of porous foams have been performed to establish an upper limit on the allowable pore sizes for instability growth. Simulations indicate that foams with higher densities than previously thought are now possible. Moreover, while at the present time we are only able to simulate foams with average pore sizes larger than 1 micron (due to computational limitations), we can conclude that these pore sizes are potentially problematic. Furthermore, the effect of low-order hohlraum radiation asymmetries on the growth of intrinsic surface perturbations is also addressed. Highly-resolved 2D simulations indicate that the transverse flows that are set up by these low-order mode features (which can excite Kelvin-Helmholtz instabilities) are not large enough to offset the overall robustness of our current design.

  12. [Keeping quality of hard boiled eggs].

    PubMed

    Partmann, W; Wedler, A

    1979-09-01

    Only a few and contradictory results are available on the storage stability of hard boiled eggs which are of considerable importance for institutional feeding. Therefore four storage experiments on about 500 hard boiled eggs each were carried out and chemical and sensorial changes occurring during storage investigated. The one-day-old eggs of the same origin were boiled for 17 minutes under standard conditions and subsequently stored in air at a relative humidity between 73 and 85% at 4 degrees C (experiment No. 1), at 20 degrees C (experiments No. 2 and 3) and in pure carbon dioxide at 20 degrees C (experiment No. 4). Immediately after boiling, the eggs used for experiments No. 3 were dipped into coloured resin for egg shells (natural Manila-Kopa; dissolved in ethanol and stained with "Acillantechtgrün). Losses in weight during storages were distincly lower in the lacquered eggs than in the non-lacquered samples otherwise treated in the same manner. The weight decrease caused by the loss of water was extraordinarily high in pure CO2 and is due mainly the the decrease of the pH in the egg whites caused by the uptake of CO2. A few days after boiling the concentration of the free amino acids reached approximately the same level in albumen and yolk and remained practically constant over the following 3 weeks. For the breakdown of lecithine in yolk determined according to Grossfeld and Peter, a "deterioration quotient" of 6, like in unboiled eggs, was fixed as the limit value for unspoiled condition. Accordingly a possible storage time of 3 to 4 weeks resulted for the eggs stored at 4 degrees C and for the eggs treated with stained resin. The non-lacquered eggs stored in air or in CO2 at 20 degrees C reached the critical value in about 10 days. From the vitamins A, B1 and B2 only vitamin A showed considerable losses during storage. On the basis of the microbiological (3) and chemical findings and of the sensorial evaluation of colour, consistency, odour and taste of egg whites and yolks, the following storage times were determined for eggs in the quality class "saleable" requiring an overall rating not lower than 6 (satisfactory): 14 to 16 days, for non-lacquered eggs stored at 4 degrees C and for lacquered eggs at 20 degrees C whereas 5 days were found to be the maximum storage time for untreated eggs stored at 20 degrees C. If boiled eggs are stored in pure carbon dioxide at 20 degrees C, a distinct quality loss is observed already after a few days. PMID:575006

  13. Shell layer variation in trace element concentration for the freshwater bivalve Elliptio complanata

    NASA Astrophysics Data System (ADS)

    Carroll, Monica; Romanek, Christopher S.

    2008-10-01

    While the elemental chemistry of marine mollusk shells contains valuable environmental information, extending these interpretations to freshwater bivalve shells may be problematic, given the wide range of aqueous chemistries that exist in freshwater environments. To better understand the significance of these records, 20 bivalves were collected from four freshwater streams to determine the geochemical relationships that exist between the bivalve shell and their sources streams. The concentrations of manganese (Mn), copper (Cu), strontium (Sr), barium (Ba), and calcium (Ca) were analyzed by laser ablation inductively coupled plasma mass spectrometry across the inner (INL) and outer nacreous layer (ONL) of each shell for comparison to stream data collected over the period of shell growth. Within an individual shell, the content of Mn, Sr, and Ba were significantly higher in the INL than the ONL, while Cu concentrations were similar. Strontium and Ba concentrations co-varied between the two layers in 1:1 relationships, while Mn displayed a preferential enrichment in the INL that increased from 2:1 to 5:1 as the Mn content of the shell decreased. Each elemental profile can be correlated between shell layers, except for the trace element Cu, which appeared to be more closely related to the organic content of the shell. These results suggest that the major element geochemistry of the shell layers differentially reflect the aqueous chemistry of the water in which a bivalve lived, but that these records are most likely overprinted by physiological processes specific to the mantle tissue from which a particular shell layer is secreted. Distribution coefficients (shell M /Ca:water M /Ca, where M = trace element of interest) were calculated using the median molar elemental concentration for each shell (by layer), and the appropriate water concentration. Bivalves from a contaminated site were excluded from this analysis because their shells were anomalous in size and color. For the remaining 15 shells, distribution coefficients (INL and ONL) were: Mn (0.50 and 0.21), Sr (0.26 and 0.17), and Ba (0.05: INL only). Inner nacreous layer values were comparable to the upper end of published estimates for freshwater bivalves and fish otoliths, while the ONL values were comparable to the lower range of values. Inclusion of shells from the contaminated site resulted in the calculation of distribution coefficients that fell outside the range of published estimates. These results suggest that exposure to pollutants may have a bearing on the biological factors that control the elemental concentration of bivalve shells in freshwater environments. While researchers generally avoid sampling shell material from the INL because of the potential for shell dissolution, the similarity in elemental profile trends observed here suggests that both the INL and ONL record accurate geochemical information, but in distinct forms. An obvious advantage of INL analysis is the relative increase in elemental concentration, but this is afforded at the expense of spatial resolution. Considered collectively, these results suggest that valuable information can be gleaned from the elemental concentration of freshwater bivalve shells when care is taken in the choice of material from which these records are extracted.

  14. Ultra-strong surface plasmon amplification characteristic of a spaser based on gold-silver core-shell nanorods

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Zhou, Jun; Zhang, Haopeng; Jiang, Tao; Lou, Cibo

    2015-03-01

    We proposed an efficient spaser based on gold-silver core-shell nanorods (NRs) encapsulated by an outer silica shell doped with a gain medium. The optical characteristics of the spaser were numerically simulated based on the finite element method (FEM). The results showed that the localized surface plasmon resonance (LSPR) amplification characteristics of the spaser strongly depend on the thickness of silver shell, the aspect ratio of the inner gold NRs, and the polarization direction of the incident light. And, the maximum absolute value of optical cross-section of the spaser can reach 21,824 ?m2, which is about 1115, 523, and 18 times higher than that of spasers based on the gold NRs, the silver NRs, and the silver-gold core-shell NRs, respectively. The ultra-strong surface plasmon amplification characteristics of the spaser have potential applications in optical information storage, high sensitivity biochemical sensing, and medical engineering.

  15. FATIGUE OF BIOMATERIALS: HARD TISSUES

    PubMed Central

    Arola, D.; Bajaj, D.; Ivancik, J.; Majd, H.; Zhang, D.

    2009-01-01

    The fatigue and fracture behavior of hard tissues are topics of considerable interest today. This special group of organic materials comprises the highly mineralized and load-bearing tissues of the human body, and includes bone, cementum, dentin and enamel. An understanding of their fatigue behavior and the influence of loading conditions and physiological factors (e.g. aging and disease) on the mechanisms of degradation are essential for achieving lifelong health. But there is much more to this topic than the immediate medical issues. There are many challenges to characterizing the fatigue behavior of hard tissues, much of which is attributed to size constraints and the complexity of their microstructure. The relative importance of the constituents on the type and distribution of defects, rate of coalescence, and their contributions to the initiation and growth of cracks, are formidable topics that have not reached maturity. Hard tissues also provide a medium for learning and a source of inspiration in the design of new microstructures for engineering materials. This article briefly reviews fatigue of hard tissues with shared emphasis on current understanding, the challenges and the unanswered questions. PMID:20563239

  16. Playing the Numbers: Hard Choices

    ERIC Educational Resources Information Center

    Doyle, William R.

    2009-01-01

    Stateline.org recently called this recession the worst in 50 years for state budgets. As has been the case in past economic downturns, higher education looks to be particularly hard hit. Funds from the American Recovery and Relief Act may have postponed some of the difficulty for many colleges and universities, but the outlook for public higher…

  17. Hard scattering in ?p interactions

    NASA Astrophysics Data System (ADS)

    Ahmed, T.; Andreev, V.; Andrieu, B.; Arpagaus, M.; Babayev, A.; Bärwolff, H.; Ban, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Beck, G. A.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Berthon, U.; Bertrand-Coremans, G.; Besancon, M.; Biddulph, P.; Binder, E.; Bizot, J. C.; Blobel, V.; Borras, K.; Bosetti, P. C.; Boudry, V.; Bourdarios, C.; Brasse, F.; Braun, U.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, C.; Cozzika, G.; Criegee, L.; Cvach, J.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; David, M.; Deffur, E.; Delcourt, B.; DelBuono, L.; Devel, M.; DeRoeck, A.; Dingus, P.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Drescher, A.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Eberle, M.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellis, N. N.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Feng, Y.; Fensome, I. F.; Ference, J.; Ferrarotto, F.; Flauger, W.; Fleischer, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formanek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Fuhrmann, P.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gellrich, A.; Gennis, M.; Gensch, U.; Genzel, H.; Gerhards, R.; Gillespie, D.; Godfrey, L.; Goerlach, U.; Goerlich, L.; Goldberg, M.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Greif, H.; Grindhammer, G.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Handschuh, D.; Hanlon, E. M.; Hapke, M.; Harjes, J.; Hartz, P.; Haydar, R.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Hedgecock, R.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladky, J.; Hoeger, K. C.; Huet, Ph.; Hufnagel, H.; Huot, N.; Ibbotson, M.; Jabiol, M. A.; Jacholkowska, A.; Jacobson, C.; Jaffre, M.; Jönsson, L.; Johannsen, K.; Johnson, D.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kasarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurca, T.; Kurzhöfer, J.; Kuznik, B.; Lander, R.; Landon, M. P. J.; Langkau, R.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Lenhardt, U.; Leuschner, A.; Leverenz, C.; Levin, D.; Levonian, S.; Ley, Ch.; Lindström, G.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marks, J.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Monnier, E.; Moreau, F.; Moreels, J.; Morris, J. V.; Morton, J. M.; Müller, K.; Murin, P.; Murray, S. A.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Newton, D.; Nguyen, H. K.; Niebergall, F.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Orenstein, S.; Ould-Saada, F.; Pascaud, C.; Patel, G. D.; Peppel, E.; Peters, S.; Phillips, H. T.; Phillips, J. P.; Pichler, Ch.; Pilgram, W.; Pitzl, D.; Prosi, R.; Raupach, F.; Rauschnabel, K.; Reimer, P.; Ribarics, P.; Riech, V.; Riedlberger, J.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rudowicz, M.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Ryseck, E.; Sacton, J.; Sahlmann, N.; Sanchez, E.; Sankey, D. P.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schmitz, W.; Schröder, V.; Schulz, M.; Schwind, A.; Scobel, W.; Seehausen, U.; Sell, R.; Seman, M.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Smolik, L.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Steiner, H.; Stella, B.; Stephens, K.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Taylor, R. E.; Thompson, G.; Thompson, R. J.; Tichomirov, I.; Trenkel, C.; Truöl, P.; Tchernyshov, V.; Turnau, J.; Tutas, J.; Urban, L.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; VanEsch, P.; Vartapetian, A.; Vasdik, J.; Vecko, M.; Verrecchia, P.; Vick, R.; Villet, G.; Vogel, E.; Wacker, K.; Walker, I. W.; Walther, A.; Weber, G.; Wegener, D.; Wegner, A.

    1992-12-01

    We report on the investigation of the final state in interactions of quasi-real photons with protons. The data were taken with the H1 detector at the HERA ep collider. Evidence for hard interactions is seen in both single particle spectra and jet formation. The data can best be described by inclusion of resolved photon processess as predicted by QCD.

  18. From core/shell to hollow Fe/?-Fe2O3 nanoparticles: evolution of the magnetic behavior

    NASA Astrophysics Data System (ADS)

    Nemati, Z.; Khurshid, H.; Alonso, J.; Phan, M. H.; Mukherjee, P.; Srikanth, H.

    2015-10-01

    High quality Fe/?-Fe2O3 core/shell, core/void/shell, and hollow nanoparticles with two different sizes of 8 and 12 nm were synthesized, and the effect of morphology, surface and finite-size effects on their magnetic properties including the exchange bias (EB) effect were systematically investigated. We find a general trend for both systems that as the morphology changes from core/shell to core/void/shell, the magnetization of the system decays and inter-particle interactions become weaker, while the effective anisotropy and the EB effect increase. The changes are more drastic when the nanoparticles become completely hollow. Noticeably, the morphological change from core/shell to hollow increases the mean blocking temperature for the 12 nm particles but decreases for the 8 nm particles. The low-temperature magnetic behavior of the 12 nm particles changes from a collective super-spin-glass system mediated by dipolar interactions for the core/shell nanoparticles to a frustrated cluster glass-like state for the shell nanograins in the hollow morphology. On the other hand for the 8 nm nanoparticles core/shell and hollow particles the magnetic behavior is more similar, and a conventional spin glass-like transition is obtained at low temperatures. In the case of the hollow nanoparticles, the coupling between the inner and outer spin layers in the shell gives rise to an enhanced EB effect, which increases with increasing shell thickness. This indicates that the morphology of the shell plays a crucial role in this kind of exchange-biased systems.

  19. Suzaku Detection of Diffuse Hard X-Ray Emission Outside Vela X

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Mori, Koji; Petre, Robert; Yamaguchi, Hiroya; Tsunemi, Hiroshi; Bocchino, Fabrizio; Bamba, Aya; Miceli, Marco; Hewitt, John W.; Temim, Tea; Uchida, Hiroyuki; Yoshii, Rie

    2011-01-01

    Vela X is a large, 3 deg x 2 deg, radio-emitting pulsar wind nebula (PWN) powered by the Vela pulsar in the Vela supernova remnant. Using four Suzaku/XIS observations pointed just outside Vela X, we find hard X-ray emission extending throughout the fields of view. The hard X-ray spectra are well represented by a power-law. The photon index is measured to be constant at Gamma approximates 2.4, similar to that of the southern outer part of Vela X. The power-law flux decreases with increasing distance from the pulsar. These properties lead us to propose that the hard X-ray emission is associated with the Vela PWN. The larger X-ray extension found in this work strongly suggests that distinct populations relativistic electrons form the X-ray PWN and Vela X, as was recently inferred from multiwavelength spectral modeling of Vela X.

  20. 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.

  1. SN 1994W: An Interacting Supernova or Two Interacting Shells?

    E-print Network

    Luc Dessart; D. John Hillier; Suvi Gezari; Stephane Basa; Tom Matheson

    2008-10-06

    We present a multi-epoch quantitative spectroscopic analysis of the Type IIn SN 1994W, an event interpreted by Chugai et al. as stemming from the interaction between the ejecta of a SN and a 0.4Msun circumstellar shell ejected 1.5yr before core collapse. During the brightening phase, our models suggest that the source of optical radiation is not unique, perhaps associated with an inner optically-thick Cold Dense Shell (CDS) and outer optically-thin shocked material. During the fading phase, our models support a single source of radiation, an hydrogen-rich optically-thick layer with a near-constant temperature of ~7000K that recedes from a radius of 4.3x10^15 at peak to 2.3x10^15cm 40 days later. We reproduce the hybrid narrow-core broad-wing line profile shapes of SN 1994W at all times, invoking an optically-thick photosphere exclusively (i.e., without any external optically-thick shell). In SN 1994W, slow expansion makes scattering with thermal electrons a key escape mechanism for photons trapped in optically-thick line cores, and allows the resulting broad incoherent electron-scattering wings to be seen around narrow line cores. In SNe with larger expansion velocities, the thermal broadening due to incoherent scattering is masked by the broad profile and the dominant frequency redshift occasioned by bulk motions. Given the absence of broad lines at all times and the very low 56Ni yields, we speculate whether SN 1994W could have resulted from an interaction between two ejected shells without core collapse. The high conversion efficiency of kinetic to thermal energy may not require a SN-like energy budget for SN1994W.

  2. SN 1994W: an interacting supernova or two interacting shells?

    NASA Astrophysics Data System (ADS)

    Dessart, Luc; Hillier, D. John; Gezari, Suvi; Basa, Stéphane; Matheson, Tom

    2009-03-01

    We present a multi-epoch quantitative spectroscopic analysis of the Type IIn supernova (Type IIn SN) 1994W, an event interpreted by Chugai et al. as stemming from the interaction between the ejecta of a SN and a 0.4Msolar circumstellar shell ejected 1.5yr before core collapse. During the brightening phase, our models suggest that the source of optical radiation is not unique, perhaps associated with an inner optically thick cold dense shell and outer optically thin shocked material. During the fading phase, our models support a single source of radiation, an hydrogen-rich optically thick layer with a near-constant temperature of ~7000K that recedes from a radius of 4.3 × 1015 at a peak to 2.3 × 1015cm 40 d later. We reproduce the hybrid narrow-core broad-wing line profile shapes of SN 1994W at all times, invoking an optically thick photosphere exclusively (i.e. without any external optically thick shell). In SN 1994W, slow expansion makes scattering with thermal electrons a key escape mechanism for photons trapped in optically thick line cores, and allows the resulting broad incoherent electron-scattering wings to be seen around narrow-line cores. In SNe with larger expansion velocities, the thermal broadening due to incoherent scattering is masked by the broad profile and the dominant frequency redshift occasioned by bulk motions. Given the absence of broad lines at all times and the very low 56Ni yields, we speculate whether SN 1994W could have resulted from an interaction between two ejected shells without core collapse. The high conversion efficiency of kinetic to thermal energy may not require a SN-like energy budget for SN1994W.

  3. Puzzling Outer-Density Profile of the Dark Matter Halo in the Andromeda Galaxy

    E-print Network

    Kirihara, Takanobu; Mori, Masao

    2014-01-01

    The cold dark matter (CDM) cosmology, which is the standard theory of the structure formation in the universe, predicts that the outer density profile of dark matter halos decreases with the cube of distance from the center. However, so far not much effort has examined this hypothesis. Large-scale stellar structures detected by the recent observations in the halo of the Andromeda galaxy (M31) provide an attractive window to explore the structure of the dark matter halo. Using an N-body simulation of the interaction between an accreting satellite galaxy and M31, we investigate the mass-density profile of the dark matter halo in M31. To reproduce the Andromeda Giant Southern Stream and the stellar shells at the east and west sides of M31, we find the sufficient condition for the power-law index $\\alpha$ of the outer density distribution of the dark matter halo. The best-fit parameter is $\\alpha=-3.7$, which is steeper than the CDM prediction.

  4. Substructure of the outer dynein arm

    PubMed Central

    1982-01-01

    The substructure of the outer dynein arm has been analyzed in quick- frozen deep-etch replicas of Tetrahymena and Chlamydomonas axonemes. Each arm is found to be composed of five morphologically discrete components: an elliptical head; two spherical feet; a slender stalk; and an interdynein linker. The feet make contact with the A microtubule of each doublet; the stalk contacts the B microtubule; the head lies between the feet and stalk; and the linker associates each arm with its neighbor. The spatial relationships between these five components are found to be distinctly different in rigor (ATP-depleted) versus relaxed (ATP- or vanadate plus ATP-treated) axonemes, and the stalk appears to alter its affinity for the B microtubule in the relaxed state. Images of living cilia attached to Tetrahymena cells show that the relaxed configuration is adopted in vivo. We relate our observations to morphological and experimental studies reported by others and propose several models that suggest how this newly described dynein morphology may relate to dynein function. PMID:6218174

  5. Substructure of the outer dynein arm.

    PubMed

    Goodenough, U W; Heuser, J E

    1982-12-01

    The substructure of the outer dynein arm has been analyzed in quick-frozen deep-etch replicas of Tetrahymena and Chlamydomonas axonemes. Each arm is found to be composed of five morphologically discrete components: an elliptical head; two spherical feet; a slender stalk; and an interdynein linker. The feet make contact with the A microtubule of each doublet; the stalk contacts the B microtubule; the head lies between the feet and stalk; and the linker associates each arm with its neighbor. The spatial relationships between these five components are found to be distinctly different in rigor (ATP-depleted) versus relaxed (ATP- or vanadate plus ATP-treated) axonemes, and the stalk appears to alter its affinity for the B microtubule in the relaxed state. Images of living cilia attached to Tetrahymena cells show that the relaxed configuration is adopted in vivo. We relate our observations to morphological and experimental studies reported by others and propose several models that suggest how this newly described dynein morphology may relate to dynein function. PMID:6218174

  6. The Outer Heliosphere: The Next Frontiers

    NASA Astrophysics Data System (ADS)

    Scherer, K.; Fichtner, Horst; Fahr, Hans Jörg; Marsch, Eckart

    The 11th COSPAR Colloquium "The Outer Heliosphere: The Next Frontiers" was held in Potsdam, Germany, from July 24 to 28, 2000, and is the second dedicated to this subject after the first one held in Warsaw, Poland in 1989. Roughly a century has passed after the first ideas by Oliver Lodge, George Francis Fitzgerald and Kristan Birkeland about particle clouds emanating from the Sun and interacting with the Earth environment. Only a few decades after the formulation of the concepts of a continuous solar corpuscular radiation by Ludwig Bierman and a solar wind by Eugene Parker, heliospheric physics has evolved into an important branch of astrophysical research. Numerous spacecraft missions have increased the knowledge about the heliosphere tremendously. Now, at the beginning of a new millenium it seems possible, by newly developed propulasion technologies to send a spacecraft beyond the boundaries of the heliosphere. Such an Interstellar Proce will start the in-situ exploration of interstellar space and, thus, can be considered as the first true astrophysical spacecraft. The year 2000 appeared to be a highly welcome occassion to review the achievements since the last COSPAR Colloquia 11 years ago, to summarize the present developments and to give new impulse for future activities in heliospheric research.

  7. The Outer Heliosphere: The Next Frontier

    NASA Astrophysics Data System (ADS)

    Heber, B.; Zank, G. P.

    Only a few decades after the formulation of the concept of a continuous solar corpus- cular radiation by Ludwig Biermann and a solar wind by Eugene Parker, heliospheric physics has evolved into an important branch of astrophysical research. The solar wind forms a bubble, called the heliosphere, in the local interstellar medium, within which the solar system resides and whose size and properties are determined by the manner in which the solar wind and the partially ionized local interstellar medium are coupled. In the last decade, great progress has been made in our understanding of the physical processes thought to describe the outer heliosphere. Numerous spacecraft missions have increased our knowledge about the large-scale structure, the properties, and the character of the heliosphere tremendously. of these, the ageing spacecraft Voyager 1,2 might encounter the inner border of the heliospheric boundary region in the not too distant future. Now, at the beginning of a new millenium, it seems possible, by newly developed technologies to send an interstellar probe beyond the boundaries of the he- liosphere, in order to explore the local interstellar medium in situ. We shall review our basic understanding of global heliospheric structure, emphasizing the importance of the LISM-solar wind coupling, emphasizing the demands and constraints that this places on a mission to the edge of interstellar space.

  8. THE OUTER MAGNETIC FIELD OF L183

    SciTech Connect

    Clemens, Dan P.

    2012-03-20

    The L183 (= L134N) dark molecular cloud has been probed using deep near-infrared imaging polarimetry of stars to beyond 14 mag in H band (1.6 {mu}m), using the Mimir instrument on the 1.83 m Perkins Telescope. Nearly 400 arcmin{sup 2} were surveyed, including the dense core in L183, as seen in WISE Band 3 (12 {mu}m) extinction, and the near surroundings, revealing 35 stars with either detected polarizations or significant upper limits. Stars with detected polarizations are reddened if closer than 8 arcmin (0.25 pc at the 110 pc cloud distance) and unreddened beyond. The polarimetric sample probes as close to the core as 3 arcmin (0.1 pc), where A{sub V} {approx} 14 mag. Compared to the relatively unextincted surrounding stars, the reddened stars show no increase in polarization with extinction, suggesting that all of the polarization is induced in the outer layers of the cloud. This 0.25 pc radius envelope magnetic field does show a strong interaction with the L183 dark cloud. The envelope field is also virtually perpendicular, on the plane of the sky, to the field seen at 850 {mu}m, though more closely aligned with the rotation axis of the dense gas core. The physical size scale at which the envelope and the core magnetic fields either decouple from each other or strongly modify their directions must be inside the 0.1 pc region probed here.

  9. Ion anisotropies in the outer Jovian magnetosphere

    SciTech Connect

    Carbary, J.F.; Krimigis, S.M.; Keath, E.P.; Gloeckler, G.; Axford, W.I.; Armstrong, T.P.

    1981-09-30

    We present results from the Voyager 1 and 2 low-energy charged particle measurement of ion anisotropies in the outer Jovian magnetosphere (R> or approx. =20 R/sub J/). Theses anisotropies represent the first observed from an instrument rotating in the spin plane of Jupiter. For the several ion species ivestigated the first-order anisotropies are all strongly in the corotational sense throughout most of the Jovian magnestophere and out to the magnetopause on the dayside. There is some evidence for a small component of outward flow in the corotating region. Beyond approx.130--150 R/sub J/ along the Voyager outbound trajectories the anisotropies indicate a magnetospheric wind flowing outward from Jupiter. The change corotational to tailward flow on the nightside occurs well inside the magnetopause. The anisotropy amplitudes increase linearly with radial distance and, in the disc regions, decrease with distance from the magnetodisc mid-plane. In one case examined in detail using separtely identified H, He, and O/S ions the convection speed at 58 R/sub J/ is found to agree with the corotation speed (..cap omega..R) to within approx.3%. A linear Compton-Getting analysis reveals that the convective speeds in the dayside magnetosphere are in agreement with rigid corotation whenever the plasma flow direction is approximately in the corotation sense, while at other times the convection speeds are substantially less than corotation.

  10. Spam Zombies from Outer Space John Aycock & Nathan Friess

    E-print Network

    Aycock, John

    Spam Zombies from Outer Space John Aycock & Nathan Friess Department of Computer Science University-mail: {aycock,friessn}@cpsc.ucalgary.ca. Keywords Zombies, botnets, spam, spyware, email worms 15th Annual EICAR Conference "Security in the Mobile and Networked World" - 164 - #12;Spam Zombies from Outer Space Abstract

  11. Newborns' Face Recognition: Role of Inner and Outer Facial Features

    ERIC Educational Resources Information Center

    Turati, Chiara; Macchi Cassia, Viola; Simion, Francesca; Leo, Irene

    2006-01-01

    Existing data indicate that newborns are able to recognize individual faces, but little is known about what perceptual cues drive this ability. The current study showed that either the inner or outer features of the face can act as sufficient cues for newborns' face recognition (Experiment 1), but the outer part of the face enjoys an advantage…

  12. Research paper Fast cochlear amplification with slow outer hair cells

    E-print Network

    Sarpeshkar, Rahul

    Research paper Fast cochlear amplification with slow outer hair cells Timothy K. Lu a,b , Serhii hair cells (OHCs) produce mechanical amplification over the entire audio-frequency range (up to 100 k reserved. Keywords: Cochlear amplifier; Outer hair cell; Receptor potential; Membrane time constant low

  13. 27 CFR 9.207 - Outer Coastal Plain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Outer Coastal Plain. 9.207 Section 9.207 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.207 Outer Coastal Plain. (a) Name. The name of...

  14. Is the outer Solar System chaotic? WAYNE B. HAYES

    E-print Network

    Loss, Daniel

    LETTERS Is the outer Solar System chaotic? WAYNE B. HAYES Computer Science Department, University. There exists both apparently unassailable evidence that the outer Solar System is chaotic1 development. The Solar System is known to be `practically stable', in the sense that none of the known planets

  15. Long-Lived Glass Mirrors For Outer Space

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.; Maag, Carl R.; Heggen, Philip M.

    1988-01-01

    Paper summarizes available knowledge about glass mirrors for use in outer space. Strengths and weaknesses of various types of first and second reflective surfaces identified. Second-surface glass mirrors used in outer space designed to different criteria more stringent for terrestrial mirrors. Protons, electrons, cosmic rays, meteorites, and orbiting space debris affect longevities of components. Contamination also factor in space.

  16. Outer-sphere adsorption of Pb(II)EDTA on goethite

    SciTech Connect

    Bargar, J.R.; Persson, P.; Brown, G.E. Jr.

    1999-10-01

    Fourier transform infrared (FTIR) and extended X-ray absorption fine structure (EXAPS) spectroscopic measurements were performed on Pb(II)ethylenediaminetetraacetic (EDTA) adsorbed on goethite as a function of pH (4--6), Pb(II)EDTA concentration (0.11--72 {micro}M), and ionic strength (16 {micro}M--0.5 M). FTIR measurements show no evidence for carboxylate-Fe(III) bonding or protonation of EDTA at Pb:EDTA = 1:1. Both FTIR and EXAFS spectroscopic measurements suggest that EDTA acts as a hexadentate ligand, with all four of its carboxylate and both of its amine groups bonded to Pb(II). No evidence was observed for inner-sphere Pb(II)-goethite bonding at Pb:EDTA = 1:1. Hence, the adsorbed complexes should have composition Pb(II)EDTA{sup 2{minus}}. Because substantial uptake of PbEDTA(II){sup 2{minus}} occurred in the samples, the authors interpret that Pb(II)EDTA{sup 2{minus}} adsorbed as outer-sphere complexes and/or as complexes that lose part of their solvation shells and hydrogen bond directly to goethite surface sites. The authors propose the term hydration-sphere for the latter type of complexes because they should occupy space in the primary hydration spheres of goethite surface functional groups and to distinguish this mode of sorption from common structural definitions of inner- and outer-sphere complexes. The lack of evidence for inner-sphere EDTA-Fe(III) bonding suggests that previously proposed metal/ligand-promoted dissolution mechanisms should be modified, specifically to account for the presence of outer-sphere precursor species.

  17. Influence of the shell thickness and charge distribution on the effective interaction between two like-charged hollow spheres

    NASA Astrophysics Data System (ADS)

    Angelescu, Daniel G.; Caragheorgheopol, Dan

    2015-10-01

    The mean-force and the potential of the mean force between two like-charged spherical shells were investigated in the salt-free limit using the primitive model and Monte Carlo simulations. Apart from an angular homogeneous distribution, a discrete charge distribution where point charges localized on the shell outer surface followed an icosahedral arrangement was considered. The electrostatic coupling of the model system was altered by the presence of mono-, trivalent counterions or small dendrimers, each one bearing a net charge of 9 e. We analyzed in detail how the shell thickness and the radial and angular distribution of the shell charges influenced the effective interaction between the shells. We found a sequence of the potential of the mean force similar to the like-charged filled spheres, ranging from long-range purely repulsive to short-range purely attractive as the electrostatic coupling increased. Both types of potentials were attenuated and an attractive-to-repulsive transition occurred in the presence of trivalent counterions as a result of (i) thinning the shell or (ii) shifting the shell charge from the outer towards the inner surface. The potential of the mean force became more attractive with the icosahedrally symmetric charge model, and additionally, at least one shell tended to line up with 5-fold symmetry axis along the longest axis of the simulation box at the maximum attraction. The results provided a basic framework of understanding the non-specific electrostatic origin of the agglomeration and long-range assembly of the viral nanoparticles.

  18. Biogenesis of mitochondrial outer membrane proteins, problems and diseases.

    PubMed

    Ellenrieder, Lars; Mårtensson, Christoph U; Becker, Thomas

    2015-10-01

    Proteins of the mitochondrial outer membrane are synthesized as precursors on cytosolic ribosomes and sorted via internal targeting sequences to mitochondria. Two different types of integral outer membrane proteins exist: proteins with a transmembrane ?-barrel and proteins embedded by a single or multiple ?-helices. The import pathways of these two types of membrane proteins differ fundamentally. Precursors of ?-barrel proteins are first imported across the outer membrane via the translocase of the outer membrane (TOM complex). The TOM complex is coupled to the sorting and assembly machinery (SAM complex), which catalyzes folding and membrane insertion of these precursors. The mitochondrial import machinery (MIM complex) promotes import of proteins with multiple ?-helical membrane spans. Depending on the topology precursors of proteins with a single ?-helical membrane anchor are imported via several distinct routes. We summarize current models and open questions of biogenesis of mitochondrial outer membrane proteins and discuss the impact of malfunctions of protein sorting on the development of diseases. PMID:25980382

  19. Molecular identity of human outer radial glia during cortical development.

    PubMed

    Pollen, Alex A; Nowakowski, Tomasz J; Chen, Jiadong; Retallack, Hanna; Sandoval-Espinosa, Carmen; Nicholas, Cory R; Shuga, Joe; Liu, Siyuan John; Oldham, Michael C; Diaz, Aaron; Lim, Daniel A; Leyrat, Anne A; West, Jay A; Kriegstein, Arnold R

    2015-09-24

    Radial glia, the neural stem cells of the neocortex, are located in two niches: the ventricular zone and outer subventricular zone. Although outer subventricular zone radial glia may generate the majority of human cortical neurons, their molecular features remain elusive. By analyzing gene expression across single cells, we find that outer radial glia preferentially express genes related to extracellular matrix formation, migration, and stemness, including TNC, PTPRZ1, FAM107A, HOPX, and LIFR. Using dynamic imaging, immunostaining, and clonal analysis, we relate these molecular features to distinctive behaviors of outer radial glia, demonstrate the necessity of STAT3 signaling for their cell cycle progression, and establish their extensive proliferative potential. These results suggest that outer radial glia directly support the subventricular niche through local production of growth factors, potentiation of growth factor signals by extracellular matrix proteins, and activation of self-renewal pathways, thereby enabling the developmental and evolutionary expansion of the human neocortex. PMID:26406371

  20. Advanced Metal Foam Structures for Outer Space

    NASA Technical Reports Server (NTRS)

    Hanan, Jay; Johnson, William; Peker, Atakan

    2005-01-01

    A document discusses a proposal to use advanced materials especially bulk metallic glass (BMG) foams in structural components of spacecraft, lunar habitats, and the like. BMG foams, which are already used on Earth in some consumer products, are superior to conventional metal foams: BMG foams have exceptionally low mass densities and high strength-to-weight ratios and are more readily processable into strong, lightweight objects of various sizes and shapes. These and other attractive properties of BMG foams would be exploited, according to the proposal, to enable in situ processing of BMG foams for erecting and repairing panels, shells, containers, and other objects. The in situ processing could include (1) generation of BMG foams inside prefabricated deployable skins that would define the sizes and shapes of the objects thus formed and (2) thermoplastic deformation of BMG foams. Typically, the generation of BMG foams would involve mixtures of precursor chemicals that would be subjected to suitable pressure and temperature schedules. In addition to serving as structural components, objects containing or consisting of BMG foams could perform such functions as thermal management, shielding against radiation, and shielding against hypervelocity impacts of micrometeors and small debris particles.

  1. Bathymetry and acoustic backscatter-outer mainland shelf, eastern Santa Barbara Channel, California

    USGS Publications Warehouse

    Dartnell, Peter; Finlayson, David P.; Ritchie, Andrew C.; Cochrane, Guy R.; Erdey, Mercedes D.

    2012-01-01

    In 2010 and 2011, scientists from the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), acquired bathymetry and acoustic-backscatter data from the outer shelf region of the eastern Santa Barbara Channel, California. These surveys were conducted in cooperation with the Bureau of Ocean Energy Management (BOEM). BOEM is interested in maps of hard-bottom substrates, particularly natural outcrops that support reef communities in areas near oil and gas extraction activity. The surveys were conducted using the USGS R/V Parke Snavely, outfitted with an interferometric sidescan sonar for swath mapping and real-time kinematic navigation equipment. This report provides the bathymetry and backscatter data acquired during these surveys in several formats, a summary of the mapping mission, maps of bathymetry and backscatter, and Federal Geographic Data Committee (FGDC) metadata.

  2. Hard spheres out of equilibrium

    NASA Astrophysics Data System (ADS)

    Hermes, M.

    2010-05-01

    In this thesis, experiments and simulations are combined to investigate the nonequilibrium behaviour of hard spheres. In the first chapters we use Molecular Dynamics simulations to investigate the dynamic glass transition of polydisperse hard spheres. We show that this dynamic transition is accompanied by a thermodynamic signature. The higher-order derivatives of the pressure change abruptly at the dynamic glass transition. If a system is compressed beyond this dynamic transition, the pressure increases until it diverges when the system is completely jammed. The density at which the pressure diverges depends on the compression speed. We proceed with experiments on colloidal polymethylmethacrylate (PMMA) particles which closely resemble hard spheres. We investigate the effect of compression using gravity and electric field gradients on the nucleation and on the glass transition. The transition from glass to crystal is gradual and is strongly effected by gravity. We go back to computer simulations to investigate two different techniques to calculate the rate at which a hard-sphere system nucleates. We find that the two techniques yield similar results for the nucleation rate as well as the critical nucleus shape. From this we conclude that the simulation techniques are valid. A combination of simulations and experiments is used to study the nucleation of hard spheres on seed structures. We initiate the nucleation with a seed of particles kept in place by optical tweezers. We show that whereas the nucleation itself can be well described as an equilibrium process, the growth after nucleation can not. We demonstrate that defects play an important role in the growth of the crystal. Colloidal hard spheres can also be driven out of equilibrium using shear. We perform experiments on an equilibrium fluid phase below the coexistence density of the fluid. We show that we can induce order in an equilibrium fluid using oscillatory shear. We find five different phases for varying frequency and amplitude: four known phases and one new phase. The formation of all phases occurs via nucleation and growth and the melting, when the shear is stopped, starts on the edges and near the defects of the crystal phases. In the final chapter, we investigate the interactions between rough colloidal particles in the presence of polymers. We investigate whether surface roughness can be used to reduce the depletion attraction. We find that when the polymer is smaller than the surface roughness the attraction can be reduced significantly compared to smooth colloids.

  3. Foam shell project: Progress report

    SciTech Connect

    Overturf, G.; Reibold, B.; Cook, B.; Schroen-Carey, D.

    1994-03-25

    The authors report on their work to produce a foam shell target for two possible applications: (1) as liquid-layered cryogenic target on Omega Upgrade, and (2) as a back-up design for the NIF. This target consists of a roughly 1 mm diameter and 100 {mu}m thick spherical low-density foam shell surrounding a central void. The foam will be slightly overfilled with liquid D{sub 2} or DT, the overfilled excess being symmetrically distributed on the inside of the shell and supported by thermal gradient techniques. The outside of the foam is overcoated with full density polymer which must be topologically smooth. The technology for manufacturing this style of foam shell involves microencapsulation techniques and has been developed by the Japanese at ILE. Their goal is to determine whether this technology can be successfully adapted to meet US ICF objectives. To this end a program of foam shell development has been initiated at LLNL in collaboration with both the General Atomics DOE Target Fabrication Contract Corporation and the Target Fabrication Group at LLE.

  4. Inner-shell double photoionization of beryllium by intense X-ray free-electron laser pulses

    NASA Astrophysics Data System (ADS)

    Barmaki, Samira; Albert, Marc Andre; Laulan, Stephane

    2015-05-01

    We study the inner-shell double photoionization of the beryllium Be (1s2 2s2) by intense X-ray free-electron laser (XFEL) pulses. The inner and the outer shell of the atom are separated by a large energy gap; the ejection of the core electrons requires photon frequencies larger than 160 eV whereas photons of 14-20 eV are sufficient to induce the double ionization of the 2s2 valence shell. In order to target only the core electrons, we use intense subfemtosecond laser pulses of photon frequencies above 170 eV so the ionization of the inner shell largely dominates that of the valence. Besides, the shortness of the pulses leaves no time for the relaxation of the outer shell to take place. The characteristics of the XFEL pulses allow us then to ``freeze'' the electrons of the valence by using a model potential, hence reducing the difficulty of the numerical investigation of the atom. In this case, the numerical study of Be becomes similar to our previous study on helium. We present the results of the electron energy distribution of ejected core electrons under different laser parameters.

  5. Proteomics of Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles

    PubMed Central

    Kieselbach, Thomas; Zijnge, Vincent; Granström, Elisabeth; Oscarsson, Jan

    2015-01-01

    Aggregatibacter actinomycetemcomitans is an oral and systemic pathogen associated with aggressive forms of periodontitis and with endocarditis. Outer membrane vesicles (OMVs) released by this species have been demonstrated to deliver effector proteins such as cytolethal distending toxin (CDT) and leukotoxin (LtxA) into human host cells and to act as triggers of innate immunity upon carriage of NOD1- and NOD2-active pathogen-associated molecular patterns (PAMPs). To improve our understanding of the pathogenicity-associated functions that A. actinomycetemcomitans exports via OMVs, we studied the proteome of density gradient-purified OMVs from a rough-colony type clinical isolate, strain 173 (serotype e) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This analysis yielded the identification of 151 proteins, which were found in at least three out of four independent experiments. Data are available via ProteomeXchange with identifier PXD002509. Through this study, we not only confirmed the vesicle-associated release of LtxA, and the presence of proteins, which are known to act as immunoreactive antigens in the human host, but we also identified numerous additional putative virulence-related proteins in the A. actinomycetemcomitans OMV proteome. The known and putative functions of these proteins include immune evasion, drug targeting, and iron/nutrient acquisition. In summary, our findings are consistent with an OMV-associated proteome that exhibits several offensive and defensive functions, and they provide a comprehensive basis to further disclose roles of A. actinomycetemcomitans OMVs in periodontal and systemic disease. PMID:26381655

  6. Cratering Rates in the Outer Solar System

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin

    2003-01-01

    We have constructed a self-consistent study of cratering rates in the outer solar system. Two papers were written, one on cratering asymmetries on synchronously rotating satellites and the other on the cratering rates themselves. The first addresses the well-founded expectation that the leading hemisphere of a synchronously rotating satellite should be more heavily cratered than the trailing hemisphere, and how our solar system has avoided showing much sign of this. We conclude that Ganymede has in the past rotated nonsynchronously, which may imply that it once harboured a thicker inner ocean than it does now. The other study began as an attempt to determine the age of the surface of Europa at a time when Europa was regarded as a major Exobiological target. In keeping with changing times the study expanded to the point that it now recommends cratering rates for worlds as diverse as Charon and Pluto, and includes the contributions of several invaluable co-authors, none of whom would agree with all of my conclusions. The nexus of the work is the size-frequency distribution of comets striking Jupiter (Figure). This was determined using the historically observed record of comets striking or nearly striking Jupiter; the size-frequency distributions of craters on lightly cratered surfaces of Europa, Ganymede, and Triton; and the size-frequncy distribution of Kuiper Belt objects. Extreme reductionists will be happy to know that the surface of Europa probably has an age of around 50 million years. Perhaps more intriguing is that Neptune's moon Triton, by origin a giant comet and by capture and orbital evolution a once fully melted giant comet, has a surface that is probably no older than Europa's.

  7. FBL Outer Can Welder Analysis Software

    SciTech Connect

    2003-04-21

    The Outer Can Welder Analysis Software (OCWAS) was originally developed by SRTC for use at Hanford to assist in the storage of their excess plutonium in the DOE standard 3013 containers until it can be properly dispositioned using one of the approved DOE methods. After that development effort, SRS funded SRTC to develop a similar system for FB-Line for use with 3013 canister welding at SRS. More robust analysis routines and techniques were used with this new version as well as enhanced graphical representation of the data. During the welding process, critical weld parameters such as weld current and voltage, can give valuable information about the weld. In the past, weld data from the TIG welding process, has been monitored using strip chart recorders. The data from the weld process, recorded on the strip chart recorder traces, are reviewed to analyze the weld. To improve this process, another software package developed by SRTC, the OCW DAS, digitizes the weld data and stores the data in a file. The OCWAS automates the weld analysis process by analyzing the data obtained during the weld process. The OCWAS reads a data file that was previously collected using the OCW DAS software. The software will read the file and parse the data. The user is first prompted to enter the file name. The file is then opened and the operator name, canister identification, and Date/Time of Acquisition are read from the file and displayed on the screen. The binary weld data is then read from the file into an array until the end of the file is reached. The current, voltage, and position data are displayed on the screen in graphical format on the front panel. The weld power and resistance are calculated and are also displayed in graphical format on the front panel.

  8. Motile responses in outer hair cells.

    PubMed

    Zenner, H P

    1986-01-01

    Motile responses of cochlear hair cells open new perspectives for the understanding of cochlear hearing mechanisms and hearing disorders located in hair cells. Direct visualization of hair cell motility was achieved by a method for the study of living isolated mammalian outer hair cells (OHCs) which has overcome some of the complexities in dealing with the heterogeneous organ of Corti. Electrophysiological giga-seal whole-cell recordings of single OHC prepared by this approach had revealed negative cell potentials ranging from -32 mV to -70 mV (Gitter et al. (1986) Oto-Rhino-Laryngol. in press). Elucidation of HC motility has come from two lines of experiments. One follows from the observation that exposure of the lateral and basal membrane parts of living OHCs to increasing bath K+ concentrations resulted in a sustained reversible depolarization of the cell. Here, we report that by depolarization of the cell membrane in the presence of 25-125 mM K+/Cl- a sustained contraction of OHC was induced. This was followed by relaxation in the presence of artificial perilymph containing 5.4 mM K+/Cl-. By alternating these procedures OHCs were made to undergo as many as five cycles of contraction and relaxation. External Ca2+ was not required for the initial contraction but was essential for relaxation. Following repeated contraction/relaxation cycles the cytoplasm of individual OHCs exhibited a filamentous network, correlating with a new infracuticular anti-actin binding capacity. The second series of experiments originates in the observation that permeabilized OHCs contracted in the presence of ATP. No response was seen in the presence of control nucleotides.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3733547

  9. FBL Outer Can Welder Analysis Software

    Energy Science and Technology Software Center (ESTSC)

    2003-04-21

    The Outer Can Welder Analysis Software (OCWAS) was originally developed by SRTC for use at Hanford to assist in the storage of their excess plutonium in the DOE standard 3013 containers until it can be properly dispositioned using one of the approved DOE methods. After that development effort, SRS funded SRTC to develop a similar system for FB-Line for use with 3013 canister welding at SRS. More robust analysis routines and techniques were used withmore »this new version as well as enhanced graphical representation of the data. During the welding process, critical weld parameters such as weld current and voltage, can give valuable information about the weld. In the past, weld data from the TIG welding process, has been monitored using strip chart recorders. The data from the weld process, recorded on the strip chart recorder traces, are reviewed to analyze the weld. To improve this process, another software package developed by SRTC, the OCW DAS, digitizes the weld data and stores the data in a file. The OCWAS automates the weld analysis process by analyzing the data obtained during the weld process. The OCWAS reads a data file that was previously collected using the OCW DAS software. The software will read the file and parse the data. The user is first prompted to enter the file name. The file is then opened and the operator name, canister identification, and Date/Time of Acquisition are read from the file and displayed on the screen. The binary weld data is then read from the file into an array until the end of the file is reached. The current, voltage, and position data are displayed on the screen in graphical format on the front panel. The weld power and resistance are calculated and are also displayed in graphical format on the front panel.« less

  10. Hardness Alternation in ?,?-Alkanedicarboxylic Acids.

    PubMed

    Mishra, Manish Kumar; Ramamurty, Upadrasta; Desiraju, Gautam R

    2015-10-01

    The variation of hardness as a function of the number of carbon atoms in ?,?-alkanedicarboxylic acids, C(N)H(2N-2)O4 (4?N?9), was examined by recourse to nanoindentation on the major faces of single crystals. Hardness exhibits odd-even alternation, with the odd acids being softer and the even ones harder; the differences decrease with increasing chain length. These variations are similar to those seen for other mechanical, physical, and thermal properties of these diacids. The softness of odd acids is rationalized due to strained molecular conformations in them, which facilitate easier plastic deformation. Relationships between structural features, such as interplanar spacing, interlayer separation distance, molecular chain length, and signatures of the nanoindentation responses, namely, discrete displacement bursts, were also examined. Shear sliding of molecular layers past each other during indentation is key to the mechanism for plastic deformation in these organic crystals. PMID:25919633

  11. Ultrasonic material hardness depth measurement

    DOEpatents

    Good, Morris S. (Richland, WA); Schuster, George J. (Kennewick, WA); Skorpik, James R. (Kennewick, WA)

    1997-01-01

    The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part.

  12. Ultrasonic material hardness depth measurement

    DOEpatents

    Good, M.S.; Schuster, G.J.; Skorpik, J.R.

    1997-07-08

    The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part. 12 figs.

  13. Why Are Drugs So Hard to Quit?

    MedlinePLUS Videos and Cool Tools

    ... Quitting drugs is hard because addiction is a brain disease. Your brain is like a control tower that sends out ... and choices. Addiction changes the signals in your brain and makes it hard to feel OK without ...

  14. Microwave assisted hard rock cutting

    DOEpatents

    Lindroth, David P. (Apple Valley, MN); Morrell, Roger J. (Bloomington, MN); Blair, James R. (Inver Grove Heights, MN)

    1991-01-01

    An apparatus for the sequential fracturing and cutting of subsurface volume of hard rock (102) in the strata (101) of a mining environment (100) by subjecting the volume of rock to a beam (25) of microwave energy to fracture the subsurface volume of rock by differential expansion; and , then bringing the cutting edge (52) of a piece of conventional mining machinery (50) into contact with the fractured rock (102).

  15. Schwannoma of the hard palate

    PubMed Central

    Sahoo, Pradyumna Kumar; Mandal, Palash Kumar; Ghosh, Saradindu

    2014-01-01

    Schwannomas are benign encapsulated perineural tumors. The head and neck region is the most common site. Intraoral origin is seen in only 1% of cases, tongue being the most common site; its location in the palate is rare. We report a case of hard-palate schwannoma with bony erosion which was immunohistochemically confirmed. The tumor was excised completely intraorally. After two months of follow-up, the defect was found to be completely covered with palatal mucosa. PMID:25298716

  16. Assessing the utility of elemental ratios as a paleotemperature proxy in shells of patelloid limpets

    NASA Astrophysics Data System (ADS)

    Graniero, Lauren; Surge, Donna; Gillikin, David

    2015-04-01

    Archaeological shell and fish middens are rich sources of paleoenvironmental proxy data. Carbonate hard part remains contained in such deposits have been used as archives of coastal marine climate and human-climate interactions. Oxygen isotope records from fast-growing limpet shells potentially capture summer and winter seasons, and thus, approach the full seasonal range of sea surface temperature (SST). Fast-growing shells are often short-lived, providing "snap-shots" of multi-year seasonal cycles. Patelloid limpet shells are common constituents in archaeological middens found along European, African, and South American coastlines. Oxygen isotope ratios of archaeological limpet shells from the genus, Patella, have been used to reconstruct seasonal SST and ocean circulation patterns during the Late Quaternary. Such studies depend on the ability to constrain the oxygen isotope ratio of seawater; therefore, alternative proxies are necessary for coastal localities where this is not possible. Elemental ratios (e.g., Sr/Ca, Mg/Ca) have been used as paleotemperature proxies in corals and foraminifera with varying degrees of success and appear problematic in bivalves. Here, we test whether such elemental ratios are useful as an alternative SST proxy in patelloid limpet shells.

  17. Dual shell pressure balanced vessel

    DOEpatents

    Fassbender, Alexander G. (West Richland, WA)

    1992-01-01

    A dual-wall pressure balanced vessel for processing high viscosity slurries at high temperatures and pressures having an outer pressure vessel and an inner vessel with an annular space between the vessels pressurized at a pressure slightly less than or equivalent to the pressure within the inner vessel.

  18. Mineralogical characterization of pristine, bio-eroded and fossil bivalve shell material for the evaluation of a species-specific alteration potential

    NASA Astrophysics Data System (ADS)

    Hippler, Dorothee; Goetschl, Katja Elisabeth; Gerstmann, Brigitte Simone; Rafael Garcia-March, Jose; Dietzel, Martin

    2015-04-01

    Biogenic carbonates of marine calcifiers can provide a wealth of information for the reconstruction of modern and palaeo-environments. However, their composite carbonate shells are often prone to different alteration processes that might occur during their lifetime, post-mortem or during early diagenesis. In order to use these calcifiers as palaeo-archives or proxy carriers, it is thus of crucial importance to assess their alteration potential. Here, we present the mineral phase composition of four different Mediterranean bivalve species (Spondylus, Lithophaga, Arca, Glycymeris) using spatially selected, powder XRD analysis, as well as in-situ high-resolution Raman spectroscopy. The sample set thereby comprises pristine-modern, bioeroded-modern, Holocene and Pleistocene specimens of the same bivalve species in order to characterize and evaluate the species-specific susceptibility to bioerosion and diagenetic alteration. We reveal species-specific shell compositions that are validated by both analytical methods. Differences in shell mineralogy occur between the outermost (periostracum), the outer (ostracum) and inner (hypostracum) layer, with the outer layer mainly composed of calcite and the inner layers of aragonite with variable portions of calcite. Considerable species-specific changes in mineralogy of the respective shell layers with increasing geological age are not found. Our results indicate that the original shell mineralogy (calcite, aragonite and carbonate fluorapatite) as well as the composition, structure and thickness of the respective shell layers are important factors favouring or preventing alteration to occur. Moreover, our findings highlight the effect of bioerosion during the alteration process. The analysis of distinct areas of the shells hinting at microbial activity reveals slight changes in shell mineralogy. We thus postulate that processes related to shell taphonomy are crucial for the shell's alteration/preservational potential and thus subsequent for diagenesis. This is a contribution to the DFG research group CHARON.

  19. Shell may expand detergent alcohols

    SciTech Connect

    1996-10-23

    Shell Chemical is studying plans to expand detergent alcohols capacity in the US, CW has learned. The company is considering adding capacity for about 80 million lbs/year. If the project is approved, it would be implemented at the company`s Geismar, LA site. Shell will make a final decision on whether to proceed with the project within six months. It has been rumored to be considering a capacity addition as a result of tightening supply of natural and synthetic detergent alcohols.

  20. Effects of shell morphology on mechanics of zebra and quagga mussel locomotion.

    PubMed

    Peyer, Suzanne M; Hermanson, John C; Lee, Carol Eunmi

    2011-07-01

    Although zebra mussels (Dreissena polymorpha) initially colonized shallow habitats within the North American Great Lakes, quagga mussels (Dreissena bugensis) are becoming dominant in both shallow- and deep-water habitats. Shell morphology differs among zebra, shallow quagga and deep quagga mussels but functional consequences of such differences are unknown. We examined effects of shell morphology on locomotion for the three morphotypes on hard (typical of shallow habitats) and soft (characteristic of deep habitats) sedimentary substrates. We quantified morphology using the polar moment of inertia, a parameter used in calculating kinetic energy that describes shell area distribution and resistance to rotation. We quantified mussel locomotion by determining the ratio of rotational (K(rot)) to translational kinetic energy (K(trans)). On hard substrate, K(rot):K(trans) of deep quagga mussels was fourfold greater than for the other morphotypes, indicating greater energy expenditure in rotation relative to translation. On soft substrate, K(rot):K(trans) of deep quagga mussels was approximately one-third of that on hard substrate, indicating lower energy expenditure in rotation on soft substrate. Overall, our study demonstrates that shell morphology correlates with differences in locomotion (i.e. K(rot):K(trans)) among morphotypes. Although deep quagga mussels were similar to zebra and shallow quagga mussels in terms of energy expenditure on sedimentary substrate, their morphology was energetically maladaptive for linear movement on hard substrate. As quagga mussels can possess two distinct morphotypes (i.e. shallow and deep morphs), they might more effectively utilize a broader range of substrates than zebra mussels, potentially enhancing their ability to colonize a wider range of habitats. PMID:21653816

  1. Uniformly Hard Languages \\Lambda Rod Downey y

    E-print Network

    Downey, Rod

    Uniformly Hard Languages \\Lambda Rod Downey y Department of Mathematics Victoria University P. O of ``uniformly hard languages,'' where a language is just not merely infinitely often not computable in polynomial­time but in fact the languages are hard nearly everywhere. We conjecture that all NP

  2. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  3. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  4. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  5. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  6. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  7. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  8. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  9. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  10. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  11. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  12. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  13. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  14. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  15. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  16. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  17. Warren G. Harding and the Press.

    ERIC Educational Resources Information Center

    Whitaker, W. Richard

    There are many parallels between the Richard M. Nixon administration and Warren G. Harding's term: both Republicans, both touched by scandal, and both having a unique relationship with the press. But in Harding's case the relationship was a positive one. One of Harding's first official acts as president was to restore the regular White House news…

  18. Using Nondeterminism to Amplify Hardness Alexander Healy

    E-print Network

    Vadhan, Salil

    Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Division of Engineering revisit the problem of hardness amplification in NP, as recently studied by O'Donnell (JCSS `04). We prove to compute f on a 1/2 - 1/s (n) fraction of inputs. In particular, 1. If s(n) = n(1) , we amplify to hardness

  19. Input Locality and Hardness Amplification Andrej Bogdanov

    E-print Network

    Bogdanov, Andrej

    Input Locality and Hardness Amplification Andrej Bogdanov Alon Rosen Abstract We establish new hardness amplification results for one-way functions in which each input bit influences only a small number is injective then it is equally hard to invert f on a (1 - )-fraction of inputs. · If f is regular

  20. Texts in Computational Complexity: Amplification of Hardness

    E-print Network

    Goldreich, Oded

    Texts in Computational Complexity: Amplification of Hardness Oded Goldreich Department of Computer a positive side, because hard problem can be ``put to work'' to our benefit, most notably in cryptography. One key issue that arises whenever one tries to utilize hard problem is bridging the gap between

  1. Distributed Verification and Hardness of Distributed Approximation

    E-print Network

    Distributed Verification and Hardness of Distributed Approximation Atish Das Sarma Google Foundation (BSF). Permission to make digital or hard copies of all or part of this work for personal on the hardness of distributed approxi- mation for many classical optimization problems including minimum spanning

  2. PROTEIN COMPOSITION AND GRAIN HARDNESS IN SORGHUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain hardness is an important quality trait in sorghum. Grain hardness has been linked to milling and food quality as well as resistance to insects and mold. Despite the importance of grain hardness in sorghum, its biochemical basis is still not well understood. In sorghum, the grain is composed...

  3. Hard Metric from Cayley Graphs Yuri Rabinovich

    E-print Network

    Newman, Ilan

    Hard Metric from Cayley Graphs Yuri Rabinovich Haifa University Joint work with Ilan Newman #12;Metric distortion and hard metrics The distortion of embedding a metric µ into an Euclidean space, c2(µ] and AR[98] claims that there exists metrics µ such that c2(µ)= (log n). We call such metrics hard. #12

  4. DISTRIBUTED VERIFICATION AND HARDNESS OF DISTRIBUTED APPROXIMATION

    E-print Network

    DISTRIBUTED VERIFICATION AND HARDNESS OF DISTRIBUTED APPROXIMATION ATISH DAS SARMA, STEPHAN HOLZER on the hardness of distributed approximation for many classical optimization problems including minimum spanning the previous hardness of approximation bound of Elkin [STOC 2004] as well as the lower bound for (exact) MST

  5. GENETIC PROGRAMMING WITH HISTORICALLY ASSESSED HARDNESS

    E-print Network

    Spector, Lee

    Chapter 1 GENETIC PROGRAMMING WITH HISTORICALLY ASSESSED HARDNESS Jon Klein1 and Lee Spector1 1 of the genetic programming algorithm, called Histor- ically Assessed Hardness (HAH), in which the fitness rewards: historically assessed hardness, implicit fitness sharing, Push, PushGP This is a preprint copy of: Klein, J

  6. Empirical Hardness Models for Combinatorial Auctions

    E-print Network

    Shoham, Yoav

    Chapter 19 Empirical Hardness Models for Combinatorial Auctions Kevin Leyton-Brown, Eugene Nudelman and Yoav Shoham In this chapter we consider the empirical hardness of the winner determination problem. We to learn, evaluate and interpret a function from these features to the predicted hardness of an instance

  7. Hardness Amplification within NP against Deterministic Algorithms

    E-print Network

    Guruswami, Venkatesan

    Hardness Amplification within NP against Deterministic Algorithms Parikshit Gopalan Microsoft Carnegie Mellon University. Abstract We study the average-case hardness of the class NP against algorithms these classes, namely we ask: How hard are languages in NP on average for deterministic polynomial time

  8. Using Nondeterminism to Amplify Hardness Alexander Healy

    E-print Network

    Vadhan, Salil

    Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Division of Engineering revisit the problem of hardness amplification in NP, as recently studied by O'Donnell (STOC `02). We prove to compute f on a 1/2 - 1/s (n) fraction of inputs. In particular, 1. If s(n) = n(1) , we amplify to hardness

  9. Cryptographic Hardness for Learning Intersections of Halfspaces

    E-print Network

    Klivans, Adam

    Cryptographic Hardness for Learning Intersections of Halfspaces Adam R. Klivans University representation-independent hardness results for PAC learning intersections of halfspaces, a central concept class in computational learning theory. Our hardness results are derived from two public-key cryptosystems due to Regev

  10. Unified characterisations of resolution hardness measures

    E-print Network

    Kullmann, Oliver

    1 Unified characterisations of resolution hardness measures Olaf Beyersdorff 1 Oliver Kullmann 2 1;2 Hardness measures for resolution Historically first and best studied size of resolution proofs tree method for space again via width [Atserias & Dalmau 08] #12;3 Why hardness measures? Correspondence

  11. Tuning structure and mobility of solvation shells surrounding tracer additives

    NASA Astrophysics Data System (ADS)

    Carmer, James; Jain, Avni; Bollinger, Jonathan A.; van Swol, Frank; Truskett, Thomas M.

    2015-03-01

    Molecular dynamics simulations and a stochastic Fokker-Planck equation based approach are used to illuminate how position-dependent solvent mobility near one or more tracer particle(s) is affected when tracer-solvent interactions are rationally modified to affect corresponding solvation structure. For tracers in a dense hard-sphere fluid, we compare two types of tracer-solvent interactions: (1) a hard-sphere-like interaction, and (2) a soft repulsion extending beyond the hard core designed via statistical mechanical theory to enhance tracer mobility at infinite dilution by suppressing coordination-shell structure [Carmer et al., Soft Matter 8, 4083-4089 (2012)]. For the latter case, we show that the mobility of surrounding solvent particles is also increased by addition of the soft repulsive interaction, which helps to rationalize the mechanism underlying the tracer's enhanced diffusivity. However, if multiple tracer surfaces are in closer proximity (as at higher tracer concentrations), similar interactions that disrupt local solvation structure instead suppress the position-dependent solvent dynamics.

  12. Tuning structure and mobility of solvation shells surrounding tracer additives

    E-print Network

    James Carmer; Avni Jain; Jonathan A. Bollinger; Frank van Swol; Thomas M. Truskett

    2015-02-05

    Molecular dynamics simulations and a stochastic Fokker-Planck equation based approach are used to illuminate how position-dependent solvent mobility near one or more tracer particle(s) is affected when tracer-solvent interactions are rationally modified to affect corresponding solvation structure. For tracers in a dense hard-sphere fluid, we compare two types of tracer-solvent interactions: (1) a hard-sphere-like interaction; and (2) a soft repulsion extending beyond the hard core designed via statistical mechanical theory to enhance tracer mobility at infinite dilution by suppressing coordination-shell structure (Carmer et al., Soft Matter 8 (2011)). For the latter case, we show that the mobility of surrounding solvent particles is also increased by addition of the soft repulsive interaction, which helps to rationalize the mechanism underlying the tracer's enhanced diffusivity. However, if multiple tracer surfaces are in closer proximity (as at higher tracer concentrations), similar interactions that disrupt local solvation structure instead suppress the position-dependent solvent dynamics.

  13. Structural Aspects of Bacterial Outer Membrane Protein Assembly.

    PubMed

    Calmettes, Charles; Judd, Andrew; Moraes, Trevor F

    2015-01-01

    The outer membrane of Gram-negative bacteria is predominantly populated by ?-Barrel proteins and lipid anchored proteins that serve a variety of biological functions. The proper folding and assembly of these proteins is essential for bacterial viability and often plays a critical role in virulence and pathogenesis. The ?-barrel assembly machinery (Bam) complex is responsible for the proper assembly of ?-barrels into the outer membrane of Gram-negative bacteria, whereas the localization of lipoproteins (Lol) system is required for proper targeting of lipoproteins to the outer membrane. PMID:26621472

  14. Radioisotope Reduction Using Solar Power for Outer Planetary Missions

    NASA Technical Reports Server (NTRS)

    Fincannon, James

    2008-01-01

    Radioisotope power systems have historically been (and still are) the power system of choice from a mass and size perspective for outer planetary missions. High demand for and limited availability of radioisotope fuel has made it necessary to investigate alternatives to this option. Low mass, high efficiency solar power systems have the potential for use at low outer planetary temperatures and illumination levels. This paper documents the impacts of using solar power systems instead of radioisotope power for all or part of the power needs of outer planetary spacecraft and illustrates the potential fuel savings of such an approach.

  15. Self-sterilization of bodies during outer planet entry

    NASA Technical Reports Server (NTRS)

    Hoffman, A. R.; Jaworski, W.; Taylor, D. M.

    1974-01-01

    A body encountering the atmosphere of an outer planet is subjected to heat loads which could result in high temperature conditions that render terrestrial organisms on or within the body nonviable. To determine whether an irregularly shaped entering body, consisting of several different materials, would be sterilized during inadvertent entry at high velocity, the thermal response of a typical outer planet spacecraft instrument was studied. The results indicate that the Teflon insulated cable and electronic circuit boards may not experience sterilizing temperatures during a Jupiter, Saturn, or Titan entry. Another conclusion of the study is that small plastic particles entering Saturn from outer space have wider survival corridors than do those at Jupiter.

  16. Analysis and measurement about atmospheric turbulent outer scale

    NASA Astrophysics Data System (ADS)

    Zong, Fei; Hu, Yuehong; Chang, Jinyong; Feng, Shuanglian; Qiang, Xiwen

    2015-10-01

    The objectives of this tutorial are to introduce an optical method of measuring atmospheric turbulent outer scale. The method utilizes the ratio between the correlation functions of the wandering in two perpendicular planes. A simple relationship to obtain the outer scale from the measured correlation functions is established for a particular model of turbulence, the modified Von Karman model. Base on the rational conclusion, an implementary project of measuring atmospheric turbulent outer scale with optical method is designed. At the same time, the plan of the experiment system is given. By predigesting the model, the calculating program of the measurement is written also.

  17. Control of the Helicity Content of a Gun-Generated Spheromak by Incorporating a Conducting Shell into a Magnetized Coaxial Plasma Gun

    NASA Astrophysics Data System (ADS)

    Matsumoto, Tadafumi; Sekiguchi, Jun'ichi; Asai, Tomohiko

    In the formation of magnetized plasmoid by a magnetized coaxial plasma gun (MCPG), the magnetic helicity content of the generated plasmoid is one of the critical parameters. Typically, the bias coil to generate a poloidal flux is mounted either on the outer electrode or inside the inner electrode. However, most of the flux generated in the conventional method spreads even radially outside of the formation region. Thus, only a fraction of the total magnetic flux is actually exploited for helicity generation in the plasmoid. In the proposed system, the plasma gun incorporates a copper shell mounted on the outer electrode. By changing the rise time of the discharge bias coil current and the geometrical structure of the shell, the magnetic field structure and its time evolution can be controlled. The effect of the copper shell has been numerically simulated for the actual gun structure, and experimentally confirmed. This may increase the magnetic helicity content results, through increased poloidal magnetic field.

  18. Alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species

    PubMed Central

    Igic, Branislav; Braganza, Kim; Hyland, Margaret M.; Silyn-Roberts, Heather; Cassey, Phillip; Grim, Tomas; Rutila, Jarkko; Moskát, Csaba; Hauber, Mark E.

    2011-01-01

    Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, and their respective hosts. Using tools developed for materials science, we discovered a novel correlate of increased strength of parasite eggs: the common cuckoo's egg exhibits a greater microhardness, especially in the inner region of the shell matrix, relative to its host and sympatric non-host species. We then tested predictions of four potential mechanisms of shell strength: (i) increased relative thickness overall, (ii) greater proportion of the structurally harder shell layers, (iii) higher concentration of inorganic components in the shell matrix, and (iv) elevated deposition of a high density compound, MgCO3, in the shell matrix. We confirmed support only for hypothesis (i). Eggshell characteristics did not differ between parasite eggs sampled from different host nests in distant geographical sites, suggesting an evolutionarily shared microstructural mechanism of stronger parasite eggshells across diverse host-races of brood parasitic cuckoos. PMID:21561966

  19. Hard Questions 1 When Hard Questions are Asked: Evaluating Writing Centers

    E-print Network

    Northern British Columbia, University of

    Hard Questions 1 When Hard Questions are Asked: Evaluating Writing Centers James H. Bell University of Northern British Columbia 3333 University Way Prince George, BC Canada V2N 4Z9 RUNNING HEAD: Hard Questions Reading and Learning. Thank you to three reviewers for their revision suggestions. #12;Hard Questions 2

  20. ESTIMATING THE DENSITY OF DRY SNOW LAYERS FROM HARDNESS, AND HARDNESS FROM DENSITY

    E-print Network

    Jamieson, Bruce

    ESTIMATING THE DENSITY OF DRY SNOW LAYERS FROM HARDNESS, AND HARDNESS FROM DENSITY Daehyun Kim 1 and hardness of dry snow layers for common grain types. These relations have been widely used to estimate), and to estimate the hardness of layers in snowpack evolution models. Since 2000, the database of snow layers has

  1. Hardness Standardization Our objective is to standardize and improve hardness measurement

    E-print Network

    Hardness Standardization METALS Our objective is to standardize and improve hardness measurement both in the U.S. and internationally. NIST is the U.S. National Metrology Institute (NMI) for hardness, and as such, is responsible for traceability in hardness measurements. Objective Impact and Customers

  2. Hard body amphiphiles at a hard wall JOSEPH M. BRADER1y

    E-print Network

    Schmidt, Matthias

    Hard body amphiphiles at a hard wall JOSEPH M. BRADER1y , CHRISTIAN VON FERBER2 and MATTHIAS 2003) We investigate the structure of amphiphilic molecules exposed to a substrate that is modelled by a hard wall. Our simple model amphiphiles consist of a hard sphere head group to which a vanishingly thin

  3. Electrocaloric effect in core-shell ferroelectric ceramics: Theoretical approach and practical conclusions

    NASA Astrophysics Data System (ADS)

    Anoufa, M.; Kiat, J. M.; Bogicevic, C.

    2015-10-01

    Most of the theoretical and experimental studies on the electrocaloric effect (ECE) are devoted to thin films, but they can be hardly envisaged for cooling macroscopic systems; moreover, the results obtained cannot be easily transposed for larger systems like multilayered ceramics. Therefore, efforts should also be focused on predicting, synthesizing, and characterizing interesting bulk single crystal or ceramics. In ferroelectric nanoparticles and ceramics, the core-shell structure of grains is of uttermost importance to explain the experimental results at small sizes. Moreover, it can be used to tailor physical properties, such as energy storage, by experimenting with the composition, thickness, and permittivity of the shell. Here, we report the effect of such structures on the electrocaloric effects in a variety of ferroelectric materials. The magnitude of ECE as well as its field and temperature-dependence are obtained for different types of core-shells. The optimal configuration for a maximal ECE is deduced.

  4. On climate reconstruction using bivalves: three methods to interpret the chemical signature of a shell.

    PubMed

    Bauwens, Maite; Ohlsson, Henrik; Barbé, Kurt; Beelaerts, Veerle; Dehairs, Frank; Schoukens, Johan

    2011-11-01

    To improve our understanding of the climate process and to assess the human impact on current global warming, past climate reconstruction is essential. The chemical composition of a bivalve shell is strongly coupled to environmental variations and therefore ancient shells are potential climate archives. The nonlinear nature of the relation between environmental condition (e.g. the seawater temperature) and proxy composition makes it hard to predict the former from the latter, however. In this paper we compare the ability of three nonlinear system identification methods to reconstruct the ambient temperature from the chemical composition of a shell. The comparison shows that nonlinear multi-proxy approaches are potentially useful tools for climate reconstructions and that manifold based methods result in smoother and more precise temperature reconstruction. PMID:20888663

  5. Insights from multiple structures of the shell proteins from the [beta]-carboxysome

    SciTech Connect

    Tanaka, S.; Sawaya, M.R.; Phillips, M.; Yeates, T.O.

    2009-03-02

    Carboxysomes are primitive bacterial organelles that function as a part of a carbon concentrating mechanism (CCM) under conditions where inorganic carbon is limiting. The carboxysome enhances the efficiency of cellular carbon fixation by encapsulating together carbonic anhydrase and the CO{sub 2}-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The carboxysome has a roughly icosahedral shape with an outer shell between 800 and 1500 {angstrom} in diameter, which is constructed from a few thousand small protein subunits. In the cyanobacterium Synechocystis sp. PCC 6803, the previous structure determination of two homologous shell protein subunits, CcmK2 and CcmK4, elucidated how the outer shell is formed by the tight packing of CcmK hexamers into a molecular layer. Here we describe the crystal structure of the hexameric shell protein CcmK1, along with structures of mutants of both CcmK1 and CcmK2 lacking their sometimes flexible C-terminal tails. Variations in the way hexamers pack into layers are noted, while sulfate ions bound in pores through the layer provide further support for the hypothesis that the pores serve for transport of substrates and products into and out of the carboxysome. One of the new structures provides a high-resolution (1.3 {angstrom}) framework for subsequent computational studies of molecular transport through the pores. Crystal and solution studies of the C-terminal deletion mutants demonstrate the tendency of the terminal segments to participate in protein-protein interactions, thereby providing a clue as to which side of the molecular layer of hexameric shell proteins is likely to face toward the carboxysome interior.

  6. SNAREs Interact with Retinal Degeneration Slow and Rod Outer Segment Membrane Protein-1 during Conventional and Unconventional Outer Segment Targeting

    PubMed Central

    Zulliger, Rahel; Conley, Shannon M.; Mwoyosvi, Maggie L.; Stuck, Michael W.; Azadi, Seifollah; Naash, Muna I.

    2015-01-01

    Mutations in the photoreceptor protein peripherin-2 (also known as RDS) cause severe retinal degeneration. RDS and its homolog ROM-1 (rod outer segment protein 1) are synthesized in the inner segment and then trafficked into the outer segment where they function in tetramers and covalently linked larger complexes. Our goal is to identify binding partners of RDS and ROM-1 that may be involved in their biosynthetic pathway or in their function in the photoreceptor outer segment (OS). Here we utilize several methods including mass spectrometry after affinity purification, in vitro co-expression followed by pull-down, in vivo pull-down from mouse retinas, and proximity ligation assay to identify and confirm the SNARE proteins Syntaxin 3B and SNAP-25 as novel binding partners of RDS and ROM-1. We show that both covalently linked and non-covalently linked RDS complexes interact with Syntaxin 3B. RDS in the mouse is trafficked from the inner segment to the outer segment by both conventional (i.e., Golgi dependent) and unconventional secretory pathways, and RDS from both pathways interacts with Syntaxin3B. Syntaxin 3B and SNAP-25 are enriched in the inner segment (compared to the outer segment) suggesting that the interaction with RDS/ROM-1 occurs in the inner segment. Syntaxin 3B and SNAP-25 are involved in mediating fusion of vesicles carrying other outer segment proteins during outer segment targeting, so could be involved in the trafficking of RDS/ROM-1. PMID:26406599

  7. Method and apparatus for an inflatable shell

    NASA Technical Reports Server (NTRS)

    Johnson, Christopher J. (Inventor)

    2012-01-01

    A method of assembling an inflatable shell of a structure comprises folding a plurality of shell sections about a set of fold lines and integrating the plurality of shell sections together with one another to form the shell. In another embodiment, an inflatable shell comprises a plurality of shell sections, each shell section having two pairs of fold lines for folding into stowage comprising a first gore section having a plurality of first gore panels layered and collectively folded about at a first set of fold lines. Each layer of the first gore panels and second gore panels are configured such that, once the first gore panel and second gore panel are attached to one another at the respective side edges of each panel, the lines of attachment forming a second set of fold lines for the shell section. A system and method for fabricating gore panels is also disclosed.

  8. Past and future of grid shell structures

    E-print Network

    Paoli, Céline (Céline Aude)

    2007-01-01

    Because of their original organic shape and the column free space that they provide, the design of grid shell structures challenges architects and structural engineers in more than one way. Very few grid shell building ...

  9. FOOD FISH FACTS SCALLOP MEAT AND SHELL

    E-print Network

    52 FOOD FISH FACTS SCALLOP MEAT AND SHELL Throughout the c enturies many romantic and historical the scallop shell is anothe r work of art that is also a source of eat ing pl easure to all people who love

  10. Anadara grandis - Shell Valve Internal View

    USGS Multimedia Gallery

    Anadara grandis seashell, internal view, with scars of the anterior and posterior adductor muscles. The shell has El Rosario, Coxiguina, written in the interior of the shell. Photograph taken 2002 or earlier....

  11. Finite element shell instability analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Formulation procedures and the associated computer program for finite element thin shell instability analysis are discussed. Data cover: (1) formulation of basic element relationships, (2) construction of solution algorithms on both the conceptual and algorithmic levels, and (3) conduction of numerical analyses to verify the accuracy and efficiency of the theory and related programs therein are described.

  12. Elliptical cutouts in cylindrical shells

    NASA Technical Reports Server (NTRS)

    Tsai, C.-J.; Sanders, J. L., Jr.

    1975-01-01

    The stress concentrations due to an elliptical cutout in a shallow cylindrical shell are determined by means of a system of singular integral equations, solved numerically. Three loading conditions are considered: tension, and internal pressure. Results confirm those obtained by previous authors by other methods and extend the range of parameters over which results are available.

  13. Shell structures for biogas plants

    SciTech Connect

    Sasse, L.

    1982-01-01

    The shell structures designed for biogas plants of the fixed-dome type by the Bremen Overseas Research and Development Association are described. Biogas digesters of the design described have been successfully tested in Rwanda and India without structural or contractural problems.

  14. Shell model description of odd sulfur isotopes

    E-print Network

    P. C. Srivastava; Jorge G. Hirsch; M. J. Ermamatov; V. K. B. Kota

    2012-07-23

    The low energy structure of $^{35,37,39,41}$S isotopes is described performing shell model calculations with the recently devised SDPF-U interaction. Protons and neutrons are restricted to the $sd$-shell for $N 20$. Natural parity states are described with only in-shell mixing, opposite parity states with 1p-1h inter-shell neutron excitations. Energy levels and intensities of electromagnetic transitions are compared with experimental data when available.

  15. Outer Continental Shelf Oil and Gas Leasing/Production Program

    SciTech Connect

    Not Available

    1988-01-01

    This annual report on the Outer Continental Shelf (OCS) Oil and Gas Leasing and Production program summarizes receipts and expenditures, and includes information on OCS safety violations as reported by the US Coast Guard. 3 figs., 12 tabs.

  16. Decreasing Outer Hair Cell Membrane Cholesterol Increases Cochlear Electromechanics

    NASA Astrophysics Data System (ADS)

    Brownell, William E.; Jacob, Stefan; Hakizimana, Pierre; Ulfendahl, Mats; Fridberger, Anders

    2011-11-01

    The effect of decreasing membrane cholesterol on the mechanical response of the cochlea to acoustic and/or electrical stimulation was monitored using laser interferometry. In contrast to pharmacological interventions that typically decrease cochlear electromechanics, reducing membrane cholesterol increased the response. The electromechanical response in untreated preparations was asymmetric with greater displacements in response to positive currents and cholesterol depletion increased the asymmetry. The results confirm that outer hair cell electromotility is enhanced by low membrane cholesterol. The asymmetry of the response indicates the outer hair cell resting membrane potential is hyperpolarized relative to the voltage of maximum gain for the outer hair cell voltage-displacement function. The magnitude of the response increase suggests a non-uniform distribution of cholesterol along the lateral wall of normal adult outer hair cells.

  17. Assembly of ?-barrel proteins in the mitochondrial outer membrane.

    PubMed

    Höhr, Alexandra I C; Straub, Sebastian P; Warscheid, Bettina; Becker, Thomas; Wiedemann, Nils

    2015-01-01

    Mitochondria evolved through endosymbiosis of a Gram-negative progenitor with a host cell to generate eukaryotes. Therefore, the outer membrane of mitochondria and Gram-negative bacteria contain pore proteins with ?-barrel topology. After synthesis in the cytosol, ?-barrel precursor proteins are first transported into the mitochondrial intermembrane space. Folding and membrane integration of ?-barrel proteins depend on the mitochondrial sorting and assembly machinery (SAM) located in the outer membrane, which is related to the ?-barrel assembly machinery (BAM) in bacteria. The SAM complex recognizes ?-barrel proteins by a ?-signal in the C-terminal ?-strand that is required to initiate ?-barrel protein insertion into the outer membrane. In addition, the SAM complex is crucial to form membrane contacts with the inner mitochondrial membrane by interacting with the mitochondrial contact site and cristae organizing system (MICOS) and shares a subunit with the endoplasmic reticulum-mitochondria encounter structure (ERMES) that links the outer mitochondrial membrane to the endoplasmic reticulum (ER). PMID:25305573

  18. 6. OUTER BLAST DOOR, WEST REAR. Edwards Air Force ...

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

    6. OUTER BLAST DOOR, WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  19. Nuclear power sources in outer space. [spacecraft propulsion legal aspects

    NASA Technical Reports Server (NTRS)

    Hosenball, S. N.

    1978-01-01

    Legal problems associated with nuclear power sources in space are discussed with particular reference to the Cosmos 954 incident. Deliberations of the Legal and Scientific and Technical Subcommittees on the Peaceful Uses of Outer Space on this subject are discussed.

  20. UNBOUNDED ORBITS FOR SEMICIRCULAR OUTER DMITRY DOLGOPYAT AND BASSAM FAYAD

    E-print Network

    Dolgopyat, Dmitry

    UNBOUNDED ORBITS FOR SEMICIRCULAR OUTER BILLIARD. DMITRY DOLGOPYAT AND BASSAM FAYAD 1. Introduction rational polygons as well as regular n-gones. Since affine 1 #12;2 DMITRY DOLGOPYAT AND BASSAM FAYAD

  1. Section 6.3 -Volume by cylindrical shells Now, we go through the final method: shell

    E-print Network

    Ee, Bernard Kuowei

    Section 6.3 - Volume by cylindrical shells Now, we go through the final method: shell method like a cylindrical shell (like a cup). We can construct any volume comprising of a series of these cylindrical shells and that's the essence of this method. Now let's express this mathematically. The textbook

  2. Nimmo and Manga: Geodynamics of Europa's Ice Shell 381 Geodynamics of Europa's Icy Shell

    E-print Network

    Nimmo, Francis

    Nimmo and Manga: Geodynamics of Europa's Ice Shell 381 381 Geodynamics of Europa's Icy Shell Processes that operate within Europa's floating icy shell and leave their signature on the surface the large amplitude of topography on Europa, the icy shell is probably more than several kilometers thick

  3. Mon. Not. R. Astron. Soc. 313, 17 (2000) The triple-shell structure and collimated outflows of the planetary nebula

    E-print Network

    Vázquez, Roberto

    2000-01-01

    of the planetary nebula NGC 6891 Martõ�n A. Guerrero,1,2 Luis F. Miranda,3 Arturo Manchado1,4 and Roberto Va�zquez3 spectroscopy of the planetary nebula NGC 6891 are presented. These observations show a great wealth of structures. The bright central nebula is surrounded by an attached shell and a detached outer halo. Both

  4. 26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...provisions; Outer Continental Shelf Lands Act Amendments of 1978. 301...provisions; Outer Continental Shelf Lands Act Amendments of 1978. ...the Outer Continental Shelf Lands Act Amendments of 1978 (92...United States an Offshore Oil Pollution Compensation Fund in...

  5. 26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...provisions; Outer Continental Shelf Lands Act Amendments of 1978. 301...provisions; Outer Continental Shelf Lands Act Amendments of 1978. ...the Outer Continental Shelf Lands Act Amendments of 1978 (92...United States an Offshore Oil Pollution Compensation Fund in...

  6. 26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...provisions; Outer Continental Shelf Lands Act Amendments of 1978. 301...provisions; Outer Continental Shelf Lands Act Amendments of 1978. ...the Outer Continental Shelf Lands Act Amendments of 1978 (92...United States an Offshore Oil Pollution Compensation Fund in...

  7. 26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...provisions; Outer Continental Shelf Lands Act Amendments of 1978. 301...provisions; Outer Continental Shelf Lands Act Amendments of 1978. ...the Outer Continental Shelf Lands Act Amendments of 1978 (92...United States an Offshore Oil Pollution Compensation Fund in...

  8. 26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...provisions; Outer Continental Shelf Lands Act Amendments of 1978. 301...provisions; Outer Continental Shelf Lands Act Amendments of 1978. ...the Outer Continental Shelf Lands Act Amendments of 1978 (92...United States an Offshore Oil Pollution Compensation Fund in...

  9. The Hard Problem of Cooperation

    PubMed Central

    Eriksson, Kimmo; Strimling, Pontus

    2012-01-01

    Based on individual variation in cooperative inclinations, we define the “hard problem of cooperation” as that of achieving high levels of cooperation in a group of non-cooperative types. Can the hard problem be solved by institutions with monitoring and sanctions? In a laboratory experiment we find that the answer is affirmative if the institution is imposed on the group but negative if development of the institution is left to the group to vote on. In the experiment, participants were divided into groups of either cooperative types or non-cooperative types depending on their behavior in a public goods game. In these homogeneous groups they repeatedly played a public goods game regulated by an institution that incorporated several of the key properties identified by Ostrom: operational rules, monitoring, rewards, punishments, and (in one condition) change of rules. When change of rules was not possible and punishments were set to be high, groups of both types generally abided by operational rules demanding high contributions to the common good, and thereby achieved high levels of payoffs. Under less severe rules, both types of groups did worse but non-cooperative types did worst. Thus, non-cooperative groups profited the most from being governed by an institution demanding high contributions and employing high punishments. Nevertheless, in a condition where change of rules through voting was made possible, development of the institution in this direction was more often voted down in groups of non-cooperative types. We discuss the relevance of the hard problem and fit our results into a bigger picture of institutional and individual determinants of cooperative behavior. PMID:22792282

  10. Direct drive double shell target implosion hydodynamics on OMEGA

    SciTech Connect

    Kyrala, George A.; Delamater, N. D.; Wilson, D. C.; Guzik, J. A.; Haynes, D. A.; Gunderson, M. A.; Klare, K. A.; Watt, R. G.; Wood, W. M.; Varnum, W. S.

    2004-01-01

    Imploding indirect-drive double shell targets may provide an alternative, non-cryogenic path to ignition on the National Ignition Facility (NIF). Experiments are being pursued at OMEGA to understand the hydrodynamics of these implosions and the possibility of scaling to NIF designs. We have used 40 beams from the OMEGA laser to directly drive the capsules, and we have used the remaining 20 beams to backlight the imploding shells from two different directions at multiple times. We will review the recent experiments to measure the hydrodynamics of the targets using two-view x-ray radiography of the capsules. We will present data on measured yields from the targets. We will present a measured time history of the hydrodynamics of the implosion. Experiments were pursued using direct drive in which the M-band effect, experienced in the indirect drive experiments, could be eliminated or controlled. It was learned in the direct drive experiments that the best performing capsules were those that had a thin outer layer of gold. This effectively causes M-band pre-heat effects giving implosion hydrodynamics and performance closer to the indirect drive case. We will review the method used to radiograph the targets and the techniques used to extract useful information to compare with calculations. The effect of imperfections in the target construction will be shown to be minimal during the initial stage of the implosion. The yields from the targets were observed to be uniformly low compared to indirect-drive.

  11. Multiphoton inner-shell ionization of the carbon atom

    NASA Astrophysics Data System (ADS)

    Rey, H. F.; van der Hart, H. W.

    2015-07-01

    We apply time-dependent R -matrix theory to study inner-shell ionization of C atoms in ultrashort high-frequency light fields with a photon energy between 170 and 245 eV. At an intensity of 1017 W /cm2, ionization is dominated by single-photon emission of a 2 ? electron, with two-photon emission of a 1 s electron accounting for about 2-3% of all emission processes, and two-photon emission of 2 ? contributing about 0.5-1%. Three-photon emission of a 1 s electron is estimated to contribute about 0.01-0.03%. Around a photon energy of 225 eV, two-photon emission of a 1 s electron, leaving C+ in either 1 s 2 s 2 p3 or 1 s 2 p4 , is resonantly enhanced by intermediate 1 s 2 s22 p3 states. The results demonstrate the capability of time-dependent R -matrix theory to describe inner-shell ionization processes including rearrangement of the outer electrons.

  12. 7 CFR 984.10 - Shelled walnuts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Shelled walnuts. 984.10 Section 984.10 Agriculture...NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.10 Shelled walnuts. Shelled walnuts means walnut...

  13. 7 CFR 984.10 - Shelled walnuts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Shelled walnuts. 984.10 Section 984.10 Agriculture...Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.10 Shelled walnuts. Shelled walnuts means walnut...

  14. 7 CFR 984.10 - Shelled walnuts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Shelled walnuts. 984.10 Section 984.10 Agriculture...Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.10 Shelled walnuts. Shelled walnuts means walnut...

  15. 7 CFR 984.10 - Shelled walnuts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Shelled walnuts. 984.10 Section 984.10 Agriculture...NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.10 Shelled walnuts. Shelled walnuts means walnut...

  16. 7 CFR 981.6 - Shelled almonds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Shelled almonds. 981.6 Section 981.6 Agriculture... and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.6 Shelled almonds. Shelled almonds mean raw or roasted almonds...

  17. 7 CFR 981.6 - Shelled almonds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Shelled almonds. 981.6 Section 981.6 Agriculture... AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.6 Shelled almonds. Shelled almonds mean raw or roasted almonds...

  18. 7 CFR 981.6 - Shelled almonds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Shelled almonds. 981.6 Section 981.6 Agriculture... and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.6 Shelled almonds. Shelled almonds mean raw or roasted almonds...

  19. 7 CFR 981.6 - Shelled almonds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Shelled almonds. 981.6 Section 981.6 Agriculture... AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.6 Shelled almonds. Shelled almonds mean raw or roasted almonds...

  20. 7 CFR 981.6 - Shelled almonds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Shelled almonds. 981.6 Section 981.6 Agriculture... and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.6 Shelled almonds. Shelled almonds mean raw or roasted almonds...