Tension Pneumopericardium as a Complication of Preoperative Localization of a Small Pulmonary Metastasis Using a Short Hook Wire and Suture System
No abstract prepared.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
SEARCH · Engineering Papers
Results for “WIRE”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Percutaneous Hepaticojejunostomy Using a Radiofrequency Wire for Management of a Postoperative Bile Leak
Postoperative biliary complications following extensive hepatic resections are complex, often requiring a multidisciplinary team approach. We describe a case of a free bile duct leak following extended right hepatectomy and surgical hepaticojejunostomy treated with percutaneous transhepatic hepaticojejunostomy in which a radiofrequency guidewire was used to gain enteral access. A modified internal/external biliary catheter was left in place. The patient was enrolled in a benign biliary stricture protocol, and 8 months later, the catheter was removed following a normal cholangiogram and biliary manometric perfusion testing. At 3-month follow-up after catheter removal, the patient is asymptomatic with no clinical, biochemical, or radiographic evidence of biliary leak or obstruction.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
Voltage Noise in a Superconducting Wire with a Constriction
We analyze voltage fluctuations in superconducting nanowires with constrictions. We argue that quantum phase slips occurring in the constriction area are responsible for both equilibrium and non-equilibrium voltage noise in such systems. We evaluate the power spectrum of the voltage noise identifying its non-trivial dependence on both frequency and external bias.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Maximum Endurance Lightning Current of Different High-Temperature Superconducting Wires
The over-current performance of high-temperature superconductors (HTSs) has been well studied. However, the superconducting devices used in power grid might also suffer lightning current. In previous researches, we have investigated the influences of the substrate layer, encapsulation layer, and tape dimension on the thermal stability of yttrium barium copper oxide (YBCO) tapes after suffering a lightning current. However, in this paper, we will focus on the maximum endurance lightning currents (MELCs) of different HTS tapes including YBCO and BSCCO tapes. We prepared and tested seven HTS samples. The critical current and n value of each sample were measured and calculated before and after the 8/20-μs lightning current tests. A maximum endurable value of lightning current which might not cause the critical current degradation was obtained from the testing results. Finally, the mechanisms causing the degradation were analyzed.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Influence of Critical Current Density Distribution on Transport AC Losses in Superconducting Wire in a DC Magnetic Field
In typical application-like conditions, the inhomogeneous distribution and anisotropy of critical current density must be considered simultaneously in transport AC loss calculation. In this paper, we derive the analytical formulas of transport AC losses for high-temperature superconductors (HTSs) with linear and quadratic distribution of critical current density under applied DC magnetic field. The influence of the inhomogeneous distribution and anisotropy of critical current density has been analyzed. The results show that the impact of the distribution form on transport AC loss is more obvious under applied DC magnetic field. And the influence of applied DC magnetic field will increase as the distribution form becomes steeper.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
The Features of Structure Formation in Chromium-Nickel Steel Manufactured by a Wire-Feed Electron Beam Additive Process
The investigations of the metal macro- and microstructure are performed using the specimens manufactured from the 302 stainless steel via electron-beam additive layer manufacturing in a laboratory setup ensuring 3D printing of articles with circular interpolation. Successive padding of metal results in the formation of a relief representing alternate crests and troughs on the lateral side of the specimen. It is shown by the methods of optical and scanning electron microscopy that the metal of these specimens has a complex heterogeneous dendritic structure containing both relatively coarse grains and subgrains and finer grains. The fine structure of the resulting metal is characterized by a combination of the regions with marked banding and those with nearly regular-shaped grains both in the longitudinal and transverse directions. The grains of more equiaxed shapes are about 5–10 μm in size. It is hypothesized that an application of the additive process would allow manufacturing textured structures with predetermined orientations.
3D PRINTING↗
Prediction and understanding of non-linear distortion on large curved wall manufactured by wire-arc direct energy deposition
Not Available
36 MATERIALS SCIENCE↗
DNA-templated programmable excitonic wires for micron-scale exciton transport
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
From Ta 2 S 5 Wires to Ta 2 O 5 and Ta 2 O 5– x S x
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Charge transport through extended molecular wires with strongly correlated electrons
Experimental studies of electron transport through an edge-fused porphyrin oligomer in a graphene junction are interpreted within a Hubbard dimer framework.
36 MATERIALS SCIENCE↗
Optical phonon modes in InGaN/GaN dot-in-a-wire heterostructures grown by molecular beam epitaxy
We report on the studies of optical phonon modes in nearly defect-free GaN nanowires embedded with intrinsic InGaN quantum dots by using oblique angle transmission infrared spectroscopy. These phonon modes are dependent on the nanowire fill-factor, doping densities of the nanowires, and the presence of InGaN dots. These factors can be applied for potential phonon based photodetectors whose spectral responses can be tailored by varying a combination of these three parameters. The optical anisotropy along the growth (c-) axis of the GaN nanowire contributes to the polarization agility of such potential photodetectors.
36 MATERIALS SCIENCE↗
Assisted extraction of the energy level spacings and lever arms in direct current bias measurements of one-dimensional quantum wires, using an image recognition routine
A multiplexer technique is used to individually measure an array of 256 split gates on a single GaAs/AlGaAs heterostructure. This results in the generation of large volumes of data, which requires the development of automated data analysis routines. An algorithm is developed to find the spacing between discrete energy levels, which form due to transverse confinement from the split gate. The lever arm, which relates split gate voltage to energy, is also found from the measured data. This reduces the time spent on the analysis. Comparison with estimates obtained visually shows that the algorithm returns reliable results for subband spacing of split gates measured at 1.4 K. The routine is also used to assess direct current bias spectroscopy measurements at lower temperatures (50 mK). This technique is versatile and can be extended to other types of measurements. For example, it is used to extract the magnetic field at which Zeeman-split 1D subbands cross one another.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Surface defects characterization in a quantum wire by coherent phonons scattering
The influence of surface defects on the scattering properties of elastic waves in a quasi-planar crystallographic waveguide is studied in the harmonic approximation using the matching method formalism. The structural model is based on three infinite atomic chains forming a perfect lattice surmounted by an atomic surface defect. Following the Landauer approach, we solve directly the Newton dynamical equation with scattering boundary conditions and taking into account the next nearest neighbour’s interaction. A detailed study of the defect-induced fluctuations in the transmission spectra is presented for different adatom masses. As in the electronic case, the presence of localized defect-induced states leads to Fano-like resonances. In the language of mechanical vibrations, these are called continuum resonances. Numerical results reveal the intimate relation between transmission spectra and localized defect states and provide a basis for the understanding of conductance spectroscopy experiments in disordered mesoscopic systems. The results could be useful for the design of phononic devices.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Spatial mapping and statistical reproducibility of an array of 256 one-dimensional quantum wires
We utilize a multiplexing architecture to measure the conductance properties of an array of 256 split gates. We investigate the reproducibility of the pinch off and one-dimensional definition voltage as a function of spatial location on two different cooldowns, and after illuminating the device. The reproducibility of both these properties on the two cooldowns is high, the result of the density of the two-dimensional electron gas returning to a similar state after thermal cycling. The spatial variation of the pinch-off voltage reduces after illumination; however, the variation of the one-dimensional definition voltage increases due to an anomalous feature in the center of the array. A technique which quantifies the homogeneity of split-gate properties across the array is developed which captures the experimentally observed trends. In addition, the one-dimensional definition voltage is used to probe the density of the wafer at each split gate in the array on a micron scale using a capacitive model.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Reverse-bias-driven dichromatic electroluminescence of n-ZnO wire arrays/p-GaN film heterojunction light-emitting diodes
Position-controlled n-ZnO microwire (MW) and nanowire-bundle (NW-B) arrays were fabricated using hydrothermal growth of ZnO on a patterned p-GaN film. Both the wire/film p–n heterojunctions showed electrical rectification features at reverse-bias (rb) voltages, analogous to backward diodes. Dichromatic electroluminescence (EL) emissions with 445- and 560-nm-wavelength peaks displayed whitish-blue and greenish-yellow light from MW- and NW-B-based heterojunctions at rb voltages, respectively. The different dichromatic EL emission colors were studied based on photoluminescence spectra and the dichromatic EL peak intensity ratios as a function of the rb voltage. The different EL colors are discussed with respect to depletion thickness and electron tunneling probability determined by wire/film junction geometry and size.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
THE WIRED SURVEY. IV. NEW DUST DISKS FROM THE McCOOK and SION WHITE DWARF CATALOG
We have compiled photometric data from the Wide-field Infrared Survey Explorer All Sky Survey and other archival sources for the more than 2200 objects in the original McCook and Sion Catalog of Spectroscopically Identified White Dwarfs. We applied color-selection criteria to identify 28 targets whose infrared spectral energy distributions depart from the expectation for the white dwarf (WD) photosphere alone. Seven of these are previously known WDs with circumstellar dust disks, five are known central stars of planetary nebulae, and six were excluded for being known binaries or having possible contamination of their infrared photometry. We fit WD models to the spectral energy distributions of the remaining ten targets, and find seven new candidates with infrared excess suggesting the presence of a circumstellar dust disk. We compare the model dust disk properties for these new candidates with a comprehensive compilation of previously published parameters for known WDs with dust disks. It is possible that the current census of WDs with dust disks that produce an excess detectable at K-band and shorter wavelengths is close to complete for the entire sample of known WDs to the detection limits of existing near-IR all-sky surveys. The WD dust disk candidates now being found using longer wavelength infrared data are drawn from a previously underrepresented region of parameter space, in which the dust disks are overall cooler, narrower in radial extent, and/or contain fewer emitting grains.
79 ASTRONOMY AND ASTROPHYSICS↗
Reduced Magnetization and Loss in Ag-Mg Sheathed Bi2212 Wires: Systematics With Sample Twist Pitch and Length
Suppression of magnetization and effective filament diameter (d eff ) with twisting was investigated for a series of recent Bi2212 strands manufactured by Oxford Superconducting Technologies. We measured magnetization as a function of field (out to 14 T), at 5.1 K, of twisted and nontwisted 37 × 18 double restack design strands. The samples were helical coils 5-6 mm in height and approximately 5 mm in diameter. The strand diameter was 0.8 mm. The magnetization of samples having twist pitches of 25.4, 12.7, and 6.35 mm were examined and compared to nontwisted samples of the same filament configuration. The critical state model was used to extract the 12-T d eff from magnetization data for comparison. Twisting the samples reduced d eff by a factor of 1.5-3. The d eff was shown to increase both with L and L p . Mathematical expressions, based upon the anisotropic continuum model, were fit to the data, and a parameter γ 2 , which quantifies the electrical connectivity perpendicular to the filament axis, was extracted. The bundle-to-bundle connectivity along the radial axis was found to be approximately 0.2%. The d eff was substantially reduced with L p . In addition, the importance of understanding sample length dependence for quantitative measurements is discussed.
36 MATERIALS SCIENCE↗