101,517 research outputs found
Miniature oxygen resuscitator
Miniature, portable resuscitation system is used during evacuation of patients to medical facilities. A carrying case contains a modified resuscitator head, cylinder of oxygen, two-stage oxygen regulator, low pressure tube, and a mask for mouth and nose
Improved fiberglass-to-metal joint produces lighter stronger fiberglass strut
Axial tension and compression are transmitted between end fittings and fiberglass tube without depending on glass-to-metal bonding, conventional fasteners or combination of these things. Joint design significantly reduces both structural weight of strut and its cross-sectional area
Fine Details of the Nodal Electronic Excitations in BiSrCaCuO
Very high energy resolution photoemission experiments on high quality samples
of optimally doped BiSrCaCuO show new features in the
low-energy electronic excitations. A marked change in the binding energy and
temperature dependence of the near-nodal scattering rates is observed near the
superconducting transition temperature, . The temperature slope of the
scattering rate measured at low energy shows a discontinuity at ~. In the
superconducting state, coherent excitations are found with the scattering rates
showing a cubic dependence on frequency and temperature. The superconducting
gap has a d-wave magnitude with negligible contribution from higher harmonics.
Further, the bi-layer splitting has been found to be finite at the nodal point.Comment: 5 pages, 4 figure
Formation of Massive Primordial Stars in a Reionized Gas
We use cosmological hydrodynamic simulations with unprecedented resolution to
study the formation of primordial stars in an ionized gas at high redshifts.
Our approach includes all the relevant atomic and molecular physics to follow
the thermal evolution of a prestellar gas cloud to very high densities of
~10^{18} cm^{-3}. We locate a star-forming gas cloud within a reionized region
in our cosmological simulation. The first run-away collapse is triggered when
the gas cloud's mass is ~40 Msun. We show that the cloud core remains stable
against chemo-thermal instability and also against gravitational deformation
throughout its evolution. Consequently, a single proto-stellar seed is formed,
which accretes the surrounding hot gas at the rate ~10^{-3} Msun/year. We carry
out proto-stellar evolution calculations using the inferred accretion rate. The
resulting mass of the star when it reaches the zero-age main sequence is M_ZAMS
~40 Msun. We argue that, since the obtained M_ZAMS is as large as the mass of
the collapsing parent cloud, the final stellar mass should be close to this
value. Such massive, rather than exceptionally massive, primordial stars are
expected to cause early chemical enrichment of the Universe by exploding as
black hole-forming super/hypernovae, and may also be progenitors of high
redshift gamma-ray bursts. The elemental abundance patterns of recently
discovered hyper metal-poor stars suggest that they might have been born from
the interstellar medium that was metal-enriched by supernovae of these massive
primordial stars.Comment: Revised version. To appear in ApJ
Automated clinical system for chromosome analysis
An automatic chromosome analysis system is provided wherein a suitably prepared slide with chromosome spreads thereon is placed on the stage of an automated microscope. The automated microscope stage is computer operated to move the slide to enable detection of chromosome spreads on the slide. The X and Y location of each chromosome spread that is detected is stored. The computer measures the chromosomes in a spread, classifies them by group or by type and also prepares a digital karyotype image. The computer system can also prepare a patient report summarizing the result of the analysis and listing suspected abnormalities
Holographic Aspects of Fermi Liquids in a Background Magnetic Field
We study the effects of an external magnetic field on the properties of the
quasiparticle spectrum of the class of 2+1 dimensional strongly coupled
theories holographically dual to charged AdS black holes at zero
temperature. We uncover several interesting features. At certain values of the
magnetic field, there are multiple quasiparticle peaks representing a novel
level structure of the associated Fermi surfaces. Furthermore, increasing
magnetic field deforms the dispersion characteristics of the quasiparticle
peaks from non-Landau toward Landau behaviour. At a certain value of the
magnetic field, just at the onset of Landau-like behaviour of the Fermi liquid,
the quasiparticles and Fermi surface disappear.Comment: 18 pages, 10 figures. Revised some of the terminology: changed
non-separable solutions to infinite-sum solution
Tunable subpicosecond electron bunch train generation using a transverse-to-longitudinal phase space exchange technique
We report on the experimental generation of a train of subpicosecond electron
bunches. The bunch train generation is accomplished using a beamline capable of
exchanging the coordinates between the horizontal and longitudinal degrees of
freedom. An initial beam consisting of a set of horizontally-separated beamlets
is converted into a train of bunches temporally separated with tunable bunch
duration and separation. The experiment reported in this Letter unambiguously
demonstrates the conversion process and its versatility.Comment: 4 pages, 5 figures, 1 table; accepted for publication in PR
Thermoelectric prospects of nanomaterials with spin-orbit surface bands
Nanostructured composites and nanowire arrays of traditional thermoelectrics
like Bi, Bi(1-x)Sb(x) and Bi(2)Te(3) have metallic Rashba surface spin-orbit
bands featuring high mobilities rivaling that of the bulk for which topological
insulator behavior has been proposed. Nearly pure surface electronic transport
has been observed at low temperatures in Bi nanowires with diameter around the
critical diameter, 50 nm, for the semimetal-to semiconductor transition. The
surface contributes strongly to the thermopower, actually dominating for
temperatures T < 100 K in these nanowires. The surface thermopower was found to
be -1 T microvolt/(K^2), a value that is consistent with theory. We show that
surface electronic transport together with boundary phonon scattering leads to
enhanced thermoelectric performance at low temperatures of Bi nanowire arrays.
We compare with bulk n-BiSb alloys, optimized CsBi(4)Te(6) and optimized
Bi(2)Te(3). Surface dominated electronic transport can be expected in
nanomaterials of the other traditional thermoelectrics.Comment: 18 pages, 3 figure
Characteristics of The Cancer Genome Atlas cases relative to U.S. general population cancer cases
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