2,545 research outputs found
Conduit purging device and method
A device for purging gas comprises a conduit assembly defining an interior volume. The conduit assembly comprises a first conduit portion having an open first end and an open second end and a second conduit portion having an open first end and a closed second end. The open second end of the first conduit portion is disposed proximate to the open first end of the second conduit portion to define a weld region. The device further comprises a supply element supplying a gas to the interior volume at a substantially constant rate and a vent element venting the gas from the interior volume at a rate that maintains the gas in the interior volume within a pressure range suitable to hold a weld bead in the weld region in equilibrium during formation of a weld to join the first conduit portion and the second conduit portion
Dipole Oscillations of a Bose-Einstein Condensate in Presence of Defects and Disorder
We consider dipole oscillations of a trapped dilute Bose-Einstein condensate
in the presence of a scattering potential consisting either in a localized
defect or in an extended disordered potential. In both cases the breaking of
superfluidity and the damping of the oscillations are shown to be related to
the appearance of a nonlinear dissipative flow. At supersonic velocities the
flow becomes asymptotically dissipationless.Comment: 4 pages, 4 figure
Intelligent multimedia indexing and retrieval through multi-source information extraction and merging
This paper reports work on automated meta-data\ud
creation for multimedia content. The approach results\ud
in the generation of a conceptual index of\ud
the content which may then be searched via semantic\ud
categories instead of keywords. The novelty\ud
of the work is to exploit multiple sources of\ud
information relating to video content (in this case\ud
the rich range of sources covering important sports\ud
events). News, commentaries and web reports covering\ud
international football games in multiple languages\ud
and multiple modalities is analysed and the\ud
resultant data merged. This merging process leads\ud
to increased accuracy relative to individual sources
Lumbosacral plexopathy due to pelvic hematoma after extracorporeal membrane oxygenation: A case report
Acting Locally in a Flat World: Global Citizenship and the Democratic Practice of Service-Learning
This paper series seems especially significant this year, as Campus Compact celebrates an important milestone. The context has certainly changed over the decades since the founding of Campus Compact twenty years ago. For while Campus Compact has grown impressively to more than 950 member campuses with 31 state offices under the leadership of Elizabeth Hollander, there is also a sense that service-learning is at a crossroads. At least one dimension for educators to consider is the connection between the local and the global, and the importance of global citizenship and democratic practices which promote global citizenship. To be engaged and relevant requires that service-learning includes a large vision, along with democratic practices for acting locally with global intentions. The flattened world which Thomas Friedman has popularly termed for the rapid rise of globalization since the start of the 21st century has important implications for service-learning educators trying to implement John Dewey\u27s vision of building democratic, neighborly communities. It requires us to ask: if democracy begins at home, what does this mean in the context of an increasingly global society
Thermal Conductivity in the Bose-Einstein Condensed State of Triplons in the Bond-Alternating Spin-Chain System Pb2V3O9
In order to clarify the origin of the enhancement of the thermal conductivity
in the Bose-Einstein Condensed (BEC) state of field-induced triplons, we have
measured the thermal conductivity along the [101] direction parallel to
spin-chains, , and perpendicular to spin-chains,
, of the S=1/2 bond-alternating spin-chain system Pb2V3O9
in magnetic fields up to 14 T. With increasing field at 3 K, it has been found
that both and are suppressed in the
gapped normal state in low fields. In the BEC state of field-induced triplons
in high fields, on the other hand, is enhanced with
increasing field, while is suppressed. That is, the
thermal conductivity along the direction, where the magnetic interaction is
strong, is markedly enhanced in the BEC state. Accordingly, our results suggest
that the enhancement of in the BEC state is caused by the
enhancement of the thermal conductivity due to triplons on the basis of the
two-fluid model, as in the case of the superfluid state of liquid 4He.Comment: 5 pages, 3 figure
A Degenerate Bose-Fermi Mixture of Metastable Atoms
We report the observation of simultaneous quantum degeneracy in a dilute
gaseous Bose-Fermi mixture of metastable atoms. Sympathetic cooling of helium-3
(fermion) by helium-4 (boson), both in the lowest triplet state, allows us to
produce ensembles containing more than 10^6 atoms of each isotope at
temperatures below 1 micro-Kelvin, and achieve a fermionic degeneracy parameter
of T/Tf=0.45. Due to their high internal energy, the detection of individual
metastable atoms with sub-nanosecond time resolution is possible, permitting
the study of bosonic and fermionic quantum gases with unprecedented precision.
This may lead to metastable helium becoming the mainstay of quantum atom
optics.Comment: 4 pages, 3 figures submitted to PR
The random Blume-Capel model on cubic lattice: first order inverse freezing in a 3D spin-glass system
We present a numerical study of the Blume-Capel model with quenched disorder
in 3D. The phase diagram is characterized by spin-glass/paramagnet phase
transitions of both first and second order in the thermodynamic sense.
Numerical simulations are performed using the Exchange-Monte Carlo algorithm,
providing clear evidence for inverse freezing. The main features at criticality
and in the phase coexistence region are investigated. The whole inverse
freezing transition appears to be first order. The second order transition
appears to be in the same universality class of the Edwards-Anderson model. The
nature of the spin-glass phase is analyzed by means of the finite size scaling
behavior of the overlap distribution functions and the four-spins real-space
correlation functions. Evidence for a replica symmetry breaking-like
organization of states is provided.Comment: 18 pages, 24 figures, 7 table
Optical quenching and recovery of photoconductivity in single-crystal diamond
We study the photocurrent induced by pulsed-light illumination (pulse
duration is several nanoseconds) of single-crystal diamond containing nitrogen
impurities. Application of additional continuous-wave light of the same
wavelength quenches pulsed photocurrent. Characterization of the optically
quenched photocurrent and its recovery is important for the development of
diamond based electronics and sensing
Oral ezatiostat HCl (Telintra®, TLK199) and Idiopathic Chronic Neutropenia (ICN): a case report of complete response of a patient with G-CSF resistant ICN following treatment with ezatiostat, a glutathione S-transferase P1-1 (GSTP1-1) inhibitor
Idiopathic chronic neutropenia (ICN) describes a heterogeneous group of hematologic diseases characterized by low circulating neutrophil levels often associated with recurrent fevers, chronic mucosal inflammation, and severe systemic infections. The severity and risk of complications, including serious infections, are inversely proportional to the absolute neutrophil count (ANC), with the greatest problems occurring in patients with an ANC of less than 0.5 × 109/L. This case report describes a 64-year-old female with longstanding rheumatoid arthritis who subsequently developed ICN with frequent episodes of sepsis requiring hospitalization and prolonged courses of antibiotics over a 4-year period. She was treated with granulocyte colony stimulating factors (G-CSF) but had a delayed, highly variable, and volatile response. She was enrolled in a clinical trial evaluating the oral investigational agent ezatiostat. Ezatiostat, a glutathione S-transferase P1-1 inhibitor, activates Jun kinase, promoting the growth and maturation of hematopoietic progenitor stem cells. She responded by the end of the first month of treatment with stabilization of her ANC (despite tapering and then stopping G-CSF), clearing of fever, and healing of areas of infection. This ANC response to ezatiostat treatment has now been sustained for over 8 months and continues. These results suggest potential roles for ezatiostat in the treatment of patients with ICN who are not responsive to G-CSF, as an oral therapy alternative, or as an adjunct to G-CSF, and further studies are warranted
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