119 research outputs found
Use of Non-Surgical Mechanical Splinting for patients with Carpal Tunnel Syndrome
Compress of the median nerve causes severe pain and paresthesia in Carpal Tunnel Syndrome (CTS). Over 2,000,000 Americans suffer from Carpal Tunnel Syndrome, making it the most common peripheral neuropathology affecting the U.S. Continual compression over time degrades the median nerve that brings sensation of movement and feeling for the wrist. The purpose of this study was to compare change in symptoms of CTS after use of a non-surgical dynamic splinting device. Methods: A retrospective analysis was accomplished for patients diagnosed with CTS who were treated with prolonged passive stretching in dynamic splinting for this pathology (N=304). The Levine Katz survey was used pre and post to measure symptoms in these patients and the mean treatment duration was 7.8 weeks. The Levine Katz (L-K) survey uses 100 point questionnaire divided into 2 sections to categorize functional, duration, intensity, and frequency of pain. The duration of L-K data ranged from four to 16 weeks and this data was recorded between 2010-2012. Results: A two tailed T-test was performed and there was a statistically significant difference for these patients (
Collective neutrino-pair emission due to Cooper pairing of protons in superconducting neutron stars
The neutrino emission due to formation and breaking of Cooper pairs of
protons in superconducting cores of neutron stars is considered with taking
into account the electromagnetic coupling of protons to ambient electrons. It
is shown that collective response of electrons to the proton quantum transition
contributes coherently to the complete interaction with a neutrino field and
enhances the neutrino-pair production. Our calculation shows that the
contribution of the vector weak current to the emissivity of
protons is much larger than that calculated by different authors without taking
into account the plasma effects. Partial contribution of the pairing protons to
the total neutrino radiation from the neutron star core is very sensitive to
the critical temperatures for the proton and neutron pairing. We show domains
of these parameters where the neutrino radiation, caused by a singlet-state
pairing of protons is dominating.Comment: 34 pages, including 9 figure
- Pairing in Dense Neutron Matter: The Spectrum of Solutions
The - pairing model is generally considered to provide an
adequate description of the superfluid states of neutron matter at densities
some 2-3 times that of saturated symmetrical nuclear matter. The problem of
solving the system of BCS gap equations expressing the - model is
attacked with the aid of the separation approach. This method, developed
originally for quantitative study of S-wave pairing in the presence of strong
short-range repulsions, serves effectively to reduce the coupled, singular,
nonlinear BCS integral equations to a set of coupled algebraic equations. For
the first time, sufficient precision becomes accessible to resolve small energy
splittings between the different pairing states. Adopting a perturbative
strategy, we are able to identify and characterize the full repertoire of real
solutions of the - pairing model, in the limiting regime of small
tensor-coupling strength. The P-F channel coupling is seen to lift the striking
parametric degeneracies revealed by a earlier separation treatment of the pure,
uncoupled pairing problem. Remarkably, incisive and robust results are
obtained solely on the basis of analytic arguments. Unlike the traditional
Ginzburg-Landau approach, the analysis is not restricted to the immediate
vicinity of the critical temperature, but is equally reliable at zero
temperature. Interesting connections and contrasts are drawn between triplet
pairing in dense neutron matter and triplet pairing in liquid He.Comment: 23 pages, 1 figur
Judith Hoffberg Oral History, 1990
On December 4th, 1990, ARLIS/NA President Lyn Korenic interviewed Judith Hoffberg, a founding member of ARLIS/NA and its director. They were joined by Amy Navratil Ciccone, Judith’s assistant at ARLIS/NA headquarters. Judith explains how in the late 60s, art librarians did not feel that their needs were being met by the American Library Association or the College Art Association. She describes the trials of forming ARLIS/NA and the intrigues of the early years
Neutrino Bremsstrahlung in Neutron Matter from Effective Nuclear Interactions
We revisit the emissivity from neutrino pair bremsstrahlung in
neutron-neutron scattering, nn -> nn nu nubar, which was calculated from the
one-pion exchange potential including correlation effects by Friman and
Maxwell. Starting from the free-space low-momentum nucleon-nucleon interaction
V_{low k}, we include tensor, spin-orbit and second-order medium-induced
non-central contributions to the scattering amplitude in neutron matter. We
find that the screening of the nucleon-nucleon interaction reduces the
emissivity from neutrino bremsstrahlung for densities below nuclear matter
density. We discuss the implications of medium modifications for the cooling of
neutron stars via neutrino emission, taking into account recent results for the
polarization effects on neutron superfluidity.Comment: 9 pages, 3 figures, minor revisions, to appear in Phys. Lett.
Kelvin Helmholtz Instability and Circulation Transfer at an Isotropic-Anisotropic Superfluid Interface in a Neutron Star
A recent laboratory experiment (Blaauwgeers et al. 2003) suggests that a
Kelvin-Helmholtz (KH) instability at the interface between two superfluids, one
rotating and anisotropic, the other stationary and isotropic, may trigger
sudden spin-up of the stationary superfluid. This result suggests that a KH
instability at the crust-core (--superfluid) boundary of a
neutron star may provide a trigger mechanism for pulsar glitches. We calculate
the dispersion relation of the KH instability involving two different
superfluids including the normal fluid components and their effects on
stability, particularly entropy transport. We show that an entropy difference
between the core and crust superfluids reduces the threshold differential shear
velocity and threshold crust-core density ratio. We evaluate the wavelength of
maximum growth of the instability for neutron star parameters and find the
resultant circulation transfer to be within the range observed in pulsar
glitches.Comment: 17 pages, 8 figures, accepted for publication in MNRA
Superfluid Phase Transitions in Dense Neutron Matter
The phase transitions in a realistic system with triplet pairing, dense
neutron matter, have been investigated. The spectrum of phases of the
model, which adequately describes pairing in this system, is
analytically constructed with the aid of a separation method for solving BCS
gap equation in states of arbitrary angular momentum. In addition to solutions
involving a single value of the magnetic quantum number (and its negative),
there exist ten real multicomponent solutions. Five of the corresponding
angle-dependent order parameters have nodes, and five do not. In contrast to
the case of superfluid He, transitions occur between phases with nodeless
order parameters. The temperature dependence of the competition between the
various phases is studied.Comment: 11 pages, 2 figure
R-mode oscillations and rocket effect in rotating superfluid neutron stars. I. Formalism
We derive the hydrodynamical equations of r-mode oscillations in neutron
stars in presence of a novel damping mechanism related to particle number
changing processes. The change in the number densities of the various species
leads to new dissipative terms in the equations which are responsible of the
{\it rocket effect}. We employ a two-fluid model, with one fluid consisting of
the charged components, while the second fluid consists of superfluid neutrons.
We consider two different kind of r-mode oscillations, one associated with
comoving displacements, and the second one associated with countermoving, out
of phase, displacements.Comment: 10 page
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The development of a high-speed 100 fps CCD camera
This paper describes the development of a high-speed CCD digital camera system. The system has been designed to use CCDs from various manufacturers with minimal modifications. The first camera built on this design utilizes a Thomson 512x512 pixel CCD as its sensor which is read out from two parallel outputs at a speed of 15 MHz/pixel/output. The data undergoes correlated double sampling after which, they are digitized into 12 bits. The throughput of the system translates into 60 MB/second which is either stored directly in a PC or transferred to a custom designed VXI module. The PC data acquisition version of the camera can collect sustained data in real time that is limited to the memory installed in the PC. The VXI version of the camera, also controlled by a PC, stores 512 MB of real-time data before it must be read out to the PC disk storage. The uncooled CCD can be used either with lenses for visible light imaging or with a phosphor screen for x-ray imaging. This camera has been tested with a phosphor screen coupled to a fiber-optic face plate for high-resolution, high-speed x-ray imaging. The camera is controlled through a custom event-driven user-friendly Windows package. The pixel clock speed can be changed from I MHz to 15 MHz. The noise was measure to be 1.05 bits at a 13.3 MHz pixel clock. This paper will describe the electronics, software, and characterizations that have been performed using both visible and x-ray photons
Nucleon-Nucleon Phase Shifts and Pairing in Neutron Matter and Nuclear Matter
We consider 1S0 pairing in infinite neutron matter and nuclear matter and
show that in the lowest order approximation, where the pairing interaction is
taken to be the bare nucleon-nucleon (NN) interaction in the 1S0 channel, the
pairing interaction and the energy gap can be determined directly from the 1S0
phase shifts. This is due to the almost separable character of the NN
interaction in this partial wave. Since the most recent NN interactions are
charge-dependent, we have to solve coupled gap equations for proton-proton,
neutron-neutron, and neutron-proton pairing in nuclear matter. The results,
however, are found to be close to those obtained with charge-independent
potentials.Comment: 5 pages, 3 figures, RevTe
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