648 research outputs found
Unitarity constraints on neutral pion electroproduction
At large virtuality , the coupling to the vector meson production
channels provides us with a natural explanation of the surprisingly large cross
section of the neutral pion electroproduction recently measured at Jefferson
Laboratory, without destroying the good agreement between the Regge pole model
and the data at the real photon point. Elastic rescattering of the
provides us with a way to explain why the node, that appears at
GeV at the real photon point, disappears as soon as differs from
zero.Comment: 7 pages; 12 figures Figures 1, 2, 10, 11, 12 updated. Axial-tensor
coupling, instead of axial-vector coupling, at the b1NN verte
Systematic Regge theory analysis of omega photoproduction
Systematic analysis of available data for -meson photoproduction is
given in frame of Regge theory. At photon energies above 20 GeV the
reaction is entirely dominated by Pomeron exchange.
However, it was found that Pomeron exchange model can not reproduce the
and data at high energies
simultaneously with the same set of parameters. The comparison between
and data indicates a large room for meson exchange contribution to
-meson photoproduction at low energies. It was found that at low
energies the dominant contribution comes from and -meson exchanges.
There is smooth transition between the meson exchange model at low energies and
Regge theory at high energies.Comment: 7 pages, 8 figures, revtex
Thermodynamics of a finite system of classical particles with short and long range interactions and nuclear fragmentation
We describe a finite inhomogeneous three dimensional system of classical
particles which interact through short and (or) long range interactions by
means of a simple analytic spin model. The thermodynamic properties of the
system are worked out in the framework of the grand canonical ensemble. It is
shown that the system experiences a phase transition at fixed average density
in the thermodynamic limit. The phase diagram and the caloric curve are
constructed and compared with numerical simulations. The implications of our
results concerning the caloric curve are discussed in connection with the
interpretation of corresponding experimental data.Comment: 11pages, LaTeX, 6 figures. Major change : A new section dealing with
numerical simulations in the framework of a cellular model has been adde
Search for Kosterlitz-Thouless transition in a triangular Ising antiferromagnet with further-neighbour ferromagnetic interactions
We investigate an antiferromagnetic triangular Ising model with anisotropic
ferromagnetic interactions between next-nearest neighbours, originally proposed
by Kitatani and Oguchi (J. Phys. Soc. Japan {\bf 57}, 1344 (1988)). The phase
diagram as a function of temperature and the ratio between first- and second-
neighbour interaction strengths is thoroughly examined. We search for a
Kosterlitz-Thouless transition to a state with algebraic decay of correlations,
calculating the correlation lengths on strips of width up to 15 sites by
transfer-matrix methods. Phenomenological renormalization, conformal invariance
arguments, the Roomany-Wyld approximation and a direct analysis of the scaled
mass gaps are used. Our results provide limited evidence that a
Kosterlitz-Thouless phase is present. Alternative scenarios are discussed.Comment: 10 pages, RevTeX 3; 11 Postscript figures (uuencoded); to appear in
Phys. Rev. E (1995
Test of renormalization predictions for universal finite-size scaling functions
We calculate universal finite-size scaling functions for systems with an
n-component order parameter and algebraically decaying interactions. Just as
previously has been found for short-range interactions, this leads to a
singular epsilon-expansion, where epsilon is the distance to the upper critical
dimension. Subsequently, we check the results by numerical simulations of spin
models in the same universality class. Our systems offer the essential
advantage that epsilon can be varied continuously, allowing an accurate
examination of the region where epsilon is small. The numerical calculations
turn out to be in striking disagreement with the predicted singularity.Comment: 6 pages, including 3 EPS figures. To appear in Phys. Rev. E. Also
available as PDF file at
http://www.cond-mat.physik.uni-mainz.de/~luijten/erikpubs.htm
Cycling exercise classes may be bad for your (hearing) health
OBJECTIVES/HYPOTHESIS: 1) Determine feasibility of smartphone-based mobile technology to measure noise exposure; and 2) measure noise exposure in exercise spin classes. STUDY DESIGN: Observational Study. METHODS: The SoundMeter Pro app (Faber Acoustical, Salt Lake City, UT) was installed and calibrated on iPhone and iPod devices in an audiology chamber using an external sound level meter to within 2 dBA of accuracy. Recording devices were placed in the bike cupholders of participants attending spin classes in Boston, Massachusetts (n = 17) and used to measure sound level (A-weighted) and noise dosimetry during exercise according to National Institute for Occupational Safety and Health (NIOSH) guidelines. RESULTS: The average length of exposure was 48.9 ± 1.2 (standard error of the mean) minutes per class. Maximum sound recorded among 17 random classes was 116.7 dBA, which was below the NIOSH instantaneous exposure guideline of 140 dBA. An average of 31.6 ± 3.8 minutes were spent at >100 dBA. This exceeds NIOSH recommendations of 15 minutes of exposure or less at 100 dBA per day. Average noise exposure for one 45-minute class was 8.95 ± 1.2 times the recommended noise exposure dose for an 8-hour workday. CONCLUSIONS: Preliminary data shows that randomly sampled cycling classes may have high noise levels with a potential for noise-induced hearing loss. Mobile dosimetry technology may enable users to self-monitor risk to their hearing and actively engage in noise protection measures. LEVEL OF EVIDENCE: NA Laryngoscope, 127:1873-1877, 2017.Accepted manuscrip
Foreword: Control and Conservation of Lampreys Beyond 2020 – Proceedings from the 3rd Sea Lamprey International Symposium (SLIS III)
This special issue summarizes outcomes from the 3rd Sea Lamprey International Symposium (SLIS III; Fig. 1) held 28 July – 2 August 2019 at Wayne State University in Detroit, Michigan, U.S.A. The first two symposia (SLIS I and SLIS II) were held 30 July – 8 August 1979 at Northern Michigan University in Marquette, Michigan and 14–18 August 2000 at Lake Superior State University in Sault Ste. Marie, Michigan, respectively. The published volumes from these symposia in 1980 (Canadian Journal of Fisheries and Aquatic Sciences, Volume 37, Issue 11) and 2003 (Journal of Great Lakes Research Volume 29, Supplement 1) have been invaluable references for the broader scientific community and for management agencies around the Laurentian Great Lakes; cited over 4800 and 3300 times, respectively. SLIS III was attended by over 150 scientists, biologists, resource managers, graduate students, and Commission advisors, including participants from Australia, Canada, China, Japan, New Zealand, Portugal, Spain, the United Kingdom, and the United States (Fig. 2). Similar to SLIS I and SLIS II, the goals of SLIS III were to provide a forum to (i) update and publish information on sea lamprey control and research on lampreys since SLIS II, (ii) exchange knowledge and ideas to bring practitioners to a common plateau of understanding, and (iii) develop innovative initiatives and stimulate new vigor in efforts to control sea lamprey in the Great Lakes and to conserve lampreys in their native ranges. The emphasis on conservation of lampreys is unique to SLIS III and reflects a heightened international recognition that scientific and management advances supporting sea lamprey control in the Great Lakes can benefit the global effort to conserve native lampreys and vice versa
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