4,814 research outputs found
Discovery of VHE and HE emission from the blazar 1ES 0414+009 with H.E.S.S and Fermi-LAT
The high energy peaked BL Lac (HBL) object 1ES 0414+009 (z=0.287) is a
distant very high-energy (VHE, E > 100 GeV) blazars with well-determined
redshift. This source was detected with the High Energy Stereoscopic System
(H.E.S.S.) between October 2005 and September 2009. It was also detected with
the Fermi Large Area Telescope (LAT) in 21 months of data. The combined high
energy (HE) and VHE spectra, once corrected for gamma-gamma absorption on the
extragalactic background light (EBL), indicate a Compton peak located above few
TeV, among the highest in the BL Lac class.Comment: proceeding from the 25th Texas Symposium on Relativistic Astrophysics
(Heidelberg, Germany, 2010
The lifetime of the Lambda hyperon bound in hypernuclei produced by p+U collisions
The nonmesonic decay of the Lambda hyperon has been investigated by
observation of delayed fission from heavy hypernuclei produced in proton-U
collisions at Tp = 1.9 GeV. The lifetime of heavy hypernuclei with masses A
approximately 220 obtained in the present work, i.e.
tau = 138 +- 6 (stat.) +-m 17 (syst.) ps,
is the most accurate result for heavy hypernuclei produced in proton and
antiproton induced collisions on a U target so far.
PACS: {13.30.-a}{Decays of baryons} {13.75.Ev}{Hyperon-nucleon interaction}
{21.80}{Hypernuclei} {25.80.Pw}{Hyperon-induced reactions}Comment: 16 pages, 4 Postscript figures, uses file appolb.cls (included),
submitted to Acta Physica Polonica B, http://th-www.if.uj.edu.pl/act
Nonmesonic decay of the Lambda hyperon in nuclear matter - implications on the weak Lambda-N interaction
The lifetime of the Lambda hyperon in heavy hypernuclei as measured by the
COSY-13 Collaboration in proton - Au, Bi and U collisions has been analysed to
yield tau(Lambda) = (145 +- 11) ps. This value for tau(Lambda) is compatible
with the lifetime extracted from antiproton annihilation on Bi and U targets,
however, much more accurate. We find that the dependence of the lifetime
tau(Lambda) on the mass of hypernuclei indicates a violation of the
phenomenological Delta I = 1/2 rule known from the weak mesonic decays of
strange particles. PACS: {13.30.-a}{Decays of baryons}
{13.75.Ev}{Hyperon-nucleon interaction} {21.80}{Hypernuclei}
{25.80.Pw}{Hyperon-induced reactions}Comment: 21 pages, 11 PostScript figures, EPJA in prin
Proton Spin Relaxation Induced by Quantum Tunneling in Fe8 Molecular Nanomagnet
The spin-lattice relaxation rate and NMR spectra of H in
single crystal molecular magnets of Fe8 have been measured down to 15 mK. The
relaxation rate shows a strong temperature dependence down to 400
mK. The relaxation is well explained in terms of the thermal transition of the
iron state between the discreet energy levels of the total spin S=10. The
relaxation time becomes temperature independent below 300 mK and is
longer than 100 s. In this temperature region stepwise recovery of the
H-NMR signal after saturation was observed depending on the return field of
the sweep field. This phenomenon is attributed to resonant quantum tunneling at
the fields where levels cross and is discussed in terms of the Landau-Zener
transition.Comment: 13 pages, 5 figure
SSR- and RAPD Analysis of a New Agropyron Repens Genotype
SSR-(single sequence repeat), and RAPD (randomly amplified polymorphic DNA) primer generated DNA fingerprints were used to distinguish a new genotype of quackgrass from its original type of Agropyron repenes L. Beauv. (= Elytrigia repens). Products of polymerase chain reactions (PCR) were separated by agarose (AGE) and denaturing gradient gel electrophoresis (DGGE). Although, both kinds of primers were found to be polymorphic, the microsatellite primer with sequence of 5í-AC(GACA)4-3í generated distinguishing fingerprints in the two types of quackgrasses. This result gives genetic evidence for the new genotype of quackgrass
Here We Come Ready or Not: Occupational Therapy Program to Help Prepare Prisoners for Reentry into Society
poster abstractAbstract
Background: In 2013 about 10 million people were involved in various stages of imprisonment world-wide. In that same year there were about 1,574,700 persons in state and federal prisons in the United States, and 29,905 in Indiana (state and federal) prisons. Most of those people will return to society, but for how long? According to the most recent data available, a little over two-thirds (67.8%) of those released were arrested for a new crime within 3 years and over three-quarters (76.6%) were arrested for a new crime within 5 years. Education is one of the most effective reducers of recidivism, but it is unclear what kinds of education best prepare people to not only return to society, but to thrive in society. Objectives: The first of a two-part study explored how 27 residents of a minimum security prison responded to an Occupational Therapy Community Living Skills Program (OTCLS) developed to help prepare residents for successful reentry into society. Method: Using a participatory action research (PAR) approach, we interviewed 27 residents who completed the program. Once the semi-structured interviews were transcribed, the PAR team conducted a summative content analysis of the data. Results: Initial content analysis yielded five concepts: doing; information; re-entry fears (socialization); technology; and self-worth. Participants seemed to gain a sense of self-worth by doing activities related to information gathering, socialization, and technology. Further interpretation yielded three overlapping themes: 1) validation of self-worth (participants expressed how self-validating it is to have “real people” come in to help), 2) doing (role playing, a common activity, “…was kind of nerve-wracking at first then [I] began to slowly ease into it…”), and 3) concerns about the future (one resident summed up the value of the program: having “…something real positive you’re looking forward to…helps in dissipating the fears perhaps in reentry.”). Conclusions: This retrospective study identified potentially powerful elements of a successful re-entry program. In the second part of the study we will evaluate a revised program using a pre-test; post-test and follow-up approach to learn more about what kinds of education best prepare people to not only return to society, but to thrive in society
Spin dynamics of Mn12-acetate in the thermally-activated tunneling regime: ac-susceptibility and magnetization relaxation
In this work, we study the spin dynamics of Mn12-acetate molecules in the
regime of thermally assisted tunneling. In particular, we describe the system
in the presence of a strong transverse magnetic field. Similar to recent
experiments, the relaxation time/rate is found to display a series of
resonances; their Lorentzian shape is found to stem from the tunneling. The
dynamic susceptibility is calculated starting from the microscopic
Hamiltonian and the resonant structure manifests itself also in .
Similar to recent results reported on another molecular magnet, Fe8, we find
oscillations of the relaxation rate as a function of the transverse magnetic
field when the field is directed along a hard axis of the molecules. This
phenomenon is attributed to the interference of the geometrical or Berry phase.
We propose susceptibility experiments to be carried out for strong transverse
magnetic fields to study of these oscillations and for a better resolution of
the sharp satellite peaks in the relaxation rates.Comment: 22 pages, 23 figures; submitted to Phys. Rev. B; citations/references
adde
Nonlinear Dynamics of the Perceived Pitch of Complex Sounds
We apply results from nonlinear dynamics to an old problem in acoustical
physics: the mechanism of the perception of the pitch of sounds, especially the
sounds known as complex tones that are important for music and speech
intelligibility
Organic component vapor pressures and hygroscopicities of aqueous aerosol measured by optical tweezers
Measurements of the hygroscopic response of aerosol and the particle-to-gas partitioning of semivolatile organic compounds are crucial for providing more accurate descriptions of the compositional and size distributions of atmospheric aerosol. Concurrent measurements of particle size and composition (inferred from refractive index) are reported here using optical tweezers to isolate and probe individual aerosol droplets over extended timeframes. The measurements are shown to allow accurate retrievals of component vapor pressures and hygroscopic response through examining correlated variations in size and composition for binary droplets containing water and a single organic component. Measurements are reported for a homologous series of dicarboxylic acids, maleic acid, citric acid, glycerol, or 1,2,6-hexanetriol. An assessment of the inherent uncertainties in such measurements when measuring only particle size is provided to confirm the value of such a correlational approach. We also show that the method of molar refraction provides an accurate characterization of the compositional dependence of the refractive index of the solutions. In this method, the density of the pure liquid solute is the largest uncertainty and must be either known or inferred from subsaturated measurements with an error of <±2.5% to discriminate between different thermodynamic treatments. (Chemical Equation Presented)
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