13,035 research outputs found
The First Fermi-LAT SNR Catalog SNR and Cosmic Ray Implications
Galactic cosmic ray (CRs) sources, classically proposed to be Supernova
Remnants (SNRs), must meet the energetic particle content required by direct
measurements of high energy CRs. Indirect gamma-ray measurements of SNRs with
the Fermi Large Area Telescope (LAT) have now shown directly that at least
three SNRs accelerate protons. With the first Fermi LAT SNR Catalog, we have
systematically characterized the GeV gamma-rays emitted by 279 SNRs known
primarily from radio surveys. We present these sources in a multiwavelength
context, including studies of correlations between GeV and radio size, flux,
and index, TeV index, and age and environment tracers, in order to better
understand effects of evolution and environment on the GeV emission. We show
that previously sufficient models of SNRs' GeV emission no longer adequately
describe the data. To address the question of CR origins, we also examine the
SNRs' maximal CR contribution assuming the GeV emission arises solely from
proton interactions. Improved breadth and quality of multiwavelength data,
including distances and local densities, and more, higher resolution gamma-ray
data with correspondingly improved Galactic diffuse models will strengthen this
constraint.Comment: 8 pages, 10 figures; in Proceedings of the 34th International Cosmic
Ray Conference (ICRC 2015), The Hague (The Netherlands
Pre-Disaster Planning at Florida Community Colleges: A Comparison of FEMA Guidelines to Processes and Practices
The purpose of this study was to explore and describe the pre-disaster planning processes and practices used by Florida’s community college administrators as of December 2008. FEMA’s Building a Disaster Resistant University (DRU) model was the conceptual lens for this study. A mixed methods research design included 15 surveys completed by Florida community college business officers and six semi-structured interviews with staff most involved in pre-disaster planning. Data were compared to DRU guidelines to establish whether processes and practices were congruent with the DRU.
Six quantitative findings were reported in this study. First, five of fourteen (35.7%) survey respondents appointed a project manager; second, fourteen of fifteen respondents (93.3%) conducted a risk assessment; third, thirteen of fifteen (87%) respondents reported contacting 2 to14 stakeholders; fourth, fourteen of fifteen (93.3%) survey respondents conducted an inventory of buildings and infrastructure assets; fifth, majority of survey respondents (87.7%) reported they identified mitigation goals and objectives; sixth, eight of fourteen (57.1%) respondents’ president formally adopted the pre-disaster mitigation plan. Qualitative findings were, first, wide internal and external stakeholder representation was organized; second, advisory committees have no mission statement; third, one site identified hazards by consulting with stakeholders, but neither one could provide a list of hazards; fourth, sites used only half of the DRU’s building inventory items; fifth, recording and mapping of infrastructure (i.e., utilities) are evolved at one site, while both sites backup administrative systems; sixth, neither site considered several hazard profile formula variables recommended by the DRU; seventh, Beta’s internal and external stakeholders conduct a rigorous vetting process, which allows it to establish a prioritized list of mitigation goals and objectives; eighth, neither site uses an adequate formula for benefit-cost analysis and no consultant has been hired to do so; ninth, only one participant could articulate how the mission guided mitigation action prioritization; tenth, key internal and external stakeholders adopted mitigation actions; eleventh, no plan for measuring mitigation action efficacy exists; and twelfth, mitigation action successes are communicated to internal stakeholders, but not external stakeholders making it difficult to achieve plan momentum and funding. Recommendations are provided for community college administrators
Influence of electromagnetic interferences on the gravimetric sensitivity of surface acoustic waveguides
Surface acoustic waveguides are increasing in interest for (bio)chemical
detection. The surface mass modification leads to measurable changes in the
propagation properties of the waveguide. Among a wide variety of waveguides,
Love mode has been investigated because of its high gravimetric sensitivity.
The acoustic signal launched and detected in the waveguide by electrical
transducers is accompanied by an electromagnetic wave; the interaction of the
two signals, easily enhanced by the open structure of the sensor, creates
interference patterns in the transfer function of the sensor. The influence of
these interferences on the gravimetric sensitivity is presented, whereby the
structure of the entire sensor is modelled. We show that electromagnetic
interferences generate an error in the experimental value of the sensitivity.
This error is different for the open and the closed loop configurations of the
sensor. The theoretical approach is completed by the experimentation of an
actual Love mode sensor operated under liquid in open loop configuration. The
experiment indicates that the interaction depends on the frequency and the mass
modifications.Comment: 28 pages, 8 figure
Simultaneous surface acoustic wave and surface plasmon resonance measurements: electrodeposition and biological interactions monitoring
We present results from an instrument combining surface acoustic wave (SAW)
propagation and surface plasmon resonance (SPR) measurements. The objective is
to use two independent methods, the former based on adsorbed mass change
measurements and the latter on surface dielectric properties variations, to
identify physical properties of protein layers, and more specifically their
water content. We display mass sensitivity calibration curves using
electrodeposition of copper leading to a sensitivity in liquid of 150
for the Love mode device used here, and the application to monitoring
biological processes. The extraction of protein layer thickness and protein to
water content ratio is also presented for S-layer proteins under investigation.
We obtain respectively 4.70.7 nm and 7515%.Comment: 13 pages, 4 figure
Cavity-aided quantum parameter estimation in a bosonic double-well Josephson junction
We describe an apparatus designed to make non-demolition measurements on a
Bose-Einstein condensate (BEC) trapped in a double-well optical cavity. This
apparatus contains, as well as the bosonic gas and the trap, an optical cavity.
We show how the interaction between the light and the atoms, under appropriate
conditions, can allow for a weakly disturbing yet highly precise measurement of
the population imbalance between the two wells and its variance. We show that
the setting is well suited for the implementation of quantum-limited estimation
strategies for the inference of the key parameters defining the evolution of
the atomic system and based on measurements performed on the cavity field. This
would enable {\it de facto} Hamiltonian diagnosis via a highly controllable
quantum probe.Comment: 8 pages, 5 figures, RevTeX4; Accepted for publication in Phys. Rev.
Allocation of budgetary resources in agricultural research.
Trabalho apresentado no Workshop on Increasing the Productivity and Impact of Agricultural Research, Yogyakarta, Indonesia, 1980
The First Fermi-LAT SNR Catalog and Cosmic Ray Implications
While supernova remnants (SNRs) are widely thought to be powerful cosmicray accelerators, indirect evidence comes from a small number of well-studied cases. Here we systematically determine the gamma-ray emission detected by the Fermi Large Area Telescope (LAT) from all known Galactic SNRs, disentangling them from the sea of cosmic-ray generated photons in the Galactic plane. Using LAT data we have characterized the 1-100 GeV emission in 279 regions containing SNRs, accounting for systematic uncertainties caused by source misattribution and instrumental response. We classified 30 sources as SNRs, using spatial overlap with the radio emission position. For all the remaining regions we evaluated upper limits on SNRs' emission. In the First Fermi -LAT SNR Catalog there is a study of the common characteristics of these SNRs, such as comparisons between GeV, radio and TeV quantities. We show that previously satisfactory models of SNRs' GeV emission no longer adequately describe the data. To address the question of cosmic ray (CR) origins, we also examine the SNRs' maximal CR contribution assuming the GeV emission arises solely from proton interactions. Improved breadth and quality of multiwavelength (MW) data, including distances and local densities, and more, higher resolution gamma-ray data with correspondingly improved Galactic diffuse models will strengthen this constraint
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