116 research outputs found
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Determination of the Quadrupole Coupling Constant in the N^{14} Atomic Ground State
The zero-field hyperfine frequencies in the ground state of atomic N14 have been measured in a hydrogen maser with sufficient accuracy to resolve the quadrupole coupling constant B. The result is B=+1.32±0.20 Hz.Molecular and Cellular Biolog
Classical and Quantum Interaction of the Dipole
A unified and fully relativistic treatment of the interaction of the electric
and magnetic dipole moments of a particle with the electromagnetic field is
given. New forces on the particle due to the combined effect of electric and
magnetic dipoles are obtained. Four new experiments are proposed, three of
which would observe topological phase shifts.Comment: 10 pages, Latex/Revtex. Some minor errors have been correcte
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Hydrogen-Maser Principles and Techniques
Techniques and design principles relevant to the construction and operation of a hydrogen maser are presented in detail. These include methods for the generation of atomic hydrogen, state selection, design of the microwave cavity, production of very low magnetic fields, coating the hydrogen storage bulb, and tuning the maser. A figure of merit is introduced which indicates the optimum choice of parameters.Molecular and Cellular BiologyPhysic
Natural and anthropogenic changes to mangrove distributions in the Pioneer River Estuary (QLD, Australia)
We analyzed a time series of aerial photographs and Landsat satellite imagery of the Pioneer River Estuary (near Mackay, Queensland, Australia) to document both natural and anthropogenic changes in the area of mangroves available to filter river runoff between 1948 and 2002. Over 54 years, there was a net loss of 137 ha (22%) of tidal mangroves during four successive periods that were characterized by different driving mechanisms: (1) little net change (1948– 1962); (2) net gain from rapid mangrove expansion (1962–1972); (3) net loss from clearing and tidal isolation (1972–1991); and (4) net loss from a severe species-specific dieback affecting over 50% of remaining mangrove cover (1991–2002). Manual digitization of aerial photographs was accurate for mapping changes in the boundaries of mangrove distributions, but this technique underestimated the total loss due to dieback. Regions of mangrove dieback were identified and mapped more accurately and efficiently after applying the Normalized Difference Vegetation Index (NDVI) to Landsat Thematic Mapper satellite imagery, and then monitoring changes to the index over time. These remote sensing techniques to map and monitor mangrove changes are important for identifying habitat degradation, both spatially and temporally, in order to prioritize restoration for management of estuarine and adjacent marine ecosystems
Quantum Measurement of a Coupled Nanomechanical Resonator -- Cooper-Pair Box System
We show two effects as a result of considering the second-order correction to
the spectrum of a nanomechanical resonator electrostatically coupled to a
Cooper-pair box. The spectrum of the Cooper-pair box is modified in a way which
depends on the Fock state of the resonator. Similarly, the frequency of the
resonator becomes dependent on the state of the Cooper-pair box. We consider
whether these frequency shifts could be utilized to prepare the nanomechanical
resonator in a Fock state, to perform a quantum non-demolition measurement of
the resonator Fock state, and to distinguish the phase states of the
Cooper-pair box
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
The domain of organizational cognitive neuroscience:theoretical and empirical challenges
In this editorial, the authors respond to the 2011 article in the Journal of Management by Becker, Cropanzano, and Sanfey, titled “Organizational Neuroscience: Taking Organizational Theory Inside the Neural Black Box.” More specifically, the authors build on the ideas of Becker et al. first to clarify and extend their work and then to explore the critical philosophical issues involved in drawing inferences from neuroscientific research. They argue that these problems are yet to be solved and that organizational researchers who wish to incorporate neuroscientific advances into their work need to engage with them
The neutron and its role in cosmology and particle physics
Experiments with cold and ultracold neutrons have reached a level of
precision such that problems far beyond the scale of the present Standard Model
of particle physics become accessible to experimental investigation. Due to the
close links between particle physics and cosmology, these studies also permit a
deep look into the very first instances of our universe. First addressed in
this article, both in theory and experiment, is the problem of baryogenesis ...
The question how baryogenesis could have happened is open to experimental
tests, and it turns out that this problem can be curbed by the very stringent
limits on an electric dipole moment of the neutron, a quantity that also has
deep implications for particle physics. Then we discuss the recent spectacular
observation of neutron quantization in the earth's gravitational field and of
resonance transitions between such gravitational energy states. These
measurements, together with new evaluations of neutron scattering data, set new
constraints on deviations from Newton's gravitational law at the picometer
scale. Such deviations are predicted in modern theories with extra-dimensions
that propose unification of the Planck scale with the scale of the Standard
Model ... Another main topic is the weak-interaction parameters in various
fields of physics and astrophysics that must all be derived from measured
neutron decay data. Up to now, about 10 different neutron decay observables
have been measured, much more than needed in the electroweak Standard Model.
This allows various precise tests for new physics beyond the Standard Model,
competing with or surpassing similar tests at high-energy. The review ends with
a discussion of neutron and nuclear data required in the synthesis of the
elements during the "first three minutes" and later on in stellar
nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic
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