1,165 research outputs found
Bulletin No. 97 - Report on the Southern Utah Experiment Station
When, in the early part of the year 1905 , the management of the Southern Utah Experiment Farm was turned over to the officials of the Utah Agricultural Experiment Station, in compliance with an act of the legislature of that year a number of experiments were under way, principally variety tests with orchard and small fruit. The State Board of Horticulture had been in charge of this farm since its establishment in 1899, and had succeeded in making out of it not only a place that will indicate the varieties of fruits adapted to that climate and soil , but also a farm that in neatness and careful arrangement can be an instructive model to anyone contemplating engaging in that industry. The new management decided not to make any radical change in the tests that were under way , but to continue them to such a conclusion a will yield the valuable results that were to come out of them. New tests or investigations are to be started with the same crop without interfering with them as variety tests, and upon the ground still available or which has not yet been set out into orchard, vineyard, or other permanent crops. Such it is planned to do as the problems suggest themselves, and as means are available
Coronal radiation belts
The magnetic field of the solar corona has a large-scale dipole character,
which maps into the bipolar field in the solar wind. Using standard
representations of the coronal field, we show that high-energy ions can be
trapped stably in these large-scale closed fields. The drift shells that
describe the conservation of the third adiabatic invariant may have complicated
geometries. Particles trapped in these zones would resemble the Van Allen Belts
and could have detectable consequences. We discuss potential sources of trapped
particles
Trajectories of charged particles trapped in Earth's magnetic field
I outline the theory of relativistic charged-particle motion in the
magnetosphere in a way suitable for undergraduate courses. I discuss particle
and guiding center motion, derive the three adiabatic invariants associated
with them, and present particle trajectories in a dipolar field. I provide
twelve computational exercises that can be used as classroom assignments or for
self-study. Two of the exercises, drift-shell bifurcation and Speiser orbits,
are adapted from active magnetospheric research. The Python code provided in
the supplement can be used to replicate the trajectories and can be easily
extended for different field geometries.Comment: 10 pages, 7 figures. Submitted to American Journal of Physic
Re-evaluating Passive Research Involvement in the Undergraduate Curriculum
In recent years, advocates for research-based education have publicized many examples of passive research
involvement, defined as undergraduates learning about the
content and lived experience of research at their institution. But the qualitative dimensions of passive research
involvement remain unknown. The authors’ study uses
Diana Laurillard’s “conversational framework” to analyze
reports from 367 undergraduate students at a UK researchintensive university who met researchers and learned
about their work. The results show a range of experiences
in student learning about faculty research. These findings
make the case that passive research involvement has its
own integrity and cannot be characterized as an absence of
participation. The authors suggest ways that the students
as audience category can enhance undergraduate connections with research
Comparison of Howland and General Impedance Converter (GIC) circuit based current sources for bio-impedance measurements
The current source is a key component in bio-impedance measurement systems. The accuracy of the current source can be measured in terms of its output impedance together with other parameters, with certain applications demanding extremely high output impedance. This paper presents an investigation and comparison of different current source designs based on the Enhanced Howland circuit combined with a General Impedance Converter (GIC) circuit using both ideal and non-ideal operational amplifiers. Under differing load conditions two different settings of the GIC are evaluated and the results are compared to show its performance settings. Whilst the study has shown that over a wide bandwidth (i.e. 100Hz-100MHz) the output impedance is limited, operation over a more limited range offers output impedance in the Giga-ohm range, which can be considered as being infinite
Nonequilibrium thermodynamics as a gauge theory
We assume that markovian dynamics on a finite graph enjoys a gauge symmetry
under local scalings of the probability density, derive the transformation law
for the transition rates and interpret the thermodynamic force as a gauge
potential. A widely accepted expression for the total entropy production of a
system arises as the simplest gauge-invariant completion of the time derivative
of Gibbs's entropy. We show that transition rates can be given a simple
physical characterization in terms of locally-detailed-balanced heat
reservoirs. It follows that Clausius's measure of irreversibility along a
cyclic transformation is a geometric phase. In this picture, the gauge symmetry
arises as the arbitrariness in the choice of a prior probability. Thermostatics
depends on the information that is disposable to an observer; thermodynamics
does not.Comment: 6 pages. Non-fatal errors in eq.(6), eq.(26) and eq.(31) have been
amende
Quantum Phonon Optics: Coherent and Squeezed Atomic Displacements
In this paper we investigate coherent and squeezed quantum states of phonons.
The latter allow the possibility of modulating the quantum fluctuations of
atomic displacements below the zero-point quantum noise level of coherent
states. The expectation values and quantum fluctuations of both the atomic
displacement and the lattice amplitude operators are calculated in these
states---in some cases analytically. We also study the possibility of squeezing
quantum noise in the atomic displacement using a polariton-based approach.Comment: 6 pages, RevTe
A Strategic Plan for Introducing, Implementing, Managing, and Monitoring an Urban Extension Platform
Florida\u27s Strategic Plan for Extension in Metropolitan Regions reflects an adaptive management approach to the state\u27s urban Extension mission within the context of establishing essential elements, performance indicators, key outcomes, and suggested alternatives for action. Extension leadership has adopted the strategic plan, and implementation efforts are under way. The successful future of urban Extension in Florida lies in fully embracing and monitoring the plan and recommendations therein. In this article, we describe the course of developing the strategic plan, which included the use of a modified Delphi process and a strategic adaptive management format. We encourage others to adapt our methods to develop plans to meet their specific needs and desired outcomes
Product rule for gauge invariant Weyl symbols and its application to the semiclassical description of guiding center motion
We derive a product rule for gauge invariant Weyl symbols which provides a
generalization of the well-known Moyal formula to the case of non-vanishing
electromagnetic fields. Applying our result to the guiding center problem we
expand the guiding center Hamiltonian into an asymptotic power series with
respect to both Planck's constant and an adiabaticity parameter already
present in the classical theory. This expansion is used to determine the
influence of quantum mechanical effects on guiding center motion.Comment: 24 pages, RevTeX, no figures; shortened version will be published in
J.Phys.
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