2,095 research outputs found
Circular 61
Rapeseed is the oil-bearing seed from plants of the Brassica genus. It grows
well in the cooler agricultural regions o f the world and for this reason has long
been thought to be a promising crop for interior Alaska.
Rapeseed has been grow n in India and China for thousands and in Europe for
hundreds o f years (Bolton 1980). Its history in North America began in 1943 when
a small quantity of seed was imported into Canada. In recent years, its production
has been largely that from cultivars bred for production of seed low in erucic acid
and glucosinolate content. Seed from these cultivars is referred to by the Canadian
Rapeseed Industry as canola. Its qualities are desirable in the edible-oil market,
the largest market for products from canola seed. Canada is now one of the world’s
largest producers and is the world’s largest exporter o f rapeseed.
The meal that remains after oil extraction is high in protein and is used as a
supplement in livestock feeds. The whole seed can also be used as a feed supplement. Some cultivars o f rapeseed that are high in erucic acid are also grow n for
use in plastics and industrial oils (Genser and Eskin 1979). In addition, forage
rapeseed cultivars can be used as livestock pasture.
Research concerning the production of rapeseed has been addressed by the
Agricultural and Forestry Experiment Station (AFES) for several years. O f specific
concern has been the selection of appropriate cultivars (Wooding et al. 1978),
response to various nitrogen (N) rates, row spacings and seeding rates (Lewis and
Knight 1987), performance in reduced-tillage systems in rotation with barley (Knight
and Lewis 1986), the potential for frost seeding in late fall and early spring (Knight
and Sparrow 1984) and response to boron (B) to enhance early seed ripening
(Wooding 1985). In addition, in 1978 the Cooperative Extension Service (CES)
began conducting seminars on production o f rapeseed for Alaskan farmers. In 1979
and 1980, CES employed Dr. J.L . Bolton, a rapeseed specialist from the University
o f Alberta, in an extension capacity to give technical assistance to farmers
on producing rapeseed (Bolton 1980)
Canonical quantization of so-called non-Lagrangian systems
We present an approach to the canonical quantization of systems with
equations of motion that are historically called non-Lagrangian equations. Our
viewpoint of this problem is the following: despite the fact that a set of
differential equations cannot be directly identified with a set of
Euler-Lagrange equations, one can reformulate such a set in an equivalent
first-order form which can always be treated as the Euler-Lagrange equations of
a certain action. We construct such an action explicitly. It turns out that in
the general case the hamiltonization and canonical quantization of such an
action are non-trivial problems, since the theory involves time-dependent
constraints. We adopt the general approach of hamiltonization and canonical
quantization for such theories (Gitman, Tyutin, 1990) to the case under
consideration. There exists an ambiguity (not reduced to a total time
derivative) in associating a Lagrange function with a given set of equations.
We present a complete description of this ambiguity. The proposed scheme is
applied to the quantization of a general quadratic theory. In addition, we
consider the quantization of a damped oscillator and of a radiating point-like
charge.Comment: 13 page
Exomoon simulations
We introduce and describe our newly developed code that simulates light
curves and radial velocity curves for arbitrary transiting exoplanets with a
satellite. The most important feature of the program is the calculation of
radial velocity curves and the Rossiter-McLaughlin effect in such systems. We
discuss the possibilities for detecting the exomoons taking the abilities of
Extremely Large Telescopes into account. We show that satellites may be
detected also by their RM effect in the future, probably using less accurate
measurements than promised by the current instrumental developments. Thus, RM
effect will be an important observational tool in the exploration of exomoons.Comment: 5 pages, 2 figures with 9 figure panels, accepted by EM&
Face Detection on Embedded Systems
Over recent years automated face detection and recognition (FDR) have gained significant attention from the commercial and research sectors. This paper presents an embedded face detection solution aimed at addressing the real-time image processing requirements within a wide range of applications. As face detection is a computationally intensive task, an embedded solution would give rise to opportunities for discrete economical devices that could be applied and integrated into a vast majority of applications. This work focuses on the use of FPGAs as the embedded prototyping technology where the thread of execution is carried out on an embedded soft-core processor. Custom instructions have been utilized as a means of applying software/hardware partitioning through which the computational bottlenecks are moved to hardware. A speedup by a factor of 110 was achieved from employing custom instructions and software optimizations
Ab initio study of the beta$-tin->Imma->sh phase transitions in silicon and germanium
We have investigated the structural sequence of the high-pressure phases of
silicon and germanium. We have focussed on the cd->beta-tin->Imma->sh phase
transitions. We have used the plane-wave pseudopotential approach to the
density-functional theory implemented within the Vienna ab-initio simulation
package (VASP). We have determined the equilibrium properties of each structure
and the values of the critical parameters including a hysteresis effect at the
phase transitions. The order of the phase transitions has been obtained
alternatively from the pressure dependence of the enthalpy and of the internal
structure parameters. The commonly used tangent construction is shown to be
very unreliable. Our calculations identify a first-order phase transition from
the cd to the beta-tin and from the Imma to the sh phase, and they indicate the
possibility of a second-order phase-transition from the beta-tin to the Imma
phase. Finally, we have derived the enthalpy barriers between the phases.Comment: 12 pages, 16 figure
Observational signatures of a non-singular bouncing cosmology
We study a cosmological scenario in which inflation is preceded by a bounce.
In this scenario, the primordial singularity, one of the major shortcomings of
inflation, is replaced by a non-singular bounce, prior to which the universe
undergoes a phase of contraction. Our starting point is the bouncing cosmology
investigated in Falciano et al. (2008), which we complete by a detailed study
of the transfer of cosmological perturbations through the bounce and a
discussion of possible observational effects of bouncing cosmologies. We focus
on a symmetric bounce and compute the evolution of cosmological perturbations
during the contracting, bouncing and inflationary phases. We derive an
expression for the Mukhanov-Sasaki perturbation variable at the onset of the
inflationary phase that follows the bounce. Rather than being in the
Bunch-Davies vacuum, it is found to be in an excited state that depends on the
time scale of the bounce. We then show that this induces oscillations
superimposed on the nearly scale-invariant primordial spectra for scalar and
tensor perturbations. We discuss the effects of these oscillations in the
cosmic microwave background and in the matter power spectrum. We propose a new
way to indirectly measure the spatial curvature energy density parameter in the
context of this model.Comment: 40 pages, 5 figures, typos corrected and reference adde
Updated Bounds on Sum of Neutrino Masses in Various Cosmological Scenarios
We present strong bounds on the sum of three active neutrino masses () in various cosmological models. We use the following baseline
datasets: CMB temperature data from Planck 2015, BAO measurements from SDSS-III
BOSS DR12, the newly released SNe Ia dataset from Pantheon Sample, and a prior
on the optical depth to reionization from 2016 Planck Intermediate results. We
constrain cosmological parameters in model with 3 massive active
neutrinos. For this model we find a upper bound of
0.152 eV at 95 C.L. Adding the high- polarization data
from Planck strengthens this bound to 0.118 eV, which is very
close to the minimum required mass of 0.1 eV for inverted
hierarchy. This bound is reduced to 0.110 eV when we also vary
r, the tensor to scalar ratio ( model), and add an
additional dataset, BK14, the latest data released from the Bicep-Keck
collaboration. This bound is further reduced to 0.101 eV in a
cosmology with non-phantom dynamical dark energy (
model with for all ). Considering the model and adding the BK14 data again, the bound can be even further
reduced to 0.093 eV. For the model
without any constraint on , the bounds however relax to
0.276 eV. Adding a prior on the Hubble constant (
km/sec/Mpc) from Hubble Space Telescope (HST), the above mentioned bounds
further improve to 0.117 eV, 0.091 eV, 0.085 eV, 0.082 eV,
0.078 eV and 0.247 eV respectively. This substantial improvement is mostly
driven by a more than 3 tension between Planck 2015 and HST
measurements of and should be taken cautiously. (abstract abridged)Comment: 31 pages, 19 figures, matches published version in JCA
Understanding person acquisition using an interactive activation and competition network
Face perception is one of the most developed visual skills that humans display, and recent work has attempted to examine the mechanisms involved in face perception through noting how neural networks achieve the same performance. The purpose of the present paper is to extend this approach to look not just at human face recognition, but also at human face acquisition. Experiment 1 presents empirical data to describe the acquisition over time of appropriate representations for newly encountered faces. These results are compared with those of Simulation 1, in which a modified IAC network capable of modelling the acquisition process is generated. Experiment 2 and Simulation 2 explore the mechanisms of learning further, and it is demonstrated that the acquisition of a set of associated new facts is easier than the acquisition of individual facts in isolation of one another. This is explained in terms of the advantage gained from additional inputs and mutual reinforcement of developing links within an interactive neural network system. <br/
Aharonov-Bohm Effect in Cyclotron and Synchrotron Radiations
We study the impact of Aharonov-Bohm solenoid on the radiation of a charged
particle moving in a constant uniform magnetic field. With this aim in view,
exact solutions of Klein-Gordon and Dirac equations are found in the
magnetic-solenoid field. Using such solutions, we calculate exactly all the
characteristics of one-photon spontaneous radiation both for spinless and
spinning particle. Considering non-relativistic and relativistic
approximations, we analyze cyclotron and synchrotron radiations in detail.
Radiation peculiarities caused by the presence of the solenoid may be
considered as a manifestation of Aharonov-Bohm effect in the radiation. In
particular, it is shown that new spectral lines appear in the radiation
spectrum. Due to angular distribution peculiarities of the radiation intensity,
these lines can in principle be isolated from basic cyclotron and synchrotron
radiation spectraComment: 38 pages, LaTex fil
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