1,173 research outputs found
A classification of the eucalypts
ABSTRACT
Pryor, L.D., and Johnson, L.A.S. (Dept. Bot., Aust. Nat. Univ., Canberra, and Roy. Bot. Gardens and Nat. Herb., Sydney). A CLASSIFICATION OF THE EUCALYPTS (Dept. Bot. Puhl.), 102 pp., 1971.-A new classification is presented of all taxa of EuaaZyptus (and Angophora) (MyrtaceaeLeptospermoideae), on the basis of studies from many disciplines and extensive field experience. This is not in the traditional revisionary form and formal nomenclatural innovations at the species and subspecies level will follow later. Infrageneric classification into subgenera, sections, series, and subseries follows a rationalised plan explicitly divorced from the traditional system embodied in the International Code of Botanical Nomenclature. This is accompanied by an equivalent and flexible system using 1- to 6-letter coded designations for taxa of the various ranks, which embodies the whole classificatory structure. There is a comprehensive index to specific and infraspecific names. Discussion covers the kinds of evidence used, the inflorescence, the operculum, the ovule, and the seed, as well as genetic behaviour, the range of variation-patterns found, and the case for recognition of segregate genera. Recognition of two (only) such genera (EuaaZyptus s. str. and Symphyomyrtus) as proposed by some recent authors is considered oversimplified and contrary to the evidence. Although division into a number of genera may perhaps be desirable in the future, it seems best
at present to consider all the eucalypts as constituting a single genus with eight subgenera. Angophora would logically be included as one of these but, to avoid possible future reversals, its generic status ·is not· formally reduced at this· stage
Changes in Field Stored large Hay Packages
During a 3-year period, 12 large hay packages (six alfalfa, six prairie hay) were made using either Haybuster or Hesston process and stored from 8 to 29 months. Stacks were core sampled at periodic intervals for physical (moisture, density) and quality parameters (crude protein, neutral-detergent fiber, Crampton and Maynard cellulose, acid-detergent fiber, acid-detergent lignin, ash and in vitro dry matter digestibility. The hay package storage areas were located in north-central South Dakota
Three sides to every story: Gender perspectives in energy transition pathways in Canada, Kenya and Spain
Transitions toward a low-carbon future are not only technical and economical, but also deeply social and gendered. The gendered nature of energy transitions is often implicit and unexplored. As a corrective, this paper explores energy pathways by applying concepts from innovations and gender studies. We examine gender perspectives and niche energy innovations which could disrupt the regime. The regime represents the mainstream pathway that includes the dominant gender perspective and energy system. We explore different gender perspectives of energy transition pathways by applying an Alternative Pathways framework that includes: (1) on-stream pathways that exist within the mainstream pathway to promote equal opportunities for women and men, as well as niches for energy innovations without challenging the high-carbon energy regime; (2) off-stream pathways that depart from the mainstream and promote differences across different genders while creating niches outside the energy regime; and (3) transformative pathways that are fundamentally different from the previous mainstream and includes all gender perspectives in a new energy regime. Applying this framing, in Canada, we explored Indigenous perspectives in the oil sands sector; in Kenya, we studied largescale renewable energy impacting Indigneous communities; in Spain, we evaluate the movement away from fossil fuels and towards renewable technologies. The framework helped to identify that mainstream pathways represented the dominant male perspective while woman's perspective were largely left out. Such absence generate energy pathways that are disconnected from local realities, lack public buy-in and slow-down a sustainable energy transition. © 2020 The Author(s)We would like to acknowledge the feedback of the two anonymous reviews as well as the TRANSrisk consortium members. We would also like to acknowledge the Maria de Maeztu excellence accreditation MDM-2017-0714 of BC3
What can we learn about GW Physics with an elastic spherical antenna?
A general formalism is set up to analyse the response of an arbitrary solid
elastic body to an arbitrary metric Gravitational Wave perturbation, which
fully displays the details of the interaction antenna-wave. The formalism is
applied to the spherical detector, whose sensitivity parameters are thereby
scrutinised. A multimode transfer function is defined to study the amplitude
sensitivity, and absorption cross sections are calculated for a general metric
theory of GW physics. Their scaling properties are shown to be independent of
the underlying theory, with interesting consequences for future detector
design. The GW incidence direction deconvolution problem is also discussed,
always within the context of a general metric theory of the gravitational
field.Comment: 21 pages, 7 figures, REVTeX, enhanced Appendix B with numerical
values and mathematical detail. See also gr-qc/000605
An NMR-based nanostructure switch for quantum logic
We propose a nanostructure switch based on nuclear magnetic resonance (NMR)
which offers reliable quantum gate operation, an essential ingredient for
building a quantum computer. The nuclear resonance is controlled by the magic
number transitions of a few-electron quantum dot in an external magnetic field.Comment: 4 pages, 2 separate PostScript figures. Minor changes included. One
reference adde
Uniformly Accelerated Charge in a Quantum Field: From Radiation Reaction to Unruh Effect
We present a stochastic theory for the nonequilibrium dynamics of charges
moving in a quantum scalar field based on the worldline influence functional
and the close-time-path (CTP or in-in) coarse-grained effective action method.
We summarize (1) the steps leading to a derivation of a modified
Abraham-Lorentz-Dirac equation whose solutions describe a causal semiclassical
theory free of runaway solutions and without pre-acceleration patholigies, and
(2) the transformation to a stochastic effective action which generates
Abraham-Lorentz-Dirac-Langevin equations depicting the fluctuations of a
particle's worldline around its semiclassical trajectory. We point out the
misconceptions in trying to directly relate radiation reaction to vacuum
fluctuations, and discuss how, in the framework that we have developed, an
array of phenomena, from classical radiation and radiation reaction to the
Unruh effect, are interrelated to each other as manifestations at the
classical, stochastic and quantum levels. Using this method we give a
derivation of the Unruh effect for the spacetime worldline coordinates of an
accelerating charge. Our stochastic particle-field model, which was inspired by
earlier work in cosmological backreaction, can be used as an analog to the
black hole backreaction problem describing the stochastic dynamics of a black
hole event horizon.Comment: Invited talk given by BLH at the International Assembly on
Relativistic Dynamics (IARD), June 2004, Saas Fee, Switzerland. 19 pages, 1
figur
Two-Electron Quantum Dot in Magnetic Field: Analytical Results
Two interacting electrons in a harmonic oscillator potential under the
influence of a perpendicular homogeneous magnetic field are considered.
Analytic expressions are obtained for the energy spectrum of the two- and
three-dimensional cases. Exact conditions for phase transitions due to the
electron-electron interaction in a quantum dot as a function of the dot size
and magnetic field are calculated.Comment: 22 pages (Latex file), 3 Postscript figures, to be published in Phys.
Rev.B 55, N 20 (1997
Nuclear effects in the Drell-Yan process at very high energies
We study Drell-Yan (DY) dilepton production in proton(deuterium)-nucleus and
in nucleus-nucleus collisions within the light-cone color dipole formalism.
This approach is especially suitable for predicting nuclear effects in the DY
cross section for heavy ion collisions, as it provides the impact parameter
dependence of nuclear shadowing and transverse momentum broadening, quantities
that are not available from the standard parton model. For p(D)+A collisions we
calculate nuclear shadowing and investigate nuclear modification of the DY
transverse momentum distribution at RHIC and LHC for kinematics corresponding
to coherence length much longer than the nuclear size. Calculations are
performed separately for transversely and longitudinally polarized DY photons,
and predictions are presented for the dilepton angular distribution.
Furthermore, we calculate nuclear broadening of the mean transverse momentum
squared of DY dileptons as function of the nuclear mass number and energy. We
also predict nuclear effects for the cross section of the DY process in heavy
ion collisions. We found a substantial nuclear shadowing for valence quarks,
stronger than for the sea.Comment: 46 pages, 18 figures, title changed and some discussion added,
accepted for publication in PR
Vibrations and Berry Phases of Charged Buckminsterfullerene
A simple model of electron-vibron interactions in buckminsterfullerene ions
is solved semiclassically. Electronic degeneracies of C induce
dynamical Jahn-Teller distortions, which are unimodal for and
bimodal for . The quantization of motion along the Jahn-Teller
manifold leads to a symmetric-top rotator Hamiltonian. I find Molecular
Aharonov-Bohm effects where electronic Berry phases determine the vibrational
spectra, zero point fluctuations, and electrons' pair binding energies. The
latter are relevant to superconductivity in alkali-fullerenes.Comment: Latex 11 pages. IIT-00
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