8,813 research outputs found
Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 4: Open recuperated and bottomed gas turbine cycles
Open-cycle recuperated gas turbine plant with inlet temperatures of 1255 to 1644 K (1800 to 2500 F) and recuperators with effectiveness values of 0, 70, 80 and 90% are considered. A 1644 K (2500 F) gas turbine would have a 33.5% plant efficiency in a simple cycle, 37.6% in a recuperated cycle and 47.6% when combined with a sulfur dioxide bottomer. The distillate burning recuperated plant was calculated to produce electricity at a cost of 8.19 mills/MJ (29.5 mills/kWh). Due to their low capital cost /kW, the open cycle gas turbine plant should see duty for peaking and intermediate load duty
Collective-coupling analysis of spectra of mass-7 isobars: ^7He, ^7Li, ^7Be, ^7B
A nucleon-nucleus interaction model has been applied to ascertain the
underlying character of the negative-parity spectra of four isobars of mass
seven, from neutron-- to proton--emitter driplines. With one single nuclear
potential defined by a simple coupled-channel model, a multichannel algebraic
scattering approach (MCAS) has been used to determine the bound and resonant
spectra of the four nuclides, of which ^7He and ^7B are particle unstable.
Incorporation of Pauli blocking in the model enables a description of all known
spin-parity states of the mass-7 isobars. We have also obtained spectra of
similar quality by using a large space no-core shell model. Additionally, we
have studied ^7Li and ^7Be using a dicluster model. We have found a
dicluster-model potential that can reproduce the lowest four states of the two
nuclei, as well as the relevant low-energy elastic scattering cross sections.
But, with this model, the rest of the energy spectra cannot be obtained.Comment: Extended version published in Phys. Rev. C, 16 pages and 5 figure
Outcaste or Internal Exile? Ambiguous Bodies in the Making of Modern Japan
Based on more orthodox interpretations of ‘exile’ such as those put forward by Edward Said, many similarities can be drawn between the ideas of exile- particularly the notion of internal exile - and the outcaste that we see in the form of the Dalit in India. In this paper, we will firstly analyse the conceptual linkages between ‘exile’, ‘outcast’, and ‘outcaste’, highlighting both points of interchangeableness and departure for these notions as they relate specifically to the late Tokugawa Japanese ‘outcaste’ groups known as eta and hinin who were officially liberated through the Emancipation Edict promulgated in 1871. Second, after a brief background discussion where we problematize the above notions through the lenses of time and space, we will examine the state/condition of being an outcaste in the late Tokugawa period, and consider how close this situation was to a state of exile. Third, we will examine a specific example of the act of re-inclusion of outcastes into their local community created by the 1871 Emancipation Edict that led to the creation of the ‘former outcaste’ or ‘new citizen’, and analyse to what extent this embodies the process of returning from exile. Lastly, the paper will conclude with a brief discussion of the extent to which a crossover between the terms ‘outcaste’ and ‘exile’ may be applicable in the Japanese context, as well as the positive aspects of attempting such a conceptual reconfiguration for historians and activists working on the Buraku problem
Modeling, Analysis, and Optimization Issues for Large Space Structures
Topics concerning the modeling, analysis, and optimization of large space structures are discussed including structure-control interaction, structural and structural dynamics modeling, thermal analysis, testing, and design
Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 6: Closed-cycle gas turbine systems
Both recuperated and bottomed closed cycle gas turbine systems in electric power plants were studied. All systems used a pressurizing gas turbine coupled with a pressurized furnace to heat the helium for the closed cycle gas turbine. Steam and organic vapors are used as Rankine bottoming fluids. Although plant efficiencies of over 40% are calculated for some plants, the resultant cost of electricity was found to be 8.75 mills/MJ (31.5 mills/kWh). These plants do not appear practical for coal or oil fired plants
Comparison of optical model results from a microscopic Schr\"odinger approach to nucleon-nucleus elastic scattering with those from a global Dirac phenomenology
Comparisons are made between results of calculations for intermediate energy
nucleon-nucleus scattering for 12C, 16O, 40Ca, 90Zr, and 208Pb, using optical
potentials obtained from global Dirac phenomenology and from a microscopic
Schr\"odinger model. Differential cross sections and spin observables for
scattering from the set of five nuclei at 65 MeV and 200 MeV have been studied
to assess the relative merits of each approach. Total reaction cross sections
from proton-nucleus and total cross sections from neutron-nucleus scattering
have been evaluated and compared with data for those five targets in the energy
range 20 MeV to 800 MeV. The methods of analyses give results that compare well
with experimental data in those energy regimes for which the procedures are
suited.Comment: 22 pages, 12 figure
Role of the Pauli principle in collective-model coupled-channels calculations
A multi-channel algebraic scattering theory, to find solutions of
coupled-channel scattering problems with interactions determined by collective
models, has been structured to ensure that the Pauli principle is not violated.
By tracking the results in the zero coupling limit, a correct interpretation of
the sub-threshold and resonant spectra of the compound system can be made. As
an example, the neutron-12C system is studied defining properties of 13C to 10
MeV excitation. Accounting for the Pauli principle in collective
coupled-channels models is crucial to the outcome.Comment: 4 pages, 1 figure, version appearing in Phys. Rev. Let
Clonal mixing in the soldier-producing aphid <i>Pemphigus spyrothecae</i> (Hemiptera: Aphididae)
Illuminating the genetic relationships within soldier-producing aphid colonies is an essential element of any attempt to explain the evolution of the altruistic soldier caste. Pemphigus spyrothecae is a soldier-producing aphid that induces galls on the leaf petioles of its host (trees of the genus Populus). At least a quarter of the aphids within the clonally produced gall population are morphologically and behaviourally distinct first-instar soldiers that defend the gall population from predation. Using field trapping and microsatellites, we investigated the degree of clonal mixing within natural gall populations. Field trapping in the UK showed that all the migrants of P. spyrothecae and of two other Pemphigus species were wingless first-instar soldiers. The average degree of mixing estimated from trapping P. spyrothecae migrants was 0.68% (range = 0–15%). Microsatellite genotyping of 277 aphids from 13 galls collected in Italy revealed an average mixing level of 10.4% (range = 0–59%). Six galls contained more than one clone (range = 2–5 clones). Non-kin aphids were not restricted to the soldier caste but were evenly distributed across instars. An additional gall, from which 527 occupants were genotyped, contained 12 non-kin aphids distributed among nine clones, showing that clonal diversity can be high even when mixing is very low. These observations suggest that although soldiers migrate regularly and can moult and reproduce within foreign galls, clonal mixing in this species is generally low and is unlikely to provide a barrier to the evolution of investment by the aphid clones in an altruistic soldier caste
Quaternary rupture of a crustal fault beneath Victoria, British Columbia, Canada
The seismic potential of crustal faults within the forearc of the northern Cascadia subduction zone in British Columbia has remained elusive, despite the recognition of recent seismic activity on nearby fault systems within the Juan de Fuca Strait. In this paper, we present the first evidence for earthquake surface ruptures along the Leech River fault, a prominent crustal fault near Victoria, British Columbia. We use LiDAR and field data to identify >60 steeply dipping, semi-continuous linear scarps, sags, and swales that cut across both bedrock and Quaternary deposits along the Leech River fault. These features are part of an ~1-km-wide and up to >60-km-long steeply dipping fault zone that accommodates active forearc transpression together with structures in the Juan de Fuca Strait and the U.S. mainland. Reconstruction of fault slip across a deformed <15 ka colluvial surface near the center of the fault zone indicates ~6 m of vertical separation across the surface and ~4 m of vertical separation of channels incising the surface. These displacement data indicate that the Leech River fault has experienced at least two surface-rupturing earthquakes since the deglaciation following the last glacial maximum ca. 15 ka, and should therefore be incorporated as a distinct shallow seismic source in seismic hazard assessments for the region.This research was supported by an NSERC Discovery grant to KM and NSF EAR IRFP Grant #1349586 to CR
Particle-unstable light nuclei with a Sturmian approach that preserves the Pauli principle
Sturmian theory for nucleon-nucleus scattering is discussed in the presence
of all the phenomenological ingredients necessary for the description of
weakly-bound (or particle-unstable) light nuclear systems. Currently, we use a
macroscopic potential model of collective nature. The analysis shows that the
couplings to low-energy collective-core excitations are fundamental but they
are physically meaningful only if the constraints introduced by the Pauli
principle are taken into account. The formalism leads one to discuss a new
concept, Pauli hindrance, which appears to be important to understand the
structure of weakly-bound and unbound systems.Comment: 5 pages, 2 figures, 1 table, contribution to proceedings of "18th
International IUPAP Conference on Few-Body Problems in Physics," Santos,
Brazil, August 21-26, 200
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