6,651 research outputs found
Boundary operators in the O(n) and RSOS matrix models
We study the new boundary condition of the O(n) model proposed by Jacobsen
and Saleur using the matrix model. The spectrum of boundary operators and their
conformal weights are obtained by solving the loop equations. Using the
diagrammatic expansion of the matrix model as well as the loop equations, we
make an explicit correspondence between the new boundary condition of the O(n)
model and the "alternating height" boundary conditions in RSOS model.Comment: 29 pages, 4 figures; version to appear in JHE
Supersymmetry on Jacobstahl lattices
It is shown that the construction of Yang and Fendley (2004 {\it J. Phys. A:
Math.Gen. {\bf 37}} 8937) to obtainsupersymmetric systems, leads not to the
open XXZ chain with anisotropy but to systems having
dimensions given by Jacobstahl sequences.For each system the ground state is
unique. The continuum limit of the spectra of the Jacobstahl systems coincide,
up to degeneracies, with that of the invariant XXZ chain for
. The relation between the Jacobstahl systems and the open XXZ
chain is explained.Comment: 6 pages, 0 figure
Boundary changing operators in the O(n) matrix model
We continue the study of boundary operators in the dense O(n) model on the
random lattice. The conformal dimension of boundary operators inserted between
two JS boundaries of different weight is derived from the matrix model
description. Our results are in agreement with the regular lattice findings. A
connection is made between the loop equations in the continuum limit and the
shift relations of boundary Liouville 3-points functions obtained from Boundary
Ground Ring approach.Comment: 31 pages, 4 figures, Introduction and Conclusion improve
Radiation effects on silicon third quarterly progress report, dec. 1, 1964 - feb. 28, 1965
Radiation effect on silicon - introduction rates of vacancy-phosphorus defect and divacancy in p-type material for solar cell applicatio
Health, Climate Change and Sustainability: A systematic Review and Thematic Analysis of the Literature
Background: Evidence of climate change and its impact continues to be accumulated, and it is argued that the consequences of climate change are likely to result in an increased demand on health services. It has been claimed that climate change presents new challenges for health services and that strategies should be adopted to address these challenges. Aim: The aim of this systematic review was to map published literature on health, climate change and sustainability by categorising papers according to their focus on effects, strategy and actions, and to provide a thematic analysis of their content. Methods: Systematic searches were conducted via a range of healthcare related databases i.e. Pubmed, Medline, CINAHL, AMED, ASSIA, IBSS and ISI Web of Knowledge. Searches focussed upon papers published in English between 1998 and 2008. Retrieved papers were studied by the authors in order to inform the thematic analysis of their content. Results: A total of 114 publications were retrieved, of which 36 met the inclusion criteria for the systematic review. These 36 publications were categorised and are discussed according to their focus on: effects/impacts, strategy/policy, action/examples. Conclusions: A number of papers report the potential health effects of climate change while others report policies and strategies to tackle these effects. However there is an urgent need to identify and report on the implementation of strategies to mitigate and adapt to these challenges and to publish real examples of actions. Actions that are taken need to be evidence/policy based, and implementations monitored, evaluated and published
Structure of the two-boundary XXZ model with non-diagonal boundary terms
We study the integrable XXZ model with general non-diagonal boundary terms at
both ends. The Hamiltonian is considered in terms of a two boundary extension
of the Temperley-Lieb algebra.
We use a basis that diagonalizes a conserved charge in the one-boundary case.
The action of the second boundary generator on this space is computed. For the
L-site chain and generic values of the parameters we have an irreducible space
of dimension 2^L. However at certain critical points there exists a smaller
irreducible subspace that is invariant under the action of all the bulk and
boundary generators. These are precisely the points at which Bethe Ansatz
equations have been formulated. We compute the dimension of the invariant
subspace at each critical point and show that it agrees with the splitting of
eigenvalues, found numerically, between the two Bethe Ansatz equations.Comment: 9 pages Latex. Minor correction
Comparison of Cellulosic Ethanol Yields from Midwestern Maize and Reconstructed Tallgrass Prairie Systems Managed for Bioenergy
Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-species reconstructed prairie was grown with and without spring nitrogen fertilization. Both maize stover and prairie biomass were harvested in the fall. We compared amounts of cellulosic biomass produced and harvested, carbohydrate contents as measured by both dietary and detergent methods, and estimated cellulosic ethanol yields per hectare. From 2009–2013, the cropping system with the largest non-grain biomass yield was fertilized prairie, averaging 10.4 Mg ha−1 year−1 aboveground biomass with average harvest removals of 7.8 Mg ha−1 year−1. The unfertilized prairie produced 7.4 Mg ha−1 year−1 aboveground biomass, with average harvests of 5.3 Mg ha−1 year−1. Lowest cellulosic (non-grain) biomass harvests were obtained from continuous maize systems, averaging 3.5 Mg ha−1 year−1 when grown with, and 3.7 Mg ha−1 year−1 when grown without a winter rye cover crop, respectively. Unfertilized prairie biomass and maize stover had equivalent dietary-determined potential biomass ethanol yields at 330 g ethanol kg−1 dry biomass, but fertilized prairie was lower at 315. The detergent method did not accurately capture these differences. Over the five-year period of the experiment, unfertilized and fertilized prairie systems averaged 810 and 1,790 L potential cellulosic ethanol ha−1 year−1 more than the maize systems, respectively. Differences in harvested biomass accounted for \u3e90 % of ethanol yield variation
Effect of water temperature on cattle performance
When average outside air temperature was about 40 F, water temperatures of 40, 60, Of\u27 80 F had little effect on water intakes of yearling steers and heifers. In addition, there were no significant differences in average daily feed or efficiency. No electrical energy was required to maintain water at 40 F, and it took about twice as much electricity to maintain water at 80 F instead of 60 F
A deformed analogue of Onsager's symmetry in the XXZ open spin chain
The XXZ open spin chain with general integrable boundary conditions is shown
to possess a q-deformed analogue of the Onsager's algebra as fundamental
non-abelian symmetry which ensures the integrability of the model. This
symmetry implies the existence of a finite set of independent mutually
commuting nonlocal operators which form an abelian subalgebra. The transfer
matrix and local conserved quantities, for instance the Hamiltonian, are
expressed in terms of these nonlocal operators. It follows that Onsager's
original approach of the planar Ising model can be extended to the XXZ open
spin chain.Comment: 12 pages; LaTeX file with amssymb; v2: typos corrected,
clarifications in the text; v3: minor changes in references, version to
appear in JSTA
The open XXZ and associated models at q root of unity
The generalized open XXZ model at root of unity is considered. We review
how associated models, such as the harmonic oscillator, and the lattice
sine-Gordon and Liouville models are obtained. Explicit expressions of the
local Hamiltonian of the spin XXZ spin chain coupled to dynamical
degrees of freedom at the one end of the chain are provided. Furthermore, the
boundary non-local charges are given for the lattice sine Gordon model and the
harmonic oscillator with open boundaries. We then identify the spectrum and
the corresponding Bethe states, of the XXZ and the q harmonic oscillator in the
cyclic representation with special non diagonal boundary conditions. Moreover,
the spectrum and Bethe states of the lattice versions of the sine-Gordon and
Liouville models with open diagonal boundaries is examined. The role of the
conserved quantities (boundary non-local charges) in the derivation of the
spectrum is also discussed.Comment: 31 pages, LATEX, minor typos correcte
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