1,253 research outputs found
Silvopastoral Agroforestry in Upland and Lowland UK Grassland: Tree Growth and Animal Performance
Trees, individually protected from herbivore damage using plastic shelters, were planted at two densities (100 and 400 stems/ha) into sheepgrazed pasture in upland and lowland UK grassland sites in 1988. Tree and animal performance were compared with conventional forestry (no sheep) and pasture (no tree) systems. Effects on tree growth and survival are highly species and site dependent although some treatment effects did emerge. Tree shelters encouraged rapid early height growth compared to forestry controls although in some cases tree form was also adversely affected. Generally tree performance within agroforestry treatments was better at the higher planting density. Eight years after planting there has been no reduction in animal production despite interception of up to 10% of total photosynthetically active radiation by the developing tree canopy
Solving the Coulomb scattering problem using the complex scaling method
Based on the work of Nuttall and Cohen [Phys. Rev. {\bf 188} (1969) 1542] and
Resigno et al{} [Phys. Rev. A {\bf 55} (1997) 4253] we present a rigorous
formalism for solving the scattering problem for long-range interactions
without using exact asymptotic boundary conditions. The long-range interaction
may contain both Coulomb and short-range potentials. The exterior complex
scaling method, applied to a specially constructed inhomogeneous Schr\"odinger
equation, transforms the scattering problem into a boundary problem with zero
boundary conditions. The local and integral representations for the scattering
amplitudes have been derived. The formalism is illustrated with numerical
examples.Comment: 3 pages, 3 figure
Anomalous Scale Dimensions from Timelike Braiding
Using the previously gained insight about the particle/field relation in
conformal quantum field theories which required interactions to be related to
the existence of particle-like states associated with fields of anomalous
scaling dimensions, we set out to construct a classification theory for the
spectra of anomalous dimensions. Starting from the old observations on
conformal superselection sectors related to the anomalous dimensions via the
phases which appear in the spectral decomposition of the center of the
conformal covering group we explore the possibility
of a timelike braiding structure consistent with the timelike ordering which
refines and explains the central decomposition. We regard this as a preparatory
step in a new construction attempt of interacting conformal quantum field
theories in D=4 spacetime dimensions. Other ideas of constructions based on the
- or the perturbative SYM approach in their relation to the
present idea are briefly mentioned.Comment: completely revised, updated and shortened replacement, 24 pages
tcilatex, 3 latexcad figure
Use of methods for specifying the target difference in randomised controlled trial sample size calculations : Two surveys of trialists' practice
© The Author(s), 2014.Peer reviewedPublisher PD
Modular Structure and Duality in Conformal Quantum Field Theory
Making use of a recent result of Borchers, an algebraic version of the
Bisognano-Wichmann theorem is given for conformal quantum field theories, i.e.
the Tomita-Takesaki modular group associated with the von Neumann algebra of a
wedge region and the vacuum vector concides with the evolution given by the
rescaled pure Lorentz transformations preserving the wedge. A similar geometric
description is valid for the algebras associated with double cones. Moreover
essential duality holds on the Minkowski space , and Haag duality for double
cones holds provided the net of local algebras is extended to a pre-cosheaf on
the superworld , i.e. the universal covering of the Dirac-Weyl
compactification of . As a consequence a PCT symmetry exists for any
algebraic conformal field theory in even space-time dimension. Analogous
results hold for a Poincar\'e covariant theory provided the modular groups
corresponding to wedge algebras have the expected geometrical meaning and the
split property is satisfied. In particular the Poincar\'e representation is
unique in this case.Comment: 23 pages, plain TeX, TVM26-12-199
Lieb-Thirring Bound for Schr\"odinger Operators with Bernstein Functions of the Laplacian
A Lieb-Thirring bound for Schr\"odinger operators with Bernstein functions of
the Laplacian is shown by functional integration techniques. Several specific
cases are discussed in detail.Comment: We revised the first versio
Hybrid Hydrogen Peroxide for Viral Disinfection
Decontamination is often necessary in facilities with sensitive spaces where pathogen elimination is critical. Historically, high concentration vaporized hydrogen peroxide technologies have been applied in these areas for pathogen disinfection. While effective, these high concentration solutions come with inherent risks to human health and safety. Alternatively, one recent innovation is a hybrid hydrogen peroxide system which combines a 7% hydrogen peroxide solution with a calibrated fogging device that delivers a mixture of vaporous and micro aerosolized particles, significantly lowering the risk of exposure to high-concentration hazardous chemicals. Studies performed with this technology demonstrate high level pathogen decontamination across a variety of tested pathogens and substrates. This chapter will cover a brief history of hydrogen peroxide technologies and their application processes; examine the correlations between viral inactivation, viral disinfection, and biological indicators for validation; demonstrate the necessity of dwell time for optimal efficacy; discuss the effects of viral disinfectant use on laboratory surfaces; and examine various studies, including virologic work performed in Biosafety Level 3 facilities and good laboratory practice (GLP) data performed by EPA-approved laboratories. This chapter will provide readers a deeper understanding of essential components and considerations when implementing hydrogen peroxide systems for viral decontamination
The Conformal Spin and Statistics Theorem
We prove the equality between the statistics phase and the conformal
univalence for a superselection sector with finite index in Conformal Quantum
Field Theory on . A relevant point is the description of the PCT symmetry
and the construction of the global conjugate charge.Comment: plain tex, 22 page
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