40,712 research outputs found
Investigation of a 2-Colour Undulator FEL Using Puffin
Initial studies of a 2-colour FEL amplifier using one monoenergetic electron
beam are presented. The interaction is modelled using the unaveraged, broadband
FEL code Puffin. A series of undulator modules are tuned to generate two
resonant frequencies along the FEL interaction and a self-consistent 2-colour
FEL interaction at widely spaced non-harmonic wavelengths at 1nm and 2.4nm is
demonstrated.Comment: Submitted to The 35th International Free-Electron Laser Conference,
Manhattan, New York (2013
Bethe ansatz solution of an integrable, non-Abelian anyon chain with D(D_3) symmetry
The exact solution for the energy spectrum of a one-dimensional Hamiltonian
with local two-site interactions and periodic boundary conditions is
determined. The two-site Hamiltonians commute with the symmetry algebra given
by the Drinfeld double D(D_3) of the dihedral group D_3. As such the model
describes local interactions between non-Abelian anyons, with fusion rules
given by the tensor product decompositions of the irreducible representations
of D(D_3). The Bethe ansatz equations which characterise the exact solution are
found through the use of functional relations satisfied by a set of mutually
commuting transfer matrices.Comment: 19 page
Artificial neural network prediction of weld distortion rectification using a travelling induction coil
An experimental investigation has been carried out to determine the applicability of an induction heating process with a travelling induction coil for the rectification of angular welding distortion. The results obtained from experimentation have been used to create artificial neural network models with the ability to predict the welding induced distortion and the distortion rectification achieved using a travelling induction coil. The experimental results have shown the ability to reduce the angular distortion for 8 mm and 10 mm thick DH36 steel plate and effectively eliminate the distortion on 6 mm thick plate. Results for 6 mm plate also show the existence of a critical induction coil travel speed at which maximum corrective bending occurs. Artificial neural networks have demonstrated the ability to predict the final distortion of the plate after both welding and induction heating. The models have also been used as a tool to determine the optimum speed to minimise the resulting distortion of steel plate after being subjected to both welding and induction heating processes
Conservation evo-devo: preserving biodiversity by understanding its origins
Unprecedented rates of species extinction increase the urgency for effective conservation biology management practices. Thus, any improvements in practice are vital and we suggest that conservation can be enhanced through recent advances in evolutionary biology, specifically advances put forward by evolutionary developmental biology (i.e., evo-devo). There are strong overlapping conceptual links between conservation and evo-devo whereby both fields focus on evolutionary potential. In particular, benefits to conservation can be derived from some of the main areas of evo-devo research, namely phenotypic plasticity, modularity and integration, and mechanistic investigations of the precise developmental and genetic processes that determine phenotypes. Using examples we outline how evo-devo can expand into conservation biology, an opportunity which holds great promise for advancing both fields
Renormalization-group approach to superconductivity: from weak to strong electron-phonon coupling
We present the numerical solution of the renormalization group (RG) equations
derived in Ref. [1], for the problem of superconductivity in the presence of
both electron-electron and electron-phonon coupling at zero temperature. We
study the instability of a Fermi liquid to a superconductor and the RG flow of
the couplings in presence of retardation effects and the crossover from weak to
strong coupling. We show that our numerical results provide an ansatz for the
analytic solution of the problem in the asymptotic limits of weak and strong
coupling.Comment: 8 pages, 3 figures, conference proceedings for the Electron
Correlations and Materials Properties, in Kos, Greece, July 5-9, 200
eHealth interventions for people with chronic kidney disease
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: This review aims to look at the benefits and harms of using eHealth interventions in the CKD population
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