2,047 research outputs found
Vapor grown silicon dioxide improves transistor base-collector junctions
Vapor grown silicon dioxide layer protects base-collector junction in silicon planar transistors during the emitter diffusion process. This oxide fills in any imperfections that exist in the thermally grown oxide layer and is of greater thickness than that layer. This process is used to deposit protective silicon dioxide coatings on optical surfaces
Topologically non-trivial quantum layers
Given a complete non-compact surface embedded in R^3, we consider the
Dirichlet Laplacian in a layer of constant width about the surface. Using an
intrinsic approach to the layer geometry, we generalise the spectral results of
an original paper by Duclos et al. to the situation when the surface does not
possess poles. This enables us to consider topologically more complicated
layers and state new spectral results. In particular, we are interested in
layers built over surfaces with handles or several cylindrically symmetric
ends. We also discuss more general regions obtained by compact deformations of
certain layers.Comment: 15 pages, 6 figure
Fast Decoders for Topological Quantum Codes
We present a family of algorithms, combining real-space renormalization
methods and belief propagation, to estimate the free energy of a topologically
ordered system in the presence of defects. Such an algorithm is needed to
preserve the quantum information stored in the ground space of a topologically
ordered system and to decode topological error-correcting codes. For a system
of linear size L, our algorithm runs in time log L compared to L^6 needed for
the minimum-weight perfect matching algorithm previously used in this context
and achieves a higher depolarizing error threshold.Comment: 4 pages, 4 figure
Optimizing the Power Take Off of a Wave Energy Converter with Regard to Wave Climate
International audienceConsidered as a source of renewable energy, wave is a resource featuring high variability at all time scales. Furthermore wave climate also changes significantly from place to place. Wave energy converters are very often tuned to suit the more frequent significant wave period at the project site. In this paper we show that optimizing the device necessitates accounting for all possible wave conditions weighted by their annual occurrence frequency, as generally given by the classical wave climate scatter diagrams. A generic and very simple wave energy converter is considered here. It is shown how the optimal parameters can be different considering whether all wave conditions are accounted for or not, whether the device is controlled or not, whether the productive motion is limited or not. We also show how they depend on the area where the device is to be deployed, by applying the same method to three sites with very different wave climate
Quantum waveguides with a lateral semitransparent barrier: spectral and scattering properties
We consider a quantum particle in a waveguide which consists of an infinite
straight Dirichlet strip divided by a thin semitransparent barrier on a line
parallel to the walls which is modeled by a potential. We show that if
the coupling strength of the latter is modified locally, i.e. it reaches the
same asymptotic value in both directions along the line, there is always a
bound state below the bottom of the essential spectrum provided the effective
coupling function is attractive in the mean. The eigenvalues and
eigenfunctions, as well as the scattering matrix for energies above the
threshold, are found numerically by the mode-matching technique. In particular,
we discuss the rate at which the ground-state energy emerges from the continuum
and properties of the nodal lines. Finally, we investigate a system with a
modified geometry: an infinite cylindrical surface threaded by a homogeneous
magnetic field parallel to the cylinder axis. The motion on the cylinder is
again constrained by a semitransparent barrier imposed on a ``seam'' parallel
to the axis.Comment: a LaTeX source file with 12 figures (11 of them eps); to appear in J.
Phys. A: Math. Gen. Figures 3, 5, 8, 9, 11 are given at 300 dpi; higher
resolution originals are available from the author
Inclusion Of The Spatial Dimension Of Population Data In Developing Policies For The Management Of AnGR âThe Case Of The Heritage Sheep Breeds
The sustainable use of farm animal genetic resources is connected with the recognition of their contribution to the society and the environment and the assessment of the threats they are facing. The category of the heritage breeds, which are genetically distinct, geographically concentrated, adapted to their environment, commercially farmed to contribute to the local economy were considered in the frame of the HERITAGESHEEP project. The aim of this project was to deliver the potential of the heritage sheep breeds for a sustainable future for medium to low input production systems, which support local rural communities throughout Europe. This was achieved by addressing the conservation of these breeds, defining the current and future threats and developing new uses and markets for products
Topological code Autotune
Many quantum systems are being investigated in the hope of building a
large-scale quantum computer. All of these systems suffer from decoherence,
resulting in errors during the execution of quantum gates. Quantum error
correction enables reliable quantum computation given unreliable hardware.
Unoptimized topological quantum error correction (TQEC), while still effective,
performs very suboptimally, especially at low error rates. Hand optimizing the
classical processing associated with a TQEC scheme for a specific system to
achieve better error tolerance can be extremely laborious. We describe a tool
Autotune capable of performing this optimization automatically, and give two
highly distinct examples of its use and extreme outperformance of unoptimized
TQEC. Autotune is designed to facilitate the precise study of real hardware
running TQEC with every quantum gate having a realistic, physics-based error
model.Comment: 13 pages, 17 figures, version accepted for publicatio
Insights into the structure and dynamics of lysyl oxidase propeptide, a flexible protein with numerous partners
Lysyl oxidase (LOX) catalyzes the oxidative deamination of lysine and hydroxylysine residues in collagens and elastin, which is the first step of the cross-linking of these extracellular matrix proteins. It is secreted as a proenzyme activated by bone morphogenetic protein-1, which releases the LOX catalytic domain and its bioactive N-terminal propeptide. We characterized the recombinant human propeptide by circular dichroism, dynamic light scattering, and small-angle X-ray scattering (SAXS), and showed that it is elongated, monomeric, disordered and flexible (Dmax: 11.7 nm, Rg: 3.7 nm). We generated 3D models of the propeptide by coarse-grained molecular dynamics simulations restrained by SAXS data, which were used for docking experiments. Furthermore, we have identified 17 new binding partners of the propeptide by label-free assays. They include four glycosaminoglycans (hyaluronan, chondroitin, dermatan and heparan sulfate), collagen I, cross-linking and proteolytic enzymes (lysyl oxidase-like 2, transglutaminase-2, matrix metalloproteinase-2), a proteoglycan (fibromodulin), one growth factor (Epidermal Growth Factor, EGF), and one membrane protein (tumor endothelial marker-8). This suggests new roles for the propeptide in EGF signaling pathway
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