18,192 research outputs found
IR-transmission glasses formed from oxides of bismuth and tellurium
Bismuth trioxide-tellurium dioxide glasses have improved infrared transmission characteristics
High dielectric thick films for screened circuit capacitors
Techniques and materials have recently been developed to obtain high dielectric films /K of 300 to 800/. High dielectric barium titanate particles are mixed in a barium titanate glass
An analysis of the variation in wear life of hot pressed molybdenum disulfide-silver electrical contact brushes in vacuum
Wear life analysis of hot pressed molybdenum disulfide-silver electrical contact brushes in vacuu
Geosynchrotron radio emission from CORSIKA-simulated air showers
Simulations of radio emission from extensive air showers we have published so
far were performed with a Monte Carlo code using analytical parametrisations to
describe the spatial, temporal, energy and angular particle distributions in
the air shower. A new version of our simulation code, which replaces these
parametrisations with precise, multi-dimensional histograms derived from
per-shower CORSIKA simulations, is now available. The new code allows an
independent selection between parametrisation and histogram for each of the
relevant distributions, enabling us to study the changes arising from using a
more realistic air shower model in detail. We describe the new simulation
strategy, present some initial results and discuss the new possibilities.Comment: 6 pages, Proceedings of the ARENA2006 workshop, Newcastle, England;
to be published in Journal of Physics: Conference Series (JPCS
Traction force microscopy on soft elastic substrates: a guide to recent computational advances
The measurement of cellular traction forces on soft elastic substrates has
become a standard tool for many labs working on mechanobiology. Here we review
the basic principles and different variants of this approach. In general, the
extraction of the substrate displacement field from image data and the
reconstruction procedure for the forces are closely linked to each other and
limited by the presence of experimental noise. We discuss different strategies
to reconstruct cellular forces as they follow from the foundations of
elasticity theory, including two- versus three-dimensional, inverse versus
direct and linear versus non-linear approaches. We also discuss how biophysical
models can improve force reconstruction and comment on practical issues like
substrate preparation, image processing and the availability of software for
traction force microscopy.Comment: Revtex, 29 pages, 3 PDF figures, 2 tables. BBA - Molecular Cell
Research, online since 27 May 2015, special issue on mechanobiolog
Calculation of the One- and Two-Loop Lamb Shift for Arbitrary Excited Hydrogenic States
General expressions for quantum electrodynamic corrections to the one-loop
self-energy [of order alpha(Zalpha)^6] and for the two-loop Lamb shift [of
order alpha^2(Z\alpha)^] are derived. The latter includes all diagrams with
closed fermion loops. The general results are valid for arbitrary excited non-S
hydrogenic states and for the normalized Lamb shift difference of S states,
defined as Delta_n = n^3 DeltaE(nS) - DeltaE(1S). We present numerical results
for one-loop and two-loop corrections for excited S, P and D states. In
particular, the normalized Lamb shift difference of S states is calculated with
an uncertainty of order 0.1 kHz.Comment: 4 pages, RevTe
Terpenoid-Induced Feeding Deterrence and Antennal Response of Honey Bees
Multiple interacting stressors negatively affect the survival and productivity of managed honey bee colonies. Pesticides remain a primary concern for beekeepers, as even sublethal exposures can reduce bee immunocompetence, impair navigation, and reduce social communication. Pollinator protection focuses on pesticide application guidelines; however, a more active protection strategy is needed. One possible approach is the use of feeding deterrents that can be delivered as an additive during pesticide application. The goal of this study was to validate a laboratory assay designed to rapidly screen compounds for behavioral changes related to feeding or feeding deterrence. The results of this investigation demonstrated that the synthetic Nasonov pheromone and its terpenoid constituents citral, nerol, and geraniol could alter feeding behavior in a laboratory assay. Additionally, electroantennogram assays revealed that these terpenoids elicited some response in the antennae; however, only a synthetic Nasonov pheromone, citral, and geraniol elicited responses that differed significantly from control and vehicle detections
Virtual Resonant States in Two-Photon Decay Processes: Lower-Order Terms, Subtractions, and Physical Interpretations
We investigate the two-photon decay rate of a highly excited atomic state
which can decay to bound states of lower energy via cascade processes. We show
that a naive treatment of the process, based on the introduction of
phenomenological decay rates for the intermediate, resonant states, leads to
lower-order terms which need to be subtracted in order to obtain the coherent
two-photon correction to the decay rate. The sum of the lower-order terms is
exactly equal to the one-photon decay rate of the initial state, provided the
naive two-photon decay rates are summed over all available two-photon channels.
A quantum electrodynamics (QED) treatment of the problem leads to an
"automatic" subtraction of the lower-order terms.Comment: 8 pages, RevTe
Electrical and infrared properties of glasses in the system b1203-te 02
Electrical and infrared properties of glass in bismuth oxide-tellurium oxide syste
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