27,107 research outputs found
An efficient prebreathing apparatus for humans during decompression
Portable prebreathing system was developed which recirculates and reconditions respiratorily exhaled oxygen. Apparatus reduces fire hazards, simplifies prebreathing procedures, and does not require extensive enclosure venting system usage
A critical analysis of the hydrino model
Recently, spectroscopic and calorimetric observations of hydrogen plasmas and
chemical reactions with them have been interpreted as evidence for the
existence of electronic states of the hydrogen atom with a binding energy of
more than 13.6 eV. The theoretical basis for such states, that have been dubbed
hydrinos, is investigated. We discuss both, the novel deterministic model of
the hydrogen atom, in which the existence of hydrinos was predicted, and
standard quantum mechanics. Severe inconsistencies in the deterministic model
are pointed out and the incompatibility of hydrino states with quantum
mechanics is reviewed.Comment: 9 page
Modelling of Electroluminescence in Polymers Using a Bipolar Charge Transport Model
Electroluminescence (EL) in polymeric materials is thought to occur due to the energy dissipation process from the recombination of opposite polarity charge carriers. It is considered as an indication of storage and transport of charge carriers in cable insulation subject to electrical stresses and may indicate the change in charge movement due to aging or degradation processes. Under ac electric fields, the interaction of opposite polarity charge carriers at the interface of polymer/conductor is enhanced compared with dc conditions, and seems to contribute a lot to the electroluminescence rather than the charge behaviours in the bulk of polymers. The dynamics of charge carriers both at the interface of polymer/conductor and in the bulk of polymers is investigated through a simulation work using a bipolar charge transport model. Figure 1 compares experimental electroluminescence results with simulated data from the recombination of injected charge carriers. The paper will give more details on EL model and comparison under various waveforms and frequencies
Antechamber facilitates loading and unloading of vacuum furnace
Antechamber facilitates the use of a furnace in which materials are heat treated in a high vacuum or a gas atmosphere. It has a high vacuum pumping system, a means for backfilling with a selected gas, an access door, glove ports, and a motor driven platform
The TTF finite-energy spectral features in photoemission of TTF-TCNQ: The Hubbard-chain description
A dynamical theory which accounts for all microscopic one-electron processes
is used to study the spectral function of the 1D Hubbard model for the whole
-plane, beyond previous studies which focused on the weight
distribution in the vicinity of the singular branch lines only. While our
predictions agree with those of the latter studies concerning the
tetracyanoquinodimethane (TCNQ) related singular features in photoemission of
the organic compound tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ)
metallic phase, the generalized theory also leads to quantitative agreement
concerning the tetrathiafulvalene (TTF) related finite-energy spectral
features, which are found to correspond to a value of the on-site repulsion
larger than for TCNQ. Our study reveals the microscopic mechanisms behind the
unusual spectral features of TTF-TCNQ and provides a good overall description
of those features for the whole -plane.Comment: To appear in Journal of Physics: Condensed Matte
A Better Definition of the Kilogram
This article reviews several recent proposed redefinitions of the kilogram,
and compares them with respect to practical realizations, uncertainties
(estimated standard deviations), and educational aspects.Comment: 10 pages, no figure
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Notations and conventions in molecular spectroscopy: part 2. Symmetry notation
The field of Molecular Spectroscopy was surveyed in order to determine a set of
conventions and symbols which are in common use in the spectroscopic literature. This
document, which is Part 2 in a series, establishes the notations and conventions used for the
description of symmetry in rigid molecules, using the Schoenflies notation. It deals firstly
with the symmetry operators of the molecular point groups (also drawing attention to the
difference between symmetry operators and elements). The conventions and notations of the
molecular point groups are then established, followed by those of the representations of these
groups as used in molecular spectroscopy. Further parts will follow, dealing inter alia with
permutation and permutation-inversion symmetry notation, vibration-rotation spectroscopy
and electronic spectroscopy
Substrate influence on the plasmonic response of clusters of spherical nanoparticles
The plasmonic response of nanoparticles is exploited in many subfields of
science and engineering to enhance optical signals associated with probes of
nanoscale and subnanoscale entities. We develop a numerical algorithm based on
previous theoretical work that addresses the influence of a substrate on the
plasmonic response of collections of nanoparticles of spherical shape. Our
method is a real space approach within the quasi-static limit that can be
applied to a wide range of structures. We illustrate the role of the substrate
through numerical calculations that explore single nanospheres and nanosphere
dimers fabricated from either a Drude model metal or from silver on dielectric
substrates, and from dielectric spheres on silver substrates.Comment: 12 pages, 13 figure
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