47,825 research outputs found
Room temperature self-assembly of mixed nanoparticles into complex material systems and devices
The ability to manufacture nanomaterials with complex and structured
composition using otherwise incompatible materials increasingly underpins the
next generation of technologies. This is translating into growing efforts
integrating a wider range of materials onto key technology platforms1 - in
photonics, one such platform is silica, a passive, low loss and robust medium
crucial for efficient optical transport2. Active functionalisation, either
through added gain or nonlinearity, is mostly possible through the integration
of active materials3, 4. The high temperatures used in manufacturing of silica
waveguides, unfortunately, make it impossible to presently integrate many
organic and inorganic species critical to achieving this extended
functionality. Here, we demonstrate the fabrication of novel waveguides and
devices made up of complex silica based materials using the self-assembly of
nanoparticles. In particular, the room temperature fabrication of silica
microwires integrated with organic dyes (Rhodamine B) and single photon
emitting nanodiamonds is presented.Comment: Key words: nanotechnology, nanoparticles, self-assembly, quantum
science, singel photon emitters, telecommunications, sensing, new materials,
integration of incompatible materials, silica, glass, breakthrough scienc
Space related biological and information studies Annual report, Mar. 1968 - Mar. 1969
Space related biotelemetry research - multichannel implantable telemeter, subcarrier oscillator, and ion concentration transducer
Space and related biological and instrumentation studies
Research and experimental effort was carried out on high-density photo-optical recorder design, implantable pH electrodes and the mangetic/doppler blood-flow sensor
Assembly and force measurement with SPM-like probes in holographic optical tweezers
We report a high fidelity tomographic reconstruction of the quantum state of photon pairs generated by parametric down-conversion with orbital angular momentum (OAM) entanglement. Our tomography method allows us to estimate an upper and lower bound for the entanglement between the down-converted photons. We investigate the two-dimensional state subspace defined by the OAM states ±ℓ and superpositions thereof, with ℓ=1, 2, ..., 30. We find that the reconstructed density matrix, even for OAMs up to around ℓ=20, is close to that of a maximally entangled Bell state with a fidelity in the range between F=0.979 and F=0.814. This demonstrates that, although the single count-rate diminishes with increasing ℓ, entanglement persists in a large dimensional state space
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How Useful are High-Precision Delta ?17O Data in Defining the Asteroidal Sources of Meteorites?: Evidence from Main-Group Pallasites, Primitive and Differentiated Achondrites
High-precision oxygen isotope analysis is capable of revealing important information about the relationship between different meteorite groups. New data confirm that the main-group pallasites are from a distinct source to either the HEDs or mesosiderites
City and Countryside Revisited. Comparative rent movements in London and the South-East, 1580-1914
Economic historians have traditionally argued that urban growth in England was driven primarily by prior improvements in agricultural supply in the two centuries before the industrial revolution. Recent revisionist scholarship by writers such as Jan Luiten van Zanden and Robert Allen has suggested that 'the city drove the countryside, not the reverse'. This paper assembles new serial data on urban and agricultural rent movements in Kent, Essex and London, from 1580-1914, which enables us to provide a tentative estimate of the strength of the urban variable and the productivity of land across the rural-urban continuum. Our initial findings support the revisionist view, and throw new light on London's position within the wider metropolitan region. Comparative rent movements suggests a greater continuity between town and countryside than has often been assumed, with sharp increases in rental values occurring on the rural-urban fringes of London and the lower Medway valley
Optical Rogue Waves in Vortex Turbulence
We present a spatio-temporal mechanism for producing 2D optical rogue waves
in the presence of a turbulent state with creation, interaction and
annihilation of optical vortices. Spatially periodic structures with bound
phase lose stability to phase unbound turbulent states in complex Ginzburg-
Landau and Swift-Hohenberg models with external driving. When the pumping is
high and the external driving is low, synchronized oscillations are unstable
and lead to spatio-temporal turbulence with high excursions in amplitude.
Nonlinear amplification leads to rogue waves close to turbulent optical
vortices, where the amplitude tends to zero, and to probability distribution
functions with long tails typical of extreme optical events.Comment: 5 pages, 7 figure
Turbulence and turbulent mixing in natural fluids
Turbulence and turbulent mixing in natural fluids begins with big bang
turbulence powered by spinning combustible combinations of Planck particles and
Planck antiparticles. Particle prograde accretions on a spinning pair releases
42% of the particle rest mass energy to produce more fuel for turbulent
combustion. Negative viscous stresses and negative turbulence stresses work
against gravity, extracting mass-energy and space-time from the vacuum.
Turbulence mixes cooling temperatures until strong-force viscous stresses
freeze out turbulent mixing patterns as the first fossil turbulence. Cosmic
microwave background temperature anisotropies show big bang turbulence fossils
along with fossils of weak plasma turbulence triggered as plasma photon-viscous
forces permit gravitational fragmentation on supercluster to galaxy mass
scales. Turbulent morphologies and viscous-turbulent lengths appear as linear
gas-proto-galaxy-clusters in the Hubble ultra-deep-field at z~7. Proto-galaxies
fragment into Jeans-mass-clumps of primordial-gas-planets at decoupling: the
dark matter of galaxies. Shortly after the plasma to gas transition,
planet-mergers produce stars that explode on overfeeding to fertilize and
distribute the first life.Comment: 23 pages 12 figures, Turbulent Mixing and Beyond 2009 International
Center for Theoretical Physics conference, Trieste, Italy. Revision according
to Referee comments. Accepted for Physica Scripta Topical Issue to be
published in 201
International consensus (ICON) on treatment of Ménière's disease
Objective: To present the international consensus for recommendations for Ménière's disease (MD) treatment. Methods: Based on a literature review and report of 4 experts from 4 continents, the recommendations have been presented during the 21st IFOS congress in Paris, in June 2017 and are presented in this work. Results: The recommendation is to change the lifestyle, to use the vestibular rehabilitation in the intercritic period and to propose psychotherapy. As a conservative medical treatment of first line, the authors recommend to use diuretics and Betahistine or local pressure therapy. When medical treatment fails, the recommendation is to use a second line treatment, which consists in the intratympanic injection of steroids. Then as a third line treatment, depending on the hearing function, could be either the endolymphatic sac surgery (when hearing is worth being preserved) or the intratympanic injection of gentamicin (with higher risks of hearing loss). The very last option is the destructive surgical treatment labyrinthectomy, associated or not to cochlear implantation or vestibular nerve section (when hearing is worth being preserved), which is the most frequent option
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