10 research outputs found
Photon-graviton pair conversion
We consider the conversion of gravitons and photons as a four-wave mixing
process. A nonlinear coupled systems of equations involving two gravitons and
two photons is obtained, and the energy exchange between the different degrees
of freedom is found. The scattering amplitudes are obtained, from which a
crossection for incoherent processes can be found. An analytical example is
given, and applications to the early Universe are discussed.Comment: 5 pages, slightly modified as compared to v1, to appear in Class.
Quantum Grav. as a Letter to the Edito
Nonlinear coupled Alfv\'{e}n and gravitational waves
In this paper we consider nonlinear interaction between gravitational and
electromagnetic waves in a strongly magnetized plasma. More specifically, we
investigate the propagation of gravitational waves with the direction of
propagation perpendicular to a background magnetic field, and the coupling to
compressional Alfv\'{e}n waves. The gravitational waves are considered in the
high frequency limit and the plasma is modelled by a multifluid description. We
make a self-consistent, weakly nonlinear analysis of the Einstein-Maxwell
system and derive a wave equation for the coupled gravitational and
electromagnetic wave modes. A WKB-approximation is then applied and as a result
we obtain the nonlinear Schr\"{o}dinger equation for the slowly varying wave
amplitudes. The analysis is extended to 3D wave pulses, and we discuss the
applications to radiation generated from pulsar binary mergers. It turns out
that the electromagnetic radiation from a binary merger should experience a
focusing effect, that in principle could be detected.Comment: 20 pages, revtex4, accepted in PR
Multidimensional reflectometry for industry (xD-Reflect) an European research project
Electronic imaging science and technology, measuring,modeling and reproducing material appearance, Francisco, California (USA), 2-6 February 2014. http://spie.org/x105078.xmlThe European Metrology Research Program (EMRP) is a metrology-focused program of coordinated Research & Development (R&D) funded by the European Commission and participating countries within the European Association of National Metrology Institutes (EURAMET). It supports and ensures research collaboration between them by launching and managing different types of project calls. Within the EMRP Call 2012 >Metrology for Industry>, the joint research project (JRP) entitled >Multidimensional Reflectometry for Industry> (xD-Reflect) was submitted by a consortium of 8 National Metrology Institutes (NMIs) and 2 universities and was subsequently funded. The general objective of xD-Reflect is to meet the demands from industry to describe the overall macroscopic appearance of modern surfaces by developing and improving methods for optical measurements which correlate with the visual sensation being evoked. In particular, the project deals with the >Goniochromatism>, >Gloss> and >Fluorescence> properties of dedicated artifacts, which will be investigated in three main work packages (WP). Two additional transversal WP reinforce the structure: >Modelling and Data Analysis> with the objective to give an irreducible set of calibration schemes and handling methods and >Visual Perception>, which will produce perception scales for the different visual attributes. Multidimensional reflectometry involves the enhancement of spectral and spatial resolution of reference gonioreflectometers for BRDF measurements using modern detectors, conoscopic optical designs, CCD cameras, line scan cameras, and modern light sources in order to describe new effects like sparkle and graininess/coarseness.Peer Reviewe
"Multidimensional Reflectometry for Industry" (xD-Reflect) a European research project
The European Metrology Research Program (EMRP) is a metrology-focused program of coordinated Research &
Development (R&D) funded by the European Commission and participating countries within the European Association
of National Metrology Institutes (EURAMET). It supports and ensures research collaboration between them by
launching and managing different types of project calls. Within the EMRP Call 2012 "Metrology for Industry", the joint research project (JRP) entitled "Multidimensional Reflectometry for Industry" (xD-Reflect) was submitted by a
consortium of 8 National Metrology Institutes (NMIs) and 2 universities and was subsequently funded. The general objective of xD-Reflect is to meet the demands from industry to describe the overall macroscopic appearance of modern surfaces by developing and improving methods for optical measurements which correlate with the visual sensation being evoked. In particular, the project deals with the "Goniochromatism", "Gloss" and "Fluorescence" properties of dedicated artifacts, which will be investigated in three main work packages (WP). Two additional transversal WP reinforce the structure: "Modelling and Data Analysis" with the objective to give an irreducible set of calibration schemes and handling methods and "Visual Perception", which will produce perception scales for the different visual attributes.
Multidimensional reflectometry involves the enhancement of spectral and spatial resolution of reference gonioreflectometers for BRDF measurements using modern detectors, conoscopic optical designs, CCD cameras, line
scan cameras, and modern light sources in order to describe new effects like sparkle and graininess/coarseness. More
information and updated news concerning the project can be found on the xD-Reflect website http://www.xdreflect.eu/.status: publishe
Platelet-derived S100A8/A9 and cardiovascular disease in systemic lupus erythematosus.
S100A8/A9, a pro-inflammatory and pro-thrombotic protein complex, is increased in several diseases and high levels predispose to cardiovascular disease (CVD). Recently, platelet S100A8/A9 synthesis was described in mouse and humans in relation to CVD. However, the role of platelet S100A8/A9 in systemic lupus erythematosus (SLE), a disease with markedly increased cardiovascular morbidity, as well as the exact platelet distribution of the S100A8/A9 proteins has not been investigated
xD-Reflect - "Multidimensional Reflectometry for Industry" a research project of the European Metrology Research Program (EMRP)
The general objective of the xD-Reflect research project is to meet the demands from European industry to measure the overall macroscopic appearance of modern surfaces by developing and improving methods for optical measurements which correlate with the visual sensation being evoked. In particular, the project deals with different attributes of dedicated artefacts, like "Goniochromatism", "Gloss" and "Fluorescence" properties, which will be investigated in three main work packages. Two additional transversal work packages reinforce the structure: "Modelling and Data Analysis" with the objective to give an irreducible set of calibration schemes and handling methods and "Visual Perception", which will produce perception scales for the different visual attributes.status: publishe
Dense genotyping of immune-related loci identifies HLA variants associated with increased risk of collagenous colitis.
Collagenous colitis (CC) is a major cause of chronic non-bloody diarrhoea, particularly in the elderly female population. The aetiology of CC is unknown, and still poor is the understanding of its pathogenesis. This possibly involves dysregulated inflammation and immune-mediated reactions in genetically predisposed individuals, but the contribution of genetic factors to CC is underinvestigated. We systematically tested immune-related genes known to impact the risk of several autoimmune diseases for their potential CC-predisposing role