10,986 research outputs found

    Low loss dichroic plate

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    A low loss dichroic plate is disclosed for passing radiation within a particular frequency band and reflecting radiation outside of that frequency band. The dichroic plate is comprised of a configuration of dipole elements defined by slots formed in a conductive plate. The slots are dimensioned so as to pass radiation of a selected frequency and are shaped so as to minimize the relationship between that frequency and the tilt angle of the plate relative to the direction of radiation. The slots are arranged so as to minimize signal power loss due to cross polarization effects

    Low-loss, circularly-polarized dichroic plate

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    Dichroic plate has orthogonally-disposed, loaded dipole apertures with their orientations arranged so as to cancel cross-coupling effects which would otherwise result in power loss to circularly polarized signal

    Near-field spectroscopy of bimodal size distribution of InAs/AlGaAs quantum dots

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    We report on high-resolution photoluminescence (PL) spectroscopy of spatial structure of InAs/AlGaAs quantum dots (QDs) by using a near-field scanning optical microscope (NSOM). The double-peaked distribution of PL spectra is clearly observed, which is associated with the bimodal size distribution of single QDs. In particular, the size difference of single QDs, represented by the doublet spectral distribution, can be directly observed by the NSOM images of PL.Comment: 3pages, 3figue

    Interplay of disorder and geometrical frustration in doped Gadolinium Gallium Garnet

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    The geometrically-frustrated, triangular antiferromagnet GGG exhibits a rich mix of short-range order and isolated quantum states. We investigate the effects of up to 1% Neodymium substitution for Gallium on the ac magnetic response at temperatures below 1 K in both the linear and nonlinear regimes. Substitutional disorder actually drives the system towards a more perfectly frustrated state, apparently compensating for the effect of imperfect Gadolinium/Gallium stoichiometry, while at the same time more closely demarcating the boundaries of isolated, coherent clusters composed of hundreds of spins. Optical measurements of the local Nd environment substantiate the picture of an increased frustration index with doping.Comment: 5 pages, 5 figure

    Inflammation and olfactory loss are associated with at least 139 medical conditions

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    Olfactory loss accompanies at least 139 neurological, somatic, and congenital/hereditary conditions. This observation leads to the question of whether these associations are correlations or whether they are ever causal. Temporal precedence and prospective predictive power suggest that olfactory loss is causally implicated in many medical conditions. The causal relationship between olfaction with memory dysfunction deserves particular attention because this sensory system has the only direct projection to memory centers. Mechanisms that may underlie the connections between medical conditions and olfactory loss include inflammation as well as neuroanatomical and environmental factors, and all 139 of the medical conditions listed here are also associated with inflammation. Olfactory enrichment shows efficacy for both prevention and treatment, potentially mediated by decreasing inflammation

    Reduction of surface fat formation on spray-dried milk powders through emulsion stabilization with λ-carrageenan

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    The appearance of surface fat during the atomization process in spray drying of milk particles often impairs the functional powder properties. To investigate a possible approach that could minimise the surface fat formation, the interaction between a whole milk model emulsion and λ-carrageenan at various concentrations was studied, as well as how it influences the atomization behaviour and the resulting particle characteristics. Carrageenan can stabilize emulsions in the presence of milk protein by adsorption on the milk fat globule membranes. If too little or too much of the polysaccharide was added, bridging flocculation or depletion flocculation, respectively, occurred inside the emulsions. The best stability and minimal fat globule size were obtained for a carrageenan content of 0.3% w/w. Rheological investigation indicated that the extensional viscosity can be an important factor influencing the emulsion disintegration behaviour during atomization. The λ-carrageenan stabilized emulsions featured a significantly increased extensional viscosity and a better fat encapsulation in the corresponding spray-dried particles, promoting solubility and oxidative stability. Surface fat extraction showed that the most stable emulsion lead to particles with the least amount of surface fat. Though the surface of these particles was still covered by fat according to spectroscopic analysis, this surface fat layer was very thin in comparison to carrageenan-free powder as observed by confocal microscopy. Yet, the addition of carrageenan was also found to have one adverse effect on the intended powder properties, as the strengthened emulsion network translated into denser particles and thus a deterioration of the powder's reconstitution behaviour

    Microstructure, Mechanical Property and Biocompatibility of Porous Ti-Nb-Zr Alloys Fabricated by Rapid Sintering using Space Holder

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    Space holder method can easily control Young’s modulus due to control the pore size, distribution and shape. In this study, porous Ti-Nb-Zr biomaterial which is not included poison elements was successfully fabricated by powder metallurgy using space holder of NH4HCO3 and foaming agent of TiH2. The consolidation of powder was conducted by spark plasma sintering process (SPS) at 850 °C under 30MPa conditions. The effect of space holder contents on pore size and distribution of Ti-Nb-Zr alloys was observed by optical microscope (OM) and scanning electron microscope (SEM). As a result of microstructure observation, a lot of pore was uniformly distributed in the sintered Ti-Nb-Zr alloys. Cell cultivation experiments were conducted using cell cultivation experimental. The porous Ti-Nb-Zr alloys were fabricated successfully with 30% pore ratio and 50-60GPa of Young’s modulus. Biocompatibility of porous Ti-Nb-Zr alloys is similar to Ti-6Al-4V alloy
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