Bounds on neutrino magnetic moment tensor from solar neutrinos

Solar neutrinos with non-zero magnetic moments will contribute to the electron scattering rates in the Super-Kamiokande experiment. The magnetic moment scattering events in Super-K can be accommodated in the standard VO or MSW solutions by a change of the parameter space of mass square difference and mixing angle-but the shifted neutrino parameters obtained from Super-K will (for some values of neutrino magnetic moments) become incompatible with the fits from SNO, Gallium and Chlorine experiments. We compute the upper bounds on the Dirac and Majorana magnetic moments of solar neutrinos by simultaneously fitting all the observed solar neutrino rates. The bounds the magnetic moment matrix elements are of the order of 10^{-10} Bohr magnetron.Comment: 9 pages latex file with 6 figures; References added, typos corrected, matches version to appear in Phys Rev

HIGH-TEMPERATURE RECEIVER DESIGNS FOR SUPERCRITICAL CO 2 CLOSED-LOOP BRAYTON CYCLES

ABSTRACT High-temperature receiver designs for solar powered supercritical CO 2 Brayton cycles that can produce ~1 MW of electricity are being investigated. Advantages of a supercritical CO 2 closed-loop Brayton cycle with recuperation include high efficiency (~50%) and a small footprint relative to equivalent systems employing steam Rankine power cycles. Heating for the supercritical CO 2 system occurs in a high-temperature solar receiver that can produce temperatures of at least 700 °C. Depending on whether the CO 2 is heated directly or indirectly, the receiver may need to withstand pressures up to 20 MPa (200 bar). This paper reviews several high-temperature receiver designs that have been investigated as part of the SERIIUS program. Designs for direct heating of CO 2 include volumetric receivers and tubular receivers, while designs for indirect heating include volumetric air receivers, molten-salt and liquid-metal tubular receivers, and falling particle receivers. Indirect receiver designs also allow storage of thermal energy for dispatchable electricity generation. Advantages and disadvantages of alternative designs are presented. Current results show that the most viable options include tubular receiver designs for direct and indirect heating of CO 2 and falling particle receiver designs for indirect heating and storage

Shared-Proton Mode Lights up the Infrared Spectrum of Fluxional Cations H₅⁺ and D₅⁺

We report experimental and calculated infrared spectra of the highly fluxional cations H₅⁺ and D₅⁺. These cations have been postulated to exist in the interstellar medium and to play a central role in the deuterium fractionation. The experiments produce these ions in a pulsed discharge supersonic nozzle ion source and utilize mass-selected photodissociation spectroscopy in the 2000−4500 cm⁻¹ region. Vibrational bands apparently broadened by rapid predissociation are detected throughout this region for both isotopologues. The calculated spectra make use of an ab initio potential energy surface and a new dipole moment surface and are based on results from fixed-node quantum diffusion Monte Carlo and variational vibrational calculations. The successful assignment of the experimental spectra requires a proper treatment of the delocalized anharmonic shared-proton mode and indicates a major breakdown of the harmonic approximation. Several calculated intense spectral features associated with this mode in the far-infrared region could guide future observational searches of these cations

Micro- and Nanotechnology Applied on Eco-friendly Smart Textiles

Smart textiles are materials designed to sense or respond to certain environmental stimuli, thus gaining special functions. Nanotechnology plays a fundamental role in the functionalization of fabrics. Metallic and metal oxide nanoparticles or nanocomposites are used to give antibacterial and deodorizing properties, UV protection, conductivity, and hydrophobicity to such textiles. On the other hand, micro- and nano-vehiculization allow smart textiles to release drugs, cosmetic ingredients, or fragrances in a controlled way. Micro- and nanotechnology are not indifferent to the current environmental pollution problems. In the last years, biosynthesis of nanoparticles through the use of microorganisms and plant extracts has gained ground to other techniques that use toxic and hazardous reagents. Likewise, the use of biopolymers as the base of the encapsulation systems is of vital importance in the development of eco-sustainable smart textiles. The aim of this chapter is to review the current developments related with the obtaining, characterization, and performance of micro- and nanofinishes to obtain eco-friendly smart textile.Fil: Romagnoli, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Gonzalez, Jimena Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Martínez, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin