Concepts of flywheels for energy storage using autostable high-T(sub c) superconducting magnetic bearings

A flywheel for energy storage using autostable high-T(sub c) superconducting magnetic bearings has been built. The rotating disk has a total weight of 2.8 kg. The maximum speed is 9240 rpm. A process that allows accelerated, reliable and reproducible production of melt-textured superconducting material used for the bearings has been developed. In order to define optimum configurations for radial and axial bearings, interaction forces in three dimensions and vertical and horizontal stiffness have been measured between superconductors and permanent magnets in different geometries and various shapes. Static as well as dynamic measurements have been performed. Results are being reported and compared to theoretical models

Layer-by-layer technique to developing functional nanolaminate films with antifungal activity

The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.The authors acknowledge financial support from FP7 IP project BECOBIOCAP^. M. J. Fabra is recipients of a Juan de la Cierva contract from the Spanish Ministry of Economy and Competitivity. Maria L. Flores-López thanks Mexican Science and Technology Council (CONACyT, Mexico) for PhD fellowship support (CONACyT Grant Number 215499/310847). The author Miguel A. Cerqueira is a recipient of a fellowship (SFRH/BPD/72753/2010) supported by Fundação para a Ciência e Tecnologia, POPH-QREN and FSE (FCT, Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP- 01-0124-FEDER-027462) and the project BBioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,^ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER. The support of EU Cost Action FA0904 is gratefully acknowledged

Atomically resolved band bending effects in a p-n heterojunction of Cu2_2O and a cobalt macrocycle

We present a hetero junction based on macrocyclic hydrogen evolution catalysts (HEC) physisorbed on a single crystalline Cu$_2$O(111) surface. Angle-resolved X-ray photoelectron spectroscopy (ARXPS) provides the spatial resolution of the band bending within the first nanometer of the subsurface region. Oxygen vacancies on the Cu$_2$O(111) surface cause a downward band bending which is conserved upon adsorption of HEC layers of various thicknesses. This allows photoexcited electrons to be directed toward the surface where they can be made available for the reduction of protons by the HEC. Furthermore, Poisson’s equation relates more subtle changes in the measured ARXPS spectra to the local charge density profile within the first 7 Å away from the surface and with atomic resolution. All observations are consistent with a polarization of the molecular layer in response to the electrical field at the oxide surface, which should be a general phenomenon at such organic-oxide heterointerfaces

Gas phase ion-molecule chemistry: controlled reactions of methyl cations with O-bearing compounds and hydrocarbons

International audienc

Testosterone restores respiratory long term facilitation in old male rats by an aromatase-dependent mechanism

Steroidal sex hormones play an important role in the neural control of breathing. Previous studies in our laboratory have shown that gonadectomy in young male rats (3 months) eliminates a form of respiratory plasticity induced by intermittent hypoxia, known as long term facilitation (LTF). Testosterone replenishment restores LTF in gonadectomized male rats, and this is dependent on the conversion of testosterone to oestradiol by aromatase. By middle age (12 months), male rats no longer exhibit LTF of hypoglossal motor output; phrenic LTF is significantly reduced, and this persists into old age. We tested the hypothesis that LTF can be restored in old male rats by administration of testosterone. Intact Fischer 344 rats (>20 months) were implanted with Silastic tubing containing testosterone (T), T plus an aromatase inhibitor (T+ADT), or 5α-dihydrotestosterone (DHT), a form of testosterone not converted to oestradiol. One week post-surgery, LTF of hypoglossal and phrenic motor output was measured. By comparison with control rats, hypoglossal LTF was increased in testosterone-treated rats, with levels approaching that of normal young rats. LTF was not restored in T+ADT or DHT-treated rats. Aromatase levels in hypoglossal and phrenic nuclei did not change with age. As serum testosterone levels did not decline with age, local bioavailability of testosterone in old rats may be a limiting factor in the expression of this form of respiratory plasticity. Our findings suggest that testosterone supplementation could potentially be used to enhance upper airway control in the elderly