The evolution of wine after bottling may be affected by the continuous supply of oxygen through the closures. I n the case of cork, oxygen may come from two different sources: permeation from outside through the cork and the release of gas from inside cork cells. I n this work we studied this later issue. The typical compression rate (volume change / uncompressed volume) of a cork stopper is about 40%. Taking in account that cork has a void volume ranging 70 to 80°/o cork cells pressure after bottling may reach 2 atm. This pressurized gas will 'escape' to both sides of the closure along many weeks. I n this work we measured the gas flow coming from cork stoppers in 3 typical starting headspace pressures: 60 mbar, 1000 mbar and 3000 mbar (absolute pressures). These conditions correspond roughly to vacuum bottling, balanced pressures bottling and bottling without any prior pumping. These experiments were performed by continuous monitoring the pressure, with a high accuracy gauge, in the headspace along several weeks keeping the bottleneck volume at constant temperature. In the case of vacuum bottling the headspace pressure continuously rises for many weeks. With balanced pressures, the pressure rises for a few days and then starts decreasing. I n the case of bottling without pumping the headspace pressure is typically higher than the cork cells pressure leading to a continuous pressure loss. These results together with those from permeation of cork provide a useful picture to those who need to know quantitavely the amount of oxygen in contact with wine in the post bottling period. (Bulletin de I'OIV, 2011, vol. 84, n0965-966-967, p. 261-269)

Superoxide reductases are enzymes involved in bacterial resistance to reactive oxygen species, catalyzing the reduction of superoxide anions to hydrogen peroxide. So far three structural classes have been identified. Class I enzymes have two iron-center containing domains. Most studies have been focused on the catalytic iron site (center II), but the role of center I is yet poorly understood. The possible roles of this iron site were approached by an integrated study using both classical and fast kinetics measurements as well as direct electrochemistry. A new heterometallic form of the protein with a zinc-substituted center I, maintaining the iron active site center II was obtained, resulting in a stable derivative useful for comparison with the native all-iron from. Second order rate constants for the electron transfer between reduced rubredoxin and the different SOR forms were determined to be 2.8x107 (M-1s-1) and 1.3x106 (M-1s-1) for SORFe(IIII)-Fe(II) and for SORFe(IIII)-Fe(III) forms respectively, and 3.2x106 (M-1s-1) for the SORZn(II)-Fe(III) form. The results obtained seem to indicate that center I transfers electrons from the putative physiologic donor, rubredoxin, to the catalytic active iron site (intramolecular process). In addition, electrochemical results show that conformational changes are associated to the redox state of center I, which may enable a faster catalytic response towards superoxide anion. The apparent rate constants calculated for the SOR-mediated electron transfer also support this observation.

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Today there is a strong interest in the scientific and industrial community concerning the use of biopolymers for electronic applications, mainly driven by low-cost and disposable applications. Adding to this interest, we must recognize the importance of the wireless auto sustained and low energy consumption electronics dream. This dream can be fulfilled by cellulose paper, the lightest and the cheapest known substrate material, as well as the Earth's major biopolymer and of tremendous global economic importance. The recent developments of oxide thin film transistors and in particular the production of paper transistors at room temperature had contributed, as a first step, for the development of disposable, low cost and flexible electronic devices. To fulfil the wireless demand, it is necessary to prove the concept of self powered devices. In the case of paper electronics, this implies demonstrating the idea of self regenerated thin film paper batteries and its integration with other electronic components. Here we demonstrate this possibility by actuating the gate of paper transistors by paper batteries. We found that when a sheet of cellulose paper is covered in both faces with thin layers of opposite electrochemical potential materials, a voltage appears between both electrodes - paper battery, which is also self-regenerated. The value of the potential depends upon the materials used for anode and cathode. An open circuit voltage of 0.5V and a short-circuit current density of 1μA/cm2 were obtained in the simplest structure produced (Cu/paper/Al). For actuating the gate of the paper transistor, seven paper batteries were integrated in the same substrate in series, supplying a voltage of 3.4V. This allows proper ON/OFF control of the paper transistor. Apart from that transparent conductive oxides can be also used as cathode/anode materials allowing so the production of thin film batteries with transparent electrodes compatible with flexible, invisible, self powered and wireless electronics. © 2011 SPIE.

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A complementary metal oxide semiconductor (CMOS) device is described. The device is based on n-(In-Ga-Zn-O) and p-type (SnO x) active oxide semiconductors and uses a transparent conductive oxide (In-Zn-O) as gate electrode that sits on a flexible, recyclable paper substrate that is simultaneously the substrate and the dielectric. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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The final thermally stimulated discharge current method allows a better selection of the experimental conditions for sample polarization. By decreasing the ratio between the charging time and the discharging time, the apparent peak is of the same order of magnitude as the genuine peaks and there is only a partial overlap between then. Two peaks have been identified for polyamide 11, one associated with the glass transition around 60 degrees C and the second associated with the Curie transition around 96 degrees C.

The final thermally stimulated discharge current method allows a better selection of the experimental conditions for sample polarization. By decreasing the ratio between the charging time and the discharging time, the apparent peak is of the same order of magnitude as the genuine peaks and there is only a partial overlap between then. Two peaks have been identified for polyamide 11, one associated with the glass transition around 60 degrees C and the second associated with the Curie transition around 96 degrees C.

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Today there is a strong interest in the scientific and industrial community concerning the use of biopolymers for electronic applications, driven mainly by low-cost and disposable applications. Adding to this interest, we must recognise the importance of the dream of wireless auto-sustained and low-energy-consumption electronics. This dream can be fulfilled by cellulose paper, the lightest and the cheapest known substrate material, as well as the Earth's major biopolymer and of tremendous global economic importance. Most of the paper used up to now is optimised in terms of the required mechanical and physical properties to be used as the support of inks of different origins. In the future, specific electronic heterogeneous paper sheets should be fabricated aiming to get paper fibers with required bulk and surface functionalities, proper water/vapour barrier, size and diameter/thickness of the fibrils and full paper thickness. This will be the function of components/devices to be incorporated/integrated such as thin-film transistors, complementary metal oxide semiconductor devices, passive electronic components (resistances, inductors and capacitors), memory transistors, electrochromics and thin-film paper batteries. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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An equivalent model and electromechanical characteristics for the disk motor was obtained based on the Steinmetz parameters. This paper describes a series of tests conducted on an axial flux motor, equipped with an aluminum rotor disc and an YBCO high temperature superconducting rotor disc, at liquid nitrogen temperature (77 K). The rotating magnetic field was produced by a four-pole, three-phase stator winding, at 50 Hz. At asynchronous permanent regime, Steinmetz-type models are able to describe both motors' behavior. From the performed tests, the parameters of both motors' models were deduced. A variable load was used to obtain both motor's characteristics (conventional and superconducting). Experimental obtained characteristics of both motors are compared with the ones predicted from parameters' calculation. The HTS motor provides high efficiency then the conventional ones.