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This work describes the development of a system designed for renewable power generation integration. It continuously acquires wind, solar and temperature data, which is automatically correlated with energy parameters, obtained from renewable energy systems. The developed system was installed in an urban building equipped with photovoltaic cells and wind renewable generation. To validate the developed application, it was analyzed data of a wind generator and a set of photovoltaic panels, installed near to the weather station. The developed application allows, in addition to the acquisition of weather and energy data, their continuous monitoring and correlation through a graphical user interface, providing a friendly interactivity with the user.

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.

The permeability of gases through uncompressed cork was investigated. More than 100 samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area of small disks 10 mm in diameter and 2 mm thick. The permeability for nitrogen, oxygen, and other gases was measured by the pressure rise technique. Boiled and nonboiled cork samples from different sections were evaluated. An asymmetric frequency distribution ranging 3 orders of magnitude (roughly from 1 to 1000 $μ$mol/(cm·atm·day)) for selected samples without macroscopic defects was found, having a peak below 100 $μ$mol/(cm·atm·day). Correlation was found between density and permeability: higher density samples tend to show lower permeability. However, boiled cork showed a mean lower permeability despite having a lower density. The transport mechanism of gases through cork was also examined. Calculations suggest that gases permeate uncompressed cork mainly through small channels between cells under a molecular flow regime. The diameter of such channels was estimated to be in the range of 100 nm, in agreement with the plasmodesmata size in the cork cell walls.

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Metal-oxide polymer diodes exhibit non-volatile resistive switching. The current-voltage characteristics have been studied as a function of temperature. The low-conductance state follows a thermally activated behaviour. The high-conductance state shows a multistep-like behaviour and below 300K an enormous positive temperature coefficient. This anomalous behaviour contradicts the widely held view that switching is due to filaments that are formed reversibly by the diffusion of metal atoms. Instead, these findings together with small-signal impedance measurements indicate that creation and annihilation of filaments is controlled by filling of shallow traps localized in the oxide or at the oxide/polymer interface. © 2011 IOP Publishing Ltd.

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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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Summary: In this paper we consider the monoid $\mathcal {OR}_{n}$ of all full transformations on a chain with $n$ elements that preserve or reverse the orientation, as well as its submonoids $\mathcal {OD}_{n}$ of all order-preserving or order-reversing elements, $\mathcal {OP}_{n}$ of all orientation-preserving elements and $\mathcal {O}_{n}$ of all order-preserving elements. By making use of some well known presentations, we show that each of these four monoids is a quotient of a bilateral semidirect product of two of its remarkable submonoids.