Reachability analysis of reversal-bounded automata on series–parallel graphs

Acta Informatica - Extensions to finite-state automata on strings, such as multi-head automata or multi-counter automata, have been successfully used to encode many infinite-state non-regular...     

Kinetics and thermodynamics of water adsorption onto rice husks ash filled polypropene composites during soaking

The kinetics and thermodynamics of water adsorption onto rice husks ash filled polypropene composites during soaking were studied at different temperatures, quantities and nature of fillers. Raw rice husk, “white” and “black” rice husks ash and Aerosil were used as fillers of polypropene. The increase of fillers contents in the polymer matrix was found to result in non-linear increase of the amount of adsorbed water. The highest adsorption capacity showed the samples filled with raw rice husks, while the lowest—those filled with black rice husks ash. The adsorption kinetics was limited by intra-particle diffusion in plane sheet particles. The values of the diffusion coefficients D, diffusion constants D ^o, activation energy of the diffusion process Е _а, changes of free energy ΔG ^≠, enthalpy ΔH ^≠ and entropy ΔS ^≠ for the formation of the activated complex from the reagent were calculated. A compensation effect between D ^o and Е _а was observed. Based on the Van’t Hoff equation, the values of the changes of standard free energy ΔG ^o, enthalpy ΔH ^o and entropy ΔS ^o of water adsorption were calculated. The sorption process is exothermal in nature and accompanied with decrease of the entropy. The values of the sorption coefficient S and permeability coefficient P were calculated at 25 and 90 °C.     

Seasonal variations on energy yield of a‐Si,hybrid, and crystalline Si PV modules

This paper presents a study of long‐term outdoor performance of a‐Si and hybrid modules mounted in the same location over several years. The modules were also characterized indoors using standard measurement methods employing pulsed solar simulators at the European Solar Test Installation (ESTI). The present study is intended to contribute to future standards on energy rating by presenting a common procedure for correcting the outdoor performance measurements to standard test conditions and comparing the resulting module performance at real and laboratory conditions. A seasonal variation in output, higher in the summer and lower in the winter, suggests that the module performance improves due to annealing when the module temperature is higher. The total output energy per month for these two technologies and a reference c‐Si technology is also presented. Copyright © 2010 John Wiley & Sons, Ltd.     

Bandwidth as currency

Provisioning bandwidth in an actuarially consistent manner has many far-reaching implications reminiscent of the commercial rationalization of railways in the 1870s - in that period's path to profitability. Mapping packet flow to willingness to pay, as rail cargo content was matched to the cost of carry, will better utilize bandwidth, enhancing network value consistent with the information being exchanged. The author discusses the notion of a packet watermark which can enable bandwidth as currency. Payment facilities are generally treated as separate, independent data flows from the actual data being transacted. Packet watermarks map payment facilities to the fidelity, discreteness, or functionality of the data demanded, representing a consistent means of determining a willingness to pay. This mapping acts as a receipt for data commerce.     

Guest Editor's Introduction: Multimedia Signal Processing and Systems in Healthcare and Life Sciences

The guest editor discusses the articles contained in this special issue and explains how this special issue reflects trends, challenges, and opportunities in the field at large.     

The role of the Mercury-Si Schottky-barrier height in /spl Psi/-MOSFETs

Pseudo-MOSFETs (/spl Psi/-MOSFET) are routinely used for silicon-on-insulator (SOI) material characterization, allowing threshold voltage, electron and hole mobility, doping density, oxide charge, interface trap density, etc. to be determined. The HgFET, one version of the /spl Psi/-MOSFET, uses mercury source and drain contacts. It is a very effective SOI test structure, but its current-voltage behavior is critically dependent on the Hg-Si interface. We have investigated this interface through current-voltage measurements of HgFETs and Schottky diodes and through device modeling. We show that modest barrier height changes of 0.2 eV lead to current changes of up to three orders of magnitude. Etching the Si surface in a mild HF :H/sub 2/O solution can easily change barrier heights and we attribute this behavior to Si surface passivation of dangling bonds. As this surface passivation diminishes with time, the Si surface becomes a more active generation site and the barrier height of the Hg-Si interface changes, taking on the order of 50-100 h at room temperature in air.     

Bright fluorescent dsDNA probes: novel polycationic asymmetric monomethine cyanine dyes based on thiazolopyridine‐quinolinium chromophore

Seven tri‐ and tetracationic monomeric and homodimeric monomethine cyanine dyes based on thiazolo[4,5‐b]pyridinium and quinolinium end groups were synthesised and characterised. The dyes were tested as fluorescent DNA intercalating probes to apply in DNA gel electrophoresis. The DNA samples stained with all dyes from the series demonstrated bright fluorescent signals. DNA fragments were successfully visualised under orange and green filters as well as under standard UV transillumination. Two of the studied dyes revealed higher sensitivity to DNA when compared with the commercial dimeric cyanine dye TOTO‐1. Their sensitivity reached that of the commercial dimeric cyanine dye YOYO‐1, but the emission was shifted to longer wavelengths. These qualities make the dyes suitable to apply in a wide range of medical and scientific analytical methods.     

Corrosion processes and control in recirculating cooling water systems in refinery and petrochemical industry

The corrosion activity of tree RCWS in Bulgaria were investigated. The highest corrosion rate was observed in RCWS‐1, a system typically contaminated by oil products. In this specific case the metal coupons were covered by a uniform and dense bio‐corrosion fouling. The maximum corrosion rate registred during the first 200 h of testing was 0.5 mm/y. These results were confirmed by electrochemical potential measurements and monitoring. The Moessbauer spectra and thermomagnetic analysis of deposits from surfaces of real heat exchangers were obtained. There is an indication of FeS₂ (pyrite) and Fe₇S₈ (pyrolite) as corrosion products in the samples studied, which can be attributed to a SRB activity in the cooling water.