Partners search and selection is an important activity in the life cycle of a Virtual Enterprise. Among other factors, the commitment of the potential partners to fulfil quality requirements is a major decision criterion during the selection phase. An approach to search suppliers in suppliers’ directories available on Internet is presented and the major negotiation steps leading to an adequate selection of partners are introduced. The quality-related information management functionalities required in a virtual enterprise support platform are also discussed.

This work refers to the main electro-optical characteristics exhibited by large area indium tin oxide films (300 × 400 mm) produced by r.f. magnetron sputtering under different oxygen concentrations and deposition pressures. Besides that, the ageing effect on the electro-optical characteristics of the films produced was also analyzed. The results achieved show that the film transparency and conductivity were highly improved (more than four orders of magnitude) by first annealing them in air at 470°C, followed by a reannealed stage under vacuum, in a hydrogen atmosphere, at 350°C. The ageing tests show that film degradation occurs when the films are produced at oxygen concentrations above 10% and/or at deposition pressures above 1.2 × 10-2 mbar. © 1999 Elsevier Science S.A. All rights reserved.

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This work reports on the performances of undoped and doped amorphous/nanocrystalline silicon films grown by hot wire plasma assisted technique. The structure (including the presence of several nanoparticles with sizes ranging from 5 nm to 50 nm), composition (oxygen and hydrogen content) and transport properties of the films are highly dependent on the temperature of the filament and on the hydrogen dilution. The undoped films grown under low r.f. power (≈4mWcm-2) and filament temperatures around 1850 K present dark conductivities below 10-10 Scm-1, optical gaps of about 1.6 eV and photosensitivities above 105, (under AM 1.5 light intensities), with almost no traces of oxygen content. For the n- and the p-doped silicon films also fabricated under the same conditions the conductivities obtained are of about 10-2Scm-1 and 10-5Scm-1, respectively. © 1998 Elsevier Science Ltd. All rights reserved.

This work reports on the performances of undoped and n doped amorphous/nano-crystalline silicon films grown by hot wire plasma assisted technique. The film's structure (including the presence of several nanoparticles with sizes ranging from 5 nm to 50 nm), the composition (oxygen and hydrogen content) and the transport properties are highly dependent on the filament temperature and on the hydrogen dilution. The undoped films grown under low r.f. power (≈4 mWcm-2) and with filament temperatures around 1850 °K have dark conductivities below 10-10 Scm-1, optical gaps of about 1.5 eV and photo-sensitivities above 105, (under AM1.5), with almost no traces of oxygen content. N-doped silicon films were also fabricated under the same conditions which attained conductivities of about 10-2 Scm-1.

The effect of doping and annealing atmosphere on the performances of zinc oxide thin films prepared by spray pyrolysis have been studied. The results show that the way doping influences the electrical and structural properties depends also on the characteristics of the doping element. Annealing the as-deposited films in an inert atmosphere leads to a substantial reduction in the resistivity of the films deposited and to an increase on the degree of film's crystallinity. © 1999 Elsevier Science S.A. All rights reserved.

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An air-stable formate dehydrogenase (FDH), an enzyme that catalyzes the oxidation of formate to carbon dioxide, was purified from the sulfate reducing organism Desulfovibrio gigas (D. gigas) NCIB 9332. D. gigas FDH is a heterodimeric protein [alpha (92 kDa) and beta (29 kDa) subunits] and contains 7 +/- 1 Fe/protein and 0.9 +/- 0.1 W/protein, Selenium was not detected. The UV/visible absorption spectrum of D, gigas FDH is typical of an iron-sulfur protein. Analysis of pterin nucleotides yielded a content of 1.3 +/- 0.1 guanine monophosphate/mol of enzyme, which suggests a tungsten coordination with two molybdopterin guanine dinucleotide cofactors. Both Mossbauer spectroscopy performed on D. gigas FDH grown in a medium enriched with Fe-57 and EPR studies performed in the native and fully reduced state of the protein confirmed the presence of two [4Fe-4S] clusters. Variable-temperature EPR studies showed the presence of two signals compatible with an atom in a d(1) configuration albeit with an unusual relaxation behavior as compared to the one generally observed for W(V) ions.

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In this paper we discuss several issues concerning the design and implementation of a debugger for parallel and distributed applications. This debugger uses a client-server approach to isolate the debugging user-interface from the debugging services, by way of a two-level structured approach: the component-level to observe and act upon individual processes; and the coordination-level to observe the interprocess relations and act upon them.

In this paper we discuss several issues concerning the design and implementation of a debugger for parallel and distributed applications. This debugger uses a client-server approach to isolate the debugging user-interface from the debugging services, by way of a two-level structured approach: the component-level to observe and act upon individual processes; and the coordination-level to observe the interprocess relations and act upon them.

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Hydrogenated amorphous silicon photochemical sensors based on Pd metal/insulator/semiconductor (Pd-MIS) structures were produced by plasma enhanced chemical vapour deposition (PECVD) with two different oxidized surfaces (thermal and chemical oxidation). The behaviour of dark and illuminated current-voltage characteristics in air and in the presence of a hydrogen atmosphere is explained by the changes induced by the gases adsorbed, in the work function of the metal, modifying the electrical properties of the interface. The photochemical sensors produced present more than two orders of magnitude variation on the reverse dark current in the presence of 400 ppm hydrogen. When the sensors are submitted to light it corresponds a decrease of 45% on the open circuit voltage.

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