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The aim of this work is to present experimental data concerning the role of the oxygen partial pressure during the production process on the properties (structure, morphology, composition, and transport properties) exhibited by doped microcrystalline silicon oxycarbide films. The films were produced by a two consecutive decomposition and deposition chamber system, where a spatial separation between the plasma and the growth regions is achieved. The films produced by this technique are highly conductive and highly transparent with suitable properties for optoelectronic applications requiring wide band-gap and low-conductivity materials. © 1995, American Vacuum Society. All rights reserved.

The aim of this work is to provide the basis for the interpretation, under steady state, of the lateral photoeffect in p-i-n a-Si:H 1D Thin Film Position Sensitive Detectors (1D TFPSD) through an analytical model. The experimental data recorded in 1D TFPSD devices with different performances are compared with the predicted curves and the obtained correlation's discussed.

The introduction into a traditional p.i.n. structure of two defective buffer layers near the p/i and i/n interfaces can improve the device stability and efficiency through an enhancement of the electric field profile at the interfaces and a reduction of the available recombination bulk centers. The defectous layer (`i-layer'), grown at a higher power density, present a high density of the defects and acts as `gettering centers' able to tailor light induced defects under degradation conditions. If the i-layer density of states remains below 1016 eV-1 cm-3 and assuming a Gaussian distribution of defect states, the gettering center distribution will not affect significantly the carrier population but only its spatial distribution. We report here about a device numerical simulation that allows us to analyze the influence of the `i- layer' position, thickness and density of states on the a-Si:H solar cells performances. Results of some systematic simulation rom the ASCA program (Amorphous Solar Cell Analysis), and for different configurations will be presented.

The aim of this work is to provide the basis for the interpretation of the lateral photoeffect in p-i-n a-Si:H one-dimensional thin-film position-sensitive detectors (1D TFPSDs) under steady state, through an analytical model. The experimental data recorded in 1D TFPSD devices with different characteristics are compared with the predicted curves and the obtained correlations are discussed. © 1996.

This work presents experimental data concerning the role of the oxygen partial pressure used during the preparation process, on the structure, composition and optoelectronic properties of wide band gap doped microcrystalline silicon oxycarbide films produced by a TCDDC system [1].

Tin doped indium oxide (ITO) films were deposited on glass substrates by rf reactive magnetron sputtering using a metallic alloy target (In-Sn, 90-10). The post-deposition annealing has been done for ITO films in air and the effect of annealing temperature on the electrical, optical and structural properties of ITO films was studied. It has been found that the increase of the annealing temperature will improve the film electrical properties. The resistivity of as-deposited film is about 1.3×10-1 Ω* cm and decreases down to 6.9×10-3 Ω* cm as the annealing temperature is increased up to 500°C. In addition, the annealing will also increase the film surface roughness which can improve the efficiency of amorphous silicon solar cells by increasing the amount of light trapping.

Tin doped indium oxide (ITO) films were deposited on glass substrates by rf reactive magnetron sputtering using a metallic alloy target (In-Sn, 90-10). The post-deposition annealing has been done for ITO films in air and the effect of annealing temperature on the electrical, optical and structural properties of ITO films was studied. It has been found that the increase of the annealing temperature will improve the film electrical properties. The resistivity of as deposited film is about 1.3 × 10-1 gW*cm and decreases down to 6.9 × 10-3 Ω*cm as the annealing temperature is increased up to 500 °C. In addition, the annealing will also increase the film surface roughness which can improve the efficiency of amorphous silicon solar cells by increasing the amount of light trapping. © 1995.

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A new multitechnique surface analysis system is presented. It has been designed for research on ion-solid interactions and for survey analysis. SIMS, XPS and AES are the main techniques used. Primary sources are an argon source for standard SIMS and a cesium source for negative and cathionized SIMS, a twin anode (Mg and Al) X-ray source for XPS, and a small spot electron gun for AES and low resolution electron microscopy. The mass spectrometer is a modified quadrupole based probe with an energy analyzer, Dynamic and static SIMS are possible as well as depth profiling. Photoelectrons and Auger electrons are analyzed by a true hemispherical energy analyzer that can also be used for ion spectroscopy. A secondary electron detector is also available. Exchanging the samples is possible through a fast entry air lock. In this small chamber a sputter gun is used to clean the sample. The sample under analysis is supported by a XYZ manipulator and can be temperature controlled in the range 130-850 K

The present communication analyses the relationships between work organisation and quality systems. The analysis is based on results from a study funded by the "Specific Programme for the Development of Portuguese Industry" (PEDIP). The main issues which have been currently associated with work organisation and quality control in the Portuguese industry are characterized. Critical features related to the implementation of quality systems and new methods of work organisation for industrial development are also discussed. A few recommendations are given in order to promote appropriate methods of work organisation for quality improvement within Portuguese industry.

In this paper one presents and discuss the hybridation concept using some aspect that integrate it, as the physical architecture of automated systems (hardware), the information system that integrates that architecture and the working places design. Analyzed are also the inter-dependences of those aspects, and we have as a reference the flexible production and assembly system existent at UNINOVA-CRI. The focus is made on possible problems that can occur with the use of possible development of those systems, namely: a) full automation with centralized human control, b) non-automated process of shop-floor work with a system “one man, one machine”, c) hybrid system of automated cells with “elastic” human jobs.

Flavodoxin was isolated and purified from Desulfovibrio desulfuricans ATCC 27774, a sulfatereducing organism that can also utilize nitrate as an alternative electron acceptor. Mid-point oxidation-reduction potentials of this flavodoxin were determined by ultraviolet/visible and EPR methods coupled to potentiometric measurements and their pH dependence studied in detail. The redox potential E(2), for the couple oxidized/semiquinone forms at pH 6.7 and 25 degrees C is -40 mV, while the value for the semiquinone/hydroquinone forms (E(1)), at the same pH, -387 mV. E(2) varies linearly with pH, while E(1) is independent of pH at high values. However, at low pH (<7.0), this value is less negative, compatible with a redox-linked protonation of the flavodoxin hydroquinone. A comparative study is presented for Desulfovibrio salexigens NCIB 8403 flavodoxin {[}Moura, I., Moura, J. J. G., Bruschi, M. and LeGall, J. (1980) Biochim. Biophys. Acta 591, 1-8]. The complete primary amino acid sequence was obtained by automated Edman degradation from peptides obtained by chemical and enzymic procedures. The amino acid sequence was confirmed by FAB/MS. Using the previously determined tridimensional structure of Desulfovibrio vulgaris flavodoxin as a model {[}similarity, 48,6%; Watenpaugh, K. D., Sieker, L. C., Jensen, L. H., LeGall, J. and Dubourdieu M. (1972) Proc. Natl Acad. Sci. USA 69, 3185-3188], the tridimensional structure of D. desulfuricans ATCC 27774 flavodoxin was predicted using AMBER force-field calculations.

This paper is based on a study about the Setúbal region, included in the internacional project “The Future of Industry in Europe” for the programme FAST-MONITOR of the European Community (1992-94). There were some information on the project VW/Ford for this region and those that are connected with research networks on industrial sectors (specially, on the automobile industry), and the network on the spatial and regional factors of regional development. Those studies allowed the scenario development on evolution trends of European industry and, specifically, on the automobile sector, and on the Setúbal region that was studied by the Portuguese team.

In this paper it is analysed the relationships between work organisation and quality systems in firms that uses some forms of advanced automation. Are characterised the existing quality control structures in the Portuguese industry, and the main factors that hidden or fosters the development of sociotechnical methods of quality control organisation strategies. Are analysed some industrial cases that explains more clearly the critical issues of the implementation of quality systems and work organisation systems. A few recommendations are given about the possibilities for the development of new forms of work organisation and the quality systems associated to automated manufacturing systems.

This paper analyses the problems and trends of the introduction of anthropocentric production systems (APS) in small less industrialized member states of the European Union, specifically the case of Portugal, based on the report for the FAST-Anthropocentric Technology Assessment Project (Monitor Programme) on “Prospects and conditions for APS in Europe by the 21st century”. Research teams from all countries of the European Community, as well as researchers from USA, Japan and Australia were participating in this project. The aim of this paper is to characterize APS and to present some special considerations related to the socioeconomic factors affecting the prospects and conditions for APS in Portugal. APS is defined as a system based on the utilization of skilled human resources and flexible technology adapted to the needs of flexible and participative organization. Among socioeconomic factors, some critical aspects for the development of APS will be focused, namely technological infrastructure, management strategies, perceived impact of introduction of automated systems on the division of labor and organizational structure, educational and vocational training and social actors strategies towards industrial automation. This analysis is based on a sample of industrial firms, built up for qualitative analysis, and on case studies analysis that can be reference examples for further development of APS, and not just for economic policy purposes alone. We have also analyzed the type of existing industrial relations, the union and employer strategies and some aspects of public policies towards the introduction of new technologies in the order to understand the extent to which there exist obstacles to and favorable conditions for the diffusion of anthropocentric systems. Finally some recommendations are presented to stress the trends for the implementation and development of anthropocentric production systems in Portugal.

A forest cover of a graph is a spanning forest for which each component has at least two nodes. If K is a subset of nodes, a K-forest cover is a forest cover including exactly one node from K in each component. We show that the weighted two matroid intersection algorithm determines the maximum cost K-forest cover.

A study on negative ion formation in the scattering of a proton beam from two monolayers of Ba on Ag( 111) surface is pre- sented. The dependence of the negative ion yield on the polar scattering angle and azimuthal orientation of the crystal has been determined for beam energies from 500 to 1000 eV. In addition the yield of fast neutrals has been determined. Based upon a shadowing and blocking analysis of the angular distributions of the H- ions, it can be concluded that the Ba overlayer shows the same crystalline structure as the Ag( 111) substrate. The recorded negative ion fractions can be explained by a simple model describing resonant charge transfer calculated by the non-perturbative CAM method and taking into account the parallel velocity effect.