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.

Desulfoferrodoxin, a non-heme iron protein, was purified previously from extracts of Desulfovibrio desulfuricans (ATCC 27774) (Moura, I., Tavares, P., Moura, J. J. G., Ravi, N., Huynh, B. H., Liu, M.-Y., and LeGall, J. (1990) J. Biol. Chem. 265, 21596-21602). The as-isolated protein displays a pink color (pink form) and contains two mononuclear iron sites in different oxidation states: a ferric site (center I) with a distorted tetrahedral sulfur coordination similar to that found in desulforedoxin from Desulfovibrio gigas and a ferrous site (center II) octahedrally coordinated with predominantly nitrogen/oxygen-containing ligands. A new form of desulfoferrodoxin which displays a gray color (gray form) has now been purified. Optical, electron paramagnetic resonance (EPR), and Mössbauer data of the gray desulfoferrodoxin indicate that both iron centers are in the high-spin ferric states. In addition to the EPR signals originating from center I at g = 7.7, 5.7, 4.1, and 1.8, the gray form of desulfoferrodoxin exhibits a signal at g = 4.3 and a shoulder at g = 9.6, indicating a high-spin ferric state with E/D approximately 1/3 for the oxidized center II. Redox titrations of the gray form of the protein monitored by optical spectroscopy indicate midpoint potentials of +4 +/- 10 and +240 +/- 10 mV for centers I and II, respectively. Mössbauer spectra of the gray form of the protein are consistent with the EPR finding that both centers are high-spin ferric and can be analyzed in terms of the EPR-determined spin Hamiltonian parameters. The Mössbauer parameters for both the ferric and ferrous forms of center II are indicative of a mononuclear high spin iron site with octahedral coordination and predominantly nitrogen/oxygen-containing ligands. Resonance Raman studies confirm the structural similarity of center I and the distorted tetrahedral FeS4 center in desulforedoxin and provide evidence for one or two cysteinyl-S ligands for center II. On the basis of the resonance Raman results, the 635 nm absorption band that is responsible for the gray color of the oxidized protein is assigned to a cysteinyl-S–>Fe(III) charge transfer transition localized on center II. The novel properties and possible function of center II are discussed in relation to those of mononuclear iron centers in other enzymes.

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Portugal has a great diversity of ecoclimatic areas and Sesimbra was chosen to carry out a study on WSP efficiencies over five years (1989 to 1993). According to Pina Manique & Albuquerque (1954), the climate is classified as Atlantic Mediterranean (AM). Some environmental and climatic parameters have been studied in order to define the area. The treatment system at Sesimbra has three ponds: anaerobic, facultative and maturation. The physical and chemical parameters studied in the WSP system were: Temperature, pH, Dissolved Oxygen, Conductivity, BOD5, COD, nitrates, nitrites, ammonia and total nitrogen, total and volatile suspended solids, total phosphorus and orthophosphates. Algal populations and the following microbiological parameters were studied: total and fecal coliforms, fecal Streptococci, Clostridium perfringens, Pseudomonas aeruginosa and some Enterobacteriaceae. The K and K20 kinetic parameters were studied and derived for the three ponds utilizing the seasonal regional characteristics from the surrounding area. These values were then correlated with temperature and the subsequent removal efficiencies for each pond deduced. The data obtained indicate a necessity to determine the seasonal fluctuations of the K and K20 kinetic parameters for the WSP systems.

A evolução do hardware dos computadores para arquitecturas paralelas, incentivou a concepção de novos modelos de programação e o desenvolvimento dos sistemas de suporte à execução correspondentes, de forma a conseguir uma melhor exploração do paralelismo. A linguagem de programação Prolog, pelas suas características declarativas e operacionais, tem vindo a ser objecto de estudo nesta área, através de adaptações da linguagem e/ou da sua máquina de inferência. Este trabalho incide sobre os aspectos de concepção e implementação de um modelo de um sistema de suporte à execução de programas em Prolog, em arquitecturas de múltiplos processadores, com unidades de memória fisicamente distribuídas. O modelo propõe extensões a um executor de Prolog convencional, de forma a disponibilizar funcionalidades que permitam o controlo do paralelismo e da distribuição. Estas funcionalidades podem ser utilizadas para a implementação de modelos de linguagens lógicas concorrentes de mais alto nível, ou então serem utilizadas directamente para a programação de sistemas distribuídos, em que múltiplos executores Prolog cooperam na resolução de um golo, comunicando com base em mensagens. Para avaliar a funcionalidade do modelo proposto, concebeu-se e implementou-se um sistema de distribuição de golos Prolog, que permite recorrer a diversas estratégias para composição sequencial e paralela de golos, escondendo os aspectos de gestão explícita dos recursos efectivos. A dissertação inclui uma discussão dos aspectos mais relevantes da realização do protótipo do modelo proposto sobre uma arquitectura baseada em Transputers.

We have developed in the past a transient technique called Flying Spot Technique (FST)[1], based on the lateral photoeffect. It allows to determine the ambipolar diffusion length and the effective lifetime of the photogenerated carriers, once the light spot velocity and geometry of the structure are known. We propose to apply this technique backwards in order to detect the path and velocity of an object that is moving toward a light source direction. The light back reflected is analyzed by a p.i.n structure measuring the transient transverse photovoltage which is dependent on the object movement (position and velocity). Details concerning material characterization and device geometry will be presented.

In this work we report experimental results on light induced metastability of a-Si: H p.i.n. devices with different microscopic/macroscopic structures and we discuss them in terms of improved stability through spatial control of charged defects grown during light exposure. By placing a thin (few A) intrinsic layer (i) between both p/i and i/n a-Si: H interfaces we are able to reduce the effective degradation rate through spatial modification of the electric field profile in the device. The electronic transport and the stability changes that accompany the change in microstructure (R) and hydrogen content (CH) of the i- and i′-layer, were monitored throughout the entire light induced degradation process and compared with the corresponding μT product (for both carriers) inferred through steady state photoconductivity and Flying Spot Technique (FST) measurements. Results show that the degradation rate is a function of CH and R of both layers and can be correlated with the density of microvoids and di-hydride bonding. Since the i′-layers have a higher CH bonded mainly as SiF2 radicals (R≈0.4), they act as an hindrance to the growth of the defect, in the active region, generating "gettering centers" whose localisation and density are tailored in such a way that they will control spatially the electric field profile during light exposure. Preliminary results show improvements in film's stability when the interfacial layer is included. So future progress toward more stable and efficient a-Si: H solar cells will depend on a careful engineering design of the devices. © 1994 Materials Research Society.

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In this paper we present results of PIN single and dual axis Thin Film Position Sensitive Detectors (TFPSD) based on hydrogenated amorphous silicon (a-Si:H) technology, with a wide detection area (up to 80 × 80 mm). These sensors provide an alternative to Charge Coupled Devices (CCDs) when large inspection areas are needed, under a requirement to use simpler technology. In this paper we analyse the forward and reverse I-V characteristics in the dark and under illumination, as well as the device linearity of TFPSD. © 1994.

Using the Flying Spot Technique (FST) we have studied minority carrier transport parallel and perpendicular to the surface of amorphous silicon films (a-Si:H). To reduce slow transients due to charge redistribution in low resistivity regions during the measurement we have applied a strong homogeneously absorbed bias light. The defect density was estimated from CPM measurements. The steady-state photocarrier grating technique (SSPG) is a 1-dimensional approach. However, the modulation depth of the carrier profile is also dependent on film surface properties, like surface recombination velocity. Both methods yield comparable diffusion lengths when applied to a-Si:H.

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