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{Nitrite reductase from the sulfate-reducing bacterium Desulfovibrio desulfuricans ATCC 27774 is a multihaem (type c) membrane-bound enzyme that catalyzes the dissimilatory conversion of nitrite to ammonia. Crystals of the oxidized form of this enzyme were obtained using PEG and CaCl2 as precipitants in the presence of 3-(decylmethylammonium)propane-1-sulfonate and belong to the space group P2(1)2(1)2(1), With unit-cell parameters a = 78.94

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One can assist to significant changes in the organisation of manufacturing systems during the last years. Lean production, network enterprise or the virtual enterprises are reference concepts of the re-organisation of manufacturing systems. Some authors mention a new enterprise paradigm, of generalisation of intelligent manufacture, organised in networks and assisted by information and communication technologies. The first part of the paper develops a critical approach to the illusion connected to these concepts, calling the attention to the diversity of the type of relationships among firms. If virtual enterprises (VE) are networks of firms with intensive usage of ICT, one can verify a predominance of a technicist perspective. This one considers that the development of VEs is a technological problem, of development and management of information systems, and of entrepreneurial share of different databases. Sociology can be useful, even fundamental in an anthropocentric approach. The last part of the paper is on the Portuguese situation in the automobile sector, approaching the types of entrepreneurial organisation.

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In order to understand the kinetics of formation of interface/surface states and its correlation on the final device performance, a preliminary study was performed on MIS structures, before and after surface oxidation/passivation, using different oxidation techniques and oxides: thermal (in air), chemical (in H2O2) and oxygen plasma. The devices used in this work are based on a glass/Cr/a-Si:H(n+)/a-Si:H(i)/SiOx/Pd structures, where the amorphous silicon intrinsic layer (i a-Si:H) with a photosensitivity of 107 was deposited by a modified plasma enhanced chemical vapour deposition (PECVD) triode system. The electrical properties of a-Si:H MIS structures were investigated by measuring their diode current-voltage characteristics in the dark and under illumination as well as the spectral response, as a function of the various oxidation techniques. Infrared spectroscopy and spectroscopic ellipsometry were used as a complementary tool to characterise the oxidised surface.

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Tetraheme cytochrome c(3) (13 kDa) and flavodoxin (16 kDa), are small electron transfer proteins that have been used to mimic, in vitro, part of the electron-transfer chain that operates between substract electron donors and respiratory electron accepters partners in Desulfovibrio species (Palma, N., Moura, I., LeGall, J., Van Beeumen, J., Wampler, J., Moura, J. J. G. (1994) Biochemistry 33, 6394-6407). The electron transfer between these two proteins is believed to occur through the formation of a specific complex where electrostatic interaction is the main driving force (Stewart, D., LeGall, J., Moura, I., Moura, J.J.G., Peck, H.D., Xavier, A.V., Weiner, P.K. and Wampler, J.E. (1988) Biochemistry 27, 2444-2450, Stewart, D., LeGall, J., Moura, I., Moura, J.J.G., Peck, H.D., Xavier, A.V., Weiner, P., Wampler, J. (1989) fur. J. Biochem. 185, 695-700). In order to obtain structural information of the pre-complex, a covalent complex between the two proteins was prepared. A water-soluble carbodiimide {[}EDC (1-ethyl-3(3 dimethylaminopropyl) carbodiimide hydrochloride] was used for the cross linking reaction. The reaction was optimized varying a wide number of experimental parameters such as ionic strength, protein and cross linker concentration, and utilization of different cross linkers and reaction time between the crosslinker and proteins. (C) 1999 Academic Press.

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The increasing demand in automation processes in finishing techniques also calls for automatic measurement and inspection methods. These methods ought to be installed as close as possible to the production process and they ought to measure the values needed in a safe and fast way, without disturbing the process itself. Simultaneously they should be free of wear and insensitive against mechanical perturbations. This approach can be reached by proper combination of the laser triangulation technique with an array of linear position sensitive detectors, able to supply information about the surface finishing of an object. This is the aim of this paper that envisages to present experimental results of the performances exhibited by such an array constituting 128 elements. The analogue information supplied by this array is processed by an analogue/digital converter, directly coupled to the array and whose information is computer processed, concerning the recognition of patterns and the processing of information collected over the object to be inspected. © 1999 Elsevier Science S.A. All rights reserved.

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This work's aim is to report for the first time the cubic to hexagonal phase transition in tin-doped In2O3 films with a Sn/In atomic ratio of 0.03, fabricated at low temperature and normal pressure from alcoholic solution of InCl3 and SnCl4. The performed X-ray diffraction measurements show a difference between crystallographic symmetry of thin (100 nm) and thick (400 nm) films prepared in the same conditions: the structure of thick films can be related to high pressure In2O3 hexagonal system with a preferred orientation of c-axis parallel to the substrate surface, while thin films present a cubic symmetry with columnar (400) grain orientation. Phase transition nature is connected with non-axial tensile deformation of indium oxide grid due to insertion of chlorine ions in the position of two diagonally opposite oxygen vacancies in In2O3 network.

Several well preserved clutches of dinosaurs have been discovered in the upper Kimmeridgian/ Tithonian of Lourinhã (Estramadur Province, Portugal). Some eggs of one clutch contained embryo elements of a theropod dinosaur. The egg-shell resembles that of eggs which have been discovered in the Upper Jurassic of Colorado

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