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2002
Martins, R., J. Figueiredo, V. Silva, H. Águas, F. Soares, A. Marques, I. Ferreira, and E. Fortunato. "32 linear array position sensitive detector based on NIP and hetero a-Si: H microdevices." Journal of non-crystalline solids. 299 (2002): 1283-1288. Abstract
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Martins, R., J. Figueiredo, V. Silva, H. Águas, F. Soares, A. Marques, I. Ferreira, and E. Fortunato. "32 linear array position sensitive detector based on NIP and hetero a-Si: H microdevices." Journal of non-crystalline solids. 299 (2002): 1283-1288. Abstract
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b b b b b b b Martins, R.a b, Figueiredo Silva Águas Soares Marques Ferreira Fortunato J. a V. a. "32 Linear array position sensitive detector based on NIP and hetero a-Si:H microdevices." Journal of Non-Crystalline Solids. 299-302 (2002): 1283-1288. AbstractWebsite

In this paper we present results concerning the performance exhibited by an integrated array of 32 one-dimensional amorphous silicon thin film position sensitive detectors based on nip and hetero amorphous silicon structures, with a total active area size below 1 cm2 linearity, its spatial resolution and response time, that make it one of the most interesting analog detector to be used in unmanned optical inspection control systems where a continuous detection process is required. This opens a wide range of applications for amorphous silicon devices in the area of image processing. © 2002 Elsevier Science B.V. All rights reserved.

Ferreira, I., P. Vilarinho, F. FERNANDES, E. Fortunato, and R. Martins. "6 Optoelectronics-Influence of Hydrogen Gas Dilution on the Properties of Silicon-Doped Thin Films Prepared by the Hot-Wire Plasma-Assisted Technique." Key Engineering Materials. 230 (2002): 591-594. Abstract
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Pereira, L., D. Brida, E. Fortunato, I. Ferreira, H. Aguas, V. Silva, M. F. M. Costa, V. Teixeira, and R. Martins. "a-Si: H interface optimisation for thin film position sensitive detectors produced on polymeric substrates." Journal of non-crystalline solids. 299 (2002): 1289-1294. Abstract
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Pereira, L., D. Brida, E. Fortunato, I. Ferreira, H. Aguas, V. Silva, M. F. M. Costa, V. Teixeira, and R. Martins. "a-Si: H interface optimisation for thin film position sensitive detectors produced on polymeric substrates." Journal of non-crystalline solids. 299 (2002): 1289-1294. Abstract
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Pereira, L.a, Brida Fortunato Ferreira Águas Silva Costa Teixeira Martins D. a E. a. "a-Si:H interface optimisation for thin film position sensitive detectors produced on polymeric substrates." Journal of Non-Crystalline Solids. 299-302 (2002): 1289-1294. AbstractWebsite

In this paper we present results concerning the optimisation of the electronic and mechanical properties presented by amorphous silicon (a-Si:H) thin films produced on polyimide (Kapton® VN) substrates with different thicknesses (25, 50 and 75 μm) by the plasma enhanced chemical vapour deposition (PECVD) technique. The purpose of this study is to obtain a low defect density as well as low residual stresses (specially at the interface) in order to provide good performances for large area (10 mm wide by 80 mm long) flexible position sensitive detectors. The electrical and optical properties presented by the films will be correlated to the sensor characteristics. The properties of samples have been measured by dark/photoconductivity, constant photocurrent measurements (CPM) and the results have been compared with films deposited on Corning 7059 glass substrates during the same run deposition. The residual stresses were measured using an active optical triangulation and angle resolved scattering. The preliminary results indicate that the thinner polymeric substrate with 25 μm presents the highest density of states, which is associated to the residual stresses and strains associated within the film. © 2002 Elsevier Science B.V. All rights reserved.

Abken, AE, YA Abrahamyan, VI Serago, VM Aroutiounian, ID Anisimova, VI Stafeev, GG Karamian, GA Martoyan, AA Mouradyan, H. Aguas, and others. "Aberle, AG, see Song, D." Solar Energy Materials & Solar Cells. 73 (2002): 449-453. Abstract
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Gil, P., António Dourado, J. Henriques, and P. Carvalho. "Adaptive Neural Model Based Predictive Control Of A Solar Power Plant." IJCNN, International Join Conference on Neural Networks. n/a 2002. Abstract
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Palma, L. B., F. Coito, and R. Silva. "Adaptive observer based fault diagnosis approach applied to a thermal plant." submitted to 10th Mediterranean Conference on Control and Automation (2002). Abstract
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Figueiredo, MO, JP Veiga, and T. Pereira da Silva. "Ageing of high-lead glazes in XVI - XVII century tiles." Proceedings of the International Conference on Non-Destructive Testing and Micro-Analysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage. 2002. 8. Abstract
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d Teixeira, V.a, Cui Meng Fortunato Martins H. N. a L. "Amorphous ITO thin films prepared by DC sputtering for electrochromic applications." Thin Solid Films. 420-421 (2002): 70-75. AbstractWebsite

Indium-Tin-Oxide (ITO) thin films were deposited on glass substrates using DC magnetron reactive sputtering at different bias voltages and substrate temperatures. Some improvements were obtained on film properties, microstructure and other physical characteristics for different conditions. Amorphous and polycrystalline films can be obtained for various deposition conditions. The transmission, absorption, spectral and diffuse reflection of ITO films were measured in some ranges of UV-Vis-NIR. The refractive index (n), Energy band gap Eg and the surface roughness of the film were derived from the measured spectra data. The carrier density (nc) and the carrier mobility (μ) of the film micro conductive properties were discussed. The films exhibited suitable optical transmittance and conductivity for electrochromic applications. © 2002 Elsevier Science B.V. All rights reserved.

Sebastião, PJ, C. Cruz, D. Pires, A. Ferraz, P. Brogueira, and M. H. Godinho. "Anisotropic hydroxypropylcellulose films as alignment layers of a bistable ferroelectric device." Liquid crystals. 29.12 (2002): 1491-1495. Abstract
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Godinho, M. H., JG Fonseca, AC Ribeiro, LV Melo, and P. Brogueira. "Atomic force microscopy study of hydroxypropylcellulose films prepared from liquid crystalline aqueous solutions." Macromolecules. 35.15 (2002): 5932-5936. Abstract
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Baroni, Aline Lúcia, Miguel Goulão, and Fernando Brito Abreu. "Avoiding the Ambiguity of Quantitative Data Extraction: An Approach to Improve the Quality of Metrics Results." Work in Progress Session at the 28th EUROMICRO Conference. Dortmund, Germany 2002. Abstract
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Figueiredo, MO, and JP Veiga. "Characterisation of materials used in the aqueduct of Zaghouan-Carthage." Protection and Conservation of the Cultural Heritage in the Mediterranean Cities: Proceedings of the 5th International Symposium, Sevilla, Spain, 5-8 April 2000. CRC Press, 2002. 101. Abstract
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Alvarez, A., R. Estrada, F. Gueddari, MO Figuiredo, JP Veiga, and L. Vilaseca. "Characterisation of materials used in the aqueduct of Zaghouan-Carthage (Tunisia) along construction and restoration periods." Protection and Conservation of the Cultural Heritage of the Mediterranean Cities. Swets & Zeitlinger, Lisse (2002): 101-106. Abstract
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Fortunato, E., P. Nunes, D. Costa, D. Brida, I. Ferreira, and R. Martins. "Characterization of aluminium doped zinc oxide thin films deposited on polymeric substrates." Vacuum. 64.3 (2002): 233-236. Abstract
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Fortunato, E., Nunes Costa Brida Ferreira Martins P. D. D. "Characterization of aluminium doped zinc oxide thin films deposited on polymeric substrates." Vacuum. 64 (2002): 233-236. AbstractWebsite

We report, for the first time, results on transparent ZnO:Al thin films deposited on polyester (Mylar type D, 100 μm thickness) substrates at room temperature by magnetron sputtering. The structural, optical and electrical properties of the deposited films have been studied. The samples are polycrystalline with a hexagonal wurtzite structure and a strong crystallographic c-axis orientation (0 0 2) perpendicular to the substrate surface. The ZnO:Al thin films with 83% transmittance in the visible region and a resistivity as low as 3.6 × 10-2 Ωcm have been obtained, as deposited. The obtained results are comparable to those obtained on glass substrates, opening a new field of low cost, light weight, small volume, flexible and unbreakable large area optoelectronic devices. © 2002 Elsevier Science Ltd. All rights reserved.

Lanca, M. C., E. R. Neagu, and J. N. Marat-Mendes. "Combined isothermal and non-isothermal current measurements applied to space charge studies in low-density polyethylene." Journal of Physics D-Applied Physics. 35 (2002): L29-L32. AbstractWebsite

A new experimental procedure combining usual isothermal DC charging and discharging with non-isothermal current measurements has been recently proposed. It is mainly suitable for very high insulating polymers and it was successfully applied to the study of space charge trapping and transport in low-density polyethylene. The analysis of the isothermal currents revealed the presence of different traps whose characteristic (de)trapping times can be deduced. The isothermal procedures allowed the selective charging of the sample. By choosing the charging field and the ratio of charge/discharge times, non-isothermal analysis permitted the differentiation of three or four peaks (at approximate to50degreesC, approximate to65degreesC, approximate to70degreesC and approximate to85degreesC) associated with charge detrapping from surface or near-surface (<20 mum) traps. These traps have activation energies between 0.21 and 1.54 eV. The mobility at 30degreesC is around 5 x 10(-16) m(2) V-1 s(-1). Samples had to be conditioned before each experiment in order to obtain reproducible results.

Lanca, M. C., E. R. Neagu, and J. N. Marat-Mendes. "Combined isothermal and non-isothermal current measurements applied to space charge studies in low-density polyethylene." Journal of Physics D-Applied Physics. 35 (2002): L29-L32. AbstractWebsite

A new experimental procedure combining usual isothermal DC charging and discharging with non-isothermal current measurements has been recently proposed. It is mainly suitable for very high insulating polymers and it was successfully applied to the study of space charge trapping and transport in low-density polyethylene. The analysis of the isothermal currents revealed the presence of different traps whose characteristic (de)trapping times can be deduced. The isothermal procedures allowed the selective charging of the sample. By choosing the charging field and the ratio of charge/discharge times, non-isothermal analysis permitted the differentiation of three or four peaks (at approximate to50degreesC, approximate to65degreesC, approximate to70degreesC and approximate to85degreesC) associated with charge detrapping from surface or near-surface (<20 mum) traps. These traps have activation energies between 0.21 and 1.54 eV. The mobility at 30degreesC is around 5 x 10(-16) m(2) V-1 s(-1). Samples had to be conditioned before each experiment in order to obtain reproducible results.

Marat-Mendes, R., C. J. Dias, and J. N. Marat-Mendes. "A comparative study of piezoelectric materials using smart angular accelerometers." Advanced Materials Forum I. Ed. T. Vieira. Vol. 230-2. Key Engineering Materials, 230-2. 2002. 181-184. Abstract
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Seco, J. C., and L. Caires ComponentJ: The Reference Manual. Departamento de Informática FCT/UNL, 2002.
c Almeida, P.L.a, Godinho Cidade Nunes Marques Martins Fortunato Figueirinhas M. H. a M. "Composite systems for flexible display applications from cellulose derivatives." Synthetic Metals. 127 (2002): 111-114. AbstractWebsite

In this work, we study the electro-optical behaviour of cellulose/liquid crystal-based composite systems, in particular the influence of the flexible substrates and its conductive layers in the electro-optical behaviour of these kind of cells. Four cells were made using, respectively, two different substrates (a flexible polymer (poly(ethylene terephthalate) (PET)) and a soda lime glass) and two different conductive layers (indium tin oxide (ITO) and aluminium zinc oxide (AZO)). The conductive layer (AZO) was deposited in both, flexible and rigid substrates, for the same conditions, and the same substrates coated with ITO are commercially available. The cells were prepared from solid films of hydroxypropylcellulose (HPC) (30 μm thick) cross linked with 1,4-diisocyanatobutane (BDI) (7% w/w) and the nematic liquid crystal E7 (Merck, UK). The four different substrates were electrically and morphologically characterised. We have analysed all samples by light transmission and determined the maximum transmission, contrast and Von. We show a comparison of the results obtained for both flexible and rigid cells and discuss them in terms of the proposed working mechanism for these systems. © 2002 Elsevier Science B.V. All rights reserved.

Almeida, PL, M. H. Godinho, M. T. Cidade, P. Nunes, A. Marques, R. Martins, E. Fortunato, and J. L. Figueirinhas. "Composite systems for flexible display applications from cellulose derivatives." Synthetic metals. 127.1 (2002): 111-114. Abstract
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