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Electronic Circuits for Wireless Optical LANs - I
Rui L. Aguiar; António Tavares; José Luis Cura; Eduardo de Vasconcelos; Luis Nero Alves; Rui Valadas; Dinis M. SantosThis is the first of two papers discussing practical issues and results on the implementation of low-cost transceivers for several wireless optical LANs, covering most physical layer elements.Target optical LANs under consideration have bit-rates varying between 4Mbps and 25Mbps, and input photodiode capacitance may vary between 10pF and 50pF. PPM modulation, either in a 4-PPM or 1...
Electronic Circuits for Wireless Optical LANs - II
Rui L. Aguiar; António Tavares; José Luis Cura; Eduardo de Vasconcelos; Luis Nero Alves; Rui Valadas; Dinis M. SantosThis is the second of two papers discussing practical issues and results on the implementation of low-cost transceivers for several wireless optical LANs, covering most physical layer elements.Target optical LANs under consideration have bit-rates varying between 4Mbps and 25Mbps, and input photodiode capacitance may vary between 10pF and 50pF. PPM modulation, either in a 4-PPM or ...
A CMOS Signal to Noise Measurement Circuit for Infrared Sectored Receivers
Luís Nero Alves; Rui L. Aguiar; Dinis M. SantosThis paper describes a circuit able to measure Signal to Noise ratios developed for Infrared applications.The Signal to Noise ratio is of major importance in IR Sectored Receivers because it provides the basis of selection or combining of signals coming from different optical sectors. This circuit estimates the ratio of the average optical signal sensed in the photo-detector and the ave...
Proton Microprobe
Dinis M. Santos; J. Sousa LopesThis thesis discusxes electronic instrumentation designed and built with a specific application in mind, namely, the application of induced X-ray emission (PIXE) to the qualitative and quantitative analysis materials.The physical principles upon which PIXE is based are briefly reviewed and a short description of the experimental arrangement - particle accelerator and peripheral equipment - where the instru...
Caso dermatológico: Escabiose
Matos, C.; Machado, S.; Carvalho, S.; Dinis, M.J.; Selores, M.The authors describe a clinical case of a 5-months-old boy with widespread rash since the first month of life. Diffuse papular rash with intensive itching. The shaved skin was inconclusive so we performed biopsy to confirm the diagnosis of scabies. It’s a dermatosis very contagious caused by the mite Sarcoptes scabiei var. hominis. In infants skin eruption may have a polymorphic presentation with characteristic...
An integrated recycling approach for GFRP pultrusion wastes: recycling and reus...
Castro, Ana Cristina Meira; Carvalho, João P.; Ribeiro, M. C. S.; Meixedo, João Paulo; Silva, Francisco J. G.; Fiúza, António; Dinis, M. L.In this study, efforts were made in order to put forward an integrated recycling approach for the thermoset based glass fibre reinforced polymer (GPRP) rejects derived from the pultrusion manufacturing industry. Both the recycling process and the development of a new cost-effective end-use application for the recyclates were considered. For this purpose, i) among the several available recycling techniques for t...
Mix design process of polyester polymer mortars modified with recycled GFRP was...
Ribeiro, M. C. S.; Fiúza, António; Castro, Ana Cristina Meira; Silva, Francisco J. G.; Dinis, M. L.; Meixedo, João Paulo; Alvim, Mário RuiIn this study, the effect of incorporation of recycled glass fibre reinforced plastics (GFRP) waste materials, obtained by means of shredding and milling processes, on mechanical behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates, between 4% up to 12% in weight, were incorporated into polyester PM materials as sand aggregates and filler replacements...
A case study on the eco-efficiency performance of a composite processing indust...
Dinis, M. L.; Fiúza, António; Ribeiro, M.C.S.; Alvim, M.R.; Castro, Ana Cristina Meira; Silva, F.J.G.; Meixedo, J.P.; Oliveira, L.In this study, an attempt was made in order to measure and evaluate the eco-efficiency performance of a pultruded composite processing company. For this purpose the recommendations of World Business Council for Sustainable Development (WCSD) and the directives of ISO 14301 standard were followed and applied. The main general indicators of eco-efficiency, as well as the specific indicators, were defined and dete...
Delay analysis of a current source CMOS inverter for use in voltage controlled ...
José L. Cura; Dinis M. SantosAn analysis is performed on the operation of a modified current-source loaded inverter, showing that the proposed modification leads to a more linear characteristic, in terms of delay versus control voltage, than the one obtained with traditional current-starved inverters. A delay cell designed around this inverter is presented. The proposed circuit is intended to be used as a delay of the cell in function of p...
PLSR Models for Mechanical Strengths of Concrete Composite Materials Reinforced...
Castro, Ana Cristina Meira; Ribeiro, M. C. S.; Meixedo, João Paulo; Silva, Francisco J. G.; Alvim, Mário Rui; Fiúza, António; Dinis, M. L.In this paper, we present two Partial Least Squares Regression (PLSR) models for compressive and flexural strength responses of a concrete composite material reinforced with pultrusion wastes. The main objective is to characterize this cost-effective waste management solution for glass fiber reinforced polymer (GFRP) pultrusion wastes and end-of-life products that will lead, thereby, to a more sustainable compo...
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