2017
Autores
Alves, RA; Costa, JC; Gomes, M; Silva, NA; Guerreiro, A;
Publicação
2017 25TH INTERNATIONAL CONFERENCE ON OPTICAL FIBER SENSORS (OFS)
Abstract
This paper presents a study for a fibre optic sensor based on quantum wires to detect and measure the amplitude and direction of a static electric field. This study is supported by the analogy of the fluid equations describing the free electrons in the quantum wires and the Madelung formalism of Quantum Mechanics. In this context, it is possible to construct a diatomic plasmonic molecule whose energy levels can be Stark shifted by an external electric field and readout using a light beam tuned to the Rabi oscillations of these levels. Choosing the adequate design parameters it is possible to estimate a sensitivity of 100nm/NC-1.
2017
Autores
Pathak, AK; Gangwar, RK; Priyadarshini, P; Singh, VK;
Publicação
Optik
Abstract
An intrinsic intensity modulated no core fiber sensor (NCFS) is presented in this paper for rapid detection of adulteration in petrol with kerosene. The sensing principle is based on the phenomenon of absorption of evanescent waves. The sensing head of NCFS is fabricated by stubbing a small section of no core fiber (NCF) between two multi-mode fibers (MMF). A high sensitivity 390 nW/% and 110 nW/% are obtained by the proposed sensor for low and high level of adulteration. The intensity variation and confinement loss with different concentrations of the kerosene in petrol are then verified theoretically by using finite element method. It is found that the theoretical results agree very well with experimental results. The proposed sensor exhibits fast response time and good repeatability in addition to its high sensitivity. The sensor can be useful in industries and automotive companies due to its small size, easy to fabricate, safe with inflammable fuels and required small amount for detection. © 2017 Elsevier GmbH
2017
Autores
Cunha, A; Silva, E; Pereira, F; Briga Sa, A; Pereira, S;
Publicação
CENTERIS 2017 - INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS / PROJMAN 2017 - INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT / HCIST 2017 - INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERI
Abstract
Water and energy are essential for human existence, and its rational use should be encouraged. According to the literature review, water consumption directly affects energy consumption and are inseparably linked resources. The energy to water part of the water/energy nexus, increasingly highlighted as an important issue for future planning and strategic policy considerations. Joint consideration of both water/energy domains can identify new options for increasing overall resource use efficiency. This work is part of the project ENERWAT that has as goal to measure in situ the water/energy consumption related with water supply end use in rural and urban dwellings in order to validate the data collected by survey. A methodology for low cost measure and store water/energy consumes was developed. Water, Gas and electricity data was stored in image format. In this paper, a CNN architecture was applied and trained to read water/energy. The models suited their proposed. The achieved accuracy for test set was: water - dozen: 0.98, unit: 0.92; gas: dozen: 0.94, unit: 0.99; and electricity - dozen: 0.99, units 0.99. The more challenge digit was water unit digit due to partial occlusion. It is presented a day of readings and discussed some events. (C) 2017 The Authors. Published by Elsevier B.V.
2017
Autores
Cala, A; Lueder, A; Cachada, A; Pires, F; Barbosa, J; Leitao, P; Gepp, M;
Publicação
2017 IEEE 15TH INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN)
Abstract
Nowadays, many organizations intend to convert their existing production systems towards ones that are characterized by adaptability, openness, flexibility and modularity. This requires a redesign of existing information processing systems especially related to control, leading possibly to cyber-physical production systems (CPPS). However, the implementation of new control technologies will have a direct impact on the normal operational status of production while engineers will also face several challenges and obstacles in adopting intelligent automation systems. New step-wise migration strategies are required to holistically support industries in their journey towards CPPS taking into account technical, economic and social aspects. This paper discusses the migration state-of-the-art strategies, analyzing them and providing a first attempt to define a migration approach for innovative production systems.
2017
Autores
Martins, J; Pinto, A;
Publicação
BULLETIN OF MATHEMATICAL BIOLOGY
Abstract
We use the reinfection SIRI epidemiological model to analyze the impact of education programs and vaccine scares on individuals decisions to vaccinate or not. The presence of the reinfection provokes the novelty of the existence of three Nash equilibria for the same level of the morbidity relative risk instead of a single Nash equilibrium as occurs in the SIR model studied by Bauch and Earn (PNAS 101:13391-13394, 2004). The existence of three Nash equilibria, with two of them being evolutionary stable, introduces two scenarios with relevant and opposite features for the same level of the morbidity relative risk: the low-vaccination scenario corresponding to the evolutionary stable vaccination strategy, where individuals will vaccinate with a low probability; and the high-vaccination scenario corresponding to the evolutionary stable vaccination strategy, where individuals will vaccinate with a high probability. We introduce the evolutionary vaccination dynamics for the SIRI model and we prove that it is bistable. The bistability of the evolutionary dynamics indicates that the damage provoked by false scares on the vaccination perceived morbidity risks can be much higher and much more persistent than in the SIR model. Furthermore, the vaccination education programs to be efficient they need to implement a mechanism to suddenly increase the vaccination coverage level.
2017
Autores
Maia, JM; Amorim, VA; Alexandre, D; Marques, PVS;
Publicação
JOURNAL OF LIGHTWAVE TECHNOLOGY
Abstract
Femtosecond laser direct writing is a three dimensional fabrication technique that can be applied to produce integrated optical components with high spatial resolution or microfluidic channels when combined with HF etching. The same fabrication technique can thus be employed to produce monolithic optofluidic devices for sensing applications. One of the most common sensing schemes involves evanescent optical interaction; therefore, the channel must meet some requirements regarding surface roughness, which will depend on the laser writing conditions, as described in this paper. However, of more significance is the distance between waveguiding medium and microfluidic channel that must be accurately defined. This control can be achieved by monitoring the etching reaction of a waveguide grating written a few microns from the channel, as introduced in this paper. In addition to its function as an etching monitor, the grating can also be used as a coarse refractive index sensor device.
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