2022
Authors
de Sa, MH; Pinto, AMFR; Oliveira, VB;
Publication
ENERGIES
Abstract
Passive small direct alcohol fuel cells (PS-DAFCs) are compact, standalone devices capable of electrochemically converting the chemical energy in the fuel/alcohol into electricity, with low pollutant emissions and high energy density. Thus, PS-DAFCs are extremely attractive as sustainable/green off-grid low-power sources (milliwatts to watts), considered as alternatives to batteries for small/portable electric and electronic devices. PS-DAFCs benefit from long life operation and low cost, assuring an efficient and stable supply of inherent non-polluting electricity. This review aims to assess innovations on PS-DAFC technology, as well as discuss the challenges and R&D needs covered on practical examples reported in the scientific literature, since 2018. Hence, this compilation intends to be a guidance tool to researchers, in order to help PS-DAFCs overcome the barriers to a broad market introduction and consequently become prime renewable energy converters and autonomous micropower generators. Only by translating research discoveries into the scale-up and commercialization process of the technology can the best balance between the economic and technical issues such as efficiency, reliability, and durability be achieved. In turn, this will certainly play a crucial role in determining how PS-DAFCs can meet pressing sustainable energy needs.
2022
Authors
Salles, AAd; Silva, ME; Teles, P;
Publication
Open Journal of Business and Management
Abstract
2022
Authors
Magalhaes, P; Ferreira, N;
Publication
Automation
Abstract
2022
Authors
Santos, SF; Gough, M; Fitiwi, DZ; Silva, AFP; Shafie Khah, M; Catalao, JPS;
Publication
IEEE SYSTEMS JOURNAL
Abstract
The generation mix of Portugal now contains a significant amount of variable renewable energy sources (RES) and the amount of RES is expected to grow substantially. This has led to concerns being raised regarding the security of the supply of the Portuguese electric system as well as concerns relating to system inertia. Deploying and efficiently using various flexibility options is proposed as a solution to these concerns. Among these flexibility options proposed is the use of battery energy storage systems (BESSs) as well as relaxing system inertia constraints such as the system nonsynchronous penetration (SNSP). This article proposes a stochastic mixed-integer linear programming problem formulation, which examines the effects of deploying BESS in a power system. The model is deployed on a real-world test case and results show that the optimal use of BESS can reduce system costs by as much as 10% relative to a baseline scenario and the costs are reduced further when the SNSP constraint is relaxed. The amount of RES curtailment is also reduced with the increased flexibility of the power system through the use of BESS. Thus, the efficiency of the Portuguese transmission system is greatly increased by the use of flexibility measures, primarily the use of BESS.
2022
Authors
Coutinho, F; Teixeira, J; Rocha, V; Oliveira, J; Jorge, PAS; Silva, NA;
Publication
Journal of Physics: Conference Series
Abstract
Optical trapping is a versatile and non-invasive technique for single particle manipulation. As such, it can be widely applied in the domains of particle identification and classification and thus used as a tool for monitoring physical and chemical processes. This creates an opportunity for integrating the method seamlessly into optofluidic chips, provided it can be automatized. Yet even though OT is well established in multiple scientific domains, a full stack approach to its integration into other technological devices is still lacking. This calls for solutions in tasks such as automatic trapping and signal analysis. In this manuscript, we describe the implementation of an algorithm seeking autonomous particle location and trapping. The methodology is based upon image-processing, allowing for particle location using real time image segmentation. A local thresholding algorithm is applied, followed by morphological techniques for closing shapes and excluding non-bounded regions - after which only the particles remain on the image. Once the centroid is identified, the stage is translated accordingly by piezo-electric actuators, followed by the laser activation. In this way, trapping is achieved, and one may proceed to analyze the forward scattered optical signal, after which a new particle inside the actuators range may be automatically trapped. This development, when compared with existent solutions involving holographic optical tweezers, allows for similar capabilities without using a spatial light modulator, thus dramatically reducing the setup costs of autonomous OT solutions. Therefore, when combined with particle classification techniques, this method is well suited for integration into possible optofluidic chips for autonomous sensing and monitoring of biochemical samples. © Published under licence by IOP Publishing Ltd.
2022
Authors
Ribeiro, J; Clarinha, B; Cunha, D; Zhu, YH; Walter, CE; Au Yong Oliveira, M;
Publication
2022 17TH IBERIAN CONFERENCE ON INFORMATION SYSTEMS AND TECHNOLOGIES (CISTI)
Abstract
Nowadays, and increasingly, Artificial Intelligence (AI) occupies a leading role in the world, being used in the most diverse contexts. The retail sector is just one of them. The starting question that originated this article is: is Portugal receptive to the use of cutting-edge Artificial Intelligence in retail? In other words, what is the opinion of the Portuguese and residents in Portugal, as consumers, regarding the use of automation by retail companies? Based on the analysis of the answers to an online questionnaire (which obtained 132 answers), we will present our conclusions regarding this matter. The goal is to understand if Portuguese people / residents in Portugal are willing and interested in going to supermarkets like Amazon Go or Continente Labs (or Pingo Doce & GO NOVA). In addition, it is intended to understand the reasons that lead them to respond skeptically, so that, in the future, strategies may be initiated by the companies of the sector, which based on greater and better education, may clarify, and perhaps change their assumptions and convictions. The results of this study reveal that the Portuguese and residents in Portugal are not yet interested in using automated supermarkets, showing some mistrust and reticence towards this new technology, although they recognize that it can increase the speed and efficiency of the service. In fact, of the 37,1% of respondents that consider it quite attractive, about 84% believe it may have a significant impact on the reduction of time spent shopping.
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