Social value and organizational performance in non-profit social organizations

This paper analyzes the roles of social entrepreneurship and transformational leadership in explaining the social value and the organizational performance of non-profit social organizations. By evaluating the role of socioeconomic context as the moderating variable, the results confirm the strong influence of social entrepreneurship on social value and the effects of social entrepreneurship and transformational leadership on organizational performance. The socioeconomic context proves to be an important moderator of the hypothesized relations. In an unfavorable context, transformational leadership becomes relevant in explaining social value and organizational performance. However, in a favorable context, social entrepreneurship provides more significant support to social value and organizational performance, and social value itself also has an effect on organizational performance.info:eu-repo/semantics/publishedVersio

Bidirectional DC-DC Converter with High Voltage Gain for the Charge/Discharge Control of Storage Systems

Trabalho apresentado em 10th Electric Power Quality and Supply Reliability Conference, 29-31 de agosto, Tallin, EstóniaThis paper presents a study of a bidirectional dc-dc converter with high voltage gain to regulate the charge and discharge of electrochemical storage systems. The converter is characterized by quadratic voltage gain characteristics in both directions. In this context it can be used to regulate a dc interface between the storage system and a dc/ac converter connected to the electrical grid. It will be analysed the converter in ideal and non-ideal conditions. A control system to regulate the output voltages and currents are also proposed. Simulation results are presented in order to validate the control system associated to the converter for the charge/discharge of the storage system.N/

Sistemas computacionais para a previsão da qualidade e segurança alimentar : uma perspectiva de sistemas complexos

Os sistemas computacionais para a previsão da qualidade e segurança alimentar assumem hoje maior relevância na prototipagem e simulação da cadeia de distribuição (e.g. gestão do armazenamento, transporte e exposição). Este manuscrito descreve a evolução dos sistemas de previsão até aos actuais sistemas baseados em sistemas complexos (SC), para avaliar o impacto na qualidade e segurança dos alimentos.Univ. do Minho e IST-ISR; FEDER

Fault detection and diagnosis technique for a SRM drive based on a multilevel converter using a machine learning approach

Trabalho apresentado em 12th International Conference on Renewable Energy Research and Applications (ICRERA 2023), 29 augusto-1 setembro 2023, Oshawa, CanadaSRM drives based on multilevel converters is now a solution well accepted due to their interesting features like extended voltage range and capability to fault tolerance. However, one aspect that is fundamental to ensure fault tolerance or preventive maintenance is the fault detection and diagnosis of failures in power semiconductors. In this way, in this paper it is presented a new diagnostic method for the failure of those semiconductors in asymmetric neutral point clamped converters. The proposed method will be based on the development of specific patterns that are associated to each semiconductor and fault type. The procedures presented here are based on the image identification of the currents patterns in the multilevel converter that allow the identification of distinct fault type. The pattern recognition system uses visual-based efficient invariants features for continuous monitoring of multilevel converter The proposed method will be verified through several tests in which were used a simulation tool and an experimental prototype.N/

Review of a disruptive vision of future power grids: a new path based on hybrid AC/DC grids and solid-state transformers

Power grids are evolving with the aim to guarantee sustainability and higher levels of power quality for universal access to electricity. More specifically, over the last two decades, power grids have been targeted for significant changes, including migration from centralized to decentralized paradigms as a corollary of intensive integration of novel electrical technologies and the availability of derived equipment. This paper addresses a review of a disruptive vision of future power grids, mainly focusing on the use of hybrid AC/DC grids and solid-state transformers technologies. Regarding hybrid AC/DC grids in particular, they are analyzed in detail in the context of unipolar and bipolar DC grids (i.e., two-wire or three-wire DC grids), as well as the different structures concerning coupled and decoupled AC configurations with low-frequency or high-frequency isolation. The contextualization of the possible configurations of solid-state transformers and the different configurations of hybrid transformers (in the perspective of offering benefits for increasing power quality in terms of currents or voltages) is also analyzed within the perspective of the smart transformers. Additionally, the paper also presents unified multi-port systems used to interface various technologies with hybrid AC/DC grids, which are also foreseen to play an important role in future power grids (e.g., the unified interface of renewable energy sources and energy storage systems), including an analysis concerning unified multi-port systems for AC or DC grids. Throughout the paper, these topics are presented and discussed in the context of future power grids. An exhaustive description of these technologies is made, covering the most relevant and recent structures and features that can be developed, as well as the challenges for the future power grids. Several scenarios are presented, encompassing the mentioned technologies, and unveiling a progressive evolution that culminates in the cooperative scope of such technologies for a disruptive vision of future power grids.This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017, and by the FCT Project DAIPESEV PTDC/EEIEEE/30382/2017

A novel control strategy based on predictive control for a bidirectional interleaved three-phase converter

An experimental confirmation of predictive control applied to a bidirectional interleaved three-phase (BIT) converter is presented. The BIT converter is a powerful solution for numerous applications, mainly, renewables interface, motor drivers, active rectifiers, and active power filters. However, a precise and robust digital control strategy is required, maintaining a low computational effort. In this paper, a predictive control based on continuous control set is proposed as a new control scheme for the BIT converter, permitting the control of the ac side current with fixed switching frequency and with a faster response. The predictive control scheme applied to the BIT converter is defined along the paper, evidencing in detail the digital employment aspects according to the discrete-time model of the BIT converter. An explicit experimental validation under realistic operating conditions is presented using a developed laboratorial prototype, highlighting the convenience of the control applied to the BIT converter.This work has been supported by FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEstUID/CEC/00319/2013. This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation < COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT < Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015< POCI< 01<0145<FEDER<016434. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency.info:eu-repo/semantics/publishedVersio

Decision process to manage renewable energy production in smart grid environment

This research work is related to the Electric Vehicle (EV) integration in the electricity market, using the OpenADR open protocol for demand response. The proposed solution integrates a local developed EV charging system and a cloud management system, to coordinate the available energy produced from renewable energy sources, taking into account its intermittent production and the requirements of the EV charging process at home. Considering the smart mobility paradigm, all transactions processes are available at mobile devices in real-time, where users can define their usual behavior, configure the energy consumption profile at home, establish new profiles for specific days according to the EV charging process, and consult the historical transactions.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

Monitorização da qualidade do leite de cabra durante a pasteurização e processamento óhmico usando sensores de fibra óptica

Este estudo avalia a viabilidade da espectroscopia UVVIS- SWNIR na degradação da qualidade do leite de cabra durante a pasteurização e aquecimento Ohmico. Foram utilizados: i) leite de cabra cru; ii) leite não processado, mas passado pelas bombas do pasteurizador e aquecimento Ohmico; e iii) leite processado por pasteurização e aquecimento Ohmico. Os espectros são recolhidos por sensor de fibra óptica em comprimentos de onda UVVIS e UV-SWNIR. As amostras foram realizadas a uma temperatura de (18±2.0ºC), e os dados foram registados em cada produto e para cada gama espectral. Os espectros das amostras foram então normalizados e corrigidos usando o algoritmo de correcção da robusta da dispersão de radiação, sendo depois decomposto utilizando o algoritmo de decomposição de valores singulares relevantes. Os resultados demonstram que a espectroscopia de refletância dá-nos uma avaliação rápida das características do leite de cabra em vários cenários de produção, sendo um execelente sensor para a monitorização e automatização do processamento de lacticínios, em especial para o desenvolvimento da monitorização e controlo com a utilização de software de Tecnometria

Levels of GABA, serotonin, dopamine, epinephrine and norepinephrine in bullfighting bulls and meat cattle under stress

O Touro de Lide é um expoente de agressividade, animal mítico e selvagem de difícil abordagem, talvez por isso, pouco estudado. As circunstâncias que fazem com que as estimulações adrenérgicas se tornem pró-nociceptivas em vez de anti-nociceptivas em modelos animais permanecem mal compreendidas [4]. Foram estudados 10 touros de lide (bravos) e 10 bovinos produtores de carne (mansos), dos quais, logo após o abate, foi recolhido e analisado o sangue, com o objectivo de se determinar os níveis de GABA, Serotonina, Dopamina, Adrenalina e Noradrenalina. Apenas o GABA mostrou diferenças extremamente significativas sendo os valores mais altos nos touros mansos; não existem diferenças significativas entre os grupos no que respeita aos níveis de Catecolaminas e de Serotonina. Em relação ao GABA, a sua diminuição nos bravos poderá estar na base de mecanismos de desinibição da dor. Pelo contrário, nos mansos, os valores mais altos poderão resultar de níveis de medo mais elevados, com possível aumento dos níveis de analgesia endógena.The bullfighting bull is an exponent of aggression, a mythical and wild animal of difficult approach and perhaps for that reason it is understudied. The circumstances that cause adrenergic stimulation to become pronociceptive rather than anti-nociceptive in animal models remain poorly understood [4]. A total of 10 bullfighting bulls and 10 meat cattle were studied, from which, after the slaughter, blood was collected and analyzed to determine the levels of GABA, Serotonin, Dopamine, Adrenaline and Noradrenaline. Only the GABA showed very significant differences being the highest values in the meat bulls; there are no significant differences between the groups in respect to catecholamine and serotonin levels. Regarding GABA, its decrease in the bullfighting bull might be the basis of the mechanisms of disinhibition of pain. On the contrary, in the meat cattle, higher values may result from higher levels of fear, with possible increase in levels of endogenous analgesia.(undefined

Influence of ferrite nanoparticle type and content on the crystallization kinetics and electroactive phase nucleation of poly(vinilidene fluoride)

This work reports on the nucleation of the β-phase of poly(vinylidene fluoride), PVDF, by incorporating CoFe2O4 and NiFe2O4 nanoparticles, leading in this way, to the preparation of magnetoelectric composites. The fraction of filler nanoparticles needed to produce the same β- to α-phase ratio in crystallized PVDF is one order of magnitude lower in the Cobalt nanoparticles. The interaction between nanoparticles and PVDF chains induce the all trans conformation in PVDF segments and this structure then propagates in crystal growth. The nucleation kinetics is enhanced by the presence of nanoparticles, as corroborated by the increasing number of spherulites with increasing nanoparticle content and by the variations of the Avrami’s exponent. Further, the decrease of the crystalline fraction of PVDF with increasing nanoparticles content indicates that an important fraction of polymer chains are confined in interphases with the filler particle.Centro de Investigación Principe FelipeInstituto de Salud Carlos III (Ministry of Science and Innovation).FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETE"Fundação para a Ciência e a Tecnologia (FCT) - NANO/NMed-SD/0156/2007, PTDC/CTM/69316/2006, SFRH/BPD/63148/2009Conselleria de Sanidad (Generalitat Valenciana)Spanish Ministry of Education through project No. MAT2010-21611-C03-01, EUI2008-0012