229 research outputs found
Do they need us?: Linking functional indispensability and voice behaviors: The roles of psychological ownership, job insecurity and organizational ambidexterity
No atual contexto de rápida mudança, as organizações dependem cada vez mais do trabalho em equipa (Mathieu et al., 2014) e os gestores precisam de mais input dos colaboradores para aumentar o desempenho e o funcionamento organizacional (Hsiung, 2012). Ao nosso conhecimento, contudo, nenhum estudo explorou como a perceção de indispensabilidade da equipa para os resultados da organização influencia o input que os colaboradores dão aos seus gestores adotando comportamentos de voz. Este estudo preenche esta lacuna ao explorar como a indispensabilidade funcional motiva os colaboradores a adotar comportamentos de voz promotiva, e que fatores influenciam esta relação. Os dados foram recolhidos através de um questionário de auto-reporte distribuído online a membros de várias organizações. Com uma amostra de 875 participantes, os resultados sugerem que a indispensabilidade funcional da equipa está positivamente associada à adoção de comportamentos de voz promotiva por parte do colaborador e que esta relação é parcialmente mediada por sentimentos de propriedade psicológica promotiva sobre a organização. Ademais, os resultados revelam que a insegurança quantitativa do trabalho modera e enfraquece a relação entre a indispensabilidade funcional e a propriedade psicológica promotiva. Como esperado, a ambidestria organizacional modera e aumenta a força da associação entre a indispensabilidade funcional e a adoção de comportamentos de voz promotiva. Contribuindo para o estudo da indispensabilidade nas organizações e para os antecedentes dos comportamentos de voz, este estudo oferece contribuições teóricas e implicações práticas que serão discutidas em detalhe, assim como as limitações deste estudo e as indicações para investigação futura.In today’s rapidly changing business environment, organizations rely more on teamwork than ever before (Mathieu et al., 2014) and managers need more input from their employees to increase organizational performance and functioning (Hsiung, 2012). To our knowledge, however, no previous research has addressed how perceptions of team indispensability to the organization’s outcomes influence employees giving their input to managers such as through engaging in voice behaviors. Our study addresses this gap in literature by exploring how perceived functional indispensability of the team motivates employees to engage in promotive voice behaviors, and what factors influence this relationship. We collected our data through a self-report questionnaire distributed online to members of various organizations. With a sample of 875 participants, our results suggest functional indispensability of the team is positively associated with the employee’s engagement in promotive voice behaviors and that this relationship is partially mediated by feelings of promotive psychological ownership towards the organization. Furthermore, our findings revealed that quantitative job insecurity moderated and weakened the link between functional indispensability and promotive psychological ownership. As we predicted, organizational ambidexterity moderated the relationship between functional indispensability and promotive voice behaviors by fostering this association. Contributing to the study of indispensability within organizations and the antecedents of voice behaviors, our research provides several theoretical contributions as well as practical implications for managers seeking their employees’ input to innovate and promote organizational success. These theoretical contributions and practical implications, as well as the limitations of our study and future directions for research are discussed
Microcredentials: an opportunity towards the digital transformation
This communication aims to present one of the online courses included in the Microcredentials portfolio of the Universidade Aberta, in Portugal. We start by presenting a framework of the European guidelines on Microcredentials, defining its main characteristics, namely highlighting its advantages in the context of reskilling or upskilling with a view to its applicability in the labor sector. Following the guidelines of the Portuguese Ministry of Higher Education, and specific EU funding under the Impulso Adultos programme, a
proposal for a Microcredential in Digital and Distance Learning was conceptualized and developed for teachers´ training, with more than 1200
teachers already involved. An evaluation carried out through a survey delivered to trainees shows very positive results in all items evaluated, with strong emphasis on the transferability and applicability of the knowledge
acquired to work contexts.
These results show that this course, developed within the scope of Microcredentials, broadly meets the needs of reskilling and upskilling, which are increasingly important in the adaptability of adults to the new challenges
that digital transformation implies.Project funded by the Recovery and Resilience Program (PRR), Portugal, and the European Union - Next Generation, EUinfo:eu-repo/semantics/publishedVersio
Thematic Comparison between ESA WorldCover 2020 Land Cover Product and a National Land Use Land Cover Map
Duarte, D., Fonte, C., Costa, H., & Caetano, M. (2023). Thematic Comparison between ESA WorldCover 2020 Land Cover Product and a National Land Use Land Cover Map. Land, 12(2), 1-16. [490]. https://doi.org/10.3390/land12020490 --- Funding: This work has been supported by projects foRESTER (PCIF/SSI/0102/2017), SCAPEFIRE (PCIF/MOS/0046/2017) and FireLoc (PCIF/MPG/0128/2017), by Centro de Investigação em Gestão de Informação (MagIC) and grant UIDB/00308/2020, all funded by the Portuguese Foundation for Science and Technology (FCT). It was also supported by Compete2020 (POCI-05-5762-FSE-000368), funded by the European Social Fund.This work presents a comparison between a global and a national land cover map, namely the ESA WorldCover 2020 (WC20) and the Portuguese use/land cover map (Carta de Uso e Ocupação do Solo 2018) (COS18). Such a comparison is relevant given the current amount of publicly available LULC products (either national or global) where such comparative studies enable a better understanding regarding different sets of LULC information and their production, focus and characteristics, especially when comparing authoritative maps built by national mapping agencies and global land cover focused products. Moreover, this comparison is also aimed at complementing the global validation report released with the WC20 product, which focused on global and continental level accuracy assessments, with no additional information for specific countries. The maps were compared by following a framework composed by four steps: (1) class nomenclature harmonization, (2) computing cross-tabulation matrices between WC20 and the Portuguese map, (3) determining the area occupied by each harmonized class in each data source, and (4) visual comparison between the maps to illustrate their differences focusing on Portuguese landscape details. Some of the differences were due to the different minimum mapping unit ofCOS18 and WC20, different nomenclatures and focuses on either land use or land cover. Overall, the results show that while WC20 detail is able to distinguish small occurrences of artificial surfaces and grasslands within an urban environment, WC20 is often not able to distinguish sparse/individual trees from the neighboring cover, which is a common occurrence in the Portuguese landscape. While selecting a map, users should be aware that differences between maps can have a range of causes, such as scale, temporal reference, nomenclature and errors.publishersversionpublishe
Exploring the value and perception of microcredentials: a case study of the Universidade Aberta
The Universidade Aberta (UAb) – the Portuguese Open University - has extensive experience inproviding continuous professional development courses for adult learners, ranging frompostgraduate certificates to short learning programmes and MOOCs. In 2021, the UAb initiateda new portfolio of short learning opportunities leading to micro-credentials, driven by anationally-funded project called "Impulso Adultos" which aims to reskill and upskill the adultpopulation either already in work or looking to transition to a new professional opportunity.Micro-credentials are a form of recognition for learning that are based on short, stackable, andfocused learning blocks, leading learners to develop specific skills or competencies. The conceptof micro-credentials has gained popularity in recent years, initially in North America andAustralia, and more recently in Europe (Brown & Mhichil, 2022). When publishing its EuropeanSkills Agenda, the Commission set out policy priorities and actions aimed at increasing theemployability of citizens and boosting the skills for the workplace (European Skills Agenda forSustainable Competitiveness, Social Fairness and Resilience, 2020). In its action 10, theCommission set the ground for the relevance given to Micro-credentials. According to theCommission, Micro-credentials should: (i) encourage the take-up of flexible and quality-assuredcourses; (ii) make learning more visible and understood; (iii) be validated and guided; and (iv)should be easy to store and communicate through Europass.
The UAb's portfolio of micro-credentials comprises over 20 courses, which have been offered tomore than 2,000 students over a period of two years. These courses cover various thematicareas, including distance and digital education, language and communication, sustainabledevelopment goals, and digital transition and transformation. All of these courses are deliveredonline and often involve collaborative development with industry and organizations. They aredesigned to be short (ranging from 1 to 4 ECTS) and cater to working students, typicallyrequiring around 7 hours of learning per week. Moreover, the assessments for these coursesare usually applicable within students' professional settings. UAb decided that the courses arepredominantly asynchronous to take advantage of the flexibility that online learning promotes.Students can access content anytime and from anywhere the flexibility of online learning suitsstudents’ needs and personal and professional commitments (Kumar, 2019) which is particularlyrelevant for adult learners that are, at the same time, employed.
This communication will present an evaluation study of the UAb micro-credentials project, witha focus on assessing students' satisfaction, their perception of the relevance of the learningexperiences, and their views on the pedagogical approach and the framework employed. Giventhe limited research available on substantial cohorts of students attending micro-credentialsand their perception of the value of this type of recognition, this study aims to shed light on howstudents perceive and value micro-credentials. Furthermore, the findings of this research willprovide evidence that can inform other projects and institutions in shaping their strategicobjectives and initiatives in this domain.Impulso 2025, PRR, PortugalN/
Bulk-surface systems on evolving domains
Bulk-surface systems on evolving domains are studied. Such problems appear
typically from modelling receptor-ligand dynamics in biological cells. Our
first main result is the global existence and boundedness of solutions in all
dimensions. This is achieved by proving -maximal regularity of parabolic
equations and duality methods in moving surfaces, which are of independent
interest. The second main result is the large time dynamics where we show,
under the assumption that the volume/area of the moving domain/surface is
unchanged and that the material velocities are decaying for large time, that
the solution converges to a unique spatially homogeneous equilibrium. The
result is proved by extending the entropy method to bulk-surface systems in
evolving domains.Comment: 44 pages. Comments are very welcom
Conception of a good-practices guide to the nature based tourism in the Azores (Portugal)
2011 Shanghai International Conference on Social Science (SICSS 2011) 17-20 August.Azorean archipelago, located in the middle of the North Atlantic Ocean, is packed with natural treasures well known in most parts of the world. In order to preserve them, the Portuguese government has set up a net of protected areas in all nine islands of the archipelago, known as “Island Parks”. Within these protected landscape we find Natura 2000 network, built upon two EC Directives: the Habitats and Birds Directives. Apart from a strict conservation objective, Natura 2000 is supposed to provide some sort of income to local communities, a goal that can be achieved through tourism. But tourism and conservation can collide unless the activities practiced in those areas, follow a set of rules aimed at its preservation. Because tourism usually has impacts upon the environment where it is practiced (e.g. soil erosion, habitat destruction, pollution), more and more tourists become sensitive to environmental protection. Tourism of Nature and Ecotourism are growing sectors within Azorean tourism. Thus, our main concern is to build a field guide of good-practices, to the touristy activities practiced in the protected areas of the Azores. We will present, in pocket guidebooks, all out-door activities that can be practiced on the islands, and where they may occur within each island. According to location, rules and good practices will be explained. A parallel will be established between them and biodiversity conservation. As a result, tourists will be informed about potential dangers to endemic fauna and flora, and be aware of how to protect them by respecting those rules. Two different guides will focus marine and terrestrial activities. The marine guidebook will refer to ludic fishing, snorkeling and scuba-diving, while the terrestrial one will resume the existing trails, speleology, bicycle and climbing.FCT e programa COMPET
Desenvolvimento e teste experimental de sensor resistivo de monitorização da formação de gelo em sistemas de refrigeração
Os sistemas de refrigeração são utilizados no quotidiano, em processos que requerem temperaturas mais baixas do que as disponíveis no ambiente. Para obter essas temperaturas, as serpentinas dos evaporadores atuam, em determinadas situações, com temperaturas inferiores ao ponto de congelação da água. Por consequência, forma-se uma camada de gelo na superfície que é prejudicial ao desempenho térmico do dispositivo.
Para eliminar ou mitigar os efeitos da camada de gelo, são aplicados diversos métodos de descongelação. No entanto, o método de deteção da formação de camada de gelo não é consensual.
No presente trabalho, foi realizado um estudo experimental de um sensor resistivo com o propósito de detetar a formação de gelo. O desempenho do sensor é analisado em função das condições de temperatura e humidade relativa do ar ambiente, da temperatura do fluido refrigerante e do seu posicionamento no evaporador. O princípio do sensor testado assenta na medição da resistência do meio presente entre dois elétrodos. Também foi concebido o suporte para os elétrodos que compõem o sensor, para incorporar na estrutura do evaporador.
Os resultados dos ensaios experimentais permitiram analisar a propagação da camada de gelo na superfície do evaporador e aferir a existência de gelo na superfície do evaporador. Na perspetiva da exatidão da medição, conclui-se que o grau de concordância dos resultados é satisfatório no que toca a deteção de água e elevado na deteção da camada de gelo depositada na superfície do evaporador.The refrigeration systems are used nowadays to preform processes that require lower temperatures than those available in the environment. To obtain those temperatures, the evaporator coils act, in certain situations, with temperatures lower than the water freezing point. Therefore, a frost layer appears on the evaporator’s surface that reduces the thermal performance of the device.
In order to eliminate or mitigate the effects of the frost layer, different defrosting methods can be applied. However, the method for the detection of the frost layer formation is not consensual.
In the present dissertation, an experimental study of a resistive sensor to detect frost formation is developed. The sensor performance is analysed in function of the temperature and relative humidity of air, the temperature of the refrigerant and the relative position of sensor on the evaporator’s surface. The function of the tested sensor lays on the measurement of the medium resistance between two electrodes. In addition, a support for the electrodes was created to be incorporated in the evaporator’s structure.
The results of the experimental study allowed to analyse the propagation of the frost layer and gauge the existence of ice on the evaporator’s surface. From the perspective of the measurement accuracy, it is concluded that the degree of agreement of the results is satisfactory for water detection and high for the detection of the frost layer on the surface of the evaporator
Function spaces, time derivatives and compactness for evolving families of Banach spaces with applications to PDEs
We develop a functional framework suitable for the treatment of partial
differential equations and variational problems on evolving families of Banach
spaces. We propose a definition for the weak time derivative that does not rely
on the availability of a Hilbertian structure and explore conditions under
which spaces of weakly differentiable functions (with values in an evolving
Banach space) relate to classical Sobolev--Bochner spaces. An Aubin--Lions
compactness result is proved. We analyse concrete examples of function spaces
over time-evolving spatial domains and hypersurfaces for which we explicitly
provide the definition of the time derivative and verify isomorphism properties
with the aforementioned Sobolev--Bochner spaces. We conclude with the proof of
well posedness for a class of nonlinear monotone problems on an abstract
evolving space (generalising the evolutionary -Laplace equation on a moving
domain or surface) and identify some additional problems that can be formulated
with the setting developed in this work
Stability and attractivity for Nicholson systems with time-dependent delays
We analyse the stability and attractivity of a class of -dimensional Nicholson systems with constant coefficients and multiple time-varying delays. Delay-independent sufficient conditions on the coefficients are given, for the existence and absolute global exponential stability of a unique positive equilibrium , generalizing and improving known results for autonomous systems. We further establish delay-dependent criteria for to be a global attractor of all positive solutions. In the latter case, upper bounds on the size of the delays which do not require an a priori explicit knowledge of the equilibrium are also derived
Complexos e materiais multifuncionais para a redução de dióxido de carbono
Tese de mestrado, Química (Química), Universidade de Lisboa, Faculdade de Ciências, 2021A elevada concentração dos gases de efeito de estufa (exs.: CO2, H2O, CH4, N2O) na atmosfera terrestre tem levado ao aumento da temperatura média global do planeta Terra que, por sua vez, tem originado alterações climáticas, colocando em risco a vida dos seres vivos que nela habitam. Deste modo, diversos investigadores têm demonstrado interesse na reutilização de CO2, utilizando processos sustentáveis, como por exemplo, a fotocatálise, que utiliza luz solar como fonte de energia. Neste âmbito, esta dissertação de mestrado explora a aplicação de diferentes complexos de coordenação e materiais no processo de fotorredução de CO2, sendo que está dividida em sete capítulos e os anexos. O Capítulo 1 consiste na introdução do tema desta dissertação, realçando a importância da redução de CO2 em moléculas de interesse industrial (exs.: CO, HCOOH, CH3OH, CH4), tendo em conta as alterações climáticas. Neste âmbito, é destacado o processo de fotocatálise, descrevendo os vários tipos de sistemas fotocatalíticos, mecanismos e componentes necessários, dando enfase à utilização de complexos de metais de transição e de materiais semicondutores. Por outro lado, são também elucidadas as vantagens de aplicar os derivados de salen como catalisadores neste processo. Em todas as secções é realizada uma pequena revisão da literatura sobre o tópico em questão. Por fim, apresentam-se os objetivos da dissertação. O Capítulo 2 refere-se à síntese e caraterização de compostos moleculares utilizados como catalisadores, nomeadamente, cinco complexos derivados de salphen mononucleares de Ni(II) e Co(II) (MLn; M = Ni(II), Co(II); n = 1, 2, 3) e dois binucleares de Ni(II) (Ni2Ln; n = 1, 2) com diferentes substituintes nos anéis aromáticos e também, um novo complexo octaédrico [Co(bpp)2][PF6]2. Apresentam-se, ainda, as tentativas de síntese de um complexo binuclear de Ru(II) e Ni(II). As técnicas de caraterização utilizadas foram a espetroscopia de ressonância magnética nuclear, espetroscopia de infravermelho com transformada de Fourier, espetroscopia de ultravioleta-visível de líquidos e análise elementar. O Capítulo 3 aborda a síntese dos materiais g-C3N4 e g-C3N4-CoL1, sendo este último novo, e a sua caraterização pelas técnicas de espetroscopia de infravermelho com transformada de Fourier, espetroscopia de ultravioleta-visível de sólidos e difração de raios-X de pós. Os estudos de fotorredução de CO2 encontram-se no Capítulo 4. Testaram-se sistemas fotocatalíticos homogéneos e coloidais, variando o catalisador (complexos derivados de salphen e [Co(bpp)2][PF6]2), fotossensibilizador molecular ([Ru(phen)3][PF6]2, purpurina, fluoresceína e eosina Y) ou material semicondutor (pontos quânticos de CdTe e g-C3N4), dador sacrificial de eletrões (trietanolamina e 1,3-dimetil-2-fenil-2,3-dihidro-1H-benzo[d]imidazole), mistura de um solvente orgânico (acetonitrilo, N,N’-dimetilformamida e metanol) com água, fonte de luz (LEDs e simulador solar) e montagem. Analisaram-se os produtos gasosos por cromatografia em fase gasosa com detetor de condutividade térmica e avaliou-se a performance fotocatalítica. Na fotorredução homogénea apenas os sistemas com [Ru(phen)3][PF6]2 levaram à redução de CO2, produzindo CO com elevada seletividade e H2 como produto minoritário. Neste sistema, a mistura de solventes acetonitrilo:água favoreceu a produção de CO, tal como a utilização do centro metálico de Co(II) e do substituinte terc-butilo nos complexos derivados de salphen mononucleares. Os catalisadores binucleares de Ni(II) não demonstraram efeito sinergético entre as unidades [Ni(salphen)]. Por outro lado, o [Co(bpp)2][PF6]2 demonstrou melhor atividade catalítica que os complexos derivados de salphen. A utilização de LEDs azuis face à lâmpada simuladora do espetro solar com filtro azul, resultou em melhor atividade fotocatalítica. A substituição dos catalisadores pelos precursores da sua síntese, demonstrou uma maior produção de CO e seletividade idêntica. O ensaio sem catalisador demonstrou atividade para a produção de CO, no entanto, a adição de catalisador foi essencial para que o sistema seja catalítico. Na fotorredução coloidal apenas o sistema com pontos quânticos de CdTe e NiL2 levou à redução de CO2, sendo que a quantidade de pontos quânticos de CdTe utilizada condicionou o tipo, quantidade e seletividade dos produtos obtidos (H2, CO, CH4). Os restantes sistemas fotocatalíticos levaram apenas à produção de H2 ou de nenhum produto gasoso. No Capítulo 5 encontram-se as principais conclusões dos resultados obtidos tal como as perspetivas. No Capítulo 6 encontra-se informação adicional e detalhes experimentais dos capítulos 2-4. As referências encontram-se no Capítulo 7. Por fim, os Anexos contêm figuras suplementares
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