596 research outputs found
A perturbed elliptic problem involving the p(x)-Kirchhoff type triharmonic operator
This paper examines the existence of weak solutions for a nonlinear boundary value problem of p(x)-Kirchhoff type involving the p(x)-Kirchhoff type triharmonic operator and perturbed external source terms. We establish our results by using a Fredholm-type result for a couple of nonlinear operators, in the framework of variable exponent Sobolev spaces
Hall viscosity in the non-Abelian quantum Hall matrix model
Quantum Hall matrix models are simple, solvable quantum mechanical systems
which capture the physics of certain fractional quantum Hall states. Recently,
it was shown that the Hall viscosity can be extracted from the matrix model for
Laughlin states. Here we extend this calculation to the matrix models for a
class of non-Abelian quantum Hall states. These states, which were previously
introduced by Blok and Wen, arise from the conformal blocks of
Wess-Zumino-Witten conformal field theory models. We show that the Hall
viscosity computed from the matrix model coincides with a result of Read, in
which the Hall viscosity is determined in terms of the weights of primary
operators of an associated conformal field theory
Computer-controlled ion-selective electrode switch
The construction of a microcomputer-controlled electrode switch for
use in potentiometric determinations is described. This can be coupled to most of the analytical equipment usually found in laboratories, to enable a setting up of automatic systems capable of performing sequential determinations with several ion-selective
electrodes. The assessment of its analytical usage and behaviour are discussed
Atividade antimicrobiana de subfrações padronizadas da planta Arrabidaea chica Verl.
Este estudo analisou o potencial terapêutico de extratos e subfrações padronizadas da planta amazônica Arrabidaea chica, visando seu uso tópico como medicamento e eficácia comprovada em doenças cutâneas
Drawbacks of ovarian ablation with goserelin in women with breast cancer
In the last few years, ovarian ablation with GnRH agonists has been used as first-line adjuvant therapy in pre and perimenopausal breast cancer. These drugs suppress ovarian function in the hypothalamic-pituitary axis and they have adverse effects in other end-organs. A retrospective study was conducted on 35 premenopausal women, with breast cancer, and treated with goserelin, in order to investigate the effects of iatrogenic estrogen suppression. All women complaint of amenorrhea and only half of them referred hot-flashes, weight gain or arthralgias. Hot-flushes and arthralgias remit spontaneously in the end of the treatment. Osteodensitometry was used to access bone mass. There was a reduction in mineral bone mass and T-score at femoral neck and lumbar spine after the treatment with goserelin, but without statistical significance, except for the T-score in lumbar spine
Redes sociais online: Um contributo positivo para o capital social dos seniores em Portugal
No âmbito da inclusão digital do segmento sénior, que hoje representa um quinto da população mundial e cujos dados do Eurostat (2017) apontam para que em 2080 a percentagem de pessoas com mais de 80 anos duplique, têm-se desenvolvido e implementado novas políticas digitais e sociais. O artigo pretende analisar a relação dos seniores com as Tecnologias da Informação e da Comunicação (TIC) e a sua inclusão no mundo das redes sociais online em Portugal, bem como perceber a importância e o contributo destas para o seu capital social. Partindo da análise conceptual de capital social e da sua relação com os laços sociais no mundo das redes sociais online dos seniores, desenvolveu-se um estudo que demonstra em que medida as redes sociais online contribuem para aumentar o capital social dos seniores portugueses. Os dados foram recolhidos através de um inquérito por questionário online, seguindo uma estratégia amostral por conveniência, entre 29 de setembro e 15 de novembro de 2019, junto de indivíduos com mais de 65 anos que acedem à internet. Explorámos campos de investigação em desenvolvimento, atestando com os dados como as redes sociais online fazem parte das vidas dos seniores e como estas apoiam na socialização e promoção dos seus relacionamentos interpessoais ao nível dos laços fortes e fracos.info:eu-repo/semantics/publishedVersio
Portuguese seniors in confinement: The contributions of online social networks to combat social isolation and loneliness
Durante o confinamento por motivo da pandemia COVID-19 em Portugal, os seniores viram as suas atividades sociais e familiares interrompidas. O isolamento social e a solidão eram um desafio a superar por se encontrarem afastados dos familiares e amigos e, até privados das suas rotinas diárias e atividades de lazer. Considerando que as redes sociais online se tornaram uma forma de socialização e de integração social para alguns seniores em Portugal e atendendo a que o seu uso está positivamente ligado à inclusão social (Richter et al., 2013), procedeu-se a um estudo com base em entrevistas semiestruturadas por telefone durante o confinamento. A amostra não probabilística e por conveniência abrangeu 19 seniores com perfil criado no Facebook. Os dados tratados em MAXQDA2020 visaram as abordagens qualitativa e quantitativa sustentadas em análise categorial. Com esta pesquisa pretendeu-se analisar os comportamentos dos seniores face ao uso das redes sociais online e como estas poderiam contribuir para minimizar o isolamento social e ajudar a reduzir o sentimento de solidão. A investigação evidenciou a existência de uma maior propensão destes indivíduos no uso das redes sociais online. Especificamente, utilizaram o Facebook para comunicarem, se relacionarem e manterem o contacto com a sua rede e como forma de entretenimento para ocuparem o tempo livre. Outra descoberta importante desta investigação foi os seniores possuírem, em período de maior isolamento, uma maior predisposição para o uso de novas ferramentas e plataformas que os ajudaram a manter os relacionamentos, as atividades offline e a participação social.info:eu-repo/semantics/publishedVersio
Biomass Valorization to Produce Porous Carbons: Applications in CO2 Capture and Biogas Upgrading to Biomethane—A Mini-Review
UIDB/50006/2020 UIDP/50006/2020 LA/P/0008/2020Porous carbon materials, derived from biomass wastes and/or as by-products, are considered versatile, economical and environmentally sustainable. Recently, their high adsorption capacity has led to an increased interest in several environmental applications related to separation/purification both in liquid- and gas-phases. Specifically, their use in carbon dioxide (CO2) capture/sequestration has been a hot topic in the framework of gas adsorption applications. Cost effective biomass porous carbons with enhanced textural properties and high CO2 uptakes present themselves as attractive alternative adsorbents with potential to be used in CO2 capture/separation, apart from zeolites, commercial activated carbons and metal-organic frameworks (MOFs). The renewable and sustainable character of the precursor of these bioadsorbents must be highlighted in the context of a circular-economy and emergent renewable energy market to reach the EU climate and energy goals. This mini-review summarizes the current understandings and discussions about the development of porous carbons derived from bio-wastes, focusing their application to capture CO2 and upgrade biogas to biomethane by adsorption-based processes. Biogas is composed by 55–65 v/v% of methane (CH4) mainly in 35–45 v/v% of CO2. The biogas upgraded to bio-CH4 (97%v/v) through an adsorption process yields after proper conditioning to high quality biomethane and replaces natural gas of fossil source. The circular-economy impact of bio-CH4 production is further enhanced by the use of biomass-derived porous carbons employed in the production process.publishersversionpublishe
A música na lupa da psicologia face à pandemia: Covid19!
The world went out of tune with the sound of a virus called Covid19, and if music was already important in our lives, it became more and more important in this mandatory quarantine for millions of habitants of planet Earth. Music emerges as a strategy for good mental health to alleviate the confrontation with the reduction of freedom that they abruptly found themselves having to accept. Thus, this exploratory study arises not only to analyze a song in its construction, planning, choice of tonic (the note that “sends”), but in what frequency vibrates, for example, the frequency 329Hz. This frequency is associated with improvements in breathing, in grounding (basis / knowledge of the facts) and improves the state of flow (flow state: mental state of operation in which the person is totally immersed in what he is doing, characterized by a total feeling involvement and success in the activity process). In this way we will try to investigate how music works, as well as placing music in the lens of Psychology at the service of the community in the face of this pandemic!O mundo desafinou ao som de um vírus chamado Covid19, e se já era importante a música na nossa vida, mais significativa se tornou, de extrema importância nesta quarentena obrigatória para milhões de habitantes do planeta terra. A música surge como estratégia para uma boa saúde mental para aliviar o confronto com a redução de liberdade que se viram abruptamente a ter que aceitar. Assim surge este estudo exploratório não só para analisarmos uma música na sua construção, planeamento, escolhas de tónicas (a nota que “manda”), como em que frequência vibra, exemplo, a frequência 329Hz. Esta frequência está associada a melhorias na respiração, no grounding (base/conhecimentos dos factos) e melhora o estado de fluxo (flow state: estado mental de operação na qual a pessoa está totalmente imersa no que está a fazer, caracterizado por um sentimento total de envolvimento e sucesso no processo de atividade). Assim procuraremos perscrutar como funciona a música, bem como colocar a música na lupa da Psicologia ao serviço da comunidade face a esta pandemia
SCALE ANALYSIS OF DECAY HEAT REMOVAL SYSTEM BETWEEN HTR-10 AND HTR-PM REACTORS UNDER ACCIDENTAL CONDITIONS
The 10 MW high-temperature gas-cooled test module (HTR-10) is a graphite-moderated and helium-cooled pebble bed reactor prototype that was designed to demonstrate the technical and safety feasibility of this type of reactor project under normal and accidental conditions. In addition, one of the systems responsible for ensuring the safe operation of this type of reactor is the passive decay heat removal system (DHRS), which operates using passive heat removal processes. A demonstration of the heat removal capacity of the DHRS under accidental conditions was analyzed based on a benchmark problem for design-based accidents on an HTR-10, i.e., the pressurized loss of forced cooling (PLOFC) described in technical reports produced by the International Atomic Energy Agency. In fact, the HTR-10 is also a proof-of-concept reactor for the high-temperature gas-cooled reactor pebble-bed module (HTR-PM), which generates approximately 25 times more heat than the HTR-10, with a thermal power of 250 MW, thereby requiring a DHRS with a higher system capacity. Thus, because an HTR-10 is a prototype reactor for an HTR-PM, a scaling analysis of the heat transfer process from the reactor to the DHRS was carried out between the HTR-10 and HTR-PM systems to verify the distortions of scale and the differences between the main dimensionless numbers from the two project
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