1,923 research outputs found

    Field-effect transistors based on Zinc oxide nanoparticles

    Get PDF
    This work reports the development of field-effect transistors (FETs), whose channel is based on zinc oxide (ZnO) nanoparticles (NPs). Using screen-printing as the primary deposition technique, different inks were developed, where the semiconducting ink is based on a ZnO NPs dispersion in ethyl cellulose (EC). These inks were used to print electrolyte-gated transistors (EGTs) in a staggered-top gate structure on glass substrates, using a lithium-based polymeric electrolyte. In another approach, FETs with a staggered-bottom gate structure on paper were developed using a sol-gel method to functionalize the paper’s surface with ZnO NPs, using zinc acetate dihydrate (ZnC4H6O4·2H2O) and sodium hydroxide (NaOH) as precursors. In this case, the paper itself was used as dielectric. The various layers of the two devices were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric and differential scanning calorimetric analyses (TG-DSC). Electrochemical impedance spectroscopy (EIS) was used in order to evaluate the electric double-layer (EDL) formation, in the case of the EGTs. The ZnO NPs EGTs present electrical modulation for annealing temperatures equal or superior to 300 ºC and in terms of electrical properties they showed On/Off ratios in the order of 103, saturation mobilities (μSat) of 1.49x10-1 cm2(Vs)-1 and transconductance (gm) of 10-5 S. On the other hand, the ZnO NPs FETs on paper exhibited On/Off ratios in the order of 102, μSat of 4.83x10- 3 cm2(Vs)-1and gm around 10-8 S

    Efeitos da suplementação com Ômega 3 sobre comportamentos relacionados à depressão em camundongos adultos expostos a estresse crônico

    Get PDF
    The characteristics of depression, in a general way, are sadness ou irritability, somatic and cognitive changes that generate huge prejudices to the global action capacity of the individual, alternating affection and neurovegetative functions. It’s not yet known the specific causes of the depressive disorder, although some researches point to a multifunctional physiopathology, hypothalamic and neurotransmission disorder. A possibility is that it occurs some disturbs in the monoaminergic transmission, reducing serotonin neurotransmission (5-HT), norepinephrine (NE) and dopamine (DA). In relation to dopamine neurotransmission, researches point that omega-3 supplementation (ω-3) on rats diet generates a 40% increase on the DA levels in the frontal cortex, such as on the DA receptor connection, which is appropriate to the dopaminergic system and behavior performance on animal adult age. Depression is also associated to high cortisol levels on the blood due to hypothalamic-pituitary-adrenal (HPA) axis malfunction. The eicosapentaenoic acid found on ω-3 can regulate the HPA axis, reducing the corticotropin (CRF) liberating hormone and the cortisol secretion. These factors demonstrate the possible antidrepressive action, modulating the oxidative reactions and the inflammatory cytokines production on the microglia and neuronal cells. In this way, this project had the objective of evaluating the effects of chronic stress by the restriction of movement, as well as the Omega 3 supplementation, being 10 microliters by animal, under the depression related behavior, studied by the behavior of Forced Swimming test. During 15 days, the animals (Balb C mouse), were divided in 4 groups: the first group received H2O, the second received ω-3, the third received H2O + stress (ES) and the fourth received ω-3 + ES. The stress was generated by movement restriction protocol that lasted 2 hours and received ω-3 or water, administrated by gavage twice by day. On the Forced Swimming test there were no significant differences between groups, although they were treated by ω-3 and the ones who weren’t exposed to stress has presented the fastest immobility time, suggesting a possible neuroprotector effect. On the used protocol in our experiments, the stress by restriction of movement hasn’t increased the behaviors related to depression and the ω-3 on the used dose, hasn’t presented neuroprotection.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorTrabalho de Conclusão de Curso (Graduação)As características da depressão de uma forma geral são humor triste ou irritável, alterações somáticas e cognitivas que geram grandes prejuízos à capacidade de ação global do indivíduo, alterando o afeto e as funções neurovegetativas. Ainda não são conhecidas as causas especificas do transtorno depressivo, porém alguns pesquisadores apontam para uma fisiopatologia multifuncional, disfunção hipotalâmica e de neurotransmissão. Uma possibilidade é que ocorram distúrbios na transmissão monoaminérgica, reduzindo a neurotransmissão de serotonina (5-HT), norepinefrina (NE) e dopamina (DA). Em relação à neurotransmissão de dopamina, pesquisas apontam que a suplementação de omega-3 (ω-3) na dieta de ratos gera aumento de 40% nos níveis de DA no córtex frontal, assim como na ligação com o receptor de DA, o que é apropriado para o desenvolvimento do sistema dopaminérgico e para o desempenho comportamental na idade adulta dos animais. A depressão também é associada à níveis elevados de cortisol no sangue devido à uma disfunção no eixo hipotalamo-hipófise-adrenal (HPA). O acido eicosapentaenoico (EPA) presente no ω-3 pode regular a disfunção do eixo HPA reduzindo o hormônio liberador de corticotropina (CRF) e a secreção de cortisol. Esses fatores demonstram a possível ação antidepressiva do (ω-3), modulando reações oxidativas e a produção de citocinas inflamatórias na micróglia e células neuronais. Neste sentido este projeto objetivou avaliar os efeitos do estresse crônico por restrição de movimentos bem como da suplementação com Ômega 3, sendo 10 microlitros por animal, sobre comportamentos relacionados à depressão, avaliados por meio do teste comportamental de Nado Forçado. Durante 15 dias os animais (camundongos Balb c) foram divididos em 4 grupos: sendo que o primeiro recebeu H2O, o segundo recebeu ω-3, o terceiro H2O + estresse (ES) e o quarto ω-3 + ES. O estresse foi gerado por um protocolo de restrição de movimento durante 2 horas e receberam ω-3 ou água, administradas por gavagem duas vezes ao dia. No teste de Nado Forçado não houve diferença significativa entre os grupos, embora o grupo tratado com ω-3 e que não foi exposto ao estresse tenha apresentado o menor tempo de imobilidade, sugerindo um possível efeito neuroprotetor. No protocolo utilizado em nossos experimentos, o estresse por restrição de movimento não aumentou os comportamentos relacionados à depressão e o ω-3, na dosagem utilizada, não apresentou efeito neuroprotetor

    Consumer behaviour in the luxury industry : getting a grasp on consumers’ intrinsic and extrinsic motivations

    Get PDF
    To our knowledge, previous studies have mostly focused on understanding reasons that lead to the purchase of luxury products, not focusing on characterizing consumers and understanding the similarities and differences on their decision-making processes. Therefore, the aim of this thesis was to provide a better understanding of luxury consumers, identifying luxury consumption beliefs and motivations and characterizing possible different profiles of the global consumer of luxury goods. To perform this analysis, first a literature review was done in order to understand what could be the drivers that lead someone to need or desire a luxury good. The outcome was a conceptual framework for luxury consumption that enables the reader to understand that there are two main orientations that a consumer can pursue when buying a luxury good: A personal and/or a social one. After this hypothesis, a cluster analysis was performed in order to find homogeneous groups of consumers that would have similar behaviours. In the end, three clusters were originated, enabling to define three different profiles of consumers and their motivations when buying luxury products. Despite the limitations and necessary steps in future research, the primary contribution of this thesis was to develop a framework for luxury consumption, integrating personal and social orientation drivers, in order to characterize and identify relevant behavioural patterns across different segments of customers in the market, enabling luxury brands to better understand their customers and their characteristics to create more efficient marketing strategies.Com base nos nossos conhecimentos, estudos anteriores focaram-se principalmente na compreensão de razões que levam à compra de produtos de luxo, não incidindo sobre a caracterização dos seus consumidores e o entendimento das semelhanças e diferenças nos seus processos de decisão. Desta forma, o objectivo desta tese foi proporcionar uma melhor compreensão dos consumidores de luxo, identificando as suas crenças e motivações, possibilitando caracterizar diferentes perfis do consumidor mundial de produtos de luxo. Para realizar esta análise, em primeiro lugar, foi feita uma revisão de literatura para se compreender quais poderiam ser os drivers que levam alguém a necessitar ou desejar um bem de luxo. O resultado foi uma conceptual framework para o consume de luxo, que permite ao leitor compreender que existem duas principais orientações que um consumidor pode seguir quando compra um bem de luxo: Uma orientação pessoal e/ou uma orientação social. Após esta hipótese, foi realizada uma análise de clusters a fim de encontrar grupos homogéneos de consumidores que tivessem um comportamento similar. No final, três grupos surgiram, permitindo definir três diferentes perfis de consumidores e as suas motivações ao comprar produtos de luxo. Apesar das limitações e passos necessários em futuras pesquisas, a principal contribuição desta tese foi desenvolver uma conceptual framework de consumo de bens de luxo, integrando drivers de orientação pessoal e social, a fim de caracterizar e identificar padrões comportamentais relevantes em diferentes segmentos de clientes no mercado. Esta análise permite que as marcas de luxo possam entender melhor os seus clientes e as suas características de forma a criar estratégias de marketing mais eficientes

    Cyber warfare in the context of international criminal law

    Get PDF
    The conceptions of warfare and battlefield have astonishingly evolved, going from a traditional view of military ammunition performed in land, sea or air, to the most novel electronic devices which rule today’s international conflict strategies in cyberspace. Some examples of the latter weapons operating in the so-called fifth domain, like pen drives, drone strikes, keyboards and malware, are even considered innocuous at the first glimpse, especially when compared to other type of classic artillery. Howbeit, these gadgets were the ones that fostered the current limitless cyber race – which was noticeably triggered by the cyber attack occurred in Estonia (2007) – and has since then proved capable of causing way more alarming consequences, mainly if targeting critical national infrastructures. This present dissertation will dwell on the analysis of the enforcement of international law bodies towards acts of cyber war carried out by state or non-state agents, taking into specific consideration the application of the international criminal law norms. Thereunder, the focus of the study will remain on the characterization of cyber attacks, as either potential crimes of war or aggression

    Supervisión en Enfermería: Estudiar el "caso" del fenómeno de la articulación interorganizacional Escuela de Enfermería y Hospital

    Get PDF
    A história desta investigação encontrou um ethos propício não só pelo percurso da investigadora, mas também pelas atuais políticas públicas de modernização e de reforma capazes de regular e transformar os sistemas educativos e de saúde, bem como os seus grupos profissionais. A reflexão entretanto desenvolvida suscitara uma perceção vincada dos processos organizacionais de mudança pelos quais estes interferiam na articulação interorganizacional Escola de Enfermagem e Hospital, onde a supervisão de estágios seria a grande protagonista, sustentada pelos significados que os atores intervenientes lhes têm atribuído. A pesquisa explícita de opções epistemológicas e metodológicas levou a olhar para o problema de uma forma mais atenta, apurando-o, tendo em conta as dimensões organizacionais. A opção por um estudo de caso prendeu-se com o facto de o método permitir responder ao propósito de conhecer e compreender o fenómeno da articulação interorganizacional Escola de Enfermagem e Hospital, concretamente através da supervisão de estágios.La historia de esta investigación encontró un ethos propicio no solamente por la ruta de la investigadora, pero también por las actuales políticas públicas de modernización y de reformas capaces de regular y transformar los sistemas educativos y de salud, y sus grupos profesionales. La reflexión mientras desarrollada ha suscitado una percepción incrementada, aunque algo difusa, sobre los procesos de cambio organizacionales, pelos cuales se interfería en la articulación interorganizacional Escuela de Enfermería y Hospital, y como tal, la supervisión de prácticas seria la gran protagonista sustentada pelos significados que los actores intervinientes les tienen atribuido. En este alcance, al procurarse explicitar las opciones epistemológicas y metodológicas se mira el problema de una forma más atenta, apurándolo, teniendo en cuenta las dimensiones organizacionales. En este sentido, la opción por un estudio de caso se ha prendido con el hecho de que el método permite responder al propósito de conocer y comprender el fenómeno de la articulación interorganizacional Escuela de Enfermería y Hospital, concretamente a través de la supervisión de prácticas.The history of this research found a suitable ethos not only by the route of the researcher, but also by the current public policies of modernization and reform that are capable of regulating and transforming the educational and health systems, as well as their professional groups. The reflection meantime developed had raised a clear perception of the organizational change processes by which they interfered with the interorganizational coordination between School of Nursing and Hospital, where internship supervision would be the main protagonist, supported by the meanings that intervening actors have assigned to them. In this context, the search for explicit epistemological and methodological choices leads to look more attentively at the problem, ascertaining it, taking into account the organizational dimensions. In this regard, the choice of a case study was related to the fact that the method allowed to answer the purpose of knowing and understanding the interorganizational coordination phenomenon between School of Nursing and Hospital, namely through the supervision of internships

    Innovation and productivity: empirical evidence for Brazilian industrial enterprises

    Get PDF
    El objetivo en este trabajo es realizar una investigación empírica sobre la relación entre la innovación y el desempeño productivo de las empresas industriales en Brasil medido por Productividad Laboral y Productividad Total de Factores. Se han utilizado datos de la Encuesta de Innovación y se han estimado modelos de corte transversal y datos de panel. Dada la pequeña magnitud de los coeficientes relacionados con los diversos indicadores de innovación, los resultados sugieren que la innovación produce impacto incipiente en la productividad de la industria nacional.Neste artigo, tem-se como objetivo realizar uma investigação empírica acerca da relação entre inovação e desempenho produtivo das empresas industriais brasileiras medido por Produtividade do Trabalho e Produtividade Total dos Fatores. Foram utilizados dados provenientes da Pesquisa de Inovação e estimados modelos cross section e de dados em painel. Dada a pequena magnitude dos coeficientes associados aos diversos indicadores de inovação, os resultados sugerem que a inovação produz impacto incipiente na produtividade da indústria nacional.The aim of this paper is to carry out an empirical investigation into the relationship between innovation and the productive performance of Brazilian businesses measured by Work Productivity and Total Factor Productivity. Data taken from the Research of Innovation and estimated cross section models and panel data was used. The results suggest that innovation produces an incipient impact on competition in the national industry, reflected in the small magnitude of coefficients associated with the diverse indicators of innovation

    Costs and Benefits of Privatization: Evidence from Brazil

    Get PDF
    Although the Brazilian privatization program has been a sweeping endeavor involving more than 100 firms and billions of dollars, most of the studies have been published only in Brazil, and in Portuguese. This paper is the most comprehensive study to date in terms of the companies covered, and includes the most recent data. It looks at the results of privatization in Brazil for a broad range of economic variables to answer the question: Has the widespread popular discontent with the program been justified? The paper also examines the effects of privatization on aspects that affect the development of financial markets, including minority shareholder rights. It concludes with recommendations for democratizing capital ownership through public offers in which workers would be entitled to participate using public sector liabilities such as FGTS deposits.

    A avaliação da leitura no Brasil entre os anos 2014-2020: instrumentos e habilidades

    Get PDF
    Este artigo apresenta os resultados de uma pesquisa de revisão sistemática que teve como tema geral a avaliação da leitura. O problema que moveu a pesquisa foi: Que parâmetros, critérios e condições da avaliação podem ser distinguidos nas investigações sobre a avaliação da leitura no Brasil? Objetivou-se, portanto, identificar, caracterizar e discutir pesquisas que foram realizadas no Brasil sobre a avaliação da leitura, entre os anos 2014 e 2020. Neste estudo, focalizaram-se três aspectos centrais das 151 publicações selecionadas, conforme rigorosos critérios de inclusão descritos no método: 1) os processos cognitivos investigados; 2) as habilidades de leitura medidas; e 3) os instrumentos de testagem utilizados. Como critério de análise foram observados os perfis das pesquisas (tipo, ano, local, instituição de vínculo, programa de pós-graduação, autoria, base de dados) e os seus conteúdos (foco, objetivo, público-alvo, instrumento de avaliação da leitura, habilidades medidas, resultados). A análise indicou que as pesquisas experimentais, voltadas principalmente para estudantes dos primeiros anos do Ensino Fundamental, foram as mais frequentes, tendo como processos cognitivos investigados pela maioria a decodificação e suas habilidades relacionadas (reconhecimento de palavras, acesso lexical e fluência). Os resultados mostraram ainda que, de forma geral, os métodos de pesquisa são relatados com poucos detalhes, o que limita a identificação das justificativas para balizar as decisões de elaboração ou escolha dos instrumentos empregados. Além disso, entende-se que a falta de rigor ou clareza desses aspectos também dificulta ao leitor a compreensão de como a pesquisa foi desenvolvida e do quão confiável ela é.This paper presents the results of a systematic review on reading assessment. The problem that inspired the research was: What parameters, criteria, and assessment conditions can be distinguished in investigations on reading assessment in Brazil? Therefore, the goal was to identify, characterize, and discuss studies that were carried out on reading assessment in Brazil between 2014 and 2020. The focus of the study was on three central aspects of the 151 selected publications, according to the strict inclusion criteria described in the method: 1) the investigated cognitive processes, 2) the measured reading skills, and 3) the testing instruments used. As a criterion for analysis, we observed the research profiles (type, year, location, institution, graduate program, authorship, database) and their contents (focus, objective, target audience, reading evaluation instrument, measured skills, results). The analysis indicated that experimental studies, aimed mainly at students in the first grades of elementary school, were the most frequent, with decoding and its related skills as the most commonly investigated cognitive processes (word recognition, lexical access, and fluency). The results also showed that, in general, authors report the research methods with little detailing, which limits the identification of arguments to guide the decisions concerning elaboration or choice of instruments used. In addition, the lack of rigor or clarity of these aspects also makes it difficult for readers to understand the development of the studies and evaluate their reliability

    The Expected Impact of Climate in the Grapevine Culture, in Madeira Region, Portugal

    Get PDF
    It's increasingly important to know the effects of climate change on crops. This study aimed to determine the bioclimatic indices for the main wine-growing areas of Madeira island, for the current period and for two simulated climate scenarios to understand the potential and limits that will be imposed on the development of vine culture. The climate characterization process was mainly based on the Multicriteria Climatic Classification System (Géoviticulture MCC System) and used for the Winkler Index (WI), used to describe the suitability of crop cultivation in different climates. Heliothermal Index (HI) in general, showed that the regions analysed will not change in terms of heat accumulation, except for the region of Quinta Grande and Santana. For the Night Cold Index (CI), the regions of Quinta Grande, São Vicente, and Santana currently have minimum ideal temperatures for a good maturation of the vineyards. The Dryness Index (DI) showed that currently and in the simulated scenarios, all regions have not suffered from drastic water restrictions. In the regions of Quinta Grande, São Vicente, Ponta do Pargo, and Santana according to the Winkler Index (WI), the quality of the wines will change if the results of the simulations come true.info:eu-repo/semantics/publishedVersio
    corecore