8,105 research outputs found
DETERMINATION OF A HIGHER-ORDER ELASTIC CONSTANT OF A SINGLE FILAMENT OF HEXTOW IM7-12K CARBON FIBER USING FINITE DEFORMATIONS
The modulus of elasticity of a homogeneous body is the same for all directions. No known crystalline materials have a Young\u27s modulus that is the same in all directions. The linear theory of elasticity states that strain is proportional to stress so that a straight line is obtained in a stress versus strain plot. As long as the forces applied to the body are proportional, the body behaves perfectly elastically, obeying Hooke\u27s law. At high enough strains, however, deviations from Hooke\u27s law will occur. Nonlinear elasticity is generally apparent when large deformations are applied and usually when the sample size is on the micro/nano scale. The nonlinear theory of elasticity of materials is more complex and leads to the introduction of higher-order elastic constants. These higher-order constants confer increased accuracy to theoretical predictions of the elastic behavior of the material. Here, equipment specifically designed for the tensile measurements of individual micro/nano-composite fibers will be introduced. The results obtained for the elastic properties of single filaments of IM7 carbon fibers, which include the usual second-order as well as the third-order elastic constants, and the piezoresistivity will be presented
Gas-phase surface oxidation and chlorination of carbon nanotubes
Carbon nanotubes (CNTs) have many desirable bulk properties, such as, very good mechanical strength, high thermal stability, and excellent electric conductance for potential use in a variety of applications. However, their surfaces often require modification in order to achieve functionality. An important first step in the adhesion to the nanotubes is often surface oxidation. To control the metallic and semiconducting properties of CNTs, electron withdrawing halogen atoms are usually covalently bonded to the surface. In this present Thesis, single-walled CNTs (SWCNT) powder and multi-walled CNTs (MWCNT) paper were modified with gaseous oxygen and chlorine atoms. The following investigations were performed: 1) UV photo-oxidation of MWCNT paper at room temperature and atmospheric pressure with wavelengths from low-pressure Hg lamps (&lambda = 253.7 and 184.9 nm) that have sufficient energy to photo-dissociate gaseous oxygen producing mainly ozone and result in chemical surface modification of the samples; 2) SWCNT powder was surface oxidized at room temperature with gaseous oxygen atoms produced by low-pressure vacuum UV (VUV) photo-oxidation (&lambda = 104.8 and 106.7 nm); 3) MWCNT paper and SWCNT powder were surface oxidized without the presence of radiation at room temperature with gaseous oxygen atoms produced from a microwave (MW) plasma discharge of an argon and oxygen (Ar-O2) mixture; 4) UV photo-chlorination of MWCNT paper and SWCNT powder at room temperature with wavelengths from medium-pressure Hg lamps (centered at ca. 300 nm for Cl2 at ca. 100 torr gas pressure) and low-pressure Hg lamps (&lambda = 253.7 and 184.9 nm for HCl at ca. 40 torr gas pressure) that have sufficient energy to photo-dissociate gaseous Cl2 and HCl producing chlorine atoms and result in chemical surface modification of the samples. The carbon-, oxygen- and chlorine-containing functional groups in the top 2 - 5 nm of the sample\u27s surface were analyzed by X-ray photoelectron spectroscopy (XPS)
Questions controversées de l’applicabilité des motifs de justification pour les delits coupables
El presente artículo trata de cuestiones controvertidas en la aplicación de las causas de justificación, que afectan a la relación existente entre tipicidad y antijuridicidad, y de esta con la culpabilidad, en el ámbito de los delitos imprudentes. Esas cuestiones se revelan todavía más problemáticas cuando a ellas añadimos consideraciones acerca del error en las causas de justificación y su repercusión en el ámbito de la punibilidad de los delitos imprudentes. Todos esos aspectos serán discutidos con el objetivo de manifestar nuestra opinión al respecto, polemizandolas posturas de los diferentes sectores de la doctrina.The present article deals with controversial issues, both concerning the application of claims of justification and affecting the relationship between typification of a crime and wrongdoing, as well as between the latter and culpability, in the sphere of negligent crimes. The said issues appear even more troublesome when considerations on error regarding claims of justification and its implications for the criminality of negligent crimes are taken into account. All these points will be discussed, debating the positions of the different sectors of doctrine, with the aim of expressing our views on the matter.Cet article traite des questions controversées dans la mise en
oeuvre des causes de justification, qui affectent la relation entre la typicité, l’antijuridicité et la culpabilité en les delits coupables. Ces questions sont révélés encore plus problématique quand il ajoute des considérations sur l’erreur dans les motifs de justification et de leur impact sur la punition des delits coupables. Tous ces aspects seront discutés avec le but d’exprimer notre opinion sur la question, arguant des positions des différents secteurs de la doctrine
Inovação educativa e subjetividade : a configuração da dimensão histórico-subjetiva implicada em um projeto inovador
Tese (doutorado)—Universidade de Brasília, Faculdade de Educação, Programa de Pós-Graduação em Educação, 2012.A presente pesquisa tem como tema a inovação educativa entendida como a introdução de novidades nos processos educacionais que visam gerar transformações e melhorias na instituição escolar. Busca-se compreender a inovação educativa a partir de uma visão complexa articulando diferentes aspectos bem como, a partir da perspectiva da subjetividade, tal como concebida na teoria histórico-cultural da subjetividade de González Rey. Nessa perspectiva teórica, a subjetividade se expressa e se constitui na sua dupla condição, social e individual. Desta forma, a pesquisa tem como objetivo compreender a configuração de elementos que possibilitam a inovação educativa, investigando a articulação de elementos históricos, contextuais e subjetivos. Realizou-se, portanto, um estudo de caso analisando-se um projeto educativo inovador implementado em uma instituição pública de Ensino Fundamental na cidade de São Paulo/SP. A pesquisa empírica foi empreendida baseada nos princípios da Epistemologia Qualitativa que norteia o processo de construção de informações, como também, as elaborações de hipóteses visando a produção do conhecimento sobre o objeto de estudo definido. Tendo em vista um conhecimento aprofundado do contexto, foram utilizadas estratégias de pesquisa e instrumentos, tais como a participação intensa e observações frequentes no cotidiano escolar da instituição, instrumentos escritos e dinâmicas conversacionais, englobando os diversos atores escolares como membros da direção, professores, familiares e alunos, assim como, colaboradores e implementadores do projeto inovador. Dentre os principais resultados, identifica-se que um conjunto de inovações incrementais e complementares conforma o projeto. Estas inovações têm origens diversas e adquirem uma trajetória histórica envolvendo o papel do coletivo, das lideranças e atuações protagonistas. Desse modo, o processo inovador se configura de maneira singular com um percurso específico de construção de instrumentos, métodos, práticas perpassadas pelo histórico da instituição e dos grupos bem como, pelas ações realizadas no processo de sua implementação. No que se refere à subjetividade no âmbito do projeto inovador, como principal resultado destaca-se a configuração de elementos da subjetividade social da escola e também a participação de elementos da subjetividade individual de atores escolares significativos para a implementação, como aqueles componentes que caracterizam e dinamizam o processo de inovar. Com base nas informações produzidas, as construções interpretativas revelam que no processo inovador ocorrem mudanças de ordem histórico-subjetiva, que reconfiguram o contexto tornando-o favorável à inovação. Por fim, elaboram-se construções que apontam para a dimensão histórica como uma importante dimensão do processo inovador. _________________________________________________________________________________ ABSTRACTThe present research has as subject the educative innovation known as the introduction of new features in the educational processes that aim to generate transformations and improvements in the educational institutions. In this investigation, the educative innovation is understood from a complex point of view that articulates different aspects, as well as from the perspective of the subjectivity, as conceived in cultural-historical theory of subjectivity of González Rey. In this theoretical perspective, the subjectivity expresses and constitutes itself in a double condition - social and individual. Therefore, the research has as objective to study the configuration of elements that make education innovation possible, investigating the articulation of historical, contextual and subjective elements. Thus, a case study of innovative project implemented in a public elementary school in the city of São Paulo/SP was analyzed. The empiric research was based on the principles of Qualitative Epistemology that guides the constructive-interpretative process of the information, as well, written instruments and conversational dynamics, involving the various actors such as: school board members, teachers, family and students, and also those who cooperate on the implementation of the innovative project design. Among the main results, it is possible to identify that a set of incremental and complementary innovations mold the project. These innovations have different origins and acquire a historical trajectory relating the role of the collective groups, the leaderships and individual protagonists. Hence, the innovative process configures itself in a singular way with a specific trajectory of instruments construction, methods, practices that depend on the institution background, groups, and the actions carried through the process of implementation. From the subjectivity perspective, as main result, the innovative design has been produced by the configuration of elements of the social subjectivity of the school and also by the participation of elements of the individual subjectivity of actors who participate in the implementation process, as those components that characterize and reorganize the innovative process. Based on the information produced, the constructive interpretative process reveals that educative innovation has been processed by historical-subjective changes that reconfigure the context turning it favorable to the innovative project. Finally, hypothesis elaborated indicate that the historical dimension is an important dimension of the innovative process. _________________________________________________________________________________ RESUMENEsta investigación tiene como tema la innovación educativa entendida como la introducción de nuevos procesos educativos destinados a generar cambios y mejoras en las instituciones educativas. Buscase comprender la innovación educativa a partir de una visión compleja según una articulación de los diferentes aspectos, como también desde la perspectiva de la subjetividad, tal como es concebida en la teoría histórico-cultural de la subjetividad de González Rey. En esta perspectiva teórica, la subjetividad expresase y constituyese en su doble condición, social e individual. Por lo tanto, la investigación tuvo como objetivo estudiar la configuración de los elementos que posibilitan la innovación educativa, enfocando la articulación de los elementos históricos, contextuales y subjetivos. De esta manera, un caso de estudio fue realizado, analizando un proyecto educativo innovador implementado en una escuela pública de Educación Primaria en la ciudad de São Paulo/SP. La investigación estuvo basada en los principios de la Epistemología Cualitativa que orientan el proceso de construcción de información, así como la elaboración de hipótesis destinadas a la producción del conocimiento sobre el objeto del estudio. Buscando un conocimiento profundo del contexto, fueron utilizadas estrategias e instrumentos de investigación, tales como la intensa participación y frecuentes observaciones en la vida diaria de la institución educativa, los instrumentos escritos y dinámica de conversación, incluyendo la participación de los diversos actores como miembros del equipo directivo, profesores, familia y estudiantes, así como los participantes de la implementación del proyecto innovador. Entre los principales resultados, identificase un conjunto de innovaciones complementares que conforman el proyecto. Estas innovaciones tienen orígenes diferentes y adquieren una trayectoria histórica que implica el papel del colectivo, el liderazgo y las acciones protagonistas. Por lo tanto, el proceso de innovación se configuró de manera singular con una trayectoria específica de construcción de instrumentos, métodos y prácticas en dependencia con la historia de la institución y de los grupos, así como de las acciones adoptadas en el proceso de implementación. Con respecto a la subjetividad implicada en el proyecto innovador, el principal resultado resalta la configuración de los elementos de la subjetividad social de la escuela y también la participación de elementos de la subjetividad individual de los actores significativos para la implementación, como aquellos componentes que caracterizan y dinamizan el proceso de innovación. Con base en la información producida, las construcciones interpretativas revelan que los cambios en el proceso de innovación se producen en la dimensión histórico-subjetiva, que reconfiguran el contexto de modo a hacerlo favorable para la innovación. Finalmente, las hipótesis elaboradas apuntan para la dimensión histórica como una dimensión importante del proceso de innovación
Analyzing social media discourse - an approach using semi-supervised learning
The ability to handle large amounts of unstructured information, to optimize strategic business opportunities, and to identify fundamental lessons among competitors through benchmarking, are essential skills of every business sector. Currently, there are dozens of social media analytics’ applications aiming at providing organizations with informed decision making tools. However, these applications rely on providing quantitative information, rather than qualitative information that is relevant and intelligible for managers. In order to address these aspects, we propose a semi-supervised learning procedure that discovers and compiles information taken from online social media, organizing it in a scheme that can be strategically relevant. We illustrate our procedure using a case study where we collected and analysed the social media discourse of 43 organizations operating on the Higher Public Polytechnic Education Sector. During the analysis we created an “editorial model” that character izes the posts in the area. We describe in detail the training and the execution of an ensemble of classifying algorithms. In this study we focus on the techniques used to increase the accuracy and stability of the classifiers.info:eu-repo/semantics/publishedVersio
Fermentação extrativa de xilanase em sistemas de duas fases aquosas
Orientadores: Elias Basile Tambourgi, Benicio Barros NetoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: Nos últimos anos, os sistemas de duas fases aquosas (SDFAs) têm encontrado aplicações nas diferentes áreas da biotecnologia, especialmente no que se refere à utilização de sistemas alternativos e de baixo custo. Dessa forma é que o sistema constituído de polissacarídeo da goma de cajueiro e polietilenoglicol foi utilizado, no presente trabalho, para o cultivo do fungo Penicillium janthinellum e produção de xilanase. Inicialmente, foram avaliados cinco resíduos agroindustriais (bagaço de cana, casca de mandioca, casca de aveia, sabugo e casca de mi1ho) como indutores para a produção desta enzima. Estes resíduos foram hidrolisados e suas frações líquidas foram utilizadas para o cultivo. A cinética de crescimento do P. janthinellum foi acompanhada para todos os resíduos durante 12 dias. O sabugo de milho e a casca de aveia foram os melhores indutores da xilanase. De posse dos me1hores resíduos, procedeu-se um planejamento, no intuito de determinar as variáveis mais importantes, tanto para fermentação convencional como para a extrativa. O planejamento fracionário em dois níveis procurou avaliar a influência das seguintes variáveis: resíduo agroindustrial, tempo de cultivo, pH inicial, agitação, temperatura e composição do sistema de duas fases aquosas. A maior produção de xilanase no meio convencional foi de 142, 85 U/mL para o hidrolisado de aveia. Isto significou um aumento de 2,58 vezes em relação ao obtido anteriormente sem o estudo das variáveis. A xilanase produzida durante a fermentação extrativa no sistema PEG/polissacarideo da goma do cajueiro concentrou-se na fase superior. O maior valor da produção de xilanase na fase superior e seu rendimento foram 160,7 U/mL e 97%, para o hidrolisado de aveia no sistema PEG 8000/ goma. Assim, o crescimento do P.janthinellum e a produção de xilanase no SDFA foram superiores quando comparados ao sistema convencional. A atividade máxima da enzima no SDFA foi obtida no quinto dia, enquanto que para o meio controle esta foi encontrada no sexto diaAbstract: In recent years, aqueous two-phase systems (ATPS) have found applications in several biotechnology areas, specially when utilizing altemative low-cost biphasic system. Therefore, in the present work, the aqueous two-phase system based on cashew-nut tree gum and polyethylene glycol was used for Penicillium janthinellum cultivation and xylanase production. lnitially five agricultural wastes (sugar cane bagasse, cassava peel, oat husk corn cob and corn husk) were evaluated for xylanolytic enzymes production by P. janthinellum. These residues were hydrolyzed and their liquid fractions used for cultivation; Growth kinetic was accomplished for all residues during twelve days. Corn cob and oat husk were the best inducers of xylanase. A factorial design was performed using corn cob and oat husk, which intended to determine the most important variables for conventional and extractive fermentation. Two level fractional factorial design evaluated the influence of the following variables: agro-industrial residue, cultivation time, pH initial, agitation, temperature and composition of aqueous two-phase system. The highest xylanase production was 142.85 U/mL in conventional medium of oat husk hydrolyzate. This mean an increase of 2.58 folds when compared to that obtained previously. Xylanase produced during extractive fermentation partitioned into the upper phase. The highest xylanase production in upper phase and its yield were 160.7 U/mL and 97%, respectively, using PEG 8000/gum with oat husk. P. janthinellum growth and enzyme production in ATPS was superior to that conventional system. Maximum xylanase activities were obtained on the 5th day for ATPS and on the 6th day for control mediumDoutoradoSistemas de Processos Quimicos e InformaticaDoutor em Engenharia Químic
EduBridge social - bridging social networks and learning management systems
The exponential growth of social media usage and the integration of digital natives in Higher Education Institutions (HEI) have been posing new challenges to both traditional and technology-mediated learning environments. Nowadays social media plays an important, if not central, role in society, for professional and personal purposes. However, it’s important to highlight that in the mind of a digital native, social media is not just a tool, it is a place that is as real and as natural as any real-life world place where formal/informal social interactions happen. Still, formal higher education contexts are still mostly imprisoned in locked up institutional Learning Management Systems (LMS), while a new world of social connections grows and develops itself outside schools. One of the main reasons we believe to be persisting in the origin of the matter is the absence of a suitable management, monitoring and analysis tools to legitimize and to efficiently manage the relationship with stud ents in social networks. In this paper we discuss the growing relevance of the “Social Student Relationship Management” concept and introduce the EduBridge Social system, which aims at connecting the most commonly used LMS, Moodle, and the most popular social network, Facebook.info:eu-repo/semantics/publishedVersio
Are we ready for remote work? Preliminary results from Portugal
Due to the pandemic crisis caused by COVID-19, people started performing their professional tasks remotely. This transition from the off-line and face-to-face work to online and remote work did not happen without pain, anxiety and some frustration as there was a need for accelerated learning and the frontiers between private and professional life were blurred. In this paper, we report on the preliminary findings of a survey-based research aimed at evaluating the main impacts and challenges faced by professionals in this transition process, in Portugal. Results show that respondents believe they work more, they feel more motivated, have better control over time, easily create methods and pace of work, and have more focus on tasks. Savings on fuel are offset by increased expenses in electricity, water, and food. Increased work-life balance but not increased leisure time are recognised. The most negative impact is social/professional seclusion, despite recognising fewer professional conflicts
Channels selection in the retail banking sector: relationship between the factors influencing the usage and the perceived service quality
Quality is regarded as one of the main objectives to achieve in a successful organization, where the corporate policy is defined around of how to stay efficient while achieving the quality requirements defined by the consumer. Thus, companies in the banking sector are concentrating their efforts to achieve excellence, beginning with the service channels, which represent the point of contact with their clients.
This dissertation aims to deepen the study on the use of two major distribution channels: the traditional bank branch and the Internet, having as backdrop the perceived of quality of service. In this context, factors influencing the choice and use of banking channels were related to assessments of their quality, allowing to create segments of consumers and to draw strategic conclusions on areas where the service quality provided by the distribution channel is poor and needs attention from the bank.
The research methodology was based on a literature research on the following fields: banking marketing, banking distribution and perceived quality of the services provided. The study was conducted in two phases.
The first corresponds to the creation of a scale to measure the perceived quality of the two channels mentioned, through a Factor Analysis and Internal Consistency.
Finally, the second phase consists of applying a questionnaire to a final sample of 225 subjects and on the interpretation of data obtained through the Importance-Performance Analysis and also, through the non-parametric tests, Mann-Whitney and Kruskal-Wallis and the Correlation Coefficient Spearman's Rho.A qualidade é considerada como um dos principais objectivos a atingir numa organização de sucesso, onde a política empresarial é definida em torno de como se manter eficiente sem deixar de atingir os requisitos de qualidade definidos pelo consumidor. Desta forma, as empresas do sector bancário concentram os seus esforços para alcançar a excelência, a começar pelos canais de atendimento, que representam o ponto de contacto com os clientes.
A presente dissertação pretende aprofundar o estudo sobre o uso de dois importantes canais de distribuição: a tradicional agência bancária e a Internet, tendo como pano de fundo a qualidade percebida do serviço. Neste âmbito, os factores que influenciam a escolha e uso dos canais bancários foram relacionados com as avaliações de qualidade dos mesmos, permitindo, criar segmentos de consumidores e retirar conclusões estratégicas sobre áreas onde a qualidade do serviço prestado pelo canal de distribuição é deficitária e necessita de atenção por parte do banco.
A metodologia de investigação assentou numa pesquisa bibliográfica sobre os seguintes campos: marketing bancário, distribuição bancária e qualidade percebida com a prestação do serviço. O estudo foi desenvolvido em duas fases.
A primeira corresponde à criação de uma escala para avaliar a qualidade percebida dos dois canais mencionados, através da Análise Factorial e de Consistência Interna.
A segunda consiste na aplicação de um questionário a uma amostra final de 225 indivíduos e na interpretação dos dados obtidos através da Análise Importância-Performance, recorrendo-se ainda aos testes não-paramétricos de Mann-Whitney e Kruskal-Wallis e ao Coeficiente de Correlação Ró de Spearman
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