Laminados compósitos de PRFV: efeitos da descontinuidade geométrica e do envelhecimento ambiental acelerado

The growing demand in the use of composite materials necessitates a better understanding of its behavior related to many conditions of loading and service, as well as under several ways of connections involved in mechanisms of structural projects. Within these project conditions are highlighted the presence of geometrical discontinuities in the area of cross and longitudinal sections of structural elements and environmental conditions of work like UV radiation, moisture, heat, leading to a decrease in final mechanical response of the material. In this sense, this thesis aims to develop studies detailed (experimental and semi-empirical models) the effects caused by the presence of geometric discontinuity, more specifically, a central hole in the longitudinal section (with reduced cross section) and the influence of accelerated environmental aging on the mechanical properties and fracture mechanism of FGRP composite laminates under the action of uniaxial tensile loads. Studies on morphological behavior and structural degradation of composite laminates are performed by macroscopic and microscopic analysis of affected surfaces, in addition to evaluation by the Measurement technique for mass variation (TMVM). The accelerated environmental aging conditions are simulated by aging chamber. To study the simultaneous influence of aging/geometric discontinuity in the mechanical properties of composite laminates, a semiempirical model is proposed and called IE/FCPM Model. For the stress concentration due to the central hole, an analisys by failures criteria were performed by Average-Stress Criterion (ASC) and Point-Stress Criterion (PSC). Two polymeric composite laminates, manufactured industrially were studied: the first is only reinforced by short mats of fiberglass-E (LM) and the second where the reinforced by glass fiber/E comes in the form of bidirectional fabric (LT). In the conception configurations of laminates the anisotropy is crucial to the final mechanical response of the same. Finally, a comparative study of all parameters was performed for a better understanding of the results. How conclusive study, the characteristics of the final fracture of the laminate under all conditions that they were subjected, were analyzed. These analyzes were made at the macroscopic level (scanner) microscope (optical and scanning electron). At the end of the analyzes, it was observed that the degradation process occurs similarly for each composite researched, however, the LM composite compared to composite LT (configurations LT 0/90º and LT ±45º) proved to be more susceptible to loss of mechanical properties in both regarding with the central hole as well to accelerated environmental aging

Compósito Polimérico Híbrido: Comportamento Mecãnico, Descotinuidade Geométrica e Resistência Residual

The growing demand in the use of hybrid composite materials makes it essential a better understanding of their behavior face of various design conditions, such as the presence of geometric discontinuities in the cross section of structural elements. This way, the purpose of this dissertation is a study of the mechanical response (strength and stiffness), modes (characteristics) of fracture and Residual Strength of an hybrid polymeric composite with and without a geometric discontinuity in its longitudinal section (with a reduction in the cross section) loaded by uniaxial tension. This geometric discontinuity is characterized by central holes of different diameters. The hybrid composite was fabricated as laminate (plate) and consisting of ortho-tereftalic polyester matrix reinforced by 04 outer layers of Jute fibers bidirectional fabrics and 01 central layer of E-glass bidirectional fabric. The laminate was industrially manufactured (Tecniplas Nordeste Indústria e Comércio Ltda.), obtained by the hand lay-up technique. Initially, a study of the volumetric density of the laminate was made in order to verify its use in lightweight structures. Also were performed comparative studies on the mechanical properties and fracture modes under the conditions of the specimens without the central hole and with the different holes. For evaluating the possible influence of the holes in the structural stability of the laminate, the Residual Strength of the composite was determined for each case of variation in hole diameter. As a complementary study, analyses of the macroscopic final fracture characteristic of the laminates were developed. The presence of the central hole of any sizes, negatively changed the ultimate tensile strength. Regarding the elastic modulus, moreover, the difference found between the specimens was within the range of tests displacement, showing the laminate stability related to the stiffness

Desenho e Construção de um protótipo gerador de jato de plasma frio a pressão atmosférica para aplicações biomédicas

Research for better performance materials in biomedical applications are constants. Thus recent studies aimed at the development of new techniques for modification of surfaces. The low pressure plasma has been highlighted for its versatility and for being environmentally friendly, achieving good results in the modification of physic chemical properties of materials. However, it is requires an expensive vacuum system and cannot able to generate superficial changes in specific regions. Furthermore, it is limits their use in polymeric materials and sensitive terms due to high process temperatures. Therefore, new techniques capable of generating cold plasma at atmospheric pressure (APPJ) were created. In order to perform surface treatments on biomaterials in specific regions was built a prototype capable of generating a cold plasma jet. The prototype plasma generator consists of a high voltage source, a support arm, sample port and a nozzle through which the ionized argon. The device was formed to a dielectric tube and two electrodes. This work was varied some parameters such as position between electrodes, voltage and electrical frequency to verify the behavior of glow discharges. The disc of titanium was polished and there was a surface modification. The power consumed, length, intensity and surface modifications of titanium were analyzed. The energy consumed during the discharges was observed by the Lissajous figure method. To check the length of the jets was realized with Image Pro Plus software. The modifications of the titanium surfaces were observed by optical microscopy (OM ) and atomic force microscopy (AFM ). The study showed that variations of the parameters such as voltage, frequency and geometric position between the electrodes influence the formation of the plasma jet. It was concluded that the plasma jet near room temperature and atmospheric pressure was able to cause modifications in titanium surface

Forró eletrônico: uma análise sobre a representação da figura feminina

Understanding music as a social manifestation, able to represent the time and culture along with their uses and mores, we look at the female figure in the electronic forró genre. Through a reading of the two genres musical and feminine we seek to identify the discourses present in the compositions, which refer to the feminine with thematic and/or terms referring to women. The study focuses on the compositions between 2009 to 2010 which became hits, ie.: those which have attained the highest number of listeners to 96 FM in a program named Paradão 96, broadcasted daily in the city of Natal/RN. Grounded in such concepts as cultural industry, mass culture, folkcommunication and gender, we analyze the processes of meaning production as a result of using the female figure and more accurately, about the representation of women through the discourse of this specific genre. We have chose the descriptive research with a qualitative approach and Discourse Analysis as a technique to identify the terms that refer to women, reflecting on what would be the possible meanings found in these speeches. We point out that in our investigation the female figure turned into a sexual object, erotic and submissive, in their turn, attributes usually given to women, was not a predominant result in the speech of electronic forró gender. With a variant thematic some playful and others about the betrayal of women we have identified that, to the surprise of many, including ourselves, romantic love was the one who led the audience requests during our time frame and that the female figure has several facets within the studied genre

A Representação discursiva da figura feminina no jornal O Porvir (Currais Novos/Rio Grande do Norte - 1926-1929)

The objective of this paper is to analyze how the female figure was portrayed in discursive narratives in the bi-weekly newspaper O PORVIR , which circulated in Currais Novos, in the state of Rio Grande do Norte, Brazil, between May 2, 1926 and January 20, 1929. Our analysis was based on the semantics of the text, by applying one of the primary concepts used in Textual Analysis of Speeches, Discursive Representation (ADAM, 2011; RODRIGUES; PASSEGGI; SILVA NETO, 2010). Textual Analysis of Speeches has its roots in Textual Linguistics and consists of a theoretical and descriptive approach (ADAM, 2011). This research is characterized as documentary (SEVERINO, 2007) and its corpus includes a review of 39 editions of the aforementioned newspaper, of which we extracted 292 articles that dealt with the female figure and 396 statements for analysis. We used the following semantic categories: referencing (CASTILHO, 2010; NEVES, 2007; KOCH; MARCUSCHI, 1998; MARCUSCHI, 2008; KOCH, 2009); predication (NEVES, 2007; RODRIGUES; PASSEGGI; SILVA NETO, 2010); modification (ADAM, 2011); and spacial and temporal localization (RODRIGUES; PASSEGGI; SILVA NETO, 2010). Our analysis revealed that lady, mother, wife and homemaker were most represented, and always combined with questions about motherhood, marriage and devotion to the home. Such representation does not diverge from pre-colonial models in the early twentieth century, which served as a standard for the female figure

Forró eletrônico: uma análise sobre a representação da figura feminina

Entendiendo la música como una manifestación social, capaz de representar el tiempo y la cultura, junto con sus usos y costumbres, dirigimos nuestra mirada en la figura femenina presente en el género forró electrónico. A través de la lectura de los dos géneros musical y femenino buscamos identificar los discursos, presentes en las composiciones, que se refieren a lo femenino con temática y/o términos que se refieren a las mujeres. El estudio se centra en las composiciones en el período 2009 a 2010 y que se convirtieron en éxitos, es decir, aquellos que han alcanzado el mayor número de oyentes de Radio 96 FM a través del programa Paradão 96, transmitido diariamente en la ciudad de Natal/RN. Basado en conceptos tales como industria cultural, cultura de masas, folkcomunicación y género, se analizan los procesos de producción de sentido como resultado del uso de la figura femenina y con mayor precisión, sobre la representación de las mujeres a través de discursos del forró electrónico. Elegimos el enfoque descriptivo cualitativo y análisis del discurso como una técnica para identificarlos términos que se refieren a las mujeres, reflexionando sobre los posibles significados que se encuentran en estos discursos. Se señala que en nuestra investigación no predominó una figura femenina convertida en un objeto sexual, erótico y sumisa, atributos dados para las mujeres, en los discursos de forró electrónico. Con variaciones en las temáticas algunas juguetones y otras acerca de la traición de la mujer identificamos que, para sorpresa de muchos, incluidos nosotros, el amor romántico fue el que llevó las solicitudes de audiencia durante nuestro período de tiempo y que la figura femenina tiene varias facetas dentro del forró electrónico

Técnica de parametrização geométrica para o fluxo de carga continuado baseado nas variáveis tensão nodal e fator de carregamento

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fluxo de carga continuado utilizando estratégia de parametrização geométrica baseada em parâmetros físicos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A figura do poeta em Friedrich von Hardenberg (Novalis) e Gaston Bachelard: algumas considerações

Através do Fogo - elemento marcante tanto em Novalis (século XVIII) quanto em Gaston Bachelard (século XX), pudemos ensaiar uma aproximação entre esses dois autores, distantes no tempo, mas próximos no tocante à valorização da imaginação (estética).

Caracterização geométrica e parametrização de depósitos transacionais recentes e sua aplicação na modelagem de reservatórios petrolíferos

In this beginning of the XXI century, the Geology moves for new ways that demand a capacity to work with different information and new tools. It is within this context that the analog characterization has important in the prediction and understanding the lateral changes in the geometry and facies distribution. In the present work was developed a methodology for integration the geological and geophysical data in transitional recent deposits, the modeling of petroliferous reservoirs, the volume calculation and the uncertainties associate with this volume. For this purpose it was carried planialtimetric and geophysics (Ground Penetrating Radar) surveys in three areas of the Parnaíba River. With this information, it was possible to visualize the overlap of different estuary channels and make the delimitation of the channel geometry (width and thickness). For three-dimensional visualization and modeling were used two of the main reservoirs modeling software. These studies were performed with the collected parameters and the data of two reservoirs. The first was created with the Potiguar Basin wells data existents in the literature and corresponding to Açu IV unit. In the second case was used a real database of the Northern Sea. In the procedures of reservoirs modeling different workflows were created and generated five study cases with their volume calculation. Afterwards an analysis was realized to quantify the uncertainties in the geological modeling and their influence in the volume. This analysis was oriented to test the generating see and the analogous data use in the model construction

Papel relativo da remodelação geométrica do ventrículo esquerdo, morfológica e funcional do miocárdio na transição da hipertrofia compensada para a falência cardíaca em ratos com estenose aórtica supravalvar

OBJETIVO: Avaliar a contribuição relativa da remodelação geométrica do ventrículo esquerdo (VE) e das alterações morfológicas e funcionais do miocárdio, em ratos com estenose aórtica supravalvar (EAS), na fase de transição da hipertrofia compensada para a insuficiência cardíaca congestiva (ICC). MÉTODOS: Vinte e uma semanas após a indução da EAS os ratos foram classificados como controles (GC,n=13), não portadores (GE,n=11) ou portadores de insuficiência cardíaca congestiva (GE-IC,n=12).Todos os grupos foram avaliados com estudo ecocardiográfico, hemodinâmico e morfológico do miocárdio. RESULTADOS: Vinte e uma semanas após EAS: índice de massa (GE-IC>GE>GC,p<0.05); pressão sistólica: (GE-IC = GE>GC, p<0,05); pressão diastólica: (GE-IC>GE>GC, p<0,05); estresse meridional sistólico e diastólico: (GE-IC>GE>GC,p<0.05); área de secção dos miócitos: (GE-IC>GE>GC, p<0,05) e conteúdo de hidroxiprolina: (GE-IC>GE>GC, p<0,05) do VE. No grupo GE-IC o remodelamento geométrico do VE foi caracterizado por aumento significante das dimensões e espessura relativa da parede normal (remodelamento excêntrico) enquanto que o grupo GE apresentou remodelamento concêntrico. Os índices de desempenho do VE do grupo GE-IC foram significantemente menores que do grupo GE. CONCLUSÃO: Os grupos GE-IC e GE diferiram primariamente no processo de remodelação geométrica do VE e estrutural do miocárdio que estabeleceu um estado cronicamente compensado no grupo GE e precipitou a ICC no grupo GE-IC na vigência de graus equivalentes de comprometimento da contratilidade. Neste modelo experimental a fase de transição da hipertrofia compensada para a ICC está mais estreitamente relacionada com o remodelamento geométrico adverso do VE e estrutural do miocárdio do que com o grau de comprometimento da contratilidade.

Caracterização geométrica de um sistema fluvial, formação Ttaquaquecetuba, Terciário da Bacia de São Paulo

The objective of this study is the geometric characterization of a fluvial system, exemplified by the Itaquaquecetuba Formation. The studied area is a quarry located in Itaquaquecetuba, distant 35 km from the city of São Paulo, which is inserted in the context of São Paulo Basin. Fluvial systems are important hydrocarbon reservoirs, and this study may contribute with an analogue for ancient reservoirs. It was elaborated ten facies logs along a distance of 200 m (log spacing of 20 m), with a vertical column (thickness) of 40 m for each log. Eight facies cycles, and its lateral chrono-correlation allowed to map the potential reservoir and non-reservoir facies within each cycle. Regarding the depositional model for the studied section, it is assumed an alluvial fan system composed of meandering and ribbon-type fluvial channels.

A figura humana fragmentada na pintura: Tiradentes esquartejado em Pedro Américo e Adriana Varejão

Pós-graduação em Artes - IA

Proposição de uma técnica de parametrização geométrica para o fluxo de carga continuado baseado nas variáveis tensão e fator de carregamento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)