Analysis of milling in composite material by non-destructive methods

In aerospace industry, composite materials offer several advantages, such as high weight-to strength ratio and corrosion resistance. Aerospace materials are costly and have high safety standards, frequently using non-destructive testing in order to evaluate the material without incurring in further damage. Acoustic emission is a non-destructive testing method, which allows the signal processing to evaluate material performance during mechanical tests for determining material defects, for example. This study focused in the machining process of composite plates, in terms of surface finishing evaluation with comprehension of process phenomenology using non-destructive testing. Manufacturing processes are complex, especially the machining of composite materials, due to their specific properties and characteristics. The detection and prediction of surface finishing and occurrence of defects during manufacturing using non-destructive techniques is industrially useful, in terms of increasing automated manufacturing systems to increase productivity and quality control. The aim of this study is to show the possibility of online monitoring of the cutting process and to understand mechanism behind variables of control, with comparisons of different milling parameters and focusing in their impacts in acoustic emission signals, infrared thermography and surface finishing. The results indicates the relationship between cutting process and acoustic emission signals, with a key differentiation of other studies because it shows the not only the capability of detecting anomalies during cutting process and to predict surface quality by acoustic emission signal analysis, but also that is possible to develop new methods of monitoring in real time machined surface of composite parts quality using acoustic emission signals.Na indústria aeroespacial, polímeros reforçados com fibra de carbono oferecem diversas vantagens, como uma melhor relação entre resistência por peso ou mesmo resistência a corrosão. A análise de sinais obtidos pela emissão acústica tem sido bem sucedida para avaliar ensaios mecânicos e também para determinar defeitos no material. Esse trabalho é focado no processo de usinagem por fresamento de materiais compósitos de resina epóxi e fibra de carbono, em termos de avaliação da qualidade superficial e com compreensão da fenomenologia do processo por ensaios não destrutivos, principalmente emissão acústica e análise de temperatura por infravermelho. Durante o processo de usinagem, o monitoramento do processo com vistas à detecção e predição da qualidade superficial e ocorrência de defeitos é industrialmente útil, podendo aumentar a automatização dos sistema de fabricação, incrementar a produtividade e prover maior controle de qualidade. O objetivo deste estudo foi de mostrar que é possível implementar um sistema de monitoramento em tempo real do processo de corte, com o entendimento dos mecanismos e variáveis de influência. As comparações dos diferentes parâmetros empregados durante o fresamento e seus efeitos nos sinais obtidos pela técnica de emissão acústica e variações de temperatura, permitiram relacionar esses métodos com a qualidade superficial. Os resultados indicam que os ensaios não destrutivos podem servir de indicativo para o estado de qualidade superficial das placas de fibra de carbono-epóxi, também são sensíveis às alterações dos parâmetros de usinagem. Além disso, a análise por emissão acústica obteve melhor desempenho do que a análise por termografia infravermelho no monitoramento do fresamento desses materiais

Cardiopatia e gravidez: análise de 15 casos.

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Pediatria, Curso de Medicina, Florianópolis, 198

The future of bioethanol

Yeasts have been domesticated by mankind before horses. After the mastering of alcoholic fermentation for centuries, yeasts have become the protagonist of one of the most important biotechnological industries worldwide: the production of bioethanol. This chapter will initially present some important challenges to be overcome in this industry, both in first and second generation biofuel production. Then, it will briefly revisit some advances obtained in recent years. Finally, it will present and discuss some opportunities, in the scope of metabolic engineering and synthetic biology, that will likely be present in the future of bioethanol

Mechanism based failure of 3D-printed continuous carbon fiber reinforced thermoplastic composites

The present work describes a computational mechanism based failure analysis conducted for 3D-printed continuous carbon fiber reinforced thermoplastic composites (CFRTPCs), which could not be seen in the available literature. The material failure is investigated based on intraply failure evaluation and adopts different failure criteria for the material constituents. The micromechanical modeling employs the Asymptotic Homogenization technique and comprises the selection of a representative volume element statistically equivalent to the microstructure of the material, which is identified from cross-section micrographs. In contrast to recent work, it is demonstrated that an additional relation is required for the macroscopic deviatoric stresses acting over the matrix. This avoids an overestimation of the matrix failure when the reinforced lamina is subjected to longitudinal and shear loads. The resulting failure envelopes are presented and compared to those provided by analytical failure theories available in the literature. The results obtained by the micromechanical approach showed its ability to predict failure of 3D-printed CFRTPCs, in addition to bring different elements for the discussion that could not be captured with analytical models. In this context, it is believed that the characteristics inherent to the microstructure reproduced in the RVE,\ua0 articularly contributed to obtaining more realistic failure envelopes

Os efeitos da poupança pública sobre o crescimento econômico:

This article analyzed the relations between public savings and economicgrowth. Initially, theoretician-descriptive analysis of these relations showed that thepublic savings is a more complete pointer of fiscal sustainability than the primary surplusand tends to present more positive effect on the product than the operational surplus. Theestimated equations and the tests of robustness of the results of the posterioreconometrical analysis, that used models of multiple regression for a panel of 38 nations,had proven, at high confidence levels, the hypothesis of positive relation between publicsavings and and per capita economic growth taxes – indicating the direction ofcausalidade between them –, besides supplying consistent and interesting results about the form of association between development and other variables. The central conclusionwas that an increase of a unit in the public savings tax must lead, in average, to a rise of0,17 units in the per capita economic growth tax

Geomorphology Drives Amphibian Beta Diversity In Atlantic Forest Lowlands Of Southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Beta diversity patterns are the outcome of multiple processes operating at different scales. Amphibian assemblages seem to be affected by contemporary climate and dispersal-based processes. However, historical processes involved in present patterns of beta diversity remain poorly understood. We assess and disentangle geomorphological, climatic and spatial drivers of amphibian beta diversity in coastal lowlands of the Atlantic Forest, southeastern Brazil. We tested the hypothesis that geomorphological factors are more important in structuring anuran beta diversity than climatic and spatial factors. We obtained species composition via field survey (N = 766 individuals), museum specimens (N = 9,730) and literature records (N = 4,763). Sampling area was divided in four spatially explicit geomorphological units, representing historical predictors. Climatic descriptors were represented by the first two axis of a Principal Component Analysis. Spatial predictors in different spatial scales were described by Moran Eigenvector Maps. Redundancy Analysis was implemented to partition the explained variation of species composition by geomorphological, climatic and spatial predictors. Moreover, spatial autocorrelation analyses were used to test neutral theory predictions. Beta diversity was spatially structured in broader scales. Shared fraction between climatic and geomorphological variables was an important predictor of species composition (13%), as well as broad scale spatial predictors (13%). However, geomorphological variables alone were the most important predictor of beta diversity (42%). Historical factors related to geomorphology must have played a crucial role in structuring amphibian beta diversity. The complex relationships between geomorphological history and climatic gradients generated by the Serra do Mar Precambrian basements were also important. We highlight the importance of combining spatially explicit historical and contemporary predictors for understanding and disentangling major drivers of beta diversity patterns.115Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2008/54472-2]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Instituto Nacional de Ciencia e Tecnologia em Toxinas (INCTTOX)Fundo de Auxilio aos Docentes e Alunos (FADA-UNIFESP)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

A Fully Attention-Based Information Retriever

Recurrent neural networks are now the state-of-the-art in natural language processing because they can build rich contextual representations and process texts of arbitrary length. However, recent developments on attention mechanisms have equipped feedforward networks with similar capabilities, hence enabling faster computations due to the increase in the number of operations that can be parallelized. We explore this new type of architecture in the domain of question-answering and propose a novel approach that we call Fully Attention Based Information Retriever (FABIR). We show that FABIR achieves competitive results in the Stanford Question Answering Dataset (SQuAD) while having fewer parameters and being faster at both learning and inference than rival methods.Comment: Accepted for presentation at the International Joint Conference on Neural Networks (IJCNN) 201

Expanding Puck and Sch\ufcrmann Inter Fiber Fracture Criterion for Fiber Reinforced Thermoplastic 3D-Printed Composite Materials

The present work expands the application of Puck and Sch\ufcrmann Inter-Fiber Fracture criterion to fiber reinforced thermoplastic 3D-printed composite materials. The effect of the ratio between the transverse compressive strength and the in-plane shear strength is discussed and a new transition point between the fracture conditions under compressive loading is proposed. The recommended values of the inclination parameters, as well as their effects on the proposed method, are also discussed. Failure envelopes are presented for different 3D-printed materials and also for traditional composite materials. The failure envelopes obtained here are compared to those provided by the original Puck and Sch\ufcrmann criterion and to those provided by Gu and Chen. The differences between them are analyzed with the support of geometrical techniques and also statistical tools. It is demonstrated that the Expanded Puck and Sch\ufcrmann is capable of providing more suitable failure envelopes for fiber reinforced thermoplastic 3D-printed composite materials in addition to traditional semi-brittle, brittle and intrinsically brittle composite materials