La dimensión cultural en los paisajes de la Cuarta Colonia de inmigración de Rio Grande do Sul – Brasil

El artículo presenta el trayecto y resultados preliminares de la tesis intitulada “Patrimonio y Planificación – Aproximación a partir del paisaje de Agudo-RS” en elaboración en el Programa de Posgrado en Planificación Urbana y Regional de la Universidade Federal do Rio Grande do Sul – Brasil. La investigación parte de la región conocida como Cuarta Colonia y trata de la relación entre patrimonio y paisaje para desarrollar una lectura amplia del territorio integrando factores culturales que no siempre son considerados, con el objetivo de discutir alternativas para su inserción de forma más eficaz en la planificación territorial del sur de Brasil. Para tanto se busca identificar y evaluar sus paisajes a partir de tres ejes de análisis: (1) experiencia y percepción local; (2) cuadro institucional del territorio; y (3) estructura histórica y estética de los paisajes.The paper presents the partial results of the thesis “Heritage and Planning – One approach from Agudo’s Landscape” in process at the Postgradutate Program in Urban and Regional Planning of the Universidade Federal do Rio Grande do Sul - Brasil. The investigation starts from a region known as Fourth Colony to discuss the relationship between landscape and heritage, so as to read the territory in a broad perspective, integrating cultural aspects not always considered, aiming alternatives for the inclusion of these factors in the territorial planning of Southern Brazil. Therefore, the research identifies and evaluates landscapes from three areas of analysis: (1) local experience and perception; (2) territorial institutional framework; and (3) historic and aesthetic structure of the landscapes.Peer Reviewe

In-situ monitoring of laser powder bed fusion applied to defect detection

Additive manufacturing technologies, particularly laser powder bed fusion (LPBF), have received much attention recently due to their numerous advantages over conventional manufacturing methods. However, the use of LPBF is still quite restricted, mainly due to two factors: its typically low productivity, which makes the technology less competitive in applications with moderate to high production volumes, and its limited reliability, particularly relevant for applications where high performance is required from the materials.The issue of low productivity is addressed in this thesis by adjusting the main LPBF process parameters. An equation for the build rate was formulated based on these parameters, determining their contributions and enabling strategies for build rate maximization. The changes in microstructure and defect populations associated with increasing productivity were determined.The reliability issue was explored by investigating defect formation, detectability and mitigation, since a major factor compromising reliability and materials’ performance is the presence of defects. Internal defects were deliberately created in LPBF-manufactured material to assess their detectability via in-situ monitoring. Two main routes of deliberate defect formation have been identified while preserving defect formation mechanisms; therefore, this thesis can be divided into two parts according to the approach employed to create defects.Defects are generated systematically if suboptimal process parameters are employed. The types, quantities, and sizes of defects in nickel-based alloy Hastelloy X resulting from varying processing conditions were thoroughly characterized. Analyzing data obtained from in-situ monitoring made it possible to distinguish virtually defect-free material from defective material.Defects are generated stochastically due to the redeposition of process by-products on the powder bed. With the aid of in-situ monitoring data, the presence of these defects can be inferred from the detection of the process by-products responsible for their formation. The comparison of data obtained in-situ with data obtained through ex-situ material characterization allowed determining how precisely detections corresponded to actual defects. The impact of these defects on the mechanical properties of Hastelloy X was assessed. A couple of in-process mitigation strategies were investigated, and their performances were evaluated. By establishing means to use LPBF process monitoring to distinguish high-quality from defective material and detect random, unavoidable defects, this thesis enables the prediction of LPBF material quality. It creates conditions necessary for the first-time-right production of defect-free material at increased build rates

Detection and classification of internal flaws in laser powder bed fusion: application of in-situ monitoring for quality control of Hastelloy X builds

Additive manufacturing technologies, in particular laser powder bed fusion (LPBF), have received much attention in recent years due to their multiple advantages over traditional manufacturing. Yet, the usage of additively manufactured products is still quite limited, mainly due to two factors: the low repeatability, which is particularly relevant for applications where high performance is required from the materials, and the typically low productivity, particularly relevant for products with a substantial production volume.The main factor that affects repeatability and compromises the performance of the materials is the presence of flaws. Hence, to assess the quality of a product and to predict its performance, it is crucial to recognize which flaws are present and ensure their detectability. Moreover, if the flaws can be detected during the manufacturing process, corrective actions can be taken. In this thesis, internal flaws were deliberately created in LPBF manufactured material to assess their detectability via in-situ monitoring. Two main routes of deliberate flaw formation have been identified while preserving flaw formation mechanisms; therefore, this thesis is split into two parts, according to the approach employed to create flaws.Flaws are generated systematically if inadequate process parameters are employed. By varying the processing conditions, different types, amounts and sizes of flaws are created. By monitoring the manufacturing process with long-exposure near-infrared imaging and applying supervised machine learning, it was possible to distinguish process conditions that generate the different flaw categories with accuracy, precision and recall of at least 96%.Flaws are created stochastically as a result of the redeposition of process by-products on the build area. It was found that substantial amounts of flaws can be provoked through this route when increasing the nominal layer thickness in the build, thus enabling the validation of the monitoring system in their detection. After applying an image analysis algorithm to all the images output from in-situ monitoring in three builds, it was possible to identify trends in the spatial distribution of spatter redeposits. Ex-situ inspection and material characterization provided cross-check for the distribution of flaws.The low productivity of LPBF makes it less competitive in applications with moderate to high production volumes. This issue is briefly addressed in this thesis. Even though one of the main approaches to increase productivity is to tune the main process parameters, dissimilar strategies were identified in the literature towards this goal. Thus, parametrization of build rates was done and applied to the processing conditions deemed to provide material with acceptable quality, based on the quantity and types of flaws present. The material manufactured in these conditions was characterized, and it was found that substantially different microstructures can be achieved within the process window, depending on the build rate

Linking in situ melt pool monitoring to melt pool size distributions and internal flaws in laser powder bed fusion

In situ monitoring of the melt pools in laser powder bed fusion (LPBF) has enabled the elucidation of process phenomena. There has been an increasing interest in also using melt pool monitoring to identify process anomalies and control the quality of the manufactured parts. However, a better understanding of the variability of melt pools and the relation to the incidence of internal flaws are necessary to achieve this goal. This study aims to link distributions of melt pool dimensions to internal flaws and signal characteristics obtained from melt pool monitoring. A process mapping approach is employed in the manufacturing of Hastelloy X, comprising a vast portion of the process space. Ex situ measurements of melt pool dimensions and analysis of internal flaws are correlated to the signal obtained through in situ melt pool monitoring in the visible and near-infrared spectra. It is found that the variability in melt pool dimensions is related to the presence of internal flaws, but scatter in melt pool dimensions is not detectable by the monitoring system employed in this study. The signal intensities are proportional to melt pool dimensions, and the signal is increasingly dynamic following process conditions that increase the generation of spatter

A neural network for identification and classification of systematic internal flaws in laser powder bed fusion

Quality control of mechanical components is crucial to ensure their expected performance and prevent their failure. For components manufactured additively, quality control performed in-process is particularly interesting, as the sequential deposition and remelting of layers represent a possibility to mitigate existing flaws. The first step towards closed-loop control is to ensure that the monitoring setup and the data analytics approach can flag and discriminate flaws. This study aims to assess the potential of a layerwise monitoring system associated with a supervised machine learning approach to identify and classify internal flaws in laser powder bed fusion of Hastelloy X. For that, systematically generated internal flaws were mapped ex-situ in 72 distinct process conditions. The outputs of the near-infrared long-exposure acquisition system were labeled according to the ex-situ characterization and used to train a fully convolutional neural network. The network was then used to classify previously unseen monitoring images into three classes, according to the predominant flaw type expected, lack of fusion, keyhole porosity, or residual porosity. Accuracy, precision and recall over 96% are obtained, indicating that the monitoring system combined with this supervised machine learning approach successfully identifies and classifies internal flaws

Frugtfølge og Markinddeling.

Frugtfølge og Markinddeling

Surface chemical analysis of spatter particles generated in laser powder bed fusion of Hastelloy X in process atmospheres with high and low oxygen content

Additive manufacturing, particularly laser powder bed fusion (LPBF), has received much attention in recent years because of its multiple benefits over traditional manufacturing. One of the key factors affecting the repeatability and performance of the materials is the existence of defects. Defects can be driven by process by-products called spatters, which consist of particles covered by an oxide layer formed during their travel time in the process atmosphere. As a standard process atmosphere consists of argon containing a residual oxygen level of around 0.1%, one possible way of addressing spatter-driven defect formation is by reducing the oxygen level, thereby reducing the oxidation of the spatter particles. In this study, Hastelloy X powder was processed by means of LPBF in an argon atmosphere containing 1000-ppm O2 or 50-ppm O2. Spatter particles were collected in a controlled manner, allowing sampling particles of different sizes, which were analyzed in terms of their surface chemical composition by means of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). By combining these two tools, a comprehensive assessment of the surface chemical composition was conducted, taking advantage of XPS for the evaluation of the overall surface chemistry and of Auger nanoprobe analysis for high lateral analytical resolution combined with depth profiling. It is shown that tighter oxygen control will both limit the overall oxidation and affect the surface chemical composition. At regular O2 level in the process atmosphere (1000 ppm), spatter particles are covered by a 70-nm-thick oxide layer, on average. The thickness is substantially greater than that measured in spatter particles collected from the process atmosphere containing 50-ppm oxygen, which averages 6\ua0nm and is comparable with that of the virgin powder, thus revealing a potential for defect mitigation through control of the process atmosphere. Nonetheless, substantial differences in the surface chemical composition were identified between spatters and virgin powder, notably with the appearance of Al- and Ti-oxides on spatter particles, revealing the influence of the manufacturing process on surface characteristics

Hestebønner.

Hestebønner

Geoprocessamento : uma experiencia na area agricola

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Agronomia

A organização pedagógica nos cursos da área da saúde e seus reflexos no processo formativo : uma análise a partir da avaliação

Tese (doutorado)—Universidade de Brasília, Faculdade de Ceilândia, Programa de Pós-Graduação em Ciências e Tecnologias em Saúde, 2015.Construir políticas de formação na área de saúde pressupõe uma articulação entre as instituições normativas, regulatórias, as instituições formadoras e o Sistema Único de Saúde (SUS), o que se constitui em desafio permanente para os que fazem saúde e educação no Brasil. A avaliação in loco preconizada pelo Sistema Nacional de Avaliação da Educação Superior (SINAES), além de ser referencial básico para o processo regulatório, é organizada e conduzida como ação indutora de qualidade. Essa tese, apresentada na modalidade escandinava, por meio de seis artigos científicos, tem como objetivo verificar os elementos de indução da qualidade e do potencial formativo das Diretrizes Curriculares Nacionais (DCN) dos Cursos da Saúde a partir dos relatórios da avaliação in loco tendo como recorte o perfil profissional e os princípios do SUS. Para tal, apresenta um panorama inédito de 1048 avaliações que foram realizadas pelo Instituto Nacional de Estudos e Pesquisas Anísio Teixeira (INEP), no período de 2012 a 2014, tendo como foco os cursos da área da saúde, em especial os indicadores da dimensão 1, do instrumento matricial, que verifica a coerência do projeto pedagógico dos cursos cujas diretrizes curriculares são o insumo para o processo avaliativo. Para atender a cada um dos objetivos da tese foi realizado a análise de conteúdo das DCN, por meio pré-análise, descrição analítica, interpretação referencial. Em relação as avaliações foi realizado o tratamento estatístico apartir dos dados extraídos do Instrumento de Avaliação de Cursos (IACG) de 2012 por meio de medidas de tendência central (média, mediana, moda) e de dispersão (desvio-padrão e variância) e simetria. Foi aplicado também o teste de hipóteses Kruskal-Wallis para identificar as diferenças e como post hoc o teste de Mann-Whitney caso a caso, com correção de Bonferroni. Os resultados encontrados nas avaliações da área da saúde refletem apenas o proposto pelas DCN elaboradas entre os anos 2001 a 2004. Os dados encontrados também evidenciam que a média 3 como resultado do processo avaliativo precisam ser observados pois eles apontam para a necessidade de inovação na construção de projetos pedagógicos alinhados aos princípios do SUS. Para que a garantia da qualidade seja eficaz conclui-se que para os cursos é necessário a internalização das DCN e; para o aprimoramento do SINAES que seja público todos os resultados de todos os indicadores das avaliações realizadas.Formulating bildung policies in health field presupposes articulation between the normative institutions, regulatory one, training institutions and the Unified Health System (SUS), which constitutes an ongoing challenge for those who make health and education in Brazil. The in loco evaluation recommended by the National System of Higher Education Assessment (SINAES), besides being basic reference for the regulatory process, is organized and conducted as inducing action of quality. This thesis presented at Scandinavian mode, through scientific articles, aim to verify the quality induction elements and the bilding potential of the National Curricular Guidelines (DCN) of the Health Courses from the reports of evaluation in loco having as cropping the professional profile and the principles of SUS. To this end, it presents an unprecedented panorama of 1048 assessments were carried out by the National Research and Studies Teixeira Institute (INEP) in 2012 to 2014, focusing on the healthcare courses, especially the indicators of dimension 1 of the evaluation instrument, a matricial tool, that checks the consistency of the education program of courses whose national curriculum guidelines (DCN) are the input to the evaluation process. To meet each of the thesis goals was conducted content analysis of DCN, through pre-analysis, analytical description, reference interpretation. Regarding evaluations was performed statistical analysis starting from data extracted from Course Evaluation Instrument (IACG) 2012 through measures of central tendency (mean, median, mode) and dispersion (standard deviation and variance) and symmetry . It was also applied the Kruskal-Wallis test hypotheses to identify the differences and how post hoc Mann-Whitney test case by case, with Bonferroni correction. The results in health assessments only reflect proposed by DCN developed between the years 2001 to 2004. The data also found evidence that the average 3 as a result of the evaluation process must be observed because they point to the need for innovation in construction pedagogical projects aligned with the SUS principles. For quality assurance to be effective it is concluded that for the courses internalization of DCN is necessary and; to improve the SINAES to be public all the results of all indicators of the evaluations