82 research outputs found
Tecnologias digitais e cursos de Engenharia no Brasil: desafios e aprendizados decorrentes da pandemia: Digital technologies and Engineering courses in Brazil: challenges and learnings arising from the pandemic
Este artigo consiste em uma revisão integrativa que visa descrever experiências nacionais e estrangeiras de cursos de graduação em Engenharia com relação ao formato de ensino remoto emergencial. O objetivo é apresentar os aportes teóricos e práticos que a área de Engenharia possui para conduzir futuras ofertas de disciplinas nas modalidades on-line. Centra-se na discussão sobre a formação de engenheiros, sobretudo, em instituições públicas federais no Brasil. Os resultados apontaram que a área de Educação em Engenharia, no cenário internacional, apresenta avanços, quando comparada com a brasileira. O uso de tecnologias digitais e a oferta de cursos e disciplinas remotas era uma prática comum em muitos países antes da deflagração da pandemia. Conclui-se que, no Brasil, a formação de engenheiros em universidades públicas federais, após a experiência da pandemia, requer a capacitação de docentes em relação ao uso de tecnologias digitais para o ensino. As equipes administrativas também necessitam estar preparadas para subsidiar decisões sobre o possível aumento da oferta de cursos e disciplinas remotas nessa área. Ao relatar quais foram os desafios e aprendizados decorrentes da pandemia, este artigo traz contribuições práticas para a melhoria do ensino de Engenharia no país
Multivariate robust modelling and optimization of cutting forces of the helical milling process of the aluminum alloy Al 7075
Helical milling is an advanced hole-making process and different approaches considering controllable variables have
been presented addressing modelling and optimization of machining forces in helical milling. None of them considers the
importance of the noise variables and the fact that machining forces components are usually correlated. Exploring this
issue, this paper presents a multivariate robust modelling and optimization of cutting forces of the helical milling of the
aluminum alloy Al 7075. For the study, the tool overhang length was defined as noise variable since in cavities
machining there are specific workpiece geometries that constrain this variable; the controllable variables were axial
feed per tooth, tangential feed per tooth and cutting speed. The cutting forces in the workpiece coordinate system were
measured and the components in the tool coordinate system, i.e., the axial and radial forces, were evaluated. Since these
two outcomes are correlated, the weighted principal component analysis was performed together with the robust
parameter design to allow the multivariate robust modelling of the mean and variance equations. The normal boundary
intersection method was used to obtain a set of Pareto robust optimal solutions related to the mean and variance
equations of the weighted principal component. The optimization of the weighted principal component through the
normal boundary intersection method was performed and the results evaluated in the axial and radial cutting forces
components. Confirmation runs were carried out and it was possible to conclude that the models presented good fit with
experimental data and that the Pareto optimal point chosen for performing the confirmation runs is robust to the tool
overhang length variation. Finally, the cutting force models were also presented for mean and variance in the workpiece
coordinate system in the time domain, presenting low error regarding the experimental test, endorsing the results.publishe
Reduction of samples chemical analysis time at a steel company using a continuous improvement team
In the current competitive scenario, organizations have been using techniques capable of increasing their production capacities and maintaining a level of competitiveness that ensures their survival.
One such technique is known as continuous improvement. Following this line of reasoning, the current study aims to describe how a continuous improvement team (quality control circle), one of the pillars of the integrated management system of a steel company, can reduce the time performing chemical analyses by the chemical laboratory in which the project was carried out. Through improvement actions to mitigate the causes prioritized by the continuous improvement team, a reduction of 27% between 2014 and 2015 was obtained in the number of samples´ analysis that were not within the maximum acceptable time of 4.5 minutes. In the period that all the improvement actions for the prioritized causes had already been implemented, there was a reduction of the analyses time of 4.26 minutes, below the target of 4.5 minutes. The best practices were standardized by reviewing the technical procedure in order to keep the time to perform analyses under the target (4.5 minutes) over the next years. According to the calculations made by the engineers, the company prevented the loss of an annual value of R$ 2.2 M with the conclusion of the project
Design of Experiments and Computational Fluid Dynamics approach to Improve the product design process / Design of Experiments and Computational Fluid Dynamics approach to Improve the product design process
Design of Experiments (DOE) techniques were applied to improve the thermal performance of a gas oven, aided with a Computational Fluid Dynamics (CFD) study in concept selection phase of Product Design Process PDP. Typical approaches to these types of activities involve developing all possible combinations of geometries changing one variable at a time, analyzing them with CFD, and predicting the main effects over the parameters surface heat flux and pressure drop, which in this application are the system responses. The develop plan for the team was to generate an script that allowed analyzing the sample space of the process variables and analyze much geometry configurations to study the geometric parameters. By utilizing DOE techniques the number of geometries was strategically reduced to 29. The metamodel of the system was obtained as a function of the input variables, with a statistical adjustment of 86.78% for the surface heat flux and 78% for the pressure drop. Subsequently we found the geometry that improves the performance of the product using the multiobjetive optimization method “Normal Boundary Intersection - NBI”.
Arginase 1 deficiency presenting as complicated hereditary spastic paraplegia
INTRODUCTION: Argininemia or arginase deficiency is a metabolic disorder caused by pathogenic variants in ARG1 and consists of a variable association of progressive spastic paraplegia, intellectual disability, and seizures. Hereditary spastic paraplegia (HSP) is a group of inherited diseases whose main feature is a progressive gait disorder characterized by lower limb spasticity. This study presents 7 patients with arginase 1 deficiency from 6 different families, all with an initial diagnosis of complicated HSP. METHODS: We evaluated the clinical data of 7 patients belonging to six independent families who were diagnosed with hyperargininemia in a neurogenetics outpatient clinic. RESULTS: All patients had lower limb spasticity and six had global developmental delay. Five individuals had intellectual disability and two had epilepsy. Psychiatric abnormalities were seen in two patients. In two participants of this study, MRI disclosed thinning of the corpus callosum. Molecular diagnosis was made by whole exome sequencing. All variants were present in homozygosis; we identified two novel missense variants, one novel frameshift variant, and one previously published missense variant. DISCUSSION: Clinical diagnosis of early onset complicated hereditary spastic paraplegia was made in all patients. Two patients were initially suspected of having SPG11 due to thinning of the corpus callosum. As argininemia may present with a highly penetrant phenotype of spastic paraplegia associated with additional symptoms, this disease may represent a specific entity amongst the complicated HSPs
Synergistic calibration of a hydrological model using discharge and remotely sensed soil moisture in the Paraná river basin
Hydrological models are useful tools for water resources studies, yet their calibration is still a challenge, especially if aiming at improved estimates of multiple components of the water cycle. This has led the hydrologic community to look for ways to constrain models with multiple variables. Remote sensing estimates of soil moisture are very promising in this sense, especially in large areas for which field observations may be unevenly distributed. However, the use of such data to calibrate hydrological models in a synergistic way is still not well understood, especially in tropical humid areas such as those found in South America. Here, we perform multiple scenarios of multiobjective model optimization with in situ discharge and the SMOS L4 root zone soil moisture product for the Upper Paraná River Basin in South America (drainage area > 900,000 km2), for which discharge data for 136 river gauges are used. An additional scenario is used to compare the relative impacts of using all river gauges and a small subset containing nine gauges only. Across the basin, the joint calibration (CAL-DS) using discharge and soil moisture leads to improved precision and accuracy for both variables. The discharges estimated by CAL-DS (median KGE improvement for discharge was 0.14) are as accurate as those obtained with the calibration with discharge only (median equal to 0.14), while the CAL-DS soil moisture retrieval is practically as accurate (median KGE improvement for soil moisture was 0.11) as that estimated using the calibration with soil moisture only (median equal to 0.13). Nonetheless, the individual calibration with discharge rates is not able to retrieve satisfactory soil moisture estimates, and vice versa. These results show the complementarity between these two variables in the model calibration and highlight the benefits of considering multiple variables in the calibration framework. It is also shown that, by considering only nine gauges inst
Avanços e desafios da ciência de recursos hídricos no Brasil: uma síntese comunitária do XXIII Simpósio Brasileiro de Recursos Hídricos
In this paper we synthesize the special sessions of the XXIII Brazilian Water Resources Symposium 2019 in order to understand the major advances and challenges in the water sciences in Brazil. We analyzed more than 250 papers and presentations of 16 special sessions covering topics of Climate Variability and Change, Disasters, Modeling, Large Scale Hydrology, Remote Sensing, Education, and Water Resources Management. This exercise highlighted the unique diversity of natural and human water features in Brazil, that offers a great opportunity for understanding coupled hydrological and societal systems. Most contributions were related to methods and the quantification of water phenomena, therefore, there is a clear necessity for fostering more research on phenomena comprehension. There is a vast network of co-authorship among institutions but mostly from academia and with some degree of regional fragmentation. The ABRhidro community now has the challenge to enhance its collaboration network, the culture of synthesis analysis, and to build a common agenda for water resources research. It is also time for us to be aligned with the international water science community and to use our experiences to actively contribute to the tackling of global water issues.Este artigo apresenta uma síntese das sessões especiais do XXIII Simpósio Brasileiro de Recursos Hídricos 2019, com o objetivo de compreender os principais avanços e desafios em recursos hídricos no Brasil. Foram analisados mais de 250 trabalhos e apresentações em 16 sessões especiais abrangendo temas como Variabilidade e Mudanças Climáticas, Desastres, Modelagem, Hidrologia de Grande Escala, Sensoriamento Remoto, Educação e Gestão de Recursos Hídricos. Esta avaliação destacou a diversidade única de atributos naturais e antrópicos dos recursos hídricos brasileiros, que oferece uma grande oportunidade para aprendizado sobre sistemas hidrológico e humano acoplados. A maioria das contribuições é relacionada a métodos e quantificação de fenômenos hídricos, existindo uma necessidade clara de incentivo a mais pesquisas em compreensão de fenômenos. Existe uma vasta rede de coautores, mas principalmente da academia e com certo grau de fragmentação regional. A comunidade da ABRhidro tem o desafio de aumentar a sua rede de colaboração, a cultura de análises de síntese, e construir uma agenda comum para a pesquisa em recursos hídricos. Também é o momento de alinhar esforços com a comunidade de recursos hídricos internacional, usando nossas experiências para contribuir ativamente na solução de questões relacionadas à água em nível global
Variabilidade do armazenamento de água no Brasil
Brazil hosts a large amount of freshwater. Knowing how this stored water is partitioned in space and time between surface and subsurface components is a crucial step towards a more correct depiction of the country’s water cycle, which has major implications for decision making related to water resources management. Here, we extracted monthly water storage (WS) variability, from 2003 to 2020, based on multiple state-of-the-art datasets representing different WS components – groundwater (GW), soil moisture (SM), surface waters (SW), and artificial reservoirs (RS) – in all Brazilian Hydrographic Regions (BHRs), and computed each component’s contribution to the total variability. Most of the variability can be attributed to SM (40-68%), followed by GW (18-40%). SW has great influence in the north-western BHRs (humid monsoon influenced) with 18-40% and the southern BHRs (subtropical system influenced) with 5-10%. RS has important contributions in the Paraná with 12.1%, São Francisco with 3.5%, and Tocantins-Araguaia with 2.1%. In terms of long-term variability, water storages have been generally decreasing in the eastern and increasing in north-western and southern BHRs, with GW and RS being the most affected, although it can also be observed in SW peaks. Comparisons made with previous studies show that the approach and datasets used can have a considerable impact in the results. Such analysis can have broad implications in identifying the nature of amplitude and phase variability across regions in order to better characterize them and to obtain better evaluations of hydrological trends under a changing environment.O Brasil abriga uma grande quantidade de água doce. Saber como essa água armazenada é repartida no espaço e no tempo entre os componentes superficiais e subsuperficiais é crucial para uma representação mais correta do ciclo hídrico do país, o que tem grandes implicações para a tomada de decisões relacionadas à gestão dos recursos hídricos. Neste estudo, extraímos a variabilidade mensal do armazenamento de água, de 2003 a 2020, com base em diferentes fontes que representam o estado da arte da informação sobre diferentes componentes de armazenamento águas subterrâneas, umidade do solo, águas superficiais, e reservatórios artificiais – em todas as regiões hidrográficas brasileiras, e computamos a contribuição de cada componente em relação a variabilidade total. A maior parte da variabilidade pode ser atribuída a umidade do solo (4068%), seguida por águas subterrâneas (18-40%). Águas superficiais tem grande influência nas regiões hidrográficas do noroeste (influência de sistemas de monção) com 18-40% e nas BHRs do sul (influência de sistemas subtropicais) com 5-10%. O estoque em reservatórios artificiais tem contribuições importantes nas regiões do Paraná com 12,1%, do São Francisco com 3,5% e do Tocantins-Araguaia com 2,1%. Em termos de variabilidade de longo prazo, os estoques de água têm geralmente diminuído nas regiões leste e aumentado no noroeste e no sul, sendo os estoques de águas subterrâneas e reservatórios os mais afetados, embora essa tendência também possa ser observada nos picos de água superficial. Comparações feitas com estudos anteriores mostram que a abordagem e os conjuntos de dados utilizados podem ter um impacto considerável nos resultados. Tal análise pode ter amplas implicações na identificação da natureza da variabilidade de amplitude e fase entre as regiões, a fim de melhor caracterizá-las e obter melhores avaliações das tendências hidrológicas
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