2,159 research outputs found

    Integration of economic MPC and modifier adaptation in slow dynamic processes with structural model uncertainty

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    Real-Time Optimization, known by its acronym RTO, uses a steady-state nonlinear model of the process to optimize a plant's economic objective subject to process constraints. This is the technology currently used in commercial RTO applications. However, no model is a perfect representation of reality, and structural and parametric model uncertainties make the optimum calculated by RTO do not match those of the actual process. One way to address this problem is to modify the optimization problem so that the Necessary Conditions of Optimality (NCO) of the problem match those of the actual plant. This strategy is known as Modifier Adaptation (MA) methodology. The MA methodology requires the gradient values of the real plant and the model to calculate the modifiers. There are several ways to accurately estimate model gradients, but estimation of the real process gradients are more difficult. In addition, the need to use stationary data is a limitation of RTO with MA, especially for slow dynamic systems. This thesis focuses on ways to mitigate the weaknesses of RTO and MA unification that we consider most critical for its application in industry. To this end, it is proposed to couple the RTO and control layers with the concepts of the Modifier Adaptation (MA) methodology by estimating process gradients or directly the MA modifiers using transient data.La Optimización en Tiempo Real, conocida por la sigla en inglés RTO usa un modelo no lineal estacionario del proceso para optimizar un objetivo económico de la planta frente a restricciones del proceso. Esta es la tecnología usada actualmente por las aplicaciones comerciales de RTO. Sin embargo, ningún modelo es una representación perfecta de la realidad y las incertidumbres estructurales y paramétricas de los modelos hacen que los óptimos calculados por la RTO no coincidan con los del proceso real. Una forma de abordar este problema es modificar el problema de optimización de modo que las condiciones necesarias de optimalidad del problema (NCO) se igualen a los de la planta real. Esa estrategia es conocida como la metodología de adaptación de modificadores (Modifier Adaptation, MA). La metodología MA necesita de los valores de gradiente de la planta real y del modelo para el cálculo de los modificadores. Hay diversas formas de estimar los gradientes del modelo con exactitud, sin embargo, la estimación en proceso real es más difícil. Además, la necesidad de usar datos en estacionario sigue siendo una limitación fundamental de la RTO con MA, principalmente para sistemas dinámicos lentos. Esta tesis se enfoca en formas de mitigar las debilidades de la unificación RTO y MA que consideramos las más críticas para su aplicación en la industria. Para eso se propone que las capas de RTO y control se unan con los conceptos de la metodología de adaptación de modificadores (Modifier Adaptation, MA) estimando los gradientes de proceso o directamente los modificadores de MA usando datos de transitorio.Escuela de DoctoradoDoctorado en Ingeniería Industria

    Hazardous thoracic and ultrafine particles from road dust in a Caribbean industrial city

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    In this study, inorganic geochemical characterization of the thoracic (or < 10 μm) fraction of road dust in Barranquilla (a major industrial city in the Caribbean region) was conducted. Samples were collected directly from street pavements, and the fraction of particles <10 μm was analyzed by inductively coupled plasma - optical emission spectroscopy (ICP-OES) and inductively coupled plasma - mass spectrometry (ICP-MS). Major elements including Al, Ca, Fe, K, Mg, Na, and S were the most abundant species, accounting for 23 ± 18% of the mass of thoracic particles. Enrichment factor was calculated obtaining that Sb, Sn, Cu, Zn, Pb, and Fe had a dominant anthropogenic influence. An exploratory analysis of morphology and geochemical composition of ultrafine particles was conducted using a field emission scanning electron microscope (FE-SEM) and high-resolution transmission electron microscope (HR-TEM). Iron particles were identified as enriched compounds and as a mineral (magnetite). Hazardous ultrafine particles (UFPs, with diameter < 100 nm) such as TiO2 and Pb (agglomerated shape), and V and Ni (almost-spherical carbonaceous particles) were also detected. The braking process was identified as a crucial urban source of thoracic particles and UFPs. The results provide data that can be used to better understand and manage road dust

    A GARANTIA DO LIVRE EXERCÍCIO DA ATIVIDADE ECONÔMICA E A PRESERVAÇÃO DA EMPRESA PELOS MECANISMOS: COMPLIANCE; TURNAROUND; RECUPERAÇÃO EXTRAJUDICIAL E JUDICIAL

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    RESUMO As empresas foram feitas para durar, e garantir o exercício da atividade econômica diante da crise é um desafio. As empresas visionárias são as organizações mais longevas, que conseguem ao longo do tempo adaptar-se às mudanças. Porém, nem todas vencem a sua inércia para implementar na gestão ferramentas capazes de inibir o estado de insolvência e diminuir o elevado e crescente número de pedidos de Recuperação Judicial, que tem sido usado de forma insipiente, e como única solução de soerguimento da empresa

    REALIDADE DO INTERCÂMBIO E DA MOBILIDADE ACADÊMICA NA UNIVERSIDADE FEDERAL DE SANTA CATARINA

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    O mundo atual apresenta um cenário mutável e sem fronteiras, ocasionando a globalização da economia, do comércio, dos processos de produção e das telecomunicações: o mundo tornouse interconectado. Nesse cenário, as universidades têm a missão de preparar cidadãos para atuarem em um ambiente globalizado, proporcionando aos mesmos uma experiência educacional internacionalizada. É nesse contexto que o presente artigo se insere, tendo por objetivo analisar a realidade do intercâmbio e mobilidade acadêmica na Universidade Federal de Santa Catarina. Como método, analisou-se documentos institucionais que indicam essa realidade, além de legislações e endereços eletrônicos. Os resultados apontaram que o intercâmbio acadêmico proporcionou experiências estrangeiras a 794 estudantes, enquanto que a mobilidade acadêmica ainda apresenta resultados modestos, não ultrapassando 50 alunos. Conclui-se que a realidade do intercâmbio e da mobilidade acadêmica é existente, ativo, incentivativo e em crescimento, com tendência a expansão de programas, convênios e acordos com diversas instituições

    Economic MPC with Modifier Adaptation using Transient Measurements

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    Producción CientíficaThis paper presents a method to estimate process dynamic gradients along the transient that combined with the idea of Modifier Adaptation (MA) improves the economic cost fuction of the examples presented. The gradient estimation method, called TMA, aims to reduce the large convergence time required to traditional MA in processes of slow dynamics. TMA is used with an economic predictive control with MA (eMPC+TMA) and was applied in two case studies: a simulation of the Williams-Otto reactor and a hybrid laboratory plant based on the Van de Vusse reactor. The results show that eMPC+TMA could reach the plant real steady-state optimum despite process-model mismatch, due to the inclusion of the effect of process dynamics in the TMA algorithm. Despite the estimation errors, the proposed methodology improved the profit of the experimental case study, with respect to the use of an eMPC with no modifiers, by about 20% for the unconstrained case, and by 130% in the constrained case.Junta de Castilla y León (CLU 2017-09 and UIC 233)FEDER - AEI (PGC2018-099312-B-C31

    INFECTION RELATED TO THE EXTERNAL VENTRICULAR SHUNT IN A NEUROSURGERY HOSPITAL

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    OBJETIVO:Identificar os fatores co-responsáveis de infecção relacionada à derivação ventricular externa.MÉTODO: estudo retrospectivo com análise quantitativa dos dados; desenvolvido no Serviço de Arquivo Médico de um hospital público referencia em neurocirurgia em Pernambuco. Amostra constituída de 140 pacientes submetidos a inserção de Derivação Ventricular Externa. Os dados foram coletados por questionário semi-estruturado; analisados através do programa software SPSS 13.0. RESULTADOS: Predominância do sexo masculino 39,7%; idade entre 20 e 39 anos 52%;tempo de internamento acima de 60 dias 72,7%; Múltiplas DVE instaladas 100%;tempo de uso da DVE acima de 30 dias 96,2%. CONLUSÃO: significância estatística para os fatores: tempo de internamento prolongado, número de DVE instaladas, tempo de uso da DVE e o desenvolvimento de infecção. Ações de enfermagem são emergentes visando garantir a segurança do paciente no ambiente hospitalar

    INFECTION RELATED TO THE EXTERNAL VENTRICULAR SHUNT IN A NEUROSURGERY HOSPITAL

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    OBJETIVO:Identificar os fatores co-respons&aacute;veis de infec&ccedil;&atilde;o relacionada &agrave; deriva&ccedil;&atilde;o ventricular externa.M&Eacute;TODO: estudo retrospectivo com an&aacute;lise quantitativa dos dados; desenvolvido no Servi&ccedil;o de Arquivo M&eacute;dico de um hospital p&uacute;blico referencia em neurocirurgia em Pernambuco. Amostra constitu&iacute;da de 140 pacientes submetidos a inser&ccedil;&atilde;o de Deriva&ccedil;&atilde;o Ventricular Externa. Os dados foram coletados por question&aacute;rio semi-estruturado; analisados atrav&eacute;s do programa software SPSS 13.0. RESULTADOS: Predomin&acirc;ncia do sexo masculino 39,7%; idade entre 20 e 39 anos 52%;tempo de internamento acima de 60 dias 72,7%; M&uacute;ltiplas DVE instaladas 100%;tempo de uso da DVE acima de 30 dias 96,2%. CONLUS&Atilde;O: signific&acirc;ncia estat&iacute;stica para os fatores: tempo de internamento prolongado, n&uacute;mero de DVE instaladas, tempo de uso da DVE e o desenvolvimento de infec&ccedil;&atilde;o. A&ccedil;&otilde;es de enfermagem s&atilde;o emergentes visando garantir a seguran&ccedil;a do paciente no ambiente hospitalar

    Possibilities of using silicate rock powder: an overview

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    This study evaluates the on use of crushed rocks (remineralizers) to increase soil fertility levels and which contributed to increase agricultural productivity, recovery of degraded areas, decontamination of water, and carbon sequestration. The use of these geological materials is part of the assumptions of rock technology and, indirectly, facilitates the achievement of sustainable development goals related to soil management, climate change, and the preservation of water resources. Research over the past 50 years on silicate rocks focused on soil fertility management and agricultural productivity. More recently, the combined use with microorganisms and organic correctives have shown positive results to mitigate soil degradation; to expand carbon sequestration and storage; and to contribute to the adsorption of contaminants from water and soil. In this article we show results obtained in several countries and we show that this technology can contribute to the sustainability of agriculture, as well as to reverse global warming. Although mineral nutrients are released more slowly from these types of inputs, they remain in the soil for a longer time, stimulating the soil biota. In addition, they are a technology to soluble synthetic fertilizers replace, since the few nutrients derived from such inputs not consumed by plants are lost by leaching, contaminating groundwater and water resources. In addition, conventional methods rely heavily on chemical pesticides which cause damage to soil's microfauna (responsible for the decomposition of organic matter and nutrient cycling) and the loss of organic carbon (in the form of dioxide), which is quickly dispersed in the atmosphere. Silicate rock powders are applied in natura, have long-lasting residual effects and reduce greenhouse gas emissions
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