Non-linear models for a gypsum kiln. A comparative analysis

INTERNATIONAL FEDERATION OF AUTOMATIC CONTROL. WORLD CONGRESS (15.2002.BARCELONA)This paper presents several non-linear models adjusted in order to capture the dynamics of a gypsum kiln. The behavior of this kind of processes is affected by nonlinear effects caused by the existence of disturbances and the coupling among some variables. The use of second order Volterra and Hammerstein models as appropriate solutions to describe the process dynamics is analyzed. A thorough study of the best model order and structure is performed. Coefficients that best fit real data are also selected. This work aims to obtain a good non-linear model in order to implement a non-linear predictive controller, able to improve the performances of those linear controllers already tested on the plant.Comisión Interministerial de Ciencia y Tecnología (CICYT) 1FD97-083

Iterative nonlinear model predictive control of a PH reactor. A comparative analysis

IFAC WORLD CONGRESS (16) (16.2005.PRAGA, REPÚBLICA CHECA)This paper describes the control of a batch pH reactor by a nonlinear predictive controller that improves performance by using data of past batches. The control strategy combines the feedback features of a nonlinear predictive controller with the learning capabilities of run-to-run control. The inclusion of real-time data collected during the on-going batch run in addition to those from the past runs make the control strategy capable not only of eliminating repeated errors but also of responding to new disturbances that occur during the run. The paper uses these ideas to devise an integrated controller that increases the capabilities of Nonlinear Model Predictive Control (NMPC) with batch-wise learning. This controller tries to improve existing strategies by the use of a nonlinear controller devised along the last-run trajectory as well as by the inclusion of filters. A comparison with a similar controller based upon a linear model is performed. Simulation results are presented in order to illustrate performance improvements that can be achieved by the new method over the conventional iterative controllers. Although the controller is designed for discrete-time systems, it can be applied to stable continuous plants after discretization

Assessing Atmospheric Pollution and Its Impacts on the Human Health

This reprint contains articles published in the Special Issue entitled "Assessing Atmospheric Pollution and Its Impacts on the Human Health" in the journal Atmosphere. The research focuses on the evaluation of atmospheric pollution by statistical methods on the one hand, and on the other hand, on the evaluation of the relationship between the level of pollution and the extent of its effect on the population's health, especially on pulmonary diseases

Proceedings of FORM 2022. Construction The Formation of Living Environment

This study examines the integration of building information modelling (BIM) technologies in operation & maintenance stage in the system of managing real estate that helps to reduce transaction costs. The approach and method are based on Digital Twin technology and Model Based System Engineering (MBSE) approach. The results of the development of a service for digital facility management and digital expertise are presented. The connection between physical and digital objects is conceptualized

Controle preditivo não-linear para sistemas de Hammerstein

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia ElétricaAs pesquisas associadas às estratégias de controle preditivo não-linear têm apresentado grande crescimento ultimamente registrando, também, um número considerável de aplicações na indústria. A representação de um processo complexo através de um modelo não-linear, com o objetivo de melhorar seu desempenho dinâmico, tende a sacrificar a simplicidade de projeto do controlador preditivo. Visando aliar a capacidade de representação da não-linearidade de um processo com a simplicidade de projeto, torna-se interessante a utilização de controladores preditivos baseados no modelo de Hammerstein o qual é constituído de um bloco estático, não-linear, seguido de um bloco linear dinâmico. Esta tese apresenta um estudo de modelagem, identificação e controle preditivo não-linear baseado em modelos de Hammerstein. Algumas técnicas de seleção de estrutura e identificação do modelo de Hammerstein são apresentadas e algumas inovações são propostas. Estratégias de controle preditivo baseado no modelo de Hammerstein são discutidas e são propostas modificações num controlador para a inclusão de perturbações mensuráveis e uma técnica analítica para solucionar a multiplicidade do sinal de controle. Para avaliar as técnicas de identificação e controle estudadas, são apresentados resultados de simulação e experimentais em uma planta solar de climatização

Basic creep and autogenous shrinkage of Limestone Calcined Clay Cement (LC3)

The use of supplementary cementitious materials (SCM) to lower the clinker factor of cements is now commonplace, for it benefits performance, economics and ecology. This thesis focuses on ternary blends of limestone and calcined kaolinitic clays, two very promising SCM thanks to their worldwide availability. In particular, this research aims to get an insight on the delayed strains in sealed condition of such binders, christened LC3 for Limestone - Calcined Clay Cement. Delayed strains refer to time-dependent deformations undergone by the material during its lifetime, such as shrinkage and creep. This work evaluates the impact of the calcined kaolinite content of the clay - which can vary in accordance with the origin of the clay - on the autogenous shrinkage and basic creep properties of LC3. Compressive creep tests on mature paste samples indicated that the presence of limestone and calcined clay dramatically reduced creep compliance. This reduction is significant even with lower grade clays and does not depend on the clay purity if it has at least 40% of calcined kaolinite. A two-dimensional finite elements model was used to simulate the creep response of the tested microstructures in order to try to determine whether the compliance reduction originated from a different phase assemblage or a higher viscosity of the C-S-H. The outputs pointed towards a different rheology of C-S-H gel. Autogenous shrinkage measurements on LC3 binders showed that these ternary blends had a lower or comparable shrinkage to plain cement reference during the two first months of hydration. Shrinkage rate and amplitude was found to be close for LC3 mixes usingmedium to high grade clays of natural origin. A study of the evolution of microstructure with shrinkage demonstrated that if the calcined clay contained enoughmetakaolin to consume most of the available portlandite, the porosity and desaturation of the microstructure were very similar regardless of the clay. As these features play a large role on the origin of shrinkage force, the macroscopic response is comparable among these specific mixes

TECHNART 2017. Non-destructive and microanalytical techniques in art and cultural heritage. Book of abstracts

440 p.TECHNART2017 is the international biannual congress on the application of Analytical Techniques in Art and Cultural Heritage. The aim of this European conference is to provide a scientific forum to present and promote the use of analytical spectroscopic techniques in cultural heritage on a worldwide scale to stimulate contacts and exchange experiences, making a bridge between science and art. This conference builds on the momentum of the previous TECHNART editions of Lisbon, Athens, Berlin, Amsterdam and Catania, offering an outstanding and unique opportunity for exchanging knowledge on leading edge developments. Cultural heritage studies are interpreted in a broad sense, including pigments, stones, metal, glass, ceramics, chemometrics on artwork studies, resins, fibers, forensic applications in art, history, archaeology and conservation science. The meeting is focused in different aspects: - X-ray analysis (XRF, PIXE, XRD, SEM-EDX). - Confocal X-ray microscopy (3D Micro-XRF, 3D Micro-PIXE). - Synchrotron, ion beam and neutron based techniques/instrumentation. - FT-IR and Raman spectroscopy. - UV-Vis and NIR absorption/reflectance and fluorescence. - Laser-based analytical techniques (LIBS, etc.). - Magnetic resonance techniques. - Chromatography (GC, HPLC) and mass spectrometry. - Optical imaging and coherence techniques. - Mobile spectrometry and remote sensing

EVOLUTION OF THE SUBCONTINENTAL LITHOSPHERE DURING MESOZOIC TETHYAN RIFTING: CONSTRAINTS FROM THE EXTERNAL LIGURIAN MANTLE SECTION (NORTHERN APENNINE, ITALY)

Our study is focussed on mantle bodies from the External Ligurian ophiolites, within the Monte Gavi and Monte Sant'Agostino areas. Here, two distinct pyroxenite-bearing mantle sections were recognized, mainly based on their plagioclase-facies evolution. The Monte Gavi mantle section is nearly undeformed and records reactive melt infiltration under plagioclase-facies conditions. This process involved both peridotites (clinopyroxene-poor lherzolites) and enclosed spinel pyroxenite layers, and occurred at 0.7–0.8 GPa. In the Monte Gavi peridotites and pyroxenites, the spinel-facies clinopyroxene was replaced by Ca-rich plagioclase and new orthopyroxene, typically associated with secondary clinopyroxene. The reactive melt migration caused increase of TiO2 contents in relict clinopyroxene and spinel, with the latter also recording a Cr2O3 increase. In the Monte Gavi peridotites and pyroxenites, geothermometers based on slowly diffusing elements (REE and Y) record high temperature conditions (1200-1250 °C) related to the melt infiltration event, followed by subsolidus cooling until ca. 900°C. The Monte Sant'Agostino mantle section is characterized by widespread ductile shearing with no evidence of melt infiltration. The deformation recorded by the Monte Sant'Agostino peridotites (clinopyroxene-rich lherzolites) occurred at 750–800 °C and 0.3–0.6 GPa, leading to protomylonitic to ultramylonitic textures with extreme grain size reduction (10–50 μm). Compared to the peridotites, the enclosed pyroxenite layers gave higher temperature-pressure estimates for the plagioclase-facies re-equilibration (870–930 °C and 0.8–0.9 GPa). We propose that the earlier plagioclase crystallization in the pyroxenites enhanced strain localization and formation of mylonite shear zones in the entire mantle section. We subdivide the subcontinental mantle section from the External Ligurian ophiolites into three distinct domains, developed in response to the rifting evolution that ultimately formed a Middle Jurassic ocean-continent transition: (1) a spinel tectonite domain, characterized by subsolidus static formation of plagioclase, i.e. the Suvero mantle section (Hidas et al., 2020), (2) a plagioclase mylonite domain experiencing melt-absent deformation and (3) a nearly undeformed domain that underwent reactive melt infiltration under plagioclase-facies conditions, exemplified by the the Monte Sant'Agostino and the Monte Gavi mantle sections, respectively. We relate mantle domains (1) and (2) to a rifting-driven uplift in the late Triassic accommodated by large-scale shear zones consisting of anhydrous plagioclase mylonites. Hidas K., Borghini G., Tommasi A., Zanetti A. & Rampone E. 2021. Interplay between melt infiltration and deformation in the deep lithospheric mantle (External Liguride ophiolite, North Italy). Lithos 380-381, 105855