MODEL UPDATING AND STRUCTURAL HEALTH MONITORING OF HORIZONTAL AXIS WIND TURBINES VIA ADVANCED SPINNING FINITE ELEMENTS AND STOCHASTIC SUBSPACE IDENTIFICATION METHODS

Wind energy has been one of the most growing sectors of the nation’s renewable energy portfolio for the past decade, and the same tendency is being projected for the upcoming years given the aggressive governmental policies for the reduction of fossil fuel dependency. Great technological expectation and outstanding commercial penetration has shown the so called Horizontal Axis Wind Turbines (HAWT) technologies. Given its great acceptance, size evolution of wind turbines over time has increased exponentially. However, safety and economical concerns have emerged as a result of the newly design tendencies for massive scale wind turbine structures presenting high slenderness ratios and complex shapes, typically located in remote areas (e.g. offshore wind farms). In this regard, safety operation requires not only having first-hand information regarding actual structural dynamic conditions under aerodynamic action, but also a deep understanding of the environmental factors in which these multibody rotating structures operate. Given the cyclo-stochastic patterns of the wind loading exerting pressure on a HAWT, a probabilistic framework is appropriate to characterize the risk of failure in terms of resistance and serviceability conditions, at any given time. Furthermore, sources of uncertainty such as material imperfections, buffeting and flutter, aeroelastic damping, gyroscopic effects, turbulence, among others, have pleaded for the use of a more sophisticated mathematical framework that could properly handle all these sources of indetermination. The attainable modeling complexity that arises as a result of these characterizations demands a data-driven experimental validation methodology to calibrate and corroborate the model. For this aim, System Identification (SI) techniques offer a spectrum of well-established numerical methods appropriated for stationary, deterministic, and data-driven numerical schemes, capable of predicting actual dynamic states (eigenrealizations) of traditional time-invariant dynamic systems. As a consequence, it is proposed a modified data-driven SI metric based on the so called Subspace Realization Theory, now adapted for stochastic non-stationary and timevarying systems, as is the case of HAWT’s complex aerodynamics. Simultaneously, this investigation explores the characterization of the turbine loading and response envelopes for critical failure modes of the structural components the wind turbine is made of. In the long run, both aerodynamic framework (theoretical model) and system identification (experimental model) will be merged in a numerical engine formulated as a search algorithm for model updating, also known as Adaptive Simulated Annealing (ASA) process. This iterative engine is based on a set of function minimizations computed by a metric called Modal Assurance Criterion (MAC). In summary, the Thesis is composed of four major parts: (1) development of an analytical aerodynamic framework that predicts interacted wind-structure stochastic loads on wind turbine components; (2) development of a novel tapered-swept-corved Spinning Finite Element (SFE) that includes dampedgyroscopic effects and axial-flexural-torsional coupling; (3) a novel data-driven structural health monitoring (SHM) algorithm via stochastic subspace identification methods; and (4) a numerical search (optimization) engine based on ASA and MAC capable of updating the SFE aerodynamic model

Cristo y el dolor en Desolación de Gabriela Mistral

En Desolación, Gabriela Mistral con frecuencia utiliza imágenes de Cristo como representación de la persona que acepta los padecimientos de la vida. Cristo está relacionado con la expresión del sufrimiento terrenal y no con el consuelo o la salvación del alma después de la muerte física, de modo que se dirige a la revisión del dolor como una posibilidad humana de experimentar la realidad, la fragilidad y la plenitud de la vida.En Desolación, Gabriela Mistral con frecuencia utiliza imágenes de Cristo como representación de la persona que acepta los padecimientos de la vida. Cristo está relacionado con la expresión del sufrimiento terrenal y no con el consuelo o la salvación del alma después de la muerte física, de modo que se dirige a la revisión del dolor como una posibilidad humana de experimentar la realidad, la fragilidad y la plenitud de la vida

Prácticas para el laboratorio de introducción a los materiales

1 archivo PDF (100 páginas) ; 2a ed. 2001, 4a reimpresión 2008.El objetivo de este trabajo es mostrar al lector el amplio espectro de la ciencia de los materiales y por esto se han seleccionado prácticas que permitan tener una idea general de las estructuras, propiedades y aplicaciones de los tres grupos de materiales ingenieriles: metales, cerámicos y polímeros

RESERVOIR CHARACTERIZATION AND MODELING OF A CRETACEOUS TRIPLE POROSITY CARBONATE RESERVOIR CONTRIBUTION OF PORE TYPES TO HYDROCARBON PORE VOLUME AND PRODUCTION, CAMPECHE SOUND, GULF OF MEXICO

Campeche Sound, located southeast of the continental shelf in the Gulf of Mexico. represents about 80% of the national hydrocarbons production of Mexico, and comprises several giant oilfields, including Cantarell and Ku-Zaap-Maloob. The reservoir rock was deposited during the Cretaceous over the Yucatan Slope and is divided into Upper, Middle, and Lower Cretaceous. The main reservoir rocks are carbonate debris flow facies in the Upper Cretaceous. The formation was diagenetically altered by dolomitization, dissolution, and fracturing processes. All these processes were related to a compressional tectonic regime. Dolomitization in this area is a major control on porosity. When dolomitization exists porosity is improved and is divided into three kinds: matrix, fracture and vug porosity. Fracture and vug porosities are the main productive porosities because they increase connectivity among porous voids. Dolomitization is not homogeneous in the Cretaceous rocks in the study area, which is an important difference with the major fields cited above. Dolomitization is present in the upper and middle part of the Upper Cretaceous and in the Middle Cretaceous, but not in the Lower Cretaceous. The lower part of the Upper Cretaceous is not completely dolomitized in the study area. This heterogeneity in the porosity, and consequently in the permeability, could form vertical barriers to the flow, and it could increase the mobility of fluid movement in the aquifer in the zone, creating early irruptions of water during the production of the future wells. To characterize these complex fields and plan their development, I developed an integrated workflow. The ultimate objective of this research was a 3D-cellular model that represented all the geological complexities identified in the fields through well and seismic data. The first part of this workflow described in Chapter 1, is to define the architecture and structure of the fields. The resulting structural model was supported by the interpretation of a 3D depth migrated seismic integrated data with previous studies in nearby fields describing lithofacies and stratigraphical units to subdivide the model based on lithology supported by image well-logs and core reports. In Chapter 2, I focus on the internal distribution of the dolomitized facies in the field. I evaluated different seismic attributes and selected the ones that on both time and depth-migrated best-differentiated dolomite from limestone. Then, I incorporated them into machine learning processes to identify the process that gave us a result that was closer to the expected geology in the area. In Chapter 3, I use Nuclear Magnetic Resonance (NMR) and image logs, I estimated a dual-porosity petrophysical model. This model was then used as a parameter to select a method from those proposed by other authors to estimate dual-porosity based on basic well-logs. The selected method can be applied to future wells in the area. Then, I distributed the petrophysical properties using geostatistical methods based on the lithofacies described in chapter one. I used the dolomitization trends estimated in chapter 2, as a second variable into the geostatistical process. The result was a 3D model, which identified sweet spots to locate new development wells, estimate original volumes and, make simulations of the production of the fields

Dinámica y control de una clase de separadores flash reactivos

En este trabajo se estudia la dinámica de una unidad flash reactivo y se diseña su control. Se alimenta un reactante ligero que reacciona dando efluente líquido rico en el producto pesado y efluente vapor rico en reactante. Las salidas a regular son el acumulado de masa reaccionante y la temperatura y las entradas de control son el flujo volumétrico del efluente líquido y la tasa de inyección de calor. Primero se caracteriza la dinámica y estática del proceso en términos de multiplicidad, estabilidad, operación óptima (máxima producción de producto pesado) y estructura variable (líquido reaccionante en ebullición, líquido con reacción y sin ebullición y vaporización total). Luego se diseña un esquema de control multivariable para regular dos salidas medidas (temperatura y el nivel de líquido) manipulando dos entradas de control (inyección de calor y extracción de líquido) de tal suerte que el sistema tenga como atractor robusto el estado estacionario óptimo (que puede ser localmente estable pero no robustamente estable). El control accionado por las salidas medidas: (i) consiste de dos lazos PI saturados y (ii) recupera (con convergencia de observador) el comportamiento de un control robusto pasivo no-lineal construido con base en el modelo detallado de la unidad. La metodología se ilustra y prueba con un caso de estudio representativo y simulaciones numéricas

Ensayo sobre los alphabetos de las letras desconocidas : que se encuentran en las mas antiguas medallas y monumentos de España

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Sign.: [ ]\p4\s, 2[calderón]\p4\s, A-X\p4\s, [ ]\p20\sPort. con grab. calcGrab. calc. en p. [1] y 1Las XX h. de grab. son calc.: "Peña", "Rodriguez" como escultores, al final de text

Basal ganglia, drug addiction and the neuroscience of maladaptive habits

The mammalian brain has developed memory systems mediating rigid, yet evolutionarily adaptive patterns of responding to invariant environmental stimuli and internal demands. Such memory systems promote the recall of specific response templates and the execution of inflexible actions to liberate buffering capacity for performing conscious, explicit cognitive processing. The dopamine-innervated neostriatum is central to the ability to learn such consistent associations between stimuli and actions implicitly. Controlled by their outcome when initially learned, actions succumb through iteration to the influence of triggering stimuli and progressively detach themselves from the pleasurable results originally produced, thereby becoming pervasive habits. This might be the case for drug-seeking and drug-taking behaviours, actions learned in part through dopamine-dependent drug-induced reinforcement when the drug is first experienced. With extended drug use, however, drugseeking actions might become conditioned to, and triggered by, specific exteroceptive stimuli and/or affective states, gradually becoming irrepressible forms of responding. We will review neuroanatomical, neuropharmacological and behavioural evidence suggesting that the basal ganglia play a prominent role in the shaping of drug addiction, here regarded as a pathological modification of otherwise adaptive habit learning systems mediated by the basal ganglia.peer-reviewe

PFC P1319 ETSIN - Arrastrero congelador factoria

Proyecto Fin de de Carrera Escuela Técnica Superior de Ingenieros Navales. Objeto: Definición, calculo y desarrollo de los distintos cuadernos que componen el proyecto. Así como documentos de defensa. Elemento: ARRASTRERO CONGELADOR FACTORIA PARA LAS ESPECIES DE FONDO Y PELAGICO