Artículos

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https://hdl.handle.net/10784/29041

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Mostrando 1 - 14 de 14

La flexibilización de la oferta académica mejora la calidad del aprendizaje
(2006-10-01) DIAZ, ADALBERTO GABRIEL; DIAZ, ADALBERTO GABRIEL; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Análisis de estructuras periódicas con descripción de fourier y redes neuronales
(IMPRENTA UNIV ANTIOQUIA, 2007-06-01) DIAZ, ADALBERTO GABRIEL; DIAZ, ADALBERTO GABRIEL; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Innovation and creativity in process control and manufacturing
(Springer-Verlag France, 2014-12-01) DIAZ, ADALBERTO GABRIEL; DIAZ, ADALBERTO GABRIEL; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Visión 3-D de rugosidades en superficies, bajo el principio de imágenes de sombras, en Aplicación Textil
(Fondo Editorial Universidad EAFIT, 2003-04-01) DIAZ, ADALBERTO GABRIEL; DIAZ, ADALBERTO GABRIEL; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Improvement of a knock model for natural gas SI engines through heat transfer evaluation
(Springer-Verlag France, 2018-11-01) Sierra Parra A.F.; Díaz Torres A.G.; Sierra Parra A.F.; Díaz Torres A.G.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Knock is an abnormal combustion phenomena capable of causing serious damage to spark ignition engines, and is a constraint to reach the maximum potential of the engine, since strategies to increase power output and improve efficiency such as turbocharging, increased compression ratio and the advancement of spark timing, also increase the possibility of knock occurrence. Therefore, it is crucial to take into account the limits imposed by knock in the design and operating conditions of the engine when using an engine computational model. In this article a zero-dimensional two-zone engine model, coupled with a chemical kinetic model for knock detection through end-gas auto-ignition is developed and validated, for a natural gas engine. Given the importance of an accurate knock prediction, five heat transfer coefficient correlations are compared to find the most suitable to predict the knock occurrence, through calculation of a knock criterion. Correlations from Sitkei and Annand were the most suitable to predict this knock criterion for the experimental data used, and the Sitkei correlation was later tested in a parametric study to predict the effect of spark timing, compression ratio, equivalence ratio and inlet temperature in knock occurrence and intensity. Results were in accordance with real engine behaviour when knock occurs. © 2017, Springer-Verlag France SAS, part of Springer Nature.
Evaluation of two strategies NMPC into HIL applied to the operation of an internal combustion engine
(Springer-Verlag France, 2018-02-01) Chica, J.A.V.; Torres, A.G.D.; Chica, J.A.V.; Torres, A.G.D.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
The hardware in the loop (HIL) platforms constitute an accelerated engineering design medium that subsequently reduces the risk of failure in the implementation process. This fact is enhanced when the designer is faced with extremely complex tasks and when design errors can lead to destructive and costly testing. The design of complex algorithms such as non-linear controllers applied to electronic control units of combustion engines, is a task of higher complexity level, and tests with incorrectly adjusted drivers can result in engine breakdown. This document reports the performance and effectiveness of a two-HIL scheme as an interactive design platform used for the design of electronic control units ECU, for internal combustion engines. The implementation and adjustment of two NMPC strategies aimed at optimizing the operation of the engine from three fronts: energetic, economic and environmental, involving independent and simultaneous objectives, give an account of the usefulness of the interactive design scheme. © 2017, Springer-Verlag France.
NMPC controller applied to the operation of an internal combustion engine: formulation and solution of the optimization problem in real time
(Springer-Verlag France, 2018-02-01) Chica, J.A.V.; Torres, A.G.D.; Acosta Maya, Diego Andres; Chica, J.A.V.; Torres, A.G.D.; Acosta Maya, Diego Andres; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Numerical optimization solve problems efficiently where such efficiency is focused on the speed with which the optimal x* is achieved, is open line of research and strong work in the scientific community in order to achieve control systems in dynamic processes with response times of the order of milliseconds. A clear example of this, is the implementation of optimal controller’s combustion engines. For subsequent approach to the design and implementation of nonlinear model predictive control controllers, it has made a comparison of yields algorithms quadratic programming by active set with linearization restrictions, and sequential quadratic programming with single shooting technique to solve quadratic optimization problem formulation referred to a dynamic internal combustion engine of spark ignition, in embedded systems with real-time processing. © 2016, Springer-Verlag France.
Diseño del proceso de extracción de aceite de sacha inchi (plukenetia Volubilis L.) con CO2 supercrítico
(Universidad Nacional de Colombia, 2016-09-21) Triana, Diana Marcela; |Torijano, Sandra Adela; Catalina Giraldo E; Triana, Diana Marcela|; Torijano, Sandra Adela; Catalina Giraldo E; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Sacha inchi (Plukenetia volubilis L.) presenta un alto contenido de proteína y aceite rico en omegas 3 (50%) y 6 (36%), lo que atribuye al aceite beneficios nutricionales y cardioprotectores previniendo enfermedades cardiovasculares...
Control of emissions in an internal combustion engine: first approach for sustainable design
(Springer-Verlag France, 2016-08-01) Amaya, A.F.D.; Torres, A.G.D.; Acosta, D.A.; Amaya, A.F.D.; Torres, A.G.D.; Acosta, D.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
A mathematical model of emissions was developed in a Twingo D7F engine. The effects of variations in compression ratio, fuel/air equivalence ratio, spark advanced and combustion duration under pollutant emissions were studied. Analysis and data collection were performed in an engine bank using a data acquisition system integrated to an Interactive Engineering Environment. A control strategy was implemented to guarantee emissions reduction.
Simultaneous Fluorometric Determination of Chlorophylls a and b and Pheophytins a and b in Olive Oil by Partial Least-Squares Calibration
(AMER CHEMICAL SOC, 2003-11-19) Diaz, TG; Meras, ID; Correa, CA; Roldan, B; Caceres, MIR; Diaz, TG; Meras, ID; Correa, CA; Roldan, B; Caceres, MIR; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
The resolution of quaternary mixtures of chlorophylls a and b and pheophytins a and b has been accomplished by partial least-squares (PLS) multivariate calibration, applied to the fluorescence signals of these pigments. The total luminescence information of the compounds has been used to optimize the spectral data set to perform the calibration. After preliminary studies, a method is described in acetone media, to avoid emulsions with the olive oil samples. Different scanning paths have been selected for each method. For the simultaneous determination of the pigments in olive oil samples, a comparative study of the results found by using excitation, emission, and synchronous spectral data, as analytical signal, was performed. The excitation spectra were selected as the better analytical signals for the determination of the pigments in olive oil samples. The optimum wavelength range to record the excitation spectra (?em = 662 nm) was selected to minimize the contribution of pheophytin a and to maximize the contribution of the other pigments, which are the minor constituents in olive oil. Determination of these pigments in olive oil samples was effected from the excitation spectra of dissolutions o suitable aliquots in acetone. Recovery values from olive oil, spiked with chlorophylls a and b and pheophytins a and b, were in the ranges of 70-112, 71-111, 76-105, and 82-109%, respectively.
First and second thermodynamic law analyses applied to spark ignition engines modelling and emissions prediction
(Springer-Verlag France, 2016-11-01) Duque Amaya, A.F.; Díaz Torres, A.G.; Acosta Maya, D.A.; Duque Amaya, A.F.; Díaz Torres, A.G.; Acosta Maya, D.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
A mathematical and numerical model of flow and combustion process for spark ignition engines is developed using the principles of the first and second law of thermodynamic. Availability (exergy) analysis is applied to cylinder of a spark ignition engine during the combustion process using a two-zone combustion model. Special attention is given to identification and quantification of irreversibility of combustion process and energy available basing on the isooctane fuel explosion. To predict emissions generation (greenhouse gases) a skeletal mechanism including 32 species and 61 reactions was developed and tested for different engine operations and exergy destructions.
Simulation NMPC in 2-HIL to design ECU
(Springer-Verlag France, 2017-11-01) Chica, J.A.V.; Torres, A.G.D.; Chica, J.A.V.; Torres, A.G.D.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
The development, testing and tuning of control systems for complex plants found hardware in the loop (HIL) technical, a perfect ally to reduce risks, costs and times redesign. HIL allows for example, in the automotive field contain an embedded system complexity nonlinear dynamics modeling the internal combustion engine, including the processes of discrete events and continuous. With the goal to represent as closely as possible the behavior of the engine, dynamics is simulated by the embedded system in real time, sensors including. On the other hand, the electronic control unit (ECU), by construction also constitutes an embedded system that the plant operates properly. Is of wide interest to optimize engine operation, and a valid opportunity, is to design ECU's that are running optimal control algorithms, such as nonlineal model predictive control (NMPC). This document is a report of the practical reliability of the implementation of a HIL simulation scheme for the design of NMPC controllers for internal combustion engine. In a RT hardware element implements the component models the nonlinear plant, in another such element is implemented and tested two NMPC optimal control algorithms: model predictive control with linearization on-line and NMPC based on sequential quadratic programming, included in the simulation loop the real actuator elements. Combined with an interface to the designer that allows actively interact with the system, evaluating an expanded field operating conditions and even bordering operating limits.
Propiedades físicas y mecánicas de granos de Jatropha curcas cultivadas en Colombia
(IMPRENTA UNIV ANTIOQUIA, 2014-01-01) Betancur-Prisco, J.C.; Mira-Hernández, C.; París-Londoño, L.S.; Betancur-Prisco, J.C.; Mira-Hernández, C.; París-Londoño, L.S.; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
Biodiesel from Jatropha curcas seeds is one promissory option in the biofuels field. This is a crop that develops in tropical countries which can grow on marginal soils with low irrigation and helps to control the erosion. This bush grows quickly and produces seeds with approximately 35% oil content and it does not compete with food crops. However, for the production of biodiesel from Jatropha to be sustainable and profitable it is required research and technological development at all stages of the production chain. This articleshows the results of a research process that aims the determination of some significant physical and mechanical characteristics of Jatropha curcas seeds. This data are important, because they provide necessary information in the design of equipment and processes for Jatropha curcas oil production; especially, for mechanical oil extraction. As a result of the research process different properties were determined, for example: compression (2.8 mm) and energy (332 N.mm) required for fracture, average dimensions of seeds (length: 10.8 mm/width: 17.8 mm/thickness: 8.6 mm), fractions of shell (38%) and albumen (62%) in the seed, moisture content of seed (5.2%), oil content (29%), calorific value of shell (0.3 MJ/kg) and albumen (0.8 MJ/kg). All these variables are important parameters in the design of equipment, but also are useful to evaluate alternative uses for by-products of the oil extraction process, for example as energy source. Besides, the available information in Colombia about Jatropha is not much.
Analysis of periodic structures with Fourier description and neuronal network
(IMPRENTA UNIV ANTIOQUIA, 2007-06-01) DIAZ, ADALBERTO GABRIEL; Gabriel Diaz, Adalberto; Universidad EAFIT. Departamento de Ingeniería de Producción; Ingeniería, Energía, Exergía y Sostenibilidad (IEXS)
This work is developed in a project of textile lattices inspection. The structure of a superficial texture is manifested with a behavior on the base of a model known as pattern which, is associated with a group of characteristics that define it as such. The identification process and classification of shortcomings in the texture consists on establishing a region of conformity in the coordinated space defined by the pattern's characteristics. The reduction process of this m-dimensional space, helps to its identification in an n-dimensional space, such that m > n, where the classification system actually depends on the characteristics of the new space, where the new characteristics truly contain the classification information. The space characteristics allow for the identification of the pattern as such in the place that is explored. The characteristic frequency corresponds to a reduction of the classification space, making it more generic in the area over the image. The classification system is modeled with neuronal networks algorithms and the complexity of the surfaces of decision is solved starting from the architecture and the algorithms of training of the neuronal net.

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