Artículos en Revistas
Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/538
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Item A disjunctive model to analyze and redefne the logistic of replenishing goods of retailing stores(Optimization and Engineering, 2022-02-09) Flores, Julio Rolando; Cúnico, Maria Laura; Vecchietti, Aldo RodomiroThis paper analyzes the distribution logistics for a retail business that has hundreds of stores located long distances from their warehouses. Given narrow revenue margins, retail companies must optimize the cost of the merchandise delivery to its stores. In general, the structure of the distribution consists of warehouses that concentrate goods which are then delivered to the stores according to a replenishment policy that contemplates its characteristics and location. The cost of the distribution logistics is signifcant and deserves special consideration. This paper presents a disjunctive multi period model to redesign the logistic infrastructure of delivering goods from warehouses to stores located in a wide geographical region. In the model, a warehouse can be installed, closed, expanded or replaced by a cross-docking terminal. The objective function is to minimize the cost of the whole distribution operation. A case study is presented to show the model capabilities.Item A fault detection and diagnosis technique for multivariate processes using a PLS-decomposition of the measurement space(2013) Vega, Jorge Ruben; Godoy, José Luis; Marchetti, JacintoA newstatisticalmonitoring technique based on partial least squares (PLS) is proposed for fault detection and di- 24 agnosis inmultivariate processes that exhibit collinearmeasurements. A typical PLS regression (PLSR)modeling 25 strategy is first extended by adding the projections of the model outputs to the latent space. Then, a PLS- 26 decomposition of the measurements into four terms that belongs to four different subspaces is derived. In 27 Q2 order to online monitor the PLS-projections in each subspace, new specific statistics with non-overlapped do- 28 mains are combined into a single index able to detect process anomalies. To reach a complete diagnosis, a further 29 decomposition of each statistic was defined as a sum of variable contributions. By adequately processing all this 30 information, the technique is able to: i) detect an anomaly through a single combined index, ii) diagnose the 31 anomaly class from the observed pattern of the four component statistics with respect to their respective confi- 32 dence intervals, and iii) identify the disturbed variables based on the analysis of themain variable contributions 33 to each of the four subspaces. The effectiveness observed in the simulated examples suggests the potential appli- 34 cation of this technique to real production systems.Item A mathematical modeling for simultaneous routing and scheduling of logging trucks in the forest supply chain(Forest Policy and Economics, 2022-01-12) Melchiori, Luciana; Nasini, Graciela; Montagna, Jorge Marcelo; Corsano, GabrielaTransportation cost in the forest industry highly impacts on the overall costs of the supply chain, and therefore it must be optimized for improving profitability. Considering the problem characteristics, the decisions related to the transport problem, such as allocation, routing, and scheduling, are usually decoupled, resorting to different decomposition strategies. As a result, suboptimal and underperforming solutions are obtained. In this article, decisions about raw material allocation, routing and scheduling are simultaneously solved through a mixed integer linear programming model. The proposed model involves an arc-based formulation for routing and a time grid discretization, including the definition of loading and unloading shifts for scheduling. This leads to detailed transportation planning for a homogeneous logging truck fleet that must fulfill the demand of varied raw material at minimum cost. Examples and performance tests are provided to assess the capabilities of the proposed exact approach.Item A new integrated approach for solving batching, production scheduling and delivery problems in single-stage batch environments(Computers & Chemical Engineering, 2024-06-02) Tibaldo, Aldana; Montagna, Jorge Marcelo; Fumero, YaninaAt operational level, production and distribution integration is very valuable in real-word applications, especially in industries where products must be delivered shortly after production, as in the case of perishable or customized products. Given that the involved decisions belong to different departments and considering their high combinatory, they are usually decoupled. Although this sequential approach simplifies decision making, it can lead to suboptimal solutions for the integrated problem. This paper presents a novel mixed-integer linear programming (MILP) model to simultaneously manage batching, production, and distribution decisions. An efficient strategy is proposed, where feasible routes that vehicles can travel are generated beforehand, which greatly simplify the formulation. Thus, infeasible routes are not considered (reduction of the search space) and several important decisions are made simultaneously when selecting a route (allocation and sequencing of the customers). The performance of this approach is superior to previous ones, especially in large problems.Item A regularized approach for derivative-based numerical solution of non-linearities in phase change static hysteresis modeling(International Communications in Heat and Mass Transfer, 2025-04) Dittler, Ramiro A.; Demarchi, María Cecilia; Álvarez-Hostos, Juan C.; Albanesi, Alejandro E.; Tourn, Benjamín A.Phase change materials (PCMs) represent a promising solution for thermal energy storage (TES) since they can store and release energy in the form of latent heat during solid↔liquid transitions. Nevertheless, accurately simulating the thermal behavior of PCMs remains challenging due to the non-linearities concerning latent heat effects and enthalpy hysteresis. This work introduces a stable and robust procedure based on the finite element method (FEM) under a mixed enthalpy–temperature formulation to address such non-linearities, which enables the numerical solutions using derivative-based algorithms such as the Newton–Raphson (NR) method. The static hysteresis model (SHM) is implemented in the FEM-based formulation via a regularization of the liquid fraction function in response to the sign of the temperature rate. This novel approach ensures a continuous and smooth heating↔cooling transition while retaining the SHM energy-conservative features to properly solve its non-linearities. The method is validated through a one-dimensional benchmark problem, demonstrating high performance and physical fidelity for both complete and partial phase changes. It achieves second-order convergence rates, ensures numerical stability even for large time steps, and maintains accuracy under diverse thermal boundary conditions. Finally, the method is extended to two-dimensional problems, highlighting its robustness and scalability for practical applications in TES systems.Item A shot in the dark : the current state of PCM hysteresis modelling in building energy simulation software(2025-02-16) Zhilyaev, Dmitry; Albanesi, Alejandro E.; Demarchi, María Cecilia; Fachinotti, Víctor D.; Bakker, Hans L. M.; Jonkers, Henk M.Phase change materials (PCM) are receiving an ever-growing attention as a promising construction material for improving building energy performance through thermal storage and peak load shifting. The analysis of PCM performance and decision-making related to PCM implementation in building envelope often rely on building energy simulation software such as EnergyPlus – a de-facto standard in the academic world and the industry. For a precise modelling of the dynamic PCM behaviour it is essential to correctly account for PCM hysteresis. This work provides an in-depth analysis of four publicly available EnergyPlus-based hysteresis models and identifies the existing limitations for each of them. Furthermore, it explores the effects of PCM model selection on decision-making using the example of novel PCM-embedded material development. The results of this study show that the current built-in hysteresis model in EnergyPlus is not implemented correctly, and none of the other analysed models is completely free of limitations. Moreover, this work draws attention to the existing contradictions between different PCM modelling approaches, highlighting the critical impact the selection of a PCM model has on PCM-related decision-making. We conclude that while the existing hysteresis models in EnergyPlus are operable – albeit with great caution – they are not yet at the stage where they could be used as a reliable decision-making support tool. Practical real-world integration of PCM in building envelopes is hardly possible without having dependable modelling tools to back it up, and the development of such tools requires far more attention than it is given at the moment.Item Algoritmo para la localización y despacho de bancos de baterías en redes de distribución(Ingenio Tecnológico, UTN - FR La Plata, 2022-06-10) Manassero, Ulises; Sanseverinatti, Carlos Ignacio; Loyarte, Ariel; Sangoi, EmmanuelLa utilización de medios de almacenamiento de energía en redes eléctricas se encuentra en pleno crecimiento en razón de los múltiples beneficios que aportan al sistema. En este trabajo, se presenta un algoritmo de optimización orientado a la gestión de bancos de baterías en redes radiales de distribución. El objetivo consiste en seleccionar la combinación de capacidades, posiciones en la red y la estrategia de operación más adecuada de los bancos de baterías. Se pretende optimizar un indicador global que incluye costos asociados a la adquisición de la energía por parte de la empresa distribuidora, pérdidas, operación y mantenimiento de las baterías, y penalizaciones por energía no suministrada ante escenarios de falla. La resolución se plantea en dos etapas acopladas: un algoritmo de Optimización por Enjambre de Partículas establece la ubicación y capacidades de los bancos a incorporar, y otros métodos tradicionales basados en gradientes obtienen el despacho de potencias, las pérdidas en la red y minimizan el impacto de los cortes de suministro. El algoritmo se evalúa sobre una red de distribución real, demostrando su validez para abordar un problema complejo con un número elevado de variables, siendo efectivo para optimizar el costo global.Item Alternativas para mejorar la eficiencia energética de un complejo industrial aprovechando calores residuales y energía fotovoltaica(Revista de la Asociación de Energías Renovables y Ambiente, 2021-06-10) Sangoi, Emmanuel; Vega, Jorge Rubén; Clementi, Luis A.En este trabajo se propone un modelo simplificado para el sistema energético de un complejo industrial petroquímico autoabastecido mediante cogeneración. El modelo se parametriza con datos disponibles en el complejo y se usa para evaluar el impacto de la incorporación de fuentes alternativas en su matriz energética. En este sentido, se analizan tres alternativas de configuración para el sistema energético actual del predio. Se propone aprovechar calores residuales con generadores eléctricos basados en ciclos Rankine orgánicos y energía solar con generadores fotovoltaicos. Luego se consideran distintas alternativas de penetración de estos recursos en base a factores ambientales de la zona y se comparan los resultados con el desempeño de la configuración actual. Se concluye que, al considerar otros recursos disponibles en el predio, es posible mejorar la eficiencia del sistema, diversificar su matriz energética y reducir el impacto ambiental.Item An adaptive soft sensor for on-line monitoring the mass conversion in the emulsion copolymerization of the continuous SBR process(Macromolecular Reaction Engineering, 2023) Sanseverinatti, Carlos Ignacio; Perdomo, Mariano Miguel; Clementi, Luis Alberto; Vega, Jorge RubénSoft sensors (SS) are of importance in monitoring polymerization processes because numerous production and quality variables cannot be measured online. Adaptive SSs are of interest to maintain accurate estimations under disturbances and changes in operating points. This study proposes an adaptive SS to online estimate the mass conversion in the emulsion copolymerization required for the production of Styrene-Butadiene rubber (SBR). The SS includes a bias term calculated from sporadic laboratory measurements. Typically, the bias is updated every time a new laboratory report becomes available, but this strategy leads to unnecessarily frequent bias updates. The SS includes a statistic-based tool to avoid unnecessary bias updates and reduce the variability of the bias with respect to classical approaches. A control chart (CC) for individual determinations combined with an algorithmic Cusum is used to monitor the statistical stability of the average prediction error. The adaptive SS enables a bias update only when a loss of said statistical stability is detected. Several bias update methods are tested on a simulated industrial train of reactors for the latex production in the SBR process. The best results are obtained by combining the proposed CC-based approach with a previously developed Bayesian bias update strategy.Item An architecture model for a distributed virtualization system(2019-10) Pessolani, PabloThe Thesis is about an architecture model for a Distributed Virtualization System, which could expand a virtual execution environment from a single physical machine to several nodes of a cluster. With current virtualization technologies, computing power and resource usage of Virtual Machines (or Containers) are limited to the physical machine where they run. To deliver high levels of performance and scalability, cloud applications are usually partitioned in several Virtual Machines (or Containers) located on different nodes of a virtualization cluster. Developers often use that processing model because the same instance of the operating system is not available on each node where their components run. The proposed architecture model is suitable for new trends in software development because it is inherently distributed. It combines and integrates Virtualization and Distributed Operating Systems technologies with the benefits of both worlds, providing the same isolated instance of a Virtual Operating System on each cluster node. Although it requires the introduction of changes in existing operating systems, thousands of legacy applications would not require modifications to obtain their benefits. A Distributed Virtualization System is suitable to deliver high-performance cloud services with provider-class features, such as high-availability, replication, migration, and load balancing. Furthermore, it is able to concurrently run several isolated instances of different guest Virtual Operating Systems, allocating a subset of nodes for each instance and sharing nodes between them. Currently, a prototype is running on a cluster of commodity hardware provided with two kinds of Virtual Operating Systems tailored for internet services (web server) as a proof of concept.Item Anàlisis comparativo de las respuestas de alumnos de quìmica general sobre el cambio quìmico(2014) Avalis, Carlos; Noseda, Juan CarlosLa reacción química constituye el eje central para el proceso de enseñanza y aprendizaje de la química. Distintas líneas de investigación en la didáctica de la química, hacen referencia a la importancia de considerar tres niveles de representación de la materia para el proceso de enseñanza - aprendizaje del cambio químico; comprenderlos y relacionarlos es necesario para lograr un aprendizaje significativo de la química. Hasta el año 2013 el tema se desarrollaba: Clase teórica donde se explicaban los tres niveles de representación, para lo cual se utilizaba pizarrón y apoyo de power point, y clase de resolución de problemas en la que se aplican los conceptos desarrollados A partir del 2014 se implementó el uso de secuencias didácticas utilizando TIC como estrategias para la enseñanza y el aprendizaje del cambio químico. El objetivo de este estudio es determinar si el empleo de secuencias didácticas favorece la comprensión del cambio químico. Se analizaron las respuestas de los alumnos regulares de química general, 132 correspondientes al año 2013 y 115 al 2014, a una evaluación anónima y voluntaria, y el tiempo asignado fue de 40 minutos. Los resultados muestran una mejora en el proceso enseñanza aprendizaje del cambio químico, utilizando secuencias didácticas, esto se ve reflejado en los porcentajes totales que pasaron del 33,4 % (2013) al 68,5 % (2014).Item Análisis de preferencias declaradas sobre movilidad sostenible en la ciudad de Santa Fe(2023) Imaz, Fernando Javier; Jaurena, Juan Francisco; Sorba, Iván AlejandroEn las últimas décadas, los cambios del estilo de vida y los modelos urbanos y territoriales han ido generando crecientes dificultades en la movilidad. Estas incluyen: congestión del tráfico, impactos ambientales y sociales que repercuten en la calidad de vida de las personas. Por esta preocupación surge el concepto de movilidad sostenible que promueve un balance entre los beneficios económicos, sociales y ambientales. Para lograr avances en tal sentido se necesitan políticas públicas que fomenten el transporte público, la bicicleta o caminar brindando beneficios al ambiente y a la calidad de vida de la población. Para poder reconocer las tendencias y expectativas de la población de la ciudad de Santa Fe sobre la problemática, resulta necesario el uso de modelos de elección discreta basados en una muestra de individuos a partir de encuestas de preferencias declaradas, considerando los modos de transporte existentes y los potenciales. El trabajo se incluye en el PID-TVTCBFE0008072TC: "Diseño de estrategias para la promoción de la movilidad sostenible en aglomerados urbanos", buscando presentar el análisis de las encuestas de preferencias declaradas realizadas en el mes de junio de 2022 a una muestra representativa de personas de la ciudad de Santa Fe donde fueron consultadas acerca de cómo actuarían frente a diferentes situaciones hipotéticas que le fueron presentadas con la finalidad de establecer la potencialidad de éxito de diferentes políticas de movilidad sostenible.Item Análisis del impacto del reemplazo de equipos de cocción y calefacción de gas natural por electrodomésticos en una red de potencia adaptada(Secretaría de Cine, Tecnología e Innovación Productiva. UTN-FR Avellaneda, 2021-04-10) Cea, Marcos; Manassero, Ulises; Marelli, Pablo; López, Diego; Steinmann, IreneEn un estudio previo se analizó la posibilidad de reemplazar aquellos equipamientos de cocción y calefacción que utilizan gas natural por electrodomésticos en hogares con acceso a la red de gas natural, a fin de generar un stock excedente del recurso para poder utilizarlo en la generación de energía eléctrica. Los resultados evidenciaron que es practicable un escenario donde la conversión de usuarios convencionales a electrointensivos a nivel nacional ronde un 7% de los hogares, lo que implicaría un incremento de demanda de energía eléctrica para la red. Es en este marco, que se debe verificar el impacto de la nueva demanda en los diferentes indicadores de operación, tanto en los niveles de transporte como en los de transmisión y subtransmisión. Para ello, se implementa una red adaptada representativa del Sistema Argentino de Interconexión, con la finalidad de determinar el impacto de la nueva demanda en indicadores de operación de la red. Los resultados dejan entrever que técnicamente la red es capaz que soportar el incremento en la demanda de energía eléctrica, no detectándose variables de operación, por fuera de los niveles admisibles.Item Capillary hydrodynamic fractionation of hydrophobic colloids: errors in the estimated particle size distribution(2013) Vega, Jorge Rubén; Clementi, Luis A.; Arretxe, Zohartze; Aguirreurreta, Ziortza; Agirre, Amaia; Leiza, José R.; Gugliotta, Luis M.Capillary hydrodynamic fractionation (CHDF) with turbidity detection at a single wavelength is an analytical technique that is often used for sizing the submicrometric particles of hydrophobic colloids. This article investigates three sources of errors that affect the particle size distribution (PSD) estimated by CHDF: diameter calibration errors, uncertainties in the particle refractive index (PRI), and instrumental broadening (IB). The study is based on simulated and experimental examples that involve unimodal and bimodal PSDs. Small errors in the diameter calibration curve can produce important deviations in the number average diameter due to systematic shifts suffered by the PSD modes. Moderate uncertainties in the PRI are unimportant in the analysis of unimodal PSDs, but in the specific case of bimodal PSDs, errors in the PRI can strongly affect the estimated number concentration of each mode. The typical IB correction (based on the IB function estimated from narrow standards) produces slightly erroneous average diameters but can lead to PSDs with underestimated widths and distorted shapes. In practice, the three investigated sources of errors can be present simultaneously, and uncertainties in the average diameters, the shape and width of the PSD, and the number concentration of the PSD modes are unavoidable.Item Comprehensive model of electromigrative transport in microfluidic paper based analytical devices(2020-01-06) Schaumburg, Federico; Kler, Pablo A.; Berli, Claudio L. A.A complete mathematical model for electromigration in paper-based analytical devices is derived, based on differential equations describing the motion of fluids by pressure sources and EOF, the transport of charged chemical species and the electric potential distribution. The porous medium created by the cellulose fibers is considered like a network of tortuous capillaries and represented by macroscopic parameters following an effective medium approach. The equations are obtained starting from their open-channel counterparts, applying scaling laws and, where necessary, including additional terms. With this approach, effective parameters are derived, describing diffusion, mobility and conductivity for porous media. While the foundations of these phenomena can be found in previous reports, here, all the contributions are analyzed systematically and provided in a comprehensive way. Moreover, a novel electrophoretically driven dispersive transport mechanism in porous materials is proposed. Results of the numerical implementation of the mathematical model are compared with experimental data, showing good agreement and supporting the validity of the proposed model. Finally, the model succeeds in simulating a challenging case of free-flow electrophoresis in paper, involving capillary flow and electrophoretic transport developed in a 2D geometry.Item Computational design of a massive solar-thermal collector enhanced with phase change materials(Energy and Buildings, 2022-11-01) Peralta, Ignacio; Fachinotti, Víctor D.; Koenders, Eduardus A. B.; Caggiano, AntonioA cement-based device that can meet, partially or completely, the heating loads of a building by absorbing the solar radiation and converting it into thermal energy can be defined as a Massive Solar-Thermal Collector. The absorbing material for the incoming radiation is made of a cementitious composite, generally concrete, and flowing water inside tubes acts as a heat transfer medium. For an optimized performance, during periods of solar radiation, the device has to efficiently conduct the heat flow from the absorbing surface of the collector and transfer this heat energy to the water. Then, when the radiation is reduced or became null, the device should retain as much as possible the heat energy, reducing the heat that is escaping the collector and consequently the losses to the surrounding environment. In this work, by performing a parametric analysis, different absorbing materials are tested with the objective of finding the best configuration that maximizes the energy efficiency of the collector. Cementitious materials, in combination with Phase Change Materials with distinct melting (and solidification) temperatures, are selected as candidate absorbing materials. The weather variables of an entire year and for two different locations are considered to evaluate the behavior of these devices in opposite climates. After numerical simulations, in where an enthalpy-based finite element formulation is used to solve the physical problem, the obtained results allow to conclude that the inclusion of Phase Change Materials within the absorber material of the collectors, if it is done in a correct way, can improve the energy performance of these devices. In this study, 34 ºC and 53 ºC are chosen as the most appropriated melting temperatures, which conduct to considerable improvements in the achieved performances, and in both warm and cold climates.Item Contact force multiscale calculation in the framework of the non-smooth dynamic approach(International Journal of Numerical Method and Engineering, 2025-03-31) Cavalieri, Federico J.; Sánchez, Eliana; Cardona, AlbertoSmooth contact models derived from the Hertz theory are widely used in structural dynamics analysis to calculate variable in time forces, stresses, and deformations. However, these models require very small time steps during the period in which bodies are in contact to integrate the equations of motion, yielding in a highly time-consuming numerical solution. Furthermore, penetration between bodies is unavoidable. On the other hand, nonsmooth techniques use an impact law to calculate the impulses. They arrive to a scheme with a constant time step resulting in very efficient calculations. However, these techniques do not provide a straightforward approach to calculate the variable in time contact forces that are needed to verify or design the structural components. In this work, a new methodology of calculation of impact forces that combines the impulse values obtained from non-smooth algorithms together with a local contact force law derived from continuous force models is presented. Thus, the computational time required to calculate the contact forces is reduced significantly. Several numerical examples are presented to show the robustness and performance of the proposed methodology.Item Contemporary difficulties and challenges for the implementation and development of compressed earth block building technology in Argentina(2022) Dorado, Pablo; Cabrera, Santiago; Rolón, GuillermoThe construction with compressed earth blocks (CEB) has provoked special worldwide interest in recent decades. In Argentina it has considerable experiences due to technical research, its use in public works and the development of some manufacturing units at different scales. The particular interest of its technology transfer to low income population sectors has been central and defines the social profile with which it has been implemented in the last time. However, its contemporary development has a low territorial impact due to the fact that problems are observed that hinder the implementation, dissemination, economic support of the manufacture and CEB commercialisation and the transfer of this technology. The aim of this article is to characterize and discuss the nature of the problems that hinder further development of CEB construction technology in Argentina. Local scientific production was analysed and the agents involved in the CEB production process were identified, who were surveyed and interviewed asking their assessment of the problems that affect the development of this technology today. The results show that the technical aspects involved in the CEB manufacturing stage are the ones that have received the most attention so far, much of the current difficulties to continue with its development are focused on the implementation, dissemination, and economic sustainability of the CEB manufacturing and commercialisation and the transfer of this technology. The lack of a specific regulatory framework for this technology is transversal to these problems mentioned. With regard to the scientific field, these issues need to be incorporated into research agendas, at least at the local level.Item Desarrollo de instrumentos virtuales en Excel como apoyo a la enseñanza de la metrología(Revista Tecnología y Ciencia, 2020-08-06) Banegas, Juan Marcos; Orué, Matías; Cámara, EdgardoLa tecnología como medio para la mejora del proceso de enseñanza-aprendizaje, ya sea a través del contacto físico en el aula o laboratorio, o por medio de sistemas virtuales en línea, tiene una potencialidad altamente positiva, haciendo posible profundizar la capacidad de asimilación de conceptos dando una nueva dimensión al aprendizaje significativo. En este trabajo, se exploran diferentes tecnologías útiles para la capacitación en metrología, y se realizan propuestas para el desarrollo de diferentes instrumentos virtuales en planillas Excel, como un recurso de fácil acceso por su masiva distribución en los ambientes educativos. Esta herramienta demostró su versatilidad tanto para el profesor como para el alumno, y su portabilidad permite una fácil migración entre diferentes plataformas con un simple intercambio de archivos. Cabe aclarar que el software utilizado para el desarrollo de los instrumentos virtuales ocupa un lugar privilegiado en la práctica metrológica dentro de los laboratorios de calibración, haciéndolo extremadamente competitivo, incluso frente a sus competidores gratuitos.Item Desarrollo de un modelo integral para el estudio de la calidad en aplicaciones web por medio de simulación(2021) Blas, Maria Julia; Leone, Horacio; Gonnet, SilvioEl estudio de los entornos de computación en la nube se divide en dos áreas principales: infraestructura y aplicación. A nivel de aplicación, los arquitectos de software especifican los productos siguiendo el modelo de servicios de software. Este trabajo propone un modelo integral basado en simulación que captura la información de las arquitecturas de software de aplicaciones web a fin de evaluar cuantitativamente aspectos de calidad en etapas tempranas de desarrollo. La propuesta integra un modelo semántico para la definición de las propiedades de calidad con una herramienta de modelado basada en patrones de diseño. Los modelos de simulación son generados en base a la combinación de ambos elementos. Estos modelos son especificados utilizando una adaptación del formalismo de simulación Discrete Event System Specification denominada Routed DEVS, la cual ha sido diseñada para abordar el estudio de problemas de ruteo.