Dynamic Modelling and Optimisation of Large-Scale Cryogenic Separation Processes

In this work, the open loop dynamic optimisation of a large-scale natural gas processing plant is performed. A rigorous differential-algebraic equation (DAE) model has been formulated to represent main plant units, such as shell and tube heat exchangers, highpressure separator and demethanizing column. In the shell and tube heat exchangers, the hot stream partially condenses and equations to consider the partial condensation of the fluids have been included. A rigorous index one model for the demethanizing column has been developed. The DAE optimisation problem is solved with a simultaneous approach, in which both state and control variables are discretised and the original DAE optimisation model is transformed into a large-scale nonlinear problem (NLP), which is solved using Sequential Quadratic Programming (SQP) methods. Optimal profiles have been obtained for main operating variables to achieve an enhanced product recovery.Fil: Rodriguez, Mariela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Bandoni, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Díaz, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentin

Solution of second kind Fredholm integral equations by means of Gauss and anti-Gauss quadrature rules

This paper is concerned with the numerical approximation of Fredholm integral equa- tions of the second kind. A Nyström method based on the anti-Gauss quadrature formula is developed and investigated in terms of stability and convergence in appro- priate weighted spaces. The Nyström interpolants corresponding to the Gauss and the anti-Gauss quadrature rules are proved to furnish upper and lower bounds for the solution of the equation, under suitable assumptions which are easily verified for a particular weight function. Hence, an error estimate is available, and the accuracy of the solution can be improved by approximating it by an averaged Nyström interpolant. The effectiveness of the proposed approach is illustrated through different numerical tests

Children and Apps: Learning to read and write digitally

La lectoescritura es uno de los aprendizajes fundamentales en la etapa escolar, y uno de los retos más importantes de los maestros. Para ello se pueden utilizar diferentes metodologías, materiales y recursos entre los cuales están las aplicaciones móviles que pueden favorecer que los niños aprendan a leer y escribir de forma sencilla, divertida e interactiva, permitiendo a los más pequeños iniciarse en esta competencia de una forma lúdica. Dado que los profesores necesitan conocer estos desarrollos, el artículo analiza las características relativas a sistema operativo, modelos de negocio, tendencias más significativas, metodología utilizada, etc. y propone una clasificación de las aplicaciones destinadas al aprendizaje de la lectura y la escritura

A viral effector suppresses cell-to-cell spread of silencing by targeting two plasmodesmal receptor-like kinases

RNA interference (RNAi) in plants can move from cell to cell, allowing for systemic spread of an anti-viral immune response. How this cell-to-cell spread of silencing is regulated is currently unknown. Here, we describe that the C4 protein from Tomato yellow leaf curl virus can inhibit the intercellular spread of RNAi. Using this viral protein as a probe, we have identified the receptor-like kinase (RLK) BARELY ANY MERISTEM 1 (BAM1) as a positive regulator of the cell-to-cell movement of RNAi, and determined that BAM1 and its closest homologue, BAM2, play a redundant role in this process. C4 interacts with the intracellular domain of BAM1 and BAM2 at the plasma membrane and plasmodesmata, the cytoplasmic connections between plant cells, interfering with the function of these RLKs in the cell-to-cell spread of RNAi. Our results identify BAM1 as an element required for the cell-to-cell spread of RNAi and highlight that signalling components have been co-opted to play multiple functions in plants.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

La celebridad deportiva como intermediario e instrumento cultural de derechos fundamentales e igualdad étnica-racial. Un estudio de la campaña corporativa “common thread”, publicada por la marca deportiva Nike en instagram

Corporate brands play a social role through the discourses they broadcast on their social media. The sports celebrity acts as a cultural intermediary and communicating instrument in the value system that the brand brings together in defence of social, cultural and ethnic diversity (Turner, 2004; Erdogan, 1999; Marshall, 1997). From this perspective, the aim of this proposal is to detect the socio-cultural elements that articulate the discourse constructed by the Nike sports brand in defence of racial and ethnic equality in sport. Methodologically, the content analysis approach is adopted (Krippendorff, 2013). The data consists of 3 short films that make up a campaign created by the sports brand Nike called "Common Thread". The criterion for their selection was the discursive projection that the brand emits in favour of socio-cultural equality on Instagram. In order to define the model of analysis, the classical studies of Greimas (1976) and McCracken (1989) is taken as a starting point. The results show that the brand manifests itself on social media as a social agent that promotes equality and racial-ethnic rights for the black sports community through sport and culture

Evaluation, valuation, negotiation: Some Reflections towards a Culture of Evaluation

Although the evaluation of public policies is a subject of growing interest in Latin America, there are problems with the design and implementation of evaluations, as well as with the limited use of their results. In many cases, the evaluations have more to do with the generation of descriptions, and less with the valuation of these activities and its use in order to improve planning and decision making. These points are explored in a case study of the evaluation of a rural development program in Argentina, emphasizing the process of negotiation and consensus building between the evaluators and the official in charge of approving the evaluation report. The lessons learnt from the experience point to the generation and consolidation of a culture of evaluation in the region.Bien que l’évaluation des politiques publiques fasse l’objet d’un intérêt croissant en Amérique latine, il existe des problèmes avec la conception et la mise en œuvre des évaluations, ainsi qu’avec l’utilisation limitée de leurs résultats. Dans de nombreux cas, les évaluations ont plus à voir avec la génération de descriptions qu’avec l’évaluation même de ces activités et son utilisation afin d’améliorer la planification et la prise de décision. Ces points sont abordés à partir d’une étude de cas sur l’évaluation d’un programme de développement rural en Argentine. L’accent est mis sur le processus de négociation et de consensus entre les évaluateurs et le responsable de l’approbation du rapport d’évaluation. Les leçons tirées de l’expérience préconise la génération et la consolidation d’une culture de l’évaluation dans la région.Fil: Rodriguez Bilella, Pablo Daniel. Universidad Nacional de San Juan. Facultad de Ciencias Sociales. Instituto de Investigaciones Socioeconómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Monterde Díaz, Rafael. Universidad Politécnica de Valencia; Españ

An algebraic topological method for multimodal brain networks comparison

Understanding brain connectivity is one of the most important issues in neuroscience. Nonetheless, connectivity data can reflect either functional relationships of brain activities or anatomical connections between brain areas. Although both representations should be related, this relationship is not straightforward. We have devised a powerful method that allows different operations between networks that share the same set of nodes, by embedding them in a common metric space, enforcing transitivity to the graph topology. Here, we apply this method to construct an aggregated network from a set of functional graphs, each one from a different subject. Once this aggregated functional network is constructed, we use again our method to compare it with the structural connectivity to identify particular brain regions that differ in both modalities (anatomical and functional). Remarkably, these brain regions include functional areas that form part of the classical resting state networks. We conclude that our method -based on the comparison of the aggregated functional network- reveals some emerging features that could not be observed when the comparison is performed with the classical averaged functional network

Valoração de uma experiência de intervenção com tecnologias socialmente apropriadas em Santiago del Estero (Argentina)

En el marco de las discusiones sobre el cambio tecnológico, las tecnologías socialmente apropiadas surgieron como una alternativa al modelo de transferencia modernizante que predominó durante muchos años en Latinoamérica. Sin embargo, a pesar del tiempo transcurrido desde su creación conceptual, no es sencillo encontrar estudios que valoren procesos de intervención realizados con este tipo de abordaje. Este trabajo busca aproximarse al tema mediante el análisis de una experiencia de estercolado de cultivos prediales con estiércol de cabra, en Santiago del Estero (Argentina). A pesar de contar con un diseño socialmente apropiado a priori, la tecnología no fue replicada por todos los experimentadores. Para abordarlo, se utilizó un enfoque cuantitativo y cualitativo de dos etapas: en la primera se prestó atención a las variables de estructura de cada experimentador y se hizo una correlación con las ocasiones en las que reiteró la práctica, y en la segunda se analizó el funcionamiento predial, mediante estudios de caso. Los resultados indican que una estructura predial determinada no garantizó un resultado en lo que se refiere a la adopción de una tecnología socialmente apropiada, así como que el funcionamiento predial y la estrategia de sobrevivencia de cada familia otorgaron al predio una dinámica propia, que muchas veces resultó determinante en el momento de adoptar la propuesta. Además, en la experiencia estudiada, no resultó suficiente diseñar la tecnología empleando recursos con control local ni presentar una única propuesta para la totalidad de los experimentadores. Los múltiples ajustes utilizados por los productores sugieren investigar los procesos de innovación local.In previous discussions about technological change, appropriate technologies emerged as one of the alternatives to the modernizing technology transfer model that prevailed for many years in Latin America. However, despite the time elapsed since its conceptual creation, it is not easy to find studies assessing interventions carried out with this type of approach. This paper addresses this subject by analyzing a technology transfer experience using goat manure as a fertilizer for household crops in Santiago del Estero (Argentina). Despite having an appropriate a priori design, the technology was not replicated by all the experimenters. A quantitative and qualitative two-stage approach was used to address it: the first approach explored structure variables used by each experimenter and correlated these with the times that he/she repeated the practice; and in the second one, an analysis of the farm operations through casestudies was carried out. The results indicate that a particular farm structure did not guarantee a result in terms of adoption of an appropriate technology,and that the operation and the survival strategy (or peasant strategy) of each family gave the farm an individual dynamic that often was decisive inadopting the proposal. In addition, at least for the current experience, technology design using locally controlled resources and the presentationof a unique proposal for all the experimenters was not enough. The multiple adjustments used by peasants suggest the need to investigate local innovation processes.Fil: Díaz, Juan Pablo. Universidad Nacional de Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez Sperat, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Estudios para el Desarrollo Social. - Universidad Nacional de Santiago del Estero. Facultad de Humanidades Ciencias Sociales y de la Salud. Instituto de Estudios para el Desarrollo Social; ArgentinaFil: Paz, Raul Gustavo. Universidad Nacional de Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dynamic optimization with a simultaneou method: Application to a heat exchanger

In this work we use a numeric method based on a combined discretization and simultaneous dynamic optimization approach to solve a system consisting of partial differential and algebraic equations. The spatial derivatives are discretized by finite differences while the resulting DAE (Differential-Algebraic Equations) optimization problem is transformed into a large-scale NLP (Nonlinear Programming) problem through collocation over finite elements. This method is implemented in a computer package resident in a remote computer located at the Department of Chemical Engineering Carnegie Mellon University, which is accessed via a high-speed internet connection (Internet 2) from a client computer at the Centro Regional de Investigaciones Basicas y Aplicadas Bahia Blanca (CRIBABB). We have applied this strategy to the resolution of the dynamic optimization model of a gas - gas heat exchanger, which is part of a larger model under development. The goal is to minimize the transient between two set points of an outlet stream temperature. The dynamic model provides profiles of controlled and manipulated variables which are in agreement with available data, and the remote optimization system performed very well.Fil: Rodriguez, Mariela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Díaz, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Bandoni, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentin