Valorization of fines from construction and demolition wastes

La economía circular es un concepto y un nuevo paradigma, ha sido la base de las normas y leyes que sustentan las nuevas prácticas sobre el manejo de residuos en los países que pertenecen a la Unión Europea. Concepto que hoy en día cobra más fuerza, desencadenado por la crisis climática que se ha convertido en un hecho y una realidad inquietante. Por ello, para 2020 en Catalunya, los gestores de residuos tenían previsto valorizar hasta el 75% de los residuos de construcción y demolición (RCD). Siendo el sector de la construcción, un sector que no solo produce residuos en las actividades de construcción y demolición, sino también en la producción de sus principales materias primas. El cemento Portland fabricado causa el 8% de las emisiones mundiales de dióxido de carbono, con una emisión total de CO2 de más de 2,5 Gt. Producido principalmente por la calcinación de la piedra caliza en la producción de Clinker. El último informe entregado por el sector de la gestión de residuos en 2021, mostró que se ha valorizado el 61,4% de los residuos de construcción y demolición para 2020. Valor muy por debajo del objetivo principal acordado. Así que, en la necesidad de mejorar este desempeño, reducir la huella de carbono y frenar eventualmente la alta explotación de minerales industriales como la caliza. El presente artículo se centra en la caracterización y valorización de dos residuos de árido fino procedentes del proceso de reciclado de los residuos de construcción y demolición. El árido fino es tratado en las plantas de reciclaje y forma un limo que no ha despertado interés económico en el último tiempo. Debido a esto, se han estudiado las propiedades térmicas (DTA/TG), plásticas, químicas (XRF) y mineralógicas (XRD y SEM/EDS) de estos materiales para evaluar su potencial uso como reemplazo parcial del cemento Portland. Demostrando que los materiales tienen una alta reactividad debido principalmente al rol del gel C-S-H una vez que es tratado térmicamente a 900°C.Circular economy is a concept and a new paradigm, it has been the base of the norms and laws that sustain the new practices on waste management in the countries that belong the European Union. Concept that is stronger nowadays, triggered by the climate crisis that is a fact and disturbing reality. Due to this, by 2020 the waste management sector had planned to valorise up to 75% of the construction and demolition waste(C&DW). The construction is a sector that not only produce waste on the construction and demolition activities, but also in the production of its main raw material. Portland cement manufactured cause 8% of the worldwide carbon dioxide emissions, with a total CO2 emission of more than 2.5 Gt. Mainly produced by the calcination of the limestone in the clinker production. The last report given by the waste management sector in 2021, showed that it has valorised 61,4% of the construction and demolition waste by 2020, value way below the main objective accorded. So, in the need to improve this performance, reduce the carbon footprint and slow down, or hopefully eventually stop the high exploitation of industrial minerals as limestone. The present article focuses on the characterization and valorisation of two different fine aggregate waste that are product of the recycling process of the construction and demolition waste. The fine aggregate is treated in the recycling plants and forms a silt that has had no economic interest. Due this, the thermal (DTA/TG), plastic, chemical (XRF) and mineralogic (XRD and SEM/EDS) properties of this materials has been studied to assess their potential use as partial replacement of Portland cement. Showing that the materials has high reactivity mostly due the roll of the C-S-H gel once it is thermally treated at 900°C. If at least 30% of replacement is carried out, the reduction of the C&DW stockpiled will allow that 77% of the C&DW be valorised. Bringing with it a reduction close to 451.000 tons of CO2

Estudio de la técnica del estilo Crol y su incidencia en el rendimiento deportivo en niños de 11 a 12 años en la piscina de Miraflores de la Concentración Deportiva de Pichincha en la ciudad de Quito, año 2018

Determinar la incidencia de la técnica del estilo crol en el rendimiento deportivo de los niños de 11 a 12 años en la piscina de Miraflores de la Concentración Deportiva de Pichincha, de la ciudad de Quito, en el año 2018.La presente investigación afronta los aspectos técnicos del estilo Crol en los niños de 11-12 años de la Concentración Deportiva de Pichincha y su incidencia en el rendimiento deportivo. Partiendo desde una pequeña reseña histórica de la evolución del estilo Crol, una perspectiva macro, meso y micro de la natación competitiva en el Ecuador. En la justificación se pone la originalidad, importancia, interés y beneficiarios de la realización de este proyecto. Se plantea determinar la incidencia de la técnica del estilo Crol en el rendimiento deportivo como objetivo general, así como valorar, evaluar y proponer una guía alternativa de ejercicios educativos como objetivos específicos. En el marco teórico se abordan todos los términos relacionados a las variables de investigación como son la técnica del estilo Crol y Rendimiento Deportivo. La metodología de la investigación permitió establecer los tipos bibliográficos, de campo y propositiva de investigación y los métodos inductivo, deductivo, analítico, sintético y estadístico que se utilizaron, así como las técnicas e instrumentos, tales como: ficha de observación test físicos entrevista y encuesta, que con su aplicación se tabuló señalando los porcentajes de los resultados, analizando con una referencia bibliográfica y comentario personal triangulando la información para su discusión. En el siguiente capítulo se realiza la propuesta “Guía didáctica de ejercicios educativos que ayuden a perfeccionar la técnica del estilo Crol en los niños de 11 a 12 años” investigando bibliográficamente las variables “ejercicios educativos” y “técnica del estil crol”. Se desarrollan dos unidades de la guía: una metodológica con los ejercicios educativos seleccionados para perfeccionar la técnica del estilo Crol organizado por fases de la brazada y secciones del cuerpo, la segunda con los talleres de socialización de la propuesta, trabajando con la categoría infantil 11 – 12 años de la piscina de Miraflores en sus sesiones de entrenamiento. Como resultados se realiza un análisis de las estadísticas obtenidas dando conclusiones y recomendaciones enfatizando en la necesidad de una base técnica en las edades infantiles para un mejor rendimiento deportivo

Centro Cultural Universidad San Francisco de Quito arquitectura como enlace con la ciudad

The University Cultural Center at the San Francisco University of Quito is an architectural project that seeks to integrate the educational community and the city. Currently the university is walled, generating an improper isolation of its surroundings. This campus also lacks specialized equipment and the infrastructure is not enough for the number of users...El Centro cultural Universitario en la Universidad San Francisco de Quito es un proyecto arquitectónico que busca integrar la comunidad educativa y la ciudad. Actualmente la universidad se encuentra amurallada, generando un aislamiento impropio de su entorno. Este campus además carece de equipamiento especializado y la infraestructura no es suficiente para la cantidad de usuarios..

Sorbent, Sublimation, and Icing Modeling Methods: Experimental Validation and Application to an Integrated MTSA Subassembly Thermal Model

This paper details the validation of modeling methods for the three core components of a Metabolic heat regenerated Temperature Swing Adsorption (MTSA) subassembly, developed for use in a Portable Life Support System (PLSS). The first core component in the subassembly is a sorbent bed, used to capture and reject metabolically produced carbon dioxide (CO2). The sorbent bed performance can be augmented with a temperature swing driven by a liquid CO2 (LCO2) sublimation heat exchanger (SHX) for cooling the sorbent bed, and a condensing, icing heat exchanger (CIHX) for warming the sorbent bed. As part of the overall MTSA effort, scaled design validation test articles for each of these three components have been independently tested in laboratory conditions. Previously described modeling methodologies developed for implementation in Thermal Desktop and SINDA/FLUINT are reviewed and updated, their application in test article models outlined, and the results of those model correlations relayed. Assessment of the applicability of each modeling methodology to the challenge of simulating the response of the test articles and their extensibility to a full scale integrated subassembly model is given. The independent verified and validated modeling methods are applied to the development of a MTSA subassembly prototype model and predictions of the subassembly performance are given. These models and modeling methodologies capture simulation of several challenging and novel physical phenomena in the Thermal Desktop and SINDA/FLUINT software suite. Novel methodologies include CO2 adsorption front tracking and associated thermal response in the sorbent bed, heat transfer associated with sublimation of entrained solid CO2 in the SHX, and water mass transfer in the form of ice as low as 210 K in the CIHX

Modelación En Programación Matemática Y Resolución Del Problema De Localización-Ruteo En Logística Urbana

The implementation of urban distribution centers near to city centers to allow freight consolidation is a widely extended initiative worldwide, seeking to improve traffic congestion and quality of life in downtown, among others. This paper considers the problem of locating urban distribution centers and proposes an exact method, based on integer linear programming for strategic, tactical and operational decision-making. The aim is to solve, in an integer manner, location, sizing and operation (vehicle routing) problems in these logistics platforms. The model is validated using real-data taken from the city of SaintÉtienne, France. Computational experiments are also carried out in order to compare the proposed model with existing procedures from the literature. Results show the efficiency and effectiveness of the proposed model and its applicability in real decision-making for medium sized data sets

Modelación En Programación Matemática Y Resolución Del Problema De Localización-Ruteo En Logística Urbana

The implementation of urban distribution centers near to city centers to allow freight consolidation is a widely extended initiative worldwide, seeking to improve traffic congestion and quality of life in downtown, among others. This paper considers the problem of locating urban distribution centers and proposes an exact method, based on integer linear programming for strategic, tactical and operational decision-making. The aim is to solve, in an integer manner, location, sizing and operation (vehicle routing) problems in these logistics platforms. The model is validated using real-data taken from the city of SaintÉtienne, France. Computational experiments are also carried out in order to compare the proposed model with existing procedures from the literature. Results show the efficiency and effectiveness of the proposed model and its applicability in real decision-making for medium sized data sets

Modeling Of Metabolic Heat Regenerated Temperature Swing Adsorption (MTSA) Subassembly For Prototype Design

This paper describes modeling methods for the three core components of a Metabolic heat regenerated Temperature Swing Adsorption (MTSA) subassembly: a sorbent bed, a sublimation (cooling) heat exchanger (SHX), and a condensing icing (warming) heat exchanger (CIHX). The primary function of the MTSA, removing carbon dioxide from a space suit Portable Life Support System (PLSS) ventilation loop, is performed via the sorbent bed. The CIHX is used to heat the sorbent bed for desorption and to remove moisture from the ventilation loop while the SHX is alternately employed to cool the sorbent bed via sublimation of a spray of water at low pressure to prepare the reconditioned bed for the next cycle. This paper describes subsystem heat a mass transfer modeling methodologies relevant to the description of the MTSA subassembly in Thermal Desktop and SINDA/FLUINT. Several areas of particular modeling interest are discussed. In the sorbent bed, capture of the translating carbon dioxide (CO2) front and associated local energy and mass balance in both adsorbing and desorbing modes is covered. The CIHX poses particular challenges for modeling in SINDA/FLUINT as accounting for solids states in fluid submodels are not a native capability. Methods for capturing phase change and latent heat of ice as well as the transport properties across a layer of low density accreted frost are developed. This extended modeling capacity is applicable to temperatures greater than 258 K. To extend applicability to the minimum device temperature of 235 K, a method for a mapped transformation of temperatures from below the limit temperatures to some value above is given along with descriptions for associated material property transformations and the resulting impacts to total heat and mass transfer. Similar considerations are given for the SHX along with functional relationships for areal sublimation rates as limited by flow mechanics in t1he outlet duct

Simulation-optimization approach for the stochastic location-routing problem

The location routing problem with stochastic transportation cost and vehicle travel speeds is considered in this paper. A hybrid solution procedure based on Ant Colony Optimisation (ACO) and Discrete-Event Simulation (DES) is proposed. After using a sequential heuristic algorithm to solve the location subproblem, the subsequent capacitated vehicle routing problem is solved using ACO. Finally, a DES model evaluates those vehicle routes in terms of their impact on the expected total costs. The approach is tested using well-known randomly generated datasets. Since no previous works in the literature studied exactly the same SLRP, the proposed procedure is compared against its deterministic version. Numerical results show the efficiency and efficacy of the hybrid ACO-DES approach

Design and Assembly of an Integrated Metabolic Heat Regenerated Temperature Swing Adsorption (MTSA) Subassembly Engineering Development Unit

Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO2) control for a Portable Life Support System (PLSS), as well as water recycling. The core of the MTSA technology is a sorbent bed that removes CO2 from the PLSS ventilation loop gas via a temperature swing. A Condensing Icing Heat eXchanger (CIHX) is used to warm the sorbent while also removing water from the ventilation loop gas. A Sublimation Heat eXchanger (SHX) is used to cool the sorbent. Research was performed to explore an MTSA designed for both lunar and Martian operations. Previously the sorbent bed, CIHX, and SHX had been built and tested individually on a scale relevant to PLSS operations, but they had not been done so as an integrated subassembly. Design and analysis of an integrated subassembly was performed based on this prior experience and an updated transient system model. Focus was on optimizing the design for Martian operations, but the design can also be used in lunar operations. An Engineering Development Unit (EDU) of an integrated MTSA subassembly was assembled based on the design. Its fabrication is discussed. Some details on the differences between the as-assembled EDU and the future flight unit are considered

DatApp: plataforma de análisis de datos para no desarrolladores (App For Non-Coders)

Dentro de la visión y alcance que se observa acerca de las nuevas tendencias de análisis de datos y el poder de las herramientas tecnológicas y su utilidad para conseguir el ordenamiento y procesamiento de grandes volúmenes de información se ha encontrado que existe una necesidad de desarrollar herramientas y plataformas de análisis de datos para personas que no cuenten con conocimientos específicos de desarrollo, en la cual puedan acceder a varias herramientas donde puedan encontrar su necesidad y mostrar gráficas o tablas, de forma que el usuario pueda adaptarlas a su necesidad. Lo anterior, permitirá que cada día más personas, sin necesidad de un amplio conocimiento especializado, puedan aprovechar los beneficios que trae consigo el creciente ecosistema de datos abiertos. Actualmente en Colombia se cuenta con bases de datos con los cuales se busca promover la apertura, el uso y el aprovechamiento de los datos abiertos en sectores estratégicos para la innovación en la generación de soluciones a problemas públicos y sociales, lo que sirve para que muchas personas pongan en práctica sus conocimientos o adquieran estos usando nuestra plataforma. Se espera que el proyecto que se describe en este documento permita de manera ágil y eficaz que el usuario interactúe y comprenda de manera amigable sus datos y la obtención de noticias y equipos para el conocimiento de nuevas tecnologías del internet de las cosas.Within the vision and scope that is observed about the new data analysis trends and the power of technological tools and their usefulness to achieve the ordering and processing of large volumes of information, it has been found that there is a need to develop tools and data analysis platforms for people who do not have specific knowledge of development, in which they can access various tools where they can find their needs and show graphs or tables, so that the user can adapt them to their needs. The foregoing will allow more and more people, without the need for extensive specialized knowledge, to take advantage of the benefits that the growing open data ecosystem brings. Currently in Colombia there are databases with which it seeks to promote the opening, use and exploitation of open data in strategic sectors for innovation in the generation of solutions to public and social problems, which serves so that many people put their knowledge into practice or acquire it using our platform. It is expected that the project described in this document will allow the user to interact and understand their data in a friendly way in an agile and effective way and to obtain news and equipment for the knowledge of new technologies of the internet of things