Numerical methods for dynamic Magnetic Resonance Imaging

Nel rapporto vengono presentati alcuni metodi nuemrici per la ricostruzione di immagini dinamiche di risonanza magnetica utilizzando anche informazioni a priori, attraverso una formula unificata che li descrive tutti. In particolare, si studia l'uso delle basi B-spline e della regolarizzazione nella ricostruzione di immagini dinamiche di risonanza magnetica

Achievement and exploitation of porous geopolymer-based spheres

Several spherification processes were applied to obtain porous geopolymer spheres, different in term of porosity, specific surface area and adsorption properties. The processes are based on the formulation of metakaolin-based geopolymer slurries, produced using a potassium- or sodium-based alkaline activating solution, and exploiting an injection-solidification method in different mediums, i.e. polyethylene glycol (PEG), liquid nitrogen or calcium chloride, to produce the spheres. When liquid nitrogen was used, the geopolymer slurries underwent a maturation step (several hours at room temperature) to trigger the geopolymerization without reaching a complete chemical consolidation. Spheres were obtained injecting in liquid N2 the mixture as it is or mixed with water, to modulate the final porosity (ice-templating process). The spheres were then freeze dried to remove the solidified water and complete the chemical consolidation of the geopolymer. Please click Additional Files below to see the full abstract

Heritage and Tourism : the gastronomic Identity of San Rafael, Mendoza

El proyecto propone una investigación científica que pretende presentar una nueva arista para el turismo en el departamento de San Rafael, provincia de Mendoza, a través del turismo cultural, y dentro de él, realizar un análisis de su patrimonio gastronómico, que permita resignificar costumbres y tradiciones propias de la historia del departamento desde los pueblos originarios a la inmigración europea del siglo XIX, contemplando también los nuevos movimientos migratorios del siglo XXI entendiendo a la suma de todos ellos como una identidad gastronómica propia del departamento.La recuperación y análisis de este legado apunta a fortalecer el patrimonio local y lograr un mayor equilibrio en lo que a estacionalidad y picos de demanda se refiere, entendiendo a la ciudad como una fusión de culturas. La propuesta se basa en la búsqueda de las raíces culinarias desde las costumbres y hábitos alimenticios del pueblo pehuenche, pasando por la inmigración europea: francesa, italiana y española; la sirio-libanesa y la presencia de otras colectividades como la japonesa, boliviana y venezolana.La investigación tendrá carácter cualitativo y exploratorio aplicado a cada uno de las etapas del proyecto: recopilación de información y determinación de fuentes, análisis de la información, diagnóstico y construcción de identidad, análisis de cierre sobre los resultados obtenidos y presentación de propuestas de acción.Los instrumentos de medición a utilizarse consistirán en la recolección directa de datos a través de entrevistas descriptivas y semi estructuradas, relevamientos y registros de información. La metodología de trabajo a abordar busca resignificar el legado cultural de las diferentes colectividades presentes en el departamento a través de su gastronomía, convirtiendo al conocimiento obtenido en un potencial recurso para que la comunidad amplíe su oferta turística.En consecuencia, el proyecto considera oportuno contemplar dentro del proceso de la investigación turística los recursos gastronómicos de la comunidad local con el objetivo de conservar su autenticidad, el respeto y el bienestar de los residentes a través de la construcción de la Identidad Gastronómica como parte del Patrimonio Cultural local.The project proposes a scientific research that aims to present a new edge for tourism in the department of San Rafael, province of Mendoza, through cultural tourism, and within it, to carry out an analysis of its gastronomic heritage, which allows resignifying customs and traditions of the history of the department from the native peoples to the European immigration of the 19th century, also contemplating the new migratory movements of the 21st century, understanding the sum of all of them as a gastronomic identity characteristic of the department.The recovery and analysis of this legacy aims to strengthen local heritage and achieve greater balance in terms of seasonality and peaks of demand, understanding the city as a fusion of cultures. The proposal is based on the search for culinary roots from the customs and eating habits of the Pehuenche people, passing through European immigration: French, Italian and Spanish; the Syrian-Lebanese and the presence of other collectivities such as the Japanese, Bolivian and Venezuelan.The research will have qualitative and exploratory character applied to each of the project stages: information gathering and identification of sources, analysis of information, diagnosis and identity construction, closure analysis on the results obtained and presentation of action proposals.The measurement instruments to be used will consist of direct data collection through descriptive and semi-structured interviews, surveys and information records.The work methodology to address seeks to resignify the cultural legacy of the different communities present in the department through its gastronomy, converting the knowledge obtained into a potential resource for the community to expand its tourism offer.Consequently, the project considers appropriate to contemplate within the tourism research process the gastronomic resources of the local community with the aim of preserving its authenticity, the respect and well-being of the residents through the construction of the Gastronomic Identity as part of the Local Cultural Heritage

Lightweight insulating geopolymer material based on expanded perlite

Expanded perlite, owing to its lightweight and excellent thermal insulating properties, has been extensively used in different industrial sectors to produce self-standing insulating boards bonded with various organic polymers or calcium-silicates. In order to improve the high temperature behavior and mechanical performances of such materials inorganic binders, such as geopolymers, can be regarded as a promising alternative. Please click Additional Files below to see the full abstract

Chemical Looping Combustion in a Bed of Iron Loaded Geopolymers

Abstract The chemical looping combustion allows for inherent CO 2 separation when burning fossil fuels in presence of a suitable oxygen carrier. The choice of the material to be used should take into account not only chemical/physical properties but also economical, environmental, and safety concerns, addressing for more common materials, like Fe oxides. In this research a geopolymeric oxygen carrier, based on Fe 2 O 3 , was tested for the first time in a laboratory CLC plant operated at high temperature for the combustion of a CO rich gas from char gasification in CO 2 . The CLC plant reliably performed in repeated cycles without decay of the CO conversion during the chemical looping combustion. The maximum CO content in the flue gas was around 1% vol. and carbon monoxide conversion achieved 97%. The calculated oxygen transport capacity was 0.66%. The plant results were confirmed by the XRD analysis that proved the presence of reduced phases in samples after chemical looping stage and by significant peaks obtained during H 2 reduction in TPR equipment

Geopolymer oxygen carriers for chemical-looping combustion

One of the best alternatives to reduce the economic cost of CO2 capture is represented by the chemical looping combustion (CLC). This technology accomplishes indirect fuel combustion by use of a solid oxygen carrier (OC), generally a metal oxide having the capability of transporting the oxygen needed for the combustion from an air reactor to a fuel reactor, usually designed as two coupled fluidized beds. The combustion takes place in the fuel reactor through the reaction between the fuel and the solid OC, which is consequently reduced to a lower oxidation state. The reduced OC is then transferred to the air reactor, where it is regenerated by oxidation in air at high temperature. Therefore, the CLC process enables the inherent separation of the produced CO2, the stream exiting the fuel reactor being only composed of CO2 and H2O, easily separable by water condensation. Please click Additional Files below to see the full abstract

Porcelain stoneware scraps recycle in alkali bonded insulating panels

Ground porcelain stoneware scraps were recycled as main component (up to 80 wt%) in alkali bonded insulating panels. Sandwich panels were prepared by varying the scraps dimension and amount in the core and skins.The binder for the alkali bonding was prepared by using highly reactive metakaolin as raw powder, while the alkali aqueous solution was KOH/K2SiO3 mixture. The setting was performed at 80?C for 24 h. The thermal conductivity at room temperature was 0.7 W.m-1.K-1. Dilatometric analyses were performed up to1200?C to study the structural modification. A thermal treatment of conditioning at 600?C prevented any structural degradation upon long term immersion in wate

Geopolymer-zeolite composites for CO2 adsorption

Geopolymer-zeolite composites were produced mixing different geopolymer matrices with a synthetic commercial Na13X zeolite, to combine the functional microporosity of the zeolite with the mesoporosity of the geopolymer matrix, with the further possibility to consolidate the zeolite powder. The new materials were designed and produced in forms of monoliths to be used as adsorbents for low temperature CO2 capture applications. A potassium or sodium silicate activating solution was used to produce the metakaolin-based geopolymer matrices, then mixed with the synthetic zeolite used as a filler. As geopolymers can be regarded as the amorphous counterpart or precursor of crystalline zeolites, it is important to underline the chemical affinity between these two constituents. As a matter of fact, the morphological characterization evidenced the presence of geopolymer nanoprecipitates covering zeolite particles for the K-based composite, while in the Na-based composite the formation of a NaA zeolite phase was evidenced (Fig. 1). Please click Additional Files below to see the full abstract

La autoevaluación institucional y la cultura de la participación

El presente documento constituye una elaboración conceptual y metodológica que sintetiza y organiza las diferentes aportaciones y contribuciones surgidas del foro sobre Autoevaluación desarrollado en el marco del Curso en línea de evaluación educativa, del Centro de Altos Estudios Universitarios de la Organización de Estados Iberoamericanos (caeu-oei). Aunque quedan cuestiones en las que profundizar, la producción que aquí presentamos puede colaborar con una reflexión en la trama compleja de la autoevaluación institucional focalizada, en este caso, en las organizaciones escolares. El documento estructura un primer debate en torno al proceso mencionado y la cultura de la participación, y un segundo orientado por los contenidos del proyecto de autoevaluación. Los miembros del foro han acercado a la discusión marcos teóricos y metodológicos así como reflexiones nacidas de la propia experiencia de campo. Ello hace que puedan leerse desde encuadres complementarios y coincidentes hasta modelos y concepciones contrapuestas, respondiendo a distintos postulados en torno al lugar de las escuelas en la sociedad, a sus fines así como a supuestos acerca de la gestión escolar, la calidad educativa y el lugar de los distintos actores institucionales