Mejoramiento del comportamiento térmico de sistemas de calentamiento de agua solares termosifónicos hechos con materiales no convencionales y con tanques de almacenamiento verticales y horizontales Performance improvement of solar thermosyphonic systems for water heating made of non conventional materials and using horizontal and vertical storage tanks

El objeto de estudio de este proyecto son los sistemas de calentamiento de agua mediante energía solar que funcionan termosifónicamente. En particular se tratará con dos diseños particulares generados por fabricantes de la Provincia de Córdoba y que han solicitado el asesoramiento del Grupo de Energía Solar (GES) para el mejoramiento de la performance térmica de dichos equipos. Se trata de dos sistemas que tienen materiales no tradicionales y se diferencian además por tener una distinta disposición del tanque de almacenamiento: uno es en forma vertical y el otro en forma horizontal. Basados en los resultados de un ensayo bajo norma internacional, donde se detectaron algunas puntos factibles de mejora, se propone en este proyecto el análisis en detalle de los equipos, para lo cual se les debe desarmar completos, para realizar un estudio analítico y experimental de los mismos con el objeto de hacer un planteo teórico-analítico del comportamiento de los mismos, con la implementación de propuestas de mejora y chequeo de los resultados. Se propone entonces como objetivo lograr un mejoramiento de la performance térmica de los citados equipos a partir de un estudio experimental y analítico. Asumiendo esta posibilidad de mejora, se plantea la hipótesis de que es posible representar el funcionamiento de estos equipos mediante modelos físico-matemáticos desarrollados a partir de ecuaciones y correlaciones conocidas y procesos a interpretar mediante resoluciones numéricas y softwares específicos de simulación. De esta manera, se plantea el despieze completo de los equipos para estudiar en detalle su estructura y conexiones internas y a partir de la geometría, dimensiones y propiedades termofísicas de materiales constructivos y fluidos de trabajo, realizar modelos físico-matemáticos que permitan realizar variaciones de propiedades y geometría y así buscar las mejores combinaciones que produzcan equipos más eficientes térmicamente. Los modelos físico-matemáticos serán codificados en lenguajes de alto nivel para poder luego de una validación de los modelos, correr simulaciones en un software de reconocimiento internacional que permite sumar dichos modelos mediante un protocolo de comunicación, haciendo que las poderosas prestaciones del software se puedan aplicar a nuestros modelos. Se complementará el estudio con un análisis exergético para identificar los puntos críticos en que se producen las pérdidas de oportunidad de aprovechar la energía disponible, para así analizar cómo solucionar los problemas en dichos puntos. Los materiales a utilizar serán los propios equipos provistos por los fabricantes, que serán modificados convenientemente para operarlos como prototipos Se espera obtener un conocimiento acabado de los procesos y principios de funcionamiento de los equipos, que permita plantear las mejoras, las cuales se implementarán en los prototipos, realizándose una medición mediante norma igual a la inicial para ver en que magnitud se logran las mejoras esperadas. Se pretende además que las mejoras a implementar, en la etapa de transferencia a las empresas involucradas, redunden no sólo en un beneficio técnico, sino que también los sea desde el punto de vista económico. Para ello se trabajará también sobre los procesos y métodos de fabricación para que los equipos mejorados no sean mas caros que los originales y de ser posible sean aún más económicos, todo esto apuntando a la difusión de la energía solar térmica y poner al alcance de todos estos equipos tan convenientes para la propagación de las energías limpias. El proyecto redundará también en un importante beneficio para el conocimiento de la comunidad científica en general, con el aporte de nuevos resultados en diseños novedosos y con nuevos materiales. Además, la institución se beneficiará con la formación que obtendrán los integrantes del proyecto, muchos de ellos en etapa de realización de sus estudios de posgrado y en una etapa importante de su vida como investigadores. The main goal of this project is the improvement of two thermosyphonic solar water heating systems, made of non conventional materials and with different arrangement of their storage tanks: one is vertical and the other one horizontal. The thermosyphonic systems are provided by manufacturers of the Córdoba Province, who came to the Solar Energy Group (GES) of the National University of Río Cuarto looking for help for the design of their products. In an agreement with these manufacturers, it was proposed this project in order to work analytically and experimentally in order to obtain physical-mathematical models of these two systems, which allow for changes to look by means of simulations the best changes to implement on the equipments for the improvement of their thermal performance. Then, the materials to be used are the proper systems provided by the manufacturers, which will be disarmed to be studied in detail. After the analytical study the proposals of improvement will be implemented in a high level language of programming to perform simulations in the environment of a well-known software for energy simulations (TRNSYS). After the simulations, the best modifications will be physically implemented in the prototypes to perform finally the same normalized test of the beginning and check the magnitude of the implemented improvements. The importance of this project is based on the offer of better systems the companies would make, which would benefit the deployment of the thermal solar energy. Another relevant point is to make the new equipments at the same cost of the previous ones or cheaper, in order to achieve a good deployment of the solar water heating systems; then, the manufacture processes and methods must be studied to obtain not only good technical solutions, but also economical equipments. In addition, this project will contribute to the increasing of the knowledge in the area of thermosyphonic solar systems and the training of postgraduate students.

Non-destruct|ve testing of non-metallic materials using microwaves

The motivatitni for" the present work is from .a project sanctioned by TSRO. The work involved the development of a quick and reliable test procedure using microwaves, for tflue inspection of cured propellant samples and a method to monitor the curing conditions of propellant mix undergoing the curing process.Normal testing CHE the propellant samples involvecuttimg a piece from each carton and testing it for their tensile strength. The values are then compared with standard ones and based on this result the sample isaccepted or rejected. The tensile strength is a measure ofdegree of cure of the propellant mix. But this measurementis a destructive procedure as it involves cutting of the sample. Moreover, it does not guarantee against nonuniform curing due to power failure, hot air-line failure,operator error etc. This necessitated the need for the development of a quick and reliable non-destructive test procedure.

Problems in bibliographic access to non-print materials : final report /

Mode of access: Internet.

Waveguide fabrication in lithium-niobo-phosphate glasses by high repetition rate femtosecond laser:route to non-equilibrium material’s states

We study waveguide fabrication in lithium-niobo-phosphate glass, aiming at a practical method of single-stage fabrication of nonlinear integrated-optics devices. We observed chemical transformations or material redistribution during the course of high repetition rate femtosecond laser inscription. We believe that the laser-induced ultrafast heating and cooling followed by elements diffusion on a microscopic scale opens the way toward the engineering non-equilibrium sates of matter and thus can further enhance Refractive Index (RI) contrasts by virtue of changing glass composition in and around the fs tracks. © 2014 Optical Society of America.

Crack propagation in non-homogenous materials: Evaluation of mixed-mode SIFs, T-stress and kinking angle using a variant EFG method

A new variant of the Element-Free Galerkin (EFG) method, that combines the diffraction method, to characterize the crack tip solution, and the Heaviside enrichment function for representing discontinuity due to a crack, has been used to model crack propagation through non-homogenous materials. In the case of interface crack propagation, the kink angle is predicted by applying the maximum tangential principal stress (MTPS) criterion in conjunction with consideration of the energy release rate (ERR). The MTPS criterion is applied to the crack tip stress field described by both the stress intensity factor (SIF) and the T-stress, which are extracted using the interaction integral method. The proposed EFG method has been developed and applied for 2D case studies involving a crack in an orthotropic material, crack along an interface and a crack terminating at a bi-material interface, under mechanical or thermal loading; this is done to demonstrate the advantages and efficiency of the proposed methodology. The computed SIFs, T-stress and the predicted interface crack kink angles are compared with existing results in the literature and are found to be in good agreement. An example of crack growth through a particle-reinforced composite materials, which may involve crack meandering around the particle, is reported.

How to optimize operational shipping processes of non-production materials? The Volkswagen Autoeuropa case study

Field lab: Entrepreneurial and innovative ventures

Aplicación de las herramientas de la web 2.0 a la enseñanza de la catalogación de documentos

En este trabajo se plantea la elaboración de un proyecto de intervención que se dirige a modificar la metodología de enseñanza para el procesamiento de documentos en el ámbito de la asignatura Procesamiento de Materiales Especiales de la carrera de Bibliotecología y Ciencia de la Información que se dicta en la Facultad de Humanidades y Ciencias de la Educación. A tal efecto se plantea introducir en el entorno de enseñanza aprendizaje las herramientas de las web 2.0 aplicadas a los entornos catalográficos, que en conjunto se denomina OPAC 2.0. Esta innovación en el entorno de la mencionada asignatura supone una innovación ya que hasta el momento este tipo de metodología, si bien desarrollada en el procesamiento de documentos en el ámbito del ejercicio profesional, no ha sido incorporada en la asignatura como parte del proceso de enseñanza

Aplicación de las herramientas de la web 2.0 a la enseñanza de la catalogación de documentos

En este trabajo se plantea la elaboración de un proyecto de intervención que se dirige a modificar la metodología de enseñanza para el procesamiento de documentos en el ámbito de la asignatura Procesamiento de Materiales Especiales de la carrera de Bibliotecología y Ciencia de la Información que se dicta en la Facultad de Humanidades y Ciencias de la Educación. A tal efecto se plantea introducir en el entorno de enseñanza aprendizaje las herramientas de las web 2.0 aplicadas a los entornos catalográficos, que en conjunto se denomina OPAC 2.0. Esta innovación en el entorno de la mencionada asignatura supone una innovación ya que hasta el momento este tipo de metodología, si bien desarrollada en el procesamiento de documentos en el ámbito del ejercicio profesional, no ha sido incorporada en la asignatura como parte del proceso de enseñanza

Aplicación de las herramientas de la web 2.0 a la enseñanza de la catalogación de documentos

En este trabajo se plantea la elaboración de un proyecto de intervención que se dirige a modificar la metodología de enseñanza para el procesamiento de documentos en el ámbito de la asignatura Procesamiento de Materiales Especiales de la carrera de Bibliotecología y Ciencia de la Información que se dicta en la Facultad de Humanidades y Ciencias de la Educación. A tal efecto se plantea introducir en el entorno de enseñanza aprendizaje las herramientas de las web 2.0 aplicadas a los entornos catalográficos, que en conjunto se denomina OPAC 2.0. Esta innovación en el entorno de la mencionada asignatura supone una innovación ya que hasta el momento este tipo de metodología, si bien desarrollada en el procesamiento de documentos en el ámbito del ejercicio profesional, no ha sido incorporada en la asignatura como parte del proceso de enseñanza

Composite artistry in the Book of Numbers : a study in biblical narrative conventions

The present thesis discusses the coherence or lack of coherence in the book of Numbers, with special regard to its narrative features. The fragmented nature of Numbers is a well-known problem in research on the book, affecting how we approach and interpret it, but to date there has not been any thorough investigation of the narrative features of the work and how they might contribute to the coherence or the lack of coherence in the book. The discussion is pursued in light of narrative theory, and especially in connection to three parameters that are typically understood to be invoked in the interpretation of narratives: 1) a narrative paradigm, or ‘story,’ meaning events related to each other temporally, causally, and thematically, in a plot with a beginning, middle, and end; 2) discourse, being the expression plane of a narrative, or the devices that an author has at hand in constructing a narrative; 3) the situation or languagegame of the narrative, prototypical examples being factual reports, which seeks to depict a state of affairs, and storytelling narratives, driven by a demand for tellability. In view of these parameters the present thesis argues that it is reasonable to form four groups to describe the narrative material of Numbers: genuine narratives (e.g. Num 12), independent narrative sequences (e.g. Num 5:1-4), instrumental scenes and situations (e.g. Num 27:1-5), and narrative fragments (e.g. Num 18:1). These groups are mixed throughout with non-narrative materials. Seen together, however, the narrative features of these groups can be understood to create an attenuated narrative sequence from beginning to end in Numbers, where one thing happens after another. This sequence, termed the ‘larger story’ of Numbers, concerns the wandering of Israel from Sinai to Moab. Furthermore, the larger story has a fragmented plot. The end-point is fixed on the promised land, Israel prepares for the wandering towards it (Num 1-10), rebels against wandering and the promise and is sent back into the wilderness (Num 13-14), returns again after forty years (Num 21ff.), and prepares for conquering the land (Num 22-36). Finally, themes of the promised land, generational succession, and obedience-disobedience, operate in this larger story. Purity is also a significant theme in the book, albeit not connected to plot in the larger story. All in all, sequence, plot, and theme in the larger story of Numbers can be understood to bring some coherence to the book. However, neither aspect entirely subsumes the whole book, and the four groups of narrative materials can also be understood to underscore the incoherence of the work in differentiating its variegated narrative contents. Numbers should therefore be described as an anthology of different materials that are loosely connected through its narrative features in the larger story, with the aim of informing Israelite identity by depicting a certain period in the early history of the people.

Book of A.S.T.M. standards.

Part of illustrative matter is folded.

Backside-surface imprinting as a new strategy to generate specific plastic antibody materials

A backside protein-surface imprinting process is presented herein as a novel way to generate specific synthetic antibody materials. The template is covalently bonded to a carboxylated-PVC supporting film previously cast on gold, let to interact with charged monomers and surrounded next by another thick polymer. This polymer is then covalently attached to a transducing element and the backside of this structure (supporting film plus template) is removed as a regular “tape”. The new sensing layer is exposed after the full template removal, showing a high density of re-binding positions, as evidenced by SEM. To ensure that the templates have been efficiently removed, this re-binding layer was cleaned further with a proteolytic enzyme and solution washout. The final material was named MAPS, as in the back-side reading of SPAM, because it acts as a back-side imprinting of this recent approach. It was able to generate, for the first time, a specific response to a complex biomolecule from a synthetic material. Non-imprinted materials (NIMs) were also produced as blank and were used as a control of the imprinting process. All chemical modifications were followed by electrochemical techniques. This was done on a supporting film and transducing element of both MAPS and NIM. Only the MAPS-based device responded to oxLDL and the sensing layer was insensitive to other serum proteins, such as myoglobin and haemoglobin. Linear behaviour between log(C, μg mL−1) versus charged tranfer resistance (RCT, Ω) was observed by electrochemical impedance spectroscopy (EIS). Calibrations made in Fetal Calf Serum (FCS) were linear from 2.5 to 12.5 μg mL−1 (RCT = 946.12 × log C + 1590.7) with an R-squared of 0.9966. Overall, these were promising results towards the design of materials acting close to the natural antibodies and applied to practical use of clinical interest.

Cement Stabilization of Embankment Materials, 2015

Embankment subgrade soils in Iowa are generally rated as fair to poor as construction materials. These soils can exhibit low bearing strength, high volumetric instability, and freeze/thaw or wet/dry durability problems. Cement stabilization offers opportunities to improve these soils conditions. The objective of this study was to develop relationships between soil index properties, unconfined compressive strength and cement content. To achieve this objective, a laboratory study was conducted on 28 granular and non-granular materials obtained from 9 active construction sites in Iowa. The materials consisted of glacial till, loess, and alluvium sand. Type I/II portland cement was used for stabilization. Stabilized and unstabilized specimens were prepared using Iowa State University 2 in. by 2 in. compaction apparatus. Specimens were prepared, cured, and tested for unconfined compressive strength (UCS) with and without vacuum saturation. Percent fines content (F200), AASHTO group index (GI), and Atterberg limits were tested before and after stabilization. The results were analyzed using multi-variate statistical analysis to assess influence of the various soil index properties on post-stabilization material properties. Results indicated that F200, liquid limit, plasticity index, and GI of the materials generally decreased with increasing cement content. The UCS of the stabilized specimens increased with increasing cement content, as expected. The average saturated UCS of the unstabilized materials varied between 0 and 57 psi. The average saturated UCS of stabilized materials varied between 44 and 287 psi at 4% cement content, 108 and 528 psi at t 8% cement content, and 162 and 709 psi at 12% cement content. The UCS of the vacuum saturated specimens was on average 1.5 times lower than that of the unsaturated specimens. Multi-variate statistical regression models are provided in this report to predict F200, plasticity index, GI, and UCS after treatment, as a function of cement content and soil index properties.

Detection of cracks in scratching tests in ceramic materials through acoustic emission

The mechanisms of material removal and the interactions among scratches performed in ceramic materials were investigated using acoustic emission signals, and scanning electron microscopy, in scratching experiments. Several testing conditions were used to produce different types of removing mechanism on a glass as well as on a polycrystalline alumina sample composed by heterogeneous grain size. It is known that the material removing process on a polycrystalline ceramic involves intergranular microfracture and grain dislodgement, unlike the chipping produced by the extension of lateral cracks in non-granular materials, such as glass. Distinct settings for velocities, loads, and two types of diamond indenter were tested. The material removal was carried out by three different methods of scratching: single passes, repeated overlapping passes, and parallel scratches. As a general result, there was a clear relationship between the acoustic emission signals and the damage intensity occurred in the material removal. More specifically, there were differences in the acoustic emission signal levels in the scratches made on the alumina and on the glass owing to the material removal mechanisms associated with the structure of these materials. A gradual increase in the acoustic emission levels was observed when the number of repeated passes was increased as a result of the damage accumulation process followed by severe material removal. It was also noticed that the acoustic emission signals were capable of reflecting the interactions between two parallel scratches.

Analysis of elastic functionally graded materials under large displacements via high-order tetrahedral elements

The purpose of this study is to present a position based tetrahedral finite element method of any order to accurately predict the mechanical behavior of solids constituted by functionally graded elastic materials and subjected to large displacements. The application of high-order elements makes it possible to overcome the volumetric and shear locking that appears in usual homogeneous isotropic situations or even in non-homogeneous cases developing small or large displacements. The use of parallel processing to improve the computational efficiency, allows employing high-order elements instead of low-order ones with reduced integration techniques or strain enhancements. The Green-Lagrange strain is adopted and the constitutive relation is the functionally graded Saint Venant-Kirchhoff law. The equilibrium is achieved by the minimum total potential energy principle. Examples of large displacement problems are presented and results confirm the locking free behavior of high-order elements for non-homogeneous materials. (C) 2011 Elsevier B.V. All rights reserved.