3D-Mesomechanical analysis of cracking and spalling of concrete subject to high temperatures

In this paper, an existing meso-structural model for concrete which had been applied to the study of the mechanical effects of high temperatures in 2D, is extended to 3D, and to more complex coupled thermo-mechanical analysis. The material is idealized as a twophase compositein which all mesh lines (or surfaces in 3D) are potential cracks equipped with fracture-based zero-thickness interface elements. Different thermal expansion laws are assumed for matrix and particles, whereby the deformation mismatch can generate cracking. Temperature distributions are obtained from a separate thermal diffusionanalysis.The thermal analysis is first assumed uncoupled, but then also coupled with the mechanical analysis, as the layers of material spalloff and the boundary conditionsare moved to the new domain boundaries. The new computational results in 3D are compared to basic experimental observations reported in the literature and to the previous computational results obtained in 2D

Analytical High-level Power model for LUT-based Components

This paper presents an extended high-level model for logic power estimation of multipliers and adders implemented in FPGAs in the presence of glitching and correlation. The model is based on an analytical computation of the switching activity produced in the component and the FPGA implementation details of the component structure. It is extended to consider operands of different word-lengths, both zero-mean and non- zero mean signals, and the glitching produced inside the component, taking into account the sign nature of the autocorrelation coefficients of the components’ inputs. The number of simulations needed for the model characterization is extremely small and can be reduced to only two. As the final power model is analytical, it is capable of providing power estimates in miliseconds. The results show that the mean relative error is within 10% of low-level power estimates given by the XPower tool

Power Measurement Methodology for FPGA Devices

The efficiency of power optimization tools depends on information on design power provided by the power estimation models. Power models targeting different power groups can enable fast identification of the most power consuming parts of design and their properties. The accuracy of these estimation models is highly dependent on the accuracy of the method used for their characterization. The highest precision is achieved by using physical onboard measurements. In this paper, we present a measurement methodology that is primarily aimed at calibrating and validating high-level dynamic power estimation models. The measurements have been carefully designed to enable the separation of the interconnect power from the logic power and the power of the clock circuitry, so that each of these power groups can be used for the corresponding model validation. The standard measurement uncertainty is lower than 2% of the measured value even with a very small number of repeated measurements. Additionally, the accuracy of a commercial low-level power estimation tool has been also assessed for comparison purposes. The results indicate that the tool is not suitable for power estimation of data path-oriented designs

Aplicación de la metalografía a la solución de problemas industriales

Por metalografía se define el estudio de la constitución y estructura interna de los metales y aleaciones relacionándolas con la composición química y características mecánicas. Sus leyes y principios pertenecen al campo de la físico-química y en la actualidad constituye uno de los medios más importantes de la investigación metalúrgica. No debe interpretarse por ello que su finalidad es puramente científica, ya que tiene también alcances prácticos como método de verificación de materiales y de procesos industriales.Universidad Nacional de La Plat

Aplicación de la metalografía a la solución de problemas industriales

Por metalografía se define el estudio de la constitución y estructura interna de los metales y aleaciones relacionándolas con la composición química y características mecánicas. Sus leyes y principios pertenecen al campo de la físico-química y en la actualidad constituye uno de los medios más importantes de la investigación metalúrgica. No debe interpretarse por ello que su finalidad es puramente científica, ya que tiene también alcances prácticos como método de verificación de materiales y de procesos industriales.Universidad Nacional de La Plat

Aplicación de la metalografía a la solución de problemas industriales

Por metalografía se define el estudio de la constitución y estructura interna de los metales y aleaciones relacionándolas con la composición química y características mecánicas. Sus leyes y principios pertenecen al campo de la físico-química y en la actualidad constituye uno de los medios más importantes de la investigación metalúrgica. No debe interpretarse por ello que su finalidad es puramente científica, ya que tiene también alcances prácticos como método de verificación de materiales y de procesos industriales.Universidad Nacional de La Plat

Ejecución de cañería perimetral y análisis técnico y económico natatorio del club cultural y deportivo La Francia

Práctica Supervisada (IC)--FCEFN-UNC, 2016Analiza técnica y económicamente la piscina que tiene condiciones especiales tales como: grandes dimensiones, instalaciones deterioradas, provisión de agua de baja calidad que derivan en malas condiciones sanitarias del natatorio. El análisis económico permitirá un eficiente uso de los escasos recursos disponibles y tendrá como objetivo disminuir los costos de operación de la pilet

Population-specific signatures of intra-individual mitochondrial DNA heteroplasmy and their potential evolutionary advantages

Heteroplasmy is the existence of more than one mitochondrial DNA (mtDNA) variant within a cell. The evolutionary mechanisms of heteroplasmy are not fully understood, despite being a very common phenomenon. Here we combined heteroplasmy measurements using high throughput sequencing on green turtles (Chelonia mydas) with simulations to understand how heteroplasmy modulates population diversity across generations and under different demographic scenarios. We found heteroplasmy to be widespread in all individuals analysed, with consistent signal in individuals across time and tissue. Significant shifts in haplotype composition were found from mother to offspring, signalling the effect of the cellular bottleneck during oogenesis as included in the model. Our model of mtDNA inheritance indicated that heteroplasmy favoured the increase of population diversity through time and buffered against population bottlenecks, thus indicating the importance of this phenomenon in species with reduced population sizes and frequent population bottlenecks like marine turtles. Individuals with recent haplotypes showed higher levels of heteroplasmy than the individuals with ancient haplotypes, suggesting a potential advantage of maintaining established copies when new mutations arise. We recommend using heteroplasmy through high throughput sequencing in marine turtles, as well as other wildlife populations, for diversity assessment, population genetics, and mixed stock analysis

La computación electrónica aplicada a la selección de los aceros

El presente trabajo tiene por objeto demostrar cómo, mediante la utilización de "una computadora electrónica, y aplicando ciertos principios técnico-científicos, se puede llegar a establecer una equivalencia entre los aceros al carbono y aleados destinados a la construcción mecánica. Para ello se ha adoptado el criterio de tres parámetros fundamentales: (Di) diámetro crítico ideal, (Ms) temperatura de transformación austenítica-mar-tensítica, y (Hr) dureza a distintas temperaturas y tiempos de revenido. Luego de un estudio crítico del sistema de equivalencia, se presentan las tablas de valores obtenidas por la computadora electrónica y se analiza la trascendencia de estas determinaciones.The purpose of the present report is to demonstrate how employing and electronic computer and certain technical-scientifical principles, it is possible to establish an equivalence between carbon and alloy steels used in mechanical constructions. To accomplish this objective it was adopted the criterium of three fundamental parameters: (Dl) ideal critical diameter, (Ms) transformation temperature austenite martensite and (Hr) hardness corresponding to different temperatures and tempering times. After a critical study of the equivalence system, tables and values obtained by electronic computer are shown and the importance of these determinations are analyzed