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

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

Expression of Glucose Transporters in the Prelaminar Region of the Optic-Nerve Head of the Pig as Determined by Immunolabeling and Tissue Culture

Background: To develop the use of cultured tissue of the prelaminar optic nerve of the pig to explore possible alterations of the astrocyte-axon metabolic pathways in glaucoma, we map the distribution of the glucose transporters GLUT1 and GLUT3 in fresh and cultured tissue.Methods: We monitor cell survival in cultures of the prelaminar optic-nerve tissue, measuring necrosis and apoptosis markers biochemically as well as morphologically, and establish the presence of the glucose transporters GLUT1 and GLUT3. We map the distribution of these transporters with immunolabeling in histological sections of the optic nerve using confocal and electronic transmission microscopy.Results: We find that the main death type in prelaminar culture is apoptosis. Caspase 7 staining reveals an increment in apoptosis from day 1 to day 4 and a reduction from day 4 to day 8. Western blotting for GLUT1 shows stability with increased culture time. CLSM micrographs locate GLUT1 in the columnar astrocytes and in the area of axonal bundles. Anti-GLUT3 predominantly labels axonal bundles. TEM immunolabeling with colloidal gold displays a very specific distribution of GLUT-1 in the membranes of vascular endothelial cells and in periaxonal astrocyte expansions. The GLUT-3 isoform is observed with TEM only in axons in the axonal bundles.Conclusions: Tissue culture is suitable for apoptosis-induction experiments. The results suggest that glucose is transported to the axonal cleft intracytoplasmically and delivered to the cleft by GLUT1 transporters. As monocarboxylate transporters have been reported in the prelaminar region of the optic-nerve head, this area is likely to use both lactate and glucose as energy sources.This work was supported by a grant from the Consejería de Salud, Junta de Andalucia, Spain, Project PI-0655-2013

Systematic approach for the life cycle multi-objective optimization of buildings combining objective reduction and surrogate modeling

With the recent trend of moving towards a more sustainable economy, the interest on designing buildings with lower cost and environmental impact has grown significantly. In this context, multi-objective optimization has attracted much attention in building design as a tool to study trade-off solutions (“cost” vs “environmental impact”) resulting from the optimization of conflicting objectives. One major limitation of this approach (as applied to building design) is that it is computationally demanding due to the need to optimize several objectives using complex models based on differential equations (which are used to estimate the energy consumed by a building). In this work, we propose a systematic framework for the design of buildings that combines a rigorous objective reduction method (which removes redundant objectives from the analysis) with a surrogate model (which simplifies the calculation of the energy requirements of the building), both of which expedite the identification of alternative designs leading to environmental improvements. The capabilities of our methodology are illustrated through a case study based on a thermal modelling of a house-like cubicle, in which we optimize the insulation thicknesses of the building envelope. Results show that significant economic and environmental improvements can be achieved compared to the base case (cubicle without insulation). Furthermore, it is clearly illustrated how the minimization of an aggregated environmental metric, like the Eco-Indicator 99, as unique environmental objective may overlook some Pareto solutions that may be appealing for decision-makers.The authors would like to acknowledge financial support from the Spanish Government (ENE2015-64117-C5-3-R (MINECO/FEDER, UE)). Joan Carreras would also like to acknowledge financial support from the Pump-Priming Research Programs of The University of Manchester

Geographic patterns of genetic variation in a broadly distributed marine vertebrate: new insights into loggerhead turtle stock structure from expanded mitochondrial DNA sequences

Previous genetic studies have demonstrated that natal homing shapes the stock structure of marine turtle nesting populations. However, widespread sharing of common haplotypes based on short segments of the mitochondrial control region often limits resolution of the demographic connectivity of populations. Recent studies employing longer control region sequences to resolve haplotype sharing have focused on regional assessments of genetic structure and phylogeography. Here we synthesize available control region sequences for loggerhead turtles from the Mediterranean Sea, Atlantic, and western Indian Ocean basins. These data represent six of the nine globally significant regional management units (RMUs) for the species and include novel sequence data from Brazil, Cape Verde, South Africa and Oman. Genetic tests of differentiation among 42 rookeries represented by short sequences (380 bp haplotypes from 3,486 samples) and 40 rookeries represented by long sequences (~800 bp haplotypes from 3,434 samples) supported the distinction of the six RMUs analyzed as well as recognition of at least 18 demographically independent management units (MUs) with respect to female natal homing. A total of 59 haplotypes were resolved. These haplotypes belonged to two highly divergent global lineages, with haplogroup I represented primarily by CC-A1, CC-A4, and CC-A11 variants and haplogroup II represented by CC-A2 and derived variants. Geographic distribution patterns of haplogroup II haplotypes and the nested position of CC-A11.6 from Oman among the Atlantic haplotypes invoke recent colonization of the Indian Ocean from the Atlantic for both global lineages. The haplotypes we confirmed for western Indian Ocean RMUs allow reinterpretation of previous mixed stock analysis and further suggest that contemporary migratory connectivity between the Indian and Atlantic Oceans occurs on a broader scale than previously hypothesized. This study represents a valuable model for conducting comprehensive international cooperative data management and research in marine ecology

The era of reference genomes in conservation genomics

Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics

Are we working towards global research priorities for management and conservation of sea turtles?

In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. To obtain a picture of how research is being focused towards these key questions, we undertook a systematic review of the peer-reviewed literature (2014 and 2015) attributing papers to the original 20 questions. In total, we reviewed 605 articles in full and from these 355 (59%) were judged to substantively address the 20 key questions, with others focusing on basic science and monitoring. Progress to answering the 20 questions was not uniform, and there were biases regarding focal turtle species, geographic scope and publication outlet. Whilst it offers some meaningful indications as to effort, quantifying peer-reviewed literature output is ob viously not the only, and possibly not the best, metric for understanding progress towards informing key conservation and management goals. Along with the literature review, an international group based on the original project consortium was assigned to critically summarise recent progress towards answering each of the 20 questions. We found that significant research is being expended towards global priorities for management and conservation of sea turtles. Although highly variable, there has been significant progress in all the key questions identified in 2010. Undertaking this critical review has highlighted that it may be timely to undertake one or more new prioritizing exercises. For this to have maximal benefit we make a range of recommendations for its execution. These include a far greater engagement with social sciences, widening the pool of contributors and focussing the questions, perhaps disaggregating ecology and conservatio