1,531 research outputs found

    Chacarita Project: Conformation and analysis of a modern and documented human osteological collection from Buenos Aires City - Theoretical, methodological and ethical aspects

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    Osteological reference collections play a key role in bioanthropological research; they allow the development and testing of methods for sexing and aging individuals using different bone and dental attributes. This paper presents the first stage results of the ongoing Chacarita Research Project, which aims to generate and study a reference collection of adult skeletons representative of the contemporary population of Buenos Aires city. The Chacarita Collection is being conformed of unclaimed human remains of individuals of known nationality, sex, age, cause and date of death from the Chacarita Public Cemetery. Unlike other similar endeavors, this sample has been completely exhumed using archaeological techniques. So far, a total of 146 adult skeletons have been recovered (60 females - 41.1% - and 86 males - 58.90% -), the majority of which have ages-at-death in the range of 71-90 years. They were born primarily in Argentina (n = 133; 91.1%), although other nationalities are also represented. Dates of death go between 1987 and 2000. In the short term, the osteological study of this collection will allow assessment of the performance of classical methods of sex determination and age-at-death estimation in a local setting. A special priority will be given to the study of osteological changes in individuals over 50 years. As the sample is being retrieved by exhumation, the impact of taphonomic agents on the most diagnostic bones structures is also being assessed. In the long term, this osteological collection will be available to generate new population-specific techniques, and to develop comparative biological studies.Fil: Bosio, L. A.. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Medicina Legal y Deontología Médica. Servicio de Antropología Forense; ArgentinaFil: García Guraieb, S.. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; ArgentinaFil: Luna, Leandro Hernan. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aranda, C.. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; Argentin

    waste silica sources as heavy metal stabilizers for municipal solid waste incineration fly ash

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    Abstract The present work discusses a new method, based on the use of silica fume, for heavy metal stabilization. The inertization procedure is reported and compared with other technologies, involving the employ of amorphous silica as stabilizing agent for municipal solid waste incinerator fly ash treatment (i.e. colloidal silica and rice husk ash). The obtained final materials are characterized in terms of chemical composition and phase analysis. The reported method, realized at room temperature, employs all waste or by-product materials. As a consequence it appears to be economically and environmentally sustainable

    Surface Induced Order in Liquid Metals and Binary Alloys

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    Measurements of the surface x-ray scattering from several pure liquid metals (Hg, Ga, and In) and from three alloys (Ga-Bi, Bi-In, and K-Na) with different heteroatomic chemical interactions in the bulk phase are reviewed. Surface-induced layering is found for each elemental liquid metal. The surface structure of the K-Na alloy resembles that of an elemental liquid metal. Bi-In displays pair formation at the surface. Surface segregation and a wetting film are found for Ga-Bi.Comment: 10 pages, 3 fig, published in Journal of Physics: Condensed Matte

    Dependability of Alternative Computing Paradigms for Machine Learning: hype or hope?

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    Today we observe amazing performance achieved by Machine Learning (ML); for specific tasks it even surpasses human capabilities. Unfortunately, nothing comes for free: the hidden cost behind ML performance stems from its high complexity in terms of operations to be computed and the involved amount of data. For this reasons, custom Artificial Intelligence hardware accelerators based on alternative computing paradigms are attracting large interest. Such dedicated devices support the energy-hungry data movement, speed of computation, and memory resources that MLs require to realize their full potential. However, when ML is deployed on safety-/mission-critical applications, dependability becomes a concern. This paper presents the state of the art of custom Artificial Intelligence hardware architectures for ML, here Spiking and Convolutional Neural Networks, and shows the best practices to evaluate their dependability

    Design, Verification, Test and In-Field Implications of Approximate Computing Systems

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    Today, the concept of approximation in computing is becoming more and more a “hot topic” to investigate how computing systems can be more energy efficient, faster, and less complex. Intuitively, instead of performing exact computations and, consequently, requiring a high amount of resources, Approximate Computing aims at selectively relaxing the specifications, trading accuracy off for efficiency. While Approximate Computing gives several promises when looking at systems’ performance, energy efficiency and complexity, it poses significant challenges regarding the design, the verification, the test and the in-field reliability of Approximate Computing systems. This tutorial paper covers these aspects leveraging the experience of the authors in the field to present state-of-the-art solutions to apply during the different development phases of an Approximate Computing system

    Zn-doped titania nanoparticles as building blocks for solid foam filters of water and air via photocatalytic oxidation

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    Photocatalytic oxidation (PCO) could provide energy-efficient purification of water and air. Its efficacy is constrained mainly by limited photocatalytic activity and active surface. To address both, solid foams with hierarchic porous structures spanning multiple length-scales, stabilized by photocatalytic Zn-doped titania nanoparticles (NP) were synthesized and tested. The NP were characterized by SEM, EDS, DLS, XRD, Raman and UV–Vis spectroscopies. Solid foams were stabilized by NP complexes with cationic surfactants. The foam morphology was characterized and photocatalytic activity was demonstrated in water. The present work paves the way for the development of efficient systems for air and water purification in demanding technological sectors, such as aerospace

    Experimental investigation of SO2 poisoning in a Molten Carbonate Fuel Cell operating in CCS configuration

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    [EN] One of the most interesting innovations in the CCS (Carbon Capture and Storage) field is the use of MCFCs as carbon dioxide concentrators, feeding their cathode side (or air side) with the exhaust gas of a traditional power plant. The feasibility of this kind of application depends on the resistance of the MCFC to air-side contaminants, with particular attention to SO2. The aim of this work is to investigate the effects of poisoning when sulphur dioxide is added to the cathodic stream in various concentrations and in different operating conditions. This study was carried out operating single cells (80 cm(2)) with a cathodic feeding composition simulating typical flue gas conditions, i.e. N-2, H2O, O-2 and CO2 in 73:9:12:6 mol ratio as reference mixture. On the anodic side a base composition was chosen with H-2, CO2 and H2O in 64:16:20 mol ratio. Starting from these reference mixtures, the effect of single species on cell poisoning was experimentally investigated considering, as main parameters chosen for the sensitivity analysis, SO2 (0-24 ppm) and CO2 (4-12%) content in the cathodic feeding mixture, H-2 (40-64%) content in the anodic stream as well as the operating temperature (620-680 degrees C). Results showed that degradation caused by SO2 poisoning is strongly affected by the operating conditions. Data gathered during this experimental campaign will be used in a future work to model the poisoning mechanisms through the definition of MCFC electrochemical kinetics which take into account the SO2 effects. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.The work was partly supported by H2FC European Infrastructure Project (Integrating European Infrastructure to support science and development of Hydrogen and Fuel Cell Technologies towards European Strategy for Sustain-able Competitive and Secure Energy) Theme [INFRA-2011-1.1.16.], Grant agreement 284522.Della Pietra, M.; Discepoli, G.; Bosio, B.; Mcphail, S.; Barelli, L.; Bidini, G.; Ribes-Greus, A. (2016). Experimental investigation of SO2 poisoning in a Molten Carbonate Fuel Cell operating in CCS configuration. International Journal of Hydrogen Energy. 41(41):18822-18836. https://doi.org/10.1016/j.ijhydene.2016.05.147S1882218836414
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