4,367 research outputs found

    Planning the Integrated Management of Organic Waste Flows and Agricultural Residues for a Circular Economy

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    In the recent years, the production, management and disposal of both organic waste and agricultural residues has become significantly difficult in Italy, due to the lack of suitable facilities. Very often, indeed, within the different regions, there are no treatment plants for the organic fraction of municipal solid waste or agricultural residues treatment centres, so as to give them a second life in the perspective of a circular economy. The lack of proximity treatment centres, forces local administrations to send these flows to plants outside their territorial area, with a consequent increase for transport and treatment costs. This paper, with reference to the study area of the Matera municipality (Basilicata region - Southern Italy), taking into consideration the organic waste flows of non-domestic users from separate collection and agricultural residues - especially those coming from the wine production chain - provides a state-of-the-art analysis of the problems related to their collection, management and disposal. Subsequently, an alternative model feasibility study - called "proximity composting", aimed at a more sustainable management of these flows based on their “zero-kilometers treatment” – has been implemented. The results obtained have demonstrated that the proposed scenario is much more sustainable when compared to the current situation, both from an economic and environmental point of view. Indeed, thanks to the use of calculation tools, the economic (€/year) and environmental (Kg CO2 avoided/year) advantages, due to the save of transport and disposal of flows outside the region, have been quantified, with consequent reduction of waste tax for citizens (€/year). In addition, the implementation of maps using a Geographical Information System (GIS) has demonstrated a better optimization of the system. Finally, it was highlighted the social utility of the proposed model, because citizens become an active part in the process and self-produce soil fertilisers

    Concrete Blocks Reinforced with Arundo donax Natural Fibers with Different Aspect Ratios for Application in Bioarchitecture

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    In recent decades, the construction industry has advanced in its use of natural green resources, such as vegetable fibers (e.g., flax, hemp, jute, etc.) added in concrete mixtures, to create building materials that are both economically and environmentally sustainable. The pricing, low energy cost, and environmental sustainability of these natural fibers are driving this interest. The quantity of fibers and the ratio of fiber length to its transverse diameter (aspect ratio) are critical characteristics that have a decisive impact on concrete’s mechanical qualities. The influence of the aspect ratio of Arundo donax fibers on the tensile characteristics of concrete blocks was specifically investigated in this study. These fibers were collected from the outer section of the stem of this plant, which grows commonly in Mediterranean locations, but that is also found all over the world. Experiments were carried out on cylindrical concrete blocks with a constant amount of fiber (1 percent by weight) and different aspect ratios: 30, 50, and 70 (mm/mm) respectively, to assess their tensile strength, even when compared with concrete blocks without any fiber addition. Tensile tests on Arundo donax fibers were also conducted, with the aim to contribute to the analysis of their interaction with cementitious matrices, and to assess differences between the various compositions. The results showed a direct impact of the aspect ratio on the final tensile strength of concrete blocks, with higher aspect ratios producing superior tensile properties

    Experimental analysis on concrete blocks reinforced with Arundo donax fibres

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    Over the last decades, there has been growing attention in research and development on non-conventional building materials, such as vegetable fibres (e.g., flax, hemp, jute, etc.), to be used as eco-friendly materials in a wide range of applications in civil construction. The main reasons for this interest are related to the specific properties, price, and sustainability of natural fibres, which can be considered ‘green’ building materials. In this article, the tensile strength of a new type of fibre extracted from the stem of the Giant Reed Arundo donax L. has been investigated. First, these fibres, which widely grow in Mediterranean areas but are diffused worldwide as well have been extracted from the outer part of the plant stem. Then, in order to have an initial idea of their influence on the mechanical properties of concrete, some experimental bricks have been prepared, with the addition of different weight percentages of this vegetal fibre. Compression and tensile tests on the whole block have been performed to assess the mechanical properties of these bricks. Hence, the differences between concrete bricks without fibre and those reinforced with different weight percentages of natural fibre have been analysed, assessing their potential applications in bio-architecture

    Experimental analysis on concrete blocks reinforced with Arundo Donax fibers.

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    Over the last decade, there has been a growing attention in research and development on non-conventional building materials and technologies, such as vegetable fibers (e.g., flax; hemp; jute; etc.), to be used as eco-friendly materials in a wide range of applications in civil construction. The main reasons of this interest are related to the specific properties, price and sustainability of natural fibers, which can be considered as “green” building materials. In this article, a new kind of fibers, extracted from stem of the Giant Reed Arundo donax L., has been investigated as a potential reinforcement of construction materials. These fibers, which widely grow in Mediterranean areas, but that are diffused all around the world as well, have been extracted from the outer part of plant stem. Then, some experimental concrete bricks, have been prepared with the addition of different weight percentages of vegetal fiber. To assess the mechanical properties of these bricks, tensile tests on single fiber have been performed, as well as compression tests on the whole block. Hence, the differences between concrete bricks without any fiber and those reinforced with different weight percentages of natural fiber have been analyzed, and their potential applications in bio-architecture have been assessed

    GIScience and Historical Cartography for Evaluating Land Use Changes and Resulting Effects on Carbon Balance

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    Multi-chronological examination of territory using GIScience and historical cartography may reveal a strategic tool for investigating changes in land use and the surrounding landscape structure. In this framework, the soil plays a key role in ecosystem evolution, since it governs all the mechanisms at the basis of vegetal growth, as well as all components of the total environment contributing to the formation of a rural landscape, including the balance of carbon dioxide. The present study was developed using a GIS approach applied to historical maps and aims to assess the environmental impact of land-use change, with particular attention to its effects on agricultural soil and atmospheric carbon dioxide balance. Thanks to a comparison between historical cartographic maps of different periods, this geospatial approach has enabled the assessment of the evolution of the rural land of the study area in the municipality of Ruoti (Basilicata Region—Southern Italy). This area, indeed, has been affected by deep land-use transformations, mainly caused by agricultural activities, with a resulting impact on the atmospheric CO2 balance. These transformations have been analyzed and quantified in order to contribute to the understanding on how the changes in land use for agricultural purposes have led to unforeseen changes in the rural landscape, ecosystems and the environment. The results showed that the greatest changes in land use were caused by the abandonment of large rural areas, resulting in the expansion of urban areas, a decrease in orchard and arable land (about less 25%), and an increase in woodland (more than 30%). These changes have resulted in a doubling in soil carbon fixation value. The final results have therefore confirmed that historical cartography within a GIS approach may decisively offer information useful for more sustainable agricultural activities, so as to reduce their negative contribution to climate change

    A HPC and Grid enabling framework for genetic linkage analysis of SNPs

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    Understanding the structure, function and development of the human genome is a key factor to improve the quality of life. In order to achieve this goal developing and using a modern ICT infrastructure is essential, and can exploit next generation High Performance Computing (HPC) systems beyond the Petaflop scale in a collaborative and efficient way. The genetic linkage analysis of Single Nucleotide Polymorphism (SNP) markers has recently become a very popular approach for genetic epidemiology and population studies, aiming to discover the genetic correlation in complex diseases. The high computational cost and memory requirements of the major algorithms proposed in the literature make analyses of medium/large data sets very hard on a single CPU. A Grid based facility has hence been set up upon a high-performance infrastructure, the EGEE Grid, in order to create a tool for achieving whole-genome linkage analysis

    A HPC and Grid enabling framework for genetic linkage analysis of SNPs

    Get PDF
    Understanding the structure, function and development of the human genome is a key factor to improve the quality of life. In order to achieve this goal developing and using a modern ICT infrastructure is essential, and can exploit next generation High Performance Computing (HPC) systems beyond the Petaflop scale in a collaborative and efficient way. The genetic linkage analysis of Single Nucleotide Polymorphism (SNP) markers has recently become a very popular approach for genetic epidemiology and population studies, aiming to discover the genetic correlation in complex diseases. The high computational cost and memory requirements of the major algorithms proposed in the literature make analyses of medium/large data sets very hard on a single CPU. A Grid based facility has hence been set up upon a high-performance infrastructure, the EGEE Grid, in order to create a tool for achieving whole-genome linkage analysis

    DISTRIBUTED-DELAY MODELS OF THE GLUCOSE-INSULIN HOMEOSTASIS AND ASYMPTOTIC STATE OBSERVATION

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    Abstract In this paper the problem of the real-time reconstruction of plasma insulin concentration by using only blood glucose measurements is investigated. This is an interesting problem because the knowledge of the time course of the glucose and insulin concentrations in an individual provides precious informations concerning its health state, and may assume the role of a clinical instrument. For the purpose of the reconstruction of the insulinemia a dynamical model of the glucose-insuline homeostasis is required. The present work considers distributed delay models. Such models have been preferred in recent papers with respect to the standard Minimal Models, available in literature from 70's, because they allow to couple the glucose and insulin dynamics in a unique extended system, whose solutions have been proven to be positive, bounded, and globally asymptotically stable around the basal values of the equilibrium point. Data are acquired according to the Intra Venous Glucose Tolerance Test (IVGTT). Simulation results are reported in order to validate the developed theory

    Simulation of macromolecule self-assembly in solution: a multiscale approach

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    One of the most common processes to produce polymer nanoparticles is to induce self-assembly by using the solvent-displacement method, in which the polymer is dissolved in a "good" solvent and the solution is then mixed with an "anti-solvent". The polymer ability to self-assemble in solution is therefore determined by its structural and transport properties in solutions of the pure solvents and at the intermediate compositions. In this work, we focus on poly-Δ-caprolactone (PCL) which is a biocompatible polymer that finds widespread application in the pharmaceutical and biomedical fields, performing simulation at three different scales using three different computational tools: full atomistic molecular dynamics (MD), population balance modeling (PBM) and computational fluid dynamics (CFD). Simulations consider PCL chains of different molecular weight in solution of pure acetone (good solvent), of pure water (anti-solvent) and their mixtures, and mixing at different rates and initial concentrations in a confined impinging jets mixer (CIJM). Our MD simulations reveal that the nano-structuring of one of the solvents in the mixture leads to an unexpected identical polymer structure irrespectively of the concentration of the two solvents. In particular, although in pure solvents the behavior of the polymer is, as expected, very different, at intermediate compositions, the PCL chain shows properties very similar to those found in pure acetone as a result of the clustering of the acetone molecules in the vicinity of the polymer chain. We derive an analytical expression to predict the polymer structural properties in solution at different solvent compositions and use it to formulate an aggregation kernel to describe the self-assembly in the CIJM via PBM and CFD. Simulations are eventually validated against experiments

    Leptogenesis beyond the limit of hierarchical heavy neutrino masses

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    We calculate the baryon asymmetry of the Universe in thermal leptogenesis beyond the usual lightest right-handed (RH) neutrino dominated scenario (N_1DS) and in particular beyond the hierarchical limit (HL), M_1 << M_2 << M_3, for the RH neutrino mass spectrum. After providing some orientation among the large variety of models, we first revisit the central role of the N_1DS, with new insights on the dynamics of the asymmetry generation and then discuss the main routes departing from it, focusing on models beyond the HL. We study in detail two examples of `strong-strong' wash-out scenarios: one with `maximal phase' and the limit of very large M_3, studying the effects arising when delta_2=(M_2-M_1)/M_1 is small. We extend analytical methods already applied to the N_1DS showing, for example, that, in the degenerate limit (DL), the efficiency factors of the RH neutrinos become equal with the single decay parameter replaced by the sum. Both cases disprove the misconception that close RH neutrino masses necessarily lead to a final asymmetry enhancement and to a relaxation of the lower bounds on M_1 and on the initial temperature of the radiation-dominated expansion. We also explain why leptogenesis tends to favor normal hierarchy compared to inverted hierarchy for the left-handed neutrino masses.Comment: 30 pages, 8 figures; corrected typo in Eq. (67); shortened Introduction, Section 3 and Conclusions; one figure removed; added 2 references; to appear in JCA
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