160 research outputs found

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    Life cycle assessment and feasibility analysis of a combined chemical looping combustion and power-to-methane system for CO2 capture and utilization

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    The ability to store effectively excess of electrical energy from peaks of production is key to the development of renewable energies. Power-To-Gas, and specifically Power-To-Methane represents one of the most promising option. This works presents an innovative process layout that integrates Chemical Looping Combustion of solid fuels and a Power-to-Methane system. The core of the proposed layout is a multiple interconnected fluidized bed system (MFB) equipped with a two-stage fuel reactor (t-FR). Performances of the system were evaluated by considering a coal as fuel and CuO supported on zirconia as oxygen carrier. A kinetic scheme comprising both heterogeneous and homogeneous reactions occurring in the MFB was considered. The methanation unit was modelled developing a thermodynamic calculation method based on minimization of the free Gibbs energy. The performance of the system was evaluated by considering that the CO/CO2 stream coming from the t-FR reacts over Ni supported on alumina catalyst with a pure H2 stream generated by an array of electrolysis cells. The number of cells to be stacked in the array was evaluated by considering that a constant H2 production able to convert the whole CO/CO2 stream produced by the CLC process should be attained. The environmental performance of the proposed process was quantified using the Life Cycle Assessment (LCA) methodology. The analysis shows i) that the majority originate from the production and disposal of the oxygen carrier used in the t-FR, and ii) that reusing part of the oxygen produced by the electrolysis cells improves significantly the environmental performance of the proposed process

    Life cycle assessment and feasibility analysis of a combined chemical looping combustion and power-to-methane system for CO2 capture and utilization

    Get PDF
    The ability to store effectively excess of electrical energy from peaks of production is key to the development of renewable energies. Power-To-Gas, and specifically Power-To-Methane represents one of the most promising option. This works presents an innovative process layout that integrates Chemical Looping Combustion of solid fuels and a Power-to-Methane system. The core of the proposed layout is a multiple interconnected fluidized bed system (MFB) equipped with a two-stage fuel reactor (t-FR). Performances of the system were evaluated by considering a coal as fuel and CuO supported on zirconia as oxygen carrier. A kinetic scheme comprising both heterogeneous and homogeneous reactions occurring in the MFB was considered. The methanation unit was modelled developing a thermodynamic calculation method based on minimization of the free Gibbs energy. The performance of the system was evaluated by considering that the CO/CO2 stream coming from the t-FR reacts over Ni supported on alumina catalyst with a pure H2 stream generated by an array of electrolysis cells. The number of cells to be stacked in the array was evaluated by considering that a constant H2 production able to convert the whole CO/CO2 stream produced by the CLC process should be attained. The environmental performance of the proposed process was quantified using the Life Cycle Assessment (LCA) methodology. The analysis shows i) that the majority originate from the production and disposal of the oxygen carrier used in the t-FR, and ii) that reusing part of the oxygen produced by the electrolysis cells improves significantly the environmental performance of the proposed process

    Decellularized skeletal muscles display neurotrophic effects in three‐dimensional organotypic cultures

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    Skeletal muscle decellularization allows the generation of natural scaffolds that retain the extracellular matrix (ECM) mechanical integrity, biological activity, and three‐dimensional (3D) architecture of the native tissue. Recent reports showed that in vivo implantation of decellularized muscles supports muscle regeneration in volumetric muscle loss models, including nervous system and neuromuscular junctional homing. Since the nervous system plays pivotal roles during skeletal muscle regeneration and in tissue homeostasis, support of reinnervation is a crucial aspect to be considered. However, the effect of decellularized muscles on reinnervation and on neuronal axon growth has been poorly investigated. Here, we characterized residual protein composition of decellularized muscles by mass spectrometry and we show that scaffolds preserve structural proteins of the ECM of both skeletal muscle and peripheral nervous system. To investigate whether decellularized scaffolds could per se attract neural axons, organotypic sections of spinal cord were cultured three dimensionally in vitro, in presence or in absence of decellularized muscles. We found that neural axons extended from the spinal cord are attracted by the decellularized muscles and penetrate inside the scaffolds upon 3D coculture. These results demonstrate that decellularized scaffolds possess intrinsic neurotrophic properties, supporting their potential use for the treatment of clinical cases where extensive functional regeneration of the muscle is required

    Decellularized skeletal muscles support the generation of in vitro neuromuscular tissue models

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    Decellularized skeletal muscle (dSkM) constructs have received much attention in recent years due to the versatility of their applications in vitro. In search of adequate in vitro models of the skeletal muscle tissue, the dSkM offers great advantages in terms of the preservation of native-tissue complexity, including three-dimensional organization, the presence of residual signaling molecules within the construct, and their myogenic and neurotrophic abilities. Here, we attempted to develop a 3D model of neuromuscular tissue. To do so, we repopulated rat dSkM with human primary myogenic cells along with murine fibroblasts and we coupled them with organotypic rat spinal cord samples. Such culture conditions not only maintained multiple cell type viability in a long-term experimental setup, but also resulted in functionally active construct capable of contraction. In addition, we have developed a customized culture system which enabled easy access, imaging, and analysis of in vitro engineered co-cultures. This work demonstrates the ability of dSkM to support the development of a contractile 3D in vitro model of neuromuscular tissue fit for long-term experimental evaluations

    Y Engineering a 3D in vitro model of human skeletal muscle at the single fiber scale

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    The reproduction of reliable in vitro models of human skeletal muscle is made harder by the intrinsic 3D structural complexity of this tissue. Here we coupled engineered hydrogel with 3D structural cues and specific mechanical properties to derive human 3D muscle constructs (“myobundles”) at the scale of single fibers, by using primary myoblasts or myoblasts derived from embryonic stem cells. To this aim, cell culture was performed in confined, laminin-coated micrometric channels obtained inside a 3D hydrogel characterized by the optimal stiffness for skeletal muscle myogenesis. Primary myoblasts cultured in our 3D culture system were able to undergo myotube differentiation and maturation, as demonstrated by the proper expression and localization of key components of the sarcomere and sarcolemma. Such approach allowed the generation of human myobundles of ~10 mm in length and ~120 μm in diameter, showing spontaneous contraction 7 days after cell seeding. Transcriptome analyses showed higher similarity between 3D myobundles and skeletal signature, compared to that found between 2D myotubes and skeletal muscle, mainly resulting from expression in 3D myobundles of categories of genes involved in skeletal muscle maturation, including extracellular matrix organization. Moreover, imaging analyses confirmed that structured 3D culture system was conducive to differentiation/maturation also when using myoblasts derived from embryonic stem cells. In conclusion, our structured 3D model is a promising tool for modelling human skeletal muscle in healthy and diseases conditions

    Co-firing of biomass and other wastes in fluidised bed systems

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    A project on co-firing in large-scale power plants burning coal is currently funded by the European Commission. It is called COPOWER. The project involves 10 organisations from 6 countries. The project involves combustion studies over the full spectrum of equipment size, ranging from small laboratory-scale reactors and pilot plants, to investigate fundamentals and operating parameters, to proving trials on a commercial power plant in Duisburg. The power plant uses a circulating fluidized bed boiler. The results to be obtained are to be compared as function of scale-up. There are two different coals, 3 types of biomass and 2 kinds of waste materials are to be used for blending with coal for co-firing tests. The baseline values are obtained during a campaign of one month at the power station and the results are used for comparison with those to be obtained in other units of various sizes. Future tests will be implemented with the objective to achieve improvement on baseline values. The fuels to be used are already characterized. There are ongoing studies to determine reactivities of fuels and chars produced from the fuels. Reactivities are determined not only for individual fuels but also for blends to be used. Presently pilot-scale combustion tests are also undertaken to study the effect of blending coal with different types of biomass and waste materials. The potential for synergy to improve combustion is investigated. Early results will be reported in the Conference. Simultaneously, studies to verify the availability of biomass and waste materials in Portugal, Turkey and Italy have been undertaken. Techno-economic barriers for the future use of biomass and other waste materials are identified. The potential of using these materials in coal fired power stations has been assessed. The conclusions will also be reported

    Intravital three-dimensional bioprinting

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    Fabrication of three-dimensional (3D) structures and functional tissues directly in live animals would enable minimally invasive surgical techniques for organ repair or reconstruction. Here, we show that 3D cell-laden photosensitive polymer hydrogels can be bioprinted across and within tissues of live mice, using bio-orthogonal two-photon cycloaddition and crosslinking of the polymers at wavelengths longer than 850 nm. Such intravital 3D bioprinting—which does not create by-products and takes advantage of commonly available multiphoton microscopes for the accurate positioning and orientation of the bioprinted structures into specific anatomical sites—enables the fabrication of complex structures inside tissues of live mice, including the dermis, skeletal muscle and brain. We also show that intravital 3D bioprinting of donor-muscle-derived stem cells under the epimysium of hindlimb muscle in mice leads to the de novo formation of myofibres in the mice. Intravital 3D bioprinting could serve as an in vivo alternative to conventional bioprinting

    Intravital three-dimensional bioprinting

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    Fabrication of three-dimensional (3D) structures and functional tissues directly in live animals would enable minimally invasive surgical techniques for organ repair or reconstruction. Here, we show that 3D cell-laden photosensitive polymer hydrogels can be bioprinted across and within tissues of live mice, using bio-orthogonal two-photon cycloaddition and crosslinking of the polymers at wavelengths longer than 850 nm. Such intravital 3D bioprinting\u2014which does not create by-products and takes advantage of commonly available multiphoton microscopes for the accurate positioning and orientation of the bioprinted structures into specific anatomical sites\u2014enables the fabrication of complex structures inside tissues of live mice, including the dermis, skeletal muscle and brain. We also show that intravital 3D bioprinting of donor-muscle-derived stem cells under the epimysium of hindlimb muscle in mice leads to the de novo formation of myofibres in the mice. Intravital 3D bioprinting could serve as an in vivo alternative to conventional bioprinting

    Forests and floods in Latin America: science, management, policy and the EPIC FORCE project

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    The EPIC FORCE project aimed to develop science-based policy recommendations for integrated forest and water resources management, relevant to extreme events for Costa Rica, Ecuador, Chile and Argentina. Data analysis and model application support the hypothesis that, as the size of the flood peak increases, the effect of forest cover becomes less important. Guidelines for integrated water and forest resources management are developed which recognize this effect but emphasize the role that forests play in reducing the flood levels of more moderate events. The research findings are transferred to policy-making for the four focus countries via a set of policy briefs, taking into account the institutional frameworks, achievable policy objectives and key stakeholders.Facultad de Ingenierí
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