21 research outputs found

    Nowcasting COVID-19 incidence indicators during the Italian first outbreak

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    A novel parametric regression model is proposed to fit incidence data typically collected during epidemics. The proposal is motivated by real-time monitoring and short-term forecasting of the main epidemiological indicators within the first outbreak of COVID-19 in Italy. Accurate short-term predictions, including the potential effect of exogenous or external variables are provided. This ensures to accurately predict important characteristics of the epidemic (e.g., peak time and height), allowing for a better allocation of health resources over time. Parameter estimation is carried out in a maximum likelihood framework. All computational details required to reproduce the approach and replicate the results are provided.publishedVersio

    Covid‐19 in Italy: Modelling, communications, and collaborations

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    When Covid-19 arrived in Italy in early 2020, a group of statisticians came together to provide tools to make sense of the unfolding epidemic and to counter misleading media narratives. Here, members of StatGroup-19 reflect on their work to dat

    Accelerating the Research Approach to Ziegler-Natta Catalysts

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    Despite 60 years of history and a stunning success, Ti-based Ziegler-Natta catalysts for the production of isotactic polypropylene remain black-box systems, and progress still relies on trial and error. This represents a limitation in a moment when the most widely used industrial systems, containing phthalates as selective modifiers, need to be replaced because of a recent REACH ban. In-view of the great complexity of the chemical and physical variables and the heavy nonlinearity of their effects, a high-/medium-throughput approach to this catalysis is highly desirable; herein we introduce an integrated medium-throughput workflow spanning from propene polymerization to polypropylene micro structural characterization and combining a 10(2)-fold throughput intensification with quality standards equal or higher than conventional methods

    Alkali-Activated Red Mud and Construction and Demolition Waste-Based Components: Characterization and Environmental Assessment

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    The aluminum Bayer production process is the most diffused process in the world, but it creates a high amount of basic waste material known as red mud (RM). The use of RM as a precursor of alkali-activated materials is one of the best opportunities for both the ecosystem and the economy. In the present work, mortar samples were obtained by alkali activation of RM with various percentages of blast-furnace slag (BFS) and inert construction and demolition sands. This process creates samples that have a low environmental impact and that can be used as an alternative in the construction industry to cement materials or ceramic ones. The development of these new materials could also represent a way to reduce the CO2 emissions linked to cement and ceramic brick production. In the present study, cubic 40 mm samples reported very interesting values in compressive strength, with a maximum of about 70 MPa for low environmental impact mortars. With such a material, it is possible to create solid bricks for structural use and concrete tiles for road paving or use it for other purposes. Mortar specimens were prepared and characterized, and an LCA analysis with a “cradle-to-gate” approach was carried out for a comparison of the environmental impact of the studied mortars with other materials currently marketed

    A High Throughput Experimentation Protocol for Quantitative Measurements of Regioselectivity in Ziegler-Natta Polypropylene Catalysis

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    This paper introduces a High Throughput Experimentation method for fast and accurate evaluations of regioselectivity in Ziegler-Natta (ZN) propene polymerizations. With a simple protocol, the (very low) fraction of regioirregular 2,1 monomeric units in the polymers can be quantitated by means of 13C NMR chain-end analyses on single H2-terminated polypropylene samples. The method, that was successfully validated for three representative ZN catalyst systems, also provides information on catalyst ‘dormancy’ and propensity to undergo chain hydrogenolysis. This opens the door to the rapid and accurate implementation of Quantitative Structure-Activity Relationship (QSAR) databases of regioselectivity and ‘hydrogen response’ in this important industrial catalysis

    Accelerating the Research Approach to Ziegler–Natta Catalysts

    No full text
    Despite 60 years of history and a stunning success, Ti-based Ziegler–Natta catalysts for the production of isotactic polypropylene remain black-box systems, and progress still relies on trial and error. This represents a limitation in a moment when the most widely used industrial systems, containing phthalates as selective modifiers, need to be replaced because of a recent REACH ban. In view of the great complexity of the chemical and physical variables and the heavy nonlinearity of their effects, a high-/medium-throughput approach to this catalysis is highly desirable; herein we introduce an integrated medium-throughput workflow spanning from propene polymerization to polypropylene microstructural characterization and combining a 10<sup>2</sup>-fold throughput intensification with quality standards equal or higher than conventional methods
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