580 research outputs found
Exploring the EU plastic value chain: A material flow analysis
The accounting of plastic flows across the economy is pivotal to assess circularity of production and consumption and to define transitions scenarios at systems level. This study established a top-down mass flow analysis model for the EU27 (2019) plastic value chain, focusing on 9 sectors and 10 polymers. Estimates indicate that 4.46Mt of plastic recyclates are produced and consumed in the EU27 territory. On average, the EU27 recycling rate was equal to 19%. Total plastic losses amounted to 4% of the total plastic production, mostly occurring during the use phase. Future 2025 scenarios were prepared considering expected trends in the plastic value chain and compared with industry targets. In the cases of combined scenarios, the total recyclates consumed by plastic converters in 2025 ranged between 9.11Mt and 11.13Mt. Considering the key commitments for actions at the EU level, an evidence-based transformation of the plastic value chain is essential
Chemical Sensor for Haemodialysis Application
Abstract The water used to supply a haemodialysis center requires particular mode of treatment in order to achieve the best technical, economic and therapeutic distribution. Dialysis patients come in contact weekly with a large amount of water through the dialysis apparatus. It is therefore essential that this solution has a high quality and purity in terms of proper electrolyte composition, low concentration or absence of organic and inorganic chemical pollutants, low concentration or absence of bacteria, yeasts, fungi and endotoxins. The chemical and microbiological quality of water intended for medical and biomedical treatments, such as haemodialysis, is generally defined on the basis of a plurality of international reference standards (ASTM International standards D1193 and D5196; International Pharmacopoeia and European Pharmacopoeia CAP / NCCLS 1988). In this work the authors have designed an electrochemical device used to characterize pure and ultrapure water for biomedical applications (Patent: TO2014A000765). The results obtained show a good ability of the device in the discrimination of different bacteria and of their concentration (CFU); Pseudomonas and E-coli have been here tested
The Origanum Collection of Gaetano Savi (1769-1844) in the Herbarium Horti Pisani (PI)
The Origanum Collection of Gaetano Savi (1769-1844) in the Herbarium Horti Pisani (PI). The collection of exsiccata of the genus Origanum, studied by Gaetano Savi and kept in the Herbarium Horti Pisani (PI) represents a valuable document of Savi's work as a taxonomist. It provides useful news for researchers of systematics and history of botany. The collection is enriched by some original drawings and includes the lectotypes of Origanum confertum Savi and O. fortuitum Savi
Lectotypification of two Origanum names (Lamiaceae) described by Gaetano Savi
Origanum confertum Savi and O. fortuitum Savi are typified on herbarium specimens kept in PI. These taxa are identifiable, as heterotypic synonyms, with O. majorana L. and O. xpaniculatum W.D.J.Koch, respectively
Renormalization group approach to vibrational energy transfer in protein
Renormalization group method is applied to the study of vibrational energy
transfer in protein molecule. An effective Lagrangian and associated equations
of motion to describe the resonant energy transfer are analyzed in terms of the
first-order perturbative renormalization group theory that has been developed
as a unified tool for global asymptotic analysis. After the elimination of
singular terms associated with the Fermi resonance, amplitude equations to
describe the slow dynamics of vibrational energy transfer are derived, which
recover the result obtained by a technique developed in nonlinear optics [S.J.
Lade, Y.S. Kivshar, Phys. Lett. A 372 (2008) 1077].Comment: 11 page
Influence of conformational fluctuations on enzymatic activity: modelling the functional motion of beta-secretase
Considerable insight into the functional activity of proteins and enzymes can
be obtained by studying the low-energy conformational distortions that the
biopolymer can sustain. We carry out the characterization of these large scale
structural changes for a protein of considerable pharmaceutical interest, the
human -secretase. Starting from the crystallographic structure of the
protein, we use the recently introduced beta-Gaussian model to identify, with
negligible computational expenditure, the most significant distortion occurring
in thermal equilibrium and the associated time scales. The application of this
strategy allows to gain considerable insight into the putative functional
movements and, furthermore, helps to identify a handful of key regions in the
protein which have an important mechanical influence on the enzymatic activity
despite being spatially distant from the active site. The results obtained
within the Gaussian model are validated through an extensive comparison against
an all-atom Molecular Dynamics simulation.Comment: To be published in a special issue of J. Phys.: Cond. Mat. (Bedlewo
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Using an Augmented Lagrangian Method and block fracturing in the DDA method
This paper presents two extensions to the Discontinuous Deformation Analysis (DDA) method orginally proposed by Shi for modeling the response of blocky rock masses to mechanical loading. The first extension consists of improving the block contact algorithm. An Augmented Lagrangian Method is used to replace the Penalty Method orginally proposed. It allows Lagrange multipliers to be introduced without increasing the number of equations that need to be solved and thus, block contract forces can be calculated more accurately. A block fracturing capability based on a three-parameter Mohr-Coulomb criterion represents the second extension. It allows for shear or tensile fracturing of intact blocks and the formation of smaller blocks
Ion exchange and DNA molecular dip sticks: studying the nanoscale surface wetting of muscovite mica
Mica is an abundant crystal mineral that has important and interesting bulk and surface properties for a variety of applications. These properties arise from its anisotropic structure, in which layers of aluminum silicate, 1 nm thick, are ionically bonded together, typically with K+ ions. The surface properties of mica can be varied through ion exchange with the exposed lattice sites. In this study, the effect of kinetics on ion exchange with nickel ions (Ni2+) and its influence on surface water accumulation as a function of time has been investigated. Mica was ion-exchanged for 30 s or 5 min for a range of Ni2+ concentrations (i.e., 1.0-20.0 mM), and its surface properties were measured for up to 96 h after incubation in a controlled environment. The nanoscale physicochemical properties of nickel-functionalized muscovite mica (Ni-mica) were investigated by reconstructing the conservative force profile between an atomic force microscopy (AFM) tip and the surface. This information provides a hint of the surface water accumulation and enables details of the spatial and temporal variations in surface properties due to the ion-mediated adsorption of water to be elucidated. Variations in the water-layer accumulation were confirmed using noncontact AFM imaging under ambient conditions and DNA molecules as "molecular dip sticks". It was found that the surface properties were largely independent of the incubating concentration but did depend on the incubation time during ion exchange and the aging time. For the longer incubation time of 5 min, the water-layer accumulation remained constant at around ∼1.5 nm deep, whereas for the short incubation time of 30 s, the accumulation was initially subnanometer but grew with aging time and converged to a similar final value after 96 h. The extracted force of adhesion (FAD) also showed the same trends, where reduced values of FAD indicated increased screening of the van der Waals interaction through thicker water layers
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