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Unveiling intrinsic material and extrinsic pinning dimensionality in superconductors: Why Fe(Se,Te) is able to mimic YBCO
Get PDFDiscovery of iron-based superconductors paved the way to a competitor of high-temperature superconductors, easier to produce, better performing in high fields, and promising to be less expensive. Critical parameters are investigated by resistivity measurements as a function of temperature, field, and angle R(T,H,θ). This work presents a deep analysis of H-θ phase diagram of PLD-processed Fe(Se,Te) superconducting films, thus revealing material and pinning anisotropy at once. By selecting different thresholds along the R(T,H,θ) curves, all possible regimes emerge. Surprisingly, anisotropy arises moving from the upper critical field toward the irreversibility line: gradually a non-monotonous transition from 3D to 2D, and backward to 3D occurs. Although Fe(Se,Te) appears as a 3D superconductor, its anisotropic pinning landscape shows up similarities with an intrinsic layered superconductor and Fe(Se,Te) definitively mimics YBCO. We propose a general method to disentangle, in any other superconductor, material dimensionality and pinning anisotropy that are key constraints for applications
A reduction in global impacts through a waste-wastewater-energy nexus: A life cycle assessment
No full textThis work presents the results of a comparison of three different management scenarios (one current and two future) of waste, wastewater, and their related energy systems in Southern European regions. A Life Cycle Assessment (LCA) has been applied to all the different steps of the complex scenarios in order to provide a more holistic, robust, and scientific approach that is able to highlight the beneficial effects of the integration of different plants (Waste to Energy - WtE, Anaerobic digestion - AD, wastewater treatment plant - WWTP) included in a symbiotic nexus. The LCA results have shown that an important reduction in the impact of Municipal Solid Waste (MSW) management is obtained from the recovery of separately collected materials, but there is still a large gap that could be filled by the introduction of energy recovery (by means of AD and WtE) and through its symbiotic use to support the anaerobic digestion, wastewater reuse, and sludge recovery processes. The proposed approach, which is based on a waste-wastewater-energy nexus and industrial symbiosis, could be adopted to support these regions to significantly increase circularity and fill the gap, thus favoring a significant rapprochement in the path toward the New Green Deal promoted by the European Union
A New Efficient Mirror Cooling for the Transmission Line of Fusion Reactor ECH Systems Based on Triply Periodic Minimal Surfaces
Get PDFAn innovative cooling strategy for the mirrors of the transmission line of the electron cyclotron heating (ECH) of a fusion research reactor, the divertor tokamak test (DTT) facility, is presented and investigated here based on triply periodic minimal surfaces (TPMSs). After the check on the manufacturability of gyroid and Split-P lattices of unit cell size ranging from 3 to 8 mm, extensive numerical investigations by conjugate heat transfer analyses have been performed. The heat removal capability has been assessed together with the pressure drop for all heat sinks. The temperature field in the mirror has been evaluated and used for the assessment of the deformation of the mirror reflective surface. The results show that all tested TPMSs are highly efficient in the heat removal, with low hotspot temperatures, minimal pressure drop, and low deformation of the reflective surface
Preliminary Batch Tests for Succinic Acid Production and Co-Products through Fermentation by Actinobacillus Succinogenes
No full textSuccinic acid is one of the most used building blocks in different production chains. Conventionally, this carboxylic acid is produced through petrochemical routes, but can be also produced via biological routes. Many microorganisms, such as Actinobacillus succinogenes, synthesized succinic acid as an intermediate of many biochemical pathways, as the Krebs cycle. Nowadays, the industrial production of bio-succinic acid has been limited due to different critical issues, like the low productivity and yield and downstreaming processes. To improve the bio-based production, the operative conditions of the fermentation process needed to be optimized especially when agro-industrial residues were used as sugars feedstock. To this aim, in this study fermentation batch tests were performed by using different concentrations of A. succinogenes at a given glucose concentration. The results suggested that glucose consumption and succinic acid production were not directly influenced by the initial bacterial concentration respect to glucose concentration. But the best results were obtained at the ratio of bacteria:glucose equal to 1:1 and further tests will be necessary to implement succinic acid yield and productivity
Monitoring of Cleaning Treatments for Paper Heritage with Raman Spectroscopy Mapping
Get PDFIn the field of book heritage, it is important to develop cleaning/disinfecting treatments that can slow down the degradation of paper to prevent evident and irreversible damage. The objectives of the cleaning treatments are to remove external contaminants and oxidation and decomposition products of the paper, but these processes must not modify the unique characteristics of the book heritage resulting in irreversible changes in the structure of the paper. Recently, several innovative cleaning treatments were developed with the aim of being minimally invasive; however, to assess the effect of these treatments on paper, it is necessary to use a diagnostic non-destructive, rapid, and affordable process. In previous work, we used surface scanning Raman spectroscopy to develop a diagnostic protocol able to follow the aging processes of the paper, discriminating between hydrolysis and oxidation. In this paper, we applied this protocol to study the action of different types of treatments (hydrogel and EUV irradiation), evaluating both their effectiveness and impact on paper parameters. The results reported here demonstrate that the developed in operando diagnostic procedure can follow the changes in the paper structure comparing them to the variability due to the intrinsic inhomogeneity of paper, without sample contact in a rapid and effective way
A methodology to characterize energy consumption in small and medium-sized enterprises at national level in European countries
No full textThe 25 million of European small and medium-sized enterprises (SMEs) represent 99% of businesses and account for the two thirds of total employment and a half of Gross Domestic Product. Thus, SMEs are considered as the backbone of European’ economy. The crucial importance of energy efficiency and its potential in SMEs is worldwide recognized. However, the energy use and consumption information of SMEs are very limited, and the disaggregated data between SMEs and large enterprises are often not available at national or European level. The aim of this work is to present a methodology for the energy consumption characterization of European SMEs at national level. The proposed methodology, based on the combination of official national energy statistics and energy consumption data according to the European Energy Efficiency Directive Article 8, has been developed and applied to Italy and Austria. Preliminary results show significant differences in the relative weight of SMEs’ energy consumption between the two countries mainly due to their specific productive structures. The application of this methodology to the available data on further five European countries provides useful insights on the impact of different national approaches to comply with Art.8. This methodology shows that harmonizing the different strategies to monitor energy audits obligation would significantly help to characterize the energy consumption of SMEs in Europe. Additionally, the knowledge of the distribution of energy consumption between large enterprises and SMEs would help in assessing the impact of mandatory and voluntary energy audits on potential savings in industrial and tertiary sectors. Graphical abstract: (Figure presented.
Symmetries of the Large Scale Structures of the Universe as a Phenomenology of a Fractal Turbulence: The Role of the Plasma Component
Get PDFWe present a new perspective on the symmetries that govern the formation of large-scale structures across the Universe, particularly focusing on the transition from the seeds of galaxy clusters to the seeds of galaxies themselves. We address two main features of cosmological fluid dynamics pertaining to both the linear and non-linear regimes. The linear dynamics of cosmological perturbations within the Hubble horizon is characterized by the Jeans length, which separates stable configurations from unstable fluctuations due to the gravitational effect on sufficiently large (and therefore, massive enough) overdensities. On the other hand, the non-linear dynamics of the cosmological fluid is associated with a turbulent behavior once the Reynolds numbers reach a sufficiently high level. This turbulent regime leads to energy dissipation across smaller and smaller scales, resulting in a fractal distribution of eddies throughout physical space. The proposed scenario suggests that the spatial scale of eddy formation is associated with the Jeans length of various levels of fragmentation from an original large-scale structure. By focusing on the fragmentation of galaxy cluster seeds versus galaxy seeds, we arrived at a phenomenological law that links the ratio of the two structure densities to the number of galaxies in each cluster and to the Hausdorff number of the Universe matter distribution. Finally, we introduced a primordial magnetic field and studied its influence on the Jeans length dynamics. The resulting anisotropic behavior of the density contrast led us to infer that the main features of the turbulence could be reduced to a 2D Euler equation. Numerical simulations showed that the two lowest wavenumbers contained the major energy contribution of the spectrum
Effects of soil moisture variations on the neutron spectra measured above ground: feasibility of a soil moisture monitor system based on neutron moderating cylinders
Get PDFMapping the soil moisture is a key activity in water management and sustainable agriculture, especially in regions characterised by fragile agri-food systems and water scarcity. Cosmic Ray Neutron Sensors (CRNS) is a contactless nuclear technology used for estimating soil moisture (SM) content on a 20–30 m scale at the landscape level. Very interestingly, this corresponds to the so-called intermediate scale gap between the local probes, operating on the meter scale, and the satellite-based technologies, working on the kilometre scale and above. In state-of-art CRNS, the cosmic neutrons degraded by the soil are simply counted by a slightly moderated thermal neutron counter. After a calibration procedure, the SM is inferred by combining this count rate with environmental parameters: the atmospheric pressure, temperature and the air humidity. As the SM affects not only the environmental neutron fluence rate but also its energy distribution, this study was organised in such a way to understand if a CRNS with spectrometric capabilities could provide improved information on the SM distribution. To this aim, an environmental neutron spectrometer was designed by extending the Bonner Spheres to a more sensitive system made of moderating cylinders embedding long BF3 proportional counters, the Moderating Cylinders Spectrometer (MCS). Relying on literature environmental neutron spectra, corresponding to different SM values in a standardised soil, the count rates in the MCS were calculated for different values of SM. To simulate various counting scenarios, these count rates were associated to different levels of “realistic” uncertainties and unfolded by means of the FRUIT code. The resulting neutron spectra are compared to the literature ones, allowing at estimating the resolving power of the spectrometer in terms of SM
RAMI analysis of ITER diagnostic radial neutron camera
Get PDFRAMI (Reliability, Availability, Maintainability and Inspectability) assessments are mandatory part of the design process for all ITER systems to anticipate possible risks in terms of reliability and availability and support reliability growth program. A RAMI assessment performed on the ITER Radial Neutron Camera (RNC) diagnostic system is presented. The assessment is aimed at evaluating the RNC design capability to provide the neutron emissivity radial profile measurement with required reliability and availability. The RNC is composed by two collimating structures equipped with neutron flux detectors, the In-Port RNC sub-system and the Ex-Port RNC sub-system respectively. Such systems radially view different plasma locations thus enabling the emissivity profile reconstruction. Both In-Port and Ex-Port detection systems (sensors, collimators, shielding) and full acquisition system chain (front-end and back-end electronics) are considered in the analysis. The RAMI performance was assessed by means of reliability block diagrams (RBDs) with respect to required mean inherent availability for 2 years of operations fixed at 99.5% for the Ex-Port system and at 88.3 % for the In-Port system. A set of failure events for each RNC component was defined by means of a failure mode and effect analysis. The resulting unavailability conditions of the systems were then identified. Hence identified groups of events were used to feed the RBDs model definition according to reliability-wise integration of the considered components. The integrated RAMI performance of RNC systems was finally estimated. Considering the current level of design development, In-Port RNC system appears able to meet stated requirement thanks to design redundancy. Ex-Port RNC, which includes Back End Electronics for data acquisition, is still below the RAMI target and requires further design improvement
Electrospun PCL Filtration Membranes Enhanced with an Electrosprayed Lignin Coating to Control Wettability and Anti-Bacterial Properties
No full textThis study reports on the two-step manufacturing process of a filtration media obtained by first electrospinning a layer of polycaprolactone (PCL) non-woven fibers onto a paper filter backing and subsequently coating it by electrospraying with a second layer made of pure acidolysis lignin. The manufacturing of pure lignin coatings by solution electrospraying represents a novel development that requires fine control of the underlying electrodynamic processing. The effect of increasing deposition time on the lignin coating was investigated for electrospray time from 2.5 min to 120 min. Microstructural and physical characterization included SEM, surface roughness analysis, porosity tests, permeability tests by a Gurley densometer, ATR-FTIR analysis, and contact angle measurements vs. both water and oil. The results indicate that, from a functional viewpoint, such a natural coating endowed the membrane with an amphiphilic behavior that enabled modulating the nature of the bare PCL non-woven substrate. Accordingly, the intrinsic hydrophobic behavior of bare PCL electrospun fibers could be reduced, with a marked decrease already for a thin coating of less than 50 nm. Instead, the wettability of PCL vs. apolar liquids was altered in a less predictable manner, i.e., producing an initial increase of the oil contact angles (OCA) for thin lignin coating, followed by a steady decrease in OCA for higher densities of deposited lignin. To highlight the effect of the lignin type on the results, two grades of oak (AL-OA) of the Quercus cerris L. species and eucalyptus (AL-EU) of the Eucalyptus camaldulensis Dehnh species were compared throughout the investigation. All grades of lignin yielded coatings with measurable antibacterial properties, which were investigated against Staphylococcus aureus and Escherichia coli, yielding superior results for AL-EU. Remarkably, the lignin coatings did not change overall porosity but smoothed the surface roughness and allowed modulating air permeability, which is relevant for filtration applications. The findings are relevant for applications of this abundant biopolymer not only for filtration but also in biotechnology, health, packaging, and circular economy applications in general, where the reuse of such natural byproducts also brings a fundamental demanufacturing advantage