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Progress in the development of industrial scale tungsten fibre-reinforced composite materials
No full textCurrently, tungsten fibre-reinforced (Wf) composites are regarded as promising materials for plasma-facing components of future magnetic confinement fusion devices. In this context, tungsten fibre-reinforced tungsten (Wf/W) is being investigated as a pseudo-ductile composite material overcoming the intrinsic brittleness of bulk tungsten while tungsten fibre-reinforced copper (Wf/Cu) is being developed as a high-strength composite heat sink material. In this contribution, we discuss the current development status and the progress that has been achieved recently with respect to characterization and upscaling of the aforementioned materials. In cooperation with industry, upscaling of multifilamentary W yarn fabrication was demonstrated. Multilayered W fibre braids were made from such yarns and used for the manufacturing of 400 mm long medium-scale tungsten fibre-reinforced copper heat sink tubes. The maturity of short tungsten fibre-reinforced tungsten composites produced by powder metallurgy allowed the fabrication of flat tile mock-ups. Test procedure and first results of high heat flux tests are shown. Finally, we discuss the challenges and the benefits of these composites for the use in high heat flux components
Liquid-Metal Thermal-Hydraulic Numerical Analyses in Support of the Upcoming CIRCE-THETIS Experimental Campaign
No full textLiquid metal cooled reactors are among the design proposals accepted by the Generation IV International Forum for the fourth generation of nuclear power plants. During the last decade, many European Union (EU) projects started with the goal to pave the way for the development of this type of reactor. The present research work is performed in the framework of the EU Partitioning And Transmuter Research Initiative in a Collaborative Innovation Action (PATRICIA) project, supporting the development of the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA). Among the cornerstones of the project are experimental and numerical analyses involving the CIRColazione Eutettico (CIRCE) facility set at the ENEA Brasimone Research Centre. The upcoming experimental campaign will address the new CIRCE-THETIS configuration, including a new kind of heat exchanger named THETIS: a helical coil steam generator (SG) whose heat transfer capabilities and impact on pool thermal hydraulics are to be investigated. The main goal of the present work is to provide numerical support to experimentalists to help them set up the CIRCE-THETIS experimental facility, the operating conditions test matrix, and postulated transients, providing information about potential needed updates or dangerous conditions. This paper reports on pretest computational fluid dynamics and system thermal-hydraulic analyses performed at the University of Pisa in the frame of the PATRICIA project. The new SG was first addressed assessing its heat transfer capabilities. Sensitivity analyses were performed; among the outcomes, the excellent heat transfer capabilities of the SG were highlighted. The pool and the reactor vessel auxiliary cooling system component were later investigated reporting valuable information concerning both postulated steady-state and transient conditions. The performed analyses had a relevant impact on the design of the facility, suggesting updates based on numerical calculations. After the experimental campaign, posttest analyses will be performed to draw lessons from the observed phenomena. This will also provide room for improvement of the adopted numerical tools
Innovative Industrial Solutions for Improving the Technical/Economic Competitiveness of Concentrated Solar Power
No full textThe modernization, efficiency, and decarbonization of the energy supply systems are among the new challenges to be faced in the coming decades to achieve the targets and objectives dictated by European strategic policies. Despite the countless benefits related to renewable energy sources (RES) integration, this brings key challenges to the power system, such as the risk of imbalance between energy generation and demand, sudden changes in flows in transmission lines with a need for expensive and time-consuming upgrades, and the withdrawal of conventional generation systems with consequent demands for new solutions and innovation to support grid services. A potential solution to limit the huge intermittence and fluctuation in power generation from RES is Concentrated Solar Power (CSP) technology integrated with thermal energy storage. The aim of this paper is to discuss the potential benefits related to the use of CSP technology by presenting innovative industrial solutions developed in the Italian SOLARGRID Project, namely the hybridization of CSP–PV systems and the solar thermo-electric system developed by MAGALDI, the parabolic trough collector of Eni, and the new linear Fresnel reflector configuration of IDEA S.r.l. These plant and component solutions are developed for improving the technical performance of CSP technology and reducing the levelized cost of electricity, thereby fostering an effective and massive deployment and encouraging the creation of new business models
Preliminary Assessment on Actinobacillus Succinogenes Growth and Succinic Acid Production for Bioplastics
No full textSevere plastics pollution derived from the wide use and the past incorrect dispersion of petroleum-based plastics. The development of bioplastics/biopolymers with the same chemical/physical characteristics of conventional plastics can be a solution to the problems of their degradability. Polybutylene succinate was among the most investigated biopolymers for these characteristics that can be produced from bio-based succinic acid and butan-1,4-diol. Succinic acid can be produced through fermentation process using microorganisms as Actinobacillus succinogenes that were able to utilise glucose from several sources as lignocellulosic biomasses. Lignocellulosic biomass can be ideal candidates for glucose supply but the processes to release fermentable sugars can produce inhibitors (acids and furans) of the biological processes for succinic acid production. The aim of this paper was to evaluate the growth of A. succinogenes for the production of succinic acid under acetic acid and furfural at different concentration on inoculum with pre-adaptation and without adaptation. The results highlighted that pre-inoculum adaptation was essential for the growth of the strain and succinic acid production that decreased strongly under the synergistic effect of acetic acid and furfural in the broth (63% inhibition rate of growth) respect to inoculum with pre-inoculum adaptation (29% inhibition rate of growth)
Global Sensitivity Analysis for Segmented Inverse Uncertainty Quantification in the Safety Analysis of Nuclear Power Plants
Get PDFWithin the Best Estimate Plus Uncertainty framework for the safety analysis of Nuclear Power Plants, the quantification of the uncertainties affecting the Thermal-Hydraulics (T-H) codes used is crucial. For this, Inverse Uncertainty Quantification (IUQ) methodologies are being developed for determining the probability density functions of relevant T-H codes input parameters, based on experimental data from Separate Effect Tests (SETs) experimental facilities. In practice, IUQ is challenged by the large range of variability of the experimental data in terms of Initial and Boundary Conditions (ICs & BCs), because the experimental campaigns are designed to cover the widest possible domain of conditions with the smallest number of experiments, so that same or similar ICs and BCs are seldomly repeated. To address this issue, we propose to use global sensitivity analysis, to tailor the IUQ on specific sub-regions described by segmented ICs & BCs domains. The methodology proposed is exemplified on two SETs, namely Sozzi-Sutherland and Super Moby Dick, whose experimental databases have been made available in the ATRIUM (Application Tests for Realization of Inverse Uncertainty quantification and validation Methodologies in thermal hydraulics) project promoted by the OECD/NEA/CSNI. The results obtained are superior to those of traditional IUQ methodologies for models highly sensitive to ICs & BCs
Slow-rolling scalar dynamics as solution for the Hubble tension
No full textWe construct a theoretical framework to interpret the Hubble tension by means of a slow-rolling dynamics of a self-interacting scalar field. In particular, we split the Friedmann equation in order to construct a system for the three unknowns, corresponding to the Hubble parameter H, the scalar field φ and its self-interaction potential V, as functions of the redshift. In the resulting picture, the vacuum energy density is provided by a constant term in the potential V(φ), while the corresponding small kinetic term is responsible for reproducing the apparent variation of the Hubble constant H0 with the redshift. The emerging solution depends on two free parameters, one of which is fixed to account for the discrepancy between the values of H0 as measured by the Super Nova Ia sample (H0=73.6±1.1 km s−1 Mpc−1 (Brout et al., 2022)) and the Planck satellite data (H0=67.4±0.5 km s−1 Mpc−1 (Aghanim et al., 2020)), respectively. The other parameter is instead determined by a fitting procedure of the apparent Hubble constant variation across the data corresponding to a 40 bin analysis of the Super Nova Pantheon sample, in each of which H0 has been independently determined. The fundamental result of the present analysis is the emerging Hubble parameter as function of the redshift, which correctly takes the Super Nova Ia prediction at z=0 and naturally approaches the profile predicted by a flat ΛCDM model corresponding to the cosmological parameters detected by Planck. It is remarkable that this achievement is reached without reducing the Super Nova Ia data to a single point for determining H(z=0), but accounting for the distribution over their redshift interval of observation, via the binned analysis
Radiopharmaceuticals for Pancreatic Cancer: A Review of Current Approaches and Future Directions
Get PDFThe poor prognosis of pancreatic cancer requires novel treatment options. This review examines the evolution of radiopharmaceuticals in the treatment of pancreatic cancer. Established strategies such as peptide receptor radionuclide therapy (PRRT) offer targeted and effective treatment, compared to conventional treatments. However, there are currently no radiopharmaceuticals approved for the treatment of pancreatic cancer in Europe, which requires further research and novel approaches. New radiopharmaceuticals including radiolabeled antibodies, peptides, and nanotechnological approaches are promising in addressing the challenges of pancreatic cancer therapy. These new agents may offer more specific targeting and potentially improve efficacy compared to traditional therapies. Further research is needed to optimize efficacy, address limitations, and explore the overall potential of these new strategies in the treatment of this aggressive and harmful pathology
OECD/NEA/CSNI state-of-the-art report on scaling in system thermal-hydraulics applications to nuclear reactor safety and design (The S-SOAR)
Get PDFThe present paper deals with scaling in nuclear-system thermal-hydraulics (SYS TH), including the connection with Nuclear Reactor Safety Technology (NST). The paper is entirely derived from the S-SOAR document issued by CSNI of NEA, NEA/CSNI/R(2016)14, 2016 (Bestion et al., 2016). Scaling has constituted ‘an issue’ since the beginning of the exploitation of nuclear energy for civil purposes, with main reference to the generation of electricity. A Nuclear Power Plant (NPP) constitutes a technologically complex industrial system and it is characterized by the impossibility of, or the large difficulty in, characterizing the system's performance under the conditions of the design. So, models were designed, constructed, and operated under downscaled ranges of values for one or more of selected parameters (e.g. power, volume, height, pressure, etc). These features lay at the origin of the scaling issue, i.e. the difficulty in demonstrating that a model behaves like the prototype. Integrated definitions of the widely adopted terms, ‘scaling’, ‘scaling issue’, and ‘addressing the scaling issue’ are part of the present document. The related application domain includes the NST, and the licensing for water-cooled nuclear reactors under operation, under construction, or under an advanced design stage at the time of publication of the (Bestion et al., 2016). Scaling-related analyses are done in different areas of SYS TH and NST. These include the design of test facilities (both integral and separate-effect test facilities, IETF and SETF), the design of experiments (including Counterpart Test, CT), the demonstration of the capability of any computational tool, and the evaluation of uncertainty affecting the prediction of the same computational tools. A variety of approaches have been used to address the scaling issue, including non-dimensional analysis of mass, energy- and momentum-balance equations, derivation and application of scaling factors, including the hierarchy of relative importance, performing experiments at different scales, and running the SYS TH computer codes. This paper discusses the key areas and the key approach for scaling. It was found that the SYS TH computer codes, following their application to differently scaled experiments, demonstrate that the accuracy of their predictions may not depend upon the scale of the considered experiments. The TH codes also may constitute an additional valuable tool for addressing the issue of scaling
Impact of the sustainable agricultural practices for governing soil health from the perspective of a rising agri-based circular bioeconomy
Get PDFSoil is a precious and nonrenewable source for agroecosystems of which own health state over time is becoming a focus of global concern. A healthy soil is a harmonious and very complex social system with a good structure, an optimal functional state, and an efficient buffering capacity to maintain a dynamic balance among all produc- tivity factors. There is an urgent need to develop new approaches for the sustainable management of soil quality in depleted soils from a long-term perspective for increasing agricultural productivity and maintaining food security due to global population expansion. Since high crop yield mainly depends on the improvement of soil quality, further efforts must be addressed to develop advanced technologies/processes in reusing waste biomass accordingly with the circular bioeconomy principles. Although the knowledge of relationships between intrinsic factors of soil fertility and crop productivity is the baseline for the optimal soil management, this issue is nevertheless overlooked by stakeholders. Soil organic matter (SOM) associates carbon availability with the plant nutrients (mainly nitrogen, phosphorus, and potassium) leading to the strongest positive impacts of the envi- ronmental functions and food production. Unfortunately, there is a progressive trend to lose the SOM stock, so altering the biological functions of the soils. Despite, farmer overlooks the mechanisms for preserving SOM accumulation by adopting inappropriate practices to counteract soil decline consequently to climate change and deterioration of agroecosystems. A wide spread of microplastic and nanoplastic pollutants (MNPs) in the envi- ronment have added further concerns due to their potentially hazardous risks for soil health thanks to their ubiquitousness and persistence. Nonetheless, the interactions of MNPs with the soil components, microbial communities, plants, and fauna that could determine the strongest impacts on the nutrient availability and food security are still poorly explored. This review work launches some challenges to reader by providing practical solutions, viewpoints, future challenges, and new perspective for restoring soil health by contrasting soil decline from a long-term perspective in organic farming systems in a sustainable agri-based circular bioeconomy syste
A comprehensive overview of NDT: From theoretical principles to implementation
No full textHeritage buildings require a wide range of procedures and expertise from a multidisciplinary approach and this can lead to use several instruments for the diagnosis. This chapter gives an overview of the most relevant non-destructive testing techniques, showing examples of case studies that were developed in different countries. For this reason, the current book chapter explains the foundations of photogrammetry, laser scanning, heat-flux meter, infrared thermography, airtightness tests, and how to combine these ones with advanced modeling (i.e., heritage building information modeling and AI). This could help to enhance the energy assessment and the decision-making of refurbishment procedures