1,138 research outputs found
Phase diagram of soft-core bosons in two dimensions
The low temperature phase diagram of Bose soft disks in two dimensions is
studied by numerical simulations. It is shown that a supersolid cluster phase
exists, within a range of the model parameters, analogous to that recently
observed for a system of aligned dipoles interacting via a softened potential
at short distance. These findings indicate that a long-range tail of the
interaction is unneeded to obtain such a phase, and that the soft-core
repulsive interaction is the minimal model for supersolidity
Analysis of the existing barriers for the market development of power to hydrogen (P2H) in Italy
New technological solutions are required to control the impact of the increasing presence of renewable energy sources connected to the electric grid that are characterized by unpredictable production (i.e., wind and solar energy). Energy storage is becoming essential to stabilize the grid when a mismatch between production and demand occurs. Among the available solutions, Power to Hydrogen (P2H) is one of the most attractive options. However, despite the potential, many barriers currently hinder P2H market development. The literature reports general barriers and strategies to overcome them, but a specific analysis is fundamental to identifying how these barriers concretely arise in national and regional frameworks, since tailored solutions are needed to foster the development of P2H local market. The paper aims to identify and to analyze the existing barriers for P2H market uptake in Italy. The paper shows how several technical, regulatory and economic issues are still unsolved, resulting in a source of uncertainty for P2H investment. The paper also suggests possible approaches and solutions to address the Italian barriers and to support politics and decision-makers in the definition and implementation of the national hydrogen strategy
Techno-economic assessment of the innovative ejectors plant technology for sediment management in harbours
Purpose: The paper aims to show the monitoring results of an innovative technology, the ejectors plant, tested in the MARINAPLAN PLUS LIFE project framework for sustainable sediment management in harbours. Materials and methods: A monitoring plan has been designed to evaluate the technical, economic and environmental impact of the ejectors plant demonstrator for 15 months, located in Cervia (Italy). In particular, the demonstrator’s effectiveness and efficiency have been assessed to determine the yearly operation and maintenance costs. Results and discussion: The techno-economic analysis shows promising results in terms of efficacy and efficiency of the ejectors plant. The ejectors plant guaranteed navigability for the whole period of operation with a yearly cost reduction compared with traditional dredging. Conclusions: The innovative technology promoted by the MARINAPLAN PLUS LIFE project is a promising solution to manage sedimentation in harbours through a cost-effective and a low environmental impact technology. The monitoring actions validated the technology fully and demonstrated its efficacy and sustainability, highlighting the further improvements needed
An Innovative Harmonic Radar to Track Flying Insects: the Case of Vespa velutina
Over the last 30 years, harmonic radars have been effective only in tracking insects flying at low altitude and over flat terrain. We developed an innovative harmonic radar, implementing the most advanced radar techniques, which covers a large field of view in elevation (with an angular aperture of about 24°) and can track insects up to a range of 500 m. We show all the components of this new harmonic radar and its first application, the tracking of Vespa velutina (yellow-legged Asian hornet). This is an invasive species which, although indigenous to South-East Asia, is spreading quickly to other regions of the world. Because of its fast diffusion and the serious threat it poses to both honeybee colonies and to humans, control measures are mandatory. When equipped with a small passive transponder, this radar system can track the flight trajectory of insects and locate nests to be destroyed. This tool has potential not only for monitoring V. velutina but also for tracking other larger insects and small size vertebrates
Low temperature district heating: An expert opinion survey
Among the available solutions for building heating and cooling, district heating (DH) and district cooling (DC) systems are considered some of the best options since they can ensure a better control of pollutant emissions and greater efficiency than individual systems. Nevertheless, improvements are needed to increase their sustainability and reliability. The so-called \u201clow temperature district heating\u201d (LTDH) concept has been introduced in recent years in an attempt i) to reduce the distribution heat losses through a temperature decrease in the DH network, ii) to favor the integration with renewable energy sources, and iii) to create the conditions required for the development of future smart energy systems. However, many concerns have been raised about its implementation in both existing and new systems. For this reason, this paper aims to identify the stakeholders\u2019 ranking of the barriers against LTDH system development and implementation over the next few years. Aiming to this, a questionnaire was designed, including an analysis of current gaps and strengths, and then submitted to more than 50 Italian and international experts in the field of DH. An in-depth analysis of the received answers was performed, focusing in particular on the Italian experts\u2019 answers. Comments and suggestions on how to promote the transition to the new LTDH approach are reported
An harmonic radar prototype for insect tracking in harsh environments
Harmonic entomological radars have been used in the last decades to track small and lightweight passive tags carried by various insects, usually flying at low altitude and over flat terrain. Despite being exploited in many applications, not a lot of progress was achieved in terms of performances over the years. This paper reviews the research work done in this topic throughout the European LIFE project STOPVESPA, from 2015 to 2019. The main objective of LIFE STOPVESPA was to contain the invasive Asian hornet (Vespa velutina) and prevent it from further invading Italy. Among the foreseen activities, a new harmonic radar has been developed as an effective tool to locate the hornets nests to be destroyed. A preliminary prototype, based on a magnetron generator, was tested in 2015, showing a detection range of about 125 m. A first upgrade of this prototype was released in 2016, allowing to increase the detection range up to 150 m. A new approach, based on a solid state power amplifier and a digitally modulated signal, was then adopted for the second prototype developed in 2017 and extensively run in 2018; the detection range raised to 500 m. A last engineered prototype was eventually built for the 2019 summer campaign with additional improvements. This tool has been extensively validated over the last years with the Asian hornet but it has potential for tracking and monitoring many other flying insects
A New Geographic Information System (GIS) Tool for Hydrogen Value Chain Planning Optimization: Application to Italian Highways
Optimizing the hydrogen value chain is essential to ensure hydrogen market uptake in replacing traditional fossil fuel energy and to achieve energy system decarbonization in the next years. The design of new plants and infrastructures will be the first step. However, wrong decisions would result in temporal, economic losses and, in the worst case, failures. Because huge investments are expected, decision makers have to be assisted for its success. Because no tools are available for the optimum design and geographical location of power to gas (P2G) and power to hydrogen (P2H) plants, the geographic information system (GIS) and mathematical optimization approaches were combined into a new tool developed by CNR-ITAE and the University of Bologna in the SuperP2G project, aiming to support the interested stakeholders in the investigation and selection of the optimum size, location, and operations of P2H and P2G industrial plants while minimizing the levelized cost of hydrogen (LCOH). In the present study, the tool has been applied to hydrogen mobility, specifically to investigate the conversion of the existing refuelling stations on Italian highways to hydrogen refuelling stations (HRSs). Middle-term (2030) and long-term (2050) scenarios were investigated. In 2030, a potential demand of between 7000 and 10,000 tons/year was estimated in Italy, increasing to between 32,600 and 72,500 tons/year in 2050. The optimum P2H plant configuration to supply the HRS was calculated in different scenarios. Despite the optimization, even if the levelized cost of hydrogen (LCOH) reduces from 7.0-7.5 euro/kg in 2030 to 5.6-6.2 euro/kg in 2050, the results demonstrate that the replacement of the traditional fuels, i.e., gasoline, diesel, and liquefied petroleum gases (LPGs), will be disadvantaged without incentives or any other economic supporting schemes
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