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Nowadays, many islands worldwide are lack of electrical energy. Thus, it is convenient to exploit available renewable energy sources, among which sea waves near the islands. This paper focuses on the power conversion system coupled with an offshore wave energy device, such as an improved linear generator, to be used for sea wave energy harvesting. Particularly, the design of the linear generator has been proposed to improve the energy efficiency of the entire system. The proposed power conversion system is composed by two Boost Rectifier (BR) directly coupled to the linear generator, and one Voltage Source Inverter (VSI), which it is used as front-end between the DC-bus and the grid. The proposed converters are realized using the Silicon Carbide (SiC) devices in order to improve the efficiency. Furthermore, the control strategy to regulate the generator side and grid side currents has been implemented. The proposed system has been validated using the Hardware-In-the-Loop (HIL) test bench and 20 kW SiC power converters.

Abstract Thermal energy storage (TES) systems are growing to a relevant role in solar cooling applications. Hence, high energy density is a desirable property of the TES system. Phase change materials (PCM) helps to increase this characteristic. A high temperature pilot plant able to test different types of TES systems and materials was designed and built at the University of Lleida (Spain). This pilot plant is composed mainly of three parts: heating system, cooling system, and different storage tanks. Two identical storage tanks based on the shell-and-tubes heat exchanger, one of them including 196 squared fins in the bundle of the tubes and the other without, were experimentally tested. Hydroquinone was selected as the storage material, having a latent heat of 205 kJ/kg and a phase change temperature between 168 and 173 °C. The aim of this paper is to test experimentally, and compare the average effectiveness of the TES systems analyzed using PCM for solar cooling and refrigeration applications. It was found out that for the same tank configurations (shell-and-tubes) even changing drastically the dimensions of the tank or the number and the diameter of the tubes, the average effectiveness curve proposed in the literature fits well with the results showed here.

In recent years, the portable technology is receiving a great interest and significant improvement due to the progresses in electronic technology development and energy storage solutions. The decrease in power requirements for working energy systems, due to the increased efficiency and to the reduction in components size, opens the access to new solutions for power supplying. In particular, alternative backup systems for battery charging or replacement could be designed taking advantage of unconventional technologies. It is the case of small photovoltaic portable panels or fuel cells technology: in these solutions different sources are used to produce limited electrical powers required to keep devices on. In this paper, a thermoelectric solution for the power generation has been considered: the generator has been designed and assembled starting from a catalytic combustor. Catalytic combustion allows safe control of the processes, and the choice of a hydrocarbon fuel ensures the power availability and a fast recharge. The size of the system is set to fit a volume close to the one of AA batteries. The electrical power output obtained is close to 1 W with a cold side temperature below 40 °C. The limited values of these physical parameters allow obtaining a portable and safe device. The generator has been fully characterized in different ranges of fuel flow rates and the performances have been thoroughly analysed for processes optimization and efficiency improvement.

AbstractReview: 105 refs.

Abstract Orange Peel Waste (OPW) is a widely produced residue whose management is complicated by its physical and chemical properties. Anaerobic digestion (AD), which is commonly used for the treatment and exploitation of many biodegradable wastes, is inefficient on OPW due to the presence of essential oils (mainly d -Limonene) as well as the low pH, which cause the process to be unstable. Here we explore the effect of alkaline pre-treatment of OPW and of the addition of granular activated carbon (GAC) and Zero Valent Iron (ZVI) in improving AD in two semi-continuous reactors at a laboratory scale. The addition and pre-treatment of ZVI/GAC were shown to help process stability up to a loading of 3 kgVS·m−3·d−1 and to increase methane production even at a sub-optimal pH. The investigation of the bacterial community, by high-throughput sequencing, has also increased our insight on their involvement in AD in the presence of ZVI, including its biotic oxidation. In addition, direct interspecies electron transfer was shown to play a role in the reactor supplemented with ZVI.

The design and assessment of net-zero buildings commonly focus exclusively on the operational phase, ignoring the embodied environmental impacts over the building life cycle. An analysis is presented on the consequences of integrating embodied impacts into the assessment of the environmental advantageousness of net-zero concepts. Fundamental issues needing consideration in the design process - based on the evaluation of primary energy use and related greenhouse gas emissions - are examined by comparing three net-zero building design and assessment cases: (1) no embodied impacts included, net balance limited to the operation stage only; (2) embodied impacts included but evaluated separately from the operation stage; and (3) embodied impacts included with the operation stage in a life cycle approach. A review of recent developments in research, standardization activities and design practice and the presentation of a case study of a residential building in Norway highlight the critical importance of performance indicator definitions and system boundaries. A practical checklist is presented to guide the process of incorporating embodied impacts across the building life cycle phases in net-zero design. Its implications are considered on overall environmental impact assessment of buildings. Research and development challenges, as well as recommendations for designers and other stakeholders, are identified.

Earth observation (EO) data are useful tools to analyse geomorphological processes, among which slow-moving landslides triggered by rainfall. EO data are also used to evaluate climate change and to assess its impact on geomorphological processes and geo-hydrological phenomena. The latter is the topic of the Project OT4Clima (Innovative Earth Observation technologies to study Climate Change and its impact on the environment) joined by CNR-IRPI within a consortium that includes other CNR institutes, universities and private companies. The OT4CLIMA project moves from the awareness that the impacts of climate change on the environment need to be better observed, understood, and modelled, especially at a regional scale, in order to put in place appropriate and effective risk mitigation strategies. Within the project, the CNR-IRPI group works on the development of rigorous methods and procedures for evaluating the impact of climate and its change on landslides, in particular on those characterized by a slow cinematic, at a regional scale. The test site is represented by four catchments located in the Basilicata region, southern Italy, namely the basins of the Bradano, Basento, Agri, and Sinni rivers. Long-term rainfall series gathered from 22 rain gauges located in the four catchments are analysed to evaluate the presence of temporal trends. To this aim, non-parametric and statistical tests are applied to the series. Historical landslide information is gathered from the analysis of the IFFI (Inventario dei Fenomeni Franosi in Italia) database, the Idrogeo platform (https://idrogeo.isprambiente.it/app/) and the AVI (Aree Vulnerate in Italia) catalogue. Only some types of landslide movements are considered, namely rotational-translational slides, slow slides/flows, complex movements. Moreover, Copernicus Sentinel-1 images are employed to detect the spatial and temporal distribution of slow earth surface deformations. The obtained results are used for checking the completeness of the landslide inventories. More in detail, the deformation maps of the test site are obtained by means of the application of the SBAS (Small BAseline Subset) technique to three datasets of Sentinel-1 images: t146 ascending orbit and t51 and t124 descending orbits, for the period 2015-2020. Then, a comparative analysis of rainfall data with displacement series is carried out with the aim of identifying clusters of satellite measurements with homogeneous behaviour likely correlated to variations in the rainfall regime. In particular, only the points with a mean velocity in the observation higher than 0.1 cm/year are considered to be moving. Moreover, only the displacement series of points located in areas mapped as landslides - as for the historical inventories - and sited within the influence regions of each rain gauge in the study area are analysed. A 10-km circular buffer centred in the stations are used to define the influence region of each station. The displacement series are analysed and compared to the rainfall series to search for correlations and to evaluate the effects of climate drivers on slow moving landslides.