Methods and tools for the optimization of renewable technologies and hybrid energy systems. Metodi e strumenti per l'ottimizzazione di tecnologie rinnovabili e sistemi energetici ibridi

The United Nations (UN) project "Sustainable energy for all" sets three ambitious objectives to favor a sustainable development and to limit climate change: - Universal access to modern energy services. Electricity is currently not available for 1.3 billion people and the global energy demand is expected to grow of about 35% within 2040, due to the increasing world population and the expanding economies - Double the global rate of improvement in energy efficiency - Double the share of renewable energy sources (RESs) in the global energy mix In addition, according to the climate scenario assessed in the fifth assessment report (AR5) of the International Panel on Climate Change (IPCC), the prevention of undesirable climate effects requires a 40-70% reduction of greenhouse gas (GHG) emissions, compared with 2010 levels, by mid-century, and to near-zero by the end of this century (IPCC, 2014). The achievement of such objectives requires and encourages the spread of RESs in the global energy mix, gradually replacing depleting and polluting energy sources based on fossil fuels, which still have the main incidence on the energy sector. RESs already play a major role in several countries, due to the technological development and the increasing market competitiveness, and the world renewable power capacity reached 22.1% in 2013, showing an increasing trend in 2014 (REN, 2014). However, supporting policies, robust investments from the private sector and efforts from the scientific community are still crucial to demonstrate the technical and economic sustainability and effectiveness of RESs, helping their large-scale diffusion. Starting from such a background, this Ph.D dissertation focuses on the study, design and development of methods and tools for the optimization and enhancement of renewable energy technologies and their effective integration with energy storage solutions and traditional energy sources powered by fossil fuels (hybrid energy systems). The analysis of the major literature and the different scenarios and perspectives of RESs in the national and international contexts have shown that their economic sustainability, and then their diffusion, is closely connected to a number of technical, economic/financial and geographical parameters. Such parameters are the input of the analytic models developed for the techno-economic design of photovoltaic (PV) plants and small wind turbines (SWTs) and applied to the economic feasibility study, through multi-scenario analysis, of such systems in some of the main European Union (EU) Countries. Among the obtained results, the self-consumption of the produced energy plays a crucial role in the economic viability of SWTs and PV plants and, particularly, after the partial or total cut of incentives and uncertainties related to supporting policies within the EU context. The study of the energy demand profile of a specific user and the adoption of battery energy storage (BES) systems have been identified as effective strategies to increase the energy self-consumption contribution. Such aspects have led to the development of an analytic model for the techno-economic design of a grid connected hybrid energy system (HES), integrating a PV plant and a BES system (grid connected PV-BES HES). The economic profitability of the grid connected PV-BES HES, evaluated for a real case study, is comparable with PV plants without storage in case of a significant gap between the cost of energy purchased from the grid and the price of energy sold to the grid, but high BES system costs due to the initial investment and the maintenance activities and the eventual presence of incentives for the energy sold to the grid can make the investment not particularly attractive. Thus, the focus has shifted to the techno-economic analysis of off-grid HES to meet the energy demand of users in remote areas. In this context, BES systems have a significant role in the operation and management of the system, in addition to the storage of exceeding energy produced by the intermittent and variable RESs. The analysis has also been strengthened by an industrial application with the aim to configure, test and install two off-grid HESs to meet the energy demand of a remote village and a telecommunication system. In parallel, two experimental activities in the context of solar concentrating technology, a promising and not fully developed technology, have been carried out. The former activity deals with the design, development and field test of a Fresnel lens pilot-scale solar concentrating prototype for the PV energy distributed generation, through multi-junction solar cells, and the parallel low temperature heat recovery (micro-cogeneration CPV/T system). The latter activity deals with the development of a low cost thermal energy (TES) storage prototype for concentrating solar power (CSP) plants. TES systems show a great potential in the CSP plants profitability since they can overcome the intermittent nature of sunlight and increase the capacity factor of the solar thermal power plant. Concluding, the present Ph.D dissertation describes effective methods and tools for the optimization and enhancement of RESs. The obtained results, showing their critical issues and potential, aim to contribute to their diffusion and favor a sustainable developmen

Pulmonary artery thrombosis in home patient with a mild COVID-19 disease

Abstract COVID-19 has been described as the cause for a proinflammatory and hypercoagulable state that induces thrombotic vascular lesions and, in more severe cases, disseminated intravascular coagulation. Increased values of d-dimers are related to the severity of the disease and are associated with worst prognosis. Intensive care studies reported an increased risk of pulmonary embolism and venous thrombosis diseases in COVID-19 compared with the historical control group even in patients who underwent the low-molecular-weight heparin (LWMH) prophylaxis. Patients with COVID-19 who have a stable clinical condition do not require hospitalisation and are treated at home with symptomatic therapy. LWMH is reserved for those with reduced mobility. In this case report, we describe a COVID-19 patient with pulmonary artery thrombosis treated at home

Are we surprised to find SMBHs with JWST at z > 9?

JWST is unveiling for the first time accreting black holes (BHs) with masses of 10^6 - 10^7 Msun at z > 4, with the most distant residing in GNz11 at z = 10.6. Are we really surprised to find them in the nuclei of z = 5 - 11 galaxies? Here we predict the properties of 4 < z < 11 BHs and their host galaxies considering an Eddington-limited (EL) and a super-Eddington (SE) BH accretion scenario, using the Cosmic Archaeology Tool (CAT) semi-analytical model. We calculate the transmitted spectral energy distribution of CAT synthetic candidates, representative of the BH/galaxy properties of GNz11. We also examine the possibility that the z = 8.7 galaxy CEERS-1019 could host an active BH. We find that the luminosity of high-z JWST detected BHs are better reproduced by the SE model, where BHs descend from efficiently growing light and heavy seeds. Conversely, the host galaxy stellar masses are better matched in the EL model, in which all the systems detectable with JWST surveys JADES and CEERS descend from heavy BH seeds. We support the interpretation that the central point source of GNz11 could be powered by a SE (lambda_Edd = 2 - 3) accreting BH with mass 1.5 10^6 Msun, while the emission from CEERS-1019 is dominated by the host galaxy; if it harbours an active BH, we find it to have a mass of M_BH = 10^7 Msun, and to be accreting at sub-Eddington rates (lambda_Edd = 0.5).Comment: 11 pages, 5 figures, accepted by MNRAS after minor revision and updated with recent observation

Lumbar spinal canal stenosis: An early sign of amyloid transthyretin related amyloidosis

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A multilevel theoretical study to disclose the binding mechanisms of gold(III) bipyridyl compounds as selective aquaglyceroporin inhibitors

Structural studies have paved the avenue to a deeper understanding of aquaporins (AQPs), small ancient proteins providing efficient transmembrane pathways for water, small uncharged solutes such as glycerol, and possibly gas molecules. Despite the numerous studies, their roles in health and disease remain to be fully disclosed. The recent discovery of AuIII complexes as potent and selective inhibitors of aquaglyceroporin isoforms paves the way to their possible therapeutic application. The binding of the selective human AQP3 inhibitor, the cationic complex [Au(bipy)Cl2]+ (Aubipy), to the protein channel has been investigated here by means of a multi-level theoretical workflow that includes QM, MD and QM/MM approaches. The hydroxo complex was identified as the prevalent form of Aubipy in physiological media and its binding to AQP3 studied by MD. Both non-covalent and coordinative Aubipy–AQP3 adducts were simulated to probe their role in the modulation of water channel functionality. The electronic structures of representative Aubipy–AQP3 adducts were then analysed to unveil the role played by the metal moiety in their stabilisation. This study spotlights the overall importance of three key aspects for AQP3 inhibition: 1) water speciation of the AuIII complex, 2) stability of non-covalent adducts and 3) conformational changes induced within the pore by the coordinative binding of AuIII. The obtained results are expected to orient future developments in the design of isoform-selective AuIII inhibitors

Evaluation of Pressure Drop and Particle Sphericity for an Air-rock Bed Thermal Energy Storage System

Abstract The pressure drop of a packed bed thermal energy storage system with irregular shaped solid pellets and tank-to-particle diameter ratio of 10.4 is investigated. The bed height to diameter ratio is 2. The particle sphericity is calculated and used to compare pressure drop correlations to the measured values in the particle Reynolds number range of 353 ≤ Re p ≤ 5206

Knowledge-of-own-factivity, the definition of surprise, and a solution to the Surprise Examination paradox

Fitch's Paradox and the Paradox of the Knower both make use of the Factivity Principle. The latter also makes use of a second principle, namely the Knowledge-of-Factivity Principle. Both the principle of factivity and the knowledge thereof have been the subject of various discussions, often in conjunction with a third principle known as Closure. In this paper, we examine the well-known Surprise Examination paradox considering both the principles on which this paradox rests and some formal characterisations of the surprise notion, crucial in this paradox. Standard formalizations of the Surprise Examination paradox in modal logic do not seem, at first glance, to depend on either factivity or knowledge-of-factivity, but we will argue that both factivity and knowledge-of-factivity play a key implicit role in the paradox. Namely, they are implicitly, perhaps unintentionally, used in order to simplify the definition of surprise. We analyze modal logical formalizations of three versions of the paradox concluding that the Surprise Examination paradox is the result of two flaws: the assumption of knowledge-of-factivity, and the over-simplification of the definition of "surprise" accordingly. By fixing these two flaws, the Surprise Examination paradox vanishes

Rational timing of combination therapy with tiotropium and formoterol in moderate and severe COPD.

AIM: To determine which timing of therapy with formoterol (FOR) and/or tiotropium (TIO) shows the greater and more continuous functional improvement during 24 h in patients with moderate to severe COPD. METHODS: In this randomised, blind, crossover study 80 patients with stable COPD (40 moderate and 40 severe) received 5 different bronchodilator 30-day treatments in a random order. Treatments (Tr) were: Tr1: TIO 18 microg once-daily (8 am); Tr2: TIO 18 microg (8 am) + FOR 12 microg (8 pm); Tr3: FOR 12 microg twice-daily (8 am and 8 pm); Tr4: TIO 18 microg (8 am) + FOR 12 microg twice-daily (8 am and 8 pm); Tr5: FOR 12 microg twice-daily (8 am and 8 pm) + TIO 18 microg (8 pm). Spirometries were performed during 24 h (13 steps) on Day1 and Day30. End-points were: gain of FEV(1) (DeltaFEV(1)) from baseline of the Day1 and Day30, AUC (Area Under Curve), Dyspnoea Index, and as-needed use of salbutamol. RESULTS: Sixty-eight patients completed all treatments. The greater and continuous daily functional improvement was showed during Tr4 and Tr5 (Day1 +135.8 mL and +119.1 mL; Day30 +160.2 mL, and +160.5 mL, respectively). Daily means of DeltaFEV(1) were significantly different between single-drug treatments and combination therapy. Dyspnoea was greater in single-drug treatments. Less use of rescue salbutamol was reported in Tr4 (0.80 puffs/die) and Tr5 (0.71 puffs/die). CONCLUSIONS: In patients with moderate to severe COPD, combination therapy with tiotropium administered in the morning (Tr4) was the most effective; in patients with prevailing night-symptoms, treatment with tiotropium in the evening (Tr5) reduced symptoms and use of salbutamol. Tr5 showed less variability of FEV(1) during the 24 h (CV=0.256). These results are relevant for opening new ways in clinical practice

GH Lib: A multi-periodic Mira, not an eclipsing binary

Over the period 2012-2016 we have obtained accurate V and R band photometry and 3400-8000 Ang spectroscopy which show the poorly studied variable GH Lib to be a multi-periodic Mira and not an Algol-type eclipsing binary. The main pulsation periods are 157 and 1180 days, with amplitudes of 3.5 and 1.0 mag, respectively. The spectral type change from M2III at maximum to M7III at minimum. The intensity of Halpha and Hbeta emission lines in GH Lib is much larger than in normal Miras, suggesting that the region of Balmer line formation is located at a larger radius (more external atmospheric layers) as if mixed with and not deeply below the region where absorption by TiO molecules occurs

Fabrication and characterization of biomimetic hydroxyapatite thin films for bone implants by direct ablation of a biogenic source

Biomimetic bone apatite coatings were realized for the first time by the novel Ionized Jet Deposition technique. Bone coatings were deposited on titanium alloy substrates by pulsed electron ablation of deproteinized bovine bone shafts in order to resemble bone apatite as closely as possible. The composition, morphology and mechanical properties of the coatings were characterized by GI-XRD, FT-IR, SEM-EDS, AFM, contact angle measurements, micro-scratch and screw-insertion tests. Different post-treatment annealing conditions (from 350 °C to 425 °C) were investigated. Bone apatite coatings exhibited a nanostructured surface morphology and a composition closely resembling that of the deposition target (i.e. natural bone apatite), also regarding the presence of magnesium and sodium ions. Crystallinity and composition of the coatings were strongly influenced by annealing temperature and duration; in particular, upon annealing at 400 °C and above, a crystallinity similar to that of bone was achieved. Finally, adhesion to the titanium substrate and hydrophilicity were significantly enhanced upon annealing, all characteristics being known to have a strong positive impact on promoting host cells attachment, proliferation and differentiation