Search

A strong development of renewable energy is envisioned in order to achieve targets of reduction for greenhouse emissions. In particular, small scale systems for distributed renewable energy production can be very useful to this purpose in urban areas where the generated power can be directly used. In this context, the present paper concerns the aerodynamic and electromechanical design of a small wind turbine for the exploitation of the wind generated by vehicles movement in road tunnels. The generated energy is directly used to power road delineators, usually equipped with LED technology and, therefore, characterized by low energy requirements, DC supply and long life. The first part of the study addressed the definition of the operating conditions of the wind turbine inside road tunnel. Then, the aerodynamic design of the turbine was conducted through CFD simulations maximizing the efficiency with reduced size and cost. The power generation section is chosen and coupled to the turbine for integrated system prototyping. Simulation results prove that power generated by a single wind turbine is suitable to supply 10 delineators maximum, covering about 100 m of tunnel. Moreover, wind turbine performance is also validated through test on a real scale prototype of the complete device. • Operating conditions inside road tunnels were identified. • The wind turbine model was developed and validated. • Four different configurations were simulated and analyzed. • The wind turbine was designed and its generated power was evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Micro-CHP technologies based on fuel cells appear to be a good answer to growing worldwide demand for less polluting forms of energy. Some components that constitute the balance of plant of these systems are resulted to be field of improvements in order to increase the overall efficiency. In particular this paper deals issues relative to the clean-up system. Considering as powering system the methane gas distribution, in fact, a high degree of desulphurization is requested to avoid poisoning of the reformer and stack catalyst. Therefore, a parametric CFD model of a typical desulphurization reactor has been developed using experimental data obtained by the FClab of the University of Perugia. Particular attention has been devoted to the kinetic of the adsorption process of the hydrogen sulphide on activated carbons Norit RB1, used in the test session. The H2S adsorption process has been modelled as a mass transfer process between the gas phase mix and the solid phase. The model has been developed and validated by means of further experimental data not used for the model development. This tool will allow, in future studies, to optimize the geometry of an innovative desulphurization system for residential application. [Copyright &y& Elsevier]

Background: Wave energy represents one of the most promising renewable energies due to its great theoretical potential. Nevertheless, the electrical compliance of grid-connected systems is a great issue nowadays, due to the highly stochastic nature of wave energy. Methods: In this paper, a Hybrid Energy Storage System (HESS) consisting of a Li-ion battery and a flywheel is coupled to a Wave Energy Converter (WEC) that operates in grid connected mode. The study is performed using real yearly wave power profiles relating to three different sites located along the European coasts. The Simultaneous Perturbation Stochastic Approximation (SPSA) principle is implemented as real-time power management strategy for HESS in wave energy conversion systems. Results: Obtained results demonstrate how the proposed HESS and the implementation of the SPSA power management coupled to a WEC allow a reduction of more than 80% of power oscillations at the Point of Common Coupling (PCC), while proving the robustness of the developed management strategy over the investigated sites. Moreover, the average energy penalty due to the HESS integration results slightly higher than 5% and battery solicitation is reduced by more than 64% with respect to the flywheel solicitation, contributing to extend its lifetime. Conclusions: HESS integration in renewable generation systems maximizes the WEC production while smoothing the power at the PCC. Specifically, flywheel-battery HESS together with the implemented power management strategy could provide a great flexibility in the view of increasing power production from waves, strongly mitigating the variability of this source while enhancing grid safety and stability., Competing Interests: No competing interests were disclosed., (Copyright: © 2023 Barelli L et al.)

Medial compartment disease is a common occurrence in dogs affected by elbow dysplasia. Despite many treatments suggested in the literature, only few studies reported comparative outcomes in the short and long term. The aim of this study is to report and compare short- and long-term clinical and radiographic outcomes of dogs treated for medial compartment disease (MCD) by distal dynamic ulnar ostectomy (DUO), bi-oblique dynamic proximal ulnar osteotomy (BODPUO) and conservative management (CM). From 2016 to 2018, all medium to large dogs, aged between 5 and 12 months, affected by uni/bilateral MCD and treated by DUO, BODPUO or CM, were enrolled in this study and followed up for 24 months. Orthopedic and radiographic examinations were performed at T 0 , T 2 , T 12 and T 24 months after treatment. Lameness score, elbow arthralgia, elbow range of motion (ROM), osteoarthritis (OA) score and percentage of ulnar subtrochlear sclerosis (%STS) were evaluated at each time point. According to the treatment performed, dogs were divided into three groups: DUO, BODPUO and CM. Forty-five elbows from twenty-six dogs, treated with DUO (n = 17), BODPUO (n = 17) or CM (n = 11), were prospectively enrolled in the study. The patients enrolled in the CM group were older and showed more severe radiographic signs of OA, compared to those enrolled in the other two groups. Lameness and arthralgia scores ( p < 10 -4 ) were significantly decreased in patients that underwent surgical treatment and increased in patients managed conservatively (lameness p < 10 -4 , arthralgia p = 0.3068), at T 12 and T 24 . OA score ( p < 0.0040) and ROM (DUO, CM p < 10 -4 ; BODPUO p = 0.0740) worsened in every study group, but %STS decreased in DUO ( p = 0.0108), increased in the CM group ( p = 0.0025) and remained unchanged in the BODPUO group ( p = 0.2740). This study supports the clinical efficacy of DUO and BODPUO in reducing lameness, arthralgia and progression of %STS. Early diagnosis and surgical attention in patients affected by MCD can improve the short- and long-term outcome and reduce the progression of secondary changes.

A 6-year-old, intact male Jack Russell terrier was diagnosed with a mass in the caudal abdomen, and ultrasound revealed a large prostatic mass. A total-body computed tomography scan was performed for staging, and lung nodules were detected. Histological examination showed a proliferation of spindle cells arranged in interlacing fascicles. Immunohistochemical staining revealed cells were cytokeratin negative and immunoreactive for vimentin and alpha-smooth muscle actin; cells stained with desmin and S-100 were negative. A diagnosis of primary prostatic leiomyosarcoma with pulmonary metastases was made. This is one of the rare cases of primary prostatic mesenchymal tumor in the canine species.