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The objective of this study is to investigate the effect of bioethanol-gasoline blends on the exhaust emissions and engine combustion of a four-stroke motorcycle. Ethanol is known as an alternative fuel for spark-ignition engines and is suitable for making blends with gasoline, increasing the oxygen content and decreasing emission of incomplete combustion products. An experimental investigation was performed on a Euro 3 large-size motorcycle fuelled with commercial gasoline and bioethanol/gasoline blends (range of bioethanol 5% v to 30% v). Regulated and unregulated emissions and fuel consumption were quantified over the execution of chassis-dynamometer tests. The combustion analysis, realized by acquiring the pressure cycle inside the cylinder, highlights the auto adjustment of the engine control unit and guarantees use within the same parameters of several tested fuels, with the except of fuel injection time, which increases with increasing ethanol percentage. A significant reduction in carbon monoxide and particle number is associated with the ethanol content of the fuel. Volatile organic compounds, mainly alkanes and aromatics, are not substantially influenced by the bioethanol content of the fuel. The contribution of carcinogenic benzene ranges between 2 and 5%.

Abstract Urban areas in developed countries are characterized by an increasing decline in air quality state mainly due to the exhaust emissions from vehicles. Besides, due to catalyst improvements and electronic mixture control of last generation engines, nowadays CO and HC cold start extra-emissions are heavily higher than emissions exhausted in hot conditions, with a clear consequence on air quality of the urban contexts. Ethanol combined with gasoline can be widely used as an alternative fuel due to the benefit of its high octane number and its self-sustaining characteristics. Ethanol, in fact, is well known as potential alcohol alternative fuel for SI engines, since it can be blended with gasoline to increase oxygen content, then decreasing CO and HC emissions and the depletion of fossil fuels. Literature data about cold emissive behaviour of SI engines powered with ethanol/gasoline blended fuels are rather limited. For this reason, the aim of this study is to experimentally investigate the effect of ethanol/gasoline blends on CO and HC cold start emissions of four-stroke SI engines: a last generation motorcycle was operated on the chassis dynamometer for exhaust emission measurements without change to the engine design, while the ethanol was mixed with unleaded gasoline in different percentages (10, 20 and 30 vol.%). Results of the experimental tests and the application of a new calculation procedure, designed and optimised to model the cold transient behaviour of SI engines using different ethanol–gasoline blends, indicate that CO and HC cold start emissions decrease compared to the use of commercial gasoline, with the 20% v/v ethanol blend achieving the highest emission reduction. Moreover, in this paper a review of the recent scientific literatures was performed on the emissive behaviour of SI engines fuelled with ethanol–gasoline blended fuels.

AbstractThis paper presents an activity concerning the development of a control strategy for power-assisted electric bicycles, also called pedelecs. A common assistance algorithm available on commercial pedelecs consists in providing predefined constant assistance electric power. This approach is lack of flexibility with respect to environmental condition and generally does not provide a good driving comfort. The proposed control method has been designed to minimize the tracking error between the actual bike velocity and the desired one, in the presence of external disturbances. The assistance electric motor torque consists of a feedforward torque integrated with a feedback one. The feedforward contribution is a nonlinear torque based on the pedelec model. The feedback action has the function to compensate the tracking error due to model uncertainties and unknown disturbances. The performance of the methodology has been evaluated applying the controller to an innovative pedelec prototype. To this aim, a mathematical model of the vehicle has been developed. Different human torque models have been implemented in order to study the influence of the rider on the pedelec dynamics. The results of a comparative analysis between the proposed algorithm and a common assistance method have demonstrated that the proposed controller provides improvements in terms of riding comfort and energy utilization.

Abstract This paper describes the methodologies to appraise the power requests and environmental analysis of an electrically assisted bicycle under real driving conditions, also containing regulations and technical-science-related aspects. For this purpose, in this study, the on-road test program of an electrically assisted bicycle was executed in the urban area of Naples on different test tracks, so a general assessment about its driving behavior under several driving conditions was performed. The power requirements in different typical riding situations were estimated by a procedure based on the experimental kinematic parameters that characterize the driving dynamics collected during the real-life applications. An environmental analysis was also performed, with a methodology that takes into account the environmental assessment of a moped by measuring the experimental moped exhaust emissions of the regulated pollutants. Starting from the results acquired during the different test samples, besides, an assessment of the electric traction offered by this pedelec on the driving comfort was evaluated for different riding situations.

Abstract Renewable energy sources are becoming more and more vital around the word from the last decades, due to the limited reserves of fossil fuels and environmental matters. Starting from this consideration, this paper investigates the possibility to provide a new urban agglomeration in Naples (Italy) with power, heat and cooling, by a modern trigeneration plant. The study was performed for thermal and refrigeration needs of the planned settlements. The analysis was carried out considering two alternative schemes, both based on internal combustion engines: in the first system solution the engines are fueled by natural gas, in the second one, by renewable vegetable oils. Energy and economic evaluations were carried out in order to assess the pay-back period of the investment for the two different systems: the plant configuration based on a renewable energy source was more convenient and profitable. For this power plant solution, finally, an environmental analysis was performed in order to assess the impact of this power system on the territory surrounding the trigeneration plant: the effect on local air quality state was minimal. This environmental analysis was carried out using the Gaussian dispersion model ISC, that determines the pollutant concentrations due to a point emissive source.

To address the growing problem of pollution and global warming, it is necessary to steer the development of innovative technologies towards systems with minimal carbon dioxide production. Thermal storage plays a crucial role in solar systems as it bridges the gap between resource availability and energy demand, thereby enhancing the economic viability of the system and ensuring energy continuity during periods of usage. Thermal energy storage methods consist of sensible heat storage, which involves storing energy using temperature differences; latent heat storage, which utilizes the latent heat of phase change materials; and thermochemical heat storage, which utilizes reversible chemical reactions through thermochemical materials. The objective of this review paper is to explore significant research contributions that focus on practical applications and scientific aspects of thermal energy storage materials and procedures. For each type of storage, different materials have been examined, taking into consideration the most recent studies, both for medium and long-term storage and, when possible, comparing methodologies for the same purpose. It has been observed that TCHS systems have the potential to reduce the volume of chemical storage tanks by 34 times using chemical reactions. Among the SHS materials, water, molten salts, and graphite exhibit the highest energy density, with graphite also possessing remarkable thermal conductivity. Nanoparticles can enhance the thermophysical properties of TES materials by increasing their thermal conductivity and wettability and improving intermolecular characteristics. The use of biobased PCMs for applications that do not require very high temperatures allows for maximizing the efficiency of such storage systems.