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Abstract High power pseudocapacitors are extremely relevant to answer specific needs in the current energy transition arena and to implement an efficient renewable energy society. However, literature shows that are still open gaps concerning improvement of their energy density at high power, conversion efficiency, cost and cycle life. Electrodes based on active transition metal compounds, and in particular metal sulphides, evidence high potential to meet these objectives. This work discusses the dependence on the synthesis route of the charge storage mechanism of manganese sulphide-based materials and relates the pseudocapacitive response of these electrodes with their polycrystalline nature. Results reveal that a manganese oxy-sulphide mixture can achieve a high specific capacitance of 231 F.g−1 at 0.5 A/g in a 0.65 V active window. These values represent a 31.5 % increase compared to pure rambergite, γ-MnS, and 436 % compared to pure hausmannite Mn3O4 prepared under the same conditions. Moreover, the results show that manganese oxy-sulphide electrodes are characterized by good charge retention (73%), and superior long term capacity retention (above 86%) after 5000 cycles, evidencing potential for high power energy storage applications.

A methodology for the sizing of domestic hot water heating and storage systems is defined, by assuming an extreme operating condition cycle composed of only two parts, a water consumption period and a system repositioning period. In both parts to respond to the extreme hot water demanding conditions, the heating is always on. The subsequent exergy analysis of this domestic hot water production system compares the irreversibility and the exergy efficiency of the water storage and the tankless situation. To carry out such analysis, some basic assumptions were made: a constant temperature heat source, a short duration operating cycle and a constant thermal energy supply. Under these circumstances it is shown that the hot water storage system leads to lower exergy losses while the tankless system is more exergy efficient, but requiring a higher instantaneous thermal power input. The use of the joule effect electricity, as the system heat source, be it a water storage one or a tankless one, maximizes the system irreversibility losses and minimizes the system exergy efficiency. The tankless system, with the joule effect electricity heat source is the worst situation.

Abstract This work assesses the impacts of aggressive driving behavior on pollutants emissions and energy consumption at a city level. Furthermore, it performs an economic analysis considering the potential avoided emissions and fuel savings and discusses potential policy measures to address this topic. The results showed that aggressive driving significantly impacts energy consumption and emissions, with energy consumption increasing by more than ∼200% and emissions by 330% for aggressive driving compared to non-aggressive driving (in MJ/km and in g/km, respectively). This increment was found to be even higher for diesel vehicles than for gasoline vehicles. On the contrary, gasoline vehicles showed higher percentages of increase for most emissions (CO, NOx and NO). Results also revealed that aggressive driving impacts are higher for local streets when examining the city level. Moreover, the economic analysis showed that significant cost reductions may be achieved by avoiding aggressive driving, reaching up to 52.5 k€ on a daily basis. In conclusion, this study is of particular relevance to policy makers and urban planners, enabling to obtain a comprehensive overview of the impacts of aggressive driving behaviors at a city level and providing new insights to perform further developments and to assess the feasibility of the implementation of policy measures.

Abstract Portugal’s performance concerning the Refuse Derived Fuel (RDF) strategy, with particular focus on perspectives for the Northern Region based on the current status of integrated municipal waste management systems in that region, was evaluated. Legal documents, official reports and the market were analyzed. The 2015 national installed capacity of waste treatment technologies, from which the high calorific value fraction (HCVF) for RDF production is obtained, is not far from what was predicted for 2013. However, only around 11% of the HCVF had such destiny and the amount of effectively produced RDF was only 30% of the material sent to RDF production (around 30 kt). In Northern Portugal, no RDF production plant was in operation in 2015; the amount of HCVF was estimated to range from 105 to 204 kt for 2015 and around 2.4 times more is expected in 2020. The strategy laydown for RDF failed so far, and thus, low diversion of waste from landfills is observed, mostly due to low landfill taxes and low HCVF quality, resulting in RDF being non-competitive with the imported higher quality product from countries with very high landfilling fees. Moreover, co-incineration and dedicated recovery solutions are scarce. In the Northern region, the HCVF may be treated in the existing municipal waste incinerator or the RDF might be recovered in new dedicated plants, receiving also non-hazardous waste fractions from other origin. Overall, to ensure a sustainable municipal waste management, the intensification of the reuse, preparation for reuse and recycling of waste components from source segregated collection must be significantly promoted.

The olive oil mill wastewater (OMW) is a by-product (with a high organic load) derived from the production of the olive oil. The OMW steam reforming (OMWSR) process was studied herein, aiming to decrease the environmental damage of such effluents; simultaneously, the waste is economically and energetically valorized with the H-2 production. Several Ni-containing catalysts were prepared and tested to compare their performances for the OMWSR using a synthetic OMW effluent; still, stability tests were also carried out. The materials were extensively characterized: thermogravimetric analysis, temperature programmed oxidation/reduction, temperature-programmed desorption of CO2/NH3, chemisorption of H-2, inductively coupled plasma optical emission spectrometry and physical adsorption-desorption of N-2 at-196 & DEG;C. Amongst the materials tested, the Ni-Ru/SiO2 sample stood out, exhibiting high catalytic performance: at 400 & DEG;C, the H-2 yield (> 8 mol(H2)& BULL;mol(OMW)(-1)) and conversion of total organic carbon (asymptotic to 75%) were high during all the 24 h of the long-term test, with only a small deactivation being noticed.

Abstract Antimony telluride (Sb 2 Te 3 ) is a chalcogenide material used in thermoelectric applications. The deposition of thin films of Sb 2 Te 3 requires a precisely controlled process to achieve a desirable high thermoelectric figure-of-merit. The optimization of the thermal co-evaporation process for p-type Sb 2 Te 3 thin-film onto plastic substrates (Kapton© polyimide) for thermoelectric applications is reported. The influence of deposition parameters and composition on thermoelectric properties was studied, seeking optimal thermoelectric performance. Energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy all confirmed the formation of Sb 2 Te 3 thin films. Seebeck coefficient (up to 190 μVK −1 ), in-plane electrical resistivity (8–15 μΩm), carrier concentration (1 × 10 19 –7 × 10 19 cm −3 ) and Hall mobility (120–180 cm 2 V −1 s −1 ) were measured at room temperature for the best Sb 2 Te 3 thin-films.

With the concept of climate services rapidly climbing research and research-funding agendas worldwide, the time is ripe for a debate about the objectives, scope and content of such services.

The objective of the present work was: (i) to enable biodiesel production from acid waste lard; (ii) to study the esterification reaction as possible pre-treatment at different temperatures, catalyst amount and reaction times; (iii) to evaluate biodiesel quality according to EN 14214 after basic transesterification of the pre-treated fat; and (iv) to predict the impact of using such waste as raw material in mixture with soybean oil. Temperature and catalyst amount were the most important reaction conditions which mostly affected biodiesel quality, namely viscosity and purity. The selected pre-treatment conditions were 65 degrees C, 2.0 wt% H(2)SO(4) and 5 h, which allowed obtaining a product with a viscosity of 4.81 mm(2) s(-1) and a purity of 99.6 wt%. The proposed pre-treatment was effective to enable acid wastes as single raw materials for biodiesel production with acceptable quality; however, low yields were obtained (65 wt%). Alkali transesterification of a mixture of waste lard and soybean oil resulted in a product with a purity of 99.8 wt% and a yield of 77.8 wt%, showing that blending might be an interesting alternative to recycle such wastes. Also, because in addition to using conventional and relatively economical processes, some biodiesel properties depending on the raw material composition (such as the iodine value) might even be improved.