9,921 research outputs found
On a game theoretic cardinality bound
The main purpose of the paper is the proof of a cardinal inequality for a
space with points , obtained with the help of a long version of the
Menger game. This result improves a similar one of Scheepers and Tall
Topological games and productively countably tight spaces
The two main results of this work are the following: if a space is such
that player II has a winning strategy in the game \gone(\Omega_x, \Omega_x)
for every , then is productively countably tight. On the other
hand, if a space is productively countably tight, then \sone(\Omega_x,
\Omega_x) holds for every . With these results, several other results
follow, using some characterizations made by Uspenskii and Scheepers
Across the Board: Federico Bella on Electrochemical Nitrogen Reduction
In this series of articles, the board members of ChemSusChem discuss recent research articles that they consider of exceptional quality and importance for sustainability. This entry features Prof. F. Bella, who discusses the electrochemical reduction of nitrogen to produce ammonia through the addition of protons and electrons under mild conditions (25â°C, 1â
atm). This reaction has the potential to replace the energyâintensive traditional HaberâBosch process but faces several challenges and pitfalls
The Latin Leaflet, Number 29
Polymer electrolytes represent the ultimate in terms of desirable properties of energy storage/conversion devices, as they can offer an all-solid-state construction, a wide variety of shapes and sizes, light-weight, low costs, high energy density and safety.
Here we present our recent results concerning a novel strategy for preparing efficient polymer membranes which are successfully demonstrated as suitable electrolytes for several energy conversion and storage devices (i.e., Li- and Na-based batteries and DSSCs). Highly ionic conducting polymer electrolytes containing PEO-based functionalities and different components (e.g., Li/Na salts, RTILs, natural biosourced and cellulosic fillers) are successfully prepared via a rapid process and, directly or subsequently, cross-linked via UV irradiation (patent pending, PCT/IT2014/000008). All the prepared materials are thoroughly characterised in terms of their physical, chemical and morphological properties and tested for their electrochemical performances and durability. The UV-curing process on such materials led to the production of elastic and resistant amorphous macromolecular networks. Noticeably increased ionic conductivities are registered (10-3 S cm-1 at RT), along with very stable interfacial and storage stability and wide electrochemical stability windows. The different lab-scale solid-state devices show remarkable performances even at ambient temperature, at the level of those using liquid electrolytes, respect to which demonstrate much greater durability and safety.
The obtained findings demonstrate a new, easy and low cost approach to fabricate and tailor-make polymer electrolytes with highly promising prospects for the next generation of advanced flexible energy production and storage devices
EXCHANGE RATE AND TRADE POLICY EFFECTS ON U.S. POULTRY EXPORT PRICES
The impact of the ruble devaluation on U.S. poultry meat exports to the Russian market was simulated as the combined effects of an export subsidy and a tariff on imports using the Global Trade Analysis Project model and data. Russian imports fell while domestic prices rose. U.S. poultry exports and dark meat prices declined.International Relations/Trade, Livestock Production/Industries,
Validation of Low-Cost Driving Simulator Based on Continuous Speed Profiles
[EN] The number of road safety studies that are based on driving simulators is growing significantly. The Polytechnic University of Valencia, Spain, developed a low-cost driving simulator for the assessment, training, and rehabilitation of drivers (SE2RCO). The main objective of this research was the validation of the driving simulator so that studies about road safety and highway geometric design that considered human factors could be performed. The validation was based on continuous speed profiles collected from 28 volunteers on a 30-km-long, two-lane rural road section. The same volunteers drove through the same road section built in SE2RCO. Speed data of 79 curves and 52 tangents were selected for the analysis. Comparison of the real and simulated speeds ensured the simulator's objective validity according to average and operating speeds. Two models were developed to predict field speeds from simulated speeds. Results showed that a simulated average speed lower than approximately 90 km/h was linked to a similar real average speed. For higher simulated speeds, the average speed in the real environment was lower than the simulated one. In addition, the actual operating speed was around 5 km/h lower than the operating speed in the driving simulator. Most volunteers assessed the quality and similarity of the virtual environment compared with the real world as medium or high and assessed the driving tasks similarly, thus achieving subjective validation of the simulator.The authors thank the Polytechnic University of Valencia, which subsidized the research project CONSIM-Desarrollo de un Modelo para la Evaluacion de la Consistencia del Diseno Geometric de Carreteras Convencionales Mediante Simuladores de Conduccion. The study presented here was also part of the research project titled CASEFU-Estudio Experimental de la Funcionalidad y Seguridad de las Carreteras Convencionales, which was subsidized by the Spanish Ministry of Economy and Competitiveness and the European Social Fund.Llopis-CastellĂł, D.; Camacho Torregrosa, FJ.; MarĂn-Morales, J.; PĂŠrez Zuriaga, AM.; GarcĂa GarcĂa, A.; Dols Ruiz, JF. (2016). Validation of Low-Cost Driving Simulator Based on Continuous Speed Profiles. Transportation Research Record Journal of the Transportation Research Board. 2602:104-114. https://doi.org/10.3141/2602-13S104114260
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