Is Semantic Vigilance Impaired by Narrative Memory Demands? Theory and Applications

OBJECTIVE: Two verbal tasks were utilized in a dual-task paradigm to explore performance theories and prior dual-tasking results. BACKGROUND: Both the decline in vigilance performance over time, or vigilance decrement, and limited dual-tasking ability may be explained by limited mental resources. Resource theorists would recommend removing task demands to avoid cognitive overload, while mindlessness theorists may recommend adding engaging task demands to prevent boredom. Prior research demonstrated interference between a verbal free recall and semantic vigilance task, but exploring tasks with greater ecological validity is necessary. METHOD: A narrative memory task and semantic vigilance task were performed individually and simultaneously. Relative performance impairments were compared to a previous dual-task pairing. RESULTS: The semantic vigilance task caused performance degradation to the narrative memory task and vice versa. A vigilance decrement was not observed, and the interference was to a lesser extent than when the semantic vigilance task was paired with a free recall task. CONCLUSION: Resource theory was supported, though passive learning effects during a semantic vigilance task with novel stimuli may prevent a vigilance decrement. The interference was less than that of a previous similar dual-task pairing, but even tasks as routine as listening to a conversation or story can impair other task performance. APPLICATION: A better understanding of resource theory and dual-task performance outcomes can help inform feasible task loads and improve efficiency and safety of operators in high-risk and other professions

Desarrollo de catalizadores tiorresistentes para el acoplamiento de tecnologías deNOX en motorización diesel

En las últimas décadas, se han desarrollado y perfeccionado diferentes estrategias y tecnologías deNOx de elevada eficacia en respuesta a las regulaciones cada vez más estrictas de las emisiones en el sector del automóvil. Dos tecnologías catalíticas ampliamente utilizadas para este propósito son el Almacenamiento y Reducción de NOx (NSR) y la Reducción Catalítica Selectiva (SCR) en motorización diésel. El acoplamiento entre una trampa de NOx seguido de un catalizador NH3-SCR conduce a una mejora de la selectividad a N2, ya que el NH3 no deseado producido en el catalizador NSR se almacena y reacciona en el sistema SCR consecutivo, se habla de sistemas híbridos. Debido a la presencia de soot en los gases de escape o de azufre en los combustibles, es necesaria la búsqueda de materiales resistentes a este tipo de especies estudiando cómo estos contaminantes afectan a su actividad catalítica, en este sentido, el estudio de la tiorresistencia resulta clave en la determinación de una adecuada formulación del sistema híbrido catalítico, atendiendo a las condiciones reales de operación. El objetivo del presente estudio ha sido el desarrollo y mejora de un sistema catalítico híbrido, NSR-SCR, en forma de monolito, a partir de una formulación base.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Waste into Fuel—Catalyst and Process Development for MSW Valorisation

The present review paper highlights recent progress in the processing of potential municipal solid waste (MSW) derived fuels. These wastes come from the sieved fraction (∅ < 40 mm), which, after sorting, can differ in biodegradable fraction content ranging from 5–60%. The fuels obtained from these wastes possess volumetric energy densities in the range of 15.6–26.8 MJL−1 and are composed mainly of methanol, ethanol, butanol, and carboxylic acids. Although these waste streams are a cheap and abundant source (and decrease the fraction going to landfills), syngas produced from MSW contains various impurities such as organic compounds, nitrogen oxides, sulfur, and chlorine components. These limit its use for advanced electricity generation especially for heat and power generation units based on high temperature fuel cells such as solid oxide fuel cells (SOFC) or molten carbonate fuel cells (MCFC). In this paper, we review recent research developments in the continuous MSW processing for syngas production specifically concentrating on dry reforming and the catalytic sorbent effects on effluent and process efficiency. A particular emphasis is placed on waste derived biofuels, which are currently a primary candidate for a sustainable biofuel of tomorrow, catalysts/catalytic sorbents with decreased amounts of noble metals, their long term activity, and poison resistance, and novel nano-sorbent materials. In this review, future prospects for waste to fuels or chemicals and the needed research to further process technologies are discussed

Modulating and Orienting an Anisotropic Zn-Based Metal Organic Framework for Selective CH4/CO2 Gas Separation

This work investigates the morphological control of the anisotropic [Zn2(NDC)2(DABCO)]n MOF (Metal organic framework) and the subsequent adsorption characteristics for CO2/CH4 gas separation. Morphology of the MOF crystals is controlled by the use of modulators. The addition of acetic acid or pyridine successfully produce rod or plate morphologies, respectively, with each morphology possessing a different major surface pore aperture. Single-component equilibrium and kinetic adsorption data for CO2 and CH4 were collected. Equilibrium analysis indicates a slight selectivity towards CO2 whereas kinetic data unexpectedly shows lower diffusion time constants for CO2 compared to CH4. Mass transfer resistances on each species is discussed. Finally, a coating technique termed solution shearing is used to orient different morphologies on substrates as a film. An increase in film orientation is observed for the rod morphology, indicating that this MOF morphology is a promising candidate to create large area, thin-film applications

In Situ-DRIFTS Study of Selective Catalytic Reduction of NO_<i>x</i> by NH₃ over Cu-Exchanged SAPO-34

The intrinsic mechanism of the selective catalytic reduction (SCR) reaction over a Cu-exchanged SAPO-34 catalyst at low temperature was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), coupled with mass spectrometry to measure inlet and outlet gas concentrations. The evolution of the surface intermediates, as well as the reactivity of NH₃ with surface NO_<i>x</i> species and NO_<i>x</i> with surface NH₃ species, was evaluated. In terms of NO_<i>x</i> adsorption, surface nitrates and nitrites are the main NO_<i>x</i> adsorption species at low temperature. When NO was exposed to the sample with NH₃ preadsorbed, surface NH₃ was not reactive because of the low surface coverage of nitrates and nitrites. However, the reactivity is significantly enhanced by the inclusion of O₂ in the feed, which promotes an increase in the concentration of surface nitrates and nitrites. DRIFTS results also reveal that the low temperature SCR reaction involves the formation of an NH₄NO₃ intermediate and its subsequent reduction by NO. The NH₄NO₃ was formed on Lewis acid sites on the Cu-SAPO-34 sample. The Brønsted acid sites act as an NH₃ reservoir that supplies additional NH₃ via migration to the Lewis acid sites for the SCR reaction. The migration of NH₃ between different acid sites was confirmed in an NH₃-temperature-programmed desorption (TPD) study. The presence of NO in the feed reduces surface NH₄NO₃ to produce N₂ at temperatures as low as 100 °C. Since NH₄NO₃ is typically considered an inhibitor, the onset temperature of the reaction between NO and NH₄NO₃ is much lower than that reported for other SCR zeolite catalysts; therefore, it is likely the key factor that results in the low temperature SCR activity of Cu-SAPO-34