51 research outputs found
Caching Behavior in Corvids: Cognition and Pattern Recognition
Caching behavior in two corvids, American crow (Corvus brachyrhynchos) and western scrub jay (Aphelocoma californica) were recorded using motion-activated cameras and direct observations in order to compare behavioral differences between the two species. Investigating bird caching behavior is important in determining the cognitive capacity of each bird species and displaying how these avian species may have adapted to living successfully in urban ecosystems with highly variable food sources. Both species were baited using peanuts. We video recorded how birds selected peanuts to examine potential size or weight preferences specific to either species. After initial observations of caching behavior with untreated peanuts, food dye was applied to peanuts with a mass greater than 2.5g. contained within a group of undyed peanuts with a mass below 1.5g. By varying which group the dye was applied to, it was possible to examine the extent to which corvids were capable of recognizing patterns associated with their food source in order to optimize caching productivity. The ability to rapidly recognize changes and patterns associated with their food sources could allow for rapid adaptation in feeding that provides corvids with a significant selective advantage in urban environments.https://digitalcommons.lmu.edu/cures_posters/1015/thumbnail.jp
Electrocatalytic reduction of CO2 at Au nanoparticle electrodes: Effects of interfacial chemistry on reduction behavior
Nanoscale Au electrocatalysts demonstrate the extraordinary ability to reduce CO2 at low overpotentials with high selectivity to CO. Here, we investigate the role of surface chemistry on CO2 reduction behavior using Au25 and 5 nm Au nanoparticles. Onset potentials for CO2 reduction at Au25 nanoparticles in Nafion binders are shifted anodically by 190 mV while the hydrogen evolution reaction is shifted cathodically by 300 mV relative to Au foil. The net effect of this beneficial separation in onset potentials is relatively high Faradayic efficiencies for CO (90% at 0.8 V versus RHE) at high current densities. Experimental results show Faradayic efficiencies for CO are greatest using electrodes made with Nafion-immobilized Au25 nanoparticles. Likewise, CO2 reduction onset potential shifts are greater for smaller nanoparticles and when Nafion binders are used instead of (sulfonate-free) polyvinylidene fluoride. X-ray photoelectron spectroscopy analysis reveals Au nanoparticles may react with the sulfonates of Nafion binders. The results suggest sulfonate interfaces may alter the binding energies of key species or lead to favorable reconstructions, either of which ultimately results in remarkable improvements in Faradayic efficiencies relative to Au foil electrodes
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Nuclear Energy Research Initiative Project No. 02 103 Innovative Low Cost Approaches to Automating QA/QC of Fuel Particle Production Using On Line Nondestructive Methods for Higher Reliability Final Project Report
This Nuclear Energy Research Initiative (NERI) project was tasked with exploring, adapting, developing and demonstrating innovative nondestructive test methods to automate nuclear coated particle fuel inspection so as to provide the United States (US) with necessary improved and economical Quality Assurance and Control (QA/QC) that is needed for the fuels for several reactor concepts being proposed for both near term deployment [DOE NE & NERAC, 2001] and Generation IV nuclear systems. Replacing present day QA/QC methods, done manually and in many cases destructively, with higher speed automated nondestructive methods will make fuel production for advanced reactors economically feasible. For successful deployment of next generation reactors that employ particle fuels, or fuels in the form of pebbles based on particles, extremely large numbers of fuel particles will require inspection at throughput rates that do not significantly impact the proposed manufacturing processes. The focus of the project is nondestructive examination (NDE) technologies that can be automated for production speeds and make either: (I) On Process Measurements or (II) In Line Measurements. The inspection technologies selected will enable particle “quality” qualification as a particle or group of particles passes a sensor. A multiple attribute dependent signature will be measured and used for qualification or process control decisions. A primary task for achieving this objective is to establish standard signatures for both good/acceptable particles and the most problematic types of defects using several nondestructive methods
To which world regions does the valence–dominance model of social perception apply?
Over the past 10 years, Oosterhof and Todorov’s valence–dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgements of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov’s methodology across 11 world regions, 41 countries and 11,570 participants. When we used Oosterhof and Todorov’s original analysis strategy, the valence–dominance model generalized across regions. When we used an alternative methodology to allow for correlated dimensions, we observed much less generalization. Collectively, these results suggest that, while the valence–dominance model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed when we use different extraction methods and correlate and rotate the dimension reduction solution
A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.
The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world
Coprocessing Biomass Fast Pyrolysis and Catalytic Fast Pyrolysis Oils with Vacuum Gas Oil in Refinery Hydroprocessing
Fast pyrolysis and catalytic fast pyrolysis (CFP) have
been considered
to be promising approaches for converting lignocellulosic biomass
into liquid bio-oils followed by upgrading to produce fuel-range hydrocarbon
products. Coprocessing fast pyrolysis and CFP bio-oils with petroleum
feedstocks leverages the existing petroleum refining infrastructure,
which reduces capital expenditure for the overall conversion technologies
for biomass to fuel and enables fast adoption of the technologies
and biofuels. Here, we reported the coprocessing of different woody
fast pyrolysis and CFP bio-oils with petroleum vacuum gas oil (VGO)
at 5–25% bio-oil blending levels over a NiMo sulfide catalyst
for hydrotreating/mild hydrocracking. The catalyst activities over
∼300 h time on stream, the product yield and properties, and
the biogenic carbon content in products are provided. Coprocessing
of the raw fast pyrolysis bio-oil in our configuration was not successful
because the instability of the bio-oil resulted in reactor plugging,
and bio-oil stabilization by hydrogenation enabled their stable coprocessing
with VGO, whereas the CFP bio-oil can be coprocessed without pretreatment.
Simultaneous hydrodesulfurization, hydrodeoxygenation, and hydrocracking
reactions occurred during coprocessing, and no obvious decrease in
hydrodesulfurization and hydrocracking conversion of VGO was observed,
suggesting the minimal impact of coprocessed bio-oils on the reaction
of VGO and also the simultaneous conversion of bio-oil and VGO to
produce fuel products with much-reduced S and O content. Biogenic
carbon content in coprocessed products calculated by yield mass balance,
together with results from isotopic measurements, indicates biogenic
carbon incorporation into liquid hydrocarbon products. Higher biogenic
carbon incorporation into fuel products was observed when coprocessing
CFP bio-oils as compared to the fast pyrolysis bio-oils, and over
90% of carbon in CFP bio-oil was incorporated into liquid hydrocarbon
products
Atomic layer deposition of ZnO on Cu-nanoclusters for methanol synthesis
The properties of ALD-grown ZnO thin films on Cu clusters supported on ZnO (10 1̄ 0) have been studied with scanning tunneling and scanning electron microscopy in combination with angle-resolved x-ray photoelectron spectroscopy. Deposition at room temperature of two monolayers of Cu on ZnO (10 1̄ 0) results in metallic Cu0 clusters ∼8 nm wide by 1.4 nm high. Higher coverages of 15 ML results in a similar morphology, with slightly larger cluster sizes. Following air-exposure and ALD-growth of two cycles of ZnO, the Cu exhibits Cu+ species characteristic of Cu2O and the thin ZnO coating is hydroxylated. Electrochemical studies of ALD ZnO coatings on Cu suggest that they are more active for CO2 reduction. © 2013 American Vacuum Society
A tissue engineering approach for prenatal closure of myelomeningocele: Comparison of gelatin sponge and microsphere scaffolds and bioactive protein coatings
Miho Watanabe, Hiaying Li, Jessica Roybal, Matthew Santore, Antonetta Radu, Jun-Ichiro Jo, Michio Kaneko, Yasuhiko Tabata, and Alan Flake. Tissue Engineering Part A.Apr 2011.1099-1110. http://doi.org/10.1089/ten.tea.2010.039
Conversion of syngas-derived C 2 + mixed oxygenates to C 3 –C 5 olefins over Zn x Zr y O z mixed oxide catalysts
International audienceIn this study we report on a ZnxZryOz mixed oxide type catalyst capable of converting a syngas-derived C2+ mixed oxygenate feedstock to isobutene-rich olefins. Aqueous model feed comprising of ethanol, acetaldehyde, acetic acid, ethyl acetate, methanol, and propanol was used as representative liquid product derived from a Rh-based mixed oxygenate synthesis catalyst. Greater than 50% carbon yield to C3–C5 mixed olefins was demonstrated when operating at 400–450 °C and 1 atm. In order to rationalize formation of the products observed feed components were individually evaluated. Major constituents of the feed mixture (ethanol, acetaldehyde, acetic acid, and ethyl acetate) were found to produce isobutene-rich olefins. C–C coupling was also demonstrated for propanol feedstock – a minor constituent of the mixed oxygenate feed – producing branched C6 olefins, revealing scalability to alcohols higher than ethanol following an analogous reaction pathway. Using ethanol and propanol feed mixtures, cross-coupling reactions produced mixtures of C4, C5, and C6 branched olefins. The presence of H2 in the feed was found to facilitate hydrogenation of the ketone intermediates, thus producing straight chain olefins as byproducts. While activity loss from coking is observed complete catalyst regeneration is achieved by employing mild oxidation. For conversion of the mixed oxygenate feed a Zr/Zn ratio of 2.5 and a reaction temperature of 450 °C provides the best balance of stability, activity, and selectivity. X-ray diffraction and scanning transmission electron microscopy analysis reveals the presence of primarily cubic phase ZrO2 and a minor amount of the monoclinic phase, with ZnO being highly dispersed in the lattice. The presence of ZnO appears to stabilize the cubic phase resulting in less monoclinic phase as the ZnO concentration increases. Infrared spectroscopy shows the mixed oxide acid sites are characterized as primarily Lewis type acidity. The direct relationship between isobutene production and the ratio of basic/acidic sites was demonstrated. An optimized balance of active sites for isobutene production from acetone was obtained with a basic/acidic site ratio of ∼2. This technology for the conversion of aqueous mixtures of C2+ mixed oxygenates provides significant advantages over other presently studied catalysts in that its unique properties permit the utilization of a variety of feeds in a consistently selective manner
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