11,483 research outputs found

    Organosolv pretreatment of Sitka spruce wood: conversion of hemicelluloses to ethyl glycosides

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    A range of organosolv pretreatments, using ethanol:water mixtures with dilute sulphuric acid, were applied to Sitka spruce sawdust with the aim of generating useful co-products as well as improving saccharification yield. The most efficient of the pretreatment conditions, resulting in subsequent saccharification yields of up to 86%, converted a large part of the hemicellulose sugars to their ethyl glycosides as identified by GC/MS. These conditions also reduced conversion of pentoses to furfural, the ethyl glycosides being more stable to dehydration than the parent pentoses. Through comparison with the behaviour of model compounds under the same reaction conditions it was shown that the anomeric composition of the products was consistent with a predominant transglycosylation reaction mechanism, rather than hydrolysis followed by glycosylation. The ethyl glycosides have potential as intermediates in the sustainable production of high-value chemicals

    Queens Performing Artists & Workspace

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    The Queens Workspace Initiative (QWI) is a project conceived and led by Exploring the Metropolis (EtM) to help ensure that the performing arts offerings in the borough of Queens are the best they can be.The major activities comprise surveying performing artists, cultural facilities and other stakeholders; making recommendations to stakeholders and policymakers; and conducting pilot programs.In 2013-14, Exploring the Metropolis has been assessing workspace needs for performing artists in Queens. We've interviewed key players, sent out surveys, held focus groups and studied ways to help the Queens performing arts community grow and thrive

    Isolation of high quality lignin as a by-product from ammonia percolation pretreatment of poplar wood

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    A two-step process combining percolation-mode ammonia pretreatment of poplar sawdust with mild organosolv purification of the extracted lignin produced high quality, high purity lignin in up to 31% yield and 50% recovery. The uncondensed fraction of the isolated lignin was up to 34%, close to that the native lignin (40%). Less lignin was recovered after pretreatment in batch mode, apparently due to condensation during the longer residence time of the solubilised lignin at elevated temperature. The lignin recovery was directly correlated with its molecular weight and its nitrogen content. Low nitrogen incorporation, observed at high ammonia concentration, may be explained by limited homolytic cleavage of -O-4 bonds. Ammonia concentrations from 15% to 25% (w/w) gave similar results in terms of lignin structure, yield and recovery

    Becoming Sonic: Ambient Poetics and the Ecology of Listening in Four Militant Sound Investigations

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    This dissertation Becoming Sonic: Ambient Poetics and the Ecology of the Ear in Four Militant Sound Investigations offers a critical and historical analysis of acoustic ecology and soundscape recording —the sounds, noises, and silences that make up our ambient sonic environment and are found and recorded “in the field” by artists to create recordings and performances are then experienced by listeners. Field recording captures the diverse and often unwanted or inconsequential sounds of a space, which can then be used to bring attention to the often unheard and unconscious processes that stratify space. By stratification I am referring to the processes of urban planning, architecture, business, policies, and governance that shape and grid the environment. Analyzing four case studies by the sound collective Ultra-Red, sound activist Christopher DeLaurenti, and field recording artist Chris Watson, that explore the soundscapes of housing redevelopment, using a food bank, public sex in parks, and the slow violence of ecological devastation, this dissertation builds on and analyzes the sonic environmental and spatial implications of ecology by both critiquing acoustic ecology and employing it as a concept to explore the political, aesthetic, and epistemological consequences of soundscape recording. The purpose of this dissertation is to examine what sound indicates through cultural practice and how it can be used and deployed to create different understandings of the places we live and act. This research articulates a poetics of listening to space that constructs worlds and questions how the environment can be used for aesthetic purposes, how the sounds of the city and ‘nature’ influence artists, how artists practice and experience sound by listening, and what kind of knowledges these aesthetic practices produce. In order to accomplish this, it relies on critical approaches to ecology, space and urbanism (Gilles Deleuze and Fèlix Guattari, David Harvey, Nigel Thrift, and Edward Soja); ecologies of sound and listening (Steve Goodman, Murray Schafer, Susan Bickford, Frances Dyson); and affective politics (Brian Massumi, Erin Manning). This dissertation makes substantiative use of interviews, newspaper articles, and artist’s writings and statements to elucidate its investigation

    Angry expressions strengthen the encoding and maintenance of face identity representations in visual working memory

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    This work was funded by a BBSRC grant (BB/G021538/2) to all authors.Peer reviewedPreprin

    Demonstration of a multi-technique approach to assess glacial microbial populations in the field

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    The ability to perform microbial detection and characterization in-field at extreme environments, rather than on returned samples, has the potential to improve the efficiency, relevance and quantity of data from field campaigns. To date, few examples of this approach have been reported. Therefore, we demonstrate that the approach is feasible in subglacial environments by deploying four techniques for microbial detection: real-time polymerase chain reaction; microscopic fluorescence cell counts, adenosine triphosphate bioluminescence assay and recombinant Factor C assay (to detect lipopolysaccharide). Each technique was applied to 12 subglacial ice samples, 12 meltwater samples and two snow samples from Engabreen, Northern Norway. Using this multi-technique approach, the detected biomarker levels were as expected, being highest in debris-rich subglacial ice, moderate in glacial meltwater and low in clean ice (debris-poor) and snow. Principal component analysis was applied to the resulting dataset and could be performed in-field to rapidly aid the allocation of resources for further sample analysis. We anticipate that in-field data collection will allow for multiple rounds of sampling, analysis, interpretation and refinement within a single field campaign, resulting in the collection of larger and more appropriate datasets, ultimately with more efficient science return

    Modification of Coulomb's law in closed spaces

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    We obtain a modified version of Coulomb's law in two- and three-dimensional closed spaces. We demonstrate that in a closed space the total electric charge must be zero. We also discuss the relation between total charge neutrality of a isotropic and homogenous universe to whether or not its spatial sector is closed.Comment: 11 pages, 3 figure

    Interaction energies of monosubstituted benzene dimers via nonlocal density functional theory

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    We present density-functional calculations for the interaction energy of monosubstituted benzene dimers. Our approach utilizes a recently developed fully nonlocal correlation energy functional, which has been applied to the pure benzene dimer and several other systems with promising results. The interaction energy as a function of monomer distance was calculated for four different substituents in a sandwich and two T-shaped configurations. In addition, we considered two methods for dealing with exchange, namely using the revPBE generalized gradient functional as well as full Hartree-Fock. Our results are compared with other methods, such as Moller-Plesset and coupled-cluster calculations, thereby establishing the usefulness of our approach. Since our density-functional based method is considerably faster than other standard methods, it provides a computational inexpensive alternative, which is of particular interest for larger systems where standard calculations are too expensive or infeasible.Comment: submitted to J. Chem. Phy
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