507 research outputs found

    Aesthetics and literature : a problematic relation?

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    The paper argues that there is a proper place for literature within aesthetics but that care must be taken in identifying just what the relation is. In characterising aesthetic pleasure associated with literature it is all too easy to fall into reductive accounts, for example, of literature as merely "fine writing". Belleslettrist or formalistic accounts of literature are rejected, as are two other kinds of reduction, to pure meaning properties and to a kind of narrative realism. The idea is developed that literature-both poetry and prose fiction-invites its own distinctive kind of aesthetic appreciation which far from being at odds with critical practice, in fact chimes well with it

    Mass detection through parametric analysis and symmetry-breaking in a MEMS array

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    International audienceDue to their low cost, size and precision M/NEMS are efficient sensors. M/NEMS sensors are used in various domains ranging from aeronautics to medicine or telecommunication, with applications such as chemical, inertial or mass sensing. Our previous researches on mass sensing were focused on a single resonator. In this work, a symmetric array of three resonant nanobeams is analysed. The originality lies in the use of a direct parametric analysis to sense an added mass during a symmetry-breaking event

    Climate forcing and air quality change due to regional emissions reductions by economic sector

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    We examine the air quality (AQ) and radiative forcing (RF) response to emissions reductions by economic sector for North America and developing Asia in the CAM and GISS composition/climate models. Decreases in annual average surface particulate are relatively robust, with intermodel variations in magnitude typically <30% and very similar spatial structure. Surface ozone responses are small and highly model dependent. The largest net RF results from reductions in emissions from the North America industrial/power and developing Asia domestic fuel burning sectors. Sulfate reductions dominate the first case, for which intermodel variations in the sulfate (or total) aerosol optical depth (AOD) responses are ~30% and the modeled spatial patterns of the AOD reductions are highly correlated (R=0.9). Decreases in BC dominate the developing Asia domestic fuel burning case, and show substantially greater model-to-model differences. Intermodel variations in tropospheric ozone burden changes are also large, though aerosol changes dominate those cases with substantial net climate forcing. The results indicate that across-the-board emissions reductions in domestic fuel burning in developing Asia and in surface transportation in North America are likely to offer the greatest potential for substantial, simultaneous improvement in local air quality and near-term mitigation of global climate change via short-lived species. Conversely, reductions in industrial/power emissions have the potential to accelerate near-term warming, though they would improve AQ and have a long-term cooling effect on climate. These broad conclusions appear robust to intermodel differences

    Past, present and future atmospheric nitrogen deposition

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    Reactive nitrogen emissions into the atmosphere are increasing due to human activities, affecting nitrogen deposition to the surface and impacting the productivity of terrestrial and marine ecosystems. An atmospheric chemistry-transport model (TM4-ECPL) is here used to calculate the global distribution of total nitrogen deposition, accounting for the first time for both its inorganic and organic fractions in gaseous and particulate phases, and past and projected changes due to anthropogenic activities. The anthropogenic and biomass burning ACCMIP historical and RCP6.0 and RCP8.5 emissions scenarios are used. Accounting for organic nitrogen (ON) primary emissions, the present-day global nitrogen atmospheric source is about 60% anthropogenic, while total N deposition increases by about 20% relative to simulations without ON primary emissions. About 20-25% of total deposited N is ON. About 10% of the emitted nitrogen oxides are deposited as ON instead of inorganic nitrogen (IN) as is considered in most global models. Almost a 3-fold increase over land (2-fold over the ocean) has been calculated for soluble N deposition due to human activities from 1850 to present. The investigated projections indicate significant changes in the regional distribution of N deposition and chemical composition, with reduced compounds gaining importance relative to oxidized ones, but very small changes in the global total flux. Sensitivity simulations quantify uncertainties due to the investigated model parameterizations of IN partitioning onto aerosols and of N chemically fixed on organics to be within 10% for the total soluble N deposition and between 25-35% for the dissolved ON deposition. Larger uncertainties are associated with N emissions

    Projecting ozone hole recovery using an ensemble of chemistry-climate models weighted by model performance and independence

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    Calculating a multi-model mean, a commonly used method for ensemble averaging, assumes model independence and equal model skill. Sharing of model components amongst families of models and research centres, conflated by growing ensemble size, means model independence cannot be assumed and is hard to quantify. We present a methodology to produce a weighted-model ensemble projection, accounting for model performance and model independence. Model weights are calculated by comparing model hindcasts to a selection of metrics chosen for their physical relevance to the process or phenomena of interest. This weighting methodology is applied to the Chemistry-Climate Model Initiative (CCMI) ensemble to investigate Antarctic ozone depletion and subsequent recovery. The weighted mean projects an ozone recovery to 1980 levels, by 2056 with a 95 % confidence interval (2052-2060), 4 years earlier than the most recent study. Perfect-model testing and out-of-sample testing validate the results and show a greater projective skill than a standard multi-model mean. Interestingly, the construction of a weighted mean also provides insight into model performance and dependence between the models. This weighting methodology is robust to both model and metric choices and therefore has potential applications throughout the climate and chemistry-climate modelling communities
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