42 research outputs found
Individuals, communities, and sound change:An introduction
Do individual differences affect sound change? Traditional approaches to phonetic and phonological change typically downplay differences between the individuals who make up a speech community that is undergoing change, but this has been questioned in recent years in a number of ways from within several distinct traditions of research. The articles in the Glossa Special Collection to which this article is an introduction consider the extent to which individual differences (at a psychological, sociological, physiological, genetic and/or behavioral level) between the members of a speech community might or might not be important in explaining the general properties of sound change. This introduction places these articles in context, considers what we might mean by ‘sound change’ and ‘individual differences’, and aims to build a synthesis of the current research landscape in the area
Splitting ‘intervocalic’: Expanding the typology of lenition environments
The basic types of lenition environments (‘initial’, ‘intervocalic’, ‘final’) need to be separately evaluated as they differ along parameters like word position (e.g., pre-consonantal vs. final codas) or stress relations. This paper argues that we need to recognise an additional such parameter: the length of the vowel preceding an intervocalic consonant. We show that a number of phenomena from varieties of English and German show lenition patterns which draw a distinction between reflexes found in post-short (vc) and post-long (vvc) environments. The theoretical consequence of our observations is that phonological theory needs to be able to account for the post-short vs. post-long distinction in the form of a parametrically-determined representational difference
Structural-Properties Of Amorphous Hydrogenated Carbon .1. A High-Resolution Neutron-Diffraction Study
The structure of samples of amorphous hydrogenated carbon, prepared from acetylene and propane precursors, containing 35 and 32 at.% hydrogen, respectively, was investigated by time-of-flight neutron diffraction in the range 0.2-50 angstrom-1 using the ISIS spallation source. The large dynamic range of the data ensures a real-space resolution sufficient to reveal directly the proportions of sp2 and sp3 hybridized carbon. The results show that, in these hard carbon materials, the carbon-atom sites are predominantly sp2 bonded, and the carbon-carbon single bond:carbon-carbon double bond ratio is about 2.5:1. The detailed information on atomic correlations thus provided is used to discuss current structural models, and in particular the data are used to show that these models require significant modification
Structural properties of amorphous hydrogenated carbon. IV. A molecular-dynamics investigation and comparison to experiments
Hydrogenated amorphous carbon structures, a-C:H, with densities of 1.8 and 2.0 g/cm3, have been generated by semiempirical density-functions (DF) molecular-dynamics (MD) rapid cooling of a liquid phase of 128 carbon and 64 hydrogen atoms within periodically arranged cubic supercells. The electronic bonding properties of the model structures are analyzed within a local-orbital description. The structural properties are compared to relevant statistical and diffraction data obtained by neutron scattering and NMR in order to achieve a fundamental understanding of structure-related properties on the molecular level of chemical bonding
A spectroscopic study of the structure of amorphous hydrogenated carbon
A range of amorphous hydrogenated carbon (a-C:H) samples have been studied using inelastic neutron spectroscopy (INS) and Fourier transform infrared (FTIR) spectroscopy. Using these complementary techniques, the bonding environments of both carbon and hydrogen can be probed in some detail, with the INS data providing not only qualitative but also quantitative information. By comparing the data from each of the samples we have been able to examine the effects of different deposition conditions, i.e. precursor gas, deposition energy and deposition method, on the atomic-scale structure of a-C:H
How sharing can contribute to more sustainable cities
\ua9 2017 by the authors. Recently, much of the literature on sharing in cities has focused on the sharing economy, in which people use online platforms to share underutilized assets in the marketplace. This view of sharing is too narrow for cities, as it neglects the myriad of ways, reasons, and scales in which citizens share in urban environments. Research presented here by the Liveable Cities team in the form of participant workshops in Lancaster and Birmingham, UK, suggests that a broader approach to understanding sharing in cities is essential. The research also highlighted tools and methods that may be used to help to identify sharing in communities. The paper ends with advice to city stakeholders, such as policymakers, urban planners, and urban designers, who are considering how to enhance sustainability in cities through sharing