5,415 research outputs found
Investigation of potential of differential absorption Lidar techniques for remote sensing of atmospheric pollutants
The NASA multipurpose differential absorption lidar (DIAL) system uses two high conversion efficiency dye lasers which are optically pumped by two frequency-doubled Nd:YAG lasers mounted rigidly on a supporting structure that also contains the transmitter, receiver, and data system. The DIAL system hardware design and data acquisition system are described. Timing diagrams, logic diagrams, and schematics, and the theory of operation of the control electronics are presented. Success in obtaining remote measurements of ozone profiles with an airborne systems is reported and results are analyzed
An experimental/analytical program to assess the utility of lidar for pollution monitoring
The development and demonstration of lidar techniques for the remote measurement of atmospheric constituents and transport processes in the lower troposphere was carried out. Particular emphasis was given to techniques for monitoring SO2 and particulates, the principal pollutants in power plant and industrial plumes. Data from a plume dispersion study conducted in Maryland during September and October 1976 were reduced, and a data base was assembled which is available to the scientific community for plume model verification. A UV Differential Absorption Lidar (DIAL) was built, and preliminary testing was done
Use of an Ilizarov apparatus to perform closed reduction of a chronic proximal dislocation following total hip arthroplasty: A case report
Microscopic expressions for the thermodynamic temperature
We show that arbitrary phase space vector fields can be used to generate
phase functions whose ensemble averages give the thermodynamic temperature. We
describe conditions for the validity of these functions in periodic boundary
systems and the Molecular Dynamics (MD) ensemble, and test them with a
short-ranged potential MD simulation.Comment: 21 pages, 2 figures, Revtex. Submitted to Phys. Rev.
Experiencing gender in UK political science:The results of a practitioner survey
Does gender matter in the way in which we âperformâ academia? Drawing on the results of a practitioner survey, we argue that gender does matter, culturally and structurally, and can be institutionalised so that women are disadvantaged. This is not to deny womenâs agency or the advances that they have made. Rather, we highlight the inequality of the playing field in which the academic endeavour is conducted. Uniquely, we ask UK political scientists about their perceptions of the impact of gender in their working lives and explore their views on recommendations for change
Young people's uses of celebrity: Class, gender and 'improper' celebrity
This is an Author's Accepted Manuscript of an article published in Discourse: Studies in the Cultural
Politics of Education, 34(1), 2013, copyright Taylor & Francis, available online at:
http://www.tandfonline.com/10.1080/01596306.2012.698865.In this article, we explore the question of how celebrity operates in young people's everyday lives, thus contributing to the urgent need to address celebrity's social function. Drawing on data from three studies in England on young people's perspectives on their educational and work futures, we show how celebrity operates as a classed and gendered discursive device within young people's identity work. We illustrate how young people draw upon class and gender distinctions that circulate within celebrity discourses (proper/improper, deserving/undeserving, talented/talentless and respectable/tacky) as they construct their own identities in relation to notions of work, aspiration and achievement. We argue that these distinctions operate as part of neoliberal demands to produce oneself as a âsubject of valueâ. However, some participants produced readings that show ambivalence and even resistance to these dominant discourses. Young people's responses to celebrity are shown to relate to their own class and gender position.The Arts and Humanities Research Council, the British Academy, the
Economic and Social Research Council, and the UK Resource Centre for
Women in Science Engineering and Technology
Homogeneous nucleation of colloidal melts under the influence of shearing fields
We study the effect of shear flow on homogeneous crystal nucleation, using
Brownian Dynamics simulations in combination with an umbrella sampling like
technique. The symmetry breaking due to shear results in anisotropic radial
distribution functions. The homogeneous shear rate suppresses crystal
nucleation and leads to an increase of the size of the critical nucleus. These
observations can be described by a simple, phenomenological extension of
classical nucleation theory. In addition, we find that nuclei have a
preferential orientation with respect to the direction of shear. On average the
longest dimension of a nucleus is along the vorticity direction, while the
shortest dimension is preferably perpendicular to that and slightly tilted with
respect to the gradient direction.Comment: 10 pages, 8 figures, Submitted to J. Phys.: Condens. Matte
Response to environmental perturbations in microbial nutrient-cycling ecosystems
The habitability of Earth is dependent upon the global recycling of elements
essential for life, such as nitrogen, sulfur and carbon. Nutrient-cycling by micro-organisms
is vital to these biogeochemical cycles because many key steps are
mediated primarily, or exclusively, by microbial life. The dynamics of these cycles
are highly complex, and environmental perturbations (such as changes in the
oceanic oxygen concentration) can have unexpected or catastrophic effects; often
causing abrupt switches between chemical states. Despite the importance of these
environmental perturbations however, few theoretical models have addressed how
they affect the dynamical behaviour of nutrient-cycling microbial ecosystems.
In this work, we investigate the effect of environmental perturbations on
microbially-mediated nutrient cycles and assess the likelihood of "sudden transitions"
between chemical states of the ecosystem occurring in a variety of ecological
contexts. To do this, we first use computational modelling of microbial nutrient-cycling,
using a "box model" approach. We then move on to an experimental
study using the microbial sulfur cycle as a model ecosystem, with freshwater
pond sediment/water microcosms. These microcosms have the advantage
of retaining many of the features of the real ecosystem (such as microbial
diversity, spatial structure, and abiotic interactions) while allowing the controlled
manipulation of environmental perturbations. We study these microcosms using
a combination of chemical measurements and high-throughput sequencing of
the microbial community. Finally, we return to the computational side, and
attempt to reproduce chemical data from our experiments in a mathematical
model containing realistic abiotic chemical interactions
"Ordinary, the same as anywhere else": notes on the management of spoiled identity in 'marginal' middle class neighbourhoods
Urban sociologists are becoming increasingly interested in neighbourhood as a source of middle-class identity. Particular emphasis is currently being given to two types of middle-class neighbourhood; gentrified urban neighbourhoods of âdistinctionâ and inconspicuous âsuburban landscapes of privilegeâ. However, there has been a dearth of work on âmarginalâ middle-class neighbourhoods that are similarly âinconspicuousâ rather than distinctive, but less exclusive, thus containing sources of âspoiled identityâ. This article draws on data gathered from two âmarginalâ middleclass neighbourhoods that contained a particular source of âspoiled identityâ: social renters. Urban sociological analyses of neighbour responses to these situations highlight a process of dis-identification with the maligned object, which exacerbates neighbour differences. Our analysis of data from the âmarginalâ middle-class neighbourhoods suggests something entirely different and Goffmanesque. This entailed the management of spoiled identity, which emphasized similarities rather than differences between neighbours.</p
- âŠ