12,960 research outputs found
Subject searching requirements : the HILT II experience
The HILT Phase II project aimed to develop a pilot terminologies server with a view to improving cross-sectoral information retrieval. In order to inform this process, it was first necessary to examine how a representative group of users approached a range of information-related tasks. This paper focuses on exploratory interviews conducted to investigate the proposed ideal and actual strategies of a group of 30 users in relation to eight separate information tasks. In addition, users were asked to give examples of search terms they may employ and to describe how they would formulate search queries in each scenario. The interview process undertaken and the results compiled are outlined, and associated implications for the development of a pilot terminologies server are discussed
Compressibility effects on fluid entrainment by turbulent mixing layers
Compressibility effects on fluid entrainment by supersonic turbulent mixing layer
Cleavage of GeâS and CâH bonds in the reaction of electron-deficient [Osâ(CO)â(ÎŒ-H)(ÎŒâ-PhâPCHâP(Ph)CâHâ)] with PhâGeSPh: Generation of thiophenol derivatives [Osâ(CO)â(ÎŒ-H)(ÎŒ-SPh)(ÎŒ-dppm)] and [Osâ(CO)â(ÎŒ-H)(ÎŒ-SPh)(ÎŒâ-SCâHâ)(ÎŒ-dppm)]
Heating the electron-deficient [Osâ(CO)â(ÎŒ-H)(ÎŒâ-PhâPCHâP(Ph)CâHâ)] (1) and PhâGeSPh in benzene at 80 °C led to the thiolato bridged compounds, [Osâ(CO)â(ÎŒ-H)(ÎŒ-SPh)(ÎŒ-dppm)] (2) and [Osâ(CO)â(ÎŒ-H)(ÎŒ-SPh)(ÎŒâ-SCâHâ)(ÎŒ-dppm)] (3), formed by cleavage of GeâS and CâS bonds of the ligand, in 40% and 17% yields, respectively. Both compounds 2 and 3 have been characterized by a combination of elemental analysis, infrared and ÂčH NMR spectroscopic data together with single crystal X-ray crystallography. Compound 3 contains an open triangle of osmium atoms bridged by a SPh and SCâHâ ligands on opposite sides of the cluster with a dppm ligand bridging one of the OsâOs edges. Compound 2 consists of a closed triangular cluster of osmium atoms with a bridging SPh, and a bridging hydride ligand on the same OsâOs edge, and a dppm ligand bridging one of the remaining OsâOs edges
Probing strongly interacting atomic gases with energetic atoms
We investigate properties of an energetic atom propagating through strongly
interacting atomic gases. The operator product expansion is used to
systematically compute a quasiparticle energy and its scattering rate both in a
spin-1/2 Fermi gas and in a spinless Bose gas. Reasonable agreement with recent
quantum Monte Carlo simulations even at a relatively small momentum k/kF>1.5
indicates that our large-momentum expansions are valid in a wide range of
momentum. We also study a differential scattering rate when a probe atom is
shot into atomic gases. Because the number density and current density of the
target atomic gas contribute to the forward scattering only, its contact
density (measure of short-range pair correlation) gives the leading
contribution to the backward scattering. Therefore, such an experiment can be
used to measure the contact density and thus provides a new local probe of
strongly interacting atomic gases.Comment: 35 pages, 11 figures; (v4) published with the new titl
SPEIR: Scottish Portals for Education, Information and Research. Final Project Report: Elements and Future Development Requirements of a Common Information Environment for Scotland
The SPEIR (Scottish Portals for Education, Information and Research) project was funded by the Scottish Library and Information Council (SLIC). It ran from February 2003 to September 2004, slightly longer than the 18 months originally scheduled and was managed by the Centre for Digital Library Research (CDLR). With SLIC's agreement, community stakeholders were represented in the project by the Confederation of Scottish Mini-Cooperatives (CoSMiC), an organisation whose members include SLIC, the National Library of Scotland (NLS), the Scottish Further Education Unit (SFEU), the Scottish Confederation of University and Research Libraries (SCURL), regional cooperatives such as the Ayrshire Libraries Forum (ALF)1, and representatives from the Museums and Archives communities in Scotland. Aims; A Common Information Environment For Scotland The aims of the project were to: o Conduct basic research into the distributed information infrastructure requirements of the Scottish Cultural Portal pilot and the public library CAIRNS integration proposal; o Develop associated pilot facilities by enhancing existing facilities or developing new ones; o Ensure that both infrastructure proposals and pilot facilities were sufficiently generic to be utilised in support of other portals developed by the Scottish information community; o Ensure the interoperability of infrastructural elements beyond Scotland through adherence to established or developing national and international standards. Since the Scottish information landscape is taken by CoSMiC members to encompass relevant activities in Archives, Libraries, Museums, and related domains, the project was, in essence, concerned with identifying, researching, and developing the elements of an internationally interoperable common information environment for Scotland, and of determining the best path for future progress
Constraints on small-scale cosmological perturbations from gamma-ray searches for dark matter
Events like inflation or phase transitions can produce large density
perturbations on very small scales in the early Universe. Probes of small
scales are therefore useful for e.g. discriminating between inflationary
models. Until recently, the only such constraint came from non-observation of
primordial black holes (PBHs), associated with the largest perturbations.
Moderate-amplitude perturbations can collapse shortly after matter-radiation
equality to form ultracompact minihalos (UCMHs) of dark matter, in far greater
abundance than PBHs. If dark matter self-annihilates, UCMHs become excellent
targets for indirect detection. Here we discuss the gamma-ray fluxes expected
from UCMHs, the prospects of observing them with gamma-ray telescopes, and
limits upon the primordial power spectrum derived from their non-observation by
the Fermi Large Area Space Telescope.Comment: 4 pages, 3 figures. To appear in J Phys Conf Series (Proceedings of
TAUP 2011, Munich
The epidemiology of the first wave of H1N1 influenza pandemic in Australia : a population-based study
Objectives: Following the recent H1N1 influenza pandemic we were able to describe seropositivity in a repre-sentative sample of adults prior to the availability of a specific vaccine.Methods: This cross-sectional serological study is set in the Barwon Statistical Division, Australia. Blood samples were collected from September 2009 through to May 2010, from 1184 individuals (569 men, 615 women; median age 61.7 years), randomly selected from electoral rolls. Serum was analysed for specific H1N1 immunity using a haemagglutina-tion inhibition test. A self-report provided information about symptoms, demographics and healthcare. Associations be-tween H1N1 infection, gender, households and occupation were determined using logistic regression, adjusting for age.Results: Of 1184 individuals, 129 (58 men, 71 women) were seropositive. Gender-adjusted age-specific prevalence was: 8.3% 20-29 years, 13.5% 30-39, 10.4% 40-49, 6.5% 50-59, 9.7% 60-69, 10.3% 70-79, 18.8% 80+. Standardised preva-lence was 10.3% (95%CI 9.6-11.0). No associations were detected between seropositivity and gender (OR=0.82, 95%CI 0.57-1.19) or being a healthcare worker (OR=1.43, 95%CI 0.62-3.29). Smokers (OR=1.86, 95%CI 1.09-3.15) and those socioeconomically disadvantaged (OR=2.52, 95%CI 1.24-5.13) were at increased risk. Among 129 seropositive individu-als, 31 reported symptoms that were either mild (n = 13) or moderate (time off work, doctor visit, n = 18). For age <60, 39.6% of seropositive individuals reported symptoms, whereas the proportion was 13.2% for age 60+.Conclusions: Following the pandemic, the proportion of seropositive adults was low, but significant subclinical infection was found. Social disadvantage increased the likelihood of infection. The low symptom rate for older ages may relate to pre-existing immunity.<br /
Investigating household recycling behaviour through the interactions between personal and situational factors
In recent years household recycling behaviour (HRB) has become a focal point in social science research to understand the concept of household waste recycling management. Household recycling systems involve two main actors: households and municipalities. This paper reports on an empirical study of the interaction between HRB and household waste recycling systems provided by municipalities. A convenience sample of 412 households was selected to complete a survey on recycling initiatives with personal and situational factors and also their interaction. Results showed that personal factors have a significant relation with situational factors (availability, accessibility, awareness and convenience) (p < 0.01) and vice versa; with a positive correlation (r (412) = +0.41). In addition, personal factors correlated positively to availability, accessibility, awareness and convenience at a p-value below 0.01. Furthermore, situational factors interact with demographical factors such that personal factors may be predicted (overall HRB). This study uses both an interdisciplinary and multi-methods approach to answer its research questions and is also accessible to both practitioner and academic domains. © 2014 WIT Press
Texture Evolution During Isothermal, Isostrain, and Isobaric Loading of Polycrystalline Shape Memory NiTi
In situ neutron diffraction was used to provide insights into martensite variant microstructures during isothermal, isobaric, and isostrain loading in shape memory NiTi. The results show that variant microstructures were equivalent for the corresponding strain, and more importantly, the reversibility and equivalency were immediately evident in variant microstructures that were first formed isobarically but then reoriented to near random self-accommodated microstructures following isothermal deformation. Variant microstructures formed isothermally were not significantly affected by a subsequent thermal cycle under constant strain. In all loading cases considered, the resulting variant microstructure correlated with strain and did not correlate with stress. Based on the ability to select a variant microstructure for a given strain despite thermomechanical loading history, the results demonstrated here can be obtained by following any sequence of thermomechanical loading paths over multiple cycles. Thus, for training shape memory alloys (repeating thermomechanical cycling to obtain the desired variant microstructure), optimal paths can be selected so as to minimize the number of training cycles required, thereby increasing the overall stability and fatigue life of these alloys in actuator or medical applications
Modified Zakharov equations for plasmas with a quantum correction
Quantum Zakharov equations are obtained to describe the nonlinear interaction
between quantum Langmuir waves and quantum ion-acoustic waves. These quantum
Zakharov equations are applied to two model cases, namely the four-wave
interaction and the decay instability. In the case of the four-wave
instability, sufficiently large quantum effects tend to suppress the
instability. For the decay instability, the quantum Zakharov equations lead to
results similar to those of the classical decay instability except for quantum
correction terms in the dispersion relations. Some considerations regarding the
nonlinear aspects of the quantum Zakharov equations are also offered.Comment: 4 figures. Accepted for publication in Physics of Plasmas (2004
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