527 research outputs found
Divergent Thermal Conductivity in Three-dimensional Nonlinear lattices
Heat conduction in three-dimensional nonlinear lattices is investigated using
a particle dynamics simulation. The system is a simple three-dimensional
extension of the Fermi-Pasta-Ulam (FPU-) nonlinear lattices, in
which the interparticle potential has a biquadratic term together with a
harmonic term. The system size is , and the heat is made to
flow in the direction the Nose-Hoover method. Although a linear
temperature profile is realized, the ratio of enerfy flux to temperature
gradient shows logarithmic divergence with . The autocorrelation function of
energy flux is observed to show power-law decay as ,
which is slower than the decay in conventional momentum-cnserving
three-dimensional systems (). Similar behavior is also observed in
the four dimensional system.Comment: 4 pages, 5 figures. Accepted for publication in J. Phys. Soc. Japan
Letter
Language clustering and knowledge sharing in multilingual organizations: A social perspective on language
American or British? L2 speakers’ recognition and evaluations of accent features in English
Recent language attitude research has attended to the processes involved in identifying and evaluating spoken language varieties. This article investigates the ability of second-language learners of English in Spain (N=71) to identify Received Pronunciation (RP) and General American (GenAm) and their perceptions of linguistic variation between these speech varieties. Data were gathered using a verbal-guise experiment in which respondents identified speakers’ places of origin and stated the reasons for their categorisations. Quantitative data analysis demonstrated high recognition rates for RP speakers, more often correctly identified than GenAm speakers. Qualitative data analysis showed that respondents’ knowledge of phonological variation informed the identification process and they often stated which linguistic features formed part of their mental representations of RP and GenAm. Additional resources informed accent recognition, including perceived linguistic quality, intelligibility, familiarity, and cultural associations. Patterns of misidentification revealed that, when GenAm was inaccurately identified as RP, it was ascribed high status. The findings provide an insight into the strategies, conceptual frameworks, and linguistic features which inform the accent identification process as performed by English-language learners in Spain. The results also highlight the usefulness of variety recognition items in interpreting attitudinal evaluations, especially with regard to patterns of misidentification
The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND)
The observation of neutrinoless double-beta decay (0)
would show that lepton number is violated, reveal that neutrinos are Majorana
particles, and provide information on neutrino mass. A discovery-capable
experiment covering the inverted ordering region, with effective Majorana
neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with
excellent energy resolution and extremely low backgrounds, at the level of
0.1 count /(FWHMtyr) in the region of the signal. The
current generation Ge experiments GERDA and the MAJORANA DEMONSTRATOR
utilizing high purity Germanium detectors with an intrinsic energy resolution
of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in
the 0 signal region of all 0
experiments. Building on this success, the LEGEND collaboration has been formed
to pursue a tonne-scale Ge experiment. The collaboration aims to develop
a phased 0 experimental program with discovery potential
at a half-life approaching or at years, using existing resources as
appropriate to expedite physics results.Comment: Proceedings of the MEDEX'17 meeting (Prague, May 29 - June 2, 2017
Anomalous Heat Conduction and Anomalous Diffusion in Low Dimensional Nanoscale Systems
Thermal transport is an important energy transfer process in nature. Phonon
is the major energy carrier for heat in semiconductor and dielectric materials.
In analogy to Ohm's law for electrical conductivity, Fourier's law is a
fundamental rule of heat transfer in solids. It states that the thermal
conductivity is independent of sample scale and geometry. Although Fourier's
law has received great success in describing macroscopic thermal transport in
the past two hundreds years, its validity in low dimensional systems is still
an open question. Here we give a brief review of the recent developments in
experimental, theoretical and numerical studies of heat transport in low
dimensional systems, include lattice models, nanowires, nanotubes and
graphenes. We will demonstrate that the phonon transports in low dimensional
systems super-diffusively, which leads to a size dependent thermal
conductivity. In other words, Fourier's law is breakdown in low dimensional
structures
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP
Promptly decaying lightest neutralinos and long-lived staus are searched for
in the context of light gravitino scenarios. It is assumed that the stau is the
next to lightest supersymmetric particle (NLSP) and that the lightest
neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector
at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of
the production of these particles is found. Hence, lower mass limits for both
kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is
found to be greater than 71.5 GeV/c^2. In the search for long-lived stau,
masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10
to 150 \eVcc . Combining this search with the searches for stable heavy leptons
and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc
may be set for the stau mas
Anomalous Heat Conduction in Three-Dimensional Nonlinear Lattices
Heat conduction in three-dimenisional nonlinear lattice models is studied
using nonequilibrium molecular dynamics simulations. We employ the FPU model,
in which there exists a nonlinearity in the interaction of biquadratic form. It
is confirmed that the thermal conductivity, the ratio of the energy flux to the
temperature gradient, diverges in systems up to 128x128x256 lattice sites. This
size corresponds to nanoscopic to mesoscopic scales of several tens of
nanometers. From these results, we conjecture that the energy transport in
insulators with perfect crystalline order exhibits anomalous behavior. The
effects of lattice structure, random impurities, and natural length in
interactions are also examined. We find that face-centered cubic (fcc) lattices
display stronger divergence than simple cubic lattices. When impurity sites of
infinitely large mass, which are hence fixed, are randomly distributed, such
divergence vanishes.Comment: 10pages, 10 figures, Fig. 1 is replaced and some minor corrections
were mad
Latin American immigrants in Indianapolis: Perceptions of prejudice and discrimination
The article focuses on immigrants’ interactions with the Indiana natives, with emphasis in the city of Indianapolis and its suburbs. More specifically, this study aims at providing an understanding of the experiences of Latin American immigrants with special attention to perceptions of prejudice and discrimination and to feelings of social exclusion. A substantial proportion of Latin American immigrants interviewed indicated that they considered Indiana natives to be prejudiced and that they had personally experienced discrimination. The study reveals specific examples of discrimination experienced by the immigrants at the work place, in housing, in stores, restaurants and by various service providers. The results of the study demonstrate the relevance of the normative and power resource theories to explain prejudice and discrimination
Voice as a design material : sociophonetic inspired design strategies in Human-Computer Interaction
While there is a renewed interest in voice user interfaces (VUI) in HCI, little attention has been paid to the design of VUI voice output beyond intelligibility and naturalness. We draw on the field of sociophonetics - the study of the social factors that influence the production and perception of speech - to highlight how current VUIs are based on a limited and homogenised set of voice outputs. We argue that current systems do not adequately consider the diversity of peoples’ speech, how that diversity represents sociocultural identities, and how voices have the potential to shape user perceptions and experiences. Ultimately, as other technological developments have influenced the ideologies of language, the voice outputs of VUIs will influence the ideologies of speech. Based on our argument, we pose three design strategies for VUI voice output design - individualisation, context awareness, and diversification - to motivate new ways of conceptualising and designing these technologies
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