276 research outputs found
Acoustic signalling reflects personality in a social mammal
Social interactions among individuals are often mediated through acoustic signals. If acoustic signals are consistent and related to an individual's personality, these consistent individual differences in signalling may be an important driver in social interactions. However, few studies in non-human mammals have investigated the relationship between acoustic signalling and personality. Here we show that acoustic signalling rate is repeatable and strongly related to personality in a highly social mammal, the domestic pig (Sus scrofa domestica). Furthermore, acoustic signalling varied between environments of differing quality, with males from a poor-quality environment having a reduced vocalization rate compared with females and males from an enriched environment. Such differences may be mediated by personality with pigs from a poor-quality environment having more reactive and more extreme personality scores compared with pigs from an enriched environment. Our results add to the evidence that acoustic signalling reflects personality in a non-human mammal. Signals reflecting personalities may have far reaching consequences in shaping the evolution of social behaviours as acoustic communication forms an integral part of animal societies
Validation of New Process Models for Large Injection-Molded Long-Fiber Thermoplastic Composite Structures
This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oak Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6
New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"
Physics beyond the Standard Model predicts the possible existence of new
particles that can be searched at the low energy frontier in the sub-eV range.
The OSQAR photon regeneration experiment looks for "Light Shining through a
Wall" from the quantum oscillation of optical photons into "Weakly Interacting
Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T
transverse magnetic field over the unprecedented length of m.
In 2014, this experiment has been run with an outstanding sensitivity, using an
18.5 W continuous wave laser emitting in the green at the single wavelength of
532 nm. No regenerated photons have been detected after the wall, pushing the
limits for the existence of axions and ALPs down to an unprecedented level for
such a type of laboratory experiment. The di-photon couplings of possible
pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit
to be less than GeV and
GeV, respectively, at 95% Confidence Level.Comment: 6 pages, 6 figure
On Varieties of Ordered Automata
The Eilenberg correspondence relates varieties of regular languages to
pseudovarieties of finite monoids. Various modifications of this correspondence
have been found with more general classes of regular languages on one hand and
classes of more complex algebraic structures on the other hand. It is also
possible to consider classes of automata instead of algebraic structures as a
natural counterpart of classes of languages. Here we deal with the
correspondence relating positive -varieties of languages to
positive -varieties of ordered automata and we present various
specific instances of this correspondence. These bring certain well-known
results from a new perspective and also some new observations. Moreover,
complexity aspects of the membership problem are discussed both in the
particular examples and in a general setting
Effect of pressure on the Raman modes of antimony
The effect of pressure on the zone-center optical phonon modes of antimony in
the A7 structure has been investigated by Raman spectroscopy. The A_g and E_g
frequencies exhibit a pronounced softening with increasing pressure, the effect
being related to a gradual suppression of the Peierls-like distortion of the A7
phase relative to a cubic primitive lattice. Also, both Raman modes broaden
significantly under pressure. Spectra taken at low temperature indicate that
the broadening is at least partly caused by phonon-phonon interactions. We also
report results of ab initio frozen-phonon calculations of the A_g and E_g mode
frequencies. Presence of strong anharmonicity is clearly apparent in calculated
total energy versus atom displacement relations. Pronounced nonlinearities in
the force versus displacement relations are observed. Structural instabilities
of the Sb-A7 phase are briefly addressed in the Appendix.Comment: 10 pages, 8 figure
Raman spectra of MgB2 at high pressure and topological electronic transition
Raman spectra of the MgB2 ceramic samples were measured as a function of
pressure up to 32 GPa at room temperature. The spectrum at normal conditions
contains a very broad peak at ~590 cm-1 related to the E2g phonon mode. The
frequency of this mode exhibits a strong linear dependence in the pressure
region from 5 to 18 GPa, whereas beyond this region the slope of the
pressure-induced frequency shift is reduced by about a factor of two. The
pressure dependence of the phonon mode up to ~ 5GPa exhibits a change in the
slope as well as a "hysteresis" effect in the frequency vs. pressure behavior.
These singularities in the E2g mode behavior under pressure support the
suggestion that MgB2 may undergo a pressure-induced topological electronic
transition.Comment: 2 figure
Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives
Recent theoretical and experimental studies highlight the possibility of new
fundamental particle physics beyond the Standard Model that can be probed by
sub-eV energy experiments. The OSQAR photon regeneration experiment looks for
"Light Shining through a Wall" (LSW) from the quantum oscillation of optical
photons into "Weakly Interacting Sub-eV Particles" (WISPs), like axion or
axion-like particles (ALPs), in a 9 T transverse magnetic field over the
unprecedented length of m. No excess of events has been
detected over the background. The di-photon couplings of possible new light
scalar and pseudo-scalar particles can be constrained in the massless limit to
be less than GeV. These results are very close to the
most stringent laboratory constraints obtained for the coupling of ALPs to two
photons. Plans for further improving the sensitivity of the OSQAR experiment
are presented.Comment: 7 pages, 7 figure
Timbre brownfield prioritization tool to support effective brownfield regeneration.
In the last decade, the regeneration of derelict or underused sites, fully or partly located in urban areas (or so called âbrownfieldsâ), has become more common, since free developable land (or so called âgreenfieldsâ) has more and more become a scare and, hence, more expensive resource, especially in densely populated areas. Although the regeneration of brownfield sites can offer development potentials, the complexity of these sites requires considerable efforts to successfully complete their revitalization projects and the proper selection of promising sites is a pre-requisite to efficiently allocate the limited financial resources. The identification and analysis of success factors for brownfield sites regeneration can support investors and decision makers in selecting those sites which are the most advantageous for successful regeneration. The objective of this paper is to present the Timbre Brownfield Prioritization Tool (TBPT), developed as a web-based solution to assist stakeholders responsible for wider territories or clusters of brownfield sites (portfolios) to identify which brownfield sites should be preferably considered for redevelopment or further investigation. The prioritization approach is based on a set of success factors properly identified through a systematic stakeholder engagement procedure. Within the TBPT these success factors are integrated by means of a Multi Criteria Decision Analysis (MCDA) methodology, which includes stakeholders' requalification objectives and perspectives related to the brownfield regeneration process and takes into account the three pillars of sustainability (economic, social and environmental dimensions). The tool has been applied to the South Moravia case study (Czech Republic), considering two different requalification objectives identified by local stakeholders, namely the selection of suitable locations for the development of a shopping centre and a solar power plant, respectively. The application of the TBPT to the case study showed that it is flexible and easy to adapt to different local contexts, allowing the assessors to introduce locally relevant parameters identified according to their expertise and considering the availability of local data
Small Fermi energy and phonon anharmonicity in MgB_2 and related compounds
The remarkable anharmonicity of the E_{2g} phonon in MgB_2 has been suggested
in literature to play a primary role in its superconducting pairing. We
investigate, by means of LDA calculations, the microscopic origin of such an
anharmonicity in MgB_2, AlB_2, and in hole-doped graphite. We find that the
anharmonic character of the E_{2g} phonon is essentially driven by the small
Fermi energy of the sigma holes. We present a simple analytic model which
allows us to understand in microscopic terms the role of the small Fermi energy
and of the electronic structure. The relation between anharmonicity and
nonadiabaticity is pointed out and discussed in relation to various materials.Comment: 5 pages, 2 figures replaced with final version, accepted on Physical
Review
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