6,092 research outputs found
Repeatable method of thermal stress fracture test of brittle materials
Method heats specimens slowly and with sufficient control so that the critical temperature gradient in the specimens cannot occur before temperature equilibrium is reached
Counter-intuitive moral judgement following traumatic brain injury
Several neurological patient populations, including Traumatic Brain Injury (TBI), appear to produce an abnormally ‘utilitarian’ pattern of judgements to moral dilemmas; they tend to make judgements that maximise the welfare of the majority, rather than deontological judgements based on the following of moral rules (e.g., do not harm others). However, this patient research has always used extreme dilemmas with highly valued moral rules (e.g., do not kill). Data from healthy participants, however, suggests that when a wider range of dilemmas are employed, involving less valued moral rules (e.g., do not lie), moral judgements demonstrate sensitivity to the psychological intuitiveness of the judgements, rather than their deontological or utilitarian content (Kahane et al., 2011). We sought the moral judgements of 30 TBI participants and 30 controls on moral dilemmas where content (utilitarian/deontological) and intuition (intuitive/counterintuitive) were measured concurrently. Overall TBI participants made utilitarian judgements in equal proportions to controls; disproportionately favouring utilitarian judgements only when they were counterintuitive, and deontological judgements only when they were counterintuitive. These results speak against the view that TBI causes a specific utilitarian bias, suggesting instead that moral intuition is broadly disrupted following TBI
Firewood, food and niche construction : the potential role of Mesolithic hunter-gatherers in actively structuring Scotland's woodlands.
Over the past few decades the potential role of Mesolithic hunter–gatherers in actively constructing their own niches, through the management of wild plants, has frequently been discussed. It is probable that Mesolithic hunter–gatherers systematically exploited specific woodland resources for food and fuel and influenced the ‘natural’ abundance or distribution of particular species within Mesolithic environments. Though there has been considerable discussion of the pollen evidence for potential small-scale human-woodland manipulation in Mesolithic Scotland, the archaeobotanical evidence for anthropogenic firewood and food selection has not been discussed in this context. This paper assesses the evidence for the active role of Mesolithic hunter–gatherer communities in systematically exploiting and managing woodlands for food and fuel in Scotland. While taphonomic factors may have impacted on the frequency of specific species in archaeobotanical assemblages, it is suggested that hunter–gatherers in Mesolithic Scotland were systematically using woodland plants, and in particular hazel and oak, for food and fuel. It is argued that the pollen evidence for woodland management is equivocal, but hints at the role of hunter–gatherers in shaping the structure of their environments, through the maintenance or creation of woodland clearings for settlement or as part of vegetation management strategies. It is proposed that Mesolithic hunter–gatherers may have actively contributed to niche construction and that the systematic use of hazel and oak as a fuel may reflect the deliberate pruning of hazel trees to increase nut-yields and the inadvertent – or perhaps deliberate – coppicing of hazel and oak during greenwood collection
Lessons and Prospects from the pMSSM after LHC Run I: Neutralino LSP
We study SUSY signatures at the 7, 8 and 14 TeV LHC employing the
19-parameter, R-Parity conserving p(henomenological)MSSM, in the scenario with
a neutralino LSP. Our results were obtained via a fast Monte Carlo simulation
of the ATLAS SUSY analysis suite. The flexibility of this framework allows us
to study a wide variety of SUSY phenomena simultaneously and to probe for weak
spots in existing SUSY search analyses. We determine the ranges of the
sparticle masses that are either disfavored or allowed after the searches with
the 7 and 8 TeV data sets are combined. We find that natural SUSY models with
light squarks and gluinos remain viable. We extrapolate to 14 TeV with both 300
fb and 3 ab of integrated luminosity and determine the expected
sensitivity of the jets + MET and stop searches to the pMSSM parameter space.
We find that the high-luminosity LHC will be powerful in probing SUSY with
neutralino LSPs and can provide a more definitive statement on the existence of
natural Supersymmetry.Comment: 41 pages, 27 figures. arXiv admin note: substantial text overlap with
arXiv:1307.844
E-learning success factors: comparing perspectives from academic staff and students
This article advances knowledge on the factors that lead to successful e-learning in universities, through a comparative study of the perspectives of academic staff and students. In particular, it contributes to the limited knowledge bases on the effectiveness of e-learning in Saudi Arabia, and on the differences in perspectives of different groups of stakeholders in e-learning. Based on previous research, a questionnaire was designed and distributed to convenience samples of academic staff and students at King Saud University, Saudi Arabia. Respondents were invited to express their opinion regarding the importance of a number of factors to the success of e-learning. Principal Component Analysis was conducted on each dataset, in turn, to assess the loading of items onto factors, and the variance explained. The most important finding from this study is that the perspectives of students and academic staff differ, with there being nine factors for academic staff and seven for students. Categories that are common to both groups are: student characteristics, instructor characteristics, ease of access, and support and training. The order for academics is: student characteristics, ease of access, instructor characteristics, and support and training; and, the order foe students is: instructor characteristics, student characteristics, support and training, and ease of access
Density Matrix Renormalization for Model Reduction in Nonlinear Dynamics
We present a novel approach for model reduction of nonlinear dynamical
systems based on proper orthogonal decomposition (POD). Our method, derived
from Density Matrix Renormalization Group (DMRG), provides a significant
reduction in computational effort for the calculation of the reduced system,
compared to a POD. The efficiency of the algorithm is tested on the one
dimensional Burgers equations and a one dimensional equation of the Fisher type
as nonlinear model systems.Comment: 12 pages, 12 figure
Quantum control via a genetic algorithm of the field ionization pathway of a Rydberg electron
Quantum control of the pathway along which a Rydberg electron field ionizes
is experimentally and computationally demonstrated. Selective field ionization
is typically done with a slowly rising electric field pulse. The
scaling of the classical ionization threshold leads to a rough mapping between
arrival time of the electron signal and principal quantum number of the Rydberg
electron. This is complicated by the many avoided level crossings that the
electron must traverse on the way to ionization, which in general leads to
broadening of the time-resolved field ionization signal. In order to control
the ionization pathway, thus directing the signal to the desired arrival time,
a perturbing electric field produced by an arbitrary waveform generator is
added to a slowly rising electric field. A genetic algorithm evolves the
perturbing field in an effort to achieve the target time-resolved field
ionization signal.Comment: Corrected minor typographic errors and changed the titl
On the decay of deformed actinide nuclei
decay through a deformed potential barrier produces significant
mixing of angular momenta when mapped from the nuclear interior to the outside.
Using experimental branching ratios and either semi-classical or
coupled-channels transmission matrices, we have found that there is a set of
internal amplitudes which are essentially constant for all even--even actinide
nuclei. These same amplitudes also give good results for the known anisotropic
particle emission of the favored decays of odd nuclei in the same mass
region.
PACS numbers: 23.60.+e, 24.10.Eq, 27.90.+bComment: 5 pages, latex (revtex style), 2 embedded postscript figures
uuencoded gz-compressed .tar file To appear in Physical Review Letter
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