12,901 research outputs found
Electrical connector pin with wiping action
Electrical connector pin with wiping action to assure reliable contac
Pseudoknots in a Homopolymer
After a discussion of the definition and number of pseudoknots, we reconsider
the self-attracting homopolymer paying particular attention to the scaling of
the number of pseudoknots at different temperature regimes in two and three
dimensions. Although the total number of pseudoknots is extensive at all
temperatures, we find that the number of pseudoknots forming between the two
halves of the chain diverges logarithmically at (in both dimensions) and below
(in 2d only) the theta-temparature. We later introduce a simple model that is
sensitive to pseudoknot formation during collapse. The resulting phase diagram
involves swollen, branched and collapsed homopolymer phases with transitions
between each pair.Comment: submitted to PR
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Heated tobacco products: another tobacco industry global strategy to slow progress in tobacco control.
There has been a global decline in tobacco consumption that, if continued, will negatively impact the tobacco industry's profits. This decline led the industry to invent and market new products, including heated tobacco products (HTP). HTP are an extension of the industry's strategies to undermine government's tobacco regulatory efforts as they are being promoted as part of the solution for the tobacco epidemic. Under the moniker of 'harm reduction', the tobacco companies are attempting to rehabilitate their reputation so they can more effectively influence governments to roll back existing tobacco control policies or create exemptions for their HTP. Rolling back tobacco control policies will make it easier for the companies to renormalise tobacco use to increase social acceptability for all their products. When regulations are absent or when loopholes exist in classifying HTP as a tobacco product (thus subject to all tobacco control regulations), the industry's marketing of HTP is making these products more visible to the public and more accessible. Governments need to ensure that HTP are regulated as tobacco products or drugs and reject partnerships with the tobacco companies to promote 'harm reduction'. The tobacco companies remain the vector of the tobacco-caused epidemic and cannot be part of the global tobacco control solution
Boundary Spatiotemporal Correlations in a Self-Organized Critical Model of Punctuated Equilibrium
In a semi-infinite geometry, a 1D, M-component model of biological evolution
realizes microscopically an inhomogeneous branching process for .
This implies in particular a size distribution exponent for
avalanches starting at a free end of the evolutionary chain. A bulk--like
behavior with is restored if `conservative' boundary conditions
strictly fix to its critical, bulk value the average number of species directly
involved in an evolutionary avalanche by the mutating species located at the
chain end. A two-site correlation function exponent is also
calculated exactly in the `dissipative' case, when one of the points is at the
border. These results, together with accurate numerical determinations of the
time recurrence exponent , show also that, no matter whether
dissipation is present or not, boundary avalanches have the same space and time
fractal dimensions as in the bulk, and their distribution exponents obey the
basic scaling laws holding there.Comment: 5 pages, 3 eps figure
The acquisition of English L2 prosody by Italian native speakers: experimental data and pedagogical implications
This paper investigates Yes-No question intonation patterns in English L2, Italian L1, and
English L1. The aim is to test the hypothesis that L2 learners may show different
acquisition strategies for different dimensions of intonation, and particularly the
phonological and phonetic components. The study analyses the nuclear intonation
contours of 4 target English words and 4 comparable Italian words consisting of sonorant
segments, stressed on the semi-final or final syllable, and occurring in Yes-No questions
in sentence-final position (e.g., Will you attend the memorial?, Hai sentito la Melania?).
The words were contained in mini-dialogues of question-answer pairs, and read 5 times
by 4 Italian speakers (Padova area, North-East Italy) and 3 English female speakers
(London area, UK). The results show that: 1) different intonation patterns may be used to
realize the same grammatical function; 2) different developmental processes are at work,
including transfer of L1 categories and the acquisition of L2 phonological categories.
These results suggest that the phonetic dimension of L2 intonation may be more difficult
to learn than the phonological one
Strong gravitational field light deflection in binary systems containing a collapsed star
Large light deflection angles are produced in the strong gravitational field
regions around neutron stars and black holes. In the case of binary systems,
part of the photons emitted from the companion star towards the collapsed
object are expected to be deflected in the direction of the earth. Based on a
semi-classical approach we calculate the characteristic time delays and
frequency shifts of these photons as a function of the binary orbital phase.
The intensity of the strongly deflected light rays is reduced by many orders of
magnitude, therefore making the observations of this phenomenon extremely
difficult. Relativistic binary systems containing a radio pulsar and a
collapsed object are the best available candidates for the detection of the
strongly deflected photons. Based on the accurate knowledge of their orbital
parameters, these systems allow to predict accurately the delays of the pulses
along the highly deflected path, such that the sensitivity to very weak signals
can be substantially improved through coherent summation over long time
intervals. We discuss in detail the cases of PSR 1913+16 and PSR 1534+12 and
find that the system geometry is far more promising for the latter. The
observation of the highly deflected photons can provide a test of general
relativity in an unprecedented strong field regime as well as a tight
constraint on the radius of the collapsed object.Comment: 7 pages, uuencoded, gzip'ed, postscript file with figures included.
Accepted for pubblication in MNRA
Hybrid lattice Boltzmann model for binary fluid mixtures
A hybrid lattice Boltzmann method (LBM) for binary mixtures based on the
free-energy approach is proposed. Non-ideal terms of the pressure tensor are
included as a body force in the LBM kinetic equations, used to simulate the
continuity and Navier-Stokes equations. The convection-diffusion equation is
studied by finite difference methods. Differential operators are discretized in
order to reduce the magnitude of spurious velocities. The algorithm has been
shown to be stable and reproducing the correct equilibrium behavior in simple
test configurations and to be Galilean invariant. Spurious velocities can be
reduced of about an order of magnitude with respect to standard discretization
procedure.Comment: Final version, to appear in Phys. Rev.
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The environmental externalities of tobacco manufacturing: A review of tobacco industry reporting.
Growing research and public awareness of the environmental impacts of tobacco present an opportunity for environmental science and public health to work together. Various United Nations agencies share interests in mitigating the environmental costs of tobacco. Since 2000, transnational tobacco industry consolidation has accelerated, spotlighting the specific companies responsible for the environmental and human harms along the tobacco production chain. Simultaneously, corporate social responsibility norms have led the industry to disclose statistics on the environmental harms their business causes. Yet, independent and consistent reporting remain hurdles to accurately assessing tobacco's environmental impact. This article is the first to analyze publicly available industry data on tobacco manufacturing pollution. Tobacco's significant environmental impact suggests this industry should be included in environmental analyses as a driver of environmental degradation influencing climate change. Countries aiming to meet UN Sustainable Development Goals must act to reduce environmental harms caused by the tobacco industry
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