2,537 research outputs found
Evaluating the impact of titanium or equivalent carbon on the hot ductility of medium carbon steels
Smoke gets in your eyes:what is sociological about cigarettes?
Contemporary public health approaches increasingly draw attention to the unequal social distribution of cigarette smoking. In contrast, critical accounts emphasize the importance of smokersâ situated agency, the relevance of embodiment and how public health measures against smoking potentially play upon and exacerbate social divisions and inequality. Nevertheless, if the social context of cigarettes is worthy of such attention, and sociology lays a distinct claim to understanding the social, we need to articulate a distinct, positive and systematic claim for smoking as an object of sociological enquiry. This article attempts to address this by situating smoking across three main dimensions of sociological thinking: history and social change; individual agency and experience; and social structures and power. It locates the emergence and development of cigarettes in everyday life within the project of modernity of the nineteenth and twentieth centuries. It goes on to assess the habituated, temporal and experiential aspects of individual smoking practices in everyday lifeworlds. Finally, it argues that smoking, while distributed in important ways by social class, also works relationally to render and inscribe it
Vacuum Energy and Renormalization on the Edge
The vacuum dependence on boundary conditions in quantum field theories is
analysed from a very general viewpoint. From this perspective the
renormalization prescriptions not only imply the renormalization of the
couplings of the theory in the bulk but also the appearance of a flow in the
space of boundary conditions. For regular boundaries this flow has a large
variety of fixed points and no cyclic orbit. The family of fixed points
includes Neumann and Dirichlet boundary conditions. In one-dimensional field
theories pseudoperiodic and quasiperiodic boundary conditions are also RG fixed
points. Under these conditions massless bosonic free field theories are
conformally invariant. Among all fixed points only Neumann boundary conditions
are infrared stable fixed points. All other conformal invariant boundary
conditions become unstable under some relevant perturbations. In finite volumes
we analyse the dependence of the vacuum energy along the trajectories of the
renormalization group flow providing an interesting framework for dark energy
evolution. On the contrary, the renormalization group flow on the boundary does
not affect the leading behaviour of the entanglement entropy of the vacuum in
one-dimensional conformally invariant bosonic theories.Comment: 10 pages, 1 eps figur
Random graphs with arbitrary degree distributions and their applications
Recent work on the structure of social networks and the internet has focussed
attention on graphs with distributions of vertex degree that are significantly
different from the Poisson degree distributions that have been widely studied
in the past. In this paper we develop in detail the theory of random graphs
with arbitrary degree distributions. In addition to simple undirected,
unipartite graphs, we examine the properties of directed and bipartite graphs.
Among other results, we derive exact expressions for the position of the phase
transition at which a giant component first forms, the mean component size, the
size of the giant component if there is one, the mean number of vertices a
certain distance away from a randomly chosen vertex, and the average
vertex-vertex distance within a graph. We apply our theory to some real-world
graphs, including the world-wide web and collaboration graphs of scientists and
Fortune 1000 company directors. We demonstrate that in some cases random graphs
with appropriate distributions of vertex degree predict with surprising
accuracy the behavior of the real world, while in others there is a measurable
discrepancy between theory and reality, perhaps indicating the presence of
additional social structure in the network that is not captured by the random
graph.Comment: 19 pages, 11 figures, some new material added in this version along
with minor updates and correction
Patients With Generalized Joint Hypermobility Have Thinner Superior Hip Capsules and Greater Hip Internal Rotation on Physical Examination
PURPOSE: To compare preoperative hip range of motion (ROM), hip capsular thickness on magnetic resonance imaging (MRI), and bony morphology on radiographs and computed tomography (CT) between patients with and without joint hypermobility as measured by the Beighton Test score (BTS), with subanalysis based on sex and age.
METHODS: Consecutive patients who underwent hip arthroscopy for a diagnosis of femoroacetabular impingement syndrome with or without dysplasia were retrospectively reviewed. Patient BTS, hip ROM, demographics, surgical data, morphologic measures on radiographs and CT, and MRI findings including hip capsule thickness at various locations were compiled. Multiple statistical tests were performed, including multivariable linear or logistic regression models, while controlling for BTS, age, and sex.
RESULTS: In total, 99 patients were included with a mean age of 29 ± 9.9 years; 62 (62.6%), were female. Forty patients (40.4%) had a BTS â„4. Female patients (P \u3c .001) and younger patients (26.7 vs 30.9 years, P = .030) were more likely to have a BTS â„4. Male patients had significantly thicker superior capsules (3.4 mm vs. 2.8 mm, P = .034). BTS was not associated with capsular thickness when controlling for sex. On CT, femoral version (18.9° vs 11.4°, P \u3c .001), and McKibben index (37.8° vs. 28.2°, P \u3c .001) were significantly greater in those with a BTS â„4. Patients with a BTS â„4 had more hip internal rotation at 90° of flexion (15.0° vs 10.0°, P \u3c .001), when prone (30.0° vs 20.0°, P = .004), and in extension (10.0° vs. 5.0°, P \u3c .001).
CONCLUSIONS: All female patients, regardless of Beighton score, and all patients with a BTS â„4 indicated for primary hip arthroscopy for femoroacetabular impingement syndrome with or without dysplasia were more likely to have thinner superior hip capsules on MRI and greater hip internal rotation on exam. Bony morphologic differences exist between sexes and between patients with and without hypermobility, likely contributing to differences in ROM.
LEVEL OF EVIDENCE: III, retrospective cohort study
Strangeness in Astrophysics and Cosmology
Some recent developments concerning the role of strange quark matter for
astrophysical systems and the QCD phase transition in the early universe are
addressed. Causality constraints of the soft nuclear equation of state as
extracted from subthreshold kaon production in heavy-ion collisions are used to
derive an upper mass limit for compact stars. The interplay between the
viscosity of strange quark matter and the gravitational wave emission from
rotation-powered pulsars are outlined. The flux of strange quark matter nuggets
in cosmic rays is put in perspective with a detailed numerical investigation of
the merger of two strange stars. Finally, we discuss a novel scenario for the
QCD phase transition in the early universe, which allows for a small
inflationary period due to a pronounced first order phase transition at large
baryochemical potential.Comment: 8 pages, invited talk given at the International Conference on
Strangeness in Quark Matter (SQM2009), Buzios, Brasil, September 28 - October
2, 200
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Enthalpy of Solvation Correlations for Gaseous Solutes Dissolved in Chloroform and 1,2-dichloroethane Based on the Abraham Model
This article discusses enthalpy of solvation correlations for gaseous solutes dissolved in chloroform and 1,2-dichloroethane based on the Abraham model
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Supporting Material for: Enthalpy of Solvation Correlations for Gaseous Solutes Dissolved in Water and in 1-Octanol Based on the Abraham Model
This document includes supporting material for an article titled, "Enthalpy of solvation correlations for gaseous solutes dissolved in water and in 1-octanol based on the Abraham model," published in the Journal of Chemical Information and Modeling
Stoics against stoics in Cudworth's "A Treatise of Freewill"
In his 'A Treatise of Freewill', Ralph Cudworth argues against Stoic determinism by drawing on what he takes to be other concepts found in Stoicism, notably the claim that some things are âup to usâ and that these things are the product of our choice. These concepts are central to the late Stoic Epictetus and it appears at first glance as if Cudworth is opposing late Stoic voluntarism against early Stoic determinism. This paper argues that in fact, despite his claim to be drawing on Stoic doctrine, Cudworth uses these terms with a meaning first articulated only later, by the Peripatetic commentator Alexander of Aphrodisias
Constraining the Size of the Circumgalactic Medium Using the Transverse Autocorrelation Function of C IV Absorbers in Paired Quasar Spectra
The circumgalactic medium (CGM) plays a vital role in the formation and
evolution of galaxies, acting as a lifeline between galaxies and the
surrounding intergalactic medium (IGM). In this study we leverage a unique
sample of quasar pairs to investigate the properties of the CGM with absorption
line tomography. We present a new sample of medium resolution Keck/ESI,
Magellan/MagE, and VLT/XSHOOTER spectra of 29 quasar pairs at redshift . We supplement the sample with additional spectra of 32 pairs from the
literature, creating a catalog of 61 quasar pairs with angular separations
between 1.7" and 132.9" and projected physical separations () between
14 kpc and 887 kpc. We construct a catalog of 906 metal-line absorption
doublets of C IV () with equivalent widths ranging
from 6 m{\AA} m{\AA}. The best fit linear model to
the log-space equivalent width frequency distribution () of the sample yields coefficients of and
. To constrain the projected extent of C IV, we calculate the
transverse autocorrelation function. The flattening of the autocorrelation
function at low provides a lower limit for the coherence length of
the metal enriched CGM - on the order of 200 comoving kpc. This
physical size constraint allows us to refine our understanding of the metals in
the CGM, where the extent of C IV in the CGM depends on gas flows, feedback,
timescale of metal injection and mixing, and the mass of the host galaxies.Comment: 19 pages, 8 figures, 2 tables, Accepted for publication by The
Astronomical Journa
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