836 research outputs found
Database independent Migration of Objects into an Object-Relational Database
This paper reports on the CERN-based WISDOM project which is studying the
serialisation and deserialisation of data to/from an object database
(objectivity) and ORACLE 9i.Comment: 26 pages, 18 figures; CMS CERN Conference Report cr02_01
Hall plateaus at magic angles in bismuth beyond the quantum limit
We present a study of the angular dependence of the resistivity tensor up to
35 T in elemental bismuth complemented by torque magnetometry measurements in a
similar configuration. For at least two particular field orientations a few
degrees off the trigonal axis, the Hall resistivity was found to become
field-independent within experimental resolution in a finite field window
corresponding to a field which is roughly three times the frequency of quantum
oscillations. The Hall plateaus rapidly vanish as the field is tilted off
theses magic angles. We identify two distinct particularities of these specific
orientations, which may play a role in the emergence of the Hall plateaus.Comment: 5 pages, 5 figure
Heat transport in Bi_{2+x}Sr_{2-x}CuO_{6+\delta}: departure from the Wiedemann-Franz law in the vicinity of the metal-insulator transition
We present a study of heat transport in the cuprate superconductor
Bi_{2+x}Sr_{2-x}CuO_{6+\delta} at subkelvin temperatures and in magnetic fields
as high as 25T. In several samples with different doping levels close to
optimal, the linear-temperature term of thermal conductivity was measured both
at zero-field and in presence of a magnetic field strong enough to quench
superconductivity. The zero-field data yields a superconducting gap of
reasonable magnitude displaying a doping dependence similar to the one reported
in other families of cuprate. The normal-state data together with the results
of the resistivity measurements allows us to test the Wiedemann-Franz(WF) law,
the validity of which was confirmed in an overdoped sample in agreement with
previous studies. In contrast, a systematic deviation from the WF law was
resolved for samples displaying either a lower doping content or a higher
disorder. Thus, in the vicinity of the metal-insulator cross-over, heat
conduction in the zero-temperature limit appears to become significantly larger
than predicted by the WF law. Possible origins of this observation are
discussed.Comment: 9 pages including 7 figures, submitted to Phys. Rev.
An electronic instability in bismuth far beyond the quantum limit
We present a transport study of semi-metallic bismuth in presence of a
magnetic field applied along the trigonal axis extended to 55 T for electric
conductivity and to 45 T for thermoelectric response. The results uncover a new
field scale at about 40 T in addition to the previously detected ones. Large
anomalies in all transport properties point to an intriguing electronic
instability deep in the ultraquantum regime. Unexpectedly, both the sheer
magnitude of conductivity and its metallic temperature dependence are enhanced
by this instability.Comment: 5 pages, 4 figure
Hippocrates transformed: crafting a Hippocratic discourse of medical semiotics in English, 1850–1930
From Springer Nature via Jisc Publications RouterHistory: received 2019-12-11, accepted 2020-06-10, registration 2020-06-12, pub-electronic 2020-07-09, online 2020-07-09, collection 2020-12Publication status: PublishedAbstract: This study presents a methodology for adapting corpus linguistics to the genealogical analysis of translation’s role in the evolution of medical concepts. This methodology is exhibited by means of a case study that draws on a number of corpora to explore how two English translators—Francis Adams, a Scottish physician, and Williams H.S. Jones, a Cambridge philologist, classicist and ancient historian—translated a set of terms in Hippocratic medical texts that refer to how the body reveals illness. Drawing on the Genealogies of Knowledge subcorpora of ancient Greek and modern English, it examines some of the ways in which translation contributes to the creation of a Hippocratic semiotic discourse in English whose lexical features differ from those attested to in the subcorpus of Greek Hippocratic texts. A comparative analysis of keyword frequency and collocations of Greek semiotic terms such as sēmeion, and English terms such as sign and symptom reveals the different translation strategies Jones and Adams used to translate the text. The result of this process is a Hippocratic semiotic discourse in English whose lexical features do not reflect those in the Hippocratic texts in a straightforward way
Laplace transformations of hydrodynamic type systems in Riemann invariants: periodic sequences
The conserved densities of hydrodynamic type system in Riemann invariants
satisfy a system of linear second order partial differential equations. For
linear systems of this type Darboux introduced Laplace transformations,
generalising the classical transformations in the scalar case. It is
demonstrated that Laplace transformations can be pulled back to the
transformations of the corresponding hydrodynamic type systems. We discuss
periodic Laplace sequences of with the emphasize on the simplest nontrivial
case of period 2. For 3-component systems in Riemann invariants a complete
discription of closed quadruples is proposed. They turn to be related to a
special quadratic reduction of the (2+1)-dimensional 3-wave system which can be
reduced to a triple of pairwize commuting Monge-Ampere equations. In terms of
the Lame and rotation coefficients Laplace transformations have a natural
interpretation as the symmetries of the Dirac operator, associated with the
(2+1)-dimensional n-wave system. The 2-component Laplace transformations can be
interpreted also as the symmetries of the (2+1)-dimensional integrable
equations of Davey-Stewartson type. Laplace transformations of hydrodynamic
type systems originate from a canonical geometric correspondence between
systems of conservation laws and line congruences in projective space.Comment: 22 pages, Late
Nernst effect in semi-metals: the meritorious heaviness of electrons
We present a study of electric, thermal and thermoelectric transport in
elemental Bismuth, which presents a Nernst coefficient much larger than what
was found in correlated metals. We argue that this is due to the combination of
an exceptionally low carrier density with a very long electronic
mean-free-path. The low thermomagnetic figure of merit is traced to the
lightness of electrons. Heavy-electron semi-metals, which keep a metallic
behavior in presence of a magnetic field, emerge as promising candidates for
thermomagnetic cooling at low temperatures.Comment: 4 pages, including 4 figure
Chiral symmetry breaking in in presence of irrelevant interactions: a renormalization group study
Motivated by recent theoretical approaches to high temperature
superconductivity, we study dynamical mass generation in three dimensional
quantum electrodynamics ) in presence of irrelevant four-fermion
quartic terms. The problem is reformulated in terms of the renormalization
group flows of certain four-fermion couplings and charge, and then studied in
the limit of large number of fermion flavors . We find that the critical
number of fermions below which the mass becomes dynamically generated
depends continuously on a weak chiral-symmetry-breaking interaction. One-loop
calculation in our gauge-invariant approach yields in pure . We also find that chiral-symmetry-preserving mass cannot become
dynamically generated in pure .Comment: 7 pages, 7 figure
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