23,340 research outputs found
Phase-locked telemetry system for rotary instrumentation of turbomachinery, phase 1
A telemetry system for use in making strain and temperature measurements on the rotating components of high speed turbomachines employs phase locked transmitters, which offer greater measurement channel capacity and reliability than existing systems which employ L-C carrier oscillators. A prototype transmitter module was tested at 175 C combined with 40,000 g's acceleration
High transverse momentum suppression and surface effects in Cu+Cu and Au+Au collisions within the PQM model
We study parton suppression effects in heavy-ion collisions within the Parton
Quenching Model (PQM). After a brief summary of the main features of the model,
we present comparisons of calculations for the nuclear modification and the
away-side suppression factor to data in Au+Au and Cu+Cu collisions at 200 GeV.
We discuss properties of light hadron probes and their sensitivity to the
medium density within the PQM Monte Carlo framework.Comment: Comments: 6 pages, 8 figures. To appear in the proceedings of Hot
Quarks 2006: Workshop for Young Scientists on the Physics of
Ultrarelativistic Nucleus-Nucleus Collisions, Villasimius, Italy, 15-20 May
200
Jet Correlations with Identified Particles from PHENIX: Methods and Results
Azimuthal angle two particle correlations have been shown to be a powerful
probe for extracting novel features of the interaction between hard scattered
partons and the medium produced in Au+Au collisions at RHIC. At intermediate
, 2-5GeV/c, the jets have been shown to be significantly modified in both
their particle composition and their angular distribution compared to p+p
collisions. Additionally, angular two particle correlations with identified
hadrons provide information on the possible role of modified hadronization
scenarios such as partonic recombination, which might allow medium modified jet
fragmentation by connecting hard scattered partons to low thermal
partons.
PHENIX has excellent particle identification capabilities and has developed
robust techniques for extracting jet correlations from the large underlying
event. We present recent PHENIX results from Au+Au collisions for a variety of
and particle type combinations. We also present p+p measurements as a
baseline. We show evidence that protons and anti-protons in the region of
enhanced baryon and anti-baryon single particle production are produced in
close angle pairs of opposite charge and that the strong modifications to the
away side shape observed for charged hadron correlations are also present when
baryons are correlated.Comment: talk given at XIth International Workshop on Correlations and
Fluctuations in Multiparticle Production, Hangzhou China November 21-24 200
To make a nanomechanical Schr\"{o}dinger-cat mew
By an explicite calculation of Michelson interferometric output intensities
in the optomechanical scheme proposed by Marshall et al. (2003), an oscillatory
factor is obtained that may go down to zero just at the time a visibility
revival ought to be observed. Including a properly tuned phase shifter offers a
simple amendment to the situation. By using a Pockels phase shifter with fast
time-dependent modulation in one arm, one may obtain further possibilities to
enrich the quantum state preparation and reconstruction abilities of the
original scheme, thereby improving the chances to reliably detect genuine
quantum behaviour of a nanomechanical oscillator.Comment: For Proc. DICE-2010 (Castiglioncello), to be published in J. Phys.
Conf. Ser., 201
Classification of integrable equations on quad-graphs. The consistency approach
A classification of discrete integrable systems on quad-graphs, i.e. on
surface cell decompositions with quadrilateral faces, is given. The notion of
integrability laid in the basis of the classification is the three-dimensional
consistency. This property yields, among other features, the existence of the
discrete zero curvature with a spectral parameter. For all integrable systems
of the obtained exhaustive list, the so called three-leg forms are found. This
establishes Lagrangian and symplectic structures for these systems, and the
connection to discrete systems of the Toda type on arbitrary graphs.
Generalizations of these ideas to the three-dimensional integrable systems and
to the quantum context are also discussed
A preliminary phylogeographic study of Flavopunctelia and Punctelia inferred from rDNA ITS-sequences
A preliminary phylogeny of the genera Flavopunctelia and Punctelia is presented. Genus and species delimitations have been investigated using ITS rDNA-sequencing of populations from different continents. Current genus delimitations of Flavopunctelia, Punctelia and Parmelia are confirmed and the species status of recently resurrected Punctelia ulophylla is confirmed. The status of three cryptic species, Flavopunctelia soredica, Punctelia perreticulata and P. stictica is discussed. Flavopunctelia borrerioides and Punctelia perreticulata are reported from China for the first time.Esitatakse perekondade Flavopunctelia ja Punctelia esialgne fülogeneesi rekonstruktsioon. Perekondade ja liikide eraldamist on uuritud erinevatelt kontinentidelt pärinevate populatsioonide ITS rDNA sekventside alusel. Senine perekondade Flavopunctelia, Punctelia ja Parmelia piiritlemine on leidnud kinnitust, samuti liigi Punctelia ulophylla staatus. Arutletakse kolme krüptilise liigi, Flavopunctelia soredica, Punctelia perreticulata ja P. stictica staatuse üle. Teatatakse liikide Flavopunctelia borrerioides ja Punctelia perreticulata esmasleidudest HiinasFil: Thell, Arne. Lund University; SueciaFil: Herber, B.. Universitat Hamburg; AlemaniaFil: Aptroot, A.. Centraalbureau voor Schimmelcultures; Países BajosFil: Adler, Monica Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Feuerer, T.. Universitat Hamburg; AlemaniaFil: Kärnefelt, Ingvar. Lund University; Sueci
A Mathematical Theory of Stochastic Microlensing II. Random Images, Shear, and the Kac-Rice Formula
Continuing our development of a mathematical theory of stochastic
microlensing, we study the random shear and expected number of random lensed
images of different types. In particular, we characterize the first three
leading terms in the asymptotic expression of the joint probability density
function (p.d.f.) of the random shear tensor at a general point in the lens
plane due to point masses in the limit of an infinite number of stars. Up to
this order, the p.d.f. depends on the magnitude of the shear tensor, the
optical depth, and the mean number of stars through a combination of radial
position and the stars' masses. As a consequence, the p.d.f.s of the shear
components are seen to converge, in the limit of an infinite number of stars,
to shifted Cauchy distributions, which shows that the shear components have
heavy tails in that limit. The asymptotic p.d.f. of the shear magnitude in the
limit of an infinite number of stars is also presented. Extending to general
random distributions of the lenses, we employ the Kac-Rice formula and Morse
theory to deduce general formulas for the expected total number of images and
the expected number of saddle images. We further generalize these results by
considering random sources defined on a countable compact covering of the light
source plane. This is done to introduce the notion of {\it global} expected
number of positive parity images due to a general lensing map. Applying the
result to microlensing, we calculate the asymptotic global expected number of
minimum images in the limit of an infinite number of stars, where the stars are
uniformly distributed. This global expectation is bounded, while the global
expected number of images and the global expected number of saddle images
diverge as the order of the number of stars.Comment: To appear in JM
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