10,080 research outputs found
The Adapted Ordering Method for Lie Algebras and Superalgebras and their Generalizations
In 1998 the Adapted Ordering Method was developed for the representation
theory of the superconformal algebras in two dimensions. It allows: to
determine maximal dimensions for a given type of space of singular vectors, to
identify all singular vectors by only a few coefficients, to spot subsingular
vectors and to set the basis for constructing embedding diagrams. In this
article we present the Adapted Ordering Method for general Lie algebras and
superalgebras, and their generalizations, provided they can be triangulated. We
also review briefly the results obtained for the Virasoro algebra and for the
N=2 and Ramond N=1 superconformal algebras.Comment: Many improvements in the redaction for pedagogical purposes. Latex,
11 page
Manifestation of geometric resonance in current dependence of AC susceptibility for unshunted array of Nb-AlOx-Nb Josephson junctions
A pronounced resonance-like structure has been observed in the current
dependence of AC susceptibility for two-dimensional array of unshunted
Nb-AlOx-Nb Josephson junctions. Using a single-plaquette approximation, we were
able to successfully fit our data assuming that resonance structure is related
to the geometric (inductive) properties of the array.Comment: to appear in Physica C (in press
Universal R-C crossover in current-voltage characteristics for unshunted array of overdamped Nb-AlO_x-Nb Josephson junctions
We report on some unusual behavior of the measured current-voltage
characteristics (CVC) in artificially prepared two-dimensional unshunted array
of overdamped Nb-AlO_x-Nb Josephson junctions. The obtained nonlinear CVC are
found to exhibit a pronounced (and practically temperature independent)
crossover at some current I_{cr}=\left(\frac{1}{2\beta_C}-1\right)I_C from a
resistance R dominated state with V_R=R\sqrt{I^2-I_C^2} below I_{cr} to a
capacitance C dominated state with V_C=\sqrt{\frac{\hbar}{4eC}} \sqrt{I-I_C}
above I_{cr}. The origin of the observed behavior is discussed within a
single-plaquette approximation assuming the conventional RSJ model with a
finite capacitance and the Ambegaokar-Baratoff relation for the critical
current of the single junction
Partition Function of Gauge Theories on a Squashed with Isometry
We study supersymmetric gauge theories on a large family of squashed
4-spheres preserving isometry and determine the
conditions under which this background is supersymmetric. We then compute the
partition function of the theories by using localization technique. The results
indicate that for SUSY, including both vector-multiplets and
hypermultiplets, the partition function is independent of the arbitrary
squashing functions as well as of the other supergravity background fields.Comment: version to appear in Nuclear Physics
On Field Induced Diaelastic Effect in a Small Josephson Contact
An analog of the diaelastic effect is predicted to occur in a small Josephson
contact with Josephson vortices manifesting itself as magnetic field induced
softening of the contact shear modulus C(T,H). In addition to Fraunhofer type
field oscillations, C(T,H) is found to exhibit pronounced flux driven
temperature oscillations near T_C
Ergodicity criteria for non-expanding transformations of 2-adic spheres
In the paper, we obtain necessary and sufficient conditions for ergodicity
(with respect to the normalized Haar measure) of discrete dynamical systems
on 2-adic spheres of radius
, , centered at some point from the ultrametric space of
2-adic integers . The map is
assumed to be non-expanding and measure-preserving; that is, satisfies a
Lipschitz condition with a constant 1 with respect to the 2-adic metric, and
preserves a natural probability measure on , the Haar measure
on which is normalized so that
Ingested insecticide to control Aedes aegypti: developing a novel dried attractive toxic sugar bait device for intra-domiciliary control
© 2020 The Author(s). Background: Illnesses transmitted by Aedes aegypti (Linnaeus, 1762) such as dengue, chikungunya and Zika comprise a considerable global burden; mosquito control is the primary public health tool to reduce disease transmission. Current interventions are inadequate and insecticide resistance threatens the effectiveness of these options. Dried attractive bait stations (DABS) are a novel mechanism to deliver insecticide to Ae. aegypti. The DABS are a high-contrast 28 inch2 surface coated with dried sugar-boric acid solution. Aedes aegypti are attracted to DABS by visual cues only, and the dried sugar solution elicits an ingestion response from Ae. aegypti landing on the surface. The study presents the development of the DABS and tests of their impact on Ae. aegypti mortality in the laboratory and a series of semi-field trials. Methods: We conducted multiple series of laboratory and semi-field trials to assess the survivability of Ae. aegypti mosquitoes exposed to the DABS. In the laboratory experiments, we assessed the lethality, the killing mechanism, and the shelf life of the device through controlled experiments. In the semi-field trials, we released laboratory-reared female Ae. aegypti into experimental houses typical of peri-urban tropical communities in South America in three trial series with six replicates each. Laboratory experiments were conducted in Quito, Ecuador, and semi-field experiments were conducted in Machala, Ecuador, an area with abundant wild populations of Ae. aegypti and endemic arboviral transmission. Results: In the laboratory, complete lethality was observed after 48 hours regardless of physiological status of the mosquito. The killing mechanism was determined to be through ingestion, as the boric acid disrupted the gut of the mosquito. In experimental houses, total mosquito mortality was greater in the treatment house for all series of experiments (P \u3c 0.0001). Conclusions: The DABS devices were effective at killing female Ae. aegypti under a variety of laboratory and semi-field conditions. DABS are a promising intervention for interdomiciliary control of Ae. aegypti and arboviral disease prevention.[Figure not available: see fulltext.
Transonic shock-induced dynamics of a flexible wing with a thick circular-arc airfoil
Transonic shock boundary layer oscillations occur on rigid models over a small range of Mach numbers on thick circular-arc airfoils. Extensive tests and analyses of this phenomena have been made in the past but essentially all of them were for rigid models. A simple flexible wing model with an 18 pct. circular arc airfoil was constructed and tested in the Langley Transonic Dynamics Tunnel to study the dynamic characteristics that a wing might have under these circumstances. In the region of shock boundary layer oscillations, buffeting of the first bending mode was obtained. This mode was well separated in frequency from the shock boundary layer oscillations. A limit cycle oscillation was also measured in a third bending like mode, involving wind vertical bending and splitter plate motion, which was in the frequency range of the shock boundary layer oscillations. Several model configurations were tested, and a few potential fixes were investigated
The benchmark aeroelastic models program: Description and highlights of initial results
An experimental effort was implemented in aeroelasticity called the Benchmark Models Program. The primary purpose of this program is to provide the necessary data to evaluate computational fluid dynamic codes for aeroelastic analysis. It also focuses on increasing the understanding of the physics of unsteady flows and providing data for empirical design. An overview is given of this program and some results obtained in the initial tests are highlighted. The tests that were completed include measurement of unsteady pressures during flutter of rigid wing with a NACA 0012 airfoil section and dynamic response measurements of a flexible rectangular wing with a thick circular arc airfoil undergoing shock boundary layer oscillations
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