888 research outputs found
London equation studies of thin-film superconductors with a triangular antidot lattice
We report on a study of vortex pinning in nanoscale antidot defect arrays in
the context of the London Theory. Using a wire network model, we discretize the
array with a fine mesh, thereby providing a detailed treatment of pinning
phenomena. The use of a fine grid has enabled us to examine both circular and
elongated defects, patterned in the form of a rhombus. The latter display
pinning characteristics superior to circular defects constructed with the
similar area. We calculate pinning potentials for defects containing zero and
single quanta, and we obtain a pinning phase diagram for the second matching
field, .Comment: 10 pages and 14 figure
Alternative splicing and genetic diversity of the white collar-1 (wc-1) gene in cereal Phaeosphaeria pathogens
The white collar-1 (wc-1) gene encodes an important light-responsive protein (wc-1) that maintains circadian clocks and controls numerous light-dependent reactions including sporulation in ascomycete fungi. The structure and expression of the wc-1 gene in wheat-biotype Phaeosphaeria nodorum (PN-w) was studied. It was shown that the full-size (3,353 bp in length) wc-1 gene in PN-w contained 4 introns in which introns 1 and 2 were flanked by GC-AG splice borders and were spliced constitutively. However, introns 3 and 4 of the wc-1 gene were alternatively spliced. As the result of alternative splicing (AS), six transcript variants were identified, encoding different lengths of deduced polypeptides (from 1,044 to 1,065aa). Ratios of the wc-1 gene transcript variants in the RNA population were the same in the sporulated and non-sporulated PN-w isolate Sn37-1 and the sporulated PN-w isolate S-79-1, grown under light/dark conditions. The AS of the wc-1 gene may control various light-dependent reactions in PN-w, which leads to diverse morphological, physiological and pathological characters for pathogen infection and spread. Based on the nucleotide and deduced amino acid sequences, the wc-1 gene in cereal Phaeosphaeria pathogens was diverse. It appeared that the deduced wc-1 polypeptide sequences of P. avenaria f. sp. avenaria (Paa), P. avenaria f. sp. triticea (Pat1 and Pat3) and barley biotype P. nodorum (PN-b) were more closely related than PN-w and Phaeosphaeeria sp. (P-rye) from Poland. Based on the wc-1 deduced polypeptide sequences, P. avenaria f. sp. triticea (Pat2) from foxtail barley (Hordeum jubatum L.) was evolutionary well separated from the other cereal Phaeosphaeria pathogens
Cosmic Microwave Background Anisotropies from Scaling Seeds: Global Defect Models
We investigate the global texture model of structure formation in cosmogonies
with non-zero cosmological constant for different values of the Hubble
parameter. We find that the absence of significant acoustic peaks and little
power on large scales are robust predictions of these models. However, from a
careful comparison with data we conclude that at present we cannot safely
reject the model on the grounds of present CMB data. Exclusion by means of
galaxy correlation data requires assumptions on biasing and statistics. New,
very stringent constraints come from peculiar velocities.
Investigating the large-N limit, we argue that our main conclusions apply to
all global O(N) models of structure formation.Comment: LaTeX file with RevTex, 27 pages, 23 eps figs., submitted to Phys.
Rev. D. A version with higher quality images can be found at
http://mykonos.unige.ch/~kunz/download/lam.tar.gz for the LaTeX archive and
at http://mykonos.unige.ch/~kunz/download/lam.ps.gz for the compiled
PostScript fil
New Phenolic Constituents from the Fruit Juice of Phyllanthus emblica
Six new phenolic constituents, L-malic acid 2-O- (1), mucic acid 2-O- (5), mucic acid 1, 4-lactone 2-O- (6), 5-O- (8), 3-O- (10), and 3, 5-di-O- (11) gallates, were isolated from the fruit juice of Phyllanthus emblica together with their methyl esters (2-4, 7, 9), and their structures were determined by spectral and chemical methods. Compounds 5, 6, and 8, the major phenolic constituents of the juice, were present as an equilibrium mixture in aqueous solution
Relationship Between the Thermodynamic Parameters, Structure, and Anticorrosion Properties of Al-Zr-Ni-Fe-Y Alloys
The influence of the chemical composition on the crystallization process, amorphous phase
formation, and the anticorrosion properties of Al-Zr-Ni-Fe-Y alloys are presented. To reduce
the number of experiments, a thermodynamic approach was applied in which the entropy and
Gibbs free energy of representative alloys were optimized. The low glass-forming ability of
Al-Zr-Ni-Fe-Y alloy systems was related to the crystallization of the Al3Zr phase from the melt.
The structural analysis showed that phases containing Ni and Fe, such as Al19Ni5Y3, Al10Fe2Y,
and Al23Ni6Y4, played a key role in the formation of amorphous alloys. According to this, the
simultaneous addition of Ni/Fe and Y is important to prevent the crystallization of Al-based
alloys in the melt. The formation of an amorphous phase in Al80Zr5Ni5Fe5Y5 alloys and the
complete amorphization of Al85Ni5Fe5Y5 alloys were responsible for the high corrosion
resistance compared with fully crystalline alloys. Moreover, the addition of Y had a significant
impact on the anticorrosion properties. The XPS results showed that the alloys tended to form a
passive Al2O3 and Y2O3 layer on the surface
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
- …