130 research outputs found
Real-space local polynomial basis for solid-state electronic-structure calculations: A finite-element approach
We present an approach to solid-state electronic-structure calculations based
on the finite-element method. In this method, the basis functions are strictly
local, piecewise polynomials. Because the basis is composed of polynomials, the
method is completely general and its convergence can be controlled
systematically. Because the basis functions are strictly local in real space,
the method allows for variable resolution in real space; produces sparse,
structured matrices, enabling the effective use of iterative solution methods;
and is well suited to parallel implementation. The method thus combines the
significant advantages of both real-space-grid and basis-oriented approaches
and so promises to be particularly well suited for large, accurate ab initio
calculations. We develop the theory of our approach in detail, discuss
advantages and disadvantages, and report initial results, including the first
fully three-dimensional electronic band structures calculated by the method.Comment: replacement: single spaced, included figures, added journal referenc
Triangulation network of 1929-1944 of the first 1:500 urban map of València
[EN] Triangulation is a surveying method on which earlier maps made were based. Although the origins
of the method can be traced back to the 16th century, it is still used today, with minor changes, to
adjust networks observed with modern geodetic techniques. In this paper we present the geodetic
survey work that was carried out for the primary triangulation network of the first 1:500 urban map of
the city of València (Spain). It spanned from 1929 to 1944 and resulted in 421 maps covering about
174 square kilometres. We focus on four key elements to define the geometric framework of a map:
(1) the geodetic network, (2) the cartographic projection, (3) the baseline measurements, and (4)
the primary triangulation. The paper is based on the interpretation of original documents and
field books recovered from the archives of the València City Council. In order to check the
accuracy and consistency of the survey work, we recomputed all calculations directly from the
field data, following the mathematical procedures of the time. We obtained a set of
transformation parameters to convert the coordinates of 1929 to current coordinates based on
the European Terrestrial Reference System of 1989 (ETRS89). Results showed that the 1929
primary triangulation angles and coordinates are accurate to 8 s of arc and 35 cm respectively,
and that the coordinates transform well into the current reference system with average residuals
of 26 cm across nine control points, demonstrating the high quality of the 1929 work.Villar-Cano, M.; Marqués-Mateu, Á.; Jiménez-Martínez, MJ. (2020). Triangulation network of 1929-1944 of the first 1:500 urban map of València. Survey Review (Online). 52(373):317-329. https://doi.org/10.1080/00396265.2018.1564599S31732952373Bitelli, G., Cremonini, S., & Gatta, G. (2014). Cartographic heritage: Toward unconventional methods for quantitative analysis of pre-geodetic maps. Journal of Cultural Heritage, 15(2), 183-195. doi:10.1016/j.culher.2013.04.003Blachut, T. J., Chrzanowski, A., & Saastamoinen, J. H. (1979). Urban Surveying and Mapping. doi:10.1007/978-1-4612-6145-2Brinker, R. C., & Minnick, R. (Eds.). (1987). The Surveying Handbook. doi:10.1007/978-1-4757-1188-2Gatta, G. 2010. Valorizzazione di cartografia storica attraverso moderne tecniche geomatiche: recupero metrico, elaborazione e consultazione in ambiente digitale [Valuation of historic cartography using modern geomatics techniques: metric recovering, making and use in digital environment]. Doctoral thesis. Bologna: Universitá di Bologna. 295 pages. (In Italian).Gorse, C., Johnston, D., & Pritchard, M. (2012). A Dictionary of Construction, Surveying and Civil Engineering. doi:10.1093/acref/9780199534463.001.0001Hotine, M. (1939). THE RE-TRIANGULATION OF GREAT BRITAIN IV—BASE MEASUREMENT. Empire Survey Review, 5(34), 211-225. doi:10.1179/sre.1939.5.34.211Kahmen, H., & Faig, W. (1988). Surveying. doi:10.1515/9783110845716Leick, A., Rapoport, L., & Tatarnikov, D. (2015). GPS Satellite Surveying. doi:10.1002/9781119018612Murdin, P. (2009). Full Meridian of Glory. doi:10.1007/978-0-387-75534-2Schofield, W., & Breach, M. (2007). Engineering Surveying. doi:10.1201/b12847Seeber, G. (2003). Satellite Geodesy. doi:10.1515/9783110200089Snyder, J. P. (1987). Map projections: A working manual. Professional Paper. doi:10.3133/pp139
Search for the standard model Higgs boson decaying to a pair in events with no charged leptons and large missing transverse energy using the full CDF data set
We report on a search for the standard model Higgs boson produced in
association with a vector boson in the full data set of proton-antiproton
collisions at TeV recorded by the CDF II detector at the
Tevatron, corresponding to an integrated luminosity of 9.45 fb. We
consider events having no identified charged lepton, a transverse energy
imbalance, and two or three jets, of which at least one is consistent with
originating from the decay of a quark. We place 95% credibility level upper
limits on the production cross section times standard model branching fraction
for several mass hypotheses between 90 and . For a Higgs
boson mass of , the observed (expected) limit is 6.7
(3.6) times the standard model prediction.Comment: Accepted by Phys. Rev. Let
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
Search for the standard model Higgs boson decaying to a bb pair in events with one charged lepton and large missing transverse energy using the full CDF data set
We present a search for the standard model Higgs boson produced in
association with a W boson in sqrt(s) = 1.96 TeV p-pbar collision data
collected with the CDF II detector at the Tevatron corresponding to an
integrated luminosity of 9.45 fb-1. In events consistent with the decay of the
Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a
neutrino, we set 95% credibility level upper limits on the WH production cross
section times the H->bb branching ratio as a function of Higgs boson mass. At a
Higgs boson mass of 125 GeV/c2 we observe (expect) a limit of 4.9 (2.8) times
the standard model value.Comment: Submitted to Phys. Rev. Lett (v2 contains clarifications suggested by
PRL
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
Search for the standard model Higgs boson decaying to a bb pair in events with two oppositely-charged leptons using the full CDF data set
We present a search for the standard model Higgs boson produced in
association with a Z boson in data collected with the CDF II detector at the
Tevatron, corresponding to an integrated luminosity of 9.45/fb. In events
consistent with the decay of the Higgs boson to a bottom-quark pair and the Z
boson to electron or muon pairs, we set 95% credibility level upper limits on
the ZH production cross section times the H -> bb branching ratio as a function
of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^2 we observe (expect) a
limit of 7.1 (3.9) times the standard model value.Comment: To be submitted to Phys. Rev. Let
Ocean turbulence, III : new GISS vertical mixing scheme
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Ocean Modelling 34 (2010): 70-91, doi:10.1016/j.ocemod.2010.04.006.We have found a new way to express the solutions of the RSM (Reynolds Stress
Model) equations that allows us to present the turbulent diffusivities for heat, salt and
momentum in a way that is considerably simpler and thus easier to implement than in
previous work. The RSM provides the dimensionless mixing efficiencies Γα (α stands for
heat, salt and momentum). However, to compute the diffusivities, one needs additional
information, specifically, the dissipation ε. Since a dynamic equation for the latter that
includes the physical processes relevant to the ocean is still not available, one must resort
to different sources of information outside the RSM to obtain a complete Mixing Scheme
usable in OGCMs.
As for the RSM results, we show that the Γα’s are functions of both Ri and Rρ
(Richardson number and density ratio representing double diffusion, DD); the Γα are
different for heat, salt and momentum; in the case of heat, the traditional value Γh = 0.2
is valid only in the presence of strong shear (when DD is inoperative) while when shear
subsides, NATRE data show that Γh can be three times as large, a result that we
reproduce. The salt Γs is given in terms of Γh. The momentum Γm has thus far been
guessed with different prescriptions while the RSM provides a well defined expression
for Γm (Ri, Rρ). Having tested Γh, we then test the momentum Γm by showing that the
turbulent Prandtl number Γm/Γh vs. Ri reproduces the available data quite well.
As for the dissipation ε, we use different representations, one for the mixed layer
(ML), one for the thermocline and one for the ocean’s bottom. For the ML, we adopt a
procedure analogous to the one successfully used in PB (planetary boundary layer)
studies; for the thermocline, we employ an expression for the variable εN-2 from studies
of the internal gravity waves spectra which includes a latitude dependence; for the ocean
bottom, we adopt the enhanced bottom diffusivity expression used by previous authors
but with a state of the art internal tidal energy formulation and replace the fixed Γα = 0.2
with the RSM result that brings into the problem the Ri,Rρ dependence of the Γα; the
unresolved bottom drag, which has thus far been either ignored or modeled with heuristic
relations, is modeled using a formalism we previously developed and tested in PBL
studies.
We carried out several tests without an OGCM. Prandtl and flux Richardson
numbers vs. Ri. The RSM model reproduces both types of data satisfactorily. DD and
Mixing efficiency Γh (Ri, Rρ). The RSM model reproduces well the NATRE data.
Bimodal ε-distribution. NATRE data show that ε (Ri1), which our model
reproduces. Heat to salt flux ratio. In the Ri>>1 regime, the RSM predictions reproduce
the data satisfactorily. NATRE mass diffusivity. The z-profile of the mass diffusivity
reproduces well the measurements at NATRE. The local form of the mixing scheme is
algebraic with one cubic equation to solve
Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study
In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4
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