1,316 research outputs found
Kohn-Sham calculations combined with an average pair-density functional theory
A recently developed formalism in which Kohn-Sham calculations are combined
with an ``average pair density functional theory'' is reviewed, and some new
properties of the effective electron-electron interaction entering in this
formalism are derived. A preliminary construction of a fully self-consitent
scheme is also presented in this framework.Comment: submitted to Int. J. Mod. Phys. B (proceedings of the 30th
International Workshop on Condensed Matter Theories
System-adapted correlation energy density functionals from effective pair interactions
We present and discuss some ideas concerning an ``average-pair-density
functional theory'', in which the ground-state energy of a many-electron system
is rewritten as a functional of the spherically and system-averaged pair
density. These ideas are further clarified with simple physical examples. We
then show that the proposed formalism can be combined with density functional
theory to build system-adapted correlation energy functionals. A simple
approximation for the unknown effective electron-electron interaction that
enters in this combined approach is described, and results for the He series
and for the uniform electron gas are briefly reviewed.Comment: to appear in Phil. Mag. as part of Conference proceedings for the
"Electron Correlations and Materials Properties", Kos Greece, July 5-9, 200
Deriving the existence of bound states from the X(3872) and Heavy Quark Symmetry
We discuss the possibility and the description of bound states between
and mesons. We argue that the existence of such a bound state can
be deduced from (i) the weakly bound X(3872) state, (ii) certain assumptions
about the short range dynamics of the system and (iii) heavy quark
symmetry. From these assumptions the binding energy of the possible
bound states is determined, first in a theory containing only
contact interactions which serves as a straightforward illustration of the
method, and then the effects of including the one pion exchange potential are
discussed. In this latter case three isoscalar states are predicted: a positive
and negative C-parity state with a binding energy of and below threshold respectively, and a positive C-parity
shallow state located almost at the threshold. However,
large uncertainties are generated as a consequence of the corrections
from heavy quark symmetry. Finally, the newly discovered isovector
state can be easily accommodated within the present framework by a minor
modification of the short range dynamics.Comment: 21 pages, 3 figures; a sign error in the potential has been corrected
and new predictions have been compute
Rapid Syphilis Tests as Catalysts for Health Systems Strengthening: A Case Study from Peru.
OBJECTIVES: Untreated maternal syphilis leads to adverse pregnancy outcomes. The use of point of care tests (POCT) offers an opportunity to improve screening coverage for syphilis and other aspects of health systems. Our objective is to present the experience of the introduction of POCT for syphilis in Peru and describe how new technology can catalyze health system strengthening. METHODS: The study was implemented from September 2009-November 2010 to assess the feasibility of the use of a POCT for syphilis for screening pregnant women in Lima, Peru. Outcomes measured included access to syphilis screening, treatment coverage, partner treatment, effect on patient flow and service efficiency, acceptability among providers and patients, and sustainability. RESULTS: Before the introduction of POCT, a pregnant woman needed 6 visits to the health center in 27 days before she received her syphilis result. We trained 604 health providers and implemented the POCT for syphilis as the "two for one strategy", offering with one finger stick both syphilis and HIV testing. Implementation of the POCT resulted in testing and treatment on the first visit. Screening and treatment coverages for syphilis improved significantly compared with the previous year. Implementation of POCT has been scaled up nationally since the study ended, and coverages for screening, treatment and partner treatment have remained over 92%. CONCLUSIONS: Implementation of POCT for syphilis proved feasible and acceptable, and led to improvement in several aspects of health services. For the process to be effective we highlight the importance of: (1) engaging the authorities; (2) dissipating tensions between providers and identifying champions; (3) training according to the needs; (4) providing monitoring, supervision, support and recognition; (5) sharing results and discussing actions together; (6) consulting and obtaining feedback from users; and (7) integrating with other services such as with rapid HIV testing
Nucleon-Nucleon interaction, charge symmetry breaking and renormalization
We study the interplay between charge symmetry breaking and renormalization
in the NN system for s-waves. We find a set of universality relations which
disentangle explicitly the known long distance dynamics from low energy
parameters and extend them to the Coulomb case. We analyze within such an
approach the One-Boson-Exchange potential and the theoretical conditions which
allow to relate the proton-neutron, proton-proton and neutron-neutron
scattering observables without the introduction of extra new parameters and
providing good phenomenological success.Comment: 15 pages, 6 figure
Recursive Detection and Analysis of Nanoparticles in Scanning Electron Microscopy Images
In this study, we present a computational framework tailored for the precise
detection and comprehensive analysis of nanoparticles within scanning electron
microscopy (SEM) images. The primary objective of this framework revolves
around the accurate localization of nanoparticle coordinates, accompanied by
secondary objectives encompassing the extraction of pertinent morphological
attributes including area, orientation, brightness, and length.
Constructed leveraging the robust image processing capabilities of Python,
particularly harnessing libraries such as OpenCV, SciPy, and Scikit-Image, the
framework employs an amalgamation of techniques, including thresholding,
dilating, and eroding, to enhance the fidelity of image processing outcomes.
The ensuing nanoparticle data is seamlessly integrated into the RStudio
environment to facilitate meticulous post-processing analysis. This encompasses
a comprehensive evaluation of model accuracy, discernment of feature
distribution patterns, and the identification of intricate particle
arrangements. The finalized framework exhibits high nanoparticle identification
within the primary sample image and boasts 97\% accuracy in detecting particles
across five distinct test images drawn from a SEM nanoparticle dataset.
Furthermore, the framework demonstrates the capability to discern nanoparticles
of faint intensity, eluding manual labeling within the control group.Comment: 9 pages, 10 figure
The automotive sector in Spain. Influence of R&D investment on the improvement of total factor productivity
Obecne zglobalizowane środowisko zostało poprzedzone ogólnym wzrostem rozpowszechnienia i wykorzystania technologii informacyjno-komunikacyjnych (ICT), jak również dużymi inwestycjami przedsiębiorstw w badania i rozwój (R&D). Okoliczność ta sprawia, że korzystanie z tych technologii ma zasadnicze znaczenie dla sektora motoryzacyjnego i gwarantuje rosnącą konkurencyjność międzynarodową. W związku z tym właściwe wykorzystanie technologii informacyjno-komunikacyjnych zapewnia poprawę wydajności, a tym samym konkurencyjności przedsiębiorstw. W artykule przeanalizowano ewolucję całkowitej produktywności czynników produkcji (TFP) w hiszpańskim sektorze motoryzacyjnym w roku 2017, w celu określenia wpływu tej zmiennej na poprawę całkowitej produktywności czynników produkcji.The current globalised environment has been preceded by a generalised increase in the diffusion and use of Information and Communication Technologies (ICT), as well as by a large investment in Research and Development (R&D) by companies. This circumstance makes the use of these technologies fundamental for the automotive sector to face with guarantees the growing international competitivity. Thus, the correct use of ICT provides an improvement in productivity, and therefore in the competitiveness of enterprises. This article analyses the evolution of total factor productivity (TFP) in the Spanish automotive sector for the year 2017, in order to determine the influence this variable has on the improvement of total factor productivity
Un modelo Poissoniano para predecir la matriculación de vehículos en países europeos
En este artículo presentamos una modelización para la matriculación de vehículos en países de Europa mediante un proceso de Poisson Doblemente Estocástico con media aleatoria Normal truncada. Apoyándonos en trabajos previos acerca de este proceso, se amplía el estudio de características de éste. Asímismo, se hace una predicción de este proceso para los años 2000 y 2001
Contribution to the report and book "The Protection of Taxpayers' Rights in International Law - Results of the ILA Study Group on International Tax Law 2018-2021"
This document contains the results of the ILA Study Group, then Committee on InternationalTax Law from 2018 to 2021. Contribution to some sections on fairness, equity, equality and neutrality.Seventh Framework Programme (FP7)758671Grenzen van fiscale soevereinitei
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