5,034 research outputs found
Coupled equations for Kähler metrics and Yang-Mills connections
We study equations on a principal bundle over a compact complex manifold
coupling a connection on the bundle with a Kahler structure on the base. These
equations generalize the conditions of constant scalar curvature for a Kahler
metric and Hermite-Yang-Mills for a connection. We provide a moment map
interpretation of the equations and study obstructions for the existence of
solutions, generalizing the Futaki invariant, the Mabuchi K-energy and geodesic
stability. We finish by giving some examples of solutions.Comment: 61 pages; v2: introduction partially rewritten; minor corrections and
improvements in presentation, especially in Section 4; added references; v3:
To appear in Geom. Topol. Minor corrections and improvements, following
comments by referee
Using the new technologies in claudication patients: CReTe: Claudication patients and telematic register
Objetivo: Presentamos una aplicación informática para teléfonos móviles ideada para el control de sesiones
de ejercicio domiciliario en claudicantes. Exponemos también nuestros resultados preliminares.
Material y métodos: La aplicación está dise˜nada para teléfonos móviles con sistema operativo Android,
tecnología de geolocalización y conexión de datos. Está conectada a una base de datos codificada que
preserva el secreto médico. Los datos que se recogen de las sesiones de ejercicio son la fecha, la hora de
inicio y de fin, el tiempo dedicado, el número de las paradas realizadas y la velocidad máxima, la
velocidad media global y la velocidad entre paradas. Durante el mes de enero de 2014 se reclutó a
aquellos pacientes que aceptaran el estudio, poseyeran y entendieran un dispositivo móvil Android con
geolocalización y conexión de datos. Los criterios de exclusión del estudio una vez comenzado fueron
progresión hacia isquemia arterial crítica, enfermedad intercurrente grave, fallecimiento y ausencia de
comunicación con el paciente. Se recogieron las principales morbilidades y los resultados de los
cuestionarios de calidad de vida SF36 y EuroQol 5D. Se midió el tiempo de primera consulta y el tiempo
dedicado por semana y paciente durante un seguimiento de 28 días. Se calculó el cumplimiento de las
sesiones con respecto a las sesiones pactadas con cada paciente, con un mínimo de 2 semanales.
Resultados: Un total de 5 pacientes fueron incluidos, con edad media de 59,3 a˜nos (mediana 52; rango
40-80). De ellos 2 se excluyeron, uno por progresión a isquemia crítica y otro por ausencia de
comunicación. El tiempo medio dedicado por consulta nueva fue de 29,1 min (mediana 27,5; rango
45-20). El cumplimiento de las sesiones fue del 100% en 2 pacientes y del 63% en otro. El tiempo dedicado
en el seguimiento semanal por paciente fue de 1,68 min.
Conclusiones: CReTe es una herramienta aplicable a nuestro medio que precisa de estudios mayores para
demostrar su utilidad.Objective: The preliminary results are presented on the use of a new application for mobile phones designed to control home exercise sessions in claudication.Materials and methods: The application is designed for Android systems with geolocation tech-nology and Internet connection. It is connected to a database encoded to ensure medical confidentiality. The data collected from the exercise sessions were the date, start time and end time, the time spent, the number of stops made, and the maximum speed, average speed and overall speed between stops. During the month of January 2014 patients who accepted and understood the study, and possessed an Android mobile device with geolocation and data connection, were enrolled. The exclusion criteria, 11 the study started, were progression to arterial ischemia, severe intercurrent illness, non-communication with the patient, and death. Major morbidities and results of quality of life questionnaires SF36 and EuroQol 5 D were collec-ted. Time of first consultation and time spent per week per patient during a 28-day follow-up was recorded. Compliance as regards the agreed sessions was calculated for each patient, with a minimum of 2 weeks.Results: The study included 5 patients with a mean age 59.3 years (median 52; range 40-80). Of these, 2 were excluded, one for progression to critical ischemia and another for non-communication. The average time spent in a new consultation was 29.1 minutes (median 27.5, range 45-20). The compliance with the sessions was 100% in 2 patients, and 63% in another. Time spent in the weekly monitoring per patient was 1.68 minutes.Conclusions: CReTe is an applicable tool in our environment that requires further study to demonstrate its usefulness
Efectos de la diversificación ganadera de las explotaciones agrícolas en la adopción de innovaciones
publishedTomo I . Sección: Sistemas Ganaderos-Economía y Gestión. Sesión: Sostenibilidad. Ponencia nº 3
Fermionic Models with Superconducting Circuits
We propose a method for the efficient quantum simulation of fermionic systems
with superconducting circuits. It consists in the suitable use of Jordan-Wigner
mapping, Trotter decomposition, and multiqubit gates, be with the use of a
quantum bus or direct capacitive couplings. We apply our method to the
paradigmatic cases of 1D and 2D Fermi-Hubbard models, involving couplings with
nearest and next-nearest neighbours. Furthermore, we propose an optimal
architecture for this model and discuss the benchmarking of the simulations in
realistic circuit quantum electrodynamics setups.Comment: Published in EPJ Quantum Technolog
Spanish biofuels heating value estimation based on structural analysis
The importance of waste biomass as an energy source is likely to increase during the coming years as a result of European energy policy objectives, and because of the wide range of possibilities that it offers: it is a cheap fuel, widespread, and available in large quantities. In addition to crops and forestry operations, the Spanish fruit, olive and wine industries generate large amounts of currently undervalued solid wastes such as stones, branches, pulps or pomaces. The use of these by-products offers environmental benefits like removing waste and preventing fires at the same time as providing an energy yield. A proper energy valorization will require a complete physicochemical characterization. In this article, a structural and thermal characterization is developed from twenty samples from the olive and wine industries, as well as from forest and agro wastes. In addition, predictive equations are proposed to determine higher heating value (HHV) from chemical composition. For this purpose, the chemical extraction method (also called the ‘classic’ method) was used, and results were obtained in accordance with the data shown in the bibliography. Two predictive equations were developed: one based on lignin and hemicellulose content, and the other based on lignin quantity. Both present an absolute average error (AAE) of 0.87% and 1.13%, respectively.Beca predoctoral Severo Ochoa (BP13058)
PSE-ARFRISOL (PS-120000-2005-1)
MINECO (CTQ2013-45155-R
Benchmarking the Variational Quantum Eigensolver through Simulation of the Ground State Energy of Prebiotic Molecules on High-Performance Computers
We use the Variational Quantum Eigensolver (VQE) as implemented in the Qiskit
software package to compute the ground state energy of small molecules derived
from water, HO, and hydrogen cyanide, HCN. The work aims to benchmark
algorithms for calculating the electronic structure and energy surfaces of
molecules of relevance to prebiotic chemistry, beginning with water and
hydrogen cyanide, and to run them on the available simulated and physical
quantum hardware. The numerical calculations of the algorithms for small
quantum processors allow us to design more efficient protocols to be run in
real hardware, as well as to analyze their performance. Future implementations
on accessible quantum processing prototypes will benchmark quantum computers
and provide tests of quantum advantage with heuristic quantum algorithms.Comment: 9 pages, 3 figures, 4 tables, MIPT2020, Moscow, 7-11 September 2020,
AIP Proceedings (Table III corrected; ref. [16] updated
Investigation of Coulomb dipole polarization effects on reactions involving exotic nuclei
We have analyzed elastic scattering angular distributions and total reaction cross sections of the exotic nuclei Li9,11 on Pb208, at energies below and above the Coulomb barrier. For this purpose, we have used an optical potential with no adjustable parameters, composed by the nuclear São Paulo potential, derived from the nonlocal nature of the interaction, and the Coulomb dipole polarization potential, derived from the semiclassical theory of Coulomb excitation. Within this formalism, we identified an unusual long-range absorption for the Li11+Pb208 system, which is dominated by the Coulomb interaction. We compare it to the absorption mechanisms observed for He6+Pb208 which, unlike those of Li11+Pb208, take place at small interacting distances, where both Coulomb and nuclear interactions are important. The proposed approach shows to be a fundamental basis to study reactions involving exotic nuclei
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