2,150 research outputs found
Dual characterization of critical fluctuations: Density functional theory & nonlinear dynamics close to a tangent bifurcation
We improve on the description of the relationship that exists between
critical clusters in thermal systems and intermittency near the onset of chaos
in low-dimensional systems. We make use of the statistical-mechanical language
of inhomogeneous systems and of the renormalization group (RG) method in
nonlinear dynamics to provide a more accurate, formal, approach to the subject.
The description of this remarkable correspondence encompasses, on the one hand,
the density functional formalism, where classical and quantum mechanical
analogues match the procedure for one-dimensional clusters, and, on the other,
the RG fixed-point map of functional compositions that captures the essential
dynamical behavior. We provide details of how the above-referred theoretical
approaches interrelate and discuss the implications of the correspondence
between the high-dimensional (degrees of freedom) phenomenon and
low-dimensional dynamics.Comment: 8 figure
Carne, demonio y mundo. Predicación y díscíplínamíento en Chile a fines del siglo XVIII
Indexación: Revista UNA
High Spectral and Spatial Resolution Observations of the PDR Emission in the NGC2023 Reflection Nebula with SOFIA and APEX
We have mapped the NGC 2023 reflection nebula in [CII] and CO(11--10) with
the heterodyne receiver GREAT on SOFIA and obtained slightly smaller maps in
13CO(3--2), CO(3--2), CO(4--3), CO(6--5), and CO(7--6) with APEX in Chile. We
use these data to probe the morphology, kinematics, and physical conditions of
the C II region, which is ionized by FUV radiation from the B2 star HD37903.
The [CII] emission traces an ellipsoidal shell-like region at a position angle
of ~ -50 deg, and is surrounded by a hot molecular shell. In the southeast,
where the C II region expands into a dense, clumpy molecular cloud ridge, we
see narrow and strong line emission from high-J CO lines, which comes from a
thin, hot molecular shell surrounding the [CII] emission. The [CII] lines are
broader and show photo evaporating gas flowing into the C II region. Based on
the strength of the [13CII] F=2--1 line, the [CII] line appears to be somewhat
optically thick over most of the nebula with an optical depth of a few. We
model the physical conditions of the surrounding molecular cloud and the PDR
emission using both RADEX and simple PDR models. The temperature of the CO
emitting PDR shell is ~ 90 -- 120 K, with densities of 10^5 -- 10^6 cm^-3, as
deduced from RADEX modeling. Our PDR modeling indicates that the PDR layer
where [CII] emission dominates has somewhat lower densities, 10^4 to a few
times 10^5 cm^-3Comment: Accepted by A&
Combination of Technologies for Architectural Planning. Parish Church of Portell
La sucesiva aplicación de las nuevas tecnologías a la expresión gráfica arquitectónica ha supuesto una revolución en cada uno de los pasos que dan como resultado el levantamiento de planos. En general se puede decir que en gran medida facilitan la consecución del trabajo a realizar. Sin embargo, su aplicación de manera generalizada e indiscriminada, puede ocasionar
un trabajo excesivo e innecesario. Por tanto, el reto de la aplicación de
nuevas tecnologías supone no sólo su conocimiento y adecuado manejo, sino además, la capacidad de descartar unos métodos frente a otros en función de las necesidades planteadas por el modelo a representar, la finalidad del trabajo a realizar, la disponibilidad de medios y de tiempo. El presente artículo es una muestra de la conveniencia en la utilización de métodos tradicionales y nuevas tecnologías, basada su combinación
en la optimización de tiempo y recursos. El estudio realizado se fundamenta en el levantamiento de planos, y análisis gráfico y metrológico, de la Iglesia Parroquial de Portell, la primera de las iglesias de planta salón valencianas construidas en el siglo XVIII
Tunable entanglement distillation of spatially correlated down-converted photons
We report on a new technique for entanglement distillation of the bipartite
continuous variable state of spatially correlated photons generated in the
spontaneous parametric down-conversion process (SPDC), where tunable
non-Gaussian operations are implemented and the post-processed entanglement is
certified in real-time using a single-photon sensitive electron multiplying CCD
(EMCCD) camera. The local operations are performed using non-Gaussian filters
modulated into a programmable spatial light modulator and, by using the EMCCD
camera for actively recording the probability distributions of the
twin-photons, one has fine control of the Schmidt number of the distilled
state. We show that even simple non-Gaussian filters can be finely tuned to a
~67% net gain of the initial entanglement generated in the SPDC process.Comment: 12 pages, 6 figure
The Revised Mental Health Inventory-5 (MHI-5) as an ultra-brief screening measure of bidimensional mental health in children and adolescents
The Mental Health Inventory-5 (MHI-5) is a brief, valid, and reliable international instrument for assessing mental health in adults. The aim of the present study is to examine the psychometric properties of the MHI-5 in children and adolescents. A sample of 595 students (10-15 years old) completed the MHI-5 Spanish version adapted for this study, as well as another measure of anxiety and depression symptoms, and a clinical interview as a gold standard. The overall coefficient obtained indicate good internal consistency. A unique factor solution explaining a 53.70% and a two-factor structure explaining 69.20% of the total variance were obtained. The correlations with total and subscale scores of anxiety and depression were significant. A ROC analysis showed good properties as a screening test to predict anxiety and depressive diagnoses in children and adolescents. The Revised MHI-5 presents two essential changes: a simplified 4-point response format and a new factor solution including distress and well-being. These outcomes show that the Revised MHI-5 is a brief, valid, and reliable measure to bidimensionally assess mental health and screening emotional disorders in children and adolescents. Copyright © 2019 Elsevier B.V. All rights reserved. KEYWORDS: Anxiety; Assessment; Depression; Detection; Distress; Factorial structure; MHI-5; Psychometrics; Spanish; Validation; Well-bein
Tree-level unitarity, causality and higher-order Lorentz and CPT violation
Higher-order effects of CPT and Lorentz violation within the SME effective
framework including Myers-Pospelov dimension-five operator terms are studied.
The model is canonically quantized by giving special attention to the arising
of indefinite-metric states or ghosts in an indefinite Fock space. As is
well-known, without a perturbative treatment that avoids the propagation of
ghost modes or any other approximation, one has to face the question of whether
unitarity and microcausality are preserved. In this work, we study both
possible issues. We found that microcausality is preserved due to the
cancellation of residues occurring in pairs or conjugate pairs when they become
complex. Also, by using the Lee-Wick prescription, we prove that the matrix
can be defined as perturbatively unitary for tree-level processes with
an internal fermion line.Comment: 19 pages, 2 figure
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