1,438 research outputs found
X-ray view of four high-luminosity Swift/BAT AGN: Unveiling obscuration and reflection with Suzaku
The Swift/BAT nine-month survey observed 153 AGN, all with ultra-hard X-ray
BAT fluxes in excess of 10^-11 erg cm^-2 s^-1 and an average redshift of 0.03.
Among them, four of the most luminous BAT AGN (44.73 < Log L(BAT) < 45.31) were
selected as targets of Suzaku follow-up observations: J2246.0+3941 (3C 452),
J0407.4+0339 (3C 105), J0318.7+6828, and J0918.5+0425. The column density,
scattered/reflected emission, the properties of the Fe K line, and a possible
variability are fully analyzed. For the latter, the spectral properties from
Chandra, XMM-Newton and Swift/XRT public observations were compared with the
present Suzaku analysis. Of our sample, 3C 452 is the only certain
Compton-thick AGN candidate because of i) the high absorption and strong
Compton reflection; ii) the lack of variability; iii) the "buried" nature, i.e.
the low scattering fraction (<0.5%) and the extremely low relative [OIII]
luminosity. In contrast 3C 105 is not reflection-dominated, despite the
comparable column density, X-ray luminosity and radio morphology, but shows a
strong long-term variability in flux and scattering fraction, consistent with
the soft emission being scattered from a distant region (e.g., the narrow
emission line region). The sample presents high (>100) X-to-[OIII] luminosity
ratios, confirming the [OIII] luminosity to be affected by residual extinction
in presence of mild absorption, especially for "buried" AGN such as 3C 452.
Three of our targets are powerful FRII radio galaxies, making them the most
luminous and absorbed AGN of the BAT Seyfert survey despite the inversely
proportional N_H - L_X relation.Comment: A&A paper in press, 17 page
Methodological and terminological issues in animal-assisted interventions: An umbrella review of systematic reviews
Recently, animal-assisted interventions (AAIs), which are defined as psychological, educational, and rehabilitation support activities, have become widespread in different contexts. For many years, they have been a subject of interest in the international scientific community and are at the center of an important discussion regarding their effectiveness and the most appropriate practices for their realization. We carried out an umbrella review (UR) of systematic reviews (SRs), created for the purpose of exploring the literature and aimed at deepening the terminological and methodological aspects of AAIs. It is created by exploring the online databases PubMed, Google Scholar, and Cochrane Library. The SRs present in the high-impact indexed search engines Web of Sciences and Scopus are selected. After screening, we selected 15 SRs that met the inclusion criteria. All papers complained of the poor quality of AAIs; some considered articles containing interventions that did not always correspond to the terminology they have explored and whose operating practices were not always comparable. This stresses the need for the development and consequent diffusion of not only operational protocols, but also research protocols which provide for the homogeneous use of universally recognized terminologies, thus facilitating the study, deepening, and comparison between the numerous experiences described
Sustainable landscape in arid zones : useful ornamental xeric species
Se analiza el valor económico,
ecológico y paisajístico de especies vegetales,
pertenecientes a la flora espontánea de
Mendoza (Argentina), resistentes a la sequía
y que pueden alcanzar porte arbóreo. Su empleo
ahorra agua de riego en espacios verdes
ornamentales y de protección ambiental.
Se sugiere medidas de conservación de
las especies espontáneas más útiles
paisajísticamente, así como normas generales
sobre métodos de plantación y mantenimiento.
Se recomiendan especies leñosas
espontáneas de la provincia, de bajo requerimiento
hídrico, utilizables paisajísticamente.This paper analyzes the economic,
ecological and landscape value of drought
resistant species from the spontaneous flora
of Mendoza (Argentina). Some of such
species could reach tree size and its use
might save the irrigation water used for ornamental
and environmental protection
areas.
Actions to protect the most useful
spontaneous species, as well as general
rules for plantation and maintenance are
suggested. Spontaneous wooden species of
low water requirements, to use in different
landscape objectives, are recommended.Fil: Codina, Ramón A..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Manzano, Enrique R..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Carrieri, Sergio A..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Fioretti, Sonia B..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuari
Photoassociation inside an optical dipole trap: absolute rate coefficients and Franck-Condon factors
We present quantitative measurements of the photoassociation of cesium
molecules inside a far-detuned optical dipole trap. A model of the trap
depletion dynamics is derived which allows to extract absolute photoassociation
rate coefficients for the initial single-photon photoassociation step from
measured trap-loss spectra. The sensitivity of this approach is demonstrated by
measuring the Franck-Condon modulation of the weak photoassociation transitions
into the low vibrational levels of the outer well of the 0g- state that
correlates to the 6s+6p3/2 asymptote. The measurements are compared to
theoretical predictions. In a magneto-optical trap these transitions have
previously only been observed indirectly through ionization of ground state
molecules
Environmental value calculus of the frontal urban gardens. : Mendoza (Argentina)
Los espacios verdes y, en general, la vegetación
que cumple funciones estéticas y de protección
ambiental son valorados, medidos y calculados
por el área destinada al cultivo, en lugar
de basar los cálculos en los elementos vegetales
constitutivos. Esto significa una simplificación excesiva
de la valoración de la vegetación (actual o
proyectada) que no aporta criterios de cuantificación
valorativa necesarios, actualmente, tanto
para preservar vegetación existente como para
políticas de desarrollo urbano y proyectos de ingeniería
del mejoramiento ambiental.
En el presente trabajo se propone aplicar a
la valoración de los jardines frontales urbanos de
la ciudad de Mendoza una metodología cuantitativa
desarrollada por R. Codina et al., que se apoya
en un concepto nuevo que es su influencia
como mejoradores ambientales. La ecuación de
cálculo se integra con índices de valoración como
el Índice de Vegetación Ambientalmente Activa y
el Índice Ambiental Urbanístico, que permiten
cuantificar la importancia urbanística y ambiental
de la vegetación.
También se propone una base para implementar
una política de incentivo de los jardines frontales
mediante la disminución del avalúo valor terreno
del impuesto inmobiliario, en una escala progresiva
según el Índice Ambiental Urbanístico de
cada propiedad, tendiente a la transformación de
la ciudad en una ciudad-jardín, mejorando la calidad
de vida y el atractivo turístico urbano.The green spaces and in general, the
vegetation used for aesthetics and environmental
protection are valuated, measured and calculated
through the area destinated to the cultivation
instead of calculus based in the component vegetal
elements. This means an excessive simplification
in the vegetal valoration (current or
projected) that not contribute with cuantitative
valoration criterion, which are needed today in
preservation of existent vegetation, urban
development policies and in engineering projects
of environmental improvement.
This work proposes the application to the
frontal urbans gardens in Mendoza city, of a
cuantitative metodology developed by R. Codina
et al., which is based in a new concept, it influences
as environmental improvement. The calculus
equation is to be composed of valoration indexes
as the Environmental Active Vegetation Index and
the Urbanistic Environmental Index, that allow the
cuantification of the urbanistic and environmental
importance of vegetation.
Also is proposed a base for the implementation
of an incentive policy of the frontals urban
gardens through the diminution of the real estate
tax land appraisal, in a progressive scale according
the Urbanistic Environmental Index of each
property, tending to transformation the city in a
garden-city, to improve the life´s quality and the
urban touristic charm.Fil: Codina, Ramón A..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Passera, Carlos B..
Universidad Autónoma de Nuevo León (México). Facultad de Ciencias BiológicasFil: Naranjo, Gabriela.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Carrieri, Sergio A..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Fioretti, Sonia B..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Manzano, Enrique R..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuari
Data model issues in the Cherenkov Telescope Array project
The planned Cherenkov Telescope Array (CTA), a future ground-based
Very-High-Energy (VHE) gamma-ray observatory, will be the largest project of
its kind. It aims to provide an order of magnitude increase in sensitivity
compared to currently operating VHE experiments and open access to guest
observers. These features, together with the thirty years lifetime planned for
the installation, impose severe constraints on the data model currently being
developed for the project.
In this contribution we analyze the challenges faced by the CTA data model
development and present the requirements imposed to face them. While the full
data model is still not completed we show the organization of the work, status
of the design, and an overview of the prototyping efforts carried out so far.
We also show examples of specific aspects of the data model currently under
development.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Formation of ultracold LiCs molecules
We present the first observation of ultracold LiCs molecules. The molecules
are formed in a two-species magneto-optical trap and detected by two-photon
ionization and time-of-flight mass spectrometry. The production rate
coefficient is found to be in the range 10^{-18}\unit{cm^3s^{-1}} to
10^{-16}\unit{cm^3s^{-1}}, at least an order of magnitude smaller than for
other heteronuclear diatomic molecules directly formed in a magneto-optical
trap.Comment: 8 pages, 2 figure
L\'evy flights of photons in hot atomic vapours
Properties of random and fluctuating systems are often studied through the
use of Gaussian distributions. However, in a number of situations, rare events
have drastic consequences, which can not be explained by Gaussian statistics.
Considerable efforts have thus been devoted to the study of non Gaussian
fluctuations such as L\'evy statistics, generalizing the standard description
of random walks. Unfortunately only macroscopic signatures, obtained by
averaging over many random steps, are usually observed in physical systems. We
present experimental results investigating the elementary process of anomalous
diffusion of photons in hot atomic vapours. We measure the step size
distribution of the random walk and show that it follows a power law
characteristic of L\'evy flights.Comment: This final version is identical to the one published in Nature
Physic
Molecular vibration in cold collision theory
Cold collisions of ground state oxygen molecules with Helium have been
investigated in a wide range of cold collision energies (from 1 K up to 10
K) treating the oxygen molecule first as a rigid rotor and then introducing the
vibrational degree of freedom. The comparison between the two models shows that
at low energies the rigid rotor approximation is very accurate and able to
describe all the dynamical features of the system. The comparison between the
two models has also been extended to cases where the interaction potential He -
O is made artificially stronger. In this case vibration can perturb rate
constants, but fine-tuning the rigid rotor potential can alleviate the
discrepancies between the two models.Comment: 11 pages, 3 figure
Molecular Dynamics Simulation of Sympathetic Crystallization of Molecular Ions
It is shown that the translational degrees of freedom of a large variety of
molecules, from light diatomic to heavy organic ones, can be cooled
sympathetically and brought to rest (crystallized) in a linear Paul trap. The
method relies on endowing the molecules with an appropriate positive charge,
storage in a linear radiofrequency trap, and sympathetic cooling. Two
well--known atomic coolant species, and
, are sufficient for cooling the molecular mass range
from 2 to 20,000 amu. The large molecular charge required for simultaneous
trapping of heavy molecules and of the coolant ions can easily be produced
using electrospray ionization. Crystallized molecular ions offer vast
opportunities for novel studies.Comment: Accepted for publication in Phys. Rev.
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