4,074 research outputs found
Impact of surface roughness in nanogap plasmonic systems
Recent results have shown unprecedented control over separation distances
between two metallic elements hundreds of nanometers in size, underlying the
effects of free-electron nonlocal response also at mid-infrared wavelengths.
Most of metallic systems however, still suffer from some degree of
inhomogeneity due to fabrication-induced surface roughness. Nanoscale roughness
in such systems might hinder the understanding of the role of microscopic
interactions. Here we investigate the effect of surface roughness in coaxial
nanoapertures resonating at mid-infrared frequencies. We show that although
random roughness shifts the resonances in an unpredictable way, the impact of
nonlocal effects can still be clearly observed. Roughness-induced perturbation
on the peak resonance of the system shows a strong correlation with the
effective gap size of the individual samples. Fluctuations due to fabrication
imperfections then can be suppressed by performing measurements on structure
ensembles in which averaging over a large number of samples provides a precise
measure of the ideal system's optical properties
FIC/FEM formulation with matrix stabilizing terms for incompressible flows at low and high Reynolds numbers
The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-006-0060-yWe present a general formulation for incompressible fluid flow analysis using the finite element method. The necessary stabilization for dealing with convective effects and the incompressibility condition are introduced via the Finite Calculus method using a matrix form of the stabilization parameters. This allows to model a wide range of fluid flow problems for low and high Reynolds numbers flows without introducing a turbulence model. Examples of application to the analysis of incompressible flows with moderate and large Reynolds numbers are presented.Peer ReviewedPostprint (author's final draft
Social segregation of indigenous migrants in Mexico: An overview from Monterrey
In Mexico, rural to urban migration is a clearly noticeable phenomenon. During the last few years, there has been spontaneous growth in the migration of indigenous people towards the northern cities of Mexico, especially to Monterrey, in search of employment. Once the migrants arrive in this metropolis, they face difficulties adjusting and adapting to the city environment because of hidden discrimination. The main argument and hypothesis of this paper is that indigenous people isolate themselves and segregate themselves socially due to fear of (cultural and racial) discrimination and violence. For this study, data were obtained from fieldwork carried out during 2009 and 2010 in Monterrey, Mexico, where we interviewed 350 indigenous people that had moved there from different parts of the country
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
The Remarkable Be Star HD110432
HD110432 has gained considerable attention because it is a hard, variable
X-ray source similar to gamma Cas. From time-serial echelle data obtained over
two weeks during 2005 January and February, we find several remarkable
characteristics in the star's optical spectrum. The line profiles show rapid
variations on some nights which can be most likely be attributed to irregularly
occurring and short-lived migrating subfeatures. Such features have only been
observed to date in gamma Cas and AB Dor, two stars for which it is believed
magnetic fields force circumstellar clouds to corotate over the stellar
surface. The star's optical spectrum also exhibits a number of mainly FeII and
HeI emission features with profiles typical of an optically thin disk viewed
edge-on. Using spectral synthesis techniques, we find that its temperature is
9800K +/-300K, that its projected area is a remarkably large 100 stellar areas,
and its emitting volume resides at a distance of 1 AU from the star. We also
find that the star's absorption profiles extend to +/-1000 km/s, a fact which
we cannot explain. Otherwise, HD110432 and gamma Cas share similarly peculiar
X-ray and optical characteristics such as high X-ray temperature, erratic X-ray
variability on timescales of a few hours, optical emission lines, and
submigrating features in optical line profiles. Because of these similarities,
we suggest that this star is a new member of a select class of "gamma Cas
analogs."Comment: 31 pages, 9 figures, accepted by ApJ (3/20/06
Approximation of the two-fluid flow problem for viscoelastic fluids using the level set method and pressure enriched finite element shape functions
The numerical simulation of complex flows has been a subject of intense research in the last years with important industrial applications in many fields. In this paper we present a finite element method to solve the two immiscible fluid flow problems using the level set method. When the interface between both fluids cuts an element, the discontinuity in the material properties leads to discontinuities in the gradients of the unknowns which cannot be captured using a standard finite element interpolation. The method presented in this work features a local enrichment for the pressure unknowns which allows one to capture pressure gradient discontinuities in fluids presenting different density values. The method is tested on two problems: the first example consists of a sloshing case that involves the interaction of a Giesekus and a Newtonian fluid. This example shows that the enriched pressure functions permit the exact resolution of the hydrostatic rest state. The second example is the classical jet buckling problem used to validate our method. To permit the use of equal interpolation between the variables, we use a variational multiscale formulation proposed recently by Castillo and Codina (2014) [21], that has shown very good stability properties, permitting also the resolution of the jet buckling flow problem in the the range of Weissenberg number 0 < We < 100, using the Oldroyd-B model without any sign of numerical instability. Additional features of the work are the inclusion of a discontinuity capturing technique for the constitutive equation and some comparisons between a monolithic resolution and a fractional step approach to solve the viscoelastic fluid flow problem from the point of view of computational requirements. (C) 2015 Elsevier B.V. All rights reserved.Postprint (author's final draft
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
Photometric Observations of Three High Mass X-Ray Binaries and a Search for Variations Induced by Orbital Motion
We searched for long period variation in V-band, Ic-band and RXTE X-ray light
curves of the High Mass X-ray Binaries (HMXBs) LS 1698 / RX J1037.5-5647, HD
110432 / 1H 1249-637 and HD 161103 / RX J1744.7-2713 in an attempt to discover
orbitally induced variation. Data were obtained primarily from the ASAS
database and were supplemented by shorter term observations made with the 24-
and 40-inch ANU telescopes and one of the robotic PROMPT telescopes. Fourier
periodograms suggested the existence of long period variation in the V-band
light curves of all three HMXBs, however folding the data at those periods did
not reveal convincing periodic variation. At this point we cannot rule out the
existence of long term V-band variation for these three sources and hints of
longer term variation may be seen in the higher precision PROMPT data. Long
term V-band observations, on the order of several years, taken at a frequency
of at least once per week and with a precision of 0.01 mag, therefore still
have a chance of revealing long term variation in these three HMXBs.Comment: Accepted, RAA, May, 201
The visual resourses in the territorial arrangement : I- Potrerillos (Mendoza, Argentina)
Se presenta la primera etapa del
relevamiento de los recursos paisajísticos de
la provincia de Mendoza, con el ajuste
metodológico efectuado mediante una prueba
piloto desarrollada sobre la Ruta Nac. N°
7, desde el Acceso sur en Luján de Cuyo
(límite este) hasta Potrerillos inclusive (límite
oeste). Los límites norte y sur están
abarcados por el horizonte observable desde
la ruta que atraviesa el área en sentido
este-oeste. Se seleccionaron los puntos representativos
mediante dos tipos de muestreo:
sistemático y discrecional.
En base a la catalogación de los recursos
visuales se diseña una zonificación
referencial general con miras al ordenamiento
territorial y uso del suelo en distintas actividades
de desarrollo futuro: turístico, reservas,
residencial, agrícola, industrial. Se valora
la calidad estética del paisaje aplicando,
además, índices valorativos de la vulnerabilidad
de los espacios a las actividades
humanas (Índice de Naturalidad e Índice de
Fragilidad), para obtener valores de la Calidad
Visual Vulnerable del paisaje.
Estos valores se grafican en planos que
representan las distintas calidades alcanzadas
y se complementa con una descripción de los
puntos analizados, recomendaciones para el
mejoramiento paisajístico a través de introducción
o conducción de vegetación y fotografías
documentales de las vistas analizadas.This paper presents the first stage of
the inventory of visual or landscape
resources of the province of Mendoza. The
metodological adjustment was done in an
area of the high basin of Mendoza river, along
the route n° 7, from the South Access in Luján
of Cuyo, to Potrerillos, as limits east and west.
The observable horizons from the route
crossing the area in east-west direction, are
the nort and south limits. Representative
points were chosen across these limits by
means of sistematic and discretional
sampling.
By the cataloguing of the visual
resources, a general reference zonification
is designed for territorial arrangement and
use of land in future development and
activities such as touristic, reserves, residencial,
agricultural, industrial. The
landscape aesthetic quality is evaluated,
applying in addition, vulnerability valoration
indexes of the spaces to the human
activities (Naturalness index and Fragility
index) to achieve Landscape Vulnerable
Visual Quality values.
These values are plotted in charts that
represents the different achieved qualities
and are complemented with a description of
analized points, recomendations for the
lanscape improvements through vegetable
introduction and management, and documental
pictures of analized views.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: Day, Mario.Fil: Passera, Carlos B..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias BiológicasFil: Fioretti, Sonia B..
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: Cappe, Osvaldo Emilio.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ingeniería Agrícol
Social deprivation and exposure to health promotion. A study of the distribution of health promotion resources to schools in England
This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 2010 Chivu and ReidpathBACKGROUND: Area deprivation is a known determinant of health. It is also known that area deprivation is associated with lower impact health promotion. It is less well known, however, whether deprived areas are less responsive to health promotion, or whether they are less exposed. Using data from a national, school-based campaign to promote vaccination against the human papilloma virus (HPV), the relationship between area deprivation and exposure was examined.
METHODS: Taking advantage of a health promotion campaign to provide information to schools about HPV vaccination, a cross sectional study was conducted to examine the relationship between area level, social deprivation, and take-up of (i.e., exposure to) available health promotion material. The sample was 4,750 schools across England, including government maintained and independent schools. The relationship between area deprivation and exposure was examined using bi- and multivariate logistic regression.
RESULTS: It was found that schools in the least deprived quintile had 1.32 times the odds of requesting health promotion materials than schools in the most deprived areas (p = .01). This effect was independent of the school size, the type of school, and the geographic region.
Conclusion
The relationship between area deprivation and the impact of health promotion may be due, at least in part, to differential levels of exposure. The study was limited in scope, pointing to the need for more research, but also points to potentially important policy implications
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