691 research outputs found
Spin wave vortex from the scattering on Bloch point solitons
The interaction of a spin wave with a stationary Bloch point is studied. The
topological non-trivial structure of the Bloch point manifests in the
propagation of spin waves endowing them with a gauge potential that resembles
the one associated with the interaction of a magnetic monopole and an electron.
By pursuing this analogy, we are led to the conclusion that the scattering of
spin waves and Bloch points is accompanied by the creation of a magnon vortex.
Interference between such a vortex and a plane wave leads to dislocations in
the interference pattern that can be measurable by means of magnon holography
La respuesta de la comunidad epilítica intermareal natural e impactada por las aguas residuales del Atlántico SO a pulsos (antes/después del verano) y descargas crónicas de aguas residuales en el período 1997 - 2014
Until 2014 Mar del Plata city discharged its untreated sewage effluents to the intertidal sector. This city has a marked seasonality in the urban discharge, varying between 2.8 and 3.5 m3.sec.-1 of effluents before/after summer. The effect on the intertidal benthic community was evaluated in both spatially, in sewage-impacted and reference sites, and temporarily in both the short term, before/after summer, and in long term along nine periods between 1997 - 2014. The bivalve Brachidontes rodriguezii, the ecosystem engineer, reach the maximum dominance and frequency in reference areas. Spatially the presence of opportunistic and tolerant species characterized the impacted areas, while in reference sites sensitive species were prevalent. The opportunistic polychaete species Capitella "capitata" sp. and Alitta succinea were dominant near the sewage discharge in firsts periods. In other periods the indicator species were Rhynchospio glutaea or Boccardia spp. From 2008 the invader Boccardia proboscidea characterized the sewage-impacted sites building massive reefs. The crustaceans Jassa falcata and Caprella sp. were very abundant at intermediate distances from the sewage discharge, while Monocorophium insidiosum was very abundant in sewage-impacted areas. The tolerant and opportunistic species are favored after the summer due to the extra organic matter input. All community parameters showed lower values after the summer, and also a trend to diminish along the studied period.Hasta el año 2014 la ciudad de Mar del Plata descargaba sus efluentes cloacales sin tratamiento al sector intermareal. Esta ciudad tiene una marcada estacionalidad en sus descargas, variando el caudal entre 2,8 a 3,5 m3.seg-1 antes/después del verano. El efecto sobre la comunidad bentónica intermareal fue evaluado en la escala espacial, en sitios de referencia y sitios impactados, y también temporalmente en el corto período de tiempo, antes/después del verano, y a lo largo de nueve períodos entre 1997 - 2014. El bivalvo Brachidontes rodriguezii, el ingeniero ecosistémico, alcanza su máxima dominancia y frecuencia en áreas de referencia. Espacialmente la presencia de especies oportunistas y tolerantes caracterizó los sitios impactados, mientras que en sitios de referencia las especies sensibles son prevalentes. En los primeros períodos el poliqueto oportunista Capitella “capitata” sp. fue dominante cerca de la descarga cloacal, y también Alitta succinea. En periodos posteriores las especies indicadoreas fueron Rhynchospio glutaea o Boccardia spp. Desde 2008 el poliqueto invasor Boccardia proboscidea caracterizó los sitios impactados por la descarga por masivos arrecifes. Los crustáceos Jassa falcata y Caprella sp. fueron muy abundantes a distancias intermedias de la descarga, mientras que Monocorophium insidiosum fue muy abundante en el àrea impactada por la descarga cloacal. Las especies tolerantes u oportunistas se vieron favorecidas después del verano debido al aporte extra de materia orgánica. Todos los parámetros comunitarios mostraron valores menores después del verano, y también se observa una tendencia a disminuir a lo largo de los períodos estudiados
Depth-based Outlier Detection for Grouped Smart Meters: a Functional Data Analysis Toolbox
Smart metering infrastructures collect data almost continuously in the form
of fine-grained long time series. These massive time series often have common
daily patterns that are repeated between similar days or seasons and shared
between grouped meters. Within this context, we propose a method to highlight
individuals with abnormal daily dependency patterns, which we term evolution
outliers. To this end, we approach the problem from the standpoint of
Functional Data Analysis (FDA), by treating each daily record as a function or
curve. We then focus on the morphological aspects of the observed curves, such
as daily magnitude, daily shape, derivatives, and inter-day evolution. The
proposed method for evolution outliers relies on the concept of functional
depth, which has been a cornerstone in the literature of FDA to build shape and
magnitude outlier detection methods. In conjunction with our evolution outlier
proposal, these methods provide an outlier detection toolbox for smart meter
data that covers a wide palette of functional outliers classes. We illustrate
the outlier identification ability of this toolbox using actual smart metering
data corresponding to photovoltaic energy generation and circuit voltage
records
Viejos y nuevos horizontes: obsidianas entre las sociedades agrícolas-pastoriles del Periodo Tardío en Antofagasta de la Sierra (provincia de Catamarca, Puna Meridional Argentina)
El presente trabajo investiga la problemática del tráfico de obsidianas entre las poblaciones tardías de Antofagasta de la Sierra (Provincia de Catamarca, Puna Meridional Argentina) y sus variaciones respecto de las poblaciones formativas que las precedieron. Busca aproximarse a los espacios y localidades a los que esos grupos habrían accedido tanto a través de estudios geoquímicos como de la procedencia de artefactos arqueológicos. Los resultados se discuten a la luz de las tendencias ambientales, políticas y sociales que, de acuerdo con diversos autores, caracterizan el período ca. 1000-500 AP en los Andes circumpuneños.This paper looks to investigate the obsidians traffic between the Late Period groups of Antofagasta de la Sierra (Province of Catamarca, Southern Argentine Pune) and its variation with respect to the previous Formative ones. It looks to approach to the spaces and localities these groups would have acceded, by means of geochemical sourcing studies of archaeological artifacts. The results are discussed at the light of the environmental, political and social tendencies that, according to diverse authors, characterize the period ca. 1000-500 BP in the Circumpune Andes
Protoariciella uncinata Hartmann-Schröeder, 1962 (Polychaeta, Orbiniidae): a new record for intertidal mussel beds of the Southwestern Atlantic shore affected by sewage effluents
Protoariciella uncinata (Polychaeta, Orbiniidae) is mentioned for the first time in southwestern Atlantic shores, from mytilid mussel beds of Brachidontes rodriguezi of the Mar del Plata area, Argentine. The species was formely described for mytilids banks of the Pacific coast of Chile and Peru. The work also provides information about spatial distribution, relationship with sewage organic enrichment, density and other ecological data.La especie Protoariciella uncinata (Polychaeta, Orbiniidae) es mencionada por primera vez para el Atlántico sudoccidental, proveniente de muestreos intermareales realizados en la comunidad del mitílido Brachidontes rodriguezi del área de Mar del Plata, Argentina. La especie ha sido anteriormente citada para bancos de mitílidos de Chile y Perú. El trabajo también brinda información sobre distribución espacial, relación con el gradiente orgánico producido por efluentes cloacales, densidad y otros datos ecológicos
Domain wall dynamics in expanding spaces
We study the effects on the dynamics of kinks due to expansions and
contractions of the space. We show that the propagation velocity of the kink
can be adiabatically tuned through slow expansions/contractions, while its
width is given as a function of the velocity. We also analyze the case of fast
expansions/contractions, where we are no longer on the adiabatic regime. In
this case the kink moves more slowly after an expansion-contraction cycle as a
consequence of loss of energy through radiation. All these effects are
numerically studied in the nonlinear Klein-Gordon equations (both for the
sine-Gordon and for the phi^4 potential), and they are also studied within the
framework of the collective coordinate evolution equations for the width and
the center of mass of the kink. These collective coordinate evolution equations
are obtained with a procedure that allows us to consider even the case of large
expansions/contractions.Comment: LaTeX, 18 pages, 2 figures, improved version to appear in Phys Rev
El clima sicoterápico dentro del hospital general
(Tesis de grado presentada por su autor para optar el título de arquitecto de la Universidad Pontificia Bolivariana).
Es mi pensamiento personal que estas tesis de grado no definan un determinado asunto arquitectónico o urbanístico con la absoluta intrascendencia de una solución particular. No deseo definir principios, ni dar normas concretas sobre un problema de extrema importancia. Pretendo solo crear una inquietud necesaria en la concepción hospitalaria sobre la cual tengo mis puntos de vista que en esta ocasión someto a vuestra respetable consideración. (…
Evaluating Labor Market Flexibility in Chile from an International Perspective
We rank Chile in terms of labor market flexibility among a group that includes both OECD and emerging economies. We use a performance-based indicator of labor-market flexibility based on the half life of unemployment responses to macroeconomic shocks. This indicator captures the cyclical behavior of the labor market and is obtained by estimating a structural VAR (SVAR). The SVAR is identified using long-run restrictions, which are based on a simple open-economy model with labor-market rigidity. We found that Korea, Hong Kong, Chile, US, and Mexico are the most flexible economies. At the other end, our index indicates that Germany, Sweden, Spain and Colombia are the most rigid labor markets.
- …