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Garcia-Ortiz C.E.,Autonomous University of Nuevo Leon | Garcia-Ortiz C.E.,University of Southern Denmark | Coello V.,Research Center Cientifica ucacion Superior Of Ensenada | Han Z.,University of Southern Denmark | And 2 more authors.
Optics Letters

We demonstrate experimentally generation of diffraction-free plasmonic beams with zeroth- and first-order Bessel intensity profiles using axicon-like structures fabricated on gold film surfaces and designed to operate at a wavelength of 700 nm. The central beam features a very low divergence (∼8π mrad) for a narrow waist of the order of one wavelength and the ability to self reconstruct, which are the main signatures of diffraction-free beams. © 2013 Optical Society of America. Source

Lavaniegos B.E.,Research Center Cientifica ucacion Superior Of Ensenada
Journal of Marine Systems

The California Current system is a large marine ecosystem with transition gradients between subarctic and tropical biomes containing diverse habitats. Biogeographic species groups must be carefully analyzed in order to detect tendencies shifting the ecosystem toward a more temperate or tropical state. Species composition of hyperiid amphipods was analyzed in July 2002 for evidence of subarctic water intrusion and for signals of the El Niño event developing in the equatorial Pacific. Multivariate analysis showed a dominance of "transition zone" species typical of the California Current. The main evidence of subarctic water intrusion was the extended distribution of Themisto pacifica, which reached as far south as 27°N, with particularly high abundances at 30-32°N. The intrusion of subarctic water took place despite evidence that an El Niño event was in progress. The zonal advection due to El Niño intersected the equatorward flow of the subarctic intrusion and probably produced a large cyclonic eddy off Baja California. This eddy maintained a limited El Niño influence at a few offshore stations near its southern boundary. The main environmental variables influencing the amphipod assemblage structure were water temperature and the abundance of salps. T. pacifica, a species with cool water affinity, was more sensitive to temperature, whereas subtropical species, such as Vibilia armata, were strongly correlated with the availability of salps. © 2014 Elsevier B.V. Source

Rodrigo C.,Andres Bello University | Diaz J.,Pontifical Catholic University of Valparaiso | Gonzalez-Fernandez A.,Research Center Cientifica ucacion Superior Of Ensenada
Latin American Journal of Aquatic Research

The Easter submarine alignment corresponds to a sequence of seamounts and oceanic islands which runs from the Ahu-Umu volcanic fields in the west to its intersection with the Nazca Ridge in the east, with a total length of about 2.900 km and a strike of N85°E. Recent bathymetric compilations that include combined satellite derived and shipboard data (Global Topography) and multibeam bathymetric data (from NGDC-NOAA) are interpreted both qualitatively and quantitatively by using a morphological analysis, which was comprised of the determination of bathymetric patterns, trends in lineations and structures; height measurements, computation of basal areas and volumes of seamounts, in order to establish clues on the origin of this seamount chain and to establish relationships with the regional tectonics. In the study region 514 seamounts were counted, of which 334 had a basal area less than the reference seamount (Moai). In general, the largest seamounts (>1000 m in height) tend to align and to have a larger volume, with an elongation of their bases along the seamount chain. On the other hand, smaller seamounts tend to be distributed more randomly with more circular bases. As a consequence of the morphological analysis, the best possible mechanism that explains the origin of the seamount chain is the existence of a localized hotspot to the west of the Salas y Gómez Island. The corresponding plume would contribute additional magmatic material towards the East Pacific Rise through canalizations, whose secondary branches would feed intermediate volcanoes. It is possible that within the Easter Island region there would be another minor contribution through fractures in the crust, due to the crustal weakening that was produced by the Easter Fracture Zone. © 2014, Escuela de Ciencias del Mar. All rights reserved. Source

Sahay P.N.,Research Center Cientifica ucacion Superior Of Ensenada

In a porous medium, the porosity perturbation, i.e., the change in porosity, is an integral part of a deformation process. Yet, there is no explicit statement about that in the Biot theory. By linking its constitutive relation to the continuity equations, the tacit assumption about the porosity perturbation in this theory is inferred. The linear dependence of the porosity perturbation on the pressure difference of the two phases is embedded in its constitutive relation. The solid and fluid pressures affect the change in porosity in equal magnitude but in opposite sense. By assuming that the fluid pressure may affect the porosity perturbation to an extent different than that of the solid pressure, the Biot constitutive relation is generalized. This introduces a nondimensional parameter. It could be named the porosity effective pressure coefficient, because the measure of the extent the fluid pressure affects the change in porosity relative to the solid pressure. In the regime in which the fluid pressure affects to a lesser extent, this parameter spans from unity, the state in which fluid resists the change in porosity in equal but opposite manner to solid, to zero, the state in which fluid ultimately ceases to affect the porosity change at all. As this parameter diminishes from unity, the undrained bulk modulus drops from being the Gassmann modulus. Ultimately, it becomes the series combination of the dry frame bulk modulus with the bulk modulus of fluid weighted by the Biot coefficient when the parameter is vanishing. The other regime is the one in which the fluid pressure affects to an extent greater than the solid pressure. Here, the parameter may span from unity to the ratio of bulk modulus of constituent solid mineral to fluid, which is its upper limit. At the upper limit, the undrained bulk modulus is the Voigt average: the upper bound of the modulus of a composite medium. © 2013 Society of Exploration Geophysicists. Source

Evans R.,Research Center Cientifica ucacion Superior Of Ensenada
Energy Procedia

In this paper we will present a newly written energy calculator built as a project between CICESE and the State Energy Commission of Baja California. The system runs server side and is written in PHP and Python storing its data on a My SQL database. The user interface allows the user to input their geographic location, and electrical energy use history. The user can then choose from a virtual warehouse of photovoltaic systems offered by local installers. Using astronomical algorithms, and weather station data the system generates a list of solar intensity values and calculates the response of chosen photovoltaic. The final values calculated are the cost predictions for the next 20 years. Because of its open-source nature, then system can be easily expanded to include wind power systems, carbon production, and ever gas and water usage. The primary user for this system is the general public with hopes that they will become educated on their energy use, and the potential effects of new photovoltaic installations. © 2014 The Authors. Published by Elsevier Ltd. Source

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