Sample records for TRANSPORTE DE CARGA (charge transport)
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1

Estructuras de deformación (¿sismitas?) en la Formación Río Negro, provincia de Río Negro, Argentina

Schillizzi, Roberto; Luna, Liliana; Falco, Juan Ignacio
2010-07-01

Resumen en español A Las estructuras de deformación (ED) en sedimentos blandos comprenden las alteraciones que se producen casi simultáneamente con la sedimentación. Estos procesos se hallan en relación directa con las características internas de los materiales sedimentarios y de los factores externos que actúan sobre ellos. Sus resultados incluyen deformaciones como inyecciones, fracturas, volcanes y laminaciones convolutas que afectan total o parcialmente la estratificación. Los se (mas) dimentos blandos deformados por sismos se incluyen bajo la denominación general de sismitas (seismites). Como objetivo de esta investigación se plantea reconocer, por primera vez, estructuras de deformación ubicadas en la Formación Río Negro presentes en el sector norte del Golfo San Matías, en inmediaciones del Faro Río Negro. La metodología empleada consistió en el reconocimiento y descripción de las estructuras, para lo cual se extrajeron muestras para determinar granulometría, mineralogía y contenido de materia orgánica. Se fotografiaron los distintos sectores con deformaciones con el fin de establecer modelos comparativos. El sector estudiado, de 4 km de extensión, se ubica entre el faro de Río Negro y el inicio del Banco Verde y morfológicamente corresponde a un frente acantilado con orientación ENE-OSO. En él se determinaron las siguientes ED: a- de carga simple, pseudonódulos contiguos y aislados, y estructuras complejas; b- de escape de fluidos y c- estructuras de deslizamiento basal y por presión dirigida. El origen de las deformaciones se debe a las características de las sedimentitas y a los procesos que las afectan tales como los efectos por carga, escapes de fluidos y las presiones dirigidas. Como origen de estos procesos se señalan: la presión de la columna litológica, las olas de tormentas y los terremotos. Por los rasgos hallados las deformaciones del litoral rionegrino tendrían un origen sísmico, proceso ocurrido en un único evento durante el ciclo Andino cuyos inicios se fijan hace aproximadamente 45 Ma. Por otra parte sus techos y bases no se hallan asociados a otros procesos de deformación y sus espesores no exceden el metro de potencia. Además se hallan acotadas a la zona de transición entre los miembros medio y superior de la Formación Río Negro descansando en algunos casos sobre arcilitas y en otros sobre limolitas, originadas en un paleorelieve de interdunas. Resumen en inglés Soft-sediment deformation structures (SSD) are alterations produced almost simultaneously with sedimentation. They are directly related to internal characteristics of sedimentary materials as well as to external factors acting on them. Results derived from such alterations are evidenced as injections, fractures, volcanoes and convolute laminations, among other forms, affecting stratification either totally or partially. Soft-sediment deformation structures resulting from (mas) seisms are known as seismites. The present study aims at determining for the first time the presence of SSD structures in the Río Negro Formation, located in the northern area of San Matías Gulf, near Río Negro Lighthouse, Argentina (Fig. 1). To this end, structures were firstly identified and further described. Samples were subsequently collected for the determination of grain-size, mineralogy and organic matter content. Photographs of the different sectors evidencing deformations were taken in order to determine further comparative models. Morphology in the study area is associated to cliffs with vertical, fractured fronts and with an average height of 70 m in whose base torn-down blocks are accumulated. The geological structure of the study area is related to the Cuenca del Colorado and the Comarca Nordpatagónica, whose basement is mainly composed of Paleozoic and Mesozoic crystalline rocks. The sedimentary tertiary cover from the Miocene-Pliocene is represented by light-blue sandstones of the Río Negro Formation (Andreis, 1965). This unit was formed in an aeolian environment with intercalations of clay-silt shallow lagoons and a marine episode located in the mid area of the Río Negro Formation. At the top of the Río Negro Formation there are Pleistocene-Holocene sedimentites having a thickness of up to 5 m. Within the local structural framework of our study area there are fractures with a NE-SW and a NW-SE direction, which are related with fractures N55º, N90º and N350º azimuth located in the abrasion platform. According to Dzulinsky and Walton (1965), Lowe (1975), Brencley and Newall (1977), Clauss (1993), van Loon (2002), Owen (2003), Neuwerth et al. (2006), Alfaro et al. (2006), Montenat et al. (2007), among others (Table 1), and, taking into account the geometry of deformations, laboratory reconstructions and field observations from our study area, it can be concluded that the classifications of SSD structures tend to establish morphologic and genetic systematizations. The following characteristics were identified in our study area: limited deformations among stratigraphic horizons; a lateral continuity of SSD structures at considerable distances; and a confinement between non-deformed strata and its lithological association with psamitic-pelitic sediments. The study area, which is 4 km long and is located between Río Negro Lighthouse and the beginning of Banco Verde, is from the morphological point of view, a cliffed front with an ENE-WSW orientation. Different types of SSD structures were identified in this area. For example, from the morphological point of view and according to the loading mechanisms observed, simple-load structures (Fig. 2), attached and detached pseudonodules (Figs. 3, 4 and 5) and complex structures (Fig. 6) were identified. Furthermore, from the genetic point of view and according to the intrusion processes observed in soft sediments, water-scape structures (Fig. 7) and plate- or fountain-like deformations (Fig. 8) were found. From the genetic point of view, and based on the collapse and pressure mechanisms observed, basal slumping (Fig. 9) and directed-pressure structures (Fig. 11) were also found. The above-mentioned SSD structures were analyzed and interpreted following Strachan´s model (2002) (Fig. 10) and Laird´s model (1968) (Fig. 12). The origin of SSD structures depends on the characteristics of sedimentites and on the mechanisms that produce them. In the study area, the materials susceptible to deformation come from an interdune environment that is characterized by granulometric variations derived from the fluctuating and restrictive climatic conditions (Cojan and Thiry, 1992) that typify the Río Negro Formation. Fine-grained materials having low cohesion and poor sorting such as the sediments of deformed strata (Fig. 13) produced SSD structures as a result of high pore pressure and liquefaction effects (Tsuchida and Hayashi, 1971; Obermeier, 1996). Grain packing with a porous value as that allows intercommunication among grains and saturated material, is also crucial to the formation of SSD structures. The mineralogic content of deformed levels is composed of i) quartz, chalcedony, orthose, plagioclase, pyroxenes and biotite, opaques (magnetite and ilmenite, autigenic pyrite) in crystalline aggregates; ii) undetermined Fe oxides; and iii) colorless and light-brown unaltered volcanic glass shards, clays identified as smectite-illite interstratified and scarce kaolinite. Grains are mainly subangular and, to a lesser extent, sub-round and round. The surface of the majority of grains in the study area was found clean and with some marks. The percentage of CaCO3 was found to vary from 0.5 to 3% and that of total organic carbon (TOC) was found to reach 1.5%. Deformations may be produced as a result of load deformation mechanisms, fluid escape, basal slumping or pressure-directed displacements. Due to load deformation mechanisms, structures are linked to gravity-related movements occurring during the initial stages of deposition. For these deformations to occur, grain-size at the overlaying levels should be thicker than at the underlying levels, for example, sandstones rather than silstones or claystones. These deformations are related to water saturation at the deformed level (fluidization-liquefaction). Therefore, deformation mechanisms, which involve both expulsion and rotation of fragments as well as fluid escape, are characterized by the action of lithostatic pressure which produces movement (deformation) and by the action of the underlying sedimentary levels. Deformations may also result from a fluid escape mechanism, i.e., from a mechanism associated to i) the spatial arrangement of grains (packing), ii) their shape, iii) their tendency to inequigranularity, and iv) the communication among macro- and micro- pores as well as the high or low sinuosity connection among themselves (Net and Limarino, 2000). Further requirements for deformations to occur include particular thixotrophic conditions, especially the presence of colloids among grains. The rupture of unions of particles either by hitting or by shearing is, among others, a cause which produces an unbalance between hydrostatic pressure and lithostatic pressure. If the latter is altered, the energetic unbalance makes fine sediments flow among the weakly lithified sandstones whose extrusion will occur via both vertical and horizontal pore ducts (Lopez Gamundi, 1986; Clauss, 1993). Basal slumping produces deformations that are associated not only to soft sediments deposited in natural slopes but also to interbedded sand- and mud-levels. Layers tend to have a prismatic-shaped geometry whose materials are under ductile-to-fragile conditions, in which antique layers support younger ones. Once horizontality is affected, movement, which is marked by a rupture of the original slope, begins. The lower levels are expected to transport the upper ones without affecting the original succession of layers. At the delay of movement derived from the compressive effect of the displacement front, fluids extrude forming cones or cut dikes (Fig. 10). Several deformations of this type initiate movement as result of differences in the hydrostatic gradient (Strachan, 2002). Deformations may be also produced as a result of pressure-directed displacements which are conditioned by the compaction level, thickness and ability of materials to deform. Thus, deformations occur because the original level is saturated in water as a result of the ductile behavior of materials (Bracco et al., 2005). Laird (1968) claims that SSD structures should meet some of the following requirements to be considered of seismic origin: slightly curved strata walls and floors to follow the original stratification and interruption of continuity of the stratum that is marked by a scar in which the sedimentary fillings keep their characteristics both above and below stratification. There could be rotated sediment clasts below the discontinuity as a result of a thrust-induced drag of the upper sedimentary packing. These processes could be, in turn, triggered either by the charge or pressure of the lithologic column, storm waves and seismicity. Storm-wave impact may also produce deformation in soft sediments. Nonetheless, no high energy structures such as cross-beddings or tsunami-type chaotic sedimentation were observed in our study area. Noteworthingly, for stormwave-derived liquefaction to occur, waves should reach magnitudes higher than 6 m (Alfaro et al., 2002), this being a phenomenon that was not recorded in our study area. Taken together, findings from the present study indicate that SSD structures in our study area are seismic alterations that occurred in an event during the Andean cycle whose beginnings are traced approximately 45 My ago. The fact that i) both the roofs and bottoms of these structures are not associated to other processes of deformation, ii) their thickness does not exceed one meter, and iii) they are confined to a transitional area between the middle and top members of the Río Negro Formation, lying in some cases on claystones and in some other cases, on siltstones, originated in an interdune paleorelief, confirms their seismic origin.

Scientific Electronic Library Online (Spanish)

2

Tunneling magnetoresistance in Fe/MgO granular multilayers

García-García, A.; Vovk, A.; Pardo, J. A.; Štrichovanec, P.; Algarabel, Pedro A.; Magen, C.; Teresa, José María de; Morellón, Luis; Ibarra, M. Ricardo
2010-02-01

Digital.CSIC (Spain)

4

Scattering of electrons in graphene by clusters of impurities

Katsnelson, M. I.; Guinea, F.; Geim, A. K.
2009-01-01

Digital.CSIC (Spain)

5

Propuesta de configuración de redes de recolección de autos al final de su vida útil en México/ Design proposal for collection networks of end-life vehicles in Mexico

CRUZ-RIVERA, Reynaldo; ERTEL, Jürgen
2010-05-01

Resumen en español El presente trabajo desarrolla el diseño de la configuración de redes de recolección de vehículos al final de su vida útil en México. El problema es modelado a través de herramientas analíticas que son utilizadas en el manejo de cadenas inversas de suministro. El problema es identificado como un Problema de Localización de Instalaciones con Capacidad Ilimitada (UFCFLP por sus siglas en inglés) y es resuelto por medio del programa de localización de instalacione (mas) s SITATION®. Se desarrollan tres escenarios para la solución del problema, cada escenario considera un porcentaje diferente de cobertura. Los resultados del trabajo presentan el comportamiento de los costos fijos, de transporte y totales del sistema. Así como la localización geográfica de los centros de recolección en México, correspondientes a cada escenario. Resumen en inglés The present work develops the configuration's design of collection networks for End-of-Life Vehicles in México. The problem uses analytic tools, widely used in the reverse logistics supply management. The problem is identified as an Uncapacitated Fixed Charge Facility Location problem (UFCFLP) and it is solved through the use of the SITATION© facility location software. Three scenarios are developed to solve the problem; every scenario takes into account a different per (mas) centage in collection coverage. The results describe for every scenario the fixed, transport and total costs' behaviorinthe system and the geographic location of collection centers within Mexico.

Scientific Electronic Library Online (Spanish)

6

Piezocomposites metal-cerámica como elementos activos en acelerómetros

Ochoa, P.; Villegas, Marina; Pons Rovira, José Luis; Fernández Lozano, José Francisco; Bengochea, M. A.
2002-01-01

Digital.CSIC (Spain)

8

Nanoparticles as smart treatment-delivery systems in plants: assessment of different techniques of microscopy for their visualization in plant tissues

González-Melendi, Pablo; Fernández-Pacheco, Rodrigo; Coronado, María José; Corredor, Eduardo; Sánchez-Testillano, Pilar; Risueño, María del Carmen; Marquina, Clara; Ibarra, M. Ricardo; Rubiales, Diego; Pérez de Luque, Alejandro
2008-01-01

Digital.CSIC (Spain)

9

Mott–Schottky behavior of strongly pinned double Schottky barriers and characterization of ceramic varistors

Fernández Hevia, D.; Frutos, J. de; Caballero, A. C.; Fernández Lozano, José Francisco
2002-09-01

Digital.CSIC (Spain)

10

Modelo de estructura empresarial para el transporte público colectivo/ Company structure model for public collective transport

Moncada Aristizábal, Carlos Alberto; Burbano Valente, Johanna
2005-12-01

Resumen en español El esquema de operación del transporte público colectivo en la ciudad de Bogotá no ha sufrido grandes variaciones en su estructura general a lo largo de 70 años. Es conocido que las empresas de transporte público urbano de pasajeros operadas con buses han funcionado, no como empresas administradoras del parque automotor sino como empresas a las que se afilian vehículos. La base operativa en el esquema de afiliación de las empresas de transporte público colectivo d (mas) e Bogotá, es la misma que puede ser encontrada en la gran mayoría de ciudades del país, con propietarios y conductores encargados del mantenimiento, control y prestación del servicio. Este documento pretende presentar un modelo teórico de estructura empresarial, enmarcado dentro de las condiciones legales y operativas que reformaron en el año 2003 la prestación del servicio en la ciudad de Bogotá, involucrando los aspectos técnicos, administrativos, organizacionales y financieros para que las organizaciones de transporte público colectivo puedan administrar de manera eficiente la flota de vehículos con los cuales se prestará el servicio, tomando como base las condiciones legales y operativas que reformaron en el año 2003 la prestación de dicho servicio en la ciudad de Bogotá. Resumen en inglés The operation scheme of the collective public transport in Bogotá (Colombia) has not suffered a big transformation in its general structure during the last seventy years. It is well known that the companies of collective public transport for passengers operated by buses has not worked like managers of the vehicles, rather they worked like companies for vehicles affiliation. The operation base for the companies in the model of affiliation (as the Bogotá case), is the sam (mas) e for all the cities with public transport around Colombia: there are owners and drivers of the vehicles in charge of the maintenance, control and service offers. This document presents a formulation of a theoretical model of company structure, remarked in the particular policies and operating conditions that transformed the service of public transport since 2003 in Bogotá city. The model involves the operative, organizational and financial aspects, looking forward for a new collective public transport company which manage the vehicles fleet in an efficient way and for a better service to the users.

Scientific Electronic Library Online (Spanish)

12

La olla a presión del transporte público en Bogotá/ The pressure cooker of public transport in Bogotá

Ardila Gómez, Arturo
2005-05-01

Resumen en español La ciudad de Bogotá tiene un problema persistente de sobreoferta de vehículos de transporte público. Explico la persistencia de la sobreoferta con un modelo de cuatro elementos. Primero, una tarifa para el transporte público inflada por encima del costo real de prestar el servicio. La tarifa inflada permite que la sobreoferta se mantenga a pesar de la baja movilización de pasajeros por día. Segundo, una agencia gubernamental a cargo del sector que es muy débil inst (mas) itucionalmente. Esto genera desbalances de poder a favor de los transportadores e impide una efectiva implantación de las medidas que buscan reducir la sobreoferta. Tercero, un arreglo institucional para la prestación del transporte público plagada de incentivos perversos. Estos incentivos motivan a varios actores (fuera de TransMilenio) a aumentar o mantener la sobreoferta. Finalmente, el transporte público colectivo en Bogotá atrae actores porque la economía no ofrece mejores alternativas de inversión y trabajo. Una posible solución está en fortalecer el gobierno de Bogotá, establecer un recaudo centralizado de la tarifa, y cambiar el pago del rodamiento que hacen los propietarios de los buses a las empresas de transporte público. Resumen en inglés The city of Bogotá has a persistent bus-oversupply problem. I explain the persistence of the oversupply with a four-part model. First, a bus fare inflated above the true cost of providing the service. The inflated fare allows the persistence of the excessive number of buses despite low ridership per bus. Second, a weak government agency in charge of the public transportation sector. This weakness generates power imbalances in favor of the private bus companies and preven (mas) ts the effective implementation of measures that seek to curb oversupply. Third, an institutional arrangement for the provision of public transportation full of perverse incentives. These incentives motivate several actors to increase or maintain the oversupply. Finally, the public transportation system (non-TransMilenio) attracts people because the economy does not offer better investment and employment opportunities. One possible solution lies in strengthening the city government, establishing a centralized fare-collection system, and changing the way bus owners pay for renting bus companies´ routes.

Scientific Electronic Library Online (Spanish)

13

Investigation of the origin of deep levels in CdTe doped with Bi

Saucedo, E.; Franc, J.; Elhadidy, H.; Horodysky, P.; Ruiz, C. M.; Bermúdez, V.; Sochinskii, N. V.
2008-05-01

Digital.CSIC (Spain)

16

From Coulomb blockade to the Kondo regime in a Rashba dot

López, Rosa; Sánchez, David; Serra, Llorenç
2007-07-06

Digital.CSIC (Spain)

17

Espectroscopia de admitancias de banda ancha aplicada al control microestructural de propiedades eléctricas en varistores cerámicos

Caballero Cuesta, Amador; Fernández Lozano, José Francisco; Frutos, J. de; Fernández Hevia, D.
2004-05-01

Digital.CSIC (Spain)

18

Electronic potential of a chemisorption interface

Zhao, Jin ; Pontius, Niko ; Winkelmann, Aimo ; Sametoglu, Vahit ; Kubo, Atsushi ; Borisov, Andrei G. ; Sánchez-Portal, Daniel

7 pages, 4 figures.-- PACS nrs.: 73.20.-r. | Chemisorption of atoms and molecules controls many interfacial phenomena such as charge transport and catalysis. The question of how the intrinsic properties of the interacting materials define the electronic structure of their interface remains one of th...

DRIVER (Spanish)

19

Electronic potential of a chemisorption interface

Zhao, Jin; Pontius, Niko; Winkelmann, Aimo; Sametoglu, Vahit; Kubo, Atsushi; Borisov, Andrei G.; Sánchez-Portal, Daniel; Silkin, Viatcheslav M.; Chulkov, Eugene V.; Echenique, Pedro M.; Petek, Hrvoje
2008-08-13

Digital.CSIC (Spain)

20

El Peaje a la congestión en Londres: su aporte a la movilidad sostenible/ The London Congestion Charge: its Contribution to Sustainable Mobility

Granada Garcés, Isabel
2009-05-01

Resumen en español No resulta fácil de definir qué tan sostenible es un esquema de transporte. Por el contrario, existen ciertos aspectos sobre los que un esquema, como el peaje a la congestión en Londres, puede o no contribuir al mejoramiento de la calidad de vida y al uso racional de recursos. De acuerdo con los criterios económico, social y medio ambiental, el siguiente documento revisa las cualidades de este esquema de transporte a la luz de la movilidad sostenible y concluye con ba (mas) se en otras investigaciones que la contribución social del esquema es evidente y positiva, pero que económicamente tiene aún un amplio campo de mejora, mientras que su aporte al medio ambiente se mantiene incierto. Resumen en inglés How sustainable is a transport scheme is not easy to define. There are certain aspects in which schemes as the London congestion charge can or can´t contribute to the improvement of the quality of life and the rational use of resources. Through 3 criteria: economic, social and environmental, the following paper reviews the characteristics of this transport scheme based on the concept of sustainable mobility to conclude that socially speaking it has been successful while economically it can be improved while its environmental effects are still to be established.

Scientific Electronic Library Online (Spanish)

21

Coupling Mechanics to Charge Transport in Carbon Nanotube Mechanical Resonators

Lassagne, Benjamin ; Tarakanov, Yury ; Kinaret, Jari ; García-Sánchez, David ; Bachtold, Adrian

4 pages, 4 figures.-- Printed version published Aug 28, 2009.-- Supporting information available at: www.sciencemag.org/cgi/content/full/1174290/DC1 | Nanoelectromechanical resonators have potential applications in sensing, cooling, and mechanical signal processing. An important parameter in these s...

DRIVER (Spanish)

22

Coupling Mechanics to Charge Transport in Carbon Nanotube Mechanical Resonators

Lassagne, Benjamin; Tarakanov, Yury; Kinaret, Jari; García-Sánchez, David; Bachtold, Adrian
2009-07-23

Digital.CSIC (Spain)

23

Coherent quantum switch driven by optimized laser pulses

Räsänen, E.; Castro, Alberto; Werschnik, J.; Rubio Secades, Ángel; Gross, E. K. U.
2007-10-11

Digital.CSIC (Spain)

25

Alterations in Photosystem II electron transport as revealed by thermoluminescence of Cu-poisoned chloroplasts

Horváth, Gábor; Arellano, Juan B.; Droppa, Magdolna; Barón Ayala, Matilde
1998-08-01

Digital.CSIC (Spain)