Un tratado sobre la extranjería de lo propio (El uruguayo de Copi)

El uruguayo de Copi es un tratado sobre la lengua, una descripción desopilante de un país, un ácido comentario político, una burla impiadosa de los valores culturales, una pesadilla personal, un golpe de teatro donde cualquier versión de la realidad se vuelve precaria y se trastoca al compás de una imaginación afiebrada que no hace más que dar rienda suelta a los materiales del inconsciente. Pero sobre todo, es la visión desnuda de la relación imposible de un escritor con el país que ha dejado atrás. Un tratado sobre el horror de confrontarse con la realidad carcelaria del pasado. Un intento de "calmar" los fantasmas, es decir, de hacerlos hablar y moverse y morir y resucitar en una trama que transita en medio de cadáveres y mares desaparecidos y un territorio que se achica constantemente. Un texto fundamental para indagar cuestiones relacionadas con la "identidad" nacional y con las maneras en que los desplazamientos culturales (con su concomitante tránsito entre lenguas y visiones del mundo), tan comunes en el mundo actual, afectan la escritura.

San Luis : Del empleo industrial al refugio estatal : Cambios y desplazamientos en la estructura ocupacional

A partir de la implementación de las leyes de promoción industrial, en la Provincia de San Luis se configuró una estructura sectorial del empleo con características particulares respecto de la del resto del país. En efecto, hasta la década de 1990, el sector secundario de la economía concentraba aproximadamente el 50 de los ocupados. Sin embargo, desde 1991 este escenario se modifica y aumentan los ocupados en el sector terciario de la economía. La pérdida de peso de la industria como generadora de empleo no fue compensada por un incremento de otros sectores productivos: las ramas que muestran un comportamiento expansivo son Servicios y Sector Público. Como resultado de estos desplazamientos, se modificaron también la estructura de las ocupaciones y las calificaciones requeridas: quienes se habían capacitado laboralmente trabajando en la industria se encuentran hoy en un escenario en el cual sus calificaciones han perdido valor en un mercado que ahora demanda distintos saberes y capacidades. Frente a esto, el empleo estatal y las ocupaciones de baja calificación en el sector Servicios configuran un refugio, una alternativa a la desocupación. Este trabajo analiza los cambios, rupturas y continuidades en la estructura ocupacional de la Provincia de San Luis a partir de datos provenientes de los Censos Nacionales de Población y Vivienda y de la Encuesta Permanente de Hogares

Updated bathymetric chart of the East Aral Sea

The Aral Sea is located in an arid region with much sand and salt deposits in the surrounding barren open land. Hence, significant displacements of sediments into the lakebed by the action of wind, water, gravity, or snow are likely. The bathymetry of the lake was last observed in the 1960s, and within the last half century, the structure of the lakebed has changed. Based on satellite observations of the temporal changes of shoreline (Landsat optical remote sensing) and water level (multi-mission satellite altimetry) over more than one decade an updated bathymetric chart for the East Basin of the Aral Sea has been generated. During this time, the geometry of the shallow East Basin experienced strong fluctuations due to the occurrence of periods of drying and strong inflow. By the year 2014 the East Basin fell dry. The dynamic behavior of the basin allowed for estimating the lake's bathymetry from a series of satellite-based information. The river mouth made its impression in the present East Aral Sea, because its shrinking led to the inflow of much sediment into the lake's interior. In addition, salt deposits along the shorelines increased the corresponding elevation, a phenomenon that is more pronounced in the reduced lakebed because of increased salinity. It must be noted that height estimates from satellite altimetry were only possible down to a minimum elevation of 27 m above sea level due to a lack of reliable altimetry data over the largely reduced water surface. In order to construct a complete bathymetric chart of the lakebed of the East Aral Sea heights below 27 m were obtained solely from Landsat optical images following the SRB (Selected Region Boundary) approach as described by Singh et al. (2015).

Fission track age determinations of rocks from north Greenland

Apatite fission track (FT) ages and length characteristics of samples obtained from Cambrian to Paleocene-aged sandstones collected along the margin of Nares Strait in Ellesmere Island in the Canadian Arctic Archipelago are dominated by a thermal history related to Paleogene relative plate movements between Greenland and Ellesmere Island. A preliminary inverse FT thermal model for a Cambrian (Archer Fiord Formation) sandstone in the hanging wall of the Rawlings Bay thrust at Cape Lawrence is consistent with Paleocene exhumational cooling, likely as a result of erosion of the thrust. This suggests that thrusting at Cape Lawrence occurred prior to the onset of Eocene compression, likely due to transpression during earlier strikeslip along the strait. Models for samples from volcaniclastic sandstones of the Late Paleocene Pavy Formation (from Cape Back and near Pavy River), and a sandstone from the Late Paleocene Mount Lawson Formation (at Split Lake, near Makinson Inlet) are also consistent with minor burial heating following known periods of basaltic volcanism in Baffin Bay and Davis Strait (c. 61-59 Ma), or related tholeiitic volcanism and intrusive activity (c. 55-54 Ma). Thermal models for samples from sea level dykes from around Smith Sound suggest a period of Late Cretaceous - Paleocene heating prior to final cooling during Paleocene time. These model results imply that Paleocene tectonic movements along Nares Strait were significant, and provide limited support for the former existence of the Wegener Fault. Apatite FT data from central Ellesmere Island suggest however, that cooling there occurred during Early Eocene time (c. 50 Ma), which was likely a result of erosion of thrusts during Eurekan compression. This diachronous cooling suggests that Eurekan deformation was partitioned at discrete intervals across Ellesmere Island, and thus it is likely that displacements along the strait were much less than the 150 km that has been previously suggested for the Wegener Fault.

Chemical and mineral composition of rocks and sediments from the Amirante Arc

New geological and geophysical data on the Amirante Arc, which locates to the south of the Seychelles Islands, are presented. These data were obtained by Pacific Oceanological Institute during the 33-rd cruise of R/V Professor Bogorov in 1990. The Amirante Arc represents a seamount chain, which has submeridional strike and total length about 400 km. To the west of the Amirante Arc there are a deep sea trench and a back-arc basin, i.e. this area is characterized by structural elements associated with the subduction zone of Western Pacific type. According to our data the Amirante Arc is composed by tholeiites of ocean plateau type. This facts are evidences that the Amirante Arc differs from typical Pacific island arcs. This gives an opportunity to distinguish a special type of oceanic structures, i.e. non-volcanic (amagmatic) ridges. The Amirante Ridge has been probably formed as a result of oceanic crust heaping due to horizontal displacements of its blocks in the process of spreding ridge formation in the Indian Ocean during Cretaceous-Paleogene.

Magnetic parameters of rocks from the Red Sea rift zone

Results of detailed geomagnetic and geomorphological studies carried out by R/V Akvanavt together with data obtained by a side-scanning sonar and high-frequency profiles from a towed Zvuk-4 vehicle plus results of visual observations of deep-sea manned Pisces submersible have shown that the spreading axis is divided into segments, whose strike (330°) differs from the overall strike (310°) of the axial magnetic anomaly. In the study area segments are about 1 km long and transform displacements are 0.5 km. Calculations on a model have shown that spreading is asymmetric: during the Brunhes epoch accretion rate of the African Plate was 6 mm/yr and that of the Arabian Plate 7 mm/yr. Earlier it had been 9 and 11 mm/yr, respectively.

Stable oxygen isotope data of Globorotalia inflata and radiocarbon dates for sediment cores GeoB6211-2, GeoB13862-1, and GeoB6308-3

The Southern Westerly Winds (SWW) exert a crucial influence over the world ocean and climate. Nevertheless, a comprehensive understanding of the Holocene temporal and spatial evolution of the SWW remains a significant challenge due to the sparsity of high-resolution marine archives and appropriate SWW proxies. Here, we present a north-south transect of high-resolution planktonic foraminiferal oxygen isotope records from the western South Atlantic. Our proxy records reveal Holocene migrations of the Brazil- Malvinas Confluence (BMC), a highly sensitive feature for changes in the position and strength of the northern portion of the SWW. Through the tight coupling of the BMC position to the large-scale wind field, the records allow a quantitative reconstruction of Holocene latitudinal displacements of the SWW across the South Atlantic. Our data reveal a gradual poleward movement of the SWW by about 1-1.5° from the early to the mid-Holocene. Afterwards variability in the SWW is dominated by millennial-scale displacements in the order of 1° in latitude with no recognizable longer-term trend. These findings are confronted with results from a state-of-the-art transient Holocene climate simulation using a comprehensive coupled atmosphere-ocean general circulation model. Proxy-inferred and modeled SWW shifts compare qualitatively, but the model underestimates both orbitally forced multi-millennial and internal millennial SWW variability by almost an order of magnitude. The underestimated natural variability implies a substantial uncertainty in model projections of future SWW shifts.

Coccolithophore taxa and PCA factor analysis of ODP Site 1233

We provide high-resolution sea surface temperature (SST) and paleoproductivity data focusing on Termination 1. We describe a new method for estimating SSTs based on multivariate statistical analyses performed on modern coccolithophore census data, and we present the first downcore reconstructions derived from coccolithophore assemblages at Ocean Drilling Project (ODP) Site 1233 located offshore Chile. We compare our coccolithophore SST record to alkenone-based SSTs as well as SST reconstructions based on dinoflagellates and radiolaria. All reconstructions generally show a remarkable concordance. As in the alkenone SST record, the Last Glacial Maximum (LGM, 19-23 kyr B.P.) is not clearly defined in our SST reconstruction. After the onset of deglaciation, three major warming steps are recorded: from 18.6 to 18 kyr B.P. (~2.6°C), from 15.7 to 15.3 kyr B.P. (~2.5°C), and from 13 to 11.4 kyr B.P. (~3.4°C). Consistent with the other records from Site 1233 and Antarctic ice core records, we observed a clear Holocene Climatic Optimum (HCO) from ~8-12 kyr B.P. Combining the SST reconstruction with coccolith absolute abundances and accumulation rates, we show that colder temperatures during the LGM are linked to higher coccolithophore productivity offshore Chile and warmer SSTs during the HCO to lower coccolithophore productivity, with indications of weak coastal upwelling. We interpret our data in terms of latitudinal displacements of the Southern Westerlies and the northern margin of the Antarctic Circumpolar Current system over the deglaciation and the Holocene.

Integral Bridge for High-Speed Railway

The structural continuity of fully integral bridges entails many advantages and some drawbacks. Among the latter, the cyclic expansions and contractions of the deck caused by seasonal thermal variations impose alternating displacements at the piers and abutments, with effects that may be difficult to establish reliably. The advantages include easier construction and cheaper maintenance but, especially, horizontal loads can be transmitted to the ground in a much better way than in conventional bridges. This paper first presents a methodology for dealing with the problems that the cyclic displacements imposed raise at the abutments and at the bridge piers. At the former, large pressures may develop, possibly accompanied by undesirable surface settlements. At the latter, the degree of cracking and the ability to carry the specified loads may be in question. Having quantified the drawbacks, simplified but realistic analyses are conducted of the response of an integral bridge to braking and seismic loads. It is shown that integral bridges constitute an excellent alternative in the context of the requirements posed by new high-speed railway lines.

Shower approach in the simulation of ion scattering from solids

An efficient approach for the simulation of ion scattering from solids is proposed. For every encountered atom, we take multiple samples of its thermal displacements among those which result in scattering with high probability to finally reach the detector. As a result, the detector is illuminated by intensive “showers,” where each event of detection must be weighted according to the actual probability of the atom displacement. The computational cost of such simulation is orders of magnitude lower than in the direct approach, and a comprehensive analysis of multiple and plural scattering effects becomes possible. We use this method for two purposes. First, the accuracy of the approximate approaches, developed mainly for ion-beam structural analysis, is verified. Second, the possibility to reproduce a wide class of experimental conditions is used to analyze some basic features of ion-solid collisions: the role of double violent collisions in low-energy ion scattering; the origin of the “surface peak” in scattering from amorphous samples; the low-energy tail in the energy spectra of scattered medium-energy ions due to plural scattering; and the degradation of blocking patterns in two-dimensional angular distributions with increasing depth of scattering. As an example of simulation for ions of MeV energies, we verify the time reversibility for channeling and blocking of 1-MeV protons in a W crystal. The possibilities of analysis that our approach offers may be very useful for various applications, in particular, for structural analysis with atomic resolution.

Researching in ancient engineering physical and chemical analysis in hidraulic roman mortars

Around ten years ago investigation of technical and material construction in Ancient Roma has advanced in favour to obtain positive results. This process has been directed to obtaining some dates based in chemical composition, also action and reaction of materials against meteorological assaults or post depositional displacements. Plenty of these dates should be interpreted as a result of deterioration and damage in concrete material made in one landscape with some kind of meteorological characteristics. Concrete mixture like calcium and gypsum mortars should be analysed in laboratory test programs, and not only with descriptions based in reference books of Strabo, Pliny the Elder or Vitruvius. Roman manufacture was determined by weather condition, landscape, natural resources and of course, economic situation of the owner. In any case we must research the work in every facts of construction. On the one hand, thanks to chemical techniques like X-ray diffraction and Optical microscopy, we could know the granular disposition of mixture. On the other hand if we develop physical and mechanical techniques like compressive strength, capillary absorption on contact or water behaviour, we could know the reactions in binder and aggregates against weather effects. However we must be capable of interpret these results. Last year many analyses developed in archaeological sites in Spain has contributed to obtain different point of view, so has provide new dates to manage one method to continue the investigation of roman mortars. If we developed chemical and physical analysis in roman mortars at the same time, and we are capable to interpret the construction and the resources used, we achieve to understand the process of construction, the date and also the way of restoration in future.

Problemas de interacción suelo estructura en cimentaciones y muros de contención. Influencia de los fenómenos de despegue y deslizamiento

Los terremotos constituyen una de las más importantes fuentes productoras de cargas dinámicas que actúan sobre las estructuras y sus cimentaciones. Cuando se produce un terremoto la energía liberada genera movimientos del terreno en forma de ondas sísmicas que pueden provocar asientos en las cimentaciones de los edificios, empujes sobre los muros de contención, vuelco de las estructuras y el suelo puede licuar perdiendo su capacidad de soporte. Los efectos de los terremotos en estructuras constituyen unos de los aspectos que involucran por su condición de interacción sueloestructura, disciplinas diversas como el Análisis Estructural, la Mecánica de Suelo y la Ingeniería Sísmica. Uno de los aspectos que han sido poco estudiados en el cálculo de estructuras sometidas a la acciones de los terremotos son los efectos del comportamiento no lineal del suelo y de los movimientos que pueden producirse bajo la acción de cargas sísmicas, tales como posibles despegues y deslizamientos. En esta Tesis se estudian primero los empujes sísmicos y posibles deslizamientos de muros de contención y se comparan las predicciones de distintos tipos de cálculos: métodos pseudo-estáticos como el de Mononobe-Okabe (1929) con la contribución de Whitman-Liao (1985), y formulaciones analíticas como la desarrollada por Veletsos y Younan (1994). En segundo lugar se estudia el efecto del comportamiento no lineal del terreno en las rigideces de una losa de cimentación superficial y circular, como la correspondiente a la chimenea de una Central Térmica o al edificio del reactor de una Central Nuclear, considerando su variación con frecuencia y con el nivel de cargas. Finalmente se estudian los posibles deslizamientos y separación de las losas de estas dos estructuras bajo la acción de terremotos, siguiendo la formulación propuesta por Wolf (1988). Para estos estudios se han desarrollado una serie de programas específicos (MUROSIS, VELETSOS, INTESES y SEPARSE) cuyos listados y detalles se incluyen en los Apéndices. En el capítulo 6 se incluyen las conclusiones resultantes de estos estudios y recomendaciones para futuras investigaciones. ABSTRACT Earthquakes constitute one of the most important sources of dynamic loads that acting on structures and foundations. When an earthquake occurs the liberated energy generates seismic waves that can give rise to structural vibrations, settlements of the foundations of buildings, pressures on retaining walls, and possible sliding, uplifting or even overturning of structures. The soil can also liquefy losing its capacity of support The study of the effects of earthquakes on structures involve the use of diverse disciplines such as Structural Analysis, Soil Mechanics and Earthquake Engineering. Some aspects that have been the subject of limited research in relation to the behavior of structures subjected to earthquakes are the effects of nonlinear soil behavior and geometric nonlinearities such as sliding and uplifting of foundations. This Thesis starts with the study of the seismic pressures and potential displacements of retaining walls comparing the predictions of two types of formulations and assessing their range of applicability and limitations: pseudo-static methods as proposed by Mononobe-Okabe (1929), with the contribution of Whitman-Liao (1985), and analytical formulations as the one developed by Veletsos and Younan (1994) for rigid walls. The Thesis deals next with the effects of nonlinear soil behavior on the dynamic stiffness of circular mat foundations like the chimney of a Thermal Power Station or the reactor building of a Nuclear Power Plant, as a function of frequency and level of forces. Finally the seismic response of these two structures accounting for the potential sliding and uplifting of the foundation under a given earthquake are studied, following an approach suggested by Wolf (1988). In order to carry out these studies a number of special purposes computer programs were developed (MUROSIS, VELETSOS, INTESES and SEPARSE). The listing and details of these programs are included in the appendices. The conclusions derived from these studies and recommendations for future work are presented in Chapter 6.

Respuesta sísmica de un edificio de estructuras metálica con aisladores : alternativas de diseño

El presente trabajo es un estudio teórico – experimental para la implementación de un edificio metálico de cuatro plantas con dispositivos disipadores de energía. Este estudio presenta una técnica para la generación de un registro sísmico artificial, que sea compatible con los espectros de diseño de las normas chilena y española. Este acelerograma se crea con una herramienta computacional denominada SIMQKE. La simulación de la estructura sometida al terremoto artificial se realizará en el programa de elementos finitos SAP200. El trabajo se encuentra dividido en cuatro capítulos, cuyos contenidos son los siguientes. En el capitulo uno, o estado del arte, se revisan las diferentes técnicas de aislamiento sísmico, se describe el dispositivo a utilizar, sus bases teóricas y formulación matemática, se revisan las normas NCh.2745 Of.2003 [12], NCSE-02 [18] y se presenta la técnica para la generación de un registro sintético compatible. El capítulo dos aborda el análisis experimental para un edificio real: una edificación de estructura metálica implementada con disipadores de energía metálicos y que será sometida a tres terremotos de diferente magnitud. El capítulo tres expone los resultados de los desplazamientos medidos para la estructura sin disipadores y con ellos, se presentan los porcentajes de disminución de desplazamientos relativos por planta y por tipo de estructura. Por último, el capítulo cuatro presenta las principales conclusiones y una breve discusión de los resultados. The present work is a theoretical and experimental study for the implementation of a fourstorey building with energy dissipating devices. This study presents a technique for generation an artificial seismic record, which is compatible with the design spectra Chilean and Spanish standards. This accelerogram is created with a computational tool called SIMQKE. The simulation of the structure subjected to artificial earthquake will take place in the finite element program SAP2000. This work is divided into four chapters whose contents are as follows. In chapter one, or state of the art, reviews the different seismic isolation techniques, describes the device used, theoretical and mathematical formulation, NCh2745 Of.2003 [12] and NCSE-02 [18] standards are checked, and presents the technique for generating a synthetic record compatible. Chapter two explains the experimental analysis to a real building: a building of steel structure implemented with metallic energy dissipators and will be submitted to three different earthquakes of magnitude. Chapter three presents the results of measured displacements for the structure without dissipators and with them, the percentages of decline relative displacements per plant and type of structure. Finally, chapter four presents the main conclusions and a brief discussion of the results.

On the monitoring of surface displacement in connection with volcano reactivation in Tenerife, Canary Islands, using space techniques

Geodetic volcano monitoring in Tenerife has mainly focused on the Las Cañadas Caldera, where a geodetic micronetwork and a levelling profile are located. A sensitivity test of this geodetic network showed that it should be extended to cover the whole island for volcano monitoring purposes. Furthermore, InSAR allowed detecting two unexpected movements that were beyond the scope of the traditional geodetic network. These two facts prompted us to design and observe a GPS network covering the whole of Tenerife that was monitored in August 2000. The results obtained were accurate to one centimetre, and confirm one of the deformations, although they were not definitive enough to confirm the second one. Furthermore, new cases of possible subsidence have been detected in areas where InSAR could not be used to measure deformation due to low coherence. A first modelling attempt has been made using a very simple model and its results seem to indicate that the deformation observed and the groundwater level variation in the island may be related. Future observations will be necessary for further validation and to study the time evolution of the displacements, carry out interpretation work using different types of data (gravity, gases, etc) and develop models that represent the island more closely. The results obtained are important because they might affect the geodetic volcano monitoring on the island, which will only be really useful if it is capable of distinguishing between displacements that might be linked to volcanic activity and those produced by other causes. One important result in this work is that a new geodetic monitoring system based on two complementary techniques, InSAR and GPS, has been set up on Tenerife island. This the first time that the whole surface of any of the volcanic Canary Islands has been covered with a single network for this purpose. This research has displayed the need for further similar studies in the Canary Islands, at least on the islands which pose a greater risk of volcanic reactivation, such as Lanzarote and La Palma, where InSAR techniques have been used already.

Mapping wide row crops with video sequences acquired from a tractor moving at treatment speed

This paper presents a mapping method for wide row crop fields. The resulting map shows the crop rows and weeds present in the inter-row spacing. Because field videos are acquired with a camera mounted on top of an agricultural vehicle, a method for image sequence stabilization was needed and consequently designed and developed. The proposed stabilization method uses the centers of some crop rows in the image sequence as features to be tracked, which compensates for the lateral movement (sway) of the camera and leaves the pitch unchanged. A region of interest is selected using the tracked features, and an inverse perspective technique transforms the selected region into a bird’s-eye view that is centered on the image and that enables map generation. The algorithm developed has been tested on several video sequences of different fields recorded at different times and under different lighting conditions, with good initial results. Indeed, lateral displacements of up to 66% of the inter-row spacing were suppressed through the stabilization process, and crop rows in the resulting maps appear straight