La literatura de viajes y la mirada antropológica

La antropología como ciencia ha sido considerada hija del colonialismo europeo. En este sentido comparte un destino similar al de la literatura de viajes e incluso puede ser considerada como el vástago más cercano a las ciencias naturales de esta última. En la conformación de su programa de investigación -que también puede comprenderse como la aplicación de la teoría evolucionista a la historia de la cultura humana-, la literatura de viajes. con su vocación referencial y su insistencia en la descripción de la diversidad humana y geográfica, ha jugado un papel fundamental. En este trabajo se intenta realizar aportes, desde algunos textos de Alexander von Humboldt, como viajero y autor de textos que pueden ser considerados parte de la literatura de viajes, a la distinción de ambos ámbitos, el literario y el más definidamente antropológico.

25 Years of Polarstern Meteorology

The most important tool in Germany's polar research program is the research and supply vessel Polarstern. The ship was commissioned in 1982, the maiden voyage started at the end of 1982. The owner of the ship is the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany. Within the last 25 years Polarstern performed a total of 44 expeditions to the Arctic and Antarctic. The ship is well equipped for meteorological research as well as for routine meteorological services. The meteorological office is permanently manned with a weather technician/- observer from the German Weather Service (DWD) who performs the routine 3-hourly synoptic observations and the daily upper air soundings. Additionally, a weather forecaster is responsible to advice the ships captain as well as the helicopter pilots and all scientists in any weather related question. The forecaster gets assistance from the weather technician who performs the satellite picture reception and manages the near real time data flow.

La accesibilidad y uso de las nuevas tecnologías de la información y la comunicación en las escuelas de educación secundaria superior : El "territorio esc olar" de la ciudad de Tandil

El presente trabajo se propone analizar la accesibilidad y uso de las Nuevas Tecnologías de la Información y la Comunicación en las Escuelas de Educación Secundaria Superior de la ciudad de Tandil, desde las manifestaciones territoriales y las prácticas de aula de la geografía escolar. El trabajo es el resultado de una investigación de carácter cuali-cuantitativo desarrollada en el marco del Programa de investigación "Educación y Territorio" de la Facultad de Ciencias Humanas (CIG-UNICEN). Como resultados de la investigación se presentarán los mapas temáticos correspondientes a la accesibilidad y uso de las nuevas tecnologías en el "Territorio escolar", que muestran la desigual territorialización de las densidades comunicacionales e informacionales. Fruto de las encuestas realizadas a directivos de las escuelas secundarias de la ciudad, podemos decir que la accesibilidad a las Nuevas Tecnologías en algunas instituciones escolares no siempre garantiza su uso en las prácticas de aula de la geografía escolar

La accesibilidad y uso de las nuevas tecnologías de la información y la comunicación en las escuelas de educación secundaria superior : El "territorio esc olar" de la ciudad de Tandil

El presente trabajo se propone analizar la accesibilidad y uso de las Nuevas Tecnologías de la Información y la Comunicación en las Escuelas de Educación Secundaria Superior de la ciudad de Tandil, desde las manifestaciones territoriales y las prácticas de aula de la geografía escolar. El trabajo es el resultado de una investigación de carácter cuali-cuantitativo desarrollada en el marco del Programa de investigación "Educación y Territorio" de la Facultad de Ciencias Humanas (CIG-UNICEN). Como resultados de la investigación se presentarán los mapas temáticos correspondientes a la accesibilidad y uso de las nuevas tecnologías en el "Territorio escolar", que muestran la desigual territorialización de las densidades comunicacionales e informacionales. Fruto de las encuestas realizadas a directivos de las escuelas secundarias de la ciudad, podemos decir que la accesibilidad a las Nuevas Tecnologías en algunas instituciones escolares no siempre garantiza su uso en las prácticas de aula de la geografía escolar

La accesibilidad y uso de las nuevas tecnologías de la información y la comunicación en las escuelas de educación secundaria superior : El "territorio esc olar" de la ciudad de Tandil

El presente trabajo se propone analizar la accesibilidad y uso de las Nuevas Tecnologías de la Información y la Comunicación en las Escuelas de Educación Secundaria Superior de la ciudad de Tandil, desde las manifestaciones territoriales y las prácticas de aula de la geografía escolar. El trabajo es el resultado de una investigación de carácter cuali-cuantitativo desarrollada en el marco del Programa de investigación "Educación y Territorio" de la Facultad de Ciencias Humanas (CIG-UNICEN). Como resultados de la investigación se presentarán los mapas temáticos correspondientes a la accesibilidad y uso de las nuevas tecnologías en el "Territorio escolar", que muestran la desigual territorialización de las densidades comunicacionales e informacionales. Fruto de las encuestas realizadas a directivos de las escuelas secundarias de la ciudad, podemos decir que la accesibilidad a las Nuevas Tecnologías en algunas instituciones escolares no siempre garantiza su uso en las prácticas de aula de la geografía escolar

Compilation of measurements from two interdisciplinary STAR-shaped surveys in the North Sea: The ZISCH - Dataset

The measurements were obtained during two North Sea wide STAR-shaped cruises during summer 1986 and winter 1987, which were performed to investigate the circulation induced transport and biologically induced pollutant transfer within the interdisciplinary research in the project "ZISCH - Zirkulation und Schadstoffumsatz in der Nordsee / Circulation and Contaminant Fluxes in the North Sea (1984-1989)". The inventory presents parameters measured on hydrodynamics, nutrient dynamics, ecosystem dynamics and pollutant dynamics in the pelagic and benthic realm. The research program had the objective of quantifying fluxes of major budgets, especially contaminants in the North Sea. In spring 1986, following the phytoplankton spring bloom, and in late winter 1987, at minimum primary production activity, the North Sea ecosystem was investigated on a station net covering the whole North Sea. The station net was shaped like a star. Sampling started in the centre, followed by the northwest section and moving counter clockwise around the North Sea following the residual currents. By this strategy, a time series was measured in the central North Sea and more synoptic data sets were obtained in the individual sections. Generally advection processes have to be considered when comparing the data from different stations. The entire sampling period lasted for more than six weeks in each cruise. Thus, a time-lag should be considered especially when comparing the data from the eastern and the western part of the central and northern North Sea, where samples were taken at the beginning and at the end of the campaign. The ZISCH investigations represented a qualitatively and quantitatively new approach to North Sea research in several respects. (1) The first simultaneous blanket coverage of all important biological, chemical and physical parameters in the entire North Sea ecosystem; (2) the first simultaneous measurements of major contaminants (metals and organohaline compounds) in the different ecosystem compartments; (3) simultaneous determinations of atmospheric inputs of momentum, energy and matter as important ecosystem boundary conditions; (4) performance of the complex measurement program during two seasons, namely the spring plankton bloom and the subsequent winter period of minimal biological activity; and (5) support of data analysis and interpretation by oceanographic and meteorological numerical models on the same scales.

Organic geochemistry of Upper Albian sediments from the Kirchrode I borehole

In the framework of a multidisciplinary research program, an organic geochemical study was carried out on a drill core which comprises a 245 m thick sequence of light-colored, Upper Albian marlstones that were deposited in the central part of the Lower Saxony basin (northern Germany). For part of the Upper Albian sequence, high-resolution measurements of carbonate contents reveal cycles which can be related to earth orbital forcing. Based on these data, sediment accumulation rates were calculated to be in the order of 15 g/m**2/yr. These high accumulation rates contrast with very low organic carbon contents and an extremely poor preservation of the autochthonous organic matter. Most of the sedimentary organic matter is of terrigenous origin and mainly derived from the erosion of older sedimentary rocks. Organic petrography reveals only a very small fraction of marine organic particles. Carbon/sulphur ratios, pristane/phytane ratios as well as the predominance of resedimented organic particles over autochthonous organic particles suggest that aerobic degradation processes rather than anaerobic processes (sulphate reduction) were responsible for the degradation of the organic matter. Furthermore, the scarcity of terrigenous organic particles (vitrinite) indicates that there was little vegetation on nearby land areas. To explain these analytical results, a depositional model was developed which could explain the scarcity of organic matter in the Upper Albian sediments. This model is based on downwelling of oxygen-rich, saline waters of Tethyan origin, which reduces the nutrient content of surface waters and thus primary bioproductivity while degradation of primary organic matter in the water column is enhanced at the same time. These conditions contrast to those which existed in Barremian and early Aptian times in this basin, when limited water exchange with adjacent oceans caused oxygen deficiency and the deposition of numerous organic carbon-rich black shales. The thick, organic matter-poor Upper Albian sequence of northern Germany also contrasts with comparatively thin, time-equivalent, deep-sea black shales from Italy. This discrepancy indicates that local and regional oceanographic factors (at least in this case) have a greater influence on organic matter deposition than global events.

Floating zone stability

The present state of de preparation of an experiment on floating liquid zones to be performed in the first Spacelab flight is presented. In this experiment,a liquid bridge is to be placed between two parallel coaxial disks (in the Fluid Physics Module)and subjected to very precise disturbances in order to check the theoretical predictions about its stability limits and behavior under mechanical inputs: stretching of the zone, filling or removing the liquid,axial vibration, rotation, disalignment, etc. Several aspects of the research are introduced:1) Relevance of the study. 2) Theoretical predictions of the liquid behavior regarding the floating-zone stability limits and the expected response to vibrational and rotational disturbances. 3) Ground support experiments using the Plateau technique or the small scale simulation. 4) Instrumental aspects of the experimentation: the Fluid Physics Module utilization and post-flight data analysis.5)Research program for future flights.

Estudio de la reactividad álcali-sílice originada por componentes reactivos minoritarios

El objetivo de la presente tesis se enmarca dentro del estudio del estado de hormigones de presas, desarrollado en los últimos años en el Laboratorio Central del CEDEX, en el que se ratifica que una de las causas más importantes del deterioro de obras hidráulicas en España es la reacción álcali-sílice. La tesis que se presenta pretende contribuir al mejor conocimiento de la reacción álcali sílice con fines normativos preventivos, abordando los aspectos relativos a la identificación de áridos reactivos en el hormigón. El conocimiento de los áridos reactivos en España (origen de la reactividad, tipos de reacción y su comportamiento, así como las herramientas disponibles para su detección) es imprescindible para evitar la futura aparición de esta patología en nuevas estructuras, ya sea evitando el uso de áridos reactivos o tomando las medidas preventivas necesarias si su utilización es inevitable. A partir del Estudio Bibliográfico realizado se han detectado diversas lagunas en la identificación y caracterización de áridos de reacción rápida, cuya característica principal es que son reactivos con concentraciones muy bajas de diferentes componentes reactivos. Para resolver las lagunas identificadas se ha planeado un estudio experimental, consistente en el análisis de áridos cuya reactividad es conocida porque han sido empleados en obras afectadas por la reacción álcali sílice. Sobre el árido grueso extraído de estas estructuras se han realizado una serie de ensayos normalizados (estudio petrográfico, ensayo acelerado de probetas de mortero, ensayo Gel Pat y ensayos químicos). El análisis de los resultados experimentales ha permitido conocer las limitaciones reales en áridos reactivos españoles de las diferentes técnicas existentes, tratando de minimizarlas para áridos cuya reactividad es debida a componentes minoritarios (áridos de reacción rápida). Además, se ha evaluado la utilización de la difracción de rayos X (no normalizada) y la creación de un nuevo ensayo (Gel Pat Modificado). Finalmente, el estudio experimental ha permitido fijar una metodología de ensayo para el estudio de áridos reactivos por su contenido en componentes minoritarios (áridos de reacción rápida). The objective of this Thesis fits into the research program developed in CEDEX the last years and focused on the durability of concrete in Dams. This research work confirms that one of the main problems related to the deterioration of hydraulic structures is the alkali silica reaction. This Thesis aims to contribute to a better understanding of alkali-silica reaction, for preventive regulation purposes, considering the aspects related to the identification of reactive aggregates. The knowledge of Spanish reactive aggregates (origin of the reactivity, types of reaction and their behavior, and the tools available to detect and describe them) is essential to avoid the appearance of this pathology in new structures, either not using the reactive aggregate or taking the necessary preventive measures available in bibliography if the use of the reactive aggregate is inevitable. From the State-of –the-Art developed, several gaps have been detected in the detection and description of rapid reactive aggregates, which main characteristic if that they are reactive with low content of some reactive components. An experimental programme has been designed to solve these gaps, consisting on studying the reactivity of aggregates used in Spanish structures affected by the alkali silica reaction. Several Standard Tests have been carried out on coarse aggregates removed from the affected structures (Petrographic description, Accelerated Mortar Bar Test, Gel Pat Test and Chemical Tests). The analysis of the results obtained in Spanish reactive aggregates allows to know the advantages and limitations of each test, trying to minimize the disadvantages to detect Spanish reactive aggregates because of the minority content of rapid reactive components (rapid reactive aggregates). Moreover, X ray diffraction (not standardized) has been tested to detect rapid reactive aggregates and also a new test has been developed for the same purpose (Optimized Gel Pat Test). Finally, the experimental programme has made possible to define a methodology for detection of Spanish rapid reactive aggregates.

Proyecto de viabilidad de una planta de tratamiento para mineral de estaño y tántalo

El proyecto tiene como objeto definir la viabilidad de explotación de un importante yacimiento de Estaño y Tántalo que se encuentra en una formación geológica de base pegmatítica situada en el norte de España. En base a las reservas calculadas, se define la capacidad de tratamiento de la planta de procesamiento del mineral para un periodo de explotación de 10 años. Como primer paso se estudian los ensayos de caracterización y concentración realizados en laboratorio a partir de muestras de mano representativas del mineral así como otros en planta piloto llevados a cabo anteriormente. Una vez definida la recuperación del Estaño y Tántalo se procede al diseño conceptual del proceso. Posteriormente se desarrolla un diseño e ingeniería preliminar más aproximados, a partir de los cuales se evalúan los costes de equipos y operacionales que, en base a los retornos por la venta de los concentrados, permitirán calcular la rentabilidad del proyecto y riesgos de la inversión. ABSTRACT The purpose of this project is to define the feasibility of mining a major deposit of tin and tantalum found in a pegmatite formation in northern Spain. Based on the estimated reserves, the operating capacity for mining and mineral processing plant was defined for a period of 10 years. As a first step for the development, a research program for characterization and concentration of the ore, were performed in the laboratory based on representative samples from the deposit. In addition, previous pilot plant results were also taken into account. Once determined the recovery of tin and tantalum, the conceptual design process was defined. As a second step, it was developed a preliminary design and engineering, from which the capital and operating costs were estimated .By means of the calculated returns from the sale of concentrates, the profitability of the project and investment risks were finally assessed

Simplified computational method for non-linear seismic analysis of bridges

After the experience gained during the past years it seems clear that nonlinear analysis of bridges are very important to compute ductility demands and to localize potential hinges. This is specially true for irregular bridges in which it is not clear weather or not it is possible to use a linear computation followed by a correction using a behaviour factor. To simplify the numerical effort several approximate methods have been proposed. Among them, the so-called Dynamic Plastic Hinge Method in which an evolutionary shape function is used to reduce the structure to a single degree of freedom system seems to mantein a good balance between accuracy and simplicity. This paper presents results obtained in a parametric study conducted under the auspicies of PREC-8 european research program.

Vanadium-Doped In and Sn Sulphides: Photocatalysts able to use the whole visible light spectrum

Using photocatalysis for energy applications depends, more than for environmental purposes or selective chemical synthesis, on converting as much of the solar spectrum as possible; the best photocatalyst, titania, is far from this. Many efforts are pursued to use better that spectrum in photocatalysis, by doping titania or using other materials (mainly oxides, nitrides and sulphides) to obtain a lower bandgap, even if this means decreasing the chemical potential of the electron-hole pairs. Here we introduce an alternative scheme, using an idea recently proposed for photovoltaics: the intermediate band (IB) materials. It consists in introducing in the gap of a semiconductor an intermediate level which, acting like a stepstone, allows an electron jumping from the valence band to the conduction band in two steps, each one absorbing one sub-bandgap photon. For this the IB must be partially filled, to allow both sub-bandgap transitions to proceed at comparable rates; must be made of delocalized states to minimize nonradiative recombination; and should not communicate electronically with the outer world. For photovoltaic use the optimum efficiency so achievable, over 1.5 times that given by a normal semiconductor, is obtained with an overall bandgap around 2.0 eV (which would be near-optimal also for water phtosplitting). Note that this scheme differs from the doping principle usually considered in photocatalysis, which just tries to decrease the bandgap; its aim is to keep the full bandgap chemical potential but using also lower energy photons. In the past we have proposed several IB materials based on extensively doping known semiconductors with light transition metals, checking first of all with quantum calculations that the desired IB structure results. Subsequently we have synthesized in powder form two of them: the thiospinel In2S3 and the layered compound SnS2 (having bandgaps of 2.0 and 2.2 eV respectively) where the octahedral cation is substituted at a â?10% level with vanadium, and we have verified that this substitution introduces in the absorption spectrum the sub-bandgap features predicted by the calculations. With these materials we have verified, using a simple reaction (formic acid oxidation), that the photocatalytic spectral response is indeed extended to longer wavelengths, being able to use even 700 nm photons, without largely degrading the response for above-bandgap photons (i.e. strong recombination is not induced) [3b, 4]. These materials are thus promising for efficient photoevolution of hydrogen from water; work on this is being pursued, the results of which will be presented.

Ion-beam damage induced in SiO2: Excitonic mechanisms under heavy electronic excitation

The Centro de Micro-Análisis de Materiales (CMAM) in the Universidad Autónoma de Madrid is carrying out an extensive research program on the processes induced by high energy heavy mass ions (SHI) on dielectric materials and their photonic applications [1?21]. A significant part of this activity constitutes a relevant contribution to the scientific program associated to the TECHNOFUSION project. It is performed in collaboration with the Instituto de Fusion Nuclear at the UPM, the CIEMAT, the Departamento de Física de Materiales at UAM and several other national institutions (INTA) and international laboratories (GANIL, France), Legnaro Italy, Grenoble?. The program has led to a large number of publications in reputed international journals.

Deformabilidad de escolleras empleadas en banquetas de cimentación de cajones portuarios

En esta tesis doctoral se presenta una investigación sobre el comportamiento deformacional de las escolleras empleadas en banquetas de cimentación de obras portuarias de cajones. El trabajo aborda el estudio de la deformabilidad de escolleras portuarias combinando (i) investigación mediante ensayos de laboratorio; (ii) análisis del comportamiento in situ de las banquetas de escolleras y (iii) cálculos realizados con modelos numéricos. Se expone en primer lugar la investigación experimental realizada en el Laboratorio de Geotecnia del Centro de Estudios y Experimentación de Obras Públicas (CEDEX) para estudiar la deformabilidad de las escolleras mediante ensayos a gran escala, habida cuenta las grandes dimensiones de las partículas de escollera. Se ha tratado de establecer una metodología de ensayo que reproduzca las solicitaciones de las escolleras colocadas en banquetas de cimentación de obras portuarias. Asimismo, se ha hecho una interpretación exhaustiva de los resultados de los ensayos con el fin de establecer unos valores que caractericen la deformabilidad de las escolleras analizadas. Es posible dar un intervalo de valores de la compresibilidad de las escolleras portuarias que, dada la escasez de literatura existente, constituyen unos valores de referencia. Asimismo, se ha propuesto una metodología para para estimar la deformabilidad de escolleras portuarias in situ. La información disponible ha permitido realizar estudios de la deformabilidad in situ en dos muelles españoles con semejanzas estructurales y constructivas. La interpretación conjunta de los resultados ha sugerido unos valores de deformabilidad in situ. Conviene destacar que la práctica ausencia de rangos de valores de compresibilidad in situ para estos rellenos empleados en obras portuarias pone de manifiesto la importancia de los resultados obtenidos. Evidencias de diferencias de comportamiento de las escolleras empleadas en banquetas de cimentaci ón de cajones portuarios en laboratorio e in situ han sido documentadas. La evaluación conjunta del comportamiento tenso-deformacional de las escolleras en laboratorio e in situ ha estimulado la búsqueda de una correlación entre la compresibilidad de las escolleras en ambos escenarios. Finalmente, se ha elaborado un modelo numérico con la formulación matemática del método sincrético (Perucho (2004, 2008)) que supone una opción interesante para evaluar la deformabilidad de los rellenos granulares. En la práctica, el empleo del modelo sincrético requiere la determinación de unos microparámetros. La disponibilidad de numerosos resultados de laboratorio realizados en las escolleras portuarias ha permitido calibrar el modelo realizado. De esta manera, se dispone de una herramienta de cálculo para evaluar la deformabilidad de los relleno granulares con un método numérico. The focus of this Thesis is to explore the deformational behavior of large rock fill materials used as rock mattress foundations for gravity caissons structures. The determination of the compressibility of large granular media focuses on (i) laboratory testing, (ii) in situ performance analysis of rock mattress foundations for caissons, and (iii) numerical modelling. First, the results of the large-scale laboratory research program, conducted at the Geotechnical Laboratory for the Center for Studies and Experimentation for Public Works (CEDEX), to determine the deformability of large rock fill materials is presented. The testing procedure was specifically designed to reproduce the loading sequence of in situ rubble mound foundations. A thoughtful analysis of the laboratory testing results suggests a range of compressibility for large granular media. The lack of currently available information regarding large rock fill deformability places a certain emphasis on the results of the testing program. Second, the results of this research includes a procedure for evaluating in situ rock fill deformational behavior. Data, collected from monitoring two caisson-type quays in Spain, provides information to study in situ rock mattress foundations. Careful interpretation of in situ data reveals a range of deformability of rock mattress foundations in caisson-type quays. Based upon a review of available literature, assessments on the behavior of rock mattress foundations for caissons using in situ analysis are quite limited. The data from this research are likely to contribute to the knowledge of the in situ behavior of rock mattress foundations for caissons. Additionally, findings indicate an appreciable variation between the laboratory and the in situ behaviour of materials from rock mattress foundations for caissons. Dissimilarities between laboratory and in situ moduli of deformation are examined in detail. Correlations between laboratory and in situ values are made. Finally, numerical modeling, based upon the research of Perucho (2004, 2008), is presented to predict the deformation behavior of large granular media. The determination of microparameters that control macropropierties requires extensive calibration effort. The calibration process was carried out using the results of large-scale laboratory testing available from previous analysis. The presented numerical method is both versatile and attractive as it reasonably predicts the compressibility of large rock fill materials.

Agent-based modeling and simulation for the design of the future european Air Traffic Management system: the experience of CASSIOPEIA

The SESAR (Single European Sky ATM Research) program is an ambitious re-search and development initiative to design the future European air traffic man-agement (ATM) system. The study of the behavior of ATM systems using agent-based modeling and simulation tools can help the development of new methods to improve their performance. This paper presents an overview of existing agent-based approaches in air transportation (paying special attention to the challenges that exist for the design of future ATM systems) and, subsequently, describes a new agent-based approach that we proposed in the CASSIOPEIA project, which was developed according to the goals of the SESAR program. In our approach, we use agent models for different ATM stakeholders, and, in contrast to previous work, our solution models new collaborative decision processes for flow traffic management, it uses an intermediate level of abstraction (useful for simulations at larger scales), and was designed to be a practical tool (open and reusable) for the development of different ATM studies. It was successfully applied in three stud-ies related to the design of future ATM systems in Europe.