The third glacier inventory of North Tyrol, Austria, for 2006

A new, third, glacier inventory (GI3) is presented for North Tyrol, which is based on Airborne Laser Scanning for the year 2006. 447 glaciers covering 235 km**2 are included. 4 small, formerly neglected glaciers have been added. Basic quantities such as size, maximum, minimum and median elevation show large variances. Very recent glacier changes between the former inventory (GI2: 1998) and GI3 show a strong reduction in area (-8%) and mean thickness (-7 m). An asymmetry of mean maximum, minimum and median elevation is quantified with approximately 200 m higher values for south-exposed glaciers. Rates of changes are around 1% per year and 1 m per year between GI2 and GI3. The strongest volume losses occurred for glaciers between 5 and 10 km**2.

Chemical and isotope compositions of main phases of metalliferous sediments from holes of DSDP Leg 92

The carbonate-free metalliferous fraction of thirty-nine sediment samples from four DSDP Leg 92 sites has been analyzed for 12 elements, and a subset of 16 samples analyzed for Pb isotopic composition. The main geochemical features of this component are as follows: i) very high concentrations of Fe and Mn, typically 25-39% and 5-14%, respectively; ii) Al and Ca contents generally less than 2% and 5%, respectively; iii) high Cu (1000-2000 ppm), and Zn and Ni (500-1000 ppm) values; and iv) Co and Pb concentrations of 100-250 ppm. In terms of element partitioning within the metalliferous fraction, amorphous to poorly crystallized oxide-oxyhydroxides removed by the second leach carry virtually all of the Mn, and about 90% of the Ca, Sr and Ni. The well-crystallized goethite-rich material removed by the third leach carries the majority of Fe, Cu, and Pb. These relations hold for sediments as young as ~1-2 Ma, indicating early partitioning of hydrothermal Fe and Mn into separate phases. Calculated mass accumulation rates (MAR) for Fe, Mn, Cu, Pb, Zn and Ni in the bulk sediment show the same overall trends at three of the sites, with greatest MAR values near the basement, and a general decrease in MAR values towards the tops of the holes (for sediments deposited above the lysocline). These relations strongly support the concept of a declining hydrothermal contribution of these elements away from a ridge axis. Nevertheless, MAR values for these metals up to ~200 km from the ridge axis are orders of magnitude higher than on abyssal seafloor plains where there is no hydrothermal influence. Mn/Fe ratios throughout the sediment column at two sites indicate that the composition of the hydrothermal precipitates changed during transport through seawater, becoming significantly depleted in Mn beyond ~200-300 km from the axis, but maintaining roughly the same proportion of Fe. Most of the Pb isotope data for the Leg 92 metalliferous sediments form approximately linear arrays in the conventional isotopic plots, extending from the middle of the field for mid-ocean ridge basalts toward the field for Mn nodules. The array of data lying between these two end-members is most readily interpreted in terms of simple linear mixing of Pb derived from basaltic and seawater end-member sources. The least radiogenic sediments reflect the average Pb isotope composition of discharging hydrothermal solutions and ocean-ridge basalt at the EPR over the ~4-8 Ma B.P. interval. Pb in sediments deposited up to 250 km from the axis can be almost entirely of basaltic-hydrothermal origin. Lateral transport of some basaltic Pb by ocean currents appears to extend to distances of at least 1000 km west of the East Pacific Rise.

The PSE-3D instability analysis methodology for flows depending strongly on two and weakly on the third spatial dimension

The present contribution discusses the development of a PSE-3D instability analysis algorithm, in which a matrix forming and storing approach is followed. Alternatively to the typically used in stability calculations spectral methods, new stable high-order finitedifference-based numerical schemes for spatial discretization 1 are employed. Attention is paid to the issue of efficiency, which is critical for the success of the overall algorithm. To this end, use is made of a parallelizable sparse matrix linear algebra package which takes advantage of the sparsity offered by the finite-difference scheme and, as expected, is shown to perform substantially more efficiently than when spectral collocation methods are used. The building blocks of the algorithm have been implemented and extensively validated, focusing on classic PSE analysis of instability on the flow-plate boundary layer, temporal and spatial BiGlobal EVP solutions (the latter necessary for the initialization of the PSE-3D), as well as standard PSE in a cylindrical coordinates using the nonparallel Batchelor vortex basic flow model, such that comparisons between PSE and PSE-3D be possible; excellent agreement is shown in all aforementioned comparisons. Finally, the linear PSE-3D instability analysis is applied to a fully three-dimensional flow composed of a counter-rotating pair of nonparallel Batchelor vortices.

Technical evaluation of a third generation optical pose tracker for motion analysis and image-guided surgery

Laparoscopic instrument tracking systems are an essential component in image-guided interventions and offer new possibilities to improve and automate objective assessment methods of surgical skills. In this study we present our system design to apply a third generation optical pose tracker (Micron- Tracker®) to laparoscopic practice. A technical evaluation of this design is performed in order to analyze its accuracy in computing the laparoscopic instrument tip position. Results show a stable fluctuation error over the entire analyzed workspace. The relative position errors are 1.776±1.675 mm, 1.817±1.762 mm, 1.854±1.740 mm, 2.455±2.164 mm, 2.545±2.496 mm, 2.764±2.342 mm, 2.512±2.493 mm for distances of 50, 100, 150, 200, 250, 300, and 350 mm, respectively. The accumulated distance error increases with the measured distance. The instrument inclination covered by the system is high, from 90 to 7.5 degrees. The system reports a low positional accuracy for the instrument tip.

Alta velocidad ferroviaria en California(USA): tercera parte (III) Fresno-Los Ángeles-San Diego = High speed railway in California(USA): third part (III) Fresno-Los Ángeles-San Diego

Implantación de la Red de Alta velocidad Ferroviaria en California. Tramo Fresno-Los Angeles-San Diego. Este artículo, tercera parte de la serie que describe la red de Alta Velocidad Ferroviaria de California (CHSRS), se ocupa de la línea Fresno-Los Angeles Airport-San Diego Airport, con el trazado propuesto en la Alternativa Missions Trail del Proyecto FARWEST, caracterizada por el paso directo de las montañas de Tehachapi, mediante dos grandes túneles de 27,5 Km (17 mile) y 25,6 Km (15,9 mile) de longitud. También por el emplazamiento de la estación terminal de Los Angeles, junto al Aeropuerto Internacional de Los Angeles y la sustitución de la circunvalación ferroviaria de la aglomeración urbana de Los Angeles, a través de Inland Empire, por el ramal Anaheim-Riverside, que da acceso a esa región, y que es cabecera de la futura Dessert Express a Las Vegas. The third of a series describing the California High Speed Railway (CHSRS), this article refers to the Fresno-Los Angeles Airport-San Diego Airport line, with the alignment as proposed in the Missions Trail Alternative of the FARWEST Project, characterized by the direct Tehachapi mountain pass through two large tunnels 27.5 Km (17 miles) and 25.6 Km (15.9 miles) long and also to the siting of the Los Angeles terminal station next to the Los Angeles International Airport and the replacement of the Los Angeles urban conglomeration railway by-pass through Inland Empire, by the Anaheim-Riverside branch providing access to that region and which is the head of the future Desert Express to Las Vegas.

The intermediate band approach in the third solar cell generation context

Hydrogenated amorphous silicon thin films were deposited using a high pressure sputtering (HPS) system. In this work, we have studied the composition and optical properties of the films (band-gap, absorption coefficient), and their dependence with the deposition parameters. For films deposited at high pressure (1 mbar), composition measurements show a critical dependence of the purity of the films with the RF power. Films manufactured with RF-power above 80W exhibit good properties for future application, similar to the films deposited by CVD (Chemical Vapor Deposition) for hydrogenated amorphous silicon.

Advances in global instability computations: from incompressible to hypersonic flow

Esta tesis constituye un gran avance en el conocimiento del estudio y análisis de inestabilidades hidrodinámicas desde un punto de vista físico y teórico, como consecuencia de haber desarrollado innovadoras técnicas para la resolución computacional eficiente y precisa de la parte principal del espectro correspondiente a los problemas de autovalores (EVP) multidimensionales que gobiernan la inestabilidad de flujos con dos o tres direcciones espaciales inhomogéneas, denominados problemas de estabilidad global lineal. En el contexto del trabajo de desarrollo de herramientas computacionales presentado en la tesis, la discretización mediante métodos de diferencias finitas estables de alto orden de los EVP bidimensionales y tridimensionales que se derivan de las ecuaciones de Navier-Stokes linealizadas sobre flujos con dos o tres direcciones espaciales inhomogéneas, ha permitido una aceleración de cuatro órdenes de magnitud en su resolución. Esta mejora de eficiencia numérica se ha conseguido gracias al hecho de que usando estos esquemas de diferencias finitas, técnicas eficientes de resolución de problemas lineales son utilizables, explotando el alto nivel de dispersión o alto número de elementos nulos en las matrices involucradas en los problemas tratados. Como más notable consecuencia cabe destacar que la resolución de EVPs multidimensionales de inestabilidad global, que hasta la fecha necesitaban de superordenadores, se ha podido realizar en ordenadores de sobremesa. Además de la solución de problemas de estabilidad global lineal, el mencionado desarrollo numérico facilitó la extensión de las ecuaciones de estabilidad parabolizadas (PSE) lineales y no lineales para analizar la inestabilidad de flujos que dependen fuertemente en dos direcciones espaciales y suavemente en la tercera con las ecuaciones de estabilidad parabolizadas tridimensionales (PSE-3D). Precisamente la capacidad de extensión del novedoso algoritmo PSE-3D para el estudio de interacciones no lineales de los modos de estabilidad, desarrollado íntegramente en esta tesis, permite la predicción de transición en flujos complejos de gran interés industrial y por lo tanto extiende el concepto clásico de PSE, el cuál ha sido empleado exitosamente durante las pasadas tres décadas en el mismo contexto para problemas de capa límite bidimensional. Típicos ejemplos de flujos incompresibles se han analizado en este trabajo sin la necesidad de recurrir a restrictivas presuposiciones usadas en el pasado. Se han estudiado problemas vorticales como es el caso de un vórtice aislado o sistemas de vórtices simulando la estela de alas, en los que la homogeneidad axial no se impone y así se puede considerar la difusión viscosa del flujo. Además, se ha estudiado el chorro giratorio turbulento, cuya inestabilidad se utiliza para mejorar las características de funcionamiento de combustores. En la tesis se abarcan adicionalmente problemas de flujos compresibles. Se presenta el estudio de inestabilidad de flujos de borde de ataque a diferentes velocidades de vuelo. También se analiza la estela formada por un elemento rugoso aislado en capa límite supersónica e hipersónica, mostrando excelentes comparaciones con resultados obtenidos mediante simulación numérica directa. Finalmente, nuevas inestabilidades se han identificado en el flujo hipersónico a Mach 7 alrededor de un cono elíptico que modela el vehículo de pruebas en vuelo HIFiRE-5. Los resultados comparan favorablemente con experimentos en vuelo, lo que subraya aún más el potencial de las metodologías de análisis de estabilidad desarrolladas en esta tesis. ABSTRACT The present thesis constitutes a step forward in advancing the frontiers of knowledge of fluid flow instability from a physical point of view, as a consequence of having been successful in developing groundbreaking methodologies for the efficient and accurate computation of the leading part of the spectrum pertinent to multi-dimensional eigenvalue problems (EVP) governing instability of flows with two or three inhomogeneous spatial directions. In the context of the numerical work presented in this thesis, the discretization of the spatial operator resulting from linearization of the Navier-Stokes equations around flows with two or three inhomogeneous spatial directions by variable-high-order stable finite-difference methods has permitted a speedup of four orders of magnitude in the solution of the corresponding two- and three-dimensional EVPs. This improvement of numerical performance has been achieved thanks to the high-sparsity level offered by the high-order finite-difference schemes employed for the discretization of the operators. This permitted use of efficient sparse linear algebra techniques without sacrificing accuracy and, consequently, solutions being obtained on typical workstations, as opposed to the previously employed supercomputers. Besides solution of the two- and three-dimensional EVPs of global linear instability, this development paved the way for the extension of the (linear and nonlinear) Parabolized Stability Equations (PSE) to analyze instability of flows which depend in a strongly-coupled inhomogeneous manner on two spatial directions and weakly on the third. Precisely the extensibility of the novel PSE-3D algorithm developed in the framework of the present thesis to study nonlinear flow instability permits transition prediction in flows of industrial interest, thus extending the classic PSE concept which has been successfully employed in the same context to boundary-layer type of flows over the last three decades. Typical examples of incompressible flows, the instability of which was analyzed in the present thesis without the need to resort to the restrictive assumptions used in the past, range from isolated vortices, and systems thereof, in which axial homogeneity is relaxed to consider viscous diffusion, as well as turbulent swirling jets, the instability of which is exploited in order to improve flame-holding properties of combustors. The instability of compressible subsonic and supersonic leading edge flows has been solved, and the wake of an isolated roughness element in a supersonic and hypersonic boundary-layer has also been analyzed with respect to its instability: excellent agreement with direct numerical simulation results has been obtained in all cases. Finally, instability analysis of Mach number 7 ow around an elliptic cone modeling the HIFiRE-5 flight test vehicle has unraveled flow instabilities near the minor-axis centerline, results comparing favorably with flight test predictions.

Looking at the Sky : Spanish Architects for the Third Millenium = Mirando al cielo

Looking at the Sky

Providing 30Mbit/s to Spain’s final third. -A techno-economic assessment.

Since the Digital Agenda for Europe released the Europe2020 flagship, Member States are looking for ways of fulfilling their agreed commitments to fast and ultrafast internet deployment. However, Europe is not a homogenous reality. The economic, geographic, social and demographic features of each country make it a highly diverse region to develop best practices over Next Generation Access Networks (NGAN) deployments. There are special concerns about NGAN deployments for “the final third”, as referred to the last 25% of the country’s population who, usually, live in rural areas. This paper assesses, through a techno-economic analysis, the access cost of providing over 30 Mbps broadband for the final third of Spain`s population in municipalities, which are classified into area types, referred to as geotypes. Fixed and mobile technologies are compared in order to determine which is the most cost-effective technology for each geotype. The demographic limit for fixed networks (cable, fibre and copper) is also discussed. The assessment focuses on the supply side and the results show the access network cost only. The research completes a previous published assessment (Techno-economic analysis of next generation access networks roll-out. The case of platform competition, regulation and public policy in Spain) by including the LTE scenario. The LTE scenario is dimensioned to provide 30 Mbps (best effort) broadband, considering a network take-up of 25%. The Rocket techno-economic model is used to assess a ten-year study period deployment. Nevertheless, the deployment must start in 2014 and be completed by 2020, in order to fulfil the Digital Agenda’s goals. The feasibility of the deployment is defined as the ability to recoup the investment at the end of the study period. This ability is highly related to network take-up and, therefore, to service adoption. Network deployment in each geotype is compared with the cost of the deployment in the Urban geotype and broadband expected penetration rates for clarity and simplicity. Debating the cost-effective deployments for each geotype, while addressing the Digital Agenda’s goals regarding fast and ultrafast internet, is the main purpose of this paper. At the end of the last year, the independent Spanish regulation agency released the Spain broadband coverage report at the first half of 2013. This document claimed that 59% and 52% of Spain’s population was already covered by NGAN capable of providing 30 Mbps and 100 Mbps broadband respectively. HFC, with 47% of population coverage, and FTTH, with 14%, were considered as a 100 Mbps capable NGAN. Meanwhile VDSL, with 12% of the population covered, was the only NGAN network considered for the 30 Mbps segment. Despite not being an NGAN, the 99% population coverage of HSPA networks was also noted in the report. Since mobile operators are also required to provide 30 Mbps broadband to 90% of the population in rural areas by the end of 2020, mobile networks will play a significant role on the achievement of the 30 Mbps goal in Spain’s final third. The assessment indicates the cost of the deployment per cumulative households coverage with 4 different NGANs: FTTH, HFC, VDSL and LTE. Research shows that an investment ranging from €2,700 (VDSL) to €5,400 (HFC) million will be needed to cover the first half of the population with any fixed technology assessed. The results state that at least €3,000 million will be required to cover these areas with the least expensive technology (LTE). However, if we consider the throughput that fixed networks could provide and achievement of the Digital Agenda’s objectives, fixed network deployments are recommended for up to 90% of the population. Fibre and cable deployments could cover up to a maximum of 88% of the Spanish population cost efficiently. As there are some concerns about the service adoption, we recommend VDSL and mobile network deployments for the final third of the population. Despite LTE being able to provide the most economical roll-out, VDSL could also provide 50 Mbps from 75% to 90% of the Spanish population cost efficiently. For this population gap, facility based competition between VDSL providers and LTE providers must be encouraged. Regarding 90% to 98.5% of the Spanish population, LTE deployment is the most appropriate. Since costumers in less populated the municipalities are more sensitive to the cost of the service, we consider that a single network deployment could be most appropriate. Finally, it has become clear that it is not possible to deliver 30Mbps to the final 1.5% of the population cost-efficiently and adoption predictions are not optimistic either. As there are other broadband alternatives able to deliver up to 20 Mbps, in the authors’ opinion, it is not necessary to cover the extreme rural areas, where public financing would be required.