If the tide is rising, who pays for the ark?

Two common goals of this meeting are to arrest the effects of sea level rise and other phenomena caused by Greenhouse Gases from anthropogenic sources ("GHG",) and to mitigate the effects. The fundamental questions are: (1) how to get there and (2) who should shoulder the cost? Given Washington gridlock, states, NGO's and citizens such as the Inupiat of the Village of Kivalina have turned to the courts for solutions. Current actions for public nuisance seek (1) to reduce and eventually eliminate GHG emissions, (2) damages for health effects and property damage—plus hundreds of millions in dollars spent to prepare for the foregoing. The U.S. Court of Appeals just upheld the action against the generators of some 10% of the CO2 emissions from human activities in the U.S., clearing the way for a trial featuring the state of the art scientific linkage between GHG production and the effects of global warming. Climate change impacts on coastal regions manifest most prominently through sea level rise and its impacts: beach erosion, loss of private and public structures, relocation costs, loss of use and accompanying revenues (e.g. tourism), beach replenishment and armoring costs, impacts of flooding during high water events, and loss of tax base. Other effects may include enhanced storm frequency and intensity, increased insurance risks and costs, impacts to water supplies, fires and biological changes through invasions or local extinctions (IPCC AR4, 2007; Okmyung, et al., 2007). There is an increasing urgency for federal and state governments to focus on the local and regional levels and consistently provide the information, tools, and methods necessary for adaptation. Calls for action at all levels acknowledge that a viable response must engage federal, state and local expertise, perspectives, and resources in a coordinated and collaborative effort. A workshop held in December 2000 on coastal inundation and sea level rise proposes a shared framework that can help guide where investments should be made to enable states and local governments to assess impacts and initiate adaptation strategies over the next decade. (PDF contains 5 pages)

Supporting regional coastal and ocean managers: Linking ocean observing tools and capabilities to the priority needs of managers and users in the southeast region

Ocean observing has been recognized by the US Commission on Ocean Policy, the Ocean Research and Resources Advisory Panel, the Joint Ocean Commission Initiative, and many other ocean policy entities and initiatives as foundational to meeting the nation’s need for more effective coastal and ocean management. The Interim Report of the Interagency Task Force on Ocean Policy (September 2009) has called for strengthening the nation’s capacity for observing the nation’s ocean, coastal, and Great Lakes systems. (PDF contains 3 pages)

Comparison of laser performances of 5at.% Yb : Gd2xY2(1-x)SiO5 crystals between different cutting directions

We investigate the laser actions of 5at.% Yb:Gd2xY2(1-x)SiO5 (Yb:GYSO; x = 0.1) crystals with different cutting directions, parallel and vertical to the growth axis. Our results show that the cutting direction of the sample plays an astonished role in the laser operation. The sample cut vertically to the growth axis possesses the favourable lasing characteristics. Its output power reaches 3.13W at 1060nm with a slope efficiency of 44.68% when the absorbed pump power is 8.9 W. In contrast, the sample cut parallel reaches only 1.65 W at 1044 nm with a slope elLiciency of 33.76% with absorbed pump power of 7.99 W. The absorption and emission spectra of the two samples are examined and the merit factor M is calculated. Our analysis is in agreement well with the experimental results. The wavelength tuning range of the superior sample covers from 1013.68 nm to 1084.82 nm.

Tools for the study of dynamical spacetimes

This thesis covers a range of topics in numerical and analytical relativity, centered around introducing tools and methodologies for the study of dynamical spacetimes. The scope of the studies is limited to classical (as opposed to quantum) vacuum spacetimes described by Einstein's general theory of relativity. The numerical works presented here are carried out within the Spectral Einstein Code (SpEC) infrastructure, while analytical calculations extensively utilize Wolfram's Mathematica program.

We begin by examining highly dynamical spacetimes such as binary black hole mergers, which can be investigated using numerical simulations. However, there are difficulties in interpreting the output of such simulations. One difficulty stems from the lack of a canonical coordinate system (henceforth referred to as gauge freedom) and tetrad, against which quantities such as Newman-Penrose Psi_4 (usually interpreted as the gravitational wave part of curvature) should be measured. We tackle this problem in Chapter 2 by introducing a set of geometrically motivated coordinates that are independent of the simulation gauge choice, as well as a quasi-Kinnersley tetrad, also invariant under gauge changes in addition to being optimally suited to the task of gravitational wave extraction.

Another difficulty arises from the need to condense the overwhelming amount of data generated by the numerical simulations. In order to extract physical information in a succinct and transparent manner, one may define a version of gravitational field lines and field strength using spatial projections of the Weyl curvature tensor. Introduction, investigation and utilization of these quantities will constitute the main content in Chapters 3 through 6.

For the last two chapters, we turn to the analytical study of a simpler dynamical spacetime, namely a perturbed Kerr black hole. We will introduce in Chapter 7 a new analytical approximation to the quasi-normal mode (QNM) frequencies, and relate various properties of these modes to wave packets traveling on unstable photon orbits around the black hole. In Chapter 8, we study a bifurcation in the QNM spectrum as the spin of the black hole a approaches extremality.

Analysis and Use of Information and Communication Tools in Economics of Climate Change

16 p.

Mecanizado por torneado en duro

[ES]Los objetivos del siguiente trabajo consisten en analizar e optimizar el proceso del torneado en duro del acero ASP-23 indagando de especial manera en la realización de diferentes soluciones para brochas. En este caso, este proyecto nace de la importancia de reducir así como los costes económicos y los costes temporales de fabricación de elementos basados en el acero ASP-23 mediante el torneado en duro; proceso de mecanizado, cuya importancia cada vez es mayor como en las industrias de automoción o aeronáutica. El desarrollo del proyecto es fruto de la necesidad de EKIN S. Coop, uno de los líderes en los procesos de máquina-herramienta de alta precisión para el brochado, de desarrollar un proceso de mecanizado más eficaz de las brochas que produce. Así en el aula máquina-herramienta (ETSIB) se han intentado demostrar los beneficios que tiene el torneado en duro en el mecanizado del ASP-23. Hoy en día, con el rápido desarrollo de nuevos materiales, los procesos de fabricación se están haciendo cada vez más complejos, por la amplia variedad de maquinas con las que se realizan los procesos, por la variedad de geometría/material de las herramientas empleadas, por las propiedades del material de la pieza a mecanizar, por los parámetros de corte tan variados con los que podemos implementar el proceso (profundidad de corte, velocidad, alimentación...) y por la diversidad de elementos de sujeción utilizados. Además debemos ser conscientes de que tal variedad implica grandes magnitudes de deformaciones, velocidades y temperaturas. He aquí la justificación y el gran interés en el proyecto a realizar. Por ello, en este proyecto intentamos dar un pequeño paso en el conocimiento del proceso del torneado en duro de aceros con poca maquinabilidad, siendo conscientes de la amplia variedad y dificultad del avance en la ingeniería de fabricación y del mucho trabajo que queda por hacer.

Aberration measurement of projection optics in lithographic tools based on two-beam interference theory

The degradation of image quality caused by aberrations of projection optics in lithographic tools is a serious problem in optical lithography. We propose what we believe to be a novel technique for measuring aberrations of projection optics based on two-beam interference theory. By utilizing the partial coherent imaging theory, a novel model that accurately characterizes the relative image displacement of a fine grating pattern to a large pattern induced by aberrations is derived. Both even and odd aberrations are extracted independently from the relative image displacements of the printed patterns by two-beam interference imaging of the zeroth and positive first orders. The simulation results show that by using this technique we can measure the aberrations present in the lithographic tool with higher accuracy. (c) 2006 Optical Society of America.

Aberration measurement of projection optics in lithographic tools by use of an alternating phase-shifting mask

As a critical dimension shrinks, the degradation in image quality caused by wavefront aberrations of projection optics in lithographic tools becomes a serious problem. It is necessary to establish a technique for a fast and accurate in situ aberration measurement. We introduce what we believe to be a novel technique for characterizing the aberrations of projection optics by using an alternating phase-shifting mask. The even aberrations, such as spherical aberration and astigmatism, and the odd aberrations, such as coma, are extracted from focus shifts and image displacements of the phase-shifted pattern, respectively. The focus shifts and the image displacements are measured by a transmission image sensor. The simulation results show that, compared with the accuracy of the previous straightforward measurement technique, the accuracy of the coma measurement increases by more than 30% and the accuracy of the spherical-aberration measurement increases by approximately 20%. (c) 2006 Optical Society of America.