3,779 research outputs found

    The Limits of Liability in Promoting Safe Geologic Sequestration of CO2

    Get PDF
    Deployment of new technologies is vital to climate change policy, but it invariably poses difficult tradeoffs. Carbon capture and storage (“CCS”), which involves the capture and permanent burial of CO2 emissions, exemplifies this problem. This article provides an overview of CCS in Part I, focusing on geologic sequestration, and analyzes the scientific work on the potential for releases of CO2 and brine from sequestrian reservoirs. Part II evaluates the comparative advantages of government regulation and common law liability. Part III examines the relative efficiencies of different doctrines of common law liability when applied to likely releases from sequestrian sites. The authors propose a hybrid legal framework in Part IV that combines a traditional regulatory regime with a novel two-tiered system of liability that is calibrated to objective site characteristics.The Kay Bailey Hutchison Center for Energy, Law, and Busines

    Finding Place for Printing

    Get PDF
    This column examines the benfits and drawbacks of printed papers and digital essays in tutoring scenarios. It considers their roles in the learning of students, and it suggests a compromise by finding the value of both mediums of writing

    Radio Observations of Super Star Clusters in Dwarf Starburst Galaxies

    Full text link
    We present new radio continuum observations of two dwarf starburst galaxies, NGC3125 and NGC5408, with observations at 4.80GHz (6cm) and 8.64GHz (3cm), taken with the Australia Telescope Compact Array (ATCA). Both galaxies show a complex radio morphology with several emission regions, mostly coincident with massive young star clusters. The radio spectral indices of these regions are negative (with alpha ~ -0.5 - -0.7), indicating that the radio emission is dominated by synchrotron emission associated with supernova activity from the starburst. One emission region in NGC5408 has a flatter index (alpha ~ -0.1) indicative of optically thin free-free emission, which could indicate it is a younger cluster. Consequently, in these galaxies we do not see regions with the characteristic positive spectral index indicative of optically obscured star-formation regions, as seen in other dwarf starbursts such as Hen 2-10.Comment: Accepted for publication in MNRA

    Exploring the limits of variational passive microwave retrievals

    Get PDF
    2017 Summer.Includes bibliographical references.Passive microwave observations from satellite platforms constitute one of the most important data records of the global observing system. Operational since the late 1970s, passive microwave data underpin climate records of precipitation, sea ice extent, water vapor, and more, and contribute significantly to numerical weather prediction via data assimilation. Detailed understanding of the observation errors in these data is key to maximizing their utility for research and operational applications alike. However, the treatment of observation errors in this data record has been lacking and somewhat divergent when considering the retrieval and data assimilation communities. In this study, some limits of passive microwave imager data are considered in light of more holistic treatment of observation errors. A variational retrieval, named the CSU 1DVAR, was developed for microwave imagers and applied to the GMI and AMSR2 sensors for ocean scenes. Via an innovative method to determine forward model error, this retrieval accounts for error covariances across all channels used in the iteration. This improves validation in more complex scenes such as high wind speed and persistently cloudy regimes. In addition, it validates on par with a benchmark dataset without any tuning to in-situ observations. The algorithm yields full posterior error diagnostics and its physical forward model is applicable to other sensors, pending intercalibration. This retrieval is used to explore the viability of retrieving parameters at the limits of the available information content from a typical microwave imager. Retrieval of warm rain, marginal sea ice, and falling snow are explored with the variational retrieval. Warm rain retrieval shows some promise, with greater sensitivity than operational GPM algorithms due to leveraging CloudSat data and accounting for drop size distribution variability. Marginal sea ice is also detected with greater sensitivity than a standard operational retrieval. These studies ultimately show that while a variational algorithm maximizes the effective signal to noise ratio of these observations, hard limitations exist due to the finite information content afforded by a typical microwave imager

    Actuarial applications of survival analysis in healthcare

    Get PDF
    Healthcare actuaries are increasingly responsible for advising their employers and clients in areas of managed care. Managed care links traditional health actuarial financial work to areas of medical practice, to address the fundamental question: what works? These relatively new responsibilities have required an expansion of actuarial techniques into non-traditional areas, and, in particular, epidemiology and biostatistics. This study is about a specific area of statistics, survival analysis, a topic of great potential application in non-traditional managed care actuarial practice. Survival analysis is used frequently in biostatistics to evaluate the efficacy of treatments and to identify factors that contribute to patient survival. In this study, we illustrate three applications of survival models to solve real-world problems in areas of health actuarial practice: the estimation of survival of permanently disabled workers receiving lifetime benefits for occupational illness and injury, the rate at which seriously ill hospice patients, at risk of polypharmacy, are weaned from non-life sustaining drugs, and the ability to predict, using a model incorporating drug dosage information and specifically changes in dosage, changes in expected future lifetimes of hospice patients. All three case studies are examples of practical models that can be applied within a business context. The study will serve a more important purpose, if it shows health actuaries the potential value of the application of a non-traditional technique within their evolving practice

    Is sentience only a nonessential component of animal welfare?

    Get PDF
    According to Broom (2014), animal welfare is a concept that can be applied to all animals, including single-celled organisms that are obviously not sentient. Such a stance makes it difficult to draw a connection between welfare and sentience, and that is the book’s downfall. Some excellent points are made about sentience and there are very good discussions on animal welfare. However, unless sentience is considered the essential component of welfare, any attempt to link the two phenomena will be unsuccessful — and that, indeed, is the case with this book

    The changing concept of animal sentience

    Get PDF
    A brief history of the concept of sentience is given. It is pointed out that the idea of sentience, at least in the mammals and birds, was accepted by lay people by the time of the Renaissance and before it was acknowledged by philosophers. It was not until the Enlightenment of the 18th century that philosophers started to accept the notion that animals have feelings. Towards the end of the 19th century, scientists and philosophers had developed a fairly sophisticated concept of sentience. Little consideration was given to sentience by scientists through much of the 20th century due to the inhibiting influence of Behaviourism. In the last quarter of the 20th century, there was a surge of interest in animal sentience, and animal welfare scientists quickly realised that welfare problems can be better tackled with an understanding of how animals feel. Methods to investigate indirectly how animals feel are described and areas requiring further elucidation are listed

    Magnetohydrodynamic turbulence: The development of lattice Boltzmann methods for dissipative systems

    Get PDF
    Computer simulations of complex phenomena have become an invaluable tool for scientists in all disciplines. These simulations serve as a tool both for theorists attempting to test the validity of new theories and for experimentalists wishing to obtain a framework for the design of new experiments. Lattice Boltzmann Methods (LBM) provide a kinetic simulation technique for solving systems governed by non-linear conservation equations. Direct LBMs use the linearized single time relaxation form of the Boltzmann equation to temporally evolve particle distribution functions on a discrete spatial lattice. We will begin with a development of LBMs from basic kinetic theory and will then show how one can construct LBMs to model incompressible resistive magnetohydrodynamic (MHD) conservation laws. We will then present our work in extending existing models to the octagonal lattice, showing that the increased isotropy of the octagonal lattice produces better numerical stability and higher Reynolds numbers in MHD simulations. Finally, we will develop LBMs that use non-uniform grids and apply them to one dimensional MHD systems
    corecore