140,059 research outputs found
Summary results of the DOE flywheel development effort
The technology and applications evaluation task focuses on defining performance and cost requirements for flywheels in the various areas of application. To date the DOE program has focused on automotive applications. The composite materials effort entails the testing of new commercial composites to determine their engineering properties. The rotor and containment development work uses data from these program elements to design and fabricate flywheels. The flywheels are then tested at the Oak Ridge Flywheel Evaluation Laboratory and their performance is evaluated to indicate possible areas for improvement. Once a rotor has been fully developed it is transferred to the private sector
Effect of habituation on the susceptibility of the rat to restraint ulcers
The frequency and gravity of restraint ulcers were found to significantly diminish in rats previously exposed to brief periods of immobilization. The rats' becoming habituated to restraint conditions probably explains this phenomenon
User's manual for a computer program to calculate discrete frequency noise of conventional and advanced propellers
A user's manual is presented for a computer program for the calculation of discrete frequency noise of conventional and advanced propellers. The structure of the program and the subroutines describing the input functions are discussed. Input variables and their default values and the variables in the output data sheet are defined. Two versions of the program are available. These differ only in the graphic output capability. One version has only printed output capability. A second version with extensive graphic output capability is available for the computer system at Langley. This Manual includes four detailed examples of both the printed and graphic outputs. These examples may be reproduced by users to check their code on their computer system
Trace formula for a dielectric microdisk with a point scatterer
Two-dimensional dielectric microcavities are of widespread use in microoptics
applications. Recently, a trace formula has been established for dielectric
cavities which relates their resonance spectrum to the periodic rays inside the
cavity. In the present paper we extend this trace formula to a dielectric disk
with a small scatterer. This system has been introduced for microlaser
applications, because it has long-lived resonances with strongly directional
far field. We show that its resonance spectrum contains signatures not only of
periodic rays, but also of diffractive rays that occur in Keller's geometrical
theory of diffraction. We compare our results with those for a closed cavity
with Dirichlet boundary conditions.Comment: 39 pages, 18 figures, pdflate
Electro and magneto statics of topological insulators as modeled by planar, spherical and cylindrical boundaries: Green function approach
The Green function (GF) method is used to analyze the boundary effects
produced by a Chern Simons (CS) extension to electrodynamics. We consider the
electromagnetic field coupled to a term that is piecewise constant in
different regions of space, separated by a common interface , the
boundary, model which we will refer to as electrodynamics
( ED). This model provides a correct low energy effective action for
describing topological insulators (TI). In this work we construct the static GF
in ED for different geometrical configurations of the
boundary, namely: planar, spherical and cylindrical interfaces. Also
we adapt the standard Green theorem to include the effects of the
boundary. These are the most important results of our work, since they allow to
obtain the corresponding static electric and magnetic fields for arbitrary
sources and arbitrary boundary conditions in the given geometries. Also, the
method provides a well defined starting point for either analytical or
numerical approximations in the cases where the exact analytical calculations
are not possible. Explicit solutions for simple cases in each of the
aforementioned geometries for boundaries are provided. The adapted
Green theorem is illustrated by studying the problem of a point like electric
charge interacting with a planar TI with prescribed boundary conditions. Our
generalization, when particularized to specific cases, is successfully compared
with previously reported results, most of which have been obtained by using the
methods of images.Comment: 24 pages, 4 figures, accepted for publication in PRD. arXiv admin
note: text overlap with arXiv:1511.0117
Calibration results for the GEOS-3 altimeter
Data from the GEOS-3 altimeter were analyzed, for both the intensive and global modes, to determine the altitude bias levels for each mode and to verify the accuracy of the time tags which have been applied to the data. The best estimates of the biases are -5.30 + or - .2 m (intensive mode) and -3.55 m + or - .4 m (global mode). These values include the approximately 1.6 m offset of the altimeter antenna focal point from the GEOS-3 spacecraft center-of-mass. The negative signs indicate that the measured altitudes are too short. The data is corrected by subtracting the above bias numbers for the respective modes. Timing corrections which should be applied to the altimeter data were calculated theoretically, and subsequently confirmed through crossover analysis for passes 6-8 revolutions apart. The time tag correction that should be applied consists of -20.8 msec + 1 interpulse period (10.240512 msec)
The regulation and structure of nonlife insurance in the United States
The insurance industry is underdeveloped in most developing countries because of low levels of income and wealth and because restrictive regulations inhibit the supply of insurance services. But several countries have begun to reform their insurance industries. To help those countries, the authors offer an overview of insurance regulation in the United States - and discuss the economics and market structure of nonlife insurance in entry and exit barriers, economies of scale, and conduct and performance studies. They conclude that the U.S. nonlife insurance industry exhibits low concentration at both national and state market levels. Concentration is low even on a line-by-line basis. The primary concern of regulators has been to protect policyholders from insolvency, but regulation has also often been used to protect the market position of local insurance companies against the entry of out-of-state competitors. Regulation has worked best when based on solvency monitoring, with limited restrictions on entry. It has been more harmful when it involved controls on premiums and products and on the industry's level of profitability. Over the years the industry has shown a remarkable degree of innovation, although it has also faced many serious and persistent problems. The problems include the widespread crisis in liability (including product liability and medical malpractice), the crisis in automobile insurance, the volatility of investment income, the effects of market-driven pricing and underwriting cycles, and the difficulty of measuring insurance solvency. The long-tailed lines of insurance - those that entail long delays in final settlements - are exposed to the vagaries of inflation and rising costs. Two mandatory lines - third party automobile insurance and workers'compensation (for work accidents) - account for nearly 55 percent of premiums. These two lines - plus medical malpractice, other liability, and aircraft insurance - had combined ratios well over 125 percent in 1989. The industry has some ability to collude and to set prices, but seems to be competitive and to earn profits below similarly situated financial firms. Insurance profitability is not consistently above or below normal returns, although earnings for mandatory and strictly regulated lines of automobile insurance and workers'compensation appear to be below-adequate for long-term viability.Insurance&Risk Mitigation,Non Bank Financial Institutions,Insurance Law,Environmental Economics&Policies,Financial Intermediation
- …