2,988 research outputs found
Impact of Electron Collision Mixing on the delay times of an electron beam excited Atomic Xenon laser
The atomic xenon (5dÂż6p) infrared laser has been experimentally and theoretically investigated using a short-pulse (30-ns), high-power (1-10-MW/cm3) coaxial electron beam excitation source. In most cases, laser oscillation is not observed during the e-beam current pulse. Laser pulses of hundreds of nanoseconds duration are subsequently obtained, however, with oscillation beginning 60-800 ns after the current pulse terminates. Results from a computer model for the xenon laser reproduce the experimental values and show that oscillation begins when the fractional electron density decays below a critical value of ≈0.2-0.8Ă—10 6. These results lend credence to the proposal that electron collision mixing of the laser levels limits the maximum value of specific power deposition that can be used to excite the atomic xenon laser efficiently on a quasi-CW basi
Laboratory studies, analysis, and interpretation of the spectra of hydrocarbons present in planetary atmospheres including cyanoacetylene, acetylene, propane, and ethane
Combining broadband Fourier transform spectrometers (FTS) from the McMath facility at NSO and from NRC in Ottawa and narrow band TDL data from the laboratories with computational physics techniques has produced a broad range of results for the study of planetary atmospheres. Motivation for the effort flows from the Voyager/IRIS observations and the needs of Voyager analysis for laboratory results. In addition, anticipation of the Cassini mission adds incentive to pursue studies of observed and potentially observable constituents of planetary atmospheres. Current studies include cyanoacetylene, acetylene, propane, and ethane. Particular attention is devoted to cyanoacetylen (H3CN) which is observed in the atmosphere of Titan. The results of a high resolution infrared laboratory study of the line positions of the 663, 449, and 22.5/cm fundamental bands are presented. Line position, reproducible to better than 5 MHz for the first two bands, are available for infrared astrophysical searches. Intensity and broadening studies are in progress. Acetylene is a nearly ubiquitous atmospheric constituent of the outer planets and Titan due to the nature of methane photochemistry. Results of ambient temperature absolute intensity measurements are presented for the fundamental and two two-quantum hotband in the 730/cm region. Low temperature hotband intensity and linewidth measurements are planned
Grand Tour-Part 2: Petrogenesis and Thermal Evolution of Deep Continental-Crust: The Record from the East Humboldt Range, Nevada
The northern part of the East Humboldt Range, Nevada, provides a rare opportunity to explore the petrogenetic environment of deep levels in the middle crust during both large-scale Mesozoic contraction and Cenozoic regional extension. On this segment of the field trip, we will explore evidence bearing on the character of the metamorphic and magmatic history of this terrane, and attempt to link these constraints to the rheology and tectonic evolution of the middle crust during the Mesozoic and Cenozoic
Dynamic R&D choice and the impact of the firms financial strength
This article investigates how a firm's financial strength affects its dynamic decision to invest in R&D. We estimate a dynamic model of R&D choice using data for German firms in high-tech manufacturing industries. The model incorporates a measure of the firm's financial strength, derived from its credit rating, which is shown to lead to substantial di¤erences in estimates of the costs and expected long-run benefits from R&D investment. Financially
strong firms have a higher probability of generating innovations from their R&D investment, and the innovations have a larger impact on productivity and profits. Averaging across all firms, the long run benefit of investing in R&D equals 6.6 percent of firm value. It ranges from 11.6 percent for firms in a strong financial position to 2.3 percent for firms in a weaker financial position
Potential Failure of A Decayed Tree Under Wind Loading
Trees with decayed wood that are subject to moderate winds often collapse and cause property damage or injury and death to people. The purpose of this paper is to describe a decision-making aid to help identify a tree that may fail in the forest or be a potential hazard in the city. A tree may fail when the probability of radial shear cracks developing for a given wind load is sufficiently high.Mathematical models are used to estimate the constant wind force on trees and to evaluate the cracking and collapse mechanisms under this loading. The physical dimensions are used to determine the wind force or drag on the tree, and the amount of decay in the tree is used to determine its ability to resist this load. Owing to uncertainties associated with accurately measuring and modeling a decayed tree, estimating the wind load, and specifying the wood strength of a tree species, reliability analysis is used to assess the potential risk of failure. Coupling this information with meteorological data for the largest wind speed value expected at the tree site and the topography of the tree site completes the analysis of potential failure. Case studies of balsam fir trees with the same exterior diameters but with different dimensions of decay columns, tree weights, tree heights, and wind speed conditions are analyzed and compared
Potential Celecoxib analogue precursors derived via Aldol condensation
https://scholarworks.moreheadstate.edu/student_scholarship_posters/1080/thumbnail.jp
Estimating dynamic R&D demand : an analysis of costs and long-run benefits
Using firm-level data from the German manufacturing sector, we estimate a dynamic,
structural model of the firm’s decision to invest in R&D and quantify the cost and longrun
benefit of this investment. The model incorporates and quantifies linkages between
the firm’s R&D investment, product and process innovations, and future productivity and
profits. The dynamic model provides a natural measure of the long-run payoff to R&D as
the difference in expected firm value generated by the R&D investment. For the median
productivity firm, investment in R&D raises firm value by 3.0 percent in a group of hightech
industries but only 0.2 percent in low-tech industries. Simulations of the model show
that cost subsidies for R&D can significantly affect R&D investment rates and productivity
changes in the high-tech industries
FINANCIAL RISK AND FINANCIAL RISK MANAGEMENT TECHNOLOGY (RMT): ISSUES AND ADVANCES
Methods for sound risk management are of increasing interest among Wall Street investment banking and
brokerage firms in the aftermath of the October 1987 crash of the stock market. We present an overview of the
basic definitions and issues related to risk, and the management of financial risk and financial risk management
technology (RMT) for information systems (IS) technology professionals. We discuss of the content of risk
management technology, including the models, the software and hardware, and the market data required to track
risk. We also discuss the identification of risky events, alternative approaches to the measurement of risk, and
how investment firms go about formulating strategies to control financial risk.
We next show how changes in the information technologies supporting these tasks have led to improvements in
the control of risk and in the design of products which involve financial risk. Advances in five areas that are
of interest are: communications software, object-oriented programming, the use of parallel processors and
supercomputers, and the application of artificial intelligence and neural nets. Although these new information
technologies create significant opportunities to improve global and departmental risk management, a basic
question that must be addressed involves the costs associated with their implementation. Thus, a third
contribution of this paper is to analyze the extent to which the implementation of these technologies will affect
firm costs. To this end, we evaluate the components of the cost function for risk management, and consider
some ways that the new technologies can be applied to reduce overall costs.Information Systems Working Papers Serie
APPLICATIONS: Financial risk and financial Risk Management Technology (RMT): Issues and advances
Methods for sound risk management are of increasing
interest among Wall Street investment banking and brokerage
firms in the aftermath of the October 1987 crash of the stock
market. As the knowledge of advanced technology applications
in risk management increases, financial firms are finding
innovative ways to use them practically, in order to insulate
themselves. The recent development in models, the software
and hardware, and the market data to track risk are all
considered advances in Risk Management Technology (RMT). -.
These advances have affected all three stages of risk management: the identification, the measurement, and the formulation of strategies to control financial risk. This article discusses
the advances made in five areas of RMT: communication
software, object-oriented programming, parallel processing, neural nets and artificial intelligence. Systems based on any of these areas may be used to add value to the business of
a firm. A business value linkage analysis shows how the utility
of advanced systems can be measured to justify their costs.Information Systems Working Papers Serie
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