25,328 research outputs found

    Cyclic growth in Atlantic region continental crust

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    Atlantic region continental crust evolved in successive stages under the influence of regular, approximately 400 Ma-long tectonic cycles. Data point to a variety of operative tectonic processes ranging from widespread ocean floor consumption (Wilson cycle) to entirely ensialic (Ampferer-style subduction or simple crustal attenuation-compression). Different processes may have operated concurrently in some or different belts. Resolving this remains the major challenge

    Bulletin No. 14: Creating New Landscapes with Herbicides, A Homeowner\u27s Guide

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    A how-to-do-it handbook describing the formulations and techniques to be used in eliminating unwanted plants such as poison ivy. The use of herbicides in naturalistic landscaping, wildlife and woodlot management are included. [Addendum on new data on chemicals inserted 1970] 30 pp

    05-05 "Teaching Ecological and Feminist Economics in the Principles Course"

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    It can be difficult to incorporate ecological and feminist concerns into introductory courses based on neoclassical analysis. We have faced these issues head-on as we have worked on writing introductory economics textbooks, Microeconomics in Context (Goodwin, Nelson, Ackerman and Weisskopf, 2005) and Macroeconomics in Context (in progress). In this essay, we will describe how we have modified the introductory curriculum to encompass these perspectives.

    Detection of Turbidity Dynamics in Tampa Bay, Florida Using Multispectral Imagery from ERTS-1

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    Detection of turbidity dynamics in Tampa Bay, Florida using multispectral imagery from ERTS-

    Space station needs, attributes, and architectural options: Space station program cost analysis

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    This report documents the principal cost results (Task 3) derived from the Space Station Needs, Attributes, and Architectural Options study conducted for NASA by the McDonnell Douglas Astronautics Company. The determined costs were those of Architectural Options (Task 2) defined to satisfy Mission Requirements (Task 1) developed within the study. A major feature of this part of the study was the consideration of realistic NASA budget constraints on the recommended architecture. Thus, the space station funding requirements were adjusted by altering schedules until they were consistent with current NASA budget trends

    Multiproduct Optimal Hedging by Time-Varying Correlations in a State Dependent model of Regime-Switching

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    Replaced with revised version of paper 07/29/10.Agribusiness, Demand and Price Analysis, Risk and Uncertainty,

    Restrictiveness and guidance in support systems

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    Restrictiveness and guidance have been proposed as methods for improving the performance of users of support systems. In many companies computerized support systems are used in demand forecasting enabling interventions based on management judgment to be applied to statistical forecasts. However, the resulting forecasts are often ‘sub-optimal’ because many judgmental adjustments are made when they are not required. An experiment was used to investigate whether restrictiveness or guidance in a support system leads to more effective use of judgment. Users received statistical forecasts of the demand for products that were subject to promotions. In the restrictiveness mode small judgmental adjustments to these forecasts were prohibited (research indicates that these waste effort and may damage accuracy). In the guidance mode users were advised to make adjustments in promotion periods, but not to adjust in non-promotion periods. A control group of users were not subject to restrictions and received no guidance. The results showed that neither restrictiveness nor guidance led to improvements in accuracy. While restrictiveness reduced unnecessary adjustments, it deterred desirable adjustments and also encouraged over-large adjustments so that accuracy was damaged. Guidance encouraged more desirable system use, but was often ignored. Surprisingly, users indicated it was less acceptable than restrictiveness

    2003 Oregon Vineyard and Winery Report

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    This statewide survey report on vineyards and wineries in Oregon covers bearing and nonbearing acres, size of vineyard operation, variety and county, size distribution, prices, yields, crush, inventory, and sales. The report also contains some comparisons of data for 2002 and 2003. According to this report, the number of vineyards and wineries in Oregon reached a record high in 2003, with nearly 1.2 million cases of wine sold

    Effective transition rates for epitaxial growth using fast modulation

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    Thin-film deposition is an industrially important process that is highly dependent on the processing conditions. Most films are grown under constant conditions, but a few studies show that modified properties may be obtained with periodic inputs. However, assessing the effects of modulation experimentally becomes impractical with increasing material complexity. Here we consider periodic conditions in which the period is short relative to the time scales of growth. We analyze a stochastic model of thin-film growth, computing effective transition rates associated with rapid periodic process parameters. Combinations of effective rates may exist that are not attainable under steady conditions, potentially enabling new film properties. An algorithm is presented to construct the periodic input for a desired set of effective transition rates. These ideas are demonstrated in three simple examples using kinetic Monte Carlo simulations of epitaxial growth

    Twist-angle dependence of electron correlations in moir\'e graphene bilayers

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    Motivated by the recent observation of correlated insulator states and unconventional superconductivity in twisted bilayer graphene, we study the dependence of electron correlations on the twist angle and reveal the existence of strong correlations over a narrow range of twist-angles near the magic angle. Specifically, we determine the on-site and extended Hubbard parameters of the low-energy Wannier states using an atomistic quantum-mechanical approach. The ratio of the on-site Hubbard parameter and the width of the flat bands, which is an indicator of the strength of electron correlations, depends sensitively on the screening by the semiconducting substrate and the metallic gates. Including the effect of long-ranged Coulomb interactions significantly reduces electron correlations and explains the experimentally observed sensitivity of strong correlation phenomena on twist angle.Comment: 17 pages, 6 figure
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