774 research outputs found
Watershed assessment of Griffin Creek headwaters tributary to Montana\u27s Clark Fork of the Columbia River
Comprehension activities for primary grades including a review of commercial products and suggestions for teacher-made materials
The purpose of this study is to seek out many different commercial sources of comprehension materials for students in grades one through three
Room temperature midinfrared electroluminescence from GaInAsSbP light emitting diodes. .
Room temperature electroluminescence in the midinfrared near 4 µm is reported from GaInAsSbP light emitting diodes grown on GaSb by liquid phase epitaxy. Comparison of the electro- and photoluminescence revealed that light is generated on the p side of the diode. The energy shift (24 meV) is consistent with band gap narrowing and recombination via band tail states due to the Zn doping (1×1018 cm−3) in the p layer of the structure. The temperature dependent behavior of the luminescence and the improved emission intensity was attributed to recombination from localized states arising from electrostatic potential fluctuations due to compositional inhomogeneities in these alloys
Implementing tradable permits for sulfur oxides emissions : a case study in the South Coast Air Basin
Tradable emissions permits have important theoretical advantages over source-specific technical standards as a means for controlling pollution. Nonetheless, difficulties can arise in trying to implement an efficient, competitive market in emissions permits. Simple workable versions of the market concept may fail to achieve the competitive equilibrium, or to take account of important complexities in the relationship between the pattern of emissions and the geographical distribution of pollution. Existing regulatory law may severely limit the range of market opportunities that states can adopt.
This report examines the feasibility of tradable permits for controlling particulate sulfates in the Los Angeles airshed. Although the empirical part of the paper deals with a specific case, the methods developed have general applicability. Moreover, the particular market design that is proposed -- an auction process that involves no net revenue collection by the state -- has attractive features as a general model
Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings
The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudomonochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo-and thermal-emission characteristics of the quantum rings. (C) 2014 AIP Publishing LLC
Incorporating Prior Knowledge into Task Decomposition for Large-Scale Patent Classification
Abstract. With the adoption of min-max-modular support vector machines (SVMs) to solve large-scale patent classification problems, a novel, simple method for incorporating prior knowledge into task decomposition is proposed and investigated. Two kinds of prior knowledge described in patent texts are considered: time information, and hierarchical structure information. Through experiments using the NTCIR-5 Japanese patent database, patents are found to have time-varying features that considerably affect classification. The experimen-tal results demonstrate that applying min-max modular SVMs with the proposed method gives performance superior to that of conventional SVMs in terms of training time, generalization accuracy, and scalability.
Euclid at Threescore Years and Ten: The Twilight of Environmental and Land-Use Regulation?
Life, Liberty, and Whose Property lecture given by Loren A. Smith, Chief Judge, United States Court of Federal Claims.
Is this the Twilight of Land Use Controls? lecture given by Charles M. Haar, Professor of Law at Harvard University Law.
Capture and Counteraction: Self-Help and Environmental Zealots lecture given by James E. Krier, Earl Warren Delano Professor of Law, University of Michigan.
Ecology and Aesthetics: Our Future and the Making of Things lecture given by William A. McDonough, Dean and Elson Professor, University of Virginia School of Architecture
Simulation of the enhanced infrared photoresponse of type-II GaSb/GaAs quantum ring solar cells
The extended photo-response of solar cells containing ten periods of GaSb/GaAs quantum rings imbedded in the p-i-n junction has been described using a single-band representation of the type-II quantum ring structure. By fitting the experimental data, the authors were able to deduce that the quantum rings are well represented by a Gaussian height distribution and a large valence band discontinuity. The simulated band of states is shown to be well matched to the photoluminescence analysis of the structure, with the inhomogeneous size distribution resulting in a band of hole states roughly 390 meV above the valence band
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