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31.
A nonlinear bilevel model for analysis of electric utility demand-side planning issues 总被引:1,自引:0,他引:1
An application of bilevel programming in the electric utility industry is presented. The model is nonlinear and is used to analyze various economic issues that affect electric utility planning. The electric utility at the upper level of the model seeks to minimize costs or maximize benefits while controlling electric rates and subsidizing energy conservation programs. Customers at the lower level attempt to maximize their net benefit by consuming electricity and investing in conservation. This model considers factors such as free riders and the rebound effect which affect the net benefits of utility resource plans but are ignored by most planning models. The model's solutions shed light on utility issues including whether there can be a practical difference between various objectives, including minimizing cost (least cost planning) and maximizing net social welfare (value based planning). 相似文献
32.
33.
The primary and secondary combination zones of an air-acetylene flame have been separated by a stream of nitrogen flowing parallel to the flame to prevent access of atmospheric oxygen to its base. The flame is very stable over a wide range of fuel-air mixture strengths, and organic solvents may be aspirated without difficulty. The low flame background enables thermal-emission and atomic-fluorescence measurements to be made with high sensitivity. Bismuth, for example, has been determined in the range 5-200 ppm by its thermal emission at 306.8 nm, with a detection limit of 2 ppm in aqueous solution, and in the range 1-10 ppm with a detection limit of 0.3 ppm in 50% ethanolic solution. Zinc and cadmium have been determined at 213.9 nm and 228.8 nm by atomic-fluorescence spectroscopy in this flame with detection limits of 2 x 10(-4) ppm and 5 x 10(-4) ppm respectively, vapour-discharge lamps being used as sources of excitation. The results obtained represent a considerable improvement over those available by the same methods in a conventional air-acetylene flame. 相似文献
34.
M L Hobbs 《Journal of Thermal Analysis and Calorimetry》2006,83(1):91-95
A decomposition
model has been developed to predict the response of removable syntactic foam
(RSF) exposed to fire-like heat fluxes. RSF consists of glass micro-balloons
(GMB) in a cured epoxy polymer matrix. A chemistry model is presented based
on the chemical structure of the epoxy polymer, mass transport of polymer
fragments to the bulk gas, and vapor-liquid equilibrium. Thermophysical properties
were estimated from measurements. A bubble nucleation, growth, and coalescence
model was used to describe changes in properties with the extent of reaction.
Decomposition of a strand of syntactic foam exposed to high temperatures was
simulated. 相似文献
35.
The properties of oscillating cuspoid integrals whose phase functions are odd and even polynomials are investigated. These integrals are called oddoids and evenoids, respectively (and collectively, oddenoids). We have studied in detail oddenoids whose phase functions contain up to three real parameters. For each oddenoid, we have obtained its Maclaurin series representation and investigated its relation to Airy–Hardy integrals and Bessel functions of fractional orders. We have used techniques from singularity theory to characterise the caustic (or bifurcation set) associated with each oddenoid, including the occurrence of complex whiskers. Plots and short tables of numerical values for the oddenoids are presented. The numerical calculations used the software package CUSPINT [N.P. Kirk, J.N.L. Connor, C.A. Hobbs, An adaptive contour code for the numerical evaluation of the oscillatory cuspoid canonical integrals and their derivatives, Comput. Phys. Commun. 132 (2000) 142–165]. 相似文献
36.
Liquid chromatographic determination of N-methyl carbamate pesticide residues at low parts-per-billion levels in eggs 总被引:1,自引:0,他引:1
Schenck FJ Podhorniak LV Hobbs J Casanova J Donoghue D 《Journal of AOAC International》2006,89(1):196-200
A reversed-phase liquid chromatographic (LC) method is presented for the analysis of N-methyl carbamate pesticide residues and piperonyl butoxide in eggs at levels as low as 2 microg/kg (ppb). The study was undertaken to provide data for dietary exposure estimates used in risk analysis. The method uses an acetonitrile extraction followed by liquid-liquid partitioning and normal-phase aminopropyl solid-phase extraction column cleanup. Determination of residues is by reversed-phase LC with an inline postcolumn reaction followed by fluorescence detection. The average recoveries of 21 fortified (most at 2.0 and 20.0 ppb) N-methyl carbamate pesticide residues and the carbamate metabolite 1-naphthol from eggs ranged from 70 to 107%. Recoveries of the pesticide synergist piperonyl butoxide ranged from 63 to 106%. Single-comb White Leghorn hens were treated with the carbamate carbaryl, and the eggs subsequently produced were analyzed for carbaryl and 1-naphthol residues. 相似文献
37.
James D. Woodyard Paul R. Morris Gregory D. Hobbs 《Journal of heterocyclic chemistry》1980,17(5):1097-1099
A rapid method for making stereochemical assignments based on variant temperature nmr data for the 7-phenyl-2-oxabicyclo[4.1.0]heptanes is described. 相似文献
38.
The effects of draw conditions were studied for initially amorphous melt‐spun poly(ethylene terephthalate) fibers in the presence of subcritical and supercritical (SC) CO2. Both in situ and posttreatment mechanical behavior along with morphological characteristics were investigated. Fibers soaked in subcritical CO2 could be drawn to 30% higher draw ratios (DRs) compared with fibers that were cold‐drawn. In situ force response measured with a custom apparatus showed that fibers in subcritical CO2 had no measurable resistance to deformation until strain hardening occurred. In contrast, fibers drawn in SC CO2 displayed a yield response, a significant decrease in ductility, and a significant difference in postyield behavior. Fibers drawn in subcritical CO2 showed slightly lower tensile properties compared with cold‐drawn samples whereas fibers treated in SC CO2 had much lower tensile properties because of the limited DR achieved. X‐ray diffraction studies indicated that CO2 enhances the development of the crystalline phase compared with cold‐drawn samples. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1881–1891, 1999 相似文献
39.
Wang ZK Lim HS Liu HY Ng SC Kuok MH Tay LL Lockwood DJ Cottam MG Hobbs KL Larson PR Keay JC Lian GD Johnson MB 《Physical review letters》2005,94(13):137208
The spin dynamics of high-aspect-ratio nickel nanorings in a longitudinal magnetic field have been investigated by Brillouin spectroscopy and the results are compared with a macroscopic theory and three-dimensional micromagnetic simulations. Good agreement is found between the measured and calculated magnetic field dependence of the spin wave frequency. Simulations show that as the field decreases from saturation, the rings switch from a "bamboo" to a novel "twisted bamboo" state at a certain critical field, and predict a corresponding dip in the dependence of the spin wave frequency on the magnetic field. 相似文献
40.