Hard x-ray absorption spectroscopy is combined with scanning microtomography to reconstruct full near-edge spectra of an elemental species at each location on an arbitrary virtual section through a sample. These spectra reveal the local concentrations of different chemical compounds of the absorbing element inside the sample and give insight into the oxidation state, the local atomic structure, and the local projected free density of states. The method is implemented by combining a quick scanning monochromator and data acquisition system with a scanning microprobe setup based on refractive x-ray lenses.

We use the x-ray extended-range technique ͑XERT͒ ͓Chantler et al., Phys. Rev. A 64, 062506 ͑2001͔͒ to measure the mass attenuation coefficients of molybdenum in the x-ray energy range of 13.5-41.5 keV to 0.02-0.15 % accuracy. Measurements made over an extended range of the measurement parameter space are critically examined to identify, quantify, and correct where necessary a number of experimental systematic errors. These results represent the most extensive experimental data set for molybdenum and include absolute mass attenuation coefficients in the regions of the x-ray absorption fine structure ͑XAFS͒ and x-ray-absorption near-edge structure ͑XANES͒. The imaginary component of the atomic form-factor f 2 is derived from the photoelectric absorption after subtracting calculated Rayleigh and Compton scattering cross sections from the total attenuation. Comparison of the result with tabulations of calculated photoelectric absorption coefficients indicates that differences of 1-15 % persist between the calculated and observed values.

A liquid-nitrogen-cooled monochromator for high-energy X-rays consisting of two bent Si(111) Laue crystals adjusted to sequential Rowland conditions has been in operation for over two years at the SRI-CAT sector 1 undulator beamline of the Advanced Photon Source (APS). It delivers over ten times more¯ux than a¯at-crystal monochromator does at high energies, without any increase in energy width (ÁEaE 9 10 À3 ). Cryogenic cooling permits optimal¯ux, avoiding a sacri®ce from the often employed alternative technique of ®ltration ± a technique less effective at sources like the 7 GeV APS, where considerable heat loads can be deposited by high-energy photons, especially at closed undulator gaps. The ®xed-offset geometry provides a fully tunable in-line monochromatic beam. In addition to presenting the optics performance, unique crystal design and stable bending mechanism for a cryogenically cooled crystal under high heat load, the bending radii adjustment procedures are described.

This article presents a system model to analyze the solid waste disposal problem in New York State. The model shows that the solid waste system will go through a costly transition from a landfill‐dominated mode of disposal to other disposal alternatives. The solid waste budget has to rise sharply during the transition. Solid waste expenses are financed by local taxes and state financial aid. If local and state governments do not respond rapidly to higher budget requirements, illegal disposal will increase and the total cost of transition will rise. Rapid response of the local authorities to increase the solid waste budget and to lower solid waste generation per capita is necessary to manage the transition with a lower total cost and less illegal disposal.

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