Monitoring of Heavy Metals By Energy Dispersive X-Ray Fluorescence Spectrometry

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Fundamentals and salient features of a projected heavy metals monitoring system are discussed. Determination of mass concentrations is achieved by using a new dust emission monitor, consisting of a "Zero Pressure Probe" for isokinetic sampling, which is connected to a "Longitudinally Oscillating Band" mass detector. The thin dust layer, precipitated on the surface of heat resistant filter tapes could be analysed nondestructively by energy-dispersive X-ray fluorescence (EDXRF). Using a small portable EDXRF-system with radioisotope-excitation, quasi-continuous monitoring of particulate heavy metals (Cd, Hg, Pb, Cu, Sb, Zn, Sn) suspended in incinerator stack gases is expected to be feasible. Another application of EDXRF-analysis is the reported investigation of electrostatic precipitator ash (ESP-fly ash). Using the "Linear Multi-Elemental-Standard Addition Method" as a fast and simple routine technique, results are reported for the concentrations of Pb, Cd, Cu and Zn in fly ash samples which had been collected in different fields (hoppers) of the electrostatic precipitator

The changing housing market: a bang or a whimper?

The U.S. housing market has had an extraordinary 15-year run in terms of prices, sales of existing homes, and new construction, especially on the East and West Coasts. Beginning in the spring of 2006, however, the housing market began to turn distinctly downward. We know that 2005 was a good year and that 2006 has not been such a good year, and we see indications that 2007 could be tough. To help understand why the market has shifted from hot to, at a minimum, cool, this paper, which is the first in a series of NEPPC policy briefs on housing, recaps some of the factors that contributed to this housing run and discusses some of the factors that will determine just how long and steep this reversal of housing fortune might be.Housing - Prices

The Central Role of Home Prices in the Current Financial Crisis: How Will the Market Clear?

macroeconomics, financial crisis, subprime, house, home, market, household

Binomial-coefficient multiples of irrationals

Denote by $x$ a random infinite path in the graph of Pascal's triangle (left and right turns are selected independently with fixed probabilities) and by $d_n(x)$ the binomial coefficient at the $n$'th level along the path $x$. Then for a dense $G_{\delta}$ set of $\theta$ in the unit interval, $\{d_n(x)\theta \}$ is almost surely dense but not uniformly distributed modulo 1.Comment: 10 pages, to appear in Monatshefte f. Mat

How the commercial real estate boom undid the banks

Real property ; Construction industry ; Regional economics