Identifying the origins of local atmospheric deposition in the steel industry basin of Luxembourg using the chemical and isotopic composition of the lichen Xanthoria parietina

Trace metal atmospheric contamination was assessed in one of the oldest European industrial sites of steel production situated in the southern part of the Grand-Duchy of Luxembourg. Using elemental ratios as well as Pb, Sr, and Nd isotopic compositions as tracers, we found preliminary results concerning the trace metal enrichment and the chemical/isotopic signatures of the most important emission sources using the lichen Xanthoria parietina sampled at 15 sites along a SW-NE transect. The concentrations of these elements decreased with increasing distance from the historical and actual steel-work areas. The combination of the different tracers (major elements, Rare Earth Element ratios, Pb, Sr and Nd isotopes) enabled us to distinguish between three principal sources: the historical steel production (old tailings corresponding to blast-furnace residues), the present steel production (industrial sites with arc electric furnace units) and the regional background (baseline) components. Other anthropogenic sources including a waste incinerator and major roads had only weak impacts on lichen chemistry and isotopic ratios. The correlation between the Sr and Nd isotope ratios indicated that the Sr–Nd isotope systems represented useful tools to trace atmospheric emissions of factories using scrap metal for steel production

Quantization of Hyperbolic N-Sphere Scattering Systems in Three Dimensions

Most discussions of chaotic scattering systems are devoted to two-dimensional systems. It is of considerable interest to extend these studies to the, in general, more realistic case of three dimensions. In this context, it is conceptually important to investigate the quality of semiclassical methods as a function of the dimensionality. As a model system, we choose various three dimensional generalizations of the famous three disk problem which played a central role in the study of chaotic scattering in two dimensions. We present a quantum-mechanical treatment of the hyperbolic scattering of a point particle off a finite number of non-overlapping and non-touching hard spheres in three dimensions. We derive expressions for the scattering matrix S and its determinant. The determinant of S decomposes into two parts, the first one contains the product of the determinants of the individual one-sphere S-matrices and the second one is given by a ratio involving the determinants of a characteristic KKR-type matrix and its conjugate. We justify our approach by showing that all formal manipulations in these derivations are correct and that all the determinants involved which are of infinite dimension exist. Moreover, for all complex wave numbers, we conjecture a direct link between the quantum-mechanical and semiclassical descriptions: The semiclassical limit of the cumulant expansion of the KKR-type matrix is given by the Gutzwiller-Voros zeta function plus diffractional corrections in the curvature expansion. This connection is direct since it is not based on any kind of subtraction scheme involving bounded reference systems. We present numerically computed resonances and compare them with the corresponding data for the similar two-dimensional N-disk systems and with semiclassical calculations.Comment: 35 pages, LaTeX plus 8 Postscript figures, uses epsf.sty, epsfig.sty and epsf.te

Future Heat Waves in Different European Capitals Based on Climate Change Indicators

Changes in the frequency and intensity of heat waves have shown substantial negative impacts on public health. At the same time, climate change towards increasing air temperatures throughout Europe will foster such extreme events, leading to the population being more exposed to them and societies becoming more vulnerable. Based on two climate change scenarios (Representative Concentration Pathway 4.5 and 8.5) we analysed the frequency and intensity of heat waves for three capital cities in Europe representing a North–South transect (London, Luxembourg, Rome). We used indices proposed by the Expert Team on Sector-Specific Climate Indices of the World Meteorological Organization to analyze the number of heat waves, the number of days that contribute to heat waves, the length of the longest heat waves, as well as the mean temperature during heat waves. The threshold for the definition of heat waves is calculated based on a reference period of 30 years for each of the three cities, allowing for a direct comparison of the projected changes between the cities. Changes in the projected air temperature between a reference period (1971–2000) and three future periods (2001–2030 near future, 2031–2060 middle future, and 2061–2090 far future) are statistically significant for all three cities and both emission scenarios. Considerable similarities could be identified for the different heat wave indices. This directly affects the risk of the exposed population and might also negatively influence food security and water supply

The case for a more binding WTO agreement on regulatory principles in telecommunication markets

On February 5, 1998, the WTO agreement on basic telecommunications services entered into force. Although the WTO agreement is a step into the right direction its impact might be rather modest. This is because apart from the many exemptions, which are likely to undermine market access and national treatment commitments, the regulatory provisions laid down in the WTO agreement are neither specific nor comprehensive enough to ensure open market access. Because there is in most cases a lack of clear definition as to the terms and conditions of regulatory provisions, there is a great danger that governments might nullify the commitments by abusing the regulatory requirements.WTO agreement on basic telecommunications services International regulation

Meta-Analysis of Strategies to Reduce NH3 Emissions from Slurries in European Agriculture and Consequences for Greenhouse Gas Emissions

The intensification of livestock production, to accommodate rising human population, has led to a higher emission of ammonia into the environment. For the reduction of ammonia emissions, different management steps have been reported in most EU countries. Some authors, however, have criticized such individual measures, because attempts to abate the emission of ammonia may lead to significant increases in either methane, nitrous oxide, or carbon dioxide. In this study, we carried out a meta-analysis of experimental European data published in peer-reviewed journals to evaluate the impact of major agricultural management practices on ammonia emissions, including the pollution swapping effect. The result of our meta-analysis showed that for the treatment, storage, and application stages, only slurry acidification was effective for the reduction of ammonia emissions (−69%), and had no pollution swapping effect with other greenhouse gases, like nitrous oxide (−21%), methane (−86%), and carbon dioxide (−15%). All other management strategies, like biological treatment, separation strategies, different storage types, the concealing of the liquid slurry with different materials, and variable field applications were effective to varying degrees for the abatement of ammonia emission, but also resulted in the increased emission of at least one other greenhouse gas. The strategies focusing on the decrease of ammonia emissions neglected the consequences of the emissions of other greenhouse gases. We recommend a combination of treatment technologies, like acidification and soil incorporation, and/or embracing emerging technologies, such as microbial inhibitors and slow release fertilizers

Simulation of sediment transport during flood events: laboratory work and field experiments

Abstract This paper aims at initiating a fundamental understanding of the suspended load transport of river sediment in unsteady flow. Laboratory erosion tests as well as artificial flood experiments are used to evaluate the influence of the transient regime on the transport efficiency of the flow. The erosion experiments reveal that the transport capacity is augmented when the unsteadiness of the flow increases. However, the influence of the transient regime is counteracted by the cohesive properties of the river bed. Field experiments with artificial floods released from a reservoir into a small canal confirm these findings and show a relationship between the friction velocity and the suspended load transport. An appropriate parameter [3 is proposed to evaluate the impact of the transient regime on the transport of suspended sediment. Key words sediment transport; unsteady flow; artificial floods; suspended load; kinematic flow; friction velocity Simulation du transport de sédiment pendant des événements de crue: expériences au laboratoire et sur le terrain Résumé Cette publication se donne pour but d'arriver à une plus grande compréhensio

Future Changes in Human-Biometeorological Index Classes in Three Regions of Luxembourg, Western-Central Europe

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress