Changes in Nonpoint Nutrient Loading into European Freshwaters: Trends and Consequences since 1950 and Not-Impossible Changes until 2080

Devising strategies that foster long-term economic development in Europe within a framework of ecological sustainability is the major theme of IIASA's study "The Future Environments for Europe: Some Implications of Alternative Development Paths. This Working Paper is a direct contribution to that study. There have been many reports in the environmental literature linking agricultural activities to ecological degradation. Few of them, however, have a time horizon of decades to a century. When viewed over such a time span, ecological alterations, that may currently appear to be minor in the short term, may cause major environmental effects due to the accumulation of small changes over many years. From a policy point of view, such effects are important for two reasons. Firstly, they may come as a "surprise" to governments and the public alike. Secondly, once the major change is observed, it may be too late to develop an appropriate management strategy to minimize much of the damage. (The sudden advent of Waldsterben in Central Europe in the early 1980's is a recent example.) From a scientific point of view, such effects are of interest because they exemplify how changes, occurring on relatively slow time scales, can trigger sudden threshold responses in the environment

Point and Diffuse Loads of Selected Pollutants in the River Rhine and Its Main Tributaries

The research described in this working paper was conducted for the study "Sources of Chemical Pollution in the Rhine Basin," a collaborative effort between IIASA and the Netherlands National Institute for Public Health and Environmental Protection (RIVM). The goal of the study was to determine, by mass balance analysis, the inputs and outputs to the Rhine Basin over the time period 1950-2010. Particular attention was given to "cradle-to-grave" analysis in which the pollutants are traced from their pathways through the industrial economy and into the environment. For the historical analysis, it was necessary to estimate emissions from various industrial sectors (point sources) and runoff from urban, agricultural and forested lands (diffuse sources). The analysis is hindered, however, by the scarcity of historical data on sources of emission. On the other hand, the Rhine River has been intensively monitored for heavy metals since the early 1970s, and for nutrients and other hydrological parameters since the 1950s. These data provide a basis for making reasonable estimates of inputs to the river in previous decades. Prior to the analysis presented herein, no comprehensive investigation of the long-term time series of chemical loads to the river had been undertaken. This working paper not only quantifies the total loads of the various chemicals over time. It also subdivides the loads into the point-source and diffuse fractions, applying a new methodology developed by the senior author of this paper. With the estimates provided here, it is possible to calibrate the emission factors assumed for industrial and diffuse sources. The paper thus makes an invaluable contribution of the major goals of the study

Point and Diffuse Loads of Selected Pollutants in the River Rhein and its Main Tributaries

This report describes a method for estimating the amount and fractions of pollutant loads from point and non-point sources. The method presented relies on the analysis of concentration-discharge and load-discharge relationships respectively, using the extensive monitoring data on the Rhein River and its tributaries given in water quality monitoring reports by the International Commission for Protection of the Rhein and the national Deutsche Kommission zum Schutz des Rheins vor Verunreinigung. The results are suitable for calibrating the runoff/chemical mobilization model, because they are obtained independently of the above-mentioned method. The method is relatively simple to apply. The quality of the results depends mainly on the scattering of the concentration-discharge/load-discharge relationship, and on the detection limits for some pollutants, e.g., cadmium. The spatial resolution depends on the density of monitoring stations within the catchment area, and the temporal resolution depends on the frequency of single measurements and the scattering of the relationship. The method used is described in detail and a summarized overview of the results regarding the estimation of point and non-point net loads of zinc, lead, cadmium, phosphorus, and nitrogen for different monitoring stations of the catchment area of the River Rhein and its main tributaries is given

Компьютерное моделирование напряженно-деформированного состояния сварных конструкций

В данной работе показано, что при оценке и обеспечении живучести сварныхметаллоконструкций важную роль играют технологические факторы. Учет их влияния реализуется на основе применения метода конечных элементов. Описана численная методика расчета остаточных сварочных напряжений и деформаций в элементах сварных металлоконструкций.Численнообосновантехнологическийметодповышенияживучестиуказанногоклассаметаллоконструкций

One-step microwave synthesis of palladium-carbon nanotubes hybrids with improved catalytic performance

7 páginas, 7 figuras, 3 tablas.-- El pdf del artículo es la versión pre-print.A fast and easy one-step linker-free approach for the synthesis of palladium nanoparticle/multiwall carbon nanotube (Pd-NP/MWCNT)hybrid materials is described using microwave irradiation for the effective decomposition of Pd2dba3 complex in the presence of MWCNTs. High loadings of Pd nanoparticles (up to 40 wt.%) having sizes between 3 and 5 nm are deposited on the surface of MWCNTs within a time of only 2 minutess. The Pd-NP/MWCNT materials serve as efficient catalysts in C-C coupling as well as in hydrogenation reactions, all characterized by high conversion rates using a small amount of catalysts, high turnover frequency values and good recyclbility.Financial support from the Spanish Ministerio de Ciencia e Innovación (MICINN) and the European Regional Development Fund (ERDF) under projects CTQ2008-01784 and MAT2007-66927-C02-01, and the Gobierno de Aragón (DGAPI086- 08) is gratefully acknowledged. M.C. thanks MICINN for her Grant No. BES-2008-003503.Peer reviewe

The role of mental disorders in the risk and speed of transition to alcohol use disorders among community youth

Background Among adolescents and young adults with DSM-IV alcohol use disorders (AUDs), there are inter-individual differences in the speed of transition from initial alcohol use (AU) to AUD. AUDs are highly co-morbid with other mental disorders. The factors associated with rapid transition from first AU to AUD remain unknown and the role of mental disorders in rapid transitions is unclear. Given this background we examined (1) whether prior anxiety, mood, externalizing and non-alcohol substance use disorders are related to the risk and speed of transition from first AU to DSM-IV alcohol abuse (AA) and alcohol dependence (AD) and (2) whether early age of onset of prior mental disorders (PMDs) is a promoter of rapid transition. Method A total of 3021 community subjects (97.7% lifetime AU) aged 14-24 years at baseline were followed up prospectively for up to 10 years. AU and mental disorders were assessed with the DSM-IV/M-CIDI. Results Among subjects with lifetime AU, several PMDs, such as specific phobia, bipolar disorder and nicotine dependence, were associated with an increased risk of AUD independent of externalizing disorders. Associations of PMDs with the speed of transition to AUDs were mostly weak and inconsistent. Only social phobia and externalizing disorders were associated with faster transitions to AD even after adjustment for other PMDs. Earlier age of onset of PMD was not associated with rapid transition. Conclusions Mental disorders are associated with the risk of AUD. With the possible exception of social phobia and externalizing disorders, they do not promote rapid transition, even if they occur particularly early. Future research needs to identify factors relevant to rapid transition to AU