Semiclassical analysis of level widths for one-dimensional potentials

We present a semiclassical study of level widths for a class of one-dimensional potentials in the presence of an ohmic environment. Employing an expression for the dipole matrix element in terms of the Fourier transform of the classical path we obtain the level widths within the Golden rule approximation. It is found that for potentials with an asymptotic power-law behavior, which may in addition be limited by an infinite wall, the width that an eigenstate of the isolated system acquires due to the coupling to the environment is proportional to its quantum number.Comment: 8 pages, 2 figures, RevTe

Voluntary Agreements in Environmental Protection - Experiences in Germany and Future Perspectives

A trend towards softer regulation, especially in the form of negotiated environmental agreements, is observable in national and international environmental policies. Such agreements are controversial, because there are fears that government will relinquish its responsibility for environmental protection. This paper analyses recent experiences with voluntary agreements in Germany. Topical German examples that have prompted public debates include the takeback agreement for cars, the voluntary agreement made by a number of industries on a C02 reduction by the year 2005 and the voluntary agreement made by the automobile industry on the development of energy-efficient cars. Proponents of voluntary agreements argue that this instrument provides incentives to the business sector for the development of efficient, innovative and environmentally-friendly solutions. Analysing the examples mentioned above, we conclude that it is hard to detect solutions derserving such attributes. These agreements are unlikely to produce results that go beyond what industry would have done in any case and they avoid using economic incentives. The agreements are' non-binding and unenforceable, with the negotiating process leading to a watering down of the environmental goals government had originally aimed at. A preference for negotiated solutions on principle, as currently espoused by the Federal Government in Germany, seems to be counterproductive. If the government clearly signals its willingness to refrain from using regulatory or economic instruments in favour of industry agreements, it weakens its negotiating position. The government also limits its options should the implementation of the agreement prove unsatisfactory. Government needs to be in control in order to leave its choice of policy instruments open and to be flexible. In a last step, we derive some general conclusions concerning reasonable strategies and applications of voluntary agreements within the European Union. --negotiated agreements,climate protection,circular economy,economic instruments of environmental policy

Economic outlook for the Euro area 2003

This article reports the spring forecast of the economic development in the Eurozone, which was carried out within the European Forecasting Network. A modest rise in GDP growth from 1.2% in 2003 up to 2.1% in 2004 is expected. The current weakness in the growth experience is caused by structural factors to a large extent. In particular, labor markets are not flexible enough in most countries.

Study on friction in automotive shock absorbers, part 2: Validation of friction simulations via novel single friction point test rigs

The most important change in the transition from partial to high automation is that the vehicle can drive autonomously, without active human involvement. This fact increases the current requirements regarding ride comfort and dictates new challenges for automotive shock absorbers. There exist two common types of automotive shock absorbers with two friction types. The intended viscous friction dissipates the chassis’ vibrations, while the unwanted solid body friction is generated by the rubbing of the damper’s seals and guides during actuation. The latter so-called static friction impairs ride comfort and demands appropriate friction modeling for the control of adaptive or active suspension systems. In the current article, the simulation approach introduced in part 1 of this study is validated against a single friction point and full damper friction measurements. To achieve that, a friction measurement method with novel test rigs has been developed, which allows for reliable determination of the friction behavior of each single friction point, while appropriately resembling the operating conditions of the real damper. The subsequent presentation of a friction simulation using friction model parameters from different geometry shows the general applicability of the overall friction investigation methodology. Accordingly, the presented simulation and measurement approaches enable the investigation of dynamic friction in automotive shock absorbers with significantly increased development efficiency

Study on friction in automotive shock absorbers, part 1: Friction simulation using a dynamic friction model in the contact zone of an FEM model

The important change in the transition from partial to high automation is that a vehicle can drive autonomously, without active human involvement. This fact increases the current requirements regarding ride comfort and dictates new challenges for automotive shock absorbers. There exist two common types of automotive shock absorber with two friction types: The intended viscous friction dissipates the chassis vibrations, while the unwanted solid body friction is generated by the rubbing of the damper’s seals and guides during actuation. The latter so-called static friction impairs ride comfort and demands appropriate friction modeling for the control of adaptive or active suspension systems. In this article, a simulation approach is introduced to model damper friction based on the most friction-relevant parameters. Since damper friction is highly dependent on geometry, which can vary widely, three-dimensional (3D) structural FEM is used to determine the deformations of the damper parts resulting from mounting and varying operation conditions. In the respective contact zones, a dynamic friction model is applied and parameterized based on the single friction point measurements. Subsequent to the parameterization of the overall friction model with geometry data, operation conditions, material properties and friction model parameters, single friction point simulations are performed, analyzed and validated against single friction point measurements. It is shown that this simulation method allows for friction prediction with high accuracy. Consequently, its application enables a wide range of parameters relevant to damper friction to be investigated with significantly increased development efficiency

Investigations on Joule heating applications by multiphysical continuum simulations in nanoscale systems

This work furthers the overall understanding of a 3w-measurement, by considering previously unexamined macroscopic influence factors within measurement by Finite Element simulations (FES). Moreover, new measuring configurations are developed to determine (an)isotropic thermal conductivities of nanoscale samples. Since no analytic solutions are available for these configurations, a new evaluation methodology is presented to determine emergent thermal conductivities by FES and Neural Networks

A Regulatory Framework for a Policy of Sustainability: Lessons from the Neo-Liberal School

In this paper targets, institutions and policy measures for describing and implementing sustainable development are evaluated in terms of their conformity with the economic framework of a market system. Firstly, from the viewpoint of neo-liberal economic thinking as conceived by the German Freiburg school of economists (Eucken), a general set of criteria is developed, including issues of operationalization and legitimation of goals as well as institutional and instrumental issues. On this basis general rules for designing an ecological framework guaranteeing the greatest possible degree of conformity with a market system are derived. The concrete application of these rules leads to recommendations for a policy of sustainability with respect to the setting of goals, the establishment of institutions (role of ecological councils, of a central environmental organization on UN level and of the GATT/WTO regime) as well as the use of appropriate instruments. --sustainability targets,regulatory rules,neo-liberal framework,environment and international trade,environmental policy assessment