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We consider electron-electron interaction effects in quantum point contacts on the first quantization plateau, taking into account all scattering processes. We compute the low-temperature linear and nonlinear conductance, shot noise, and thermopower, by perturbation theory and a self-consistent nonperturbative method. On the conductance plateau, the low-temperature corrections are solely due to momentum-nonconserving processes that change the relative number of leftand right-moving electrons. This leads to a suppression of the conductance for increasing temperature or voltage. The size of the suppression is estimated for a realistic saddle-point potential, and is largest in the beginning of the conductance plateau. For large magnetic field, interaction effects are strongly suppressed by the Pauli principle, and hence the first spin-split conductance plateau has a much weaker interaction correction. For the nonperturbative calculations, we use a self-consistent nonequilibrium Green's function approach, which suggests that the conductance saturates at elevated temperatures. These results are consistent with many experimental observations related to the so-called 0.7 anomaly.

We present the effective low-energy theory for interacting 1D quantum wires subject to Rashba spin-orbit coupling. Under a one-loop renormalization group scheme including all allowed interaction processes for not too weak Rashba coupling, we show that electron-electron backscattering is an irrelevant perturbation. Therefore no gap arises and electronic transport is described by a modified Luttinger liquid theory. As an application of the theory, we discuss the RKKY interaction between two magnetic impurities. Interactions are shown to induce a slower power-law decay of the RKKY range function than the usual 1D noninteracting cos(2kF x)/|x| law. Moreover, in the noninteracting Rashba wire, the spin-orbit coupling causes a twisted (anisotropic) range function with several different spatial oscillation periods. In the interacting case, we show that one special oscillation period leads to the slowest decay, and therefore dominates the RKKY interaction for large separation.

The aim of this paper is to present current work to develop a system of performance indicators (PI) for wastewater services undertaken under the auspices of IWA and coordinated by LNEC. Present day wastewater utilities manage their services and systems in an increasingly demanding and complex way. For this reason, it is important to support their work and decision processes with the best available tools in order to deliver services with the most effective and efficient performance. The paper focuses on proposed performance indicators (PIs) for wastewater services and on the main aspects of PI assessment. These are based on data related to: environmental, operational, personnel, physical, quality of service and economic and financial performance. Data are mostly made available through the various common-use information systems in the utilities. This IWA forum has been important not only for the dissemination of the work already developed but also as promotion of a wider discussion to enhance the final draft version of the IWA Manual of Best Practice due for publication in 2003.

This is the accepted version of the paper.This version of the publication may differ from the final published version. The electronic spin-orbit coupling in carbon nanotubes is strongly enhanced by the curvature of the tube surface and has important effects on the single-particle spectrum. Here, we include the full spin-orbit interaction in the formulation of the effective low-energy theory for interacting electrons in metallic single-wall carbon nanotubes and study its consequences. The resulting theory is a four-channel Luttinger liquid, where spin and charge modes are mixed. We show that the analytic structure of the spectral function is strongly affected by this mixing, which can provide an experimental signature of the spin-orbit interaction. Permanent