Hybrid propulsion systems for motor vehicles with predominantly intermittent modes of operation

A small delivery vehicle was equipped with a flywheel-hybrid drive and compared in test stand and driving tests with a conventional drive vehicle. It turned out that with the hybrid drive, energy can be saved and exhaust emissions can be reduced

Boltzmann-type approach to transport in weakly interacting one-dimensional fermionic systems

We investigate transport properties of one-dimensional fermionic tight binding models featuring nearest and next-nearest neighbor hopping, where the fermions are additionally subject to a weak short range mutual interaction. To this end we employ a pertinent approach which allows for a mapping of the underlying Schr\"odinger dynamics onto an adequate linear quantum Boltzmann equation. This approach is based on a suitable projection operator method. From this Boltzmann equation we are able to numerically obtain diffusion coefficients in the case of non-vanishing next-nearest neighbor hopping, i.e., the non-integrable case, whereas the diffusion coefficient diverges without next-nearest neighbor hopping. For the latter case we analytically investigate the decay behavior of the current with the result that arbitrarily small parts of the current relax arbitrarily slowly which suggests anomalous diffusive transport behavior within the scope of our approach.Comment: 6 pages, 4 figures, accepted for publication in Phys. Rev.

Characteristics of cancer patients using homeopathy compared with those in conventional care: a cross-sectional study

Background: There are only few studies on cancer patients who are treated in complementary and alternative medicine clinics and comparing them with patients in conventional care. We will present the comparison of characteristics of two patient cohorts: one was treated in a homeopathic cancer care clinic and one was treated in a conventional oncology care (CC) outpatient clinic. Patients and methods: Six-hundred and forty-seven patients were included in this cross-sectional cohort study and had to fill in questionnaires [health-related quality of life (QoL) (Functional Assessment of Cancer Therapy—General Scale), depression and anxiety (Hospital Anxiety and Depression Scale), fatigue (Multidimensional Fatigue Inventory) and expectancies toward treatment]. Clinical data were extracted from medical records. This study presents the comparison of both cohorts. Results: Patients in the homeopathy cohort are younger, better educated and more often employed than patients in the CC cohort. The most pronounced differences indicate longer disease histories and different diagnostic and clinical pretreatment variables. Despite the clinical differences, QoL as well as anxiety, depression and fatigue was similar in both the groups. Conclusions: Homeopathic treatment is sought by cancer patients at a different phase during the course of the disease, which has particular implications for research. However, expectancies toward the benefit of the treatment as well as QoL data are simila

Dynamical typicality of quantum expectation values

We show that the vast majority of all pure states featuring a common expectation value of some generic observable at a given time will yield very similar expectation values of the same observable at any later time. This is meant to apply to Schroedinger type dynamics in high dimensional Hilbert spaces. As a consequence individual dynamics of expectation values are then typically well described by the ensemble average. Our approach is based on the Hilbert space average method. We support the analytical investigations with numerics obtained by exact diagonalization of the full time-dependent Schroedinger equation for some pertinent, abstract Hamiltonian model. Furthermore, we discuss the implications on the applicability of projection operator methods with respect to initial states, as well as on irreversibility in general.Comment: 4 pages, 1 figure, accepted for publication in Phys. Rev. Let

Semiclassical quantization of the hydrogen atom in crossed electric and magnetic fields

The S-matrix theory formulation of closed-orbit theory recently proposed by Granger and Greene is extended to atoms in crossed electric and magnetic fields. We then present a semiclassical quantization of the hydrogen atom in crossed fields, which succeeds in resolving individual lines in the spectrum, but is restricted to the strongest lines of each n-manifold. By means of a detailed semiclassical analysis of the quantum spectrum, we demonstrate that it is the abundance of bifurcations of closed orbits that precludes the resolution of finer details. They necessitate the inclusion of uniform semiclassical approximations into the quantization process. Uniform approximations for the generic types of closed-orbit bifurcation are derived, and a general method for including them in a high-resolution semiclassical quantization is devised

Consideration of the Mechanisms for Tidal Bore Formation in an Idealized Planform Geometry

A tidal bore is a positive wave traveling upstream along the estuary of a river, generated by a relatively rapid rise of the tide, often enhanced by the funneling shape of the estuary. The swell produced by the tide grows and its front steepens as the flooding tide advances inland, promoting the formation of a sharp front wave, i.e., the tidal bore. Because of the many mechanisms and conditions involved in the process, it is difficult to formulate an effective criterion to predict the bore formation. In this preliminary analysis, aimed at bringing out the main processes and parameters that control tidal bore formation, the degrees of freedom of the problem are largely reduced by considering a rectangular channel of constant width with uniform flow, forced downstream by rising the water level at a constant rate. The framework used in this study is extremely simple, yet the problem is still complex and the solution is far from being trivial. From the results of numerical simulations, three distinctive behaviors emerged related to conditions in which a tidal bore forms, a tidal bore does not form, and a weak bore forms; the latter has a weakly steep front and after the bore formed it rapidly vanishes. Based on these behaviors, some criteria to predict the bore formation are proposed and discussed. The more effective criterion, suitably rearranged, is checked against data from real estuaries and the predictions are found to compare favorably with the available data