Relativistic treatment of harmonics from impurity systems in quantum wires

Within a one particle approximation of the Dirac equation we investigate a defect system in a quantum wire. We demonstrate that by minimally coupling a laser field of frequency omega to such an impurity system, one may generate harmonics of multiples of the driving frequency. In a multiple defect system one may employ the distance between the defects in order to tune the cut-off frequency.Comment: 9 pages Latex, 8 eps figures, section added, numerics improve

Particles-vortex interactions and flow visualization in He4

Recent experiments have demonstrated a remarkable progress in implementing and use of the Particle Image Velocimetry (PIV) and particle tracking techniques for the study of turbulence in He4. However, an interpretation of the experimental data in the superfluid phase requires understanding how the motion of tracer particles is affected by the two components, the viscous normal fluid and the inviscid superfluid. Of a particular importance is the problem of particle interactions with quantized vortex lines which may not only strongly affect the particle motion, but, under certain conditions, may even trap particles on quantized vortex cores. The article reviews recent theoretical, numerical, and experimental results in this rapidly developing area of research, putting critically together recent results, and solving apparent inconsistencies. Also discussed is a closely related technique of detection of quantized vortices negative ion bubbles in He4.Comment: To appear in the J Low Temperature Physic

A large diversity of hydrated minerals formed from interaction with hydrothermal fluids in Noctis Labyrinthus Mars

International audienc

Recommendations for ECG diagnostic coding

The Oxford dictionary defines code as "a body of laws so related to each other as to avoid inconsistency and overlapping". It is obvious that natural language with its high degree of ambiguity does not qualify as a code in the sense of this definition. Everyday experiences provide ample evidence that natural language, because of its richness and lack of uniqueness, is subject to multiple interpretations and thus not suitable for conveying ideas or data in an unequivocal, uniform and concise manner. For this reason codes have been developed and used in several areas of medicine [1-3] to describe, document, and transmit qualitative medical data. It is rather surprising that electrocardiography has been able to exist for so long without any formalized language to describe its findings. Increased use of electrocardiograms in epidemiology, large scale electrocardiographic studies and last but not least computerized EeG interpretation have provided incentives to develop codes. Initial efforts in this direction [4-6] were primarily guided by loc al needs for improved storage, retrieval and handling of information; without major modifications they do not, however, satisfy all the requirements one expects from an EeG code today. Nevertheless, the experience gained in the use of these early EeG codes provides an important source of information on which to build specifications for a new or expanded code. It is significant that several members of this working group have been extensive users of the Booth-Hull code [4] and the Utrecht coding system [5]