Coherence creation in an optically thick medium by matched propagation of a chirped laser pulse pair

We consider the simultaneous propagation of a pair of Raman-resonant, frequency-modulated (chirped) laser pulses in an optically thick medium, modeled by an ensemble of $\Lambda$-atoms. A self-organization ('matching`) effect is shown for the chirped pulse pair, which leads to a quasi-lossless propagation. Furthermore, we demonstrate that a well-defined coherent superposition of the atomic ground states and, correspondingly, a coherence is robustly created in the medium that can be controlled by amplitudes of the laser pulses. The proposed scheme can be applied to substantially increase the efficiency of the optical wave mixing processes, as well as in other nonlinear processes where the initial preparation of a spatially extended medium in a coherent superposition state is required

Modern mechanisms make manless Martian mission mobile: Spin-off spells stairclimbing self-sufficiency for earthbound handicapped

Concepts were developed for three wheel chairs from progressively improving designs of a proposed unmanned roving vehicle for the surface exploration of Mars; as a spin-off, a concept for a stair-climbing wheel chair was generated. The mechanisms employed in these are described. The Mars mission is envisioned using the booster rockets and aeroshell of the Viking missions

The chiral transition as an Anderson transition

At low temperature the low-lying QCD Dirac spectrum obeys random matrix statistics. Recently we found that above $T_{c}$ the lowest part of the spectrum consists of localized modes that obey Poisson statistics. An interesting implication of this is that as the system crosses $T_{c}$ from above, the spectral statistics at $\lambda=0$ changes from Poisson to random matrix. Here we study this transition and its possible implications for the finite temperature transition of QCD-like theories.Comment: 7 pages, 4 figures, Contribution to the 32nd International Symposium on Lattice Field Theory (Lattice 2014), 23-28 June 2014, Columbia University, New York, NY, US

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

Problems related to the design and control of an autonomous rover for the purpose of unmanned exploration of the planets were considered. Building on the basis of prior studies, a four wheeled rover of unusual mobility and maneuverability was further refined and tested under both laboratory and field conditions. A second major effort was made to develop autonomous guidance. Path selection systems capable of dealing with relatively formidable hazard and terrains involving various short range (1.0-3.0 meters), hazard detection systems using a triangulation detection concept were simulated and evaluated. The mechanical/electronic systems required to implement such a scheme were constructed and tested. These systems include: laser transmitter, photodetectors, the necessary data handling/controlling systems and a scanning mast. In addition, a telemetry system to interface the vehicle, the off-board computer and a remote control module for operator intervention were developed. Software for the autonomous control concept was written. All of the systems required for complete autonomous control were shown to be satisfactory except for that portion of the software relating to the handling of interrupt commands

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

Problems related to an unmanned exploration of the planet Mars by means of an autonomous roving planetary vehicle are investigated. These problems include: design, construction and evaluation of the vehicle itself and its control and operating systems. More specifically, vehicle configuration, dynamics, control, propulsion, hazard detection systems, terrain sensing and modelling, obstacle detection concepts, path selection, decision-making systems, and chemical analyses of samples are studied. Emphasis is placed on development of a vehicle capable of gathering specimens and data for an Augmented Viking Mission or to provide the basis for a Sample Return Mission

Managing Access to Biobanks:How Can We Reconcile Privacy and Public Interests in Genetic Research?

This article is concerned with the ultimate objectives of genetic biobanks set up to promote the public interest—being the sharing of samples and data for medical research—and the consequences for personal privacy of realising them. Our aim is to chart the values, interests and principles in play, to consider the challenges of realizing biobanking objectives on a global scale, and to propose viable ways forward that ensure, as far as possible, that access provisions remain fit for purpose throughout the entire life of a biobank, while adequately protecting the privacy interests at stake. It is argued that key features in any robust access model must include mechanisms to (a) maintain participant trust in management of the resource and to measure and respond to participants’ expectations, (b) facilitate and promote the sharing of benefits, and (c) respond timeously and effectively to new challenges

Anticorps et Protéides

Sandor Georges. Anticorps et Protéides. In: Bulletin de l'Académie Vétérinaire de France tome 101 n°8, 1948. pp. 346-348