Carrier dynamics of electrons and holes in moderately doped silicon

A time-domain spectroscopic technique, based on the generation and detection of a collimated beam of subpicosecond broadband terahertz pulses, is used to measure the absorption and dispersion of n- and p-type silicon, with resistivities of 0.1, 1, and 10 Ohm-cm in the submillimeter range of 0.1-2 THz. From the transmission measurements performed at room temperature and at 80 K, the absorption and dispersion, and concomitantly the full complex conductivity, of the doped silicon could be obtained. The results provide an accurate view on the dynamics of the electrons and the holes. Although the simple Drude model, with an energy-independent relaxation time, gives a surprisingly accurate description of the observed carrier dynamics, the measurements do show that some refinements are needed. An extended model, with an energy-dependent carrier-relaxation rate, can explain most of the observed deviations from the simple Drude model.Peer reviewedElectrical and Computer Engineerin

LDH in physical, chemical, bio-chemical and life science.

After a brief recall of layered double hydroxides (LDH) features to underline the reasons of the present exponential growth of the number of patents and papers dealing with application in several sometime unexpected fields, the chapter will deal only with selected applications, namely, (1) environmental protection and agricultural aids; (2) heterogeneous catalysis; (3) nanofillers for polymers; (4) photophysics and photochemistry; (5) biotechnology; and (6) pharmaceutical technology and cosmetics. Also are described the preparation of LDH nanocrystals and their exfoliation into individual layers to be used as building blocks for the layer-by-layer deposition of functional thin films containing luminescent dyes, molecular magnets, quantum dots for potential application in several electronic devices. At the end of this chapter, a brief note describes other potential niche applications and future developments

Formation par simulation à l’annonce d’une malformation fœtale découverte en échographie de dépistage : résultats d’une étude pilote

International audienceBreaking bad news (BBN) to a pregnant woman with fetal abnormalities (FA) on ultrasound (US) examination is a challenge. Announcement technique influences patient reaction. Physicians receive little training in BBN. The simulation and using a BBN protocol as the English SPIKES protocol which guides the announcement consultation according to 6 steps (Setting Up, Perception, Invitation, Knowledge, Emotions and Empathy, Strategy and Summary) can be used for this teaching. The objective was to assess feasibility simulation scenarii of BBN for FA discovered during US and to evaluate the usefulness of SPIKES protocol in this situation.Methods: Two scenarios have been created combining US simulator (US Mentor, Symbionix®) with simulated patient (SP). Scenarii objectives were to diagnose FA and break it to SP. Checklist derived from SPIKES was fulfilled by two investigators thanks to video recording, the SP and every participant (residents, physicians, fetal medicine specialists [FMS]). Participants filled out survey about the usefulness of this exercise too.Results: Nine physicians (3 residents, 4 physicians, 2 FMS) produced 18 scenarii. Seventy-eight percent of physicians thought simulation was like real situation of BBN during US examination. Majority of participant (88%) found that this simulation training could help them to increase their ability to BBN and that it can be used to teach residents (89%) or physicians (100%). FMS had better SPIKES checklist than physicians (P<0,05).Conclusion: Simulation scenario of BBN for FA discovered during US is feasible by combining US simulator and SP. SPIKES protocol can be useful but a validated checklist should be created