Probability density of irradiance fluctuations observed over terrestrial ranges

The irradiance fluctuations imposed on a laser beam that has propagated over horizontal terrestrial paths in the range of 2 to 24 km are compared to lognormal (LN) and gamma-gamma (GG) distributions. For the direct links reported here the irradiance fluctuations follow a LN distribution except in cases of weak turbulence, characterized by a scintillation index of less than 1 and a Fried parameter larger than the receiver aperture, in which case the GG distribution gives an improved fit. In very weak turbulence the difference between the two distributions is insignificant.     

Gas chromatography/mass spectrometry as a suitable tool for the Li-ion battery electrolyte degradation mechanisms study

To allow electric vehicles to be powered by Li-ion batteries, scientists must understand further their aging processes in view to extend their cycle life and safety. For this purpose, we focused on the development of analytical techniques aiming at identifying organic species resulting from the degradation of carbonate-based electrolytes (EC-DMC/LiPF(6)) at low potential. As ESI-HRMS provided insightful information to the mechanism and chronological formation of ethylene oxide oligomers, we implemented "gas" GC/MS experiments to explore the lower mass range corresponding to highly volatile compounds. With the help of chemical simulation tests, we were able to discriminate their formation pathways (thermal and/or electrochemical) and found that most of the degradation compounds originate from the electrochemically driven linear alkyl carbonate reduction upon cycling and to a lesser extent from a two-step EC reduction. Deduced from these results, we propose an overall electrolyte degradation scheme spanning the entire mass range and the chemical or electrochemical type of processes.     

Twin mirrors for laser interferometric gravitational-wave detectors

Gravitational-wave detectors such as Virgo and the laser interferometric gravitational-wave observatory (LIGO) use a long-baseline Michelson interferometer with Fabry-Perot cavities in the arms to search for gravitational waves. The symmetry between the two Fabry-Perot cavities is crucial to reduce the interferometer's sensitivity to the laser amplitude and frequency noise. To this purpose, the transmittance of the mirrors in both cavities should be as close as possible. This paper describes the realization and the characterization of the first twin large low-loss mirrors with transmissions differing by less than 0.01%.     

Hypoglycaemia‐free artificial pancreas project

Driving blood glycaemia from hyperglycaemia to euglycaemia as fast as possible while avoiding hypoglycaemia is a major problem for decades for type‐1 diabetes and is solved in this study. A control algorithm is designed that guaranties hypoglycaemia avoidance for the first time both from the theory of positive systems point of view and from the most pragmatic clinical practice. The solution consists of a state feedback control law that computes the required hyperglycaemia correction bolus in real‐time to safely steer glycaemia to the target. A rigorous proof is given that shows that the control‐law respects the positivity of the control and of the glucose concentration error: as a result, no hypoglycaemic episode occurs. The so‐called hypo‐free strategy control is tested with all the UVA/Padova T1DM simulator patients (i.e. ten adults, ten adolescents, and ten children) during a fasting‐night scenario and in a hybrid closed‐loop scenario including three meals. The theoretical results are assessed by the simulations on a large cohort of virtual patients and encourage clinical trials.Inspec keywords: biochemistry, medical control systems, blood, diseases, medical computing, closed loop systems, biomedical equipment, state feedback, patient treatment, patient monitoring, biomedical measurement, physiological models, sugarOther keywords: fasting‐night scenario, hybrid closed‐loop scenario, hypoglycaemia‐free artificial pancreas project, blood glycaemia, euglycaemia, type‐1 diabetes, control algorithm, guaranties hypoglycaemia avoidance, pragmatic clinical practice, state feedback control law, required hyperglycaemia correction bolus, rigorous proof, control‐law, glucose concentration error, hypo‐free strategy control     

The plastic-crystalline phase of succinonitrile as a universal matrix for solid-state ionic conductors

Solid ionic conductors are actively sought for their potential application in electrochemical devices, particularly lithium batteries. We have found high ionic conductivity for a large variety of salts dissolved in the highly polar medium based on the plastic-crystal form of succinonitrile (N[triple bond]C[bond]CH(2)[bond]CH(2)[bond]C[triple bond]N). Its high diffusivity, plasticity and solvating power allowed the preparation of a large number of materials with high ionic conductivity, reaching values of 3 mS cm(-1) at 25 degrees C (two orders of magnitude above polymers). Their ease of preparation and processing allowed us to study the influence of the solute on ionic conduction within this medium. Comparisons revealed a dichotomy between plastic crystals and conventional polymer media. The usefulness of these new, easily processed electrolytes was asserted in electrochemical tests with lithium intercalation electrodes.     

Degradable and bioresorbable polymers in surgery and in pharmacology: beliefs and facts

The number of articles dealing with degradable polymers and macromolecules is increasing rapidly and the number of proposed compounds as well. However, not all have a high potential for effective applications. This contribution examines first the criteria to be taken into account when commercialisation of polymeric compounds and devices aimed at helping the body for a limited period of time, i.e. the healing time, is the main goal. What is really known is tentatively analysed by considering some of the candidates present in literature confronted to the targeted potential applications. Tentative comments are made on what should be done to qualify a candidate. Last but not least, trends in the search for polymers to be exploited in presently attracting areas such as bioresorbable stents, hydrogels to deliver bioactive macromolecules like proteins and polynucleotides or polyelectrolytes to temporarily complex charged biomacromolecules like proteins or genes are considered.     

Attribution et vécu émotionnel post-divorce.

Examined the relationship between postdivorce adjustment, attachment to ex-partner, and attributions for marriage failure using 97 female and 30 male divorced or separated Ss. Questionnaire data revealed that Ss who attributed marriage breakup to themselves were significantly more attached to their ex-partners and less adjusted than Ss who attributed their breakup to their ex-partners or to interactional factors. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)