Thin crystalline silicon solar cells based on epitaxial films grown at 165 °C by RF-PECVD

We report on heterojunction solar cells whose thin intrinsic crystalline absorber layer has been obtained by plasma enhanced chemical vapor deposition at 165 °C on highly doped p-type (1 0 0) crystalline silicon substrates. We have studied the effect of the epitaxial intrinsic layer thickness in the range from 1 to 2.5 μm. This absorber is responsible for photo-generated current whereas highly doped wafer behave like electric contact, as confirmed by external quantum efficiency measurements and simulations. A best conversion efficiency of 7% is obtained for a 2.4 μm thick cell with an area of 4 cm², without any light trapping features. Moreover, the achievement of a fill factor as high as 78.6% is a proof that excellent quality of the epitaxial layers can be produced at such low temperatures.     

Semisynthesis and screening of a small library of pro-apoptotic squamocin analogues: selection and study of a benzoquinone hybrid with an improved biological profile

Acetogenins of Annonaceae, including squamocin (1), exert spectacular cytotoxicity and the most potent inhibition of NADH:ubiquinone oxidoreductase known so far. Cell death induced by these natural products was identified as apoptosis and was thought to be linked to alterations in mitochondrial function. Quinone-squamocin hybrid compounds were semisynthesized and evaluated for their pro-apoptotic properties with a screening method based on dissipation of the mitochondrial transmembrane potential (DeltaPsim). Herein, we report a short one-step synthesis of a squamocin carboxylic acid analogue. For the first time on a natural product, the radical decarboxylation and quinone addition reaction has enabled preparation of a library of squamocin-quinone hybrids and four other analogues. Squamoquinone, tenfold more potent than squamocin as an inducer of apoptosis, emerged as a promising compound, as it induces apoptosis through a mitochondrial caspase-dependent pathway.     

A versatile nanotechnology to connect individual nano-objects for the fabrication of hybrid single-electron devices

We report on the high yield connection of single nano-objects as small as a few nanometres in diameter to separately elaborated metallic electrodes, using a 'table-top' nanotechnology. Single-electron transport measurements validate that transport occurs through a single nano-object. The vertical geometry of the device natively allows an independent choice of materials for each electrode and the nano-object. In addition ferromagnetic materials can be used without encountering oxidation problems. The possibility of elaborating such hybrid nanodevices opens new routes for the democratization of spintronic studies in low dimensions.     

The structure of academic self-concepts revisited: The nested Marsh/Shavelson model.

The nested Marsh/Shavelson (NMS) model integrates structural characteristics of academic self-concepts that have proved empirically incompatible in previous studies. Specifically, it conceives of academic self-concepts to be subject specific, strongly separated across domains, and hierarchically organized, with general academic self-concept at the top of the hierarchy. In Part 1 of the present study, data from a representative sample of eighth graders (N = 4,847) from Luxembourg showed that the NMS model captures the structure of self-concepts in six core subjects. In Part 2, the NMS model was integrated into a longitudinal extended internal/external frame-of-reference model. The developmental dynamics between general and subject-specific achievement, as measured in Grade 6, and the corresponding academic self-concepts in Grade 8 were examined, with data from a subsample of students (N = 3,045). Given its theoretical and empirical bases, the NMS model has clear potential to guide future research on academic self-concepts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative behavioral effects between synthetic 2,4,5-trimethylthiazoline (TMT) and the odor of natural fox (Vulpes vulpes) feces in mice.

Synthetic 2,4,5-trimethylthiazoline (TMT)--a component of red fox (Vulpes vulpes) feces--is frequently used to induce unconditioned fear in rodents. Surprisingly, direct comparison between TMT and natural fox feces odor is almost nonexistent. In this study, Experiment 1 compared the avoidance in relation to TMT concentration, natural fox feces, and gender of fox and mice. Results show that the avoidance is (a) higher with either pure or 50% TMT as compared to natural fox feces, whereas the difference is slight with 10% TMT, and (b) significantly higher for the female mouse group compared to the male mouse group with TMT as well as natural fox feces. In addition, no clear difference in effect was observed between male and female fox feces. Experiment 2 compared behavioral parameters recorded as an index of fear and anxiety, general activity, and avoidance in elevated plus-maze and open-field chamber between 10% TMT and natural fox feces in relation to the estrus cycle of the mice. Results show no cycle period effect--except for the avoidance parameter "distance to odorant"--and no different effects between 10% TMT and natural fox feces except for freezing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The social acceptability of AI systems: Legitimacy,epistemology and marketing

The expression, ‘the culture of the artificial’ results from the confusion between nature and culture, when nature mingles with culture to produce the ‘artificial’ and science becomes ‘the science of the artificial’. Artificial intelligence can thus be defined as the ultimate expression of the crisis affecting the very foundation of the system of legitimacy in Western society, i.e. Reason, and more precisely, Scientific Reason. The discussion focuses on the emergence of the culture of the artificial and the radical forms of pragmatism, sophism and marketing from a French philosophical perspective. The paper suggests that in the postmodern age of the ‘the crisis of the systems of legitimacy’, the question of social acceptability of any action, especially actions arising out of the application of AI, cannot be avoided.     

Aerobic and anaerobic profiles, heart rate and match analysis in older soccer players

The aim of the present study was to provide aerobic (maximal oxygen consumption--VO2max) and anaerobic [jump tests: counter-movement jump (CMJ) and bounce jump (BJ); and running tests: 10 m sprint and 10 m dribbling the ball (10 mDB)] profiles of older soccer players (n = 12), and heart rate (HR), blood lactate accumulation (La) and match analysis (individual motor activity and team behaviour) aspects of a soccer match. The maximal aerobic test values were: HRmax, 154 +/- 14 beat min(-1); maximal power, 160 +/- 24 W; VO2peak, 36.3 +/- 11.3 ml kg(-1) min(-1); peak La, 8.2 +/- 1.8 mM. Jump test values were: CMJ, 21.2 +/- 4.5 cm; BJ, 17.3 +/- 4.8 cm. Running performances were: 10 m sprint, 2.06 +/- 0.36 s; 10 mDB, 2.17 +/- 0.21 s. Running showed similar values in the two halves (first half, 82%; second half, 88%), while walking lasted longer during the second half. Regarding the technical aspects of the match, 42% of the consecutive passes made in possession of the ball exceeded three passes, indicating that their play was structured in a cooperative manner. Older soccer players succeeded in maintaining good aerobic and anaerobic physical capability.     

Magnetic microchip traps and single-atom detection

Microchip traps provide a promising approach to quantum information processing and communication (QIPC) with neutral atoms: strong and complex potentials can be produced for acting on the qubit atoms, and the potentials can be scaled to higher qubit numbers by virtue of the microfabrication process. We describe experimental results that are relevant to use in QIPC, such as the transport of Bose-Einstein-condensed atomic ensembles along the chip surface with the help of a magnetic conveyor belt. The second part of the paper is devoted to single-atom detection on the chip.