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The diffusion of the heavy alkali element rubidium (Rb) in Cu(In,Ga)Se2 (CIGS) layers was investigated over a temperature range from 148 °C to 311 °C by outdiffusion from a rubidium fluoride layer. The diffusion profiles were measured by secondary ion mass spectrometry. By using CIGS layers with different grain sizes, diffusion along grain boundaries could be distinguished from diffusion into the grain interior. Rb was found to diffuse from the CIGS surface along grain boundaries but also within the grain bulk. Based on these data, the slower diffusion coefficient in the volume can be described by the Arrhenius equation DV (Rb) = 3.8·10−8 exp(−0.44 eV/kBT) cm2 s−1 and the fast diffusion along the grain boundaries by DGB (Rb) = 5.7·10−9 exp(−0.29 eV/kBT) cm2 s−1. Further, the effect of Na on Rb diffusion was investigated by comparing Rb diffusion into a Na-containing CIGS layer in contrast to Rb diffusion into an alkali-free CIGS layer. This comparison revealed some aspects of the ion exchange mechanism. Finally, the effect of Rb on the solar cell parameters of CIGS thin-film solar cells was investigated. Rb was found to enhance the open-circuit voltage, the fill factor, and charge carrier density in a similar manner as observed for potassium and sodium.

Abstract The Divertor Tokamak Test (DTT) facility has been launched to investigate alternative power exhaust solutions for DEMO. DTT should offer sufficient flexibility to be able to incorporate the best candidate divertor concept (e.g. conventional, Snowflake, Super-X, Double Null, liquid metals). In this paper, the revised up-down symmetric DTT device is presented. The up-down symmetrisation of the device makes it possible to have the reference values of the plasma current up to 5.5 MA and, at the same time, it has an impact on the costs, for which a slight revision of the main parameters has been considered. The DTT alternative magnetic configurations, such as Double Null, SnowFlake, Super-X, Double Super-X and Single Null with reverse triangularity, guarantee suitable constraints on the plasma-wall distance and the plasma elongation. The feasibility of the configurations is evaluated in terms of maximum vertical forces and currents on the PF coils along the scenarios.

The first European mission to Venus (Venus Express) is described. It is based on a repeated use of the Mars Express design with minor modifications dictated in the main by more severe thermal environment at Venus. The main scientific task of the mission is global exploration of the Venusian atmosphere, circumplanetary plasma, and the planet surface from an orbiting spacecraft. The Venus Express payload includes seven instruments, five of which are inherited from the missions Mars Express and Rosetta. Two instruments were specially designed for Venus Express. The advantages of Venus Express in comparison with previous missions are in using advanced instrumentation and methods of remote sounding, as well as a spacecraft with a broad spectrum of capabilities of orbital observations. © Pleiades Publishing, Inc., 2006.

Luminescence thermometry in biomedical sciences is a highly desirable, but also highly challenging and demanding technology. Numerous artifacts have been found during steady-state spectroscopy temperature quantification, such as ratiometric spectroscopy. Oppositely, the luminescence lifetime is considered as the most reliable indicator of temperature thermometry because this luminescent feature is not susceptible to sample properties or luminescence reabsorption by the nanothermometers themselves. Unfortunately, this type of thermometer is much less studied and known. Here, the thermometric properties of Yb3+ ions in Nd0.5RE0.4Yb0.1PO4 luminescent temperature probes were evaluated, aiming to design and optimize luminescence lifetime based nanothermometers. Temperature dependence of the luminescence lifetimes is induced by thermally activated phonon assisted energy transfer from the 2F5/2 state of Yb3+ ions to the 4F3/2 state of Nd3+ ions, which in turn is responsible for the significant quenching of the Yb3+:2F5/2 lifetime. It was also found that the thermal quenching and thus the relative sensitivity of the luminescent thermometer can be intentionally altered by the RE ions used (RE = Y, Lu, La, and Gd). The highest relative sensitivity was found to be SR = 1.22% K−1 at 355 K for Nd0.5Y0.4Yb0.1PO4 and it remains above 1% K−1 up to 500 K. The high sensitivity and reliable thermometric performance of Nd0.5La0.4Yb0.1PO4 were confirmed by the high reproducibility of the temperature readout and the temperature uncertainty being as low as δT = 0.05 K at 383 K.

International audience; In the framework of a French Joint program COVADIS, an innovative system is developed for the simultaneous detection of benzene, toluene and xylenes in indoor air. The present work is mainly focused on the benzene detection. The detection is based on absorbance measurements over the 250 nm-300 nm range with a cooled spectrophotometer. The prototype includes an exposure chamber, which contains five sensors. The sensors are nanoporous disks, whose pore sizes are tailored to efficiently entrap the targeted pollutants. 20 ppb of benzene have been successfully detected within 40 minutes of exposure.

As the Earth warms, carbon sinks on land and in the ocean will weaken, thereby increasing the rate of warming. Although natural mechanisms contributing to this positive climate–carbon feedback have been evaluated using Earth system models, analogous feedbacks involving human activities have not been systematically quantified. Here we conceptualize and estimate the magnitude of several economic mechanisms that generate a carbon–climate feedback, using the Kaya identity to separate a net economic feedback into components associated with population, GDP, heating and cooling, and the carbon intensity of energy production and transportation. We find that climate-driven decreases in economic activity (GDP) may in turn decrease human energy use and thus fossil fuel CO2 emissions. In a high radiative forcing scenario, such decreases in economic activity reduce fossil fuel emissions by 13% this century, lowering atmospheric CO2 by over 100 ppm in 2100. The natural carbon–climate feedback, in contrast, increases atmospheric CO2 over this period by a similar amount, and thus, the net effect including both feedbacks is nearly zero. Our work highlights the importance of improving the representation of climate–economic feedbacks in scenarios of future change. Although the effects of climate warming on the economy may offset weakening land and ocean carbon sinks, a loss of economic productivity will have high societal costs, potentially increasing wealth inequity and limiting resources available for effective adaptation. Significance The response of different economic sectors and energy infrastructure to climate warming is complex and difficult to compare with land and ocean carbon cycle feedbacks. Our analysis provides a framework for assessing such economic responses and comparing climate feedbacks in integrated assessment and earth system models. A better understanding of the potential effect of an economically driven feedback may improve our ability to estimate limits on cumulative emissions necessary to meet specific climate stabilization targets. We find that a net negative feedback from economic damages on fossil fuels may be strong enough to offset the positive feedback from terrestrial and marine ecosystems; however, these economic losses may disproportionately affect vulnerable populations and make climate mitigation more difficult.

International audience; Pipeline networks dominate the oil and gas mid-stream sector, and although the safest means of transportation for oil and gas products, they are susceptible to failures. These failures are due to manufacturing defects, environmental effects, material degradation, or third party interference through sabotage and vandalism. Internet of Things (IoT)-based solutions are promising to address these by monitoring and predicting failures. However, some challenges remain in the deployment of industrial IoT-based solutions, as the reliability, the robustness, the maintainability, the scalability, the energy consumption, etc. This paper is therefore aimed at highlighting potential solutions for detection and mitigation of pipeline failures while addressing the robustness, the cost and scalability issues of such approach efficiently across the network infrastructure, data and service layers.

Abstract With the addition of an energy storage system (ESS) and advanced controls, a hybrid electric propulsion system can considerably improve the fuel economy over a pure mechanical powertrain. However, the high cost and relatively short operating life of the battery ESS constitute a significant portion of the total operation cost (TOC) of an electrified vehicle, particularly for heavy-duty vehicles with a larger ESS. In this work, a new method for generating the optimal energy management strategy (EMS), considering the TOC of a hybrid electric mining truck (HEMT), is introduced. The cost associated with battery performance degradation and operation life-shortening under different battery use patterns is added to form the globally optimal, TOC-based EMS. The optimal EMS under different vehicle operation profiles are identified using dynamic programming (DP) to serve as benchmarks. An intelligent optimal ESS energy management method for achieving the minimum TOC during real-time, open-pit HEMT operations is introduced by combining an artificial neural network (ANN) model and a fuzzy-logic controller (FLC). The new, real-time intelligent optimal EMS led to twenty-one percent TOC reduction of the HEMT over the traditional, pure fuel economy-oriented optimal EMS, and formed the foundation of TOC-based, optimal EMS development for hybrid electric vehicles (HEVs).