Noise and thermal stability of vibrating micro-gyrometers preamplifiers

The preamplifier is a critical component of gyrometer's electronics. Indeed the resolution of the sensor is limited by its signal to noise ratio, and the gyrometer's thermal stability is limited by its gain drift. In this paper, five different kinds of preamplifiers are presented and compared. Finally, the design of an integrated preamplifier is shown in order to increase the gain stability while reducing its noise and size.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Corrosion in MEA units for CO2 capture: Pilot plant studies

AbstractAmong the technologies that are under study for CO2 capture from flue gas, the separation process using monoethanolamine (MEA) could be the first to be available for immediate industrial applications in the next few years. The principles of CO2 separation using alkanolamines were discovered nearly a century ago. The process has been applied successfully for several decades in areas such as natural gas processing or coal gasification. The application to flue gas treatment was introduced in the early 1980s, but was not widespread.In such industrial processes, corrosion represents one of the major operational problems. For the capture of CO2 from flue gas using MEA, the problem is even more critical since (i) MEA is one of the most corrosive amine when compared to secondary or tertiary amines that are also used for gas sweetening, and (ii) flue gas contains a certain amount of oxygen, which can react with the amine to form corrosive degradation products.In the framework of the CAPRICE project, which is an International cooperation and exchange project supported by the EU, The International Test centre for CO2 Capture from the University of Regina (CA) and IFP (F) have shared their experience on corrosion monitoring from CO2 capture pilot plants. The first pilot plant facility is owned by ITC. It has a capacity to capture 1 ton CO2/day from a natural gas burner. It is equipped with corrosion control instruments and other monitoring systems. The second pilot plant is located in a coal fired power station in Esbjerg (DK). It was built with the financial support of the UE through the CASTOR project under the lead of IFP. It has been in operation since early 2006, and has a capacity of 1.0 ton CO2/hour. It is equipped with weight loss coupons for corrosion evaluation at different locations in the process.This paper presents the major results of corrosion testing from both pilot plants under MEA operation. It appeared from both pilot plants that the areas most susceptible to corrosion were the stripper inlet and outlet, with corrosion rates around 1 mm.year−1 for carbon steel

Architecture for Integrated Mems Resonators Quality Factor Measurement

In this paper, an architecture designed for electrical measurement of the quality factor of MEMS resonators is proposed. An estimation of the measurement performance is made using PSPICE simulations taking into account the component's non-idealities. An error on the measured Q value of only several percent is achievable, at a small integration cost, for sufficiently high quality factor values (Q > 100).Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Damping of optomechanical disks resonators vibrating in air

We report on miniature GaAs disk optomechanical resonators vibrating in air in the radiofrequency range. The flexural modes of the disks are studied by scanning electron microscopy and optical interferometry, and correctly modeled with the elasticity theory for annular plates. The mechanical damping is systematically measured, and confronted with original analytical models for air damping. Formulas are derived that correctly reproduce both the mechanical modes and the damping behavior, and can serve as design tools for optomechanical applications in fluidic environment

Integrating the multiple perspectives of people and nature in place-based marine spatial planning

Marine spatial planning (MSP) has emerged as a tool to enable marine ecosystem-based management that seeks to balance human demands for ocean space with environmental protection. However, there is a history of thinking about our ocean systems as spaces, not places. As a result, most MSPs have been implemented without consideration of place. The relationship between people and the rest of nature is at the core of the UN SDGs (Sustainable Development Goals). Due to significant knowledge gaps in sociocultural connections, people and their place-based perspectives and needs are often overlooked in the MSP process. New approaches are required to equip societies with information to inform sustainable ocean planning relevant to environmental change and the local sociocultural context. We encourage the inclusion of a distinct place-based characteristic in MSP and argue that bringing in the concepts of space and place from the discipline of geography can enable a broader view of the seascape in MSP. Here, we provide five core considerations of place-based MSP that include: (1) sense of place; (2) social-ecological systems; (3) ocean and human health; (4) multiple ways of knowing; and (5) social knowledge. We review available methods and suggest a multi-evidence-based approach that can highlight dynamic eco-cultural connections between people and the biophysical patterns and processes of interlinked landscapes and seascapes. Moving towards place-based MSP can help to solve three important issues in the current context of global socio-environmental transformations. First, these key concepts are relevant for interdisciplinary science, as solving problems raised by MSP requires more than superimposing spatial layers of scientific knowledge. Second, marine planning and management is less efficient if policies are not integrated and if issues are addressed by each individual sector rather than in a holistic manner. Third, a place-based approach accounts for individual and collective values and may open new ways to solve governance issues. A shift from understanding and managing ocean spaces to including ocean places can support progress towards sustainable and equitable MSP goals

Palladium-catalysed annulation reaction of allenyltins with beta-iodo vinylic acids: selective synthesis of alpha-pyrones

Palladium-catalysed regio- and stereoselective annulation of allenyl stannanes by beta-iodo vinylic acids gives the corresponding alpha-pyrones in high yields. This annulation most probably proceeds through a Stille reaction/cyclisation sequence