EMU evolution

Evolution of Extravehicular Mobility Unit (EMU) technology is necessary to support the Extravehicular Activity (EVA) requirements of the Space Station Freedom Program and those of the Space Exploration Initiative (SEI). Key qualities supporting long-duration missions include technologies that are highly reliable, durable, minimize logistics requirements, and are in-flight maintainable and serviceable. While these qualities are common to SSF and SEI EVA, development paths will differ where specific mission requirements impose different constraints. Development of reusable, regenerative technologies is necessary to minimize the logistics penalties. Increased battery discharge/recharge cycle life and usable wet life, compact high current density fuel cells, reusable CO2 absorbing media, and thermal radiation coupled with venting heat rejection technologies are just some methods of reducing consumables. Development must strive for durable, reliable systems that are in-flight serviceable and maintainable, which are vital for missions where logistics capabilities are extremely constrained. Key areas include suit components (e.g., gloves, boots, and cooling garments), and life support hardware such as fans, pumps, instrumentation, and emergency O2 systems. Higher pressure suits will reduce EVA prebreathe requirements and pre-EVA operations overall. Many challenges of higher pressure suits have been addressed by on-going development. Emphasis on glove development is necessary to provide low fatigue, dexterous glove mobility at higher suit pressures. Minimum impact hooks and scars which support an advanced SSF EMU have been identified. These accommodations permit upgrades that support servicing of low volume, high pressure oxygen systems, and hydrogen technologies such as fuel cell, and venting hydrogen heat rejection systems

Democratising data to address health system inequities in Australia

Understanding the health status of a population or community is crucial to equitable service planning. Among other uses, data on health status can help local and national planners and policy makers understand patterns and trends in current or emerging health and well-being, especially how disparities relating to geography, ethnicity, language and living with disability influence access to services. In this practice paper we draw attention to the nature of Australia’s health data challenges and call for greater ‘democratisation’ of health data to address health system inequities. Democratisation implies the need for greater quality and representativeness of health data as well as improved access and usability that enable health planners and researchers to respond to health and health service disparities efficiently and cost-effectively. We draw on learnings from two practice examples, marred by inaccessibility, reduced interoperability and limited representativeness. We call for renewed and urgent attention to, and investment in, improved data quality and usability for all levels of health, disability and related service delivery in Australia

Continuous measurement of stream pH. Evaluation of procedures and comparison of resulting hydrogen ion budgets with those from flow-weighted integrating samplers.

The pH of Tarn Head Beck, an acidic upland stream in the English Lake District, was continuously recorded for a period of 6 months. Preliminary measurements showed that electrodes should be completely immersed to avoid problems associated with the difference in temperature between water and air. For a site without mains power good results were obtained by deploying electrodes within the stream in purpose-built units. There was good agreement between these directly deployed electrodes and electrodes immersed in an auxiliary flow in an instrument box on the bank of the stream. Spot measurements taken from the continuous record also compared well with dip samples collected into bottles and subsequently measured in the laboratory. There were no problems associated with long-term drift under field conditions, even though preliminary laboratory experiments had indicated that the stability of the electrodes would be inadequate. Electrodes appear to perform more reproducibly after long-term immersion in a relatively constant medium. Measurements of hydrogen ion fluxes over 14 day periods obtained using an automatic integrating sampler and the total flow were compared with measurements calculated from continuously recorded pH and flow. Although agreement was good at low and medium flow, the integrating sampler results appeared to underestimate results at high flow. For annual budget studies, the use of event triggered samplers is recommended

Reduction des substrats phosphores par electrochimie

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : AR 14052 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

From Environmentally Friendly Reusable Ionic-Tagged Ruthenium-Based Complexes to Industrially Relevant Homogeneous Catalysts: Toward a Sustainable Olefin Metathesis

International audienceThis account describes our investigations, over the past decade, on the design of ruthenium-based complexes dedicated to sustainable olefin metathesis. An overview of different classes of catalysts, from reusable ionically tagged systems to industrially relevant homogeneous complexes, including latent catalysts, is disclosed. Challenging applications involving these robust complexes, including the valorization of olefin feedstock derived from biomass into valuable building blocks, are also discussed. 1 Introduction 2 Reusable Ionically Tagged Ruthenium Complexes for Olefin Metathesis in RTILs and Related SILP Processes 2.1 The First Generation: Olefin Metathesis in [BMIM]PF6 2.2 The Second Generation: Olefin Metathesis in Biphasic [BMIM]PF6/ ­Toluene Medium 2.3 Initiation Rates Versus Recyclability: The Linker Choice 2.4 Modulation of the NHC Unit: Toward the Optimum Reusable Catalytic System 2.5 Introduction of Aminocarbonyl-Based Linkers 2.6 The SILP Technology: Toward Olefin Metathesis in Continuous Flow 2.7 Catalysts Bearing an Ionically Tagged NHC Ligand 3 Structural Modifications Around the Styrenyl Ether Ligand for the Control of Initiation Rates: Toward a Library of Industrially Relevant Homogeneous Hoveyda-Type Complexes 3.1 Aminocarbonyl-Functionalized Complexes (M7) 3.1.1 Industrial-Scale Production of Complexes M71-SIPr and M73-SIPr 3.2 Aminosulfonyl-Tagged Ruthenium Complexes 3.3 Oxazine- and Oxazinone-Functionalized Ruthenium Complexes 3.4 Synthetic Applications 3.4.1 Production of High Added-Value Molecules 3.4.2 Valorization of Bio-Sourced Molecules 4 Ruthenium Complexes Bearing Unsymmetrical Cycloalkyl-NHCs: Efficient and Selective Catalysts for the Metathesis of α-Olefins 4.1 A Low-Cost Synthetic Route: The Arduengo Process Revisited Providing Unsymmetrical Unsaturated (U2)-NHCs and their Corresponding Ruthenium Complexes 4.2 Application in the Selective Metathesis of α-Olefins from Bio-Sourced Fischer-Tropsch Feeds 5 Design of Latent Ruthenium Complexes 5.1 A 'Dormant' Catalyst Bearing a Chelating Carboxylate Ligand 5.2 Ruthenium-Indenylidene Catalysts Bearing a Bidentate Picolinate Ligand 5.3 Serendipitous Discovery of Cationic Bis-NHC Hoveyda-Type Complexes 6 Conclusions and Outlook. © Georg Thieme Verlag Stuttgart · New York