Materials Coatings and Enhanced Characterisation for Alkaline Water-Splitting Devices

A number of material coatings were investigated, specifically for 316-grade stainlesssteel electrodes, for use with alkaline water-splitting electrolysis. The aim was to enhancelongevity, particularly with respect to the highly intermittent usage that is typical of renewableenergy generation, and to increase activity. Long-term experiments were conductedover many thousands of cycles of on-off accelerated ageing at constant current density. Theeffects of ageing were analysed using chronopotentiometry, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy, energy dispersivex-ray spectroscopy, x-ray photoelectron spectroscopy and gas chromatography. It was foundthat titanium nitride did not have high activity for the hydrogen evolution reaction (HER),and underwent rapid oxidation and destruction if used as an anode. A new version ofelectrodeposited Raney nickel was developed that demonstrated improved activity, includingan overpotential for the HER at 10mAcm-2 of just 28 mV. As a bifunctional catalystit demonstrated an overpotential at 10mAcm-2 of just 319 mV, making it the second mostactive catalyst known, and certainly the simplest to deposit. This activity was traced to theincreased electrochemical surface area of the coating, which was higher as deposited, andincreased by up to a factor of three after ageing. During surface-area measurements, anapparent anomaly was discovered between results obtained for the same electrode via EISand CV. New methods of equivalent circuit fitting to transient waveforms were developed,and the anomaly was explained by time-domain simulations of the constant-phase elementrepresentation of the double-layer capacitance. A zero-gap electrolyser was constructed inorder to investigate its performance, and it was found that woven stainless-steel mesh couldoperate as a gas-separation membrane

Electrolysing mud: Membraneless electrolysis of water for hydrogen production using montmorillonite-rich marine mud

This paper describes a design for a low-cost membraneless water electrolyser for the production of green hydrogen that used a viscous electrolyte of naturally abundant montmorillonite-rich marine mud in a DEFT (divergent electrode flow through) geometry with stainless steel (304) mesh electrodes. The ratio of smectite to non-swelling clays in the mud was 1:2. The electrolyte was prepared by resuspending the mud in tap-water to remove the salt, and NaOH 1 M added to enhance the ionic conductivity, as measured by both Electrochemical Impedance Spectroscopy (EIS) and by the slope of DC current/voltage curves. Successful separation and collection of the hydrogen and oxygen gas was inferred from the ratio of 2:1 in the volumes of hydrogen and oxygen collected. Both acid and alkali treatments were trialled and it was found that, whereas acid treatment flocculated the mud, adding NaOH increased the dispersion, conductivity and viscosity, and reduced clogging. The conductivity of both the 24% dry mass alkali mud and a control 4% dry mass alkali bentonite suspension increased to that of pure NaOH 1 M when repeatedly electrolysed. Hydrogen and oxygen gas was collected for 10% and 24% dry mass muds. The less viscous 10% dry mass mud showed turbulent liquid-like behaviour which led to gas mixing but the 24% mud showed stable, solid-like flow and reliable gas separation. Three components of the energy efficiency of the electrolysis process are reported and discussed – the voltage efficiency of 42%, a gas collection efficiency of 50% and the auxiliary power efficiency of 60%. The overall energy efficiency due to these three contributing efficiencies, was 13% of the Higher Heating Value of 142 MJ/kg H2 for a current density of 45 mA/cm2. This mud electrolyser may still be considered worth developing for an off-grid, low budget site with a low-power source of renewable energy

The Hydrogen Bike: Communicating the Production and Safety of Green Hydrogen

As the international community aims to reduce its reliance on fossil fuels, green hydrogen has great potential to replace methane as a clean source of fuel. A novel public engagement activity, The Hydrogen Bike, has been developed to demonstrate the production and use of green hydrogen from water. The aim of the activity is to educate, entertain and inform young people and adults so that they have an opportunity to form an opinion about the use of hydrogen as a fuel. Using a novel two-part data collection system participants are briefly surveyed for their opinion on hydrogen before and after participating in The Hydrogen Bike activity. Through this we have found that most participants (73%) are considered to have no opinion or a neutral opinion on hydrogen before participating in The Hydrogen Bike activity. After participation 88% of those who were originally neutral or had no opinion on hydrogen self-reported a positive feeling about hydrogen. The method of data collection was quick, intuitive and suitable for an audience attracted from passing footfall

Trajectory Based Operations and the Legacy Flight Deck: Envisioning Design Enhancements for the Flight Crew

DTFAWA-10-A-80031This study addresses the gap in scientific information at the intersection of Trajectory-Based Operations (TBO), realistic flight deck \u2013 pilot tasking environments, and human performance assessment. The study explored pilot performance, pain points, and system improvements in a human-in-the-loop heuristic evaluation of prototype displays for selected Next Generation Air Transportation System (NextGen) TBO scenarios. Legacy flight deck systems represent the baseline for innovation of TBO concepts. Because \u201cclean sheet\u201d design of both the NAS and the flight deck is seldom possible, designing human-centered \u201cNowGen\u201d interventions for existing systems is a prudent way to evolve toward NextGen. Study Approach: Three legacy and current generation interfaces were adapted using human-centered design heuristics to support Four-dimensional (4D) RTA-TBO, including a Multifunction Control Display Unit (MCDU), an Electronic Flight Bag (EFB), and an integrated Graphical Flight Planning (GFP) system. Seven airline, corporate, and technical pilots evaluated the interfaces in scenarios using different flight phases, weather, and NAS/Air Traffic Control (ATC) conditions. We obtained feedback from pilots on how well the prototyped interfaces supported pilot decision making, how easy they were to learn, their effect on self-reported workload, and the way in which the information was presented. Results: Evaluation participants responded favorably to the MCDU and integrated GFP RTA-prototypes, while the EFB prototype received less favorable feedback. However, the data collected in this study must be considered preliminary, until we have completed more rigorous human factors evaluation and objective pilot performance measurements. The report concludes with our recommendations for further work to develop and refine recommendations for TBO flight deck design requirements and guidance, including refinement and evaluation of EFB design that could support legacy aircraft participation in TBO

Computing and Data Grids for Science and Engineering

We use the term "Grid" to refer to a software system that provides uniform and location independent access to geographically and organizationally dispersed, heterogeneous resources that are persistent and supported. While, in general, Grids will provide the infrastructure to support a wide range of services in the scientific environment (e.g. collaboration and remote instrument control) in this paper we focus on services for high performance computing and data handling. We describe the services and architecture of NASA's Information Power Grid ("IPG") -- an early example of a large-scale Grid -- and some of the issues that have come up in its implementation. Keywords: Grids, distributed computing architecture, distributed resource management 1 Introduction "Grids" (see [1]) are an approach for building dynamically constructed problem solving environments using distributed and federated, high performance computing and data handling infrastructure that manages geographically and organ..

Information Power Grid: Distributed High-Performance Computing and Large-Scale Data Management for Science and Engineering

The term "Grid" refers to distributed, high performance computing and data handling infrastructure that incorporates geographically and organizationally dispersed, heterogeneous resources that are persistent and supported. The vision for NASN's Information Power Grid - a computing and data Grid - is that it will provide significant new capabilities to scientists and engineers by facilitating routine construction of information based problem solving environments / frameworks that will knit together widely distributed computing, data, instrument, and human resources into just-in-time systems that can address complex and large-scale computing and data analysis problems. IPG development and deployment is addressing requirements obtained by analyzing a number of different application areas, in particular from the NASA Aero-Space Technology Enterprise. This analysis has focussed primarily on two types of users: The scientist / design engineer whose primary interest is problem solving (e.g., determining wing aerodynamic characteristics in many different operating environments), and whose primary interface to IPG will be through various sorts of problem solving frameworks. The second type of user if the tool designer: The computational scientists who convert physics and mathematics into code that can simulate the physical world. These are the two primary users of IPG, and they have rather different requirements. This paper describes the current state of IPG (the operational testbed), the set of capabilities being put into place for the operational prototype IPG, as well as some of the longer term R&D tasks