Improving electrochemical performance of Nickel - Yttria stabilized Zirconia cermet anodes employing nickel nanoparticles

Nickel-Yttria Stabilized Zirconia (Ni-YSZ) cermets are used as anodes in solid oxide fuel cells. These anodes are stable for tens of thousands of hours during operation and have low cost. In this work, Ni-YSZ anodes are infiltrated with nickel nanoparticles to increase the density of electrochemical reaction sites and improve their performance. However, infiltrated nickel nanoparticles are isolated from one another, so they are not electrochemically active. Two approaches have been utilized to activate infiltrated nickel nanoparticles: in-situ nickel spreading and simultaneous infiltration of nickel with Gd0.1Ce0.9O2-δ (GDC). In-situ nickel spreading, which occurs during exposure to anodic mass transfer limited currents, connects and activates nickel nanoparticles, improving anode performance but inherently causing nanoparticle coarsening. Simultaneous infiltration of Ni and GDC results in substantially improved anode performance, and the infiltrated nanostructures are more stable than infiltrated nickel. Detailed analysis of the electrochemical impedance by equivalent circuit modeling is used to separate the contributions of nickel and GDC infiltrants to the overall cell performance

The Dynamic Structure of Thrombin in Solution

AbstractThe backbone dynamics of human α-thrombin inhibited at the active site serine were analyzed using R1, R2, and heteronuclear NOE experiments, variable temperature TROSY 2D [1H-15N] correlation spectra, and Rex measurements. The N-terminus of the heavy chain, which is formed upon zymogen activation and inserts into the protein core, is highly ordered, as is much of the double beta-barrel core. Some of the surface loops, by contrast, remain very dynamic with order parameters as low as 0.5 indicating significant motions on the ps-ns timescale. Regions of the protein that were thought to be dynamic in the zymogen and to become rigid upon activation, in particular the γ-loop, the 180s loop, and the Na+ binding site have order parameters below 0.8. Significant Rex was observed in most of the γ-loop, in regions proximal to the light chain, and in the β-sheet core. Accelerated molecular dynamics simulations yielded a molecular ensemble consistent with measured residual dipolar couplings that revealed dynamic motions up to milliseconds. Several regions, including the light chain and two proximal loops, did not appear highly dynamic on the ps-ns timescale, but had significant motions on slower timescales

Reaching out: Golden Key local evaluation phase 1 full report

This report presents a preliminary analysis of the evidence collated for Phase 1 of the local evaluation of Bristol Golden Key. Evidence has been collected between November 2014 and March 2016 through a variety of means, including interviews with around 40 key stakeholders, observation at over 25 key meetings and events, and review of documentation.Golden Key is a long-term, complex initiative and at this relatively early stage the evaluation is primarily formative in focus – providing observations and reflections on how Golden Key has developed since inception and emerging indicators of how it is perceived and experienced by different stakeholders. The main aim of this report is to ‘capture the learning’ so far and to raise issues and questions that should inform further development as Golden Key progresses. It does not purport to give an objective assessment of progress against project aims given the paucity of quantitative data to support such an analysis at this stage.The report is informed by the evaluation framework developed to support this investigation, which uses a realist approach to identifying how behaviours, processes, outcomes and impacts develop in relation to three main pathways: client engagement; the Golden Key partnership and processes; and citywide engagement and systems change. Chapters are presented for each of these areas, concluding with a set of key learning points and discussion questions

Reaching out: Golden Key local evaluation phase 1 summary report

This report summarises the findings from Phase 1 of the local evaluation of Golden Key though the first 18 months of initial development, progress towards delivery and operational services delivery from Autumn 2014 to Spring 2016.Bristol Golden Key is one of 12 programmes across the UK to have received funding from the Big Lottery Fund Fulfilling Lives programme to support the development and provision of services for people with multiple complex needs

Effect of anodic current density on the spreading of infiltrated nickel nanoparticles in nickel-yttria stabilized zirconia cermet anodes

This study is supported through the United States of America Department of Energy National Energy Technology Laboratory (award number DE-FE0026096). The authors would also like to acknowledge the contributions of Dr. Alexey Nikiforov, Anlee Krupp, Dr. Ruofan Wang, and Zhihao Sun. (DE-FE0026096 - United States of America Department of Energy National Energy Technology Laboratory)https://www.sciencedirect.com/science/article/pii/S037877531831231XAccepted manuscrip

Co-infiltration of nickel and mixed conducting Gd0.1Ce0.9O2−δ and La0.6Sr0.3Ni0.15Cr0.85O3−δ phases in Ni-YSZ anodes for improved stability and performance

Accepted manuscrip

"Knees" in lithium-ion battery aging trajectories

Lithium-ion batteries can last many years but sometimes exhibit rapid, nonlinear degradation that severely limits battery lifetime. In this work, we review prior work on "knees" in lithium-ion battery aging trajectories. We first review definitions for knees and three classes of "internal state trajectories" (termed snowball, hidden, and threshold trajectories) that can cause a knee. We then discuss six knee "pathways", including lithium plating, electrode saturation, resistance growth, electrolyte and additive depletion, percolation-limited connectivity, and mechanical deformation -- some of which have internal state trajectories with signals that are electrochemically undetectable. We also identify key design and usage sensitivities for knees. Finally, we discuss challenges and opportunities for knee modeling and prediction. Our findings illustrate the complexity and subtlety of lithium-ion battery degradation and can aid both academic and industrial efforts to improve battery lifetime.Comment: Submitted to the Journal of the Electrochemical Societ

The political economy of natural disaster damage

Economic damage from natural hazards can sometimes be prevented and always mitigated. However, private individuals tend to underinvest in such measures due to problems of collective action, information asymmetry and myopic behavior. Governments, which can in principle correct these market failures, themselves face incentives to underinvest in costly disaster prevention policies and damage mitigation regulations. Yet, disaster damage varies greatly across countries. We argue that rational actors will invest more in trying to prevent and mitigate damage the larger a country's propensity to experience frequent and strong natural hazards. Accordingly, economic loss from an actually occurring disaster will be smaller the larger a country's disaster propensity – holding everything else equal, such as hazard magnitude, the country's total wealth and per capita income. At the same time, damage is not entirely preventable and smaller losses tend to be random. Disaster propensity will therefore have a larger marginal effect on larger predicted damages than on smaller ones. We employ quantile regression analysis in a global sample to test these predictions, focusing on the three disaster types causing the vast majority of damage worldwide: earthquakes, floods and tropical cyclones

Probing the Interstellar Medium in Early type galaxies with ISO observations

Four IRAS-detected early type galaxies were observed with ISO. With the exception of the 15 micron image of NGC1052, the mid-IR emission from NGC1052, NGC1155, NGC5866 and NGC6958 at 4.5, 7 and 15 microns show extended emission. Mid-IR emission from NGC1052, NGC1155, and NGC6958 follows a de Vaucouleurs profile. The ratio of 15/7 micron flux decreases with radius in these galaxies, approaching the values empirically observed for purely stellar systems. In NGC5866, the 7 and 15 micron emission is concentrated in the edge-on dust lane. All the galaxies are detected in the [CII] line, and the S0s NGC1155 and NGC5866 are detected in the [OI] line as well. The ISO-LWS observations of the [CII] line are more sensitive measures of cool, neutral ISM than HI and CO by about a factor of 10-100. Three of four early type galaxies, namely NGC1052, NGC6958 and NGC5866, have low ratio FIR/Blue and show a lower [CII]/FIR, which is due to a softer radiation field from old stellar populations. The low [CII]/CO ratio in NGC5866 ([CII]/CO(1-0) < 570) confirms this scenario. We estimate the UV radiation expected from the old stellar populations in these galaxies and compare it to that needed to heat the gas to account for the cooling observed [CII] and [OI] lines. In three out of four galaxies, NGC1052, NGC5866 and NGC6958, the predicted UV radiation falls short by a factor of 2-3. In view of the observed intrinsic scatter in the "UV-upturn" in elliptical galaxies and its great sensitivity to age and metallicity effects, this is not significant. However, the much larger difference (about a factor of 20) between the UV radiation from old stars and that needed to produce the FIR lines for NGC 1155 is strong evidence for the presence of young stars, in NGC1155.Comment: To appear in the Astrophysical Journal. Figure 1 appears as a separate jpg figur