Evaluating sulfur-tolerance of metal/Ce0.80Gd0.20O1.90 co-impregnated La0.20Sr0.25Ca0.45TiO3 anodes for solid oxide fuel cells

The authors acknowledge funding from the University of St Andrews, HEXIS AG and the EPSRC Grants: EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes” and EP/L017008/1 “Capital for Great Technologies”.The Ni-based cermet Solid Oxide Fuel Cell (SOFC) anode is prone to poisoning by sulfur-based odourising agents, and naturally occurring sulfur species, present in unprocessed natural gas feeds. Next generation SOFC anodes should be able to withstand exposure to these poisons in the event of a malfunction or breakdown of desulfurisation units. Here, we present results pertaining to the sulfur-tolerance of Ni/Ce0.80Gd0.20O1.90 (CGO), Pt/CGO and Rh/CGO co-impregnated La0.20Sr0.25Ca0.45TiO3 anode ‘backbone’ microstructures and their ability to recover performance after being exposed to H2S. The Ni/CGO co-impregnated system exhibited severe poisoning by H2S, however, the Rh/CGO system displayed good stability in Area Specific Resistance (ASR) upon introduction of 1–2 ppm of H2S and the Pt/CGO system showed minimal increases in ASR with the addition of 1–8 ppm H2S. Recovery measurements performed in non-humidified H2 at 300 mA cm−2, after exposure to 8 ppm H2S, indicated that the Pt/CGO and Rh/CGO systems could recover within 10 min, whilst 60 min were required to achieve almost a full recovery of performance for the Ni/CGO system. Additionally, all three impregnate systems showed good stability in operating voltage, after an initial drop, in a fuel gas containing simulated syngas (2:1 H2:CO) with 8 ppm H2S.PostprintPeer reviewe

Integration of sustainability principles into construction project delivery

Construction clients and governments recognise the significant impact the design, construction and occupation of buildings have on the environment and society. The construction industry and governments have a central role in driving the sustainable development agenda. Good sustainable design can deliver buildings with low running costs-an attribute that is highly attractive to both the society and businesses. The aim of this paper was therefore to examine the integration of sustainability principles into construction projects. The review provided key evidence of the link between sustainability and better project performance, through the integration of sustainability principles. In addition, it proposed a sustainable framework for better construction project, based on the philosophies of sustainable constructio

Recent advances in Rh/CGO co-impregnated La0.20Sr0.25Ca0.45TiO3 anodes for solid oxide fuel cells : evaluation of upscaling and durability

Funding: University of St Andrews and HEXIS AG; UK EPSRC grants: EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes” and EP/L017008/1 “Capital for Great Technologies”.Recent research carried out at the University of St Andrews and HEXIS has focussed on a novel A-site deficient perovskite: La0.20Sr0.25Ca0.45TiO3 (LSCTA-) as a potential replacement material for the Ni-based cermet. LSCTA- is a mixed ionic and electronic conductor, which exhibits a high effective electrical conductivity for this class of limited conductivity perovskite, allowing a single-phase anode 'backbone' to be employed and removing the challenges associated with utilisation of a structural Ni phase. Co-impregnating this 'backbone' with a variety of transition/platinum group metals, as well as Ce0.80Gd0.20O1.90 (CG20), produces intricately nanostructured anode materials with high electrocatalytic activity for fuel oxidation. Here we provide an overview of the first 'all-oxide' SOFC stack test at HEXIS, as well as an in depth exploration of the 'powder-to-power' development of these co-impregnated LSCTA- anodes including: ceramic processing, catalyst selection, short-term testing, characterisation by AC impedance spectroscopy and durability testing of promising candidate catalyst systems.Postprin

Correlations, compressibility, and capacitance in double-quantum-well systems in the quantum Hall regime

In the quantum Hall regime, electronic correlations in double-layer two-dimensional electron systems are strong because the kinetic energy is quenched by Landau quantization. In this article we point out that these correlations are reflected in the way the partitioning of charge between the two-layers responds to a bias potential. We report on illustrative calculations based on an unrestricted Hartree-Fock approximation which allows for spontaneous inter-layer phase coherence. The possibility of studying inter-layer correlations by capacitive coupling to separately contacted two-dimensional layers is discussed in detail.Comment: RevTex style, 21 pages, 6 postscript figures in a separate file; Phys. Rev. B (in press

Soft Openings: The psycho-technological expertise of third sector curriculum reform

Since the late 1990s the "third sector" has become active in generating new curriculum programmes in England. Based on tracing third sector participation in public education during the New Labour years, the article explores a documentary archive of third sector curriculum texts and argues that the programmes, strategies and techniques of the third sector have sought to pursue a new form of governmentality. The type of governmentality pursued by the third sector takes form as a "soft" style of curriculum reform derived from assembling together cybernetic and psychological forms of expertise, interactionist and constructivist pedagogies, and an emerging "psycho-technology" of subjectivity. The third sector fabricates reform proposals for a curriculum of the future in which governance is done by cross-sectoral networking, epistemological categories are blurred, and student subjectivities are made up to be malleable, soft-skilled and psychologically self-shaping. The article examines how third sector texts have assembled this new psycho-technological expertise of curriculum reform through both cybernetic and psychological styles of thinking

Comparison of advanced gravitational-wave detectors

We compare two advanced designs for gravitational-wave antennas in terms of their ability to detect two possible gravitational wave sources. Spherical, resonant mass antennas and interferometers incorporating resonant sideband extraction (RSE) were modeled using experimentally measurable parameters. The signal-to-noise ratio of each detector for a binary neutron star system and a rapidly rotating stellar core were calculated. For a range of plausible parameters we found that the advanced LIGO interferometer incorporating RSE gave higher signal-to-noise ratios than a spherical detector resonant at the same frequency for both sources. Spheres were found to be sensitive to these sources at distances beyond our galaxy. Interferometers were sensitive to these sources at far enough distances that several events per year would be expected

A High-End Estimate of Sea Level Rise for Practitioners

Sea level rise (SLR) is a long-lasting consequence of climate change because global anthropogenic warming takes centuries to millennia to equilibrate for the deep ocean and ice sheets. SLR projections based on climate models support policy analysis, risk assessment and adaptation planning today, despite their large uncertainties. The central range of the SLR distribution is estimated by process-based models. However, risk-averse practitioners often require information about plausible future conditions that lie in the tails of the SLR distribution, which are poorly defined by existing models. Here, a community effort combining scientists and practitioners builds on a framework of discussing physical evidence to quantify high-end global SLR for practitioners. The approach is complementary to the IPCC AR6 report and provides further physically plausible high-end scenarios. High-end estimates for the different SLR components are developed for two climate scenarios at two timescales. For global warming of +2°C in 2100 (RCP2.6/SSP1-2.6) relative to pre-industrial values our high-end global SLR estimates are up to 0.9 m in 2100 and 2.5 m in 2300. Similarly, for a (RCP8.5/SSP5-8.5), we estimate up to 1.6 m in 2100 and up to 10.4 m in 2300. The large and growing differences between the scenarios beyond 2100 emphasize the long-term benefits of mitigation. However, even a modest 2°C warming may cause multi-meter SLR on centennial time scales with profound consequences for coastal areas. Earlier high-end assessments focused on instability mechanisms in Antarctica, while here we emphasize the importance of the timing of ice shelf collapse around Antarctica. This is highly uncertain due to low understanding of the driving processes. Hence both process understanding and emission scenario control high-end SLR

Magnetic Field Amplification in Galaxy Clusters and its Simulation

We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which amplify tiny magnetic seed fields to the microGauss values that are observed in the intracluster medium. This process is intimately connected to the properties of turbulence and the microphysics of the intra-cluster medium. Additional roles are played by merger induced shocks that sweep through the intra-cluster medium and motions induced by sloshing cool cores. The accurate simulation of magnetic field amplification in clusters still poses a serious challenge for simulations of cosmological structure formation. We review the current literature on cosmological simulations that include magnetic fields and outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure

Opioid suppression of conditioned anticipatory brain responses to breathlessness

Opioid painkillers are a promising treatment for chronic breathlessness, but are associated with potentially fatal side effects. In the treatment of breathlessness, their mechanisms of action are unclear. A better understanding might help to identify safer alternatives. Learned associations between previously neutral stimuli (e.g. stairs) and repeated breathlessness induce an anticipatory threat response that may worsen breathlessness, contributing to the downward spiral of decline seen in clinical populations. As opioids are known to influence associative learning, we hypothesized that they may interfere with the brain processes underlying a conditioned anticipatory response to breathlessness in relevant brain areas, including the amygdala and the hippocampus. Healthy volunteers viewed visual cues (neutral stimuli) immediately before induction of experimental breathlessness with inspiratory resistive loading. Thus, an association was formed between the cue and breathlessness. Subsequently, this paradigm was repeated in two identical neuroimaging sessions with intravenous infusions of either low-dose remifentanil (0.7ng/ml target controlled infusion) or saline (randomised). During saline infusion, breathlessness anticipation activated the right anterior insula and the adjacent operculum. Breathlessness was associated with activity in a network including the insula, operculum, dorsolateral prefrontal cortex, anterior cingulate cortex and the primary sensory and motor cortices. Remifentanil reduced breathlessness unpleasantness but not breathlessness intensity. Remifentanil depressed anticipatory activity in the amygdala and the hippocampus that correlated with reductions in breathlessness unpleasantness. During breathlessness, remifentanil decreased activity in the anterior insula, anterior cingulate cortex and sensory motor cortices. Remifentanil-induced reduction in breathlessness unpleasantness was associated with increased activity in the rostral anterior cingulate cortex and nucleus accumbens, components of the endogenous opioid system known to decrease the perception of aversive stimuli. These findings suggest that in addition to effects on brainstem respiratory control, opioids palliate breathlessness through an interplay of altered associative learning mechanisms. These mechanisms provide potential targets for novel ways to develop and assess treatments for chronic breathlessness

The unusually long duration gamma-ray burst GRB 000911: Discovery of the afterglow and host galaxy

Of all the well-localized gamma-ray bursts, GRB 000911 has the longest duration (T90 = 500 s) and ranks in the top 1% of BATSE bursts for fluence. Here we report the discovery of the afterglow of this unique burst. In order to simultaneously fit our radio and optical observations, we are required to invoke a model involving a hard electron distribution, p ∼ 1.5, and a jet-break time less than 1.5 days. A spectrum of the host galaxy taken 111 days after the burst reveals a single emission line, interpreted as [011] at a redshift z = 1.0585, and a continuum break that we interpret as the Balmer limit at this redshift. Despite the long 790, the afterglow of GRB 000911 is not unusual in any other way when compared to the set of afterglows studied to date. We conclude that the duration of the GRB plays little part in determining the physics of the afterglow