Development of lanthanum nickelate as a cathode for use in intermediate temperature solid oxide fuel cells

The performance of lanthanum nickelate, La2NiO4+δ (LNO), as a cathode in IT-SOFCs with the electrolyte cerium gadolinium oxide, Ce0.9Gd0.1O2−δ (CGO), has been investigated by AC impedance spectroscopy of symmetrical cells. A significant reduction in the area specific resistance (ASR) has been achieved with a layered cathode structure consisting of a thin compact LNO layer between the dense electrolyte and porous electrode. This decrease in ASR is believed to be a result of contact at the electrolyte/cathode boundary enhancing the oxygen ion transfer to the electrolyte. An ASR of 1.0 Ω cm2 at 700 °C was measured in a symmetrical cell with this layered structure, compared to an ASR of 7.4 Ω cm2 in a cell without the compact layer. In addition, further improvements were observed by enhancing the cell current collection and it is anticipated that a symmetrical cell consisting of a layered structure with adequate current collection would lower these ASR values further

Prediction of the functional properties of ceramic materials from composition using artificial neural networks

We describe the development of artificial neural networks (ANN) for the prediction of the properties of ceramic materials. The ceramics studied here include polycrystalline, inorganic, non-metallic materials and are investigated on the basis of their dielectric and ionic properties. Dielectric materials are of interest in telecommunication applications where they are used in tuning and filtering equipment. Ionic and mixed conductors are the subjects of a concerted effort in the search for new materials that can be incorporated into efficient, clean electrochemical devices of interest in energy production and greenhouse gas reduction applications. Multi-layer perceptron ANNs are trained using the back-propagation algorithm and utilise data obtained from the literature to learn composition-property relationships between the inputs and outputs of the system. The trained networks use compositional information to predict the relative permittivity and oxygen diffusion properties of ceramic materials. The results show that ANNs are able to produce accurate predictions of the properties of these ceramic materials which can be used to develop materials suitable for use in telecommunication and energy production applications

Emotional representations of space vary as a function of peoples' affect and interoceptive sensibility

Most research on people’s representation of space has focused on spatial appraisal and navigation. But there is more to space besides navigation and assessment: people have different emotional experiences at different places, which create emotionally tinged representations of space. Little is known about the emotional representation of space and the factors that shape it. The purpose of this study was to develop a graphic methodology to study the emotional representation of space and some of the environmental features (non-natural vs. natural) and personal features (affective state and interoceptive sensibility) that modulate it. We gave participants blank maps of the region where they lived and asked them to apply shade where they had happy/sad memories, and where they wanted to go after Covid-19 lockdown. Participants also completed self-reports on affective state and interoceptive sensibility. By adapting methods for analyzing neuroimaging data, we examined shaded pixels to quantify where and how strong emotions are represented in space. The results revealed that happy memories were consistently associated with similar spatial locations. Yet, this mapping response varied as a function of participants’ affective state and interoceptive sensibility. Certain regions were associated with happier memories in participants whose affective state was more positive and interoceptive sensibility was higher. The maps of happy memories, desired locations to visit after lockdown, and regions where participants recalled happier memories as a function of positive affect and interoceptive sensibility overlayed significantly with natural environments. These results suggest that people’s emotional representations of their environment are shaped by the naturalness of places, and by their affective state and interoceptive sensibility

Oxygen diffusion in Sr_0.75Y_0.25CoO_2.625: a molecular dynamics study

Oxygen diffusion in Sr0.75Y0.25CoO2.625 is investigated using molecular dynamics simulations in conjunction with an established set of Born model potentials. We predict an activation energy of diffusion for 1.56 eV in the temperature range of 1000-1400 K. We observe extensive disordering of the oxygen ions over a subset of lattice sites. Furthermore, oxygen ion diffusion both in the a-b plane and along the c axis requires the same set of rate-limiting ion hops. It is predicted that oxygen transport in Sr0.75Y0.25CoO2.625 is therefore isotropic

Relationship between cardiac cycle and the timing of actions during action execution and observation

Previous research suggests that there may be a relationship between the timing of motor events and phases of the cardiac cycle. This relationship has thus far only been researched using simple isolated movements such as key-presses in reaction-time tasks and only in a single subject acting alone. Other research has shown both movement and cardiac coordination among interacting individuals. Here, we investigated how the cardiac cycle relates to ongoing self-paced movements in both action execution and observation using a novel dyadic paradigm. We recorded electrocardiography (ECG) in 26 subjects who formed 19 dyads containing an action executioner and observer as they performed a self-paced sequence of movements. We demonstrated that heartbeats are timed to movements during both action execution and observation. Specifically, movements were less likely to culminate synchronously with the heartbeat around the time of the R-peak of the ECG. The same pattern was observed for action observation, with the observer's heartbeats occurring off-phase with movement culmination. These findings demonstrate that there is coordination between an action executioner's cardiac cycle and the timing of their movements, and that the same relationship is mirrored in an observer. This suggests that previous findings of interpersonal coordination may be caused by the mirroring of a phasic relationship between movement and the heart

Fitness costs associated with building and maintaining the burying beetle's carrion nest

It is well-known that features of animal nest architecture can be explained by fitness benefits gained by the offspring housed within. Here we focus on the little-tested suggestion that the fitness costs associated with building and maintaining a nest should additionally account for aspects of its architecture. Burying beetles prepare an edible nest for their young from a small vertebrate carcass, by ripping off any fur or feathers and rolling the flesh into a rounded ball. We found evidence that only larger beetles are able to construct rounder carcass nests, and that rounder carcass nests are associated with lower maintenance costs. Offspring success, however, was not explained by nest roundness. Our experiment thus provides rare support for the suggestion that construction and maintenance costs are key to understanding animal architecture.Cambridge Trust, CONACyT, European Research Council (Consolidators Grant ID: 310785 BALDWINIAN_BEETLES), Royal Society (Wolfson Merit Award), Natural Environment Research Council (Grant ID: NE/H019731/1

Dopaminergic Modulation of Sensory Attenuation in Parkinson's Disease: Is There an Underlying Modulation of Beta Power?

Background and Aims: Pathological high amplitude of beta oscillations is thought as the underlying mechanism of motor symptoms in Parkinson's disease (PD), in particular with regard to bradykinesia. In addition, abnormality in a neurophysiological phenomenon labeled sensory attenuation has been found in patients with PD. The current study explored the hypothesis that the abnormal sensory attenuation has a causal link with the typical abnormality in beta oscillations in PD. Methods: The study tested sixteen right-handed patients with a diagnosis of PD and 22 healthy participants, which were matched by age and gender. Somatosensory evoked potentials were elicited through electrical stimulation of the median nerve at the wrist. Electrical activity was recorded at the scalp using a 128 channels EEG. Somatosensory evoked potentials were recorded in 2 conditions: at rest and at the onset of a voluntary movement, which was a self-paced abduction movement of the right thumb. Results: Healthy participants showed a reduction of the N20-P25 amplitude at the onset of the right thumb abduction compared to the rest condition (P < 0.05). When patients were OFF medication, they showed mild reduction of the N20-P25 component at movement onset (P < 0.05). On the contrary, they did show greater attenuation of the N20-P25 component at the onset of movement compared to the rest condition when ON medication (P < 0.05). There was no significant evidence of a link between the degree of sensory attenuation and the change in beta oscillations in our cohort of patients. Conclusion: These results confirmed a significant link between dopaminergic modulation and sensory attenuation. However, the sensory attenuation and beta oscillations were found as two independent phenomena

The interaction of molecular oxygen on LaO terminated surfaces of La2NiO4

Rare-earth metal oxides with perovskite-type crystal structures are under consideration for use as air electrode materials for intermediate to high temperature electrochemical device applications. The surface chemistry of these materials plays a critical role in determining the kinetics of oxygen reduction and exchange reactions. Among various perovskite-structured oxides, certain members of the Ruddlesden–Popper series, e.g. La2NiO4, have been identified as significantly active for surface oxygen interactions. However, the challenge remains to be the identification of the structure and composition of active surfaces, as well as the influence of these factors on the mechanisms of surface exchange reactions. In this contribution, the changes in the electronic structure and the energetics of oxygen interactions on the surfaces of La2NiO4 are analysed using first principles calculations in the Density Functional Theory (DFT) formalism. As for the surface chemistry, LaO termination rather than NiO2 termination is presumed due to recent experimental evidence of the surfaces of various perovskite structured oxides after heat treatment in oxidizing environments being transition metal free. Our findings substantiate the fact that the LaO-terminated surface can indeed participate in the formation of surface superoxo species. Detailed charge transfer analyses revealed that it is possible for such a surface to be catalytically active owing to the enhanced electronic configurations on the neighbouring La sites to surface species. In addition, positively charged oxygen vacancies, relative to the crystal lattice, can act as active sites and catalyse the O–O bond cleavage

Insight into structure: function relationships in a molecular spin-crossover crystal, from a related weakly cooperative compound

This is a repository copy of Insight into structure: function relationships in a molecular spin-crossover crystal, from a related weakly cooperative compound. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/83008/ Version: Accepted Version Article: Elhaïk, J, Kilner, C and Halcrow, MA (2014) Insight into structure: function relationships in a molecular spin-crossover crystal, from a related weakly cooperative compound. European Journal of Inorganic Chemistry, 2014 (26). 4250 -4253. ISSN 14344250 -4253. ISSN -1948 https://doi.org/10.1002/ejic.201402623 [email protected] https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher&apos;s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. Insight into Compound Jérôme Elhaïk, [a] Colin A. Kilner, [a] and Malcolm A. Halcrow* [a] Abstract: The ClO4 − salt of [FeL2] 2+ (L = 2,6-bis(3-methylpyrazol-1-yl)pyridine) undergoes very gradual thermal spin-crossover centered just below room temperature. In contrast, the BF4 − salt of the same complex exhibits an abrupt and structured spin-transition at lower temperature, with a complicated structural chemistry. The difference can be attributed to a much larger change in molecular structure between the spin states of the complex in the more cooperative BF4 − salt, leading to an increased kinetic barrier for their interconversion. Consistent with that suggestion, the high-spin and low-spin structures of weakly cooperative [FeL2][ClO4]2 are almost superimposable. The continuing interest in thermally and optically switchable spin-crossover (SCO) materials [9] Its thermal spin-transition takes place in two steps, via a re-entrant symmetry-breaking transition to an intermediate crystal phase, with a tripled unit cell containing a mixture of high-spin and low-spin sites. The first of these steps occurs abruptly with hysteresis, but at a temperature that varies according to the water content of the sample (x). In contrast the second step is kinetically slow, and is only achieved when the sample is poised at 100 K for 1.5 hrs. [10] Its excited spin-state trapping (LIESST [11] ) behavior is also unique, in that its thermodynamic high low spin transition and kinetically controlled high low spin-state relaxation exhibit different profiles and are effectively decoupled from each other. [12] Although unexceptional in itself, 1[ClO4]2 provides useful insight into the structural origin of the unusual behavior of the BF4 − salt by providing a rare comparison between strongly and weakly cooperative spin-crossover materials based on the same complex molecule. At 300 K, MT for 1[ClO4]2 is 2.4 cm 3 mol -1 K, lower than expected for a high-spin iron(II) complex with this ligand type (3.4-3.6 cm 3 mol -1 K)