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Understanding the interfacial dynamics of batteries is crucial to control degradation and increase electrochemical performance and cycling life. If the chemical potential of a negative electrode material lies outside of the stability window of an electrolyte (either solid or liquid), a decomposition layer (interphase) will form at the interface. To better understand and control degradation at interfaces in batteries, theoretical models describing the rate of formation of these interphases are required. This study focuses on the growth kinetics of the interphase forming between solid electrolytes and metallic negative electrodes in solid-state batteries. More specifically, we demonstrate that the rate of interphase formation and metal plating during charge can be accurately described by adapting the theory of coupled ion-electron transfer (CIET). The model is validated by fitting experimental data presented in the first part of this study. The data was collected operando as a Na metal layer was plated on top of a NaSICON solid electrolyte (Na3.4Zr2Si2.4P0.6O12 or NZSP) inside an XPS chamber. This study highlights the depth of information which can be extracted from this single operando experiment and is widely applicable to other solid-state electrolyte systems.

Non-equilibrium thermodynamics describe the current–voltage characteristics of electrochemical devices. For conventional electrode–electrolyte interfaces, the local activation overpotential is used to describe the electrostatic potential step between the two materials as a current is generated. However, the activation overpotential for the metal/mixed ionic-electronic conducting (MIEC) composite electrodes studied in this work originates at the MIEC–gas interface. Moreover, we have studied the effects of non-equilibrium on the electrostatic surface potential and evaluated its influence over electrode kinetics. By investigating two phase (2PB) and three phase boundary (3PB) reactions at the Ni/Ce1−xGdxO2−δ (Ni/CGO) electrode, we have demonstrated that the driving force for coupled ion-electron transfer is held at the CGO–gas interface for both reaction pathways. We also determined that the rate of coupled ion-electron transfer via the 3PB scales with the availability of free sites on the metallic surface, revealing a Sabatier-like relationship with regards to the selection of metallic phases. Finally, we demonstrated how the theory of the electrostatic surface potential can be applied to other systems outside of the well-studied H2/H2O electrode environment. These findings therefore provide an insight into the design of future electrode structures for a range of electrochemical devices.

To harness all of the benefits of solid-state battery (SSB) architectures in terms of energy density, their negative electrode should be an alkali metal. However, the high chemical potential of alkali metals makes them prone to reduce most solid electrolytes (SE), resulting in a decomposition layer called an interphase at the metal|SE interface. Quantitative information about the interphase chemical composition and rate of formation is challenging to obtain because the reaction occurs at a buried interface. In this study, a thin layer of Na metal (Na0) is plated on the surface of an SE of the NaSICON family (Na3.4Zr2Si2.4P0.6O12 or NZSP) inside a commercial X-ray photoelectron spectroscopy (XPS) system while continuously analyzing the composition of the interphase operando. We identify the existence of a solid electrolyte interphase at the Na0|NZSP interface, and more importantly, we demonstrate for the first time that this protocol can be used to study the kinetics of interphase formation. A second important outcome of this article is that the surface chemistry of NZSP samples can be tuned to improve their stability against Na0. It is demonstrated by XPS and time-resolved electrochemical impedance spectroscopy (EIS) that a native NaxPOy layer present on the surface of as-sintered NZSP samples protects their surface against decomposition.

Electrochemical impedance spectroscopy (EIS) is a powerful tool in characterisation of processes in electrochemical systems, allowing us to elucidate the resistance and characteristic frequency of physical properties such as reaction and transport rates. The essence of EIS is the relationship between current and potential at a given frequency. However, it is often the case that we do not understand the electrochemical system well enough to fit a meaningful physical model to EIS data. The distribution of relaxation times (DRT) calculation assumes an infinite series of relaxation processes distributed over a characteristic timescale. The DRT calculation may identify the number of processes occurring, as well as their respective resistivity and characteristic timescale, and may resolve processes which have relatively similar timescales. Using a nonparametric tool known as Gaussian process (GP) regression, we showcase a method of finding a unique solution to the ill-posed DRT problem by optimising kernel hyperparameters as opposed to ad-hoc regularisation. In this work, we use finite GP regression under inequality constraints (fGP) to analysed EIS data generated by a (Ni/CGO|CGO|YSZ|Reference Cathode) solid-oxide fuel cell in a gas mixture of 0.5 bar H2/0.5 bar H2O and at a temperature of 600 ◦C. By varying the current density, we can characterise the current-voltage relationship of the electrode and shed light on the reaction mechanism governing charge transfer at the solid-gas interface. Our findings also show that even at relatively high current densities (±600 mA cm− 2) the electrode process is limited by charge transfer.

To harness all the benefits of solid-state battery (SSB) architectures in terms of energy density, their negative electrode should be an alkali metal. However, the high chemical potential of alkali metals makes them prone to reduce most solid electrolytes (SE), resulting in a decomposition layer called an interphase at the metal|SE interface. Quantitative information about the interphase chemical composition and rate of formation are challenging to obtain because the reaction occurs at a buried interface. In this study, a thin layer of Na metal (Na0) is plated on the surface of a SE of the NaSICON family (Na3.4Zr2Si2.4P0.6O12 or NZSP) inside a commercial XPS system whilst continuously analysing the composition of the interphase operando. We identify the existence of an interphase at the Na0|NZSP interface, and more importantly, we demonstrate for the first time that this protocol can be used to study the kinetics of interphase formation. A second important outcome of this article is that the surface chemistry of NZSP samples can be tuned to improve their stability against Na0. It is demonstrated by XPS and time-resolved electrochemical impedance spectroscopy (EIS) that a native Na3PO4 layer present on the surface of as-sintered NZSP samples protects their surface against decomposition.

Understanding the interfacial dynamics of batteries is crucial to control degradation and increase electrochemical performance and cycling life. If the chemical potential of a negative electrode material lies outside of the stability window of an electrolyte (either solid or liquid), a decomposition layer (interphase) will form at the interface. To better understand and control degradation at interfaces in batteries, theoretical models describing the rate of formation of these interphases are required. This study focuses on the growth kinetics of the interphase forming between solid electrolytes and metallic negative electrodes in solid-state batteries. More specifically, we demonstrate that the rate of interphase formation and metal plating during charge can be accurately described by adapting the theory of coupled ion-electron transfer (CIET). The model is validated by fitting experimental data presented in the first part of this study. The data was collected operando as a Na metal layer was plated on top of a NaSICON solid electrolyte (Na3.4Zr2Si2.4P0.6O12 or NZSP) inside a XPS chamber. This study highlights the depth of information which can be extracted from this single operando experiment, and is widely applicable to other solid-state electrolyte systems.

Activation losses at solid oxide-fuel cell (SOFC) electrodes have been widely attributed to charge transfer at the electrode surface. The electrostatic nature of electrode-gas interactions allows us to study these phenomena by simulating an electric field across the electrode-gas interface, where we are able to describe the activation overpotential using Density Functional Theory (DFT). The electrostatic responses to the electric field are used to approximate the behaviour of an electrode under electrical bias, and have found a correlation with experimental data for three different reduction reactions at a mixed ionic-electronic conducting (MIEC) electrode surfaces (H_2O and CO_2 on CeO_2), and {O_2 on LaFeO_3). In this work , we demonstrate the importance of decoupled ion-electron transfer and charged adsorbates on the performance of electrodes under nonequilibrium conditions. Finally, our findings on MIEC-gas interactions have potential implications in the fields of energy storage and catalysis.

Understanding the interfacial dynamics of batteries is crucial to control degradation and increase electrochemical performance and cycling life. If the chemical potential of a negative electrode material lies outside of the stability window of an electrolyte (either solid or liquid), a decomposition layer (interphase) will form at the interface. To better understand and control degradation at interfaces in batteries, theoretical models describing the rate of formation of these interphases are required. Yet, experimental data which could support these models are challenging to obtain considering that the decomposition reaction is dynamic in nature and occurs at a deeply buried interface making it inaccessible to quantitative non-destructive techniques such as X-ray photoelectron spectroscopy (XPS) which has a limited depth of analysis. In the first article of this two-parts study, an experiment was designed to study the formation of an interphase at the interface between a Na metal negative electrode and a NaSICON solid electrolyte (Na3.4Zr2Si2.4P0.6O12 or NZSP) using a recent XPS protocol. Data was collected operando as a Na metal layer was plated on top of the NZSP electrolyte inside the XPS chamber. It was demonstrated that an interphase forms at the Na0|NZSP interface but that a native Na3PO4 layer present on thermally activated NZSP samples can minimize the extent of decomposition. In this second article, it is demonstrated that the rate of plating and interphase formation at the Na0|NZSP interface can be accurately described by adapting the theory of coupled ion-electron transfer (CIET). Models are fitted using experimental data from the first part of this study (in particular, the peak positions and peak areas as a function of Na0 plating time). This second part of the study therefore highlights the depth of information which can be extracted from this single operando experiment.

To harness all the benefits of solid-state battery (SSB) architectures in terms of energy density, their negative electrode should be an alkali metal. However, the high chemical potential of alkali metals make them prone to reduce most solid electrolytes (SE), resulting in a decomposition layer called an interphase at the metal|SE interface. Quantitative information about the interphase chemical composition and rate of formation are challenging to obtain because the reaction occurs at a buried interface. In this study, a thin layer of Na metal (Na0) is plated on the surface of a SE of the NaSICON family (Na3.4Zr2Si2.4P0.6O12 or NZSP) inside a commercial XPS system whilst continuously analysing the composition of the interphase operando. We identify the existence of an interphase at the Na0|NZSP interface, and more importantly, we demonstrate for the first time that this protocol can be used to study the kinetics of interphase formation. A second important outcome of this article is that the surface chemistry of NZSP samples can be tuned to improve their stability against Na0. It is demonstrated by XPS and time-resolved electrochemical impedance spectroscopy (EIS) that a native Na3PO4 layer present on the surface of as-sintered NZSP samples protects their surface against decomposition.

The local activation overpotential describes the electrostatic potential shift away from equilibrium at an electrode/electrolyte interface. This electrostatic potential is not entirely satisfactory for describing the reaction kinetics of a mixed ionic–electronic conducting (MIEC) solid-oxide cell (SOC) electrode where charge transfer occurs at the electrode–gas interface. Using the theory of the electrostatic potential at the MIEC–gas interface as an electrochemical driving force, charge transfer at the ceria–gas interface has been modelled based on the intrinsic dipole potential of the adsorbate. This model gives a physically meaningful reason for the enhancement in electrochemical activity of a MIEC electrode as the steam and hydrogen pressure is increased in both fuel cell and electrolysis modes. This model was validated against operando XPS data from previous literature to accurately predict the outer work function shift of thin film Sm0.2Ce0.8O1.9 in a H2/H2O atmosphere as a function of overpotential.

We consider maximal non-l-intertwining collections, which are a higher-dimensional version of the maximal non-crossing collections which give clusters of Plücker coordinates in the Grassmannian coordinate ring, as described by Scott. We extend a method of Scott for producing such collections, which are related to tensor products of higher Auslander algebras of typeA. We show that a higher preprojective algebra of the tensor product of twod-representation-finite algebras has ad-precluster-tilting subcategory. Finally, we relate mutations of these collections to a form of tilting for these algebras.

We combine insights from subsurface studies and published numerical models to propose a three-phase conceptual model that considers the potential deformation patterns that form during the emplacement, evacuation and welding, and post-welding phases of tertiary weld formation. The proposed model aims to: 1) help establish the timing of deformation adjacent to a tertiary weld based on the geometry of deformation patterns, and 2) serve as a guide for future work that examines deformation adjacent to tertiary welds and beneath allochthonous salt. We apply the model, along with new, 1:10,000 scale geological mapping and mesostructural analysis of deformation patterns along the Kingston tertiary salt weld and contiguous Witchelina-Breaden Hill salt canopy in the Willouran Ranges of South Australia to constrain the evolution of the allochthonous salt system and the style, extent, and timing of adjacent deformation. Deformation near the weld is dominated by opening mode fractures that exhibit spatial heterogeneity in their orientation both along the strike of allochthonous salt and in suprasalt versus subsalt strata. A halokinetic drape fold, decimeter to decameter scale folding, and localized debris flow deposits are present in subsalt strata, whereas no evidence of thrust imbricates, or laterally continuous shear and/or rubble zones was observed anywhere below the canopy-weld complex. We hypothesize that remnant evaporite distribution and the juxtaposition of units exert the primary, largest-scale control on the hydrological behavior of tertiary welds. The influence of deformation occurs at a much smaller scale and is more heterogeneous and difficult to predict. Higher resolution models and additional field studies are required to identify and rank the many variables that control this deformation.

The catalytic and transport properties of mixed ionic-electronic conducting (MIEC) electrodes for solid oxide fuel cells (SOCs) are well documented and utilised, yet poorly understood. In the current study, a novel kinetic framework for the electrochemical behaviour of hydrogen at the MIEC-gas interface will be discussed for three parallel treatments: as an ideal gas, as an adsorbate on the electrode surface and as a charge carrier dissolved in the oxide lattice. This model gives a physically meaningful reason for the enhancement in electrochemical activity of a MIEC electrode as the steam pressure is increased in both fuel cell and electrolysis modes, and is ubiquitous for any electrochemical system where the electric double layer is described as a Heaviside step function. The process of charge transfer at the MIEC electrode/gas interface comprises of ambipolar exchange of ions and electronic species. The result of such a process causes charge separation and an associated dipole moment at the electrode surface. By applying an overpotential η to the MIEC electrode, an electrostatic surface potential shift away from equilibrium may be established where an effective double layer is formed between the electrode surface and the adsorbed species. Although no net charge transfer occurs, this surface potential shift modifies the surface chemistry and is the driving force for the ambipolar exchange of ions and electronic species. Density Functional Theory (DFT) calculations were used to study the electrostatic potential at the ceria [111] surface, where we were able to calculate the dipole moment and adsorption energy as a function of hydroxyl coverage. The theory of the electrostatic potential at the MIEC-gas interface was then applied to predict the surface electrochemical properties as a function of local overpotential. The mechanistic understanding gained from this model is widely applicable to a range of MIEC systems and provides a basis upon which the operating conditions can be tailored.

The prevalence and effectiveness of phishing attacks, despite the presence of a vast array of technical defences, are due largely to the fact that attackers are ruthlessly targeting what is often referred to as the weakest link in the system – the human. This paper reports the results of an investigation into how end users behave when faced with phishing websites and how this behaviour exposes them to attack. Specifically, the paper presents a proof of concept computer model for simulating human behaviour with respect to phishing website detection based on the ACT-R cognitive architecture, and draws conclusions as to the applicability of this architecture to human behaviour modelling within a phishing detection scenario. Following the development of a high-level conceptual model of the phishing website detection process, the study draws upon ACT-R to model and simulate the cognitive processes involved in judging the validity of a representative webpage based primarily around the characteristics of the HTTPS padlock security indicator. The study concludes that despite the low-level nature of the architecture and its very basic user interface support, ACT-R possesses strong capabilities which map well onto the phishing use case, and that further work to more fully represent the range of human security knowledge and behaviours in an ACT-R model could lead to improved insights into how best to combine technical and human defences to reduce the risk to end users from phishing attacks.

The important role that non-motorised transport plays in urban sustainability is discussed with particular reference to the developing world and to the links between environmental and poverty issue...

This paper reports the findings of a project to assess the costs and benefits of adopting environment‐friendly construction practices for social rented housing in Scotland. Two contrasted dwelling specifications — one for a conventional building (the Control) and one for an environmentally responsible building (Eco‐Type 1) — are compared using Life Cycle Analysis and Life Cycle Costing methodologies. An assessment is made of the environmental and economic implications of adopting environmentally conscious construction practices in social rented housing. It is concluded that the provision of environmentally responsible dwellings could bring large‐scale reductions in the environmental burden of housing, and economic savings for housing providers and tenants over the life cycle of a dwelling with only a small increase in capital costs.

Gallstone ileus is a rare but significant cause of intestinal obstruction particularly among the elderly population. Symptoms are often vague and therefore a high suspicious index is required for successful diagnosis. In this report, we present the case of an 87-year-old gentleman with a background history of cholelithiasis and ileostomy for ulcerative colitis who was admitted with a 24-h history of his stoma not functioning. He had an abdominal x-ray and CT which were consistent with small bowel obstruction with no identifiable cause. He underwent an examination of his stoma under general anaesthesia which revealed a 2.5 cm gallstone wedged several centimetres near the entry point of the stoma. The purpose of this report is to highlight the importance of considering gallstones as a potential cause of a non-functioning stoma in any patient with a significant history of cholelithiasis.

Background The best management of large, diffuse or inflammatory breast cancers is uncertain and the place of radiotherapy and/or surgery is not clearly defined. Methods A cohort of 123 patients with non-metastatic locally advanced or inflammatory breast cancer 3cm or more in diameter or T4, was treated between 1989 and 2006. All patients received primary chemotherapy followed by radiotherapy, 40Gy in 15 fractions with 10Gy boost. Patients with ER positive tumours received Tamoxifen. Assessment was carried out 8 weeks post-treatment and surgery was reserved for residual or recurrent disease. Results For each stage there were T2/3: 63, T4b: 31 and T4d: 29 patients. 80 had complete clinical response (65%) but 18 patients were never free of inoperable local disease. 25 patients had residual operable disease at assessment and 12 patients who initially had a complete response developed operable local recurrence (LR). 37 Patients (30%) had surgery at a mean of 15 months post diagnosis. At 5 years, overall survival (OS) of the two surgical groups was not significantly different from those 68 patients who had complete remission without surgery, p =0.218, HR 1.46 (0.80–2.55). Surgery as an independent variable to predict survival was not significant on a Cox proportional hazards model ( p =0.97). LR in the surgical groups was 13.5% vs 17.5% in the non-surgical patients. The median OS was 64.5 months and disease-free survival (DFS) was 52.5 months. 5-Year OS was 54% and DFS survival 43%. Conclusion In patients with a complete or partial response to chemo-radiotherapy for locally advanced or inflammatory breast cancer, reserving surgery for those with residual or recurrent local disease did not appear to compromise survival. This finding would support examination of this treatment strategy by a randomised controlled trial.

Privatization of public rental housing has been a key element of Government housing policy in Britain since 1979, and the longer term consequences are now becoming apparent. In particular the role that the former public rental dwellings plays in the housing market on resale is becoming clearer. This article examines resales in rural Scotland and concludes that the dwellings are not being used as second homes or retirement homes and that most are being bought by locals on moderate incomes. Most incoming buyers, however, are elderly with property to sell and they can outbid local buyers. The dwellings will not be meeting the housing needs of the poorest households, however, as they are no longer available to rent. In the absence of new rented housing to replace dwellings lost to the rented sector through the Right‐to‐Buy, the housing choices of some of those who need to rent may have been seriously diminished.

The long‐term consequences of the sale of public sector dwellings to sitting tenants are under‐researched; in particular, the experience of tenant purchasers in the housing market subsequent to purchase is little known. This paper reports research designed to fill this gap in knowledge. Over 200 tenants who had bought their dwelling from the Scottish Special Housing Association and subsequently resold on the open market were traced using the Register fo Sasines and the Land Register and interviewed. Most had made considerable capital gains on resale and had used some of the realised capital to trade up in the housing market. They were, on average, slightly more affluent and younger than sitting tenant purchasers generally; they represented a group of households who were privileged within the public sector through living as tenants in the best stock and who were enabled by the Right to Buy to convert that good luck into hard cash and move into mainstream owner occupation. This good luck compounded...

British housing policy has, since 1979, been dominated by a shift from collectivist to market-oriented strategies. The single most important element of this policy shift has been the sale of public-sector dwellings to sitting tenants. The patterns of such sales have been well documented, but the longer-term effects on the broader housing market are less well understood. This paper is a report of the results of a research project into the resale by purchasing tenants of Scottish Special Housing Association dwellings over the period 1979–90. The findings are placed in the broader context of the general government housing policy aimed at widening the access to owner occupation for lower-income households. The authors conclude that the long-term impact of the sale of public-sector dwellings is more likely to widen choice for existing owners rather than to increase access to owner occupation.

The voting behaviour and general ideological values of samples of purchasers and non‐purchasers of council houses were investigated against the general theoretical debate concerning the relationship of tenure and political attitudes. It was hypothesised on the basis of this debate that purchasers would have been more likely than non‐purchasers to switch from Labour to Conservative between 1979 and 1983 and that they would be more likely to favour privatised and individualistic attitudes in general. It was found that purchasers were indeed more likely to vote Conservative than non‐purchasers, but that desertions from the Labour Party were more in favour of the Alliance than the Conservatives. Purchasers were more likely than non‐purchasers to favour privatised and individualistic political attitudes, but when controlling for social class this relationship was restricted to manual social classes only.

The pattern of council house sales in one housing authority, the City of Aberdeen, was monitored over a two year period since the 'Right to Buy' legislation came into force. The pattern of sales was variable, both spatially and between house types. Semi-detached and terraced properties sold at a greater rate than flatted properties, and estates with higher socio-economic status and a higher popularity rating experienced a greater level of sales. This suggests that over the medium to long term, a continued policy of unrestricted sales will have a deleterious effect on the desirability of the remaining public sector stock and will increase the pressures towards a residualisation of public sector housing.

The distribution of crime within the city of Aberdeen for the years 1981 and 1982 was analysed, both in terms of total numbers of crimes in each police beat and in terms of crime rates per 1000 resident population. Crime rates were also analysed in conjunction with selected variables from the 1981 Census. Distinctive patterns were found in which crime rates were shown to be statistically related to social class, tenure and unemployment. High crime rates were found in the city centre, and areas of public sector housing, and low crime rates were found in the more affluent owner‐occupied suburbs.

The various attempts that have been made to analyse and develop a theory of spatial choice are reviewed and the weaknesses of these attempts highlighted. In particular the use of revealed-preference theory is criticised on the grounds that mere modification of aspatial economic theories to take account of the spatial dimension may reduce the original aspatial economic theory to an inconsistent and nonoperational set of ideas. Neoclassical economic theory and behavioural notions are seen not as mutually exclusive but as points on a spectrum of possible choice models, and a general framework for the analysis of spatial choices is suggested which attempts to marry these approaches together in a logical, integrated way.

It has been argued that council house sales will contribute towards a more general process of residualization of public sector housing. Empirical evidence is presented in this context derived from surveys of purchasers and non-purchasers of council dwellings in the city of Aberdeen. This evidence confirms that purchasers and non-purchasers exhibit different socio-economic characteristics and after only four years of the Right to Buy legislation significant numbers of households in social classes I, II and III have left the public sector via the mechanism of sales. The small number of sales relative to the stock as a whole, however, has meant that the overall contribution of sales towards residualization has been small. This evidence from Aberdeen is compared to evidence from elsewhere and related to the varying pattern of sales across the country as a whole.

The recently published Housing Bill for Scotland proposes major changes in the way rented housing is provided north of the border and a much reduced role for local authorities. This short paper summarises the proposed legislation and offers a brief assessment of its possible consequences.

Recent years have seen rapid and continuing change in education in general and in higher education in particular. This paper reviews the implications of these changes for teaching and research in geography in universities in Scotland. It concludes that geography departments in universities in Scotland may look to the future with optimism. The review is based on statistics collected by Professor D.E. Sugden from Heads of Departments of Geography in universities in Scotland. The assistance and cooperation of Professor Sugden and other departmental heads are gratefully acknowledged.