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Seebeck measurements of n-type amorphous germanium telluride thin films (100 nm) containing oxygen and implanted with Bismuth (Bi) have been studied under dark and monochromatic light conditions from 1800 to 400 nm. The Bi-doped film has a negative Seebeck coefficient indicating its n-type nature that results from the implantation compared to the p-type undoped films. Upon illumination with monochromatic light across the near-infrared and visible region the magnitude of the measured Seebeck voltage increases (becomes more negative). This increase in Seebeck coefficient displays distinctive behaviours in different spectral regions and is caused by the inclusion of Bi ions as foreign impurities. Furthermore, the Seebeck coefficients are used to determine the film electrical properties and enable, along with complementary characterisation including X-ray photoelectron spectroscopy, electronic band diagrams to be proposed for before and after Bi ion implantation. The photo-Seebeck technique is utilised for the first time to probe the trap states created due to the implantation, providing an understanding of the mechanisms behind non-equilibrium carrier-type reversal in an amorphous system, including the modification of electronic and optoelectronic properties such as the optical bandgap.

Wetting of carbon surfaces is one of the most widespread, yet poorly understood, physical phenomena. Control over wetting properties underpins the operation of aqueous energy-storage devices and carbon-based filtration systems. Electrowetting, the variation in the contact angle with an applied potential, is the most straightforward way of introducing control over wetting. Here, we study electrowetting directly on graphitic surfaces with the use of aqueous electrolytes to show that reversible control of wetting can be achieved and quantitatively understood using models of the interfacial capacitance. We manifest that the use of highly concentrated aqueous electrolytes induces a fully symmetric and reversible wetting behavior without degradation of the substrate within the unprecedented potential window of 2.8 V. We demonstrate where the classical "Young-Lippmann" models apply, and break down, and discuss reasons for the latter, establishing relations among the applied bias, the electrolyte concentration, and the resultant contact angle. The approach is extended to electrowetting at the liquid|liquid interface, where a concentrated aqueous electrolyte drives reversibly the electrowetting response of an insulating organic phase with a significantly decreased potential threshold. In summary, this study highlights the beneficial effect of highly concentrated aqueous electrolytes on the electrowettability of carbon surfaces, being directly related to the performance of carbon-based aqueous energy-storage systems and electronic and microfluidic devices.

Conductometric gas sensors (CGS) provide a reproducible gas response at a low cost but their operation mechanisms are still not fully understood. In this paper, we elucidate the nature of interactions between SnO2, a common gas-sensitive material, and O2, a ubiquitous gas central to the detection mechanisms of CGS. Using synchrotron radiation, we investigated a working SnO2 sensor under operando conditions via near-ambient pressure (NAP) XPS with simultaneous resistance measurements, and created a depth profile of the variable near-surface stoichiometry of SnO2−x as a function of O2 pressure. Our results reveal a correlation between the dynamically changing surface oxygen vacancies and the resistance response in SnO2-based CGS. While oxygen adsorbates were observed in this study we conclude that these are an intermediary in oxygen transport between the gas phase and the lattice, and that surface oxygen vacancies, not the observed oxygen adsorbates, are central to response generation in SnO2-based gas sensors.

Significance The trend toward individual quota and discard bans presents a challenge for mixed fisheries: how to avoid widespread underutilization of quota due to choking effects of individual species for which quota is exhausted. Iceland’s demersal fishery has met this challenge using the most elaborate set of balancing mechanisms in the world. We investigated the performance of the Icelandic system and find pervasive incentives inherent in the system’s design. The absence of persistent overfishing of individual stocks is attributed to limits that have been tightened over time and are very strict for the primary target species. These results highlight the potential for balancing mechanisms to facilitate sustainable exploitation of distinct interconnected resources and the importance of adapting implementation to local circumstances., Fishers with individual catch quota, but limited control over the mix of species caught, depend on trade and catch–quota balancing allowances to fully utilize their quota without discarding. However, these allowances can theoretically lead to overfishing if total allowable catches (TACs) are consistently exceeded. This study investigates usage of balancing allowances by the Icelandic demersal fleet over 2001–2017, for over 1,900 vessels. When a vessel’s demersal catch exceeds owned and leased quota for a given species, the gap can be bridged by borrowing quota from the subsequent fishing period or transforming unutilized quota in other species, restricted by limits. Conversely, excess quota can be saved or transformed into quota for species where there is a shortfall. We found evidence that balancing behavior is frequently similar across the fleet. Transformations are consistent with indicators of a general quota shortage and potential for arbitrage caused by differences in conversion ratios used for transformation and lease prices. Larger companies contribute more to these patterns. Nevertheless, TAC overages are generally modest especially in recent years—key reasons appear to be the tightening of vessel transformation limits and the central role of Atlantic cod, which is the main target species but cannot be persistently overfished due to a specific prohibition on positive transformations into the species. These results show how the tailored design of the Icelandic catch–quota balancing system has helped in balancing economic and ecological goals of management. We suggest policy changes that could further reduce ecological risks, e.g., prioritizing between-year transfers over transformations.

Conductometric gas sensors (CGS) provide a reproducible gas response at a low cost but their operation mechanisms are still not fully understood. In this paper, we elucidate the nature of interactions between SnO

Developing a simple, safe, and efficient route for the preparation of nanoparticulate ternary Chevrel phases MxMo6S8 (CPs; where M = metal) is of great interest because of their applications in energy conversion and storage technologies. Currently, the wide use of these materials is restricted by the prolonged reaction time, the high energy demands required for their synthesis, the complexity of the preparation process, and the ambiguity in the size of the resultant particles. Herein, we report a simple, efficient, and controllable molecular precursor approach for the synthesis of nanoscale CPs without the use of hydrogen gas as a reducing agent. A mixture of precursors based on molybdenum and copper dithiocarbamate complexes was subjected to thermolysis in the presence of finely divided molybdenum to furnish the copper CP, Cu2Mo6S8. The successful formation of the Cu2Mo6S8 CP is confirmed by X-ray diffraction analysis and Raman spectroscopy, while the surface chemistry of the material was examined by X-ray photoelectron spectroscopy photon depth profiling via tunable synchrotron radiation. Microscopic characterization results demonstrate that the synthesized material has a homogeneous structure at the nanoscale, in contrast to the microparticles obtained from conventional approaches previously reported. The prepared CP was assessed as an electrocatalyst for the hydrogen evolution reaction in acidic media. Because of its unique nanoscale texturing, the Cu-leached CP, Mo6S8, exhibits a highly promising electrocatalytic activity toward hydrogen evolution with an overpotential required to reach a current density of 10 mA cm-2 equal to 265 mV versus reversible hydrogen electrode. The overpotential reduces to 232 mV upon mixing of the catalyst with 20% w/w of high-conductivity carbon. It is expected that the proposed synthetic strategy, which represents a facile route to tailored CPs, can be extended to the preparation of versatile, easily tunable CP Mo6S8-based electrode materials for applications in electrocatalysis.

The scarcity and cost of noble metals used in commercial electrolyzers limit the sustainability and scalability of water electrolysis for green hydrogen production. Herein, we report the ultralow loading of Au nanoparticles onto MoS2 electrodes by the spontaneous process of galvanic deposition. AuNP@MoS2 electrode synthesis was optimized, and electrodes containing the smallest Au nanoparticle diameter (2.9 nm) and the lowest Au loading (0.044 μg cm–2) exhibited the best overall and intrinsic electrocatalytic performance. This enhancement is attributed to an increased Au–MoS2 interaction with smaller nanoparticles, making the MoS2 electrode more n-type. DC electrochemical characterization for the AuNP@MoS2 electrodes showed an exchange current density of 7.28 μA cm–2 and an overpotential at 10 mA cm–2 of −323 mV. These values are 4.5 times higher and 100 mV lower than those of the unmodified MoS2 electrode, respectively. Electrochemical AC experiments were used to evaluate the electrodes’ intrinsic catalytic activity, and it was shown that the AuNP@MoS2 electrodes exhibited an enhanced activity by as much as 3.5 times compared with MoS2. Additionally, the turnover frequency as estimated by the reciprocal of the RctCdl product, the latter calculated from the AC data, is estimated to be 58.8 s–1 and is among one of the highest reported for composite MoS2 materials.

The kidneys eliminate most drugs and their metabolites from the body. Inappropriate dosing of drugs in the setting of renal insufficiency is therefore a major hazard for patient safety. Moreover, drugs can be the cause of kidney disease, and nephrotoxicity manifests in a number of ways.

Scalable synthesis of 2D materials is a prerequisite for their commercial exploitation. Here, a novel method of producing nanocrystalline molybdenum disulfide (MoS2) at the liquid–liquid interface is demonstrated by decomposing a molecular precursor (tetrakis(N,N-diethyldithiocarbamato) molybdenum(IV)) in an organic solvent. The decomposition occurs over a few hours at room temperature without stirring or the addition of any surfactants, producing MoS2 which can be isolated onto substrates of choice. The formation of MoS2 at the liquid–liquid interface can be accelerated by the inclusion of hydroxide ions in the aqueous phase, which we propose to act as a catalyst. The precursor concentration was varied to minimize MoS2 thickness, and the organic solvent was chosen to optimize the speed and quality of formation. The kinetics of the MoS2 formation has been investigated, and a reaction mechanism has been proposed. The synthesis method is, to the best of our knowledge, the first reported room-temperature synthesis of transition-metal dichalcogenides, offering a potential solution to scalable 2D material production.

We report a rapid solution-phase strategy to synthesize alloyed PtNi nanoparticles which demonstrate outstanding functionality for the oxygen reduction reaction (ORR). This one-pot co-reduction colloidal synthesis results in a monodisperse population of single-crystal nanoparticles of rhombic dodecahedral morphology, with Pt enriched edges and compositions close to Pt1Ni2. We use nanoscale 3D compositional analysis to reveal for the first time that oleylamine (OAm)-aging of the rhombic dodecahedral Pt1Ni2 particles results in Ni leaching from surface facets, producing aged particles with concave faceting, an exceptionally high surface area and a composition of Pt2Ni1. We show that the modified atomic nanostructures catalytically outperform the original PtNi rhombic dodecahedral particles by more than 2-fold and also yield improved cycling durability. Their functionality for the ORR far exceeds commercially available Pt/C nanoparticle electrocatalysts, both in terms of mass-specific activities (up to a 25-fold increase) and intrinsic area-specific activities (up to a 27-fold increase)., Comment: 14 pages, 4 figures, supplementary information

Graphene nanobubbles (GNBs) have become the subject of recent research due to their novel physical properties. However, present methods to create them involve either extreme conditions or complex sample fabrication. We present a novel approach which relies on the intercalation of small molecules (NH3), their surface-mediated decomposition and the formation of larger molecules (N2) which are then entrapped beneath the graphene in bubbles. Our hypothesised reaction mechanism requires the copper substrate, on which our graphene is grown via chemical vapour deposition (CVD), to be oxidised before the reaction can occur. This was confirmed through X-ray photoelectron spectroscopy (XPS) data of both oxidised and reduced Cu substrate samples. The GNBs have been analysed through atomic force microscopy (AFM, after NH3 treatment) and XPS, which reveals the formation of five distinct N 1s peaks, attributed to N2 entrapment, N doping species and atomic nitrogen bonded with the Cu within the substrate. This method is simple, occurs at low temperatures (520 K) and integrates very easily with conventional CVD graphene growth, so presents an opportunity to open up this field of research further.

Cu and CuAl alloy (90%:10% wt) films deposited on thermally grown SiO2 were studied using thermal stress testing in vacuum, N2 flow and atmosphere ambient all at a temperature of 500 °C, in order to rigorously test the effectiveness of the incorporation of Al into a Cu film at preventing degradation of the metal layer and diffusion of Cu into the underlying SiO2 dielectric. Capacitance voltage testing of metal-oxide-semiconductor (MOS) devices, using the Cu and the CuAl alloy as the gate metal show the failure of the Cu reference set via diffusion of Cu at the metal / SiO2 interface in contrast to the stability of the CuAl alloy devices, even following a 500 °C anneal in atmosphere ambient. The flatband voltage of the Cu reference MOS structures were altered by the application of an external applied voltage bias, consistent with the diffusion and mobility of Cu+ ions into the underlying SiO2 layer. Optical and scanning electron microscopies of the surface metal layers show the degradation and delamination of the pure Cu films throughout the experimental anneal stages, in contrast to the stability of the CuAl alloy. X-ray photoelectron spectroscopy shows the growth of Al oxide at the surface of the CuAl alloy following thermal anneal which acts to passivate the film, preventing Cu oxide formation which was identified in the pure Cu reference sample set. Transmission electron microscopy analysis shows the inter-diffusion of Cu at the Cu / SiO2 interface following anneal, in contrast to the CuAl alloy which shows the growth of a continuous barrier layer interface. Time-of-flight secondary ion mass spectroscopy (ToF-SIMS) was used to profile the entire metal / SiO2 / Si stack via 3 dimensional reconstructions, showing the inward diffusion of Cu within the Cu control samples and containment of Cu within the metal layer of the CuAl alloy samples.

Hydrogenation of benzoic acid in the liquid phase over Pt/SnO2 has afforded excellent selectivity to benzyl alcohol under mild reaction conditions (97 % at 98 % conversion of benzoic acid). DFT calculations have shown that the favoured mode of adsorption of benzoic acid switched from the aromatic ring to the acid carbonyl group with partial reduction of the SnO2 support. The switch in adsorption mode corroborates the experimentally observed selectivity with acid carbonyl group adsorption and hydrogenation occurring over Pt/SnO2. Reduction of Pt/SnO2 was observed by in-situ XPS forming a degree of metallic tin and complete reduction of Pt which could lead to Pt-Sn alloy phases and/or migration of SnOx onto Pt blocking sites for ring hydrogenation. No hydrogenation of benzene or the benzene ring of benzoic acid was observed over Pt/SnO2 with oxidic tin species at the interface of Pt particles proposed to activate the acid carbonyl group for hydrogenation.

ZnO nanorods were grown on silicon (Si) substrates by two techniques: (i) Chemical Bath Deposition (CBD) and (ii) a CBD seed layer combined with Carbothermal Reduction Vapor Phase Transport (CTR-VPT). The structured ZnO nanorods were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and contact angle measurments. The photoelectrochemical property of ZnO nanorods were analyzed by linear voltammetry under UV-ABC light excitation. Using the ZnO nanorod samples as photoanodes, the removal of methylene blue (MB) as a representative organic compound was studied by the photoelectrocatalytic (PEC) technique applying a potential (E) of 0.6 V. For comparison purposes, experiments were performed under the same conditions using photocatalysis (PC), direct photolysis and using samples of pure Si (support material) as working electrodes in PEC. XRD analyses of ZnO prepared by both methods showed the expected ZnO wurtzite phase and a preferred c-axial orientation in the growth of the nanorods. The presence of ZnO was further confirmed by XPS and contact angle measurements showed that ZnO grown by CBD (ZnO/CBD) had a slightly hydrophobic behavior while ZnO grown by CTR-VPT (ZnO/CTR-VPT) is hydrophilic. Both ZnO sample types were shown to be photoactive, with ZnO/CBD showing higher resultant photocurrent compared to ZnO/CTR-VPT. For the degradation of MB 53% of the compound was removed using ZnO/CBD as a working electrode, while using the ZnO/CTR-VPT electrode led to a removal of 43% of MB. However, direct photolysis alone removed 39% of the MB. The lower removal of MB using ZnO/CTR-VPT samples was related to surface dissociation during the degradation process. The results show that ZnO nanorods prepared by the CBD techique are a promising photoelectrode for PEC applications. Our data also indicate that CTR-VPT-grown nanorods produce uniform nanorod arrays, but this uniform nanostructure deposit does not lead to any increase in PEC activity.

© 2019 Elsevier B.V. Proton conducting oxide electrolyte materials could potentially lower the operating temperature of metal-supported solid oxide cells (MS-SOCs) to the intermediate range 400 to 600 °C. The porous metal substrate provides the advantages of MS-SOCs such as high thermal and redox cycling tolerance, low-cost of structural materials, and mechanical ruggedness. In this work, viability of co-sintering fabrication of metal-supported proton conducting solid oxide cells is investigated. Candidate proton conducting oxides including perovskite oxides BaZr 0.7 Ce 0.2 Y 0.1 O 3−δ , SrZr 0.5 Ce 0.4 Y 0.1 O 3−δ , and Ba 3 Ca 1.18 Nb 1.82 O 9−δ , pyrochlore oxides La 1.95 Ca 0.05 Zr 2 O 7−δ and La 2 Ce 2 O 7 , and acceptor doped rare-earth ortho-niobate La 0.99 Ca 0.01 NbO 4 are synthesized via solid state reactive or sol-gel methods. These ceramics are sintered at 1450 °C in reducing environment alone and supported on Fe-Cr alloy metal support, and their key characteristics such as phase formation, sintering property, and chemical compatibility with metal support are determined. Most electrolyte candidates suffer from one or more challenges identified for this fabrication approach, including: phase decomposition in reducing atmosphere, evaporation of electrolyte constituents, contamination of the electrolyte with Si and Cr from the metal support, and incomplete electrolyte sintering. In contrast, La 0.99 Ca 0.01 NbO 4 is found to be highly compatible with the metal support and co-sintering processing in reducing atmosphere. A metal-supported cell is fabricated with La 0.99 Ca 0.01 NbO 4 electrolyte, ferritic stainless steel support, Pt air electrode and nanoparticulate ceria-Ni hydrogen electrocatalyst. The total resistance is 50 Ω·cm 2 at 600 °C. This work clearly demonstrates the challenges, opportunities, and breakthrough of metal-supported proton-conducting solid oxide cells by co-sintering fabrication.

Developing inexpensive, earth abundant materials for electrocatalytic and photoelectrochemical water splitting is critical to the decarburization of our energy system. Aerosol-assisted chemical vapor deposition (AACVD) is a potentially scalable, one-step synthesis technique that can produce large area, homogenous edge-aligned films of transition metal dichalcogenides including MoS2. Herein, we report a hydrogen evolution reaction (HER) study on such electrode films under acidic conditions. Using iR compensated near-steady state DC current-potential measurements and linear sweep voltammetry, the HER onset potential is recorded at −175 mV vs. RHE (current density 0.1 mA cm−2), while a current density of 10 mA cm−2 per nominal area is reached at an overpotential of −430 mV vs. RHE. A Tafel slope of 113 mV dec−1 suggests the existence of increased edge-active sites on the surface of 2H-MoS2. The electrodes offered high stability over 5000 cycles, which continued to improve with cycling, with the current density at −350 mV improved by a factor exceeding 20 between the 1st and 5000th cycle. X-ray photoelectron spectroscopy, contact angle measurements and electrochemical impedance spectroscopy were employed to provide thorough insights on the changes in the intrinsic properties of the material, which led to the observed HER activity enhancement with cycling. It is shown that a reduction in the surface oxide layer and increased electrowetting are the reasons for the improved performance. Electrodes of differing thicknesses were prepared and their performance was compared in association with the surface morphology. The best performing electrode had the lowest mass loading of MoS2, which is attributed to improved faradaic efficiency through the resistive 2H-MoS2 electrode.

Limiting the use of fossil fuels in fisheries is important for industry competitiveness and for achievement of greenhouse gas reduction targets, particularly in countries like Iceland where fishing contributes significantly to both the economy and emissions. This article analyses harvesting fuel intensity in Iceland between 2002 and 2017 and examines potential underlying drivers. Fuel intensity for demersal vessel segments and species declined over the period whereas pelagic intensities increased slightly. Variation was strongly correlated with stock levels, highlighting the potential for stock rebuilding to reduce fuel intensity. Correlation was weaker in the demersal sector. A potential explanation is that increased abundance of cod led to choke effects as vessels sought to avoid cod. Analysis of operational data indicated a lower average engine load for a sample of pelagic vessels compared to demersal vessels, suggesting engine load-balancing as an opportunity to improve engine efficiency. Finally, a potential policy instrument for reducing emission in ITQ-managed fisheries is presented, in which harvesters own and trade individual emissions quota based on total allowable emissions for the fishery.

In-situ analysis of the TiO2/water interface via near ambient pressure–x-ray photoelectron spectroscopy (NAP–XPS) is demonstrated in both a lab based system (NAP-cell configuration) and synchrotron endstation (backfill configuration). Ultra-thin wetting layers of liquid water (∼10 nm) are formed on a rutile TiO2 surface with minimal contamination present in addition to unique insight during the growth of the liquid films as indicated via NAP–XPS, in-situ sample temperature and background vapour pressure monitoring. Chemical changes at the solid/liquid interface are also demonstrated via healing of Ti3+ surface defect states. Photon depth profiling of the as grown liquid layers indicate that the formed films are ultra-thin (∼10 nm) and likely to be continuous in nature. This work demonstrates a novel and flexible approach for studying the solid/liquid interface via NAP–XPS which is readily integrated with any form of NAP–XPS system, thereby making a critical interface of study available to a wide audience of researchers for use in operando electrochemical and photocatalytic research.

The introduction of Iceland's current ITQ system in 1991 has been followed by significant consolidation of the harvesting sector. This paper quantifies the rate of consolidation by measuring the concentration of quota holdings at company and vessel level for eight commercially important demersal and pelagic species over the period 1991–2017, using concentration ratios and the Herfindahl-Hirschman index. These metrics are complemented by calculation of the Instability Index, which is a measure of competitive rivalry. The results indicate a significant increase in concentration across all species at both company and vessel level, although company consolidation appeared to accelerate relative to fleet consolidation during the early 2000′s when the Icelandic financial sector was privatised and then slowed in the wake of the financial crisis in 2008. The Instability Index fell for all species, indicating a general decline in competitive rivalry. Concentration varies greatly by species, and is lowest for cod and haddock which are caught extensively by small and medium-sized vessels and highest in the pelagic sector, reaching levels associated with market power. Finally, there is evidence that regulatory limits on individual company quota holdings may be starting to hamper further consolidation and any associated efficiency gains.

Copper/SiO2/Si metal-oxide-semiconductor (MOS) devices both with and without a MnSiO3 barrier layer at the Cu/SiO2 interface have been fabricated in an ultrahigh vacuum X-ray photoelectron spectroscopy (XPS) system, which allows interface chemical characterization of the barrier formation process to be directly correlated with electrical testing of barrier layer effectiveness. Capacitance voltage (CV) analysis, before and after tube furnace anneals of the fabricated MOS structures showed that the presence of the MnSiO3 barrier layer significantly improved electric stability of the device structures. Evidence of improved adhesion of the deposited copper layer to the MnSiO3 surface compared to the clean SiO2 surface was apparent both from tape tests and while probing the samples during electrical testing. Secondary ion mass spectroscopy (SIMS) depth profiling measurements of the MOS test structures reveal distinct differences of copper diffusion into the SiO2 dielectric layers following the thermal anneal depending on the presence of the MnSiO3 barrier layer.

We have produced isotopically enriched ZnO nanorods using Zn-enriched ZnO source powder by vapour phase transport on silicon substrates buffer coated with unenriched ZnO seed layers. SEM and XRD data confirm successful growth of high quality, dense, c-axis aligned nanorods over a substantial surface area. Raman. data show a shift of greater than 1 cm(-1) in the peak position of the Raman scattered peaks due to the E-2(low) and E-2(high) phonon modes when the Zn isotope is changed from Zn-64 to Zn-68, consistent with previous work, thus confirming successful isotopic enrichment. SIMS data provides additional confirmation of enrichmenr. The optical qualiry (as dererrninecl by phoLoluminescence feature inrensiLy and line width) is excellenr. Samples with Zn isoLopic enrichmenr ranging from (ZnO)-Zn-64 to (ZnO)-Zn-68 display a shift in recombinarion energy of the bound excirons al. the band edge (3.34-3.37 eV) of similar to 0.6 meV. This blue-shift is also consisren d. with previously published data, further confirming both the excellen d. oprical qualiry and successful isoLopic subsfiLurion of ZnO nanorods using this relarively simple growth method. (c) 2015 Elsevier B.V. All rights reserved.

Kidney disease presents in a number of different ways and to a variety of practitioners. The presentation may be non-specific and a high index of suspicion is required to allow early detection and intervention. A systematic clinical assessment is vital to facilitate timely referral and appropriate management of renal disease. The history and examination should be tailored to the type of presentation, and will be dictated by the degree of chronicity of the disease process. In all cases the urine dipstick is a crucial part of the clinical examination. This article presents an overview of the approach to evaluation and diagnosis in the patient with kidney disease. It is intended to be read in conjunction with the other articles in these chapters.

In this work the potential of thin manganese oxide layers deposited by physical vapor deposition at moderate vacuum pressure to significantly retard the corrosion of silicon photo-anodes during the oxidation of water is reported. Results show that manganese oxide layers up to 10 nm thick display sufficient transmission of solar frequency radiation and electrical conductivity to facilitate efficient oxidation of water by the underlying silicon while offering complete protection from oxidation of the silicon substrate for more than 14 h. Data from x-ray photoelectron spectroscopy confirms that the increased lifetime observed when using manganese oxide as a protective layer is a result of the inhibition of the growth of silicon oxide during the reaction.

Rare earth oxides (REOs) are attracting attention for use as cost-effective, high-performance dropwise condensers because of their favorable thermal properties and robust nature. However, to engineer a suitable surface for industrial applications, the mechanism governing wetting must be first fully elucidated. Recent studies exploring the water-wetting state of REOs have suggested that these oxides are intrinsically hydrophobic owing to the unique electronic structure of the lanthanide series. These claims have been countered with evidence that they are inherently hydrophilic and that adsorption of contaminants from the environment is responsible for the apparent hydrophobic nature of these surfaces. Here, using X-ray photoelectron spectroscopy and dynamic water contact angle measurements, we provide further evidence to show that REOs are intrinsically hydrophilic, with ceria demonstrating advancing water contact angles of ≈6° in a clean surface state and similar surface energies to two transition metal oxides (≳72 mJ/m

Si 2p spectra displaying the use of deposited Si as a BE reference on different carbon doped oxide surfaces. Highlights the carbon doped oxide substrate shift to lower BE with increasing carbon content.Display Omitted Deposited films on CDO films provide BE references for Si2p and O1s core levels.Correlation between carbon content in the films and the BE of the core level peaks.XPS has been used to characterize MnSiO3 formation on the range of substrates.The use of oxidised Mn films tend to minimize the formation of Mn carbide. In this study X-ray photoelectron spectroscopy (XPS) has been used to characterize manganese silicate Cu diffusion barrier layer formation on a range of ultralow-? (ULK) carbon doped oxide (CDO) layers. Ultra-thin Si and Mn oxide films were deposited in order to provide accurate binding energy (BE) references for the Si 2p and O 1s core levels of the dielectric materials. The results indicate that there is a strong correlation between carbon content in the CDO films and the BE position of both the Si 2p and O 1s core level peaks. Furthermore, it has been shown that the full width half maximum (FWHM) of these peaks are significantly larger than those observed in SiO2 leading to complications in the analysis and identification of barrier layer formation on these low-? substrates. In a separate experiment, the deposition and high temperature annealing of thin fully oxidized Mn layers (MnOy, where y?1) on these ULK CDO substrates suggests the formation of an interface layer consistent with MnSiO3 based on analysis of both the O 1s and Mn 2p core level spectra. It is also shown that the use of oxidized Mn films tend to minimize the formation of Mn carbide within the barrier layer region in agreement with previous studies on other CDO substrates.

The chemical interaction of Al on a SiO 2 dielectric layer and the addition of Al into Ru thin films on SiO 2 for use as copper diffusion barrier layers are assessed in situ using X-ray photoelectron spectroscopy. Thin (∼1–2 nm) Al films were deposited on a SiO 2 substrate and in a separate experiment on a 3 nm Ru liner layer on SiO 2 , and both Al/SiO 2 and Al/Ru/SiO 2 structures were subsequently thermally annealed. Results indicate the reduction of SiO 2 and the subsequent formation of Al 2 O 3 with the release of Si from the dielectric. The Al/Ru/SiO 2 structure showed evidence for the diffusion of Al through the Ru layer and the subsequent interaction of the Al with the underlying SiO 2 dielectric to form Al 2 O 3 . In this case, the reduction of SiO 2 leads to the release of Si from the dielectric and the subsequent chemical interaction of Ru with Si.

The large gap between observed profitability and estimated potential efficiency of the ITQ-based Icelandic harvesting sector begs the question – how much is due to rent dissipation and how much to transfers? This paper examines the contribution of rent transfers from vessel owners to other stakeholders, focusing on processors, fishermen and the government, and finds evidence of substantial transfers, particularly to the first two groups. The mechanisms underlying these transfers are shown to involve internal transfer prices of fish within integrated harvester-processors and fishermen crew shares, both of which are centrally negotiated by vessel owner and fishermen organisations. A speculative model is proposed whereby the security of grandfathered quota property rights is undermined by public pressure to tax visible resource rent. Vessel owners alleviate this pressure by shifting profits downstream to vertically integrated processing facilities, in cooperation with fishermen unions.

Proton conducting oxide electrolyte materials could potentially lower the operating temperature of metal-supported solid oxide cells (MS-SOCs) to the intermediate range 400 to 600 °C. The porous metal substrate provides the advantages of MS-SOCs such as high thermal and redox cycling tolerance, low-cost of structural materials, and mechanical ruggedness. The cell structure for fuel cell and electrolysis operation is shown in Figure 1. To incorporate proton-conductors into metal-supported cell configuration through co-sintering fabrication, a key factor is that the proton conductors must be compatible with reducing atmosphere sintering, as the porous metal substrate can not be fired in oxidizing atmosphere. In this work, viability of co-sintering fabrication of metal-supported proton conducting solid oxide cells is investigated. Candidate proton-conducting ceramics including perovskite-type oxides BaZr0.7Ce0.2Y0.1O3-δ (BZCY), SrZr0.5Ce0.4Y0.1O3-δ (SZCY), and Ba3Ca1.18Nb1.82O9-δ (BCN), pyrochlore-type oxides La1.95Ca0.05Zr2O7-δ (LCZ) and La2Ce2O7 (LCO), and acceptor doped rare-earth ortho-niobates La0.99Ca0.01NbO4 (LCN) were synthesized via solid state reactive synthesis or sol-gel synthesis. These ceramics are sintered at 1450°C in reducing environment alone and supported on Fe-Cr alloy metal support, and their key characteristics such as phase formation, sintering property, and chemical compatibility with metal support are determined. Most electrolyte candidates suffer from one or more challenges identified for this fabrication approach, including: phase decomposition in reducing atmosphere, evaporation of electrolyte constituents, contamination of the electrolyte with Si and Cr from the metal support, and incomplete electrolyte sintering. BZCY is particularly interesting because of its high proton conductivity, but it is found to suffer from reaction with Si and Cr present in the metal support, and loss of Ba via evaporation during sintering. Various approaches to overcome these limitations are proposed, and preliminary assessment indicates that the use of barrier layers, low-Si-content stainless steel, and sintering aids warrant further development. In contrast, La0.99Ca0.01NbO4 is found to be highly compatible with the metal support and co-sintering processing in reducing atmosphere, allowing dense electrolyte and porous electrode made of LCN to be co-sintered on porous stainless steel, Figure 2. A metal-supported cell is fabricated with La0.99Ca0.01NbO4 electrolyte, ferritic stainless steel support, Pt air electrode and nanoparticulate ceria-Ni hydrogen electrocatalyst. The total resistance is 50 Ω∙cm2 at 600 °C. This work clearly demonstrates the challenges, opportunities, and breakthrough of metal-supported proton-conducting solid oxide cells by co-sintering fabrication. Figure 1

This study shows direct experimental evidence of the catalytic activity of bimetallic ruthenium/manganese surfaces toward oxygen and determines how this activity impacts the thermodynamic stability of Ru/Mn-based copper diffusion barrier layers for advanced microelectronic devices. X-ray photoemission spectroscopy (XPS) analysis, as part of a fully in situ experimental procedure, showed the thermal dissociation of manganese monoxide (MnO) and the desorption of oxygen in the presence of Ru at 500 °C. This is in contrast with the thermal stability of MnO in the absence of Ru at temperatures up to 700 °C and suggests that the presence of Ru increases the catalytic activity of Mn surfaces by reducing the MnO dissociation energy and the oxygen desorption energy. XPS analysis showed no evidence of a change in the chemical composition of the Ru layer, consistent with previously proposed mechanisms for oxygen catalysis on bimetallic surfaces. Further studies investigated the impact of the presence of Ru on the ch...

Lattice Boltzmann (LB) computational code developed by the authors is used to simulate the development of thermal explosion in reactive mixtures subjected to convection. The work demonstrates an LB modeling application to reactive flows by considering practically important combustion and fire research problem. The problem of convection-affected thermal explosion is of particular interest from both theoretical and practical points of view. Critical conditions for convection-affected thermal explosion are found in the range of Rayleigh numbers 103–108.

Metal-supported solid oxide fuel cells (MS-SOFC) display a number of advantages over conventional all-ceramic SOFCs, including low-cost structural materials (e.g. stainless steel), mechanical ruggedness, excellent tolerance to redox cycling, and extremely fast start-up capability. These properties make MS-SOFCs ideally suited for range extenders in vehicles due to tolerance to thermal fluctuations following load changes or intermittent fuel flow. Directly fueled with ethanol or ethanol-water mixture, MS-SOFCs provide promising alternative for mobile applications. In this talk, the recent progress on performance and durability of symmetric MS-SOFCs, pioneered at LBNL, will be addressed. The development of new electrolyte, new cathode and anode catalysts, optimized cell configuration, and processing techniques will be discussed. The catalyst infiltration technique allows for flexible and layered electrode composition, depending on the system applications and fuels. Our current state-of-the-art MS-SOFCs achieve power density of ≥1.5 W/cm2 at 700 °C and ≥2.85 W/cm2 at 800 °C when fueled with humidified hydrogen which is, to the best of our knowledge, the highest performance reported in the literature for stainless steel MS-SOFCs. However, catalyst coarsening and Cr deposition from the stainless steel metal support are known to occur1, and the primary degradation mechanisms are elucidated and tackled to improve the durability. The cell area specific resistance (ASR) of 2 at 700 °C meets the projected requirements for commercialization in vehicles. Initial studies on button cells fueled with ethanol/water mixture are investigated and further efforts towards increasing power density and durability are addressed. 1M.C. Tucker, Journal of Power Sources, 369, 6-12, Nov. 2017. Acknowledgments The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency – Energy (ARPA-E), U.S. Department of Energy under work authorization number 13/CJ000/04/03. This work was funded in part by the U.S. Department of Energy under contract no. DE-AC02-05CH11231. Figure 1. (a) Illustration of a symmetric MS-SOFC configuration developed at LBNL, and (b) the highest cell performance obtained so far on the stainless steel MS-SOFCs. Figure 1

A copper–aluminium (CuAl) alloy (90%:10% wt) has been investigated in relation to segregation of the alloying element Al, from the alloy bulk during vacuum anneal treatments. X-ray photoelectron spectroscopy (XPS) measurements were used to track the surface enrichment of Al segregating from the alloy bulk during in situ ultra-high vacuum anneals. Secondary ion mass spectroscopy (SIMS) indicates a build-up of Al at the surface of the annealed alloy relative to the bulk composition. Metal oxide semiconductor (MOS) CuAl/SiO 2 /Si structures show a shift in flatband voltage upon thermal anneal consistent with the segregation of the Al to the alloy/SiO 2 interface. Electrical four point probe measurements indicate that the segregation of Al from the alloy bulk following thermal annealing results in a decrease in film resistivity. X-ray diffraction data shows evidence for significant changes in crystal structure upon annealing, providing further evidence for expulsion of Al from the alloy bulk.

The surface treatment of low-k dielectric layers by exposure to atomic oxygen is presented as an alternative to plasma based treatments prior to barrier layer formation. High carbon content porous low-k dielectric films were subjected to increasing exposures of atomic oxygen and x-ray photoelectron spectroscopy (XPS) studies reveal both the depletion of carbon and the addition of oxygen at the surface. This treatment is shown to be thermally stable up to 400 °C. High resolution electron energy loss spectroscopy (EELS) elemental profiles show the removal of carbon from the surface of the treated films to a depth of ∼ 20 nm. In a separate experiment manganese (∼1–2 nm) was deposited on an oxygen treated substrate and thermally annealed to form MnSiO 3 . It is shown that the modification of the low-k surface made the chemical identification of MnSiO 3 formation possible by XPS analysis.

A copper-aluminium alloy (90:10wt%) has been investigated as a possible candidate for future interconnect applications. The tendency of the Al to segregate at the surface of the Cu following thermal anneal makes this alloy potentially suitable to function as a self-forming Cu diffusion barrier layer. X-ray photoelectron spectroscopy (XPS) and electrical characterisation measurements were used to study the segregation of Al from the alloy bulk during annealing treatments. Four point probe measurements were used to gain additional information as to the electrical resistance of the CuAl alloy when annealed at various temperatures in vacuum using pure Cu as a reference. Capacitance-voltage (CV), current-voltage (IV) and bias thermal stress (BTS) test measurements were made on metal-oxide-semiconductor (MOS) structures fabricated with the CuAl alloy and compared to identical structures with pure Cu and Al contacts.

The chemical interaction of Al and Mn deposited on Ru thin films for use as copper diffusion barrier layers are assessed in-situ using x-ray photoelectron spectroscopy (XPS). Thin (∼1–2 nm) Al and Mn films were separately deposited on 3 nm Ru liner layers on SiO 2 , and both Al/Ru/SiO 2 and Mn/Ru/SiO 2 structures were subsequently thermally annealed. Results indicate the diffusion of both metals through the Ru thin films and the subsequent chemical interaction with the underlying SiO 2 substrate to form Al 2 O 3 and MnSiO 3 . In both cases, the reduction of SiO 2 leads to the release of Si from the dielectric and the upward diffusion of Si into the Ru liner layers.

The surface treatment of ultralow-κ dielectric layers by exposure to atomic oxygen is presented as a potential mechanism to modify the chemical composition of the dielectric surface to facilitate copper diffusion barrier layer formation. High carbon content, low-κ dielectric films of varying porosity were exposed to atomic oxygen treatments at room temperature, and x-ray photoelectron spectroscopy studies reveal both the depletion of carbon and the incorporation of oxygen at the surface. Subsequent dynamic water contact angle measurements show that the chemically modified surfaces become more hydrophilic after treatment, suggesting that the substrates have become more “SiO2-like” at the near surface region. This treatment is shown to be thermally stable up to 400 °C. High resolution electron energy loss spectroscopy elemental profiles confirm the localised removal of carbon from the surface region. Manganese (≈1 nm) was subsequently deposited on the modified substrates and thermally annealed to form surfa...