Surface EXAFS studies of chromium and titanium upon α-quartz (0001) surfaces

In this thesis two studies of reactive metal adsorption upon a low index single crystal silicon dioxide surface are presented in addition to a study of sulphur adsorption upon a low index single crystal nickel surface. Chromium growth upon the a-quartz Si02(0001) (J84xJ84) Rll 0 surface is studied at three coverages, 0.25±O.08 ML, 0.5±O.16 ML and 1.0±0.33 ML, using surface extended x-ray absorption fine structure (SEXAFS). SEXAFS measurements, from the chromium K-edge, recorded at both grazing and normal incidence show that chromium growth proceeds via the formation of mesoscopic particles with a body centred cubic (b.c.c.) like structure having an average nearest neighbour Cr-Cr distance of 2.36±O.03 A. This represents a contraction of 5.6 % from the bulk b.c.c. lattice spacing of 2.49 A. There is no evidence of a surface reaction between chromium and the surface oxygen. SEXAFS was used to study titanium reactional growth on a-quartz (0001) (J84xJ84) Rll 0 and (lx1). Three nominal coverages were studied, 0.25±O.08 ML, 0.5±O.16 ML and 1.0±O.33 ML. Both normal and grazing incidence SEXAFS data were recorded and show the formation of a spatially extensive region in which an interfacial reaction has occurred between surface oxygen and adsorbate titanium atoms. Coupled with this is the formation of subnanometre titanium clusters. The metal oxide has nearest neighbour Ti-O distances close to those of both the anatase and rutile forms of titania with the metallic titanium clusters having a Ti-Ti distance within experimental error that of bulk hexagonal close packed (h.c.p.) titanium, 2.89 A. A re-examination of the surface geometry of Ni(1l0)c(2x2)S using SEXAFS has been performed. Data out to an electron wavevector of 9 A-I are analysed with a new code to assess the influence of multiple scattering. The first shell S-Ni distance is determined to be 2.20±O.02 A with the next nearest neighbour distance being 2.29±O.02 A, giving a top-layer Ni expansion of 14±3% relative to the bulk. The influence of multiple scattering does not significantly alter these values from earlier studies

The rule-based insensitivity effect : a systematic review

Background. Adherence to inaccurate rules has been viewed as a characteristic of human rule-following (i.e., the rule-based insensitivity effect; RBIE) and has been thought to be exacerbated in individuals suffering from clinical conditions. This review intended to systematically examine these claims in adult populations. Methodology. We screened 1464 records which resulted in 21 studies that were deemed eligible for inclusion. Each of these studies was examined to determine: (1) if there is evidence for the RBIE in adults and (2) if this effect is larger in those suffering from psychological problems compared to their non-suffering counterparts. In addition, we investigated how (3) different operationalizations of the RBIE, and (4) the external validity and risks of bias of the experimental work investigating this effect, might influence the conclusions that can be drawn from the current systematic review. Results. (1) Out of the 20 studies that were relevant for examining if evidence exists for the RBIE in adults, only 11 were eligible for vote counting. Results showed that after the contingency change, the rule groups were more inclined to demonstrate behavior that was reinforced before the change, compared to their non-instructed counterparts. Critically, however, none of these studies examined if their no-instructions group was an adequate comparison group. As a result, this made it difficult to determine whether the effects that were observed in the rule groups could be attributed to the rules or instructions that were manipulated in those experiments. (2) The single study that was relevant for examining if adults suffering from psychological problems demonstrated larger levels of the RBIE, compared to their non-clinical counterparts, was not eligible for vote counting. As a result, no conclusions could be drawn about the extent to which psychological problems moderated the RBIE in that study. (3) Similar procedures and tasks have been used to examine the RBIE, but their precise parameters differ across studies; and (4) most studies report insufficient information to evaluate all relevant aspects affecting their external validity and risks of bias. Conclusions. Despite the widespread appeal that the RBIE has enjoyed, this systematic review indicates that, at present, only preliminary evidence exists for the idea that adults demonstrate the RBIE and no evidence is available to assume that psychological problems exacerbate the RBIE in adults

The Semantic Web MIDI Tape: An Interface for Interlinking MIDI and Context Metadata

The Linked Data paradigm has been used to publish a large number of musical datasets and ontologies on the Semantic Web, such as MusicBrainz, AcousticBrainz, and the Music Ontology. Recently, the MIDI Linked Data Cloud has been added to these datasets, representing more than 300,000 pieces in MIDI format as Linked Data, opening up the possibility for linking fine-grained symbolic music representations to existing music metadata databases. Despite the dataset making MIDI resources available in Web data standard formats such as RDF and SPARQL, the important issue of finding meaningful links between these MIDI resources and relevant contextual metadata in other datasets remains. A fundamental barrier for the provision and generation of such links is the difficulty that users have at adding new MIDI performance data and metadata to the platform. In this paper, we propose the Semantic Web MIDI Tape, a set of tools and associated interface for interacting with the MIDI Linked Data Cloud by enabling users to record, enrich, and retrieve MIDI performance data and related metadata in native Web data standards. The goal of such interactions is to find meaningful links between published MIDI resources and their relevant contextual metadata. We evaluate the Semantic Web MIDI Tape in various use cases involving user-contributed content, MIDI similarity querying, and entity recognition methods, and discuss their potential for finding links between MIDI resources and metadata

The effect of the beta phase on the micromechanical response of dual-phase titanium alloys

This paper investigates the role of beta phase on the micro-mechanical behaviour of dual-phase titanium alloys, with particular emphasis on the phenomenon of cold dwell fatigue, which occurs in such alloys under room temperature conditions. A strain gradient crystal plasticity model is developed and calibrated against micro-pillar compression test data for a dual-phase alpha-beta specimen. The effects of key microstructural variables, such as relative beta lath orientation, on the micromechanical response of idealised alpha-beta colony microstructures are shown to be consistent with previously-published test data. A polycrystal study on the effects of the calibrated alpha-beta crystal plasticity model on the local micromechanical variables controlling cold dwell fatigue is presented. The presence of the alpha-beta phase is predicted to increase dwell fatigue resistance compared to a pure alpha phase microstructure

Southeastern Association of Law Libraries Annual Meeting

The 2009 SEAALL Annual Meeting was held in Athens Georgia, April 16-18, 2009

Breaking Functional Connectivity into Components: A Novel Approach Using an Individual-Based Model, and First Outcomes

Landscape connectivity is a key factor determining the viability of populations in fragmented landscapes. Predicting ‘functional connectivity’, namely whether a patch or a landscape functions as connected from the perspective of a focal species, poses various challenges. First, empirical data on the movement behaviour of species is often scarce. Second, animal-landscape interactions are bound to yield complex patterns. Lastly, functional connectivity involves various components that are rarely assessed separately. We introduce the spatially explicit, individual-based model FunCon as means to distinguish between components of functional connectivity and to assess how each of them affects the sensitivity of species and communities to landscape structures. We then present the results of exploratory simulations over six landscapes of different fragmentation levels and across a range of hypothetical bird species that differ in their response to habitat edges. i) Our results demonstrate that estimations of functional connectivity depend not only on the response of species to edges (avoidance versus penetration into the matrix), the movement mode investigated (home range movements versus dispersal), and the way in which the matrix is being crossed (random walk versus gap crossing), but also on the choice of connectivity measure (in this case, the model output examined). ii) We further show a strong effect of the mortality scenario applied, indicating that movement decisions that do not fully match the mortality risks are likely to reduce connectivity and enhance sensitivity to fragmentation. iii) Despite these complexities, some consistent patterns emerged. For instance, the ranking order of landscapes in terms of functional connectivity was mostly consistent across the entire range of hypothetical species, indicating that simple landscape indices can potentially serve as valuable surrogates for functional connectivity. Yet such simplifications must be carefully evaluated in terms of the components of functional connectivity they actually predict

Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment

As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.Peer reviewe

AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space

Abstract: We propose in this White Paper a concept for a space experiment using cold atoms to search for ultra-light dark matter, and to detect gravitational waves in the frequency range between the most sensitive ranges of LISA and the terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment for Dark Matter and Gravity Exploration (AEDGE), will also complement other planned searches for dark matter, and exploit synergies with other gravitational wave detectors. We give examples of the extended range of sensitivity to ultra-light dark matter offered by AEDGE, and how its gravitational-wave measurements could explore the assembly of super-massive black holes, first-order phase transitions in the early universe and cosmic strings. AEDGE will be based upon technologies now being developed for terrestrial experiments using cold atoms, and will benefit from the space experience obtained with, e.g., LISA and cold atom experiments in microgravity. KCL-PH-TH/2019-65, CERN-TH-2019-12