883 research outputs found
A Numerical Model of Crossed Andreev Reflection and Charge Imbalance
We present a numerical model of local and nonlocal transport properties in a
lateral spin valve structure consisting of two magnetic electrodes in contact
with a third perpendicular superconducting electrode. By considering the
transport paths for a single electron incident at the local F/S interface - in
terms of probabilities of crossed or local Andreev reflection, elastic
cotunneling or quasiparticle transport - we show that this leads to nonlocal
charge imbalance. We compare this model with experimental data from an
aluminum-permalloy (Al/Py) lateral spin valve geometry device and demonstrate
the effectiveness of this simple approach in replicating experimental behavior.Comment: 9 pages, 14 figure
Modeling Non-Stationary Processes Through Dimension Expansion
In this paper, we propose a novel approach to modeling nonstationary spatial
fields. The proposed method works by expanding the geographic plane over which
these processes evolve into higher dimensional spaces, transforming and
clarifying complex patterns in the physical plane. By combining aspects of
multi-dimensional scaling, group lasso, and latent variables models, a
dimensionally sparse projection is found in which the originally nonstationary
field exhibits stationarity. Following a comparison with existing methods in a
simulated environment, dimension expansion is studied on a classic test-bed
data set historically used to study nonstationary models. Following this, we
explore the use of dimension expansion in modeling air pollution in the United
Kingdom, a process known to be strongly influenced by rural/urban effects,
amongst others, which gives rise to a nonstationary field
2010 FIFA World Cup stadium investment: Does the post-event usage justify the expenditure?
This paper provides an ex-post analysis of the utilisation of the stadiums that were built for the 2010 FIFA World Cup. The South African government invested approximately US523 million into the development of new stadiums and upgrades to existing stadiums, respectively. This paper determines whether the substantial investments into the stadiums’ infrastructure are justified by the utilisation of the stadiums after the 2010 FIFA World Cup event. A utilisation rate and a stadium usage index were used to analyse the utilisation benefits derived from the stadiums. Generally, the results suggest that there has been a significant decline in the utilisation of stadiums following the 2010 FIFA World Cup. Furthermore, the results indicate that the exorbitant costs of the stadiums for the 2010 FIFA World Cup were significant in relation to the underutilisation of the stadiums in the wake of the event. The 2010 FIFA World Cup has left the country with an expenditure legacy of an oversupply of stadiums, thus making some of the stadiums unsustainable. The results of this study appear to be in line with existing empirical research, which suggests that stadiums tend be underutilised and pose a financial burden for a host nation, subsequent to a mega-event.Keywords: 2010 FIFA World Cup; Stadium investment; Utilisatio
Number and plural semantics: Empirical evidence from Marori
This paper presents new empirical evidence from Marori (a Papuan language of Southern
New Guinea) for the semantics of number in a complex number system. Marori has a basic
three-way number system, singular/dual/plural. Marori is notable for showing distributed
number exponence and constructed number strategies, in sharp contrast with familiar twoway, morphologically simpler number systems in languages such as English. Unlike in
English, the reference of plurals in Marori in many contexts is to a group of three or more
individuals. While Marori’s number system is typologically quite different from English, it
shows an intriguing similarity in that in certain contexts, plural/nonsingular forms allow an
inclusive reading (i.e. reference to any number of individuals, including one). The paper also
presents evidence that all number types, including constructed dual, can be used for generic
reference. The paper concludes with remarks on the theoretical significance of our findings
Determining the presence of scour around bridge foundations using vehicle-induced vibrations
Bridge scour is the number one cause of failure in bridges located over waterways. Scour leads to rapid losses in foundation stiffness and can cause sudden collapse. Previous research on bridge health monitoring has used changes in natural frequency to identify damage in bridge beams. The possibility of using a similar approach to identifying scour is investigated in this paper. To assess if this approach is feasible, it is necessary to establish how scour affects the natural frequency of a bridge, and if it is possible to measure changes in frequency using the bridge dynamic response to a passing vehicle. To address these questions, a novel vehicle–bridge–soil interaction (VBSI) model was developed. By carrying out a modal study in this model, it is shown that for a wide range of possible soil states, there is a clear reduction in the natural frequency of the first mode of the bridge with scour. Moreover, it is shown that the response signals on the bridge from vehicular loading are sufficient to allow these changes in frequency to be detected
Factors Influencing the Prediction of Pile Driveability Using CPT-Based Approaches
This paper investigates the applicability of Cone Penetration Test (CPT)-based axial capacity approaches, used for estimating pile static capacity, to the prediction of pile driveability. An investigation of the influence of various operational parameters in a driveability study is conducted. A variety of axial capacity approaches (IC-05, UWA-05 and Fugro-05) are assessed in unmodified and modified form to appraise their ability to be used in estimating the driveability of open-ended steel piles used to support, for example, offshore jackets or bridge piers. Modifications to the CPT-based design approaches include alterations to the proposed base resistance to account for the resistance mobilized under discrete hammer impacts and the presence of residual stresses, as well as accounting for the effects of static capacity increases over time, namely ageing. Furthermore, a study on the influence of various operational parameters within a wave equation solver is conducted to ascertain the relative impact of uncertain data in this respect. The purpose of the paper is not to suggest a new design procedure for estimating pile driveability, rather to investigate the influence of the various operating parameters in a driveability analysis and how they affect the magnitude of the resulting predictions. The study will be of interest to geotechnical design of piles using CPT data
Representations of obesity in Australian and UK news coverage : A diachronic comparison
In both Australia and the UK, the number of adults living with obesity has been increasing over the last 30 years (AIHW, 2023; Baker, 2023). Although policy has emphasised ‘community-based interventions’ in Australia (AIHW, 2017) and ‘system-wide approaches’ in the UK (Ulijaszek and McLennan, 2016) for overcoming the challenges of obesity, previous research has shown that media representations have been dominated by representations promoting individual responsibility (e.g., Kim & Willis, 2007). In this paper, we report our observations of representations documented in corpora of media coverage from Australia and the UK between 2008-2017. The corpora amount to 16.4 million tokens and 36 million tokens, respectively. We identify key semantic domains for each year of the corpora and discuss both consistent and shifting themes in the data. Our findings show that the Australian coverage provides a more sustained focus on responses to obesity at the societal level, referring to practices in the food industry and differences between communities that can lead to health disparities. By comparison, while there is an increase in the amount of coverage in the UK press referring to obesity, the content became more narrowly focussed on food consumption and weight loss over the study period. The findings demonstrate how media coverage contributes to public understanding of how to respond to the challenges of obesity
Bayesian meta-analysis across genome-wide association studies of diverse phenotypes
Genome-wide association studies (GWAS) are a powerful tool for understanding the genetic basis of diseases and traits, but most studies have been conducted in isolation, with a focus on either a single or a set of closely related phenotypes. We describe MetABF, a simple Bayesian framework for performing integrative meta-analysis across multiple GWAS using summary statistics. The approach is applicable across a wide range of study designs and can increase the power by 50% compared with standard frequentist tests when only a subset of studies have a true effect. We demonstrate its utility in a meta-analysis of 20 diverse GWAS which were part of the Wellcome Trust Case Control Consortium 2. The novelty of the approach is its ability to explore, and assess the evidence for a range of possible true patterns of association across studies in a computationally efficient framework.Peer reviewe
Microwave-optical double resonance in a erbium-doped whispering-gallery-mode resonator
We showcase an erbium-doped whispering-gallery-mode resonator with optical
modes that display intrinsic quality factors better than (linewidths
less than 2 MHz), and coupling strengths to collective erbium transitions of up
to 21.2 GHz - enough to reach the ensemble strong coupling regime.
Our optical cavity sits inside a microwave resonator, allowing us to probe the
spin transition which is tuned by an external magnetic field. We show a
modified optically detected magnetic resonance measurement that measures
population transfer by a change in coupling strength rather than absorption
coefficient. This modification was enabled by the strong coupling to our modes,
and allows us to optically probe the spin transition detuned by more than the
inhomogeneous linewidth. We contrast this measurement with electron
paramagnetic resonance to experimentally show that our optical modes are
confined in a region of large microwave magnetic field and we explore how such
a geometry could be used for coherent microwave-optical transduction.Comment: 8 pages, 6 figure
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