Do Employers Discriminate by Gender? A Field Experiment in Female-Dominated Occupations

We test for gender discrimination by sending fake CVs to apply for entry-level jobs. Female candidates are more likely to receive a callback, with the difference being largest in occupations that are more female-dominated.discrimination, field experiments, employment, gender

Do Employers Discriminate by Gender? A Field Experiment in Female-Dominated Occupations

We test for gender discrimination by sending fake CVs to apply for entry-level jobs. Female candidates are more likely to receive a callback, with the difference being largest in occupations that are more female-dominated.discrimination, field experiments, employment, gender

Designing Wind Turbine Condition Monitoring Systems Suitable for Harsh Environments

Research into wind turbine condition monitoring is continually receiving greater attention due to the potential benefits from condition monitoring systems (CMS). These benefits can only be realised with high reliability of the condition monitoring system itself. This paper discusses how CMS reliability can be increased, by introducing four types of robustness and how to design the CMS to meet these requirements. The paper uses a case study CMS installation to illustrate the design requirements, and lessons learned from the installation process

Does Racial and Ethnic Discrimination Vary Across Minority Groups? Evidence from a Field Experiment

We conduct a large-scale audit discrimination study to measure labor market discrimination across different minority groups in Australia – a country where one quarter of the population was born overseas. To denote ethnicity, we use distinctively Anglo-Saxon, Indigenous, Italian, Chinese, and Middle Eastern names, and our goal is a comparison across multiple ethnic groups rather than focusing on a single minority as in most other studies. In all cases, we applied for entry-level jobs and submitted a CV showing that the candidate had attended high school in Australia. We find economically and statistically significant differences in callback rates, suggesting that ethnic minority candidates would need to apply for more jobs in order to receive the same number of interviews. These differences vary systematically across groups, with Italians (a more established migrant group) suffering less discrimination than Chinese and Middle Easterners (who have typically arrived more recently). We also explore various explanations for our empirical findings.discrimination, field experiments, employment

Inertia emulation control of VSC-HVDC transmission system

The increasing penetration of power electronics interfaced renewable generation (e.g. offshore wind) has been leading to a reduction in conventional synchronous-machine based generation. Most converter-interfaced energy sources do not contribute to the overall power system inertia; and therefore cannot support the system during system transients and disturbances. It is therefore desirable that voltage-source-converter (VSC) based high voltage direct current (HVDC) interfaces, which play an important role in delivery of renewable power to AC systems, could contribute a virtual inertia and provide AC grid frequency support. In this paper, an inertia emulation control (IEC) system is proposed that allows VSC-HVDC system to perform an inertial response in a similar fashion to synchronous machines (SM), by exercising the electro-static energy stored in DC shunt capacitors of the HVDC system. The proposed IEC scheme has been implemented in simulations and its performance is evaluated using Matlab/Simulink

Collocation methods for a class of second order initial value problems with oscillatory solutions

We derive and analyse two families of multistep collocation methods for periodic initial-value problems of the form y" = f(x, y); y((^x)o) = yo, y(^1)(xo) = zo involving ordinary differential equations of second order in which the first derivative does not appear explicitly. A survey of recent results and proposed numerical methods is given in chapter 2. Chapter 3 is devoted to the analysis of a family of implicit Chebyshev methods proposed by Panovsky k Richardson. We show that for each non-negative integer r, there are two methods of order 2r from this family which possess non-vanishing intervals of periodicity. The equivalence of these methods with one-step collocation methods is also established, and these methods are shown to be neither P-stable nor symplectic. In chapters 4 and 5, two families of multistep collocation methods are derived, and their order and stability properties are investigated. A detailed analysis of the two-step symmetric methods from each class is also given. The multistep Runge-Kutta-Nystrom methods of chapter 4 are found to be difficult to analyse, and the specific examples considered are found to perform poorly in the areas of both accuracy and stability. By contrast, the two-step symmetric hybrid methods of chapter 5 are shown to have excellent stability properties, in particular we show that all two-step 27V-point methods of this type possess non-vanishing intervals of periodicity, and we give conditions under which these methods are almost P-stable. P-stable and efficient methods from this family are obtained and demonstrated in numerical experiments. A simple, cheap and effective error estimator for these methods is also given

Impacts of desiccation cracking and climate change on highway cutting hydrology

Climate change is predicted to have a global effect on temperatures and precipitation rates throughout the world. The UK Climate projections expect that in the United Kingdom this will lead to warmer, drier summers and wetter winters, where events of extreme rainfall are more common. These changes are expected to impact on slope hydrology, and concurrently slope stability. In the United Kingdom this impact is expected to be negative, whereas in other countries, such as Italy and France it could lead to slopes being more stable. Infrastructure slopes in the UK range in age and construction quality, they are susceptible to serviceability problems, characterised by heterogeneous material properties and can fail unexpectedly due to progressive reduction in soil shear strength. In this thesis the effects of climate change on a highway cutting in the south of England are modelled, using numerical methods. A finite element model is created and developed in the software package GeoStudio VADOSE/W. The model has been validated against observed pore water pressure trends and magnitudes and is shown to be able to accurately replicate the behaviour. By incorporating the effects of desiccation cracking on the soil s material properties, by the means of bimodal soil water characteristic curve and hydraulic conductivity function, the replication of these trends is improved even further. A series of future climate series were created using the UKCP09 Weather Generator 2.0. These series were implemented with the VADOSE/W model as climate boundary conditions and models were run, and the results compared to control, current climate results. The results were investigated by the means of statistical analyses which revealed that climate change will have some significant effects on the slope s hydrology, increasing magnitudes of evapotranspiration greatly which can have further significant effects on the magnitude of suctions developing in the slope throughout the summer. It is thought that the results suggest that climate change will not have significant negative effects on slope stability. However it is important to remember that the results only apply with certainty to the specific slope and climate change scenario investigated here. The methods used and developed within this thesis can be extended to other locations, in the UK and internationally, analysing the effects of different climate change scenarios

Biodegradation, water solubility and characterisation studies of unresolved complex mixtures (UCMs) of aromatic hydrocarbons

Following release to the environment, crude oil becomes subject to weathering processes which remove the simple, volatile hydrocarbons leaving an unresolved complex mixture (UCM) comprising the more environmentally persistent components. Aromatic UCMs have been reported in a wide variety of environmental matrices. Recent studies indicate such material, particularly monoaromatic hydrocarbons, is sufficiently bioavailable to marine organisms (e. g. mussels) to elicit toxicological responses. However, little else is known about the environmental fate and composition of petroleum-derived aromatic UCMs. The overall aim of this work was to investigate aromatic UCMs with particular emphasis on their biodegradability, water solubility and composition. To assess persistence in the environment, an 'aromatic' UCM was isolated from Tia Juana Pesado crude oil (Venezuela) and this UCM exposed to the hydrocarbon degrading bacterium Pseudomonas fluorescens (Texaco). Five synthesised alkylcyclohexyltetralins and an alkylcyclohexylnaphthalene, proposed previously as 'average' structures for some aromatic UCM components, were also exposed under the same conditions. After 50 days, biodegradation of the compounds had not exceeded 20%, the most resistant (-2% biodegradation) being those with C3-C5 alkyl chains. These latter results were comparable to those observed for the 'aromatic' UCM (-2%). Using North Sea oil or n-hexadecane as co-substrates, the synthetic compounds were also exposed to a natural consortium of bacteria to provide more environmentally realistic conditions. After 119 days the branched chain C5 homologue (-60%) and the naphthalene (-12%) still remained, yet under these severe conditions the components of the North Sea crude oil co-substrate were extensively degraded with even the highly bioresistant pentacyclic hopanes exhibiting biodegradation. Aqueous solutions of an 'aromatic' and 'monoaromatic' UCM were produced (at 25 'C) using a generator column technique. These 'solubilised' UCM fractions may represent UCM hydrocarbons which are bioavailable, and which are most toxic to aquatic organisms. An altered UCM was clearly evident in the aqueous phase extracts, suggesting that many of the compounds in the original aromatic and monoaromatic UCMs exhibited similar physicochemical properties and mole fractions. However, higher molecular weight hydrocarbons were absent from the generated 'solutions', indicating a solubility cut-off point based predominantly on molecular weight. The molecular weight distribution differed significantly for the 'solubilised' aromatic and monoaromatic UCMs, indicating that Raoult's Law may describe a critical control in the dissolution of complex mixtures. Comprehensive two-dimensional gas chromatography-time of flight-mass spectrometry (GCxGC-ToF-MS) analysis was used to provide vastly increased separation power and characterisation of a water 'soluble' monoaromatic UCM. Over 1200 compounds were separated by the chromatography, of which about 500 had distinct mass spectra from the ToF-MS analysis. A detailed characterisation of some of these monoaromatic UCM hydrocarbons via comparison to mass spectra registered in the NIST library permitted the identities of over 100 monoaromatic UCM components to be inferred. Compounds identified include novel alkylated homologues of benzene, indene, indan, tetralin, biphenyl, diphenylmethane and tetrahydrophenanthrene. This study has shown that a UCM appeared to be comprised of the geochernically minor isomers and analogues of known major crude oil constituents. This finding is extremely important given that the narcotic toxicity of petroleum hydrocarbons is additive. As UCMs often account for a large proportion of crude oil mass, these persistent residues may also contribute significantly to the observed narcotic toxicity of crude oil.the Natural Environment Research Council (NERC

Mortality in intensive care: The impact of bacteremia and the utility of systemic inflammatory response syndrome

Background: The purpose of this study was to determine the impact of bacteremia on intensive care unit (ICU) mortality and to develop a bacteremia prediction tool using systemic inflammatory response syndrome (SIRS) criteria. Methods: Patients included those aged >18 years who had blood cultures taken in the ICU from January 1, 2011-December 31, 2013. Eligible patients were identified from microbiology records of the Glasgow Royal Infirmary, Scotland. Clinical and outcome data were gathered from ICU records. Patients with clinically significant bacteremia were matched to controls using propensity scores. SIRS criteria were gathered and used to create decision rules to predict the absence of bacteremia. The main outcome was mortality at ICU discharge. The utility of the decision tools was measured using sensitivity and specificity. Results: One hundred patients had a clinically significant positive blood culture and were matched to 100 controls. Patients with bacteremia had higher ICU mortality (odds ratio [OR], 2.35; P = .001) and longer ICU stay (OR, 17.0 vs 7.8 days; P ≤ .001). Of 1,548 blood culture episodes, 1,274 met ≥2 SIRS criteria (106 significant positive cultures and 1,168 negative cultures). There was no association between SIRS criteria and positive blood cultures (P = .11). A decision rule using 3 SIRS criteria had optimal predictive performance (sensitivity, 56%; specificity, 50%) but low accuracy. Conclusions: ICU patients with bacteremia have increased mortality and length of ICU stay. SIRS criteria cannot be used to identify patients at low risk of bacteremia