Advanced hydrogen electrode for hydrogen-bromide battery

Binary platinum alloys are being developed as hydrogen electrocatalysts for use in a hydrogen bromide battery system. These alloys were varied in terms of alloy component mole ratio and heat treatment temperature. Electrocatalyst evaluation, performed in the absence and presence of bromide ion, includes floating half cell polarization studies, electrochemical surface area measurements, X ray diffraction analysis, scanning electron microscopy analysis and corrosion measurements. Results obtained to date indicate a platinum rich alloy has the best tolerance to bromide ion poisoning

Group and extended target tracking with the probability hypothesis density filter

Multiple target tracking concerns the estimation of an unknown and time-varying number of objects (targets) as they dynamically evolve over time from a sequence of measurements obtained from sensors at discrete time intervals. In the Bayesian ltering framework the estimation problem incorporates natural phenomena such as false measurements and target birth/death. Though theoretically optimal, the generally intractable Bayesian lter requires suitable approximations. This thesis is particularly motivated by a rst-order moment approximation known as the Probability Hypothesis Density (PHD) lter. The emphasis in this thesis is on the further development of the PHD lter for handling more advanced target tracking problems, principally involving multiple group and extended targets. A group target is regarded as a collection of targets that share a common motion or characteristic, while an extended target is regarded as a target that potentially generates multiple measurements. The main contributions are the derivations of the PHD lter for multiple group and extended target tracking problems and their subsequent closed-form solutions. The proposed algorithms are applied in simulated scenarios and their estimate results demonstrate that accurate tracking performance is attainable for certain group/extended target tracking problems. The performance is further analysed with the use of suitable metrics.Engineering and Physical Sciences Research Council (EPSRC) Industrial CASE Award Studentshi

Novel excitations in driven vortex channels in a superconductor, and solitary waves of light and atoms in photonic crystal fibres

This is a thesis in two parts. In Part I, we will study the shear response of confined vortices. In Part 2, we will study light and matter interactions in photonic crystal fibres. Whilst the approaches of each are completely different, they both have the same central theme: solitons. In the first part of this thesis we study the static and dynamic properties of vortices within a Type-II superconductor, confined within a channel. The channel comprises a collection of pinned vortices, which form the perfect triangular lattice in the boundary, and rows of “free” particles which are driven via an external force. We provide two main results within this system. First we calculate the potential stemming from the boundary, and derive (under certain approximations) the phenomenologically accepted result for the critical shear dependence on the system width. We then study a novel system in which a defect is placed in a deformable potential; specifically a system comprised of two channels where one or both channels have a defect. This system provides a mechanism for the proliferation of kink/kink and anti-kink/anti-kink pairs as the defect binds to a local excitation in the form of a “breather”. We observe and explain what appears to be an action at a distance style interaction between excitations. In Part II, we will utilise the nonlinear effects of a Bose condensate and the unique optical properties of a photonic crystal fibre to demonstrate there are nonlinearly stable configurations which exist in the vicinity of an optical mode with a cut-off. These are solitary waves, whose relative composition of atoms and photons may be changed via altering the detuning of light from an atomic transition and Feshbach resonances

Particulate matter exposure and community-acquired pneumonia mortality among hospitalized adults with pneumococcal pneumonia: incidence study (HAPPI) participants.

The role of air pollution as an agent of elevated morbidity and mortality has come under increasingly intense scrutiny in recent years. As the body of literature grows, so too does our understanding of how extensive the harm of such pollutants can be. Particulate matter (PM) particularly harmful due to its small size, ability to travel great distance while airborne, and capacity to infiltrate numerous bodily systems, often to the detriment of those exposed. Besides being associated with increased mortality risk in more heavily exposed populations, PM exposure has also been associated with complications in the respiratory, cardiovascular, and nervous systems. Additionally, exposures to PM are often unequally distributed among populations, with the greatest burden placed upon already marginalized groups. The purpose of this dissertation study was to examine the impact of PM exposure at the time of hospitalization on pneumonia-related mortality risk among individuals hospitalized due to community-acquired pneumonia (CAP). The study sample for this dissertation work came from the Hospitalized Adults with Pneumococcal Pneumonia: Incidence (HAPPI) study conducted in Jefferson County, KY, USA from 2014 to 2016, containing adult residents of the county who were hospitalized due to CAP during that timeframe. PM10 and PM2.5 concentration data were derived from online sources published by the US Environmental Protection Agency (EPA) based on a limited number of air monitoring stations located within Jefferson County. A spatial interpolation method called spatial averaging was used to determine specific levels of PM exposure ascribed to each participant at the time of their hospitalization. Mortality within thirty days of hospitalization was the primary outcome examined as it is likely to reflect CAP-specific mortality. The relationships between PM exposures and mortality were examined using a variety of methods, including logistic and Cox proportional hazards regression and we additionally conducted effect modification analyses. Feasibility of alternative spatial interpolation methods was also examined. Age and race, as well as a number of hospitalization and medical history-oriented covariates, were found to be significantly associated with mortality in preliminary regression analysis. According to the preferred model containing all noted confounders and strong predictors, the primary PM exposures of interest were not found to be significantly associated with mortality; however, effect modification analysis did yield significant results. Black participants exposed to higher levels of PM10 had a greater odds of thirty-day mortality, based on both continuous PM10 (AOR = 1.19 per five-unit increase, 95% CI = 1.04-1.37) and PM10 quartiles (greatest versus lowest quartile; AOR = 2.70, 95% CI = 1.31-5.55). Female participants in the greatest PM10 exposure quartile had higher odds of death within thirty days versus those in the lowest quartile (AOR = 1.46, 95% CI = 1.01-2.14). The same elevated associations were not observed among white or male participants. Additionally, the more advanced spatial interpolation method kriging was not found to be feasible due to sparsity of monitor data at a given time point. The results of the study indicate that certain segments of the population may be disproportionately impacted by PM10 exposure. Additionally, the results provide insight into the risks and benefits associated with specific hospitalization / medical history-oriented covariates. Given the simplistic nature of spatial averaging and the inability to properly conduct kriging with the data that was available, future research on this subject would benefit greatly from alternative, more extensive sources of PM data within cities. For now, it appears that PM10 exposure is associated with elevated thirty-day mortality among Black and female populations within Jefferson County, KY

Coal ash exposure and asthma in children.

This study examined the association between exposure to coal ash in the home among children aged 6-14 and asthma. Data was collected using personal modular impactors, lift tape samples, toe/finger nail samples, questionnaires, and peak flow meters. Laboratory methods used to analyze the samples included gravimetric analysis, scanning electron microscopy (SEM) / energy dispersive x-ray (EDX), and proton-induced x-ray emission (PIXE). Statistical methods used to analyze the data included the Chi Square Test of Independence, logistic regression, the Hosmer-Lemeshow Goodness of Fit test, Fisher’s Exact Test, and the Anderson-Darling Normality Test. Sample size was small, making statistical significance in calculated values unachievable. Though statistical results were not significant, it was suggested that a relationship between asthma risk and exposure was possible. In particular, it was noted that male participants averaged lower peak flow values when compared to the pediatric norm. It was also noted that mean residential distances from the studied power plants were lower in asthma cases than for non-asthma cases. Although results are preliminary and findings were inconsistent, asthma prevalence within the study group was high, compared to the national average in children and requires further study

Automation, Work, and Ideology: The Next Industrial Revolution and the Transformation of Labor

Over the last several decades, scholars and commentators from a variety of different fields, expertise, and ideological positions have written on automation technologies and their potential to cause technological unemployment. As a sociological analysis and critical examination of how experts ideologically frame these issues, this thesis demonstrates that ideology plays a crucial role in the revived debate over automation and technological displacement. Weberian ideal types are developed to demonstrate how three major ideological positions—liberal, conservative, and radical—approach and frame the link between automation, technological displacement, and the potential for technological unemployment. The qualitative tools of ideal type construction and theme analysis facilitate synthesis and reconstruction as ideal types the most salient aspects of each ideological perspective on the link between automation and technological displacement. The liberal ideal type focuses on how liberal concerns that the present circumstances (“this time”) may be different, that predicted technological displacement will greatly exacerbate economic inequality, and that technological unemployment could undermine social stability. By contrast, conservative commentators contend that technological displacement will not cause structural technological unemployment, and that disruptions will most likely follow the same patterns of “creative destruction” (Schumpeter) observed throughout the history of capitalism. Finally, radical commentators typically regard the continuation of automation as an opportunity to think of new ways to organize society beyond wage labor, and endeavor to develop a political program designed to transcend the current problems plaguing capitalism. The final sections critically analyzes all three ideological positions and shows how, ultimately, current arguments and debates are structurally flawed. The tool of ideology critique is used to explain how the mainstream debate between conservatives, liberals, and radicals is devoid of systematic critical understanding of the dynamics of modern society. Relying on the works of the critical Marxian school of value-critique, a critique of current debates is formulated to explain how the historical dynamics of capital continuously transform labor in modern society in ways that will likely subvert the expectations of all three ideologies. The critical concept of a “logic of capital” must be central to any understanding of the processes of automation and technological displacement

Equations of Electrogasdynamics and Applications

This report presents in summary work done in the period from 1959 to 1963 at the Hypersonic Research Project, Graduate Aeronautical Laboratories California Institute of Technology, on some theoretical aspects of the dynamics of ionized gases. The objective of this work was to set up a system of conservation equations when no magnetic field or complicated chemical effects are present. Emphasis is placed on the gross exchange processes among species at a point, rather than the gradient transport mechanisms (e. g. , viscosity and heat conduction); in the past this point of view was often called "Gaseous Electronics". In subordinatipg the magnetic field and the chemistry to the dynamics it has been possible to explain a gratifying number of commonplace physical phenomena from first principles and to demonstrate the intimate connection between gaseous electronics and aerodynamics. The conservation equations needed for a neutral-ion-electron mixture were derived with the aid of the elementary integral transport (Maxwell-Chapman) theory exactly as used for any ternary mixture. Departures made necessary because of the ionization include (a) the collisionless ("Vlasov") approximation, (b) a reformulation of the Chapman-Enskog prosedure to include electric forces and (c) a convenient recourse to the inverse-fifth-power interparticle force law. Even so the resulting equations are merely a re-statement of the formidable problem of plasma physics. "Inviscid" equations are therefore written as counterparts of the inviscid (ideal) equations of aerodynamics. To illustrate where mathematical difficulties first appear, practical problems are solved with the aid of further approximations. These problems, as well as the physical departures mentioned above, are relegated to Appendices