Development of a reinforcing fibre light-guide for use as a damage sensor within composite structures

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This study presents the results of an investigation to develop a novel sensor which would give a direct indication of the extent of impact damage in a composite. This was achieved by using glass reinforcing fibres to produce a light-guide, which was embedded within a composite laminate. The laminate was then subjected to impact events or bending stresses of sufficient magnitude to cause damage. The impact energies used in this study varied between 2 and 10 Joules, and the indentation depths varied between 0.125 and 1 mm, allowing damage propagation to be monitored. The fall-off in the transmitted light was used to monitor the level of damage, along with C-scanning and sectioning to provide reference data. The use of reinforcing fibres to produce the sensor meant that the strains required to cause failure in the fibres was realistically close to those of the composite constituents. Changes in the transmission characteristics of the sensor were found to correspond to real failure events occurring during impact.This study is funded by Mr D. Coward at Royal Mail Securities and the EPSRC

Juvenile crime stories use police blotter without comment from suspects

This article discusses a research on news media coverage of juvenile crime. It seeks to answer two questions: what sources do present-day reporters rely on in writing juvenile justice stories; and, are reporters more likely to balance police and defendants comments. The study focused on stories published in Connecticut\u27s three largest newspapers--the Hartford Courant, the New Haven Register, and the Connecticut Post--between January 1, 2002, and March 31, 2002. The study\u27s design was based on a census of all newspaper stories, not a random sample, in the three-month period. The methodology yielded 180 news stories, those generated by both the staff and six Associated Press stories. Results suggest that, at least in the newspapers studied here, not much has changed since Doris Graber first documented the shortcomings of crime reporting more than two decades ago in her book, Crime News and the Public. The economic efficiency that allows reporters to chum out stories with little effort from the police blotter has not changed. Coverage of juvenile crime issues followed the same pattern

Processes underlying the nutritional programming of embryonic development by iron deficiency in the rat

Peer reviewedPublisher PD

Methods for the analysis of incidence rates in cluster randomized trials.

BACKGROUND: The published literature on cluster randomized trials focuses on outcomes that are either continuous or binary. In many trials, the outcome is an incidence rate, such as mortality, based on person-years data. In this paper we review methods for the analysis of such data in cluster randomized trials and present some simple approaches. METHODS: We discuss the choice of the measure of intervention effect and present methods for confidence interval estimation and hypothesis testing which are conceptually simple and easy to perform using standard statistical software. The method proposed for hypothesis testing applies a t-test to cluster observations. To control confounding, a Poisson regression model is fitted to the data incorporating all covariates except intervention status, and the analysis is carried out on the residuals from this model. The methods are presented for unpaired data, and extensions to paired or stratified clusters are outlined. RESULTS: The methods are evaluated by simulation and illustrated by application to data from a trial of the effect of insecticide-impregnated bednets on child mortality. CONCLUSIONS: The techniques provide a straightforward approach to the analysis of incidence rates in cluster randomized trials. Both the unadjusted analysis and the analysis adjusting for confounders are shown to be robust, even for very small numbers of clusters, in situations that are likely to arise in randomized trials

The challenges, uncertainties and opportunities of bioaerosol dispersion modelling from open composting facilities

Bioaerosols are ubiquitous organic particles that comprise viruses, bacteria and coarser fractions of organic matter. Known to adversely affect human health, the impact of bioaerosols on a population often manifests as outbreaks of illnesses such as Legionnaires Disease and Q fever, although the concentrations and environmental conditions in which these impacts occur are not well understood. Bioaerosol concentrations vary from source to source, but specific human activities such as water treatment, intensive agriculture and composting facilitate the generation of bioaerosol concentrations many times higher than natural background levels. Bioaerosols are not considered ‘traditional’ pollutants in the same way as PM10, PM2.5, and gases such as NO2, and consequently dispersion models do not include a bespoke method for their assessment. As identified in previous studies, priority areas for improving the robustness of these dispersion models include: 1) the development of bespoke monitoring studies designed to generate accurate modelling input data; 2) the publication of a robust emissions inventory; 3) a code of practice to provide guidelines for consistent bioaerosol modelling practices; and 4) a greater understanding of background bioaerosol emissions. The aim of this research project, funded by the Natural Environmental Research Council (NERC), is to address these key areas through a better understanding of the generation, concentration and potential dispersion of bioaerosols from intensive agricultural and biowaste facilities, using case studies developed at specific locations within the UK. The objective is to further refine existing bioaerosol monitoring and modelling guidelines to provide a more robust framework for regulating authorities and site operators. This contribution outlines the gaps that hinder robust dispersion modelling, and describes the on-site bioaerosol data collection methods used in the study, explaining how they might be used to close these gaps. Examples of bioaerosol dispersion modelled using ADMS 5 are presented and discussed

A Controlled Study on the Characterisation of Bioaerosols Emissions from Compost

Bioaerosol emissions arising from biowaste treatment are an issue of public concern. To better characterise the bioaerosols, and to assess a range of measurement methods, we aerosolised green waste compost under controlled conditions. Viable and non-viable Andersen samplers, cyclone samplers and a real time bioaerosol detection system (Spectral Intensity Bioaerosol Sensor (SIBS)) were deployed simultaneously. The number-weighted fraction of fluorescent particles was in the range 22–26% of all particles for low and high emission scenarios. Overall fluorescence spectral profiles seen by the SIBS exhibited several peaks across the 16 wavelength bands from 298 to 735 nm. The size-fractionated endotoxin profile showed most endotoxin resided in the 2.1–9 μm aerodynamic diameter fraction, though up to 27% was found in a finer size fraction. A range of microorganisms were detected through culture, Matrix Assisted Laser Desorption and Ionisation Time of Flight Mass Spectrometry (MALDI-TOF) and quantitative polymerase chain reaction (qPCR), including Legionella pneumophila serogroup 1. These findings contribute to our knowledge of the physico-chemical and biological characteristics of bioaerosols from composting sites, as well as informing future monitoring approaches and data interpretation for bioaerosol measurement

Towards improved bioaerosol model validation and verification

Bioaerosols, comprised of bacteria, fungi and viruses are ubiquitous in ambient air. Known to adversely affect human health, the impact of bioaerosols on a population often manifests as outbreaks of illnesses such as Legionnaires Disease and Q fever, although the concentrations and environmental conditions in which these impacts occur are not well understood. Bioaerosol concentrations vary from source to source, but specific industrialised human activities such as water treatment, intensive agriculture and open windrow composting facilitate the generation of bioaerosol concentrations many times higher than natural background levels. Bioaerosol sampling is currently undertaken according to the requirements of the Environment Agency’s regulatory framework, in which the collection of bioaerosols and not its long-term measurement is of most importance. As a consequence, sampling devices are often moved around site according to changing wind direction and sampling intervals are invariably short-term. The dispersion modelling of bioaerosols from composting facilities typically relies on proxy pollutant parameters. In addition, the use of short term emission data gathering strategies in which monitors are moved frequently with wind direction, do not provide a robust reliable and repeatable dataset by which to validate any modelling or to verify its performance. New sampling methods such as the Spectral Intensity Bioaerosol Sensor (SIBS) provide an opportunity to address several gaps in bioaerosol model validation and verification. In the context of model validation, this paper sets out the current weaknesses in bioaerosol monitoring from the perspective of robust modelling requirements

Flow system for heterocyclic synthesis

The potential of the silver-catalysed cyclisation has been illustrated by the synthesis of furans, pyrroles and pyrazole-N-oxides. With yields predominantly being >95%, and ubiquitous high purity, the results herein show the compatibility of many substituents including alkyl, aryl and silyl, to name but a few. Extended investigations have improved our understanding of reaction rates, the effect of stereochemistry and the use of protection strategies as well as identifying a handful of limitations. With the above results in hand, and a desire to recognise the practical advantages of a metal-catalysed procedure, we have further described two continuous flow systems for heterocyclic synthesis. The first, a trickle-bed reactor, produces heterocycles in excellent yields (>95% except where volatile products were produced) and has been shown to exhibit 95%), when used in batch mode, and in slightly lower yield (>70%) when used in a continuous fashion. Once again silver leaching was seen to be <1 ppm. The success of these two systems, and the speed in which their success was achieved, clearly demonstrates the ease of working with silver-catalysed cyclisations. In a further brief foray, the use of heat and microwave irradiation is discussed in view of potential applications to other continuous systems. Finally, several specific applications of the silver-catalysed cyclisation have been shown. It is seen that this procedure is suitable for the synthesis of scented furans and has uses in the preparation of heterocyclic substrates, which can be used for bigger and better things. One such example, which is described in Chapter 6, is the formation of oxepan-4-ones, oxepin-4-ones and oxocins-5-ones from their corresponding furyl alcohols.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The impact of the ILO: fragmented policy networks and the battle for Labour standards in Czechia and Slovakia

World politics is characterised by challenges to effective multilateralism with repercussions across several areas such as trade, the environment and nuclear proliferation. This research investigates the impact of international organisations under contemporary conditions of globalisation and does so using the International Labour Organization (ILO) as an instance of this wider issue. Economic integration can result in negative social externalities, the responsibility of which cuts across state lines and requires cooperation at the international level. However, states are often reluctant to assign organisations concerned with human rights the necessary authority to fulfil their mandates. For the ILO, this has meant a reliance on powers of persuasion to achieve its goals; because compliance rates vary and because the organisation is without legal or economic means of enforcement, it has gained a reputation for being irrelevant and toothless. As a result, observers tend explain variation in labour standards across states as being caused solely by differences in their domestic politics. This thesis seeks to refine the domestic politics argument and to challenge the conventional wisdom on enforcement. In doing so, it illustrates not only whether and how the ILO makes an impact but draws attention to the fragmented policy environment in which it must operate. Here, some organisations work in support of the ILO e.g. global trade unions; but the norms diffused from others such as the International Monetary Fund (IMF), World Bank and the Organization for Economic Co-operation and Development (OECD) often challenge it. Using the comparative case of Czechia and Slovakia, the proceeding chapters will argue that the ILO does make an impact and does so via its ability to provide monitoring, supervision and technical/legal assistance. However, the research further finds that the extent to which the ILO is successful in this regard depends to some degree on the ways in which competing configurations of domestic and international actors impede or facilitate its work

Stereoselective synthesis of highly substituted tetrahydrofurans by diverted carbene O–H insertion reaction

Copper or rhodium catalyzed reaction of diazocarbonyl compounds with β-hydroxyketones gives highly substituted tetrahydrofurans with excellent diastereoselectivity, under mild conditions, in a single step process that starts as a carbene O–H insertion reaction but is diverted by an intramolecular aldol reaction