The potential of increasing disease problems through the use of recycled irrigation water in horticultural operations is a serious concern, yet basic research on waterborne plant pathogens in Virginia is lacking. In this work seasonal fluctuations and locations of Pythiaceae in a recycled water irrigation system at a container nursery were determined. <i>Pythium</i> spp. were recovered more frequently and in greater numbers than <i>Phytophthora</i> spp. Species of <i>Phytophthora</i> recovered in filtering assays were identified as <i>P. capsici, P. citricola, P. citrophthora, P. cryptogea, P. drechsleri,</i> and <i>P. nicotianae. P. cryptogea</i> and <i>P. drechsleri</i> were the only <i>Phytophthora</i> spp. recovered from baits placed on the surface of the irrigation reservoir, whereas a greater diversity of species was recovered from baits placed at depths. Hymexazol-amended medium was found to have limitations in recovery of <i>Phytophthora</i> spp. In pathogenicity tests, <i>P. cactorum, P. capsici, P. citrophthora,</i> and <i>P. nicotianae</i> caused significant mortality of <i>Salvia officinalis</i> and <i>P. cactorum</i> showed limited pathogenicity on <i>Gerbera jamesonii</i>. Asymptomatic (aboveground) plants were found to harbor inoculum long after <i>Phytophthora</i>-inoculation. Fresh weight analyses of roots and shoots of asymptomatic plants demonstrated that <i>Phytophthora</i> inoculation may either reduce or stimulate plant shoot growth, but little effect is apparent on roots. Irrigation with naturally infested irrigation water reduced plant growth. This research provides data for prioritizing development of detection technology and management practices for plant pathogens in irrigation water. The results may also lead to improvements in conventional water assay protocols for plant pathogens. / Master of Science

yes / Purpose – Cost reduction through the use of technology has become the competitive strength of companies. The benefits of technology integration are quite credible and have been effective in business competition. The purpose of this paper is to describe an integrated manufacturing strategy for the deployment of a CAD/CAM system in a small, medium manufacturing enterprise (SMME). Design/methodology/approach – A case study of a SMME is utilised in deploying an integrated CAD/CAM system for practical application of manufacturing technology for achieving sustainable growth through lean systems design (LSD). The paper presents a techno-economic and technology change management framework, with an application of a holistic set of lean deployment tools that include establishing a strategic and operational plan for implementing CAD/CAM systems as a means to achieving world-class performance. Findings – The paper shows that the CAD/CAM integration within the case company increased knowledge of CAD/CAM technology, productivity, and flexibility whilst reducing throughput times. Based on the literature review and the current case study, a framework for ideal CAD/CAM implementation has been proposed. The paper also shows that management and organisational structures are key inhibitors for successful implementation of technology integration. Research limitations/implications – The paper uses a single case study to validate deployment of the integrated manufacturing strategy in SMMEs. Hence there is a limitation to its generality. Practical implications – ThepaperprovidesanopportunitytofurtherunderstandCAD/CAMsystem implementation protocols within a well structured framework and its configuration within SMMEs. Social implications – The CAD/CAM implementation framework will allow the SMMEs to achieve Lean manufacturing (thereby minimising wastes) leading to improved growth and employment rates. Originality/value – The presentation of conceptualisation, development and implementation of an integrated CAD/CAM system in support of organisational wide Lean manufacturing initiative in SMMEs is an originality of this paper.

Yes / Manufacturing is a global activity that started during the industrial revolution in the late 19th century to cater for the large-scale production of products. Since then, manufacturing has changed tremendously through the innovations of technology, processes, materials, communication and transportation. The major challenge facing manufacturing is to produce more products using less material, less energy and less involvement of labour. To face these challenges, manufacturing companies must have a strategy and competitive priority in order for them to compete in a dynamic market. A review of the literature on the decomposition of manufacturing processes outlines three main processes, namely: high volume, medium volume and low volume. The decomposition shows that each sub process has its own characteristics and depends on the nature of the firm’s business. Two extreme processes are continuous line production (fast extreme) and project shop (slow extreme). Other processes are in between these two extremes of the manufacturing spectrum. Process flow patterns become less complex with cellular, line and continuous flow compared with jobbing and project. The review also indicates that when the product is high variety and low volume, project or functional production is applied. / The financial support by the Malaysian Government, Universiti Malaysia Pahang and Bradford University for this research is gratefully acknowledged.

Based on an ethnographic investigation, the dissertation examines the emergence and significance of discourses around “the environment” in the Lake District of the Araucanía region of Chile (Araucanía Lacustre). These are understood as part of the discursive aspect of globalization – the process by which the territory and its population are integrated ever more tightly into the networks of global market society – and considered in conjunction with discourses around Mapuche indigenous identity. Drawing on mediacultural studies, actor network theory, and medium theory, the analysis seeks to advance an ecological concept of communication that does not privilege human consciousness and agency. Communication is argued to be the principle by which space (physical and metaphysical) is configured and connected. Through a discussion of the physical and human geography of the territory it is argued that discourse is mutually immanent with material realities, including human practice and pre-discursive, nonhuman elements (chapter 3). The connection between environmental discourse and Mapuche culture is examined through the stereotype of the ecologically virtuous indigenous subject – a stereotype whose significance is changing as parallel neoliberal multicultural and sustainable development discourses boost the prestige of both Mapuche culture and ecological responsibility, even as the steady expansion of market society undermines both (Chapter 2). A program run by an NGO, funded by the Chilean state, and intended to market the agro-ecological produce of Mapuche small farmers to tourists, provides a concrete case of the intersection of neoliberal multiculturalism with environmental discourse (Chapter 4). The concept of “postmaterialism” is adapted, with a critical edge, in an exploration of the environmental activism and a certain dissatisfaction with modernity among college educated immigrants to the District from Santiago, North America and Europe (chapter 5). The process of globalization, through which Mapuche campesinos come to use environmentalist discourses, involves interactions among old and new information technologies, transportation technologies, and the nonanthropogenic realities of physical space-time and geography (chapter 6). The dissertation concludes with a normative argument about the ethical and epistemological inadequacy of globalizing market society.

The principal research question of this study is framed as: Do prevailing, industrially and politically sourced definitions of Digital Exhibition faithfully represent the phenomenon¿s position within the contemporary media theory framework? Within this work Digital Exhibition is defined as: The practice of presenting moving images, either live or pre-recorded, to paying audiences, in public spaces, by means of digital distribution and projection. The majority of established literatures concerning Digital Exhibition are aimed at producing categorical definitions of the phenomenon. These ¿meaning making¿ discourses commonly stem from potentially ideologically affected sources. To address this issue, the author has investigated the political economy of key commentators, and Digital Exhibition has been impartially researched following a ¿case studies¿ methodology; with an analytical framework based upon a series of ¿plausible rival hypotheses¿. These hypotheses include that Digital Exhibition isM ¿ a form of the cinema ¿ a form of television ¿ a new (new media) medium ¿ multiple media ¿ not a medium It is presented that each investigated hypothesis can be argued to be legitimate when employing established media theories as the means of rationalisation. Nevertheless, the author concludes that individual industrially / politically charged definitions still do not provide an adequately comprehensive account as to the wealth of interpretations that can be drawn for Digital Exhibition. The author also presents his own perspective as to the subjective nature of contemporary media taxonomies, and ultimately proposes that Digital Exhibition is not a medium, but is a designation offered to a subjectively defined collection of events made possible through the transmission of computational binary pulse signals.

<p> A study of metal enrichment of the intergalactic medium (IGM) using a series of smooth particle hydrodynamics (SPH) simulations is presented, employing models for metal cooling and the turbulent diffusion of metals and thermal energy. An adiabatic feedback mechanism was adopted where gas cooling was prevented on the timescale of supernova bubble expansion to generate galactic winds without explicit wind particles. The simulations produced a cosmic star formation history (SFH) that is broadly consistent with observations until z ~ 0.5, and a steady universal neutral hydrogen fraction (OHI) that compares reasonably well with observations. The evolution of the mass and metallicities in stars and various gas phases was investigated. At z=O, about 40% of the baryons are in the warm-hot intergalactic medium (WHIM), but most metals (80%-90%) are locked in stars. At higher redshifts the proportion of metals in the IGM is higher due to more efficient loss from galaxies. The results also indicate that IGM metals primarily reside in the WHIM throughout cosmic history, which differs from simulations with hydrodynamically decoupled explicit winds. The metallicity of the WHIM lies between 0.01 and 0.1 solar with a slight decrease at lower redshifts. The metallicity evolution of the gas inside galaxies is broadly consistent with observations, but the diffuse IGM is under-enriched at z ~ 2.5. Metals enhance cooling which allows WHIM gas to cool onto galaxies and increases star formation. Metal diffusion allows winds to mix prior to escape, decreasing the IGM metal content in favour of gas within galactic halos and star forming gas. Diffusion significantly increases the amount of gas with low metallicities and improves the density-metallicity relation. </p> <p> The galactic wind generation mechanism and the wind properties from our simulations were investigated. It was found that: 1. Galactic winds are most efficient for halos in the intermediate mass range 10^10Mo - 10^11 Mo . These winds dominate the metal ejection at all redshifts, although towards lower redshift the contributions from larger halos become relatively more important. At the low mass end gas is prevented from accreting onto halos and has very low metallicities. At the high mass end, the fraction of halo baryons escaped as winds declines along with the decline of stellar mass fraction in these halos. The decrease in wind ejection is likely because of the decreases in star formation activity, wind mass loading and wind escape efficiency as the halo mass increases. 2. The adiabatic feedback can generate winds with mass loading factors comparable to the ones used in explicit superwind models. The mass loading factor decreases towards lower redshift, implying that smaller halos have larger mass loading. 3. Metals located at lower density were generated at earlier epochs from small halos, suggesting that the wind traveling speed can affect the metal distribution in the IGM. </p> / Thesis / Doctor of Philosophy (PhD)

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