Headwater drainage features (HDFs) in the GTA are commonly subjected to land-use modifications including agricultural uses and urbanization. A temporal study design approach was used to test whether the runoff being exported from previously modified HDFs differed from runoff exported from less disturbed forested channels. Drift nets were deployed in the permanent reaches of streams and in the HDF channels, to give an indication of the quality and quantity of drifting materials. Gastric lavage was used to remove stomach contents from creek chub living downstream from HDFs and these contents were used to determine if invertebrates in HDF runoff could act as food immediately upon reaching fish-bearing sections of stream. Reaches of streams associated with forested HDFs were found to have more fish than either those associated with agricultural or urban HDFs (203, 184 and 145 fish per forested, agricultural and urban site, respectively). Sites associated with forested catchments also had a greater number of salmonids per site. Conditions of high flow in the stream and the HDF coincided with an increased quantity of drifting invertebrates in all site types and land uses, as well as a decrease in the proportion of creek chub with empty stomachs. Overall, aquatic Diptera were the most numerous invertebrates captured in drift nets and in the stomach contents of creek chub. Hymenoptera, terrestrial Oligochaeta and Diplopoda also made major contributions to the diets of creek chub. Results indicate that HDFs in all land uses are exporting both aquatic and terrestrial invertebrates to main streams at times of high flow. Creek chub consume more prey at times of high flow, and this often includes terrestrial invertebrates, which must have been imported from terrestrial sources to the aquatic environment, however the degree to which they are exported by HDFs is still not clear. The series of complex interactions occurring at the HDF/main stream interface requires further study.

Thesis (Ph. D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (Ph. D.)--University of Adelaide, Dept. of Civil Engineering, 1984. / Includes bibliographical references (leaves 390-404).

Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on June 18, 2008). Includes bibliographical references (p. 42-47).

The recession portion of the ephemeral stream hydrograph is modeled as a conceptual analog of the discharge from a single leaky reservoir. Physically, the reservoir may be considered to approximate that portion of the ephemeral stream channel that is flowing at the beginning of recession. The discharging reservoir is described by a continuity equation and by discharge-stage and storage-stage relations. No input is routed through the reservoir. It is assumed that initially (at the beginning of recession) the reservoir has water in storage. The discharge-stage relation for the reservoir is defined by the rating curve for the stream and storage-stage depends on reservoir configuration. A good agreement between observed and model curves is obtained by optimizing two parameters, reservoir leakage rate and initial storage, The agreement is most sensitive to changes in initial storage. Best parameter values are physically realistic and best reservoir configuration has leakage that varies directly with stage (depth) and storage that varies as the square of stage.

The architectural theorist and practitioner Bernard Tschumi asserts that enquiring and working at the limits of a discipline expands our knowledge and experience. Within this thesis I examine the limits of architecture as they relate to the non-material and the nonvisible elements of space. As Mark Wigley observes in his essay on atmosphere, architects, at different times, have sought to understand, capture and control the otherwise ungraspable aspects of space. The elusive nature of such ephemeral architectural aspects and elements makes them hard to manage and map. Their examination provides a challenging exercise within architectural research. Atmosphere is such an elusive element; as Zizek would call it, it is that which remains always as a backdrop to daily life. It seems to vanish when subjected to conscious scrutiny. Non-visual sensations such as sounds, smell, textures, temperature, clearly constitute invisible elements that are notoriously difficult to represent. As a further example, event, the way in which a space is or could be deployed or inhabited over time, provides another unpredictable and ambiguous design consideration. Spaces relate to performance. The performance of a place constitutes its nature, character, function and meaning. However, the complexity, changeability, and potentiality of spatial performance render it as something abstract and non-representable. As Steven Connor, and Jonathan Hill, amongst other theorists, observe, new media, electromagnetic fields, and digital gadgets, also constitute invisible elements of space. They create invisible fields, territories, links and boundaries, affecting everyday spaces and relationships. So a typology of the elusive and ephemeral characteristics of space would include: non-conventional materials, elements changing over time, electromagnetic fields, electronic equipment, nonvisually representable sensations, situations, processes and events. Attending closely to these themes reveals some key questions. Why do these themes appear (or re-appear) now, at this particular moment in history? How are they related to contemporary thought, practice, and to current shifts in society, culture and technological development? New technology, new means of representation, and emerging design media change both the way in which we inhabit space, and also the way in which we understand and represent it. Digital media allow us to record and represent time and duration. Hence, events and situations occurring over time can be documented and studied. Subsequently, new media can also function as a new tool to think about space, and for designing accordingly. As Marshall McLuhan claimed in the 1960s, the emergence of new digital media has caused a ‘shift in the sensorium’ and has readdressed the significance and role of experiencing and sensing other than through the visual sense. In this thesis I discuss in turn a series of limits and the qualities of the spaces that they reveal. Each chapter title is based on a binary and a theme that indicates its transgression: (a) the visual versus the non-visible – the sensuous (chapter 2), (b) the discourse about the formal versus the material – the performative (chapter 3), (c) the physical versus the digital – the hybrid (chapter 4). In order to examine these themes and explore the design potential they entail, I review relevant literature in parallel with the conduct of a series of design experiments. The experimental processes deployed are of three kinds: (1) mapping and documentation of sensory situations, (2) design experiments that challenge the issues discussed and (3) real-scale interventions that test some of the design ideas at a 1:1 scale and in an actual place. The latter includes a major installation at the 2009 Venice Biennale on the theme of Athens by Sound initiated and designed by a team involving the author.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

The evolving concept of Ephemeral State Processing (ESP) is overviewed. ESP allows development of new scalable end-to-end network user services. An evolving macro-level language is being developed to support ESP at the network node level. Three approaches for implementing ESP services at network routers can be considered. One approach is to use the existing processing capability within commercially available network routers. Another approach is to add a small scale existing ASIC based general-purpose processor to an existing network router. This thesis research concentrates on a third approach of developing a special-purpose programmable Ephemeral State Processor (ESPR) Instruction Set Architecture (ISA) and implementing microarchitecture for deployment within each ESP-capable node to implement ESP service within that node. A unique architectural characteristic of the ESPR is its scalable and temporal Ephemeral State Store (ESS) associative memory, required by the ESP service for storage/retrieval of bounded (short) lifetime ephemeral (tag, value) pairs of application data. The ESPR will be implemented to Programmable Logic Device (PLD) technology within a network node. This offers advantages of reconfigurability, in-field upgrade capability and supports the evolving growth of ESP services. Correct functional and performance operation of the presented ESPR microarchitecture is validated via Hardware Description Language (HDL) post-implementation (virtual prototype) simulation testing. Suggestions of future research related to improving the performance of the ESPR rnicroarchitecture and experimental deployment of ESP are discussed.

No description available.