published_or_final_version / abstract / toc / Chinese Historical Studies / Master / Master of Arts

We investigate the uses of gravitational lensing for analysing the dark matter haloes around galaxies, comparing galaxies within groups and clusters to those in the field. We consider two cases: when only photometric redshift data is available, and when spectroscopic redshift data is available for a sufficiently large sample of galaxies. For the case of data with photometric redshifts, we analyse the CFHTLenS dataset. This dataset is derived from the CFHTLS-Wide survey, and encompasses 154 deg^2 of high-quality shape data. Using the photometric redshifts to estimate local density, we divide the sample of lens galaxies with stellar masses in the range 10^9 Msun to 10^10.5 Msun into those likely to lie in high-density environments (HDE) and those likely to lie in low-density environments (LDE). Through comparison with galaxy catalogues extracted from the Millennium Simulation, we show that the sample of HDE galaxies should primarily (~61%) consist of satellite galaxies in groups, while the sample of LDE galaxies should consist of mostly (~87%) non-satellite (field and central) galaxies. Comparing the lensing signals around samples of HDE and LDE galaxies matched in stellar mass, we show that the subhaloes of HDE galaxies are less massive than those around LDE galaxies by a factor 0.65+/-0.12, significant at the 2.9 sigma level. A natural explanation is that the haloes of satellite galaxies are stripped through tidal effects in the group environment. Our results are consistent with a typical tidal truncation radius of ~40 kpc. For the case of data with spectroscopic redshifts, we analyse the GAMA-I and the ongoing GAMA-II surveys. We demonstrate the possibility of detecting tidal stripping of dark matter subhaloes within galaxy groups using weak gravitational lensing. We have run ray-tracing simulations on galaxy catalogues from the Millennium Simulation to generate mock shape catalogues. The ray-tracing catalogues assume a halo model for galaxies and groups, using various models with different distributions of mass between galaxy and group haloes to simulate different stages of group evolution. Using these mock catalogues, we forecast the lensing signals that will be detected around galaxy groups and satellite galaxies, as well as test two different methods for isolating the satellites' lensing signals. A key challenge is to determine the accuracy to which group centres can be identified. We show that with current and ongoing surveys, it will possible to detect stripping in groups of mass 10^12 Msun to 10^15 Msun.

In the Maritimes, only two striped bass spawning populations remain: the Miramichi River in New Brunswick and the Shubenacadie – Stewiacke system in Nova Scotia. The Shubenacadie – Stewiacke system is subjected to a well pronounced twice daily tidal bore which induces dramatic changes in water parameters and challenges pelagic life. This system will be subject to potential change through brine discharge, a by-product of the Alton Natural Gas Storage Project. . Examining the temporal distribution of mysids, striped bass eggs and larvae at a fixed location around the Alton Project site will provide baseline information on population structure and insights into how egg and larvae distributions change with respect to tidal cycles, temperature and salinity. Surface plankton net tows from the top 0.75m of the water column were used to collect mysids, striped bass eggs and larvae over 14 months over two years. Daily mean egg abundance surpassed 1000 eggs/m3 once in 2008. A decrease of 1.9 °C in water temperature at the Alton Project site coincided with a cessation of eggs, and presumably, spawning. Spawning resumed when temperatures surpassed 15 °C. In contrast, the largest spawning event of the 2009 season occurred as water temperatures decreased (14 to 12.7 °C). The 2009 spawning season was longer (49 days) than 2008 (31 days) by 18 days, and in both years spawning peaked within the last week of May and first week of June. Two large spawning events, over 4000 daily mean eggs/m3 apiece, were detected May 24 and June 2, 2009. Mysids were present in high numbers throughout May to November, with some tows greater than 14,000 individuals/m3 in June 2008 and August 2009. Over the length of the ebb tide, as salinity decreases, mysid abundance also decreased. Whereas, striped bass egg abundance was consistently lowest at high tide and increased progressively over about 300 minutes through the ebb tide. Both striped bass larvae and mysids displayed patchiness in their temporal distribution suggesting passive transport in the this system. In both 2008 and 2009, larvae were detected at the Alton Project site for 38 days. The colder temperatures and larger tidal range of 2009, coupled with large increase in rainfall during the larval season contributed to the over 30-fold lower abundance over that found in 2008. When abundance was related in concert with temperature and salinity, mysids were ever present at high abundances except on three occasions. Mysid abundance decreased when salinity dropped beneath 5 ‰ during both years, and in 2008 when temperatures were lower than 15 °C. Salinity was impacted according to a seven-day lag after rainfall in both years, although the minimum volume of rainfall and associated impact on salinity have yet to be described.

The kinetic energy present in tidal currents and other water courses has long been appreciated as a vast resource of renewable energy. The work presented in this doctoral thesis is devoted to both the characteristics of the hydro-kinetic resource and the technology for energy conversion. An assessment of the tidal energy resource in Norwegian waters has been carried out based on available data in pilot books. More than 100 sites have been identified as interesting with a total estimated theoretical resource—i.e. the kinetic energy in the undisturbed flow—in the range of 17 TWh. A second study was performed to analyse the velocity distributions presented by tidal currents, regulated rivers and unregulated rivers. The focus is on the possible degree of utilization (or capacity factor), the fraction of converted energy and the ratio of maximum to rated velocity, all of which are believed to be important characteristics of the resource affecting the economic viability of a hydro-kinetic energy converter. The concept for hydro-kinetic energy conversion studied in this thesis comprises a vertical axis turbine coupled to a directly driven permanent magnet generator. One such cable wound laboratory generator has been constructed and an experimental setup for deployment in the river Dalälven has been finalized as part of this thesis work. It has been shown, through simulations and experiments, that the generator design at hand can meet the system requirements in the expected range of operation. Experience from winding the prototype generators suggests that improvements of the stator slot geometry can be implemented and, according to simulations, decrease the stator weight by 11% and decrease the load angle by 17%. The decrease in load angle opens the possibility to reduce the amount of permanent magnetic material in the design.

Tidigare vårdforskning inom psykiatrin har främst utgått ifrån personalens erfarenheter. Forskning har visat på ett behov att studera patienters erfarenheter. När det gäller unga vuxnas erfarenheter av psykiatrisk vård saknas forskning och det har därför varit intressant att studera det. Som teoretisk utgångspunkt har Barker och Buchanan-Barkers tidvattenmodell använts. Data samlades in via tre intervjuer som sedan analyserades med kvalitativ innehållsanalys. Syftet med studien var att belysa vad unga vuxna (18-24 år) beskriver som värdefullt i kommunikationen med sjuksköterskan. I analysen framkom tre kategorier samt ett tema. Kategorierna var betydelsen av personligt möte, att få vara delaktig och att få känna sig betydelsefull Temat som identifierades var att existera i ett sammanhang. Slutsatserna mynnade ut i fem viktiga frågor att tänka på för att etablera en god kommunikation med patienten. Ett område för fortsatt forskning skulle kunna vara att ta reda på hur sjusköterskor skulle kunna tillbringa mer tid med patienter. / Earlier research in the psychiatric field has primarily focused on the experiences of the staff. Research has shown that there is a need to study the experiences of the patients. When it comes to young adults experiences of psychiatric care there is a lack of research. Therefore it has been interesting to study that. The Tidal Model by Barker and Buchanan-Barker was used as a theoretical starting point. Data was collected from three interviews. The interviews where then analyzed with qualitative content analysis. The aim of this study was to highlight what young adults (18-24 years) described as valuable in nurse patient communication. The analysis gave three categories. They were the meaning of a personal meeting, to be involved and to feel important. The theme to exist in a context was identified. The final conclusions rendered five important questions to think of in order to establish a good communication with the patient. One area for further research could be to study how nurses could spend more time with patients.

Interest is growing worldwide among utility companies and governments of maritime countries in assessing the power potential of tidal streams. While the latest assessment for Canadian coastlines estimates a resource of approximately 42 GW, these results are based on the average kinetic energy flux through the channel. It has been shown, however, that this method cannot be used to obtain the maximum extractable power for electricity generation. This work presents an updated theory for the extractable power from a channel linking a bay to the open ocean. A mathematical model is developed for one-dimensional, non-steady flow through a channel of varying cross-section. Flow acceleration, bottom drag, and exit separation effects are included in the momentum balance. The model is applied to Masset Sound and Masset Inlet in Haida Gwaii, a remote island region, to determine the extractable power and its associated impacts to the tidal amplitude and volume flow rate through the channel.

This thesis examines the barotropic M2 tidal circulation and associated oceanographic properties in the Kyuquot Sound. The main contribution of this thesis is the development of a simple analytical model based on results from a Finite-Volume Coastal Ocean Model (FVCOM), describing a two-channel system. The simple analytical model allows us to estimate the energy dissipation rate in Crowther Channel and recognizes that friction is responsible for phase difference (between currents and elevation) variations as we move along the channel. This is done without running complex numerical models or collecting extensive observation data. We found a difference in velocity phases between a dominant channel (Kyuquot Channel) and a secondary channel (Crowther Channel) in Kyuquot Sound. The velocity phase response in the secondary channel is out of phase with the dominant channel, and varies when we move along the channel, while the elevation phases are consistent between the two channels. This result has a potentially significant impact on future biological and navigation decisions. Our research is also focused on getting a general understanding of the circulation in Kyuquot Sound, and offers an energy budget comparison between the analytical and numerical model results. These results allow the contrast between the simple analytical and the numerical model to be clarified, as the advantages and limitations of both are discussed in detail. / Graduate / 0415 / 0759 / 0547 / diwan@uvic.ca

Errata pasted onto front end paper. / Bibliography: leaves 131-136. / v, 136 leaves : ill., maps (one col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The hydrodynamics of the Persian Gulf waters are of great importance because of oil transport activities and consequential oil spills. This thesis developed and applied a new technique for improving mathematical models to examine tidal movement in the Gulf, especially around the Iranian coast. Three different numerical tidal models, namely a uniform grid Cartesian model, a uniform grid spherical model and a spherical model containing dynamically nested regions with finer spatial and temporal grids were examined, with results compared with Admiralty chart 5081 and tidal constants computed from records from tidal stations. Results from the dynamically nested model better matched recorded values. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1998?

Coastal wetlands dominated by mangroves provide important ecological services to the coastal zone, many of which are associated with tidal inundation . In this study I investigated whether all coastal wetlands provide similar ecosystem services, or whether these varied depending on their geomorphological setting and the eutrophication level of the floodwater. Sampling was conducted over two years with significantly different levels of rainfall over six estuaries in Southeast Queensland, Australia. Sediment, nutrient and carbon exchange were investigated in tidal and riverine estuaries dominated by mangrove forests. The estuaries selected also comprised a gradient from low mesotrophic to low eutrophic. Spatial variation within the coastal wetlands was also investigated, comparing nutrient exchange in the low and high intertidal cyanobacteria mat . To assess sediment exchange, I measured retention of total suspended solids and sedimentation rates. Additionally, in order to assess the origin of sediment deposited in mangroves, glomalin, a novel terrestrial soil carbon (C) tracer, was used. Nutrient and C exchange were quantified by comparison of concentrations of soluble reactive phosphorus (SRP), nitrogen oxides (NOx--N), ammonium (NH4+) total organic carbon (TOC) and dissolved organic C (DOC) in water entering and leaving the mangroves during complete tidal cycles (3 tidal cycles in 6 estuaries for 2 years). Finally, the biogeochemical function of the cyanobacteria mat was measured through experiments investigating nitrogen fixation (N) and nutrient exchange in the extensive mats in the Exmouth Gulf, Western Australia. My results show that the seaward fringe mangrove retains the majority of sediment entering the wetland during a tidal cycle accounting for 52.5 ± 12.5 % of the total sedimentation (fringe mangrove + scrub mangrove + saltmarsh/ cyanobacteria mat). Geomorphological setting had a stronger influence on spatial patterns of deposition than on sedimentation rates. Riverine mangroves had more homogeneous distribution of sediments across the intertidal zone than tidal mangroves, where most sedimentation occurred in the seaward fringe mangrove zone. The presence of glomalin in sediments, and thus the relative importance of terrigenous sediment, was strongly influenced by geomorphological setting. Glomalin was primarily delivered to riverine mangroves and deposited within the scrub mangrove zone, while tidal mangroves received less glomalin during tidal inundation and most of it was deposited within the fringe mangrove zone. Overall, NOx--N concentrations decreased in the floodwater after flooding the coastal wetland, suggesting that these ecosystems act as sinks of dissolved NOx--N during tidal inundation. In average, NOx--N concentrations in the floodwater decreased 28 %. Additionally, during periods of high rainfall the decrease in nutrient concentrations was more pronounced, and not only NOx--N but also SRP and NH4+ concentrations decreased to up to 51 % and 83 %, respectively. My results suggest that rainfall enhances nutrient removal by coastal wetlands in the region. Geomorphological setting also affected nutrient removal. Riverine mangroves received stronger nutrient pulses, which resulted in strongest rates of nutrient removal during tidal inundation. Nutrient removal was closely related to the nutrient concentration of the floodwater: high nutrient removal occurred when floodwater was rich in nutrients. The C entering the wetland in the floodwater was mainly composed of DOC and its exchange did not vary among sites with differing geomorphological setting. However, DOC exchange was strongly affected by the water quality of floodwater inundating the coastal wetland. DOC concentrations were higher in the flood compared to the ebb tide in sites flooded by water high in C, NH4+ and SRP, suggesting DOC import. Contrary, DOC concentrations were lower in the flood compared to the ebb tide in sites flooded by water high in C, NH4+ and SRP, suggesting DOC export. The high intertidal cyanobacteria mat was important in regulating N fluxes in coastal wetlands. In the arid Exmouth Gulf, where cyanobacteria mats are abundant, nitrogen fixation rates were 4.9 ± 3.2 nmol cm-1 h-1. Cyanobacteria mats also removed N from the floodwater in the form of NOx--N (0.47 ± 0.45 g m-2 h-1) and NH4+ (0.31 ± 0.02 g m-2 h-1). N fixation and nutrient removal from the floodwater was highly variable spatially and temporally. N fixation rates were highest during the day in the mat situated at low tidal elevations. Overall, I found that the material exchange in coastal wetlands is variable within the coastal zone as a result of natural factors, such as geomorphology, vegetation composition and rainfall. But material exchange in wetlands is also affected by anthropogenic factors, particularly eutrophication. From all these factors, eutrophication of the floodwater appears to be the most critical, shifting the mangrove function from a DOC source to a nutrient and DOC sink. Approximate thresholds of nutrient and C concentrations in the floodwater that are likely to trigger shifts in ecosystem function in coastal wetlands in Southeast Queensland, and thus in the ecosystem services they provide, are 0.02 mg L-1 of SRP, 0.04 mg L-1 of NH4+ and 7.5 mg L-1 of DOC.

Coastal wetlands dominated by mangroves provide important ecological services to the coastal zone, many of which are associated with tidal inundation . In this study I investigated whether all coastal wetlands provide similar ecosystem services, or whether these varied depending on their geomorphological setting and the eutrophication level of the floodwater. Sampling was conducted over two years with significantly different levels of rainfall over six estuaries in Southeast Queensland, Australia. Sediment, nutrient and carbon exchange were investigated in tidal and riverine estuaries dominated by mangrove forests. The estuaries selected also comprised a gradient from low mesotrophic to low eutrophic. Spatial variation within the coastal wetlands was also investigated, comparing nutrient exchange in the low and high intertidal cyanobacteria mat . To assess sediment exchange, I measured retention of total suspended solids and sedimentation rates. Additionally, in order to assess the origin of sediment deposited in mangroves, glomalin, a novel terrestrial soil carbon (C) tracer, was used. Nutrient and C exchange were quantified by comparison of concentrations of soluble reactive phosphorus (SRP), nitrogen oxides (NOx--N), ammonium (NH4+) total organic carbon (TOC) and dissolved organic C (DOC) in water entering and leaving the mangroves during complete tidal cycles (3 tidal cycles in 6 estuaries for 2 years). Finally, the biogeochemical function of the cyanobacteria mat was measured through experiments investigating nitrogen fixation (N) and nutrient exchange in the extensive mats in the Exmouth Gulf, Western Australia. My results show that the seaward fringe mangrove retains the majority of sediment entering the wetland during a tidal cycle accounting for 52.5 ± 12.5 % of the total sedimentation (fringe mangrove + scrub mangrove + saltmarsh/ cyanobacteria mat). Geomorphological setting had a stronger influence on spatial patterns of deposition than on sedimentation rates. Riverine mangroves had more homogeneous distribution of sediments across the intertidal zone than tidal mangroves, where most sedimentation occurred in the seaward fringe mangrove zone. The presence of glomalin in sediments, and thus the relative importance of terrigenous sediment, was strongly influenced by geomorphological setting. Glomalin was primarily delivered to riverine mangroves and deposited within the scrub mangrove zone, while tidal mangroves received less glomalin during tidal inundation and most of it was deposited within the fringe mangrove zone. Overall, NOx--N concentrations decreased in the floodwater after flooding the coastal wetland, suggesting that these ecosystems act as sinks of dissolved NOx--N during tidal inundation. In average, NOx--N concentrations in the floodwater decreased 28 %. Additionally, during periods of high rainfall the decrease in nutrient concentrations was more pronounced, and not only NOx--N but also SRP and NH4+ concentrations decreased to up to 51 % and 83 %, respectively. My results suggest that rainfall enhances nutrient removal by coastal wetlands in the region. Geomorphological setting also affected nutrient removal. Riverine mangroves received stronger nutrient pulses, which resulted in strongest rates of nutrient removal during tidal inundation. Nutrient removal was closely related to the nutrient concentration of the floodwater: high nutrient removal occurred when floodwater was rich in nutrients. The C entering the wetland in the floodwater was mainly composed of DOC and its exchange did not vary among sites with differing geomorphological setting. However, DOC exchange was strongly affected by the water quality of floodwater inundating the coastal wetland. DOC concentrations were higher in the flood compared to the ebb tide in sites flooded by water high in C, NH4+ and SRP, suggesting DOC import. Contrary, DOC concentrations were lower in the flood compared to the ebb tide in sites flooded by water high in C, NH4+ and SRP, suggesting DOC export. The high intertidal cyanobacteria mat was important in regulating N fluxes in coastal wetlands. In the arid Exmouth Gulf, where cyanobacteria mats are abundant, nitrogen fixation rates were 4.9 ± 3.2 nmol cm-1 h-1. Cyanobacteria mats also removed N from the floodwater in the form of NOx--N (0.47 ± 0.45 g m-2 h-1) and NH4+ (0.31 ± 0.02 g m-2 h-1). N fixation and nutrient removal from the floodwater was highly variable spatially and temporally. N fixation rates were highest during the day in the mat situated at low tidal elevations. Overall, I found that the material exchange in coastal wetlands is variable within the coastal zone as a result of natural factors, such as geomorphology, vegetation composition and rainfall. But material exchange in wetlands is also affected by anthropogenic factors, particularly eutrophication. From all these factors, eutrophication of the floodwater appears to be the most critical, shifting the mangrove function from a DOC source to a nutrient and DOC sink. Approximate thresholds of nutrient and C concentrations in the floodwater that are likely to trigger shifts in ecosystem function in coastal wetlands in Southeast Queensland, and thus in the ecosystem services they provide, are 0.02 mg L-1 of SRP, 0.04 mg L-1 of NH4+ and 7.5 mg L-1 of DOC.