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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Teacher professional development and communities of practice

Hirtz, Janine Renee Marie 05 1900 (has links)
The larger research project seeks to examine the role of technology and factors that influence its overall use and efficacy in supporting a community of teachers engaged in professional development. This thesis examines factors that appear to influence teacher participation in the online community of practice engaging in an overarching research project conducted by Dr. Balcaen and a team from UBC O Faculty of Education and funded by the Southern Alberta Professional Development Consortium (SAPDC). The two groups are acting in partnership for supporting and sustaining communities of practice in social studies in southern Alberta. SAPDC is allowing teachers release time to engage in the project while TC² is providing professional development for the participant teachers to become proficient at embedding TC² critical thinking tools into their classroom practices. Various technologies are used during this study as part of the design of providing professional development for the participants including supporting an online community presence. The guiding question for this thesis is: In a blended approach of face-to-face and online supported professional development for embedding critical thinking into the new social studies curriculum, what significant factors appear to influence teacher participation in the online community of practice during the first year of the project? Overall results during the first year of this project show that various technologies used during the project are valuable and effective in nurturing this community of practice by enabling and promoting collaboration, communication, and the completion and delivery of products to be used in teaching the new curriculum. I also examine negative factors that appear to prevent some teachers’ technology use and online participation and collaboration during this project. Findings show that there are several significant factors that influence participation in the online community and while some participants are reluctant to engage or enter the online environment, others have emerged as leaders and play a significant role in building and sustaining the community of practice. These results provide critical information about implementing and integrating an online component and using technology to sustain communities of practice engaged in this form of teacher professional development.
252

Bandwidth regulation and performance enhancements for Open-iSCSI networked storage

Zhang, Yongjian Unknown Date
No description available.
253

The Masses of Proton-Rich Isotopes of Nb, Mo, Tc, Ru and Rh and Their Influence on the Astrophysical rp and νp Processes

Fallis, Jennifer 14 September 2009 (has links)
The Canadian Penning Trap mass spectrometer located at Argonne National Laboratory has been built for the purpose of studying the masses of both stable and unstable nuclides. For this thesis 18 proton-rich unstable nuclides of elements Nb, Mo, Tc, Ru and Rh have been measured with this apparatus to an average precision of 7.8 x10^−8. The masses of 6 of these nuclides had not been measured when this thesis was undertaken, and 4 more were not known to the precisions required for use in astrophysical nucleosynthesis models. The masses of these nuclides were of particular interest as the reaction paths of two proposed nucleosynthetic processes, the rp and νp processes, pass through this region. The rp process is thought to occur in X-ray bursts and directly affects the X-ray luminosity which is emitted from these objects. The νp process is thought to occur in the inner regions of the material ejected during a core-collapse supernova explosion and is of particular interest as it may answer some outstanding questions about the origins of the chemical elements in the Universe. The Canadian Penning Trap and associated apparatus were used to determine the masses of 18 nuclides, some for the first time ever. Our measurements improve the precision on all of the masses, by a factor of 70 in some cases. Our results are necessary to determine the proton-separation energies for these nuclides which are critical for determining the paths and reaction rates of the rp and νp processes. In particular, the effect of our measurements of 92Ru and 93Rh on the expected production ratio of 92Mo to 94Mo in the νp process, and the effect of our measurement of 87Mo on the path of this process will be discussed.
254

LOCATING HOT SPOTS OF FECAL POLLUTION IN AN URBAN WATERSHED OF CENTRAL KENTUCKY USING <i>BACTEROIDES</i> 16S rRNA MARKERS

Coakley, Tricia L. 01 January 2011 (has links)
The field of molecular fecal source tracking in the water environment has developed rapidly since the first PCR assays for general and host-­‐specific Bacteroides 16s rRNA markers were published. Numerous host-­‐specific molecular markers and PCR assays have been developed, adding greater specificity, sensitivity and quantitative methods to the array of options. The public demand for readying methods for transfer to the commercial lab, so that they may be used to generate data for public utilities, citizen action groups and regulatory agencies, has fueled the development of an entire new research community. These methods, however plentiful, have not found community agreement and there is no consensus concerning the appropriate implementation of molecular fecal source tracking in the field. Some issues plaguing the implementation include imperfect marker specificity, environmental variability, DNA extraction variability, PCR inhibition and high cost of molecular analysis. This thesis presents an approach for locating hot spots of human fecal pollution in an urban watershed by using published methodologies for the collection of molecular fecal source tracking data along with a tiered watershed screening tool for cost reduction and two data normalization techniques which ameliorate several known sources of error and strengthen the efficacy of watershed application.
255

Identifying Hot-Spots of Fecal Contamination in the Royal Spring Karstshed

Lee, Samuel C 01 January 2012 (has links)
The City of Georgetown, Kentucky relies on a vast karst spring network as a drinking water source. This karst feature has several inputs from sinkholes and streams in the Cane Run Watershed: a watershed associated with a variety of land uses in the recharge area. The recharge area encompasses the area from North Lexington to Georgetown and is composed of urban, suburban, agricultural and industrial usage. A serious water quality issue exists with respect to the impact of fecal contamination within the spring recharge area. Identification of fecal contamination is quantified by microbial indicators adapted from surface water applications: fecal load (E. coli), fecal source (two human-host specific Bacteroides DNA markers) and fecal age (AC/TC ratio). These three criteria are used in a categorical Microbial Source Tracking (MST) model to assign a Sanitary Category Value (SCV) between 0 and 3 for each sample location. Low SCVs (1.5) are associated with high values of fecal load, low fecal age and detectable concentration of human-specific markers. SCV measured during dry weather conditions are indicative of potentially leaking human sewers. Due to retention and conservation of fecal load (E. coli) and age (AC/TC) microbial indicators in the karstic environment, ambiguous SCV model results cannot pinpoint, with statistical confidence, fecal sources in a karstic environment. Human-host specific genetic markers (HF183 and HuBac) were also detected at all sample sites above limits of detection, indicating steady inflow of fecal material during all sample events. By adding a flow multiplier and expressing HF183 and HuBac values as a load, it was strongly indicated that a human fecal source was entering the groundwater conduit and impacting Royal Spring independent from other upstream fecal sources. Interpretation of these trends, while strongly indicated, cannot be supported with statistical evidence.
256

A statistical-process based approach for modelling beach profile variability

Pender, Douglas January 2013 (has links)
As the debate into a changing global climate continues, it is important that coastal engineers and scientists have the most advanced tools to quantify any resulting variation in the coastal environment. This will aid the creation and implementation of effective shoreline management plans to mitigate these changes. This thesis presents a new combined Statistical-Process based Approach (SPA) for modelling storm driven, cross-shore, beach profile variability at a medium-term (annual to decadal) timescale. The methodology presented involves combining the detailed statistical modelling of offshore storm data and a process based morphodynamic model (XBeach), to assess, and quantify, the medium-term morphodynamic response of cross-shore beach profiles. Up until now the use of process-based models has been curtailed at the storm event timescale. This approach allows inclusion of the post-storm recovery period, in addition to individual event impacts, thus allowing longer-term predictions. The use of a process-based model for simulating, both erosion and recovery, expands on previous work on the subject by allowing for the inclusion of antecedent beach profiles within the modelling framework. The XBeach model and the overall SPA procedure were calibrated and validated using measured wave and beach profile data from Narrabeen Beach, NSW, Australia. XBeach was shown to give a good prediction of the post-storm profile for four varying storm events. In addition, by accounting for the hydrodynamic processes that govern accretion, and calibrating parameters accordingly, XBeach was also shown to provide a good representation of berm accretion during recovery periods. The combination of the erosion and accretion models was shown to produce extremely encouraging results at an annual timescale, by successfully following the trends in beach volume and the position of the 0m and 2m beach contours. The simulation of a longer sequence provided comparable medium-term erosion return levels.
257

Characterisation of superconducting Nd123 solid solutions and related phases

Duncan, Fiona Hazel January 1999 (has links)
The stoichiometry of the Nd<sub>1+x</sub>Ba<sub>2-x</sub>Cu<sub>3</sub>O<sub>7-δ</sub> solid solution has been investigated using XRD and EPMA. At 980°C in air, an essentially continuous solid solution forms with limiting compositions x<sub>min</sub> = 0.03(1) and x<sub>max</sub> = 0.92(2). The solid solution limits are independent of temperature over the range 300 to 1050°C, i.e. stoichiometric Nd123 does not form. Preliminary studies show that annealing in an Ar atmosphere does not affect x<sub>min</sub>. Three structurally distinct polymorphs of Nd123ss exist - tetragonal Nd123ss, orthorhombic Nd123ss and orthorhombic Nd123ss. The stability range of each in air has been determined. Quenched samples with 0.03 ≤ x ≤ 0.6 have the tetragonal Nd123ss structure. On oxygenation, samples with 0.03 ≤ x <˜0.2 are orthorhombic. The orthorhombic-tetragonal phase transition is second order, both with increasing temperature and increasing x. Samples with 0.7-0.9 have the orthorhombic Nd213ss structure at all oxygen contents. Tetragonal Nd123ss is isostructural with tetragonal Y123 and orthorhombic Nd123ss is isostructural with orthorhombic Y123. Orthorhombic Nd213ss has the ideal stoichiometry Nd<sub>2</sub>BaCu<sub>3</sub>O<sub>7-δ</sub> and is based on a 2a x b x 2c superstructure of the Nd123ss structure. The supercell is due to ordering of the Nd and Ba atoms, which leads to ordering of the oxygen atoms. Melting temperatures decrease with x. Two distinct regions of melting behaviour are observed; the first for 0.03 ≤ x ≤ 0.6 with a thermal minimum at x˜0.4, and the second for 0.7 ≤ x ≤ 0.9. Oxygen contents increase with x. Samples with larger x values have a smaller range of oxygen contents. High pressure oxygen annealing results in a constant Cu valence state of ˜2.35 for all values of x. Average copper valence states <2 are only obtained readily for x ≤ 0.3. T<sub>c</sub> decreases with x and samples become non-superconducting at x˜0.5. For samples annealed in 1 bar O<sub>2</sub>, 'double plateau' behaviour is observed.
258

The Masses of Proton-Rich Isotopes of Nb, Mo, Tc, Ru and Rh and Their Influence on the Astrophysical rp and νp Processes

Fallis, Jennifer 14 September 2009 (has links)
The Canadian Penning Trap mass spectrometer located at Argonne National Laboratory has been built for the purpose of studying the masses of both stable and unstable nuclides. For this thesis 18 proton-rich unstable nuclides of elements Nb, Mo, Tc, Ru and Rh have been measured with this apparatus to an average precision of 7.8 x10^−8. The masses of 6 of these nuclides had not been measured when this thesis was undertaken, and 4 more were not known to the precisions required for use in astrophysical nucleosynthesis models. The masses of these nuclides were of particular interest as the reaction paths of two proposed nucleosynthetic processes, the rp and νp processes, pass through this region. The rp process is thought to occur in X-ray bursts and directly affects the X-ray luminosity which is emitted from these objects. The νp process is thought to occur in the inner regions of the material ejected during a core-collapse supernova explosion and is of particular interest as it may answer some outstanding questions about the origins of the chemical elements in the Universe. The Canadian Penning Trap and associated apparatus were used to determine the masses of 18 nuclides, some for the first time ever. Our measurements improve the precision on all of the masses, by a factor of 70 in some cases. Our results are necessary to determine the proton-separation energies for these nuclides which are critical for determining the paths and reaction rates of the rp and νp processes. In particular, the effect of our measurements of 92Ru and 93Rh on the expected production ratio of 92Mo to 94Mo in the νp process, and the effect of our measurement of 87Mo on the path of this process will be discussed.
259

The non-tidal, navigable Thames : a bank erosion management strategy

Reed, Sue January 1999 (has links)
Processes and mechanisms of bank erosion on the non-tidal, navigable River Thames were identified and investigated using site specific monitoring and extensive geomorphic surveys. As a lowland, impounded river the Thames has little potential for bank erosion associated with reach-scale morphological channel adjustments. In fact, erosion is closely related to local conditions at the bank and significant processes and mechanisms include fluvial entrainment, slumping, and weakening and weathering of in situ bank material. Approximately 38.5km of eroding bankline was measured (-10% of the total length). Average rates of bank erosion monitored ranged from 0.05ni/yr to -0.5m/yr. The relative contribution to bank retreat of each process or mechanism depends on local conditions such as the use of the bank, the type of bank material and the bank geometry and the type of vegetation. Analysis of the causes of bank retreat at 147 sites along the River Thames revealed that erosion was generally influenced by a combination of factors. Navigation related activities contribute to the bank erosion at nearly all sites (-90%) but is solely responsible for erosion at only about 12%. Factors related to the use of the bank and adjacent land contribute to erosion along -65% of the total length of eroding bank but are the sole influence at only -5%. Channel planform and geometry contribute to -53% of observed bank erosion, but are the sole influence at less than <1% of the erosion sites. A review of selected of erosion control techniques applied on the River Thames suggested that solutions tend to be over-engineered and that strategies adopted were not necessarily appropriate for the causes and consequences of the bank erosion. Furthermore, whilst mitigation measures are often incorporated into the solutions, environmental enhancements are rarely included. Assessment of the causes and consequences of erosion has led to the development of a bank erosion management strategy for the River Thames based on geomorphological and sustainability principles. The strategy is presented as a transferable tool through which to achieve sustainable river management.
260

Three-dimensional single-sail static aeroelastic analysis & design method to determine sailing loads, shapes & conditions with applications for a FINN Class sail

Malpede, Sabrina Maria January 2001 (has links)
The development of modern sailing boats has been based almost entirely on the cooperative efforts of enthusiastic skippers, designers and sail-makers, with very little contribution from scientists and technologists and using just basic scientific principles. In recent times, urgent and strong requests for improved performance, mostly for racing yachts, have guided the interest and the attention of the scientific community in the optimisation of sail performance and design approach. Sailing performance depends on the sailboat velocity, aerodynamic and hydrodynamic characteristics. This thesis focuses on the importance of the quantitative evaluation of the sail loads and how this contributes to the improvement of the performance of a sailboat through the development of a system for aiding sail design and assisting mast design. The objective of this study is to provide an integrated design system, which supplies analysis method and design features via a user-friendly graphical interface of a single-sail configuration. The major achievement is the development of an integrating numerical method, which evaluates loads and their distribution and the consequent deformed sail-shape. It improves sail performance analyses and design of new sails. Summarising, the major achievements are: • efficacy of accurate performance analysis for each sail, for any given shape over all the possible sailing courses; • critical investigation of the sail behaviour in the above-mentioned cases; improved approach to an integrated sail design; improvements in mast design from the structural and aerodynamic point of view; limited design costs, in terms of time consumed and computational power employed; efficacy of the visualisation of novel designed sail and predicted performance, which reduces the number of possible design flaws. hi conclusion, the integrated sail analysis and design system presented has important margins of improvements and diversification: extensions to non-homogeneous and anisotropic sailcloth, to two-sail configuration, windsurfs and integration of the mast.

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