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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.
221

Form and function of the Waihao-Wainono barrier, South Canterbury.

Stapleton, Joanne Maree January 2005 (has links)
The mixed sand and gravel barrier beaches located on the South Island's East Coast are formed predominantly of Greywacke, eroded from the mountains, and transported via the major river systems. These barriers act as the interface between the South Pacific Ocean and the surrounding hinterland. In times of high energy coastal events, breaching is common. This thesis examines the form and function of the Waihao-Wainono barrier, a section of the coastline situated north of the Waitaki River. Breaches along this part of the barrier are frequent and several have rendered the surrounding farmland unusable for several years due to the effects of saltwater inundation. There is some concern among the local community as to exactly why the barrier breaches at certain locations and not others, making land planning and management a difficult task for farmers. Several of the local landowners believe that since the construction of the Waitaki Dam in 1935, a significant decrease in sediment size along the barrier has occurred. It is also thought that the barrier form has experienced substantial change. Through the use of physical techniques used in the field of coastal science, 17 sites along the Waihao-Wainono barrier were studied. Excavations were carried out, surface and substrate profiles recorded and sediment samples collected from the surface. sub-surface and substrate of the barrier. Analysis of the barrier form and barrier volume concluded that the past breach sites consisted of steeper lower foreshore slopes than the non-breach sites, and at two sites, the substrate was not reached. Breach areas display the greatest barrier volume of all the study sites, which is contrary to belief. In relation to the surface sediments, the majority of barrier profiles displayed the distinct mean grain size cross shore zonation, characteristic of mixed sand and gravel beaches. The best and most consistent surface sorting was also identified as being a characteristic of the breach sites. The sediment size is not shown to have drastically reduced over the thirty year sampling period as was perceived by the local community. Within the sub-surface of the barrier, the sediments displayed chaotic sizes and generally poorly sorted material. Several of the breach sites contained a distinct change in sediment size between the coarser surface layer and the finer layer located immediately below. This layering of coarse and fine sized sediments leads to differences in permeability within the barrier, which is thought to be a major factor in why these sites have breached. Resulting from these findings, a group of characteristics of breach sites was formed and several predictions made as to where the barrier may breach in the near future.
222

The modelling of the wind profile under stable stratification at heights relevant to wind power: A comparison of models of varying complexity

Optis, Michael 23 April 2015 (has links)
The accurate modelling of the wind speed profile at altitudes relevant to wind energy (i.e. up to 200m) is important for preliminary wind resource assessments, forecasting of the wind resource, and estimating shear loads on turbine blades. Modelling of the wind profile at these altitudes is particularly challenging in stable stratification due to weak turbulence and the influence of a broad range of additional processes. Models used to simulate the wind profile range from equilibrium-based 1D analytic extrapolation models to time-evolving 3D atmospheric models. Extrapolation models are advantageous due to their low computational requirements but provide a very limited account of atmospheric physics. Conversely, 3D models are more physically comprehensive but have considerably higher computational cost and data requirements. The middle ground between these two approaches has been largely unexplored. The intent of this research is to compare the ability of a range of models of varying complexity to model the wind speed profile up to 200m under stable stratification. I focus in particular on models that are more physically robust than conventional extrapolation models but less computationally expensive than a 3D model. Observational data taken from the 213-m Cabauw meteorological tower in the Netherlands provide a basis for much of this analysis. I begin with a detailed demonstration of the limitations and breakdown in stable stratification of Monin-Obukhov similarity theory (MOST), the theoretical basis for the logarithmic wind speed profile model. I show that MOST (and its various modifications) are reasonably accurate up to 200m for stratification no stronger than weakly stable. At higher stratifications, the underlying assumptions of MOST break down and large errors in the modelled wind profiles are found. I then consider the performance of a two-layer MOST-Ekman layer model, which provides a more physically-comprehensive description of turbulence compared to MOST-based models and accounts for the Coriolis force and large-scale wind forcing (i.e. geostrophic wind). I demonstrate considerable improvements in wind profile accuracy up to 200m compared to MOST-based approaches. Next, I contrast the performance of a two-layer model with a more physically-comprehensive equilibrium-based single-column model (SCM) approach. I demonstrate several limitations of the equilibrium SCM approach - including frequent model breakdown - that limit its usefulness. I also demonstrate no clear association between the accuracy of the wind profile and the order of turbulence closure used in the SCM. Furthermore, baroclinic influences due to the land-sea temperature gradient are shown to have only modest influence on the SCM wind speed profile in stable conditions. Overall, the equilibrium SCM (when it does not break down) is found to generally outperform the two-layer model. Finally, I contrast the performance of the equilibrium SCM with a time-evolving SCM and a time-evolving 3D mesoscale model using a composite set of low-level jet (LLJ) case studies as well as a 10-year dataset at Cabauw. For the LLJ case studies, the time-evolving SCM and 3D model are found to accurately simulate the evolving stratification, the inertial oscillation, and the LLJ. The equilibrium SCM is shown to have comparatively less skill. Over the full 10-year data set, the sensitivity of the time-evolving SCM to horizontally-driven temperature changes in the ABL is found to be a considerable limitation. Despite its various limitations and simplified physics, the time-evolving SCM is generally found to be equally as accurate as the mesoscale model while using a fraction of the computational cost and requiring only a minimal amount of easily attainable local observations. Overall, the time-evolving SCM model is found to perform the best (considering both accuracy and robustness) compared to a range of equilibrium approaches as well as a time-evolving 3D model, while offering the best balance of observational data requirements, physical applicability, and computational requirements. This thesis presents a compelling case for the use of SCMs in the field of wind energy meteorology. / Graduate
223

Determining housing need in rural Manitoba

Sumner, Kevan 14 October 2005 (has links)
With the aim of developing a housing needs assessment tool for rural Manitoba, the research investigates definitions of ‘rural’, the concept of housing need, and approaches to its assessment. The main question is: how can housing need be identified and quantified at the community or regional level? The response comes in the development of a community-based rural housing needs assessment guidebook (documented in Volume 2). Literature reviewed (Part 2) targets definitions of rural, and an examination of: methods of assessing housing need, the nature of housing need, trends in housing policy, housing services programming, and the determination of housing need at a local level. Throughout, there is a focus on application of relevant literature to informing the design and development of the guidebook. The key informant interview process and related ethical considerations are presented in Part 3. The precedents review, of prior housing needs assessments and guides, is also described. The results from these research methods interviews are presented in Part 4, again with a focus on identifying how each informed development of the guidebook. Part 4 concludes with a description of the design of the housing needs assessment guidebook, addressing the structure and scope of the assessment process, key considerations and components included in the guide, the two-phase process that constitutes the main information-generating component of the tool, and the discrepancy model used to guide the user through the assessment process. Design of a sample survey (an optional component of the guide) is also briefly discussed, as well as perceived limitations of the guide including the need for a complementary strategic planning process that picks up where the assessment leaves off, which might merit a second guide that details such further steps. Certain realities of housing needs assessment in rural Manitoba, and complicating aspects of the discrepancy model, are also discussed. Part 5 details the early stages of application of components of the housing needs assessment guide in the Minnedosa area of Manitoba. Strengths and weaknesses of the components are identified, and associated refinements and changes are noted. It is concluded (Part 6) that the rural housing needs assessment guide is a viable means of identifying housing need in rural Manitoba. Possible benefits of its application are noted, but there are also cautions regarding further desirable or necessary research.
224

Madeleine McCann - hela världens dotter : En studie om svenska medier rapportering kring en brittisk flickas försvinnande

Wugk, Cecilia January 2014 (has links)
Syftet med denna uppsats är att undersöka den första månadens rapportering kring försvinnandet av Madeleine McCann och på så sätt få en bild av vilka faktorer som skapade ett så stort publikt och medialt intresse för just detta fall. För att kunna svara på detta ställs tre övergripande frågor – vilka aspekter lyfter medierna fram i rapporteringen, hur bidrar dramaturgisk bearbetning till att forma rapporteringen samt vilken betydelse får huvudaktörer i rapporteringen. Undersökningen görs genom en kvalitativ analys av återkommande teman i rapporteringen. Denna kompletteras med en kvantitativ innehållsanalys för att få fram statistik på hur mycket utrymme visa aspekter får samt vilka benämningar som görs vid porträtteringen av Madeleine McCann. Det undersökta materialet består av artiklar från tidsperioden 5 maj 2007 till och med den 7 juni 2007 i Aftonbladet, Expressen och Dagens Nyheter. De teoretiska ramverk uppsatsen utgår ifrån är teorier om socialkonstruktivism, nyhetsvärde, medielogik och narrativ berättande. Resultatet visade att den främsta faktorn till att fallet uppmärksammades är genom den personifiering som gjordes av Madeleine McCann och hennes föräldrar. Personifieringen leder till att rapporteringen kan konstrueras till en nyhetsberättelse. Genom mediernas dramaturgi och berättartekniker konstruerats fallet till ett high-profile-crime som leder till att en parasocial-interaktion uppstår mellan Madeleine och publiken.
225

A profile of the child-on-child sexual abuser in a children's home / T. Mocke.

Mocke, Tarina January 2013 (has links)
Child-on-child sexual abuse is seen as a severe social as well as a psychological problem, because of the current increasing dimension of sexual abuse in South-Africa. If the profile of a sexually abusive child in a children’s home is known, the individual development plan for the specific child can be accurately determined, in order to insure that the child receives the correct intervention. The risk that other children may be exposed to sexual abuse or sexual inappropriate behaviour might decrease, if the profile of a sexually abusive child in a children’s home is known. The purpose of the research study was to focus on child-on-child sexual abuse in a children’s home, explaining to the reader the reasons and consequences of child-on-child sexual abuse and also to determine a profile of a child-on-child sexual abuser in a children’s home. The researcher followed a qualitative approach. Four children who are or were perpetrators in child-on-child sexual abuse in a children’s home were intensively studied. Six social workers working with sexually abused children in children’s homes were interviewed. The interviews with the participants in the study focused on the following main themes: Theme 1 Removal of children from parental care Theme 2 Child-on-child sexual abuse in children’s homes Theme 3 The child as sexual perpetrator in a children’s home Theme 4 Intervention that the children received Theme 5 Reasons why children abuse other children Theme 6 Consequences of child-on-child sexual abuse Theme 7 A profile of the child-on-child sexual abuser in a children’s home The results of the data were devided into subthemes for detailed clarification of the respondents’s experiences in order to make usefull recommendations. / Thesis (MSW (Forensic Practice))--North-West University, Potchefstroom Campus, 2013.
226

A profile of the child-on-child sexual abuser in a children's home / T. Mocke.

Mocke, Tarina January 2013 (has links)
Child-on-child sexual abuse is seen as a severe social as well as a psychological problem, because of the current increasing dimension of sexual abuse in South-Africa. If the profile of a sexually abusive child in a children’s home is known, the individual development plan for the specific child can be accurately determined, in order to insure that the child receives the correct intervention. The risk that other children may be exposed to sexual abuse or sexual inappropriate behaviour might decrease, if the profile of a sexually abusive child in a children’s home is known. The purpose of the research study was to focus on child-on-child sexual abuse in a children’s home, explaining to the reader the reasons and consequences of child-on-child sexual abuse and also to determine a profile of a child-on-child sexual abuser in a children’s home. The researcher followed a qualitative approach. Four children who are or were perpetrators in child-on-child sexual abuse in a children’s home were intensively studied. Six social workers working with sexually abused children in children’s homes were interviewed. The interviews with the participants in the study focused on the following main themes: Theme 1 Removal of children from parental care Theme 2 Child-on-child sexual abuse in children’s homes Theme 3 The child as sexual perpetrator in a children’s home Theme 4 Intervention that the children received Theme 5 Reasons why children abuse other children Theme 6 Consequences of child-on-child sexual abuse Theme 7 A profile of the child-on-child sexual abuser in a children’s home The results of the data were devided into subthemes for detailed clarification of the respondents’s experiences in order to make usefull recommendations. / Thesis (MSW (Forensic Practice))--North-West University, Potchefstroom Campus, 2013.
227

An injury profile of amateur and semi-professional KwaZulu-Natal triathletes

Coetzee, Cuan Wayne 20 May 2014 (has links)
Submitted in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic, Durban University of Technology, 2013. / Background: A triathlon comprises of a combination of swimming, cycling and running. Triathlons are usually classified as sprint distance, Olympic distance, and Ironman or ultra-distance. Triathlon was popularized in the 2000 Summer Olympic Games and, despite this, there is insufficient data relating to injuries in the South African context. This study aimed to determine the injury profile of amateur and semi-professional Kwa-Zulu Natal triathletes. Methods: This Institutional Research Board approved, cross sectional study, included 80 active members of the Kwa-Zulu Natal Triathlon Association. All triathletes completed a questionnaire on training and injury profiles; with only those having had a musculoskeletal complaint additionally completing a clinical consultation. In order to assess associations between presence of injury and explanatory variables, binary logistic regression using backward selection based on likelihood ratios was used. Data was described using frequency tables for categorical data and summary statistics for continuous data. Odds ratios was reported and a p value <0.05 was considered statistically significant. For triathletes reporting injuries, linear regression was used for factors associated with injury severity. Results: Fifty seven triathletes responded giving a response rate of 71% (68% male, 32% female). The point and period (year) prevalence of triathlon-related musculoskeletal pain was 17.5% and 68.4% respectively. The ranking of the most common site of injury in the last 12 months included the knee (64%), low back (21%) and thigh (18%); with females having had a significantly higher risk of injury than males (p=.019). Additionally, injury risk also increased with weight (p=.055), number of triathlons undertaken in the previous year (p=.031), number of triathlons in the last 4 months (p=.009) and running distance during competition times (p=.011). Injury risk decreased with increasing distance of cycling (p=.061) and swimming (p=.030) in a competition, and length of training in- and off-season (p=.105 and p=.043 respectively). Strong trends were demonstrated between injury severity and long-slow training distance (p=.006) and weight (p=.006). By contrast to risk of injury, injury severity was negatively associated with weight, while a long-slow distance was positively associated with the severity of the injury. Of all the health professions, chiropractic was the most utilized health profession. Conclusion and recommendations: The results concur with previous research, but add insights into factors predisposing triathletes to injury. The most common injuries require investigation to develop preventative interventions to reduce injuries in triathletes. Health professionals require education about triathlon-related injuries to improve preventative and curative interventions.
228

Development of a tool to analyse helicopter performance incorporating novel systems

Porras Perucho, Henry Andres 09 1900 (has links)
The aerospace industry has always been looking forward new developments with the aim to create more environmental friendly aircraft, as well as to improve their performance. Over the last few years, a prominent research topic to achieve these challenging goals has been focussed on the incorporation of more electric Secondary Power Systems (SPS), this concept is known as More Electric Aircraft (MEA) or All Electric Aircraft (AEA) when the internal combustion engine is also replaced. Among others, Airbus is using Electro-hydrostatic Actuators, (EHAs) to combine hydraulic and electric power in A320 and A340 for flight tests since 1993. The company TTTECH applied the same concept by working on the development of an electrical steering system for an aircraft nose landing gear, and power source rationalization and electrical power flexibility in aircraft. Some of the advantages stated when the MEA concept is applied are: reduction in aircraft weight and performance penalties related to conventional SPS. Although the More/All electric aircraft concept provided satisfactory results for fixed-wing aircraft, research for rotary-wing aircraft is less common. This encourages the assessment of fuel consumption and performance penalties due to conventional and more electric SPS at conceptual level, which could achieve similar outcomes, while finding the best configuration possible. This project takes into account the previous research focused on fixed-wing aircraft and studies on new technologies for SPS within Cranfield University, this includes electrical Ice Protection System (IPS), Environmental Control System (ECS) and Actuation System (AS). Additionally, Fuel System (FS) and Electrical System (ES) capabilities were added, developing a generic tool able to predict the total power requirements depending on the flight conditions. This generic tool was then integrated with a performance model, where overall fuel consumption is calculated for a flight mission, giving continuity and improvement to the work already done. Secondary systems configuration and operating characteristics for a representative light single-engine rotary-wing aircraft were tailored, and the systems behaviour is presented. Finally, fuel consumption was calculated for a baseline mission profile, and compared to the fuel consumption when the systems are not included. The baseline mission set the initial flight conditions from which a parametric study was carried out; by varying these conditions the parametric study determined total fuel requirements for the analysed flight segments. An increment of up to %1.9 in the fuel consumption was found by integrating the proposed systems to the performance model, showing the impact produced by the systems, and the importance of studying different technologies to minimise it.
229

Determining housing need in rural Manitoba

Sumner, Kevan 14 October 2005 (has links)
With the aim of developing a housing needs assessment tool for rural Manitoba, the research investigates definitions of ‘rural’, the concept of housing need, and approaches to its assessment. The main question is: how can housing need be identified and quantified at the community or regional level? The response comes in the development of a community-based rural housing needs assessment guidebook (documented in Volume 2). Literature reviewed (Part 2) targets definitions of rural, and an examination of: methods of assessing housing need, the nature of housing need, trends in housing policy, housing services programming, and the determination of housing need at a local level. Throughout, there is a focus on application of relevant literature to informing the design and development of the guidebook. The key informant interview process and related ethical considerations are presented in Part 3. The precedents review, of prior housing needs assessments and guides, is also described. The results from these research methods interviews are presented in Part 4, again with a focus on identifying how each informed development of the guidebook. Part 4 concludes with a description of the design of the housing needs assessment guidebook, addressing the structure and scope of the assessment process, key considerations and components included in the guide, the two-phase process that constitutes the main information-generating component of the tool, and the discrepancy model used to guide the user through the assessment process. Design of a sample survey (an optional component of the guide) is also briefly discussed, as well as perceived limitations of the guide including the need for a complementary strategic planning process that picks up where the assessment leaves off, which might merit a second guide that details such further steps. Certain realities of housing needs assessment in rural Manitoba, and complicating aspects of the discrepancy model, are also discussed. Part 5 details the early stages of application of components of the housing needs assessment guide in the Minnedosa area of Manitoba. Strengths and weaknesses of the components are identified, and associated refinements and changes are noted. It is concluded (Part 6) that the rural housing needs assessment guide is a viable means of identifying housing need in rural Manitoba. Possible benefits of its application are noted, but there are also cautions regarding further desirable or necessary research.
230

Dosage ranging effect and safety evaluation of conjugated linoleic acid (CLA) in a hamster model

Liu, Xiaoran 09 September 2010 (has links)
The objectives of this study was to examine the efficacy and safety of graded doses of c9, t11, t10, c12 CLA isomers on body composition, energy expenditure, lipid profile and hepatic biomarkers in hamsters. Male Golden Syrian hamsters (n=105) were randomized to seven treatments (control; 1, 2, 3% of c9, t11; 1, 2, 3% of t10, c12) for 28 days. Compared with control, 1% and 3% t10, c12 had lowered food intake with all three doses of t10, c12 lowering (p<0.0001) body fat mass (g). Groups fed with 1, 2, 3% t10, c12 and 3% c9, t11 treatments showed higher lean mass compared to control and other treatment groups. However, neither body weights, nor serum HDL or triglyceride levels differed across treatment groups. The 3% t10, c12 groups exhibited higher (p<0.0001) cholesterol and LDL-C levels compared to control or other treatment groups. The 2% and 3% t10, c12 groups also presented elevated ALT level (p<0.05). The present data suggest that 3% t10, c12 possess potential adverse effects on liver and posing unfavorable change in lipid profile.

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