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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.
91

Evaluation of pavement roughness and vehicle vibrations for road surface profiling

Onuorah, Chinedum Anthony January 2018 (has links)
The research explores aspects of road surface measurement and monitoring, targeting some of the main challenges in the field, including cost and portability of high-speed inertial profilers. These challenges are due to the complexities of modern profilers to integrate various sensors while using advanced algorithms and processes to analyse measured sensor data. Novel techniques were proposed to improve the accuracy of road surface longitudinal profiles using inertial profilers. The thesis presents a Half-Wavelength Peak Matching (HWPM) model, designed for inertial profilers that integrate a laser displacement sensor and an accelerometer to evaluate surface irregularities. The model provides an alternative approach to drift correction in accelerometers, which is a major challenge when evaluating displacement from acceleration. The theory relies on using data from the laser displacement sensor to estimate a correction offset for the derived displacement. The study also proposes an alternative technique to evaluating vibration velocity, which improves on computational factors when compared to commonly used methods. The aim is to explore a different dimension to road roughness evaluation, by investigating the effect of surface irregularities on vehicle vibration. The measured samples show that the drift in the displacement calculated from the accelerometer increased as the vehicle speed at which the road measurement was taken increased. As such, the significance of the HWPM model is more apparent at higher vehicle speeds, where the results obtained show noticeable improvements to current techniques. All results and analysis carried out to validate the model are based on real-time data obtained from an inertial profiler that was designed and developed for the research. The profiler, which is designed for portability, scalability and accuracy, provides a Power Over Ethernet (POE) enabled solution to cope with the demand for high data transmission rates.
92

The study on diffusion behaviors of water molecules within carbon nanocoils by molecular dynamics simulation

Chen, Ming-Chang 08 August 2012 (has links)
In this study, molecular dynamics (MD) simulations was employed to investigate (5,5), (10,10) single-walled nanocoils and (5,5)@(10,10) double-walled carbon nanocoils. The study can be arranged into two parts¡G In part I: Investigate the mechanical properties of (5,5), (10,10) single-walled nanocoils and (5,5)@(10,10) double-walled carbon nanocoils. The second reactive empirical bond order (REBO) potential was employed to model the interaction between carbon atoms. The contours of atomic slip vector and sequential slip vector were used to investigate the structural variations at different strains during the tension process. The yielding stress, maximum tensile strength, and Young¡¦s modulus were determined from the tensile stress-strain profiles. The results show that the nanocoils have superelastic characteristics to the carbon nanotube in the same tube diameter. In part II: Investigate the diffusion behavior of water molecules confined inside narrow (5,5) and (10,10) carbon nanocoils under different tensile strains. The condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) potential was employed to model the interaction between carbon-carbon atoms¡Acarbon atoms-water molecules and water-water molecules. To analysis the kinetic behavior of water molecules in two carbon nanocoils, the diffusion coefficients, square displacement (SD) and mean square displacement (MSD) of water molecules were calculated. The results show that diffusion coefficient of water will increase with the strains of carbon nanocoils. However, the diffusion coefficient has a significant decrease in a large strain due to the structural deformation of carbon nanocoils. The diffusion behaviors of water inside the (5,5) and (10,10) carbon nanotubes were also investigated to compare the results in (5,5) and (10,10) carbon nanotubes. Our results indicate that two carbon nanocoils have a lower diffusion coefficient of water than that of carbon nanotubes because the geometry of carbon nanocoil is easily to block up the diffusion of water molecules.
93

Proteomic analysis of human cerebrospinal fluid from patients with painful and non-painful degenerative disc disease

Lim, Tony K. Y., January 1900 (has links)
Thesis (M.Sc.). / Written for the Dept. of Pharmacology and Therapeutics. Title from title page of PDF (viewed 2009/06/29). Includes bibliographical references.
94

Contribuição ao desenvolvimento de transdutores indutivos de deslocamento

Motta, Eduardo Costa da January 2002 (has links)
O presente trabalho enfoca o estudo de transdutores indutivos de deslocamento linear. Dentre os diversos dispositivos dessa natureza, procurou-se desenvolver um estudo mais aprofundado do transdutor indutivo diferencial com núcleo de esferas. O desenvolvimento experimental, com a construção de quatro protótipos, levou ao projeto de um transdutor com características adequadas ao uso industrial. / The present work focuses on the study of inductive transducers of linear displacement. Among the several devices of that nature, a more detailed study of the inductive differential transducer was attempted with core of spherical balls. The experimental development of four prototypes resulted in a transducer with characteristics adequate for industrial use to be designed.
95

Contribuição ao desenvolvimento de transdutores indutivos de deslocamento

Motta, Eduardo Costa da January 2002 (has links)
O presente trabalho enfoca o estudo de transdutores indutivos de deslocamento linear. Dentre os diversos dispositivos dessa natureza, procurou-se desenvolver um estudo mais aprofundado do transdutor indutivo diferencial com núcleo de esferas. O desenvolvimento experimental, com a construção de quatro protótipos, levou ao projeto de um transdutor com características adequadas ao uso industrial. / The present work focuses on the study of inductive transducers of linear displacement. Among the several devices of that nature, a more detailed study of the inductive differential transducer was attempted with core of spherical balls. The experimental development of four prototypes resulted in a transducer with characteristics adequate for industrial use to be designed.
96

Contribuição ao desenvolvimento de transdutores indutivos de deslocamento

Motta, Eduardo Costa da January 2002 (has links)
O presente trabalho enfoca o estudo de transdutores indutivos de deslocamento linear. Dentre os diversos dispositivos dessa natureza, procurou-se desenvolver um estudo mais aprofundado do transdutor indutivo diferencial com núcleo de esferas. O desenvolvimento experimental, com a construção de quatro protótipos, levou ao projeto de um transdutor com características adequadas ao uso industrial. / The present work focuses on the study of inductive transducers of linear displacement. Among the several devices of that nature, a more detailed study of the inductive differential transducer was attempted with core of spherical balls. The experimental development of four prototypes resulted in a transducer with characteristics adequate for industrial use to be designed.
97

What is the value of home? : A quantitative study on the effects of natural resource extraction on conflict-induced displacement

Stensö, Theodor January 2021 (has links)
Conflict-induced displacement, a relatively novel term, is well researched but not well  understood. There is a significant amount of findings on this subject, but many have been disproven at a later stage, leaving behind a research field largely lacking in substantial findings. As conflict-induced displacement has steadily increased over the previous years, this is a significant problem. However, recent findings, hinting at a relationship between natural resource prevalence in armed conflicts and displacement, could help provide an explanation as for what causes these differences. A large-n study looking at 207 cases of armed conflict, varying over relative value of natural resource extraction, is here conducted. The results find that while there is not a statistically significant relationship between the two variables, and this relationship varies depending on whether cross- or within border displacement is the focus, there is some level of covarying relationship.
98

Methods of Improving Oil Agglomeration

Smith, Sarah Ann 05 June 2012 (has links)
A simple thermodynamic analysis suggests that oil can spontaneously displace water from coal's surface if the coal particle has a water contact angle greater than 90°. However, the clean coal products obtained from laboratory-scale dewatering-by-displacement (DbD) test work assayed moistures substantially higher than expected. These high moisture contents were attributed to the formation of water-in-oil emulsions stabilized by coal particles. Four different approaches were taken to overcome this problem and obtain low-moisture agglomeration products. These included separating the water droplets by screening, breaking emulsions with ultrasonic energy, breaking agglomerates with ultrasonic energy, and breaking agglomerates using vibrating mesh plates. On the basis of the laboratory test work, a semi-continuous test circuit was built and tested using an ultrasonic vibrator to break the water-in-oil emulsions. The most promising results were obtained agglomerates were broken using the ultrasonic probe and the vibrating mesh plates. Tests conducted on flotation feed from the Kingston coal preparation plant gave a clean coal product containing 1% by weigh of moisture with a 94% combustible recovery. The separation efficiency of 93% is substantially higher than results achievable using froth flotation. When agglomerates formed from thermal coal from the Bailey coal preparation plant were broken using either ultrasonic energy or vibrating mesh plates, the obtained results were very similar: clean coal products assayed less than 5% moisture with separation efficiencies of 86% in average. / Master of Science
99

Displacing AIDS : therapeutic transitions in Northern Uganda

Wilhelm-Solomon, M. M. January 2014 (has links)
This doctoral project, entitled 'Displacing AIDS: Therapeutic Transitions in Northern Uganda' examines the biosocial transitions engendered by the treatment of HIV, focusing on antiretroviral therapy (ART/ARV) interventions, and the ways these are intertwined with the social transitions of conflict, displacement and return. The research involved an inter-disciplinary qualitative study with internally displaced communities living with HIV in northern Uganda, during 10 months fieldwork between 2006 and 2009. Northern Uganda has experienced a two decade civil war between the government of Uganda and the Lord’s Resistance Army (1987 to 2006). In 2006, after a cessation of hostilities was signed, hundreds of thousands of the displaced began returning ‘home’. The effects of conflict and social displacement were to significantly shape both the social and medical aspects of ART provision. I argue that northern Uganda was significantly excluded from widespread national community-based responses as a result of the war during the 1990s and early 2000s. Given this background, ART interventions were to engender rapid social transformations among those with HIV, but also in relation to the perceptions of HIV/AIDS in the broader community. I explore these intersecting biosocial and displacement-induced transitions through several streams: the social transitions of forced displacement and the return process; the transitions from illness to a precarious health; from social exclusion to a contested inclusion; transitions between local and biomedical understandings of healing; transitions in authority and biopower; as well as continually shifting forms of identity, support and affiliation. I give particular emphasis to forms of socio-spatial and medico -moral transformations. I argue that ARV interventions have been nested in the social and moral spaces of displacement. In particular the spatial configurations of encampment, involving extreme congestion and lack of privacy, have shaped patterns of disclosure and community and identity formation. The influence of Catholicism, shaped by missionary histories in the region, has also had a strong impact. Themes of militarism, lack of productivity, and encampment have shaped the language and perceptions of HIV and AIDS. Theoretically I engage with debates around biosociality, stigmatisation and ‘clientship’ within the emerging literature on ARVs. I trace the intersections of these questions with those in forced migration studies regarding the social transformations of displacement and return. Furthermore, I use this social analysis to engage with public-health perspectives on ARV provision. I argue that community-based strategies require adaptation to the social contexts of displacement. Such adaptations, involving attentiveness to the socio-spatial specificity of displaced contexts, are critical for the long-term provision and sustainability of antiretroviral therapy to displaced communities. In particular the return phase has created unexpected challenges for treatment continuity, arising from large-scale population movements. The thesis has a strong narrative focus and traces the experiences of several people living with HIV through the paths of displacement and return.
100

An investigation of cultural dislocation in the work of selected artists

De Vries, Jetteke 08 1900 (has links)
Submitted in partial fulfilment of the requirements of the degree of Master of Technology: Fine Art, Durban University of Technology, Durban, South Africa, 2015. / This dissertation sets out to investigate cultural dislocation in the work of Leora Farber (1964), Viviane Sassen (1972), George Alamidis (1954) and my art practice. The paper begins by highlighting the importance of this study and defines terminology for the purpose of this research. In addition an explanation of the research methodology used is provided. The study is contextualised through a discussion of writings by Stuart Hall (1997), Edward Said (1987), Heidi Armbruster (2010), Chloe Sells (2011), Katheryn Woodward (1997), Michel Foucault (1967), Leora Farber (2012) and Lorin Friesen (2013). An analysis of the selected artists’ work reveals an investigation of cultural dislocation within diverse cultural contexts. Farber investigates her position as a second generation Jewish woman in post- colonial, post-Apartheid South Africa through the use of three protagonists. She does this in an attempt to create a lasting Jewish / South African hybrid identity. She explores not only her Jewish heritage and its connotations, but also the changing notions of white identity in post 1994 South Africa. Sassen, in her photographic depiction of obscured African subjects, challenges the viewer’s perceptions of Africa and positions herself as being ‘in-between’ Africa and the Netherlands, where she “will always be the stranger … and will never be part of the culture” (Sassen in Jaeger 2010). Alamidis’ work explores cultural dislocation in the context of migration, eloquently expressed through the use of the identity cards of 1950s Greek immigrants as visual metaphors for the loss of identity. I explore cultural dislocation through the history of three female protagonists (my grandmother, mother and myself) and their migration between the Netherlands and Southern Africa. The protagonists’ cultural narratives provide an historical context for a discussion of my art practice in the form of an exhibition titled Discovering Home. The conclusion outlines the research findings and identifies possible areas of future research. The main research finding reveals that the formation of a new subject identity, post migration, is dependent on a specific (historical) time and (geographical and psychological) space. An area of possible future research, in the context of cultural dislocation, is the use of Foucault’s (1967) theory of heterotopias to explore the idea of the ‘third space’ functioning as a personal heterotopia. / M

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