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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.
151

Optimisation and characterisation of a curved bimetallic blade and its performance within a thermal motor

Angel, Geoffrey Dennis January 2014 (has links)
In most flat bimetallic strip applications, the bending is employed in the transverse direction, that is, upon the application of uniform heating to the entire strip, the initially straight strip bends transversely up from the flat plane. This study is concerned with a pre-curved bimetallic strip that upon heating up from the ambient, straightens up along the chord line tending to become flatter. The initial ambient radius of curvature of the strip is smaller, and upon heating, the radius of curvature becomes larger. By mounting the curved bimetallic strip with a rotational degree of freedom at each end, and fixing one end against displacement, a chord line displacement of the free end of the strip occurs when the strip is uniformly heated. It is this chord line case that this work investigates and characterises. This work provides a way of evaluating the net combined axial loading case whereby an external load is applied to the free end of the strip as it uniformly heated. The main application of this work is for the characterisation of a curved bimetallic blade within a thermal motor. This is a novel device for converting renewable heat energy into mechanical energy and power as part of a larger energy harvesting network. The curved bimetallic strip with minor modifications, functions as a curved bimetallic blade within the thermal motor. The application of this work has a wider impact, in that it can be used in any other temperature induced force and displacement applications. Thus as a result of this investigation, a new form of linear actuator has been created that can utilise an input heat differential, and produce an output axial force and displacement. The displacements and forces generated by the axial case can be quite large, and as a result of this work, relatively easy to calculate, when designing a thermally driven linear actuator. The thermal motor, which possesses the curved bimetallic strip at the heart of its mechanism, can also be powered by other secondary heating sources such exhaust, or waste heat, that would otherwise be lost to the surroundings.
152

Role of kinins in mediating vascular function in healthy pregnancy and pre-eclampsia

Moyes, Amie Jane January 2010 (has links)
Pre-eclampsia is a pregnancy-related disorder characterised by high blood pressure, proteinuria and oedema. The aetiology of the disease is unclear but evidence suggests that endothelial dysfunction is central to the development of the maternal syndrome. Kinins are endogenous peptides released by the endothelium that contribute to the regulation of cardiovascular homeostasis by inducing vasodilation, fibrinolysis and angiogenesis. Given that pre-eclampsia is associated with reduced endotheliumdependent relaxation, coagulation abnormalities and an angiogenic imbalance, it was hypothesised that alterations of kinin receptor-mediated responses may be involved in the pathogenesis of the condition. To investigate whether changes in kinin receptor activity are involved in the impairment of endothelium-dependent relaxation observed in pre-eclampsia, the effects of specific B2 and B1 receptor agonists and antagonists on myometrial vascular tone were tested on arteries from healthy pregnancy and pre-eclampsia. The results demonstrated that in addition to classical bradykinin B2 receptor-mediated relaxation, a subset of healthy patients exhibited nitric oxide-dependent relaxation to the B1 receptor agonist Lys-des- Arg9-BK (LDABK) which could not be inhibited by either B1 or B2 receptor antagonists. Also, vessels that exhibited this novel response to LDABK were more sensitive to bradykinin. Furthermore, this study revealed that patients with pre-eclampsia had an attenuated response to both bradykinin and LDABK. Immunolocalisation and mRNA expression of the kinin receptors in the myometrium revealed no differences between healthy pregnancy and pre-eclampsia suggesting that disturbances of kinin receptor signalling rather than changes in receptor distribution or expression levels may be involved in the reduction of kinin-mediated responses in these patients. The role of kinins in mediating placental angiogenesis in healthy pregnancy and preeclampsia was determined using the endothelial tube formation assay in primary human umbilical vein endothelial cells (HUVECs) isolated from healthy women and women with pre-eclampsia. B2 and B1 receptor agonists induced endothelial tube formation via a VEGF-dependent, nitric oxide-independent mechanism in healthy HUVECs cultured in normoxic conditions. HUVECs isolated from women with pre-eclampsia cultured under normoxia and HUVECs from healthy pregnancies cultured under hypoxia exhibited greater levels of angiogenic branching compared with healthy normoxic cells, but were unresponsive to bradykinin and LDABK. Incubation of these cells with a VEGF receptor inhibitor reduced the elevated levels of tube formation indicating that this effect may be due to hypoxic upregulation of VEGF or an intrinsic difference in their angiogenic capacity. Further studies are required to determine the cause for the differences in angiogenic potential between healthy and pre-eclamptic cells and the impact this could have on placental vascular development and the pathogenesis of preeclampsia.
153

”We can make great things happen with sexuality education”: Pre-service teachers’ perceptions of sexuality education : A Minor Field Study in the Philippines

Ohlström, Tove January 2016 (has links)
This semi-structured interview study aimed to gain a deeper understanding of Filipino pre-service teachers’ perceptions of sexuality education. It also aimed to study how the pre-service teachers’ perceptions related to international recommendations on sexuality education and the theoretical perspectives of gender and power and Freiran theory that these draw on. Main findings included that the pre-service teachers critically reflected on own experiences of sexuality education and did not intend to repeat the education they received to future students. Furthermore, they expressed problem-focused perceptions of sexuality education content but positive approaches to the subject in general, and were hopeful of positive sexual health outcomes in the Philippines. Objections from the Catholic Church and parents to future students were perceived as the biggest challenges to the implementation of sexuality education. More information to, and collaboration with, parents regarding sexuality education were suggested as means to face resistance in the Philippine society. The pre-service teachers’ perceptions agreed with international recommendations on sexuality education to some extent, but results showed contradicting opinions regarding gender equality and sexual diversity. This point to a conclusion that the pre-service teachers need extended and improved teacher training on sexuality education, that develop their knowledge and allow them to critically reflect on norms in their society.
154

Hydrodynamic cavitation applied to food waste anaerobic digestion

Tran, David January 2016 (has links)
Innovative pre-treatment methods applied to anaerobic digestion (AD) have developed to enhance the methane yields of food waste. This study investigates hydrodynamic cavitation, which induce disintegration of biomass through microbubble formations, impact on food waste solubilisation and methane production during following AD. Two different sub-streams of food waste (before and after the digestion) pre-treated by hydrodynamic cavitation were evaluated in lab scale for its potential for implementation in a full scale practise. First, the optimum condition for the hydrodynamic cavitation device was determined based on the solids and chemical changes in the food waste. The exposure time was referred to as the number of cycles that the sample was recirculated through the cavitation inducer’s region. The optimal cycles were later tested as a pre-treatment step in a BMP test and semi-CSTR lab scale operation. The tests showed that sufficient impact from the hydrodynamic cavitation was achieved by 20 cavitation cycles. Due to the pre-treatment, food waste solubilisation increased, up to 400% and 48% in terms of turbidity and sCOD measurements, respectively. In the BMP test, the treated samples improved the methane yield by 9-13%, where the digested food waste increased its kinetic constant by 60%. Fresh food waste was then processed in the semi-CSTR operation and the methane yield was increased by up to 17% with hydrodynamic cavitation for two reference periods. These promising results suggest that the hydrodynamic cavitation can be implemented for full scale production with food waste.
155

Advanced Data Acquisition and Processing System (ADAPS) – The Current State of the System

Hafner, F. W. (Bill) 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The technology growth in the Aerospace industry, as manifested and embodied in the current fighter technology, presents many challenges in the area of flight test and data processing. Past papers have delineated the concepts brought to bear in the design and implementation of the AFFTC’s latest generation of telemetry data systems in the Advanced Data Acquisition and Processing System (ADAPS) program. The current deployed system incorporates the planned approach of commercial-off-the-shelf (COTS) and government-off-the-shelf (GOTS) elements as basic to the system solution. The state of the program has advanced through full development, delivery and performance testing. The system is currently deployed in support of flight testing at Edwards AFB. This paper will present the status of the program.
156

IDENTIFICATION AND CHARACTERIZATION OF COMPONENTS OF THE YEAST SPLICEOSOME

Pandit, Shatakshi Shreekant 01 January 2007 (has links)
The spliceosome is a complex, dynamic ribonucleoprotein (RNP) complex that undergoes numerous conformational changes during its assembly, activation, catalysis and disassembly. Defects in spliceosome assembly are thought to trigger active dissociation of faulty splicing complexes. A yeast genetic screen was performed to identify components of the putative discard pathway. This study found that weak mutant alleles of SPP382 suppress defects in several proteins required for spliceosome activation (Prp38p, Prp8p and Prp19p) as well as substrate mutations (weak branch point mutants). This evolutionary conserved protein had been found in both yeast and mammalian splicing complexes. However, its role in splicing had not been elucidated. This study focused on understanding the cellular role of Spp382p in splicing and particularly in the discard pathway. Spp382p was found to be essential for normal splicing and for efficient intron turnover. Since Spp382p binds Prp43p and is required for intron release in vitro, spp382 mediated suppression of splicing factor mutations might reflect lowered Prp43p activity. In agreement with this, we find that prp43 mutants also act as suppressors. This leads us to propose a model in which defects in spliceosome assembly, like those caused by prp38-1, prompt Spp382p-mediated disassembly of the defective complex via Prp43p Bolstering this theory, we find that Spp382p is specifically recruited to defective complexes lacking the 5 exon cleavage intermediate and spp382 mutants suppress other splicing defects. I show by stringent proteomic and two-hybrid analyses that Spp382p interacts with Cwc23p, a DnaJ-like protein present in the spliceosome and co-purified the Prp43p-DExD/H-box protein. In this study, I also show that Cwc23p is itself essential for splicing and normal intron turnover. Enhanced expression of another protein, Sqs1p, structurally related to Spp382p and also found associated with Prp43p is inhibitory to both growth and splicing. Synthetic lethal and dosage suppression studies bolster a functional linkage between Spp382p, Cwc23p, Sqs1p and Prp43p and together, the data support the existence of a Spp382p -dependent spliceosome integrity (SPIN) complex acting to remove defective spliceosomes.
157

Fire Resistance of Connections in Pre-Stressed Heavy Timber Structures

Gerard, Robert Buonomo January 2010 (has links)
Construction with composite materials has become increasingly popular in contemporary structural design for multi-storey residential, commercial, and industrial buildings. As a composite structure, pre-stressed heavy timber buildings offer sustainable, environmentally-friendly advantages over competing construction technologies utilising structural steel and concrete components. Research at the University of Canterbury is continually investigating the performance and behaviour of this composite heavy timber construction assembly. The following research report provides a fire resistance analysis for pre-stressed heavy timber structures that includes: • A comprehensive literature review detailing the fire resistance for pre-stressed heavy timber structural components and typical connections; and • A four-phase series of experiments with epoxy grouted steel threaded rods and proprietary mechanical fasteners to determine the fire resistance properties of steel to wood connections. Laboratory experimentation includes cold testing to determine connection performance at ambient temperature, oven testing to evaluate heating effects on steel to wood connections, cooled testing to determine the residual strength of connections in minor fires and, finally, furnace testing to generate fire resistance design and analysis equations to be utilised for steel to wood connections. Recommendations for the fire performance of connections in pre-stressed heavy timber structures are included in the report.
158

Image transmission over time varying channels

Chippendale, Paul January 1998 (has links)
No description available.
159

Studies on the development of sensitization to acute surgical pain in the rat and dog

Lascelles, B. Duncan X. January 1995 (has links)
No description available.
160

The application of heat pumps to low temperature drying

Toal, B. R. H. January 1985 (has links)
No description available.

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