Academic literature on the topic 'Light-Behaviour'

Liquid Crystal Displays are commonly used in automotive dashboards. The back lighting necessary for a Liquid Crystal Display (LCD) can be achieved by the use of a light source and a light box, light pipe, or a diffusing screen. The space constraints of an automobile dashboard often mean that the light pipe is the most suitable method of illumination. At present an optimum design for the light pipe is obtained by a "Cut and Try" approach in which several light pipes are usually moulded and tested before a satisfactory candidate is found. This thesis reports on experimental and theoretical work to improve the legibility and readability of 'on' and 'off' segments of liquid crystal displays and to automate the design of the light pipes using Computer-Aided Design.

Anionic chromate (VI) compounds are inhibitive pigments and have been effectively incorporated into organic coatings to protect metal surfaces from aggressive ions, but their risk as a human carcinogen and being harmful to the environment has led to the search of suitable alternatives. Aluminium alloy, AA2024-T3, is the substrate metal alloy used in the experiments and can be found in aircraft fuselage structures due to their high strength-to-weight ratio. However, the presence of intermetallic particles increases susceptibility to localised corrosion. To investigate the protection mechanisms of primers on light alloys, many different factors must be taken into account; from aluminium alloy corrosion processes, the effects of intermetallic additions to coating chemistry, morphology and inhibitive pigments. The chemical environment in which the samples are tested in will also affect the corrosion mechanisms of the alloy as well as the performance of the coatings and release of pigments. It will be important to consider which factors are operating under particular conditions so that experimental results can then be best interpreted. As part of this project, potentiodynamic polarisation, electrochemical impedance spectroscopy and electrochemical noise analysis have been used to investigate the protective mechanisms in which chromate-based paints protect against corrosion and UV-Visible spectroscopy, scanning acoustic microscopy and optical microscopy have been used to investigate pigment release mechanism to identify what characteristics are important when developing new primers.

Studium chování opticky zachycených částic nám umožňuje porozumět základním fyzikálním jevům plynoucím z interakce světla a hmoty. Předkládaná práce podává vysvětlení zesílení tažné síly působící na opticky svázané částice ve strukturovaném světelném poli, tzv. tažném svazku. Ukazujeme, že pohyb dvou opticky svázaných objektů v tažném svazku je silně závislý na jejich vzájemné vzdálenosti a prostorové orientaci, což rozšiřuje možnosti manipulace hmoty pomocí světla. Následně se práce zaměřuje na levitaci opticky zachycených částic ve vakuu. Představujeme novou metodologii na charakterizaci vlastností slabě nelinearního Duffingova oscilátoru reprezentovaného opticky levitující částicí. Metoda je založena na průměrování trajektorií s určitou počáteční pozicí ve fázovém prostoru sestávajícím z polohy a rychlosti částice a poskytuje informaci o parametrech oscilátoru přímo ze zaznamenaného pohybu. Náš inovativní postup je srovnán s běžně užívanou metodou založenou na analýze spektrální hustoty polohy částice a za využití numerických simulací ukazujeme její použitelnost i v nízkých tlacích, kde nelinearita hraje významnou roli.

The behaviour, ecology and energetics of the East Canadian High Arctic light-bellied brent goose (Bronto bernicla hrota) was investigated to determine winter feeding Site selection on Strangford Lough, Co Down, Northern Ireland. The seasonal use of mudflats, saltmarsh and improved pasture was assessed to evaluate the role these habitats play in fulfilling the energy requirements of the geese throughout the wintering period. Brent geese began feeding on eelgrasses Zostera spp. on arrival in late August early September. Single adults arrived first and were in poorer physical condition than paired or family adults which arrived later. Differences in distribution of feeding and physical condition suggests that families are more able than paired or single birds to maintain access to a better quality/quantity food supply over the winter. The activity budget and net energy results highlight the importance of Zostera spp. and the energetic constraints faced by brent geese feeding on Zostera spp. over winter. Position-sensitive radio telemetry provided an accurate and effective method for determining the time spent feeding by individual brent geese throughout the 24hour period in late winter early spring. At this time brent geese rely heavily on the contribution from improved pasture in order to meet their daily net energy . requirement prior to spring migration. Brent geese engaged in night time feeding, exclusively on the mudflats. Night-time feeding occurred from October to April, peaking in mid-winter. This activity appears to be a strategy for the geese to meet their energy requirements during shorter, colder winter days. Feeding on saltmarsh vegetation occurs subsequent to the depletion of Zostera spp. and at a critical time in mid winter and is constrained by the availability and quality, rather than quantity, of the food resource. The study's findings would suggest that for the future conservation of the geese the main conservation requirements for the population is the maintenance of intertidal habitat quality together with the creation of inland refuaes in areas where there may be conflict with agricultural interests.

Deliberate and accidental explosions along with the heightened risk of loss of life and property damage during such events have highlighted the need for research in the behaviour of materials under high strain rates. Where an extensive body of research is available on steel and concrete structures, little to no details on how to address the design or retrofitting of wood structures subjected to a blast threat are available. Studies reported in the literature that focused on full scale light-frame wood structures did not quantify the increase in capacity due to the dynamic loading while the studies that did quantify the increase mostly stems from small clear specimens that are not representative of the behaviour of structural size members with defects. Tests on larger-scale specimens have mostly focused on the material properties and not the structural behaviour of subsystems. Advancements in design and construction techniques have greatly contributed to the emergence of taller and safer wood structures which increase potential for blast threat. This thesis presents results on the flexural behaviour of light-frame wood stud walls subjected to shock wave loading using the University of Ottawa shock tube. The emphasis is on the overall behaviour of the wall subsystem, especially the interaction between the sheathing and the studs through the nailed connection. The approach employed in this experimental program was holistic, where the specimens were investigated at the component and the subsystem levels. Twenty walls consisting of 38 mm x 140 mm machine stress-rated (MSR) studs spaced 406 mm on center and sheathed with two different types and sheathing thicknesses were tested to failure under static and dynamic loads. The experimental results were used to determine dynamic increase factors (DIFs) and a material predictive model was validated using experimental data. The implications of the code are also discussed and compared to the experimental data. Once validated, an equivalent single-degree-of-freedom (SDOF) model incorporating partial composite action was used to evaluate current analysis and design assumptions. The results showed that a shock tube can effectively be used to generate high strain-rate flexural response in wood members and that the material predictive model was found suitable to effectively predict the displacement resulting from shock wave loading. Furthermore, it was found that current analysis and design approaches overestimated the wall displacements.