Establishing usability specifications as measurable attributes in repeatable scenarios has been an essential task in the management and continuous improvement processes [1]. Early studies in Usability Analysis were primarily conducted to assist software developers and hardware designers in improving the Human- Computer Interface (HCI) or Man- Machine Interface (MMI). However, this study was conducted to provide comparative data supporting broad conclusions regarding the comparative merits of one technology (nonstereoscopic, conventional CAD systems) competed against another (tracked, stereoscopic virtual environments). Competing environments to establish usability features and preferences provides a new tool to the interface designer. Benchmark scenarios were designed and executed to measure navigation, fault identification/repair, and spatial awareness through a sequence of choices and to provide user preference of one GUI paradigm over another functionally similar paradigm. This study, performed on a ship design application, included an analysis of the effects of user collaboration in virtual environments.

I explore nature in order to understand something that is becoming increasingly unfamiliar. I wonder about accelerated human transactions with nature: the control of animals, land, and resources for pleasure, consumption or survival; and how these actions manifest themselves visually in the modern world. Through images, I create new ideas about my surroundings. My questions about nature are documented through my work employing subtlety to narrate stories of contemporary environments.

In nuclear reprocessing, PUREX, a solvent extraction process, has long been the separation method employed for the separation of the bulk components of irradiated nuclear fuel (namely uranium and plutonium) from the fission products and other minor actinides produced during the fuel use. The uranium and plutonium constitutes approximately 96 % by mass of the irradiated fuel and for this to be removed, requires large volumes of extractant and equipment with large surface area contactors and therefore floor space requirements. The PUREX process has for nearly 60 years been the largely unchallenged separation technology for the reprocessing of irradiated fuel, for both nuclear weapon production and commercial nuclear power generation. The merits and ability of this process are unquestionable since it achieves the objectives of highly purified plutonium and uranium which both can be eventually recycled. Although well proven and predictable, the PUREX process is not without its challenges: the generation of significant quantities of highly active aqueous liquid containing fission products (FPs) and minor actinides (MAs), and the degradation of the solvent phase reagents and non-specific nature of the extractant TriButylPhosphate (TBP) may have contributed to only a fraction of the total annual output of irradiated fuel being reprocessed. Fission products are elements which are produced in a nuclear reactor and are the atomic fragments left after a large atomic nucleus (typically uranium-235) undergoes nuclear fission, splitting into two smaller nuclei, along with a few neutrons, the release of heat energy (kinetic energy of the nuclei), and gamma rays. Minor actinides such as neptunium, americium, curium, berkelium, californium, einsteinium, and fermium are the actinide elements in irradiated nuclear fuel other than uranium and plutonium; they are minor as they represent a very small proportion of actinides in comparison to U and Pu. This thesis explores the possibility of using a continuous chromatographic method to extract the lesser components of the irradiated fuel. One of the major problems with the use of chromatography as an industrial process is the expansion from the batch separations on the bench top to a continuous efficient process, capable of processing large volumes. This thesis, through existing concepts, will describe a proof of concept chromatographic separation of surrogates and isotopes of the components of irradiated fuels which can be readily scaled up to a continuous chromatographic separation. The project is a radical departure from PUREX and will offer many advantages over PUREX. It is based on the separation of FPs and MAs from uranium and plutonium isotopes using continuous chromatographic separation. This thesis assesses a number of commercial resins for their suitability for the proposed continuous chromatography reprocessing method. The experiments were all undertaken at elevated nitric acid concentrations and as such are describing interactions which are rarely required commercially and therefore seldom reported, with batch studies to assess separation factors between ions, uptake kinetics and isotherms over a range of nitric acid concentrations to more dynamic column breakthrough and eventually separations. The research demonstrates that a separation can be achieved at an elevated HNO3 concentration on a commercially available ion exchange resin.

Functional programming offers an accessible and powerful algebraic model for computing. JavaScript is the language of the ubiquitous Web, but it does not support functional programs well due to its single-threaded, asynchronous nature and lack of rich control flow operators. The purpose of this work is to extend JavaScript to a language environment that satisfies the needs of functional programs on the Web. This extended language environment uses sophisticated control operators to provide an event-driven functional programming model that cooperates with the browser's DOM, along with synchronous access to JavaScript's asynchronous APIs. The results of this work are used toward two projects: (1) a programming environment called WeScheme that runs in the web browser and supports a functional programming curriculum, and (2) a tool-chain called Moby that compiles event-driven functional programs to smartphones, with access to phone-specific features.

An analysis of the photoperiodic induction of flowering in Arabidopsis thaliana (L.) Heyne, Landsberg erecta ecotype, was carried out. This revealed that 4 day old seedlings, at which time the cotyledons where expanding and greening, could differentiate between a LD and a SD. At this stage the critical daylength was between 8 and 10 hours. Plants grown in daylengths of 8 hours, a short day, flowered after 50-70 days and when grown in 16 hour daylengths, a long day, flowered after 24-27 days. At 7 days seedlings required five long days to fully induce flowering and as the seedlings aged in short days they became more sensitive to interposed long days, so that by day 20 one long day was fully inductive. It was found that there were two different photomorphogenic responses shown by plants grown in short days, firstly flowering was delayed and secondly further leaves were induced. The short days delay of flowering occurred in newly germinated seedlings older than 4 days and further leaves were induced in plants older than 10 days. From light quality experiments it was concluded that both a blue light photoreceptor and phytochrome promoted flowering. The induction of flowering by phytochrome was through a HIR mode. Three of the photoreceptor mutants, hy, isolated by Koornneef et al. (1980) were used. In daylength transfer experiments all the hy mutants studied showed delay in flowering by short days and all responded to long days by flowering earlier. Both hy2 and hy3 produced far fewer leaves than Ler when grown in short days. The hy4 mutants flowered later in both long days and short days than Ler and had an increased leaf number. A scheme is proposed in which photoperiodic induction depends on the ability of the plant to sense photoperiod, the stage of development and the photobiological input. It also proposes that phyA or C and the blue light photoreceptor promote flowering whereas phyB promotes vegetative development. Two screens were set up to isolate novel photoperiodic mutants. Six mutants were isolated, from ethtylmethane sulphonate mutated seed, which all flowered earlier than Ler in SD. They were called FUN 1-6, flowering pjcoupled. Genetic analysis showed that all were non allelic and that they were recessive except .tun4 which was semi-dominant. Physiological studies showed that there were two types of mutants: firstly funl and 2 whose flowering was not significantly delayed by SD in comparison to long day treatments and flowered early in the dark; and secondly fun3-6 which all showed a delay in flowering when grown in SD. The .funl, and 2 mutants had poorly developed leaves as did fun5. The other mutants did not show any other clearly defined phenotypes. These results suggest that funl and 2 mutants are constitutive flowering mutants and the remaining mutants are transduction chain mutants.

Microbial attachment and proliferation on a surface leads to the formation of a structure known as a biofllm. In this thesis attention is directed towards the attachment of microorganisms to submerged surfaces in private swimming pools Samples were taken from two private swimming pools located in West Lancashire, England. The planktonic phase of the water was sampled using a standard fluid grab technique and the submerged surfaces (e.g. the pool lining, the steps and the water recirculation trap) were sampled using swabs and a scalpel blade to scrape the surface. Using these techniques, thirteen different bacteria (e.g. Pseudomonas spp. and Staphylococcus spp.) and one alga (Chlorella vulgaris) were isolated from the two private swimming poois. In both cases the use of a swimming pool sanitiser (Baquacil, ICI Chemicals) showed excellent control of the planktonic population. Only algae were recovered from the fluid grab sample when incubated in appropriate media. Bacteria were found to be present only on plates incubated aerobically and from areas where swabbing/scraping had taken place. No anaerobic bacteria were isolated even after a long incubation period of 120 h. On further investigation it was shown that two of the isolated species, Pseudomonas maltophilia and Ps.putida, were capable of producing extracellular polymeric substance (EPS). Production of this material has been implicated in the initial adhesion of bacteria, and further, it can act as a barrier against the diffusion of the sanitiser so that organisms exhibit higher levels of tolerance to the added swimming pooi sanitiser. Laboratory studies demonstrated that planktonic populations of one of the isolates, Pseudomonas fluorescens, attached rapidly to the surface of PVC coupons from a planktonic population thereby mimicking the in vivo situation. The shortest time investigated for attachment (3.5 h) demonstrated that up to 1x10 7 cells/cm2 were firmly adhered to the surface. Attacimient to the coupons wasalso shown to provide resistance to the swimming pool sanitiser below, at and above the recommended levels (Chapter 2), the greatest increase in resistance being two fold. Planktonic populations of bacteria were reduced to acceptable levels after incubation for only 3 hours in a dilute medium. It was also shown that the organism attached to the surface produced extracellular material. On screening of Ps.fluorescens mutants (approximately 2000, induced by transposon mutagenesis, Chapter 4) for altered sanitiser resistance, it was found that 14 of these mutants had an increased resistance to the sanitiser above that shown by the wild type cells. Polyacrylamide gel electrophoresis of total cell protein extracts of thirteen of these mutants revealed that in 11 cases, a band with a molecular weight between 52,000 and 54,000 was induced or enhanced when biocide was added to the system. If a swimming pool is not to become a potential source of infection to the bathers then attention must be paid to the submerged surface-attached population of microorganisms. Planktonic sampling will indicate that there is little microbial activity within the main body of the pool water but the techniques used only assess the quality of the bulk fluid phase of the system and not the submerged surfaces. The attachment of potentially pathogenic micro-organisms to submerged surfaces must be accepted as a nornrnl occurrence. In this state, the organisms often exhibit increased resistance to the swimming pool sanitiser. Therefore, regular cleaning (i.e. scrubbing/vacuuming) of the submerged surfaces is suggested as a part of the recommended maintenance programme for domestic swimming pools of this type.

Chan Yiu Wah Eva. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2003-2004, design report." / Includes bibliographical references.

Grid computing enables computers on different networks to share their resources in an organized way. Authorized users can deploy the resources as if they were in the same organization. This resource sharing environment is called a Virtual Organization (VOs). To enable an open Grid to support resource sharing between multiple heterogeneous VOs, an authorization policy management framework is required to support authorization for VOs using heterogeneous authorization systems. The challenges include dynamic Grid memberships, VO trust relationships, and heterogeneous authorization systems. / To solve these problems in a loose-coupling way, we propose a dynamic, distributive and heterogeneous authorization policy management framework. The framework is called Dynamic Policy Management Framework (DPMF). DPMF groups VOs of the same authorization systems to form a virtual cluster. Authorization policy management is divided into inter-cluster heterogeneous policy management, and intra-cluster homogeneous policy management. Inside a virtual cluster, the workloads of policy management can be distributed among the VOs according to their trust relationships. The Conflict Analysis with Partial Information (CAPI) mechanism is developed to make authorization decisions in open environments without complete policy information. A Heterogeneous Policy Management mechanism is developed for DPMF to support inter-cluster heterogeneous policy management. / Traditional authorization policy management frameworks work well in authorization for a single VO where the participating hosts agree to follow a global authorization system. However, they are not capable of authorization policy management for multiple VOs which deploys heterogeneous authorization systems. / Yu, Chiu Man. / "April 2007." / Adviser: Ng Kam Wing. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0447. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 200-206). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

We experimentally investigate the phenomena of large jet rebound, a mode of fluid transfer following oblique jet impacts on hydrophobic substrates. We initially seek to describe the jet rebound regimes in tests conducted in the weightless environment of a drop tower. A parametric study reveals the dependence of the flow structure on the relevant dimensionless groups such as Reynolds number and Weber number defined on the velocity component perpendicular to the substrate. We show that significantly larger diameter jets behave similarly as much smaller jets demonstrated during previous terrestrial investigations is some parameter ranges while the flow is fundamentally different in others. Level-set numerical predictions are provided for comparisons where practicable. Simple models are developed predicting landing geometry and the onset of instability that are found to yield good agreement with experiments and simulations. Improving our understanding of such jet rebound opens avenues for unique transport capabilities.

This thesis illustrates the specific aspects that influence or limit the application of remotely-sensed data for information retrieval from coastal marine, estuarine and riverine environments. The thesis is drawn principally from ten separate studies and is divided into discrete sections, or experiments, that provide an understanding of the fundamental aspects of the effects of the atmosphere, water surface, water column and bottom on sensor-received reflected signal.The results show the importance of precise calculation of acquisition parameters and the absolute importance of relevant reference data. Most instrumentation for remote sensing at visible wavelengths has been developed for terrestrial applications where signal is rarely limiting and target features are relatively static. For in-water applications, where signal is small and noise can be large, the features to be sensed may be temporally dynamic and obscured.However, the work presented also shows the great benefit and spatial cost-effectiveness that can be obtained if the spectral and temporal specification is adequately considered. The prime motivation for such applications usually comes from the requirement to detect and quantify water column characteristics, such as phytoplankton forming as algal blooms, and bottom stratigraphic condition, such as benthic habitat mapping for fishery or conservation purposes.