Central fuelling is a fundamental issue in the neat generation tokamak ITER (International Thermonuclear Experimental Reactor). It is essential for optimization of the bootstrap current which is proportional to the pressure gradient of trapped particles. The conventional tokamak fuelling techniques, such as gas puffing and cryogenic pellet injection, are considered to be inadequate to fulfill this goal due to premature ionization caused by high plasma temperature and density. Fuelling by injecting a compact torus (CT) may be the only viable method suitable for a reactor-grade tokamak. CTs can be injected at different angles with respect to the tokamak toroidal magnetic field, either horizontally or vertically. In vertical injection, deeper CT penetration is expected due to the absence of the gradient of tokamak toroidal magnetic field in that direction. This thesis contributes to experimental investigation of vertical compact torus injection into the STOR-M tokamak. <p>To perform vertical injection, the original injector- USCTI (University of Saskatchewan Compact Torus Injector) was modified by attaching a segment of 90˚ curved drift tube to bend the CT trajectory from horizontal to vertical. Bench tests have shown that a CT injected horizontally can be deflected effectively to the vertical direction. The velocity of 130 kms^{-1}has been achieved while the CT passes through the 90˚ curved drift tube. It was found that the CT magnetic field structure kept intact as a typical structure of compact torus plasma. By further optimization of the USCTI configuration, the velocity has been increased to 270 kms^{-1}. Based on the encouraging bench test results, actual vertical CT injection experiments have been performed in the STOR-M tokamak. Experimental results demonstrated, for the first time, vertical CT injection into a tokamak. Prompt increases both in line averaged electron density and in soft X-ray emission (central cord) are observed following vertical injection. Some H-mode phenomena, characterized by suppression of the m =2 Mirnov oscillation level and drop in Hα radiation level, have also been observed following the vertical injection. Fuelling effects caused by vertical injection and by tangential injection are discussed. The experimental results suggest that vertical CT injection is a feasible tokamak fuelling technique.

Steam injection with added surface active chemicals is one of general EOR processes aimed to recover residual oil after primary production processes. It has been demonstrated that, after waterflooding, an oil swept area can be increased by steam surfactant flow due to the reduced steam override effect as well as reduced interfacial tension between oil and water in the formation. To investigate the ability to improve recovery of 20.5oAPI California heavy oil with steam surfactant injection, several experiments with a one-dimensional model were performed. Two experimental models with similar porous media, fluids, chemicals, as well as injection and production conditions, were applied. The first series of experiments were carried out in a vertical cylindrical injection cell with dimensions of 7.4 cm x 67 cm. The second part of experiment was conducted using a horizontal tube model with dimensions of 3.5 cm x 110.5 cm. The horizontal model with a smaller diameter than the vertical injection cell is less subject to channel formation and is therefore more applicable for the laboratory scale modeling of the one-dimensional steam injection process. Nonionic surfactant Triton X-100 was coinjected into the steam flow. For both series of experimental work with vertical and horizontal injection cells, the concentration of Triton X-100 surfactant solution used was chosen 3.0 wt%. The injection rates were set to inject the same 0.8 pore volumes of steam for the vertical model and 1.8 pore volumes of steam for horizontal model. The steam was injected at superheated conditions of 200oC and pressure of 100 psig. The liquid produced from the separator was sampled periodically and treated to determine oilcut and produced oil properties. The interfacial tension (IFT) of the produced oil and water were measured with an IFT meter and compared to that for the original oil. The experimental study demonstrated that the average incremental oil recovery with steam surfactant flood is 7 % of the original oil-in-place above that with pure steam injection.

An in-home evaluation of steaks from the M. Serratus ventralis was conducted to determine consumer acceptance. Steaks were also evaluated by Warner-Bratzler shear force (WBS) evaluations. Steaks from the M. Serratus ventralis were either blade tenderized, injected with a salt, phosphate, and papain solution, or served as a control. Consumers (n = 136) were not given a specific method of cookery, but were asked to document cooking method and degree of doneness, overall-like, tenderness desirability, tenderness of cut, juiciness desirability, juiciness of cut, flavor desirability, and flavor intensity. When cooked on the grill, in the oven, or in a skillet, injected steaks received the highest (P < 0.05) ratings for tenderness. Furthermore, consumers rated injected and blade tenderized steaks higher (P<0.05) for overall like when they were cooked on the grill to a higher degree of doneness. Oven cooked steaks that were injected, rated higher (P<0.05) than blade tenderized steaks for juiciness. When cooked on the grill, juiciness ratings were also higher (P<0.05) for injected steaks compared to control steaks. Moreover, injected steaks had significantly lower (P<0.05) WBS values when compared to blade tenderized and control steaks. Overall, ratings for all steaks were adequate, confirming the M. Serratus ventralis as a potential high quality steak for use in the retail market.

Thèse d'exercice : Pharmacie : Université de Nantes : 2003. / Bibliogr. f. 74-76 [36 réf.].

This document is the statement of independent and original contribution to knowledge represented by the published works in partial fulfilment of the requirements of the University of Brighton for the degree of Doctor of Philosophy (by publication). The thesis reviews the impact of research work conducted between 1992 and 1998 on various concepts to improve the economy and emissions of gasoline engines in order to address environmental and legislative pressures. The research has a common theme, examining the dilution of the intake charge (with either recycled exhaust gas [EGR], excess air, or the two in combination) in both conventional port injected [MPI] and direct injection [G-DI] combustion systems. After establishing the current status of gasoline engine technology before the programme of research was started, the thesis concentrates on seven major pieces of research between 1992 and 1996. These explored a subsequently patented method of applying recycled exhaust gas to conventional port injected gasoline engines to improve their economy and emissions whilst staying compatible with three-way catalyst systems. Nine other studies are reviewed which took place between 1992 and 1999 covering other methods of improving gasoline engines, specifically direct injection and two-stroke operation. Together, all the studies provide a treatise on methods to improve the gasoline engine and the thesis allows a view from a broader perspective than was possible at the time each study was conducted. In particular, the review identifies a range of strategies that use elements of the research that can be used to improve economy and emissions. Four major categories of systems researched include: conventional stoichiometric MPI engines developed to tolerate high EGR rates [CCVS]; two-stroke G-DI engines; G-DI engines operating stoichiometrically with high EGR rates; and G-DI engines operating with high dilution from both excess air and EGR. The findings of the studies illustrate that although good fuel economy improvements and emissions can be obtained with EGR dilution of stoichiometric engines, the highest fuel economy improvements require lean deNOx aftertreatment [LNA] and these, in turn, require new aftertreatment technologies and preferably new fuel specifications. The development of suitable LNA and the cost of implementation of these approaches represents one of the main barriers to improving gasoline engine fuel economy and emissions.

The desired lifetime for CO₂ injection for sequestration is several decades at a high injection rate (up to 10 bbl/min or 2,400 tons/day per injector). Government regulations and geomechanical design constraints may impose a limit on the injection rate such that, for example, the bottomhole pressure remains less than 90% of the hydraulic fracture pressure. Despite injecting below the critical fracture pressure, fractures can nevertheless initiate and propagate due to a thermoelastic stress reduction caused by cool CO₂ encountering hot reservoir rock. Here we develop a numerical model to calculate whether mechanical and thermal equilibrium between the injected CO₂ and the reservoir evolves, such that fracture growth ceases. When such a condition exists, the model predicts the corresponding fracture geometry and time to reach that state. The critical pressure for fracture propagation depends on the thermoelastic stress, a function of rock properties and the temperature difference between the injected fluid and the reservoir (ΔT). Fractures will propagate as long as the thermoelastic stress and the fluid pressure at the fracture tip exceed a threshold; we calculate the extent of a fracture such that the tip pressure falls below the thermoelastically modified fracture propagation pressure. Fracture growth is strongly dependent upon the formation permeability, the level of injection pressure above fracture propagation pressure, and ΔT. / text

Not available / text

published_or_final_version / abstract / toc / Mechanical Engineering / Master / Master of Philosophy

No description available.

Despite thirty published evaluation reports citing the effectiveness of Vancouver’s safe injection site (Small 2008), the Canadian federal government refuses to endorse safe injection sites as a health service option available to injection drug users (IDUs). Insite’ s evaluation results are undergoing debate, because two communicative spheres of knowledge, each with a unique authoritative language, are conflicting as each is attempting to gain moral authority over the right to recontextualize drug users. Drawing on a literature review of two harm reduction programs in Vancouver, Insite and Sheway, and expert interviews with evaluators, I show that what constitutes “evidence” is in fact subjective, determined by spheres of communicability that are built upon social, professional and political contexts. To confront the problematic nature of this issue, I suggest that evaluators and overseers need to treat program evaluation as a process of negotiation, best approached in a fluid manner. By obscuring multiple user experiences in the evaluation of harm reduction programs, evaluators and overseers risk imposing their communicative ideologies on what it means to be a drug user.