a b s t r a c tA conventional wisdom about the progress of physics holds that successive theories wholly encompass the domains of their predecessors through a process that is often called "reduction." While certain influential accounts of inter-theory reduction in physics take reduction to require a single "global" derivation of one theory's laws from those of another, I show that global reductions are not available in all cases where the conventional wisdom requires reduction to hold. However, I argue that a weaker "local" form of reduction, which defines reduction between theories in terms of a more fundamental notion of reduction between models of a single fixed system, is available in such cases and moreover suffices to uphold the conventional wisdom. To illustrate the sort of fixed-system, inter-model reduction that grounds inter-theoretic reduction on this picture, I specialize to a particular class of cases in which both models are dynamical systems. I show that reduction in these cases is underwritten by a mathematical relationship that follows a certain liberalized construal of Nagel/Schaffner reduction, and support this claim with several examples. Moreover, I show that this broadly Nagelian analysis of inter-model reduction encompasses several cases that are sometimes cited as instances of the "physicist's" limit-based notion of reduction.

The majority of the technology development for CO 2 capture and storage (CCS) is driven by the electric-utility industry, in which the emphasis is on large centralized units for electric-power generation with coal as the primary fuel. The implementation of CCS in oilsands operations has significant potential to provide meaningful carbon-emissions reductions. This paper presents various concepts for integrating leading CO 2-capture techniques to bitumen-extraction and-upgrading processes. The main carbon-capture technologies are reviewed, and their relative advantages and disadvantages for implementation in bitumen mining, thermal bitumen extraction, and bitumen upgrading are discussed, leading to a qualitative assessment of their suitability for each oil-sands process. SAGD Extraction. Although there are various in-situ methods for extracting bitumen from underground reservoirs, the dominant technology is SAGD. SAGD extraction involves drilling horizontal well pairs in the oil-sands reservoir. Steam injected through the upper well rises through the deposit and heats the bitumen. The hot bitumen separates from the sand and flows along with condensed steam into the lower well and is then pumped to the surface. Bitumen is separated from other fluids removed from the reservoir and diluted with light oil fractions to facilitate its transport. Most commercial SAGD extraction processes produce steam in once-through gas-fired steam generators. Cogeneration plants also can be used to supply power and steam to the process. The energy demands of SAGD processes consist overwhelmingly of steam, with electricity usually accounting for less than 5% of the

No abstract

The majority of the technology development for CO2 Capture and Storage (CCS) is driven by the electric utility industry, where the emphasis is on large centralized units for electric power generation with coal as the primary fuel. The implementation of CCS in oil sands operations has significant potential to provide meaningful carbon emissions reductions. This paper presents various concepts for integrating leading CO2 capture techniques to bitumen extraction and upgrading processes. The main carbon capture technologies are reviewed and their relative advantages and disadvantages for implementation in bitumen mining, thermal bitumen extraction, and upgrading are discussed, leading to a qualitative assessment of their suitability for each oil sands process.