The Comparison of Bitumens from Oil Sands with Different Recovery Profiles

Abstract

It has been proposed that, regardless of origin, the recovery of bitumen from oil sands is related to its viscosity. Asphaltene and resin contents are known to affect the viscosity of bitumen. In this article we compare the composition of solvent-extracted bitumens from several Athabasca oil sands with very different recovery profiles. After careful removal of any associated mineral matter by ultra-centrifugation, each bitumen sample was separated into saturate, aromatic, resin, and asphaltene (SARA) fractions by an enhanced SARA technique. The individual components were then characterized by several complementary analytical techniques, including carbon, nitrogen, nitrogen, sulfur, size exclusion chromatography molecular weight (MW_n) plus proton and ¹³C nuclear magnetic resonance spectroscopy. Based on this comparison, we see no correlation between the recovery of bitumen and its composition.     

A unification of network coding and tree-packing (routing) theorems

Given a network of lossless links with rate constraints, a source node, and a set of destination nodes, the multicast capacity is the maximum rate at which the source can transfer common information to the destinations. The multicast capacity cannot exceed the capacity of any cut separating the source from a destination; the minimum of the cut capacities is called the cut bound. A fundamental theorem in graph theory by Edmonds established that if all nodes other than the source are destinations, the cut bound can be achieved by routing. In general, however, the cut bound cannot be achieved by routing. Ahlswede et al. established that the cut bound can be achieved by performing network coding, which generalizes routing by allowing information to be mixed. This paper presents a unifying theorem that includes Edmonds' theorem and Ahlswede et al.'s theorem as special cases. Specifically, it shows that the multicast capacity can still be achieved even if information mixing is only allowed on edges entering relay nodes. This unifying theorem is established via a graph theoretic hardwiring theorem, together with the network coding theorems for multicasting. The proof of the hardwiring theorem implies a new proof of Edmonds' theorem.     

GIS in Seismic Evaluation of Essential Facilities

Abstract: This research used PC ARC/INFO, a geographic information system (GIS), to assess the potential seismic vulnerability of essential facilities in Memphis and Shelby County, Tennessee. The GIS is a powerful tool for spatial operations. It offers a link between spatial data in a computerized map form and related nonspatial attribute files. It has the ability to overlay, compare, and analyze several maps in digital form with speed and efficiency. In order to assess the potential vulnerability of essential facilities, evaluation criteria with rational weighting (including soil type, liquefaction potential, slope, foundation, structural conditions, and important elements of bridges such as detour length and average daily traffic) were identified. This research proved that GIS is a reliable and efficient tool for vulnerability assessment of essential facilities in an earthquake-prone area. The GIS is convenient and productive in data management. It is easy to produce special-purpose maps at selected scale and tabular analysis reports in desired format. Results of the study are important for future facility maintenance and improvement and earthquake preparedness /response planning.     

我国出台十大措施加速国企改革央企将减至百户

从国务院国资委获悉，《关于推进国有资本调整和国有企业重组的指导意见》出台十项措施促进国企改革重组，并明确到2010年中央企业调整重组至80到100户。