Sediment core ARC4-BN05 collected from the Canada Basin, Arctic Ocean, covers the late to middle Quaternary (Marine Isotope Stage -MIS -1-15, ca. 0.5-0.6 Ma) as estimated by correlation to earlier proposed Arctic Ocean stratigraphies and AMS 14 C dating of the youngest sediments. Detailed examination of clay and bulk mineralogy along with grain size, content of Ca and Mn, and planktic foraminiferal numbers in core ARC4-BN05 provides important new information about sedimentary environments and provenance. We use increased contents of coarse debris as an indicator of glacier collapse events at the margins of the western Arctic Ocean, and identify the provenance of these events from mineralogical composition. Notably, peaks of dolomite debris, including large dropstones, track the Laurentide Ice Sheet (LIS) discharge events to the Arctic Ocean. Major LIS inputs occurred during the stratigraphic intervals estimated as MIS 3, intra-MIS 5 and 7 events, MIS 8, and MIS 10. Inputs from the East Siberian Ice Sheet (ESIS) are inferred from peaks of smectite, kaolinite, and chlorite associated with coarse sediment. Major ESIS sedimentary events occurred in the intervals estimated as MIS 4, MIS 6 and MIS 12. Differences in LIS vs. ESIS inputs can be explained by ice-sheet configurations at different sea levels, sediment delivery mechanisms (iceberg rafting, suspension plumes, and debris flows), and surface circulation. A longterm change in the pattern of sediment inputs, with an apparent step change near the estimated MIS 7-8 boundary (ca. 0.25 Ma), presumably indicates an overall glacial expan-sion at the western Arctic margins, especially in North America.
Accurate estimates of losses occurring during secondary petroleum migration are of vital importance for valid petroleum systems assessments. In this paper, we discuss the development of migration pathways and the corresponding hydrocarbon losses using data from laboratory experiments based on diphasic immiscible draining processes. These experiments permitted us to study the formation of migration pathways, the distribution of non‐wetting oil along these pathways, and the re‐utilization of existing pathways by later pulses of migrating oil.
The configuration of a migration pathway can be characterized by a phase diagram whose coordinates are two dimensionless numbers: the capillary number and the Bond number (a measure of the buoyancy force). NMR imaging was used to measure the saturation of residual oil within the pathways. It was found that, after migration, the average residual oil saturation within a pathway was generally less than 40% at a resolution of 0.4mm. Hydrocarbon losses during migration were estimated as the product of the volumetric proportion of the migrating cluster structure, defined using this spatial resolution, multiplied by the average residual oil saturation in the pathway.
The vital differences using three types of thermoplastic starches (TPS), including potato starch, corn starch, and soluble potato starch, with two different gelatinization degrees to blend with poly(hydroxy butyrate) (PHB) are thoroughly discussed in this study. For blends containing a certain amount of PHB, thermal stability remains in a certain degree. In all cases of this study, mechanical properties of TPS blended with PHB confer higher performance than those of pristine TPS. In particular, a significant increase on tensile strength and tear strength is observed for TPS (potato starch) blended with PHB at low gelatinization degree. A suitable degree of gelatinization of starch is critical to achieve optimum performance. The investigation on the morphological observation partly features the supporting evidence of the above findings. The assessment of biodegradability indicates that the values of water absorption and weight loss increase with increasing treatment period and glycerol content, but decrease with increasing amount of PHB content. Among three types of starches investigated, the TPS (soluble starch)/PHB blend gives the highest level of water absorption and weight loss.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.