7 research outputs found
strayer_etal_dreissena_figsS13+S14
No full textthis file contains the data used to produce Figures S13 and S14 in Supplementary Material
Steam as the working fluid for power recovery from exhaust gases by means of screw expanders
No full textRankine cycle systems, using steam as a working fluid, are not well suited to the recovery of power fromheat sources in the 300-450 °C temperature range, such as internal combustion engine exhaust gases, mainly due to the relatively large enthalpy of vaporization of water. Admitting the steam to the expander as vapour approximately 50 per cent dry, would be preferable but turbines cannot be used to expand vapours from this state. However, screw expanders can operate well in this mode. It is shown that, apart from being environmentally benign and free from flammability risks, a screw-driven wet steam cycle system can recover power from engine exhaust gases, with comparable efficiencies to turbine-driven systems using organic fluids at a significantly lower cost per unit output
(Table 1) Replicate Analyses of Ba/Ca in Neogloboquadrina pachyderma sinistra of sediment core 94B17
No full textData from Intensity Ratios (IR) are from Rosenthal et al. (1999)
(Table 2) Ba content and stable isotope composition of Neogloboquadrina pachyderma sinistral of sediment core 94B17
No full text(Table 2) Ba content and stable isotope composition of Neogloboquadrina pachyderma sinistral of sediment core 94B1
(Table 2) Ba/Ca ratios of Cibicides wuellerstorfi and Orbulina universa from Bahaman sediment cores
No full textThis geochemical investigation utilizes Ba/Ca in the benthic foraminifer Cibicides wuellerstorfi from cores taken from the Bahama Banks and the Caribbean Sea to reconstruct changes in basal thermocline ventilation (800–1000 m) and middepth thermohaline circulation (1000–2000 m) in the western North Atlantic during the last glacial period, focusing on the deglacial transition. Previous studies show that an increase in ventilation of the North Atlantic subtropical gyre during the Last Glacial Maximum (LGM) caused a 30–60% decrease in labile nutrients within the thermocline layer. Using foraminiferal Ba/Ca as a proxy of refractory nutrients, increased ventilation during the LGM produced a depletion of less than 20% compared to Holocene values. Following glaciation, the production of Glacial North Atlantic Intermediate Water (GNAIW) shut down owing to the presence of meltwater in the surface ocean, which resulted in a decrease in ventilation, as seen by an enrichment of barium in the basal thermocline. GNAIW was subsequently replaced by barium-rich southern component water in the middepth western North Atlantic. Foraminiferal Ba/Ca data suggest a 38% contribution from southern component water to a depth as shallow as 1475 m and a 14% contribution at 1123 m during deglaciation
Ba/Ca ratios in Neogloboquadrina pachyderma of sedimet core 94B17
No full textDown-core samples of the planktonic foraminifer Neogloboquadrina pachyderma sinistral from the Mendeleyev Ridge in the western Arctic Ocean have been analyzed for Ba/Ca and d18O. The apparent distribution coefficient for N. pachyderma sin. is estimated at DBa = 0.22 ± 0.02. A meltwater event is identified at around 11.8 14C kyr BP and is coincident with elevated Ba/Ca ratios. The barium enrichment is believed to be the result of enhanced weathering and erosion following glaciation. Additionally, barium may have desorbed from shelf sediments as sea level rose. Changes in Ba/Ca correlate with the retreat of the Laurentide Ice Sheet and the evolution of the Mackenzie River drainage basin. Therefore maximum Ba/Ca in Arctic surface waters at 11.8 ka may be indicative of an increase in the export of freshwater from the Arctic to the North Atlantic, potentially contributing to the onset of the Younger Dryas. This work suggests that Ba/Ca in planktonic foraminifera may be a useful indicator of the timing and processes associated with deglaciation
On the origins of border effects: insights from the Habsburg Customs Union
No full textThis paper examines the emergence and dynamics of border effects over time. We exploit the unique historical setting of the multi-national Habsburg Empire prior to the Great War to explore the hypothesis that border effects emerged as a result of persistent trade effects of ethno-linguistic networks within an overall integrating economy. While markets tended to integrate, the process was strongly asymmetric and shaped by a simultaneous rise in national consciousness and organisation among Austria-Hungary’s different ‘nationalities’. We find that the political borders which separated the empire’s successor states after the First World War became visible in the price dynamics of grain markets already 25-30 years before the First World War. This effect of a ‘border before a border’ cannot be explained by factors such as physical geography, changes in infrastructure or patterns of asymmetric integration with neighbouring regions outside of the Habsburg customs and monetary union. However, controlling for the changing ethno-linguistic composition of the population across the regional capital cities of the empire does explain most of the estimated border effects
