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51.
Colin McLeay 《GeoJournal》2006,65(1-2):91-102
In the 1990s the artistic autonomy of the territorial subsidiaries of the major record companies increased. Local scale “cultural freedom” did not mitigate the role of national regulation, with the music industry remaining bound by regulation imposed by agencies representing nation-states. National-scale policy rhetoric highlighting the need for “cultural protection” focused attention away from an interest in the economics of popular music, a balance evident in policies of Australian federal governments. In seeking to increase the export potential of locally produced music, Australian governments have come to hold an important place in the political economy of contemporary Australian music. 相似文献
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54.
Adrian Lawrence Marianne Stuart Colin Cheney Neil Jones Richard Moss 《Hydrogeology Journal》2006,14(8):1470-1482
Contaminant migration behaviour in the unsaturated zone of a fractured porous aquifer is discussed in the context of a study site in Cheshire, UK. The site is situated on gently dipping sandstones, adjacent to a linear lagoon historically used to dispose of industrial wastes containing chlorinated solvents. Two cores of more than 100 m length were recovered and measurements of chlorinated hydrocarbons (CHCs), inorganic chemistry, lithology, fracturing and aquifer properties were made. The results show that selecting an appropriate vertical sampling density is crucial both to providing an understanding of contaminant pathways and distinguishing whether CHCs are present in the aqueous or non-aqueous phase. The spacing of such sampling should be on a similar scale to the heterogeneity that controls water and contaminant movement. For some sections of the Permo-Triassic aquifer, significant changes in lithology and permeability occur over vertical distances of less than 1 m and samples need to be collected at this interval, otherwise considerable resolution is lost, potentially leading to erroneous interpretation of data. At this site, although CHC concentrations were high, the consistent ratio of the two main components of the plume (tetrachloroethene and trichloroethene) provided evidence of movement in the aqueous phase rather than in dense non-aqueous phase liquid (DNAPL). 相似文献
55.
Yang Liu Alfred T. Anderson Colin J. N. Wilson Andrew M. Davis Ian M. Steele 《Contributions to Mineralogy and Petrology》2006,151(1):71-87
Large pyroclastic rhyolites are snapshots of evolving magma bodies, and preserved in their eruptive pyroclasts is a record
of evolution up to the time of eruption. Here we focus on the conditions and processes in the Oruanui magma that erupted at
26.5 ka from Taupo Volcano, New Zealand. The 530 km3 (void-free) of material erupted in the Oruanui event is comparable in size to the Bishop Tuff in California, but differs
in that rhyolitic pumice and glass compositions, although variable, did not change systematically with eruption order. We
measured the concentrations of H2O, CO2 and major and trace elements in zoned phenocrysts and melt inclusions from individual pumice clasts covering the range from
early to late erupted units. We also used cathodoluminescence imaging to infer growth histories of quartz phenocrysts. For
quartz-hosted inclusions, we studied both fully enclosed melt inclusions and reentrants (connecting to host melt through a
small opening). The textures and compositions of inclusions and phenocrysts reflect complex pre-eruptive processes of incomplete
assimilation/partial melting, crystallization differentiation, magma mixing and gas saturation. ‘Restitic’ quartz occurs in
seven of eight pumice clasts studied. Variations in dissolved H2O and CO2 in quartz-hosted melt inclusions reflect gas saturation in the Oruanui magma and crystallization depths of ∼3.5–7 km. Based
on variations of dissolved H2O and CO2 in reentrants, the amount of exsolved gas at the beginning of eruption increased with depth, corresponding to decreasing
density with depth. Pre-eruptive mixing of magma with varying gas content implies variations in magma bulk density that would
have driven convective mixing.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
56.
Validation of a fish farm waste resuspension model by use of a particulate tracer discharged from a point source in a coastal environment 总被引:2,自引:0,他引:2
Chris J. Cromey Thom D. Nickell Kenneth D. Black Paul G. Provost Colin R. Griffiths 《Estuaries and Coasts》2002,25(5):916-929
To validate a resuspension model of particulate material (salmonid farm wastes), a UV fluorescent particle tracer was selected with similar settling characteristics. Tracer was introduced to the seabed (water depth ≈30 m) and sediment samples taken on days 0, 3, 10, 17 and 30 to measure the horizontal and vertical distribution of tracer in sediments. A concentric sampling grid was established at radii of 25, 50, 100, 150, 200, 400, 700 and 1, 000 m from the source on transects 30° apart. The bulk of the deployed tracer was initially concentrated in an area 25 m radius from the release point; tracer was observed to steadily decrease to zero over a period of 30 days. In a 200 m region measured from the release point in the direction of the residual current, the redeposition of tracer was low. A Lagrangian particle tracking model was validated using these observed data by varying resuspension model parameters within limits to obtain the best agreement between spatial and temporal distributions. The validated model generally gave good predictions of total mass budgets (±7% of total tracer released), particulary where tracer concentrations were high near the release point. Best fit model parameters (critical erosion shear stress=0.018 N m−2, erodibility constan=60 g m−2 d−1) are at the low end of reported parameters for coastal resuspension models. Such a low critical erosion shear stress indicates that the frequency of resuspension and deposition events for freshly deposited material is high. 相似文献
57.
58.
To prevent harm to human health from degrading ecosystems, epidemiologists need useful indicators that are sensitive to those
shifts in health status that might parallel these declines. Traditional measures of health (e.g., life expectancy, infant
mortality) are intuitively linkable to effects from environmental degradation but, in fact, they do not appear to provide
early warning indications of negative ecological impacts on health. Alternative health measures, such as social well-being,
may be needed for epidemiological research. New measures must combine those factors having policy relevance, including sensitive
measures of well-being and of health, with models of those human behaviours that contribute to ecological declines. Exposure
factors (e.g., pollution) made worse by ecosystem changes (e.g., global warming) also are relevant. In addition, epidemiologists
must be able to relate health outcomes not only to the traditional base of geo-political boundaries (e.g., census tracts or
countries), but more appropriately to eco-regions (e.g., climate regions). Only then could direct comparisons of effect be
made between areas that have eco-region as the common base for defining both denominators and numerator events for rate calculations
and comparisons. In conclusion, administrative infrastructure is needed so that meaningful eco-epidemiology can be conducted.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
59.
v--vThis second paper (Part 2) pertaining to optimized site-specific threshold monitoring addresses the application of the method to regions covered by a teleseismic or a combined regional-teleseismic network. In the first paper (Part 1) we developed the method for the general case, and demonstrated its application to an area well-covered by a regional network (the Novaya Zemlya nuclear test site). In the present paper, we apply the method to the Indian and Pakistani nuclear test sites, and show results during the periods of nuclear testing by these two countries in May 1998. Since the coverage by regional stations in these areas is poor, an optimized approach requires the use of selected, high-quality stations at teleseismic distances.¶To optimize the threshold monitoring of these test sites, we use as calibration events either one of the nuclear explosions or a nearby earthquake. From analysis of the calibration events we derive values for array beamforming steering delays, filter bands, short-term averages (STA) lengths, phase travel times (P waves), and amplitude-magnitude relationships for each station. By applying these parameters, we obtain a monitoring capability of both test sites ranging from mb 2.8-3.0 using teleseismic stations only. When including the nearby Nilore station to monitor the Indian tests, we show that the threshold can be reduced by about 0.4 magnitude units. In particular, we demonstrate that the Indian tests on 13 May, 1998, which were not detected by any known seismic station, must have corresponded to a magnitude (mb) of less than 2.4.¶We also discuss the effect of a nearby aftershock sequence on the monitoring capability for the Pakistani test sites. Such an aftershock sequence occurred in fact on the day of the last Pakistani test (30 May, 1998), following a large (mb 5.5) earthquake in Afghanistan located about 1100 km from the test site. We show that the threshold monitoring technique has sufficient resolution to suppress the signals from these interfering aftershocks without significantly affecting the true peak of the nuclear explosion on the threshold trace. 相似文献
60.
Sean W. Campbell John C. Dixon Colin E. Thorn & Robert G. Darmody 《Geografiska Annaler: Series A, Physical Geography》2002,84(3&4):179-185
This study examines the spatial and temporal variability of chemical denudation rates in Kärkevagge, northern Sweden. The chemical flux rates within the valley are strongly influenced by the local geology. Chemical denudation rates determined for the study period are more than double those previously reported in the literature for this valley. Rates of greater than 46t km−2 a−1 were measured at the valley mouth over the course of the melt season. This difference is likely due to differences in measurement technique compared to that used by past researchers. This rate is also much higher than for other arctic and alpine watersheds. Chemical denudation in Kärkevagge is comparable to larger temperate rivers. The rapid chemical denudation in Kärkevagge is likely due to sulfide weathering creating acid solutions. 相似文献