An investigation into the removal of oil from rock utilising magnetic particle technology     

Orbell JD  Dao HV  Kapadia J  Ngeh LN  Bigger SW  Healy M  Jessop R  Dann P 《Marine pollution bulletin》2007,54(12):1958-1961

The application of magnetic particle technology to environmental remediation has tended to focus, up to now, upon the removal of oil contamination from plumage and fur. The present research demonstrates the potential of this technology to remove oil contamination from the surface of rock. Specifically, a single treatment has been demonstrated to remove more than 80% by weight of heavy bunker oil from the surface of a common foreshore rock type. A further three treatments have been shown to result in an optimum removal of up to 94% by weight. The results are highly reproducible and offer the possibility of achieving up to 100% removal with the appropriate use of pre-conditioners.  相似文献   

Cycles and shifts: 1,300 years of multi-decadal temperature variability in the Gulf of Alaska   总被引：2，自引：0，他引：2  

Rob Wilson  Greg Wiles  Rosanne D’Arrigo  Chris Zweck 《Climate Dynamics》2007,28(4):425-440

The Gulf of Alaska (GOA) is highly sensitive to shifts in North Pacific climate variability. Here we present an extended tree-ring record of January–September GOA coastal surface air temperatures using tree-ring width data from coniferous trees growing in the mountain ranges along the GOA. The reconstruction (1514–1999), based on living trees, explains 44% of the temperature variance, although, as the number of chronologies decreases back in time, this value decreases to, and remains around ∼30% before 1840. Verification of the calibrated models is, however, robust. Utilizing sub-fossil wood, we extend the GOA reconstruction back to the early eighth century. The GOA reconstruction correlates significantly (95% CL) with both the Pacific Decadal Oscillation Index (0.53) and North Pacific Index (−0.42) and therefore likely yields important information on past climate variability in the North Pacific region. Intervention analysis on the GOA reconstruction identifies the known twentieth century climate shifts around the 1940s and 1970s, although the mid-1920s shift is only weakly expressed. In the context of the full 1,300 years record, the well studied 1976 shift is not unique. Multi-taper method spectral analysis shows that the spectral properties of the living and sub-fossil data are similar, with both records showing significant (95% CL) spectral peaks at ∼9–11, 13–14 and 18–19 years. Singular spectrum analysis identifies (in order of importance) significant oscillatory modes at 18.7, 50.4, 38.0, 91.8, 24.4, 15.3 and 14.1 years. The amplitude of these modes varies through time. It has been suggested (Minobe in Geophys Res Lett 26:855–858, 1999) that the regime shifts during the twentieth century can be explained by the interaction between pentadecadal (50.4 years) and bidecadal (18.7 years) oscillatory modes. Removal of these two modes of variance from our GOA time series does indeed remove the twentieth century shifts, but many are still identified prior to the twentieth century. Our analysis suggests that climate variability of the GOA is very complex, and that much more work is required to understand the underlying oscillatory behavior that is observed in instrumental and proxy records from the North Pacific region.

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Rob WilsonEmail:

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Nekton Density Patterns in Tidal Ponds and Adjacent Wetlands Related to Pond Size and Salinity     

Lawrence P. Rozas  Thomas J. Minello 《Estuaries and Coasts》2010,33(3):652-667

We examined the distribution of nekton across the marsh landscape using a 1-m² drop sampler to compare nekton densities across three different salinity zones (intermediate, brackish, saline), three pond sizes (diameter <40 m = small, ∼250–300 m = medium, >750 m = large), and two habitat types (pond, adjacent marsh) in the Barataria Bay Estuary, Louisiana. Nekton assemblages of ponds and the adjacent marsh appeared to be structured by the responses of individual species to the estuarine salinity gradient at the landscape scale and to pond habitat attributes locally. Our results indicate that ponds in the brackish and saline zones are more important nursery areas for most fishery species than ponds in the intermediate zone. Medium and large ponds supported higher densities of most species than small ponds. Most species of nekton were associated with vegetation structure, and individuals of these species were either concentrated among plant stems at the marsh edge or within submerged aquatic vegetation in ponds.  相似文献   

A framework for reading and unifying heliophysics time series data     

Jon Vandegriff  Lawrence Brown 《Earth Science Informatics》2010,3(1-2):75-86

We describe a framework designed to simplify the acquisition and integration of data from multiple, diversely formatted, geographically distributed science data sets. Our domain is Heliophysics where measurements of magnetic fields, plasmas, and charged particles are often made in-situ, with the data made available in relatively low volume data sets consisting of time series tables. Data format diversity has proven to be a significant barrier to the type of integrated, multi-mission analysis that is now very important in Heliophysics. Therefore we have developed a Java framework capable of reading, interpreting, and providing uniform access to the science content of any distributed time series data set. The framework exposes data only through fully abstract interfaces that represent data content while hiding all access details such as file format, data file granularity and access protocols. Furthermore, specialized interfaces for representing measurement-specific details are also employed, so that our framework enables data sets to be recast into scientifically interoperable representations. The context of our efforts is an increasingly distributed Heliophysics data environment that employs a collection of discipline-specific Virtual Observatories (VOs), each providing data search and retrieval services for one Heliophysics sub-discipline. Our framework is bundled in a library that ultimately will serve as a universal reader for Heliophysics data, solving the formats problem and serving as key infrastructure for advanced, science-sensitive data manipulation services.  相似文献   

Xiang Biao,Global ‘Body Shopping’: An Indian Labor System in the Information Technology Industry     

Mark Lawrence Santiago 《Singapore journal of tropical geography》2009,30(3):405-407

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The Spectral Irradiance Monitor (SIM): Early Observations     

Gary Rottman  Jerald Harder  Juan Fontenla  Thomas Woods  Oran R. White  George M. Lawrence 《Solar physics》2005,230(1-2):205-224

This paper presents and interprets observations obtained by the Spectral Irradiance Monitor (SIM) on the Solar Radiation and Climate Experiment (SORCE) over a time period of several solar rotations during the declining phase of solar cycle 23. The time series of visible and infrared (IR) bands clearly show significant wavelength dependence of these variations. At some wavelengths the SIM measurements are qualitatively similar to the Mg II core-to-wing ratio, but in the visible and IR they show character similar to the Total Solar Irradiance (TSI) variations. Despite this overall similarity, different amplitudes, phases, and temporal features are observed at various wavelengths. The TSI can be explained as a complex sum of the various wavelength components. The SIM observations are interpreted with the aid of solar images that exhibit a mixture of solar activity features. Qualitative analysis shows how the sunspots, faculae, plage, and active network provide distinct contributions to the spectral irradiance at different wavelengths, and ultimately, how these features combine to produce the observed TSI variations. Most of the observed variability appears to be qualitatively explained by solar surface features related directly to the magnetic activity.  相似文献   

The plasma plumes of Europa and Callisto   总被引：1，自引：0，他引：1  

Aharon Eviatar  Chris Paranicas 《Icarus》2005,178(2):360-366

We investigate the proposition that Europa and Callisto emit plasma plumes, i.e., a contiguous body of ionospheric plasma, extended in the direction of the corotation flow, analogous to the plume of smoke emitted in the downwind direction from a smokestack. Such plumes were seen by Voyager 1 to be emitted by Titan. We find support for this proposition in published data from Galileo Plasma Science and Plasma Wave observations taken in the corotation wakes of both moons and from magnetometer measurements reported from near the orbit of, but away from, Europa itself. This lends credence to the hypothesis that the plumes escaping from the ionospheres of Europa and Callisto are wrapped around Jupiter by corotation, survive against dispersion for a fairly long time and are convected radially by magnetospheric motions. We present simple models of plume acceleration and compare the plumes of the Europa and Callisto to the known plumes of Titan.  相似文献   

The Spectral Irradiance Monitor: Measurement Equations and Calibration   总被引：2，自引：0，他引：2  

Jerald W. Harder  Juan Fontenla  George Lawrence  Thomas Woods  Gary Rottman 《Solar physics》2005,230(1-2):169-204

The Spectral Irradiance Monitor (SIM) is a satellite-borne spectrometer aboard the Solar Radiation and Climate Experiment (SORCE) that measures solar irradiance between 200 and 2700 nm. This instrument employs a Fèry prism as a dispersing element, an electrical substitution radiometer (ESR) as the primary detector, and four additional photodiode detectors for spectral scanning. Assembling unit level calibrations of critical components and expressing the sensitivity in terms of interrelated measurement equations supplies the instrument's radiant response. The calibration and analysis of the spectrometer's dispersive and transmissive properties, light aperture metrology, and detector characteristics provide the basis for these measurement equations. The values of critical calibration parameters, such as prism and detector response degradation, are re-measured throughout the mission to correct the ground-based calibration.  相似文献   

The 2dF Galaxy Redshift Survey: correlation with the ROSAT-ESO flux-limited X-ray galaxy cluster survey     

Matt Hilton  Chris Collins  Roberto De Propris  Ivan K. Baldry  Carlton M. Baugh  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Shaun Cole  Matthew Colless  Warrick J. Couch  Gavin B. Dalton  Simon P. Driver  George Efstathiou  Richard S. Ellis  Carlos S. Frenk  Karl Glazebrook  Carole A. Jackson  Ofer Lahav  Ian Lewis  Stuart Lumsden  Steve J. Maddox  Darren Madgwick  Peder Norberg  John A. Peacock  Bruce A. Peterson  Will Sutherland  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2005,363(2):661-674

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Late Pleistocene ice export events into the Arctic Ocean from the M'Clure Strait Ice Stream, Canadian Arctic Archipelago   总被引：3，自引：1，他引：2  

Chris R. Stokes  Chris D. Clark  Dennis A. Darby  Douglas A. Hodgson 《Global and Planetary Change》2005,49(3-4):139-162

Rapidly-flowing sectors of an ice sheet (ice streams) can play an important role in abrupt climate change through the delivery of icebergs and meltwater and the subsequent disruption of ocean thermohaline circulation (e.g., the North Atlantic's Heinrich events). Recently, several cores have been raised from the Arctic Ocean which document the existence of massive ice export events during the Late Pleistocene and whose provenance has been linked to source regions in the Canadian Arctic Archipelago. In this paper, satellite imagery is used to map glacial geomorphology in the vicinity of Victoria Island, Banks Island and Prince of Wales Island (Canadian Arctic) in order to reconstruct ice flow patterns in the highly complex glacial landscape. A total of 88 discrete flow-sets are mapped and of these, 13 exhibit the characteristic geomorphology of palaeo-ice streams (i.e., parallel patterns of large, highly elongated mega-scale glacial lineations forming a convergent flow pattern with abrupt lateral margins). Previous studies by other workers and cross-cutting relationships indicate that the majority of these ice streams are relatively young and operated during or immediately prior to deglaciation. Our new mapping, however, documents a large (> 700 km long; 110 km wide) and relatively old ice stream imprint centred in M'Clintock Channel and converging into Viscount Melville Sound. A trough mouth fan located on the continental shelf suggests that it extended along M'Clure Strait and was grounded at the shelf edge. The location of the M'Clure Strait Ice Stream exactly matches the source area of 4 (possibly 5) major ice export events recorded in core PS1230 raised from Fram Strait, the major ice exit for the Arctic Ocean. These ice export events occur at 12.9, 15.6, 22 and 29.8 ka (¹⁴C yr BP) and we argue that they record vigorous episodes of activity of the M'Clure Strait Ice Stream. The timing of these events is remarkably similar to the North Atlantic's Heinrich events and we take this as evidence that the M'Clure Strait Ice Stream was also activated around the same time. This may hold important implications for the cause of the North Atlantic's Heinrich events and hints at the possibility of a pan-ice sheet response.  相似文献