Geochemical Fingerprinting by Handheld Laser‐Induced Breakdown Spectroscopy          下载免费PDF全文

Russell S. Harmon  Richard R. Hark  Chandra S. Throckmorton  Eugene C. Rankey  Michael A. Wise  Andrew M. Somers  Leslie M. Collins 《Geostandards and Geoanalytical Research》2017,41(4):563-584

A broad suite of geological materials was studied a using a handheld laser‐induced breakdown spectroscopy (LIBS) instrument. Because LIBS is simultaneously sensitive to all elements, the full broadband emission spectrum recorded from a single laser shot provides a ‘chemical fingerprint’ of any material – solid, liquid or gas. The distinguishing chemical characteristics of the samples analysed were identified through principal component analysis (PCA), which demonstrates how this technique for statistical analysis can be used to identify spectral differences between similar sample types based on minor and trace constituents. Partial least squares discriminant analysis (PLSDA) was used to distinguish and classify the materials, with excellent discrimination achieved for all sample types. This study illustrates through four examples (carbonate minerals and rocks, the oxide mineral pair columbite–tantalite, the silicate mineral garnet and native gold) how portable, handheld LIBS analysers can be used for real‐time chemical analysis under simulated field conditions for element or mineral identification, plus such applications as stratigraphic correlation, provenance determination and natural resource exploration.  相似文献   

Fundamental Changes in In Situ Air Sparging How Patterns     

Michael C. Brooks  William R. Wise  Michael D. Annable 《Ground Water Monitoring & Remediation》1999,19(2):105-113

Two types of gas-phase flow patterns have been discussed and observed in the in situ air sparging (ISAS) literature: bubble flow and air channels. A critical factor affecting the flow pattern at a given location is the grain size of the porous medium. Visualization experiments reported in the literature indicate that a change in the flow pattern occurs around 1 to 2 mm grain diameters, with air channels occurring below the transition size and bubbles above. Analysis of capillary and buoyancy forces suggests that for a given gas-liquid-solid system, there is a critical size that dictates the dominant force, and the dominant force will in turn dictate the flow pattern. The dominant forces, and consequently the two-phase flow patterns, were characterized using a Bond number modified with the porous media aspect ratio (pore throat to pore body ratio). Laboratory experiments were conducted to observe flow patterns as a function of porous media size and air flow rate. The experimental results and the modified Bond number analysis support the relationship of flow patterns to grain size reported in the literature.  相似文献   

RCP4.5: a pathway for stabilization of radiative forcing by 2100   总被引：3，自引：2，他引：1  

Allison M. Thomson  Katherine V. Calvin  Steven J. Smith  G. Page Kyle  April Volke  Pralit Patel  Sabrina Delgado-Arias  Ben Bond-Lamberty  Marshall A. Wise  Leon E. Clarke  James A. Edmonds 《Climatic change》2011,109(1-2):77-94

Representative Concentration Pathway (RCP) 4.5 is a scenario that stabilizes radiative forcing at 4.5?W?m^?2 in the year 2100 without ever exceeding that value. Simulated with the Global Change Assessment Model (GCAM), RCP4.5 includes long-term, global emissions of greenhouse gases, short-lived species, and land-use-land-cover in a global economic framework. RCP4.5 was updated from earlier GCAM scenarios to incorporate historical emissions and land cover information common to the RCP process and follows a cost-minimizing pathway to reach the target radiative forcing. The imperative to limit emissions in order to reach this target drives changes in the energy system, including shifts to electricity, to lower emissions energy technologies and to the deployment of carbon capture and geologic storage technology. In addition, the RCP4.5 emissions price also applies to land use emissions; as a result, forest lands expand from their present day extent. The simulated future emissions and land use were downscaled from the regional simulation to a grid to facilitate transfer to climate models. While there are many alternative pathways to achieve a radiative forcing level of 4.5?W?m^?2, the application of the RCP4.5 provides a common platform for climate models to explore the climate system response to stabilizing the anthropogenic components of radiative forcing.  相似文献   

DISCUSSION OF "On the Relation Between Saturated Conductivity and Capillary Retention Characteristics," by S. Mishra and J. C. Parker, September-October 1990 issue. v. 28, no. 5, pp. 775-777     

William R. Wise 《Ground water》1991,29(2):272-273

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Chromatographic Evidence for Nonlinear Partitioning of Aromatic Compounds Between Petroleum and Water     

William R. Wise  George C. Robinson  Philip B. Bedient 《Ground water》1992,30(6):936-944

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Balancing global water availability and use at basin scale in an integrated assessment model     

Son H. Kim  Mohamad Hejazi  Lu Liu  Katherine Calvin  Leon Clarke  Jae Edmonds  Page Kyle  Pralit Patel  Marshall Wise  Evan Davies 《Climatic change》2016,136(2):217-231

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Geography and the state: an essay in political geography: Johnston R. J. London: Macmillan, 1982. 283 pp. £15 hardback; £5.95 paperback     

Mark Wise 《Applied geography (Sevenoaks, England)》1984,4(4):345

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Capturing Raster Data From Scanned Thematic Maps Using Desktop Graphics Software     

Stephen Wise 《Transactions in GIS》2002,6(3):327-337

Data capture from paper maps remain a slow and costly part of many Geographic Information System projects. In this paper a simple method is described which makes use of the facilities of desktop graphics software to capture raster data from scanned thematic maps. The first stage is to use the flood fill tool to identify the regions of the map that represent the data values and set them to a separate colour for each thematic category. This edited image is then imported into a GIS, where a specially written majority filter is used to classify any remaining pixels to produce a raster GIS layer. The technique is tested on samples from three maps, giving accuracy levels of over 90% in all cases when compared with digitising the same maps by hand. The technique could be useful for situations where a rapid and simple means of data capture is needed and could be developed further by drawing on techniques for contextual classification rather than relying on a general purpose flood fill algorithm.  相似文献   

Metal tissue levels in Steller sea lion (Eumetopias jubatus) pups     

Holmes AL  Wise SS  Goertz CE  Dunn JL  Gulland FM  Gelatt T  Beckmen KB  Burek K  Atkinson S  Bozza M  Taylor R  Zheng T  Zhang Y  Aboueissa AM  Wise JP 《Marine pollution bulletin》2008,56(8):1416-1421

The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample. Mercury appears to be the most toxicologically significant metal with concentrations in the liver well above the current action level for mercury in fish. The concentrations of aluminum, arsenic, silver, cadmium and lead were present in one-fourth to two-thirds of all samples and were at either comparable or below concentrations previously reported. Neither gender nor region had a significant effect on metal burdens. Future work should consider metal concentrations in juveniles and adults and toxicological studies need to be performed to begin to assess the toxicity of these metals.  相似文献