A spatio-contextual probabilistic model for extracting linear features in hilly terrains from high-resolution DEM data     

Xiran Zhou  Samantha T. Arundel 《International journal of geographical information science》2019,33(4):666-686

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Character and origin of De Geer moraines in the Seacoast region of New Hampshire,USA          下载免费PDF全文

Samantha N. Sinclair  Joseph M. Licciardi  Seth W. Campbell  Brian M. Madore 《第四纪科学杂志》2018,33(2):225-237

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Hiding in the howardites: Unequilibrated eucrite clasts as a guide to the formation of Vesta's crust          下载免费PDF全文

Rhiannon G. Mayne  Samantha E. Smith  C. M. Corrigan 《Meteoritics & planetary science》2016,51(12):2387-2402

204 howardites in the National Meteorite Collection at the Smithsonian were examined for the presence of fine‐grained eucrite clasts, with the goal of better understanding the formation of the uppermost crust of asteroid 4Vesta. Eight clasts were identified and characterized in terms of their textures and mineral chemistry, and their degree of thermal metamorphism was assessed. The paucity of fine‐grained eucrites, both within the unbrecciated eucrites and as clasts within the howardites, suggests that they originate from small‐scale units on the surface of Vesta, most likely derived from partial melting. Six of the eight clasts described were found to be unequilibrated, meaning that they preserve their original crystallization trends. The vast majority of eucrites are at least partially equilibrated, making these samples quite rare and important for deciphering the petrogenesis of the vestan crust. Biomodal grain populations suggest that eucrite melts often began crystallizing pyroxene and plagioclase during their ascent to the surface, where they were subject to more rapid cooling, crystallization, and later metasomatism. Pyroxene compositions from this study and prior work indicate that the products of both primitive and evolved melts were present at the vestan surface after its formation. Two howardite thin sections contained multiple eucrite composition clasts with different crystallization and thermal histories; this mm‐scale diversity reflects the complexity of the current day vestan surface that has been observed by Dawn.  相似文献   

Groundwater Modeling with MODFLOW as a Web Application          下载免费PDF全文

Yao Hu  Albert J. Valocchi  Samantha A. Lindgren  Evan A. Ramos  Rebecca A. Byrd 《Ground water》2015,53(6):834-835

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Occurrence of selected volatile organic compounds in a bra cup manufacturing facility     

R. K. A. Kularatne 《International Journal of Environmental Science and Technology》2017,14(2):315-322

This article presents a review of the types and levels of volatile organic compounds (VOC) detected in a bra cup manufacturing facility (considering the past 4 years) while conducting a human health risk assessment to selected VOCs. Most of the tested VOCs were undetected, except in the flocking section in 2014. However, from time to time dichloromethane and toluene were detected in the facility. Dichloromethane levels showed an increase with time in the laminating section (except during 2014) with drastically higher levels in 2015. SWIFT VS1 6016/5A (an adhesive) as per the material safety data sheet (MSDS) was the dichloromethane source. However, none of the MSDS revealed the occurrence of carcinogenic benzene (which was detected in 2014 in the flocking section) and 1,4-dichlorobenzene (which was detected in 2013 in the laminating and injection molding sections) and non-carcinogenic toluene indicating that MSDS do not accurately provide the identity of chemicals. Hazard Indices (HI) for non-carcinogenic VOCs and the total lifetime cancer risks (LCRs) and occupational exposure indices (E _i ) for carcinogenic VOCs varied during the different time periods. Toluene in many cases accounted for 100 % of the HI. LCRs and E _i of dichloromethane accounted for 100 % of the total LCR and total E _i , respectively (except in the flocking section in 2014). LCR and E _i of the individual VOCs (even the total LCR and E _i values) were simultaneously high whenever the levels of the individual VOCs had exceeded the regulatory limits posing a health risk. Some measures needed to prevent exposure to VOCs are discussed in this article.  相似文献   

Turbulent kinetic energy and sediment resuspension due to wave groups     

Samantha Kularatne  Charitha Pattiaratchi 《Continental Shelf Research》2008

Wave-induced sediment resuspension in nearshore regions has been observed occurring in an event-like manner and associated with the passage of wave groups. This paper describes field measurements of turbulent velocities obtained simultaneously with suspended sediment concentration and water surface elevation from Floreat Beach, Perth, Western Australia. The data were used to study the relationship between turbulent kinetic energy (TKE) on suspension events caused by wave groups and the intermittent nature of bottom turbulence production and sediment suspension. The field measurements showed the high TKE events occurred under wave crests, and sometimes under wave toughs, when the wave heights were increasing during the passage of a wave group; the TKE decreased after the maximum wave in the wave group had passed over the measurement location. High suspended sediment concentrations (ssc) and the intermittent high TKE events were not related rather the higher ssc events were associated with a secondary peak in the surface elevation, close to the maxima in the offshore velocity, and “burst” events in the Reynolds stress.  相似文献   

Oligocene uplift of the Western Greater Caucasus: an effect of initial Arabia–Eurasia collision     

Stephen J. Vincent  Andrew C. Morton  Andrew Carter  Samantha Gibbs  Teimuraz G. Barabadze 《地学学报》2007,19(2):160-166

The Greater Caucasus is Europe's largest mountain belt. Significant uncertainties remain over the evolution of the range, largely due to a lack of primary field data. This work demonstrates that depositional systems within the Oligocene–Early Miocene Maykop Series on either side of the Western Greater Caucasus (WGC) display a similar provenance and divergent palaeocurrents away from the range, constraining a minimum age for the subaerial uplift of the range as early Early Oligocene. An Eocene–Oligocene hiatus, basal Oligocene olistostromes and a marked increase in nannofossil reworking also point to initial deformation in the earliest Oligocene. The initial uplift of the WGC occurred during the final assembly of the Tethysides to its south. Uplift commenced after the Late Eocene final suturing of northern Neotethys and during the initial collision of Arabia with the southern accreted margin of Eurasia. This suggests that compressional deformation was rapidly transferred across the collision zone from the indenting Arabian plate to its northern margin.  相似文献   

Shark interactions in pelagic longline fisheries   总被引：1，自引：0，他引：1  

Eric Gilman  Shelley Clarke  Nigel Brothers  Joanna Alfaro-Shigueto  John Mandelman  Jeff Mangel  Samantha Petersen  Susanna Piovano  Nicola Thomson  Paul Dalzell  Miguel Donoso  Meidad Goren  Tim Werner 《Marine Policy》2008

Substantial ecological, economic and social problems result from shark interactions in pelagic longline fisheries. Improved understanding of industry attitudes and practices towards shark interactions assists with managing these problems. Information on fisher knowledge and new strategies for shark avoidance may benefit sharks and fishers. A study of 12 pelagic longline fisheries from eight countries shows that incentives to avoid sharks vary along a continuum, based on whether sharks represent an economic disadvantage or advantage. Shark avoidance practices are limited, including avoiding certain areas, moving when shark interaction rates are high, using fish instead of squid for bait and deeper setting. Some conventionally employed fishing gear and methods used to target non-shark species contribute to shark avoidance. Shark repellents hold promise; more research and development is needed. Development of specifically designed equipment to discard sharks could improve shark post release survival prospects, reduce gear loss and improve crew safety. With expanding exploitation of sharks for fins and meat, improved data collection, monitoring and precautionary shark management measures are needed to ensure that shark fishing mortality levels are sustainable.  相似文献   

Diver-operated piston corer for nearshore use     

Francis J. Sansone  James T. Hollibaugh  Sue M. Vink  Randoph M. Chambers  Samantha B. Joye  Brian N. Popp 《Estuaries and Coasts》1994,17(3):716-720

A diver-operated piston corer suitable for collecting cores of >3 m length from fine-grained nearshore sediment has been developed. The corer uses a platform that rests on the sediment surface supporting both the operators and a derrick that maintains the piston at the sediment-water interface. The core is insected into and recovered from the sediment manually. The technique offers several advantages; low cost, minimal disruption of the sediment-water interface, little compaction of the sediment, the ability to collect longer length cores than is possible with gravity corers, and the ability to be deployed from relatively small boats. Dissolved ammonium and inorganic carbon data are presented from a 3.3-m core collected by this technique from Tomales Bay, California.  相似文献   

Erratum to Beth! Orcutt, Antje Boetius, Marcus Elvert, Vladmir Samarkin and Samantha B. Joye (2005) “Molecular biogeochemistry of sulfate reduction, methanogenesis and the anaerobic oxidation of methane at Gulf of Mexico cold seeps”, Geochimica et Cosmochimica Acta 69, 4267-4281     

Samantha B. Joye 《Geochimica et cosmochimica acta》2005,69(23):5633

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