Geochemical Variations in a Core of Hydrogeologic Units Near Freehold, New Jersey     

Amleto A. Pucci  Jr.  James P. Owens 《Ground water》1989,27(6):802-812

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Recent developments in ocean data telemetry at Woods HoleOceanographic Institution     

Frye  D.E. Owens  W.B. 《Oceanic Engineering, IEEE Journal of》1991,16(4):350-359

The Woods Hole Oceanographic Institution is developing techniques for telemetering oceanographic data from the deep ocean to the laboratory in near real time. Three general approaches that provide a link between subsurface instruments and surface buoys equipped with satellite transmitters are being pursued. These approaches are: cabled systems that use electromechanical cables to connect subsurface instruments to a central controller; high data rate acoustic modems to transfer information between multiple remote units and a central controller; and inductive modems that use standard mechanical mooring lines as the transmission medium between instruments deployed on the mooring and a central controller. These telemetry systems are targeted for general use by the oceanographic community and are designed to be power efficient, low in cost, and capable of integration with most oceanographic data collection systems  相似文献   

Using in situ hyperspectral reflectance data to distinguish nine aquatic plant species     

J.H. Everitt  C. Yang  K.R. Summy  C.S. Owens  L.M. Glomski  R.M. Smart 《国际地球制图》2013,28(6):459-473

In situ hyperspectral reflectance data were studied at 50 bands (10 nm bandwidth) over the 400–900 nm spectral range to determine their potential for distinguishing among nine aquatic plant species: American lotus [Nelumbo lutea (Willd.) Pers.], American pondweed (Potamogeton nodusus Poir.), giant duckweed [Spirodela polyrrhiza (L.) Schleid.], Mexican waterlily (Nymphaea mexicana Zucc.), white waterlily (Nymphaea odorata Aiton), spatterdock [Nuphar lutea (L.) Sm.], giant salvinia (Salvinia molesta Mitchell), waterhyacinth [Eichhornia crassipes (Mart.) Solms] and waterlettuce (Pistia stratiotes L.). The species were studied on three dates: 30 May, 1 July and 3 August 2009. All nine species were studied in July and August, while only eight species were studied in May; giant duckweed was not studied in May due to insufficient availability. Two procedures were used to determine the optimum bands for discriminating among species: multiple comparison range tests and stepwise discriminant analysis. Multiple comparison range tests results for May showed that most separations among species occurred at bands 795–865 nm in the near-infrared (NIR) spectral region where up to six species could be distinguished. For July, few species could be distinguished amongthe 50 bands; most separations occurred at the 715 nm red-NIR edge band where four species could be differentiated. The optimum bands in August occurred in the green (525–595 nm), red (605–635 nm) and red-NIR edge (695–705 nm) spectral regions where up to six species could be distinguished. Stepwise discriminant analysis identified 11 bands in the blue, green, red-NIR edge and NIR spectral regions to be significant to discriminate among the eight species in May. For July and August, stepwise discriminant analysis identified 15bands and 13 bands, respectively, from the blue to NIR regions to be significant for discriminating among the nine species.  相似文献   

RECREATlON AND RESTRICTIONS: COMMUNITY SKATEBOARD PARKS IN THE UNITED STATES     

Patsy Eubanks Owens 《Urban geography》2013,34(8):782-797

Communities in the United States have provided limited recreational areas specifically for teenagers. The recent construction of skateboard parks is an exception. Although these facilities provide recreational opponunities for some skateboarders, they are usually accompanied by restrictions such as confining skateboarding to defined bounds, requiring protective clothing, and enacting restrictive skateboard ordinances. This case study examines community skateboard parks in three California communities. This examination reveals three main themes associated with these public facilities - motivation, design and management, and use. Community motivations include wanting both to provide teens with a place to go and to prohibit skateboarding in other areas. Skateboarders want a place to skateboard, but do not want to be restricted to one place. Considerations in design and management include location selection, liability and safety concerns, and design style. Use of these facilities is limited to those teens specifically interested in skateboarding. Consequently, community skateboard parks fulfill only to a limited degree the recreational needs of teenagers as a group. [Key words: adolescents, skateboard parks, design, recreation.]  相似文献   

Screening Indian Mustard Genotypes for Phytoremediating Arsenic‐Contaminated Soils     

Mohd Kafeel Ahmad Ansari  Hong‐Bo Shao  Shahid Umar  Altaf Ahmad  Shahid Hussain Ansari  Muhammad Iqbal  Gary Owens 《洁净——土壤、空气、水》2013,41(2):195-201

Ten Indian mustard (Brassica juncea L.) genotypes were screened for their phytoremediation potential for arsenic (As) contaminated water under laboratory‐controlled conditions. The genotypes were grown in a hydroponic chamber for 20 days in 250‐mL beakers containing As‐contaminated water. During plant development, changes in plant growth, biomass, and total As were evaluated. Of the 10 genotypes (Pusa Agrani, BTO, Pusa Kranti, Pusa Bahar, Pusa Bold, Pusa Basant, Pusa Jai Kisan, Arka Vardhan, Varuna, and Vaibhav) Pusa Jai Kisan was the most effective in phytoremediating As‐contaminated water under hydroponic conditions. This will provide new information for Indian mustard genotypes for phytoremediating As‐contaminated soils.  相似文献   

The development of the SCAT process for the assessment of oiled shorelines     

Owens EH  Sergy GA 《Marine pollution bulletin》2003,47(9-12):415-422

The Shoreline Cleanup Assessment Team (SCAT) process is a tool to assess oiled shorelines and is now an integral component of spill response operations. The key element of a SCAT survey is a systematic documentation using standard terms and definitions of the shoreline in the areas affected by an oil spill. SCAT programs were initially established to provide objective and accurate shoreline oiling information directly to cleanup operations. The role of the SCAT program has since expanded and the information generated by the field teams is used now by planners and decision-makers and to develop shoreline treatment recommendations, to select appropriate treatment techniques, and to establish the level or degree of treatment that is appropriate. This latter point is an integral part of establishing shoreline treatment criteria or standards and treatment end points.  相似文献   

New Scintillators for Focal Plane Detectors in Gamma-Ray Missions     

Ernst-Jan Buis  Marco Beijersbergen  Stefan Kraft  Alan Owens  Francesco Quarati  Sytze Brandenburg  Reint Ostendorf 《Experimental Astronomy》2005,20(1-3):333-339

Recent developments of cerium-doped lanthanum-halide scintillators like LaBr₃:Ce show a remarkable performance in gamma-ray spectroscopy. When high energy resolution in combination with stopping power is required they provide excellent gamma-ray detector candidates for the use in space missions. Moreover, irradiation tests have shown that such detectors are radiation tolerant. In this paper we discuss a possible application of LaBr in nuclear astrophysics missions. We show results on recent proton irradiation tests at KVI in Groningen (NL) and discuss the damage and activation effects after irradiation. A possible implementation for a focal plane detector in a gamma-ray telescope and the expected performance is presented.  相似文献   

Long-term modeling of soil C erosion and sequestration at the small watershed scale   总被引：1，自引：0，他引：1  

R. C. Izaurralde  J. R. Williams  W. M. Post  A. M. Thomson  W. B. McGill  L. B. Owens  R. Lal 《Climatic change》2007,80(1-2):73-90

The soil C balance is determined by the difference between inputs (e.g., plant litter, organic amendments, depositional C) and outputs (e.g., soil respiration, dissolved organic C leaching, and eroded C). There is a need to improve our understanding of whether soil erosion is a sink or a source of atmospheric CO₂. The objective of this paper is to discover the long-term influence of soil erosion on the C cycle of managed watersheds near Coshocton, OH. We hypothesize that the amount of eroded C that is deposited in or out of a watershed compares in magnitude to the soil C changes induced via microbial respiration. We applied the erosion productivity impact calculator (EPIC) model to evaluate the role of erosion–deposition processes on the C balance of three small watersheds (∼1 ha). Experimental records from the USDA North Appalachian Experimental Watershed facility north of Coshocton, OH were used in the study. Soils are predominantly silt loam and have developed from loess-like deposits over residual bedrock. Management practices in the three watersheds have changed over time. Currently, watershed 118 (W118) is under a corn (Zea mays L.)–soybean (Glycine max [L.] Merr.) no till rotation, W128 is under conventional till continuous corn, and W188 is under no till continuous corn. Simulations of a comprehensive set of ecosystem processes including plant growth, runoff, and water erosion were used to quantify sediment C yields. A simulated sediment C yield of 43 ± 22 kg C ha⁻¹ year⁻¹ compared favorably against the observed 31 ± 12 kg C ha⁻¹ year⁻¹ in W118. EPIC overestimated the soil C stock in the top 30-cm soil depth in W118 by 21% of the measured value (36.8 Mg C ha⁻¹). Simulations of soil C stocks in the other two watersheds (42.3 Mg C ha⁻¹ in W128 and 50.4 Mg C ha⁻¹ in W188) were off by <1 Mg C ha⁻¹. Simulated eroded C re-deposited inside (30–212 kg C ha⁻¹ year⁻¹) or outside (73–179 kg C ha⁻¹ year⁻¹) watershed boundaries compared in magnitude to a simulated soil C sequestration rate of 225 kg C ha⁻¹ year⁻¹ and to literature values. An analysis of net ecosystem carbon balance revealed that the watershed currently under a plow till system (W128) was a source of C to the atmosphere while the watersheds currently under a no till system (W118 and W188) behaved as C sinks of atmospheric CO₂. Our results demonstrate a clear need for documenting and modeling the proportion of eroded soil C that is transported outside watershed boundaries and the proportion that evolves as CO₂ to the atmosphere.  相似文献   

The orientation of grains in a sheared dispersion — reply     

W.H. Owens 《Tectonophysics》1980,66(4):374-377

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Contemporary and Post-glacial Rates of Aeolian Deposition in the Coast Mountains of British Columbia, Canada     

Philip N. Owens  & Olav Slaymaker 《Geografiska Annaler: Series A, Physical Geography》1997,79(4):267-276

Contemporary and post-glacial rates of aeolian deposition are determined for three small catchments that straddle the alpine-subalpine ecotone in the Pacific Ranges of the Coast Mountains of British Columbia. From process measurement over a single year, the mean annual regional (allochthonous) rate of aeolian deposition for the catchments is estimated to be approximately 11 g m⁻². The average rate of annual deposition over the post-glacial period is calculated from the soil profiles to be c . 6 g m⁻², although fallout rates are likely to have varied significantly over the Holocene epoch due to changes in climate and catchment conditions. It would appear that the vegetated ground strata in these catchments are net receivers of aeolian dust fallout. Consequently, many of the soils are cumulic in nature and protect the bedrock in these catchments from subaerial weathering. These results have implications for sediment transfers in alpine and sub-alpine environments in southwestern British Columbia.  相似文献