Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Attached Vertical Stacks, More than 8 hours, 10 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Attached Vertical Stacks , 8 Hours or Less, 10 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Attached Vertical Stacks, 8 Hours or Less, 50 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Attached Vertical Stacks , 8 Hours or Less, 25 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Attached Vertical Stacks, More than 8 hours, 25 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Attached Vertical Stacks, More than 8 hours, 50 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, More than 8 Hours, 25 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks , 8 Hours or Less, 5 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, More than 8 Hours, 5 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, 8 Hours or Less, 10 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, 8 Hours or Less, 50 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, 8 Hours or Less, 25 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, More than 8 Hours, 50 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Open Area Vertical Stacks, More than 8 Hours, 10 Foot Stack Height

EPA Pesticide Factsheets

This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

Distribution, densities, and ecology of Siberian cranes in the Khroma River region of northern Yakutia in northeastern Russia

USGS Publications Warehouse

Bysykatova, Inga P.; Krapu, Gary L.; Germogenov, Nicolai I.; Buhl, Deborah A.; Aborn, David

2014-01-01

The Siberian crane (Grus leucogeranus) is the third rarest crane species in the world with a breeding range now centered on 3 core areas and a buffer zone in the arctic of northern Yakutia in northeastern Russia. During 16 July-2 August 2009, we undertook ground surveys within the Khroma River core breeding area, surrounding buffer zone, and lands lying to the west of the known rbeeding range to estimate densities and determine habitat use and social status of Siberian cranes. A total of 142 Siberian cranes were sighted (including 55 pairs) at 54 locations with 32 cranes (including 13 pairs) sighted outside the currently known breeding range in the lower drainages of the Syalakh and Syuryuktyakh Rivers. After adjusting for a probability of detection of 0.484 (95% CI = 0.281-0.833), Siberian crane densities in the Khroma core area and the buffer zone averaged 0.0921 cranes/km2 and 0.0363 cranes/km2, respectively. A majority of cranes (n = 93 [65%]) occurred in complexes of large basin wetlands, with use centered in those having extensive beds of pendant grass (Arctophila fulva). Of the 142 cranes seen, 110 (77%) were paired, 21 (15%) were singles, and 11 (8%) were in groups of 3-5. The Khroma core supports 1 of 2 large concentrations of breeding Siberian cranes remaining in the wild; therefore, we recommend that consideration be given to designating a nature reserve that would encompass the Khroma core, adjacent buffer zone, and lands to the west (including coastal tundra areas along the lower drainages of the Syalah and Syuryuktyah Rivers). Further research is needed to gain additional insight into Siberian crane distribution and numbers on lands beyond the currently delineated western boundary of the Siberian crane breeding range in the Ust-Yana District of northern Yakutia. Important gaps remain in information needed to effectively guide conservation efforts for the Eastern Population, and recent advances in remote tracking technology offer potential opportunities to help address several key information needs.

Buffer Zone Fact Sheets

EPA Pesticide Factsheets

New requirements for buffer zones and sign posting contribute to soil fumigant mitigation and protection for workers and bystanders. The buffer provides distance between the pesticide application site and bystanders, reducing exposure risk.

Conservation Beyond Park Boundaries: The Impact of Buffer Zones on Deforestation and Mining Concessions in the Peruvian Amazon.

PubMed

Weisse, Mikaela J; Naughton-Treves, Lisa C

2016-08-01

Many researchers have tested whether protected areas save tropical forest, but generally focus on parks and reserves, management units that have internationally recognized standing and clear objectives. Buffer zones have received considerably less attention because of their ambiguous rules and often informal status. Although buffer zones are frequently dismissed as ineffective, they warrant attention given the need for landscape-level approaches to conservation and their prevalence around the world-in Peru, buffer zones cover >10 % of the country. This study examines the effectiveness of buffer zones in the Peruvian Amazon to (a) prevent deforestation and (b) limit the extent of mining concessions. We employ covariate matching to determine the impact of 13 buffer zones on deforestation and mining concessions from 2007 to 2012. Despite variation between sites, these 13 buffer zones have prevented ~320 km(2) of forest loss within their borders during the study period and ~1739 km(2) of mining concessions, an outcome associated with the special approval process for granting formal concessions in these areas. However, a closer look at the buffer zone around the Tambopata National Reserve reveals the difficulties of controlling illegal and informal activities. According to interviews with NGO employees, government officials, and community leaders, enforcement of conservation is limited by uncertain institutional responsibilities, inadequate budgets, and corruption, although formal and community-based efforts to block illicit mining are on the rise. Landscape-level conservation not only requires clear legal protocol for addressing large-scale, formal extractive activities, but there must also be strategies and coordination to combat illegal activities.

Conservation Beyond Park Boundaries: The Impact of Buffer Zones on Deforestation and Mining Concessions in the Peruvian Amazon

NASA Astrophysics Data System (ADS)

Weisse, Mikaela J.; Naughton-Treves, Lisa C.

2016-08-01

Many researchers have tested whether protected areas save tropical forest, but generally focus on parks and reserves, management units that have internationally recognized standing and clear objectives. Buffer zones have received considerably less attention because of their ambiguous rules and often informal status. Although buffer zones are frequently dismissed as ineffective, they warrant attention given the need for landscape-level approaches to conservation and their prevalence around the world—in Peru, buffer zones cover >10 % of the country. This study examines the effectiveness of buffer zones in the Peruvian Amazon to (a) prevent deforestation and (b) limit the extent of mining concessions. We employ covariate matching to determine the impact of 13 buffer zones on deforestation and mining concessions from 2007 to 2012. Despite variation between sites, these 13 buffer zones have prevented ~320 km2 of forest loss within their borders during the study period and ~1739 km2 of mining concessions, an outcome associated with the special approval process for granting formal concessions in these areas. However, a closer look at the buffer zone around the Tambopata National Reserve reveals the difficulties of controlling illegal and informal activities. According to interviews with NGO employees, government officials, and community leaders, enforcement of conservation is limited by uncertain institutional responsibilities, inadequate budgets, and corruption, although formal and community-based efforts to block illicit mining are on the rise. Landscape-level conservation not only requires clear legal protocol for addressing large-scale, formal extractive activities, but there must also be strategies and coordination to combat illegal activities.

Separation of abscission zone cells in detached Azolla roots depends on apoplastic pH.

PubMed

Fukuda, Kazuma; Yamada, Yoshiya; Miyamoto, Kensuke; Ueda, Junichi; Uheda, Eiji

2013-01-01

In studies on the mechanism of cell separation during abscission, little attention has been paid to the apoplastic environment. We found that the apoplastic pH surrounding abscission zone cells in detached roots of the water fern Azolla plays a major role in cell separation. Abscission zone cells of detached Azolla roots were separated rapidly in a buffer at neutral pH and slowly in a buffer at pH below 4.0. However, cell separation rarely occurred at pH 5.0-5.5. Light and electron microscopy revealed that cell separation was caused by a degradation of the middle lamella between abscission zone cells at both pH values, neutral and below 4.0. Low temperature and papain treatment inhibited cell separation. Enzyme(s) in the cell wall of the abscission zone cells might be involved in the degradation of the pectin of the middle lamella and the resultant, pH-dependent cell separation. By contrast, in Phaseolus leaf petioles, unlike Azolla roots, cell separation was slow and increased only at acidic pH. The rapid cell separation, as observed in Azolla roots at neutral pH, did not occur. Indirect immunofluorescence microscopy, using anti-pectin monoclonal antibodies, revealed that the cell wall pectins of the abscission zone cells of Azolla roots and Phaseolus leaf petioles looked similar and changed similarly during cell separation. Thus, the pH-related differences in cell separation mechanisms of Azolla and Phaseolus might not be due to differences in cell wall pectin, but to differences in cell wall-located enzymatic activities responsible for the degradation of pectic substances. A possible enzyme system is discussed. Copyright © 2012 Elsevier GmbH. All rights reserved.

Riparian buffer zones on selected rivers in Lower Silesia - an important conservation practice and the management strategy in urban planning

NASA Astrophysics Data System (ADS)

Adamska, Maryna

2013-09-01

Buffer zones are narrow strips of land lying along the surface water, covered with appropriately selected vegetation. They separate aquatic ecosystems from the direct impact of agricultural land and reduce the movement of nutrients in the environment. In 2008 the European Commission established requirements for the implementation of buffer strips along water courses. Poland committed to the enforcement of these requirements until 1 January 2012. This was one of the reasons of this study. The subject of the analysis included the following rivers in Lower Silesia: Smortawa, Krynka, Czarna Woda and the selected transects of Ślęza and Nysa Łużycka. Detailed studies were designed to estimate the buffer zones occurring on these watercourses and assess these zones’ structure. This will be used to develop clear criteria for the selection of the width of these zones based on land use land management. It can be used in the implementation of executive acts at different levels of space management. Field research consisted of inventory the extent of riparian buffer strips on selected water courses and photographic documentation. Species composition of the vegetation forming a buffer zone was identified by using Braun-Blanquet method. There was lack of continuity of the riparian buffer zones on investigated rivers. Buffer zones should have carefully formulated definition and width because they are element of the significant ecological value, they perform important environmental protective functions and they are also the subject of Community law.

A method for quantifying and comparing the costs and benefits of alternative riparian zone buffer widths

Treesearch

Chris B. LeDoux; Ethel Wilkerson

2008-01-01

We developed a method that can be used to quantify the opportunity costs and ecological benefits of implementing alternative streamside management zones/buffer zone widths. The opportunity costs are computed based on the net value of the timber left behind in the buffer zone, the stump-to-mill logging costs for the logging technology that would have been used to...

33 CFR 100.35T07-0297 - Special Local Regulation, 50 Aniversario Balneario de Boqueron, Bahia de Boqueron; Boqueron, PR.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Buffer Zone. All waters of the Bahia de Boqueron, Boqueron, Puerto Rico encompassed within an imaginary... west back to origin. All persons and vessels except those persons and vessels enforcing the buffer zone are prohibited from entering, transiting through, anchoring in, or remaining within the buffer zone...

33 CFR 100.35T07-0297 - Special Local Regulation, 50 Aniversario Balneario de Boqueron, Bahia de Boqueron; Boqueron, PR.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Buffer Zone. All waters of the Bahia de Boqueron, Boqueron, Puerto Rico encompassed within an imaginary... west back to origin. All persons and vessels except those persons and vessels enforcing the buffer zone are prohibited from entering, transiting through, anchoring in, or remaining within the buffer zone...

Stennis Space Center Environmental Geographic Information System

NASA Technical Reports Server (NTRS)

Lovely, Janette; Cohan, Tyrus

2000-01-01

As NASA's lead center for rocket propulsion testing, the John C. Stennis Space Center (SSC) monitors and assesses the off-site impacts of such testing through its Environmental Office (SSC-EO) using acoustical models and ancillary data. The SSC-EO has developed a geographical database, called the SSC Environmental Geographic Information System (SSC-EGIS), that covers an eight-county area bordering the NASA facility. Through the SSC-EGIS, the Enivronmental Office inventories, assesses, and manages the nearly 139,000 acres that comprise Stennis Space Center and its surrounding acoustical buffer zone. The SSC-EGIS contains in-house data as well as a wide range of data obtained from outside sources, including private agencies and local, county, state, and U.S. government agencies. The database comprises cadastral/geodetic, hydrology, infrastructure, geo-political, physical geography, and socio-economic vector and raster layers. The imagery contained in the database is varied, including low-resolution imagery, such as Landsat TM and SPOT; high-resolution imagery, such as IKONOS and AVIRIS; and aerial photographs. The SSC-EGIS has been an integral part of several major projects and the model upon which similar EGIS's will be developed for other NASA facilities. The Corps of Engineers utilized the SSC-EGIS in a plan to establish wetland mitigation sites within the SSC buffer zone. Mississippi State University employed the SSC-EGIS in a preliminary study to evaluate public access points within the buffer zone. The SSC-EO has also expressly used the SSC-EGIS to assess noise pollution modeling, land management/wetland mitigation assessment, environmental hazards mapping, and protected areas mapping for archaeological sites and for threatened and endangered species habitats. The SSC-EO has several active and planned projects that will also make use of the SSC-EGIS during this and the coming fiscal year.

Protected areas and agricultural expansion: Biodiversity conservation versus economic growth in the Southeast of Brazil.

PubMed

Moraes, Mayra Cristina Prado de; Mello, Kaline de; Toppa, Rogério Hartung

2017-03-01

The conversion of natural ecosystems to agricultural land and urban areas plays a threat to the protected areas and the natural ecosystems conservation. The aim of this paper is to provide an analysis of the agricultural expansion and its impact on the landscape spatial and temporal patterns in a buffer zone of a protected area located in the transition zone between the Atlantic Forest and Cerrado, in the State of São Paulo, Brazil. The land use and land cover were mapped between 1971 and 2008 and landscape metrics were calculated to provide a spatiotemporal analysis of the forest structure and the expansion of the croplands. The results showed that the landscape patterns were affected by the economic cycles. The predominant crop surrounding the protected area is sugar cane, which increased by 39% during this period, followed by citrus. This landscape change is connected to the Brazilian oil crisis in 1973. The rapid expansion of sugar cane was largely driven by Brazil's biofuel program, the "Proálcool" (pro-alcohol), a project in 1975 that mixed ethanol with gas for automotive fuel. The forest loss occurred mainly between 1971 and 1988, decreasing the forest cover from 17% in 1971 to 12.7% in 2008. Most of the forest patches are smaller than 50 ha and has low connectivity. Throughout the years, the fragments in the buffer zone have become smaller and with an elongated shape, and the park has become isolated. This forest fragmentation process and the predominance of monoculture lands in the buffer zone threaten the protected areas, and can represent a barrier for these areas to provide the effective biodiversity conservation. The measures proposed are necessary to ensure the capability of this ecosystem to sustain its original biodiversity. Copyright © 2016 Elsevier Ltd. All rights reserved.

30 CFR 761.15 - Procedures for waiving the prohibition on surface coal mining operations within the buffer zone...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Procedures for waiving the prohibition on surface coal mining operations within the buffer zone of an occupied dwelling. 761.15 Section 761.15... surface coal mining operations within the buffer zone of an occupied dwelling. (a) This section does not...

30 CFR 761.15 - Procedures for waiving the prohibition on surface coal mining operations within the buffer zone...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Procedures for waiving the prohibition on surface coal mining operations within the buffer zone of an occupied dwelling. 761.15 Section 761.15... surface coal mining operations within the buffer zone of an occupied dwelling. (a) This section does not...

30 CFR 761.15 - Procedures for waiving the prohibition on surface coal mining operations within the buffer zone...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Procedures for waiving the prohibition on surface coal mining operations within the buffer zone of an occupied dwelling. 761.15 Section 761.15... surface coal mining operations within the buffer zone of an occupied dwelling. (a) This section does not...

30 CFR 761.15 - Procedures for waiving the prohibition on surface coal mining operations within the buffer zone...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Procedures for waiving the prohibition on surface coal mining operations within the buffer zone of an occupied dwelling. 761.15 Section 761.15... surface coal mining operations within the buffer zone of an occupied dwelling. (a) This section does not...

30 CFR 761.15 - Procedures for waiving the prohibition on surface coal mining operations within the buffer zone...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Procedures for waiving the prohibition on surface coal mining operations within the buffer zone of an occupied dwelling. 761.15 Section 761.15... surface coal mining operations within the buffer zone of an occupied dwelling. (a) This section does not...

Purification effect of two typical water source vegetation buffer zones on land-sourced pollutants

NASA Astrophysics Data System (ADS)

Li, Gang

2017-03-01

Two vegetation buffer zones (tree-shrub-grass pattern and tree-grass pattern) were selected as test objects around Siming reservoir in Yuyao City of China. The effect of the storm runoff intensity (low and high intensity) and the buffer zone width (1 m, 3 m, 5 m, 7 m, 9 m, 12 m, 16 m) on pollutants (suspended solids, ammonium nitrogen and total phosphorus) was studied by the artificial simulation runoff. The results showed that with the increase of the width of buffer zone, the pollutant concentration was decreased. The purification effect of the two buffer zones on suspended solids and total phosphorus was basically stable at 52-55% and 34-37%, respectively. But the purification effect on ammonium nitrogen was the tree-shrub-grass pattern (69.7%) significantly better than that of tree-grass pattern (52.1%). The purification rate at the low runoff intensity was 1.8-2.0 times that at the high runoff intensity. The relationship between the purification rate and buffer zone width can be expressed by the natural logarithm equation, and the model adjustment coefficient was greater than 0.92.

Dynamics and mitigation of six pesticides in a "Wet" forest buffer zone.

PubMed

Passeport, Elodie; Richard, Benjamin; Chaumont, Cédric; Margoum, Christelle; Liger, Lucie; Gril, Jean-Joël; Tournebize, Julien

2014-04-01

Pesticide pollution is one of the main current threats on water quality. This paper presents the potential and functioning principles of a "Wet" forest buffer zone for reducing concentrations and loads of glyphosate, isoproturon, metazachlor, azoxystrobin, epoxiconazole, and cyproconazole. A tracer injection experiment was conducted in the field in a forest buffer zone at Bray (France). A fine time-scale sampling enabled to illustrate that interactions between pesticides and forest buffer substrates (soil and organic-rich litter layer), had a retarding effect on molecule transfer. Low concentrations were observed for all pesticides at the forest buffer outlet thus demonstrating the efficiency of "Wet" forest buffer zone for pesticide dissipation. Pesticide masses injected in the forest buffer inlet directly determined concentration peaks observed at the outlet. Rapid and partially reversible adsorption was likely the major process affecting pesticide transfer for short retention times (a few hours to a few days). Remobilization of metazachlor, isoproturon, desmethylisoproturon, and AMPA was observed when non-contaminated water flows passed through the forest buffer. Our data suggest that pesticide sorption properties alone could not explain the complex reaction mechanisms that affected pesticide transfer in the forest buffer. Nevertheless, the thick layer of organic matter litter on the top of the forest soil was a key parameter, which enhanced partially reversible sorption of pesticide, thus retarded their transfer, decreased concentration peaks, and likely increased degradation of the pesticides. Consequently, to limit pesticide pollution transported by surface water, the use of already existing forest areas as buffer zones should be equally considered as the most commonly implemented grass buffer strips.

Particulate capture efficiency of a vegetative environmental buffer surrounding an animal feeding operation

USDA-ARS?s Scientific Manuscript database

Particulate matter emitted from tunnel-ventilated animal feeding operations (AFOs) is known to transport malodorous compounds. As a mitigation strategy, vegetative environmental buffers (VEBs) are often installed surrounding AFOs to capture particulates and induce lofting and dispersion. Currently, ...

Buffer strip design for protecting water quality and fish habitat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belt, G.H.; O'Laughlin, J.

1994-04-01

Buffer strips are protective areas adjacent to streams or lakes. Among other functions, they protect water quality and fish habitat. A typical buffer strip is found in western Oregon, where they are called Riparian Management Areas (RMAs). The authors use the term buffer strip to include functional descriptions such as filter, stabilization, or leave strips, and administrative designations such as Idaho's Stream Protection Zone (SPZ), Washington's Riparian Management Zone (RMZ), and the USDA Forest Service's Streamside Management Zone (SMZ). They address water quality and fishery protective functions of buffer strips on forestlands, pointing out improvements in buffer strip design possiblemore » through research or administrative changes. Buffer strip design requirements found in some western Forest Practices Act (FPA) regulations are also compared and related to findings in the scientific literature.« less

Evaluating social-ecological aspects of buffer zones at the borders of Etosha National Park, Namibia

Treesearch

Lelani M. Mannetti; Ulrich Zeller; Karen J. Esler

2015-01-01

The study aims to investigate the premise that the implementation of a buffer zone around a national park provides opportunities for local communities to become active in the management of such areas. The study focuses on the Etosha National Park in Namibia, where the implementation of a buffer zone has been proposed, since the park fence is a potential barrier for...

Assessing protected area effectiveness using surrounding (buffer) areas environmentally similar to the target area.

PubMed

Mas, Jean-François

2005-06-01

Many studies are based on the assumption that an area and its surrounding (buffer) area present similar environmental conditions and can be compared. For example, in order to assess the effectiveness of a protected area, the land use/cover changes are compared inside the park with its surroundings. However, the heterogeneity in spatial variables can bias this assessment: we have shown that most of the protected areas in Mexico present significant environmental differences between their interior and their surroundings. Therefore, a comparison that aims at assessing the effectiveness of conservation strategies, must be cautioned. In this paper, a simple method which allows the generation of a buffer area that presents similar conditions with respect to a set of environmental variables is presented. The method was used in order to assess the effectiveness of the Calakmul Biosphere Reserve, a protected area located in the south-eastern part of Mexico. The annual rate of deforestation inside the protected area, the standard buffer area (based upon distance from the protected area only) and the similar buffer area (taking into account distance along with some environmental variables) were 0.3, 1.3 and 0.6%, respectively. These results showed that the protected area was effective in preventing land clearing, but that the comparison with the standard buffer area gave an over-optimistic vision of its effectiveness.

Soil water nitrate concentrations in giant cane and forest riparian buffer zones

Treesearch

Jon E. Schoonover; Karl W. J. Williard; James J. Zaczek; Jean C. Mangun; Andrew D. Carver

2003-01-01

Soil water nitrate concentrations in giant cane and forest riparian buffer zones along Cypress Creek in southern Illinois were compared to determine if the riparian zones were sources or sinks for nitrogen in the rooting zone. Suction lysimeters were used to collect soil water samples from the lower rooting zone in each of the two vegetation types. The cane riparian...

The effective boundary conditions and their lifespan of the logistic diffusion equation on a coated body

NASA Astrophysics Data System (ADS)

Li, Huicong; Wang, Xuefeng; Wu, Yanxia

2014-11-01

We consider the logistic diffusion equation on a bounded domain, which has two components with a thin coating surrounding a body. The diffusion tensor is isotropic on the body, and anisotropic on the coating. The size of the diffusion tensor on these components may be very different; within the coating, the diffusion rates in the normal and tangent directions may be in different scales. We find effective boundary conditions (EBCs) that are approximately satisfied by the solution of the diffusion equation on the boundary of the body. We also prove that the lifespan of each EBC, which measures how long the EBC remains effective, is infinite. The EBCs enable us to see clearly the effect of the coating and ease the difficult task of solving the PDE in a thin region with a small diffusion tensor. The motivation of the mathematics includes a nature reserve surrounded by a buffer zone.

Conservation value of remnant riparian forest corridors of varying quality for amazonian birds and mammals.

PubMed

Lees, Alexander C; Peres, Carlos A

2008-04-01

Forest corridors are often considered the main instrument with which to offset the effects of habitat loss and fragmentation. Brazilian forestry legislation requires that all riparian zones on private landholdings be maintained as permanent reserves and sets fixed minimum widths of riparian forest buffers to be retained alongside rivers and perennial streams. We investigated the effects of corridor width and degradation status of 37 riparian forest sites (including 24 corridors connected to large source-forest patches, 8 unconnected forest corridors, and 5 control riparian zones embedded within continuous forest patches) on bird and mammal species richness in a hyper-fragmented forest landscape surrounding Alta Floresta, Mato Grosso, Brazil. We used point-count and track-sampling methodology, coupled with an intensive forest-quality assessment that combined satellite imagery and ground truthed data. Vertebrate use of corridors was highly species-specific, but broad trends emerged depending on species life histories and their sensitivity to disturbance. Narrow and/or highly disturbed riparian corridors retained only a depauperate vertebrate assemblage that was typical of deforested habitats, whereas wide, well-preserved corridors retained a nearly complete species assemblage. Restriction of livestock movement along riparian buffers and their exclusion from key areas alongside deforested streams would permit corridor regeneration and facilitate restoration of connectivity.

Microbial community structure across a wastewater-impacted riparian buffer zone in the southeastern coastal plain.

PubMed

Ducey, T F; Johnson, P R; Shriner, A D; Matheny, T A; Hunt, P G

2013-01-01

Riparian buffer zones are important for both natural and developed ecosystems throughout the world because of their ability to retain nutrients, prevent soil erosion, protect aquatic environments from excessive sedimentation, and filter pollutants. Despite their importance, the microbial community structures of riparian buffer zones remains poorly defined. Our objectives for this study were twofold: first, to characterize the microbial populations found in riparian buffer zone soils; and second, to determine if microbial community structure could be linked to denitrification enzyme activity (DEA). To achieve these objectives, we investigated the microbial populations of a riparian buffer zone located downslope of a pasture irrigated with swine lagoon effluent, utilizing DNA sequencing of the 16S rDNA, DEA, and quantitative PCR (qPCR) of the denitrification genes nirK, nirS, and nosZ. Clone libraries of the 16S rDNA gene were generated from each of twelve sites across the riparian buffer with a total of 986 partial sequences grouped into 654 operational taxonomic units (OTUs). The Proteobacteria were the dominant group (49.8% of all OTUs), with the Acidobacteria also well represented (19.57% of all OTUs). Analysis of qPCR results identified spatial relationships between soil series, site location, and gene abundance, which could be used to infer both incomplete and total DEA rates.

Surrounding land cover types as predictors of palustrine wetland vegetation quality in conterminous USA

USGS Publications Warehouse

Stapanian, Martin A.; Gara, Brian; Schumacher, William

2018-01-01

The loss of wetland habitats and their often-unique biological communities is a major environmental concern. We examined vegetation data obtained from 380 wetlands sampled in a statistical survey of wetlands in the USA. Our goal was to identify which surrounding land cover types best predict two indices of vegetation quality in wetlands at the regional scale. We considered palustrine wetlands in four regions (Coastal Plains, North Central East, Interior Plains, and West) in which the dominant vegetation was emergent, forested, or scrub-shrub. For each wetland, we calculated weighted proportions of eight land cover types surrounding the area in which vegetation was assessed, in four zones radiating from the edge of the assessment area to 2 km. Using Akaike's Information Criterion, we determined the best 1-, 2- and 3-predictor models of the two indices, using the weighted proportions of the land cover types as potential predictors. Mean values of the two indices were generally higher in the North Central East and Coastal Plains than the other regions for forested and emergent wetlands. In nearly all cases, the best predictors of the indices were not the dominant surrounding land cover types. Overall, proportions of forest (positive effect) and agriculture (negative effect) surrounding the assessment area were the best predictors of the two indices. One or both of these variables were included as predictors in 65 of the 72 models supported by the data. Wetlands surrounding the assessment area had a positive effect on the indices, and ranked third (33%) among the predictors included in supported models. Development had a negative effect on the indices and was included in only 28% of supported models. These results can be used to develop regional management plans for wetlands, such as creating forest buffers around wetlands, or to conserve zones between wetlands to increase habitat connectivity.

Effects of Terrestrial Buffer Zones on Amphibians on Golf Courses

PubMed Central

Puglis, Holly J.; Boone, Michelle D.

2012-01-01

A major cause of amphibian declines worldwide is habitat destruction or alteration. Public green spaces, such as golf courses and parks, could serve as safe havens to curb the effects of habitat loss if managed in ways to bolster local amphibian communities. We reared larval Blanchard's cricket frogs (Acris blanchardi) and green frogs (Rana clamitans) in golf course ponds with and without 1 m terrestrial buffer zones, and released marked cricket frog metamorphs at the golf course ponds they were reared in. Larval survival of both species was affected by the presence of a buffer zone, with increased survival for cricket frogs and decreased survival for green frogs when reared in ponds with buffer zones. No marked cricket frog juveniles were recovered at any golf course pond in the following year, suggesting that most animals died or migrated. In a separate study, we released cricket frogs in a terrestrial pen and allowed them to choose between mown and unmown grass. Cricket frogs had a greater probability of using unmown versus mown grass. Our results suggest that incorporating buffer zones around ponds can offer suitable habitat for some amphibian species and can improve the quality of the aquatic environment for some sensitive local amphibians. PMID:22761833

Buffer Zone Sign Template

EPA Pesticide Factsheets

The certified pesticide applicator is required to post a comparable sign, designating a buffer zone around the soil fumigant application block in order to control exposure risk. It must include the don't walk symbol, product name, and applicator contact.

Calculating Buffer Zones: A Guide for Applicators

EPA Pesticide Factsheets

Buffer zones provide distance between the application block (i.e., edge of the treated field) and bystanders, in order to control pesticide exposure risk from soil fumigants. Distance requirements may be reduced by credits such as tarps.

Modeling of Coupled Thermo-Hydro-Mechanical-Chemical Processes for Bentonite in a Clay-rock Repository for Heat-generating Nuclear Waste

NASA Astrophysics Data System (ADS)

Xu, H.; Rutqvist, J.; Zheng, L.; Birkholzer, J. T.

2016-12-01

Engineered Barrier Systems (EBS) that include a bentonite-based buffer are designed to isolate the high-level radioactive waste emplaced in tunnels in deep geological formations. The heat emanated from the waste can drive the moisture flow transport and induce strongly coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes within the bentonite buffer and may also impact the evolution of the excavation disturbed zone and the sealing between the buffer and walls of an emplacement tunnel The flow and contaminant transport potential along the disturbed zone can be minimized by backfilling the tunnels with bentonite, if it provides enough swelling stress when hydrated by the host rock. The swelling capability of clay minerals within the bentonite is important for sealing gaps between bentonite block, and between the EBS and the surrounding host rock. However, a high temperature could result in chemical alteration of bentonite-based buffer and backfill materials through illitization, which may compromise the function of these EBS components by reducing their plasticity and capability to swell under wetting. Therefore, an adequate THMC coupling scheme is required to understand and to predict the changes of bentonite for identifying whether EBS bentonite can sustain higher temperatures. More comprehensive links between chemistry and mechanics, taking advantage of the framework provided by a dual-structure model, named Barcelona Expansive Model (BExM), was implemented in TOUGHREACT-FLAC3D and is used to simulate the response of EBS bentonite in in clay formation for a generic case. The current work is to evaluate the chemical changes in EBS bentonite and the effects on the bentonite swelling stress under high temperature. This work sheds light on the interaction between THMC processes, evaluates the potential deterioration of EBS bentonite and supports the decision making in the design of a nuclear waste repository in light of the maximum allowance temperature.

Directions for Determining Buffer Zone Distances for Commodity and Structural Fumigation with Methyl Bromide

EPA Pesticide Factsheets

Buffer zones for commodity and food handling structural applications are distributed across numerous tables. This document provides directions for determining the factors to use to identify the correct table for a given application.

Particle control near reticle and optics using showerhead

DOEpatents

Delgado, Gildardo R.; Chilese, Frank; Garcia, Rudy; Torczynski, John R.; Geller, Anthony S.; Rader, Daniel J.; Klebanoff, Leonard E.; Gallis, Michail A.

2016-01-26

A method and an apparatus to protect a reticle against particles and chemicals in an actinic EUV reticle inspection tool are presented. The method and apparatus utilizes a pair of porous metal diffusers in the form of showerheads to provide a continual flow of clean gas. The main showerhead bathes the reticle surface to be inspected in smoothly flowing, low pressure gas, isolating it from particles coming from surrounding volumes. The secondary showerhead faces away from the reticle and toward the EUV illumination and projection optics, supplying them with purge gas while at the same time creating a buffer zone that is kept free of any particle contamination originating from those optics.

40 CFR 98.449 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... CO2 plume at the end of year t, plus an all around buffer zone of one-half mile or greater if known... until the CO2 plume has stabilized plus an all-around buffer zone of at least one-half mile. Research...

40 CFR 98.449 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... CO2 plume at the end of year t, plus an all around buffer zone of one-half mile or greater if known... until the CO2 plume has stabilized plus an all-around buffer zone of at least one-half mile. Research...

40 CFR 98.449 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... CO2 plume at the end of year t, plus an all around buffer zone of one-half mile or greater if known... until the CO2 plume has stabilized plus an all-around buffer zone of at least one-half mile. Research...

Effectiveness of vegetation buffers surrounding playa wetlands at contaminant and sediment amelioration

USGS Publications Warehouse

Haukos, David A.; Johnson, Lacrecia A.; Smith, Loren M.; McMurry, Scott T.

2016-01-01

Playa wetlands, the dominant hydrological feature of the semi-arid U.S. High Plains providing critical ecosystem services, are being lost and degraded due to anthropogenic alterations of the short-grass prairie landscape. The primary process contributing to the loss of playas is filling of the wetland through accumulation of soil eroded and transported by precipitation from surrounding cultivated watersheds. We evaluated effectiveness of vegetative buffers surrounding playas in removing metals, nutrients, and dissolved/suspended sediments from precipitation runoff. Storm water runoff was collected at 10-m intervals in three buffer types (native grass, fallow cropland, and Conservation Reserve Program). Buffer type differed in plant composition, but not in maximum percent removal of contaminants. Within the initial 60 m from a cultivated field, vegetation buffers of all types removed >50% of all measured contaminants, including 83% of total suspended solids (TSS) and 58% of total dissolved solids (TDS). Buffers removed an average of 70% of P and 78% of N to reduce nutrients entering the playa. Mean maximum percent removal for metals ranged from 56% of Na to 87% of Cr. Maximum removal was typically at 50 m of buffer width. Measures of TSS were correlated with all measures of metals and nutrients except for N, which was correlated with TDS. Any buffer type with >80% vegetation cover and 30–60 m in width would maximize contaminant removal from precipitation runoff while ensuring that playas would continue to function hydrologically to provide ecosystem services. Watershed management to minimize erosion and creations of vegetation buffers could be economical and effective conservation tools for playa wetlands.

Using FIA and GIS Data to Estimate Areas and Volumes of Potential Stream Management Zones and Road Beautifying Buffers

Treesearch

Michael Zasada; Chris J. Cieszewski; Roger C. Lowe; Jarek Zawadzki; Mike Clutter; Jacek P. Siry

2005-01-01

Georgia Stream Management Zones (SMZ) are voluntary and have an unknown extent and impact. We use FIA data, Landsat TM imagery, and GAP and other GIS data to estimate the acreages and volumes of these buffers. We use stream data classified into trout, perennial, and intermittent, combined with DEM files containing elevation values, to assess buffers with widths...

33 CFR 209.138a - Authorization for exploratory drilling in the Gulf of Santa Catalina, Calif.

Code of Federal Regulations, 2014 CFR

2014-07-01

... feasible to perform exploratory work from outside the traffic lanes or 1/4 mile buffer zones, or... cables, anchors, buoys, or other associated equipment within the traffic lanes, 1/4 mile buffer zones, or...

33 CFR 209.138a - Authorization for exploratory drilling in the Gulf of Santa Catalina, Calif.

Code of Federal Regulations, 2012 CFR

2012-07-01

... feasible to perform exploratory work from outside the traffic lanes or 1/4 mile buffer zones, or... cables, anchors, buoys, or other associated equipment within the traffic lanes, 1/4 mile buffer zones, or...

33 CFR 209.138a - Authorization for exploratory drilling in the Gulf of Santa Catalina, Calif.

Code of Federal Regulations, 2013 CFR

2013-07-01

... feasible to perform exploratory work from outside the traffic lanes or 1/4 mile buffer zones, or... cables, anchors, buoys, or other associated equipment within the traffic lanes, 1/4 mile buffer zones, or...

Application of Classification Algorithm of Machine Learning and Buffer Analysis in Torism Regional Planning

NASA Astrophysics Data System (ADS)

Zhang, T. H.; Ji, H. W.; Hu, Y.; Ye, Q.; Lin, Y.

2018-04-01

Remote Sensing (RS) and Geography Information System (GIS) technologies are widely used in ecological analysis and regional planning. With the advantages of large scale monitoring, combination of point and area, multiple time-phases and repeated observation, they are suitable for monitoring and analysis of environmental information in a large range. In this study, support vector machine (SVM) classification algorithm is used to monitor the land use and land cover change (LUCC), and then to perform the ecological evaluation for Chaohu lake tourism area quantitatively. The automatic classification and the quantitative spatial-temporal analysis for the Chaohu Lake basin are realized by the analysis of multi-temporal and multispectral satellite images, DEM data and slope information data. Furthermore, the ecological buffer zone analysis is also studied to set up the buffer width for each catchment area surrounding Chaohu Lake. The results of LUCC monitoring from 1992 to 2015 has shown obvious affections by human activities. Since the construction of the Chaohu Lake basin is in the crucial stage of the rapid development of urbanization, the application of RS and GIS technique can effectively provide scientific basis for land use planning, ecological management, environmental protection and tourism resources development in the Chaohu Lake Basin.

Designing cost efficient buffer zone programs: An application of the FyrisSKZ tool in a Swedish catchment.

PubMed

Collentine, Dennis; Johnsson, Holger; Larsson, Peter; Markensten, Hampus; Persson, Kristian

2015-03-01

Riparian buffer zones are the only measure which has been used extensively in Sweden to reduce phosphorus losses from agricultural land. This paper describes how the FyrisSKZ web tool can be used to evaluate allocation scenarios using data from the Svärta River, an agricultural catchment located in central Sweden. Three scenarios are evaluated: a baseline, a uniform 6-m-wide buffer zone in each sub-catchment, and an allocation of areas of buffer zones to sub-catchments based on the average cost of reduction. The total P reduction increases by 30 % in the second scenario compared to the baseline scenario, and the average reduction per hectare increases by 90 % while total costs of the program fall by 32 %. In the third scenario, the average cost per unit of reduction (163 kg P(-1)) is the lowest of the three scenarios (58 % lower than the baseline) and has the lowest total program costs.

Mapping the ecosystem service delivery chain: Capacity, flow, and demand pertaining to aesthetic experiences in mountain landscapes.

PubMed

Egarter Vigl, Lukas; Depellegrin, Daniel; Pereira, Paulo; de Groot, Rudolf; Tappeiner, Ulrike

2017-01-01

Accounting for the spatial connectivity between the provision of ecosystem services (ES) and their beneficiaries (supply-benefit chain) is fundamental to understanding ecosystem functioning and its management. However, the interrelationships of the specific chain links within ecosystems and the actual benefits that flow from natural landscapes to surrounding land have rarely been analyzed. We present a spatially explicit model for the analysis of one cultural ecosystem service (aesthetic experience), which integrates the complete ecosystem service delivery chain for Puez-Geisler Nature Park (Italy): (1) The potential service stock (ES capacity) relies on an expert-based land use ranking matrix, (2) the actual supply (ES flow) is based on visibility properties of observation points along recreational routes, (3) the beneficiaries of the service (ES demand) are derived from socioeconomic data as a measure of the visitation rate to the recreation location, and (4) the supply-demand relationship (ES budget) addresses the spatially explicit oversupply and undersupply of ES. The results indicate that potential ES stocks are substantially higher in core and buffer zones of protected areas than in surrounding land owing to the specific landscape composition. ES flow maps reveal service delivery to 80% of the total area studied, with the highest actual service supply to locations with long and open vistas. ES beneficiary analyses show the highest demand for aesthetic experiences in all-season tourist destinations like Val Badia and Val Gardena, where both recreational amenity and overnight stays are equally high. ES budget maps identify ES hot and cold spots in terms of ES delivery, and they highlight ES undersupply in nature protection buffer zones although they are characterized by highest ES capacity. We show how decision/policy makers can use the presented methodology to plan landscape protection measures and develop specific regulation strategies for visitors based on the ES delivery chain concept. Copyright © 2016 Elsevier B.V. All rights reserved.

The relationship between mosquito abundance and rice field density in the Republic of Korea

PubMed Central

2010-01-01

Background Japanese encephalitis virus (JEV), the causative agent of Japanese encephalitis (JE), is endemic to the Republic of Korea (ROK) where unvaccinated United States (U.S.) military Service members, civilians and family members are stationed. The primary vector of the JEV in the ROK is Culex tritaeniorhynchus. The ecological relationship between Culex spp. and rice fields has been studied extensively; rice fields have been shown to increase the prevalence of Cx. tritaeniorhynchus. This research was conducted to determine if the quantification of rice field land cover surrounding U.S. military installations in the ROK should be used as a parameter in a larger risk model that predicts the abundance of Cx. tritaeniorhynchus populations. Mosquito data from the U.S. Forces Korea (USFK) mosquito surveillance program were used in this project. The average number of female Cx. tritaeniorhynchus collected per trap night for the months of August and September, 2002-2008, was calculated. Rice fields were manually digitized inside 1.5 km buffer zones surrounding U.S. military installations on high-resolution satellite images, and the proportion of rice fields was calculated for each buffer zone. Results Mosquito data collected from seventeen sample sites were analyzed for an association with the proportion of rice field land cover. Results demonstrated that the linear relationship between the proportion of rice fields and mosquito abundance was statistically significant (R2 = 0.62, r = .79, F = 22.72, p < 0.001). Conclusions The analysis presented shows a statistically significant linear relationship between the two parameters, proportion of rice field land cover and log10 of the average number of Cx. tritaeniorhynchus collected per trap night. The findings confirm that agricultural land cover should be included in future studies to develop JE risk prediction models for non-indigenous personnel living at military installations in the ROK. PMID:20573242

Defining Steamside Management Zones or Riparian Buffers

Treesearch

Thomas M. Williams; Donald J. Lipscomb; Christopher J. Post

2004-01-01

Forestry Best Management Practices (BMPs) have been highly successful in protecting water quality throughout the Southeast. Numerous studies have found them to be effective in protecting water quality. Despite being mostly voluntary, compliance is generally about 90 percent across the region. Streamside Management Zones (SMZs) or riparian buffers are specified for...

Body Buffer Zone and Proxemics in Blocking.

ERIC Educational Resources Information Center

Stockwell, John C.; Bahs, Clarence W.

This paper investigates the effect of personal body buffer zones on compositional arrangements staged by novice directors. Relationships between directors' concepts of personal space and their projection of its dimensions into staging are studied through the use of a variety of proximity measures--distance, area angles of approach, and physical…

Urban Runoff: Model Ordinances for Aquatic Buffers

EPA Pesticide Factsheets

Aquatic Buffers serve as natural boundaries between local waterways and existing development. The model and example ordinaces below provide suggested language or technical guidance designed to create the most effective stream buffer zones possible.

Methods for improved growth of group III nitride semiconductor compounds

DOEpatents

Melnik, Yuriy; Chen, Lu; Kojiri, Hidehiro

2015-03-17

Methods are disclosed for growing group III-nitride semiconductor compounds with advanced buffer layer technique. In an embodiment, a method includes providing a suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. The method includes forming an AlN buffer layer by flowing an ammonia gas into a growth zone of the processing chamber, flowing an aluminum halide containing precursor to the growth zone and at the same time flowing additional hydrogen halide or halogen gas into the growth zone of the processing chamber. The additional hydrogen halide or halogen gas that is flowed into the growth zone during buffer layer deposition suppresses homogeneous AlN particle formation. The hydrogen halide or halogen gas may continue flowing for a time period while the flow of the aluminum halide containing precursor is turned off.

Neighbourhood walkability, leisure-time and transport-related physical activity in a mixed urban-rural area.

PubMed

de Sa, Eric; Ardern, Chris I

2014-01-01

Objectives. To develop a walkability index specific to mixed rural/suburban areas, and to explore the relationship between walkability scores and leisure time physical activity. Methods. Respondents were geocoded with 500 m and 1,000 m buffer zones around each address. A walkability index was derived from intersections, residential density, and land-use mix according to built environment measures. Multivariable logistic regression models were used to quantify the association between the index and physical activity levels. Analyses used cross-sectional data from the 2007-2008 Canadian Community Health Survey (n = 1158; ≥18 y). Results. Respondents living in highly walkable 500 m buffer zones (upper quartiles of the walkability index) were more likely to walk or cycle for leisure than those living in low-walkable buffer zones (quartile 1). When a 1,000 m buffer zone was applied, respondents in more walkable neighbourhoods were more likely to walk or cycle for both leisure-time and transport-related purposes. Conclusion. Developing a walkability index can assist in exploring the associations between measures of the built environment and physical activity to prioritize neighborhood change.

Setting priorities for research on pollution reduction functions of agricultural buffers.

PubMed

Dosskey, Michael G

2002-11-01

The success of buffer installation initiatives and programs to reduce nonpoint source pollution of streams on agricultural lands will depend the ability of local planners to locate and design buffers for specific circumstances with substantial and predictable results. Current predictive capabilities are inadequate, and major sources of uncertainty remain. An assessment of these uncertainties cautions that there is greater risk of overestimating buffer impact than underestimating it. Priorities for future research are proposed that will lead more quickly to major advances in predictive capabilities. Highest priority is given for work on the surface runoff filtration function, which is almost universally important to the amount of pollution reduction expected from buffer installation and for which there remain major sources of uncertainty for predicting level of impact. Foremost uncertainties surround the extent and consequences of runoff flow concentration and pollutant accumulation. Other buffer functions, including filtration of groundwater nitrate and stabilization of channel erosion sources of sediments, may be important in some regions. However, uncertainty surrounds our ability to identify and quantify the extent of site conditions where buffer installation can substantially reduce stream pollution in these ways. Deficiencies in predictive models reflect gaps in experimental information as well as technology to account for spatial heterogeneity of pollutant sources, pathways, and buffer capabilities across watersheds. Since completion of a comprehensive watershed-scale buffer model is probably far off, immediate needs call for simpler techniques to gage the probable impacts of buffer installation at local scales.

Free-Piston Stirling Machine for Extreme Temperatures

NASA Technical Reports Server (NTRS)

Wood, James Gary (Inventor)

2013-01-01

A free piston Stirling machine including a thermal buffer tube extending from the machine's expansion space and surrounded by its heat rejector and its regenerator, a displacer cylinder extending from the thermal buffer tube to the compression space and surrounded by the heat rejecting heat exchanger, and a displacer that reciprocates within an excursion limit that extends into the regenerator by no more than 20% of the length of the regenerator during normal operation and preferably within excursion limits that are substantially the length of the heat rejector.

Hydrochemical buffer assessment in agricultural landscapes: from local to catchment scale.

PubMed

Viaud, Valérie; Merot, Philippe; Baudry, Jacques

2004-10-01

Non-point-source pollution of surface and groundwater is a prominent environmental issue in rural catchments, with major consequences on water supply and aquatic ecosystem quality. Among surface-water protection measures, environmental or landscape management policies support the implementation and the management of buffer zones. Although a great number of studies have focused on buffer zones, quantification of the buffer effect is still a recurring question. The purpose of this article is a critical review of the assessment of buffer-zone functioning. Our objective is to provide land planners and managers with a set of variables to assess the limits and possibilities for quantifying buffer impact at the catchment scale. We first consider the scale of the local landscape feature. The most commonly used empirical method for assessing buffers is to calculate water/nutrient budgets from inflow-outflow monitoring at the level of landscape structures. We show that several other parameters apart from mean depletion of flux can be used to describe buffer functions. Such parameters include variability, with major implication for water management. We develop a theoretical framework to clarify the assessment of the buffer effect and propose a systematic analysis taking account of temporal variability. Second, we review the current assessment of buffer effects at the catchment scale according to the theoretical framework established at the local scale. Finally, we stress the limits of direct empirical assessment at the catchment scale and, in particular, we emphasize the hierarchy in hydrological processes involved at the catchment scale: The landscape feature function is constrained by other factors (climate and geology) that are of importance at a broader spatial and temporal scale.

META-ANALYSIS OF NITROGEN REMOVAL IN RIPARIAN BUFFERS

EPA Science Inventory

Riparian buffer zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Riparian buffer width may be positively related to nitrogen removal effectiveness by influencing nitrog...

43 CFR 3931.100 - Boundary pillars and buffer zones.

Code of Federal Regulations, 2013 CFR

2013-10-01

... otherwise specified in writing by the BLM. Boundary and other main pillars may be mined only with the BLM's prior written consent or on the BLM's order. For in-situ operations, a 50-foot buffer zone from the..., mine out and remove all available oil shale in such boundary pillar, both in the lands covered by the...

43 CFR 3931.100 - Boundary pillars and buffer zones.

Code of Federal Regulations, 2012 CFR

2012-10-01

... otherwise specified in writing by the BLM. Boundary and other main pillars may be mined only with the BLM's prior written consent or on the BLM's order. For in-situ operations, a 50-foot buffer zone from the..., mine out and remove all available oil shale in such boundary pillar, both in the lands covered by the...

43 CFR 3931.100 - Boundary pillars and buffer zones.

Code of Federal Regulations, 2014 CFR

2014-10-01

... otherwise specified in writing by the BLM. Boundary and other main pillars may be mined only with the BLM's prior written consent or on the BLM's order. For in-situ operations, a 50-foot buffer zone from the..., mine out and remove all available oil shale in such boundary pillar, both in the lands covered by the...

43 CFR 3931.100 - Boundary pillars and buffer zones.

Code of Federal Regulations, 2011 CFR

2011-10-01

... otherwise specified in writing by the BLM. Boundary and other main pillars may be mined only with the BLM's prior written consent or on the BLM's order. For in-situ operations, a 50-foot buffer zone from the..., mine out and remove all available oil shale in such boundary pillar, both in the lands covered by the...

Concentrated flow paths in riparian buffer zones of southern Illinois

Treesearch

R.C. Pankau; J.E. Schoonover; K.W.J. Willard; P.J. Edwards

2012-01-01

Riparian buffers in agricultural landscapes should be designed to trap pollutants in overland flow by slowing, filtering, and infiltrating surface runoff entering the buffer via sheet flow. However, observational evidence suggests that concentrated flow is prevalent from agricultural fields. Over time sediment can accumulate in riparian buffers forming berms that...

Digital geologic map data for the Ozark National Scenic Riverways and adjacent areas along the Current River and Jacks Fork, Missouri

USGS Publications Warehouse

Weary, David J.; Orndorff, Randall C.; Harrison, Richard W.; Weems, Robert E.

2016-09-23

The geology of the Ozark National Scenic Riverways (ONSR) in southern Missouri has been mapped at 1:24,000 scale. This endeavor was achieved through the combined efforts of U.S. Geological Survey and Missouri Geological Survey individual quadrangle mapping and additional fieldwork by the authors of this report. Geologic data covering the area of the ONSR and a 1-mile (1.6-kilometer) buffer zone surrounding the park, as well as geologic data from a few key adjoining areas, have been compiled into a single, seamless geographic information system database. The intent is to provide base geologic information for natural science research and land management in the park and surrounding areas. The data are served online at ScienceBase (https://www.sciencebase.gov/catalog/), where they are provided in Environmental Systems Research Institute (ESRI) file geodatabase format, and are accompanied by metadata files. These data can be accessed at: http://dx.doi.org/10.5066/F7CJ8BKB. Additional detailed geologic information about the ONSR and surrounding areas is available in the separate 1:24,000-scale quadrangle maps and in a 1:100,000-scale map and report on the regional geology.

The transition from riparian to upland forest plant communities on headwater streams in the southern Sierra Nevada, California, United States

Treesearch

Christopher R. Dolanc; Carolyn T. Hunsaker

2017-01-01

Abstract. Fixed-width buffer zones on rivers and streams are designed to protect the diverse riparian community and its important function in the ecosystem. However, recent data suggest that riparian areas of some western forests have become more fire prone because of restrictions on fuel reduction treatments within buffer zones....

Stand-off thermal IR minefield survey: system concept and experimental results

NASA Astrophysics Data System (ADS)

Cremer, Frank; Nguyen, Thanh T.; Yang, Lixin; Sahli, Hichem

2005-06-01

A detailed description of the CLEARFAST system for thermal IR stand-off minefield survey is given. The system allows (i) a stand-off diurnal observation of hazardous area, (ii) detecting anomalies, i.e. locating and searching for targets which are thermally and spectrally distinct from their surroundings, (iii) estimating the physical parameters, i.e. depth and thermal diffusivity, of the detected anomalies, and (iv) providing panoramic (mosaic) images indicating the locations of suspect objects and known markers. The CLEARFAST demonstrator has been successfully deployed and operated, in November 2004, in a real minefield within the United Nations Buffer Zone in Cyprus. The paper describes the main principles of the system and illustrates the processing chain on a set of real minefield images, together with qualitative and quantitative results.

Using fluorescent dyes as proxies to study herbicide removal by sorption in buffer zones.

PubMed

Dollinger, Jeanne; Dagès, Cécile; Voltz, Marc

2017-04-01

The performance of buffer zones for removing pesticides from runoff water varies greatly according to landscape settings, hydraulic regime, and system design. Evaluating the performance of buffers for a range of pesticides and environmental conditions can be very expensive. Recent studies suggested that the fluorescent dyes uranine and sulforhodamine B could be used as cost-effective surrogates of herbicides to evaluate buffer performance. However, while transformation mechanisms in buffers have been extensively documented, sorption processes of both dyes have rarely been investigated. In this study, we measured the adsorption, desorption, and kinetic sorption coefficients of uranine and sulforhodamine B for a diverse range of buffer zone materials (soils, litters, plants) and compared the adsorption coefficients (Kd) to those of selected herbicides. We also compared the global sorption capacity of 6 ditches, characterized by varying proportions of the aforementioned materials, between both dyes and a set of four herbicides using the sorption-induced pesticide retention indicator (SPRI). We found that both the individual Kd of uranine for the diverse buffer materials and the global sorption capacity of the ditches are equivalent to those of the herbicides diuron, isoproturon, and metolachlor. The Kd of sulforhodamine B on plants and soils are equivalent to those of glyphosate, and the global sorption capacities of the ditches are equivalent for both molecules. Hence, we demonstrate for the first time that uranine can be used as a proxy of moderately hydrophobic herbicides to evaluate the performance of buffer systems, whereas sulforhodamine B can serve as a proxy for more strongly sorbing herbicides.

Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

PubMed

Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

2008-09-01

Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

Periodic Nanoneedle and Buffer Zones Constructed on a Titanium Surface Promote Osteogenic Differentiation and Bone Calcification In Vivo.

PubMed

Yu, Peng; Zhu, Xiaojing; Wang, Xiaolan; Wang, Shuangying; Li, Weiping; Tan, Guoxin; Zhang, Yu; Ning, Chengyun

2016-02-04

Rapid and effective bone mineralization at the bone/implant interface is required for successful orthopedic and dental implants. In this study, two periodic microscale functionalized zones on titanium (MZT) are created, namely, nanoneedle zones and buffer zones. The aim of this design is to provide spatially regulated topographical cues on titanium to enhance the efficacy of bone regeneration. This goal is achieved using a versatile and effective technique in which nanoneedle structures are hydrothermally constructed on the surface of titanium sheets, after which selective laser irradiation is used to construct buffer zones. The zonal structures of the MZT overcome the suppressive effect of the nanoneedle film on osteoblasts. Additionally, the MZT exhibits zone-selective apatite deposition and protein adsorption. The accelerated in vitro osteoblast differentiation and nodule deposition on the MZT are confirmed. Elemental analysis of the bone nodules formed by the osteoblasts growing on the titanium and MZT demonstrates they have different compositions. Histological and scanning electron microscope analysis of the bone formation on in vivo implants shows that this process is also enhanced by the MZT implant. The concept of constructing functionalized zones on titanium implant could facilitate future research on improving the design of orthopedic and dental implant surfaces. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mapping tradeoffs in values at risk at the interface between wilderness and non-wilderness lands

Treesearch

Alan Watson; Roian Matt; Tim Waters; Kari Gunderson; Steve Carver; Brett Davis

2009-01-01

On the Flathead Indian Reservation in Montana, U.S., the Mission Mountains Tribal Wilderness is bordered by a buffer zone. To successfully improve forest health within that buffer zone and restore fire in the wilderness, the managing agency and the public need to work together to find solutions to increasingly threatening fuel buildups. A combination of qualitative,...

The use of staggered scheme and an absorbing buffer zone for computational aeroacoustics

NASA Technical Reports Server (NTRS)

Nark, Douglas M.

1995-01-01

Various problems from those proposed for the Computational Aeroacoustics (CAA) workshop were studied using second and fourth order staggered spatial discretizations in conjunction with fourth order Runge-Kutta time integration. In addition, an absorbing buffer zone was used at the outflow boundaries. Promising results were obtained and provide a basis for application of these techniques to a wider variety of problems.

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining operations within the buffer zone of a public... operations within the buffer zone of a public road. (a) This section does not apply to: (1) Lands for which a...

Impact of Stream Management Zones and Road Beautifying Buffers on Long-Term Fiber Supply in Georgia

Treesearch

Michal Zasada; Chris J. Cieszewski; Roger C. Lowe

2005-01-01

Streamside management zones (SMZs) and road beautifying buffers (RBBs) in Georgia have had an unknown impact on the available wood supply in the state. We used Forest Inventory and Analysis data, Landsat Thematic Mapper imagery, Gap Analysis Program and other geographic information system data to estimate the potential impact of SMZs and RBBs in the current and future...

Inequality, green spaces, and pregnant women: roles of ethnicity and individual and neighbourhood socioeconomic status.

PubMed

Dadvand, Payam; Wright, John; Martinez, David; Basagaña, Xavier; McEachan, Rosemary R C; Cirach, Marta; Gidlow, Christopher J; de Hoogh, Kees; Gražulevičienė, Regina; Nieuwenhuijsen, Mark J

2014-10-01

Evidence of the impact of green spaces on pregnancy outcomes is limited with no report on how this impact might vary by ethnicity. We investigated the association between residential surrounding greenness and proximity to green spaces and birth weight and explored the modification of this association by ethnicity and indicators of individual (maternal education) and neighbourhood (Index of Multiple Deprivation) socioeconomic status. Our study was based on 10,780 singleton live-births from the Born in Bradford cohort, UK (2007-2010). We defined residential surrounding greenness as average of satellite-based Normalized Difference Vegetation Index (NDVI) in buffers of 50 m, 100 m, 250 m, 500 m and 1000 m around each maternal home address. Residential proximity to green spaces was defined as living within 300 m of a green space with an area of ≥ 5000 m(2). We utilized mixed effects models to estimate adjusted change in birth weight associated with residential surrounding greenness as well as proximity to green spaces. We found a positive association between birth weight and residential surrounding greenness. Furthermore, we observed an interaction between ethnicity and residential surrounding greenness in that for White British participants there was a positive association between birth weight and residential surrounding greenness whereas for participants of Pakistani origin there was no such an association. For surrounding greenness in larger buffers (500 m and 1000 m) there were some indications of stronger associations for participants with lower education and those living in more deprived neighbourhoods which were not replicated for surrounding greenness in smaller buffer sizes (i.e. 50 m, 100 m, and 250 m). The findings for residential proximity to a green space were not conclusive. Our study showed that residential surrounding greenness is associated with better foetal growth and this association could vary between different ethnic and socioeconomic groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Role of Legacy Effects and Reactive Amendments on Phosphorus Retention Within Riparian Zones

NASA Astrophysics Data System (ADS)

Surridge, B.; Habibiandehkordi, R.; Quinton, J.

2014-12-01

Undisturbed riparian zones, including river floodplains and field buffer strips, can significantly reduce phosphorus (P) export associated with agricultural production. However, riparian zones are frequently disturbed, including through conversion to agricultural land. Restoring disturbed riparian zones is promoted widely within agri-environment schemes. However, restoration presents significant challenges, two of which are considered in this paper: understanding the impacts of restoration on legacy P within riparian zone soils; and maximising the efficacy of riparian zones for removal of all P fractions, including the more immediately bioavailable soluble P fractions. Firstly, we examine changes in porewater soluble P concentration following re-wetting of a river floodplain in Norfolk, UK, using laboratory mesocosms and in-situ field monitoring. Substantial release of P from sediment to porewater was observed following re-wetting (porewater soluble P concentration exceeded 6.5 mg P L-1), probably associated with reductive-dissolution of iron-bound P within floodplain sediments. Export of soluble P from porewater into adjacent receiving waters was observed following both natural hydrological events and management of the hydrological regime within the floodplain. Secondly, we examine how retention of soluble P with grass buffer strips can be enhanced through application of reactive industrial by-products, focussing on ochre and aluminium-based water treatment residuals. Application of these by-products to buffer strips increased removal of soluble P from surface runoff by over 50% compared to non-amended buffer strips. The long-term effectiveness of reactive amendments is also considered, using repeated runoff events under field conditions. Taken together, the research offers new insights into riparian zone P biogeochemistry within agricultural landscapes.

33 CFR 165.1411 - Security zone; waters surrounding U.S. Forces vessel SBX-1, HI.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security zone; waters surrounding U.S. Forces vessel SBX-1, HI. 165.1411 Section 165.1411 Navigation and Navigable Waters COAST GUARD... § 165.1411 Security zone; waters surrounding U.S. Forces vessel SBX-1, HI. (a) Location. The following...

Evaluating the effects of land use on headwater wetland amphibian assemblages in coastal Alabama

USGS Publications Warehouse

Alix, Diane M.; Anderson, Christopher J.; Grand, James B.; Guyer, Craig

2014-01-01

Anthropogenic land use is known to impact aquatic ecosystems in several ways, including increased frequency and intensity of floods, stream channel incision, sedimentation, and loss of microtopography. Amphibians are susceptible to changes in wetland and surrounding habitats. This study evaluated amphibian assemblages of fifteen headwater slope wetlands in coastal Alabama across a gradient of land uses. Amphibians were surveyed on a seasonal basis and land use was delineated within wetland watersheds and within a 200-m buffer surrounding each wetland. Amphibian presence/absence and land use data were used to develop species occupancy models. Both urban and agricultural land use were shown to influence amphibian occurrence. Species richness ranged from five to ten species across sites; however, five species only occurred in wetlands surrounded by forested lands. Many species were detected more frequently on these wetlands compared to wetlands surrounded by urban or mixed land uses. Occupancy models showed Acris gryllus was negatively associated with the amount of agriculture within a buffer around the wetland. Hyla squirella, Lithobates clamitans, and L. sphenocephalus were positively associated with agricultural land within a watershed. Anaxyrus terrestris and the non-native Eleutherodactylus planirostris were positively associated with the amount of impervious surface area within the wetland buffer.

Reducing sedimentation of depressional wetlands in agricultural landscapes

USGS Publications Warehouse

Skagen, S.K.; Melcher, Cynthia; Haukos, D.A.

2008-01-01

Depressional wetlands in agricultural landscapes are easily degraded by sediments and contaminants accumulated from their watersheds. Several best management practices can reduce transport of sediments into wetlands, including the establishment of vegetative buffers. We summarize the sources, transport dynamics, and effect of sediments, nutrients, and contaminants that threaten wetlands and the current knowledge of design and usefulness of grass buffers for protecting isolated wetlands. Buffer effectiveness is dependent on several factors, including vegetation structure, buffer width, attributes of the surrounding watershed (i.e., area, vegetative cover, slope and topography, soil type and structure, soil moisture, amount of herbicides and pesticides applied), and intensity and duration of rain events. To reduce dissolved contaminants from runoff, the water must infiltrate the soil where microbes or other processes can break down or sequester contaminants. But increasing infiltration also diminishes total water volume entering a wetland, which presents threats to wetland hydrology in semi-arid regions. Buffer effectiveness may be enhanced significantly by implementing other best management practices (e.g., conservation tillage, balancing input with nutrient requirements for livestock and crops, precision application of chemicals) in the surrounding watershed to diminish soil erosion and associated contaminant runoff. Buffers require regular maintenance to remove sediment build-up and replace damaged or over-mature vegetation. Further research is needed to establish guidelines for effective buffer width and structure, and such efforts should entail a coordinated, regional, multi-scale, multidisciplinary approach to evaluate buffer effectiveness and impacts. Direct measures in "real-world" systems and field validations of buffer-effectiveness models are crucial next steps in evaluating how grass buffers will impact the abiotic and biotic variables attributes that characterize small, isolated wetlands. ?? 2008 The Society of Wetland Scientists.

33 CFR 165.1192 - Security Zones; Waters surrounding San Francisco International Airport and Oakland International...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zones; Waters... Security Zones; Waters surrounding San Francisco International Airport and Oakland International Airport, San Francisco Bay, California. (a) Locations. The following areas are security zones: (1) San...

33 CFR 165.1192 - Security Zones; Waters surrounding San Francisco International Airport and Oakland International...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zones; Waters... Security Zones; Waters surrounding San Francisco International Airport and Oakland International Airport, San Francisco Bay, California. (a) Locations. The following areas are security zones: (1) San...

33 CFR 165.1192 - Security Zones; Waters surrounding San Francisco International Airport and Oakland International...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zones; Waters... Security Zones; Waters surrounding San Francisco International Airport and Oakland International Airport, San Francisco Bay, California. (a) Locations. The following areas are security zones: (1) San...

33 CFR 165.1192 - Security Zones; Waters surrounding San Francisco International Airport and Oakland International...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zones; Waters... Security Zones; Waters surrounding San Francisco International Airport and Oakland International Airport, San Francisco Bay, California. (a) Locations. The following areas are security zones: (1) San...

33 CFR 165.1192 - Security Zones; Waters surrounding San Francisco International Airport and Oakland International...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zones; Waters... Security Zones; Waters surrounding San Francisco International Airport and Oakland International Airport, San Francisco Bay, California. (a) Locations. The following areas are security zones: (1) San...

Relating rheology to geometry in large-scale natural shear zones

NASA Astrophysics Data System (ADS)

Platt, John

2016-04-01

The geometry and width of the ductile roots of plate boundary scale faults are very poorly understood. Some field and geophysical data suggests widths of tens of km in the lower crust, possibly more in the upper mantle. Other observations suggest they are much narrower. Dip slip shear zones may flatten out and merge into zones of subhorizontal lower crustal or asthenospheric flow. The width of a ductile shear zone is simply related to relative velocity and strain rate. Strain rate is related to stress through the constitutive relationship. Can we constrain the stress, and do we understand the rheology of materials in ductile shear zones? A lot depends on how shear zones are initiated. If they are localized by pre-existing structures, width and/or rheology may be inherited, and we have too many variables. If shear zones are localized primarily by shear heating, initial shear stress has to be very high (> 1 GPa) to overcome conductive heat loss, and very large feedbacks (both positive and negative) make the system highly unstable. Microstructural weakening requires a minimum level of stress to cause deformation and damage in surrounding rock, thereby buffering the stress. Microstructural weakening leads to grain-size sensitive creep, for which we have constitutive laws, but these are complicated by phase mixing in polyphase materials, by viscous anisotropy, by hydration, and by changes in mineral assemblage. Here are some questions that need to be addressed. (1) If grain-size reduction by dynamic recrystallization results in a switch to grain-size sensitive creep (GSSC) in a stress-buffered shear zone, does dynamic recrystallization stop? Does grain growth set in? If grain-size is still controlled by dislocation processes, then the effective stress exponent for GSSC is 4-5, even though the dominant mechanism may be diffusion and/or grain-boundary sliding (GBS). (2) Is phase mixing in ultramylonites primarily a result of GBS + neighbour switching, creep cavitation and diffusion, or metamorphic reactions? (3) In two-phase / polyphase mixtures, does the strong phase generally form a load-bearing framework, favoring constant strain-rate (Voigt) bound behavior, or does the weak phase form through-going strain pathways, favoring constant stress (Reuss) bound behavior, or do the phases remain well mixed, favoring an intermediate behavior (e.g., Tullis et al model)? (4) How do we deal with the rheological effect of water? Is it simply an unconstrained variable in nature? Is the water fugacity model in flow laws adequate? (5) How can we better relate experimental results (often carried out at constant strain-rate, and not reaching microstructural steady state) to deformation in natural shear zones? Rheological observations on well-constrained natural shear zones are helping us answer some of these questions.

[Land layout for lake tourism based on ecological restraint].

PubMed

Wang, Jian-Ying; Li, Jiang-Feng; Zou, Li-Lin; Liu, Shi-Bin

2012-10-01

To avoid the decrease and deterioration of lake wetlands and the other ecological issues such as lake water pollution that were caused by the unreasonable exploration of lake tourism, a land layout for the tourism development of Liangzi Lake with the priority of ecological security pattern was proposed, based on the minimal cumulative resistance model and by using GIS technology. The study area was divided into four ecological function zones, i. e., core protection zone, ecological buffer zone, ecotone zone, and human activity zone. The core protection zone was the landscape region of ecological source. In the protection zone, new tourism land was forbidden to be increased, and some of the existing fundamental tourism facilities should be removed while some of them should be upgraded. The ecological buffer zone was the landscape region with resistance value ranged from 0 to 4562. In the buffer zone, expansion of tourism land should be forbidden, the existing tourism land should be downsized, and human activities should be isolated from ecological source by converting the human environment to the natural environment as far as possible. The ecotone zone was the landscape region with resistance value ranged from 4562 to 30797. In this zone, the existing tourism land was distributed in patches, tourism land could be expanded properly, and the lake forestry ecological tourism should be developed widely. The human activity zone was the landscape region with resistance value ranged from 30797 to 97334, which would be the key area for the land layout of lake tourism. It was suggested that the land layout for tourism with the priority of landscape ecological security pattern would be the best choice for the lake sustainable development.

Methods to prioritize placement of riparian buffers for improved water quality

Treesearch

Mark D. Tomer; Michael G. Dosskey; Michael R. Burkart; David E. James; Matthew J. Helmers; Dean E. Eisenhauer

2008-01-01

Agroforestry buffers in riparian zones can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, surficial geology, and hydrology determine the capability of forest buffers to intercept and treat these flows. This paper describes two landscape analysis techniques for identifying...

pH Control for Effective Anaerobic Bioremediation of Chlorinated Solvents

NASA Astrophysics Data System (ADS)

Robinson, C.; Barry, D.; Gerhard, J. I.; Kouznetsova, I.

2007-12-01

SABRE (Source Area BioREmediation) is a 4-year collaborative project that aims to evaluate the performance of enhanced anaerobic bioremediation for the treatment of chlorinated solvent DNAPL source areas. The project focuses on a pilot scale demonstration at a trichloroethene (TCE) DNAPL field site, and includes complementary laboratory and modelling studies. Organic acids and hydrogen ions (HCl) typically build up in the treatment zone during anaerobic bioremediation. In aquifer systems with relatively low buffering capacity the generation of these products can cause significant groundwater acidification thereby inhibiting dehalogenating activity. Where the soil buffering capacity is exceeded, addition of buffer may be needed for the effective continuation of TCE degradation. As an aid to the design of remediation schemes, a geochemical model was designed to predict the amount of buffer required to maintain the source zone pH at a suitable level for dechlorinating bacteria (i.e. > 6.5). The model accounts for the amount of TCE to be degraded, site water chemistry, type of organic amendment and soil mineralogy. It assumes complete dechlorination of TCE, and further considers mineral dissolution and precipitation kinetics. The model is applicable to a wide range of sites. For illustration we present results pertinent to the SABRE field site. Model results indicate that, for the extensive dechlorination expected in proximity to the SABRE DNAPL source zone, significant buffer addition may be necessary. Additional simulations are performed to identify buffer requirements over a wider range of field conditions.

Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China

PubMed Central

Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

2015-01-01

Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (p<0.05) than provincial protected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies. PMID:26382763

Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China.

PubMed

Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

2015-01-01

Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (p<0.05) than provincial protected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies.

The number and type of food retailers surrounding schools and their association with lunchtime eating behaviours in students.

PubMed

Seliske, Laura; Pickett, William; Rosu, Andrei; Janssen, Ian

2013-02-07

The primary study objective was to examine whether the presence of food retailers surrounding schools was associated with students' lunchtime eating behaviours. The secondary objective was to determine whether measures of the food retail environment around schools captured using road network or circular buffers were more strongly related to eating behaviours while at school. Grade 9 and 10 students (N=6,971) who participated in the 2009/10 Canadian Health Behaviour in School Aged Children Survey were included in this study. The outcome was determined by students' self-reports of where they typically ate their lunch during school days. Circular and road network-based buffers were created for a 1 km distance surrounding 158 schools participating in the HBSC. The addresses of fast food restaurants, convenience stores and coffee/donut shops were mapped within the buffers. Multilevel logistic regression was used to determine whether there was a relationship between the presence of food retailers near schools and students regularly eating their lunch at a fast food restaurant, snack-bar or café. The Akaike Information Criteria (AIC) value, a measure of goodness-of-fit, was used to determine the optimal buffer type. For the 1 km circular buffers, students with 1-2 (OR= 1.10, 95% CI: 0.57-2.11), 3-4 (OR=1.45, 95% CI: 0.75-2.82) and ≥5 nearby food retailers (OR=2.94, 95% CI: 1.71-5.09) were more likely to eat lunch at a food retailer compared to students with no nearby food retailers. The relationships were slightly stronger when assessed via 1 km road network buffers, with a greater likelihood of eating at a food retailer for 1-2 (OR=1.20, 95% CI:0.74-1.95), 3-4 (OR=3.19, 95% CI: 1.66-6.13) and ≥5 nearby food retailers (OR=3.54, 95% CI: 2.08-6.02). Road network buffers appeared to provide a better measure of the food retail environment, as indicated by a lower AIC value (3332 vs. 3346). There was a strong relationship between the presence of food retailers near schools and students' lunchtime eating behaviours. Results from the goodness of fit analysis suggests that road network buffers provide a more optimal measure of school neighbourhood food environments relative to circular buffers.

Influence of management of variables, sampling zones and land units on LR analysis for landslide spatial prevision

NASA Astrophysics Data System (ADS)

Greco, R.; Sorriso-Valvo, M.

2013-09-01

Several authors, according to different methodological approaches, have employed logistic Regression (LR), a multivariate statistical analysis adopted to assess the spatial probability of landslide, even though its fundamental principles have remained unaltered. This study aims at assessing the influence of some of these methodological approaches on the performance of LR, through a series of sensitivity analyses developed over a test area of about 300 km2 in Calabria (southern Italy). In particular, four types of sampling (1 - the whole study area; 2 - transects running parallel to the general slope direction of the study area with a total surface of about 1/3 of the whole study area; 3 - buffers surrounding the phenomena with a 1/1 ratio between the stable and the unstable area; 4 - buffers surrounding the phenomena with a 1/2 ratio between the stable and the unstable area), two variable coding modes (1 - grouped variables; 2 - binary variables), and two types of elementary land (1 - cells units; 2 - slope units) units have been tested. The obtained results must be considered as statistically relevant in all cases (Aroc values > 70%), thus confirming the soundness of the LR analysis which maintains high predictive capacities notwithstanding the features of input data. As for the area under investigation, the best performing methodological choices are the following: (i) transects produced the best results (0 < P(y) ≤ 93.4%; Aroc = 79.5%); (ii) as for sampling modalities, binary variables (0 < P(y) ≤ 98.3%; Aroc = 80.7%) provide better performance than ordinated variables; (iii) as for the choice of elementary land units, slope units (0 < P(y) ≤ 100%; Aroc = 84.2%) have obtained better results than cells matrix.

Efficacy of buffer zones in disconnecting roads and streams in the coastal plain

Treesearch

J.M. III Grace; E. Davis

2010-01-01

Established forest BMPs rely heavily on the forest floor to disconnect upslope activities from stream systems. Optimizing the buffer length required to negate the storm runoff contribution of upslope activities has been a point of interest for soil scientist, hydrologist, and conservation professionals for the last century. Minimum buffer lengths have been recommended...

Does tree harvesting in riparian areas increase stream sedimentation and turbidity - world-wide experience relative to Australia.

NASA Astrophysics Data System (ADS)

Neary, D.; Smethurst, P.; Petrone, K.

2009-04-01

A typical improved-pasture property in the high-rainfall zone of Australia contains 0.5-2.0 km of waterways per 100 ha. Nationwide, some 25-30 million ha of improved pasture contains about 100,000 km of streams, of which about 75% are currently un-buffered and contributing to soil and water degradation. Farmers and natural resource managers are considering ways to enhance environmental outcomes at farm and catchment scales using stream-side buffers of trees and other perennial vegetation. Benefits of buffers include improved water quality, biodiversity, carbon sequestration and aesthetics. Lack of sound information and funding for establishing and managing buffer zones is hindering wide-scale adoption of this practice. Stream-side areas of farms are generally highly productive (wet and nutrient-rich) and contain a high biodiversity, but they are also high-risk zones for soil and water values and stock safety. Development of options based on a balance between environmental and economic outcomes would potentially promote wider adoption. Australian codes of forest practice currently discourage or prevent harvesting of trees in streamside buffers. These codes were developed exclusively for large-scale native forests and industrial-scale plantations, and were applicable to farm forestry as now required. In countries including USA and Germany trees in stream-side buffers are harvested using Best Management Practices. Trees may grow at a faster rate in riparian zones and provide a commercial return, but the impacts of tree establishment and harvesting on water yield and quality must be evaluated. However, there have been few designed experiments investigating this problem. Australia has recently initiated studies to explore the use of high-value timber species and associated vegetation in riparian zones to improve water quality, particularly suspended sediment. Preliminary information from the Yan Yan Gurt Catchment in Victoria indicate that forested riparian strips can retain 98% of the sediment entrained in runoff from agricultural sections of the catchment. This paper examines the science background from North American and European experiences relative to Australia, with particular emphasis on sediment relationships after tree harvesting using Best Management Practices.

The effect of adipose derived stromal vascular fraction on stasis zone in an experimental burn model.

PubMed

Eyuboglu, Atilla Adnan; Uysal, Cagri A; Ozgun, Gonca; Coskun, Erhan; Markal Ertas, Nilgun; Haberal, Mehmet

2018-03-01

Stasis zone is the surrounding area of the coagulation zone which is an important part determining the extent of the necrosis in burn patients. In our study we aim to salvage the stasis zone by injecting adipose derived stromal vascular fraction (ADSVF). Thermal injury was applied on dorsum of Sprague-Dawley rats (n=20) by the "comb burn" model as described previously. When the burn injury was established on Sprague-Dawley rats (30min); rat dorsum was separated into 2 equal parts consisting of 4 burn zones (3 stasis zone) on each pair. ADSVF cells harvested from inguinal fat pads of Sprague-Dawley rats (n=5) were injected on the right side while same amount of phosphate buffered saline (PBS) injected on the left side of the same animal. One week later, average vital tissue on the statis zone was determined by macroscopy, angiography and microscopy. Vascular density, inflammatory cell density, gradient of fibrosis and epithelial thickness were determined via immunohistochemical assay. Macroscopic stasis zone tissue viability (32±3.28%, 57±4.28%) (p<0.01), average number of vessels (10.28±1.28, 19.43±1.72) (p<0.01), capillary count (15.67±1.97, 25.35±2.15) (p<0.01) vascular density (1.55±0.38, 2.14±0.45) (p<0.01) epithelial thickness (0.014±0.009mm, 0.024±0.0011mm) were higher on ADSVF side. Fibrosis gradient (1.87±0.51, 1.50±0.43) (p<0.01) and inflammatory cell density (1.33±0.40, 1.20±0.32) (p<0.01) were higher on the PBS side. Macroscopic and microscopic findings determined that ADSVF has a statistically significant benefit for salvaging stasis zone on acute burn injuries. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Effects of riparian buffer width on wood loading in headwater streams after repeated forest thinning

Treesearch

Julia I. Burton; Deanna H. Olson; Klaus J. Puettmann

2016-01-01

Forested riparian buffer zones are used in conjunction with upland forest management, in part, to provide for the recruitment for large wood to streams. Small headwater streams account for the majority of stream networks in many forested regions. Yet, our understanding of how riparian buffer width influences wood dynamics in headwater streams is relatively less...

Delineation of preventative landslide buffers along steep streamside slopes in northern California

Treesearch

Jason S. Woodward; David W. Lamphear; Matthew R. House

2012-01-01

Green Diamond Resource Co (GDRCo) applies tree retention buffers to steep slopes along fish bearing (Class I) and non-fish bearing (Class II) streams that are in addition to the standard riparian management zones associated with timber harvest plans. These Steep Streamside Slope (SSS) buffers were designed to reduce the amount of sediment delivering to watercourses as...

Family Smoking Prevention And Tobacco Control Act: banning outdoor tobacco advertising near schools and playgrounds.

PubMed

Luke, Douglas A; Ribisl, Kurt M; Smith, Carson; Sorg, Amy A

2011-03-01

The tobacco industry has challenged new FDA rules restricting outdoor tobacco advertising near schools and playgrounds on First Amendment grounds, arguing that they would lead to a near complete ban on tobacco advertising in dense urban areas. To examine how the 2009 Family Smoking Prevention and Tobacco Control Act (FSPTCA) rules banning outdoor tobacco advertising near schools and playgrounds would affect tobacco retailers. GIS spatial analyses of two different states (Missouri, New York), along with more detailed analyses of two urban areas within those states (St. Louis, New York City), were conducted in 2010. The percentage of tobacco retailers falling within 350-, 500-, and 1000-foot buffer zones was then calculated. 22% of retailers in Missouri and 51% in New York fall within 1000-foot buffers around schools. In urban settings, more retailers are affected, 29% in St. Louis and 79% in New York City. Sensitivity analyses demonstrate that smaller buffers decrease the proportion of affected retailers. That is, 350-foot buffers affect only 6.7% of retailers in St. Louis and 29% in New York City. The effects of new outdoor tobacco advertising restrictions vary by location and population density. In Missouri and New York, outdoor tobacco advertising would still be permitted in many locations if such advertising was prohibited in a 1000-foot buffer zone around schools and playgrounds. Much smaller buffer zones of 350 feet may result in almost no reduction of outdoor advertising in many parts of the country. Copyright © 2011. Published by Elsevier Inc.

Study of strain boundary conditions and GaAs buffer sizes in InGaAs quantum dots

NASA Technical Reports Server (NTRS)

Oyafuso, F.; Klimeck, G.; Boykin, T. B.; Bowen, R. C.; Allmen, P. von

2003-01-01

NEMO 3-D has been developed for the simulation of electronic structure in self-assembled InGaAs quantum dots on GaAs substrates. Typical self-assembled quantum dots in that material system contain about 0.5 to 1 million atoms. Effects of strain by the surrounding GaAs buffer modify the electronic structure inside the quantum dot significantly and a large GaAs buffer must be included in the strain and electronic structure.

Spatial characterization of riparian buffer effects on sediment loads from watershed systems.

PubMed

Momm, Henrique G; Bingner, Ronald L; Yuan, Yongping; Locke, Martin A; Wells, Robert R

2014-09-01

Understanding all watershed systems and their interactions is a complex, but critical, undertaking when developing practices designed to reduce topsoil loss and chemical/nutrient transport from agricultural fields. The presence of riparian buffer vegetation in agricultural landscapes can modify the characteristics of overland flow, promoting sediment deposition and nutrient filtering. Watershed simulation tools, such as the USDA-Annualized Agricultural Non-Point Source (AnnAGNPS) pollution model, typically require detailed information for each riparian buffer zone throughout the watershed describing the location, width, vegetation type, topography, and possible presence of concentrated flow paths through the riparian buffer zone. Research was conducted to develop GIS-based technology designed to spatially characterize riparian buffers and to estimate buffer efficiency in reducing sediment loads in a semiautomated fashion at watershed scale. The methodology combines modeling technology at different scales, at individual concentrated flow paths passing through the riparian zone, and at watershed scales. At the concentrated flow path scale, vegetative filter strip models are applied to estimate the sediment-trapping efficiency for each individual flow path, which are aggregated based on the watershed subdivision and used in the determination of the overall impact of the riparian vegetation at the watershed scale. This GIS-based technology is combined with AnnAGNPS to demonstrate the effect of riparian vegetation on sediment loadings from sheet and rill and ephemeral gully sources. The effects of variability in basic input parameters used to characterize riparian buffers, onto generated outputs at field scale (sediment trapping efficiency) and at watershed scale (sediment loadings from different sources) were evaluated and quantified. The AnnAGNPS riparian buffer component represents an important step in understanding and accounting for the effect of riparian vegetation, existing and/or managed, in reducing sediment loads at the watershed scale. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Examining the sensitivity of modelled evapotranspiration to vegetation structural characteristics within boreal peatlands, riparian ecosystems and upland mixedwood forest

NASA Astrophysics Data System (ADS)

Petrone, R. M.; Chasmer, L. E.; Brown, S. M.; Mendoza, C. A.; Diiwu, J.; Quinton, W. L.; Hopkinson, C.; Devito, K. J.

2010-12-01

The Western Boreal Plain (WBP) of northern Alberta is comprised of a complex mosaic of small ponds, riparian buffer zones, and upland aspen dominated mixedwood forests surrounded by low-lying peatlands. The hydrology of the WBP is strongly influenced by climatic drivers and geology, whereby water budgets are often controlled by vertical fluxes. During most years, potential evapotranspiration (PET) exceeds precipitation (P), and changes in P as a result of climatic change will likely alter actual evapotranspiration (AET) and regional water balances. In recent years, the WBP has also undergone intense anthropogenic disturbance via oil and gas exploration and extraction, and silvicultural and forest harvesting activities. The extent to which changes in land cover types/characteristics affect estimates of PET and AET is currently unknown. This study examines the sensitivity of PET using a simple estimate of equilibrium ET (Priestley-Taylor) and AET (Penman-Monteith variant) to variability in canopy structural and ground surface characteristics at 12 sites throughout the 2008 growing season (June, July, August). Energy balance meteorological stations are deployed within four peatland ecosystems, four riparian buffer zones, two regenerating upland mixedwood forests and two mature upland mixedwood forests. Airborne Light Detection and Ranging (LiDAR) is used to derive metrics of canopy height, leaf area index (LAI), uplands and lowlands, elevation, zero plane displacement, roughness length governing momentum, roughness length governing heat and vapour, and understory vegetation characteristics. LiDAR land surface metrics and energy balance measurements are used to model evapotranspiration for classified land cover types throughout the larger basin. Sensitivity of potential and actual estimates to changes in land cover characteristics within each of the three land cover types (peatland, riparian and upland) is quantified.

Habitat features influencing jaguar Panthera onca (Carnivora: Felidae) occupancy in Tortuguero National Park, Costa Rica.

PubMed

Arroyo-Arce, Stephanny; Guilder, James; Salom-Pérez, Roberto

2014-12-01

Habitat characteristics and human activities are known to play a major role in the occupancy of jaguars Panthera onca across their range, however the key variables influencing jaguar distribution in Tortuguero National Park, Costa Rica, have yet to be identified. This study evaluated jaguar occupancy in Tortuguero National Park and the surrounding area. Jaguar detection/non-detection data was collected using digital camera traps distributed within the boundaries of the protected area. Local community members were also interviewed to determine jaguar occurrence in the Park's buffer zone. Occupancy models were then applied to identify the habitat characteristics that may better explain jaguar distribution across the study area. From June 2012 to June 2013, a total of 4,339 camera trap days were used to identify 18 individual jaguars inside the protected area; 17 of these jaguars were exclusively detected within the coastal habitat, whilst the remaining individual was detected solely within the interior of the Park. Interviewees reported 61 occasions of jaguar presence inside the buffer zone, between 1995 and 2013, with 80% of these described by the communities of Lomas de Sierpe, Barra de Parismina and La Aurora. These communities also reported the highest levels of livestock predation by jaguars (85% of attacks). In the study area, jaguar occurrence was positively correlated with the seasonal presence of nesting green turtles Chelonia mydas, and negatively correlated with distance to the Park boundary. Our findings suggested that the current occupancy of the jaguar in the study area may be a response to: 1) the vast availability of prey (marine turtles) on Tortuguero beach, 2) the decline of its primary prey species as a result of illegal hunting inside the Park, and 3) the increase in anthropogenic pressures in the Park boundaries.

Elastic wave velocities of iron-bearing Ringwoodite (Mg0.8Fe0.2)2SiO2 to 12GPa at room temperature

NASA Astrophysics Data System (ADS)

Higo, Y.; Li, B.; Inoue, T.; Irifune, T.; Libermann, R. C.

2002-12-01

At present, it is widely accepted that olivine is the most important mineral in the Earth's upper mantle. The elastic property changes associated with the phase transformations to its high-pressure polymorphs are very important parameters to constrain the composition of the mantle transition zone. In this study, we measured the elastic wave velocity of iron-bearing Ringwoodite (Mg0.8Fe0.2)2SiO4. The specimen was hot-pressed at 18GPa and 1273K in a 2000-ton Uniaxial Split Sphere Apparatus (ORANGE-2000: GRC at ehime university). The recovered polycrystalline specimen was characterized by x-ray diffraction, EPMA, ultrasonic techniques, and the density was determined by Archimedes' method, and found to be single-phase and fine-grained. Bench top measurements of the compressional and shear wave velocities yielded Vp=9.10 km/s and Vs=5.52 km/s. High-pressure ultrasonic measurement was carried out in a 1000-ton Uniaxial Split-Cylinder Apparatus (USCA-1000: SUNY) at pressures up to 12GPa at room temperature using ZnTe as internal pressure marker. The sample was surrounded by lead to minimize the deviatoric stress. Also in this experiment, the travel times of the Al2O3 buffer rod were used for pressure calculation. The travel times of the buffer rod under the same cell geometry have been calibrated as a function of sample pressure by the thermal equation of state of NaCl using in-situ X-ray diffraction techniques. The results of our high-pressure experiment, including the elastic moduli and their pressure dependence, effect of iron on the elastic moduli, as well as their implication for the mantle transition zone, will be presented.

Impacts of Surrounding Land Cover on Headwater Wetland Edaphic Habitat Types and Their Associated Microbial Communities

NASA Astrophysics Data System (ADS)

Moon, J. B.; Wardrop, D. H.; Smithwick, E. A.

2010-12-01

Although small in size, headwater wetland complexes provide a disproportionate share of microbially mediated ecosystem services to the surrounding landscape and hydroscape. Two services that are of current interest to scientists and managers, given their role in regulating climate and water quality, are the retention and transformation of carbon and nitrogen pools. Although it is the wetland complex’s geographic position between the landscape and hydroscape that creates these hotspots of ecosystem function, continuous shifts in the surrounding scapes can also affect the complex’s transformational capacity through changes to its natural hydrologic disturbance regime and subsequent material fluxes. We have begun to investigate the influence of surrounding land cover and associated differences in hydrology on wetland edaphic habitats and their associated microbial communities. These studies are taking place in wetland complexes located in the headwaters of the Chesapeake Bay Watershed, within the Ridge and Valley Region of central Pennsylvania. Within this region, surrounding land cover ranges from intact forested buffers to a matrix of land cover types (e.g., mixed forest, grassland, and impermeable surfaces). Over a preliminary six-month collection period we found higher frequency and intensity of hydrologic fluctuations in wetlands surrounded by a matrix of land cover types, compared to highly stable saturated conditions of wetland complexes with intact forested buffers. Differences were also found in both the abundances of edaphic habitats as well as in the types of habitats present within these surrounding land cover groups. Wetlands with intact forested buffers had (1) fresh organic residue soils with high overall microbial biomasses and relatively high abundances of microeukaryotic groups, (2) reduced muck soils with relatively large proportions of branched fatty acid microbial groups, and (3) carbon and nutrient depleted sandy mineral soils with relatively low microbial biomasses. Riparian wetland complexes surrounded by a matrix of land cover types had narrower ranges of soil properties and were predominately high pH clay loam soils dominated by bacterial groups. Although these wetland complexes had fewer edaphic habitat types than wetland complexes with intact forested buffers, preliminary investigations using the DeNitrification-DeComposition (DNDC) model showed that their higher pH levels and hydrological fluctuations could make them more suitable environments for higher rates of complete denitrification. However, depending on the depth of the water table, wetland complexes surrounded by a matrix of land cover types could also transition into hotspots of methanogenesis. These initial hypotheses will be further refined with additional hydrologic, climatic, vegetation, and soils data and tested over the next year using methods such as push-pull denitrification.

Timber Management of NASA's John C. Stennis Space Station

NASA Technical Reports Server (NTRS)

Carr, Hugh; Johnson, Gary; Smoot, James; Cohan, Tyrus; O'Connor, Tina

2001-01-01

John C. Stennis Space Center occupies over 48560 hectares or just over 120000 acres in southwestern Mississippi and southeastern Louisiana near border of the two states. This area includes the Stennis Fee Area, which is the Center itself and the Acoustic Buffer Zone (ABZ) surrounding the Center. The ABZ is owned by several government, public and private entities and managed accordingly. The Fee Area and ABZ include wetlands, pine woodlands and areas of mixed floral species. The included maps detail the delineation of land in and around the Stennis Space Center. Areas owned by the federal government are divided into three stands to facilitate timber management. The stands are classified by species, density and average size to determine several timber in management issues including the schedule for controlled burns, economic viability of stands, and the creation of low impact recreational areas such as scenic trails or bike paths.

How to Comply with Requirements to Protect California Red-legged Frog from Pesticides

EPA Pesticide Factsheets

This document describes buffer areas around certain habitats of the California red-legged frog, and limits on use of certain pesticides within those habitats and buffer zones to protect the red-legged frog from certain pesticides.

A hybrid Lagrangian Voronoi-SPH scheme

NASA Astrophysics Data System (ADS)

Fernandez-Gutierrez, D.; Souto-Iglesias, A.; Zohdi, T. I.

2018-07-01

A hybrid Lagrangian Voronoi-SPH scheme, with an explicit weakly compressible formulation for both the Voronoi and SPH sub-domains, has been developed. The SPH discretization is substituted by Voronoi elements close to solid boundaries, where SPH consistency and boundary conditions implementation become problematic. A buffer zone to couple the dynamics of both sub-domains is used. This zone is formed by a set of particles where fields are interpolated taking into account SPH particles and Voronoi elements. A particle may move in or out of the buffer zone depending on its proximity to a solid boundary. The accuracy of the coupled scheme is discussed by means of a set of well-known verification benchmarks.

A hybrid Lagrangian Voronoi-SPH scheme

NASA Astrophysics Data System (ADS)

Fernandez-Gutierrez, D.; Souto-Iglesias, A.; Zohdi, T. I.

2017-11-01

A hybrid Lagrangian Voronoi-SPH scheme, with an explicit weakly compressible formulation for both the Voronoi and SPH sub-domains, has been developed. The SPH discretization is substituted by Voronoi elements close to solid boundaries, where SPH consistency and boundary conditions implementation become problematic. A buffer zone to couple the dynamics of both sub-domains is used. This zone is formed by a set of particles where fields are interpolated taking into account SPH particles and Voronoi elements. A particle may move in or out of the buffer zone depending on its proximity to a solid boundary. The accuracy of the coupled scheme is discussed by means of a set of well-known verification benchmarks.

Optimization of buffer injection for the effective bioremediation of chlorinated solvents in aquifers

NASA Astrophysics Data System (ADS)

Brovelli, A.; Robinson, C.; Barry, A.; Kouznetsova, I.; Gerhard, J.

2008-12-01

Various techniques have been proposed to enhance biologically-mediated reductive dechlorination of chlorinated solvents in the subsurface, including the addition of fermentable organic substrate for the generation of H2 as an electron donor. One rate-limiting factor for enhanced dechlorination is the pore fluid pH. Organic acids and H+ ions accumulate in dechlorination zones, generating unfavorable conditions for microbial activity (pH < 6.5). The pH variation is a nonlinear function of the amount of reduced chlorinated solvents, and is affected by the organic material fermented, the chemical composition of the pore fluid and the soil's buffering capacity. Consequently, in some cases enhanced remediation schemes rely on buffer injection (e.g., bicarbonate) to alleviate this problem, particularly in the presence of solvent nonaqueous phase liquid (NAPL) source zones. However, the amount of buffer required - particularly in complex, evolving biogeochemical environments - is not well understood. To investigate this question, this work builds upon a geochemical numerical model (Robinson et al., Science of the Total Environment, submitted), which computes the amount of additional buffer required to maintain the pH at a level suitable for bacterial activity for batch systems. The batch model was coupled to a groundwater flow/solute transport/chemical reaction simulator to permit buffer optimization computations within the context of flowing systems exhibiting heterogeneous hydraulic, physical and chemical properties. A suite of simulations was conducted in which buffer optimization was examined within the bounds of the minimum concentration necessary to sustain a pH favorable to microbial activity and the maximum concentration to avoid excessively high pH values (also not suitable to bacterial activity) and mineral precipitation (e.g., calcite, which may lead to pore-clogging). These simulations include an examination of the sensitivity of this buffer concentration range to aquifer heterogeneity and groundwater velocity. This work is part of SABRE (Source Area BioREmediation), a collaborative international research project that aims to evaluate and improve enhanced bioremediation of chlorinated solvent source zones. In this context, numerical simulations are supporting the upscaling of the technique, including identifying the most appropriate buffer injection strategies for field applications

The number and type of food retailers surrounding schools and their association with lunchtime eating behaviours in students

PubMed Central

2013-01-01

Background The primary study objective was to examine whether the presence of food retailers surrounding schools was associated with students’ lunchtime eating behaviours. The secondary objective was to determine whether measures of the food retail environment around schools captured using road network or circular buffers were more strongly related to eating behaviours while at school. Methods Grade 9 and 10 students (N=6,971) who participated in the 2009/10 Canadian Health Behaviour in School Aged Children Survey were included in this study. The outcome was determined by students’ self-reports of where they typically ate their lunch during school days. Circular and road network-based buffers were created for a 1 km distance surrounding 158 schools participating in the HBSC. The addresses of fast food restaurants, convenience stores and coffee/donut shops were mapped within the buffers. Multilevel logistic regression was used to determine whether there was a relationship between the presence of food retailers near schools and students regularly eating their lunch at a fast food restaurant, snack-bar or café. The Akaike Information Criteria (AIC) value, a measure of goodness-of-fit, was used to determine the optimal buffer type. Results For the 1 km circular buffers, students with 1–2 (OR= 1.10, 95% CI: 0.57-2.11), 3–4 (OR=1.45, 95% CI: 0.75-2.82) and ≥5 nearby food retailers (OR=2.94, 95% CI: 1.71-5.09) were more likely to eat lunch at a food retailer compared to students with no nearby food retailers. The relationships were slightly stronger when assessed via 1 km road network buffers, with a greater likelihood of eating at a food retailer for 1–2 (OR=1.20, 95% CI:0.74-1.95), 3–4 (OR=3.19, 95% CI: 1.66-6.13) and ≥5 nearby food retailers (OR=3.54, 95% CI: 2.08-6.02). Road network buffers appeared to provide a better measure of the food retail environment, as indicated by a lower AIC value (3332 vs. 3346). Conclusions There was a strong relationship between the presence of food retailers near schools and students’ lunchtime eating behaviours. Results from the goodness of fit analysis suggests that road network buffers provide a more optimal measure of school neighbourhood food environments relative to circular buffers. PMID:23391296

Seismic evidence for water transport out of the mantle transition zone beneath the European Alps

NASA Astrophysics Data System (ADS)

Liu, Zhen; Park, Jeffrey; Karato, Shun-ichiro

2018-01-01

The mantle transition zone has been considered a major water reservoir in the deep Earth. Mass transfer across the transition-zone boundaries may transport water-rich minerals from the transition zone into the water-poor upper or lower mantle. Water release in the mantle surrounding the transition zone could cause dehydration melting and produce seismic low-velocity anomalies if some conditions are met. Therefore, seismic observations of low-velocity layers surrounding the transition zone could provide clues of water circulation at mid-mantle depths. Below the Alpine orogen, a depressed 660-km discontinuity has been imaged clearly using seismic tomography and receiver functions, suggesting downwellings of materials from the transition zone. Multitaper-correlation receiver functions show prominent ∼0.5-1.5% velocity reductions at ∼750-800-km depths, possibly caused by partial melting in the upper part of lower mantle. The gap between the depressed 660-km discontinuity and the low-velocity layers is consistent with metallic iron as a minor phase in the topmost lower mantle reported by laboratory studies. Velocity drops atop the 410-km discontinuity are observed surrounding the Alpine orogeny, suggesting upwelling of water-rich rock from the transition zone in response to the downwelled materials below the orogeny. Our results provide evidence that convective penetration of the mantle transition zone pushes hydrated minerals both upward and downward to add hydrogen to the surrounding mantle.

Agricultural conservation planning framework: 2. Classification of riparian buffer design types with application to assess and map stream corridors.

PubMed

Tomer, M D; Boomer, K M B; Porter, S A; Gelder, B K; James, D E; McLellan, E

2015-05-01

A watershed's riparian corridor presents opportunities to stabilize streambanks, intercept runoff, and influence shallow groundwater with riparian buffers. This paper presents a system to classify these riparian opportunities and apply them toward riparian management planning in hydrologic unit code 12 watersheds. In two headwater watersheds from each of three landform regions found in Iowa and Illinois, high-resolution (3-m grid) digital elevation models were analyzed to identify spatial distributions of surface runoff contributions and zones with shallow water tables (SWTs) (within 1.5 m of the channel elevation) along the riparian corridors. Results were tabulated, and a cross classification was applied. Classes of buffers include those primarily placed to (i) trap runoff and sediment, (ii) influence shallow groundwater, (iii) address both runoff and shallow groundwater, and (iv) maintain/improve stream bank stability. Riparian buffers occupying about 2.5% of these six watersheds could effectively intercept runoff contributions from 81 to 94% of the watersheds' contributing areas. However, extents of riparian zones where a narrow buffer (<10 m wide) would adequately intercept runoff but where >25 m width of buffer vegetation could root to a SWT varied according to landform region ( < 0.10). Yet, these wide-SWT riparian zones were widespread and occupied 23 to 53% of the lengths of stream banks among the six watersheds. The wide-SWT setting provides opportunities to reduce dissolved nutrients (particularly NO-N) carried via groundwater. This riparian classification and mapping system is part of a ArcGIS toolbox and could provide a consistent basis to identify riparian management opportunities in Midwestern headwater catchments wherever high-resolution elevation data are available. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Method for producing chemical energy

DOEpatents

Jorgensen, Betty S.; Danen, Wayne C.

2004-09-21

Fluoroalkylsilane-coated metal particles having a central metal core, a buffer layer surrounding the core, and a fluoroalkylsilane layer attached to the buffer layer are prepared by combining a chemically reactive fluoroalkylsilane compound with an oxide coated metal particle having a hydroxylated surface. The resulting fluoroalkylsilane layer that coats the particles provides them with excellent resistance to aging. The particles can be blended with oxidant particles to form energetic powder that releases chemical energy when the buffer layer is physically disrupted so that the reductant metal core can react with the oxidant.

Energetic powder

DOEpatents

Jorgensen, Betty S.; Danen, Wayne C.

2003-12-23

Fluoroalkylsilane-coated metal particles. The particles have a central metal core, a buffer layer surrounding the core, and a fluoroalkylsilane layer attached to the buffer layer. The particles may be prepared by combining a chemically reactive fluoroalkylsilane compound with an oxide coated metal particle having a hydroxylated surface. The resulting fluoroalkylsilane layer that coats the particles provides them with excellent resistance to aging. The particles can be blended with oxidant particles to form energetic powder that releases chemical energy when the buffer layer is physically disrupted so that the reductant metal core can react with the oxidant.

The Impact of DNAPL Source-Zone Architecture on Contaminant Mass Flux and Plume Evolution in Heterogeneous Porous Media

DTIC Science & Technology

2013-08-01

remediation, ISCO, permanganate , persistence, DNAPL 16. SECURITY CLASSIFICATION OF: U 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF...focus on the lower-K zone 2 and surrounding higher-K matrix sand during the constant permanganate injection………………………… 45 Figure 5.1.3-3...Photographic image of the lower-K zone 2 and surrounding area after permanganate injection, exhibiting the shadow zone downgradient of the lower-K zone

The combined effect of glass buffer strips and stitching on the damage tolerance of composites

NASA Technical Reports Server (NTRS)

Kullerd, Susan M.

1993-01-01

Recent research has demonstrated that through-the-thickness stitching provides major improvements in the damage tolerance of composite laminates loaded in compression. However, the brittle nature of polymer matrix composites makes them susceptible to damage propagation, requiring special material applications and designs to limit damage growth. Glass buffer strips, embedded within laminates, have shown the potential for improving the damage tolerance of unstitched composite laminates loaded in tension. The glass buffer strips, less stiff than the surrounding carbon fibers, arrest crack growth in composites under tensile loads. The present study investigates the damage tolerance characteristics of laminates that contain both stitching and glass buffer strips.

Degradation in landscape matrix has diverse impacts on diversity in protected areas

PubMed Central

Brotons, Lluís; Rajasärkkä, Ari; Tornberg, Risto

2017-01-01

Introduction A main goal of protected areas is to maintain species diversity and the integrity of biological assemblages. Intensifying land use in the matrix surrounding protected areas creates a challenge for biodiversity conservation. Earlier studies have mainly focused on taxonomic diversity within protected areas. However, functional and especially phylogenetic diversities are less studied phenomena, especially with respect to the impacts of the matrix that surrounds protected areas. Phylogenetic diversity refers to the range of evolutionary lineages, the maintenance of which ensures that future evolutionary potential is safeguarded. Functional diversity refers to the range of ecological roles that members of a community perform. For ecosystem functioning and long-term resilience, they are at least as important as taxonomic diversity. Aim We studied how the characteristics of protected areas and land use intensity in the surrounding matrix affect the diversity of bird communities in protected boreal forests. We used line-transect count and land-cover data from 91 forest reserves in Northern Finland, and land-cover data from buffer zones surrounding these reserves. We studied if habitat diversity and productivity inside protected areas, and intensity of forest management in the matrix have consistent effects on taxonomic, functional and phylogenetic diversities, and community specialization. Results We found that habitat diversity and productivity inside protected areas have strong effects on all diversity metrics, but matrix effects were inconsistent. The proportion of old forest in the matrix, reflecting low intensity forest management, had positive effects on community specialization. Interestingly, functional diversity increased with increasing logging intensity in the matrix. Conclusions Our results indicate that boreal forest reserves are not able to maintain their species composition and abundances if embedded in a severely degraded matrix. Our study also highlights the importance of focusing on different aspects of biodiversity. PMID:28950017

RIPARIAN BUFFER WIDTH, VEGETATIVE COVER, AND NITROGEN REMOVAL EFFECTIVENESS: A REVIEW OF CURRENT SCIENCE AND REGULATIONS

EPA Science Inventory

Riparian zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Buffer width may be positively related to nitrogen removal efficiency by influencing nitrogen retention throug...

INFLUENCE OF BORATE BUFFERS ON THE ELECTROPHORETIC BEHAVIOR OF HUMIC SUBSTANCES IN CAPILLARY ZONE ELECTROPHORESIS

EPA Science Inventory

The influence of tetrahydroxyborate ions on the electrophoretic mobility of humic acids was evaluated by capillary electrophoresis (CE). Depending on the molarity of borate ions in the separation buffer, the humic acids exhibit electropherograms with sharp peaks consistently exte...

A simple method to identify areas of environmental risk due to manure application.

PubMed

Flores, Héctor; Arumí, José Luis; Rivera, Diego; Lagos, L Octavio

2012-06-01

The management of swine manure is becoming an important environmental issue in Chile. One option for the final disposal of manure is to use it as a biofertilizer, but this practice could impact the surrounding environment. To assess the potential environmental impacts of the use of swine manure as a biofertilizer, we propose a method to identify zones of environmental risk through indices. The method considers two processes: nutrient runoff and solute leaching, and uses available information about soils, crops and management practices (irrigation, fertilization, and rotation). We applied the method to qualitatively assess the environmental risk associated with the use of swine manure as a biofertilizer in an 8,000-pig farm located in Central Chile. Results showed that the farm has a moderate environmental risk, but some specific locations have high environmental risks, especially those associated with impacts on areas surrounding water resources. This information could assist the definition of better farm-level management practices, as well as the preservation of riparian vegetation acting as buffer strips. The main advantage of our approach is that it combines qualitative and quantitative information, including particular situations or field features based on expert knowledge. The method is flexible, simple, and can be easily extended or adapted to other processes.

Using Aerial Photography to Estimate Riparian Zone Impacts in a Rapidly Developing River Corridor

NASA Astrophysics Data System (ADS)

Owers, Katharine A.; Albanese, Brett; Litts, Thomas

2012-03-01

Riparian zones are critical for protecting water quality and wildlife, but are often impacted by human activities. Ongoing threats and uncertainty about the effectiveness of buffer regulations emphasize the importance of monitoring riparian buffers through time. We developed a method to rapidly categorize buffer width and landuse attributes using 2007 leaf-on aerial photography and applied it to a 65 km section of the Toccoa River in north Georgia. We repeated our protocol using 1999 leaf-off aerial photographs to assess the utility of our approach for monitoring. Almost half (45%) of the length of the Toccoa River was bordered by buffers less than 50 ft wide in 2007, with agricultural and built-up lands having the smallest buffers. The percentage of river length in each buffer width category changed little between 1999 and 2007, but we did detect a 5% decrease in agricultural land use, a corresponding increase in built-up land use, and an additional 149 buildings within 100 ft of the river. Field verification indicated that our method overestimated buffer widths and forested land use and underestimated built-up land use and the number of buildings within 100 ft of the river. Our methodology can be used to rapidly assess the status of riparian buffers. Including supplemental data (e.g., leaf-off imagery, road layers) will allow detection of the fine-scale impacts underestimated in our study. Our results on the Toccoa River reflect historic impacts, exemptions and variances to regulations, and the ongoing threat of vacation home development. We recommend additional monitoring, improvements in policy, and efforts to increase voluntary protection and restoration of stream buffers.

Using aerial photography to estimate riparian zone impacts in a rapidly developing river corridor.

PubMed

Owers, Katharine A; Albanese, Brett; Litts, Thomas

2012-03-01

Riparian zones are critical for protecting water quality and wildlife, but are often impacted by human activities. Ongoing threats and uncertainty about the effectiveness of buffer regulations emphasize the importance of monitoring riparian buffers through time. We developed a method to rapidly categorize buffer width and landuse attributes using 2007 leaf-on aerial photography and applied it to a 65 km section of the Toccoa River in north Georgia. We repeated our protocol using 1999 leaf-off aerial photographs to assess the utility of our approach for monitoring. Almost half (45%) of the length of the Toccoa River was bordered by buffers less than 50 ft wide in 2007, with agricultural and built-up lands having the smallest buffers. The percentage of river length in each buffer width category changed little between 1999 and 2007, but we did detect a 5% decrease in agricultural land use, a corresponding increase in built-up land use, and an additional 149 buildings within 100 ft of the river. Field verification indicated that our method overestimated buffer widths and forested land use and underestimated built-up land use and the number of buildings within 100 ft of the river. Our methodology can be used to rapidly assess the status of riparian buffers. Including supplemental data (e.g., leaf-off imagery, road layers) will allow detection of the fine-scale impacts underestimated in our study. Our results on the Toccoa River reflect historic impacts, exemptions and variances to regulations, and the ongoing threat of vacation home development. We recommend additional monitoring, improvements in policy, and efforts to increase voluntary protection and restoration of stream buffers.

Do Riparian Buffers Protect Stream Invertebrate Communities in South American Atlantic Forest Agricultural Areas?

PubMed

Hunt, L; Marrochi, N; Bonetto, C; Liess, M; Buss, D F; Vieira da Silva, C; Chiu, M-C; Resh, V H

2017-12-01

We investigated the influence and relative importance of insecticides and other agricultural stressors in determining variability in invertebrate communities in small streams in intensive soy-production regions of Brazil and Paraguay. In Paraguay we sampled 17 sites on tributaries of the Pirapó River in the state of Itapúa and in Brazil we sampled 18 sites on tributaries of the San Francisco River in the state of Paraná. The riparian buffer zones generally contained native Atlantic forest remnants and/or introduced tree species at various stages of growth. In Brazil the stream buffer width was negatively correlated with sediment insecticide concentrations and buffer width was found to have moderate importance in mitigating effects on some sensitive taxa such as mayflies. However, in both regions insecticides had low relative importance in explaining variability in invertebrate communities, while various habitat parameters were more important. In Brazil, the percent coverage of soft depositional sediment in streams was the most important agriculture-related explanatory variable, and the overall stream-habitat score was the most important variable in Paraguay streams. Paraguay and Brazil both have laws requiring forested riparian buffers. The ample forested riparian buffer zones typical of streams in these regions are likely to have mitigated the effects of pesticides on stream invertebrate communities. This study provides evidence that riparian buffer regulations in the Atlantic Forest region are protecting stream ecosystems from pesticides and other agricultural stressors. Further studies are needed to determine the minimum buffer widths necessary to achieve optimal protection.

Identifying riparian zones appropriate for installation of saturated buffers: A multi-watershed assessment

USDA-ARS?s Scientific Manuscript database

Saturated riparian buffers are a new type of conservation practice that divert a portion of subsurface tile drainage from discharge to surface water into distribution pipes that discharge tile water into riparian soils. This enables natural processes of biological uptake and denitrification to decre...

RIPARIAN BUFFER WIDTH, VEGETATIVE COVER, AND NITROGEN REMOVAL EFFECTIVENESS: A REVIEW OF CURRENT SCIENCE AND REGULATIONS

EPA Science Inventory

Riparian zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Buffer width may be related to nitrogen removal efficiency by influencing nitrogen retention through plant seq...

Integration of multi-source and multi-scale datasets for 3D structural modeling for subsurface exploration targeting, Luanchuan Mo-polymetallic district, China

NASA Astrophysics Data System (ADS)

Wang, Gongwen; Ma, Zhenbo; Li, Ruixi; Song, Yaowu; Qu, Jianan; Zhang, Shouting; Yan, Changhai; Han, Jiangwei

2017-04-01

In this paper, multi-source (geophysical, geochemical, geological and remote sensing) datasets were used to construct multi-scale (district-, deposit-, and orebody-scale) 3D geological models and extract 3D exploration criteria for subsurface Mo-polymetallic exploration targeting in the Luanchuan district in China. The results indicate that (i) a series of region-/district-scale NW-trending thrusts controlled main Mo-polymetallic forming, and they were formed by regional Indosinian Qinling orogenic events, the secondary NW-trending district-scale folds and NE-trending faults and the intrusive stock structure are produced based on thrust structure in Caledonian-Indosinian orogenic events; they are ore-bearing zones and ore-forming structures; (ii) the NW-trending district-scale and NE-trending deposit-scale normal faults were crossed and controlled by the Jurassic granite stocks in 3D space, they are associated with the magma-skarn Mo polymetallic mineralization (the 3D buffer distance of ore-forming granite stocks is 600 m) and the NW-trending hydrothermal Pb-Zn deposits which are surrounded by the Jurassic granite stocks and constrained by NW-trending or NE-trending faults (the 3D buffer distance of ore-forming fault is 700 m); and (iii) nine Mo polymetallic and four Pb-Zn targets were identified in the subsurface of the Luanchuan district.

Wetlands, climate zones and Barmah Forest virus disease in Queensland, Australia.

PubMed

Naish, Suchithra; Mengersen, Kerrie; Hu, Wenbiao; Tong, Shilu

2012-12-01

Barmah Forest virus (BFV) disease is the second most common mosquito-borne disease in Australia, but the linkages of the wetlands and climate zones with BFV transmission remain unclear. We aimed to examine the relationship between the wetlands, climate zones and BFV risk in Queensland, Australia. Data on the wetlands, climate zones, population and BFV cases for the period 1992 to 2008 were obtained from relevant government agencies. BFV risk was grouped as low-, medium- and high-level based on BFV incidence percentiles. The buffer zones around each BFV case were made using 1, 5, 10, 15, 20, 25 and 50km distances. We performed a discriminant analysis to determine the differences between wetland classes and BFV risk within each climate zone. The discriminant analyses show that saline 1, riverine and saline tidal influence were the most significant contributors to BFV risk in all climate and buffer zones, while lacustrine, palustrine, estuarine and saline 2 and saline 3 wetlands were less important. These models had classification accuracies of 76%, 98% and 100% for BFV risk in subtropical, tropical and temperate climate zones, respectively. This study demonstrates that BFV risk varies with wetland class and climate zone. The discriminant analysis is a useful tool to quantify the links between wetlands, climate zones and BFV risk. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Methods for improved growth of group III nitride buffer layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro

Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphologymore » of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).« less

Remote Sensing of Wildland Fire-Induced Risk Assessment at the Community Level.

PubMed

Ahmed, M Razu; Rahaman, Khan Rubayet; Hassan, Quazi K

2018-05-15

Wildland fires are some of the critical natural hazards that pose a significant threat to the communities located in the vicinity of forested/vegetated areas. In this paper, our overall objective was to study the structural damages due to the 2016 Horse River Fire (HRF) that happened in Fort McMurray (Alberta, Canada) by employing primarily very high spatial resolution optical satellite data, i.e., WorldView-2. Thus, our activities included the: (i) estimation of the structural damages; and (ii) delineation of the wildland-urban interface (WUI) and its associated buffers at certain intervals, and their utilization in assessing potential risks. Our proposed method of remote sensing-based estimates of the number of structural damages was compared with the ground-based information available from the Planning and Development Recovery Committee Task Force of Regional Municipality of Wood Buffalo (RMWB); and found a strong linear relationship (i.e., r² value of 0.97 with a slope of 0.97). Upon delineating the WUI and its associated buffer zones at 10 m, 30 m, 50 m, 70 m and 100 m distances; we found existence of vegetation within the 30 m buffers from the WUI for all of the damaged structures. In addition, we noticed that the relevant authorities had removed vegetation in some areas between 30 m and 70 m buffers from the WUI, which was proven to be effective in order to protect the structures in the adjacent communities. Furthermore, we mapped the wildland fire-induced vulnerable areas upon considering the WUI and its associated buffers. Our analysis revealed that approximately 30% of the areas within the buffer zones of 10 m and 30 m were vulnerable due to the presence of vegetation; in which, approximately 7% were burned during the 2016 HRF event that led the structural damages. Consequently, we suggest to remove the existing vegetation within these critical zones and also monitor the region at a regular interval in order to reduce the wildland fire-induced risk.

Plasma discharge elemental detector for a mass spectrometer

NASA Astrophysics Data System (ADS)

Heppner, R. A.

1983-06-01

A material to be analyzed is injected into a mirowave-induced plasma discharge unit, in which the material is carried with a flow of buffer gas through an intense microwave energy field which produces a plasma discharge in the buffer gas. As the material exits from the plasma discharge, the material is sampled and conveyed along a capillary transfer tube to a mass spectrometer where it is analyzed. The plasma discharge causes dissociation of complex organic molecules into simpler molecules which return to the neutral ground state before they are analyzed in the mass spectrometer. The buffer gas is supplied to one end portion of the discharge tube and is withdrawn from the other end portion by a vacuum pump which maintains a subatmospheric pressure in the discharge tube. The sample material is injected by a capillary injection tube into the buffer gas flow as it enters the plasma discharge zone. The dissociated materials are sampled by an axial sampling tube having an entrance where the buffer gas exits from the plasma discharge zone. The sample material may be supplied by a gas chromatography having a capillary effluent line connected to the capillary injection tube, so that the effluent material is injected into the microwave induced plasma discharge. The microwave field is produced by a cavity resonator through which the discharge tube passes.

Simultaneous determination of phenylethanoid glycosides and aglycones by capillary zone electrophoresis with running buffer modifier.

PubMed

Dong, Shuqing; Gao, Ruibin; Yang, Yan; Guo, Mei; Ni, Jingman; Zhao, Liang

2014-03-15

Although the separation efficiency of capillary electrophoresis (CE) is much higher than that of other chromatographic methods, it is sometimes difficult to adequately separate the complex ingredients in biological samples. This article describes how one effective and simple way to develop the separation efficiency in CE is to add some modifiers to the running buffer. The suitable running buffer modifier β-cyclodextrin (β-CD) was explored to fast and completely separate four phenylethanoid glycosides and aglycones (homovanillyl alcohol, hydroxytyrosol, 3,4-dimethoxycinnamic acid, and caffeic acid) in Lamiophlomis rotata (Lr) and Cistanche by capillary zone electrophoresis with ultraviolet (UV) detection. It was found that when β-CD was used as running buffer modifier, a baseline separation of the four analytes could be accomplished in less than 20 min and the detection limits were as low as 10(-3) mg L(-1). Other factors affecting the CE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage, and sample injection time, were investigated extensively. Under the optimal conditions, a successful practical application on the determination of Lr and Cistanche samples confirmed the validity and practicability of this method. Copyright © 2014 Elsevier Inc. All rights reserved.

Green space definition affects associations of green space with overweight and physical activity.

PubMed

Klompmaker, Jochem O; Hoek, Gerard; Bloemsma, Lizan D; Gehring, Ulrike; Strak, Maciej; Wijga, Alet H; van den Brink, Carolien; Brunekreef, Bert; Lebret, Erik; Janssen, Nicole A H

2018-01-01

In epidemiological studies, exposure to green space is inconsistently associated with being overweight and physical activity, possibly because studies differ widely in their definition of green space exposure, inclusion of important confounders, study population and data analysis. We evaluated whether the association of green space with being overweight and physical activity depended upon definition of greenspace. We conducted a cross-sectional study using data from a Dutch national health survey of 387,195 adults. Distance to the nearest park entrance and surrounding green space, based on the Normalized Difference Vegetation Index (NDVI) or a detailed Dutch land-use database (TOP10NL), was calculated for each residential address. We used logistic regression analyses to study the association of green space exposure with being overweight and being moderately or vigorously physically active outdoors at least 150min/week (self-reported). To study the shape of the association, we specified natural splines and quintiles. The distance to the nearest park entrance was not associated with being overweight or outdoor physical activity. Associations of surrounding green space with being overweight or outdoor physical activity were highly non-linear. For NDVI surrounding greenness, we observed significantly decreased odds of being overweight [300m buffer, odds ratio (OR) = 0.88; 95% CI: 0.86, 0.91] and increased odds for outdoor physical activity [300m buffer, OR = 1.14; 95% CI: 1.10, 1.17] in the highest quintile compared to the lowest quintile. For TOP10NL surrounding green space, associations were mostly non-significant. Associations were generally stronger for subjects living in less urban areas and for the smaller buffers. Associations of green space with being overweight and outdoor physical activity differed considerably between different green space definitions. Associations were strongest for NDVI surrounding greenness. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Role of Remote Sensing and Geographyc Information System Mapping for Protected Areas Land Rice Field Subak, Buffer Zones, and Area Conversion (Case Studies In Gianyar Regency, Bali Province)

NASA Astrophysics Data System (ADS)

Lanya, Indayati; Netera Subadiyasa, N.

2016-11-01

Conversion of rice fields in Bali 2579 ha/year, Law Number 41 of 2009 [1] and five of Government Regulation (GR), mandates the Local Government (LG) has a Regional Regulation (RR) or Rule Regent/Mayor, on the protection of agricultural land sustainable food (PALSF). Yet none provincial government of Bali has PALSF; although Subak as world cultural heritage. Similarly, Gianyar regency development strategy directed to integrate agriculture with tourism. Landsat 8 images, Word View Coverage 2015 Gianyar district and ArcGIS 10.3 software used for of rice field mapping and zoning of land protection Subak. Ten thematic maps (watersheds, land use, irrigation, relief/slope, rainfall, spatial planning, land suitability, productivity, the distance from downtown) as a variable parameter, weighted and balanced numerically. Numerical classification agricultura land using for the overlay menu and reselek. The total value of >125 as rice need to be protected, 100-125 value for buffer zone, and the value of <100 rice fields can be converted to 40 next year. For the 20 next year, the total value of> 100, 50-100 and <50 respectively to rice fields that need to be protected, wetland buffer, and rice fields can be converted. Region Subak sustainable of rice field protection, buffer and can be converted in a row for the next 20 years is 10973 ha, 3855 ha and 311 ha. For the next 40 years Subak conserved of rice field (8019 ha), buffer (5855 ha), and can be converted (3124 ha). Subak land pattern of spread can be converted to an supply of land for non-agricultural development of the region downstream to the access road Ida Bagus Matera (Jln. Province / national) in the coastal areas of Gianyar.

Scale effects on spatially varying relationships between urban landscape patterns and water quality.

PubMed

Sun, Yanwei; Guo, Qinghai; Liu, Jian; Wang, Run

2014-08-01

Scientific interpretation of the relationships between urban landscape patterns and water quality is important for sustainable urban planning and watershed environmental protection. This study applied the ordinary least squares regression model and the geographically weighted regression model to examine the spatially varying relationships between 12 explanatory variables (including three topographical factors, four land use parameters, and five landscape metrics) and 15 water quality indicators in watersheds of Yundang Lake, Maluan Bay, and Xinglin Bay with varying levels of urbanization in Xiamen City, China. A local and global investigation was carried out at the watershed-level, with 50 and 200 m riparian buffer scales. This study found that topographical features and landscape metrics are the dominant factors of water quality, while land uses are too weak to be considered as a strong influential factor on water quality. Such statistical results may be related with the characteristics of land use compositions in our study area. Water quality variations in the 50 m buffer were dominated by topographical variables. The impact of landscape metrics on water quality gradually strengthen with expanding buffer zones. The strongest relationships are obtained in entire watersheds, rather than in 50 and 200 m buffer zones. Spatially varying relationships and effective buffer zones were verified in this study. Spatially varying relationships between explanatory variables and water quality parameters are more diversified and complex in less urbanized areas than in highly urbanized areas. This study hypothesizes that all these varying relationships may be attributed to the heterogeneity of landscape patterns in different urban regions. Adjustment of landscape patterns in an entire watershed should be the key measure to successfully improving urban lake water quality.

Assessing the ecological benefits and opportunity costs of alternative stream management zone widths for eastern hardwoods

Treesearch

Chris B. LeDoux; Ethel Wilkerson

2008-01-01

Leaving buffer zones adjacent to waterways can effectively reduce the water quality concerns associated with timber harvesting. However, riparian areas are also some of the most productive sites and can yield high quality wood. The amount of unharvested timber left in SMZs (Streamside Management Zones) can represent a substantial opportunity cost to landowners. In this...

Assessing the ecological benefits and opportunity costs of alternative stream management zone widths

Treesearch

Chris B. LeDoux; Ethel Wilkerson

2008-01-01

Leaving buffer zones adjacent to waterways can effectively reduce the water quality concerns associated with timber harvesting. However, riparian areas are also some of the most productive sites and can yield high quality wood. The amount of unharvested timber left in SMZs (Streamside Management Zones) can represent a substantial opportunity cost to landowners. In this...

Tularosa Basin Play Fairway Analysis: Partial Basin and Range Heat and Zones of Critical Stress Maps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adam Brandt

Interpolated maps of heat flow, temperature gradient, and quartz geothermometers are included as TIF files. Zones of critical stress map is also included as a TIF file. The zones are given a 5km diameter buffer. The study area is only a part of the Basin and Range, but it does includes the Tularosa Basin.

On buffer layers as non-reflecting computational boundaries

NASA Technical Reports Server (NTRS)

Hayder, M. Ehtesham; Turkel, Eli L.

1996-01-01

We examine an absorbing buffer layer technique for use as a non-reflecting boundary condition in the numerical simulation of flows. One such formulation was by Ta'asan and Nark for the linearized Euler equations. They modified the flow inside the buffer zone to artificially make it supersonic in the layer. We examine how this approach can be extended to the nonlinear Euler equations. We consider both a conservative and a non-conservative form modifying the governing equations in the buffer layer. We compare this with the case that the governing equations in the layer are the same as in the interior domain. We test the effectiveness of these buffer layers by a simulation of an excited axisymmetric jet based on a nonlinear compressible Navier-Stokes equations.

Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.

PubMed

Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

2015-03-01

The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Corrosion Effects on the Fatigue Crack Propagation of Giga-Grade Steel and its Heat Affected Zone in pH Buffer Solutions for Automotive Application

NASA Astrophysics Data System (ADS)

Lee, H. S.

2018-03-01

Corrosion fatigue crack propagation test was conducted of giga-grade steel and its heat affected zone in pH buffer solutions, and the results were compared with model predictions. Pure corrosion effect on fatigue crack propagation, particularly, in corrosive environment was evaluated by means of the modified Forman equation. As shown in results, the average corrosion rate determined from the ratio of pure corrosion induced crack length to entire crack length under a cycle load were 0.11 and 0.37 for base metal and heat affected zone, respectively, with load ratio of 0.5, frequency of 0.5 and pH 10.0 environment. These results demonstrate new interpretation methodology for corrosion fatigue crack propagation enabling the pure corrosion effects on the behavior to be determined.

Constraints on Development of Wind Energy in Poland due to Environmental Objectives. Is There Space in Poland for Wind Farm Siting?

PubMed

Hajto, Małgorzata; Cichocki, Zdzisław; Bidłasik, Małgorzata; Borzyszkowski, Jan; Kuśmierz, Agnieszka

2017-02-01

The objective of the study was to evaluate spatial effects of adopting environmental criteria for wind farm siting, i.e., the criteria related to the settlement system and those with regards to landscape values. The set of criteria was elaborated on the basis of literature and experience-based knowledge. Some of the criteria selected are legally binding. The analyses were carried out with the use of GIS tools. Settlement areas with 1000 and 2000 m wide buffer zones, and the areas with the highest landscape values, were assumed as particularly sensitive receptors to wind farm impacts. The results show significant constraints on wind farm siting in Poland. Although the constraints are regionally diversified, they concern 93.9 % of the total country area (1000 m buffer zone) or 99.1 % (2000 m buffer zone). Presumably even greater constraints would be revealed by an additional detailed analysis at a local level. The constraints on wind farm siting in Poland cannot be decreased, because of both social attitudes and demand for appropriate environmental standards, which should be taken into account in spatial and energy policies at all decision making level.

Climate regulation, energy provisioning and water purification: Quantifying ecosystem service delivery of bioenergy willow grown on riparian buffer zones using life cycle assessment.

PubMed

Styles, David; Börjesson, Pål; D'Hertefeldt, Tina; Birkhofer, Klaus; Dauber, Jens; Adams, Paul; Patil, Sopan; Pagella, Tim; Pettersson, Lars B; Peck, Philip; Vaneeckhaute, Céline; Rosenqvist, Håkan

2016-12-01

Whilst life cycle assessment (LCA) boundaries are expanded to account for negative indirect consequences of bioenergy such as indirect land use change (ILUC), ecosystem services such as water purification sometimes delivered by perennial bioenergy crops are typically neglected in LCA studies. Consequential LCA was applied to evaluate the significance of nutrient interception and retention on the environmental balance of unfertilised energy willow planted on 50-m riparian buffer strips and drainage filtration zones in the Skåne region of Sweden. Excluding possible ILUC effects and considering oil heat substitution, strategically planted filter willow can achieve net global warming potential (GWP) and eutrophication potential (EP) savings of up to 11.9 Mg CO 2 e and 47 kg PO 4 e ha -1 year -1 , respectively, compared with a GWP saving of 14.8 Mg CO 2 e ha -1 year -1 and an EP increase of 7 kg PO 4 e ha -1 year -1 for fertilised willow. Planting willow on appropriate buffer and filter zones throughout Skåne could avoid 626 Mg year -1 PO 4 e nutrient loading to waters.

Combining SAR with LANDSAT for Change Detection of Riparian Buffer Zone in a Semi-arid River Basin

NASA Astrophysics Data System (ADS)

Chang, N.

2006-12-01

A combination of RADARSAT-1 and Landsat 5 TM satellite images linking the soil moisture variation with Normalized Difference Vegetation Index (NDVI) measurements were used to accomplish remotely sensed change detection of riparian buffer zone in the Choke Canyon Reservoir Watershed (CCRW), South Texas. The CCRW was selected as the study area contributing to the reservoir, which is mostly agricultural and range land in a semi-arid coastal environment. This makes the study significant due to the interception capability of non-point source impact within the riparian buffer zone and the maintenance of ecosystem integrity region wide. First of all, an estimation of soil moisture using RADARSAT-1 Synthetic Aperture Radar (SAR) satellite imagery was conducted. With its all-weather capability, the RADARSAT-1 is a promising tool for measuring the surface soil moisture over seasons. The time constraint is almost negligible since the RADARSAT-1 is able to capture surface soil moisture over a large area in a matter of seconds, if the area is within its swath. RADARSAT-1 images presented at here were captured in two acquisitions, including April and September 2004. With the aid of five corner reflectors deployed by Alaska Satellite Facility (ASF), essential radiometric and geometric calibrations were performed to improve the accuracy of the SAR imagery. The horizontal errors were reduced from initially 560 meter down to less than 5 meter at the best try. Then two Landsat 5 TM satellite images were summarized based on its NDVI. The combination of and NDVI and SAR data obviously show that soil moisture and vegetation biomass wholly varies in space and time in the CCRW leading to identify the riparian buffer zone evolution over seasons. It is found that the seasonal soil moisture variation is highly tied with the NDVI values and the change detection of buffer zone is technically feasible. It will contribute to develop more effective management strategies for non-point source pollution control, bird habitat monitoring, and grazing and live stock handlings in the future. Future research focuses on comparison of soil moisture variability within RADARSAT-1 footprints and NDVI variations against interferometric SAR for studying riparian ecosystem functioning on a seasonal basis.

An inventory survey at the site of the proposed Kilauea Middle East Rift Zone (KMERZ), Well Site No. 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, Joseph

1991-03-01

At the request of True Mid Pacific Geothermal, Archaeological Consultants of Hawaii, Inc. has conducted an inventory survey at the site of the proposed Kilauea Middle East Rift Zone (KMERZ), Well Site No.2, TMK: 1-2-10:3. The Principal Investigator was Joseph Kennedy M.A., assisted by Jacob Kaio, Field Supervisor and field crew Mark Borrello B.A., Michael O'Shaughnessy B.A., and Randy Adric. This report supercedes all previous reports submitted to the Historic Presentation Section of the Department of Land and Natural Resources. In addition to 100% surface coverage of the 400 x 400 foot well pad itself, 100% surface coverage of amore » substantial buffer zone was also completed. This buffer zone was established by the Department of Land and Natural Resources, Historic Preservation personnel and extends 1000 feet east and west of the well site and 500 feet north and south of the well site.« less

a Buffer Analysis Based on Co-Location Algorithm

NASA Astrophysics Data System (ADS)

Zhou, G.; Huang, S.; Wang, H.; Zhang, R.; Wang, Q.; Sha, H.; Liu, X.; Pan, Q.

2018-05-01

Buffer analysis is a common tool of spatial analysis, which deals with the problem of proximity in GIS. Buffer analysis researches the relationship between the center object and other objects around a certain distance. Buffer analysis can make the complicated problem be more scientifically and visually, and provide valuable information for users. Over the past decades, people have done a lot of researches on buffer analysis. Along with the constantly improvement of spatial analysis accuracy needed by people, people hope that the results of spatial analysis can be more exactly express the actual situation. Due to the influence of some certain factors, the impact scope and contact range of a geographic elements on the surrounding objects are uncertain. As all we know, each object has its own characteristics and changing rules in the nature. They are both independent and relative to each other. However, almost all the generational algorithms of existing buffer analysis are based on fixed buffer distance, which do not consider the co-location relationship among instances. Consequently, it is a waste of resource to retrieve the useless information, and useful information is ignored.

Plasma-catalyzed fuel reformer

DOEpatents

Hartvigsen, Joseph J.; Elangovan, S.; Czernichowski, Piotr; Hollist, Michele

2013-06-11

A reformer is disclosed that includes a plasma zone to receive a pre-heated mixture of reactants and ionize the reactants by applying an electrical potential thereto. A first thermally conductive surface surrounds the plasma zone and is configured to transfer heat from an external heat source into the plasma zone. The reformer further includes a reaction zone to chemically transform the ionized reactants into synthesis gas comprising hydrogen and carbon monoxide. A second thermally conductive surface surrounds the reaction zone and is configured to transfer heat from the external heat source into the reaction zone. The first thermally conductive surface and second thermally conductive surface are both directly exposed to the external heat source. A corresponding method and system are also disclosed and claimed herein.

50 CFR 216.184 - Mitigation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Frequency Active (SURTASS LFA sonar) Sonar § 216.184 Mitigation. The activity identified in § 216.180(a....54 nm) buffer zone extending beyond the 180-dB zone), SURTASS LFA sonar transmissions will be... active acoustic monitoring described in § 216.185. (c) The high-frequency marine mammal monitoring sonar...

50 CFR 216.184 - Mitigation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Frequency Active (SURTASS LFA sonar) Sonar § 216.184 Mitigation. The activity identified in § 216.180(a....54 nm) buffer zone extending beyond the 180-dB zone), SURTASS LFA sonar transmissions will be... active acoustic monitoring described in § 216.185. (c) The high-frequency marine mammal monitoring sonar...

Sustainability: Land Management

DTIC Science & Technology

2012-05-24

8217. .’" , .. . . . . Aqula Harbour , , MCB Quantico Notification Area MMF Legend Flight Tracks - FixedW1ng - Rot;wy Wing TBS :::_-, FIXed Wing Alea ...Rot;wy Wing Alea TBS Rotary Wing /Vea lmpuln Noise Buffer SMile APZ~l Range Safety Zone C Range Safety Zone A IZ2Zl Corr4losile Su1ace

Blast dynamics at Mount St Helens on 18 May 1980

USGS Publications Warehouse

Kieffer, S.W.

1981-01-01

At 8.32 a.m. on 18 May 1980, failure of the upper part of the north slope of Mount St Helens triggered a lateral eruption ('the blast') that devastated the conifer forests in a sector covering ???500 km2 north of the volcano. I present here a steady flow model for the blast dynamics and propose that through much of the devastated area the blast was a supersonic flow of a complex multiphase (solid, liquid, vapour) mixture. The shape of the blast zone; pressure, temperature, velocity (Mach number) and density distributions within the flow; positions of weak and strong internal shocks; and mass flux, energy flux, and total energy are calculated. The shape of blast zone was determined by the initial areal expansion from the reservoir, by internal expansion and compression waves (including shocks), and by the density of the expanding mixture. The pressure within the flow dropped rapidly away from the source of the blast until, at a distance of ???11 km, the flow became underpressured relative to the surrounding atmosphere. Weak shocks within the flow subparallel to the east and west margins coalesced at about this distance into a strong Mach disk shock, across which the flow velocities would have dropped from supersonic to subsonic as the pressure rose back towards ambient. The positions of the shocks may be reflected in differences in the patterns of felled trees. At the limits of the devastated area, the temperature had dropped only 20% from the reservoir temperature because the entrained solids thermally buffered the flow (the dynamic and thermodynamic effects of the admixture of the surrounding atmosphere and the uprooted forest and soils into the flow are not considered). The density of the flow decreased with distance until, at the limits of the blast zone, 20-25 km from the volcano, the density became comparable with that of the surrounding (dirty) atmosphere and the flow became buoyant and ramped up into the atmosphere. According to the model, the mass flux per unit area at the source was 0.6 ?? 104 g s-1 cm-2 and the energy flux per unit area was 2.5 MW cm-2. From the measured total ejected mass, 0.25 ?? 1015 g, the total energy released during the eruption was 1024 erg or 24 megatons. The model, triggering of the eruption and the transition from unsteady to steady flow, and applications to eyewitness observations and atmospheric effects are discussed in ref. 1. ?? 1981 Nature Publishing Group.

Tailoring the strain in Si nano-structures for defect-free epitaxial Ge over growth.

PubMed

Zaumseil, P; Yamamoto, Y; Schubert, M A; Capellini, G; Skibitzki, O; Zoellner, M H; Schroeder, T

2015-09-04

We investigate the structural properties and strain state of Ge nano-structures selectively grown on Si pillars of about 60 nm diameter with different SiGe buffer layers. A matrix of TEOS SiO2 surrounding the Si nano-pillars causes a tensile strain in the top part at the growth temperature of the buffer that reduces the misfit and supports defect-free initial growth. Elastic relaxation plays the dominant role in the further increase of the buffer thickness and subsequent Ge deposition. This method leads to Ge nanostructures on Si that are free from misfit dislocations and other structural defects, which is not the case for direct Ge deposition on these pillar structures. The Ge content of the SiGe buffer is thereby not a critical parameter; it may vary over a relatively wide range.

Fuel injection staged sectoral combustor for burning low-BTU fuel gas

DOEpatents

Vogt, Robert L.

1981-01-01

A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone; this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe; swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone; this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

Fuel injection staged sectoral combustor for burning low-BTU fuel gas

DOEpatents

Vogt, Robert L.

1985-02-12

A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone: this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe: swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone: this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

Study of the plastic zone around the ligament of thin sheet D.E.N.T specimen subjected to tensile

NASA Astrophysics Data System (ADS)

Djebali, S.; Larbi, S.; Bilek, A.

2015-03-01

One of the assumptions of Cotterell and Reddel's method of the essential work of fracture determination is the existence of a fracture process zone surrounded by an outer plastic zone extending to the whole ligament before crack initiation. To verify this hypothesis we developed a method based on micro hardness. The hardness values measured in the domain surrounding the tensile fracture area of ST-37-2 steel sheet D.E.N.T specimens confirm the existence of the two plastic zones. The extension of the plastic deformations to the whole ligament before the crack initiation and the circular shape of the outer plastic zone are revealed by the brittle coating method.

Fast separation and determination of tyrosol, hydroxytyrosol and other phenolic compounds in extra-virgin olive oil by capillary zone electrophoresis with ultraviolet-diode array detection.

PubMed

Bonoli, Matteo; Montanucci, Marina; Gallina Toschi, Tullia; Lercker, Giovanni

2003-09-05

Olive oil is the main source of fat in the Mediterranean diet, and its consumption has been related to a low incidence of coronary heart disease and certain cancers. Recent findings demonstrate that olive oil phenolics are powerful in vitro and in vivo antioxidants and display other biological activities that could partially account for the observed healthful effects of the Mediterranean diet. A detailed method optimization plan was carried out to separate the most popular phenols in olive oil for four separation parameters: buffer concentration, buffer pH, applied voltage and temperature. Consequently, an analytical method capable of separating 21 different phenols and polyphenols by capillary zone electrophoresis was developed; the separation was performed within 10 min, using a 40 cm x 50 microm capillary, with a 45 mM sodium tetraborate buffer (pH 9.60), at 27 kV and 30 degrees C. The optimized method was applied to methanolic extracts of several Italian extra-virgin olive oils obtained by different technologies in order to characterize and to compare their antioxidant profile. Positive correlations of phenolic compounds found by capillary zone electrophoresis (CZE) and two colorimetric indexes (total polyphenols and o-diphenols) were found and discussed.

Remote Sensing of Wildland Fire-Induced Risk Assessment at the Community Level

PubMed Central

Hassan, Quazi K.

2018-01-01

Wildland fires are some of the critical natural hazards that pose a significant threat to the communities located in the vicinity of forested/vegetated areas. In this paper, our overall objective was to study the structural damages due to the 2016 Horse River Fire (HRF) that happened in Fort McMurray (Alberta, Canada) by employing primarily very high spatial resolution optical satellite data, i.e., WorldView-2. Thus, our activities included the: (i) estimation of the structural damages; and (ii) delineation of the wildland-urban interface (WUI) and its associated buffers at certain intervals, and their utilization in assessing potential risks. Our proposed method of remote sensing-based estimates of the number of structural damages was compared with the ground-based information available from the Planning and Development Recovery Committee Task Force of Regional Municipality of Wood Buffalo (RMWB); and found a strong linear relationship (i.e., r2 value of 0.97 with a slope of 0.97). Upon delineating the WUI and its associated buffer zones at 10 m, 30 m, 50 m, 70 m and 100 m distances; we found existence of vegetation within the 30 m buffers from the WUI for all of the damaged structures. In addition, we noticed that the relevant authorities had removed vegetation in some areas between 30 m and 70 m buffers from the WUI, which was proven to be effective in order to protect the structures in the adjacent communities. Furthermore, we mapped the wildland fire-induced vulnerable areas upon considering the WUI and its associated buffers. Our analysis revealed that approximately 30% of the areas within the buffer zones of 10 m and 30 m were vulnerable due to the presence of vegetation; in which, approximately 7% were burned during the 2016 HRF event that led the structural damages. Consequently, we suggest to remove the existing vegetation within these critical zones and also monitor the region at a regular interval in order to reduce the wildland fire-induced risk. PMID:29762504

Featured collection introduction: Riparian ecosystems and buffers II

Treesearch

Paul M. Mayer; Kathleen A. Dwire; Judith A. Okay; Philipe G. Vidon

2014-01-01

Riparian ecosystems, the interface of terrestrial and aquatic systems, are zones of high biodiversity (Naiman et al., 1993), rapid biogeochemical activity (Vidon et al., 2010), complex hydrologic activity (Mayer et al., 2010a), and offer solace that can bestow significant mental health benefits (Alcock et al., 2014). Yet, many riparian zones also represent...

Method for forming synthesis gas using a plasma-catalyzed fuel reformer

DOEpatents

Hartvigsen, Joseph J; Elangovan, S; Czernichowski, Piotr; Hollist, Michele

2015-04-28

A method of forming a synthesis gas utilizing a reformer is disclosed. The method utilizes a reformer that includes a plasma zone to receive a pre-heated mixture of reactants and ionize the reactants by applying an electrical potential thereto. A first thermally conductive surface surrounds the plasma zone and is configured to transfer heat from an external heat source into the plasma zone. The reformer further includes a reaction zone to chemically transform the ionized reactants into synthesis gas comprising hydrogen and carbon monoxide. A second thermally conductive surface surrounds the reaction zone and is configured to transfer heat from the external heat source into the reaction zone. The first thermally conductive surface and second thermally conductive surface are both directly exposed to the external heat source. A corresponding apparatus and system are also disclosed herein.

Demographic consequences of terrestrial habitat loss for pool-breeding amphibians: predicting extinction risks associated with inadequate size of buffer zones.

PubMed

Harper, Elizabeth B; Rittenhouse, Tracy A G; Semlitsch, Raymond D

2008-10-01

Much of the biodiversity associated with isolated wetlands requires aquatic and terrestrial habitat to maintain viable populations. Current federal wetland regulations in the United States do not protect isolated wetlands or extend protection to surrounding terrestrial habitat. Consequently, some land managers, city planners, and policy makers at the state and local levels are making an effort to protect these wetland and neighboring upland habitats. Balancing human land-use and habitat conservation is challenging, and well-informed land-use policy is hindered by a lack of knowledge of the specific risks of varying amounts of habitat loss. Using projections of wood frog (Rana sylvatica) and spotted salamander (Ambystoma maculatum) populations, we related the amount of high-quality terrestrial habitat surrounding isolated wetlands to the decline and risk of extinction of local amphibian populations. These simulations showed that current state-level wetland regulations protecting 30 m or less of surrounding terrestrial habitat are inadequate to support viable populations of pool-breeding amphibians. We also found that species with different life-history strategies responded differently to the loss and degradation of terrestrial habitat. The wood frog, with a short life span and high fecundity, was most sensitive to habitat loss and isolation, whereas the longer-lived spotted salamander with lower fecundity was most sensitive to habitat degradation that lowered adult survival rates. Our model results demonstrate that a high probability of local amphibian population persistence requires sufficient terrestrial habitat, the maintenance of habitat quality, and connectivity among local populations. Our results emphasize the essential role of adequate terrestrial habitat to the maintenance of wetland biodiversity and ecosystem function and offer a means of quantifying the risks associated with terrestrial habitat loss and degradation.

Exploration of Characteristics Governing Dynamics of Whirlwinds: Application to Dust Devils

NASA Astrophysics Data System (ADS)

Pandey, Sanjay Kumar; Maurya, Jagdish Prasad

2017-08-01

It is intended to model mathematically an ideal whirlwind which characterises this geo-physical phenomenon and eventually helps us decode the inherent dynamics. A dense cylindrical aerial mass is taken into consideration surrounding a rarer aerial region in order to keep a radial favourable gradient of pressure to sustain a rotational motion. It has been concluded that the whirlwind will survive as long as the low pressure region exists. The vertical pressure gradient also plays an equally important role. Since it is not connected to any cloud and the axial velocity is in the vertically upward direction, the momentary vertical gradient of pressure is required for its growth and survival. Horizontal ambient winds that rush towards low pressure zone, crush the air in the buffer zone, and turn vertically upward may also take the dust carried with them visibly to some height. It is considered that the angular azimuthal velocity varies within the annulus. An inference is that no whirlwind without a low pressure region within it can survive. This may be termed as the fundamental characteristic of whirlwind. It is further concluded that if the radial pressure difference between the outermost and innermost layers is larger, the whirlwind is thicker and consequently, it will last longer. Moreover, another conclusion arrived at is that the angular velocity will vanish if the inner radius is zero.

Sensitivity analysis and metamodeling of a toolchain of models to help sizing vetetative filter strips in a watershed.

NASA Astrophysics Data System (ADS)

Lauvernet, Claire; Noll, Dorothea; Muñoz-Carpena, Rafael; Carluer, Nadia

2014-05-01

In Europe, environmental agencies do the finding a significant presence of contaminants in surface water, which is partly due to pesticide applications. Vegetative filter strips (VFS), often located along rivers, are a common tool among other buffer zones to reduce non point source pollution of water by reducing surface runoff. However, they need to be adapted to the agro-pedo-climatic conditions, both in terms of position and size, in order to be efficient. This is one of the roles of TOPPS-PROWADIS project which involves European experts and stakeholders to develop and recommend Best Management Practices (BMPs) to reduce pesticide transfer by drift or runoff in several European countries. In this context, Irstea developed a guide accompanying the use of different tools, which allows designing VFS by simulating their efficiency to limit transfers. It needs the user to define both a scenario of incoming surface runoff and the buffer zone characteristics. First, the contributive zone (surface, length, slope) is derived from the topography by a GIS tool, HydroDem. ; 2nd, the runoff hydrograph coming in the buffer zone is generated from a rainfall hyetogram typical of the area, using Curve Number theory, taking into account soil characteristics. The VFS's optimal width is then deduced for a given desired efficiency (for example 70% of runoff reduction), by using VFSMOD model, which simulates water, suspended matters (and pesticides) transfer inside a vegetative filter strip. Results also indicate if this kind of buffer zone is relevant in that situation (if too high, another type of buffer zone may be more relevant, for example constructed wetland). This method assumes that the user supplies quite a lot of field knowledge and data, which are not always easily available. In order to fill in the lack of real data, a set of virtual scenarios was tested, which is supposed to cover a large range of agro-pedo-climatic conditions in Europe, considering both the upslope agricultural field and the VFS characteristics. These scenarios are based on: 2 types of climates (North and South-west of France), different rainfall intensities and durations, different lengths and slopes of hillslope, different humidity conditions, 4 soil types (silt loam, sandy loam, clay loam, sandy clay loam), 2 crops (wheat and corn) for the contributive area, 2 water table depths (1m and 2.5m) and 4 soil types for the VFS. The sizing method was applied for all these scenarios, and a sensitivity analysis of the VFS optimal length was performed for all the input parameters in order to understand their influence, and to identify for which a special care has to be given. Based on that sensitivity analysis, a metamodel has been developed. The idea is to simplify the whole toolchain and to make it possible to perform the buffer sizing by using a unique tool and a smaller set of parameters, given the available information from the end users. We first compared several mathematical methods to compute the metamodel, and then validated them on an agricultural watershed with real data in the North-West of France.

33 CFR 165.1141 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Guard District § 165.1141 Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA. (a) Location. The following area is a safety zone: All waters of the Pacific Ocean surrounding San Clemente... Safety Zone, San Clemente Island, CA. 165.1141 Section 165.1141 Navigation and Navigable Waters COAST...

33 CFR 165.1141 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Guard District § 165.1141 Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA. (a) Location. The following area is a safety zone: All waters of the Pacific Ocean surrounding San Clemente... Safety Zone, San Clemente Island, CA. 165.1141 Section 165.1141 Navigation and Navigable Waters COAST...

33 CFR 165.1141 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Guard District § 165.1141 Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA. (a) Location. The following area is a safety zone: All waters of the Pacific Ocean surrounding San Clemente... Safety Zone, San Clemente Island, CA. 165.1141 Section 165.1141 Navigation and Navigable Waters COAST...

33 CFR 165.1141 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Guard District § 165.1141 Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA. (a) Location. The following area is a safety zone: All waters of the Pacific Ocean surrounding San Clemente... Safety Zone, San Clemente Island, CA. 165.1141 Section 165.1141 Navigation and Navigable Waters COAST...

33 CFR 165.1141 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Guard District § 165.1141 Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA. (a) Location. The following area is a safety zone: All waters of the Pacific Ocean surrounding San Clemente... Safety Zone, San Clemente Island, CA. 165.1141 Section 165.1141 Navigation and Navigable Waters COAST...

40 CFR 230.41 - Wetlands.

Code of Federal Regulations, 2010 CFR

2010-07-01

... circulation patterns that flush large expanses of wetland systems, by interfering with the filtration function... buffer zone shielding upland areas from wave actions, storm damage and erosion. ...

Sample collection system for gel electrophoresis

DOEpatents

Olivares, Jose A.; Stark, Peter C.; Dunbar, John M.; Hill, Karen K.; Kuske, Cheryl R.; Roybal, Gustavo

2004-09-21

An automatic sample collection system for use with an electrophoretic slab gel system is presented. The collection system can be used with a slab gel have one or more lanes. A detector is used to detect particle bands on the slab gel within a detection zone. Such detectors may use a laser to excite fluorescently labeled particles. The fluorescent light emitted from the excited particles is transmitted to low-level light detection electronics. Upon the detection of a particle of interest within the detection zone, a syringe pump is activated, sending a stream of buffer solution across the lane of the slab gel. The buffer solution collects the sample of interest and carries it through a collection port into a sample collection vial.

The chemical composition and source identification of soil dissolved organic matter in riparian buffer zones from Chongming Island, China.

PubMed

Wang, Yulai; Yang, Changming; Li, Jianhua; Shen, Shuo

2014-09-01

Dissolved organic matter (DOM) that is derived from the soil of riparian buffer zones has a complex chemical composition, and it plays an important role in the transport and transformation of pollutants. To identify the source of DOM and to better understand its chemical and structural properties, we collected 33 soil samples from zones with fluctuating water levels along the major rivers on Chongming Island, evaluated the DOM contents in riparian soil, analyzed the chemical composition and functional groups and traced DOM origins by using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) combined with clustering analysis. All sampling sites were divided into four groups by principal component analysis (PCA) on the basis of the DOM molecules. The results showed that there was no significant difference in the DOM contents between every two groups; however, the DOM fractions differed significantly among the different site groups in the following order: Σ lipids and Σ proteins>Σ sugars and Σ fatty acids>Σ amino acids, Σ indoles and Σ alkaloids. DOM in the riparian buffer zones originated from riparian plants, domestic sewage and agricultural activities, and the hydrophobic and amphiphilic fractions accounting for over 60% of the identified molecules were the dominant fractions. Our study has confirmed the heterogeneous properties of DOM, and it is of vital importance to isolate and characterize the various DOM fractions at the molecular level for a better understanding of the behavior and roles of DOM in the natural environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implementing Safety Measures

EPA Pesticide Factsheets

Required risk mitigation measures for soil fumigants protect handlers, applicators, and bystanders from pesticide exposure. Measures include buffer zones, sign posting, good agricultural practices, restricted use pesticide classification, and FMPs.

Calculating terrain indices along streams: A new method for separating stream sides

Treesearch

T. J. Grabs; K. G. Jencso; B. L. McGlynn; J. Seibert

2010-01-01

There is increasing interest in assessing riparian zones and their hydrological and biogeochemical buffering capacity with indices derived from hydrologic landscape analysis of digital elevation data. Upslope contributing area is a common surrogate for lateral water flows and can be used to assess the variability of local water inflows to riparian zones and streams....

76 FR 78157 - Safety Zone; Eisenhower Expressway Bridge Rehabilitation Project; Chicago River South Branch...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

...-AA00 Safety Zone; Eisenhower Expressway Bridge Rehabilitation Project; Chicago River South Branch... the Eisenhower Expressway Bridge. This temporary safety zone is necessary to protect the surrounding... Bridge. Entry into this zone is prohibited unless specifically authorized by the Captain of the Port...

Soil Fumigant Labels - Dazomet

EPA Pesticide Factsheets

Updated labels include new safety requirements for buffer zones and related measures. Find information from the Pesticide Product Labeling System (PPLS) for products such as Basamid G, manufactured by Amvac.

Tarps

EPA Pesticide Factsheets

Soil fumigant applications can qualify for buffer zone reduction credits if applicators use tarps that are highly impermeable to pesticide chemicals. There are special tarp requirements for the active ingredient dimethyl disulfide (DMDS).

Free-Flow Zone Electrophoresis of Peptides and Proteins in PDMS Microchip for Narrow pI Range Sample Prefractionation Coupled with Mass Spectrometry

PubMed Central

Song, Yong-Ak; Chan, Michael; Celio, Chris; Tannenbaum, Steven R.; Wishnok, John S.; Han, Jongyoon

2010-01-01

In this paper, we are evaluating the strategy of sorting peptides / proteins based on the charge to mass without resorting to ampholytes and / or isoelectric focusing, using a single- and two-step free-flow zone electrophoresis. We developed a simple fabrication method to create a salt bridge for free-flow zone electrophoresis in PDMS chips by surface printing a hydrophobic layer on a glass substrate. Since the surface-printed hydrophobic layer prevents plasma bonding between the PDMS chip and the substrate, an electrical junction gap can be created for free-flow zone electrophoresis. With this device, we demonstrated a separation of positive and negative peptides and proteins at a given pH in standard buffer systems, and validated the sorting result with LC/MS. Furthermore, we coupled two sorting steps via off-chip titration, and isolated peptides within specific pI ranges from sample mixtures, where the pI range was simply set by the pH values of the buffer solutions. This free-flow zone electrophoresis sorting device, with its simplicity of fabrication, and a sorting resolution of 0.5 pH unit, can potentially be a high-throughput sample fractionation tool for targeted proteomics using LC/MS. PMID:20163146

75 FR 21990 - Safety Zone; Extended Debris Removal in the Lake Champlain Bridge Construction Zone (Between...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-27

...-AA00 Safety Zone; Extended Debris Removal in the Lake Champlain Bridge Construction Zone (Between... surrounding the Lake Champlain Bridge construction zone between Chimney Point, VT and Crown Point, NY. This... of debris from the old Crown Point bridge demolition. The debris must be cleared from the navigable...

Prediction of Bicarbonate Requirements for Enhanced Reductive Bioremediation of Chlorinated Solvent-Contaminated Sites

NASA Astrophysics Data System (ADS)

Robinson, C.; Barry, D. A.

2008-12-01

Enhanced anaerobic dechlorination is a promising technology for in situ remediation of chlorinated ethene DNAPL source areas. However, the build-up of organic acids and HCl in the source zone can lead to significant groundwater acidification. The resulting pH drop inhibits the activity of the dechlorinating microorganisms and thus may stall the remediation process. Source zone remediation requires extensive dechlorination, such that it may be common for soil's natural buffering capacity to be exceeded, and for acidic conditions to develop. In these cases bicarbonate addition (e.g., NaHCO3, KHCO3) is required for pH control. As a design tool for treatment strategies, we have developed BUCHLORAC, a Windows Graphical User Interface based on an abiotic geochemical model that allows the user to predict the acidity generated during dechlorination and associated buffer requirements for their specific operating conditions. BUCHLORAC was motivated by the SABRE (Source Area BioREmediation) project, which aims to evaluate the effectiveness of enhanced reductive dechlorination in the treatment of chlorinated solvent source zones.

Long-term chloride concentrations in North American and European freshwater lakes

PubMed Central

Dugan, Hilary A.; Summers, Jamie C.; Skaff, Nicholas K.; Krivak-Tetley, Flora E.; Doubek, Jonathan P.; Burke, Samantha M.; Bartlett, Sarah L.; Arvola, Lauri; Jarjanazi, Hamdi; Korponai, János; Kleeberg, Andreas; Monet, Ghislaine; Monteith, Don; Moore, Karen; Rogora, Michela; Hanson, Paul C.; Weathers, Kathleen C.

2017-01-01

Anthropogenic sources of chloride in a lake catchment, including road salt, fertilizer, and wastewater, can elevate the chloride concentration in freshwater lakes above background levels. Rising chloride concentrations can impact lake ecology and ecosystem services such as fisheries and the use of lakes as drinking water sources. To analyze the spatial extent and magnitude of increasing chloride concentrations in freshwater lakes, we amassed a database of 529 lakes in Europe and North America that had greater than or equal to ten years of chloride data. For each lake, we calculated climate statistics of mean annual total precipitation and mean monthly air temperatures from gridded global datasets. We also quantified land cover metrics, including road density and impervious surface, in buffer zones of 100 to 1,500 m surrounding the perimeter of each lake. This database represents the largest global collection of lake chloride data. We hope that long-term water quality measurements in areas outside Europe and North America can be added to the database as they become available in the future. PMID:28786983

Long-term chloride concentrations in North American and European freshwater lakes.

PubMed

Dugan, Hilary A; Summers, Jamie C; Skaff, Nicholas K; Krivak-Tetley, Flora E; Doubek, Jonathan P; Burke, Samantha M; Bartlett, Sarah L; Arvola, Lauri; Jarjanazi, Hamdi; Korponai, János; Kleeberg, Andreas; Monet, Ghislaine; Monteith, Don; Moore, Karen; Rogora, Michela; Hanson, Paul C; Weathers, Kathleen C

2017-08-08

Anthropogenic sources of chloride in a lake catchment, including road salt, fertilizer, and wastewater, can elevate the chloride concentration in freshwater lakes above background levels. Rising chloride concentrations can impact lake ecology and ecosystem services such as fisheries and the use of lakes as drinking water sources. To analyze the spatial extent and magnitude of increasing chloride concentrations in freshwater lakes, we amassed a database of 529 lakes in Europe and North America that had greater than or equal to ten years of chloride data. For each lake, we calculated climate statistics of mean annual total precipitation and mean monthly air temperatures from gridded global datasets. We also quantified land cover metrics, including road density and impervious surface, in buffer zones of 100 to 1,500 m surrounding the perimeter of each lake. This database represents the largest global collection of lake chloride data. We hope that long-term water quality measurements in areas outside Europe and North America can be added to the database as they become available in the future.

An instrument-free, screen-printed paper microfluidic device that enables bio and chemical sensing.

PubMed

Mohammadi, Saeed; Maeki, Masatoshi; Mohamadi, Reza M; Ishida, Akihiko; Tani, Hirofumi; Tokeshi, Manabu

2015-10-07

This paper describes a simple and instrument-free screen-printing method to fabricate hydrophilic channels by patterning polydimethylsiloxane (PDMS) onto chromatography paper. Clearly recognizable border lines were formed between hydrophilic and hydrophobic areas. The minimum width of the printed channel to deliver an aqueous sample was 600 μm, as obtained by this method. Fabricated microfluidic paper-based analytical devices (μPADs) were tested for several colorimetric assays of pH, glucose, and protein in both buffer and artificial urine samples and results were obtained in less than 30 min. The limits of detection (LODs) for glucose and bovine serum albumin (BSA) were 5 mM and 8 μM, respectively. Furthermore, the pH values of different solutions were visually recognised with the naked eye by using a sensitive ink. Ultimately, it is expected that this PDMS-screen-printing (PSP) methodology for μPADs can be readily translated to other colorimetric detection and hydrophilic channels surrounded by a hydrophobic polymer can be formed to transport fluids toward target zones.

Detecting deforestation with a spectral change detection approach using multitemporal Landsat data: a case study of Kinabalu Park, Sabah, Malaysia.

PubMed

Phua, Mui-How; Tsuyuki, Satoshi; Furuya, Naoyuki; Lee, Jung Soo

2008-09-01

Tropical deforestation is occurring at an alarming rate, threatening the ecological integrity of protected areas. This makes it vital to regularly assess protected areas to confirm the efficacy of measures that protect that area from clearing. Satellite remote sensing offers a systematic and objective means for detecting and monitoring deforestation. This paper examines a spectral change approach to detect deforestation using pattern decomposition (PD) coefficients from multitemporal Landsat data. Our results show that the PD coefficients for soil and vegetation can be used to detect deforestation using change vector analysis (CVA). CVA analysis demonstrates that deforestation in the Kinabalu area, Sabah, Malaysia has significantly slowed from 1.2% in period 1 (1973 and 1991) to 0.1% in period 2 (1991 and 1996). A comparison of deforestation both inside and outside Kinabalu Park has highlighted the effectiveness of the park in protecting the tropical forest against clearing. However, the park is still facing pressure from the area immediately surrounding the park (the 1 km buffer zone) where the deforestation rate has remained unchanged.

Emerging dragonfly diversity at small Rhode Island (U.S.A.) wetlands along an urbanization gradient

USGS Publications Warehouse

Aliberti Lubertazzi, Maria A.; Ginsberg, Howard S.

2010-01-01

Natal habitat use by dragonflies was assessed on an urban to rural land-use gradient at a set of 21 wetlands, during two emergence seasons (2004, 2005). The wetlands were characterized for urbanization level by using the first factor from a principal components analysis combining chloride concentration in the wetland and percent forest in the surrounding buffer zone. Measurements of species diversity and its components (species richness and evenness) were analyzed and compared along the urbanization gradient, as were distributions of individual species. Dragonfly diversity, species richness, and evenness did not change along the urbanization gradient, so urban wetlands served as natal habitat for numerous dragonfly species. However, several individual species displayed strong relationships to the degree of urbanization, and most were more commonly found at urban sites and at sites with fish. In contrast, relatively rare species were generally found at the rural end of the gradient. These results suggest that urban wetlands can play important roles as dragonfly habitat and in dragonfly conservation efforts, but that conservation of rural wetlands is also important for some dragonfly species.

Hexagonal Hollow Tube Based Energy Absorbing Crash Buffers for Roadside Fixed Objects

NASA Astrophysics Data System (ADS)

Uddin, M. S.; Amirah Shafie, Nurul; Zivkovic, Grad

2017-03-01

The purpose of this study was to investigate the deformation of the energy absorbing hexagonal hollow tubes in a lateral compression. The aim is to design cost effective and high energy-absorbing buffer systems, which are capable of controlling out-of-control vehicles in high-speed zones. A nonlinear quasi-static finite element analysis was applied to determine the deformation and energy absorption capacity. The main parameters in the design were diameter and wall thickness of the tubes. Experimental test simulating the lateral compressive loading on a single tube was performed. Results show that as the diameter and the thickness increase, the deformation strength increases. Hexagonal tube with diameter of 219 mm and thickness of 4 mm is shown to have the highest energy absorption capability. Compared to existing cylindrical and octagonal shapes, the hexagonal tubes show the highest energy absorption capacity. Hexagonal tubes therefore can be regarded as a potential candidate for buffer designs in high speed zones. In addition, they would be compact, cost effective and facilitate ease of installation.

Protection reduces loss of natural land-cover at sites of conservation importance across Africa.

PubMed

Beresford, Alison E; Eshiamwata, George W; Donald, Paul F; Balmford, Andrew; Bertzky, Bastian; Brink, Andreas B; Fishpool, Lincoln D C; Mayaux, Philippe; Phalan, Ben; Simonetti, Dario; Buchanan, Graeme M

2013-01-01

There is an emerging consensus that protected areas are key in reducing adverse land-cover change, but their efficacy remains difficult to quantify. Many previous assessments of protected area effectiveness have compared changes between sets of protected and unprotected sites that differ systematically in other potentially confounding respects (e.g. altitude, accessibility), have considered only forest loss or changes at single sites, or have analysed changes derived from land-cover data of low spatial resolution. We assessed the effectiveness of protection in reducing land-cover change in Important Bird Areas (IBAs) across Africa using a dedicated visual interpretation of higher resolution satellite imagery. We compared rates of change in natural land-cover over a c. 20-year period from around 1990 at a large number of points across 45 protected IBAs to those from 48 unprotected IBAs. A matching algorithm was used to select sample points to control for potentially confounding differences between protected and unprotected IBAs. The rate of loss of natural land-cover at sample points within protected IBAs was just 42% of that at matched points in unprotected IBAs. Conversion was especially marked in forests, but protection reduced rates of forest loss by a similar relative amount. Rates of conversion increased from the centre to the edges of both protected and unprotected IBAs, but rates of loss in 20-km buffer zones surrounding protected IBAs and unprotected IBAs were similar, with no evidence of displacement of conversion from within protected areas to their immediate surrounds (leakage).

Integration of logistic regression and multicriteria land evaluation to simulation establishment of sustainable paddy field zone in Indramayu Regency, West Java Province, Indonesia

NASA Astrophysics Data System (ADS)

Nahib, Irmadi; Suryanta, Jaka; Niedyawati; Kardono, Priyadi; Turmudi; Lestari, Sri; Windiastuti, Rizka

2018-05-01

Ministry of Agriculture have targeted production of 1.718 million tons of dry grain harvest during period of 2016-2021 to achieve food self-sufficiency, through optimization of special commodities including paddy, soybean and corn. This research was conducted to develop a sustainable paddy field zone delineation model using logistic regression and multicriteria land evaluation in Indramayu Regency. A model was built on the characteristics of local function conversion by considering the concept of sustainable development. Spatial data overlay was constructed using available data, and then this model was built upon the occurrence of paddy field between 1998 and 2015. Equation for the model of paddy field changes obtained was: logit (paddy field conversion) = - 2.3048 + 0.0032*X1 – 0.0027*X2 + 0.0081*X3 + 0.0025*X4 + 0.0026*X5 + 0.0128*X6 – 0.0093*X7 + 0.0032*X8 + 0.0071*X9 – 0.0046*X10 where X1 to X10 were variables that determine the occurrence of changes in paddy fields, with a result value of Relative Operating Characteristics (ROC) of 0.8262. The weakest variable in influencing the change of paddy field function was X7 (paddy field price), while the most influential factor was X1 (distance from river). Result of the logistic regression was used as a weight for multicriteria land evaluation, which recommended three scenarios of paddy fields protection policy: standard, protective, and permissive. The result of this modelling, the priority paddy fields for protected scenario were obtained, as well as the buffer zones for the surrounding paddy fields.

Effects of riparian zone buffer widths on vegetation diversity in southern Appalachian headwater catchments

Treesearch

Katherine J. Elliott; James M. Vose

2016-01-01

In mountainous areas such as the southern Appalachians USA, riparian zones are difficult to define. Vegetation is a commonly used riparian indicator and plays a key role in protecting water resources, but adequate knowledge of floristic responses to riparian disturbances is lacking. Our objective was to quantify changes in stand-level floristic diversity of...

Recovery of Nitrogen Pools and Processes in Degraded Riparian Zones in the Southern Appalachians

Treesearch

John T. Walker; James M. Vose; Jennifer Knoepp; Christopher D. Geron

2009-01-01

Establishment of riparian buffers is an effective method for reducing nutrient input to streams. However, the underlying biogeochemical processes are not fully understood. The objective of this 4-yr study was to examine the effects of riparian zone restoration on soil N cycling mechanisms in a mountain pasture previously degraded by cattle. Soil inorganic N pools,...

Watershed scale assessment of the impact of forested riparian zones on stream water quality

Treesearch

J. A. Webber; K. W. J. Williard; M. R. Whiles; M. L. Stone; J. J. Zaczek; D. K. Davie

2003-01-01

Federal and state land management agencies have been promoting forest and grass riparian zones to combat non-point source nutrient and sediment pollution of our nations' waters. The majority of research examining the effectiveness of riparian buffers at reducing nutrient and sediment inputs to streams has been conducted at the field scale. This study took a...

50 CFR 218.104 - Mitigation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Bombing Exercises (explosive bombs and rockets): (i) If surface vessels are involved, trained lookouts... within the buffer zone. (12) Air-to-Surface At-Sea Bombing Exercises (Non-explosive Bombs and Rockets...

Buffers more than buffering agent: introducing a new class of stabilizers for the protein BSA.

PubMed

Gupta, Bhupender S; Taha, Mohamed; Lee, Ming-Jer

2015-01-14

In this study, we have analyzed the influence of four biological buffers on the thermal stability of bovine serum albumin (BSA) using dynamic light scattering (DLS). The investigated buffers include 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), 4-(2-hydroxyethyl)-1-piperazine-propanesulfonic acid (EPPS), 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid sodium salt (HEPES-Na), and 4-morpholinepropanesulfonic acid sodium salt (MOPS-Na). These buffers behave as a potential stabilizer for the native structure of BSA against thermal denaturation. The stabilization tendency follows the order of MOPS-Na > HEPES-Na > HEPES ≫ EPPS. To obtain an insight into the role of hydration layers and peptide backbone in the stabilization of BSA by these buffers, we have also explored the phase transition of a thermoresponsive polymer, poly(N-isopropylacrylamide (PNIPAM)), a model compound for protein, in aqueous solutions of HEPES, EPPS, HEPES-Na, and MOPS-Na buffers at different concentrations. It was found that the lower critical solution temperatures (LCST) of PNIPAM in the aqueous buffer solutions substantially decrease with increase in buffer concentration. The mechanism of interactions between these buffers and protein BSA was probed by various techniques, including UV-visible, fluorescence, and FTIR. The results of this series of studies reveal that the interactions are mainly governed by the influence of the buffers on the hydration layers surrounding the protein. We have also explored the possible binding sites of BSA with these buffers using a molecular docking technique. Moreover, the activities of an industrially important enzyme α-chymotrypsin (α-CT) in 0.05 M, 0.5 M, and 1.0 M of HEPES, EPPS, HEPES-Na, and MOPS-Na buffer solutions were analyzed at pH = 8.0 and T = 25 °C. Interestingly, the activities of α-CT were found to be enhanced in the aqueous solutions of these investigated buffers. Based upon the Jones-Dole viscosity parameters, the kosmotropic or chaotropic behaviors of the investigated buffers at 25 °C have been examined.

78 FR 71546 - Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... 1625-AA00 Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY AGENCY: Coast... safety zone on the navigable waters of Gerritsen Inlet surrounding the Belt Parkway Bridge. This proposed rule would allow the Coast Guard to prohibit all vessel traffic through the safety zone during bridge...

Forested landscapes promote richness and abundance of native bees (Hymenoptera: Apoidea: Anthophila) in Wisconsin apple orchards.

PubMed

Watson, J C; Wolf, A T; Ascher, J S

2011-06-01

Wild bees provide vital pollination services for many native and agricultural plant species, yet the landscape conditions needed to support wild bee populations are not well understood or appreciated. We assessed the influence of landscape composition on bee abundance and species richness in apple (Malus spp.) orchards of northeastern Wisconsin during the spring flowering period. A diverse community of bee species occurs in these apple orchards, dominated by wild bees in the families Andrenidae and Halictidae and the honey bee, Apis mellifera L. Proportion of forest area in the surrounding landscape was a significant positive predictor of wild bee abundance in orchards, with strongest effects at a GIS (Geographic Information Systems) buffer distance of 1,000 m or greater. Forest area also was positively associated with species richness, showing strongest effects at a buffer distance of 2,000 m. Nonagricultural developed land (homes, lawns, etcetera) was significantly negatively associated with species richness at buffer distances >750 m and wild bee abundance in bowl traps at all distances. Other landscape variables statistically associated with species richness or abundance of wild bees included proportion area of pasture (positive) and proportion area of roads (negative). Forest area was not associated with honey bee abundance at any buffer distance. These results provide clear evidence that the landscape surrounding apple orchards, especially the proportion of forest area, affects richness and abundance of wild bees during the spring flowering period and should be a part of sustainable land management strategies in agro-ecosystems of northeastern Wisconsin and other apple growing regions.

Neighborhood-based PA and its environmental correlates: a GIS- and GPS based cross-sectional study in the Netherlands.

PubMed

Jansen, Marijke; Kamphuis, Carlijn B M; Pierik, Frank H; Ettema, Dick F; Dijst, Martin J

2018-02-09

To improve our understanding of the neighborhood environment - physical activity (PA) relationship, it is of importance to assess associations between neighborhood environmental characteristics and neighborhood-based PA. Participants' (N = 308; 45-65 years) light PA (LPA) and moderate-vigorous PA (MVPA) within a 400, 800, and 1600 m buffer around adults' homes was measured using accelerometers and GPS-devices. Land use data in ArcGIS provided neighborhood characteristics for the same buffers. Multilevel linear regression models, adjusted for socio-demographic variables and attitude towards PA, were used to assess associations of objective neighborhood characteristics with neighborhood-based LPA and MVPA. LPA was positively associated with the proportions of roads (within a 400 m buffer), and negatively associated with the proportions of recreational areas (within an 800 m buffer), and the proportion of green space (within the 800 m and 1600 m buffers). Multiple characteristics of 400 m buffers were positively associated with MVPA, i.e. proportions of green space, blue space, residences, shops and foodservice industry, sports terrain, and public social-cultural facilities. Also, characteristics of larger buffers were positively associated with MVPA, i.e. the proportions of shops and foodservice industry, sports terrain, and blue space (within an 800 m buffer), and the proportion of public social-cultural facilities (within the 800 m and 1600 m buffers). Objective neighborhood characteristics of smaller as well as larger sized buffers were associated with neighborhood-based LPA and MVPA. Green and blue spaces seem to be of particular importance for PA in the smallest buffer, i.e. in the direct surrounding of adults' homes.

Soil contamination with emissions of non-ferrous metallurgical plants

NASA Astrophysics Data System (ADS)

Vodyanitskii, Yu. N.; Plekhanova, I. O.; Prokopovich, E. V.; Savichev, A. T.

2011-02-01

The upper soil horizons are strongly contaminated in the area influenced by the Mid-Urals copper smelter. In the technogenic desert and impact zones, the contents of a number of elements (Cu, Zn, As, Pb, P, and S) by many times exceed their clarke values and the maximum permissible concentrations (or provisional permissible concentrations). The degree of technogeneity (Tg) for these elements is very high in these zones. In the far buffer zone, Tg is about zero for many elements and increases up to Tg = 27-42% for four heavy elements (Cu, Zn, Pb, and As) and up to 81-98% for P and S. The buffer capacity of the humus horizon depends on the soil's location within the technogeochemical anomaly and also on the particular pollutant. In the impact zone, it is equal to 70-77% for lead and arsenic, although other technogenic elements (Zn, Cr, S, and P) are poorly retained and readily migrate into the deeper horizons (the buffer capacity is equal to 14-25%). Nearly all the heavy metals enter the soil in the form of sulfides. The soils in the area affected by the Noril'sk mining and smelting metallurgical enterprise are subdivided into two groups according to the degree of their contamination, i.e., the soils within Noril'sk proper and the soils in its suburbs to a distance of 4-15 km. The strongest soil contamination is recorded in the city: the clarke values are exceeded by 287, 78, 16, 4.1, and 3.5 times for Cu, Ni, Cr, Fe, and S, respectively. The major pollutants enter the soil from the ferruginous slag. The soil's contamination degree is lower in the suburbs, where heavy metal sulfides reach the soils with the aerial emission from the enterprise.

Soil Fumigant Fact Sheet Compilation

EPA Pesticide Factsheets

These cover information about buffer zones and the sign posting requirements, fumigant management plans, certified pesticide applicators and handlers, and resources for tribal and state lead agencies (SLAs) and residents of agricultural communities.

Methyl Bromide Fumigant Management Plan Phase 2 Templates

EPA Pesticide Factsheets

Templates provide a checklist and framework for elements including certified pesticide applicator details, application block, buffer zones, sign posting, tarp plan, soil conditions, air monitoring, and good agricultural practices (GAPs).

The distribution of actin immunoreactivity in rhabdomeres of tipulid flies in relation to extracellular membrane shedding.

PubMed

Blest, A D; Stowe, S; Clausen, J A; Carter, M

1991-09-01

Rhabdomeres of tipulid flies lose membrane during turnover from a 'shedding zone' composed of microvillar tips. These distal domains lack intramicrovillar cytoskeletons and appear to be empty sacs of membrane. Recent concerns about the role of ninaC mechano-enzymes in the architecture of dipteran rhabdomeral microvilli and the dynamic role that they may play in the creation of shedding zones demand an examination of the distribution of actin in tipulid rhabdomeres. We compared rhabdomeres from tipulid retinae incubated before fixation for immunocytochemistry in a buffer without additives and a stabilising buffer that contained a cocktail of cysteine protease inhibitors; both were challenged by an anti-actin antibody for immunogold labelling after embedding in LR White Resin. Shedding zones thus processed collapse to structureless detritus. Stabilised and unstabilized shedding zones were immunonegative to anti-actin. To ensure that the negative results were not consequent upon conformational changes generated by the processing protocol, we examined microvilli of degenerating rhabdomeres of the Drosophila light-dependent retinal degeneration mutant rdgBKS222 (which separate and collapse without creating a shedding zone) and found the detritus they generate to be immunopositive to anti-actin. Stabilised and unstabilized regions of basal regions of tipulid rhabdomeres were equally immunopositive. We infer that (a) actin is absent from shedding zones; (b) actin is not degraded by microvillar cysteine proteases. The implications of these conclusions are discussed in relation to some functional models of arthropod photoreceptor microvilli.

Buffered and unbuffered dike emplacement on Earth and Venus - Implications for magma reservoir size, depth, and rate of magma replenishment

NASA Technical Reports Server (NTRS)

Parfitt, E. A.; Head, J. W., III

1993-01-01

Models of the emplacement of lateral dikes from magma chambers under constant (buffered) driving pressure conditions and declining (unbuffered) driving pressure conditions indicate that the two pressure scenarios lead to distinctly different styles of dike emplacement. In the unbuffered case, the lengths and widths of laterally emplaced dikes will be severely limited and the dike lengths will be highly dependent on chamber size; this dependence suggests that average dike length can be used to infer the dimensions of the source magma reservoir. On Earth, the characteristics of many mafic-dike swarms suggest that they were emplaced in buffered conditions (e.g., the Mackenzie dike swarm in Canada and some dikes within the Scottish Tertiary). On Venus, the distinctive radial fractures and graben surrounding circular to oval features and edifices on many size scales and extending for hundreds to over a thousand km are candidates for dike emplacement in buffered conditions.

Self-distancing Buffers High Trait Anxious Pediatric Cancer Caregivers against Short- and Longer-term Distress

PubMed Central

Penner, Louis A; Guevarra, Darwin A.; Harper, Felicity W. K.; Taub, Jeffrey; Phipps, Sean; Albrecht, Terrance L.; Kross, Ethan

2015-01-01

Pediatric cancer caregivers are typically present at their child’s frequent, invasive treatments, and such treatments elicit substantial distress. Yet, variability exists in how even the most anxious caregivers cope. Here we examined one potential source of this variability: caregivers’ tendencies to self-distance when reflecting on their feelings surrounding their child’s treatments. We measured caregivers’ self-distancing and trait anxiety at baseline, anticipatory anxiety during their child’s treatment procedures, and psychological distress and avoidance three months later. Self-distancing buffered high (but not low) trait anxious caregivers against short- and long-term distress without promoting avoidance. These findings held when controlling for other buffers, highlighting the unique benefits of self-distancing. These results identify a coping process that buffers vulnerable caregivers against a chronic life stressor while also demonstrating the ecological validly of laboratory research on self-distancing. Future research is needed to explicate causality and the cognitive and physiological processes that mediate these results. PMID:27617183

Use of a land-use-based emissions inventory in delineating clean-air zones

Treesearch

Victor S. Fahrer; Howard A. Peters

1977-01-01

Use of a land-use-based emissions inventory from which air-pollution estimates can be projected was studied. First the methodology used to establish a land-use-based emission inventory is described. Then this inventory is used as input in a simple model that delineates clean air and buffer zones. The model is applied to the town of Burlington, Massachusetts....

Monitoring Liverworts to Evaluate the Effectiveness of Hydroriparian Buffers

NASA Astrophysics Data System (ADS)

Higgins, Kellina L.; Yasué, Maï

2014-01-01

In the coastal temperate rainforest of British Columbia (BC) in western Canada, government policies stipulate that foresters leave unlogged hydroriparian buffer strips up to 25 m on each side of streams to protect wildlife habitat. At present, studies on the effectiveness of these buffers focus on mammals, birds, and amphibians while there is comparably little information on smaller organisms such as liverworts in these hydroriparian buffers. To address this gap of knowledge, we conducted field surveys of liverworts comparing the percent cover and community composition in hydroriparian forested areas ( n = 4 sites, n = 32 plots with nested design) to hydroriparian buffer zones ( n = 4 sites, n = 32 plots). We also examined how substrate type affected the cover of liverworts. Liverwort communities in buffers were similar to those in riparian forest areas and most liverworts were found on downed wood. Thus, hydroriparian buffers of 25-35 m on each side in a coastal temperate rainforest effectively provide habitat for liverworts as long as downed wood is left intact in the landscape. Because liverworts are particularly sensitive to changes in humidity, these results may indicate that hydroriparian buffers are an effective management strategy for bryophytes and possibly for a range of other riparian species that are particularly sensitive to forestry-related changes in microclimate.

Enhancement of visible photoluminescence in the SiNx films by SiO2 buffer and annealing

NASA Astrophysics Data System (ADS)

Xu, M.; Xu, S.; Chai, J. W.; Long, J. D.; Ee, Y. C.

2006-12-01

The authors report a simple method to significantly enhance the photoluminescence (PL) of SiNx films by incorporating a SiO2 buffer and annealing treatment under N2 protection. Strong visible PL is achieved with annealing temperature above 650°C. Optimal PL is obtained at 800°C. The composition and structure analysis reveal that strong PL is directly related to the content of the Si-O and Si-N bonds in the SiNx films. These bonds provide effective luminescent centers and passivate the interface between Si core and the surrounding oxide.

Surface Melt and Firn Density Evolution in the Western Greenland Percolation Zone Over the Past 50 Years

NASA Astrophysics Data System (ADS)

Graeter, K.; Osterberg, E. C.; Hawley, R. L.; Thundercloud, Z. R.; Marshall, H. P.; Ferris, D. G.; Lewis, G.

2016-12-01

Predictions of the Greenland Ice Sheet's (GIS) contribution to sea-level rise in a warming climate depend on our ability to model the surface mass balance (SMB) processes occurring across the ice sheet. These processes are poorly constrained in the percolation zone, the region of the ice sheet where surface melt refreezes in the firn, thus preventing that melt from directly contributing to GIS mass loss. In this way, the percolation zone serves as a buffer to higher temperatures increasing mass loss. However, it is unknown how the percolation zone is evolving in a changing climate and to what extent the region will continue to serve as a buffer to future runoff. We collected seven shallow ( 22-30 m) firn cores from the Western Greenland percolation zone in May-June 2016 as part of the Greenland Traverse for Accumulation and Climate Studies (GreenTrACS) project. Here we present data on melt layer stratigraphy, density, and annual accumulation for each core to determine: (1) the temporal and spatial accumulation and melt refreeze patterns in the percolation zone of W. Greenland over the past 40 - 55 years, and (2) the impacts of changing melt and refreeze patterns on the near-surface density profile of the percolation zone. Three of the GreenTrACS firn cores re-occupy firn core sites collected in the 1970's-1990's, allowing us to more accurately quantify the evolution of the percolation zone surface melt and firn density during the most recent decades of summertime warming. This work is the basis for broader investigations into how changes in W. Greenland summertime climate are impacting the SMB of the Greenland Ice Sheet.

Pest Cockroaches May Overcome Environmental Restriction Due to Anthropization.

PubMed

Schapheer, Constanza; Sandoval, Gino; Villagra, Cristian A

2018-06-08

Our species have altered their surroundings since its early dispersion on Earth. Unfortunately, thanks to human-modified habitats, several pest organisms such as domiciliary insects have expanded their distributions. Moreover, pest-related microorganisms may also be aided by anthropization. Pest cockroaches are globally distributed and capable of carrying several diseases. We explored if urbanization may buffer environmental conditions allowing pest insects to expand their distribution. Specifically, we suggest that human settlements may generate suitable microhabitats for synanthropic cockroaches, helping them to survive and establish with disregard to overall climatic restrictions. To test this idea we studied the distribution of pest cockroaches spanning the length of Chilean territory. Chile, along its 4270 km length north to south extent, is a country offering a formidable sampling of Earth's climatic diversity accompanied by dense urbanizations. We studied entomological collections and spatially analyzed pest cockroach distribution found in Chile and discovered that synanthropic cockroach populations are consistently concentrated near most urban developed zones of the country and not limited by overall temperature. Furthermore, health-concern pest cockroach species were widely distributed in Chilean territory, found even in its most southern urban centers as well as Easter Island. Therefore, these disease vectors could exist even in isolated and extreme climatic zones as long as urbanization provides the adequate microhabitat. We discuss the need for further research in order to assess if these distributions can be extrapolated to the pathogenic strains these pest insects may be carrying as reported in other regions of the planet.

Soil Fumigant Labels - Dimethyl Disulfide (DMDS)

EPA Pesticide Factsheets

Search by EPA registration number, product name, or company and follow the link to the Pesticide Product Labeling System (PPLS) for label details. Updated labels include new safety requirements for buffer zones and related measures.

Soil Fumigant Labels - Metam Sodium/Potassium

EPA Pesticide Factsheets

Search by EPA registration number, product name, or company; and follow the link to the Pesticide Product Label System (PPLS) for details. Updated labels include new safety requirements for buffer zones and related measures.

Emergency Preparedness and Response Requirements

EPA Pesticide Factsheets

To reduce exposure risks to people who may be near a buffer zone, soil fumigant pesticide applicators are required to either provide on-site monitoring of the perimeter, or provide emergency response information directly to neighbors.

Tarp Testing Guidance

EPA Pesticide Factsheets

Since the reactivity, stability, and other chemical properties are different for each soil fumigant pesticide, the permeability of each fumigant through a film will be different. Certain tarps that qualify for buffer zone reduction credits are listed.

Chloropicrin Fumigant Management Plan Phase 2 Templates

EPA Pesticide Factsheets

These forms provide a framework for detailing the FMP elements of pesticide products containing the active ingredient chloropicrin, including application block, buffer zones, emergency response plan, tarp plan, soil conditions, and air monitoring.

Dimethyl Disulfide (DMDS) Fumigant Management Plan Template Phase 2

EPA Pesticide Factsheets

These templates provide a framework for developing your FMP, including sections on your supervising pesticide applicator, buffer zones, emergency response plan, handler information, tarp plan, soil conditions, signage, and air monitoring plan.

Sensitive determination of phenolic acids in extra-virgin olive oil by capillary zone electrophoresis.

PubMed

Carrasco Pancorbo, Alegría; Cruces-Blanco, Carmen; Segura Carretero, Antonio; Fernández Gutiérrez, Alberto

2004-11-03

A sensitive, rapid, efficient, and reliable method for the separation and determination of phenolic acids by capillary zone electrophoresis has been carried out. A detailed method optimization was carried out to separate 14 different compounds by studying parameters such as pH, type and concentration of buffer, applied voltage, and injection time. The separation was performed within 16 min, using a 25 mM sodium borate buffer (pH 9.6) at 25 kV with 8 s of hydrodynamic injection. With this method and using a liquid-liquid extraction system, with recovery values around 95%, it has been possible to detect small quantities of phenolic acids in olive oil samples. This is apparently the first paper showing the quantification of this specific family of phenolic compounds in virgin olive oil samples.

Hidden imperfect synchronization of wall turbulence.

PubMed

Tardu, Sedat F

2010-03-01

Instantaneous amplitude and phase concept emerging from analytical signal formulation is applied to the wavelet coefficients of streamwise velocity fluctuations in the buffer layer of a near wall turbulent flow. Experiments and direct numerical simulations show both the existence of long periods of inert zones wherein the local phase is constant. These regions are separated by random phase jumps. The local amplitude is globally highly intermittent, but not in the phase locked regions wherein it varies smoothly. These behaviors are reminiscent of phase synchronization phenomena observed in stochastic chaotic systems. The lengths of the constant phase inert (laminar) zones reveal a type I intermittency behavior, in concordance with saddle-node bifurcation, and the periodic orbits of saddle nature recently identified in Couette turbulence. The imperfect synchronization is related to the footprint of coherent Reynolds shear stress producing eddies convecting in the low buffer.

Numerical simulation on zonal disintegration in deep surrounding rock mass.

PubMed

Chen, Xuguang; Wang, Yuan; Mei, Yu; Zhang, Xin

2014-01-01

Zonal disintegration have been discovered in many underground tunnels with the increasing of embedded depth. The formation mechanism of such phenomenon is difficult to explain under the framework of traditional rock mechanics, and the fractured shape and forming conditions are unclear. The numerical simulation was carried out to research the generating condition and forming process of zonal disintegration. Via comparing the results with the geomechanical model test, the zonal disintegration phenomenon was confirmed and its mechanism is revealed. It is found to be the result of circular fracture which develops within surrounding rock mass under the high geostress. The fractured shape of zonal disintegration was determined, and the radii of the fractured zones were found to fulfill the relationship of geometric progression. The numerical results were in accordance with the model test findings. The mechanism of the zonal disintegration was revealed by theoretical analysis based on fracture mechanics. The fractured zones are reportedly circular and concentric to the cavern. Each fracture zone ruptured at the elastic-plastic boundary of the surrounding rocks and then coalesced into the circular form. The geometric progression ratio was found to be related to the mechanical parameters and the ground stress of the surrounding rocks.

Numerical Simulation on Zonal Disintegration in Deep Surrounding Rock Mass

PubMed Central

Chen, Xuguang; Wang, Yuan; Mei, Yu; Zhang, Xin

2014-01-01

Zonal disintegration have been discovered in many underground tunnels with the increasing of embedded depth. The formation mechanism of such phenomenon is difficult to explain under the framework of traditional rock mechanics, and the fractured shape and forming conditions are unclear. The numerical simulation was carried out to research the generating condition and forming process of zonal disintegration. Via comparing the results with the geomechanical model test, the zonal disintegration phenomenon was confirmed and its mechanism is revealed. It is found to be the result of circular fracture which develops within surrounding rock mass under the high geostress. The fractured shape of zonal disintegration was determined, and the radii of the fractured zones were found to fulfill the relationship of geometric progression. The numerical results were in accordance with the model test findings. The mechanism of the zonal disintegration was revealed by theoretical analysis based on fracture mechanics. The fractured zones are reportedly circular and concentric to the cavern. Each fracture zone ruptured at the elastic-plastic boundary of the surrounding rocks and then coalesced into the circular form. The geometric progression ratio was found to be related to the mechanical parameters and the ground stress of the surrounding rocks. PMID:24592166

77 FR 65623 - Security Zones; USCGC WILLIAM FLORES Commissioning Ceremony, Ybor Channel; Tampa, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-30

...-AA87 Security Zones; USCGC WILLIAM FLORES Commissioning Ceremony, Ybor Channel; Tampa, FL AGENCY: Coast... zone on the waters of Ybor Channel in Tampa, Florida around the USCGC WILLIAM FLORES immediately before... FLORES, official parties, dignitaries, the public, and surrounding waterways from terrorist acts...

Orthopyroxene oikocrysts in the MG1 chromitite layer of the Bushveld Complex: implications for cumulate formation and recrystallisation

NASA Astrophysics Data System (ADS)

Kaufmann, Felix E. D.; Vukmanovic, Zoja; Holness, Marian B.; Hecht, Lutz

2018-02-01

Two typical mineral textures of the MG 1 chromitite of the Bushveld Complex, South Africa, were observed; one characterised by abundant orthopyroxene oikocrysts, and the other by coarse-grained granular chromitite with only minor amounts of interstitial material. Oikocrysts form elongate clusters of several crystals aligned parallel to the layering, and typically have subhedral, almost chromite-free, core zones containing remnants of olivine. The core zones are surrounded by poikilitic aureoles overgrowing euhedral to subhedral chromite chadacrysts. Chromite grains show no preferred crystal orientation, whereas orthopyroxene grains forming clusters commonly share the same crystallographic orientation. Oikocryst core zones have lower Mg# and higher concentrations of incompatible trace elements compared to their poikilitic aureoles. Core zones are relatively enriched in REE compared to a postulated parental magma (B1) and did not crystallise in equilibrium with the surrounding minerals, whereas the composition of the poikilitic orthopyroxene is consistent with growth from the B1 magma. These observations cannot be explained by the classic cumulus and post-cumulus models of oikocryst formation. Instead, we suggest that the oikocryst core zones in the MG1 chromitite layer formed by peritectic replacement of olivine primocrysts by reaction with an upwards-percolating melt enriched in incompatible trace elements. Poikilitic overgrowth on oikocryst core zones occurred in equilibrium with a basaltic melt of B1 composition near the magma-crystal mush interface. Finally, adcumulus crystallisation followed by grain growth resulted in the surrounding granular chromitite.

A Survey of Display Hardware and Software.

ERIC Educational Resources Information Center

Poore, Jesse H., Jr.; And Others

Reported are two papers which deal with the fundamentals of display hardware and software in computer systems. The first report presents the basic principles of display hardware in terms of image generation from buffers presumed to be loaded and controlled by a digital computer. The concepts surrounding the electrostatic tube, the electromagnetic…

50 CFR 216.254 - Mitigation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... safety for marine mammals with a radius of no less than 5 nm (9.3 km) for single bombs and 10 nm (18.5 km) for double bombs and a buffer zone from the outer edge of the safety zone with a radius of at least 2.5 nm (4.6 km) for single bombs and 5 nm (18.5 km) for double bombs. (b) Prior to a JASSM or SDB...

Chloropicrin and 1,3-D Fumigant Management Plan Phase 2 Templates

EPA Pesticide Factsheets

Plans for soil fumigant pesticide products that contain chloropicrin or 1,3-dichloropropene should include application block information, tarp plan, sign posting for treated area and buffer zone, and other requirements.

Implementation Schedule for Soil Fumigant Safety Measures

EPA Pesticide Factsheets

This fact sheet summarizes the soil fumigant pesticide product label changes that are going into effect during each of two phases. New requirements cover worker protection, training, good agricultural practices, buffer zones, sign posting, and more.

Soil Fumigant Labels - Methyl Bromide

EPA Pesticide Factsheets

Search soil fumigant pesticide labels by EPA registration number, product name, or company, and follow the link to The Pesticide Product Label System (PPLS) for details. Updated labels include new safety requirements for buffer zones and related measures.

Soil Fumigant Labels - Chloropicrin

EPA Pesticide Factsheets

Search by EPA registration number, product name, or company name, and follow the link to the Pesticide Product Label System (PPLS) for details on each fumigant. Updated labels include new safety requirements for buffer zones and related measures.

Metam Sodium and Metam Potassium Fumigant Management Plan Phase 2 Templates

EPA Pesticide Factsheets

These templates provide a framework for structuring and reporting a plan for this type of pesticide product. Required data fields include application block size, buffer zone signage, soil conditions, and tarp plans.

Community Outreach and Education on Soil Fumigants

EPA Pesticide Factsheets

Information on how outreach programs can help address the risk of bystander exposure by educating community members about fumigants, buffer zones, how to recognize warning signs, and how to respond appropriately in case of an incident.

Phase 2 Site-Specific Fumigant Management Plans and Post-Application Summaries

EPA Pesticide Factsheets

New soil fumigant pesticide requirements protect handlers and other workers from exposure risks. FMP elements include application block information, tarp plan, buffer zone and sign posting requirements, air monitoring, and hazard communication.

Paladin® EC (Dimethyl Disulfide, DMDS) Fumigant Safe Handling Guide

EPA Pesticide Factsheets

Certified pesticide applicators are required to provide safety information to handlers working in an application block or buffer zone, including instruction on personal protective equipment, air monitoring, respiratory protection, and exposure mitigation.

Dazomet Fumigant Management Plan Phase 2 Templates

EPA Pesticide Factsheets

These templates provide a framework for reporting application block information, buffer zones, emergency response plan, tarp plan, soil conditions, air monitoring, and more for pesticide products containing the active ingredient dazomet, such as Basamid G.

Steady flows in the chromosphere and transition-zone above active regions as observed by OSO-8

NASA Technical Reports Server (NTRS)

Lites, B. W.

1980-01-01

Two years of data from the University of Colorado ultraviolet spectrometer aboard OSO-8 were searched for steady line-of-sight flows in the chromosphere and transition-zone above active regions. The most conspicuous pattern that emerges from this data set is that many sunspots show persistent blueshifts of transition-zone lines indicating velocities of about 20 km/s with respect to the surrounding plage areas. The data show much smaller shifts in ultraviolet emission lines arising from the chromosphere: the shifts are frequently to the blue, but sometimes redshifts do occur. Plage areas often show a redshift of the transition-zone lines relative to the surrounding quiet areas, and a strong gradient of the vertical component of the velocity is evident in many plages. One area of persistent blueshift was observed in the transition-zone above an active region filament. The energy requirement of these steady flows over sunspots is discussed.

78 FR 60218 - Safety Zone; Old Mormon Slough, Stockton, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-01

... decontaminate soil, groundwater, and sediment in Old Mormon Slough and the surrounding basin. This safety zone... safety zone in Old Mormon Slough to further the efforts of the EPA to rehabilitate soil, sediment, and... water collection ponds. The unlined oily waste ponds were closed in 1981. Sampling has shown that soils...

76 FR 32313 - Safety Zone; Chelsea St. Bridge Demolition, Chelsea River, Chelsea, MA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-06

...-AA00 Safety Zone; Chelsea St. Bridge Demolition, Chelsea River, Chelsea, MA AGENCY: Coast Guard, DHS... Sector Boston Captain of the Port (COTP) Zone for the demolition of the Chelsea St. Bridge. This safety... Chelsea St. Bridge during the operations surrounding the bridge's demolition and removal. Discussion of...

78 FR 29086 - Safety Zone; Discovery World Fireworks, Milwaukee Harbor, Milwaukee, WI

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... [Docket No. USCG-2013-0326] RIN 1625-AA00 Safety Zone; Discovery World Fireworks, Milwaukee Harbor... World Pier. This proposed safety zone is necessary to protect the surrounding public and vessels from... Discovery World Pier. The Captain of the Port, Lake Michigan, has determined that the likelihood of...

A versatile electrophoresis system for the analysis of high- and low-molecular-weight proteins

PubMed Central

Tastet, Christophe; Lescuyer, Pierre; Diemer, Hélène; Luche, Sylvie; van Dorsselaer, Alain; Rabilloud, Thierry

2003-01-01

A new, versatile, multiphasic buffer system for high resolution sodium dodecyl sulfatepolyacrylamide gel electrophoresis of proteins in the relative molecular weight Mw range of 300,000-3000 Da is described. The system, based on the theory of multiphasic zone electrophoresis, allows complete stacking and destacking of proteins in the above Mw range. The buffer system uses taurine and chloride as trailing and leading ion, respectively, and Tris, at a pH close to its pKa, as the buffering counter ion. Coupled with limited variation in the acrylamide concentration, this electrophoresis system allows to tailor the resolution in the 6–200 kDa Mw range, with minimal difficulties in the post electrophoretic identification processes. PMID:12783456

The Underground Library.

ERIC Educational Resources Information Center

American School and University, 1983

1983-01-01

Recessed 25 feet below grade, the library at the Lawrence Institute of Technology has a garden area below the light well. A large atrium with four skylights above the library serves as a buffer zone and an informal gathering place. (Author/MLF)

Safety Information for Fumigant Handlers

EPA Pesticide Factsheets

Available in both English and Spanish, there are two types of information: developed by EPA, and developed by pesticide registrants and approved by EPA. Certified applicators are required to provide this to handlers in application blocks or buffer zones.

Safety Information for Handlers of Pesticide Soil Fumigants

EPA Pesticide Factsheets

Certified applicators are required to provide this training to handlers in an application block or buffer zone. Information must include signs and symptoms of exposure, and where to find the Fumigant Management Plan and Worker Protection Standard.

Fatigue of graphite/epoxy buffer strip panels with center cracks

NASA Technical Reports Server (NTRS)

Bigelow, C. A.

1985-01-01

The effects of fatigue loading on the behavior of graphite/epoxy panels with either S-Glass or Kevlar-49 buffer strips is studied. Buffer strip panels are fatigued and tested in tension to measure their residual strength with crack-like damage. Panels are made with 45/0/-45/90 sub 2s layup with either S-Glass or Kevlar-49 buffer strip material. The buffer strips are parallel to the loading direction and made by replacing narrow strips of the 0-degree graphite plies with strips of either 0-degree S-Glass/epoxy or Kevlar-49/epoxy on a one-for-one basis. The panels are subjected to a fatigue loading spectrum MINITWIST, the shortened version of the standardized load program for the wing lower surface of a transport aircraft. Two levels of maximum strain are used in the spectrum with three durations of the fatigue spectrum. One group of panels is preloaded prior to the application of the fatigue cycling. The preload consists of statistically loading the spectrum in tension until the crack-tip damage zone reaches the ajacent buffer strips. After fatigue loading, all specimens are statistically loaded in tension to failure to determine their residual strengths.

Analyzing the Implications of Climate Data on Plant Hardiness Zones for Green Infrastructure Planning: Case Study of Knoxville, Tennessee and Surrounding Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sylvester, Linda M.; Omitaomu, Olufemi A.; Parish, Esther S.

Downscaled climate data for Knoxville, Tennessee and the surrounding region were used to investigate future changing Plant Hardiness Zones due to climate change. The methodology used is the same as the US Department of Agriculture (USDA), well-known for their creation of the standard Plant Hardiness Zone map used by gardeners and planners. USDA data were calculated from observed daily data for 1976–2005. The modeled climate data for the past is daily data from 1980-2005 and the future data is projected for 2025–2050. The average of all the modeled annual extreme minimums for each time period of interest was calculated. Eachmore » 1 km raster cell was placed into zone categories based on temperature, using the same criteria and categories of the USDA. The individual models vary between suggesting little change to the Plant Hardiness Zones to suggesting Knoxville moves into the next two Hardiness Zones. But overall, the models suggest moving into the next warmer Zone. USDA currently has the Knoxville area categorized as Zone 7a. None of the Zones calculated from the climate data models placed Knoxville in Zone 7a for the similar time period. The models placed Knoxville in a cooler Hardiness Zone and projected the area to increase to Zone 7. The modeled temperature data appears to be slightly cooler than the actual temperature data and this may explain the zone discrepancy. However, overall Knoxville is projected to increase to the next warmer Zone. As the modeled data has Knoxville, overall, moving from Zone 6 to Zone 7, it can be inferred that Knoxville, Tennessee may increase from their current Zone 7 to Zone 8.« less

Experimental and Numerical Investigation of Internal Gravity Waves Excited by Turbulent Penetrative Convection in Water Around Its Density Maximum

NASA Astrophysics Data System (ADS)

Perrard, Stéphane; Le Bars, Michaël; Le Gal, Patrice

This study is devoted to the experimental and numerical analysis of the excitation of gravity waves by turbulent convection. This situation is representative of many geophysical or astrophysical systems such as the convective bottom layer of the atmosphere that radiates internal waves in the stratosphere, or the interaction between the convective and the radiative zones in stars. In our experiments, we use water as a working fluid as it possesses the remarkable property of having a maximum density at 4 °C. Therefore, when establishing on a water layer a temperature gradient between 0 °C at the bottom and room temperature at the top, a turbulent convective region appears spontaneously under a stably stratified zone. In these conditions, gravity waves are excited by the convective fluid motions penetrating the stratified layer. Although this type of flow, called penetrative convection, has already been described, we present here the first velocity field measurement of wave emission and propagation. We show in particular that an intermediate layer that we call the buffer layer emerges between the convective and the stratified zones. In this buffer layer, the angle of propagation of the waves varies with the altitude since it is slaved to the Brunt-Väisälä frequency which evolves rapidly between the convective and the stratified layer. A minimum angle is reached at the end of the buffer layer. Then we observe that an angle of propagation is selected when the waves travel through the stratified layer. We expect this process of wave selection to take place in natural situations.

Herptofaunal species richness responses to forest landscape structure in Arkansas

Treesearch

Craig Loehle; T. Bently Wigley; Paul A. Shipman; Stanley F. Fox; Scott Rutzmoser; Ronald E. Thill; M. Anthony Melchiors

2005-01-01

Species accumulation curves were used to study reiationships between herpetofaunal richness and habitat characteristics on four watersheds in Arkansas that differed markedly with respect to management intensity. Selected habitat characteristics were estimated for stands containing the sample points and within buffers with radii of 250. 500 m, and 1 km surrounding the...

Within What Distance Does “Greenness” Best Predict Physical Health? A Systematic Review of Articles with GIS Buffer Analyses across the Lifespan

PubMed Central

2017-01-01

Is the amount of “greenness” within a 250-m, 500-m, 1000-m or a 2000-m buffer surrounding a person’s home a good predictor of their physical health? The evidence is inconclusive. We reviewed Web of Science articles that used geographic information system buffer analyses to identify trends between physical health, greenness, and distance within which greenness is measured. Our inclusion criteria were: (1) use of buffers to estimate residential greenness; (2) statistical analyses that calculated significance of the greenness-physical health relationship; and (3) peer-reviewed articles published in English between 2007 and 2017. To capture multiple findings from a single article, we selected our unit of inquiry as the analysis, not the article. Our final sample included 260 analyses in 47 articles. All aspects of the review were in accordance with PRISMA guidelines. Analyses were independently judged as more, less, or least likely to be biased based on the inclusion of objective health measures and income/education controls. We found evidence that larger buffer sizes, up to 2000 m, better predicted physical health than smaller ones. We recommend that future analyses use nested rather than overlapping buffers to evaluate to what extent greenness not immediately around a person’s home (i.e., within 1000–2000 m) predicts physical health. PMID:28644420

Probing Buffer-Gas Cooled Molecules with Direct Frequency Comb Spectroscopy in the Mid-Infrrared

NASA Astrophysics Data System (ADS)

Spaun, Ben; Changala, Bryan; Bjork, Bryce J.; Heckl, Oliver H.; Patterson, David; Doyle, John M.; Ye, Jun

2015-06-01

We present the first demonstration of cavity-enhanced direct frequency comb spectroscopy on buffer-gas cooled molecules.By coupling a mid-infrared frequency comb to a high-finesse cavity surrounding a helium buffer-gas chamber, we can gather rotationally resolved absorption spectra with high sensitivity over a broad wavelength region. The measured ˜10 K rotational and translational temperatures of buffer-gas cooled molecules drastically simplify the observed spectra, compared to those of room temperature molecules, and allow for high spectral resolution limited only by Doppler broadening (10-100 MHz). Our system allows for the extension of high-resolution spectroscopy to larger molecules, enabling detailed analysis of molecular structure and dynamics, while taking full advantage of the powerful optical properties of frequency combs. A. Foltynowicz et al. Cavity-enhanced optical frequency comb spectroscopy in the mid-infrared application to trace detection of hydrogen peroxide. Applied Physics B, vol. 110, pp. 163-175, 2013. {D. Patterson and J. M. Doyle. Cooling molecules in a cell for FTMW spectroscopy. Molecular Physics 110, 1757-1766, 2012

Investigating vegetation spectral reflectance for detecting hydrocarbon pipeline leaks from multispectral data

NASA Astrophysics Data System (ADS)

Adamu, Bashir; Tansey, Kevin; Bradshaw, Michael J.

2013-10-01

The aim of this paper is to analyse spectral reflectance data from Landsat TM of vegetation that has been exposed to hydrocarbon contamination from oil spills from pipelines. The study is undertaken in an area of mangrove and swamp vegetation where the detection of an oil spill is traditionally difficult to make. We used a database of oil spill records to help identify candidate sites for spectral analysis. Extracted vegetation spectra were compared between polluted and nonpolluted sites and supervised (neural network) classification was carried out to map hydrocarbon (HC) contaminated sites from the sample areas. Initial results show that polluted sites are characterised by high reflectance in the visible (VIS) 0.4μm - 0.7μm, and a lower reflectance in the near-infrared (NIR) 0.7μm - 1.1μm. This suggests that the vegetation is in a stressed state. Samples taken from pixels surrounding polluted sites show similar spectral reflectance values to that of polluted sites suggesting possible migration of HC to the wider environment. Further work will focus on increasing the sample size and investigating the impact of an oil spill on a wider buffer zone around the spill site.

Piloting a 'spatial isolation' index: the built environment and sexual and drug use risks to sex workers.

PubMed

Deering, Kathleen N; Rusch, Melanie; Amram, Ofer; Chettiar, Jill; Nguyen, Paul; Feng, Cindy X; Shannon, Kate

2014-05-01

Employing innovative mapping and spatial analyses of individual and neighbourhood environment data, we examined the social, physical and structural features of overlapping street-based sex work and drug scenes and explored the utility of a 'spatial isolation index' in explaining exchanging sex for drugs and exchanging sex while high. Analyses drew on baseline interview and geographic data (January 2010-October 2011) from a large prospective cohort of street and off-street sex workers (SWs) in Metropolitan Vancouver and external publically-available, neighbourhood environment data. An index measuring 'spatial isolation' was developed from seven indicators measuring features of the built environment within 50m buffers (e.g., industrial or commercial zoning, lighting) surrounding sex work environments. Bivariate and multivariable logistic regression was used to examine associations between the two outcomes (exchanged sex for drugs; exchanged sex while high) and the index, as well as each individual indicator. Of 510 SWs, 328 worked in street-based/outdoor environments (e.g., streets, parks, alleys) and were included in the analyses. In multivariable analysis, increased spatial isolation surrounding street-based/outdoor SWs' main places of servicing clients as measured with the index was significantly associated with exchanging sex for drugs. Exchanging sex for drugs was also significantly positively associated with an indicator of the built environment suggesting greater spatial isolation (increased percent of parks) and negatively associated with those suggesting decreased spatial isolation (increased percent commercial areas, increased count of lighting, increased building footprint). Exchanging sex while high was negatively associated with increased percent of commercial zones but this association was removed when adjusting for police harassment. The results from our exploratory study highlight how built environment shapes risks within overlapping street-based sex work and drug scenes through the development of a novel index comprised of multiple indicators of the built environment available through publicly available data, This study informs the important role that spatially-oriented responses, such as safer-environment interventions, and structural responses, such as decriminalization of sex work can play in improving the health, safety and well-being of SWs. Copyright © 2013 Elsevier B.V. All rights reserved.

Piloting a ‘Spatial Isolation’ Index: The Built Environment and Sexual and Drug Use Risks to Sex Workers

PubMed Central

Deering, Kathleen N; Rusch, Melanie; Amram, Ofer; Chettiar, Jill; Nguyen, Paul; Feng, Cindy X; Shannon, Kate

2014-01-01

Background Employing innovative mapping and spatial analyses of individual and neighborhood environment data, we examined the social, physical and structural features of overlapping street-based sex work and drug scenes and explored the utility of a ‘spatial isolation index’ in explaining exchanging sex for drugs and exchanging sex while high. Methods Analyses drew on baseline interview and geographic data (Jan/10-Oct/11) from a large prospective cohort of street and off-street sex workers (SWs) in Metropolitan Vancouver and external publically-available, neighborhood environment data. An index measuring ‘spatial isolation’ was developed from seven indicators measuring features of the built environment within 50m buffers (e.g. industrial or commercial zoning, lighting) surrounding sex work environments. Bivariate and multivariable logistic regression was used to examine associations between the two outcomes (exchanged sex for drugs; exchanged sex while high) and the index, as well as each individual indicator. Results Of 510 SWs, 328 worked in street-based/outdoor environments (e.g. streets, parks, alleys) and were included in the analyses. In multivariable analysis, increased spatial isolation surrounding street-based/outdoor SWs’ main places of servicing clients as measured with the index was significantly associated with exchanging sex for drugs. Exchanging sex for drugs was also significantly positively associated with an indicator of the built environment suggesting greater spatial isolation (increased percent of parks) and negatively associated with those suggesting decreased spatial isolation (increased percent commercial areas, increased count of lighting, increased building footprint). Exchanging sex while high was negatively associated with increased percent of commercial zones but this association was removed when adjusting for police harassment. Conclusions The results from our exploratory study highlight how built environment shapes risks within overlapping street-based sex work and drug scenes through the development of a novel index comprised of multiple indicators of the built environment available through publicly available data, This study informs the important role that spatially-oriented responses, such as safer-environment interventions, and structural responses, such as decriminalization of sex work can play in improving the health, safety and well-being of SWs. PMID:24433813

77 FR 74784 - Safety Zone for Recovery Operations for East Jefferson Street Train Derailment, Mantua Creek...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-18

... 1625-AA00 Safety Zone for Recovery Operations for East Jefferson Street Train Derailment, Mantua Creek... establishing a safety zone one mile north and one mile south of the East Jefferson Street Railroad Bridge... materials into Mantua Creek and the surrounding air. This regulation is necessary to provide for the safety...

The Role of Long-Term Tectonic Deformation on the Distribution of Present-Day Seismic Activity in the Caribbean and Central America

NASA Astrophysics Data System (ADS)

Schobelock, J.; Stamps, D. S.; Pagani, M.; Garcia, J.; Styron, R. H.

2017-12-01

The Caribbean and Central America region (CCAR) undergoes the entire spectrum of earthquake types due to its complex tectonic setting comprised of transform zones, young oceanic spreading ridges, and subductions along its eastern and western boundaries. CCAR is, therefore, an ideal setting in which to study the impacts of long-term tectonic deformation on the distribution of present-day seismic activity. In this work, we develop a continuous tectonic strain rate model based on inter-seismic geodetic data and compare it with known active faults and earthquake focal mechanism data. We first create a 0.25o x 0.25o finite element mesh that is comprised of block geometries defined in previously studies. Second, we isolate and remove transient signals from the latest open access community velocity solution from UNAVCO, which includes 339 velocities from COCONet and TLALOCNet GNSS data for the Caribbean and Central America, respectively. In a third step we define zones of deformation and rigidity by creating a buffer around the boundary of each block that varies depending on the size of the block and the expected deformation zone based on locations of GNSS data that are consistent with rigid block motion. We then assign each node within the buffer a 0 for the deforming areas and a plate index outside the buffer for the rigid. Finally, we calculate a tectonic strain rate model for CCAR using the Haines and Holt finite element approach to fit bi-cubic Bessel splines to the the GNSS/GPS data assuming block rotation for zones of rigidity. Our model of the CCAR is consistent with compression along subduction zones, extension across the mid-Pacific Rise, and a combination of compression and extension across the North America - Caribbean plate boundary. The majority of CCAR strain rate magnitudes range from -60 to 60 nanostrains/yr. Modeling results are then used to calculate expected faulting behaviors that we compare with mapped geologic faults and seismic activity.

High-resolution monitoring across the soil-groundwater interface - Revealing small-scale hydrochemical patterns with a novel multi-level well

NASA Astrophysics Data System (ADS)

Gassen, Niklas; Griebler, Christian; Stumpp, Christine

2016-04-01

Biogeochemical turnover processes in the subsurface are highly variable both in time and space. In order to capture this variability, high resolution monitoring systems are required. Particular in riparian zones the understanding of small-scale biogeochemical processes is of interest, as they are regarded as important buffer zones for nutrients and contaminants with high turnover rates. To date, riparian research has focused on influences of groundwater-surface water interactions on element cycling, but little is known about processes occurring at the interface between the saturated and the unsaturated zone during dynamic flow conditions. Therefore, we developed a new type of high resolution multi-level well (HR-MLW) that has been installed in the riparian zone of the Selke river. This HR-MLW for the first time enables to derive water samples both from the unsaturated and the saturated zone across one vertical profile with a spatial vertical resolution of 0.05 to 0.5 m to a depth of 4 m b.l.s. Water samples from the unsaturated zone are extracted via suction cup sampling. Samples from the saturated zone are withdrawn through glass filters and steel capillaries. Both, ceramic cups and glass filters, are installed along a 1" HDPE piezometer tube. First high resolution hydrochemical profiles revealed a distinct depth-zonation in the riparian alluvial aquifer. A shallow zone beneath the water table carried a signature isotopically and hydrochemically similar to the nearby river, while layers below 1.5 m were influenced by regional groundwater. This zonation showed temporal dynamics related to groundwater table fluctuations and microbial turnover processes. The HR-MLW delivered new insight into mixing and turnover processes between riverwater and groundwater in riparian zones, both in a temporal and spatial dimension. With these new insights, we are able to improve our understanding of dynamic turnover processes at the soil - groundwater interface and of surface -groundwater interactions in riparian zones. In the future, a better prediction and targeted management of buffer mechanisms in riparian zones will be possible.

Predicting minimum habitat characteristics for the Indiana bat in the Champlain Valley

USGS Publications Warehouse

Watrous, K.S.; Donovan, T.M.; Mickey, R.M.; Darling, S.R.; Hicks, A.C.; Von Oettingen, S. L.

2006-01-01

Predicting potential habitat across a landscape for rare species is extremely challenging. However, partitioned Mahalanobis D2 methods avoid pitfalls commonly encountered when surveying rare species by using data collected only at known species locations. Minimum habitat requirements are then determined by examining a principal components analysis to find consistent habitat characteristics across known locations. We used partitioned D 2 methods to examine minimum habitat requirements of Indiana bats (Myotis sodalis) in the Champlain Valley of Vermont and New York, USA, across 7 spatial scales and map potential habitat for the species throughout the same area. We radiotracked 24 female Indiana bats to their roost trees and across their nighttime foraging areas to collect habitat characteristics at 7 spatial scales: 1) roost trees, 2) 0.1-ha circular plots surrounding the roost trees, 3) home ranges, and 4-7) 0.5-km, 1-km, 2-km, and 3-km buffers surrounding the roost tree. Roost trees (n = 50) typically were tall, dead, large-diameter trees with exfoliating bark, located at low elevations and close to water. Trees surrounding roosts typically were smaller in diameter and shorter in height, but they had greater soundness than the roost trees. We documented 14 home ranges in areas of diverse, patchy land cover types that were close to water with east-facing aspects. Across all landscape extents, area of forest within roost-tree buffers and the aspect across those buffers were the most consistent features. Predictive maps indicated that suitable habitat ranged from 4.7-8.1% of the area examined within the Champlain Valley. These habitat models further understanding of Indiana bat summer habitat by indicating minimum habitat characteristics at multiple scales and can be used to aid management decisions by highlighting potential habitat. Nonetheless, information on juvenile production and recruitment is lacking; therefore, assessments of Indiana bat habitat quality in the region are still incomplete.

Design of suitable carrier buffer for free-flow zone electrophoresis by charge-to-mass ratio and band broadening analysis.

PubMed

Kong, Fan-Zhi; Yang, Ying; He, Yu-Chen; Zhang, Qiang; Li, Guo-Qing; Fan, Liu-Yin; Xiao, Hua; Li, Shan; Cao, Cheng-Xi

2016-09-01

In this work, charge-to-mass ratio (C/M) and band broadening analyses were combined to provide better guidance for the design of free-flow zone electrophoresis carrier buffer (CB). First, the C/M analyses of hemoglobin and C-phycocyanin (C-PC) under different pH were performed by CLC Protein Workbench software. Second, band dispersion due to the initial bandwidth, diffusion, and hydrodynamic broadening were discussed, respectively. Based on the analyses of the C/M and band broadening, a better guidance for preparation of free-flow zone electrophoresis CB was obtained. Series of experiments were performed to validate the proposed method. The experimental data showed high accordance with our prediction allowing the CB to be prepared easily with our proposed method. To further evaluate this method, C-PC was purified from crude extracts of Spirulina platensis with the selected separation condition. Results showed that C-PC was well separated from other phycobiliproteins that have similar physicochemical properties, and analytical grade product with purity up to 4.5 (A620/A280) was obtained. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Agent-Based Modeling and Simulation in the Dilemma Zone

DOT National Transportation Integrated Search

2015-12-01

The goal of this study is to develop a realistic dilemma zone (DZ) model that considers the effects of factors surrounding vehicles at an intersection, particularly focusing on driver decision-making behavior, such as the presence of a pedestrian cou...

Endangered Species Case – Northwest Center for Alternatives to Pesticides v. EPA

EPA Pesticide Factsheets

EPA is reinstating streamside no-spray buffer zones to protect endangered or threatened Pacific salmon and steelhead in California, Oregon and Washington State, which were originally established in prior litigation brought against EPA by WTC and others.

ANALYTICAL TOOLS FOR GROUNDWATER POLLUTION ASSESSMENT

EPA Science Inventory

This paper deals with the development of analytical screening-exposure models (indices) and their potential application to regulate the use of hazardous chemicals and the design of groundwater buffer strips. The indices describe the leaching of solutes below the root zone (mass f...

Soil fumigation? In my area? What should I know?

EPA Pesticide Factsheets

When soil fumigants are applied, pesticides are released in the form of a gas and so must be carefully contained. There should be signs posted around the treated area indicating a buffer zone, in order to limit your exposure risk.

Featured collection introduction: riparian ecosystems and buffers II

EPA Science Inventory

Riparian ecosystems, the interface of terrestrial and aquatic systems, are zones of high biodiversity (Naiman et al., 1993), rapid biogeochemical activity (Vidon et al., 2010), complex hydrologic activity (Mayer et al., 2010a), and offer solace that can bestow significant mental ...

Nitrogen and groundwater at Green Island restoration site

EPA Science Inventory

The Ground Water and Ecosystem Restoration Division (GWERD) of the USEPA investigates best management practices (BMP’s) and restoration techniques in aquatic ecosystems throughout the United States. Research on a) river restoration b) riparian buffer zones c) macrophytes, and d) ...

The influence of partial timber harvest in riparian management zones on macroinvertebrate and fish communities on first- and second-order streams in northern Minnesota

USGS Publications Warehouse

Chizinski, Christopher J.; Vondracek, Bruce C.; Blinn, Charles R.; Newman, Raymond M.; Atuke, Dickson M.; Fredricks, Keith; Hemstad, Nathaniel A.; Merten, Eric; Schlesser, Nicholas

2010-01-01

Relatively few evaluations of aquatic macroinvertebrate and fish communities have been published in peer-reviewed literature detailing the effect of varying residual basal area (RBA) after timber harvesting in riparian buffers. Our analysis investigated the effects of partial harvesting within riparian buffers on aquatic macroinvertebrate and fish communities in small streams from two experiments in northern Minnesota northern hardwood-aspen forests. Each experiment evaluated partial harvesting within riparian buffers. In both experiments, benthic macroinvertebrates and fish were collected 1 year prior to harvest and in each of 3 years after harvest. We observed interannual variation for the macroinvertebrate abundance, diversity and taxon richness in the single-basin study and abundance and diversity in the multiple-basin study, but few effects related to harvest treatments in either study. However, interannual variation was not evident in the fish communities and we detected no significant changes in the stream fish communities associated with partially harvested riparian buffers in either study. This would suggest that timber harvesting in riparian management zones along reaches ≤200 m in length on both sides of the stream that retains RBA ≥ 12.4 ± 1.3 m2 ha−1 or on a single side of the stream that retains RBA ≥ 8.7 ± 1.6 m2 ha−1 may be adequate to protect macroinvertebrate and fish communities in our Minnesota study systems given these specific timber harvesting techniques.

Analysis of metolachlor ethane sulfonic acid (MESA) chirality in groundwater: A tool for dating groundwater movement in agricultural settings.

PubMed

Rice, Clifford P; McCarty, Gregory W; Bialek-Kalinski, Krystyna; Zabetakis, Kara; Torrents, Alba; Hapeman, Cathleen J

2016-08-01

To better address how much groundwater contributes to the loadings of pollutants from agriculture we developed a specific dating tool for groundwater residence times. This tool is based on metolachlor ethane sulfonic acid, which is a major soil metabolite of metolachlor. The chiral forms of metolachlor ethane sulfonic acid (MESA) and the chiral forms of metolachlor were examined over a 6-year period in samples of groundwater and water from a groundwater-fed stream in a riparian buffer zone. This buffer zone bordered cropland receiving annual treatments with metolachlor. Racemic (rac) metolachlor was applied for two years in the neighboring field, and subsequently S-metolachlor was used which is enriched by 88% with the S-enantiomer. Chiral analyses of the samples showed an exponential increase in abundance of the S-enantiomeric forms for MESA as a function of time for both the first order riparian buffer stream (R(2)=0.80) and for groundwater within the riparian buffer (R(2)=0.96). However, the S-enrichment values for metolachlor were consistently high indicating different delivery mechanisms for MESA and metolachlor. A mean residence time of 3.8years was determined for depletion of the initially-applied rac-metolachlor. This approach could be useful in dating groundwater and determining the effectiveness of conservation measures. A mean residence time of 3.8years was calculated for groundwater feeding a first-order stream by plotting the timed-decay for the R-enantiomer of metolachlor ethane sulfonic acid. Published by Elsevier B.V.

FOOTPRINT: A COMPUTER APPLICATION FOR ESTIMATING PLUME AREAS OF BTEX COMPOUNDS IN GROUND WATER IMPACTED BY A SPILL OF GASOLINE CONTAINING ETHANOL

EPA Science Inventory

FOOTPRINT estimates the overall area of a plume of BTEX compounds that were contained within two biodegradation zones, one zone where ethanol is present and there is no biodegradation of BTEX compounds, surrounded by a second zone where the ethanol has been removed by natural bio...

75 FR 8804 - Safety Zone; NASSCO Launching of USNS Charles Drew, San Diego Bay, San Diego, CA.

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

...-AA00 Safety Zone; NASSCO Launching of USNS Charles Drew, San Diego Bay, San Diego, CA. AGENCY: Coast... United States Naval Ship (USNS) Charles Drew. The safety zone is necessary to provide for the safety of... to the safety of the USNS Charles Drew and surrounding vessels as this ship launches from NASSCO...

33 CFR 165.763 - Moving and Fixed Security Zone, Port of Fredericksted, Saint Croix, U.S. Virgin Islands.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., Saint Croix, U.S. Virgin Islands. (a) Location. A moving and fixed security zone is established that surrounds all cruise ships entering, departing, mooring or anchoring in the Port of Fredericksted, Saint Croix, U.S. Virgin Islands. The security zone extends from the cruise ship outward and forms a 50-yard...

33 CFR 165.763 - Moving and Fixed Security Zone, Port of Fredericksted, Saint Croix, U.S. Virgin Islands.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., Saint Croix, U.S. Virgin Islands. (a) Location. A moving and fixed security zone is established that surrounds all cruise ships entering, departing, mooring or anchoring in the Port of Fredericksted, Saint Croix, U.S. Virgin Islands. The security zone extends from the cruise ship outward and forms a 50-yard...

33 CFR 165.763 - Moving and Fixed Security Zone, Port of Fredericksted, Saint Croix, U.S. Virgin Islands.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., Saint Croix, U.S. Virgin Islands. (a) Location. A moving and fixed security zone is established that surrounds all cruise ships entering, departing, mooring or anchoring in the Port of Fredericksted, Saint Croix, U.S. Virgin Islands. The security zone extends from the cruise ship outward and forms a 50-yard...

33 CFR 165.763 - Moving and Fixed Security Zone, Port of Fredericksted, Saint Croix, U.S. Virgin Islands.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., Saint Croix, U.S. Virgin Islands. (a) Location. A moving and fixed security zone is established that surrounds all cruise ships entering, departing, mooring or anchoring in the Port of Fredericksted, Saint Croix, U.S. Virgin Islands. The security zone extends from the cruise ship outward and forms a 50-yard...

33 CFR 165.763 - Moving and Fixed Security Zone, Port of Fredericksted, Saint Croix, U.S. Virgin Islands.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., Saint Croix, U.S. Virgin Islands. (a) Location. A moving and fixed security zone is established that surrounds all cruise ships entering, departing, mooring or anchoring in the Port of Fredericksted, Saint Croix, U.S. Virgin Islands. The security zone extends from the cruise ship outward and forms a 50-yard...

Landscape, community, countryside: linking biophysical and social scales in US Corn Belt agricultural landscapes

Treesearch

Ryan C. Atwell; Lisa A. Schulte; Lynne M. Westphal

2009-01-01

Understanding the interplay between ecological and social factors across multiple scales is integral to landscape change initiatives in productive agricultural regions such as the rural US Corn Belt. We investigated the cultural context surrounding the use of perennial cover types--such as stream buffers, wetlands, cellulosic bioenergy stocks, and diverse cropping...

3D features of delayed thermal convection in fault zones: consequences for deep fluid processes in the Tiberias Basin, Jordan Rift Valley

NASA Astrophysics Data System (ADS)

Magri, Fabien; Möller, Sebastian; Inbar, Nimrod; Siebert, Christian; Möller, Peter; Rosenthal, Eliyahu; Kühn, Michael

2015-04-01

It has been shown that thermal convection in faults can also occur for subcritical Rayleigh conditions. This type of convection develops after a certain period and is referred to as "delayed convection" (Murphy, 1979). The delay in the onset is due to the heat exchange between the damage zone and the surrounding units that adds a thermal buffer along the fault walls. Few numerical studies investigated delayed thermal convection in fractured zones, despite it has the potential to transport energy and minerals over large spatial scales (Tournier, 2000). Here 3D numerical simulations of thermally driven flow in faults are presented in order to investigate the impact of delayed convection on deep fluid processes at basin-scale. The Tiberias Basin (TB), in the Jordan Rift Valley, serves as study area. The TB is characterized by upsurge of deep-seated hot waters along the faulted shores of Lake Tiberias and high temperature gradient that can locally reach 46 °C/km, as in the Lower Yarmouk Gorge (LYG). 3D simulations show that buoyant flow ascend in permeable faults which hydraulic conductivity is estimated to vary between 30 m/yr and 140 m/yr. Delayed convection starts respectively at 46 and 200 kyrs and generate temperature anomalies in agreement with observations. It turned out that delayed convective cells are transient. Cellular patterns that initially develop in permeable units surrounding the faults can trigger convection also within the fault plane. The combination of these two convective modes lead to helicoidal-like flow patterns. This complex flow can explain the location of springs along different fault traces of the TB. Besides being of importance for understanding the hydrogeological processes of the TB (Magri et al., 2015), the presented simulations provide a scenario illustrating fault-induced 3D cells that could develop in any geothermal system. References Magri, F., Inbar, N., Siebert, C., Rosenthal, E., Guttman, J., Möller, P., 2015. Transient simulations of large-scale hydrogeological processes causing temperature and salinity anomalies in the Tiberias Basin. Journal of Hydrology, 520(0), 342-355. Murphy, H.D., 1979. Convective instabilities in vertical fractures and faults. Journal of Geophysical Research: Solid Earth, 84(B11), 6121-6130. Tournier, C., Genthon, P., Rabinowicz, M., 2000. The onset of natural convection in vertical fault planes: consequences for the thermal regime in crystalline basementsand for heat recovery experiments. Geophysical Journal International, 140(3), 500-508.

Disparities in the food environment surrounding US middle and high schools

PubMed Central

Sturm, Roland

2010-01-01

Summary Background Disparities in the type and density of food retail outlets have been hypothesized as a possible cause of differential obesity rates across racial/ethnic and income groups. Several local studies have documented differences in business environments by sociodemographic neighbourhood characteristics, but no data specific for youth have been published. This study analyses the food environment surrounding all public middle and high schools in the USA. Methods Buffers were calculated with a radius of 400 and 800 m from the main entrance of public secondary schools in the USA (n = 31,622), and business establishments within those buffers were identified using InfoUSA proprietary business listings. Indicators of any convenience store, limited-service restaurant, snack store or off-licences/liquor store and counts of businesses were regressed on the proportion of students eligible for free school meals, Title I eligibility of the school, racial/ethnic composition, location and student/teacher ratio. Results Hispanic youth are particularly likely to attend schools that are surrounded by convenience stores, restaurants, snack stores or off-licences. This effect is independent and in addition to poverty (i.e. students eligible for free school meals or schools that are Title I eligible) or location (urban core, suburban, town, rural). The association between other racial groups and nearby businesses is weaker, with the exception of off-licences, where a higher proportion of minority groups increases the probability of off-licences in close proximity to the school. Middle schools have fewer surrounding businesses than high schools, and larger schools have fewer surrounding businesses than smaller schools. Conclusions Easy availability of snacks, sodas and fast food in the immediate vicinity of a school could easily negate school food policies, especially among students who can leave campus. Surrounding food outlets could also lower the effectiveness of health education in the classroom by setting a highly visible example that counters educational messages. There are several clear differences across sociodemographic groups with, arguably, the most pernicious being the location of off-licences. These disparities may represent an important type of environmental injustice for minorities and lower-income youth, with potential adverse consequences for dietary behaviours. PMID:18207475

Theoretical and experimental separation dynamics in capillary zone electrophoresis

NASA Technical Reports Server (NTRS)

Thormann, Wolfgang; Michaud, Jon-Pierre; Mosher, Richard A.

1986-01-01

The mathematical model of Bier et al. (1983) is used in a computer aided analysis of the conditions in capillary zone electrophoresis (ZE) under which sample zones migrate noninteractively with the carrier electrolyte. The monitoring of sample zones with a capillary analyzer that features both on-line conductivity and UV detection at the end of the separation trough is discussed. Data from a ZE analysis of a 5-component mixture are presented, and it is noted that all five components can be monitored via their conductivity change if enough sample is present. It is suggested from the results that the concentration ratio of background buffer to sample should be a minimum of 100:1 to effectively apply the plate concept to ZE.

9 CFR 50.17 - Payment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED BECAUSE OF TUBERCULOSIS Dairy... this subpart in connection with a buffer zone depopulation program due to tuberculosis, provided the... free of bovine tuberculosis, as determined epidemiologically by APHIS, but in any event for a period of...

9 CFR 50.17 - Payment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED BECAUSE OF TUBERCULOSIS Dairy... this subpart in connection with a buffer zone depopulation program due to tuberculosis, provided the... free of bovine tuberculosis, as determined epidemiologically by APHIS, but in any event for a period of...

9 CFR 50.17 - Payment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED BECAUSE OF TUBERCULOSIS Dairy... this subpart in connection with a buffer zone depopulation program due to tuberculosis, provided the... free of bovine tuberculosis, as determined epidemiologically by APHIS, but in any event for a period of...

9 CFR 50.17 - Payment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED BECAUSE OF TUBERCULOSIS Dairy... this subpart in connection with a buffer zone depopulation program due to tuberculosis, provided the... free of bovine tuberculosis, as determined epidemiologically by APHIS, but in any event for a period of...

Low Elevation Old Channel Features of the Willamette River Floodplain Support High Subsurface Denitrification Rates

EPA Science Inventory

Background/Question/Methods: Large river floodplains are poor nitrate pollution buffers when polluted groundwater moves beneath biogeochemically retentive zones prior to entering the main channel. However, in floodplain regions with extensive backwaters and organic carbon acc...

Impact of contact lens zone geometry and ocular optics on bifocal retinal image quality

PubMed Central

Bradley, Arthur; Nam, Jayoung; Xu, Renfeng; Harman, Leslie; Thibos, Larry

2014-01-01

Purpose To examine the separate and combined influences of zone geometry, pupil size, diffraction, apodisation and spherical aberration on the optical performance of concentric zonal bifocals. Methods Zonal bifocal pupil functions representing eye + ophthalmic correction were defined by interleaving wavefronts from separate optical zones of the bifocal. A two-zone design (a central circular inner zone surrounded by an annular outer-zone which is bounded by the pupil) and a five-zone design (a central small circular zone surrounded by four concentric annuli) were configured with programmable zone geometry, wavefront phase and pupil transmission characteristics. Using computational methods, we examined the effects of diffraction, Stiles Crawford apodisation, pupil size and spherical aberration on optical transfer functions for different target distances. Results Apodisation alters the relative weighting of each zone, and thus the balance of near and distance optical quality. When spherical aberration is included, the effective distance correction, add power and image quality depend on zone-geometry and Stiles Crawford Effect apodisation. When the outer zone width is narrow, diffraction limits the available image contrast when focused, but as pupil dilates and outer zone width increases, aberrations will limit the best achievable image quality. With two-zone designs, balancing near and distance image quality is not achieved with equal area inner and outer zones. With significant levels of spherical aberration, multi-zone designs effectively become multifocals. Conclusion Wave optics and pupil varying ocular optics significantly affect the imaging capabilities of different optical zones of concentric bifocals. With two-zone bifocal designs, diffraction, pupil apodisation spherical aberration, and zone size influence both the effective add power and the pupil size required to balance near and distance image quality. Five-zone bifocal designs achieve a high degree of pupil size independence, and thus will provide more consistent performance as pupil size varies with light level and convergence amplitude. PMID:24588552

Disk diffusion antimicrobial susceptibility testing of members of the family Legionellaceae including erythromycin-resistant variants of Legionella micdadei.

PubMed Central

Dowling, J N; McDevitt, D A; Pasculle, A W

1984-01-01

Disk diffusion antimicrobial susceptibility testing of members of the family Legionellaceae was accomplished on buffered charcoal yeast extract agar by allowing the bacteria to grow for 6 h before placement of the disks, followed by an additional 42-h incubation period before the inhibitory zones were measured. This system was standardized by comparing the zone sizes with the MICs for 20 antimicrobial agents of nine bacterial strains in five Legionella species and of 19 laboratory-derived, erythromycin-resistant variants of Legionella micdadei. A high, linear correlation between zone size and MIC was found for erythromycin, trimethoprim, penicillin, ampicillin, carbenicillin, cephalothin, cefamandole, cefoxitin, moxalactam, chloramphenicol, vancomycin, and clindamycin. Disk susceptibility testing could be employed to screen Legionella isolates for resistance to any of these antimicrobial agents, of which only erythromycin is known to be efficacious in the treatment of legionellosis. With selected antibiotics, disk susceptibility patterns also appeared to accurately identify to the species level the legionellae. The range of the MICs of the legionellae for rifampin and the aminoglycosides was too small to determine whether the correlation of zone size with MIC was linear. However, laboratory-derived, high-level rifampin-resistant variants of L. micdadei demonstrated no inhibition zone around the rifampin disk, indicating that disk susceptibility testing would likely identify a rifampin-resistant clinical isolate. Of the antimicrobial agents tested, the only agents for which disk susceptibility testing was definitely not possible on buffered charcoal yeast extract agar were oxacillin, the tetracyclines, and the sulfonamides. PMID:6565706

Effects Of Hydrothermal Alteration On Magnetic Properties And Magnetic Signatures - Implications For Predictive Magnetic Exploration Models

NASA Astrophysics Data System (ADS)

Clark, D.

2012-12-01

Magnetics is the most widely used geophysical method in hard rock exploration and magnetic surveys are an integral part of exploration programs for many types of mineral deposit, including porphyry Cu, intrusive-related gold, volcanic-hosted epithermal Au, IOCG, VMS, and Ni sulfide deposits. However, the magnetic signatures of ore deposits and their associated mineralized systems are extremely variable and exploration that is based simply on searching for signatures that resemble those of known deposits and systems is rarely successful. Predictive magnetic exploration models are based upon well-established geological models, combined with magnetic property measurements and geological information from well-studied deposits, and guided by magnetic petrological understanding of the processes that create, destroy and modify magnetic minerals in rocks. These models are designed to guide exploration by predicting magnetic signatures that are appropriate to specific geological settings, taking into account factors such as tectonic province; protolith composition; post-formation tilting/faulting/ burial/ exhumation and partial erosion; and metamorphism. Patterns of zoned hydrothermal alteration are important indicators of potentially mineralized systems and, if properly interpreted, can provided vectors to ore. Magnetic signatures associated with these patterns at a range of scales can provide valuable information on prospectivity and can guide drilling, provided they are correctly interpreted in geological terms. This presentation reviews effects of the important types of hydrothermal alteration on magnetic properties within mineralized systems, with particular reference to porphyry copper and IOCG deposits. For example, an unmodified gold-rich porphyry copper system, emplaced into mafic-intermediate volcanic host rocks (such as Bajo de la Alumbrera, Argentina) exhibits an inner potassic zone that is strongly mineralized and magnetite-rich, which is surrounded by an outer potassic zone that contains less abundant, but still significant, magnetite. The inner potassic zone represents relatively intense development of qtz-mt-Kfsp veins, whereas the outer potassic zone corresponds to bio-Kfsp-qtz-mt alteration. A shell of magnetite-destructive phyllic alteration with very low susceptibility envelops the potassic zones. The phyllic zone is surrounded by a zone of intense propylitic alteration, which is partially magnetite-destructive, which passes out into weak propylitic alteration and then into unaltered, moderately magnetic volcanics. For such a system, emplaced into magnetic intermediate-mafic igneous host rocks and exposed after removal by erosion of ~ 1 km of overburden, a strong central RTP high is surrounded by a relatively weak annular low over the phyllic zone, gradually returning to background levels over the propylitic zone (an "archery target" signature). For a completely buried system, however, the signature is basically an alteration low due to the large volume of magnetite-destructive alteration surrounding the deeply buried magnetic core.

Riparian Buffers for Runoff Control and Sensitive Species Habitat on U.S. Army Corps of Engineers Lake and Reservoir Projects

DTIC Science & Technology

2016-10-01

Fischer 2004). The use of soil amendments and/or irrigation may be necessary to establish plants . Commercial fertilizers can often help with...closer to shore Aquatic plants Aquatic zone Figure 1. Conceptual Drawing of Riparian Zone. ERDC WQTN-16-1 October 2016 2 Benefits of Riparian...Bell’s Vireo is a small, migratory, insectivorous bird (Brown 2010) that breeds in the central and southwestern U.S. and winters in southern Mexico and

Significance of pre-Quaternary climate change for montane species diversity: insights from Asian salamanders (Salamandridae: Pachytriton).

PubMed

Wu, Yunke; Wang, Yuezhao; Jiang, Ke; Hanken, James

2013-01-01

Despite extensive focus on the genetic legacy of Pleistocene glaciation, impacts of earlier climatic change on biodiversity are poorly understood. Because amphibians are highly sensitive to variations in precipitation and temperature, we use a genus of Chinese montane salamanders (Salamandridae: Pachytriton) to study paleoclimatic change in East Asia, which experienced intensification of its monsoon circulation in the late Miocene associated with subsequent Pliocene warming. Using both nuclear and mitochondrial DNA sequences, we reconstruct the species tree under a coalescent model and demonstrate that all major lineages originated before the Quaternary. Initial speciation within the genus occurred after the summer monsoon entered a stage of substantial intensification. Heavy summer precipitation established temporary water connectivity through overflows between adjacent stream systems, which may facilitate geographic range expansion by aquatic species such as Pachytriton. Species were formed in allopatry likely through vicariant isolation during or after range expansion. To evaluate the influence of Pliocene warming on these cold-adapted salamanders, we construct a novel temperature buffer-zone model, which suggests widespread physiological stress or even extinction during the warming period. A significant deceleration of species accumulation rate is consistent with Pliocene range contraction, which affected P. granulosus and P. archospotus the most because they lack large temperature buffer zones. In contrast, demographic growth occurred in species for which refugia persist. The buffer-zone model reveals the Huangshan Mountain as a potential climatic refugium, which is similar to that found for other East Asian organisms. Our approach can incorporate future climatic data to evaluate the potential impact of ongoing global warming on montane species (particularly amphibians) and to predict possible population declines. Copyright © 2012 Elsevier Inc. All rights reserved.

The utility of microsatellite DNA markers for the evaluation of area-wide integrated pest management using SIT for the fruit fly, Bactrocera dorsalis (Hendel), control programs in Thailand.

PubMed

Aketarawong, Nidchaya; Chinvinijkul, Suksom; Orankanok, Watchreeporn; Guglielmino, Carmela Rosalba; Franz, Gerald; Malacrida, Anna Rodolfa; Thanaphum, Sujinda

2011-01-01

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a key pest that causes reduction of the crop yield within the international fruit market. Fruit flies have been suppressed by two Area-Wide Integrated Pest Management programs in Thailand using Sterile Insect Technique (AW-IPM-SIT) since the late 1980s and the early 2000s. The projects' planning and evaluation usually rely on information from pest status, distribution, and fruit infestation. However, the collected data sometimes does not provide enough detail to answer management queries and public concerns, such as the long term sterilization efficacy of the released fruit fly, skepticism about insect migration or gene flow across the buffer zone, and the re-colonisation possibility of the fruit fly population within the core area. Established microsatellite DNA markers were used to generate population genetic data for the analysis of the fruit fly sampling from several control areas, and non-target areas, as well as the mass-rearing facility. The results suggested limited gene flow (m < 0.100) across the buffer zones between the flies in the control areas and flies captured outside. In addition, no genetic admixture was revealed from the mass-reared colony flies from the flies within the control area, which supports the effectiveness of SIT. The control pests were suppressed to low density and showed weak bottleneck footprints although they still acquired a high degree of genetic variation. Potential pest resurgence from fragmented micro-habitats in mixed fruit orchards rather than pest incursion across the buffer zone has been proposed. Therefore, a suitable pest control effort, such as the SIT program, should concentrate on the hidden refuges within the target area.

Climate Change and Mountain Community Fire Management in the Cordillera Blanca, Peru

NASA Astrophysics Data System (ADS)

All, J.; Medler, M.; Cole, R. J.; Arques, S.; Schmitt, C. G.

2014-12-01

In the central Andes of Peru, climate change is altering fire risk through changes in local meteorology and fuel loading. Greater moisture and favorable growing conditions are increasing vegetative productivity, which in turn increases fuel loads. This process is accentuated during El Nino events and potentially results in increased fire occurrence and frequency during relatively dry La Nina events. Park officials are concerned about the ramification of the changes on local ecology and tourist use of the resources. However, using a time-series of two different products from the MODIS Terra and Aqua platforms (Active Fire and Burned Area), TRMM 3B43 precipitation data, and Multivariate ENSO Index data we document fire occurrence and extent from 2000 to 2010 and our analysis indicates that fires are burning exclusively during winter months when there are no natural ignition sources. Globally, fire is used in conjunction with grazing to improve the regeneration and yield of grasses. During our interviews, locals claimed to only set fires in the buffer zone outside of the park, but our analysis indicates that the buffer zone rarely burns and that most fires begin within the park and only occasionally move into the buffer zones. Additionally, we determined that although this is small-scale fire activity every year, overall fire is having a very minor effect on local systems. The park service must develop programs to work with local grazing stakeholders to better limit the impacts of fire, while also address the negative perceptions from tourists in the future. In this instance, fire perception and fire reality are not the same and the challenge for resource managers is how to reconcile these two factors in order to more effectively manage the parklands.

Dynamics of a lightning corona sheath—A constant field approach using the generalized traveling current source return stroke model

NASA Astrophysics Data System (ADS)

Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Radosavljevic, Radovan; Osmokrovic, Predrag

2012-11-01

A generalized lightning traveling current source return stroke model has been used to examine the characteristics of the lightning channel corona sheath surrounding a thin channel core. A model of the lightning channel consisting of a charged corona sheath and a narrow, highly conducting central core that conducts the main current flow is assumed. Strong electric field, with a predominant radial direction, has been created during the return stroke between the channel core and the outer channel sheath containing the negative charge. The return stroke process is modeled with the positive charge coming from the channel core discharging the negative leader charge in the corona sheath. The corona sheath model that predicts the charge motion in the sheath is used to derive the expressions of the sheath radius vs. time during the return stroke. According to the corona sheath model proposed earlier by Maslowski and Rakov (2006) and Maslowski et al. (2009), it consists of three zones, zone 1 (surrounding channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (outer zone representing the virgin air without charges). We adopted the assumption of a constant electric field inside zone 1 of the corona sheath observed in the experimental research of corona discharges in a coaxial geometry by Cooray (2000). This assumption seems to be more realistic than the assumption of a uniform corona space charge density used previously in the study of Maslowski and Rakov (2006), Marjanovic and Cvetic (2009), and Tausanovic et al. (2010). Applying the Gauss' law on the infinitesimally small cylindrical section of the channel the expressions for time-dependence of the radii of zones 1 and 2 during the return stroke are derived. The calculations have shown that the overall channel dynamics concerning electrical discharge is roughly 50% slower and the maximum radius of zone 1 is about 33% smaller compared to the corresponding values calculated in the study of Tausanovic et al. (2010).

Identifying risk factors of avian infectious diseases at household level in Poyang Lake region, China.

PubMed

Jiang, Qian; Zhou, Jieting; Jiang, Zhiben; Xu, Bing

2014-09-01

Poultry kept in backyard farms are susceptible to acquiring and spreading infectious diseases because of free ranging and poor biosecurity measures. Since some of these diseases are zoonoses, this is also a significant health concern to breeders and their families. Backyard farms are common in rural regions of China. However, there is lack of knowledge of backyard poultry in the country. To obtain first-hand information of backyard poultry and identify risk factors of avian infectious diseases, a cross-sectional study was carried out at household level in rural regions around Poyang Lake. A door-to-door survey was conducted to collect data on husbandry practices, trading practices of backyard farmers, and surrounding environments of backyard farms. Farms were categorized into cases and controls based on their history of poultry death. Data were collected for 137 farms, and the association with occurrence of poultry death event was explored by chi-square tests. Results showed that vaccination implementation was a protective factor (odds ratio OR=0.40, 95% confidence interval CI: 0.20-0.80, p=0.01), while contact with other backyard flocks increased risk (OR=1.72, 95% CI: 0.79-3.74, p=0.16). A concept of "farm connectivity" characterized by the density of particular land-use types in the vicinity of the farm was proposed to characterize the degree of contact between poultry in one household farm and those in other household farms. It was found that housing density in a 20-m buffer zone of the farmhouse was most significantly associated with poultry death occurrence (OR=1.08, 95% CI: 1.02-1.17, p=0.03), and was in agreement with observation of villagers. Binary logistic regression was applied to evaluate the relationship between poultry death event and density of land-use types in all buffer zones. When integrated with vaccination implementation for poultry, prediction accuracy of poultry death event reached 72.0%. Results combining questionnaire survey with geographical approaches indicated that occurrence of poultry death event among backyard farms within a village was heavily impacted by farm connectivity. This study provides new insight for the study and help to develop more targeted prevention and countermeasure in a typical rural environment of China. Copyright © 2014 Elsevier B.V. All rights reserved.

A hydrogeologic approach to identify land uses that overlie ground-water flow paths, Broward County, Florida

USGS Publications Warehouse

Sonenshein, R.S.

1995-01-01

A hydrogeologic approach that integrates the use of hydrogeologic and spatial tools aids in the identification of land uses that overlie ground- water flow paths and permits a better understanding of ground-water flow systems. A mathematical model was used to simulate the ground-water flow system in Broward County, particle-tracking software was used to determine flow paths leading to the monitor wells in Broward County, and a Geographic Information System was used to identify which land uses overlie the flow paths. A procedure using a geographic information system to evaluate the output from a ground-water flow model has been documented. The ground-water flow model was used to represent steady-state conditions during selected wet- and dry-season months, and an advective flow particle- tracking program was used to simulate the direction of ground-water flow in the aquifer system. Digital spatial data layers were created from the particle pathlines that lead to the vicinity of the open interval of selected wells in the Broward County ground-water quality monitoring network. Buffer zone data layers were created, surrounding the particle pathlines to represent the area of contribution to the water sampled from the monitor wells. Spatial data layers, combined with a land-use data layer, were used to identify the land uses that overlie the ground-water flow paths leading to the monitor wells. The simulation analysis was performed on five Broward County wells with different hydraulic parameters to determine the source of ground-water stress, determine selected particle pathlines, and identify land use in buffer zones in the vicinity of the wells. The flow paths that lead to the grid cells containing wells G-2355, G-2373, and G-2373A did not vary between the wet- and dry-season conditions. Changes in the area of contribution for wells G-2345X and G-2369 were attributed to variations in rainfall patterns, well-field pumpage, and surface-water management practices. Additionally, using a different open interval at a site, such as for wells G-2373 and G-2373A, can result in a very different area that overlies the flow path leading to the monitor well.

75 FR 80841 - Notice of Realty Action: Direct Sale of Public Land in Kern County, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-23

... County wishes to secure the land for a buffer zone for their existing landfill. In accordance with 43 CFR..., including the mining laws, except for the sale provisions of the FLPMA. Until completion of the sale, the...

Oxygen buffering of Kilauea volcanic gases and the oxygen fugacity of Kilauea basalt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerlach, T.M.

1993-02-01

Volcanic gases collected during episode 1 of the Puu Oo eruption along the east rift zone of Kilauea Volcano, Hawaii, have uniform C-O-H-S-Cl-F compositions that are sharply depleted in CO[sub 2]. The CO[sub 2]-poor gases are typical of Type II volcanic gases (GERLACH and GRAEBER, 1985) and were emitted from evolved magma stored for a prolonged period of time in the east rift zone after releasing CO[sub 2]-rich gases during an earlier period of temporary residence in the summit magma chamber. The samples are remarkably free of contamination by atmospheric gases and meteoric water. Thermodynamic evaluation of the analytical datamore » shows that the episode 1 gases have equilibrium compositions appropriate for temperatures between 935 and 1032[degrees]C. Open- and closed-system equilibrium models of species distributions for the episode 1 gases show unequivocally that coexisting lavas buffered the gas oxygen fugacities during cooling. These models indicate that the F[sub o[sub 2

Hydrothermal ore-forming processes in the light of studies in rock- buffered systems: II. Some general geologic applications

USGS Publications Warehouse

Hemley, J.J.; Hunt, J.P.

1992-01-01

The experimental metal solubilities for rock-buffered hydrothermal systems provide important insights into the acquisition, transport, and deposition of metals in real hydrothermal systems that produced base metal ore deposits. Water-rock reactions that determine pH, together with total chloride and changes in temperature and fluid pressure, play significant roles in controlling the solubility of metals and determining where metals are fixed to form ore deposits. Deposition of metals in hydrothermal systems occurs where changes such as cooling, pH increase due to rock alteration, boiling, or fluid mixing cause the aqueous metal concentration to exceed saturation. Metal zoning results from deposition occurring at successive saturation surfaces. Zoning is not a reflection simply of relative solubility but of the manner of intersection of transport concentration paths with those surfaces. Saturation surfaces will tend to migrate outward and inward in prograde and retrograde time, respectively, controlled by either temperature or chemical variables. -from Authors

[Determination of inorganic ions in explosive residues by capillary zone electrophoresis].

PubMed

Feng, Junhe; Guo, Baoyuan; Lin, Jin-Ming; Xu, Jianzhong; Zhou, Hong; Sun, Yuyou; Liu, Yao; Quan, Yangke; Lu, Xiaoming

2008-11-01

Five anions (chlorate, perchlorate, nitrate, nitrite, and sulfate) and two cations (ammonium and potassium) in explosive residues have been separated and determined by capillary zone electrophoresis (CZE) with indirect ultraviolet detection. The electrolyte buffer for the cation separation was 10 mmol/L pyridine (pH 4.5) -3 mmol/L 18-crown-6-ether. Ammonium and potassium ions were baseline separated in less than 2.6 min with the detection limits of 0.10 mg/L and 0.25 mg/L (S/N = 3), respectively. The electrolyte buffer for the anion separation consisted of 40 mmol/L boric acid-1.8 mmol/L potassium dichromate-2 mmol/L sodium tetraborate (pH 8.6), and tetramethyl ammonium hydroxide (TMAOH) was used as electroosmotic flow modifier. All five anions were well separated in less than 4.6 min with the detection limit range of 0.10 - 1.85 mg/L (S/N = 3). The method was successfully used in real sample investigations to confirm the type of explosives.

Road displacement model based on structural mechanics

NASA Astrophysics Data System (ADS)

Lu, Xiuqin; Guo, Qingsheng; Zhang, Yi

2006-10-01

Spatial conflict resolution is an important part of cartographic generalization, and it can deal with the problems of having too much information competing for too little space, while feature displacement is a primary operator of map generalization, which aims at resolving the spatial conflicts between neighbor objects especially road features. Considering the road object, this paper explains an idea of displacement based on structural mechanics. In view of spatial conflict problem after road symbolization, it is the buffer zones that are used to detect conflicts, then we focus on each conflicting region, with the finite element method, taking every triangular element for analysis, listing stiffness matrix, gathering system equations and calculating with iteration strategy, and we give the solution to road symbol conflicts. Being like this until all the conflicts in conflicting regions are solved, then we take the whole map into consideration again, conflicts are detected by reusing the buffer zones and solved by displacement operator, so as to all of them are handled.

Dependency of plasmon resonance sensitivity of colloidal gold nanoparticles on the identity of surrounding ionic media

NASA Astrophysics Data System (ADS)

Mehrdel, B.; Aziz, A. Abdul

2018-03-01

The plasmon resonance sensitivity of gold nanoparticles (AuNPs) in sodium chloride (NaCl) liquid in near-infrared to the visible spectral region was investigated. The correlation between NaCl concentration and refractive index was analyzed using concentration dependency and Lorenz-Lorenz methods. The first derivative method was applied to the measured absorption spectra to quantitatively evaluate the plasmon resonance sensitivity. To understand the influence of the identity of the surrounding medium on the plasmon resonance sensitivity, experiments were repeated by replacing NaCl with sodium hydroxide (NaOH), followed by phosphate buffered saline (PBS). Experimental results showed that NaCl is the most effective ionic surrounding medium, which gives prominent plasmon resonance response. AuNPs size can have a significant influence on the plasmon resonance sensitivity. For tiny AuNPs (∼10 nm AuNPs), the plasmon resonance is insensitive to the identity of the surrounding medium due to their low cross-section value.

75 FR 45055 - Security Zone; 2010 Seattle Seafair Fleet Week Moving Vessels, Puget Sound, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

... security zones surrounding the HMCS NANAIMO (NCSM 702), HMCS EDMONTON (NCSM 703), and the HMCS BRANDON...), HMCS EDMONTON (NCSM 703), and the HMCS BRANDON (NCSM 710) while underway in the Puget Sound COTP AOR... 703), and the [[Page 45057

Cenozoic Tectonic Evolution of Northeast China and Surrounding Areas Reproduced by Slab Subduction Models

NASA Astrophysics Data System (ADS)

Yang, T.; Moresi, L. N.; Zhao, D.; Sandiford, D.

2017-12-01

Northeast China lies at the continental margin of the western Pacific subduction zone where the Pacific Plate subducts beneath the Eurasia Plate along the Kuril-Japan trench during the Cenozoic, after the consumption of the Izanagi Plate. The Izanagi Plate and the Izanagi-Pacific mid-ocean ridge recycled to the mantle beneath Eurasia before the early Cenozoic. Plate reconstructions suggest that (1) age of the incoming Pacific Plate at the trench increases with time; (2) convergence rate between the Pacific and Eurasia Plates increased rapidly from the late Eocene to the early Miocene. Northeast China and surrounding areas suffered widespread extension and magmatism during the Cenozoic, culminating in the opening of the Japan Sea and the rifting of the Baikal Rift Zone. The Japan Sea opened during the early Miocene and kept spreading until the late Miocene, since when compression tectonics gradually prevailed. The Baikal Rift Zone underwent slow extension in the Cenozoic but its extension rate has increased rapidly since the late Miocene. We investigate the Cenozoic tectonic evolution of Northeast China and surrounding areas with geodynamic models. Our study suggests that the rapid aging of the incoming Pacific Plate at the subduction zone leads to the increase of plate convergence and trench motion rates, and explains the observed sequence of regional tectonic events. Our geodynamic model, which reproduces the Cenozoic regional tectonic events, predicts slab morphology and stress state consistent with seismic observations, including over 1000 km of slab stagnant in the transition zone, and the along-dip principal compressional stress direction. Our model requires a value of the 660 km phase transition Clapeyron slope of -2.5 MPa/K to reproduce the stagnant slab and tectonic events in the study region. This suggests that the Pacific slab is hydrated in the transition zone, explaining geochemical characteristics of some regional Cenozoic igneous rocks which were suggested to originate from a hydrous mantle transition zone.

The role of SiGe buffer in growth and relaxation of Ge on free-standing Si(001) nano-pillars.

PubMed

Zaumseil, P; Kozlowski, G; Schubert, M A; Yamamoto, Y; Bauer, J; Schülli, T U; Tillack, B; Schroeder, T

2012-09-07

We study the growth and relaxation processes of Ge nano-clusters selectively grown by chemical vapor deposition on free-standing 90 nm wide Si(001) nano-pillars with a thin Si(0.23)Ge(0.77) buffer layer. We found that the dome-shaped SiGe layer with a height of about 28 nm as well as the Ge dot deposited on top of it partially relaxes, mainly by elastic lattice bending. The Si nano-pillar shows a clear compliance behavior-an elastic response of the substrate on the growing film-with the tensile strained top part of the pillar. Additional annealing at 800 °C leads to the generation of misfit dislocation and reduces the compliance effect significantly. This example demonstrates that despite the compressive strain generated due to the surrounding SiO(2) growth mask it is possible to realize an overall tensile strain in the Si nano-pillar and following a compliant substrate effect by using a SiGe buffer layer. We further show that the SiGe buffer is able to improve the structural quality of the Ge nano-dot.

Riparian buffer strips as a multifunctional management tool in agricultural landscapes: introduction.

PubMed

Stutter, Marc I; Chardon, Wim J; Kronvang, Brian

2012-01-01

Catchment riparian areas are considered key zones to target mitigation measures aimed at interrupting the movement of diffuse substances from agricultural land to surface waters. Hence, unfertilized buffer strips have become a widely studied and implemented "edge of field" mitigation measure assumed to provide an effective physical barrier against nitrogen (N), phosphorus (P), and sediment transfer. To ease the legislative process, these buffers are often narrow mandatory strips along streams and rivers, across different riparian soil water conditions, between bordering land uses of differing pollution burdens, and without prescribed buffer management. It would be easy to criticize such regulation for not providing the opportunity for riparian ecosystems to maximize their provision for a wider range of ecosystem goods and services. The scientific basis for judging the best course of action in designing and placing buffers to enhance their multifunctionality has slowly increased over the last five years. This collection of papers aims to add to this body of knowledge by giving examples of studies related to riparian buffer management and assessment throughout Europe. This introductory paper summarizes discussion sessions and 13 selected papers from a workshop held in Ballater, UK, highlighting research on riparian buffers brought together under the EU COST Action 869 knowledge exchange program. The themes addressed are (i) evidence of catchment- to national-scale effectiveness, (ii) ecological functioning linking terrestrial and aquatic habitats, (iii) modeling tools for assessment of effectiveness and costs, and (iv) process understanding enabling management and manipulation to enhance pollutant retention in buffers. The combined understanding led us to consider four principle key questions to challenge buffer strip research and policy. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Modeling early in situ wetting of a compacted bentonite buffer installed in low permeable crystalline bedrock

NASA Astrophysics Data System (ADS)

Dessirier, B.; Frampton, A.; Fransson, À.; Jarsjö, J.

2016-08-01

The repository concept for geological disposal of spent nuclear fuel in Sweden and Finland is planned to be constructed in sparsely fractured crystalline bedrock and with an engineered bentonite buffer to embed the waste canisters. An important stage in such a deep repository is the postclosure phase following the deposition and the backfilling operations when the initially unsaturated buffer material gets hydrated by the groundwater delivered by the natural bedrock. We use numerical simulations to interpret observations on buffer wetting gathered during an in situ campaign, the Bentonite Rock Interaction Experiment, in which unsaturated bentonite columns were introduced into deposition holes in the floor of a 417 m deep tunnel at the Äspö Hard Rock Laboratory in Sweden. Our objectives are to assess the performance of state-of-the-art flow models in reproducing the buffer wetting process and to investigate to which extent dependable predictions of buffer wetting times and saturation patterns can be made based on information collected prior to buffer insertion. This would be important for preventing insertion into unsuitable bedrock environments. Field data and modeling results indicate the development of a de-saturated zone in the rock and show that in most cases, the presence or absence of fractures and flow heterogeneity are more important factors for correct wetting predictions than the total inflow. For instance, for an equal open-hole inflow value, homogeneous inflow yields much more rapid buffer wetting than cases where fractures are represented explicitly thus creating heterogeneous inflow distributions.

Stress, Social Support, and Outcomes in Two Probability Samples of Homeless Adults

ERIC Educational Resources Information Center

Toro, Paul A.; Tulloch, Elizabeth; Ouellette, Nicole

2008-01-01

This study investigated the main effects of social support measures and their stress-buffering effects in two samples of homeless adults (Ns =249 and 219) obtained in the same large county (surrounding Detroit) at different points in time over an 8-year period (1992-1994 and 2000-2002). The findings suggest that the construct of social support,…

Do Social Support, Self-Efficacy and Resilience Influence the Experience of Stress in Ghanaian Orphans? An Exploratory Study

ERIC Educational Resources Information Center

Salifu Yendork, Joana; Somhlaba, Nceba Z.

2015-01-01

Much of the literature suggests that the availability of certain protective factors can help to buffer the adverse effects of negative life events such as parental loss and the negative experiences surrounding placement in orphanages. Following on from this perspective, the present study explores the influence of perceived social support,…

How old are lunar lobate scarps? 1. Seismic resetting of crater size-frequency distributions

NASA Astrophysics Data System (ADS)

van der Bogert, Carolyn H.; Clark, Jaclyn D.; Hiesinger, Harald; Banks, Maria E.; Watters, Thomas R.; Robinson, Mark S.

2018-05-01

Previous studies have estimated the ages of lunar lobate scarps, some of the youngest tectonic landforms on the Moon, based on the estimated life-times of their fresh morphologies and associated small graben, using crater degradation ages, or via buffered and traditional crater size-frequency distribution (CSFD) measurements. Here, we reexamine five scarps previously dated by Binder and Gunga (1985) with crater degradation ages to benchmark the evaluation of both the buffered and traditional CSFD approaches for determination of absolute model ages (AMAs) at scarps. Both CSFD methods yield similar ages for each individual scarp, indicating that fault activity not only can be measured on the scarp itself, but also in the surrounding terrain - an indication that tectonic activity causes surface renewal both adjacent to and even kilometers distant from scarps. Size-frequency variations in the regions surrounding the scarps are thus useful for studying the extent and severity of the ground motion caused by coseismic slip events during scarp formation. All age determination approaches continue to indicate that lunar lobate scarps were active in the late Copernican, with some scarps possibly experiencing activity within the last 100 Ma.

How Old are Lunar Lobate Scarps? 1. Seismic Resetting of Crater Size-Frequency Distributions

NASA Technical Reports Server (NTRS)

Van Der Bogert, Carolyn H.; Clark, Jaclyn D.; Hiesinger, Harald; Banks, Maria E.; Watters, Thomas R.; Robinson, Mark S.

2018-01-01

Previous studies have estimated the ages of lunar lobate scarps, some of the youngest tectonic landforms on the Moon, based on the estimated life-times of their fresh morphologies and associated small graben, using crater degradation ages, or via buffered and traditional crater size-frequency distribution (CSFD) measurements. Here, we reexamine five scarps previously dated by Binder and Gunga (1985) with crater degradation ages to benchmark the evaluation of both the buffered and traditional CSFD approaches for determination of absolute model ages (AMAs) at scarps. Both CSFD methods yield similar ages for each individual scarp, indicating that fault activity not only can be measured on the scarp itself, but also in the surrounding terrain - an indication that tectonic activity causes surface renewal both adjacent to and even kilometers distant from scarps. Size-frequency variations in the regions surrounding the scarps are thus useful for studying the extent and severity of the ground motion caused by coseismic slip events during scarp formation. All age determination approaches continue to indicate that lunar lobate scarps were active in the late Copernican, with some scarps possibly experiencing activity within the last 100 Ma.

Patterns of residual stresses due to welding

NASA Technical Reports Server (NTRS)

Botros, B. M.

1983-01-01

Residual stresses caused by welding result from the nonuniform rate of cooling and the restrained thermal contraction or non-uniform plastic deformation. From the zone of extremely high temperature at the weld, heat flows into both the adjoining cool body and the surrounding atmosphere. The weld metal solidifies under very rapid cooling. The plasticity of the hot metal allows adjustment initially, but as the structure cools the rigidity of the surrounding cold metal inhibits further contraction. The zone is compressed and the weld is put under tensile stresses of high magnitude. The danger of cracking in these structural elements is great. Change in specific volume is caused by the change in temperature.

Crowding, Proximity, Inmate Violence, and the Eighth Amendment.

ERIC Educational Resources Information Center

Anson, Richard H.; Hancock, Barry W.

1992-01-01

Rejects federal court ruling that prison crowding must be considered in light of total space availability of given institution. Notes variability in body buffer zones for each individual inmate, aggression potential, and variability between violent and nonviolent inmates. Contends that correctional practitioners should allocate institutional space…

EFFECTS OF NUTRIENT LOADING ON BIOGEOCHEMICAL AND MICROBIAL PROCESSES IN A NEW ENGLAND SALT MARSH

EPA Science Inventory

Coastal marshes represent an important transitional zone between uplands and estuaries. One important function of marshes is to assimilate nutrient inputs from uplands, thus providing a buffer for anthropogenic nutrient loads. We examined the effects of nitrogen (N) and phosphoru...

77 FR 66938 - Special Local Regulations; 2012 Holiday Boat Parades, Captain of the Port Miami Zone; FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-08

... North Palm Beach and end at Loxahatchee River Daymark 7 east of the Glynn Mayo Highway Bridge in Jupiter... Loxahatchee River Daymark 7 east of the Glynn Mayo Highway Bridge in Jupiter, FL, which will include a buffer...

Thermal buffering of concrete by seaweeds during a prolonged summer heatwave

NASA Astrophysics Data System (ADS)

Naylor, Larissa; Coombes, Martin

2014-05-01

Hard coastal infrastructure is subject to aggressive environmental conditions, including a suite of weathering processes in the intertidal zone. These processes, along with waves, lead to costly deterioration of coastal structures. Existing methods (e.g. coatings, less porous concrete) to reduce the risk of concrete deterioration rapidly lose their effectiveness in the intertidal zone. Additionally, a changing climate will lead to increased frequency of storms, higher sea level and higher extreme temperatures - and therefore, pose an increased risk of deterioration. Might there be a biogenic solution? New research (Coombes et al. 2013) has shown that fucoid seaweeds reduce microclimatic extremes and variability under normal summer conditions. The results presented here supplement these findings in two ways. First, they demonstrate that fucoid seaweeds act as a thermal buffer during a prolonged summer heatwave in Britain (July 2013). Over 36 days of continuous monitoring at two sites in Cornwall, UK, 19 of which were during the official heatwave, there were statistically significant differences (p = 0.000) in the maximum temperatures between thick seaweed (7.5 - 9.5 cm thickness) and thin seaweed (2 - 2.5 cm thickness) plots. Maximum temperatures reached 22°C and 33°C, for thick seaweed and thin seaweed plots, respectively. Variations in maximum temperatures between the two sites appear to be related to aspect. Second, the significantly different maximum temperature results between plots also demonstrate that seaweed thickness is an important factor influencing thermal buffering capacity. These data clearly demonstrate that fucoid seaweeds buffer concrete seawalls against extreme temperature fluxes during a heatwave, probably limiting the efficiency of deteriorative processes such as thermal expansion and contraction and salt crystallisation.

75 FR 34376 - Safety Zone; City of Pittsburg Independence Day Celebration, Pittsburg, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-17

... associated with the pyrotechnics. Unauthorized persons or vessels are prohibited from entering into... of the dangers posed by the pyrotechnics used in this fireworks display, the safety zone is necessary... restricted area on the waters surrounding the fireworks launch site during loading of the pyrotechnics, and...

75 FR 3372 - Safety Zone: Congress Street Bridge, Pequonnock River, Bridgeport, CT

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-21

...-AA00 Safety Zone: Congress Street Bridge, Pequonnock River, Bridgeport, CT AGENCY: Coast Guard, DHS... waters surrounding the Congress Street Bridge over the Pequonnock River in Bridgeport, Connecticut. This... and equipment that are being utilized for partial demolition of the Congress Street Bridge. Entry into...

{open_quotes}In close proximity{close_quotes} to E&P waste management facilities: Lessons of three communities in the Four Corners Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shuey, C.

1994-12-31

Contaminant releases from E&P waste management facilities located near residences in three communities in the Four Corners Area -- two in New Mexico and one in Utah -- spurred vocal concern among local residents in recent years. Noxious odors, including hydrogen sulfide, were present in all cases and releases of production wastes and oil spills were prevalent in two of the cases. In all three, residents said they felt powerless to change operator or agency decisions about siting of facilities close to places where people congregate. These cases illustrate the need for regulators to consider facility locations in permitting decisions.more » They also demonstrate the need for creation of statutorily recognized buffer zones around new oil and gas production and processing facilities where releases of pollutants to the air, land and water can reasonably be expected, regardless of the level of pollution control. Buffer zones may be especially important in states where local governments have not elected to adopt land use and zoning requirements that affect the siting of E&P facilities. Agency and corporate sensitivity to siting concerns will engender public confidence in permitting decisions and avoid the needless waste of public and private resources.« less

Five key attributes can increase marine protected areas performance for small-scale fisheries management

NASA Astrophysics Data System (ADS)

di Franco, Antonio; Thiriet, Pierre; di Carlo, Giuseppe; Dimitriadis, Charalampos; Francour, Patrice; Gutiérrez, Nicolas L.; Jeudy de Grissac, Alain; Koutsoubas, Drosos; Milazzo, Marco; Otero, María Del Mar; Piante, Catherine; Plass-Johnson, Jeremiah; Sainz-Trapaga, Susana; Santarossa, Luca; Tudela, Sergi; Guidetti, Paolo

2016-12-01

Marine protected areas (MPAs) have largely proven to be effective tools for conserving marine ecosystem, while socio-economic benefits generated by MPAs to fisheries are still under debate. Many MPAs embed a no-take zone, aiming to preserve natural populations and ecosystems, within a buffer zone where potentially sustainable activities are allowed. Small-scale fisheries (SSF) within buffer zones can be highly beneficial by promoting local socio-economies. However, guidelines to successfully manage SSFs within MPAs, ensuring both conservation and fisheries goals, and reaching a win-win scenario, are largely unavailable. From the peer-reviewed literature, grey-literature and interviews, we assembled a unique database of ecological, social and economic attributes of SSF in 25 Mediterranean MPAs. Using random forest with Boruta algorithm we identified a set of attributes determining successful SSFs management within MPAs. We show that fish stocks are healthier, fishermen incomes are higher and the social acceptance of management practices is fostered if five attributes are present (i.e. high MPA enforcement, presence of a management plan, fishermen engagement in MPA management, fishermen representative in the MPA board, and promotion of sustainable fishing). These findings are pivotal to Mediterranean coastal communities so they can achieve conservation goals while allowing for profitable exploitation of fisheries resources.

Five key attributes can increase marine protected areas performance for small-scale fisheries management.

PubMed

Di Franco, Antonio; Thiriet, Pierre; Di Carlo, Giuseppe; Dimitriadis, Charalampos; Francour, Patrice; Gutiérrez, Nicolas L; Jeudy de Grissac, Alain; Koutsoubas, Drosos; Milazzo, Marco; Otero, María Del Mar; Piante, Catherine; Plass-Johnson, Jeremiah; Sainz-Trapaga, Susana; Santarossa, Luca; Tudela, Sergi; Guidetti, Paolo

2016-12-01

Marine protected areas (MPAs) have largely proven to be effective tools for conserving marine ecosystem, while socio-economic benefits generated by MPAs to fisheries are still under debate. Many MPAs embed a no-take zone, aiming to preserve natural populations and ecosystems, within a buffer zone where potentially sustainable activities are allowed. Small-scale fisheries (SSF) within buffer zones can be highly beneficial by promoting local socio-economies. However, guidelines to successfully manage SSFs within MPAs, ensuring both conservation and fisheries goals, and reaching a win-win scenario, are largely unavailable. From the peer-reviewed literature, grey-literature and interviews, we assembled a unique database of ecological, social and economic attributes of SSF in 25 Mediterranean MPAs. Using random forest with Boruta algorithm we identified a set of attributes determining successful SSFs management within MPAs. We show that fish stocks are healthier, fishermen incomes are higher and the social acceptance of management practices is fostered if five attributes are present (i.e. high MPA enforcement, presence of a management plan, fishermen engagement in MPA management, fishermen representative in the MPA board, and promotion of sustainable fishing). These findings are pivotal to Mediterranean coastal communities so they can achieve conservation goals while allowing for profitable exploitation of fisheries resources.

Free-zone electrophoresis of animal cells. 1: Experiments on cell-cell interactions

NASA Technical Reports Server (NTRS)

Todd, P. W.; Hjerten, S.

1985-01-01

The electrophoretically migrating zones wasa monitored. The absence of fluid flows in the direction of migration permits direct measurement of electrophoretic velocities of any material. Sedimentation is orthogonal to electrokinetic motion and the effects of particle-particle interaction on electrophoretic mobility is studied by free zone electrophoresis. Fixed erythrocytes at high concentrations, mixtures of fixed erythrocytes from different animal species, and mixtures of cultured human cells were studied in low ionic strength buffers. The electrophoretic velocity of fixed erythrocytes was not altered by increasing cell concentration or by the mixing of erythrocytes from different species. When zones containing cultured human glial cells and neuroblastoma cells are permitted to interact during electrophoresis, altered migration patterns occur. It is found that cell-cell interactions depends upon cell type.

Water chemistry at Snowshoe Mountain, Colorado: mixed processes in a common bedrock

USGS Publications Warehouse

Hoch, A.R.; Reddy, M.M.

2001-01-01

At Snowshoe Mountain the primary bedrock is quite homogeneous, but weathering processes vary as waters moves through the soils, vadose zone and phreatic zone of the subsurface. In the thin soil, physical degradation of tuff facilitates preferential dissolution of potassium ion from glass within the rock matrix, while other silicate minerals remain unaltered. In the vadose zone, in the upper few meters of fractured bedrock, dilute water infiltrates during spring snowmelt and summer storms, leading to preferential dissolution of augite exposed on fracture surfaces. Deeper yet, in the phreatic zone of the fractured bedrock, Pleistocene calcite fracture fillings dissolve, and dioctahedral and trioctahedral clays form as penetrative weathering alters feldspar and pyroxene. Alkalinity is generated and silica concentrations are buffered by mineral alteration reactions.

Two-phase/two-phase heat exchanger simulation analysis

NASA Technical Reports Server (NTRS)

Kim, Rhyn H.

1992-01-01

The capillary pumped loop (CPL) system is one of the most desirable devices to dissipate heat energy in the radiation environment of the Space Station providing a relatively easy control of the temperature. A condenser, a component of the CPL system, is linked with a buffer evaporator in the form of an annulus section of a double tube heat exchanger arrangement: the concentric core of the double tube is the condenser; the annulus section is used as a buffer between the conditioned space and the radiation surrounding but works as an evaporator. A CPL system with this type of condenser is modeled to simulate its function numerically. Preliminary results for temperature variations of the system are shown and more investigations are suggested for further improvement.

Quantifying Spatial Misclassification in Exposure to Noise Complaints Among Low-Income Housing Residents Across New York City Neighborhoods: A Global Positioning System (GPS) Study

PubMed Central

Duncan, Dustin T.; Tamura, Kosuke; Regan, Seann D.; Athens, Jessica; Elbel, Brian; Meline, Julie; Al-Ajlouni, Yazan A.; Chaix, Basile

2016-01-01

Purpose To examine if there was spatial misclassification in exposure to neighborhood noise complaints among a sample of low-income housing residents in New York City, comparing home-based spatial buffers and Global Positioning Systems (GPS) daily path buffers. Methods Data came from the community-based NYC Low-Income Housing, Neighborhoods and Health Study, where GPS tracking of the sample was conducted for a week (analytic n=102). We created a GPS daily path buffer (a buffering zone drawn around GPS tracks) of 200-meters and 400-meters. We also used home-based buffers of 200-meters and 400-meters. Using these “neighborhoods” (or exposure areas) we calculated neighborhood exposure to noisy events from 311 complaints data (analytic n=143,967). Friedman tests (to compare overall differences in neighborhood definitions) were applied. Results There were differences in neighborhood noise complaints according to the selected neighborhood definitions (p<0.05). For example, the mean neighborhood noise complaint count was 1196 per square kilometer for the 400-meter home-based and 812 per square kilometer for the 400-meter activity space buffer, illustrating how neighborhood definition influences the estimates of exposure to neighborhood noise complaints. Conclusions These analyses suggest that, whenever appropriate, GPS neighborhood definitions can be used in spatial epidemiology research in spatially mobile populations to understand people's lived experience. PMID:28063754

Electrical properties of n-type GaSb substrates and p-type GaSb buffer layers for InAs/InGaSb superlattice infrared detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchel, W. C., E-mail: William.Mitchel.1@us.af.mil; Haugan, H. J.; Mou, Shin

2015-09-15

Lightly doped n-type GaSb substrates with p-type GaSb buffer layers are the preferred templates for growth of InAs/InGaSb superlattices used in infrared detector applications because of relatively high infrared transmission and a close lattice match to the superlattices. We report here temperature dependent resistivity and Hall effect measurements of bare substrates and substrate-p-type buffer layer structures grown by molecular beam epitaxy. Multicarrier analysis of the resistivity and Hall coefficient data demonstrate that high temperature transport in the substrates is due to conduction in both the high mobility zone center Γ band and the low mobility off-center L band. High overallmore » mobility values indicate the absence of close compensation and that improved infrared and transport properties were achieved by a reduction in intrinsic acceptor concentration. Standard transport measurements of the undoped buffer layers show p-type conduction up to 300 K indicating electrical isolation of the buffer layer from the lightly n-type GaSb substrate. However, the highest temperature data indicate the early stages of the expected p to n type conversion which leads to apparent anomalously high carrier concentrations and lower than expected mobilities. Data at 77 K indicate very high quality buffer layers.« less

A 3-D view of field-scale fault-zone cementation from geologically ground-truthed electrical resistivity

NASA Astrophysics Data System (ADS)

Barnes, H.; Spinelli, G. A.; Mozley, P.

2015-12-01

Fault-zones are an important control on fluid flow, affecting groundwater supply, hydrocarbon/contaminant migration, and waste/carbon storage. However, current models of fault seal are inadequate, primarily focusing on juxtaposition and entrainment effects, despite the recognition that fault-zone cementation is common and can dramatically reduce permeability. We map the 3D cementation patterns of the variably cemented Loma Blanca fault from the land surface to ~40 m depth, using electrical resistivity and induced polarization (IP). The carbonate-cemented fault zone is a region of anomalously low normalized chargeability, relative to the surrounding host material. Zones of low-normalized chargeability immediately under the exposed cement provide the first ground-truth that a cemented fault yields an observable IP anomaly. Low-normalized chargeability extends down from the surface exposure, surrounded by zones of high-normalized chargeability, at an orientation consistent with normal faults in the region; this likely indicates cementation of the fault zone at depth, which could be confirmed by drilling and coring. Our observations are consistent with: 1) the expectation that carbonate cement in a sandstone should lower normalized chargeability by reducing pore-surface area and bridging gaps in the pore space, and 2) laboratory experiments confirming that calcite precipitation within a column of glass beads decreases polarization magnitude. The ability to characterize spatial variations in the degree of fault-zone cementation with resistivity and IP has exciting implications for improving predictive models of the hydrogeologic impacts of cementation within faults.

Deep Fracturing of the Hard Rock Surrounding a Large Underground Cavern Subjected to High Geostress: In Situ Observation and Mechanism Analysis

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Pei, Shu-Feng; Jiang, Quan; Zhou, Yang-Yi; Li, Shao-Jun; Yao, Zhi-Bin

2017-08-01

Rocks that are far removed from caverns or tunnels peripheries and subjected to high geostress may undergo `deep fracturing'. Deep fracturing of hard rock can cause serious hazards that cause delays and increase the cost of construction of underground caverns with high sidewalls and large spans (especially when subjected to high geostress). To extensively investigate the mechanism responsible for deep fracturing, and the relationship between fracturing and the excavation & support of caverns, this paper presents a basic procedure for making in situ observations on the deep fracturing process in hard rock. The basic procedure involves predicting the stress concentration zones in the surrounding rocks of caverns induced by excavation using geomechanical techniques. Boreholes are then drilled through these stress concentration zones from pre-existing tunnels (such as auxiliary galleries) toward the caverns before its excavation. Continuous observations of the fracturing of the surrounding rocks are performed during excavation using a borehole camera in the boreholes in order to analyze the evolution of the fracturing process. The deep fracturing observed in a large underground cavern (high sidewalls and large span) in southwest China excavated in basalt under high geostress is also discussed. By continuously observing the hard rock surrounding the arch on the upstream side of the cavern during the excavation of the first three layers, it was observed that the fracturing developed into the surrounding rocks with downward excavation of the cavern. Fracturing was found at distances up to 8-9 m from the cavern periphery during the excavation of Layer III. Also, the cracks propagated along pre-existing joints or at the interfaces between quartz porphyry and the rock matrix. The relationship between deep fracturing of the surrounding rocks and the advance of the cavern working faces was analyzed during excavation of Layer Ib. The results indicate that the extent of the stress relief zone is about 7 m if footage of 3 m is adopted for the rate of advance of the cavern faces. An analysis of the effects of the initial geostress and evolving stress concentration on deep fracturing was also made. It could be concluded that the deep fracturing of the rocks in the upstream side of the cavern is caused by the combined effect of the high initial geostress, the transfer of the stress concentration zone toward the deep surrounding rocks, and the occurrence of discontinuities.

High-resolution geophysical data from the sea floor surrounding the Western Elizabeth Islands, Massachusetts

USGS Publications Warehouse

Pendleton, Elizabeth A.; Twichell, David C.; Foster, David S.; Worley, Charles R.; Irwin, Barry J.; Danforth, William W.

2011-01-01

Geophysical and geospatial data were collected in the nearshore area surrounding the western Elizabeth Islands, Massachusetts on the U.S. Geological Survey research vessel Rafael during September 2010 in a collaborative effort between the U.S. Geological Survey and the Massachusetts, Office of Coastal Zone Management. This report describes the results of the short-term goals of this collaborative effort, which were to map the geology of the inner shelf zone of the western Elizabeth Islands and study the geologic processes that have contributed to its evolution. Data collected during the survey include: Bathymetric and sidescan-sonar data, chirp seismic-reflection data , sound velocity profiles, and navigation data. The long-term goals of this project are to provide high-resolution geophysical data that will support research on the influence of sea-level change and sediment supply on coastal evolution and inventory subtidal marine habitat type and distribution within the coastal zone of Massachusetts.

Enhanced transpiration by riparian buffer trees in response to advection in a humid temperate agricultural landscape

USGS Publications Warehouse

Hernandez-Santana, V.; Asbjornsen, H.; Sauer, T.; Isenhart, T.; Schilling, K.; Schultz, Ronald

2011-01-01

Riparian buffers are designed as management practices to increase infiltration and reduce surface runoff and transport of sediment and nonpoint source pollutants from crop fields to adjacent streams. Achieving these ecosystem service goals depends, in part, on their ability to remove water from the soil via transpiration. In these systems, edges between crop fields and trees of the buffer systems can create advection processes, which could influence water use by trees. We conducted a field study in a riparian buffer system established in 1994 under a humid temperate climate, located in the Corn Belt region of the Midwestern U.S. (Iowa). The goals were to estimate stand level transpiration by the riparian buffer, quantify the controls on water use by the buffer system, and determine to what extent advective energy and tree position within the buffer system influence individual tree transpiration rates. We primarily focused on the water use response (determined with the Heat Ratio Method) of one of the dominant species (Acer saccharinum) and a subdominant (Juglans nigra). A few individuals of three additional species (Quercus bicolor, Betula nigra, Platanus occidentalis) were monitored over a shorter time period to assess the generality of responses. Meteorological stations were installed along a transect across the riparian buffer to determine the microclimate conditions. The differences found among individuals were attributed to differences in species sap velocities and sapwood depths, location relative to the forest edge and prevailing winds and canopy exposure and dominance. Sapflow rates for A. saccharinum trees growing at the SE edge (prevailing winds) were 39% greater than SE interior trees and 30% and 69% greater than NW interior and edge trees, respectively. No transpiration enhancement due to edge effect was detected in the subdominant J. nigra. The results were interpreted as indicative of advection effects from the surrounding crops. Further, significant differences were document in sapflow rates between the five study species, suggesting that selection of species is important for enhancing specific riparian buffer functions. However, more information is needed on water use patterns among diverse species growing under different climatic and biophysical conditions to assist policy and management decisions regarding effective buffer design. ?? 2011.

IN-SITU TREATMENT OF CHROMIUM SOURCE AREA USING REDOX MANIPULATION

EPA Science Inventory

Sodium dithionite was used to treat a chromium source zone in soils beneath an old chrome plating shop. The sodium dithionite was injected as a buffered solution into the soils to transform the chromium from the oxidized (+6) state to the reduced (+3) state. Once reduced the chro...

REDUCTIVE DETOXIFICATION AND IMMOBILIZATION OF CHROMATE PRESENT IN SOILS

EPA Science Inventory

Sodium dithionite was used to treat a chromium source zone in soils beneath an old chrome plating shop. The sodium dithionite was injected as a buffered solution into the soils to transform the chromium from the oxidized (+6) state to the reduced (+3) state. Once reduced the chro...

Reducing pesticide drift by considering propeller rotation effects from aerial application and near buffer zones

USDA-ARS?s Scientific Manuscript database

Off-target drift of chemical from agricultural spraying can damage sensitive crops, destroy beneficial insects, and intrude on human and domestic animal habitats, threatening environmental quality. Reduction of drift from aerial application can be facilitated at the edge of a field by offsetting spr...

NITRATE REMOVAL EFFECTIVENESS OF A RIPARIAN BUFFER ALONG A SMALL AGRICULTURAL STREAM IN WESTERN OREGON

EPA Science Inventory

We established two study sites with similar soils and hydrology but contrasting riparian vegetation along Lake Creek, an intermittent stream that drains perennial ryegrass fields in the Willamette Valley of western Oregon. One site had a non-cultivated riparian zone with a plant...

Riparian Zone Analysis for Forest Land Cover for the Conterminous US

EPA Science Inventory

One data layer describing the amount of forest land cover contained within a buffer area extending 30 meters to each side of all streams contained within the basin (Watershed Boundary Dataset (WBD) 12-digit Hydrologic Unit Code (HUC)) and from the edge of water bodies such as la...

Healthy food availability and participation in WIC (Special Supplemental Nutrition Program for Women, Infants, and Children) in food stores around lower- and higher-income elementary schools.

PubMed

Tester, June M; Yen, Irene H; Pallis, Lauren C; Laraia, Barbara A

2011-06-01

The nutritional intake of schoolchildren is affected not only by what is consumed at school but also by what is available in food outlets near schools. The present study surveys the range of food outlets around schools and examines how the availability of healthy food in the food stores encountered varies by income status of the school and by store participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) food assistance programme. Network buffer zones were created to reflect a quarter-mile (400 m) walk from elementary schools with lower- and higher-income student populations in Oakland, CA, USA. All food outlets within these zones were categorised by type, and audits were conducted within food stores using a checklist to assess for the presence or absence of twenty-eight healthy items (in five domains). Mid-sized city in the USA. Food outlets near public elementary schools. There were considerably more food outlets around lower-income schools. Food stores near higher-income schools had higher scores in two of the five domains (healthy beverages/low-fat dairy and healthy snacks). However, there were more food stores near lower-income schools that accepted WIC vouchers. Stratification showed that WIC stores scored higher than non-WIC stores on four of the five domains. Although higher-income students have more access to healthy food in the environment surrounding their school, this disparity appears to be mitigated by stores that accept WIC and offer more healthy snacking options. Federal programmes such as this may be particularly valuable for children in lower-income areas.

"Barnacle Bill" and Surrounding from Super-Pan

NASA Image and Video Library

1997-10-14

This is an image from the super-pan sequence. Of importance are some of the features around the rock nicknamed Barnacle Bill in the left foreground. The rock shows a "streamlined tail" composed of particles deposited by wind on the leeward (downwind) side of the rock. Also seen is a "moat" around the opposite (windward) side of the rock where either erosion (or non-deposition) of fine sediment has occurred. Mars Pathfinder scientist believe that the wind blowing over and around rocks like Barnacle Bill creates an airflow pattern wherein a buffer zone is formed immediately upwind of the rock and airflow patterns keep sediment from being deposited directly upwind of Barnacle Bill. On the downwind side, however, the airflow is complex and a small wake and tapered "dead air zone" form. Sediment can be deposited within this region, the shape of the formed deposit corresponds to the airflow patterns that exist behind the rock. Similar features have been observed at the Viking landing sites, and are thought to form under high wind conditions during the autumn and winter seasons in the northern hemisphere. This image mosaic was processed by the U.S. Geological Survey in support of the NASA/JPL Mars Pathfinder Mars Mission. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA00982

Analysis of pilocarpine and its trans epimer, isopilocarpine, by capillary electrophoresis.

PubMed

Baeyens, W; Weiss, G; Van Der Weken, G; Van Den Bossche, W

1993-05-28

Capillary zone electrophoresis was used for the separation of pilocarpine from its epimer, isopilocarpine, using coated fused-silica capillaries of 20 cm x 25 microm I.D., 8 kV running voltage, migration buffer of 0.1 M sodium dihydrogenphosphate pH 8, detection at 217 nm and injection by electromigration. Injections of aqueous, acid and basic solutions were compared. Linearity of the signal for pilocarpine hydrochloride up to 200 microg ml(-1) in 0.05 M hydrochloric acid was obtained, using naphazoline nitrate as internal standard. Optimization of migration buffer pH using coated silica capillaries of 50 cm x 50 microm I.D. showed that at pH 6.9 pilocarpine can be separated from ++isopilocarpine. Inclusion of beta-cyclodextrin in the buffer allows full baseline separation of both epimers. The method was applied to the analysis of a commercial ophthalmic pilocarpine solution.

Multi scale modelling of landslide hazard and risk assessment in data scarce area - a case study on Dhalai District, Tripura, India

NASA Astrophysics Data System (ADS)

Ghosh, Kapil; De, Sunil Kumar

2017-04-01

Successful landslide management plans and policy depends on in-depth knowledge about the hazard and associated risk. Thus, the present research is intended to present an integrated approach involving uses of geospatial technologies for landslide hazard and risk assessment at different scales (site specific to regional level). The landslide hazard map at regional scale (district level) is prepared by using weight-rating based method. To analyze landslide manifestation in the Dhalai district of Tripura different causative factor maps (lithology, road buffer, slope, relative relief, rainfall, fault buffer, landuse/landcover and drainage density) are derived. The analysis revealed that the geological structure and human interference have more influence than other considered factors on the landslide occurrences. The landslide susceptibility zonation map shows that about 1.64 and 16.68% of the total study area is falling under very high and high susceptibility zones respectively. The landslide risk assessment at district level is generated by integrating hazard scouring and resource damage potential scouring (fuzzy membership values) maps. The values of landslide risk matrix are varying within the range of 0.001 to 0.18 and the risk assessment map shows that only 0.45% (10.80 km2) of the district is under very high risk zone, whereas, about 50% pixels of existing road section are under very high to high level of landslide risk. The major part (94.06%) of the district is under very low to low risk zone. Landslide hazard and risk assessment at site specific level have been carried out through intensive field investigation in which it is found that the Ambassa landslide is located within 150 m buffer zone of fault line. Variation of geo-electrical resistivity (2.2Ωm to 31.4Ωm) indicates the complex geological character in this area. Based on the obtained geo-technical result which helps to identify the degree of risk to the existing resource, it is appropriate to implement the management plans such as construction of sub-surface drainage, extension of retaining walls, cutting/filling of slope in scientific manner. Keywords: landslide, hazard, risk, fuzzy set theory

[Photometric determination of butyl "aeroflot" flotation agent (sodium dibutyl dithiophosphate) in the air of work zone and skin washings].

PubMed

Dorogova, V B; Kucheriavykh, E I; Sokolova, T V

1989-01-01

Photometric procedure of butyl "aeroflot" identification in the work zone air and in wash-out from workers' integument was developed, The procedure was based on the formation of yellow- and orange-dyed copper dibutyl dithiophosphate under butyl "aeroflot" interaction with copper sulphate with the subsequent photometry of dyed solutions for the wavelength of 420 nm in the 10-mm cell. Buffer solution with pH-9.2 was used as an absorbing solution for the workplace air sampling and integument wash-out.

Performance Characteristics of the Electronic Snow Water Equivalent (SWE) Sensor in Arctic, Marine, and Humid Continental Climates

NASA Astrophysics Data System (ADS)

Johnson, J.; Gelvin, A. B.; Duvoy, P.; Schaefer, G. L.; Poole, G.; Horton, G. D.

2011-12-01

The USA ERDC CRREL and the USDA NRCS developed a 3-m square electronic SWE sensor (e-SWE sensor) consisting of nine perforated panels (a center panel to measure SWE and eight outer panels to buffer edge stress concentrations). Seven e-SWE sensors were installed in five different climate zones including north central and north coastal Alaska, Oregon, Newfoundland, and New York State. With the exception of New York State, the e-SWE sensors accurately measured SWE. The e-SWE sensor at Hogg Pass, OR, accurately measured SWE during five years of observations even when edge stress concentrations occurred. In windy conditions of northern Alaska, the sensor measured losses and gains in SWE with more reliability and higher accuracy than other standard methods. The sensor also detected snowdrift migration (comparing video and sensor measurements). In the thin, icy snow of New York the electronic SWE sensors over-measured SWE during midwinter. Over-measurement errors were caused by edge stress concentrations associated with strong icy layers, a shallow snow cover and possibly using a backfill material with different thermal properties and a large freeboard compared to the surrounding soil . Measurement accuracy improved in spring due to increased snow creep, associated with warming snow temperatures, which reduced edge stress concentrations.

Identifying the characteristic of SundaParahiyangan landscape for a model of sustainable agricultural landscape

NASA Astrophysics Data System (ADS)

Dahlan, M. Z.; Nurhayati, H. S. A.; Mugnisjah, W. Q.

2017-10-01

This study was an explorative study of the various forms of traditional ecological knowledge (TEK) of Sundanese people in the context of sustainable agriculture. The qualitative method was used to identify SundaParahiyangan landscape by using Rapid Participatory Rural Appraisal throughsemi-structured interviews, focus group discussions, and field survey. The Landscape Characteristic Assessment and Community Sustainability Assessment were used to analyze the characteristic of landscape to achieve the sustainable agricultural landscape criteria proposed by US Department of Agriculture. The results revealed that the SundaParahiyangan agricultural landscape has a unique characteristic as a result of the long-term adaptation of agricultural society to theirlandscape through a learning process for generations. In general, this character was reflected in the typical of Sundanese’s agroecosystems such as forest garden, mixed garden, paddy field, and home garden. In addition, concept of kabuyutan is one of the TEKs related to understanding and utilization of landscape has been adapted on revitalizing the role of landscape surrounding the agroecosystem as the buffer zone by calculating and designating protected areas. To support the sustainability of production area, integrated practices of agroforestry with low-external-input and sustainable agriculture (LEISA) system can be applied in utilizing and managing agricultural resources.

Noninvasive genetic population survey of snow leopards (Panthera uncia) in Kangchenjunga conservation area, Shey Phoksundo National Park and surrounding buffer zones of Nepal.

PubMed

Karmacharya, Dibesh B; Thapa, Kamal; Shrestha, Rinjan; Dhakal, Maheshwar; Janecka, Jan E

2011-11-28

The endangered snow leopard is found throughout major mountain ranges of Central Asia, including the remote Himalayas. However, because of their elusive behavior, sparse distribution, and poor access to their habitat, there is a lack of reliable information on their population status and demography, particularly in Nepal. Therefore, we utilized noninvasive genetic techniques to conduct a preliminary snow leopard survey in two protected areas of Nepal. A total of 71 putative snow leopard scats were collected and analyzed from two different areas; Shey Phoksundo National Park (SPNP) in the west and Kangchanjunga Conservation Area (KCA) in the east. Nineteen (27%) scats were genetically identified as snow leopards, and 10 (53%) of these were successfully genotyped at 6 microsatellite loci. Two samples showed identical genotype profiles indicating a total of 9 individual snow leopards. Four individual snow leopards were identified in SPNP (1 male and 3 females) and five (2 males and 3 females) in KCA. We were able to confirm the occurrence of snow leopards in both study areas and determine the minimum number present. This information can be used to design more in-depth population surveys that will enable estimation of snow leopard population abundance at these sites.

Noninvasive genetic population survey of snow leopards (Panthera uncia) in Kangchenjunga conservation area, Shey Phoksundo National Park and surrounding buffer zones of Nepal

PubMed Central

2011-01-01

Background The endangered snow leopard is found throughout major mountain ranges of Central Asia, including the remote Himalayas. However, because of their elusive behavior, sparse distribution, and poor access to their habitat, there is a lack of reliable information on their population status and demography, particularly in Nepal. Therefore, we utilized noninvasive genetic techniques to conduct a preliminary snow leopard survey in two protected areas of Nepal. Results A total of 71 putative snow leopard scats were collected and analyzed from two different areas; Shey Phoksundo National Park (SPNP) in the west and Kangchanjunga Conservation Area (KCA) in the east. Nineteen (27%) scats were genetically identified as snow leopards, and 10 (53%) of these were successfully genotyped at 6 microsatellite loci. Two samples showed identical genotype profiles indicating a total of 9 individual snow leopards. Four individual snow leopards were identified in SPNP (1 male and 3 females) and five (2 males and 3 females) in KCA. Conclusions We were able to confirm the occurrence of snow leopards in both study areas and determine the minimum number present. This information can be used to design more in-depth population surveys that will enable estimation of snow leopard population abundance at these sites. PMID:22117538

Spatial variations in water quality of river Ganga with respect to land uses in Varanasi.

PubMed

Sharma, Shikha; Roy, Arijit; Agrawal, Madhoolika

2016-11-01

Water quality of a river is a function of surrounding environment and land use due to its connectivity with land, resulting in pollutants finding their way through land. This necessitates a spatially explicit study of river ecology. The paper presents a pioneer study to establish and explore the linkage between land use and water quality of river Ganga in Varanasi district. The land use land cover (LULC) map of 20 km of river stretch for buffer radii of 1000 m in Varanasi revealed that riparian vegetation is negligible in the district. The hierarchical cluster analysis of LULC data suggested that there are two major land use categories, viz., urban and agriculture. The land use wise principal component analysis (PCA) suggested that urbanized areas are major contributor of metals, whereas agricultural land contributes organic matter into the river. The Spearman correlation study revealed that with rising urbanization, the pollutant load into the river increased compared to that from agricultural land use. The statistical analysis of the data clearly concluded that water quality of river Ganga at Varanasi was a function of adjacent land use. The study provides an insight anticipating the Indian government to embrace the relationship of land use to river water quality while formulating policies for the upcoming River Regulation Zone.

Seismic Tomography of the Arabian-Eurasian Collision Zone and Surrounding Areas

DTIC Science & Technology

2010-05-20

zone. The crustal models correlate well with geologic and tectonic features. The upper mantle tomograms show the images of the subducted Neotethys...We first obtain Pn and Sn velocities using local and regional arrival time data. Second, we obtain the 3-D crustal P and S velocity models...teleseismic tomography provides a high-resolution, 3-D P-wave velocity model for the crust, upper mantle, and the transition zone. The crustal models

Mapping Soil pH Buffering Capacity of Selected Fields

NASA Technical Reports Server (NTRS)

Weaver, A. R.; Kissel, D. E.; Chen, F.; West, L. T.; Adkins, W.; Rickman, D.; Luvall, J. C.

2003-01-01

Soil pH buffering capacity, since it varies spatially within crop production fields, may be used to define sampling zones to assess lime requirement, or for modeling changes in soil pH when acid forming fertilizers or manures are added to a field. Our objective was to develop a procedure to map this soil property. One hundred thirty six soil samples (0 to 15 cm depth) from three Georgia Coastal Plain fields were titrated with calcium hydroxide to characterize differences in pH buffering capacity of the soils. Since the relationship between soil pH and added calcium hydroxide was approximately linear for all samples up to pH 6.5, the slope values of these linear relationships for all soils were regressed on the organic C and clay contents of the 136 soil samples using multiple linear regression. The equation that fit the data best was b (slope of pH vs. lime added) = 0.00029 - 0.00003 * % clay + 0.00135 * % O/C, r(exp 2) = 0.68. This equation was applied within geographic information system (GIS) software to create maps of soil pH buffering capacity for the three fields. When the mapped values of the pH buffering capacity were compared with measured values for a total of 18 locations in the three fields, there was good general agreement. A regression of directly measured pH buffering capacities on mapped pH buffering capacities at the field locations for these samples gave an r(exp 2) of 0.88 with a slope of 1.04 for a group of soils that varied approximately tenfold in their pH buffering capacities.

33 CFR 147.T08-849 - DEEPWATER HORIZON Mobile Offshore Drilling Unit Safety Zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DEEPWATER HORIZON Mobile Offshore Drilling Unit Safety Zone. (a) Location. All areas within 500 meters (1640... area surrounds the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU), that sank in the... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false DEEPWATER HORIZON Mobile Offshore...

50 CFR 648.148 - Special management zones.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Black Sea Bass Fishery § 648.148 Special management zones. The recipient of a U.S. Army Corps of... purposes of fishing may request that an area surrounding and including the site be designated by the MAFMC... fishing gear that are not compatible with the intent of the artificial reef or fish attraction device or...

76 FR 49664 - Safety Zone; M/V DAVY CROCKETT, Columbia River

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-11

...-AA00 Safety Zone; M/V DAVY CROCKETT, Columbia River AGENCY: Coast Guard, DHS. ACTION: Temporary final... waters of the Columbia River surrounding the M/ V DAVY CROCKETT at approximate river mile 117. The... operations involving the M/ V DAVY CROCKETT. All persons and vessels are prohibited from entering or...

78 FR 53668 - Regulated Navigation Area; Maine Kennebec Bridge Construction Zone, Kennebec River, Richmond, ME

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-30

...-AA11 Regulated Navigation Area; Maine Kennebec Bridge Construction Zone, Kennebec River, Richmond, ME... surrounding the Maine Kennebec Bridge between Richmond, ME, and Dresden, ME. This RNA allows the Coast Guard to enforce speed and wake restrictions and prohibit all vessel traffic through the RNA during bridge...

A Landscape-based model for predicting Mycobacterium ulcerans infection (Buruli Ulcer disease) presence in Benin, West Africa.

PubMed

Wagner, Tyler; Benbow, M Eric; Burns, Meghan; Johnson, R Christian; Merritt, Richard W; Qi, Jiaguo; Small, Pamela L C

2008-03-01

Mycobacterium ulcerans infection (Buruli ulcer [BU] disease) is an emerging tropical disease that causes severe morbidity in many communities, especially those in close proximity to aquatic environments. Research and control efforts are severely hampered by the paucity of data regarding the ecology of this disease; for example, the vectors and modes of transmission remain unknown. It is hypothesized that BU presence is associated with altered landscapes that perturb aquatic ecosystems; however, this has yet to be quantified over large spatial scales. We quantified relationships between land use/land cover (LULC) characteristics surrounding individual villages and BU presence in Benin, West Africa. We also examined the effects of other village-level characteristics which we hypothesized to affect BU presence, such as village distance to the nearest river. We found that as the percent urban land use in a 50-km buffer surrounding a village increased, the probability of BU presence decreased. Conversely, as the percent agricultural land use in a 20-km buffer surrounding a village increased, the probability of BU presence increased. Landscape-based models had predictive ability when predicting BU presence using validation data sets from Benin and Ghana, West Africa. Our analyses suggest that relatively small amounts of urbanization are associated with a decrease in the probability of BU presence, and we hypothesize that this is due to the increased availability of pumped water in urban environments. Our models provide an initial approach to predicting the probability of BU presence over large spatial scales in Benin and Ghana, using readily available land use data.

Accuracy of buffered-force QM/MM simulations of silica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peguiron, Anke; Moras, Gianpietro; Colombi Ciacchi, Lucio

2015-02-14

We report comparisons between energy-based quantum mechanics/molecular mechanics (QM/MM) and buffered force-based QM/MM simulations in silica. Local quantities—such as density of states, charges, forces, and geometries—calculated with both QM/MM approaches are compared to the results of full QM simulations. We find the length scale over which forces computed using a finite QM region converge to reference values obtained in full quantum-mechanical calculations is ∼10 Å rather than the ∼5 Å previously reported for covalent materials such as silicon. Electrostatic embedding of the QM region in the surrounding classical point charges gives only a minor contribution to the force convergence. Whilemore » the energy-based approach provides accurate results in geometry optimizations of point defects, we find that the removal of large force errors at the QM/MM boundary provided by the buffered force-based scheme is necessary for accurate constrained geometry optimizations where Si–O bonds are elongated and for finite-temperature molecular dynamics simulations of crack propagation. Moreover, the buffered approach allows for more flexibility, since special-purpose QM/MM coupling terms that link QM and MM atoms are not required and the region that is treated at the QM level can be adaptively redefined during the course of a dynamical simulation.« less

Factors influencing dust exposure: finishing activities in drywall construction.

PubMed

Simmons, Catherine E; Jones, Rachael M; Boelter, Fred W

2011-05-01

Sanding drywall joint compound is a dusty construction activity. We studied potential factors influencing exposure to respirable and total dust for sanders and bystanders in the area of drywall joint compound finishing in 17 test events within a room-scale isolation chamber. We found the air change rate to be negatively correlated with dust C(twa) both in the sander's personal breathing zone and surrounding area. We could not conclude that sanding tool type systematically influences dust C(twa), but the use of 80-grit abrasive was associated with the highest dust C(twa). We found respirable dusts were uniformly dispersed 1-8.2 m from sanding activities at a fixed location. As anticipated, both respirable and total dust C(twa) in the sander's personal breathing zone are higher than in the surrounding area. The respirable fraction of the total dust mass C(twa) was greater in the surrounding area than in the sander's personal breathing zone. Respirable dust concentrations measured in real time increased over the duration of sanding, exhibiting a temporal trend that is similar to that predicted by the well-mixed box model with contaminant removal by mechanical ventilation only, and continuous emission. Dust concentrations returned to pre-activity (background) levels 2-4 hr after cessation of the sanding activity.

The geography of crime and violence surrounding tobacco shops, medical marijuana dispensaries, and off-sale alcohol outlets in a large, urban low-income community of color.

PubMed

Subica, Andrew M; Douglas, Jason A; Kepple, Nancy J; Villanueva, Sandra; Grills, Cheryl T

2018-03-01

Tobacco shops, medical marijuana dispensaries (MMD), and off-sale alcohol outlets are legal and prevalent in South Los Angeles, California-a high-crime, low-income urban community of color. This research is the first to explore the geographic associations between these three legal drug outlets with surrounding crime and violence in a large low-income urban community of color. First, spatial buffer analyses were performed using point-location and publically accessible January-December 2014 crime data to examine the geography of all felony property and violent crimes occurring within 100, 200, 500, and 1000-foot buffers of these three legal drug outlet types across South Los Angeles. Next, spatial regression analyses explored the geographic associations between density of these outlets and property and violent crimes at the census tract level. Results indicated that mean property and violent crime rates within 100-foot buffers of tobacco shops and alcohol outlets-but not MMDs-substantially exceeded community-wide mean crime rates and rates around grocery/convenience stores (i.e., comparison properties licensed to sell both alcohol and tobacco). Spatial regression analyses confirmed that tobacco shops significantly positively associated with property and violent crimes after controlling for key neighborhood factors (poverty, renters, resident mobility, ethnic/racial heterogeneity). Thus, study findings provide the first empirical evidence that tobacco shops may constitute public health threats that associate with crime and violence in U.S. low-income urban communities of color. Implementing and enforcing control policies that regulate and monitor tobacco shops in these communities may promote community health by improving public safety. Copyright © 2017 Elsevier Inc. All rights reserved.

How well do route survey areas represent landscapes at larger spatial extents? An analysis of land cover composition along Breeding Bird Survey routes

USGS Publications Warehouse

Veech, Joseph A.; Pardieck, Keith L.; Ziolkowski, David

2017-01-01

The occurrence of birds in a survey unit is partly determined by the habitat present. Moreover, some bird species preferentially avoid some land cover types and are attracted to others. As such, land cover composition within the 400 m survey areas along a Breeding Bird Survey (BBS) route clearly influences the species available to be detected. Ideally, to extend survey results to the larger landscape, land cover composition within the survey area should be similar to that at larger spatial extents defining the landscape. Such representativeness helps minimize possible roadside effects (bias), here defined as differences in bird species composition and abundance along a roadside as compared to a larger surrounding landscape. We used land cover data from the 2011 National Land Cover Database to examine representativeness of land cover composition along routes. Using ArcGIS, the percentages of each of 15 land cover types within 400 m buffers along 2,696 U.S. BBS routes were calculated and compared to percentages in 2 km, 5 km, and 10 km buffers surrounding each route. This assessment revealed that aquatic cover types and highly urbanized land tend to be slightly underrepresented in the survey areas. Two anthropogenic cover types (pasture/hay and cropland) may be slightly overrepresented in the survey areas. Over all cover types, 92% of the 2,696 routes exhibited “good” representativeness, with <5 percentage points per cover type difference in proportional cover between the 400 m and 10 km buffers. This assessment further supports previous research indicating that any land-cover-based roadside bias in the bird data of the BBS is likely minimal.

A reaction-diffusion model of CO2 influx into an oocyte

PubMed Central

Somersalo, Erkki; Occhipinti, Rossana; Boron, Walter F.; Calvetti, Daniela

2012-01-01

We have developed and implemented a novel mathematical model for simulating transients in surface pH (pHS) and intracellular pH (pHi) caused by the influx of carbon dioxide (CO2) into a Xenopus oocyte. These transients are important tools for studying gas channels. We assume that the oocyte is a sphere surrounded by a thin layer of unstirred fluid, the extracellular unconvected fluid (EUF), which is in turn surrounded by the well-stirred bulk extracellular fluid (BECF) that represents an infinite reservoir for all solutes. Here, we assume that the oocyte plasma membrane is permeable only to CO2. In both the EUF and intracellular space, solute concentrations can change because of diffusion and reactions. The reactions are the slow equilibration of the CO2 hydration-dehydration reactions and competing equilibria among carbonic acid (H2CO3)/bicarbonate ( HCO3-) and a multitude of non-CO2/HCO3- buffers. Mathematically, the model is described by a coupled system of reaction-diffusion equations that—assuming spherical radial symmetry—we solved using the method of lines with appropriate stiff solvers. In agreement with experimental data (Musa-Aziz et al, PNAS 2009, 106:5406–5411), the model predicts that exposing the cell to extracellular 1.5% CO2/10 mM HCO3- (pH 7.50) causes pHi to fall and pHS to rise rapidly to a peak and then decay. Moreover, the model provides insights into the competition between diffusion and reaction processes when we change the width of the EUF, membrane permeability to CO2, native extra-and intracellular carbonic anhydrase-like activities, the non-CO2/HCO3- (intrinsic) intracellular buffering power, or mobility of intrinsic intracellular buffers. PMID:22728674

Snow Water Equivalent Pressure Sensor Performance in a Deep Snow Cover

NASA Astrophysics Data System (ADS)

Johnson, J. B.; Gelvin, A. B.; Schaefer, G. L.

2006-12-01

Accurate measurements of snow water equivalent are important for a variety of water resource management operations. In the western US, real-time SWE measurements are made using snow pillows that can experience errors from snow-bridging, poor installation configuration, and enhanced solar radiation absorption. Snow pillow installations that place the pillow abnormally above or below the surrounding terrain can affect snow catchment. Snow pillows made from dark materials can preferentially absorb solar radiation penetrating the snow causing accelerated melt. To reduce these problems, the NRCS and CRREL developed an electronic SWE sensor to replace the snow pillow. During the winter of 2005-2006 the NRCS/CRREL electronic sensor was deployed at Hogg Pass, Oregon, with a total SWE accumulation of about 1000 mm. The NRCS/CRREL sensor consists of a center panel surrounded by eight outer panels whose purpose is to buffer snow bridging loads. By separately monitoring load cell outputs from the sensor, snow-bridging events are directly measured. A snow-bridging event associated with a 180 mm SWE accumulation in a 24-hour period exhibited a SWE over-measurement of 60% at the sensor edge while the center panel showed less than a 10% effect. Individual load cell outputs were used to determine the most representative SWE value, which was within 5% of the adjacent snow pillow value. During the spring melt the NRCS/CRREL sensor melt recession lagged that of the snow pillow by about a week. Physical examination of the Hogg Pass site indicated that the CRREL sensor results were consistent with snow-on-the-ground observations. The snow pillow experienced accelerated melt because it was installed on a mound above the surrounding terrain and absorbed solar radiation through the snow. SWE pressure sensor accuracy is significantly improved by using an active center panel surrounded by buffer panels, monitoring several individual load cell to detect and correct snow-bridging errors, and reducing the radiation and topographic profile of the sensor.

Electrohydrodynamic distortion of sample streams in continuous flow electrophoresis

NASA Technical Reports Server (NTRS)

Rhodes, Percy H.; Snyder, Robert S.; Roberts, Glyn O.

1989-01-01

Continuous flow electrophoresis experiments were carried out, using an electrolyte and a sample both made of aqueous solutions of phosphate buffer (with polystyrene latex added for visibility), to investigate causes of the sample spreading in this procedure. It is shown theoretically that an electric field perpendicular to a circular filament of conducting fluid surrounded by a fluid of different conductivity produces an electrohydrodynamic flow, which distorts the filament into an ellipse. Experimental results were found to be fully consistent with theretical predictions. It was found that the rate of distortion of the sample stream into a ribbon was proportional to the square of the applied voltage gradient. Furthermore, the orientation of the ribbon depends on the ratios of dielectric constant and electrical conductivity between the buffer and the sample.

Dry creek long-term watershed study: buffer zone performance as viable amphibian habitat

Treesearch

Brooke L. Talley; Thomas L. Crisman

2006-01-01

As bioindicators, amphibians typically require both terrestrial and aquatic habitats to complete their life cycles. Pre- timber-harvest monitoring (December 2002 through September 2003) of salamander and frog (Hylidae) populations was conducted in four watersheds of Decatur County, GA. Post- timber-harvest monitoring (December 2003 through September...

Surface Water and Groundwater Nitrogen Dynamics in a Well Drained Riparian Forest within a Poorly Drained Agricultural Landscape

EPA Science Inventory

The effectiveness of riparian zones in mitigating nutrients in ground and surface water depends on the climate, management and hydrogeomorphology of a site. The purpose of this study was to determine the efficacy of a well-drained, mixed-deciduous riparian forest to buffer a ri...

75 FR 17151 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, OMB No...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-05

.... 1660--NEW; FEMA Form 089-23, Buffer Zone Plan; FEMA Form 089-23A, Vulnerability Reduction Purchasing...-23A, Vulnerability Reduction Purchasing Plan. Abstract: The information collection activity is the... enables FEMA to evaluate applications and make award decisions, monitor ongoing performance and manage the...

EnviroAtlas - Percent Stream Buffer Zone As Natural Land Cover for the Conterminous United States

EPA Pesticide Factsheets

This EnviroAtlas dataset shows the percentage of land area within a 30 meter buffer zone along the National Hydrography Dataset (NHD) high resolution stream network, and along water bodies such as lakes and ponds that are connected via flow to the streams, that is classified as forest land cover, modified forest land cover, and natural land cover using the 2006 National Land Cover Dataset (NLCD) for each Watershed Boundary Dataset (WBD) 12-digit hydrological unit (HUC) in the conterminous United States. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Quality control of benserazide-levodopa and carbidopa-levodopa tablets by capillary zone electrophoresis.

PubMed

Fanali, S; Pucci, V; Sabbioni, C; Raggi, M A

2000-07-01

In modern practice, the treatment of Parkinson's disease and syndrome is carried out using pharmaceutical formulations containing a combination of levodopa and a decarboxylation inhibitor (carbidopa or benserazide). Two pharmaceutical formulations were quantified by capillary zone electrophoresis using two procedures which differed only in the kind of background electrolyte used. One procedure used a 25 mM phosphate buffer, pH 2.5, while the second one used a 25 mM borate buffer, pH 8.5. The electrophoretic analysis was carried out using an uncoated fused- silica capillary, a separation voltage of 20 kV with currents typically less than 60 microA, and spectrophotometric detection at 205 nm. Calibration curves were performed for levodopa (concentration range 1-100 microg/mL), for carbidopa and benserazide (1-50 microg/mL), and the plots of the peak area versus concentration were found to be linear with a correlation coefficient better than 0.9990. Satisfactory results were obtained when commercial tablets were analyzed in terms of accuracy (98-102%), repeatability (0.6-2.0%), and intermediate precision (1.1-2.6%).

Two-dimensional capillary electrophoresis: capillary isoelectric focusing and capillary zone electrophoresis with laser-induced fluorescence detection

PubMed Central

Dickerson, Jane A.; Ramsay, Lauren M.; Dada, Oluwatosin O.; Cermak, Nathan

2011-01-01

Capillary isoelectric focusing and capillary zone electrophoresis are coupled with laser-induced fluorescence detection to create an ultrasensitive two-dimensional separation method for proteins. In this method, two capillaries are joined through a buffer filled interface. Separate power supplies control the potential at the injection end of the first capillary and at the interface; the detector is held at ground potential. Proteins are labeled with the fluorogenic reagent Chromeo P503, which preserves the isoelectric point of the labeled protein. The labeled proteins were mixed with ampholytes and injected into the first dimension capillary. A focusing step was performed with the injection end of the capillary at high pH and the interface at low pH. To mobilize components, the interface was filled with a high pH buffer, which was compatible with the second dimension separation. A fraction was transferred to the second dimension capillary for separation. The process of fraction transfer and second dimension separation was repeated two dozen times. The separation produced a spot capacity of 125. PMID:20603830

The effects of glycosaminoglycan degradation on the mechanical behavior of the posterior porcine sclera

PubMed Central

Murienne, Barbara J.; Jefferys, Joan L.; Quigley, Harry A.; Nguyen, Thao D.

2014-01-01

Pathological changes in scleral glycosaminoglycan (GAG) content and in scleral mechanical properties have been observed in eyes with glaucoma and myopia. The purpose of this study is to investigate the effect of GAG removal on the scleral mechanical properties to better understand the impact of GAG content variations in the pathophysiology of glaucoma and myopia. We measured how the removal of sulphated GAG (s-GAG) affected the hydration, thickness and mechanical properties of the posterior sclera in enucleated eyes of 6–9 month-old pigs. Measurements were made in 4 regions centered on the optic nerve head (ONH) and evaluated under 3 conditions: no treatment (control), after treatment in buffer solution alone, and after treatment in buffer containing chondroitinase ABC (ChABC) to remove s-GAGs. The specimens were mechanically tested by pressure-controlled inflation with full-field deformation mapping using digital image correlation (DIC). The mechanical outcomes described the tissue tensile and viscoelastic behavior. Treatment with buffer alone increased the hydration of the posterior sclera compared to controls, while s-GAG removal caused a further increase in hydration compared to buffer-treated scleras. Buffer-treatment significantly changed the scleral mechanical behavior compared to the control condition, in a manner consistent with an increase in hydration. Specifically, buffer-treatment led to an increase in low-pressure stiffness, hysteresis, and creep rate, and a decrease in high-pressure stiffness. ChABC-treatment on buffer-treated scleras had opposite mechanical effects than buffer-treatment on controls, leading to a decrease in low-pressure stiffness, hysteresis, and creep rate, and an increase in high-pressure stiffness and transition strain. Furthermore, s-GAG digestion dramatically reduced the differences in the mechanical behavior among the 4 quadrants surrounding the ONH as well as the differences between the circumferential and meridional responses compared to the buffer-treated condition. These findings demonstrate a significant effect of s-GAGs on both the stiffness and time-dependent behavior of the sclera. Alterations in s-GAG content may contribute to the altered creep and stiffness of the sclera of myopic and glaucoma eyes. PMID:25448352

Quantifying spatial misclassification in exposure to noise complaints among low-income housing residents across New York City neighborhoods: a Global Positioning System (GPS) study.

PubMed

Duncan, Dustin T; Tamura, Kosuke; Regan, Seann D; Athens, Jessica; Elbel, Brian; Meline, Julie; Al-Ajlouni, Yazan A; Chaix, Basile

2017-01-01

To examine if there was spatial misclassification in exposure to neighborhood noise complaints among a sample of low-income housing residents in New York City, comparing home-based spatial buffers and Global Positioning System (GPS) daily path buffers. Data came from the community-based NYC Low-Income Housing, Neighborhoods and Health Study, where GPS tracking of the sample was conducted for a week (analytic n = 102). We created a GPS daily path buffer (a buffering zone drawn around GPS tracks) of 200 m and 400 m. We also used home-based buffers of 200 m and 400 m. Using these "neighborhoods" (or exposure areas), we calculated neighborhood exposure to noisy events from 311 complaints data (analytic n = 143,967). Friedman tests (to compare overall differences in neighborhood definitions) were applied. There were differences in neighborhood noise complaints according to the selected neighborhood definitions (P < .05). For example, the mean neighborhood noise complaint count was 1196 per square kilometer for the 400-m home-based and 812 per square kilometer for the 400-m activity space buffer, illustrating how neighborhood definition influences the estimates of exposure to neighborhood noise complaints. These analyses suggest that, whenever appropriate, GPS neighborhood definitions can be used in spatial epidemiology research in spatially mobile populations to understand people's lived experience. Copyright © 2016 Elsevier Inc. All rights reserved.

Three-stage nucleation and growth of Ge self-assembled quantum dots grown on partially relaxed SiGe buffer layers

NASA Astrophysics Data System (ADS)

Kim, H. J.; Zhao, Z. M.; Xie, Y. H.

2003-11-01

Three-stage nucleation and growth of Ge self-assembled quantum dots (SAQDs) on a relaxed SiGe buffer layer has been studied. Plastic relaxation of the SiGe buffer layer is associated with a network of buried 60° dislocations leading to an undulating strain field. As a result, the surface possesses three different types of sites for the nucleation and growth of Ge SAQDs: over the intersection of two perpendicular buried dislocations, over a single dislocation line, and in the region beyond one diffusion length away from any dislocation. Ge SAQDs are observed to nucleate exclusively over the dislocation intersections first, followed by over single dislocation lines, and finally in the region far away from dislocations. By increasing the Ge coverage at a slow rate, the prenucleation stage at the various sites is observed. It appears that the varying strain field has a significant effect on both the diffusion of Ge adatoms before SAQD nucleation, as well as the shape evolution of the SAQDs after they form. Moreover, two distinctly different self-assembly mechanisms are observed at different sites. There exist denuded zones free of Ge SAQDs adjacent to dislocation lines. The width of the denuded zone can be used to make direct determination of the Ge adatom diffusion lengths. The partially relaxed substrate provides a useful experimental vehicle for the in-depth understanding of the formation mechanism of SAQDs grown epitaxially in the Stranski-Krastanov growth mode.

Insights of Mixing on the Assembly of DNA Nanoparticles

NASA Astrophysics Data System (ADS)

Williams, Manda S.

Size is a crucial parameter in the delivery of nanoparticle therapeutics, affecting mechanisms such as tissue delivery, clearance, and cellular uptake. The morphology of nanoparticles is dependent both upon chemistry and the physical process of assembly. Polyplexes, a major class of non-viral gene delivery vectors, are conventionally prepared by vortex mixing, resulting in non-uniform nanoparticles and poor reproducibility. Better understanding and control of the physical process of assembly, and mixing in particular, will produce polyplexes of a more uniform and reliable size, optimizing their efficiency for laboratory and clinical use. "Mixing" is the reduction of length scale of a system to accelerate diffusion until a uniform concentration is achieved. Vortex mixing is poorly characterized and sensitive to protocols. Microfluidic systems are notable for predictable fluid behavior, and are ideal for analyzing and controlling the physical interaction of reagents on the microscale, realm where mixing occurs. Several microdevices for the preparation of DNA polyplexes are explored here. Firstly, the staggered herringbone mixer, a chaotic advection micromixer, is used to observe the effects of mixing time on nanoparticle size. Next, a novel device to surround the reagent flows with a sheath of buffer, preventing interaction with the walls and confining the complexation to a zone of lower, less variable shear and residence time, is used to demonstrate the role of shear in nanoparticle assembly. Lastly, uneven diffusion between ion pairs produces a small separation of charge at fluid interfaces; this short-lived electric field has a significant impact on the transport of DNA over the time scales of mixing and complexation. The effects of common buffers on the transport of DNA are examined for possible applications to mixing and complexation. These three investigations demonstrate the importance of the physical process in polyplex assembly, and indicate several important considerations in the development of new protocols and devices.

Legal space for syringe exchange programs in hot spots of injection drug use-related crime.

PubMed

Allen, Sean T; Ruiz, Monica S; Jones, Jeff; Turner, Monique M

2016-04-26

Copious evidence indicates that syringe exchange programs (SEPs) are effective structural interventions for HIV prevention among persons who inject drugs (PWID). The efficacy of SEPs in supporting the public health needs of PWID populations is partially dependent on their accessibility and consistent utilization among injectors. Research has shown that SEP access is an important predictor of PWID retention at SEPs, yet policies exist that may limit the geographic areas where SEP operations may legally occur. Since 2000 in the District of Columbia (DC), SEP operations have been subject to the 1000 Foot Rule (§48-1121), a policy that prohibits the distribution of "any needle or syringe for the hypodermic injection of any illegal drug in any area of the District of Columbia which is within 1000 feet of a public or private elementary or secondary school (including a public charter school)." The 1000 Foot Rule may impede SEP services in areas that are in urgent need for harm reduction services, such as locations where injections are happening in "real time" or where drugs are purchased or exchanged. We examined the effects of the 1000 Foot Rule on SEP operational space in injection drug use (IDU)-related crime (i.e., heroin possession or distribution) hot spots from 2000 to 2010. Data from the DC Metropolitan Police Department were used to identify IDU-related crime hot spots. School operation data were matched to a dataset that described the approximate physical property boundaries of land parcels. A 1000-ft buffer was applied to all school property boundaries. The overlap between the IDU-related crime hot spots and the school buffer zones was calculated by academic year. When overlaying the land space associated with IDU-related crime hot spots on the maps of school boundaries per the 1000-ft buffer zone stipulation, we found that the majority of land space in these locations was ineligible for legal SEP operations. More specifically, the ineligible space in the identified hot spots in each academic year ranged from 51.93 to 88.29 % of the total hot spot area. The removal of the 1000 Foot Rule could significantly improve the public health of PWID via increased access to harm reduction services. Buffer zone policies that restrict SEP operational space negatively affect the provision of harm reduction services to PWID.

Managing individual nests promotes population recovery of a top predator

USGS Publications Warehouse

Cruz, Jennyffer; Windels, Steve K.; Thogmartin, Wayne E.; Crimmins, Shawn M.; Grim, Leland; Zuckerberg, Benjamin

2018-01-01

Threatened species are managed using diverse conservation tactics implemented at multiple scales ranging from protecting individuals, to populations, to entire species. Individual protection strives to promote recovery at the population‐ or species‐level, although this is seldom evaluated.After decades of widespread declines, bald eagles, Haliaeetus leucocephalus, are recovering throughout their range due to legal protection and pesticide bans. However, like other raptors, their recovery remains threatened by human activities. Bald eagle nests are commonly managed using buffer zones to minimize human disturbance, but the benefits of this practice remain unquantified.Within Voyageurs National Park (VNP), Minnesota, USA, managers have monitored bald eagle populations for over 40 years, and since 1991, have protected at‐risk nests from human disturbance using buffer zones (200 and 400 m radius). We aimed to (1) quantify the recovery of bald eagles in VNP (1973–2016), and (2) provide a first‐ever evaluation of the individual‐ and population‐level effects of managing individual nests. To do so, we developed Bayesian Integrated Population Models combining observations of nest occupancy and reproductive output (metrics commonly collected for raptors) to estimate nest‐level probabilities of occupancy, nest success, and high productivity (producing ≥2 nestlings), as well as population‐level estimates of abundance and growth.The breeding population of bald eagles at VNP increased steadily from <10 pairs in the late 1970s to 48 pairs by 2016. At the nest‐level, management significantly improved occupancy and success. At the population‐level, management led to 8% and 13% increases in nest success and productivity rates, respectively, resulting in a 37% increase in breeding pair abundance.Synthesis and applications. There is a clear need to evaluate how management approaches at multiple scales assist in species recovery. Our study uses an Integrated Population Model to reveal the population‐level benefits of a widely used, individual‐based management action (protecting nests using buffer zones) on a recovering raptor.

Neighborhood sampling: how many streets must an auditor walk?

PubMed

McMillan, Tracy E; Cubbin, Catherine; Parmenter, Barbara; Medina, Ashley V; Lee, Rebecca E

2010-03-12

This study tested the representativeness of four street segment sampling protocols using the Pedestrian Environment Data Scan (PEDS) in eleven neighborhoods surrounding public housing developments in Houston, TX. The following four street segment sampling protocols were used (1) all segments, both residential and arterial, contained within the 400 meter radius buffer from the center point of the housing development (the core) were compared with all segments contained between the 400 meter radius buffer and the 800 meter radius buffer (the ring); all residential segments in the core were compared with (2) 75% (3) 50% and (4) 25% samples of randomly selected residential street segments in the core. Analyses were conducted on five key variables: sidewalk presence; ratings of attractiveness and safety for walking; connectivity; and number of traffic lanes. Some differences were found when comparing all street segments, both residential and arterial, in the core to the ring. Findings suggested that sampling 25% of residential street segments within the 400 m radius of a residence sufficiently represents the pedestrian built environment. Conclusions support more cost effective environmental data collection for physical activity research.

Doxorubicin hinders DNA condensation promoted by the protein bovine serum albumin (BSA).

PubMed

Lima, C H M; de Paula, H M C; da Silva, L H M; Rocha, M S

2017-12-01

In this work, we have studied the interaction between the anticancer drug doxorubicin (doxo) and condensed DNA, using optical tweezers. To perform this task, we use the protein bovine serum albumin (BSA) in the working buffer to mimic two key conditions present in the real intracellular environment: the condensed state of the DNA and the abundant presence of charged macromolecules in the surrounding medium. In particular, we have found that, when doxo is previously intercalated in disperse DNA, the drug hinders the DNA condensation process upon the addition of BSA in the buffer. On the other hand, when bare DNA is firstly condensed by BSA, doxo is capable to intercalate and to unfold the DNA condensates at relatively high concentrations. In addition, a specific interaction between BSA and doxo was verified, which significantly changes the chemical equilibrium of the DNA-doxo interaction. Finally, the presence of BSA in the buffer stabilizes the double-helix structure of the DNA-doxo complexes, preventing partial DNA denaturation induced by the stretching forces. © 2017 Wiley Periodicals, Inc.

Effect of template post-annealing on Y(Dy)BaCuO nucleation on CeO2 buffered metallic tapes

NASA Astrophysics Data System (ADS)

Hu, Xuefeng; Zhong, Yun; Zhong, Huaxiao; Fan, Feng; Sang, Lina; Li, Mengyao; Fang, Qiang; Zheng, Jiahui; Song, Haoyu; Lu, Yuming; Liu, Zhiyong; Bai, Chuanyi; Guo, Yanqun; Cai, Chuanbing

2017-08-01

Substrate engineering is very significant in the synthesis of the high-temperature superconductor (HTS) coated conductor. Here we design and synthesize several distinct and stable Cerium oxide (CeO2) surface reconstructions which are used to grow epitaxial films of the HTS YBa2Cu3O7-δ (YBCO). To identify the influence of annealing and post-annealing surroundings on the nature of nucleation centers, including Ar/5%H2, humid Ar/5%H2 and O2 in high temperature annealing process, we study the well-controlled structure, surface morphology, crystal constants and surface redox processes of the ceria buffers by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FE-SEM), respectively. The ceria film post-annealed under humid Ar/5%H2 gas shows the best buffer layer properties. Furthermore, the film absorbs more oxygen ions, which appears to contribute to oxygenation of superconductor film. The film is well-suited for ceria model studies as well as a perfect substitute for CeO2 bulk material.

Neighborhood sampling: how many streets must an auditor walk?

PubMed Central

2010-01-01

This study tested the representativeness of four street segment sampling protocols using the Pedestrian Environment Data Scan (PEDS) in eleven neighborhoods surrounding public housing developments in Houston, TX. The following four street segment sampling protocols were used (1) all segments, both residential and arterial, contained within the 400 meter radius buffer from the center point of the housing development (the core) were compared with all segments contained between the 400 meter radius buffer and the 800 meter radius buffer (the ring); all residential segments in the core were compared with (2) 75% (3) 50% and (4) 25% samples of randomly selected residential street segments in the core. Analyses were conducted on five key variables: sidewalk presence; ratings of attractiveness and safety for walking; connectivity; and number of traffic lanes. Some differences were found when comparing all street segments, both residential and arterial, in the core to the ring. Findings suggested that sampling 25% of residential street segments within the 400 m radius of a residence sufficiently represents the pedestrian built environment. Conclusions support more cost effective environmental data collection for physical activity research. PMID:20226052

Study on ecological conservation planning of Xianyue Park in Xiamen City, China

NASA Astrophysics Data System (ADS)

Xu, Naizhong; Xi, Rong; Ren, Tingyan; Zhao, Peng; Chuai, Zeyao

2017-08-01

The paper discusses the current situation and existing problems of ecological restoration and tourist infrastructure development of Xiamen Xianyue Park located in Xiamen Island, China. Issues of ecosystem restoration and landscape improvement, restoring habitats, and ecosystem management system are analyzed. Options of further optimization of the tourist-targeted infrastructure are proposed, which take into account the ecological system and landscape pattern optimization, promotion of ecotourism, and implementation of the ecological management system. The particular solution envisages the park zoning with three primary zones (ecological protection, ecological buffer, and general activity zones) and five secondary ones (scenic landscape, ecotourism, religious activity, buildings and structures, and entertainment zones). By integrating the ecological principles into other land use objectives, taking full advantage of the park ecological and cultural heritage, and improving its ecological management, it is expected to provide the ecological restoration of the park under study and optimize its contribution to the regional economic and social development.

Genecology and seed zones for tapertip onion in the US Great Basin

Treesearch

R. C. Johnson; Barbara C. Hellier; Ken W. Vance-Borland

2013-01-01

The choice of germplasm is critical for sustainable restoration, yet seed transfer guidelines are lacking for all but a few herbaceous species. Seed transfer zones based on genetic variability and climate were developed using tapertip onion (Allium acuminatum Hook.) collected in the Great Basin and surrounding areas in the United States. Bulbs from 53 locations were...

77 FR 44472 - Safety Zone; Port Valdez, Alaska Maritime Highway System Ferry Terminal

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... Game, which does not afford time for public feedback on a safety zone that will be in effect only when... month of July, the Alaska Department of Fish and Game has announced fishing openers in the Port of... an Alaska Department of Fish and Game fish opener that includes the 200-yard radius surrounding the...

The Impact of Laptop-Free Zones on Student Performance and Attitudes in Large Lectures

ERIC Educational Resources Information Center

Aguilar-Roca, Nancy M.; Williams, Adrienne E.; O'Dowd, Diane K.

2012-01-01

The goal of this study was to determine if laptop use in lecture negatively impacts learning outcomes of surrounding students taking notes on paper. Two sections of a large introductory biology course (greater than 400 students/section) were zoned into a laptop-permitted and a laptop-free area. Two sections in which laptop users could sit anywhere…

The Influence of Heating Mains on Yeast Communities in Urban Soils

NASA Astrophysics Data System (ADS)

Tepeeva, A. N.; Glushakova, A. M.; Kachalkin, A. V.

2018-04-01

The number and species diversity of yeasts in urban soils (urbanozems) affected by heating mains and in epiphytic yeast complexes of grasses growing above them were studied. The number of yeasts in the soil reached 103-104 CFU/g; on the plants, 107 CFU/g. Significant (by an order of magnitude) increase in the total number of soil yeasts in the zone of heating mains in comparison with the surrounding soil was found in winter period. Overall, 25 species of yeasts were isolated in our study. Yeast community of studied urbanozems was dominated by the Candida sake, an eurybiont of the temperate zone and other natural ecotopes with relatively low temperatures, but its share was minimal in the zone of heating mains. In general, the structure of soil and epiphytic yeast complexes in the zones of heating mains differed from that in the surrounding area by higher species diversity and a lower share of pigmented species among the epiphytic yeasts. The study demonstrated that the number and species structure of soil yeast communities in urban soils change significantly under the influence of the temperature factor and acquire a mosaic distribution pattern.

30 CFR 761.14 - Procedures for relocating or closing a public road or waiving the prohibition on surface coal...

Code of Federal Regulations, 2010 CFR

2010-07-01

... road or waiving the prohibition on surface coal mining operations within the buffer zone of a public road. 761.14 Section 761.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT... Procedures for relocating or closing a public road or waiving the prohibition on surface coal mining...

Using classified Landsat Thematic Mapper data for stratification in a statewide forest inventory

Treesearch

Mark H. Hansen; Daniel G. Wendt

2000-01-01

The 1998 Indiana/Illinois forest inventory (USDA Forest Service, Forest Inventory and Analysis (FIA)) used Landsat Thematic Mapper (TM) data for stratification. Classified images made by the National Gap Analysis Program (GAP) stratified FIA plots into four classes (nonforest, nonforest/ forest, forest/nonforest, and forest) based on a two pixel forest edge buffer zone...

Using Classified Landsat Thematic Mapper Data for Stratification in a Statewide Forest Inventory

Treesearch

Mark H. Hansen; Daniel G. Wendt

2000-01-01

The 1998 Indiana/Illinois forest inventory (USDA Forest Service, Forest Inventory and Analysis (FIA)) used Landsat Thematic Mapper (TM} data for stratification. Classified images made by the National Gap Analysis Program (GAP) stratified FIA plots into four classes (nonforest, nonforest/forest, forest/nonforest, and forest) based on a two pixel forest edge buffer zone...

77 FR 19231 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... break, presence of glassy foam, and/or perhaps scattered whitecaps). Applicable mitigation zones are... California based on passive acoustic detection of two distinct echolocation click patterns. No population... 10 1,020 1,220 (2) ZOI and Swim Speed-Time-Buffer Addition Based on acoustic propagation modeling and...

Persistent impacts to the deep soft-bottom benthos one year after the Deepwater Horizon event.

PubMed

Montagna, Paul A; Baguley, Jeffrey G; Cooksey, Cynthia; Hyland, Jeffrey L

2017-03-01

In fall 2010, several months after the Deepwater Horizon blowout was capped, zones of moderate and severe impacts to deep-sea, soft-bottom benthos were identified that together extended over an area of 172 km 2 . A subset of stations sampled in 2010 was resampled in May and June 2011, 10 to 11 months after the event, to determine whether the identified adverse effects were persisting. The design compared 20 stations from the combined moderate and severe impact zone to 12 stations in the reference zone that were sampled in both years. There were no statistically significant differences in contaminant concentrations between the impact and nonimpact zones from 2010 to 2011, which indicates contaminants persisted after 1 y. Whereas there were some signs of recovery in 2011 (particularly for the meiofauna abundance and diversity), there was evidence of persistent, statistically significant impacts to both macrofauna and meiofauna community structure. Macrofaunal taxa richness and diversity in 2011 were still 22.8% and 35.9% less, respectively, in the entire impact zone than in the surrounding nonimpact area, and meiofaunal richness was 28.5% less in the entire impact zone than in the surrounding area. The persistence of significant biodiversity losses and community structure change nearly 1 y after the wellhead was capped indicates that full recovery had yet to have occurred in 2011. Integr Environ Assess Manag 2017;13:342-351. © 2016 SETAC. © 2016 SETAC.

Aboriginal hunting buffers climate-driven fire-size variability in Australia's spinifex grasslands.

PubMed

Bliege Bird, Rebecca; Codding, Brian F; Kauhanen, Peter G; Bird, Douglas W

2012-06-26

Across diverse ecosystems, greater climatic variability tends to increase wildfire size, particularly in Australia, where alternating wet-dry cycles increase vegetation growth, only to leave a dry overgrown landscape highly susceptible to fire spread. Aboriginal Australian hunting fires have been hypothesized to buffer such variability, mitigating mortality on small-mammal populations, which have suffered declines and extinctions in the arid zone coincident with Aboriginal depopulation. We test the hypothesis that the relationship between climate and fire size is buffered through the maintenance of an anthropogenic, fine-grained fire regime by comparing the effect of climatic variability on landscapes dominated by Martu Aboriginal hunting fires with those dominated by lightning fires. We show that Aboriginal fires are smaller, more tightly clustered, and remain small even when climate variation causes huge fires in the lightning region. As these effects likely benefit threatened small-mammal species, Aboriginal hunters should be considered trophic facilitators, and policies aimed at reducing the risk of large fires should promote land-management strategies consistent with Aboriginal burning regimes.

[Research advances in macroinvertebrate ecology of the stream hyporheic zone].

PubMed

Zhang, Yue-Wei; Yuan, Xing-Zhong; Liu, Hong; Ren, Hai-Qing

2014-11-01

The stream hyporheic zone is an ecotone of surface water-ground water interactions, which is rich in biodiversity, and is an important component of stream ecosystem. The macroinvertebrates, which are at the top of food webs in the hyporheic zone to directly influence the matter and energy dynamics of the hyporheic zone, and are potential indicators of river ecological health to adjust the function of environment purification and ecological buffer. The macroinvertebrates in the hyporheic zone are divided into three categories: stygoxenes, stygophiles and stygobites. The key factors which influenced macroinvertebrates distribution in the hyporheic zone are physical size of interstitial spaces, interstitial current velocity, dissolved oxygen (DO), water temperature, available organic matter, hydraulic conductivity and hydraulic retention time. A suitable sampling method should be used for diverse research purposes in the special ecological interface. In the future, some necessary researches should focus on the life-history and life history strategy of the macroinvertebrates in the hyporheic zone, the quantitative analysis on the matter and energy dynamics in the ecological system of stream, the assessment systems of river ecological health based on the macroinvertebrates of the stream hyporheic zone, and the ecological significance of the hyporheic zone as a refuge for distribution and evolution of the macroinvertebrates.

Effects of geodynamic setting on the redox state of fluids released by subducted mantle lithosphere

NASA Astrophysics Data System (ADS)

Evans, K. A.; Reddy, S. M.; Tomkins, A. G.; Crossley, R. J.; Frost, B. R.

2017-05-01

Magnetite breakdown during subduction of serpentinised ultramafic rocks may produce oxidised fluids that oxidise the deep Earth and/or the sub-arc mantle, either via direct transport of ferric iron, or via redox reactions between ferric iron and other elements, such as sulfur. However, so far, there is no consensus on the oxidation state of fluids released during subduction of ultramafic rocks, or the factors that control this oxidation state. Subducted samples from a magma-poor rifted margin and a supra-subduction zone geodynamic setting were compared to examine evidence of changes in opaque phase assemblage and ferric iron content as a consequence of subduction, and as a function of geodynamic setting. Thermodynamic calculations in the system Fe-Ni-O-H-S and Fe-Ni-O-S at the pressures and temperatures of interest were used to constrain oxygen activities and fluid compositions. Samples from New Caledonia, which exemplify supra-subduction zone mantle, contain awaruite (FeNi3) and equilibrated with hydrogen-bearing fluids at oxygen activity less than the FMQ (fayalite-magnetite-quartz) buffer. In contrast, samples from the Zermatt Saas Zone ophiolite, Western Alps, which are thought to represent mantle from a subducted magma-poor rifted margin, contain magnetite plus sulfur-rich phases such as pyrite (FeS2), and are inferred to have equilibrated with hydrogen-poor fluids at oxygen activity greater than FMQ. This major difference is independent of differences in subduction pressure-temperature conditions, variation in peridotite protolith composition, or the nature of adjacent units. We propose that the Zermatt Saas Zone samples would have undergone more complete serpentinisation prior to subduction than the supra-subduction zone (SSZ) New Caledonian samples. This difference explains the different fluid compositions, because incompletely serpentinised rocks containing olivine and brucite retain or evolve awaruite-bearing assemblages that buffer fluid compositions to high hydrogen activity (aH2). Ultramafic rocks are associated with two distinctly different fluid compositions during pre-subduction and subduction serpentinisation. Initially, while olivine is in equilibrium with infiltrating fluid, mineral assemblages that include awaruite in the rocks buffer fluids to H2-bearing, low aO2 compositions. Deserpentinisation of incompletely serpentinised rocks in which awaruite is present also produces H2-bearing fluids. Once awaruite is exhausted, H2-poor, high aO2 fluids co-exist with awaruite-absent assemblages, and deserpentinisation of such rocks would produce H2O-rich fluids. Thus, deserpentinisation of ultramafic rocks could produce either hydrogen-bearing fluids that could infiltrate and reduce the sub-arc mantle, or more oxidised fluids, which could transfer redox budget to other geochemical reservoirs such as the sub-arc mantle. Therefore, the redox contribution of subducted ultramafic rocks to the deep Earth and sub-arc mantle depends on the extent of protolith serpentinisation. Pre-subduction settings that promote extensive serpentinisation by oxidised fluids at high fluid:rock ratios in open systems, such as slow and ultraslow spreading ridges, transform faults, oceanic core complexes, and exhumed mantle at rifted continental margins, may produce more oxidised fluids than those associated with less pervasive serpentinisation and fluids that may be rock-buffered to a reduced state.

Rheological structure of the lithosphere in plate boundary strike-slip fault zones

NASA Astrophysics Data System (ADS)

Chatzaras, Vasileios; Tikoff, Basil; Kruckenberg, Seth C.; Newman, Julie; Titus, Sarah J.; Withers, Anthony C.; Drury, Martyn R.

2016-04-01

How well constrained is the rheological structure of the lithosphere in plate boundary strike-slip fault systems? Further, how do lithospheric layers, with rheologically distinct behaviors, interact within the strike-slip fault zones? To address these questions, we present rheological observations from the mantle sections of two lithospheric-scale, strike-slip fault zones. Xenoliths from ˜40 km depth (970-1100 ° C) beneath the San Andreas fault system (SAF) provide critical constraints on the mechanical stratification of the lithosphere in this continental transform fault. Samples from the Bogota Peninsula shear zone (BPSZ, New Caledonia), which is an exhumed oceanic transform fault, provide insights on lateral variations in mantle strength and viscosity across the fault zone at a depth corresponding to deformation temperatures of ˜900 ° C. Olivine recrystallized grain size piezometry suggests that the shear stress in the SAF upper mantle is 5-9 MPa and in the BPSZ is 4-10 MPa. Thus, the mantle strength in both fault zones is comparable to the crustal strength (˜10 MPa) of seismogenic strike-slip faults in the SAF system. Across the BPSZ, shear stress increases from 4 MPa in the surrounding rocks to 10 MPa in the mylonites, which comprise the core of the shear zone. Further, the BPSZ is characterized by at least one order of magnitude difference in the viscosity between the mylonites (1018 Paṡs) and the surrounding rocks (1019 Paṡs). Mantle viscosity in both the BPSZ mylonites and the SAF (7.0ṡ1018-3.1ṡ1020 Paṡs) is relatively low. To explain our observations from these two strike-slip fault zones, we propose the "lithospheric feedback" model in which the upper crust and lithospheric mantle act together as an integrated system. Mantle flow controls displacement and the upper crust controls the stress magnitude in the system. Our stress data combined with data that are now available for the middle and lower crustal sections of other transcurrent fault systems support the prediction for constant shear strength (˜10 MPa) throughout the lithosphere; the stress magnitude is controlled by the shear strength of the upper crustal faults. Fault rupture in the upper crust induces displacement rate loading of the upper mantle, which in turn, causes strain localization in the mantle shear zone beneath the strike-slip fault. Such forced localization leads to higher stresses and strain rates in the shear zone compared to the surrounding rocks. Low mantle viscosity within the shear zone is critical for facilitating mantle flow, which induces widespread crustal deformation and displacement loading. The lithospheric feedback model suggests that strike-slip fault zones are not mechanically stratified in terms of shear stress, and that it is the time-dependent interaction of the different lithospheric layers - rather than their relative strengths - that governs the rheological behavior of the plate boundary, strike-slip fault zones.

Heavy metal exposure and risk charaterization of topsoils in urban playgrounds and parks (Hungary)

NASA Astrophysics Data System (ADS)

Puskás, Irén; Farsang, Andrea; Csépe, Zoltán; Bartus, Máté

2014-05-01

Contamination in urban soils can directly pose significant human risks through oral ingestion, particle inhalation and dermal contact, especially in public spaces. Parks and playgrounds are green areas in cities where dwellers (mainly children and seniors) can spend their outside freetime, thus the highest possibility of the human and soil interaction can be presumed here. Therefore, in 2013, composite surface samples (0-5 cm, from 10-15 subsoil samples) were collected from 96 public parks and 89 playgrounds (around playing equipment) of main functional zones (downtown, housing estates, industrial, prestigious, commuting areas) of three Hungarian cities (Budapest, Szeged, Gyula) representing capital, regional city and local town. Pseudo total metal content (Mn, Ni, Pb, Zn, As, Cd, Cr, Cu, Ba, Co) and physical, chemical soil properties influencing metal mobility (artefact, mechanical soil type, carbonate, humus, pH(H2O), salt) were determined to evaluate impacts of various anthropogenic activities in functional zones on the studied soils; to give the environmental buffering capacity and to model human health risk of exposure pathways (by RISC 4.0 ) in the case of contaminated soils. Insignificant amount of artefact, neutral pH, high humus and carbonate content, mainly loamy and loamy-clay texture, low salt content can provide suitable buffering capacity for the studied soils. The type and spatial location of functional zones have not exerted considerable impact on variability of soil properties. Out of 189 analyzed areas, 36 have exceeded the threshold values regulated by Hungarian government (6/2009. (IV. 14) KvVM-EüM-FVM collective decree). Based on quantitative and qualitative evaluation of results, the identification of spatial patterns and the possible source of metal pollution have been carried out. In accordance with statistical analysis (correlation, cluster, factor analysis), we can explore relationship between metal concentrations and features of sample areas (e.g. age, location, height of surrounding buildings, landfill or/and soil replacement). In this study, factor analysis with special transformation is first application in soil science during which the mutual influence of metals is investigated. In order to gain information on significance of the distance from busy roads in soil contamination weighted vehicle unit was applied. Assessing human health risk of the contaminated soils, the highest human health risk quotient (HRQ) can be detected in town Gyula sampling areas of which there has not been soil replacement and reconstruction opposite to larger cities as yet. Contributing to a more accurate health risk assessment of the soils in recreation areas of cities, our results may support a safer and sustainable urban green area. This research was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP 4.2.4. A/1-11-1-2012-0001 'National Excellence Program'

Wild versus domestic prey in the diet of reintroduced tigers (Panthera tigris) in the livestock-dominated multiple-use forests of Panna Tiger Reserve, India.

PubMed

Kolipaka, S S; Tamis, W L M; van 't Zelfde, M; Persoon, G A; de Iongh, H H

2017-01-01

Grazing livestock in openly accessible areas is a common practice in the multiple-use forests of India; however, its compatibility with the reintroduction of tigers to these areas requires examination. Here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the Panna Tiger Reserve, India. We hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock by tigers, even when wild prey are available. We used generalised linear models to test whether predation of livestock versus wild animals was influenced by (1) the sex and age class of tigers, (2) season, and (3) the distance of prey from the core-zone boundary of the reserve. Overall, sub-adult tigers and male tigers killed more livestock than wild prey, even when wild prey was available. In the winter and rainy seasons livestock were killed in higher numbers in the buffer zone than in summers, this may be because of the seasonally changing livestock herding patterns in the area. Further, with increasing distance from the core-zone boundary, all tigers killed more livestock, possibly because livestock were more easily accessible than wild prey. Our results show that open-access and unregulated livestock grazing is not currently compatible with large carnivore conservation in the same landscape. Such practices will lead to an increase in negative tiger-human-livestock interactions. In conclusion, we suggest the need to encourage locals to corral valuable cattle, leaving feral/unwanted livestock for tigers. This simple strategy would benefit both local inhabitants and tiger conservation in the multiple-use forests of India.

Wild versus domestic prey in the diet of reintroduced tigers (Panthera tigris) in the livestock-dominated multiple-use forests of Panna Tiger Reserve, India

PubMed Central

Tamis, W. L. M.; van ‘t Zelfde, M.; Persoon, G. A.; de Iongh, H. H.

2017-01-01

Grazing livestock in openly accessible areas is a common practice in the multiple-use forests of India; however, its compatibility with the reintroduction of tigers to these areas requires examination. Here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the Panna Tiger Reserve, India. We hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock by tigers, even when wild prey are available. We used generalised linear models to test whether predation of livestock versus wild animals was influenced by (1) the sex and age class of tigers, (2) season, and (3) the distance of prey from the core-zone boundary of the reserve. Overall, sub-adult tigers and male tigers killed more livestock than wild prey, even when wild prey was available. In the winter and rainy seasons livestock were killed in higher numbers in the buffer zone than in summers, this may be because of the seasonally changing livestock herding patterns in the area. Further, with increasing distance from the core-zone boundary, all tigers killed more livestock, possibly because livestock were more easily accessible than wild prey. Our results show that open-access and unregulated livestock grazing is not currently compatible with large carnivore conservation in the same landscape. Such practices will lead to an increase in negative tiger-human-livestock interactions. In conclusion, we suggest the need to encourage locals to corral valuable cattle, leaving feral/unwanted livestock for tigers. This simple strategy would benefit both local inhabitants and tiger conservation in the multiple-use forests of India. PMID:28379997

Thermal - Hydraulic Behavior of Unsaturated Bentonite and Sand-Bentonite Material as Seal for Nuclear Waste Repository: Numerical Simulation of Column Experiments

NASA Astrophysics Data System (ADS)

Ballarini, E.; Graupner, B.; Bauer, S.

2015-12-01

For deep geological repositories of high-level radioactive waste (HLRW), bentonite and sand bentonite mixtures are investigated as buffer materials to form a a sealing layer. This sealing layer surrounds the canisters and experiences an initial drying due to the heat produced by HLRW and a successive re-saturation with fluid from the host rock. These complex thermal, hydraulic and mechanical processes interact and were investigated in laboratory column experiments using MX-80 clay pellets as well as a mixture of 35% sand and 65% bentonite. The aim of this study is to both understand the individual processes taking place in the buffer materials and to identify the key physical parameters that determine the material behavior under heating and hydrating conditions. For this end, detailed and process-oriented numerical modelling was applied to the experiments, simulating heat transport, multiphase flow and mechanical effects from swelling. For both columns, the same set of parameters was assigned to the experimental set-up (i.e. insulation, heater and hydration system), while the parameters of the buffer material were adapted during model calibration. A good fit between model results and data was achieved for temperature, relative humidity, water intake and swelling pressure, thus explaining the material behavior. The key variables identified by the model are the permeability and relative permeability, the water retention curve and the thermal conductivity of the buffer material. The different hydraulic and thermal behavior of the two buffer materials observed in the laboratory observations was well reproduced by the numerical model.

Potential export of soluble reactive phosphorus from a coastal wetland in a cold-temperate lagoon system: Buffer capacities of macrophytes and impact on phytoplankton.

PubMed

Berthold, M; Karstens, S; Buczko, U; Schumann, R

2018-03-01

The main pathways for phosphorus flux from land to sea are particle-associated (erosion) and dissolved runoff (rivers, groundwater, and agricultural drainage systems). These pathways can act as diffused sources for aquatic systems and support primary production, therefore, counteracting the efforts aimed at reducing phosphorus input from point sources such as sewage treatment plants. Phosphorus supports primary production in the water column and can elevate phytoplankton and macrophyte growth. Coastal wetlands with emerged (Phragmites australis) and submerged (Stuckenia pectinata and Chara sp.) macrophytes can affect phosphorus fluxes in the land-water transitional zone. The macrophytes have the potential to act as a buffer for phosphorus run-off. The aim of this study was to determine the phosphorus stocks in the transitional land-sea zone of a cold temperate lagoon at the southern Baltic Sea. Phosphorus in macrophytes, water samples, and phytoplankton growth were analyzed along a gradient moving away from the wetland. The phosphorus stocks in the above ground biomass of the Phragmites plants were the highest at the end of August and with more than 8000mgPm -2 in the interior zone of the wetland, threefold the amount of P in Phragmites plant tissue at the wetland fringe. The submerged macrophytes stored only 300mgPm -2 , close to the wetland. Concentrations of soluble reactive phosphorus in the water column were higher in the zones of emerged macrophytes than in the zones of submerged macrophytes and decreased along the land-sea transect. Phytoplankton could grow proximal to the wetland during all seasons, but not further away. This study indicates that macrophytes can act as phosphorus sinks. However, short-term releases of phosphate within the Phragmites wetland have the potential to lead to phytoplankton growth. Phytoplankton can use these nutrient pulses either immediately or later, and support high biomass and turbidity within the system. Copyright © 2017. Published by Elsevier B.V.

Dynamics from Seconds to Hours in Hodgkin-Huxley Model with Time-Dependent Ion Concentrations and Buffer Reservoirs

PubMed Central

Hübel, Niklas; Dahlem, Markus A.

2014-01-01

The classical Hodgkin-Huxley (HH) model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds), the buffer time constants (tens of seconds), and the slower backward buffering (minutes to hours). The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively. PMID:25474648

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chong

We present a simple approach for determining ion, electron, and radiation temperatures of heterogeneous plasma-photon mixtures, in which temperatures depend on both material type and morphology of the mixture. The solution technique is composed of solving ion, electron, and radiation energy equations for both mixed and pure phases of each material in zones containing random mixture and solving pure material energy equations in subdivided zones using interface reconstruction. Application of interface reconstruction is determined by the material configuration in the surrounding zones. In subdivided zones, subzonal inter-material energy exchanges are calculated by heat fluxes across the material interfaces. Inter-material energymore » exchange in zones with random mixtures is modeled using the length scale and contact surface area models. In those zones, inter-zonal heat flux in each material is determined using the volume fractions.« less

Assessment of rockfall hazard at Al-Noor Mountain, Makkah city (Saudi Arabia) using spatio-temporal remote sensing data and field investigation

NASA Astrophysics Data System (ADS)

Youssef, Ahmed M.; Pradhan, Biswajeet; Al-Kathery, Mohamed; Bathrellos, George D.; Skilodimou, Hariklia D.

2015-01-01

Rockfall is one of the major concerns along different urban areas and highways all over the world. Al-Noor Mountain is one of the areas that threaten rockfalls to the Al-Noor escarpment track road and the surrounding urban areas. Thousands of visitors and tourisms use the escarpment track road to visit Hira cave which is located at the top of Al-Noor Mountain. In addition, the surrounding urban areas of Al-Noor Mountain are continuously spreading over the recent years. The escarpment track road and the surrounding urban areas are highly vulnerable and suffers from recurrent rockfall mostly in the rainy season. The steep and highly jointed slope along the different faces of the mountain makes these zones prone to failure due to different actions such as weathering, erosion and anthropogenic effect. Therefore, an attempt has been made in this study to determine the Al-Noor cliff stability, by identifying the unstable areas, and to apply the rockfall simulations. A combination of remote sensing, field study and 2D computer simulation rockfall program were performed to assess surface characteristics of the cliff faces. Bounce height, total and translational kinetic energy, translational velocity, and number of blocks have been estimated. Different unstable zones along the Al-Noor Mountain and escarpment track road were determined using filed investigation and remote sensing based image analysis. In addition the rockfall simulation analysis indicated that rockfall in zone 1 and zone 2 of the Al-Noor Mountain may reach the urban areas, whereas rockfall in zone 3 will not reach the urban areas, and rockfalls along the Al-Noor escarpment track road will have highly impact on the tourists. Proper preventive measures are also suggested to arrest the movement of falling rocks before reaching the urban areas and the Al-Noor escarpment track road. If proper care is taken, then further uncertain rockfall hazards can be prevented.

[Reptiles from Cerro Colorado and its surroundings, Cumana, Sucre State, Venezuela].

PubMed

Oliveros, O; Prieto, A; Comejo, P

2000-01-01

An inventory of the reptiles that inhabit in Cerro Colorado and its surroundings, was performed from March, 1994 to March, 1995. There were reported 8 species of snakes and 7 of lizards enclosed in 4 and 5 families repectively. Aspects observed were ecolology as habitat, activity, reproduction and relative abundance. The more abundant species of lizards were: Cnemidophorus femniscatus, Ameiva bifrontata, (Teiidae), Tropidurus hispidus (Tropiduridae), Gonatodes vittatus and Hemidactylus mabouia (Gekkonidae) and the ophidians: Leptodeira annulata and Mastigodryas amarali (Colubridae). It is believed that the changes occurred in the zone influenced the increase of the relative abundance of the species Leptotyphlops goudotii (Leptotyphlopidae) arid Gymnophthalmus speciosus(Gymnophthalmidae) and perhaps in the disappearance of others that have been reported at the xerophitic or semixerophitic zones of the Sucre State of Venezuela.

Effects of urbanization on stream quality at selected sites in the seacoast region in New Hampshire, 2001-03

USGS Publications Warehouse

Deacon, Jeffrey R.; Soule, Sally A.; Smith, Thor E.

2005-01-01

A study of selected water-quality and macroinvertebrate community data was conducted at 10 stream sites in the Seacoast region of New Hampshire to determine if a relation is present between stream quality and the extent of urbanization in a watershed. Watersheds with similar characteristics, but varying in their degree of urban development, were studied. The percent of impervious surface, the percent of urban land use in a watershed, and the percent of urban land use in two types of stream buffers were compared and correlated with stream-quality variables. Specific conductance, turbidity, nitrite plus nitrate yields, and selected macroinvertebrate community data were significantly correlated with most measures of urbanization used in this study; however, concentrations and total phosphorus yields were not statistically correlated with most measures of urbanization in this study. The measures of urbanization that had the highest correlations with stream-quality variables were those measures that were associated with the percent of urban land in buffer zones near and upstream of a sampling site. A water-quality and habitat conditions score was negatively correlated with the percent of urban land in a 1-kilometer radial buffer of the sampling site (rho (r) = -0.86; p < 0.001), the percent of impervious surface (r = -0.70; p < 0.05), and the percent of urban land in the watershed (r = -0.67; p < 0.05). A biological condition score also was negatively correlated with the percent of urban land in a 1-kilometer radial buffer of the sampling site (r = -0.95; p < 0.0001), the percent of impervious surface (r = -0.75; p < 0.05), and the percent of urban land in the watershed (r = -0.79; p < 0.01). The percent of urban land in a 25-meter stream buffer along the stream corridor also had negative correlations with a water-quality and habitat conditions score (r = -0.80; p < 0.01) and a biological condition score (r = -0.86; p < 0.01). Mean Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa richness showed a response to urbanization in a watershed, indicating that EPT taxa richness may be an appropriate metric to evaluate the effects of urban land use on small streams in this region. Results from this study indicate that the percent of urban land use in buffer zones and the percent of impervious surface in a watershed can be used as indicators of stream quality.

An Experimental Study of Diffusivity of Technetium-99 in Hanford Vadose Zone Sediments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.

2012-11-01

One of the methods being considered at the Hanford site in Washington for safely disposing of low-level radioactive wastes (LLW) is to encase the waste in concrete and entomb the packages in the Hanford vadose zone sediments. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages with concrete. Any failure of the concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion andmore » move into the surrounding subsurface sediments. It is therefore necessary to conduct an assessment of the performance of the concrete encasement structure and the surrounding soil’s ability to retard radionuclide migration. The retardation factors for radionuclides contained in the waste packages can be determined from measurements of diffusion coefficients for these contaminants through concrete and fill material. Because of their anionic nature in aqueous solutions, the radionuclides, 99Tc and 129I were identified as long-term dose contributors in LLW. The leachability and/or diffusion of these radionuclide species must be measured in order to assess the long-term performance of waste grouts when contacted with vadose-zone porewater or groundwater. To measure the diffusivity, a set of experiments were conducted using 99Tc-spiked concrete (with 0 and 4% metallic iron additions) in contact with unsaturated soil half-cells that reflected the typical moisture contents of Hanford vadose zone sediments. The 99Tc diffusion profiles in the soil half cells were measured after a time lapse of ~1.9 yr. Using the concentration profiles, the 99Tc diffusivity coefficients were calculated based on Fick’s Second Law.« less

Baseline report - tall upland shrubland at the Rocky Flats Environmental Technology Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Rocky Flats Environmental Technology Site (Site) is located on the Colorado Piedmont east of the Front Range between Boulder and Golden. At an elevation of approximately 6,000 feet, the Site contains a unique ecotonal mixture of mountain and prairie plant species, resulting from the topography and close proximity to the mountain front. The Buffer Zone surrounding the Industrial Area is one of the largest remaining undeveloped areas of its kind along the Colorado Piedmont. A number of plant communities at the Site have been identified as increasingly rare and unique by Site ecologists and the Colorado Natural Heritage Program (CNHP).more » These include the xeric tallgrass prairie, tall upland shrubland, wetlands, and Great Plains riparian woodland communities. Many of these communities support populations of increasingly rare animals as well, including the Preble`s meadow jumping mouse, grasshopper sparrow, loggerhead shrike, Merriam`s shrew, black crowned night heron, and Hops blue and Argos skipper butterflies. One of the more interesting and important plant communities at the Site is the tall upland shrubland community. It has been generally overlooked by previous Site ecological studies, probably due to its relatively small size; only 34 acres total. Although mentioned in a plant community ordination study conducted by Clark et al. and also in the Site baseline ecological study, few data were available on this plant community before the present study.« less

Disturbance to wintering western snowy plovers

USGS Publications Warehouse

Lafferty, Kevin D.

2001-01-01

In order to better understand the nature of disturbances to wintering snowy plovers, I observed snowy plovers and activities that might disturb them at a beach near Devereux Slough in Santa Barbara, California, USA. Disturbance (activity that caused plovers to move or fly) to wintering populations of threatened western snowy plovers was 16 times higher at a public beach than at protected beaches. Wintering plovers reacted to disturbance at half the distance (∼40 m) as has been reported for breeding snowy plovers (∼80 m). Humans, dogs, crows and other birds were the main sources of disturbance on the public beach, and each snowy plover was disturbed, on average, once every 27 weekend min and once every 43 weekday min. Dogs off leash were a disproportionate source of disturbance. Plovers were more likely to fly from dogs, horses and crows than from humans and other shorebirds. Plovers were less abundant near trail heads. Over short time scales, plovers did not acclimate to or successfully find refuge from disturbance. Feeding rates declined with increased human activity. I used data from these observations to parameterize a model that predicted rates of disturbance given various management actions. The model found that prohibiting dogs and a 30 m buffer zone surrounding a 400 m stretch of beach provided the most protection for plovers for the least amount of impact to beach recreation.

Efficiency of natural self-purification of ecosystems vs. countermeasures applied at the East-Ural Radioactive Trace (EURT)

NASA Astrophysics Data System (ADS)

Molchanova, I.; Pozolotina, V.; Mikhailovskaya, L.; Antonova, E.

2012-04-01

As a result of the radiation accident in 1957 at the Production Association "Mayak" (Russia, the Urals) a fast area (23000 km^2), later named the East-Ural radioactive trace, was contaminated. Accidental emission presented by the long-living radionuclides was found to be dominated by Sr-90. In 1967 the EURT area was subjected to a secondary contamination resulting from radioactive sediments transport by wind from "Mayak" technological reservoir, Karachay Lake. Currently, the stock of Sr-90, Cs-137 and Pu-239,240 in the EURT's soil cover consist of 640•10^12 Bq. This study is aimed to compare an efficiency of the countermeasures adopted at the EURT and natural processes responsible for self-purification of contaminated ecosystems. With concern to the principle of ranging the contaminated areas two zones were established: impact and buffer ones. The impact zone is situated near the accident epicenter, i.e. within 2-30 km from of the Trace central axis. After accident this zone was removed from agricultural utilization. The buffer zone has permanent anthropogenic pressure. The native, undisturbed during the reclamation operations, flow adjacent of landscape sites were chosen within the impact and buffer zones. They included of a watershed area and bank area of the lakes. The impact zone demonstrated the lowest concentration of the radionuclides around the frequently flooded lake shore. Absence of anthropogenic pressure, the high density of the plant cover and deficit of the soil moisture in summer time are the main reasons for decreasing the intensity of the water runoff from watershed. As a result the self-purification processes are dominated around the shoreline soils. The buffer zone is characterized by an opposite regularity appeared in increasing of the Sr-90 content in the soils of the lake shore. In this case, the intensive agricultural utilization of the flat watersheds leads to increase of erosion and degradation processes and, as consequently, to the accumulation of the radionuclides within bank area of the lakes. Analysis of the radionuclides depth distribution in the soil profiles across the watershed area showed about 80-87% of Sr-90 and Cs-137 in account to their total contents are retained in the upper humus layer (0-30 cm). The radionuclides are distributed more or less evenly in the soils of accumulative plots of landscape. Some countermeasures were taken around the EURT's territory in order to create relatively safe conditions for human habitation, to reduce the background radiation and intake of the radionuclides in the herbaceous plants. One of them is undercutting contaminated layer for a depth of the soil profile. The success of this measure was provided by heavy-loam of the soil texture. Last research of these plots has shown the maximum contamination is still shifted out of the root layer. As a result the first link of the food chain presented by herbaceous vegetation showed significantly lower level of the radionuclides accumulation in comparison to the non reclaimed areas. Another countermeasure connected with removal and disposal of the soil surface layer was used in the resettled villages. In this case, the stock of radionuclides in the soil was shown to be twice lower comparing to the contiguous non reclaimed areas. This fact particularly indicates positive changes occurred in ecosystems around the resettled villages. Thus, the countermeasures developed around the EURT should be considered as successful and effective for achievement of the main task focused on complex improvement of the radiation conditions across the EURT. These countermeasures will be effective in other contaminated areas having the similar characteristics of the soils, landscapes and climate.

Influence of forest road buffer zones on sediment transport in the Southern Appalachian Region

Treesearch

Johnny M. Grace; Stanley J. Zarnoch

2013-01-01

A gap exists in the understanding of the effectiveness of forest road best management practices (BMP) in controlling sediment movement and minimizing risks of sediment delivery to forest streams. The objective of this paper is to report the findings of investigations to assess sediment travel distances downslope of forest roads in the Appalachian region, relate...

Hillslope hydrologic connectivity controls riparian groundwater turnover: Implications of catchment structure for riparian buffering and stream water sources

Treesearch

Kelsey G. Jencso; Brian L. McGlynn; Michael N. Gooseff; Kenneth E. Bencala; Steven M. Wondzell

2010-01-01

Hydrologic connectivity between catchment upland and near stream areas is essential for the transmission of water, solutes, and nutrients to streams. However, our current understanding of the role of riparian zones in mediating landscape hydrologic connectivity and the catchment scale export of water and solutes is limited. We tested the relationship between the...

Riparian and upland small mammals on the east slope of the Cascade Range, Washington

Treesearch

John F. Lehmkuhl; Roger D. Peffer; Margaret A. O' Connell

2008-01-01

Differences in small mammal diversity and abundance between riparian and upland areas have not been consistently shown in the Pacific Northwest, and the issue is expected to be complex along the east slope of the Cascade Range with its complex biogeography and forest landscape structure. The information is important for evaluating buffer zone management and the...

How resilient are ecosystems in adapting to climate variability

NASA Astrophysics Data System (ADS)

Savenije, Hubert H. G.

2015-04-01

The conclusion often drawn in the media is that ecosystems may perish as a result of climate change. Although climatic trends may indeed lead to shifts in ecosystem composition, the challenge to adjust to climatic variability - even if there is no trend - is larger, particularly in semi-arid or topical climates where climatic variability is large compared to temperate climates. How do ecosystems buffer for climatic variability? The most powerful mechanism is to invest in root zone storage capacity, so as to guarantee access to water and nutrients during period of drought. This investment comes at a cost of having less energy available to invest in growth or formation of fruits. Ecosystems are expected to create sufficient buffer to overcome critical periods of drought, but not more than is necessary to survive or reproduce. Based on this concept, a methodology has been developed to estimate ecosystem root zone storage capacity at local, regional and global scale. These estimates correspond well with estimates made by combining soil and ecosystem information, but are more accurate and more detailed. The methodology shows that ecosystems have intrinsic capacity to adjust to climatic variability and hence have a high resilience to both climatic variability and climatic trends.

Outdoor tobacco advertising in six Boston neighborhoods. Evaluating youth exposure.

PubMed

Pucci, L G; Joseph, H M; Siegel, M

1998-08-01

The Food and Drug Administration (FDA), in its 1996 regulations to restrict certain forms of cigarette advertising likely to appeal to adolescents, prohibited outdoor tobacco advertising within 1,000 feet of schools and playgrounds. No published studies have determined the density of outdoor tobacco advertising within the FDA's prescribed 1,000-foot buffer zone around schools. To determine the prevalence, type, and proximity to public schools of all stationary, outdoor tobacco advertising in six Boston neighborhoods. A cross-sectional field survey conducted in six Boston neighborhoods with varying ethnic, cultural, and socioeconomic characteristics. The main outcome measure was advertising density within buffer zones around public schools. Youth in the six neighborhoods are heavily exposed to stationary, outdoor cigarette advertising. This exposure is intense in areas close to public schools, and more intense in neighborhoods with more children, with significant Black and Hispanic/Latino populations, and with low socioeconomic status. Advertising strategies employed by the tobacco industry are in line with accepted professional marketing practice that targets adolescents for other products. Given the pervasive nature of the outdoor tobacco advertising we observed in the present study, it appears that the only way to protect youth from exposure is by eliminating it from the community.

Quantitative analysis of flavonoids and phenolic acid in Coreopsis tinctoria Nutt. by capillary zone electrophoresis.

PubMed

Deng, Yong; Lam, Shing-Chung; Zhao, Jing; Li, Shao-Ping

2017-10-01

Capillary zone electrophoresis was developed for the simultaneous determination of five flavonoids and one phenolic acid, including taxifolin-7-O-glucoside, flavanomarein, quercetagetin-7-O-glucoside, okanin 4'-O-glucoside, okanin, and chlorogenic acid, in different parts and origins of Coreopsis tinctoria and its related species. Effects of acidity, running-buffer concentration, and modifier concentration were investigated to determine the optimum conditions for analyte determination. Analysis was performed within 18 min by using 50 mM borax buffer containing 15% acetonitrile as a modifier (pH 9.0) at 25 kV and 25°C. Hyperoside was used as internal standard for quantification. The method was accurate, simple, and repeatable, and was successfully applied to the analysis in 13 samples with satisfactory assay results. Results showed that C. tinctoria obviously differed from the related flower tea materials, "Hangju" and "Gongju". The parts (flowers, buds, seeds, stems, and leaves) of C. tinctoria also varied among one another. This study can serve as a foundation for the quality control and pharmacological evaluation of different parts of C. tinctoria and its related species. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A spatial ammonia emission inventory for pig farming

NASA Astrophysics Data System (ADS)

Rebolledo, Boris; Gil, Antonia; Pallarés, Javier

2013-01-01

Atmospheric emissions of ammonia (NH3) from the agricultural sector have become a significant environmental and public concern as they have impacts on human health and ecosystems. This work proposes an improved methodology in order to identify administrative regions with high NH3 emissions from pig farming and calculates an ammonia density map (kg NH3-N ha-1), based on the number of pigs and available agricultural land, terrain slopes, groundwater bodies, soil permeability, zones sensitive to nitrate pollution and surface water buffer zones. The methodology has been used to construct a general tool for locating ammonia emissions from pig farming when detailed information of livestock farms is not available.

Identification of the Appropriate Boundary Size to Use When Measuring the Food Retail Environment Surrounding Schools

PubMed Central

Seliske, Laura; Pickett, William; Rosu, Andrei; Janssen, Ian

2012-01-01

This study included 6,971 students in grades 9 and 10 (ages 13 to 16 years) from 158schools who participated in the 2009/2010 Health Behaviour in School-aged Children Study. Students provided information on where they typically ate lunch. The number of food retailers was obtained for six road network buffer sizes (500, 750, 1,000, 1,500, 2,000, and 5,000 meters) surrounding schools. Associations between the presence of food retailers near schools and students’ lunchtime eating behaviours were examined using multilevel logistic regression. Comparisons of model fit statistics indicated that the 1,000 m buffer provided the best fit. At this distance, students with ≥3 food retailers near their schools had a 3.42 times greater relative odds (95% CI: 2.12–5.52) of eating their lunchtime meal at a food retailer compared to students with no nearby food retailers. Students who had ≥2 food retailers within 750 m of their schools had a 2.74 times greater relative odds (95% CI: 1.75–4.29), while those who had ≥1 food retailer within 500 m of their schools had 2.27 times greater relative odds of eating at food retailer (95% CI: 1.46–3.52) compared to those with no nearby food retailers. For distances greater than 1,000 m, no consistent relationships were found. PMID:23066392

Behavior of ectopic surface: effects of β-adrenergic stimulation and uncoupling

PubMed Central

Arutunyan, Ara; Pumir, Alain; Krinsky, Valentin; Swift, Luther; Sarvazyan, Narine

2011-01-01

By using both experimental and theoretical means, we have addressed the progression of ectopic activity from individual cardiac cells to a multicellular two-dimensional network. Experimental conditions that favor ectopic activity have been created by local perfusion of a small area of cardiomyocyte network (I-zone) with an isoproterenol-heptanol containing solution. The application of this solution initially slowed down and then fully blocked wave propagation inside the I-zone. After a brief lag period, ectopically active cells appeared in the I-zone, followed by evolution of the ectopic clusters into slowly propagating waves. The changing pattern of colliding and expanding ectopic waves confined to the I-zone persisted for as long as the isoproterenol-heptanol environment was present. On restoration of the control environment, the ectopic waves from the I-zone broke out into the surrounding network causing arrhythmias. The observed sequence of events was also modeled by FitzHugh-Nagumo equations and included a cell’s arrangement of two adjacent square regions of 20 × 20 cells. The control zone consisted of well-connected, excitable cells, and the I-zone was made of weakly coupled cells (heptanol effect), which became spontaneously active as time evolved (isoproterenol effect). The dynamic events in the system have been studied numerically with the use of a finite difference method. Together, our experimental and computational data have revealed that the combination of low coupling, increased excitability, and spatial heterogeneity can lead to the development of ectopic waves confined to the injured network. This transient condition appears to serve as an essential step for the ectopic activity to “mature” before escaping into the surrounding control network. PMID:12893638

Behavior of ectopic surface: effects of beta-adrenergic stimulation and uncoupling.

PubMed

Arutunyan, Ara; Pumir, Alain; Krinsky, Valentin; Swift, Luther; Sarvazyan, Narine

2003-12-01

By using both experimental and theoretical means, we have addressed the progression of ectopic activity from individual cardiac cells to a multicellular two-dimensional network. Experimental conditions that favor ectopic activity have been created by local perfusion of a small area of cardiomyocyte network (I-zone) with an isoproterenol-heptanol containing solution. The application of this solution initially slowed down and then fully blocked wave propagation inside the I-zone. After a brief lag period, ectopically active cells appeared in the I-zone, followed by evolution of the ectopic clusters into slowly propagating waves. The changing pattern of colliding and expanding ectopic waves confined to the I-zone persisted for as long as the isoproterenol-heptanol environment was present. On restoration of the control environment, the ectopic waves from the I-zone broke out into the surrounding network causing arrhythmias. The observed sequence of events was also modeled by FitzHugh-Nagumo equations and included a cell's arrangement of two adjacent square regions of 20 x 20 cells. The control zone consisted of well-connected, excitable cells, and the I-zone was made of weakly coupled cells (heptanol effect), which became spontaneously active as time evolved (isoproterenol effect). The dynamic events in the system have been studied numerically with the use of a finite difference method. Together, our experimental and computational data have revealed that the combination of low coupling, increased excitability, and spatial heterogeneity can lead to the development of ectopic waves confined to the injured network. This transient condition appears to serve as an essential step for the ectopic activity to "mature" before escaping into the surrounding control network.

Geochemical behavior of rare earth elements of the hydrothermal alterations within the Tepeoba porphyry Cu-Mo-Au deposits at Balikesir, NW Turkey

NASA Astrophysics Data System (ADS)

Doner, Zeynep; Abdelnasser, Amr; Kiran Yildirim, Demet; Kumral, Mustafa

2016-04-01

This work reports the geochemical characteristics and behavior of the rare earth elements (REE) of the hydrothermal alteration of the Tepeoba porphyry Cu-Mo-Au deposit located in the Anatolian tectonic belt at Biga peninsula (Locally Balikesir province), NW Turkey. The Cu-Mo-Au mineralization at this deposit hosted in the hornfels rocks and related to the silicic to intermediate intrusion of Eybek pluton. It locally formed with brecciated zones and quartz vein stockworks, as well as the brittle fracture zones associated with intense hydrothermal alteration. Three main alteration zones with gradual boundaries formed in the mine area in the hornfels rock that represents the host rock, along that contact the Eybek pluton; potassic, propylitic and phyllic alteration zones. The potassic alteration zone that formed at the center having high amount of Cu-sulfide minerals contains biotite, muscovite, and sericite with less amount of K-feldspar and associated with tourmalinization alteration. The propylitic alteration surrounds the potassic alteration having high amount of Mo and Au and contains chlorite, albite, epidote, calcite and pyrite. The phyllic alteration zone also surrounds the potassic alteration containing quartz, sericite and pyrite minerals. Based on the REE characteristics and content and when we correlate the Alteration index (AI) with the light REEs and heavy REEs of each alteration zone, it concluded that the light REEs decrease and heavy REEs increase during the alteration processes. The relationships between K2O index with Eu/Eu* and Sr/Sr* reveals a positive correlation in the potassic and phyllic alteration zones and a negative correlation in the propylitic alteration zone. This refers to the hydrothermal solution which is responsible for the studied porphyry deposits and associated potassic and phyllic alterations has a positive Eu and Sr anomaly as well as these elements were added to the altered rock from the hydrothermal solution. Keywords: Rare earth elements geochemistry; Tepeoba porphyry Cu-Mo-Au deposits; Balikesir; Turkey

Borehole geophysical, fluid, and hydraulic properties within and surrounding the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, 2010-11

USGS Publications Warehouse

Thomas, Jonathan V.; Stanton, Gregory P.; Lambert, Rebecca B.

2012-01-01

Although analyses of daily mean equivalent freshwater heads for the East Uvalde transect indicated that the gradient across the freshwater/saline-water interface varied between into and out of the freshwater zone, the data indicate that there was a slightly longer period during which the gradient was out of the freshwater zone. Analyses of all daily mean equivalent freshwater heads for the Tri-County transect indicated that the lateral-head gradients across the freshwater/saline-water interface were typically mixed (not indicative of flow into or out of freshwater zone). Assessment of the daily mean equivalent freshwater heads indicated that, although the lateral-head gradient at the Kyle transect varied between into and out of the freshwater zone, the lateral-head gradient was typically from the transition zone into the freshwater zone.

Laser imprint reduction for the critical-density foam buffered target driven by a relatively strong foot pulse at early stage of laser implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, J. W., E-mail: li-jiwei@iapcm.ac.cn; He, X. T.; Institute of Applied Physics and Computational Mathematics, P. O. Box 8009, Beijing 100094

In order to reduce the effect of laser imprint in direct-drive ignition scheme a low-density foam buffered target has been proposed. This target is driven by a laser pulse with a low-intensity foot at the early stage of implosion, which heats the foam and elongates the thermal conduction zone between the laser absorption region and ablation front, increasing the thermal smoothing effect. In this paper, a relatively strong foot pulse is adopted to irradiate the critical-density foam buffered target. The stronger foot, near 1 × 10{sup 14 }W/cm{sup 2}, is able to drive a radiative shock in the low-density foam, which helps smoothmore » the shock and further reduce the effect of laser imprint. The radiative shock also forms a double ablation front structure between the two ablation fronts to further stabilize the hydrodynamics, achieving the similar results to a target with a high-Z dopant in the ablator. 2D analysis shows that for the critical-density foam buffered target irradiated by the strong foot pulse, the laser imprint can be reduced due to the radiative shock in the foam and an increased thermal smoothing effect. It seems viable for the critical-density foam buffered target to be driven by a relatively strong foot pulse with the goal of reducing the laser imprint and achieving better implosion symmetry in the direct-drive laser fusion.« less

Beneficial effects of humic acid on micronutrient availability to wheat

NASA Technical Reports Server (NTRS)

Mackowiak, C. L.; Grossl, P. R.; Bugbee, B. G.

2001-01-01

Humic acid (HA) is a relatively stable product of organic matter decomposition and thus accumulates in environmental systems. Humic acid might benefit plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA on growth and micronutrient uptake in wheat (Triticum aestivum L.) grown hydroponically. Four root-zone treatments were compared: (i) 25 micromoles synthetic chelate N-(4-hydroxyethyl)ethylenediaminetriacetic acid (C10H18N2O7) (HEDTA at 0.25 mM C); (ii) 25 micromoles synthetic chelate with 4-morpholineethanesulfonic acid (C6H13N4S) (MES at 5 mM C) pH buffer; (iii) HA at 1 mM C without synthetic chelate or buffer; and (iv) no synthetic chelate or buffer. Ample inorganic Fe (35 micromoles Fe3+) was supplied in all treatments. There was no statistically significant difference in total biomass or seed yield among treatments, but HA was effective at ameliorating the leaf interveinal chlorosis that occurred during early growth of the nonchelated treatment. Leaf-tissue Cu and Zn concentrations were lower in the HEDTA treatment relative to no chelate (NC), indicating HEDTA strongly complexed these nutrients, thus reducing their free ion activities and hence, bioavailability. Humic acid did not complex Zn as strongly and chemical equilibrium modeling supported these results. Titration tests indicated that HA was not an effective pH buffer at 1 mM C, and higher levels resulted in HA-Ca and HA-Mg flocculation in the nutrient solution.

Strain-dependent Damage Evolution and Velocity Reduction in Fault Zones Induced by Earthquake Rupture

NASA Astrophysics Data System (ADS)

Zhong, J.; Duan, B.

2009-12-01

Low-velocity fault zones (LVFZs) with reduced seismic velocities relative to the surrounding wall rocks are widely observed around active faults. The presence of such a zone will affect rupture propagation, near-field ground motion, and off-fault damage in subsequent earth-quakes. In this study, we quantify the reduction of seismic velocities caused by dynamic rup-ture on a 2D planar fault surrounded by a low-velocity fault zone. First, we implement the damage rheology (Lyakhovsky et al. 1997) in EQdyna (Duan and Oglesby 2006), an explicit dynamic finite element code. We further extend this damage rheology model to include the dependence of strains on crack density. Then, we quantify off-fault continuum damage distribution and velocity reduction induced by earthquake rupture with the presence of a preexisting LVFZ. We find that the presence of a LVFZ affects the tempo-spatial distribu-tions of off-fault damage. Because lack of constraint in some damage parameters, we further investigate the relationship between velocity reduction and these damage prameters by a large suite of numerical simulations. Slip velocity, slip, and near-field ground motions computed from damage rheology are also compared with those from off-fault elastic or elastoplastic responses. We find that the reduction in elastic moduli during dynamic rupture has profound impact on these quantities.

Isotropic events observed with a borehole array in the Chelungpu fault zone, Taiwan.

PubMed

Ma, Kuo-Fong; Lin, Yen-Yu; Lee, Shiann-Jong; Mori, Jim; Brodsky, Emily E

2012-07-27

Shear failure is the dominant mode of earthquake-causing rock failure along faults. High fluid pressure can also potentially induce rock failure by opening cavities and cracks, but an active example of this process has not been directly observed in a fault zone. Using borehole array data collected along the low-stress Chelungpu fault zone, Taiwan, we observed several small seismic events (I-type events) in a fluid-rich permeable zone directly below the impermeable slip zone of the 1999 moment magnitude 7.6 Chi-Chi earthquake. Modeling of the events suggests an isotropic, nonshear source mechanism likely associated with natural hydraulic fractures. These seismic events may be associated with the formation of veins and other fluid features often observed in rocks surrounding fault zones and may be similar to artificially induced hydraulic fracturing.

Setback Distances as a Conservation Tool in Wildlife-Human Interactions: Testing Their Efficacy for Birds Affected by Vehicles on Open-Coast Sandy Beaches

PubMed Central

Schlacher, Thomas A.; Weston, Michael A.; Lynn, David; Connolly, Rod M.

2013-01-01

In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviour. PMID:24039711

Monitoring the excavation damaged zone by three-dimensional reconstruction of electrical resistivity

NASA Astrophysics Data System (ADS)

Lesparre, Nolwenn; Gibert, Dominique; Nicollin, Florence; Nussbaum, Christophe; Adler, Andy

2013-11-01

A damaged zone is formed during the excavation of underground galleries, altering the rock properties. From a perspective of nuclear waste storage in deep geological sites, there is a clear interest to monitor the rock properties in such zones. We constructed electrical resistivity tomograms as a function of time to monitor the damaged area in gallery 04 of the Mont Terri underground rock laboratory (Switzerland). Measurements were performed using electrode rings surrounding the gallery. The experience showed a heterogeneous distribution of damages around the gallery and their fast formation after the excavation. Two main areas were concerned by damage formation, located in regions where the bedding was tangential to the excavated gallery. Such regions represented an extension of about 2 m along the gallery walls and reached a depth of 1.5 m. Main damages were created during the next months following the excavation process. Slight variations were still observed 3 yr after the excavation that may be related to the gallery environmental condition fluctuation. The method applied here demonstrates the interest to monitor the whole region surrounding excavated galleries dedicated to host nuclear wastes.

Sea floor topography and backscatter intensity of the Historic Area Remediation Site (HARS), offshore of New York, based on multibeam surveys conducted in 1996, 1998, and 2000

USGS Publications Warehouse

Butman, Bradford; Danforth, W.W.; Knowles, S.C.; May, Brian; Serrett, Laurie

2000-01-01

An area offshore of Sandy Hook, New Jersey, has been used extensively for disposal of dredged and other materials, derived from the New York/New Jersey Harbor and surrounding areas, since the late 1800's (Figure 1). Between 1976 and 1995, the New York Bight Dredged Material Disposal Site, also known as the Mud Dump Site (Figure 2), received on average about 6 million cubic yards of material each year from federal and private maintenance dredging and from harbor deepening activities (Massa and others, 1996). In September 1997 the Mud Dump Site (MDS) was closed as an official ocean disposal site by the U.S. Environmental Protection Agency (http://www.epa.gov/), and the MDS and surrounding areas were designated as the Historic Area Remediation Site (HARS). The HARS is subdivided into a Primary Remediation Area (PRA, subdivided into 9 cells), a Buffer Zone, and a No-Discharge Zone (Figure 2). The sea floor of the HARS, approximately 9 square nautical miles in area, is being remediated by placing at least a one-meter cap of Category I (clean) dredged material on top of the existing surface sediments that exhibit varying degrees of degradation. (See http://www.nan.usace.army.mil/business/prjlinks/dmmp/benefic/hars.htm)(Category I sediments have no potential short or long-term impacts and are acceptable for unrestricted ocean disposal (EPA, 1996)). About 1.1 million cubic yards of dredged material for remediation was placed in the HARS in 1999, and 2.5 million cubic yards in 2000. Three multibeam echosounder surveys were carried out to map the topography and surficial geology of the HARS. The surveys were conducted November 23 - December 3, 1996, October 26 - November 11, 1998, and April 6 - 30, 2000. The surveys were carried out as part of a larger survey of the Hudson Shelf Valley and adjacent shelf (Butman and others, 1998, (http://pubs.usgs.gov/openfile/of98-616/). This report presents maps showing topography, shaded relief, and backscatter intensity (a measure of sea floor texture and roughness) at a scale of 1:25,000. Comparison of the topography and backscatter intensity from the three surveys show changes in topography and surficial sediment properties resulting from placement of dredged material in 1996 and 1997 prior to closure of the Mud Dump Site, as well as placement of capping material for remediation of the HARS. The surficial geology and sediments of the HARS and the surrounding region are described in Butman and others (1998), (http://pubs.usgs.gov/openfile/of98-616/, Schwab and others (1997, 2000, http://pubs.usgs.gov/openfile/of00-295/). A history of waste disposal in the New York Bight region is presented in Massa and others (1996).

Mid-continent earthquake zones; lessons from New Madrid, Missouri

USGS Publications Warehouse

Mitchell, B. J.

1991-01-01

Many seismically active regions occur throughout the world as concentrated zones surrounded by the relatively stable crust of shields or platforms. Examples occur in central and eastern North America, northeastern Brazil, Australia, Norway, Svalbard, Greenland, and other places. Some of these zones, such as those at New Madrid, Missouri, and in the St. Lawrence Valley on the Canadian border, extend over relatively large areas and are marked by a high level of seismicity. Others, such as that near Anna Ohio, are smaller, and the level of activity is lower. Some zones are occasinoally sites for major earthquakes which, if they are in populated regions, can cause widespread destrucion and loss of life. 

Evaluation of strategies for the eradication of Pseudorabies virus (Aujeszky's disease) in commercial swine farms in Chiang-Mai and Lampoon Provinces, Thailand, using a simulation disease spread model.

PubMed

Ketusing, N; Reeves, A; Portacci, K; Yano, T; Olea-Popelka, F; Keefe, T; Salman, M

2014-04-01

Several strategies for eradicating Pseudorabies virus (Aujeszky's disease) in Chiang-Mai and Lampoon Provinces, Thailand, were compared using a computer simulation model, the North American Animal Disease Spread Model (NAADSM). The duration of the outbreak, the number of affected herds and the number of destroyed herds were compared during these simulated outbreaks. Depopulation, zoning for restricted movement and improved detection and vaccination strategies were assessed. The most effective strategies to eradicate Pseudorabies as per the findings from this study are applying depopulation strategies with MOVEMENT RESTRICTIONS in 3-, 8- and 16-km ZONES surrounding infected herds and enhancing the eradication with vaccination campaign on 16-km radius surrounding infected herds. © 2012 Blackwell Verlag GmbH.

Preliminary study of the effects of headwater riparian reserves with upslope thinning on stream habitats and amphibians in western Oregon.

Treesearch

D.H. Olson; C. Rugger

2007-01-01

We conducted a preliminary examination of the responses of stream amphibians and instream habitat conditions to alternative riparian buffer zones with forest thinning upslope. Pre- and posttreatment surveys were carried out on 68 headwater stream reaches (including 23 unthinned reference reaches) at 11 sites in western Oregon. Streams were in managed conifer stands 40...

How effective were mangroves as a defence against the recent tsunami?

PubMed

Dahdouh-Guebas, F; Jayatissa, L P; Di Nitto, D; Bosire, J O; Lo Seen, D; Koedam, N

2005-06-21

Whether or not mangroves function as buffers against tsunamis is the subject of in-depth research, the importance of which has been neglected or underestimated before the recent killer tsunami struck. Our preliminary post-tsunami surveys of Sri Lankan mangrove sites with different degrees of degradation indicate that human activity exacerbated the damage inflicted on the coastal zone by the tsunami.

Implications of groundwater hydrology to buffer design in the southeastern U.S.

Treesearch

Ge Sun; James M. Vose; Devendra M. Amatya; Carl Trettin; Steven G. McNulty

2008-01-01

The objective of this study was to examine the hydrologic processes of shallow groundwater to better define and design forest riparian management zones in headwater streams of two contrasting terrains in the southeastern U.S. We employed two long-term experimental watersheds, WS80 (206 ha) and WS77 (151 ha) at the Santee Experimental Forests in South Carolina, and WS2...

The Gujarat earthquake (2001) experience in a seismically unprepared area: community hospital medical response.

PubMed

Roy, Nobhojit; Shah, Hemant; Patel, Vikas; Coughlin, R Richard

2002-01-01

At 08:53 hours on 26 January 2001, an earthquake measuring 6.9 on the Richter scale devastated a large, drought-affected area of northwestern India, the state of Gujarat. The known number killed by the earthquake is 20,005, with 166,000 injured, of whom 20,717 were "seriously" injured. About 370,000 houses were destroyed, and another 922,000 were damaged. A community health worker using the local language interviewed all of the patients admitted to the Gandhi-Lincoln hospital with an on-site, oral, real-time, Victim Specific Questionnaire (VSQ). The census showed a predominance of women, children, and young adults, with the average age being 28 years. The majority of the patients had other family members who were also injured (84%), but most had not experienced deaths among family members (86%). Most of the patients (91%) had traveled more than 200 kilometers using their family cars, pick-ups, trucks, or buses to reach the buffer zone hospitals. The daily hospital admission rate returned to pre-event levels five days after the event, and all of the hospital services were restored by nine days after the quake. Most of the patients (83%) received definitive treatment in the buffer zone hospitals; 7% were referred to tertiary-care centers; and 9% took discharge against medical advice. The entrapped village folk with their traditional architecture had lesser injuries and a higher rescue rate than did the semi-urban townspeople, who were trapped in collapsed concrete masonry buildings and narrow alleys. However, at the time of crisis, aware townspeople were able to tap the available health resources better than were the poor. There was a low incidence of crush injuries. Volunteer doctors from various backgrounds teamed up to meet the medical crisis. International relief agencies working through local groups were more effective. Local relief groups needed to coordinate better. Disaster tourism by various well-meaning agencies took a toll on the providers. Many surgeries may have contributed to subsequent morbidity. The injury profile was similar to that reported for most other daytime earthquakes. Buffer zone treatment outcomes were better than were the field and damaged hospital outcomes.

Near Wall Velocity and Vorticity Measurements, In A Very High R(theta) Turbulent Boundary Layer

DTIC Science & Technology

2006-06-15

Fluctuation in temperature 7 Angle of the oncoming flow with respect to the axis of the probe body Superscripts + Variables scaled on inner parameters Denotes...at high Reynolds numbers (Re = 5* 106). They examined flow in the viscous sublayer and buffer layer to explore the influence of very high Reynolds...Great Salt Lake and surrounding "salt flats" sit in the drying basin of what is believed to have once been a much larger body of water covering the

A novel method for high-pressure annealing experiments in a water-rich environment: hydrogen solubility and speciation in natural, gem-quality diopside

NASA Astrophysics Data System (ADS)

Bromiley, G. D.; Keppler, H.; Bromiley, F. A.; Jacobsen, S. D.

2003-04-01

Previous experimental invesitgations on the incorporation of structurally-bound hydrogen in nominally anhydrous minerals have either involved synthesis experiments or annealing of natural samples under hydrothermal conditions. For investigation of hydrogen incorporation using FTIR, large, good quality crystals are required. Because of experimental difficulties, synthesis experiments are limited to the investigation of end-member systems. Annealing experiments may be used to investigate chemically more complex systems. However, in previous investigations problems have arisen due to reaction of samples with chemical buffers and fluids at elevated pressures and temperatures, and run times have been limited to less than 48 hours, raising questions regarding attainment of equilbrium. In the present study, a novel method for conducting long duration (100 s of hours) annealing experiments to investigate hydrogen incorporation in samples at high-pressure has been developed. The method relies on the use of a semi-permeable platinum membrane, which protects the sample during the experiment. Samples, cut into 1×2×3 mm blocks, are surrounded by a thin platinum jacket, which is "shrink-wrapped" around the samples. The samples are then loaded into larger Pt10%Rh capsules with a buffer mixture of the same composition as the Cr-diopside, a large amount of excess water, excess silica and a Ni-NiO buffer to control oxygen fugacity. At elevated pressures and temperatures, hydrogen can diffuse freely through the platinum membrane, but the samples are protected from reaction with the surrounding buffer material and fluid. Capsules are loaded into a specially designed low-friction NaCl cells for use in piston-cylinder apparatus. Samples are recovered completely intact and crack-free. Several experiments have been performed at 1.5 GPa, with increasing run duration, to demonstrate the attainment of equilibrium hydrogen contents in the sample. Experiments have been performed at pressures from 0.5 to 4.0 GPa, 1000 to 1100^oC, with run times of several hundred hours. The effects of increasing pressure and oxygen fugacity on hydeogen solubility, and hydrogen speciation in the diopside have been fully characterised using polarised FTIR spectoscopy. The high-quality of recovered samples means that further investigations on the effects of increasing water contents on other physical properties in the samples should be possible.

Environmental Assessment for Terminal Area Improvements, Charleston International Airport

DTIC Science & Technology

2011-11-17

Resources and/or USFWS . 7. An erosion and sedimentation control plan that includes the use of construction controls to prevent degradation of water...CCAA property and surrounding lands were historically used for phosphate fertilizer mining. Prior to the development of this property as an airport...number of zoning classifications which control land use within the city limits. The Airport is in an area zoned as "Light Industrial District" a

Aboriginal hunting buffers climate-driven fire-size variability in Australia’s spinifex grasslands

PubMed Central

Bliege Bird, Rebecca; Codding, Brian F.; Kauhanen, Peter G.

2012-01-01

Across diverse ecosystems, greater climatic variability tends to increase wildfire size, particularly in Australia, where alternating wet–dry cycles increase vegetation growth, only to leave a dry overgrown landscape highly susceptible to fire spread. Aboriginal Australian hunting fires have been hypothesized to buffer such variability, mitigating mortality on small-mammal populations, which have suffered declines and extinctions in the arid zone coincident with Aboriginal depopulation. We test the hypothesis that the relationship between climate and fire size is buffered through the maintenance of an anthropogenic, fine-grained fire regime by comparing the effect of climatic variability on landscapes dominated by Martu Aboriginal hunting fires with those dominated by lightning fires. We show that Aboriginal fires are smaller, more tightly clustered, and remain small even when climate variation causes huge fires in the lightning region. As these effects likely benefit threatened small-mammal species, Aboriginal hunters should be considered trophic facilitators, and policies aimed at reducing the risk of large fires should promote land-management strategies consistent with Aboriginal burning regimes. PMID:22689979

Proliferation zones in the axolotl brain and regeneration of the telencephalon

PubMed Central

2013-01-01

Background Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. Results There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. Conclusion There is a continual generation of neuronal cells from neural progenitor cells located within the ventricular zone of the axolotl brain. Variable rates of proliferation were detected across brain regions. These neural progenitor cells appear to mediate telencephalic tissue regeneration through an injury-induced olfactory cue. Identification of this cue is our future goal. PMID:23327114

Proliferation zones in the axolotl brain and regeneration of the telencephalon.

PubMed

Maden, Malcolm; Manwell, Laurie A; Ormerod, Brandi K

2013-01-17

Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. There is a continual generation of neuronal cells from neural progenitor cells located within the ventricular zone of the axolotl brain. Variable rates of proliferation were detected across brain regions. These neural progenitor cells appear to mediate telencephalic tissue regeneration through an injury-induced olfactory cue. Identification of this cue is our future goal.

Use of fiber-optic DTS to investigate physical processes in thermohaline environments

NASA Astrophysics Data System (ADS)

Suarez, F. I.; Sarabia, A.; Silva, C.

2014-12-01

Salt-gradient solar ponds are artificial thermohaline environments that collect and store thermal energy for long time-periods. A solar pond consists of three distinctive zones: the upper convective zone, which is a thin layer of cooler, less salty water; the non-convective zone that has gradients in temperature and salinity; and the lower convective zone, a layer of high salinity brine where temperatures are the highest. The solar radiation that penetrates the upper layers of the pond reaches the lower convective zone and heats the high salinity brine, which does not rise beyond the lower convective zone because the effect of salinity on density is greater than the effect of temperature. The sediments beneath the pond are also heated due to the temperature increase in the lower convective zone, providing an additional volume for energy storage. To study the different physical processes occurring within a solar pond and its surroundings, we deployed a helicoidally wrapped distributed-temperature-sensing (DTS) system in a small-scale solar pond (1-m deep, 2.5-m long and 1.5-m width). In this installation, the pond is surrounded by a sandy soil that serves as an additional energy storage volume. The thermal profile is observed at a spatial sampling resolution of 1.1 cm (spatial resolution of 2.2. cm), a temporal resolution ranging from 15 s to 5 min, and a thermal resolution ranging from 0.05 to 0.5°C. These resolutions allow closing the energy balance and inferring physical processes such as double-diffusive convection, solar radiation absorption, and heat conduction through the sediments or through the non-convective zone. Independent thermal measurements are also being made to evaluate strengths and limitations of DTS systems in thermohaline environments, and to assess different calibration algorithms that have been proposed in the past.

Ground Tilt Time Delays between Kilauea Volcano's Summit and East Rift Zone Caused by Magma Reservoir Buffering

NASA Astrophysics Data System (ADS)

Haney, M. M.; Patrick, M. R.; Anderson, K. R.

2016-12-01

A cyclic pattern of ground deformation, called a deflation-inflation (DI) cycle, is commonly observed at Kilauea Volcano, Hawai`i. These cycles are an important part of Kilauea's eruptive activity because they directly influence the level of the summit lava lake as well as the effusion rate (and resulting lava flow hazard) at the East Rift Zone eruption site at Pu`u `O`o. DI events normally span several days, and are measured both at the summit and at Pu`u `O`o cone (20 km distance). Signals appear first at the summit and are then observed at Pu`u `O`o after an apparent delay of between 0.5 and 10 hours, which has been previously interpreted as reflecting magma transport time. We propose an alternate explanation, in which the apparent delay is an artifact of buffering by the small magma reservoir thought to exist at Pu`u `O`o. Simple Poiseuille flow modeling demonstrates that this apparent delay can be reproduced by the changing balance of inflow (from the summit) and outflow (to surface lava flows) at the Pu`u `O`o magma reservoir. The apparent delay is sensitive to the geometry of the conduit leaving Pu`u `O`o, feeding surface lava flows. We demonstrate how the reservoir buffering is quantitatively equivalent to a causal low-pass filter, which explains both the apparent delay as well as the smoothed, skewed nature of the signal at Pu`u `O`o relative to the summit. By comparing summit and Pu`u `O`o ground tilt signals over an extended time period, it may be possible to constrain the changing geometry of the shallow magmatic system through time.

The Fate of Nitrate in Intertidal Permeable Sediments

PubMed Central

Marchant, Hannah K.; Lavik, Gaute; Holtappels, Moritz; Kuypers, Marcel M. M.

2014-01-01

Coastal zones act as a sink for riverine and atmospheric nitrogen inputs and thereby buffer the open ocean from the effects of anthropogenic activity. Recently, microbial activity in sandy permeable sediments has been identified as a dominant source of N-loss in coastal zones, namely through denitrification. Some of the highest coastal denitrification rates measured so far occur within the intertidal permeable sediments of the eutrophied Wadden Sea. Still, denitrification alone can often account for only half of the substantial nitrate (NO3 −) consumption. Therefore, to investigate alternative NO3 − sinks such as dissimilatory nitrate reduction to ammonium (DNRA), intracellular nitrate storage by eukaryotes and isotope equilibration effects we carried out 15NO3 − amendment experiments. By considering all of these sinks in combination, we could quantify the fate of the 15NO3 − added to the sediment. Denitrification was the dominant nitrate sink (50–75%), while DNRA, which recycles N to the environment accounted for 10–20% of NO3 − consumption. Intriguingly, we also observed that between 20 and 40% of 15NO3 − added to the incubations entered an intracellular pool of NO3 − and was subsequently respired when nitrate became limiting. Eukaryotes were responsible for a large proportion of intracellular nitrate storage, and it could be shown through inhibition experiments that at least a third of the stored nitrate was subsequently also respired by eukaryotes. The environmental significance of the intracellular nitrate pool was confirmed by in situ measurements which revealed that intracellular storage can accumulate nitrate at concentrations six fold higher than the surrounding porewater. This intracellular pool is so far not considered when modeling N-loss from intertidal permeable sediments; however it can act as a reservoir for nitrate during low tide. Consequently, nitrate respiration supported by intracellular nitrate storage can add an additional 20% to previous nitrate reduction estimates in intertidal sediments, further increasing their contribution to N-loss. PMID:25127459

The fate of nitrate in intertidal permeable sediments.

PubMed

Marchant, Hannah K; Lavik, Gaute; Holtappels, Moritz; Kuypers, Marcel M M

2014-01-01

Coastal zones act as a sink for riverine and atmospheric nitrogen inputs and thereby buffer the open ocean from the effects of anthropogenic activity. Recently, microbial activity in sandy permeable sediments has been identified as a dominant source of N-loss in coastal zones, namely through denitrification. Some of the highest coastal denitrification rates measured so far occur within the intertidal permeable sediments of the eutrophied Wadden Sea. Still, denitrification alone can often account for only half of the substantial nitrate (NO3-) consumption. Therefore, to investigate alternative NO3- sinks such as dissimilatory nitrate reduction to ammonium (DNRA), intracellular nitrate storage by eukaryotes and isotope equilibration effects we carried out 15NO3- amendment experiments. By considering all of these sinks in combination, we could quantify the fate of the 15NO3- added to the sediment. Denitrification was the dominant nitrate sink (50-75%), while DNRA, which recycles N to the environment accounted for 10-20% of NO3- consumption. Intriguingly, we also observed that between 20 and 40% of 15NO3- added to the incubations entered an intracellular pool of NO3- and was subsequently respired when nitrate became limiting. Eukaryotes were responsible for a large proportion of intracellular nitrate storage, and it could be shown through inhibition experiments that at least a third of the stored nitrate was subsequently also respired by eukaryotes. The environmental significance of the intracellular nitrate pool was confirmed by in situ measurements which revealed that intracellular storage can accumulate nitrate at concentrations six fold higher than the surrounding porewater. This intracellular pool is so far not considered when modeling N-loss from intertidal permeable sediments; however it can act as a reservoir for nitrate during low tide. Consequently, nitrate respiration supported by intracellular nitrate storage can add an additional 20% to previous nitrate reduction estimates in intertidal sediments, further increasing their contribution to N-loss.

Seismic Velocity and Elastic Properties of Plate Boundary Faults

NASA Astrophysics Data System (ADS)

Jeppson, Tamara N.

The elastic properties of fault zone rock at depth play a key role in rupture nucleation, propagation, and the magnitude of fault slip. Materials that lie within major plate boundary fault zones often have very different material properties than standard crustal rock values. In order to understand the mechanics of faulting at plate boundaries, we need to both measure these properties and understand how they govern the behavior of different types of faults. Mature fault zones tend to be identified in large-scale geophysical field studies as zones with low seismic velocity and/or electrical resistivity. These anomalous properties are related to two important mechanisms: (1) mechanical or diagenetic alteration of the rock materials and/or (2) pore fluid pressure and stress effects. However, in remotely-sensed and large-length-scale data it is difficult to determine which of these mechanisms are affecting the measured properties. The objective of this dissertation research is to characterize the seismic velocity and elastic properties of fault zone rocks at a range of scales, with a focus on understanding why the fault zone properties are different from those of the surrounding rock and the potential effects on earthquake rupture and fault slip. To do this I performed ultrasonic velocity experiments under elevated pressure conditions on drill core and outcrops samples from three plate boundary fault zones: the San Andreas Fault, California, USA; the Alpine Fault, South Island, New Zealand; and the Japan Trench megathrust, Japan. Additionally, I compared laboratory measurements to sonic log and large-scale seismic data to examine the scale-dependence of the measured properties. The results of this study provide the most comprehensive characterization of the seismic velocities and elastic properties of fault zone rocks currently available. My work shows that fault zone rocks at mature plate boundary faults tend to be significantly more compliant than surrounding crustal rocks and quantifies that relationship. The results of this study are particularly relevant to the interpretation of field-scale seismic datasets at major fault zones. Additionally, the results of this study provide constraints on elastic properties used in dynamic rupture models.

Explaining variations in the diversity of parasitoid assemblages in a biosphere reserve of Mexico: evidence from vegetation, land management and seasonality.

PubMed

González-Moreno, A; Bordera, S; Leirana-Alcocer, J; Delfín-González, H; Ballina-Gómez, H S

2017-11-23

Insect fauna biodiversity in natural protected areas has not been thoroughly studied. Therefore, the aim of this work was to assess whether and how vegetation types, land management and seasonality influence the diversity of Ichneumonidae (Hymenoptera) in the Ría Lagartos Biosphere Reserve (Mexico). A sampling programme was conducted using Malaise traps from 2008 to 2009 in three vegetation types, each with two conservation zones (core and buffer zones). Three seasons were considered: rainy, dry and north-winds (isolated storms from November to February). A total of 336 species were identified. Rarefaction and Generalized Linear Model indicated higher species richness and abundance, respectively, in the buffer zone of the dry forest; possible explanations for this finding include the intermediate disturbance hypothesis, wherein diversity can be higher in sites where disturbance is not very frequent or very intense, and the 'enemies hypothesis', wherein structural complexity and high plant diversity favour increased predators or, in this case, parasitoids. Diversity was higher during the rainy season, which may have been due to the higher availability of resources. Vegetation and management had a positive impact on the Coc (attack cocoons and pupae) and Myc (attack concealed larvae living in the fruiting bodies of mushrooms) parasitoid guilds. Members of the Coc guild are generalist parasitoids, which may be favoured in complex vegetation with a high richness of potential hosts and non-hosts. The Myc guild requires certain environmental conditions that promote fungal growth, such as humidity, that is absent in the other vegetation types of savannah and coastal dune scrubland.

Tensiometer for shallow or deep measurements including vadose zone and aquifers

DOEpatents

Faybishenko, B.

1999-08-24

A two cell tensiometer is described in which water level in the lower cell is maintained at a relatively constant height, and in equilibrium with the water pressure of materials that surround the tensiometer. An isolated volume of air in the lower cell changes pressure proportionately to the changing water pressure of the materials that surround the tensiometer. The air pressure is measured remotely. The tensiometer can be used in drying as well as wetting cycles above and below the water table. 8 figs.

Tensiometer for shallow or deep measurements including vadose zone and aquifers

DOEpatents

Faybishenko, Boris

1999-01-01

A two cell tensiometer is described in which water level in the lower cell is maintained at a relatively constant height, and in equilibrium with the water pressure of materials that surround the tensiometer. An isolated volume of air in the lower cell changes pressure proportionately to the changing water pressure of the materials that surround the tensiometer. The air pressure is measured remotely. The tensiometer can be used in drying as well as wetting cycles above and below the water table.

The influence of partial timber harvesting in riparian buffers on macroinvertebrate and fish communities in small streams in Minnesota, USA

USGS Publications Warehouse

Chizinski, Christopher J.; Vondracek, Bruce C.; Blinn, Charles R.; Newman, Raymond M.; Atuke, Dickson M.; Fredricks, Keith; Hemstad, Nathaniel A.; Merten, Eric C.; Schlesser, Nicholas

2010-01-01

Relatively few evaluations of aquatic macroinvertebrate and fish communities have been published in peer-reviewed literature detailing the effect of varying residual basal area (RBA) after timber harvesting in riparian buffers. Our analysis investigated the effects of partial harvesting within riparian buffers on aquatic macroinvertebrate and fish communities in small streams from two experiments in northern Minnesota northern hardwood-aspen forests. Each experiment evaluated partial harvesting within riparian buffers. In both experiments, benthic macroinvertebrates and fish were collected 1 year prior to harvest and in each of 3 years after harvest. We observed interannual variation for the macroinvertebrate abundance, diversity and taxon richness in the single-basin study and abundance and diversity in the multiple-basin study, but few effects related to harvest treatments in either study. However, interannual variation was not evident in the fish communities and we detected no significant changes in the stream fish communities associated with partially harvested riparian buffers in either study. This would suggest that timber harvesting in riparian management zones along reaches ≤200 m in length on both sides of the stream that retains RBA ≥ 12.4 ± 1.3 m2 ha−1 or on a single side of the stream that retains RBA ≥ 8.7 ± 1.6 m2 ha−1 may be adequate to protect macroinvertebrate and fish communities in our Minnesota study systems given these specific timber harvesting techniques.

Capacity estimation of soil organic carbon pools in the intertidal zone of the Bohai Bay

NASA Astrophysics Data System (ADS)

Tian-Yu, Mao; Ting-Ting, Shi; Ya-Juan, Li

2018-03-01

Based on the data obtained from the field survey in the intertidal zone of the Binhai New Area of Tianjin Bay in October 2014, the distribution characteristics of soil organic carbon pool in intertidal zone were studied. The results showed that the highest organic carbon content of soil is 22.913g/kg; the average is 16.304g/kg. The soil organic carbon pool in the intertidal zone is in the 6.58-30.40kg/m3, almost close the level of forest soil in the Binhai New Area. Moreover, close to the surrounding wetland such as Yellow River Estuary or Liaohe River Estuary. In conclusion, the soil carbon storage of the beach tidal flats is higher in the coastal zone, and the carbon storage will be significantly reduced after artificial backfilling.

Influence of hyporheic flow and geomorphology on temperature of a large, gravel-bed river, Clackamas River, Oregon, USA

Treesearch

Vol. 22 Hydrological Processes

2008-01-01

The hyporheic zone influences the thermal regime of rivers, buffering temperature by storing and releasing heat over a range of timesscales. We examined the relationship between hyporheic exchange and temperature along a 24-km reach of the lower Clackamas River, a large gravel-bed river in northwestern Oregon (median discharge = 75·7 m3/s;...

First report on invasion of yellow fever mosquito, Aedes aegypti, at Narita International Airport, Japan in August 2012.

PubMed

Sukehiro, Nayu; Kida, Nori; Umezawa, Masahiro; Murakami, Takayuki; Arai, Naoko; Jinnai, Tsunesada; Inagaki, Shunichi; Tsuchiya, Hidetoshi; Maruyama, Hiroshi; Tsuda, Yoshio

2013-01-01

The invasion of the yellow fever mosquito Aedes aegypti at Narita International Airport, Japan was detected for the first time. During the course of routine vector surveillance at Narita International Airport, 27 Ae. aegypti adults emerged from larvae and pupae collected from a single larvitrap placed near No. 88 spot at passenger terminal 2 on August 8, 2012. After the appearance of Ae. aegypti in the larvitrap, we defined a 400-m buffer zone and started an intensive vector survey using an additional 34 larvitraps and 15 CO2 traps. International aircraft and passenger terminal 2 were also inspected, and one Ae. aegypti male was collected from the cargo space of an international aircraft from Darwin via Manila on August 28, 2012. Larvicide treatment with 1.5% fenitrothion was conducted in 64 catch basins and one ditch in the 400-m buffer zone. Twenty-four large water tanks were also treated at least once with 0.5% pyriproxyfen, an insect growth regulator. No Ae. aegypti eggs or adults were found during the 1-month intensive vector survey after finding larvae and pupae in the larvitrap. We concluded that Ae. aegypti had failed to establish a population at Narita International Airport.

1. VIEW, LOOKING NORTH, OF THE SOUTH ELEVATION OF BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VIEW, LOOKING NORTH, OF THE SOUTH ELEVATION OF BUILDING 901. BUILDING 901 IS ONE OF FOUR GUARD TOWERS INSTALLED AS PART OF THE PERIMETER SECURITY ZONE TO PROVIDE PROTECTIVE FORCE PERSONNEL WITH A CLEAR HIGH VIEW OF THE SURROUNDING AREAS. THE PERIMETER SECURITY ZONE CONSISTS OF A DOUBLE PERIMETER FENCE WITH CLOSED CIRCUIT TELEVISIONS, ALARMS, AND AN UNINTERRUPTED POWER SUPPLY. - Rocky Flats Plant, Guard Tower, Southeast corner of protected area, Golden, Jefferson County, CO

Managing breaches of containment and eradication of invasive plant populations.

PubMed

Fletcher, Cameron S; Westcott, David A; Murphy, Helen T; Grice, Anthony C; Clarkson, John R

2015-02-01

Containment can be a viable strategy for managing invasive plants, but it is not always cheaper than eradication. In many cases, converting a failed eradication programme to a containment programme is not economically justified. Despite this, many contemporary invasive plant management strategies invoke containment as a fallback for failed eradication, often without detailing how containment would be implemented.We demonstrate a generalized analysis of the costs of eradication and containment, applicable to any plant invasion for which infestation size, dispersal distance, seed bank lifetime and the economic discount rate are specified. We estimate the costs of adapting eradication and containment in response to six types of breach and calculate under what conditions containment may provide a valid fallback to a breached eradication programme.We provide simple, general formulae and plots that can be applied to any invasion and show that containment will be cheaper than eradication only when the size of the occupied zone exceeds a multiple of the dispersal distance determined by seed bank longevity and the discount rate. Containment becomes proportionally cheaper than eradication for invaders with smaller dispersal distances, longer lived seed banks, or for larger discount rates.Both containment and eradication programmes are at risk of breach. Containment is less exposed to risk from reproduction in the 'occupied zone' and three types of breach that lead to a larger 'occupied zone', but more exposed to one type of breach that leads to a larger 'buffer zone'.For a well-specified eradication programme, only the three types of breach leading to reproduction in or just outside the buffer zone can justify falling back to containment, and only if the expected costs of eradication and containment were comparable before the breach. Synthesis and applications . Weed management plans must apply a consistent definition of containment and provide sufficient implementation detail to assess its feasibility. If the infestation extent, dispersal capacity, seed bank longevity and economic discount rate are specified, the general results presented here can be used to assess whether containment can outperform eradication, and under what conditions it would provide a valid fallback to a breached eradication programme.

A Global Analysis of Deforestation in Moist Tropical Forest Protected Areas.

PubMed

Spracklen, B D; Kalamandeen, M; Galbraith, D; Gloor, E; Spracklen, D V

2015-01-01

Protected areas (PAs) have been established to conserve tropical forests, but their effectiveness at reducing deforestation is uncertain. To explore this issue, we combined high resolution data of global forest loss over the period 2000-2012 with data on PAs. For each PA we quantified forest loss within the PA, in buffer zones 1, 5, 10 and 15 km outside the PA boundary as well as a 1 km buffer within the PA boundary. We analysed 3376 tropical and subtropical moist forest PAs in 56 countries over 4 continents. We found that 73% of PAs experienced substantial deforestation pressure, with >0.1% a(-1) forest loss in the outer 1 km buffer. Forest loss within PAs was greatest in Asia (0.25% a(-1)) compared to Africa (0.1% a(-1)), the Neotropics (0.1% a(-1)) and Australasia (Australia and Papua New Guinea; 0.03% a(-1)). We defined performance (P) of a PA as the ratio of forest loss in the inner 1 km buffer compared to the loss that would have occurred in the absence of the PA, calculated as the loss in the outer 1 km buffer corrected for any difference in deforestation pressure between the two buffers. To remove the potential bias due to terrain, we analysed a subset of PAs (n = 1804) where slope and elevation in inner and outer 1 km buffers were similar (within 1° and 100 m, respectively). We found 41% of PAs in this subset reduced forest loss in the inner buffer by at least 25% compared to the expected inner buffer forest loss (P<0.75). Median performance (P) of subset reserves was 0.87, meaning a reduction in forest loss within the PA of 13%. We found PAs were most effective in Australasia (P = 0.16), moderately successful in the Neotropics (P = 0.72) and Africa (p = 0.83), but ineffective in Asia (P = 1). We found many countries have PAs that give little or no protection to forest loss, particularly in parts of Asia, west Africa and central America. Across the tropics, the median effectiveness of PAs at the national level improved with gross domestic product per capita. Whilst tropical and subtropical moist forest PAs do reduce forest loss, widely varying performance suggests substantial opportunities for improved protection, particularly in Asia.

A Land-Use Perspective for Birdstrike Risk Assessment: The Attraction Risk Index.

PubMed

Coccon, Francesca; Zucchetta, Matteo; Bossi, Giulia; Borrotti, Matteo; Torricelli, Patrizia; Franzoi, Piero

2015-01-01

Collisions between aircraft and birds, birdstrikes, pose a serious threat to aviation safety. The occurrence of these events is influenced by land-uses in the surroundings of airports. Airports located in the same region might have different trends for birdstrike risk, due to differences in the surrounding habitats. Here we developed a quantitative tool that assesses the risk of birdstrike based on the habitats within a 13-km buffer from the airport. For this purpose, we developed Generalized Linear Models (GLMs) with binomial distribution to estimate the contribution of habitats to wildlife use of the study area, depending on season. These GLMs predictions were combined to the flight altitude of birds within the 13-km buffer, the airport traffic pattern and the severity indices associated with impacts. Our approach was developed at Venice Marco Polo International airport (VCE), located in northeast Italy and then tested at Treviso Antonio Canova International airport (TSF), which is 20 km inland. Results from the two airports revealed that both the surrounding habitats and the season had a significant influence to the pattern of risk. With regard to VCE, agricultural fields, wetlands and urban areas contributed most to the presence of birds in the study area. Furthermore, the key role of distance of land-uses from the airport on the probability of presence of birds was highlighted. The reliability of developed risk index was demonstrated since at VCE it was significantly correlated with bird strike rate. This study emphasizes the importance of the territory near airports and the wildlife use of its habitats, as factors in need of consideration for birdstrike risk assessment procedures. Information on the contribution of habitats in attracting birds, depending on season, can be used by airport managers and local authorities to plan specific interventions in the study area in order to lower the risk.

A Land-Use Perspective for Birdstrike Risk Assessment: The Attraction Risk Index

PubMed Central

Coccon, Francesca; Zucchetta, Matteo; Bossi, Giulia; Borrotti, Matteo; Torricelli, Patrizia; Franzoi, Piero

2015-01-01

Collisions between aircraft and birds, birdstrikes, pose a serious threat to aviation safety. The occurrence of these events is influenced by land-uses in the surroundings of airports. Airports located in the same region might have different trends for birdstrike risk, due to differences in the surrounding habitats. Here we developed a quantitative tool that assesses the risk of birdstrike based on the habitats within a 13-km buffer from the airport. For this purpose, we developed Generalized Linear Models (GLMs) with binomial distribution to estimate the contribution of habitats to wildlife use of the study area, depending on season. These GLMs predictions were combined to the flight altitude of birds within the 13-km buffer, the airport traffic pattern and the severity indices associated with impacts. Our approach was developed at Venice Marco Polo International airport (VCE), located in northeast Italy and then tested at Treviso Antonio Canova International airport (TSF), which is 20 km inland. Results from the two airports revealed that both the surrounding habitats and the season had a significant influence to the pattern of risk. With regard to VCE, agricultural fields, wetlands and urban areas contributed most to the presence of birds in the study area. Furthermore, the key role of distance of land-uses from the airport on the probability of presence of birds was highlighted. The reliability of developed risk index was demonstrated since at VCE it was significantly correlated with bird strike rate. This study emphasizes the importance of the territory near airports and the wildlife use of its habitats, as factors in need of consideration for birdstrike risk assessment procedures. Information on the contribution of habitats in attracting birds, depending on season, can be used by airport managers and local authorities to plan specific interventions in the study area in order to lower the risk. PMID:26114958

Pencil graphite electrodes for improved electrochemical detection of oleuropein by the combination of Natural Deep Eutectic Solvents and graphene oxide.

PubMed

Gomez, Federico J V; Spisso, Adrian; Fernanda Silva, María

2017-11-01

A novel methodology is presented for the enhanced electrochemical detection of oleuropein in complex plant matrices by Graphene Oxide Pencil Grahite Electrode (GOPGE) in combination with a buffer modified with a Natural Deep Eutectic Solvent, containing 10% (v/v) of Lactic acid, Glucose and H 2 O (LGH). The electrochemical behavior of oleuropein in the modified-working buffer was examined using differential pulse voltammetry. The combination of both modifications, NADES modified buffer and nanomaterial modified electrode, LGH-GOPGE, resulted on a signal enhancement of 5.3 times higher than the bare electrode with unmodified buffer. A calibration curve of oleuropein was performed between 0.10 to 37 μM and a good linearity was obtained with a correlation coefficient of 0.989. Detection and quantification limits of the method were obtained as 30 and 102 nM, respectively. In addition, precision studies indicated that the voltammetric method was sufficiently repeatable, %RSD 0.01 and 3.16 (n = 5) for potential and intensity, respectively. Finally, the proposed electrochemical sensor was successfully applied to the determination of oleuropein in an olive leaf extract prepared by ultrasound-assisted extraction. The results obtained with the proposed electrochemical sensor were compared with Capillary Zone Electrophoresis analysis with satisfactory results. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of cytokinins in coconut (Cocos nucifera L.) water using capillary zone electrophoresis-tandem mass spectrometry.

PubMed

Ge, Liya; Yong, Jean Wan Hong; Tan, Swee Ngin; Ong, Eng Shi

2006-06-01

The applicability of CZE in combination with MS and MS/MS methods for the simultaneous separation and determination of 12 cytokinins was investigated for the first time. Cytokinins were first completely separated by CZE within less than 20 min using a volatile buffer and then detected directly by MS or MS/MS. Satisfactory separation of the 12 cytokinin standards was achieved using a 25 mM ammonium formate/formic acid buffer (pH 3.4) and 3% ACN v/v with a separation voltage of 25 kV. On the basis of the resolution of the neighboring peaks, the various parameters for CZE-MS optimization, such as buffer pH value, concentration of buffer and organic modifier, applied voltage and sheath liquid, were evaluated systematically. MS/MS with multiple reaction monitoring detection was carried out to obtain sufficient selectivity and sensitivity. The combination of on-line sample stacking and CZE-MS/MS achieved a detection limit in the range of 0.05-0.18 microM for the 12 cytokinins at an S/N of 3. The optimized CZE-MS/MS method was simple, rapid, low cost, robust and highly selective. Furthermore, the developed method was successfully applied to screen for endogenous cytokinins in purified coconut water extract sample. Nine cytokinins were detected and quantified in coconut water after SPE.

Release of dissolved phosphorus from riparian wetlands: Evidence for complex interactions among hydroclimate variability, topography and soil properties.

PubMed

Gu, Sen; Gruau, Gérard; Dupas, Rémi; Rumpel, Cornélia; Crème, Alexandra; Fovet, Ophélie; Gascuel-Odoux, Chantal; Jeanneau, Laurent; Humbert, Guillaume; Petitjean, Patrice

2017-11-15

In agricultural landscapes, establishment of vegetated buffer zones in riparian wetlands (RWs) is promoted to decrease phosphorus (P) emissions because RWs can trap particulate P from upslope fields. However, long-term accumulation of P risks the release of dissolved P, since the unstable hydrological conditions in these zones may mobilize accumulated particulate P by transforming it into a mobile dissolved P species. This study evaluates how hydroclimate variability, topography and soil properties interact and influence this mobilization, using a three-year dataset of molybdate-reactive dissolved P (MRDP) and total dissolved P (TDP) concentrations in soil water from two RWs located in an agricultural catchment in western France (Kervidy-Naizin), along with stream P concentrations. Two main drivers of seasonal dissolved P release were identified: i) soil rewetting during water-table rise after dry periods and ii) reductive dissolution of soil Fe (hydr)oxides during prolonged water saturation periods. These mechanisms were shown to vary greatly in space (according to topography) and time (according to intra- and interannual hydroclimate variability). The concentration and speciation of the released dissolved P also varied spatially depending on soil chemistry and local topography. Comparison of sites revealed a similar correlation between soil P speciation (percentage of organic P ranging from 35-70%) and the concentration and speciation of the released P (MRDP from <0.10 to 0.40mgl -1 ; percentage of MRDP in TDP from 25-70%). These differences propagated to stream water, suggesting that the two RWs investigated were the main sources of dissolved P to streams. RWs can be critical areas due to their ability to biogeochemically transform the accumulated P in these zones into highly mobile and highly bioavailable dissolved P forms. Hydroclimate variability, local topography and soil chemistry must be considered to decrease the risk of remobilizing legacy soil P when establishing riparian buffer zones in agricultural landscapes. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduced range of the endangered crested capuchin monkey (Sapajus robustus) and a possible hybrid zone with Sapajus nigritus.

PubMed

Martins, Waldney Pereira; Lynch Alfaro, Jessica; Rylands, Anthony B

2017-10-01

The crested capuchin monkey (Sapajus robustus) is an endangered species endemic to the highly fragmented Atlantic Forest of Brazil. Surveys for S. robustus were carried out over a 25-month period (2003-2005) to obtain more precise geographical limits for the western range of the species. Previously published localities for S. robustus were mapped, and each point was given a 25-km radius "buffer zone." The largest forest remnants in the buffer zones (>300 ha) in Minas Gerais were visited in order to interview the local people and/or survey the forests directly using playback recordings of S. robustus. Camera traps were used in key localities if interviews suggested the presence of capuchins but no animals were sighted during the surveys. Of 127 valid interviews, only 39 people reported the presence of Sapajus in nearby forest fragments. We confirmed the presence of Sapajus in only 19 of these. S. robustus occurred in four, and S. libidinosus, S. nigritus, S. xanthosternos, or S. robustus × S. nigritus (hybrids?) occurred in the remaining 15. Based on our study, the estimated geographical distribution of S. robustus is 119,654 km 2 , which represents a reduction of more than 70,000 km 2 when compared to its formerly described range. The geographical limits as defined in this study are: northeast-the Jequitinhonha River; northwest and west-the Jequitinhonha River; southwest-the Suaçuí Grande River and the Espinhaço mountains; southeast-the Doce River; east-the Atlantic Ocean. A probable hybrid zone where capuchin monkeys have morphological features of both S. nigritus and S. robustus was found between the Santo Antônio and the Suaçuí Grande rivers. The elucidation of the geographical distribution of S. robustus is important for its conservation, facilitating the delineation of priority areas for the creation of reserves and the initiation of studies of the species' ecology and behavior. © 2017 Wiley Periodicals, Inc.

Field demonstration of foam injection to confine a chlorinated solvent source zone.

PubMed

Portois, Clément; Essouayed, Elyess; Annable, Michael D; Guiserix, Nathalie; Joubert, Antoine; Atteia, Olivier

2018-05-01

A novel approach using foam to manage hazardous waste was successfully demonstrated under active site conditions. The purpose of the foam was to divert groundwater flow, that would normally enter the source zone area, to reduce dissolved contaminant release to the aquifer. During the demonstration, foam was pre generated and directly injected surrounding the chlorinated solvent source zone. Despite the constraints related to the industrial activities and non-optimal position of the injection points, the applicability and effectiveness of the approach have been highlighted using multiple metrics. A combination of measurements and modelling allowed definition of the foam extent surrounding each injection point, and this appears to be the critical metric to define the success of the foam injection approach. Information on the transport of chlorinated solvents in groundwater showed a decrease of contaminant flux by a factor of 4.4 downstream of the confined area. The effective permeability reduction was maintained over a period of three months. The successful containment provides evidence for consideration of the use of foam to improve traditional flushing techniques, by increasing the targeting of contaminants by remedial agents. Copyright © 2018 Elsevier B.V. All rights reserved.

Functional remineralization of carious dentin

NASA Astrophysics Data System (ADS)

Pugach, Megan Kardon

A primary goal of dental tissue engineering is the biological reconstruction of tooth substrate destroyed by caries or other diseases affecting tooth mineralization. Traditionally, dentists treat caries by using invasive techniques to remove the diseased dental tissue and restore the lesion, ideally preventing further progression of decay. Success in strategies associated with remineralization of enamel and root caries have contributed to the less invasive prospect of remineralization of dentinal carious lesions. The central hypothesis of this dissertation is that carious dentin lesions can be remineralized if the lesions contain residual mineral. Caries Detector (CD) stained zones (pink, light pink, transparent and normal) of arrested carious dentin lesions were characterized according to microstructure by atomic force microscopy (AFM) imaging, mineral content by digital transverse microradiography, and nanomechanical properties by AFM-based nanoindentation. CD-stained and unstained zones had significantly different microstructure, mineral content and nanomechanical properties. Furthermore, the most demineralized carious zone contained residual mineral. To obtain reproducible, standardized dentin caries lesions, we characterized the lesions from an artificial carious dentin lesion model using a 0.05M acetate demineralization buffer. The artificial caries-like lesions produced by the buffer had similar mineral content and nanomechanical properties in the stained and unstained zones as natural dentin lesions. Both natural and artificial lesions had significant correlations between mineral content and nanomechanical properties. Mineral crystallite size and shape was examined by small angle x-ray scattering. Both natural and artificial carious dentin had different mineral sizes than normal dentin. Collagen in natural and artificial carious dentin lesions was examined by trichrome stain, AFM high-resolution imaging, and UV resonance Raman spectroscopy, to determine if fibrils were intact and mineralization levels. It appeared that the collagen in the most demineralized pink zones of the lesions was intact and contained intrafibrillar mineral. Natural and artificial carious dentin lesions were treated with remineralization solutions containing different amounts of Ca2+ and PO 43-, with and without CO32- and with and without 2 ppm fluoride. The hydrated nanomechanical properties of the lesions were partially restored. This suggests that the most CD-stained zones of arrested dentin caries lesions may be remineralizable. These results suggest that remineralization as an approach of minimally invasive dentistry using non-invasive treatments to restore dental tissues is possible.

Fault Damage Zone Permeability in Crystalline Rocks from Combined Field and Laboratory Measurements: Can we Predict Damage Zone Permeability?

NASA Astrophysics Data System (ADS)

Mitchell, T. M.; Faulkner, D. R.

2009-04-01

Models predicting crustal fluid flow are important for a variety of reasons; for example earthquake models invoking fluid triggering, predicting crustal strength modelling flow surrounding deep waste repositories or the recovery of natural resources. Crustal fluid flow is controlled by both the bulk transport properties of rocks as well as heterogeneities such as faults. In nature, permeability is enhanced in the damage zone of faults, where fracturing occurs on a wide range of scales. Here we analyze the contribution of microfracture damage on the permeability of faults that cut through low porosity, crystalline rocks by combining field and laboratory measurements. Microfracture densities surrounding strike-slip faults with well-constrained displacements ranging over 3 orders of magnitude (~0.12 m - 5000 m) have been analyzed. The faults studied are excellently exposed within the Atacama Fault Zone, where exhumation from 6-10 km has occurred. Microfractures in the form of fluid inclusion planes (FIPs) show a log-linear decrease in fracture density with perpendicular distance from the fault core. Damage zone widths defined by the density of FIPs scale with fault displacement, and an empirical relationship for microfracture density distribution throughout the damage zone with displacement is derived. Damage zone rocks will have experienced differential stresses that were less than, but some proportion of, the failure stress. As such, permeability data from progressively loaded, initially intact laboratory samples, in the pre-failure region provide useful insights into fluid flow properties of various parts of the damage zone. The permeability evolution of initially intact crystalline rocks under increasing differential load leading to macroscopic failure was determined at water pore pressures of 50 MPa and effective pressure of 10 MPa. Permeability is seen to increase by up to, and over, two orders of magnitude prior to macroscopic failure. Further experiments were stopped at various points in the loading history in order to correlate microfracture density within the samples with permeability. By combining empirical relationships determined from both quantitative fieldwork and experiments we present a new model that allows microfracture permeability distribution throughout the damage zone to be determined as function of increasing fault displacement.

The nylon scintillator containment vessels for the Borexino solar neutrino experiment

NASA Astrophysics Data System (ADS)

Cadonati, L.; Calaprice, F.; Galbiati, C.; Pocar, A.; Shutt, T.

2014-06-01

The neutrino event rate in the Borexino scintillator is very low ( 0.5 events per day per ton) and concentrated in an energy region well below the 2.6 MeV threshold of natural radioactivity. The intrinsic radioactive contaminants in the photomultipliers (PMTs), in the Stainless Steel Sphere, and in other detector components, play special requirements on the system required to contain the scintillator. The liquid scintillator must be shielded from the Stainless Steel Sphere and from the PMTs by a thick barrier of buffer fluid. The fluid barrier, in addition, needs to be segmented in order to contain migration of radon and daughters emanated by the Stainless Steel Sphere and by the PMTs. These requirements were met by designing and building two spherical vessel made of thin nylon film. The inner vessel contains the scintillator, separating it from the surrounding buffer. The buffer region itself is divided into two concentric shells by the second, outer nylon vessel. In addition, the two nylon vessels must satisfy stringent requirements for radioactivity and for mechanical, optical and chemical properties. This paper describes the requirements of the the nylon vessels for the Borexino experiment and offers a brief overview of the construction methods adopted to meet those requirements.

Provisioning of nestling Dickcissels in native warm-season grass field buffers

USGS Publications Warehouse

Mitchell, K.L.; Riffell, Samuel K.; Burger, L. Wes; Vilella, Francisco

2012-01-01

We used video cameras in 2008–2009 to record provisioning activities at Dickcissel (Spiza americana) nests in and around Conservation Reserve Program field buffers in north-central Mississippi, USA. We simultaneously observed foraging flight distances of parents. Provisioning rate (P  =  0.412), biomass (P  =  0.161), and foraging distance (P  =  0.159) did not increase with nestling age. Parents delivered larger items to meet demand associated with older nestlings (P  =  0.010–0.001). This suggests energetic costs of changes in prey selection were less than costs of increasing the number or distance of provisioning trips. Presence of male helpers increased provisioning rate (P < 0.001) but not biomass (P  =  0.992) because males brought smaller prey items (P  =  0.001–0.021). Presence of observers 30 m from the nest reduced provisioning rates (P  =  0.005) and biomass delivered (P  =  0.066). Lack of habitat effects for any aspect of provisioning suggests grass field buffers provided nestling food resources similar to surrounding habitats. Use of continuous video monitoring of nest activity allows well-concealed activities including provisioning and male helping to be directly observed and better quantified.

Control and monitoring of oxygen fugacity in piston cylinder experiments

NASA Astrophysics Data System (ADS)

Matjuschkin, Vladimir; Brooker, Richard A.; Tattitch, Brian; Blundy, Jon D.; Stamper, Charlotte C.

2015-01-01

We present a newly developed capsule design that resolves some common problems associated with the monitoring and control of oxygen fugacity ( fO2) in high-pressure piston cylinder experiments. The new fO2 control assembly consists of an AuPd outer capsule enclosing two inner capsules: one of AuPd capsule containing the experimental charge (including some water), and the other of Pt containing a solid oxygen buffer plus water. The inner capsules are separated by crushable alumina. The outer capsule is surrounded by a Pyrex sleeve to simultaneously minimise hydrogen loss from the cell and carbon infiltration from the graphite furnace. Controlled fO2 experiments using this cell design were carried out at 1.0 GPa and 1,000 °C. We used NiPd, CoPd and (Ni, Mg)O fO2 sensors, whose pressure sensitivity is well calibrated, to monitor the redox states achieved in experiments buffered by Re-ReO2, Ni-NiO and Co-CoO, respectively. Results for the fO2 sensors are in good agreement with the intended fO2 established by the buffer, demonstrating excellent control for durations of 24-48 h, with uncertainties less than ± 0.3 log bar units of fO2.

Inclined dislocation arrays in AlGaN/AlGaN quantum well structures emitting at 290 nm

NASA Astrophysics Data System (ADS)

Chang, T. Y.; Moram, M. A.; McAleese, C.; Kappers, M. J.; Humphreys, C. J.

2010-12-01

We report on the structural and optical properties of deep ultraviolet emitting AlGaN/AlGaN multiple quantum wells (MQWs) grown on (0001) sapphire by metal-organic vapor phase epitaxy using two different buffer layer structures, one containing a thin (1 μm) AlN layer combined with a GaN interlayer and the other a thick (4 μm) AlN layer. Transmission electron microscopy analysis of both structures showed inclined arrays of dislocations running through the AlGaN layers at an angle of ˜30°, originating at bunched steps at the AlN surface and terminating at bunched steps at the surface of the MQW structure. In all layers, these inclined dislocation arrays are surrounded by AlGaN with a relatively higher Ga content, consistent with plan-view cathodoluminescence maps in which the bunched surface steps are associated with longer emission wavelengths. The structure with the 4 μm-thick AlN buffer layer had a dislocation density lower by a factor of 2 (at (1.7±0.1)×109 cm-2) compared to the structure with the 1 μm thick AlN buffer layer, despite the presence of the inclined dislocation arrays.

Open ocean dead zones in the tropical North Atlantic Ocean

NASA Astrophysics Data System (ADS)

Karstensen, J.; Fiedler, B.; Schütte, F.; Brandt, P.; Körtzinger, A.; Fischer, G.; Zantopp, R.; Hahn, J.; Visbeck, M.; Wallace, D.

2015-04-01

Here we present first observations, from instrumentation installed on moorings and a float, of unexpectedly low (<2 μmol kg-1) oxygen environments in the open waters of the tropical North Atlantic, a region where oxygen concentration does normally not fall much below 40 μmol kg-1. The low-oxygen zones are created at shallow depth, just below the mixed layer, in the euphotic zone of cyclonic eddies and anticyclonic-modewater eddies. Both types of eddies are prone to high surface productivity. Net respiration rates for the eddies are found to be 3 to 5 times higher when compared with surrounding waters. Oxygen is lowest in the centre of the eddies, in a depth range where the swirl velocity, defining the transition between eddy and surroundings, has its maximum. It is assumed that the strong velocity at the outer rim of the eddies hampers the transport of properties across the eddies boundary and as such isolates their cores. This is supported by a remarkably stable hydrographic structure of the eddies core over periods of several months. The eddies propagate westward, at about 4 to 5 km day-1, from their generation region off the West African coast into the open ocean. High productivity and accompanying respiration, paired with sluggish exchange across the eddy boundary, create the "dead zone" inside the eddies, so far only reported for coastal areas or lakes. We observe a direct impact of the open ocean dead zones on the marine ecosystem as such that the diurnal vertical migration of zooplankton is suppressed inside the eddies.

Integrated melt inclusion and crystal zoning study to track the timescales and pre-eruption dynamics of violent Strombolian eruptions at Llaima volcano, Chile

NASA Astrophysics Data System (ADS)

Ruth, D. C.; Costa Rodriguez, F.; Bouvet de Maisonneuve, C.; Calder, E. S.

2013-12-01

Melt inclusion compositions in crystals from many volcanic systems are notoriously variable and some times difficult to interpret. Their compositions can be a combination of rapid crystal growth, entrapment of local melt, and diffusive re-equilibration, among other processes. Additionally, chemical zoning in olivine records changing environmental conditions, most importantly temperature and magma composition. Many geochemical studies focus on either melt inclusion data or chemical zoning data to ascertain volcanic processes. Here we combine melt inclusion data with that of chemical zoning of the olivine host crystals from the 2008 violent Strombolian eruption of Llaima volcano, Chile, to obtain a more refined understanding of the processes related to crystal growth, melt inclusion formation, and magma dynamics. We investigated zoning characteristics in a suite of olivine crystals, created X-ray element maps (Al, Ca, Mg, P, Fe), and collected quantitative elemental abundances across chemical zones for detailed diffusion modeling. Melt inclusion compositions were collected via electron microprobe analysis and LA-ICPMS. We observe three types of zoning in the host olivine crystals: normal, reverse, and multiple zones with fluctuating Fo content. Reverse zoning was more common than the other types. Regardless of zoning character, multiple melt inclusions are present within a given olivine, often found near the crystal rim. For some of these melt inclusions, the olivine surrounding the melt inclusion was also zoned, often to a similar composition as the olivine rim. This implies that these inclusions remained connected with interstitial matrix melt until melt inclusion closure. These ';open' melt inclusions exhibited slightly different major (higher SiO2, Na2O+K2O, TiO2) and trace elements (positive Eu and Sr anomalies) compared to melt inclusions in the same olivine that were not surrounded by compositional zoning. Quantitative elemental profiles produce modeled timescales on the order of 10s-100s days prior to eruption. Zoning textures, melt inclusion compositions, and timescale modeling indicates that crystal dissolution (open melt inclusions), mafic magma injection (reverse zoning), and partial melting of upper crustal plagioclase-rich cumulates (positive Eu and Sr anomalies) were occurring in the months prior to the 2008 eruption. The combination of both melt inclusion data and textural data of the host crystals provides deeper insight into the nature and timing of deep and shallow reservoir processes that generate violent Strombolian eruptions at Llaima.

Copper speciation in the gill microenvironment of carp (Cyprinus carpio) at various levels of pH.

PubMed

Tao, Shu; Long, Aimin; Xu, Fuliu; Dawson, R W

2002-07-01

The fish gill microenvironment of Cyprinus carpio under stress of copper exposure was investigated. pH and other parameters including free copper activity, alkalinity, and inorganic and organic carbons in the surrounding water (inspired water) and in the gill microenvironment (expired water) were measured or calculated at various levels of pH and varying total copper concentrations. The chemical equilibrium calculation (from MINEQA2) and complexation modeling (mucus-copper) were coupled to calculate both species distribution. The results indicate that the pH in the fish gill microenvironment was different from that in the surrounding water with a balance point around 6.9. The secretion of both CO(2) and mucus was affected in both linear and nonlinear ways when the fish were exposed to elevated concentrations of copper. The complexation capacity of the gill mucus was characterized by a conditional stability constant (logk(Cu-mucus)) of 5.37 along with a complexation equivalent concentration (L(Cu-mucus)) of 0.96 mmol Cu/mg C. For both the fish microenvironment and the surrounding water, the dominant copper species shifted from Cu(2+) to CuCO(3)(0) and to Cu(OH)(2)(0) when the pH of the surrounding water changed from 6.12 to 8.11. The change in copper speciation in the gill microenvironment is smaller than that in the surrounding water due to the pH buffering capacity of the fish gills.

PYCNOIB: Biodiversity and Biogeography of Iberian Pycnogonids

PubMed Central

Soler-Membrives, Anna; Munilla, Tomás

2015-01-01

Biodiversity and biogeographic studies comparing the distribution patterns of benthic marine organisms across the Iberian Atlantic and Mediterranean waters are scarce. The Pycnogonida (sea spiders) are a clear example of both endemicity and diversity, and are considered a key taxon to study and monitor biogeographic and biodiversity patterns. This is the first review that compiles data about abundance and diversity of Iberian pycnogonids and examines their biogeographic patterns and bathymetric constraints using GIS tools. A total of 17762 pycnogonid records from 343 localities were analyzed and were found to contain 65 species, 21 genera and 12 families. Achelia echinata and Ammothella longipes (family Acheliidae) were the most abundant comprising ~80% of the total records. The Acheliidae is also the most speciose in Iberian waters with 15 species. In contrast, the family Nymphonidae has 7 species but is significantly less abundant (<1% of the total records) than Acheliidae. Species accumulation curves indicate that further sampling would increase the number of Iberian species records. Current sampling effort suggests that the pycnogonid fauna of the Mediterranean region may be richer than that of the Atlantic. The Strait of Gibraltar and the Alboran Sea are recognized as species-rich areas that act as buffer zones between the Atlantic and Mediterranean boundaries. The deep waters surrounding the Iberian Peninsula are poorly surveyed, with only 15% of the sampling sites located below 1000 m. Further deep-water sampling is needed mainly on the Iberian Mediterranean side. PMID:25781483

Experimental detailed power distribution in a fast spectrum thermionic reactor fuel element at the core/BeO reflector interface region

NASA Technical Reports Server (NTRS)

Klann, P. G.; Lantz, E.

1973-01-01

A zero-power critical assembly was designed, constructed, and operated for the prupose of conducting a series of benchmark experiments dealing with the physics characteristics of a UN-fueled, Li-7-cooled, Mo-reflected, drum-controlled compact fast reactor for use with a space-power conversion system. The critical assembly was modified to simulate a fast spectrum advanced thermionics reactor by: (1) using BeO as a reflector in place of some of the existing molybdenum, (2) substituting Nb-1Zr tubing for some of the existing Ta tubing, and (3) inserting four full-scale mockups of thermionic type fuel elements near the core and BeO reflector boundary. These mockups were surrounded with a buffer zone having the equivalent thermionic core composition. In addition to measuring the critical mass of this thermionic configuration, a detailed power distribution in one of the thermionic element stages in the mixed spectrum region was measured. A power peak to average ratio of two was observed for this fuel stage at the midplane of the core and adjacent to the reflector. Also, the power on the outer surface adjacent to the BeO was slightly more than a factor of two larger than the power on the inside surface of a 5.08 cm (2.0 in.) high annular fuel segment with a 2.52 cm (0.993 in. ) o.d. and a 1.86 cm (0.731 in.) i.d.

In Situ Observation of Hard Surrounding Rock Displacement at 2400-m-Deep Tunnels

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Yao, Zhi-Bin; Li, Shao-Jun; Wu, Shi-Yong; Yang, Cheng-Xiang; Guo, Hao-Sen; Zhong, Shan

2018-03-01

This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China's Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel's side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

Gliopathic Pain: When Satellite Glial Cells Go Bad

PubMed Central

Ohara, Peter T.; Vit, Jean-Philippe; Bhargava, Aditi; Romero, Marcela; Sundberg, Christopher; Charles, Andrew C.; Jasmin, Luc

2010-01-01

Neurons in sensory ganglia are surrounded by satellite glial cells (SGCs) that perform similar functions to the glia found in the CNS. When primary sensory neurons are injured, the surrounding SGCs undergo characteristic changes. There is good evidence that the SGCs are not just bystanders to the injury but play an active role in the initiation and maintenance of neuronal changes that underlie neuropathic pain. In this article the authors review the literature on the relationship between SGCs and nociception and present evidence that changes in SGC potassium ion buffering capacity and glutamate recycling can lead to neuropathic pain-like behavior in animal models. The role that SGCs play in the immune responses to injury is also considered. We propose the term gliopathic pain to describe those conditions in which central or peripheral glia are thought to be the principal generators of principal pain generators. PMID:19826169

Global root zone storage capacity from satellite-based evaporation data

NASA Astrophysics Data System (ADS)

Wang-Erlandsson, Lan; Bastiaanssen, Wim; Gao, Hongkai; Jägermeyr, Jonas; Senay, Gabriel; van Dijk, Albert; Guerschman, Juan; Keys, Patrick; Gordon, Line; Savenije, Hubert

2016-04-01

We present an "earth observation-based" method for estimating root zone storage capacity - a critical, yet uncertain parameter in hydrological and land surface modelling. By assuming that vegetation optimises its root zone storage capacity to bridge critical dry periods, we were able to use state-of-the-art satellite-based evaporation data computed with independent energy balance equations to derive gridded root zone storage capacity at global scale. This approach does not require soil or vegetation information, is model independent, and is in principle scale-independent. In contrast to traditional look-up table approaches, our method captures the variability in root zone storage capacity within land cover type, including in rainforests where direct measurements of root depth otherwise are scarce. Implementing the estimated root zone storage capacity in the global hydrological model STEAM improved evaporation simulation overall, and in particular during the least evaporating months in sub-humid to humid regions with moderate to high seasonality. We find that evergreen forests are able to create a large storage to buffer for extreme droughts (with a return period of up to 60 years), in contrast to short vegetation and crops (which seem to adapt to a drought return period of about 2 years). The presented method to estimate root zone storage capacity eliminates the need for soils and rooting depth information, which could be a game-changer in global land surface modelling.

Characterization of a high-transmissivity zone by well test analysis: Steady state case

USGS Publications Warehouse

Tiedeman, Claire; Hsieh, Paul A.; Christian, Sarah B.

1995-01-01

A method is developed to analyze steady horizontal flow to a well pumped from a confined aquifer composed of two homogeneous zones with contrasting transmissivities. Zone 1 is laterally unbounded and encloses zone 2, which is elliptical in shape and is several orders of magnitude more transmissive than zone 1. The solution for head is obtained by the boundary integral equation method. Nonlinear least squares regression is used to estimate the model parameters, which include the transmissivity of zone 1, and the location, size, and orientation of zone 2. The method is applied to a hypothetical aquifer where zone 2 is a long and narrow zone of vertical fractures. Synthetic data are generated from three different well patterns, representing different areal coverage and proximity to the fracture zone. When zone 1 of the hypothetical aquifer is homogeneous, the method correctly estimates all model parameters. When zone 1 is a randomly heterogeneous transmissivity field, some parameter estimates, especially the length of zone 2, become highly uncertain. To reduce uncertainty, the pumped well should be close to the fracture zone, and surrounding observation wells should cover an area similar in dimension to the length of the fracture zone. Some prior knowledge of the fracture zone, such as that gained from a surface geophysical survey, would greatly aid in designing the well test.

Hydrology of the unsaturated zone, Yucca Mountain, Nevada

USGS Publications Warehouse

Lecain, Gary D.; Stuckless, John S.

2012-01-01

The unsaturated zone at Yucca Mountain was investigated as a possible site for the nation's first high-level nuclear waste repository. Scientific investigations included infiltration studies, matrix properties testing, borehole testing and monitoring, underground excavation and testing, and the development of conceptual and numerical models of the hydrologic processes at Yucca Mountain. Infiltration estimates by empirical and geochemical methods range from 0.2 to 1.4 mm/yr and 0.2–6.0 mm/yr, respectively. Infiltration estimates from numerical models range from 4.5 mm/yr to 17.6 mm/yr. Rock matrix properties vary vertically and laterally as the result of depositional processes and subsequent postdepositional alteration. Laboratory tests indicate that the average matrix porosity and hydraulic conductivity values for the main level of the proposed repository (Topopah Spring Tuff middle nonlithophysal zone) are 0.08 and 4.7 × 10−12 m/s, respectively. In situ fracture hydraulic conductivity values are 3–6 orders of magnitude greater. The permeability of fault zones is approximately an order of magnitude greater than that of the surrounding rock unit. Water samples from the fault zones have tritium concentrations that indicate some component of postnuclear testing. Gas and water vapor movement through the unsaturated zone is driven by changes in barometric pressure, temperature-induced density differences, and wind effects. The subsurface pressure response to surface barometric changes is controlled by the distribution and interconnectedness of fractures, the presence of faults and their ability to conduct gas and vapor, and the moisture content and matrix permeability of the rock units. In situ water potential values are generally less than −0.2 MPa (−2 bar), and the water potential gradients in the Topopah Spring Tuff units are very small. Perched-water zones at Yucca Mountain are associated with the basal vitrophyre of the Topopah Spring Tuff or the Calico Hills bedded tuff. Thermal gradients in the unsaturated zone vary with location, and range from ~2.0 °C to 6.0 °C per 100 m; the variability appears to be associated with topography. Large-scale heater testing identified a heat-pipe signature at ~97 °C, and identified thermally induced and excavation-induced changes in the stress field. Elevated gas-phase CO2 concentrations and a decrease in the pH of water from the condensation zone also were identified. Conceptual and numerical flow and transport models of Yucca Mountain indicate that infiltration is highly variable, both spatially and temporally. Flow in the unsaturated zone is predominately through fractures in the welded units of the Tiva Canyon and Topopah Spring Tuffs and predominately through the matrix in the Paintbrush Tuff nonwelded units and Calico Hills Formation. Isolated, transient, fast-flow paths, such as faults, do exist but probably carry only a small portion of the total liquid-water flux at Yucca Mountain. The Paintbrush Tuff nonwelded units act as a storage buffer for transient infiltration pulses. Faults may act as flow boundaries and/or fast pathways. Below the proposed repository horizon, low-permeability lithostratigraphic units of the Topopah Spring Tuff and/or the Calico Hills Formation may divert flow laterally to faults that act as conduits to the water table. Advective transport pathways are consistent with flow pathways. Matrix diffusion is the major mechanism for mass transfer between fractures and the matrix and may contribute to retardation of radionuclide transport when fracture flow is dominant. Sorption may retard the movement of radionuclides in the unsaturated zone; however, sorption on mobile colloids may enhance radionuclide transport. Dispersion is not expected to be a major transport mechanism in the unsaturated zone at Yucca Mountain. Natural analogue studies support the concepts that percolating water may be diverted around underground openings and that the percentage of infiltration that becomes seepage decreases as infiltration decreases.

Quantifying the remineralization of artificial caries lesions using PS-OCT

NASA Astrophysics Data System (ADS)

Jones, Robert S.; Fried, Daniel

2006-02-01

New optical imaging methods are needed to determine whether caries lesions (tooth decay) are active and progressing or have become remineralized and arrested and are no longer progressing. The objective of this study was to use Polarization Sensitive Optical Coherence Tomography (PS-OCT) to image the fluoride enhanced remineralization of artificial enamel lesions. Artificial lesions were created by an acetate buffer on smooth enamel surfaces and were exposed for 20 days to a 2 ppm fluoride containing remineralization solution. PS-OCT images revealed the presence of a low scattering surface zone after the artificial lesions were remineralized. These samples displayed intact nondepolarizing surface zones when analyzed with Polarized Light Microscopy (PLM). No statistical difference in lesion depth before and after remineralization was found with both PS-OCT and PLM. The remineralized lesions showed a significant decrease in the overall integrated reflectivity compared with the demineralized lesions. Digital Microradiography confirmed the increase in mineral volume of the remineralized surface zone. This study determined that PS-OCT can image the restoration of the surface zone enamel after fluoride-enhanced remineralization of artificial in vitro dental caries.

Soil manganese redox cycling in suboxic zones: Effects on soil carbon stability

EPA Science Inventory

Suboxic soil environments contain a disproportionately higher concentration of highly reactive free radicals relative to the surrounding soil matrix, which may have significant implications for soil organic matter cycling and stabilization. This study investigated how Mn-ozidizin...

Idle reduction programs and potential benefits to schools

DOT National Transportation Integrated Search

2010-11-01

School districts in Texas and many other states have, in recent years, increased the walk zones : surrounding schools to a 2-mile perimeter. Inside this perimeter, either no school bus service is : offered, or service is offered only with a fee...

Simultaneous determination of anthraquinones, their 8-beta-D-glucosides, and sennosides of Rhei Rhizoma by capillary electrophoresis.

PubMed

Koyama, Junko; Morita, Izumi; Fujiyoshi, Hirotaka; Kobayashi, Norihiro

2005-05-01

The simultaneous separation and determination of major anthraquinones (emodin, chrysophanol, rhein and their glucosides, aloe-emodin, sennoside A, and sennoside B) of Rhei Rhizoma were achieved by cyclodextrin modified capillary zone electrophoresis. The running electrolyte used in this method was 0.005 M alpha-cyclodextrin in 0.03 M borate buffer (pH 10.0) containing 20% acetonitrile, with an applied voltage of 20 kV.

Afforestation and forests at the dryland edges: Lessons learned and future outlooks

Treesearch

Csaba Mátyás; Ge Sun; Yaoqi Zhang

2013-01-01

In the Drylands of Northern China, such as the Loess Plateau region, a buffer zone of planted forests—a “Green Great Wall”—has been created in the last five decades. These government programs have often generated unintended environmental consequences, and have failed to achieve the desired benefits. Planted forests withhold erosion, dust storms and silting of streams...

The verification of wilderness area boundaries as part of a buffer zone demarcation process: A case study from the uKhahlamba Drakensberg Park World Heritage Site

Treesearch

Sonja C. Kruger; Ian A. Rusworth; Kirsten Oliver

2011-01-01

Wilderness areas are by definition free from the sights and sounds of modern man. The boundaries of wilderness areas have traditionally been defined based on the management authorities' perceptions of which areas have wilderness quality. Experience shows that many areas classified as wilderness do not actually have wilderness qualities and do not provide a true...

Near real-time traffic routing

NASA Technical Reports Server (NTRS)

Yang, Chaowei (Inventor); Xie, Jibo (Inventor); Zhou, Bin (Inventor); Cao, Ying (Inventor)

2012-01-01

A near real-time physical transportation network routing system comprising: a traffic simulation computing grid and a dynamic traffic routing service computing grid. The traffic simulator produces traffic network travel time predictions for a physical transportation network using a traffic simulation model and common input data. The physical transportation network is divided into a multiple sections. Each section has a primary zone and a buffer zone. The traffic simulation computing grid includes multiple of traffic simulation computing nodes. The common input data includes static network characteristics, an origin-destination data table, dynamic traffic information data and historical traffic data. The dynamic traffic routing service computing grid includes multiple dynamic traffic routing computing nodes and generates traffic route(s) using the traffic network travel time predictions.

Identifying security checkpoints locations to protect the major U.S. urban areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuellar-Hengartner, Leticia; Watkins, Daniel; Kubicek, Deborah A.

Transit networks are integral to the economy and to society, but at the same time they could allow terrorists to transport weapons of mass destruction into any city. Road networks are especially vulnerable, because they lack natural checkpoints unlike air networks that have security measures in place at all major airports. One approach to mitigate this risk is ensuring that every road route passes through at least one security checkpoint. Using the Ford-Fulkerson maximum-flow algorithm, we generate a minimum set of checkpoint locations within a ring-shaped buffer area surrounding the 50 largest US urban areas. We study how the numbermore » of checkpoints changes as we increase the buffer width to perform a cost-benefit analysis and to identify groups of cities that behave similarly. The set of required checkpoints is surprisingly small (10-124) despite the hundreds of thousands of road arcs in those areas, making it feasible to protect all major cities.« less

Identifying security checkpoints locations to protect the major U.S. urban areas

DOE PAGES

Cuellar-Hengartner, Leticia; Watkins, Daniel; Kubicek, Deborah A.; ...

2015-09-01

Transit networks are integral to the economy and to society, but at the same time they could allow terrorists to transport weapons of mass destruction into any city. Road networks are especially vulnerable, because they lack natural checkpoints unlike air networks that have security measures in place at all major airports. One approach to mitigate this risk is ensuring that every road route passes through at least one security checkpoint. Using the Ford-Fulkerson maximum-flow algorithm, we generate a minimum set of checkpoint locations within a ring-shaped buffer area surrounding the 50 largest US urban areas. We study how the numbermore » of checkpoints changes as we increase the buffer width to perform a cost-benefit analysis and to identify groups of cities that behave similarly. The set of required checkpoints is surprisingly small (10-124) despite the hundreds of thousands of road arcs in those areas, making it feasible to protect all major cities.« less