These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Buried organic horizons represent amino acid reservoirs in boreal forest soils Nancy R. Werdin-Pfisterer, Knut Kielland*, Richard D. Boone  

E-print Network

Buried organic horizons represent amino acid reservoirs in boreal forest soils Nancy R. Werdin Keywords: Amino acids Boreal forest Buried organic horizons Floodplain soils Nitrogen cycle Organic nitrogen Succession a b s t r a c t We examined the composition and concentration of amino acids by soil

Wagner, Diane

2

Buried dark soil horizons and archaeological features in the Neolithic settlement region of the Lower Rhine area, NW Germany: Formation, geochemistry and chronostratigraphy  

Microsoft Academic Search

The properties and age of buried humic and clay-rich dark soil remains (Bht-horizons and pits) at archaeological excavations in the Lower Rhine Basin (NW Germany) were investigated. These Bht-features were formerly described as a component of Luvic Phaeozems and as relics of chernozemic soils.Field observations challenge this interpretation. The Bht-horizons in the Lower Rhine Basin occur in a patchy distribution

R. Gerlach; P. Fischer; E. Eckmeier; A. Hilgers

3

Soil Horizons  

NSDL National Science Digital Library

This activity involves previously collected soils from each horizon of a soil profile. The bags from one soil profile are given to a group and the students put the bags in the proper order. This involves student groups looking at each other's sample bags as well as their own and sharing information. After some discussion, during which the instructor makes certain that the students have gotten the soil samples into their correct horizon sequence, the bags are opened and examined to let the students see the different textures and properties of each horizon. Students will discover that each soil is different due to different bedrock and weathering conditions. Some soils may not show all of the above horizons, while other soils may clearly show the development of each layer. The thickness of the individual layers may vary greatly also.

4

Using 14C dating of stable humin fractions to assess upbuilding pedogenesis of a buried Holocene humic soil horizon, Towada volcano, Japan  

Microsoft Academic Search

The genesis of a 40-cm-thick buried Holocene humic soil horizon in a 6-m-high sequence near Towada volcano, Japan, was examined by dating stable, plant-derived humin particles by AMS-based radiocarbon (14C), and by analyzing stable carbon isotope ratios (?13C), phytolith composition, and soil chemical properties. The AMS dating yielded calibrated ages ranging from 7570–7679 to 6180?6313calyr BP. We obtained a strong

Yudzuru Inoue; Syuntaro Hiradate; Takashi Sase; Mamoru Hosono; Sayaka Morita; Hiroyuki Matsuzaki

2011-01-01

5

Soil Biology & Biochemistry 40 (2008) 8596 Microbially available carbon in buried riparian soils  

E-print Network

Soil Biology & Biochemistry 40 (2008) 85­96 Microbially available carbon in buried riparian soils 2007 Available online 9 August 2007 Abstract Buried horizons and lenses in riparian soil profiles 14 riparian zones Rhode Island, USA, where soil profiles are characterized by glacial outwash

Gurwick, Noel P.

6

Distinct microbial communities associated with buried soils in the Siberian tundra  

NASA Astrophysics Data System (ADS)

Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze-thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes.

Gittel, Antje; Bárta, Ji?í; Kohoutová, Iva; Mikutta, Robert; Owens, Sarah; Gilbert, Jack; Schnecker, Jörg; Wild, Birgit; Hannisdal, Bjarte; Maerz, Joeran; Lashchinskiy, Nikolay; ?apek, Petr; Šantr??ková, Hana; Gentsch, Norman; Shibistova, Olga; Guggenberger, Georg; Richter, Andreas; Torsvik, Vigdis; Schleper, Christa; Urich, Tim

2014-05-01

7

Distinct microbial communities associated with buried soils in the Siberian tundra  

PubMed Central

Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze–thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes. PMID:24335828

Gittel, Antje; Bárta, Ji?í; Kohoutová, Iva; Mikutta, Robert; Owens, Sarah; Gilbert, Jack; Schnecker, Jörg; Wild, Birgit; Hannisdal, Bjarte; Maerz, Joeran; Lashchinskiy, Nikolay; ?apek, Petr; Šantr??ková, Hana; Gentsch, Norman; Shibistova, Olga; Guggenberger, Georg; Richter, Andreas; Torsvik, Vigdis L; Schleper, Christa; Urich, Tim

2014-01-01

8

Distinct microbial communities associated with buried soils in the Siberian tundra.  

PubMed

Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze-thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes. PMID:24335828

Gittel, Antje; Bárta, Ji?í; Kohoutová, Iva; Mikutta, Robert; Owens, Sarah; Gilbert, Jack; Schnecker, Jörg; Wild, Birgit; Hannisdal, Bjarte; Maerz, Joeran; Lashchinskiy, Nikolay; Capek, Petr; Santr??ková, Hana; Gentsch, Norman; Shibistova, Olga; Guggenberger, Georg; Richter, Andreas; Torsvik, Vigdis L; Schleper, Christa; Urich, Tim

2014-04-01

9

Continuum soil modeling in the static analysis of buried structures  

SciTech Connect

Soil loading traditionally has been modeled as a hydrostatic pressure, a practice acceptable for many design applications. In the analyses of buried structure with predictive goals, soil compliance and load redistribution in the presence of soil plasticity are important factors to consider in determining the appropriate response of the structure. In the analysis of existing buried waste-storage tanks at the US Department of Energy`s Hanford Site, three soil-tank interaction modeling considerations are addressed. First, the soil interacts with the tank as the tank expands and contracts during thermal cycles associated with changes in the heat generated by the waste material as a result of additions and subtractions of the waste. Second, the soil transfers loads from the surface to the tank and provides support by resisting radial displacement of the tank haunch. Third, conventional finite-element mesh development causes artificial stress concentrations in the soil associated with differential settlement.

Julyk, L.J.; Marlow, R.S.; Moore, C.J. [Westinghouse Hanford Co., Richland, WA (United States); Day, J.P.; Dyrness, A.D. [Advent Engineering Services, Inc., San Ramon, CA (United States)

1993-10-01

10

Buried treasure: soil biodiversity and conservation  

Microsoft Academic Search

Soils are incredibly biodiverse habitats, yet soil-dwelling organisms have received little attention within the field of conservation\\u000a biology. Due to difficulties involved in studying soil biota, and to taxonomic biases in conservation research, the full extent\\u000a of soil biodiversity is not well understood, and soil-dwelling organisms are rarely candidates for conservation. The biogeography\\u000a of soil biota differs significantly from that

Sophie S. Parker

2010-01-01

11

Aeolian cliff-top deposits and buried soils in the White River Badlands, South Dakota, USA  

USGS Publications Warehouse

Aeolian deposits in the North American Great Plains are important sources of Holocene palaeo-environmental records. Although there are extensive studies on loess and dune records in the region, little is known about records in aeolian cliff-top deposits. These are common on table (mesa) edges in the White River Badlands. These sediments typically have loam and sandy-loam textures with dominantly very fine sand, 0.5-1% organic carbon and 0.5-5% CaCO3. Some of these aeolian deposits are atypically coarse and contain granules and fine pebbles. Buried soils within these deposits are weakly developed with A-C and A-AC-C profiles. Beneath these are buried soils with varying degrees of pedogenic development formed in fluvial, aeolian or colluvial deposits. Thickness and number of buried soils vary. However, late-Holocene soils from several localities have ages of approximately 1300, 2500 and 3700 14C yrs BP. The 1300 14C yr BP soil is cumulic, with a thicker and lighter A horizon. Soils beneath the cliff-top deposits are early-Holocene (typically 7900 but as old as 10000 14C yrs BP) at higher elevation (???950 m) tables, and late-Holocene (2900 14C yrs BP) at lower (???830 m) tables. These age estimates are based on total organic matter 14C ages from the top 5 cm of buried soils, and agreement is good between an infrared stimulated luminescence age and bracketing 14C ages. Our studies show that cliff-top aeolian deposits have a history similar to that of other aeolian deposits on the Great Plains, and they are another source of palaeoenvironmental data.

Rawling, J. E., III; Fredlund, G.G.; Mahan, S.

2003-01-01

12

Temperature dependence of the activity of polyphenol peroxidases and polyphenol oxidases in modern and buried soils  

NASA Astrophysics Data System (ADS)

Under conditions of the global climate warming, the changes in the reserves of soil humus depend on the temperature sensitivities of polyphenol peroxidases (PPPOs) and polyphenol oxidases (PPOs). They play an important role in lignin decomposition, mineralization, and humus formation. The temperature dependence of the potential enzyme activity in modern and buried soils has been studied during incubation at 10 or 20°C. The experimental results indicate that it depends on the availability of the substrate and the presence of oxygen. The activity of PPOs during incubation in the absence of oxygen for two months decreases by 2-2.5 times, which is balanced by an increase in the activity of PPPOs by 2-3 times. The increase in the incubation temperature to 20°C and the addition of glucose accelerates this transition due to the more abrupt decrease in the activity of PPOs. The preincubation of the soil with glucose doubles the activity of PPPOs but has no significant effect on the activity of PPOs. The different effects of temperature on two groups of the studied oxidases and the possibility of substituting enzymes by those of another type under changing aeration conditions should be taken into consideration in predicting the effect of the climate warming on the mineralization of the soil organic matter. The absence of statistically significant differences in the enzymatic activity between the buried and modern soil horizons indicates the retention by the buried soil of some of its properties (soil memory) and the rapid restoration of high enzymatic activity during the preincubation.

Yakushev, A. V.; Kuznetsova, I. N.; Blagodatskaya, E. V.; Blagodatsky, S. A.

2014-05-01

13

Direct estimates of pedogenic magnetite as a tool to reconstruct past climates from buried soils  

NASA Astrophysics Data System (ADS)

Variations in magnetic properties of buried soils can be used to reconstruct past climatic conditions during paleosol formation. Most methods, however, are based on comparisons between the magnetically enriched upper soil horizons and the magnetically unaltered parent material. In thin loess-paleosol sequences such a comparison can be problematic because all horizons, soil and underlying loess, may be affected to varying degrees by pedogenesis. We propose two direct estimates of pedogenic magnetite based on the analysis of anhysteretic remanent magnetization ratios (?ARM/isothermal remanent magnetization) and coercivity distributions. These estimates are independent of any information regarding the parent material and are possible if pedogenic minerals have similar magnetic properties throughout the study region. This condition seems to be met throughout the Midwestern United States and a few loessic soils elsewhere. The remanence-carrying part of pedogenic magnetite is composed of single-domain particles with consistent, well-constrained magnetic properties. These particles are extremely well dispersed in the soil matrix as indicated by the absence of noticeable magnetostatic interaction effects. Our analyses of over 70 modern loessic soil profiles demonstrate that the abundance of pedogenic magnetite correlates well with modern climate and that the method is suited for reconstruction of past climates from paleosols.

Geiss, Christoph E.; Egli, Ramon; Zanner, C. William

2008-11-01

14

Buried soil organic inclusions in non-sorted circles fields in northern Sweden: Age and Paleoclimatic context  

NASA Astrophysics Data System (ADS)

Although burial of surface organic soil horizons into deeper mineral soil layers helps drive the long-term buildup of carbon in arctic soils, when and why buried horizons formed as result of cryoturbation in northern Sweden remain unclear. In this study, we used 14C and 210Pb dating to assess when organic matter was buried within non-sorted circles fields near Abisko in northern Sweden. In addition, we used aerial photos from 1959 and 2008 to detect eventual trends in cryogenic activities during this period. We found that organic matter from former organic horizons (stratigraphically intact or partly fragmented) corresponds to three major periods: 0-100 A.D., 900-1250 A.D., and 1650-1950 A.D. The latter two periods were indicated by several dated samples, while the extent of the oldest period is more uncertainty (indicated by only one sample). The aerial photos suggest a net overgrowth by shrub vegetation of previously exposed mineral soil surfaces since 1959. This overgrowth trend was seen in most of the studied fields (92 out of 137 analyzed fields), indicating that the cryogenic activity has mainly decreased in studied non-sorted circles fields since the 1950s. This latter interpretation is also supported by the absence of buried organic layers formed during the last decades. We suggest that the organic matter was buried during the transition from longer cold periods to warmer conditions. We believe these climatic shifts could have triggered regional scale burial of soil organic matter and thus affected how these soils sequestered carbon.

Becher, Marina; Olid, Carolina; Klaminder, Jonatan

2013-03-01

15

CONSERVATION MANAGEMENT DECISIONS FOR COMPACTED COASTAL SOILS IN COTTON WITH BURIED MICROIRRIGATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Because of high soil strengths in Coastal Plain soils, producers using buried microirrigation tubes may have to decide whether to increase the amount of tubing used or to deep till between tubes. In cotton that was irrigated with buried microirrigation tubes on coastal sandy soils, high soil strengt...

16

Characterization of the microbial communities in the modern and buried under kurgans soils of solonetzic complexes in the dry steppes of the Lower Volga region  

NASA Astrophysics Data System (ADS)

The microbial communities were studied in the modern and buried under kurgans (1st century AD) soils of solonetzic complexes on the dry steppes of the northern part of the Yergeni Upland. It was found that the changes in the numbers of microorganisms from different trophic groups and in the biomass of the fungal mycelium along the profiles of the modern and buried solonetzic chestnut soils and solonetzes do not differ significantly. The quantitative estimate of the impact of the solonetzic process on the spatial variability of the microbiological parameters of the soils was given on the basis of the ANOVA. As a rule, the values of the microbiological parameters in all the horizons of the modern and buried chestnut soils were 1.2-2.8 times higher than those in the modern and buried solonetzes. The influence of the degree of solonetzicity of the buried paleosols on the microbiological parameters manifested itself in the entire profile, though in each particular horizon it was only seen in the numbers of some particular trophic groups of microorganisms. The comparison between the mean weighted values of the microbiological parameters in the entire soil profiles (the A1 + B1 + B2 horizons) demonstrated an inverse relationship between the population density of the microorganisms utilizing easily available organic matter and the degree of solonetzicity of the buried paleosols. The maximum biomass of the fungal mycelium was found in the solonetzic chestnut paleosol; it exceeded the biomass of the fungal mycelium in the other paleosols (which did not differ significantly in that parameter from one another) by 1.5-1.6 times.

Demkina, T. S.; Popova, I. V.; Demkin, V. A.

2013-07-01

17

Study of soils buried under embankments to determine the potential of burial as a preservation technique for archaeological sites  

E-print Network

). If the buried soil behaves semi- plastically, due to a high moisture content, coarsening of the buried soil's structure can occur. A decrease in water in the overlying strata will relieve some of the pressure at depth, allowing the buried soil to swell...

Gonzalez, Tania

1989-01-01

18

SOLUBLE ALUMINUM IN ACIDIFIED ORGANIC HORIZONS OF FOREST SOILS  

EPA Science Inventory

Concentrations of labile and total Al in soil extracts were measured as a function of equilibrium solution pH in six forest soil organic horizons acidified with HNO, (0-20 cmol H+.kg-1) under controlled conditions of ionic strength (0.05 M NaNO3), temperature (23 C), and solution...

19

Acoustic Interrogation of Soil and Possible Remote Detection of Shallow Buried Inclusions  

E-print Network

the problem of remotely interrogating the shallow subsurface of soil using low power mechanical energy. A deeper understanding of mechanical energy propagation in soil will only allow us to finesse the presentAcoustic Interrogation of Soil and Possible Remote Detection of Shallow Buried Inclusions Laura E

Sen, Surajit

20

Geochemical soil sampling for deeply-buried mineralized breccia pipes, northwestern Arizona  

USGS Publications Warehouse

Thousands of solution-collapse breccia pipes crop out in the canyons and on the plateaus of northwestern Arizona; some host high-grade uranium deposits. The mineralized pipes are enriched in Ag, As, Ba, Co, Cu, Mo, Ni, Pb, Sb, Se, V and Zn. These breccia pipes formed as sedimentary strata collapsed into solution caverns within the underlying Mississippian Redwall Limestone. A typical pipe is approximately 100 m (300 ft) in diameter and extends upward from the Redwall Limestone as much as 1000 m (3000 ft). Unmineralized gypsum and limestone collapses rooted in the Lower Permian Kaibab Limestone or Toroweap Formation also occur throughout this area. Hence, development of geochemical tools that can distinguish these unmineralized collapse structures, as well as unmineralized breccia pipes, from mineralized breccia pipes could significantly reduce drilling costs for these orebodies commonly buried 300-360 m (1000-1200 ft) below the plateau surface. Design and interpretation of soil sampling surveys over breccia pipes are plagued with several complications. (1) The plateau-capping Kaibab Limestone and Moenkopi Formation are made up of diverse lithologies. Thus, because different breccia pipes are capped by different lithologies, each pipe needs to be treated as a separate geochemical survey with its own background samples. (2) Ascertaining true background is difficult because of uncertainties in locations of poorly-exposed collapse cones and ring fracture zones that surround the pipes. Soil geochemical surveys were completed on 50 collapse structures, three of which are known mineralized breccia pipes. Each collapse structure was treated as an independent geochemical survey. Geochemical data from each collapse feature were plotted on single-element geochemical maps and processed by multivariate factor analysis. To contrast the results between geochemical surveys (collapse structures), a means of quantifying the anomalousness of elements at each site was developed. This degree of anomalousness, named the "correlation value", was used to rank collapse features by their potential to overlie a deeply-buried mineralized breccia pipe. Soil geochemical results from the three mineralized breccia pipes (the only three of the 50 that had previously been drilled) show that: (1) Soils above the SBF pipe contain significant enrichment of Ag, Al, As, Ba, Ga, K, La, Mo, Nd, Ni, Pb, Sc, Th, U and Zn, and depletion in Ca, Mg and Sr, in contrast to soils outside the topographic and structural rim; (2) Soils over the inner treeless zone of the Canyon pipe show Mo and Pb enrichment anf As and Ga depletion, in contrast to soils from the surrounding forest; and (3) The soil survey of the Mohawk Canyon pipe was a failure because of the rocky terrane and lack of a B soil horizon, or because the pipe plunges. At least 11 of the 47 other collapse structures studied contain anomalous soil enrichments similar to the SBF uranium ore-bearing pipe, and thus have good potential as exploration targets for uranium. One of these 11, #1102, does contain surface mineralized rock. These surveys suggest that soil geochemical sampling is a useful tool for the recognition of many collapse structures with underlying ore-bearing breccia pipes. ?? 1994.

Wenrich, K.J.; Aumente-Modreski, R. M.

1994-01-01

21

Genesis of petroduric and petrocalcic horizons in Latinamerica volcanic soils  

NASA Astrophysics Data System (ADS)

Introduction. In Latinamerica, from Mexico to Chile, there are indurated volcanic soils horizons, named 'tepetate' in Mexico or cangahua in the Andes Mountains. Apart from original volcanic tuffs, these horizons were produced by pedogenesis: either through a former weathering of volcanic ash layers into fragic and later to petrocalcic horizons; or after a former soil formation through a second process of transformation from clayey volcanic soils to silicified petroduric horizons. This oral presentation will briefly deal with the formation of petroduric horizons in Mexico and petrocalcic horizon in Ecuador. Petroduric horizon genesis in Mexico. A soil climato-toposequence, near to Veracruz (Rossignol & Quantin, 1997), shows downwards an evolution from a ferralic Nitisol to a petroduric Durisol. A Durisol profile comports these successive horizons: at the top A and Eg, then columnar Btg-sim, laminar Bt-sim , prismatic Bsim, plinthite Cg, over andesite lava flow. Among its main features are especially recorded: clay mineralogy, microscopy and HRTEM. These data show: an increase in cristobalite at the expenses of 0.7 nm halloysite in Egsiltans, laminar Bt-sim, around or inside the columns or prisms of Btg-sim and Bsimhorizons. HRTEM (Elsass & al 2000) on ultra thin sections reveals an 'epigenesis' of clay sheets by amorphous silica, to form successively A-opal, Ct-opal and microcrystalline cristobalite. From these data and some groundwater chemical analyses, a scenario of duripan formation from a past clayey Nitisol is inferred: clay eluviation-illuviation process? alternate redoximorphy? clay degradation, Al leaching and Si accumulation, to form successively A-opal, Ct-opal and cristobalite. Petrocalcic horizon genesis in Ecuador. A soil climato-toposequence on pyroclastic flows, near to Bolivar in Ecuador (Quantin & Zebrowski, 1997), shows downwards the evolution from fragic-eutric-vitric Cambisols to petrocalcic-vitric Phaeozems, at the piedmont under semi-arid climate. A complex soil profile of petrocalcic Phaeozem, derived from 4 pyroclastic layers, shows among its successive horizons: in layer 3 the 'upper cangahua' with petrocalcic features and in layer 4 the 'lower cangahua' with hard fragipan properties. The features of the petrocalcic cangahua differ from a Mexican fragipan (Hidalgo & al 1997) by: a hard calcrete, higher alkalinity, stability in water after HCl and NaOH treatment, 2-4% of 'free silica'. The macro and micro-morphology shows: the laminar calcite crust, at the top of cangahua, with alternate micrite-sparite layers; downwards, microcalcite infillings in the voids of a prismatic structure, invading the groundmass by epigenesis of clay sheets, together whith microcrystalline opal. From these data this scenario is inferred: after a former weathering of volcanic glass to form a clayey matrix, as well amorphous silica and microcalcite coatings and infillings, then a second process, perhaps due to drier climate, produced the laminar crust formation, by invasion of microcalcite in the matrix. Conclusion. The petrocalcic horizon in Ecuador was produced by two processes: from a former phase of weathering giving a fragic horizon to a second producing the accumulation of calcite and some opal over and inside the matrix, due to climate change. The petroduric horizon in Mexico, is the product of a very complex soil transformation, from a former clayey Nitisol, through four successive processes: clay eluviation-illuviation, alternate redoximorphy, clay degradation, finally a progressive silicification over and inside the groundmass, probably due to pedoclimate change. References F. Elsass, D. Dubroeucq & M. Thiry. 2000. Clay Minerals, 35, 477-489. C. Hidalgo, P. Quantin & F. Elsass. 1997. Memorias del III Simposio Internacional sobre Suelos volcanicos endurecidos (Quito 1996), p. 65-72. - P. Quantin & C. Zebrowski. 1997. idem, p. 29-47.- J.P. Rossignol & P. Quantin. 1997. idem, p. 73-82.

Quantin, Paul

2010-05-01

22

The influence of time on the magnetic properties of late Quaternary periglacial and alluvial surface and buried soils along the Delaware River, USA  

NASA Astrophysics Data System (ADS)

Magnetic susceptibility of soils has been used as a proxy for rainfall, but other factors can contribute to magnetic enhancement in soils. Here we explore influence of century- to millennial-scale duration of soil formation on periglacial and alluvial soil magnetic properties by assessing three terraces with surface and buried soils ranging in exposure ages from <0.01 to ~16 kyrs along the Delaware River in northeastern USA. The A and B soil horizons have higher Xlf, Ms, and S-ratios compared to parent material, and these values increase in a non-linear fashion with increasing duration of soil formation. Magnetic remanence measurements show a mixed low- and high-coercivity mineral assemblage likely consisting of goethite, hematite and maghemite that contributes to the magnetic enhancement of the soil. Room-temperature and low-temperature field-cooled and zero field-cooled remanence curves confirm the presence of goethite and magnetite and show an increase in magnetization with increasing soil age. These data suggest that as the Delaware alluvial soils weather, the concentration of secondary ferrimagnetic minerals increase in the A and B soil horizons. We then compared the time-dependent Xlf from several age-constrained buried alluvial soils with known climate data for the region during the Quaternary. Contradictory to most studies that suggest a link between increases in magnetic susceptibility and high moisture, increased magnetic enhancement of Delaware alluvial soils coincides with dry climate intervals. Early Holocene enhanced soil Xlf (9.5 – 8.5 ka) corresponds with a well-documented cool-dry climate episode. This relationship is probably related to less frequent flooding during dry intervals allowing more time for low-coercive pedogenic magnetic minerals to form and accumulate, which resulted in increased Xlf. Middle Holocene enhanced Xlf (6.1 – 4.3 ka) corresponds with a transitional wet/dry phase and a previously documented incision event.......

Stinchcomb, Gary; Peppe, Daniel

2014-08-01

23

Transformation of lignin in surface and buried soils of mountainous landscapes  

NASA Astrophysics Data System (ADS)

The content and composition of the lignin phenols in plants and soils of vertical natural zones were studied in the Northern Caucasus region and Northwestern Tien Shan. Three types of lignin transformation were revealed: steppe, forest, and meadow ones. It was shown that the degree of oxidation of the biopolymer during the transformation of organic matter increased when going from the living plant tissues to humic acids in surface and buried soils. The portion of lignin fragments remained unchanged during the biopolymer transformation in the following series: plant tissues-falloff-litter-soil-humic acids-buried humic acids. It was also shown that the biochemical composition of the plants had a decisive effect on the structure of the humic acids in the soils. The quantitative analysis of the lignin phenols and the 13C NMR spectroscopy proved that the lignin in higher plants was involved in the formation of specific compounds of soil humus, including aliphatic and aromatic molecular fragments. The first analysis of the lignin content and composition in buried soils of different ages was performed, and an increase in the degree of oxidation of the lignin structures was revealed in the soil chronoseries. It was proposed to use the proportions of lignin phenols in surface and buried soils as diagnostic criteria of the vegetation types in different epochs.

Kovaleva, N. O.; Kovalev, I. V.

2009-11-01

24

Role and development of soil parameters for seismic responses of buried lifelines  

SciTech Connect

Buried lifelines, e.g. oil, gas, water and sewer pipelines have been damaged heavily in recent earthquakes such as 1971 San Fernando Earthquake, in U.S.A., 1976 Tangshan Earthquake, in China, and 1978 MiyagiKen-Oki Earthquake, in Japan, among others. Researchers on the seismic performance of these buried lifelines have been initiated in the United States and many other countries. Various analytical models have been proposed. However, only limited experimental investigations are available. The sources of earthquake damage to buried lifelines include landslide, tectonic uplift-subsidence, soil liquefaction, fault displacement and ground shaking (effects of wave propagation). This paper is concerned with the behavior of buried lifeline systems subjected to surface faulting and ground shaking. The role and development of soil parameters that significantly influence the seismic responses are discussed. The scope of this paper is to examine analytically the influence of various soil and soilstructure interaction parameters to the seismic responses of buried pipelines, to report the currently available physical data of these and related parameters for immediate applications, and to describe the experiments to obtain additional information on soil resistant characteristics to longitudinal pipe motions.

Wang, L.R.L.

1983-01-01

25

Soil organic matter transformation in cryoturbated horizons of permafrost affected soils  

NASA Astrophysics Data System (ADS)

Cryoturbated soil horizons are special feature of permafrost affected soils. These soils are known to store great amount of organic carbon and cryoturbation undoubtedly contribute to it to large extent. Despite this fact there is almost no information about soil organic matter (SOM) transformation in cryoturbated horizons. Therefore we carried out long term incubation experiment in which we inspect SOM transformation in cryoturbated as well as in organic and mineral soil horizons under different temperature and redox regimes as potential drivers. We found out that lower SOM transformation in cryoturbated horizons compared to organic horizons was mainly limited by the amount of microbial biomass, which is extremely low in absolute numbers or expressed to SOM concentration. The biochemical transformation ensured by extracellular enzymes is relatively high leading to high concentrations of dissolved organic carbon in cryoturbated horizons. Nevertheless the final step of SOM transformation leading to C mineralization to CO2 or CH4 seems to be restricted by low microbial biomass. Critical step of biochemical transformation of complex SOM is dominated by phenoloxidases, which break down complex organic compounds to simple ones. Their oxygen consumption greatly overwhelms oxygen consumption of the whole microbial community. However the phenoloxidase activity shows strong temperature response with optimum at 13.7° C. Therefore we suggest that apparent SOM stability in cryoturbated horizons, which is expressed in old C14 dated age, is caused by low amount of microbial biomass and restricted diffusion of oxygen to extracellular enzymes in field.

Capek, Petr; Diakova, Katerina; Dickopp, Jan-Erik; Barta, Jiri; Santruckova, Hana; Wild, Birgit; Schnecker, Joerg; Guggenberg, Georg; Gentsch, Norman; Hugelius, Gustaf; Kuhry, Peter; Lashchinsky, Nikolaj; Gittel, Antje; Schleper, Christa; Mikutta, Robert; Palmtag, Juri; Shibistova, Olga; Urich, Tim; Zimov, Sergey; Richter, Andreas

2014-05-01

26

Effects of buried obstacles on penetration resistance in cohesionless soils  

NASA Technical Reports Server (NTRS)

Recent experiments concerning penetration of cohesionless soils in special molds that include solid obstacles embedded within the soil matrix are reported. The relative effects of these obstacles with respect to the soil properties of relative density, texture, and gradation are also discussed. Because lunar soil is fairly cohesionless, special attention was given to the Apollo lunar simulant, AP-12.

Deluca, E. W.; Carrasco, L. H.

1972-01-01

27

Explosives-related chemical concentrations in surface soils over buried land mines  

Microsoft Academic Search

Night Vision Electronic Sensors Directorate (NVESD) has initiated a program for land mine sensor development based upon explosives-related chemical (ERC) detection. As part of the NVESD ERC sensor program, we have sampled soils surrounding buried land mines at the experimental mine lanes, U.S. Army Test Site, with the assistance of the Army Corps of Engineers, Cold Regions Research and Engineering

Kira D. Hutchinson; Scott L. Grossman; Thomas F. Jenkins; Kelly D. Sherbondy

2002-01-01

28

Using soil E horizon in salvaged topsoil material - effect on soil texture  

Technology Transfer Automated Retrieval System (TEKTRAN)

Topsoil is a limited natural resource that needs to be efficiently salvaged during landscape reconstruction operations for its further use as topsoil. Current guidelines for borrowed topsoil define topsoil as the surface layer of native soil, or soil A horizon. Using information from nearly 8,000 ...

29

Lanthanides in humic acids of soils, paleosols and cultural horizons (Southern Urals, Russia)  

NASA Astrophysics Data System (ADS)

In recent years, commercial interest in this element group increases. As consequence, their content may increase in environment, including soil and soil components. This requires quantitative estimations of rare metal accumulation by soils and their humic acids. The latter began to be actively used as fertilizers and it is alarming, because information about rare element participation (including lanthanides) in metabolism of live organisms is inconsistent. There was investigated lanthanide content in humic acids extracted from humus horizons of different objects of archaeological site Steppe 7 (Southern Urals, Russia). Humic acids were extracted from modern background soils and paleosols and cultural horizons of the Bronze Age as well. According to archaeological data burial of paleosols under a barrow and formation of the cultural layer (CL) took place 3600 and 3300-3200 years BP, respectively. The area of the site is located in the forest-steppe landscape, far from industrial plants. Lanthanides in soils are immobile elements, and such number of objects will allow to receive information about their content changing over time and to have more detailed basis for the future monitoring of this territory as well. Humic acids were precipitated from 0,1 n NaOH extraction after preliminary decalcification. Cleaning of humic acid preparations by 6N HCl or HF+HCl was not carried out. Determination of La, Ce, Sm, Eu, Tb, Yb and Lu was performed by multi-element neutron-activation analysis. According to carried out diagnostics and reconstruction of natural conditions of all object formation, all objects correspond to steppe type landscape with a different level of humidity. Analysis of received data has shown that cerium is presented in humic acid preparations in the largest quantities among lanthanides (on average 4,0-6,6 mg/kg of preparation mass). The average content of samarium, europium, ytterbium and lutetium in the humic acids in the order of magnitude ranges from 0.13 to 0.49 mg/kg, terbium and lutetium - two orders of magnitude. The quantities determined by us for lanthanum is also high at 1,9-3,3 mg/kg. In this case all lanthanides in modern soils have the degree of accumulation in humic acids distinguished from other objects: Ce>La>Sm>Yb>Eu>Tb>Lu. In the paleosols and cultural layer these series are identical: Ce>La>Yb>Sm>Eu>Lu>Tb. There is suggested the approach to direct estimation of share of the lanthanides connected by humic acids in the their total soil pool which includes recalculation of the content of separate elements in humic acid preparations on carbon of soil humic acids (in mg/kg) and the subsequent correlation of their quantities. The content of the total organic carbon in soil, a share of humic acids as a humus part, the lanthanide content and weight carbon percentage in humic acid preparations were considered during recalculations. The results have shown that the highest shares of all elements are found in modern background soils, the lowest - in the soils buried under barrows. The total percentage of all lanthanides in humic acids is 4.63% in relation to their content in modern soil, 1.56% - in CL and 1.36% - in buried paleosols.

Dergacheva, Maria; Nekrasova, Olga

2013-04-01

30

The influence of soil moisture on losses of buried seeds to fungi  

NASA Astrophysics Data System (ADS)

Although soil fungi are likely to be a major cause of mortality for buried seeds, few ecological studies have examined the role these pathogens play in natural systems. In particular, few studies have investigated whether losses of seeds to soil fungi are habitat-dependent. We used fungicide treatments to investigate whether losses of buried seeds of four grasses ( Bromus inermis, Danthonia spicata, Glyceria striata, and Poa pratensis) to soil fungi differed among meadows differing in soil moisture. We also applied water to some treatments, to determine whether this increased losses of seeds to fungi. For all four grasses, fungicide additions improved one or more measures of seed viability, though this effect was small. For Danthonia and Glyceria, fungicide was less likely to improve viability in dry meadows than in wet and/or mesic meadows. Adding water reduced some measures of viability of seeds of Danthonia and Poa in dry meadows, but fungicide partly counteracted these negative effects, suggesting that adding water reduced performance by increasing fungal attack. These results indicate that fungi represent a hazard for buried seeds of these species, particularly in wetter soils, and potentially may contribute to the reduction of populations of vulnerable species in wetter sites.

Schafer, Michelle; Kotanen, Peter M.

2003-12-01

31

A disconnect between O horizon and mineral soil carbon - Implications for soil C sequestration  

SciTech Connect

Changing inputs of carbon to soil is one means of potentially increasing carbon sequestration in soils for the purpose of mitigating projected increases in atmospheric CO{sub 2} concentrations. The effect of manipulations of aboveground carbon input on soil carbon storage was tested in a temperate, deciduous forest in east Tennessee, USA. A 4.5-year experiment included exclusion of aboveground litterfall and supplemental litter additions (three times ambient) in an upland and a valley that differed in soil nitrogen availability. The estimated decomposition rate of the carbon stock in the O horizon was greater in the valley than in the upland due to higher litter quality (i.e., lower C/N ratios). Short-term litter exclusion or addition had no effect on carbon stock in the mineral soil, measured to a depth of 30 cm, or the partitioning of carbon in the mineral soil between particulate- and mineral-associated organic matter. A two-compartment model was used to interpret results from the field experiments. Field data and a sensitivity analysis of the model were consistent with little carbon transfer between the O horizon and the mineral soil. Increasing aboveground carbon input does not appear to be an effective means of promoting carbon sequestration in forest soil at the location of the present study because a disconnect exists in carbon dynamics between O horizon and mineral soil. Factors that directly increase inputs to belowground soil carbon, via roots, or reduce decomposition rates of organic matter are more likely to benefit efforts to increase carbon sequestration in forests where carbon dynamics in the O horizon are uncoupled from the mineral soil.

Garten Jr, Charles T [ORNL

2009-01-01

32

Pore morphology characteristics of vesicular horizons in undisturbed and disturbed arid soils; implications for arid  

E-print Network

, length and width; comparisons were also made for particle size, pH, calcium carbonate equivalent (CCE vesicular soil horizon in a disturbed and undis- turbed state. This surface vesicular horizon this hypothesis, we examined the pore mor- phology of the vesicular horizon as expressed in area, perimeter

Ahmad, Sajjad

33

Predicting the long-term fate of buried organic carbon in colluvial soils  

NASA Astrophysics Data System (ADS)

A significant part of the soil organic carbon (SOC) that is eroded in uplands is deposited and buried in colluvial settings. Understanding the fate of this deposited soil organic carbon is of key importance for the understanding of the role of (accelerated) erosion in the global C cycle: the residence time of the deposited carbon will determine if, and for how long, accelerated erosion due to human disturbance will induce sequestration of SOC from the atmosphere to the soil. Experimental studies may provide useful information, but, given the time scale under consideration, the response of the colluvial SOC can only be simulated using numerical models which need careful calibration using field data. In this study, we present a depth explicit SOC model including soil profile evolution due to sedimentation to simulate the long-term C dynamics in colluvial soils. The SOC profile predicted by our model is in good agreement with field observations. The C burial efficiency (the ratio of current C content of the buried sediments to the original C content at the time of sedimentation) of deposited sediments exponentially decreases with time and gradually reaches an equilibrium value. This equilibrium C burial efficiency is positively correlated with the sedimentation rate. The sedimentation rate is crucial for the long-term dynamics of the deposited SOC as it controls the time that buried sediments spend at a given soil depth, thereby determining its temporal evolution of C input and decomposition rate during the burial process: C input and decomposition rate vary with depth due to the vertical variation of root distribution and soil environmental factors such as (but not limited to) humidity, temperature, and aeration. The model demonstrates that, for the profiles studied, it takes circa 300 years for the buried SOC to lose half of its C load. It would also take centuries for the SOC accumulated in colluvial soils over the past decades due to soil redistribution under mechanized agriculture to be released to the atmosphere after the application of soil conservation measures such as conservation tillage.

Wang, Zhengang; Van Oost, Kristof; Govers, Gerard

2015-01-01

34

Acidity field of soils as ion-exchange systems and the diagnostics of genetic soil horizons  

NASA Astrophysics Data System (ADS)

For the comprehensive description of the acidity of a two-phase ion-exchange system, we should analyze two curves of the ionite titration by a strong base in water and salt solutions and find the quantitative relationships between the corresponding pH characteristics. An idea of the three-dimensional field of acidity of ion-exchange systems (the phase space of the soil acidity characteristics) and its three two-dimensional projections is suggested. For soils, three interrelated characteristics—the pH values of the salt and water extracts and the degree of base saturation—can serve as spatial coordinates for the acidity field. Representation of factual data in this field makes it possible to compare and analyze the acidity characteristics of different soils and soil horizons and to determine their specific features. Differentiation of the field into separate volumes allows one to present the data in a discrete form. We have studied the distribution patterns of the groups of soil horizons from Leningrad oblast and other regions of northwestern Russia in the acidity field. The studied samples are grouped in different partially overlapping areas of the projections of the acidity field. The results of this grouping attest to the correctness of the modern classification of Russian soils. A notion of the characteristic soil area in the acidity field is suggested; it can be applied to all the soils with a leaching soil water regime.

Kokotov, Yu. A.; Sukhacheva, E. Yu.; Aparin, B. F.

2014-12-01

35

Vapor-phase transport of explosives from buried sources in soils.  

PubMed

The fate and transport of explosives in the soil pore vapor spaces affects both the potential detection of buried ordnance by chemical sensors and vadose zone transport of explosives residues. The efficacy of chemical sensors and their potential usefulness for detecting buried unexploded ordnance (UXO) is difficult to determine without understanding how its chemical signatures are transported through soil. The objectives of this study were to quantify chemical signature transport through soils under various environmental conditions in unsaturated soils and to develop a model for the same. Flux chambers, large soil containers, and batch tests were used to determine explosives signature movement and process descriptors for model development. Low signatures were observed for explosives (2,4-dinitrotoluene, 2,6-dinitrotoluene, and 1,3-dinitrobenzene) under all environmental conditions. A diffusion model was used to describe the chemical transport mechanism in the soil pore air. The soil-air partition constant was treated as a fit parameter in the model owing to the uncertainty in its a priori estimation. The model predictions of the trends in experimental fluxes and the soil concentration were only marginal at best. It was concluded that better estimates of the partition constant are required for more accurate estimation of the chemical concentration at the soil-air interface. Chemical sensors will need to be very sensitive because of low signatures. However, this may result in many false alarms because of explosives residues not associated with UXO on firing ranges. Low explosives signatures also should result in insignificant air environmental exposures. PMID:15648390

Ravikrishna, Raghunathan; Valsaraj, Kalliat T; Price, Cynthia B; Brannon, James M; Hayes, Charolett A; Yost, Sally L

2004-12-01

36

The effect of soil texture on the degradation of textiles associated with buried bodies.  

PubMed

There are many factors which affect the rate of decomposition in a grave site including; the depth of burial, climatic conditions, physical conditions of the soil (e.g. texture, pH, moisture), and method of burial (e.g. clothing, wrappings). Clothing is often studied as a factor that can slow the rate of soft tissue decomposition. In contrast, the effect of soft tissue decomposition on the rate of textile degradation is usually reported as anecdotal evidence rather than being studied under controlled conditions. The majority of studies in this area have focused on the degradation of textiles buried directly in soil. The purpose of this study was to investigate the effect of soil texture on the degradation and/or preservation of textile materials associated with buried bodies. The study involved the burial of clothed domestic pig carcasses and control clothing in contrasting soil textures (silty clay loam, fine sand and fine sandy loam) at three field sites in southern Ontario, Canada. Graves were exhumed after 2, 12 and 14 months burial to observe the degree of degradation for both natural and synthetic textiles. Recovered textile samples were chemically analyzed using infrared (IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) to investigate the lipid decomposition by-products retained in the textiles. The findings of this study demonstrate that natural textile in contact with a buried decomposing body will be preserved for longer periods of time when compared to the same textile buried directly in soil and not in contact with a body. The soil texture did not visually impact the degree of degradation or preservation. Furthermore, the natural-synthetic textile blend was resistant to degradation, regardless of soil texture, contact with the body or time since deposition. Chemical analysis of the textiles using GC-MS correctly identified a lipid degradation profile consistent with the degree of soft tissue decomposition. Such information may be important for estimating time since deposition in instances where only grave goods and associated materials are recovered from a burial site. PMID:23890657

Lowe, A C; Beresford, D V; Carter, D O; Gaspari, F; O'Brien, R C; Stuart, B H; Forbes, S L

2013-09-10

37

Radiocarbon dating of buried soils-- Humate fractionation, delta C-13 correction and paleoclimatic signals: Geoarchaeological implications in the central Great Plains  

SciTech Connect

Due to perceived uncertainties associated with humate-derived C-14 ages from buried soils, samples were collected and dated from buried A horizons developed in alluvium and loess within the Kansas River basin of Kansas, Nebraska, and Colorado. Soils range in age from c. 30ka to latest Holocene. Samples were split, sent to two laboratories (SMU and Pittsburgh), and fractionated. Ages were determined from three fractions: total bulk, base-soluble (humic acid), and residue (humins). For individual samples, a significant age difference exists among the three fractions, with very little interlaboratory variation. No apparent relationship exists among the three fractions dated; the residual fraction is not consistently the oldest as anticipated, and the total humate fraction is not the youngest. Percent variation among fractions may be a depth/age function for soils within a given profile of sequence. Delta C-13 values derived from the different fractions indicate more negative values for the total humate fraction. Percent variation in delta C-13 values among the three fractions seems unrelated to age or depth. A strong paleoclimatic signal is contained within the temporal record of delta C-13 values derived from soils dating c. 36-1ka. Warm-season (C4-type) grasses were apparently more important in the middle Holocene period of aridity (Altithermal). Change from a cooler environment of the latest Pleistocene to the relatively warmer conditions of the earliest Holocene is recorded in the humates distributed within the A horizon of the Brady geosol. Humates from the Gilman Canyon Formation geosol dating c. 36-20ka exhibit delta C-13 values indicating an initial warm-season grass environment which subsequently evolved into a cool-season grass environment.

Johnson, W.C. (Univ. of Kansas, Lawrence, KS (United States). Dept. of Geography); Martin, C.W. (Kansas State Univ., Manhattan, KS (United States). Dept. of Geography)

1992-01-01

38

Disturbances in the soil: finding buried bodies and other evidence using ground penetrating radar.  

PubMed

Ground penetrating radar (GPR) is an efficient and effective means to search for buried evidence, whether it be a clandestine grave, formal burial, or certain missing articles from a crime scene. The procedures for GPR used by the U.S. Army Central Identification Laboratory, Hawaii (CILHI), are the result of several years of experimentation on a variety of ground surfaces in Hawaii, Southeast Asia and the mainland U.S. This remote sensing method does not usually provide direct information that there is a body or other specific object beneath the ground. Most of the time the GPR has been used to determine where a target object is not located. The key feature of GPR is that it can detect recent changes in shallow soil conditions caused by the disturbance of soil and the intrusion of different material. Using the methods described here, the investigator should be able to determine the precise metric grid coordinates for a subsurface disturbance, as well as the approximate size, the general shape, and the depth of the buried material. Success will vary with soil conditions. The conditions suitable or not practical for using GPR are summarized. This remote sensing technology can have wider use in crime scene investigations due to the recent introduction of more user-friendly software and more portable hardware. PMID:8754575

Miller, P S

1996-07-01

39

Site- and horizon-specific patterns of microbial community structure and enzyme activities in permafrost-affected soils of Greenland.  

PubMed

Permafrost-affected soils in the Northern latitudes store huge amounts of organic carbon (OC) that is prone to microbial degradation and subsequent release of greenhouse gasses to the atmosphere. In Greenland, the consequences of permafrost thaw have only recently been addressed, and predictions on its impact on the carbon budget are thus still highly uncertain. However, the fate of OC is not only determined by abiotic factors, but closely tied to microbial activity. We investigated eight soil profiles in northeast Greenland comprising two sites with typical tundra vegetation and one wet fen site. We assessed microbial community structure and diversity (SSU rRNA gene tag sequencing, quantification of bacteria, archaea and fungi), and measured hydrolytic and oxidative enzyme activities. Sampling site and thus abiotic factors had a significant impact on microbial community structure, diversity and activity, the wet fen site exhibiting higher potential enzyme activities and presumably being a hot spot for anaerobic degradation processes such as fermentation and methanogenesis. Lowest fungal to bacterial ratios were found in topsoils that had been relocated by cryoturbation ("buried topsoils"), resulting from a decrease in fungal abundance compared to recent ("unburied") topsoils. Actinobacteria (in particular Intrasporangiaceae) accounted for a major fraction of the microbial community in buried topsoils, but were only of minor abundance in all other soil horizons. It was indicated that the distribution pattern of Actinobacteria and a variety of other bacterial classes was related to the activity of phenol oxidases and peroxidases supporting the hypothesis that bacteria might resume the role of fungi in oxidative enzyme production and degradation of phenolic and other complex substrates in these soils. Our study sheds light on the highly diverse, but poorly-studied communities in permafrost-affected soils in Greenland and their role in OC degradation. PMID:25360132

Gittel, Antje; Bárta, Ji?í; Kohoutová, Iva; Schnecker, Jörg; Wild, Birgit; Capek, Petr; Kaiser, Christina; Torsvik, Vigdis L; Richter, Andreas; Schleper, Christa; Urich, Tim

2014-01-01

40

Site- and horizon-specific patterns of microbial community structure and enzyme activities in permafrost-affected soils of Greenland  

PubMed Central

Permafrost-affected soils in the Northern latitudes store huge amounts of organic carbon (OC) that is prone to microbial degradation and subsequent release of greenhouse gasses to the atmosphere. In Greenland, the consequences of permafrost thaw have only recently been addressed, and predictions on its impact on the carbon budget are thus still highly uncertain. However, the fate of OC is not only determined by abiotic factors, but closely tied to microbial activity. We investigated eight soil profiles in northeast Greenland comprising two sites with typical tundra vegetation and one wet fen site. We assessed microbial community structure and diversity (SSU rRNA gene tag sequencing, quantification of bacteria, archaea and fungi), and measured hydrolytic and oxidative enzyme activities. Sampling site and thus abiotic factors had a significant impact on microbial community structure, diversity and activity, the wet fen site exhibiting higher potential enzyme activities and presumably being a hot spot for anaerobic degradation processes such as fermentation and methanogenesis. Lowest fungal to bacterial ratios were found in topsoils that had been relocated by cryoturbation (“buried topsoils”), resulting from a decrease in fungal abundance compared to recent (“unburied”) topsoils. Actinobacteria (in particular Intrasporangiaceae) accounted for a major fraction of the microbial community in buried topsoils, but were only of minor abundance in all other soil horizons. It was indicated that the distribution pattern of Actinobacteria and a variety of other bacterial classes was related to the activity of phenol oxidases and peroxidases supporting the hypothesis that bacteria might resume the role of fungi in oxidative enzyme production and degradation of phenolic and other complex substrates in these soils. Our study sheds light on the highly diverse, but poorly-studied communities in permafrost-affected soils in Greenland and their role in OC degradation. PMID:25360132

Gittel, Antje; Bárta, Ji?í; Kohoutová, Iva; Schnecker, Jörg; Wild, Birgit; ?apek, Petr; Kaiser, Christina; Torsvik, Vigdis L.; Richter, Andreas; Schleper, Christa; Urich, Tim

2014-01-01

41

Mach stem due to an underground explosion near a rigid structure buried in soil  

NASA Astrophysics Data System (ADS)

This paper presents recent results of an analysis of pressure distributions along the circumference of underground structures of various shapes due to a nearby buried explosion. The present study examines the effect of the standoff distance on the results and special attention is given to the soil medium equation of state characteristics and their effect on the Mach stem. It was found that for a short standoff distance and a steep growth of pressure beyond the full compaction point that characterizes dense soils, the envelope of the pressure distributions shows a maximum value, which is located at some distance away from the plane of symmetry rather than along it, as is the case for a distant explosion. This phenomenon causes the distortion of the frontal part of the explosive cavity. This effect is more pronounced for more dense soils that show a sharper pressure increase in the equation of state. It has been proven that these pressure distributions and associated shapes of the explosion cavities are caused by the Mach stem effect appearing in a soil medium with full locking.

Karinski, Y. S.; Feldgun, V. R.; Racah, E.; Yankelevsky, D. Z.

2015-01-01

42

Sorption of acetochlor, S-metolachlor, and atrazine in surface and subsurface soil horizons of Argentina.  

PubMed

Understanding herbicide sorption within soil profiles is the first step to predicting their behavior and leaching potential. Laboratory studies were conducted to determine the influence of surface and subsurface soil properties on acetochlor, atrazine, and S-metolachlor sorption. Soil samples were taken from horizons A, B, and C of two loamy soils of the humid pampas of Argentina under no-till management; horizon A was divided into two layers, A(0) (0-5 cm) and A(1) (5 cm to the full thickness of an A horizon). Sorption isotherms were determined from each sampled horizon using the batch equilibrium method and seven concentrations (0, 0.1, 0.5, 2.0, 5.0, 10.0, and 20.0 mg?L(-1)). Sorption affinity of herbicides was approximated by the Freundlich equation. The sorption strength K(f) (mg(1 - 1/n) kg(-1) L(1/n) ) over the soils and horizons studied followed the order S-metolachlor (16.51-29.19)?>?atrazine (4.85-12.34) ? acetochlor (5.17-11.97), which was closely related to the hydrophobicity of herbicides expressed as octanol-water partition coefficient (K(OW) ). The K(f) values of the three herbicides were positively correlated with soil organic carbon, with a significance of p < 0.01. Values of K(f) for the three herbicides decreased with depth in the two soils, indicating greater sorption onto surficial soil horizons and possibly a delayed transport toward subsurface soils and subsequent pollution of groundwater. PMID:21692102

Bedmar, Francisco; Daniel, Peter E; Costa, José L; Giménez, Daniel

2011-09-01

43

A geophysical and biochemical investigation of buried remains in contrasting soil textures in southern Ontario  

NASA Astrophysics Data System (ADS)

Ground penetrating radar (GPR) is a non-invasive, geophysical tool used for the detection of clandestine graves. GPR operates by detecting density differences in soil by the transmission of high frequency electromagnetic (EM) waves from an antenna. A 500 Megahertz (MHz) frequency antenna is typically used for forensic investigations, as it provides a suitable compromise between depth of penetration and sub-surface resolution. Domestic pig (Sus scrofa) carcasses were clothed in 100% cotton t-shirts and 50% cotton/50% polyester briefs, and buried at a consistent depth at three field sites of contrasting soil texture (silty clay loam, fine sand and fine sandy loam) in southern Ontario. GPR was used to detect and monitor the graves for a period of 14 months post burial. Analysis of collected data revealed that GPR had applicability in the detection of clandestine graves containing remains in silty clay loam and fine sandy loam soils, but was not suitable for detection in fine sandy soil. Specifically, within a fine sandy loam soil, there is the potential to estimate the post burial interval (PBI), as hyperbolic grave response was well defined at the beginning of the 14 month burial duration, but became less distinctive near the completion of the study. Following the detection of a clandestine grave containing a carcass, collection of gravesoil, tissue and textile samples is important for the estimation of the stage of decomposition and the post burial interval (PBI) of the remains. Throughout the decomposition process of a carcass, adipose tissue is subjected to hydrolytic enzymes that convert triglycerides to their corresponding unsaturated, saturated and salts of fatty acids. The composition of fatty acids in the decomposed tissue will vary with the post mortem period, but it is unknown what affect the soil texture has on lipid degradation. As decomposition proceeds, fatty acids can leach from the tissues into the surrounding burial environment. Fatty acid analysis of gravesoil, tissue and textile samples, exhumed at two, eleven and fourteen month post burial intervals, was conducted using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and gas chromatography-mass spectrometry (GC-MS). Infrared (IR) spectroscopy analysis of the samples provided a qualitative profile of lipid degradation. Analysis of gravesoil samples did not reveal IR spectroscopy bands attributable to fatty acid degradation or adipocere formation. IR spectroscopy analysis of tissue samples is applicable for the estimation of carcass decomposition in all of the soil textures tested. Results of textile IR spectroscopy analysis revealed limited potential to estimate the stage of carcass decomposition in silty clay loam soil. GC-MS was used to quantify the peak area ratio (area/int std area) (PAR) of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0) and oleic (C18:1) acids. GC-MS results revealed that analysis of both tissue and textile samples can be useful in the estimation of the stage of decomposition and the PBI of carcasses in all three of the soil textures tested. The results of this research may have applicability within forensic investigations involving decomposing bodies by aiding in the location of clandestine graves in silty clay loam and fine sandy loam soil through the use of GPR. Infrared spectroscopy and GC-MS analysis of the fatty acid composition of tissue and textile samples may also be incorporated into investigational protocols to aid in the estimation of the stage of decomposition and the PBI of a body. Key Words: forensic science, ground penetrating radar, soil texture, buried remains, fatty acids, gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy

Lowe, Amanda C.

44

Survival of two enterobacteria in feces buried in soil under field conditions.  

PubMed Central

Feces samples, inoculated with 10(6) Escherichia coli resistant to streptomycin and nalidixic acid and with 10(5) Salmonella typhimurium per g, were buried at five mountain field sites ranging from 2,005 to 2,730 m in elevation. Counts of each bacterium rose initially and then declined to 10(3) or 10(4) per g of feces in 8 weeks. The survival pattern was similar at all sites regardless of marked differences in elevation, soil, moisture, exposure, and vegetation. S. typhimurium numbers were consistently higher than E. coli numbers after week 3. The test encompassed most of the time that the area is snow-free and accessible for hiking. The results were judged to discredit the recommendation for shallow burial of feces and to indicate a potential health hazard under intensive use. PMID:6999999

Temple, K L; Camper, A K; McFeters, G A

1980-01-01

45

Uplifting Behavior of Shallow Buried Pipe in Liquefiable Soil by Dynamic Centrifuge Test  

PubMed Central

Underground pipelines are widely applied in the so-called lifeline engineerings. It shows according to seismic surveys that the damage from soil liquefaction to underground pipelines was the most serious, whose failures were mainly in the form of pipeline uplifting. In the present study, dynamic centrifuge model tests were conducted to study the uplifting behaviors of shallow-buried pipeline subjected to seismic vibration in liquefied sites. The uplifting mechanism was discussed through the responses of the pore water pressure and earth pressure around the pipeline. Additionally, the analysis of force, which the pipeline was subjected to before and during vibration, was introduced and proved to be reasonable by the comparison of the measured and the calculated results. The uplifting behavior of pipe is the combination effects of multiple forces, and is highly dependent on the excess pore pressure. PMID:25121140

Liu, Jingwen; Ling, Daosheng

2014-01-01

46

Experimental investigation of thermal and moisture behaviors of wet and dry soils with buried capillary heating system  

Microsoft Academic Search

An experimental study of thermal and moisture behaviors of dry and wet soils heated by buried capillary plaits was done. This study was carried out on a prototype similar to an agricultural tunnel greenhouse. The experimental procedure consisted on three different measuring phases distinguished by three different operational conditions of the capillary plaits: heating at 70°C, heating at 40°C and

M. Balghouthi; S. Kooli; A. Farhat; H. Daghari; A. Belghith

2005-01-01

47

Late quaternary temperature record from buried soils of the North American Great Plains  

USGS Publications Warehouse

We present the first comprehensive late Quaternary record of North American Great Plains temperature by assessing the behavior of the stable isotopic composition (??13C) of buried soils. After examining the relationship between the ??13C of topsoil organic matter and July temperature from 61 native prairies within a latitudinal range of 46??-38??N, we applied the resulting regression equation to 64 published ??13C values from buried soils of the same region to construct a temperature curve for the past 12 k.y. Estimated temperatures from 12 to 10 ka (1 k.y. = 1000 14C yr B.P.) fluctuated with a periodicity of ???1 k.y. with two cool excursions between -4.5 and -3.5 ??C and two warmer excursions between -1 and 0 ??C, relative to modern. Early Holocene temperatures from ca. 10-7.5 ka were -1.0 to -2.0 ??C before rising to +1.0 ??C in the middle Holocene between 6.0 and 4.5 ka. After a cool interlude from 4.2 to 2.6 ka, when temperatures dropped to slightly below modern, another warm interval ensued from 2.6 to 1 ka as temperatures increased to ???+0.5 ??C. A final decline in temperature to below modern occurred beginning ca. 0.5 ka. Cooler than present temperatures in the Great Plains indicate telecommunications with cool-water episodes in the Gulf of Mexico and North Atlantic potentially governed by a combination of glacial meltwater pulses and low solar irradiance. ?? 2007 Geological Society of America.

Nordt, L.; Von Fischer, J.; Tieszen, L.

2007-01-01

48

Preferential Flow Paths Allow Deposition of Mobile Organic Carbon Deep into Soil B Horizons  

NASA Astrophysics Data System (ADS)

Most of our understanding of soil carbon (C) dynamics derives from the top 10 to 20 cm, although globally the majority of the bulk soil C pool is found below those depths. Mineral associated C in deep soil is more stable than that held in surface horizons, and its long-term persistence may contribute to sequestration of anthropogenic C. Carbon can enter deep soil horizons in multiple ways: through biologically-mediated or abiotic physical mixing, illuviation, root inputs, or through a physical disturbance that would cause the burial of an originally shallow organic horizon. In this study, we investigated the role of dissolved organic matter (DOM) in the transport and stabilization of soil C in tropical rainforest volcanic soils, where high rainfall, a highly productive forest, and dominance of highly reactive, non-crystalline minerals contribute to large soil C stocks at depth with long mean residence times. DOM plays an important role in many biological and chemical processes in soils, including nutrient transfer within and across ecosystems. Carbon storage in these soils is linked to movement of both DOC and particulate organic C along infiltration pathways. Climate and soil mineralogical properties create the right conditions for C to be pumped from the organic horizons where microbial activity is highest, to deep mineral horizons, where the potential for stabilization is greatest. High rainfall preserves hydrated short-range order minerals that are subject to strong shrinkage during occasional drought periods. The resulting cracks in subsurface B horizons become pathways for DOM complexed with Fe and Al moving in soil solution during subsequent wet periods. Preferential flow of these organically rich solutes and/or colloids moves C to depth where C, Fe and Al are preferentially deposited on near-vertical crack surfaces and along near-horizonal flow surfaces at horizon boundaries. Long-term deposition forms discontinuous Fe- and OM-cemented lamella that serve to reinforce preferential flow paths. SOM in the deepest mineral horizons has C:N ratios similar to that of the forest floor which is dominated by recent litter inputs, suggesting an accumulation of plant-derived material that has undergone little microbial processing. SOM accumulating at depth differs chemically from decomposing roots as determined by 13C-NMR spectrometry, and shows strong contributions of organic acids, pointing to a likely DOM source. NMR spectra and radiocarbon concentrations of SOM at depth also match material in the surface humic mineral horizons (Bh), where the network of cracks and channels are first observable. Microbial biomass is significantly lower in the deepest mineral horizons but the differences with soil depth disappear when corrected for total soil C. Radiocarbon concentrations of bulk soils and of respired CO2 from incubated mineral horizons at 50 cm show that SOM at depth is a mixture of modern and old C, providing further evidence for the downward movement of significant amounts of fresh C from the surface horizons.

Marin-Spiotta, E.; Chadwick, O.; Kramer, M. G.

2009-12-01

49

Micromorphology of diagnostic horizons in aridic soils (complementary to the new classification system of soils of Russia)  

NASA Astrophysics Data System (ADS)

The micromorphological data on aridic soils are far from numerous; therefore, the information presented here contributes to the development of pedogenetic ideas and characterization of diagnostic horizons and genetic properties in substantive-genetic classification systems. The diversity, functioning, and resilience of aridic soils are basically determined by the properties of their topsoils, which are regarded as recent dynamic formations as opposed to subsoils that formed under a different paleoclimatic environment; topsoil properties are more important for soil classification. Each of the two upper horizons in the new system of soil classification (the light-humus and xero-humus) has the same micromorphological features in different soils; however, in a sequence of soils, some individual micromorphological properties were revealed that indicate increasing aridity. The micromorphological properties of topsoils make it possible to identify the mechanisms of certain phenomena: aeolian deposition, structural rearrangement, the dynamics of secondary carbonates, and cryptosolonetzic manifestations.

Lebedeva-Verba, M. P.; Gerasimova, M. I.

2009-12-01

50

Thaw Characteristics of Soil around Buried Pipeline in Permafrost Regions Based on Numerical Simulation of Temperature Fields  

NASA Astrophysics Data System (ADS)

The freezing-thawing processes of the soil around the buried oil and gas pipelines in permafrost regions due to the effect of the pipe and atmospheric environment may bring about dangers to the pipelines as frost heave and thaw settlement occur and go on, and then the buried pipes may face huge challenges for safe operation. To analyze the thermal effect of the buried pipe on the surrounding soil, a two-dimensional computational model of the soil temperature fields was established based on the process of the heat transfer with phase change in the soil. The temperature fields and the thaw characteristics of the soil around the operating pipeline in permafrost regions were studied using numerical methods via the software FLUENT in this paper. The developments of the maximum thawed cylinders and corresponding thaw depths under the pipeline within operation life cycle were predicted and analyzed for various medium temperatures, water contents of soils, insulation layer thicknesses and imposed boundary conditions by climatic warming. In addition, the maximum thaw settlement of the soil under the pipeline in 5 typical permafrost areas along the Russia — China oil pipeline (the section in China) within operation life cycle was calculated. The medium temperatures were assumed to be constant and sinusoidal. The results indicated that the maximum thaw depths and thawed cylinders around the pipeline in permafrost regions enlarged with time elapse and the decrease in water content of the soils under the same boundary conditions. The maximum thaw depths and thawed cylinders increased with the increase of medium temperatures after the same operation time. The insulation layer weakened heat exchange between the pipeline and the surrounding soils and thus reduced the development of the thawed cylinders effectively during the early operation period. This research may provide an effective method for engineering application, and the results may provide references for predicting the thaw settlement of the soil and pipeline in permafrost regions.

Fu, Zaiguo; Yu, Bo; Zhu, Jie; Li, Wang

51

Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons.  

PubMed

Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations. PMID:25750650

Barry, Karen M; Janos, David P; Nichols, Scott; Bowman, David M J S

2015-01-01

52

Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons  

PubMed Central

Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations. PMID:25750650

Barry, Karen M.; Janos, David P.; Nichols, Scott; Bowman, David M. J. S.

2015-01-01

53

2.5 SOIL WATER POTENTIAL ESTIMATES Soil moisture retention curves were evaluated for representative A, AE, and EB horizon soils  

E-print Network

ESTIMATES Soil moisture retention curves were evaluated for representative A, AE, and EB horizon soils, additional litter and soil temperature measurements were conducted periodically from 1994 through 1996 to determine if the TDE infrastructure had a microclimatic effect that differed with the extent of leaf

54

Effects of ecological succession on surface mineral horizons in Japanese volcanic ash soil  

Microsoft Academic Search

Japanese volcanic ash soils have very thick and dark-colored A horizons with large amounts of black humic acids which are characterized by their extremely high aromatic structure and stabilities such as black carbon. Nevertheless, the disappearance of the melanic epipedon with a decreasing aromatic C and increasing alkyl C proportion of humic acids was observed in ecological succession for only

Yasuo Iimura; Mari Fujimoto; Mitsuru Hirota; Kenji Tamura; Teruo Higashi; Koyo Yonebayashi; Nobuhide Fujitake

2010-01-01

55

Zn Speciation in the Organic Horizon of a Contaminated Soil by  

E-print Network

Zn Speciation in the Organic Horizon of a Contaminated Soil by Micro-X-ray Fluorescence, Micro. Such an organic topsoil, located downwind of an active zinc smelter and extremely rich in Zn (2%, dry weight), was investigated by X-ray diffraction, synchrotron-based X-ray microfluorescence, and powder- and micro-extended X

56

Psychrotolerant actinomycetes of plants and organic horizons in tundra and taiga soils  

NASA Astrophysics Data System (ADS)

It has been revealed that in organic horizons and plants of the tundra and taiga ecosystems under low temperatures, actinomycetal complexes form. The population density of psychrotolerant actinomycetes in organic horizons and plants reaches tens and hundreds of thousands CFU/g of substrate or soil, and decreases in the sequence litters > plants > soils > undecomposed plant remains > moss growths. The mycelium length of psychrotolerant actinomycetes reaches 220 m/g of substrate. Application of the FISH method has demonstrated that metabolically active psychrotolerant bacteria of the phylum Actinobacteria constitute 30% of all metabolically active psychrotolerant representatives of the Bacterià domain of the prokaryotic microbial community of soils and plants. Psychrotolerant actinomycetes in tundra and taiga ecosystems possess antimicrobial properties.

Dubrova, M. S.; Zenova, G. M.; Yakushev, A. V.; Manucharova, N. A.; Makarova, E. P.; Zvyagintsev, D. G.; Chernov, I. Yu.

2013-08-01

57

RECONSTRUCTING CLIMATE ON THE GREAT PLAINS FROM BURIED SOILS: A QUANTITATIVE APPROACH  

E-print Network

The Great Plains, U.S.A. lack quantitative paleoclimatic data for the late Quaternary largely because two common sources of paleoclimatic data, tree ring and pollen records, are rare in the region. Sequences of buried ...

Zung, Ashley B.

2013-05-31

58

Functional assays and metagenomic analyses reveals differences between the microbial communities inhabiting the soil horizons of a Norway spruce plantation.  

PubMed

In temperate ecosystems, acidic forest soils are among the most nutrient-poor terrestrial environments. In this context, the long-term differentiation of the forest soils into horizons may impact the assembly and the functions of the soil microbial communities. To gain a more comprehensive understanding of the ecology and functional potentials of these microbial communities, a suite of analyses including comparative metagenomics was applied on independent soil samples from a spruce plantation (Breuil-Chenue, France). The objectives were to assess whether the decreasing nutrient bioavailability and pH variations that naturally occurs between the organic and mineral horizons affects the soil microbial functional biodiversity. The 14 Gbp of pyrosequencing and Illumina sequences generated in this study revealed complex microbial communities dominated by bacteria. Detailed analyses showed that the organic soil horizon was significantly enriched in sequences related to Bacteria, Chordata, Arthropoda and Ascomycota. On the contrary the mineral horizon was significantly enriched in sequences related to Archaea. Our analyses also highlighted that the microbial communities inhabiting the two soil horizons differed significantly in their functional potentials according to functional assays and MG-RAST analyses, suggesting a functional specialisation of these microbial communities. Consistent with this specialisation, our shotgun metagenomic approach revealed a significant increase in the relative abundance of sequences related glycoside hydrolases in the organic horizon compared to the mineral horizon that was significantly enriched in glycoside transferases. This functional stratification according to the soil horizon was also confirmed by a significant correlation between the functional assays performed in this study and the functional metagenomic analyses. Together, our results suggest that the soil stratification and particularly the soil resource availability impact the functional diversity and to a lesser extent the taxonomic diversity of the bacterial communities. PMID:23418476

Uroz, Stéphane; Ioannidis, Panos; Lengelle, Juliette; Cébron, Aurélie; Morin, Emmanuelle; Buée, Marc; Martin, Francis

2013-01-01

59

The origin of lead in the organic horizon of tundra soils: atmospheric deposition, plant translocation from the mineral soil or soil mineral mixing?  

PubMed

Knowledge of the anthropogenic contribution to lead (Pb) concentrations in surface soils in high latitude ecosystems is central to our understanding of the extent of atmospheric Pb contamination. In this study, we reconstructed fallout of Pb at a remote sub-arctic region by using two ombrotrophic peat cores and assessed the extent to which this airborne Pb is able to explain the isotopic composition ((206)Pb/(207)Pb ratio) in the O-horizon of tundra soils. In the peat cores, long-range atmospheric fallout appeared to be the main source of Pb as indicated by temporal trends that followed the known European pollution history, i.e. accelerated fallout at the onset of industrialization and peak fallout around the 1960s-70s. The Pb isotopic composition of the O-horizon of podzolic tundra soil ((206)Pb/(207)Pb=1.170 ± 0.002; mean ± SD) overlapped with that of the peat ((206)Pb/(207)Pb=1.16 ± 0.01) representing a proxy for atmospheric aerosols, but was clearly different from that of the parent soil material ((206)Pb/(207)Pb=1.22-1.30). This finding indicated that long-range fallout of atmospheric Pb is the main driver of Pb accumulation in podzolic tundra soil. In O-horizons of tundra soil weakly affected by cryoturbation (cryosols) however, the input of Pb from the underlying mineral soil increased as indicated by (206)Pb/(207)Pb ratios of up to 1.20, a value closer to that of local soil minerals. Nevertheless, atmospheric Pb appeared to be the dominant source in this soil compartment. We conclude that Pb concentrations in the O-horizon of studied tundra soils - despite being much lower than in boreal soils and representative for one of the least exposed sites to atmospheric Pb contaminants in Europe - are mainly controlled by atmospheric inputs from distant anthropogenic sources. PMID:21820157

Klaminder, Jonatan; Farmer, John G; MacKenzie, Angus B

2011-09-15

60

A new compilation of depth to calcic horizons in soils for interpreting former rainfall from paleosols  

SciTech Connect

Many studies since the seminal work of Hans Jenny in 1941 have demonstrated that the depth of the calcic horizon in soils can be related to mean annual rainfall during their development. Depth to calcic horizon is not the same as depth of leaching of carbonate, which increases with time, not rainfall. A new compilation of 381 soils of known rainfall from all continents as well as New Zealand and Greenland, including only moderately developed soils on sedimentary parent materials, gave a relationship between depth to calcic horizon (D in cm) and precipitation (P in mm) of D = -40.49-0.0852P-0.002455P[sup 2] with a correlation coefficient (r) of 0.78 and standard error ([sigma]) of [+-]33 cm. For interpreting paleosols the converse relationships is more useful (P = 139.6--6.388D--0.01303D[sup 2], with r = 0.79 and [sigma] = [+-]141 mm). Also worth considering for the interpretation of paleosols are the carbon dioxide composition of the atmosphere at the time they formed, the degree to which they have been eroded before burial, and the amount of compaction during burial. These problems are illustrated with the example of Eocene and Oligocene paleosols of Badlands National Park, South Dakota, which shows stepwise drying of paleoclimate during mid-Tertiary time.

Retallack, G.J. (Univ. of Oregon, Eugene, OR (United States). Dept. of Geological Sciences)

1992-01-01

61

Study of the acid-base properties of mineral soil horizons using pK spectroscopy  

NASA Astrophysics Data System (ADS)

The presence of groups 4 and 5 participating in acid-base equilibria was revealed in samples from mineral horizons of the gley-podzolic soil of the Komi Republic using pK spectroscopy (the mathematical processing of potentiometric titration curves for plotting the distribution of acid groups according to their pK values). The specific quantity of acid-base sites in soil samples was calculated. The contribution of organic and mineral soil components to the groups of acid-base sites was estimated. The pK values of groups determining the potential, exchangeable, and unexchangeable acidities were found. The heterogeneity of acid components determining different types of soil acidity was revealed.

Shamrikova, E. V.; Vanchikova, E. V.; Ryazanov, M. A.

2007-11-01

62

Temporal Changes in the Ectomycorrhizal Community in Two Soil Horizons of a Temperate Oak Forest? †  

PubMed Central

The species structure of an ectomycorrhizal (ECM) community was assessed monthly for 15 months in the two horizons (A1 and A2) of an oak temperate forest in northeastern France. Ectomycorrhizal species were identified each month by internal transcribed spacer sequencing. Seventy-five fungal symbionts were identified. The community was dominated by Tomentellaceae, Russulaceae, Cortinariaceae, and Boletales. Four species are abundant in the study site: Lactarius quietus, Tomentella sublilacina, Cenococcum geophilum, and Russula sp1. The relative abundance of each species varied depending on the soil horizon and over time. Some species, such as L. quietus, were present in the A1 and A2 horizons. C. geophilum was located particularly in the A2 horizon, whereas T. sublilacina was more abundant in A1. Some species, such as Clavulina sp., were detected in winter, while T. sublilacina and L. quietus were present all year long. Our results support the hypothesis that a rapid turnover of species composition of the ECM community occurs over the course of a month. The spatial and temporal unequal distribution of ECM species could be explained by their ecological preferences, driven by such factors as root longevity, competition for resources, and resistance to environmental variability. PMID:18658284

Courty, Pierre-Emmanuel; Franc, Alain; Pierrat, Jean-Claude; Garbaye, Jean

2008-01-01

63

Buried pipe design  

Microsoft Academic Search

This book covers basic information on proper, cost-effective design of buried-pipe systems for underground fluid transportation. Examines various pipe products available. Discusses soil engineering and piping mechanics. Specific topics include pipe-wall stresses and strains; design bases; rigid- and flexible-pipe analysis; soil pressure; and longitudinal, wheel, expansive-soil, and frost loading.

Mosler

1990-01-01

64

Quantitative assessment of the piping erosion susceptibility of loess-derived soil horizons using the pinhole test  

NASA Astrophysics Data System (ADS)

The pinhole test is an empirical test based on the qualitative evaluation of the dispersivity (colloidal erodibility) of compacted fined-grained soils. This paper evaluates the pinhole test device for the quantitative assessment of the susceptibility of soil horizons to piping, assesses the effects of hydraulic head, water quality, antecedent soil moisture content and soil disturbance on the hydrological and erosion response during pipeflow, and formulates recommendations for the application of the pinhole test to study piping erosion processes. In total, 255 pinhole test experiments were conducted. The results obtained from disturbed soil samples (A p horizon) indicate: (i) a significant positive linear increase in pipeflow discharge ( Qw) and sediment discharge ( Qs) with increasing hydraulic head, (ii) no relationship between Qw and antecedent soil moisture content ( ASM), but significant and negative relationship between Qs and ASM, and (iii) significantly higher Qs for distilled water than for tap water. The use of disturbed soil samples resulted in significantly more rapid flow responses and lower sediment discharges than for undisturbed soil samples. The pinhole test experiments performed on different loess-derived soil horizons show that the plowed topsoil (A p) and the underlying clay-enriched horizon (B t) are at least two times less susceptible to piping than the decalcified (C 1) and the calcareous horizons (C 2). This confirms field observations indicating that loess-derived soil horizons are very susceptible for piping erosion, especially when the C horizon crops out. This study demonstrates that the pinhole test is suitable for assessing the susceptibility of soil horizons to piping in a quantitative way (i.e. Qw, Qs, the time to outflow and the cross-section of the pipe after the test). We recommend the use of: (i) two different hydraulic heads (i.e. 180 and 1020 mm), (ii) distilled water, (iii) contrasting antecedent soil moisture contents of the soil samples to be tested, and (iv) different soil sampling methods to investigate the effect of soil disturbance, and particularly to obtain a better understanding of the sediment response during pipeflow.

Nadal-Romero, E.; Verachtert, E.; Maes, R.; Poesen, J.

2011-12-01

65

Macro- and micromorphological features of genetic horizons in a solonetzic soil complex at the Dzhanybek Research Station  

NASA Astrophysics Data System (ADS)

The comparative analysis of macro- and microfabrics of soil horizons in a trench crossing a solonetzic soil complex on a virgin plot has shown incomplete correspondence between the macro- and micromorphological features. Solonetzic and solodic horizons and features are differently manifested in different types of soils. The soils of the complex are subjected to continuous transformation dictated by the general trend of the landscape evolution in the Caspian Lowland and by the local changes related to the activity of burrowing animals and fluctuations in the groundwater level. The current trends of evolutionary changes are reflected in the soil microfabrics and salt pedofeatures, whereas more ancient processes are recorded in the properties of the clayey plasma. In the soil of the microlow, the most complete correspondence between the macro- and micromorphological features is observed. At the microlevel, the horizons of this soil resemble the humus-accumulative and metamorphic horizons of dark-colored chernozem-like soils of vast mesodepressions. A variant of the soil evolution within the solonetzic complex is discussed.

Lebedeva-Verba, M. P.; Gerasimova, M. I.

2009-03-01

66

Buried soils in a perched dunefield as indicators of late holecene lake-level change in the Lake Superior basin  

USGS Publications Warehouse

A stratigraphic analysis of buried soils within the Grand Sable Dunes, a dune field perched 90 m above the southern shore of Lake Superior, reveals a history of eolian activity apparently linked with lake-level fluctuations over the last 5500 yr. A relative rise in the water plane of the Nipissing Great Lakes initially destabilized the lakeward bluff face of the Grand Sable plateau between 5400 and 4600 14C yr B.P. This led to the burial of the Sable Creek soil by eolian sediments derived from the bluff face. Subsequent episodes of eolian activity appear to be tied to similar destabilizing events; high lake levels may have initiated at least four and perhaps eleven episodes of dune building as expressed by soil burials within the dunes. Intervening low lake levels probably correlate with soil profile development, which varies from the well-developed Sable Creek Spodosol catena to thin organic layers containing in-place stumps and tree trunks. Paleoecological reconstructions available for the area do not imply enough climatic change to account for the episodic dune activity. Burial of soils by fine-fraction sediments links dune-building episodes with destabilization of the lower lake-facing bluff, which is rich in fines.

Anderton, John B.; Loope, Walter L.

1995-01-01

67

The role of organic matter in controlling aluminum solubility in acidic mineral soil horizons  

NASA Astrophysics Data System (ADS)

Despite the ecological importance of potentially phytotoxic Al, its solubility control in acidic mineral soils remains unresolved. We examined the solubility of Al in mineral horizons of two acidic forest soils (Inceptisol and Spodosol) in southern Sweden using a series of batch experiments. Dissolution of Al was found to consist of a rapid solubilization of reactive solid phase Al, which quickly reached an equilibrium state, superimposed on a slow dissolution of less reactive Al-containing phases (e.g., primary Al-silicates). Titration experiments in the pH range 3.2-4.7 using an equilibration time of 5 days showed that at pH < 4.1, all suspensions were undersaturated with respect to gibbsite (Al(OH) 3; log ?K SO = 8.85 at 8° C) . Under such conditions, the Al solubility could be explained qualitatively by equilibrium complexation reactions with soil organic matter. Quantitatively, our results could be reproduced reasonably well using the mechanistic model WHAM, which describes the binding of Al by humic substances in organic soils. This suggests that the pool of organically bound soil Al controls the Al solubility in suspensions of strongly acidic soils. Due to the kinetically constrained release of Al from primary and secondary minerals, the amount of organically bound Al, and therefore the Al solubility in the suspensions, gradually increases with time. Consequently, a quantitative evaluation of Al solubility data from long-term batch experiments should consider both equilibrium and kinetic processes.

Berggren, Dan; Mulder, Jan

1995-10-01

68

Original article The influence of soil moisture on losses of buried seeds to fungi  

E-print Network

striata, and Poa pratensis) to soil fungi differed among meadows differing in soil moisture. We also and Poa in dry meadows, but fungicide partly counteracted these negative effects, suggesting that adding

69

A Test Study to Display Buried Anti-Tank Landmines with GPR and Research Soil Characteristics with CRS  

NASA Astrophysics Data System (ADS)

An anti-tank mine (AT mine) is a type of land mine designed to damage or destroy vehicles including tanks and armored fighting vehicles. Anti-tank mines typically have a much larger explosive charge, and a fuze designed only to be triggered by vehicles or, in some cases, tampering with the mine. There are a lot of AT mine types. In our test study, MK4 and MK5 AT mine types has been used. The Mk 5 was a cylindrical metal cased U.K. anti-tank blast mine that entered service in 1943, during the Second World War. General Specifications of them are 203 mm diameter, 127 mm height, 4.4-5.7 kg weight, 2.05-3.75 kg of TNT explosive content and 350 lbs operating pressure respectively. The aims of the test study were to image anti-tank landmine with GPR method and to analyse the soil characteristics before the mines made explode and after made be exploded and determine changing of the soil characteristics. We realized data measurement on the real 6 unexploded anti-tank landmine buried approximately 15 cm in depth. The mines spaced 3 m were buried in two lines. Space between lines was 1.5 m. We gathered data on the profiles, approximately 7 m, with a Ramac CUII system and 800 MHz shielded antenna. We collected soil samples on the mines, near and around the mines, on the area in village. We collected soil samples before exploding and after exploding mines. We imaged anti-tank landmines on the depth slices of the GPR data and in their interactive transparent 3D subsets successfully. We used polarized microscope and confocal Raman spectroscopy (CRS) to identify soil characteristic before and after exploitation. The results presented that GPR method and its 3D imaging were successful to determine AT mines, and there was no important changing on mineralogical and petrographical characterization of the soil before and after exploding processing. This project has been supported by Ankara University under grant no 11B6055002. The study is a contribution to the EU funded COST action TU1208, "Civil Engineering Applications of Ground penetrating Radar".

Kadioglu, Selma; Kagan Kadioglu, Yusuf

2014-05-01

70

Comparison of buried soil sensors, surface chambers and above ground measurements of carbon dioxide fluxes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil carbon dioxide (CO2) flux is an important component of the terrestrial carbon cycle. Accurate measurements of soil CO2 flux aids determinations of carbon budgets. In this study, we investigated soil CO2 fluxes with time and depth and above ground CO2 fluxes in a bare field. CO2 concentrations w...

71

Persistence of 137Cs in the litter layers of forest soil horizons of Mount IDA/Kazdagi, Turkey.  

PubMed

In 2010-2012, an extensive study was performed in forest sites of Mount IDA (Kazdagi)/Edremit 26 years after the Chernobyl accident. The (137)Cs activity concentrations were determined by gamma-ray spectrometry in the forest soil layers (OL, OF + OH and A horizons) separately. Based on 341 surface soil samples and 118 soil profiles, activity concentrations of (137)Cs in OL horizons varied between 0.25 ± 0.14 and 70 ± 1 Bq kg(-1), while the ranges of (137)Cs activity concentrations in OF + OH and A horizons were 13 ± 1-555 ± 3 Bq kg(-1) and 2 ± 1-253 ± 2 Bq kg(-1), respectively. Cesium-137 deposition in the study area was estimated to be in the range of 1-39 kBq m(-2) and a linear relationship between the deposition of (137)Cs and the altitude was observed. The distributions of (137)Cs activities in OL, OF + OH and A horizons throughout the region were mapped in detail. The highest (137)Cs activities were found in OF + OH horizons, with markedly lower (137)Cs activity in mineral horizons of soil profiles. It is observed that (137)Cs content of humus layer increases with the thickness of the humus layer for coniferous forest sites. The (137)Cs activity concentrations were higher than the recommended screening limits (150 Bq kg(-1)) at some of the investigated areas. The current activity concentration of top soil layers indicates that over many years since the initial deposition, (137)Cs activity is keeping still high in the organic horizons. PMID:25464048

Karadeniz, Özlem; Karakurt, Hidayet; Çak?r, Rukiye; Çoban, Fatih; Büyükok, Emir; Akal, Cüneyt

2015-01-01

72

The formation of frangipane horizons and their influence on physical-chemical properties of soils from glass houses  

NASA Astrophysics Data System (ADS)

The pedological, mineralogical and geochemical studies performed by as on soils (s.s hortic antrosols) from Iasi (Copou glass house), Barlad and Bacau glass houses have show that, in most of cases, the profile of hortic antrosols have the following compositions: Aho-AC-C or Ck, and Aho-B/C or Ck, respectively. In function of parental material nature and specific exploitation technologies, can appear the diagnostic horizons of association (hiposalic-sc, hiponatric-ac etc.) and / or of transition (A/B, A/C, C/A, A+C, ABk etc.). Specific for soils from glass houses are intense modifications of soil profile, large variability of mineralogy and chemistry, salinization processes (by progressive accumulation of soluble salts) at superior horizons level and formation, at 50 cm depth, of a compact and impermeable horizon (frangipane horizon). From chemical point of view, the hortic antrosols are generally characterized by high values of saturation in bases, of accessible phosphorus and of ratio between humic and fulvic acids (organic matter is dominant in intense humified fraction). Regarding the formation conditions, the mineralogy and geochemistry of frangipane horizons, in this moment, in literature are not too many data. In case of studied soils, the frangipane horizons appear in specific forms, where their structure, morphology and chemistry varied in large limits. In hortic antrosols where are formed, the frangipane horizons determined a sever pedogeochemical segregation. Thus, the horizons situated above to the frangipane horizon evolutes in weak oxidant conditions, weak acid-neutral pH (5.87 - 6.95), high salinity and humidity, intense biological activity; while the horizons situated below to the frangipane horizon evolutes in weak reduction conditions, neutral - weak alkaline pH (7.61 - 8.04), reduced salinity and humidity, weak biological activity. This determined an important differentiation of micro-elements and organic compounds dynamic, evidenced by the reduction of the accessibility of these for cultivated vegetables, and have important consequences on the productivity and on the quality of obtained products. Under these conditions, in the same time with the formation of frangipane horizons, the fast degradation of physical-mechanical and chemical properties of antrosols occurs. The conditions for the frangipane horizons formation are not yet elucidated. Ours experimental results indicate that the formation of frangipane horizons in soils from glass houses is first determined by the intensive technologies used for vegetables cultivation, by the application of a supra-dimensional irrigation system, the maintaining of high and relatively constants humidity state and temperatures (in comparison with un-protected soils). The nature of parental material has also, an important influence on the physical-chemical and mineralogical properties of frangipane horizons and these control the formation and spatial extension rates of these horizons. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07).

Filipov, F.; Bulgariu, D.; Avarvarei, I.

2009-04-01

73

Anion retention in soil: Possible application to reduce migration of buried technetium and iodine  

SciTech Connect

This report summarizes a literature review of our present knowledge of the anion exchange properties of a number of soils and minerals, which may potentially be used as anion exchangers to retard migration of such anions as iodide (I{sup {minus}}), iodate (IO{sub 3}{sup {minus}}) and pertechnetate (TcO{sub 4}{sup {minus}}) away from disposal site. The amorphous clays allophane and imogolite, are found to be among the most important soil components capable of developing appreciable amounts of positive charge for anion exchange even at about neutral pH. Decreases in the SiO{sub 2}/Al{sub 2}O{sub 3} ratio and soil pH result in an increase in soil AEC. Allophane and imogolite rich soils have an AEC ranging from 1 to 18 meq/100g at pH about 6. Highly weathered soils dominated by Fe and Al oxides and kaolinite may develop a significant amount of AEC as soil pH falls. The retention of iodine (I) and technetium ({Tc}), by soils is associated with both soil organic matter, and Fe and Al oxides, whereas sorption on layer silicate minerals in negligible. Fe and Al oxides become more important in the retention of anionic I{sup {minus}}, IO{sub 3}{sup {minus}}, and TcO{sub 4}{sup {minus}} as pH falls, since more positive charge is developed on the oxide surfaces. Although few studies, if any, have been conducted on I and {Tc} sorption by soil allophane and imogolite, it is estimated that a surface plough soil (2 million pounds soil per acre) with 5 meq/100g AEC, as is commonly found in andisols, shall retain approximately 5900 kg I and 4500 kg {Tc}. It is conceivable that an anion exchanger such as an andisol could be used to modify the near field environment of a radioactive waste disposal facility. This whole disposal system would then offer similar migration resistance to anions as is normally afforded to cations by usual and normal soils. 93 refs., 10 figs., 7 tabs.

Gu, B.; Schulz, R.K. (California Univ., Berkeley, CA (United States). Dept. of Soil Science)

1991-10-01

74

The geochemistry of soils on a catena on basalt at Khon Buri, northeast Thailand  

Microsoft Academic Search

A geochemistry study was carried out on a catenary sequence of soils formed on basalt under a tropical climate. Four soil profiles developed on crest, backslope, footslope and valley floor positions on an undulating basaltic lava corrosion plain were sampled and analyzed by optical microscopy, XRD, XRF, ICP-MS and SEM\\/EDS analytical techniques.Aluminum, Si, Fe and Ti are the major elements

Suphicha Thanachit; Anchalee Suddhiprakarn; Irb Kheoruenromne; Robert J. Gilkes

2006-01-01

75

Microbial weathering of apatite and wollastonite in a forest soil: Evidence from minerals buried in a root-free zone  

NASA Astrophysics Data System (ADS)

Mineral weathering is an important process in biogeochemical cycling because it releases nutrients from less labile pools (e.g., rocks) to the food chain. A field experiment was undertaken to determine the degree to which microbes - both fungi and bacteria - are responsible for weathering of Ca-bearing minerals. The experiment was performed at the Hubbard Brook Experimental Forest (HBEF) in the northeastern USA, where acid deposition has leached plant-available calcium from soils for decades. Trees obtain soil nutrients through root uptake as well as through mycorrhizal fungi with which they are symbiotically associated. These fungi extend their hyphae from the tree roots into the soil and exude organic acids that may enhance mineral dissolution. The two most common types of symbiotic fungal-tree associations are ectomycorrhizae, which are associated with spruce (Picea), fir (Abies), and beech (Fagus); and arbuscular mycorrhizae which are commonly associated with angiosperms, such as maples (Acer). To examine the role of fungi and bacteria in weathering of Ca- and/or P-bearing minerals, mesh bags containing sand-sized grains of quartz (as a control), quartz plus 1% wollastonite (CaSiO3), or quartz plus 1% apatite (Ca5(PO4)3F) were buried ~15 cm deep in mineral soil beneath American beech, sugar maple, and mixed spruce and balsam fir stands at the HBEF. Half of the bags were constructed of 50-?m mesh to exclude roots but allow fungal hyphae and bacteria to enter the bags; the remaining bags had 1-?m mesh to exclude fungi and roots but allow bacteria to enter. The bags were retrieved ~ 1, 2 or 4 years after burial. Microbial community composition and biomass in the mesh bags and surrounding soil were characterized and quantified using phospholipid fatty acid (PLFA) analysis. Fungal biomass in the soil and control bags did not differ significantly among stand types. In contrast, the degree of fungal colonization in apatite- and wollastonite-amended bags varied significantly, suggesting that microbial response was due to tree species, type of mycorrhizal fungi, nutrient status of the soils, and mineral composition of the mesh bags. Mineral surfaces were examined using scanning electron microscopy (SEM) to investigate the degree of mineral dissolution as a function of stand type, microbial composition, and time.

Nezat, C. A.

2011-12-01

76

Degradation behavior of biocomposites based on cassava starch buried under indoor soil conditions.  

PubMed

Degradation of cassava (tapioca) starch based composite films during indoor soil burial experiments was analyzed using five factors, three levels Box-Behnken response surface design. From the results, it was observed that, increased water sorption promotes the entry of soil microorganism and it utilizes the starch films as a source of energy for their growth. The reduction in weight and mechanical property was associated with preferential loss of matrix components of the films. The microorganisms associated with the degradation of films were quantified and identified. Scanning electron microscopy (SEM) analysis showed the formation of patterns and cracks on the surface of the materials aged in the soils. From the results, second order polynomial models were developed for the responses. The results of the study demonstrated that, the tapioca starch based composites were showed a limited lifetime in biotic environment which make them suitable for being disposed in landfills after their use. PMID:24299744

Maran, J Prakash; Sivakumar, V; Thirugnanasambandham, K; Sridhar, R

2014-01-30

77

Ectomycorrhizal-dominated boreal and tropical forests have distinct fungal communities, but analogous spatial patterns across soil horizons.  

PubMed

Fungi regulate key nutrient cycling processes in many forest ecosystems, but their diversity and distribution within and across ecosystems are poorly understood. Here, we examine the spatial distribution of fungi across a boreal and tropical ecosystem, focusing on ectomycorrhizal fungi. We analyzed fungal community composition across litter (organic horizons) and underlying soil horizons (0-20 cm) using 454 pyrosequencing and clone library sequencing. In both forests, we found significant clustering of fungal communities by site and soil horizons with analogous patterns detected by both sequencing technologies. Free-living saprotrophic fungi dominated the recently-shed leaf litter and ectomycorrhizal fungi dominated the underlying soil horizons. This vertical pattern of fungal segregation has also been found in temperate and European boreal forests, suggesting that these results apply broadly to ectomycorrhizal-dominated systems, including tropical rain forests. Since ectomycorrhizal and free-living saprotrophic fungi have different influences on soil carbon and nitrogen dynamics, information on the spatial distribution of these functional groups will improve our understanding of forest nutrient cycling. PMID:23874569

McGuire, Krista L; Allison, Steven D; Fierer, Noah; Treseder, Kathleen K

2013-01-01

78

Ectomycorrhizal-Dominated Boreal and Tropical Forests Have Distinct Fungal Communities, but Analogous Spatial Patterns across Soil Horizons  

PubMed Central

Fungi regulate key nutrient cycling processes in many forest ecosystems, but their diversity and distribution within and across ecosystems are poorly understood. Here, we examine the spatial distribution of fungi across a boreal and tropical ecosystem, focusing on ectomycorrhizal fungi. We analyzed fungal community composition across litter (organic horizons) and underlying soil horizons (0–20 cm) using 454 pyrosequencing and clone library sequencing. In both forests, we found significant clustering of fungal communities by site and soil horizons with analogous patterns detected by both sequencing technologies. Free-living saprotrophic fungi dominated the recently-shed leaf litter and ectomycorrhizal fungi dominated the underlying soil horizons. This vertical pattern of fungal segregation has also been found in temperate and European boreal forests, suggesting that these results apply broadly to ectomycorrhizal-dominated systems, including tropical rain forests. Since ectomycorrhizal and free-living saprotrophic fungi have different influences on soil carbon and nitrogen dynamics, information on the spatial distribution of these functional groups will improve our understanding of forest nutrient cycling. PMID:23874569

McGuire, Krista L.; Allison, Steven D.; Fierer, Noah; Treseder, Kathleen K.

2013-01-01

79

Why high seed densities within buried mesh bags may overestimate depletion rates of soil seed banks  

Microsoft Academic Search

1. Estimates of seed bank depletion rates are essential for modelling and management of plant populations. The seed bag burial method is often used to measure seed mortality in the soil. However, the density of seeds within seed bags is higher than densities in natural seed banks, which may elevate levels of pathogens and influence seed mortality. The aim of

Mourik van T. A; T. J. Stomph; A. J. Murdoch

2005-01-01

80

Effect of hydrothermally carbonized char application on trace gas emissions from two sandy soil horizons.  

PubMed

The application of biochar to soil is a potential tool for the long-term sequestration of C and a possible mitigation of greenhouse gas (GHG) emissions. Among the various processes available to produce biochar, hydrothermal carbonization is one technique that is suitable for moist feedstock like digestates from biogas production. The aim of this study was to investigate the stability of C and emissions of NO after the addition of (i) digested wheat ( L.) straw (digestate) and (ii) hydrothermally carbonized (HTC) char of wheat straw as well as (iii) HTC char of digested wheat straw to two soil horizons that differed in C content. The HTC chars were obtained from wheat straw and digested wheat straw that were hydrothermally carbonized at 230°C for 6 h. The digestate and HTC chars were mixed with soil and incubated in 125-mL vessels. The GHG emissions of CO and NO were measured at regular intervals. Additionally, after 108 d, N was applied in the form of NHNO equivalent to 100 kg N ha. After 500 d of incubation, the digestate had lost 34% of C, while the soil mixture with the corresponding HTC char lost 12% of C in the form of CO from the topsoil. The estimated bi-exponential half-life of the recalcitrant C was more than 50% longer for the carbonized material than for the untreated digestate. The NO emissions from both HTC chars were significantly reduced compared with untreated digestate. The reductions were up to 64% for the topsoil and 60% for the subsoil samples. These laboratory results show that HTC holds the potential to increase the C stability of fermented and carbonized biomasses and to reduce NO emissions. PMID:25603263

Dicke, Christiane; Lanza, Giacomo; Mumme, Jan; Ellerbrock, Ruth; Kern, Jürgen

2014-09-01

81

The effect of moisture content on the thermal conductivity of moss and organic soil horizons from black spruce ecosystems in interior alaska  

USGS Publications Warehouse

Organic soil horizons function as important controls on the thermal state of near-surface soil and permafrost in high-latitude ecosystems. The thermal conductivity of organic horizons is typically lower than mineral soils and is closely linked to moisture content, bulk density, and water phase. In this study, we examined the relationship between thermal conductivity and soil moisture for different moss and organic horizon types in black spruce ecosystems of interior Alaska. We sampled organic horizons from feather moss-dominated and Sphagnum-dominated stands and divided horizons into live moss and fibrous and amorphous organic matter. Thermal conductivity measurements were made across a range of moisture contents using the transient line heat source method. Our findings indicate a strong positive and linear relationship between thawed thermal conductivity (Kt) and volumetric water content. We observed similar regression parameters (?? or slope) across moss types and organic horizons types and small differences in ??0 (y intercept) across organic horizon types. Live Sphagnum spp. had a higher range of Kt than did live feather moss because of the field capacity (laboratory based) of live Sphagnum spp. In northern regions, the thermal properties of organic soil horizons play a critical role in mediating the effects of climate warming on permafrost conditions. Findings from this study could improve model parameterization of thermal properties in organic horizons and enhance our understanding of future permafrost and ecosystem dynamics. ?? 2009 by Lippincott Williams & Wilkins, Inc.

O'Donnell, J. A.; Romanovsky, V.E.; Harden, J.W.; McGuire, A.D.

2009-01-01

82

The implications of microbial and substrate limitation for the fates of carbon in different organic soil horizon types: a mechanistically based model analysis  

NASA Astrophysics Data System (ADS)

The large magnitudes of soil carbon stocks provide potentially large feedbacks to climate changes, highlighting the need to better understand and represent the environmental sensitivity of soil carbon decomposition. Most soil carbon decomposition models rely on empirical relationships omitting key biogeochemical mechanisms and their response to climate change is highly uncertain. In this study, we developed a multi-layer mechanistically based soil decomposition model framework for boreal forest ecosystems. A global sensitivity analysis was conducted to identify dominating biogeochemical processes and to highlight structural limitations. Our results indicate that substrate availability (limited by soil water diffusion and substrate quality) is likely to be a major constraint on soil decomposition in the fibrous horizon (40-60% of SOC pool size variation), while energy limited microbial activity in the amorphous horizon exerts a predominant control on soil decomposition (>70% of SOC pool size variation). Elevated temperature alleviated the energy constraint of microbial activity most notably in amorphous soils; whereas moisture only exhibited a marginal effect on dissolved substrate supply and microbial activity. Our study highlights the different decomposition properties and underlying mechanisms of soil dynamics between fibrous and amorphous soil horizons. Soil decomposition models should consider explicitly representing different boreal soil horizons and soil-microbial interactions to better characterize biogeochemical processes in boreal ecosystems. A more comprehensive representation of critical biogeochemical mechanisms of soil moisture effects may be required to improve the performance of the soil model we analyzed in this study.

He, Y.; Zhuang, Q.; Harden, J. W.; McGuire, A. D.; Fan, Z.; Liu, Y.; Wickland, K. P.

2014-02-01

83

Near-infrared spectroscopy for analysis of chemical and microbiological properties of forest soil organic horizons in a heavy-metal-polluted area  

Microsoft Academic Search

In industrial areas, heavy metals may accumulate in forest soil organic horizons, affecting soil microorganisms and causing\\u000a changes in the chemical composition of the accumulated organic matter. The objectives of this study were to test the ability\\u000a of near-infrared spectroscopy (NIRS) to detect heavy metal effects on the chemical composition of forest soil O horizons and\\u000a to test whether NIRS

Marcin Chodak; Maria Nikli?ska; Friedrich Beese

2007-01-01

84

Large loop EMI sensor for detection of deeply buried munitions in magnetic soils  

NASA Astrophysics Data System (ADS)

This paper presents an active source Electromagnetic Induction (EMI) sensor that offers extended detection ranges (> 2m) with minimal sensitivity to magnetic geology. The Ultra Deep Search (ULTRA) EMI system employs a large (20 - 40m), stationary, surface-laid transmitter loop that produces a relatively uniform magnetic field within the search region. This primary field decays slowly with depth due to the non-dipolar nature of the field within the search volume. An array of 3-axis receiver cubes measures the time derivative of secondary field decays produced by subsurface metallic objects. The large-loop transmitter combined with the vector sensing induction coil receivers produces a deep search capability that remains robust in environments containing highly magnetic soils. In this paper, we assess the general detection capabilities of the ULTRA system and present data collected over a set of standardized UXO targets. Additionally, we evaluate the potential for target feature extraction through dipole fit analysis of several data sets.

Miller, Jonathan S.; Billings, Stephen; Keranen, Joe; Schultz, Gregory; Bassani, Chet

2012-06-01

85

Wavenumber prediction and measurement of axisymmetric waves in buried fluid-filled pipes: Inclusion of shear coupling at a lubricated pipe/soil interface  

NASA Astrophysics Data System (ADS)

Acoustic methods have been widely used to detect water leaks in buried fluid-filled pipes, and these technologies also have the potential to locate buried pipes and cables. Relatively predictable for metal pipes, there is considerably more uncertainty with plastic pipes, as the wave propagation behaviour becomes highly coupled between the pipe wall, the contained fluid and surrounding medium. Based on the fully three-dimensional effect of the surrounding soil, pipe equations for n=0 axisymmetric wave motion are derived for a buried, fluid-filled pipe. The characteristics of propagation and attenuation are analysed for two n=0 waves, the s=1 wave and s=2 wave, which correspond to a predominantly fluid-borne wave and a compressional wave predominantly in the shell, respectively. At the pipe/soil interface, two extreme cases may be considered in order to investigate the effects of shear coupling: the "slip" condition representing lubricated contact; and the "no slip" condition representing compact contact. Here, the "slip" case is considered, for which, at low frequencies, analytical expressions can be derived for the two wavenumbers, corresponding to the s=1 and s=2 waves. These are both then compared with the situations in which there is no surrounding soil and in which the pipe is surrounded by fluid only, which cannot support shear. It is found that the predominant effect of shear at the pipe/soil interface is to add stiffness along with damping due to radiation. For the fluid-dominated wave, this causes the wavespeed to increase and increases the wave attenuation. For the shell-dominated wave there is little effect on the wavespeed but a marked increase in wave attenuation. Comparison with experimental measurements confirms the theoretical findings.

Muggleton, J. M.; Yan, J.

2013-03-01

86

Horizon Partitioning of Soil CO2 Sources and their Isotopic Composition (13C) in a Pinus Sylvestris Stand  

NASA Astrophysics Data System (ADS)

The overall aim of this study is to contribute to a better understanding of mechanisms behind soil CO2 efflux using carbon stable isotopes. The approach combines a soil multilayer analysis and the isotopic tool in an in situ study. The specific goal of this work is to quantify the origin and the determinism of 13CO2 and 12CO2 production processes in the different soil layers using the gradient-efflux approach. To meet this, the work includes an experimental setup and a modeling approach. The experimental set up (see also communication of Parent et al., session B008) comprised a combination of different systems, which were installed in a Scot Pine temperate forest at the Hartheim site (Southwestern Germany). Measurements include (i) half hourly vertical profiles of soil CO2 concentration (using soil CO2 probes), soil water content and temperature; (ii) half hourly soil surface CO2 effluxes (automatic chambers); (iii) half hourly isotopic composition of surface CO2 efflux and soil CO2 concentration profile and (iv) estimation of soil diffusivity through laboratory measurements conducted on soil samples taken at several depths. Using the data collected in the experimental part, we developed and used a diffusive transport model to simulate CO2 (13CO2 and 12CO2) flows inside and out of the soil based on Fick's first law. Given the horizontal homogeneity of soil physical parameters in Hartheim, we treated the soil as a structure consisting of distinctive layers of 5 cm thick and expressed the Fick's first law in a discrete formalism. The diffusion coefficient used in each layer was derived from (i) horizon specific relationships, obtained from laboratory measurements, between soil relative diffusivity and its water content and (ii) the soil water content values measured in situ. The concentration profile was obtained from in situ measurements. So, the main model inputs are the profiles of (i) CO2 (13CO2 and 12CO2) concentration, (ii) soil diffusion coefficient and (iii) soil water content. Once the diffusive fluxes deduced at each layer interface, the CO2 (13CO2 and 12CO2) production profile was calculated using the (discretized) mass balance equation in each layer. The results of the Hartheim measurement campaign will be presented. The CO2 source vertical profile and its link with the root and the Carbon organic content distribution will be showed. The dynamic of CO2 sources and their isotopic signature will be linked to climatic variables such soil temperature and soil water content. For example, we will show that the dynamics of CO2 sources was mainly related to temperature while changing of isotopic signature was more correlated to soil moisture.

Goffin, S.; Parent, F.; Plain, C.; Maier, M.; Schack-Kirchner, H.; Aubinet, M.; Longdoz, B.

2012-12-01

87

Buried Ends  

NASA Technical Reports Server (NTRS)

7 August 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a flow or landslide feature on a hillslope facing north (toward top/upper right) that is buried on both ends. Both the uphill portion of the slide (just below the center of the image) and the bottom end of the slide, or flow feature (near the upper right corner of the image), is buried. Whether this partially buried landform was formed by simple, dry mass movement (a landslide) or by flow of an ice-rich material, is unclear. The features in this image occur among the massifs located east of the Hellas basin.

Location near: 45.6oS, 248.5oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Autumn

2006-01-01

88

Autonomous real-time adaptive management of soil salinity using a receding horizon control algorithm: a pilot-scale demonstration.  

PubMed

Soil salinization is a potentially negative side effect of irrigation with reclaimed water. While optimization schemes have been applied to soil salinity control, these have typically failed to take advantage of real-time sensor feedback. This study incorporates current soil observation technologies into the optimal feedback-control scheme known as Receding Horizon Control (RHC) to enable successful autonomous control of soil salinization. RHC uses real-time sensor measurements, physically-based state prediction models, and optimization algorithms to drive field conditions to a desired environmental state by manipulating application rate or irrigation duration/frequency. A simulation model including the Richards equation coupled to energy and solute transport equations is employed as a state estimator. Vertical multi-sensor arrays installed in the soil provide initial conditions and continuous feedback to the control scheme. An optimization algorithm determines the optimal irrigation rate or frequency subject to imposed constraints protective of soil salinization. A small-scale field test demonstrates that the RHC scheme is capable of autonomously maintaining specified salt levels at a prescribed soil depth. This finding suggests that, given an adequately structured and trained simulation model, sensor networks, and optimization algorithms can be integrated using RHC to autonomously achieve water reuse and agricultural objectives while managing soil salinization. PMID:21742431

Park, Yeonjeong; Harmon, Thomas C

2011-10-01

89

The implications of microbial and substrate limitation for the fates of carbon in different organic soil horizon types of boreal forest ecosystems: a mechanistically based model analysis  

NASA Astrophysics Data System (ADS)

The large amount of soil carbon in boreal forest ecosystems has the potential to influence the climate system if released in large quantities in response to warming. Thus, there is a need to better understand and represent the environmental sensitivity of soil carbon decomposition. Most soil carbon decomposition models rely on empirical relationships omitting key biogeochemical mechanisms and their response to climate change is highly uncertain. In this study, we developed a multi-layer microbial explicit soil decomposition model framework for boreal forest ecosystems. A thorough sensitivity analysis was conducted to identify dominating biogeochemical processes and to highlight structural limitations. Our results indicate that substrate availability (limited by soil water diffusion and substrate quality) is likely to be a major constraint on soil decomposition in the fibrous horizon (40-60% of soil organic carbon (SOC) pool size variation), while energy limited microbial activity in the amorphous horizon exerts a predominant control on soil decomposition (>70% of SOC pool size variation). Elevated temperature alleviated the energy constraint of microbial activity most notably in amorphous soils, whereas moisture only exhibited a marginal effect on dissolved substrate supply and microbial activity. Our study highlights the different decomposition properties and underlying mechanisms of soil dynamics between fibrous and amorphous soil horizons. Soil decomposition models should consider explicitly representing different boreal soil horizons and soil-microbial interactions to better characterize biogeochemical processes in boreal forest ecosystems. A more comprehensive representation of critical biogeochemical mechanisms of soil moisture effects may be required to improve the performance of the soil model we analyzed in this study.

He, Y.; Zhuang, Q.; Harden, J. W.; McGuire, A. D.; Fan, Z.; Liu, Y.; Wickland, K. P.

2014-08-01

90

Preliminary Systems Design Study assessment report. [Evaluation of using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil  

SciTech Connect

The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept.

Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

1991-11-01

91

A Soil-Based Methodology for Locating Buried Early Prehistoric Cultural Deposits in Draws on the High Plains of Eastern Colorado and Western Kansas  

E-print Network

105 is not mapped as the Goshen series, the cultural materials at 14SN105 were recovered from a buried soil formed in alluvium beneath a narrow (1-3 m wide) terrace remnant that is geomorphologically very similar to the alluvial terraces at sites 14... temperature range. The average annual temperature at Goodland, KS is 10.7º C (51.3º F), and the average low and high temperatures are 2.9 º C (37.2 º F) and 18.6 º C (65.4º F), respectively (High Plains Regional Climate Center 2010). The average first...

West, Kristopher R.

2013-05-31

92

Distributions of microorganisms in Afroalpine and subalpine paleosols on Mount Kenya, East Africa: implications for radiocarbon dating of buried paleosols  

NASA Astrophysics Data System (ADS)

Microorganisms consisting of bacteria, fungi, and actinomycetes have been identified in most buried (Ab) and subsurface horizons of fourteen paleosols examined on Mount Kenya, East Africa. A comprehensive microbiological survey shows that microorganisms observed in buried paleosols could also be observed in ground soils. Microorganism counts obtained by plating on standard Difco media, produced three distinct distributions or trends with depth, in surface and buried paleosols, that provide information concerning biogeochemical contamination and its effect on radiocarbon dates. The most frequently encountered distribution, termed sequential decline, is found in paleosols with decreasing counts vs. depth. This distribution produces internally consistent and accurate radiocarbon dates. Paleosol profiles with disjunct or bimodal microflora distributions, at various depths, often yield internally inconsistent sequences of radiocarbon dated buried substrates. Preliminary results suggest that counts up to 1.5 × 10 3 g -1 soil for fungi and 3.0 × 10 4 g -1 for bacteria in buried A horizons do not appear to affect the validity of radiocarbon dates. Beyond this threshold value, contamination appears to result in erroneous dates, the difference between true age and radiocarbon age widening with increasing numbers of microorganisms.

Mahaney, W. C.

93

Abiotic factors influence microbial diversity in permanently cold soil horizons of a maritime-associated Antarctic Dry Valley.  

PubMed

The McMurdo Dry Valleys collectively comprise the most extensive ice-free region in Antarctica and are considered one of the coldest arid environments on Earth. In low-altitude maritime-associated valleys, mineral soil profiles show distinct horizontal structuring, with a surface arid zone overlying a moist and biologically active zone generated by seasonally melted permafrost. In this study, long-term microenvironmental monitoring data show that temperature and soil humidity regimes vary in the soil horizons of north- and south-facing slopes within the Miers Valley, a maritime valley in the McMurdo Dry Valleys. We found that soil bacterial communities varied from the north to the south. The microbial assemblages at the surface and shallow subsurface depths displayed higher metabolic activity and diversity compared to the permafrost soil interface. Multivariate analysis indicated that K, C, Ca and moisture influenced the distribution and structure of microbial populations. Furthermore, because of the large % RH gradient between the frozen subsurface and the soil surface we propose that water transported to the surface as water vapour is available to microbial populations, either as a result of condensation processes or by direct adsorption from the vapour phase. PMID:22428950

Stomeo, Francesca; Makhalanyane, Thulani P; Valverde, Angel; Pointing, Stephen B; Stevens, Mark I; Cary, Craig S; Tuffin, Marla I; Cowan, Don A

2012-11-01

94

Buried Bones  

NSDL National Science Digital Library

In this activity, pairs of learners will create two make-believe dig sites by burying chicken bones in plaster of Paris--a powder that hardens when wet. Then, learners try to excavate (dig out) their partner's "fossils." Learners will discover that excavating fossils requires skill, patience, and the right tools. Note: this activity requires adult supervision as working with plaster of Paris can be dangerous if not done properly.

2012-06-26

95

Preliminary systems design study assessment report. [Evaluation of using specific technologies, system concepts for treating the buried waste and surrounding contaminated soil  

SciTech Connect

The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each. This volume contains the descriptions and other relevant information of the four subsystems required for most of the ex situ processing systems. This volume covers the metal decontamination and sizing subsystem, soils processing subsystem, low-level waste subsystem, and retrieval subsystem.

Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

1992-01-01

96

Soil morphology of a debris flow chronosequence in a coniferous forest, southern California, USA  

USGS Publications Warehouse

Soils on a series of debris flow deposits, ranging from < 1 to 244??years old, were described and sampled in order to investigate the early stages of soil development. The parent material at the site is debris flow regolith, composed mainly of gneiss, the soil moisture regime is xeric, and the vegetation is mixed coniferous forest. Ages of the deposits were assessed using dendrochronology. Morphologic trends in the organic horizons included a thickening of the humus form over time, along with the development of Fm and Hr horizons. The humus forms underwent a progression from Mormodors (20??years old), to Hemimors (26-101??years old), and finally Lignomors (163??years old) and Resimors (184-244??years old). Changes in physical properties of the uppermost mineral horizons as a function of increasing age included a decrease in the volume of coarse fragments, a linear decrease in bulk density, and a darkening and reddening of the soil color. No significant soil development took place in the subsoil during the time span of this chronosequence. The soils described were classified as Typic Xerofluvents and Typic Xerorthents (Regosols and Leptosols). Buried A horizons were observed in many of the soils. Where the A horizons could be linked to dendrochronology to assess the age of the buried surface, we found that the properties of the buried A horizons do not serve as a good indicator of the age of the surface. This study suggests rapid development of the humus form profile (organic horizons and A horizon) following debris flow deposition and rapid degradation of these horizons when the debris flow surface is buried. ?? 2008 Elsevier B.V.

Turk, J.K.; Goforth, B.R.; Graham, R.C.; Kendrick, K.J.

2008-01-01

97

Laser ablation ICP-MS and traditional micromorphological techniques applied to the study of different genetic horizons in thin sections: soil genesis and trace element distribution  

NASA Astrophysics Data System (ADS)

This work focuses on an innovative methodological approach to investigate in situ chemical composition of trace and rare earth (REE) elements in discrete soil features from different soil horizons: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied to clay coatings, pedogenic matrix and skeletal parent rock fragments in thin sections, coupled with traditional pedological investigations, specially clay mineralogy and micromorphology. Analyses were performed on 80 ?m-thick sections obtained from undisturbed soil samples, which represent three reddish argillic (Bt) horizons from an Alfisol developed on late Pleistocene slope deposits and three brown organic-mineral (A) horizons from an Entisol formed on Holocene aggrading fluvial sediments in the Muravera area (southeast Sardinia, Italy). Validation of the LA-ICP-MS technique provides in situ accurate and reproducible (RSD 13-18%) analysis of low concentration trace elements in the studied soil samples (0.001-0.1 ppm). Our results showed a high reliability of this method on soil thin sections and revealed that concentrations of trace and rare earth elements in the different portions of a soil profile can be used to investigate their distribution, as a response to soil-forming processes. A general trend of increase of most trace elements from rock fragments to (both clayey and organic-rich) soil matrix, to clay coatings in argillic horizons is clearly highlighted. On this basis a prominent role of pedogenetic processes in element fractionation and distribution during weathering can be supposed. In particular, element adsorption onto reactive sites of organic matter and clay particles (and possibly Fe-oxyhydroxides) and clay illuviation appear the main pedogenetic processes able to promote element enrichment after their release from the weathering of primary minerals. As clay coatings exhibit the highest concentration of trace elements, and specifically of REEs, and represent the most mobile solid phase in the soil profile, this tool can be used as a reliable indicator of soil weathering after a preliminary assessment of illuvial clay pedofeatures. This feature is consistent with a progressively increasing time of soil development, testified by the older age of the Alfisol than the Entisol profile. Such a result is also supported by a comparison of trace element concentrations between the clay and the fine earth fractions of the bulk soil horizons performed with ICP-MS in solution, showing REE enrichment in the clays from the former soil. Moreover, trace element patterns show some discontinuous trends among soil features of different horizons, coherently with erosive and/or depositional discontinuities described in the field.

Scarciglia, Fabio; Barca, Donatella; de Rosa, Rosanna; Pulice, Iolanda; Vacca, Andrea

2010-05-01

98

Buried Craters  

NASA Technical Reports Server (NTRS)

26 December 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two circular features on the plains of northern Utopia. A common sight on the martian northern plains, these rings indicate the locations of buried impact craters.

Location near: 65.1oN, 261.2oW Image width: 2 km (1.2 mi) Illumination from: lower left Season: Northern Summer

2005-01-01

99

The implications of microbial and substrate limitation for the fates of carbon in different organic soil horizon types: a mechanistically based model analysis  

NASA Astrophysics Data System (ADS)

The large magnitudes of soil carbon stocks along with potentially large feedbacks to climate change makes the understanding of environment dependence of soil carbon decomposition a critical issue. Models of soil carbon decomposition, which mostly rely on empirical relationships that relate environmental variables to microbial metabolic rates of using soil carbon substrates, provide estimates that diverge from observations. In this study, we developed a multi-layer mechanistically based soil decomposition model framework for boreal forest ecosystems. A global sensitivity analysis was conducted to identify dominating biogeochemical processes and to highlight structural limitations was conducted. Our results indicates that substrate availability is likely to be a major constraint on soil decomposition in fibrous horizon (explains 50-60% of SOC pool size variation), while microbial activity exerts a predominant control on amorphous soils with tightly coupled interactions with soil moisture content (explains >80% of SOC pool size variation). Temperature and moisture significantly impact substrate supply and microbial activity (increased contribution by 15%). Our study highlights the different decomposition properties and underlying mechanism of soil dynamics between fibrous and amorphous soil horizons. These results suggest that while temperature and moisture are of key importance to decomposition and C fate, an explicit representation of substrate and microbial physiology in soil C dynamic models may be considered in future soil decomposition models.

He, Y.; Zhuang, Q.; Harden, J. W.; McGuire, A. D.; Fan, Z.; Liu, Y.

2013-12-01

100

Sarret G., Balesdent J., Bouziri L., Garnier J. M., Marcus M. A., Geoffroy N., Panfili F., and Manceau A. (2004) Zn speciation in the organic horizon of a contaminated soil by micro X-ray fluorescence,  

E-print Network

., and Manceau A. (2004) Zn speciation in the organic horizon of a contaminated soil by micro X-ray fluorescence speciation in the organic horizon of a contaminated soil by micro X-ray fluorescence, micro and powder EXAFS, micro and powder EXAFS spectroscopy and isotopic dilution. Environ. Sci. Technol. 38, 2792-2801. Zn

Paris-Sud XI, Université de

2004-01-01

101

SULFUR DYNAMICS IN MINERAL HORIZONS OF TWO NORTHERN HARDWOOD SOILS A COLUMN STUDY WITH 35S  

EPA Science Inventory

Sulfur dynamics of two Spodosols were ascertained using soil columns constructed from homogenized mineral soil from northern hardwood ecosystems at the Huntington Forest (HF) in the Adirondack Mountains of New York and Bear Brook Watershed in Maine (BBWM). olumns were leached for...

102

Spatial Variability and Correlation of Selected Soil Properties in the AP Horizon of the CRP Grassland  

Technology Transfer Automated Retrieval System (TEKTRAN)

Knowledge of the spatial variability of soil properties in agricultural fields is important for implementing various precision agricultural management practices. This paper examines spatial variation of selected soil physical and chemical properties and explores their spatial correlation in the A ho...

103

Electromagnetic scattering from buried objects  

SciTech Connect

Radar imaging and detection of objects buried in soil has potentially important applications in the areas of nonproliferation of weapons, environmental monitoring, hazardous-waste site location and assessment, and even archeology. In order to understand and exploit this potential, it is first necessary to understand how the soil responds to an electromagnetic wave, and how targets buried within the soil scatter the electromagnetic wave. We examine the response of the soil to a short pulse, and illustrate the roll of the complex dielectric permittivity of the soil in determining radar range resolution. This leads to a concept of an optimum frequency and bandwidth for imaging in a particular soil. We then propose a new definition for radar cross section which is consistent with the modified radar equation for use with buried targets. This radar cross section plays the same roll in the modified radar equation as the traditional radar cross section does in the free-space radar equation, and is directly comparable to it. The radar cross section of several canonical objects in lossy media is derived, and examples are given for several object/soil combinations.

Brock, B.C.; Sorensen, K.W.

1994-10-01

104

Soils  

NSDL National Science Digital Library

The purpose of the handout is to identify the three major types of soils: pedalfer, pedocal, and laterite, and to understand the soil profile. This is accomplished with brief descriptions of the soil horizons and the designation of common elements to pedalfers, pedocals, and laterite soils. The handout is concluded with a discussion of soil erosion. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Pamela Gore

1995-08-29

105

Mean residence time of O horizon carbon along a climatic gradient in Scandinavia estimated by 14 C measurements of archived soils  

Microsoft Academic Search

We used two datasets of 14C analyses of archived soil samples to study carbon turnover in O horizons from spruce dominated old-growth stands on well-drained\\u000a podzols in Scandinavia. The main data set was obtained from archived samples from the National Forest Soil Inventory in Sweden\\u000a and represents a climatic gradient in temperature. Composite samples from 1966, 1972, 1983 and 2000

Mats Fröberg; Edward Tipping; Johan Stendahl; Nicholas Clarke; Charlotte Bryant

2011-01-01

106

Instrumental neutron activation analysis to measure short-term accretion and erosion in wetlands using rare earth element soil horizon markers  

Microsoft Academic Search

Instrumental neutron activation analysis (INAA) was employed to estimate sediment accumulations (accretion) in Louisiana in a freshwater wetland habitat four years after the application of rare earth, samarium (Sm) and dysprosium (Dy), soil horizon markers. The sediment cores used to measure accretion also were used to construct a sodium (Na) profile (Na concentration vs. depth) in three locations. Additionally, in

R. M. Knaus

1991-01-01

107

Fire, temperature and nutrient responses on the C balance of arctic tundra soils from surface, mineral horizons and permafrost  

NASA Astrophysics Data System (ADS)

Models predict substantial release of carbon (C) from thawing permafrost as the climate warms. Therefore, determining how the decomposition of the organic matter stored in near surface permafrost is controlled represents a key research priority. Important questions remain regarding how readily decomposable the organic matter may be, as well as the extent to which microbial activity is limited by the low temperatures, the rate of new labile C inputs, and/or nitrogen (N) availability. Accurate model predictions require that these questions are addressed.Disturbances, including fire, which is becoming increasingly common in the tundra biome, may promote rates of permafrost thaw. In 2007, the Anaktuvuk River fire burned over 1,000 km2 of tundra on the North Slope of the Brooks Range, Alaska, USA, doubling the cumulative area burned in this region over the past 50 years. This fire enhanced active layer thickness by removing insulating plant biomass and exposing surfaces with low albedo. In this study we investigated how temperature, N and labile C additions affected rates of CO2 production over a one-year incubation of samples collected from different depths (topsoil, mineral horizons and near-surface permafrost) in burnt and unburnt sites within the Anaktuvik river catchment. The results show that respiration rates did not decline substantially during the 1-year incubation, indicating there were relatively large amounts of readily decomposable C present. However, decomposition rates per gram of C did decline with depth, especially in the burnt sites where some of the surface soil may have been lost. This indicates that the C present in the near surface permafrost may be less labile than C nearer the soil surface. In addition, respiration rates in the deeper horizons were more temperature sensitive, potentially reflecting the lower lability of the C present. Against expectations, N addition inhibited respiration in the deeper layers, especially at low temperatures. Labile C additions promoted the decomposition of soil organic matter in the deep soil samples, but not in the surface samples, with the positive priming effect being lost following N addition. This study indicates that there is the potential for considerable loss of C following the thaw of near-surface permafrost in Alaskan tussock tundra, although the C present may be slightly less readily decomposable than C stored nearer the surface. The decomposition of near-surface permafrost C was shown to be highly temperature sensitive and thus accurately simulating the soil thermal regime post-thaw is likely to be important in predicting rates of C release. In addition, root colonisation of previously frozen horizons may stimulate decomposition if labile C inputs increase. On the other hand, the inhibition of activity by N addition suggests that the positive feedback associated with reduced microbial N limitation in a warming Arctic may not be ubiquitous.

De Baets, S. L.; Lewis, R.; van de Weg, M. J.; Quine, T. A.; Shaver, G. R.; Hartley, I. P.

2013-12-01

108

A Mesophilic, Autotrophic, Ammonia-Oxidizing Archaeon of Thaumarchaeal Group I.1a Cultivated from a Deep Oligotrophic Soil Horizon  

PubMed Central

Soil nitrification plays an important role in the reduction of soil fertility and in nitrate enrichment of groundwater. Various ammonia-oxidizing archaea (AOA) are considered to be members of the pool of ammonia-oxidizing microorganisms in soil. This study reports the discovery of a chemolithoautotrophic ammonia oxidizer that belongs to a distinct clade of nonmarine thaumarchaeal group I.1a, which is widespread in terrestrial environments. The archaeal strain MY2 was cultivated from a deep oligotrophic soil horizon. The similarity of the 16S rRNA gene sequence of strain MY2 to those of other cultivated group I.1a thaumarchaeota members, i.e., Nitrosopumilus maritimus and “Candidatus Nitrosoarchaeum koreensis,” is 92.9% for both species. Extensive growth assays showed that strain MY2 is chemolithoautotrophic, mesophilic (optimum temperature, 30°C), and neutrophilic (optimum pH, 7 to 7.5). The accumulation of nitrite above 1 mM inhibited ammonia oxidation, while ammonia oxidation itself was not inhibited in the presence of up to 5 mM ammonia. The genome size of strain MY2 was 1.76 Mb, similar to those of N. maritimus and “Ca. Nitrosoarchaeum koreensis,” and the repertoire of genes required for ammonia oxidation and carbon fixation in thaumarchaeal group I.1a was conserved. A high level of representation of conserved orthologous genes for signal transduction and motility in the noncore genome might be implicated in niche adaptation by strain MY2. On the basis of phenotypic, phylogenetic, and genomic characteristics, we propose the name “Candidatus Nitrosotenuis chungbukensis” for the ammonia-oxidizing archaeal strain MY2. PMID:24705324

Jung, Man-Young; Park, Soo-Je; Kim, So-Jeong; Kim, Jong-Geol; Sinninghe Damsté, Jaap S.

2014-01-01

109

Buried Crater  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

With a location roughly equidistant between two of the largest volcanic constructs on the planet, the fate of the 50 km impact crater in this image was sealed. It has been buried to the rim by lava flows. The MOLA context image shows pronounced flow lobes surrounding the crater, a clear indication of the most recent episode of volcanism that could have contributed to its infilling. Breaches in the rim are clearly evident in the image and suggest locations through which lavas could have flowed. These openings appear to be limited to the west side of the crater. Other craters in the area are nearly obliterated by the voluminous lava flows, further demonstrating one of the means by which Mars renews its surface.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2002-01-01

110

Buried pipelines essentially involve problems of soil-structure interaction that include several complex factors such as geometry, material properties, and boundary  

E-print Network

to calculate stresses and strains of buried pipes. Using the obtained results, regression equations were developed to predict the absolute maximum stress and diameter change of buried pipes. Personal computer;2 developed by Cornell University for the Gas Research Institute to perform calculation of pipe stresses under

Al-Shayea, Naser Abdul-Rahman

111

Frost heave induced mechanics of buried pipelines  

SciTech Connect

This paper examines the problem of the flexural interaction between a long-distance buried pipeline embedded in a soil medium that experiences differential frost heave. The modeling takes into consideration the interaction at a transition zone between a frozen region and a frost-susceptible region that experiences a time-dependent growth of a frost bulb around the buried pipeline. The heave that accompanies the development of a frost bulb induces the soil-pipeline interaction process. The analysis focuses on the development of a computational scheme that addresses the three-dimensional nature of the soil-pipeline interaction problem, the creep susceptibility of the frozen region, and a prescribed time- and stress-dependent heave in an evolving frost bulb zone. The numerical results presented in the paper illustrate the influence of the heave process and the creep behavior of the frozen soil on the displacements and stresses in the buried pipeline.

Selvadurai, A.P.S. [McGill Univ., Montreal, Quebec (Canada). Dept. of Civil Engineering; Shinde, S.B. [Canada Ltd., Calgary, Alberta (Canada). Engineering Research and Technology Div.

1993-12-01

112

Substrate discrimination in burying beetles, Nicrophorus orbicollis (Coleoptera: Silphidae)  

USGS Publications Warehouse

Burying beetles Nicrophorus orbicollis (Coleoptera: Silphidae) secure and bury small vertebrate carcasses as a food resource for their offspring and themselves. Burial may take place at the point of carcass discovery or at some distance from that site. Burying beetles were tested to determine if they discriminate between different substrates when burying a carcass. Three substrates were presented simultaneously. Substrate one contained soil from typical beetle habitat; substrates two and three contained 2:1 and 5:1 ratios, respectively, of soil and a senescent prairie grass (Panicum virgatum), which added a bulk structural component to the soil. Beetles generally moved and buried the carcass within 24 hours. Results for both paired and individual trials suggest that burying beetles discriminate between substrates, preferring substrates with added bulk over those without.

Muths, Erin Louise

1991-01-01

113

Adsorption coefficients for TNT on soil and clay minerals  

NASA Astrophysics Data System (ADS)

To understand the fate and transport mechanisms of TNT from buried landmines is it essential to determine the adsorption process of TNT on soil and clay minerals. In this research, soil samples from horizons Ap and A from Jobos Series at Isabela, Puerto Rico were studied. The clay fractions were separated from the other soil components by centrifugation. Using the hydrometer method the particle size distribution for the soil horizons was obtained. Physical and chemical characterization studies such as cation exchange capacity (CEC), surface area, percent of organic matter and pH were performed for the soil and clay samples. A complete mineralogical characterization of clay fractions using X-ray diffraction analysis reveals the presence of kaolinite, goethite, hematite, gibbsite and quartz. In order to obtain adsorption coefficients (K d values) for the TNT-soil and TNT-clay interactions high performance liquid chromatography (HPLC) was used. The adsorption process for TNT-soil was described by the Langmuir model. A higher adsorption was observed in the Ap horizon. The Freundlich model described the adsorption process for TNT-clay interactions. The affinity and relative adsorption capacity of the clay for TNT were higher in the A horizon. These results suggest that adsorption by soil organic matter predominates over adsorption on clay minerals when significant soil organic matter content is present. It was found that, properties like cation exchange capacity and surface area are important factors in the adsorption of clayey soils.

Rivera, Rosángela; Pabón, Julissa; Pérez, Omarie; Muñoz, Miguel A.; Mina, Nairmen

2007-04-01

114

Quantum Horizons  

E-print Network

Treating macro-black hole as quantum states, and using Brown-York quaselocal gravitational energy definition and Heisenberg uncertainty principle, we find out the classical horizon with singularity spreads into a quantum horizon in which the space-time is non-commutative and the spread range is determined dynamically. A Quantum Field Theory (QFT) model in curved space with quantum horizon is constructed. By using it, the black hole entropy and the Hawking temperature are calculated successfully. The $\\phi-$field mode number is predicted and our quantum horizon model favors to support the Minimal Super-symmetric Standard Model.

Hua Bai; Mu-Lin Yan

2005-02-11

115

Is there a chronological record of atmospheric mercury and lead deposition preserved in the mor layer (O-horizon) of boreal forest soils?  

NASA Astrophysics Data System (ADS)

The organic horizon (the mor layer) of podzolized boreal forest soils has accumulated atmospheric fallout of mercury and lead over centuries, resulting in current concentrations close to levels where negative effects on soil biota are thought to occur. To what extent the pollution history is preserved in the stratigraphy of this horizon is not well known. In this study we asses whether the chronology of a large historic pulse of atmospheric pollution emitted from the Rönnskär smelter in northern Sweden, particularly between 1950 and 1980, is preserved within the stratigraphy of the mor layer, which is typically 5-cm thick. Vertical sub-sampling (?5 mm) of five mor profiles sampled along a 100-km pollution gradient away from the smelter are analyzed for mercury and lead concentrations, spheroidal carbonaceous particles from fossil fuel combustion (SCPs) and stable lead isotopes ( 206Pb/ 207Pb and 208Pb/ 207Pb). Their vertical distribution is compared with the temporal variations in atmospheric inputs reconstructed for the last ˜100 years from analyses of an ombrotrophic peat core and a varved lake sediment core sampled within a distance of 50 km of the smelter. The mor profiles situated ?12 km from the smelter record the pollution history of the smelter. There is a 20 to 40-times enrichment of Hg, Pb and SCP at the transition in the O-horizon from the F- to H-layer compared to the basal part and a distinct peak in the 206Pb/ 207Pb ratio (˜1.22) in the F-layer. The mor profiles situated outside the historical contamination range of the smelter (80 and 100 km away) record no obvious influence from the Rönnskär smelter, instead their vertical 206Pb/ 207Pb profiles follow the general regional pollution history in northern Sweden. We conclude that the mor layer preserves a record of atmospheric Hg, Pb and SCP inputs and due to low leaching rates this organic horizon serves as a semi-archive of atmospheric Hg and Pb pollution. We stress the need of including this property in the existing 'black-box' models predicting the fate of Hg and Pb within contaminated boreal forest soils.

Klaminder, Jonatan; Bindler, Richard; Rydberg, Johan; Renberg, Ingemar

2008-02-01

116

Nano-scale investigation of the association of microbial nitrogen residues with iron (hydr)oxides in a forest soil O-horizon  

NASA Astrophysics Data System (ADS)

Amino sugars in fungal cell walls (such as chitin) represent an important source of nitrogen (N) in many forest soil ecosystems. Despite the importance of this material in soil nitrogen cycling, comparatively little is known about abiotic and biotic controls on and the timescale of its turnover. Part of the reason for this lack of information is the inaccessibility of these materials to classic bulk extraction methods. To address this issue, we used advanced visualization tools to examine transformation pathways of chitin-rich fungal cell wall residues as they interact with microorganisms, soil organic matter and mineral surfaces. Our goal was to document initial micro-scale dynamics of the incorporation of 13C- and 15N-labeled chitin into fungi-dominated microenvironments in O-horizons of old-growth forest soils. At the end of a 3-week incubation experiment, high-resolution secondary ion mass spectrometry imaging of hyphae-associated soil microstructures revealed a preferential association of 15N with Fe-rich particles. Synchrotron-based scanning transmission X-ray spectromicroscopy (STXM/NEXAFS) of the same samples showed that thin organic coatings on these soil microstructures are enriched in aliphatic C and amide N on Fe (hydr)oxides, suggesting a concentration of microbial lipids and proteins on these surfaces. A possible explanation for the results of our micro-scale investigation of chemical and spatial patterns is that amide N from chitinous fungal cell walls was assimilated by hyphae-associated bacteria, resynthesized into proteinaceous amide N, and subsequently concentrated onto Fe (hydr)oxide surfaces. If confirmed in other soil ecosystems, such rapid association of microbial N with hydroxylated Fe oxide surfaces may have important implications for mechanistic models of microbial cycling of C and N.

Keiluweit, Marco; Bougoure, Jeremy J.; Zeglin, Lydia H.; Myrold, David D.; Weber, Peter K.; Pett-Ridge, Jennifer; Kleber, Markus; Nico, Peter S.

2012-10-01

117

Buried paleoindian-age landscapes in stream valleys of the central plains, USA  

USGS Publications Warehouse

A systematic study of late-Quaternary landscape evolution in the Central Plains documented widespread, deeply buried paleosols that represent Paleoindian-age landscapes in terrace fills of large streams (> 5th order), in alluvial fans, and in draws in areas of western Kansas with a thick loess mantle. Alluvial stratigraphic sections were investigated along a steep bio-climatic gradient extending from the moist-subhumid forest-prairie border of the east-central Plains to the dry-subhumid and semi-arid shortgrass prairie of the west-central Plains. Radiocarbon ages indicate that most large streams were characterized by slow aggradation accompanied by cumulic soil development from ca. 11,500 to 10,000??14C yr B.P. In the valleys of some large streams, such as the Ninnescah and Saline rivers, these processes continued into the early Holocene. The soil-stratigraphic record in the draws of western Kansas indicates slow aggradation punctuated by episodes of landscape stability and pedogenesis beginning as early as ca. 13,300??14C yr B.P. and spanning the Pleistocene-Holocene boundary. The development record of alluvial fans in western Kansas is similar to the record in the draws; slow aggradation was punctuated by multiple episodes of soil development between ca. 13,000 and 9000??14C yr B.P. In eastern Kansas and Nebraska, development of alluvial fans was common during the early and middle Holocene, but evidence shows fan development as early as ca. 11,300??14C yr B.P. Buried soils dating between ca. 12,600 and 9000??14C yr B.P. were documented in fans throughout the region. In stream valleys across the Central Plains, rapid alluviation after ca. 9000??14C yr B.P. resulted in deeply buried soils that may harbor Paleoindian cultural deposits. Hence, the paucity of recorded stratified Paleoindian sites in the Central Plains is probably related to poor visibility (i.e., deep burial in alluvial deposits) instead of limited human occupation in the region during the terminal Pleistocene and early Holocene. The thick, dark, cumulic A horizons of soils, representing buried Paleoindian-age landscapes, are targets for future archaeological surveys. ?? 2008 Elsevier B.V. All rights reserved.

Mandel, R.D.

2008-01-01

118

Active aluminum status in surface horizons showing continuous climosequence of volcanic ash-derived soils in Towada district, northeastern Japan  

Microsoft Academic Search

The relationship between the status of active Al of surface horizons formed in Towada-a ash and climatic conditions was studied in the Towada district, Aomori Prefecture. The mean monthly air temperature and precipitation were estimated from 1-km mesh data supplied by the Japan Meteorological Agency. Thornthwaite’s P-E (precipitation-evapotranspiration) index was used as the single climatic index combining the temperature and

Tadashi Takahashi; Sadao Shoji

1996-01-01

119

Wavy Horizons?  

E-print Network

We describe the application of a gravity wave-generating technique to certain higher dimensional black holes. We find that the induced waves generically destroy the event horizon producing parallelly propagated curvature singularities.

R. C. Myers

1998-09-14

120

HORIZON SENSING  

Microsoft Academic Search

With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section

Larry G. Stolarczyk

2003-01-01

121

Prediction of soil water retention properties after stratification by combining texture, bulk density and the type of horizon  

E-print Network

1 Prediction of soil water retention properties after stratification by combining texture, bulk water retention properties at continental and national scales because only very basic soils data (topsoil and subsoil). The performance of these class-PTFs was validated against water retained at -33

Paris-Sud XI, Université de

122

A versatile parameter for comparing the capacities of soils for sorption and retention of heavy metals dumped individually or together: results for cadmium, copper and lead in twenty soil horizons.  

PubMed

Heavy metals can be immobilized by soils and their distribution among the particulate soil components depends on the identity and amount of the metal, the properties of the soil, and other environmental factors. Cd, Cu and Pb are among the most potentially toxic heavy metals, are present--often together--in numerous polluting spills and in agrochemicals. We evaluated the individual and competitive sorption and retention of Cd, Cu and Pb on 20 soil horizons. As is usual, the isotherms constructed were so irregular, especially the retention isotherms, that it was not possible to classify and compare them in terms of the conventional isotherm shapes. Nor could they be compared using Langmuir or Freundlich parameters, since not all could be fitted with either of these equations. They were therefore characterized and compared in terms of several varieties of distribution coefficient, including a novel adimensional parameter K(r) which on the basis of correlation and principal components analyses was judged to be the most coherent and generally applicable to all experimental conditions (sorption and desorption starting from single- or multi-metal solutions). K(r) proved to be mainly determined by soil pH, effective cation exchange capacity, and Mn oxides content. PMID:18786678

Vega, F A; Covelo, E F; Andrade, M L

2008-11-15

123

Buried Craters of Utopia  

NASA Technical Reports Server (NTRS)

MGS MOC Release No. MOC2-365, 19 May 2003

Beneath the northern plains of Mars are numerous buried meteor impact craters. One of the most heavily-cratered areas, although buried, occurs in Utopia Planitia, as shown in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. The history of Mars is complex; impact craters provide a tool by which to understand some of that history. In this case, a very ancient, cratered surface was thinly-buried by younger material that is not cratered at all. This area is near 48.1oN, 228.2oW; less than 180 km (112 mi) west of the Viking 2 lander site. Sunlight illuminates the scene from the lower left.

2003-01-01

124

Stringy Horizons  

E-print Network

We argue that classical $(\\alpha')$ effects qualitatively modify the structure of Euclidean black hole horizons in string theory. While low energy modes experience the geometry familiar from general relativity, high energy ones see a rather different geometry, in which the Euclidean horizon can be penetrated by an amount that grows with the radial momentum of the probe. We discuss this in the exactly solvable SL(2,R)/U(1) black hole, where it is a manifestation of the black hole/Sine-Liouville duality.

Amit Giveon; Nissan Itzhaki; David Kutasov

2015-03-02

125

Stringy Horizons  

E-print Network

We argue that classical $(\\alpha')$ effects qualitatively modify the structure of Euclidean black hole horizons in string theory. While low energy modes experience the geometry familiar from general relativity, high energy ones see a rather different geometry, in which the Euclidean horizon can be penetrated by an amount that grows with the radial momentum of the probe. We discuss this in the exactly solvable SL(2,R)/U(1) black hole, where it is a manifestation of the black hole/Sine-Liouville duality.

Giveon, Amit; Kutasov, David

2015-01-01

126

Molecular Investigation of the Short-term Sequestration of Natural Abundance 13C -labelled Cow Dung in the Surface Horizons of a Temperate Grassland Soil  

NASA Astrophysics Data System (ADS)

An adequate understanding of the carbon (C) sequestration potential of grasslands requires that the quantity and residence times of C inputs be measured. Herbivore dung is largely comprised of plant cell wall material, a significant source of stable C in intensively grazed temperate grassland ecosystems that contributes to the soil carbon budget. Our work uses compound-specific isotope analysis to identify the pattern of input of dung-derived compounds from natural abundance 13C/-labelled cow dung into the surface horizons of a temperate grassland soil over one year. C4 dung (? 13C \\-12.6 ‰ ) from maize fed cows was applied to a temperate grassland surface (? 13C \\-29.95 ‰ ) at IGER-North Wyke (Devon, UK), and dung remains and soil cores beneath the treatments collected at ? = 7, 14, 28, 56, 112, 224 and 372 days. Bulk dung carbon present in the 0\\-1 cm and 1\\-5 cm surface horizons of a grassland soil over one year was estimated using ? 13C between C4 dung and C3 dung, after Bol {\\et al.} (2000). The major biochemical components of dung were quantified using proximate forage fibre analyses, after Goering and Van Soest (1970) and identified using `wet' chemical and GC-MS methods. Plant cell wall polysaccharides and lignin were found to account for up to 67 {%} of dung dry matter. Hydrolysed polysaccharides were prepared as alditol acetates for analyses (after Docherty {\\et al.}, 2001), and a novel application of an off-line pyrolysis method applied to measure lignin-derived phenolic compounds (after Poole & van Bergen, 2002). This paper focuses on major events in the incorporation of dung carbon, estimated using natural abundance 13C&-slash;labelling technique. This revealed a major bulk input of dung carbon after a period of significant rainfall with a consequent decline in bulk soil ? 13C values until the end of the experiment (Dungait {\\et al.}, submitted). Findings will be presented revealing contribution of plant cell wall polysaccharides and lignin to these bulk ? 13C values, and their potential for sequestration considered. References: Bol, R., Amelung, W., Friedrich, C. Ostle, N. (2000). Tracing dung-derived carbon in temperate grassland using 13C natural abundance measurements. Soil Biology and Biochemistry, 32, 1337-1343. Goering and Van Soest (1970). Forage fibre analysis (apparatus, reagents, procedures and some applications). In: USDA-ARS Agricultural Handbook, 379. U. S. Government Printing Office, Washington D.C. Docherty, G., Jones, V. and Evershed, R.P. (2001). Practical and theoretical considerations in the gas chromatography/combustion/isotope ratio mass spectrometry ? 13C analysis of small polyfunctional compounds. Rapid Communications in Mass Spectrometry, 15, 730-738. Poole, I. & van Bergen, P. F. (2002). Carbon isotope ratio analysis of organic moieties from fossil mummified wood: establishing optimum conditions for off-line pyrolysis extraction using gas chromatography/mass spectrometry. Rapid Communications in Mass Spectrometry, 16, 1976-1981. Dungait, J. A. J., Bol, R. and Evershed, R.P. (submitted). The Fate of Dung Carbon in Temperate Grassland Soil: 1. Preliminary Findings Based on Bulk Stable Carbon Isotope Determinations. Isotopes in Health and Environmental Studies

Dungait, J.; Bol, R.; Evershed, R. P.

2004-12-01

127

Horizon Calendar  

NSDL National Science Digital Library

This activity enables students to better understand the motion of the Sun and how we use it to measure time. Students create a "horizon calendar" at their school by carefully observing and recording the horizon and the Sun at sunset (or sunrise, for early risers) over a period of weeks or months. Part 1 of this activity can be done as a whole group and involves selecting and drawing a detailed map of the site. Part 2 of this activity can be done as a whole group and involves determining the direction west and drawing the horizon line. Part 3 should be done by the teacher since it involves making weekly observations at sunset (or sunrise), which is outside of regular school hours. Part 4 can be done with the whole class and involves using the data from the observations to calculate the average rate of change in sunset time and respond to discussion questions. The activity is not time-consuming, but must be conducted over a period of at least a few weeks. It is best as a semester unit, or even a project for the entire school year. Also, the best time of year to run this activity is around the equinoxes: March and September. The lesson plan includes discussion questions, background information about desert horizons, and a math extension activity in which students calculate how the time of sunrise or sunset changes from day to day. This activity is the sixth lesson in the Ancient Eyes Look to the Skies curriculum guide.

128

HORIZON SENSING  

SciTech Connect

With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section of the seam most desired. HS also enables accurate cutting of minimum height if that is the operator's objective. Often when cutting is done out-of-seam, the head-positioning function facilitates a fixed mining height to minimize dilution. With this technology, miners can still be at a remote location, yet cut only the clean coal, resulting in a much more efficient overall process. The objectives of this project were to demonstrate the feasibility of horizon sensing on mining machines and demonstrate that Horizon Sensing can allow coal to be cut cleaner and more efficiently. Stolar's primary goal was to develop the Horizon Sensor (HS) into an enabling technology for full or partial automation or ''agile mining''. This technical innovation (R&D 100 Award Winner) is quickly demonstrating improvements in productivity and miner safety at several prominent coal mines in the United States. In addition, the HS system can enable the cutting of cleaner coal. Stolar has driven the HS program on the philosophy that cutting cleaner coal means burning cleaner coal. The sensor, located inches from the cutting bits, is based upon the physics principles of a Resonant Microstrip Patch Antenna (RMPA). When it is in proximity of the rock-coal interface, the RMPA impedance varies depending on the thickness of uncut coal. The impedance is measured by the computer-controlled electronics and then sent by radio waves to the mining machine. The worker at the machine can read the data via a Graphical User Interface, displaying a color-coded image of the coal being cut, and direct the machine appropriately. The Horizon Sensor program began development in 1998 and experienced three major design phases. The final version, termed HS-3, was commissioned in 2000 with the assistance of the DOE-Mining Industry of the Future program, commercialized in 2002, and has been used 14 times in 12 different mines within the United States. The Horizon Sensor has applications in both underground and surface mining operations. This technology is primarily used in the coal industry, but is also used to mine trona and potash. All horizon sensor components have Mine Safety and Health Administration (MSHA) (United States) and IEC (International) certification. Horizon Sensing saves energy by maximizing cutting efficiency, cutting only desired material. This desired material is cleaner fuel, therefore reducing pollutants to the atmosphere when burned and burning more efficiently. Extracting only desired material increases productivity by reducing or eliminating the cleaning step after extraction. Additionally, this technology allows for deeper mining, resulting in more material gained from one location. The remote sensing tool allows workers to operate the machinery away from the hazards of cutting coal, including noise, breathing dust and gases, and coal and rock splintering and outbursts. The HS program has primarily revolved around the development of the technology. However, the end goal of the program has always been the commercialization of the technology and only within the last 2 years of the program has this goal been realized. Real-time horizon sensing on mining machines is becoming an industry tool. Detailed monitoring of system function, user experience, and mining benefits is ongoing.

Larry G. Stolarczyk

2003-03-18

129

Using X-Ray Computed Tomography Visualizations of Large Soil Columns to Study Hydropedologic Relationships at the Horizon Scale  

Technology Transfer Automated Retrieval System (TEKTRAN)

The prominent contribution of macropores to water flow and solute transport points to the need for thorough characterization of their void structure. Large soil columns need to be studied to infer topological properties of macropores. We have sampled and studied undisturbed columns (7.5 cm ID, 20 cm...

130

The Spatial and Temporal Variability of Water Content in an Organic Soil in Dartmoor National Park, UK and its Relation to Microtopography and Organic Soil Horizon Depth.  

NASA Astrophysics Data System (ADS)

The water content of organic and mineral soils is an important parameter which links energy and mass balances at the earth's surface and as such is essential to understanding the spatial and temporal organization of many biological, biogeochemical, and hydrological processes. The characterization of surface water content in space and time is also important for the continued development of regional-scale and global circulation climate models and has large implications for agriculture and land-use planning. A field study was performed in Dartmoor National Park, Devon, UK in August 2008 for the purpose of exploring the predictive power of terrain indices on wetness patterns in an organic soil. Point samples were taken over the course of three days on two hill slopes of varying aspect in order to assess the influence of incident solar radiation on water storage. Additionally, the depth of the organic layer was estimated for each sample location and topographic information collected for the creation of a digital elevation model. A weak correlation between peat water content and organic soil layer depth was demonstrated and found to be strongest in shallow soils. Microtopography was found to influence the variability of soil moisture over the sampled area with surface roughness (measured by using residual elevation from the mean transect slope). Based on repeated observations over the sampling grids temporal persistence of water content patterns is evident and can be linked to terrain indices and depth of the organic layer.

Rogers, J.; Miles, H.; Berg, A.

2009-05-01

131

Cracked Plain, Buried Craters  

NASA Technical Reports Server (NTRS)

4 September 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a cracked plain in western Utopia Planitia. The three circular crack patterns indicate the location of three buried meteor impact craters. These landforms are located near 41.9oN, 275.9oW. The image covers an area approximately 3 km (1.9 mi) across. Sunlight illuminates this scene from the lower left.

2004-01-01

132

In situ vitrification of buried waste: Containment issues and suppression systems  

SciTech Connect

Pacific Northwest Laboratory (PNL) and Idaho National Engineering Laboratory (INEL) are developing a remedial action technology for buried waste through the adaptation of the in situ vitrification (ISV) process. The ISV process is a thermal treatment process originally developed for the US Department of Energy (DOE) to stabilize soils contaminated with transuranic waste. ISV tests with buried waste forms have demonstrated that the processing of buried waste is more dynamic than the processing of soils. This paper will focus on the issue of containment of the gases released during the processing of buried waste and on engineered suppression systems to alleviate transient events associated with dynamic off-gassing from the ISV melt.

Luey, J.; Powell, T.D.

1992-03-01

133

Laser neutralization of surface and buried munitions  

NASA Astrophysics Data System (ADS)

In recent years NVESD has been investigating laser-based neutralization of buried mines and minelike targets. This paper covers the most recent efforts in this area. A field-test was conducted to demonstrate the state-of-the-art capability for standoff laser neutralization of surface and buried mines. The neutralization laser is a Ytterbium fiber laser with a nominal power output of 10 kW and a beam quality of M2 ~ 1.8 at maximum power. Test trials were conducted at a standoff range of 50 meters with a 20° angle of attack. The laser was focused to a submillimeter spot using a Cassegrain telescope with a 12.5 inch diameter primary mirror. The targets were 105 mm artillery rounds with a composition B explosive fill. Three types of overburden were studied: sand, soil, and gravel. Laser neutralization capability was demonstrated under these conditions for live rounds buried under 7 cm of dry sand, 4 cm of soil, and 2 cm of gravel.

Habersat, James D.; Schilling, Bradley W.; Alexander, Joe; Lehecka, Thomas

2012-06-01

134

DOE complex buried waste characterization assessment  

SciTech Connect

The work described in this report was conducted by Pacific Northwest Laboratory to provide information to the Buried Waste Integrated Demonstration (BWID) program. The information in this report is intended to provide a complex-wide planning base for th.e BWID to ensure that BWID activities are appropriately focused to address the range of remediation problems existing across the US Department of Energy (DOE) complex. This report contains information characterizing the 2.1 million m[sup 3] of buried and stored wastes and their associated sites at six major DOE facilities. Approximately 85% of this waste is low-level waste, with about 12% TRU or TRU mixed waste; the remaining 3% is low-level mixed waste. In addition, the report describes soil contamination sites across the complex. Some of the details that would be useful in further characterizing the buried wastes and contaminated soil sites across the DOE complex are either unavailable or difficult to locate. Several options for accessing this information and/or improving the information that is available are identified in the report. This document is a companion to Technology Needs for Remediation: Hanford and Other DOE Sites, PNL-8328 (Stapp 1993).

Kaae, P.S.; Holter, G.M.; Garrett, S.M.K.

1993-01-01

135

Bury Me Not!  

NSDL National Science Digital Library

This activity (page 2 of the PDF) is a full inquiry investigation into decomposition. Groups of learners will carefully observe and record the appearance of items, such as an apple, that can decompose, taking weights, measurements, and noting other physical markings. The items are then buried in buckets of various earth materials for at least two weeks. Learners will then dig up the objects to inspect, record observations to compare with their previous notes, and graph changes over time. Relates to linked video, DragonflyTV GPS: Bogs.

Twin Cities Public Television, Inc.

2006-01-01

136

Digital Horizons  

NSDL National Science Digital Library

Digital Horizons was established in 2007 by a consortium that includes Prairie Public Broadcasting, the State Historical Society of North Dakota, and several other organizations. The goal of their work is to provide and maintain access to "a wide range of historical and significant content related to North Dakota and Minnesota." Visitors can use the search engine here to look for items by general subject heading or collection. All told, there are over fifteen collections included in this archive, including "Korean War Propaganda Leaflets", "Dakota Lithographs and Engravings", and "North Dakota Blue Books". For those looking for a place to start, they can take advantage of the "Popular Searches" list, which includes topical headings such as "floods", "bonanza farms", and "homesteading". This last heading is a great place to check out, as visitors will find evocative (and sometimes quite lonely) photographs of 19th century homesteads.

137

Secondary Metabolites Released by The Burying Beetle Nicrophorus vespilloides : Chemical Analyses and Possible Ecological Functions  

Microsoft Academic Search

Burying beetles of the genus Nicrophorus localize small vertebrate carcasses by emitted volatiles. The carcass that serves as reproduction and breeding site is buried\\u000a in the soil by the beetles. Biparental care for offspring includes both preservation of the carrion and its preparation as\\u000a diet and nursery. Buried carcasses show no signs of microbial decay, and those experimentally treated with

Thomas Degenkolb; Andreas Vilcinskas

138

Evidence for an underground runoff and soil permeability at the Ouled Fayet (Algiers, Algeria) buried waste pilot project: needs for a specific landfill implantation code  

NASA Astrophysics Data System (ADS)

Results from geophysical investigations (electrical resistivity, electromagnetic mapping and seismic refraction) on an empty excavated rack of the Ouled Fayet (Algiers, Algeria) pilot landfill evidenced a more permeable soil than found by a feasibility study and the presence of an underground runoff underneath the rack. The problem was to evaluate the degree of confidence of the feasibility study, based on 76 10-m drilling cores only, 6 of them performed on the studied rack. To the contrary of what is claimed in the feasibility study a threat of lixiviate pollution is real. It is more than urgent to elaborate a code for landfill implantation in Algeria, which should include mandatory geophysical prospecting and deeper drilling cores. Keywords: Landfill, Geophysical prospecting, Underground runoff, Permeability, Algeria.

Djadia, Leila; Abtout, Abdslam; Boudella, Amar

2014-05-01

139

Aeolian sands and buried soils in the Mecklenburg Lake District, NE Germany: Holocene land-use history and pedo-geomorphic response  

NASA Astrophysics Data System (ADS)

The present study is a pedo-geomorphic approach to reconstructing Holocene aeolian sand dynamics in the Mecklenburg Lake District (NE Germany). Stratigraphical, sedimentological and soil research supplemented by morphogenetic interpretations of the genesis of dunes and aeolian sands are discussed. A complex Late Holocene aeolian stratigraphy within a drift sand area was developed at the shore of Lake Müritz. The results were confirmed using palynological records, archaeological data and regional history. Accelerated aeolian activity was triggered by the intensification of settlement and land-use activities during the 13th and in the 15th to 16th century AD. After a period of stability beginning with population decline during the ‘Thirty Years War' and continuing through the 18th century, a final aeolian phase due to the establishment of glassworks was identified during the 19th century AD. We assume a direct link between Holocene aeolian dynamics and human activities. Prehistoric Holocene drift sands on terrestrial sites have not been documented in the Mecklenburg Lake District so far. This might be explained either by erosion and incorporation of older aeolian sediments during younger aeolian phases and/or a lower regional land-use intensity in older periods of the Holocene. The investigated drift sands are stratigraphically and sedimentologically characterised by a high degree of heterogeneity, reflecting the spatial and temporal variability of Holocene human impact.

Küster, Mathias; Fülling, Alexander; Kaiser, Knut; Ulrich, Jens

2014-04-01

140

Buried, viable seeds in two California bunchgrass sites and their bearing on the definition of a flora  

Microsoft Academic Search

A complete description of a plant community must include the buried viable seeds in the soil. The plants occurring in this form are a part of the flora, which helps to determine the community, even though they are not readily evident. The importance of defining an ecosystem's flora is reviewed. When the soil's buried viable seed population is used to

Jack Major; William T. Pyott

1966-01-01

141

DETECTION OF BURIED AGRICULTURAL DRAINAGE PIPE WITH GEOPHYSICAL METHODS  

Technology Transfer Automated Retrieval System (TEKTRAN)

One of the more frustrating problems confronting farmers and land improvement contractors in the Midwest U.S. involves locating buried agricultural drainage pipes. Enhancing the efficiency of soil water removal on land already containing a subsurface drainage system typically involves installing new...

142

DOE complex buried waste characterization assessment. Buried Waste Integrated Demonstration Program  

SciTech Connect

The work described in this report was conducted by Pacific Northwest Laboratory to provide information to the Buried Waste Integrated Demonstration (BWID) program. The information in this report is intended to provide a complex-wide planning base for th.e BWID to ensure that BWID activities are appropriately focused to address the range of remediation problems existing across the US Department of Energy (DOE) complex. This report contains information characterizing the 2.1 million m{sup 3} of buried and stored wastes and their associated sites at six major DOE facilities. Approximately 85% of this waste is low-level waste, with about 12% TRU or TRU mixed waste; the remaining 3% is low-level mixed waste. In addition, the report describes soil contamination sites across the complex. Some of the details that would be useful in further characterizing the buried wastes and contaminated soil sites across the DOE complex are either unavailable or difficult to locate. Several options for accessing this information and/or improving the information that is available are identified in the report. This document is a companion to Technology Needs for Remediation: Hanford and Other DOE Sites, PNL-8328 (Stapp 1993).

Kaae, P.S.; Holter, G.M.; Garrett, S.M.K.

1993-01-01

143

Soils of paleocryogenic hummocky-hollow landscapes in the southern Baikal region  

NASA Astrophysics Data System (ADS)

The features of ancient periglacial phenomena are widespread in landscapes lying beyond the modern permafrost zone. The specificity of the paleogeographic conditions in the south of the Baikal region resulted in the formation of paleocryogenic landscapes with hummocky-hollow landforms. The paleocryogenic mounds (hummocks) are of rounded or elongated shape, their height is up to 2-3 m, and their width is up to 20-25 m. They are separated by microlows (hollows). This paleocryogenic microtopography favors the differentiation of the pedogenesis on the mounds and in the hollows, so the soil cover pattern becomes more complicated. It is composed of polychronous soils organized in complexes with cyclic patterns. Light gray and gray forest soils and leached and ordinary chernozems are developed on the mounds; gray and dark gray forest soils and chernozems with buried horizons are developed in the hollows. The soils of the paleocryogenic complexes differ from one another in their morphology, physical and chemical properties, elemental composition, and humus composition. For the first time, radiocarbon dates have been obtained for the surface and buried humus horizons in the hollows. The results prove the heterochronous nature of the soils of the paleocryogenic landscapes in the south of the Baikal region.

Kozlova, A. A.; Kuz'min, V. A.; Zazovskaya, E. P.

2014-05-01

144

Insect arrival pattern and succession on buried carrion in Michigan.  

PubMed

This study examined pig carcasses buried at two different depths, 30 and 60 cm, to determine if insects were able to colonize buried carcasses, when they arrive at each depth, and what fauna were present over seven sampling dates to establish an insect succession database on buried carrion in East Lansing, MI. Thirty-eight pigs were buried, 18 at 30 cm and 20 at 60 cm. Four control carcasses were placed on the soil surface. Three replicates at each depth were exhumed after 3, 7, 14, 21, 30, and 60 d, respectively. One pig also was exhumed from 60 cm after 90 d and another after 120 d. Sarcophaga bullata (Parker) (Diptera: Sarcophagidae) and Hydrotaea sp. (Diptera: Muscidae) were found colonizing buried carrion 5 d after burial at 30 cm. Insect succession at 30 cm proceeded with flesh and muscid flies being the first to colonize, followed by blow flies. Insects were able to colonize carcasses at 60 cm and Hydrotaea sp. and Megaselia scalaris (Loew) (Diptera: Phoridae) were collected 7 d after burial. Insect succession at 60 cm did not proceed similarly, instead muscid and coffin flies were the only larvae collected. Overall these results reveal postburial interval estimates for forensic investigations in mid-Michigan during the summer, depending on climatic and soil conditions. PMID:23540133

Pastula, E C; Merritt, R W

2013-03-01

145

Soil Characterization Protocol  

NSDL National Science Digital Library

The purpose of this resource is to characterize the physical and chemical properties for each horizon in a soil profile. Students identify the horizons of a soil profile at a soil characterization site, then measure and record the top and bottom depth for each horizon. For each horizon, students describe the structure, color, consistence, texture, and abundance of roots, rocks, and carbonates. Samples are collected and prepared for additional laboratory analysis.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

146

Physical observability of horizons  

NASA Astrophysics Data System (ADS)

Event horizons are (generically) not physically observable. In contrast, apparent horizons (and the closely related trapping horizons) are generically physically observable—in the sense that they can be detected by observers working in finite-size regions of spacetime. Consequently event horizons are inappropriate tools for defining astrophysical black holes, or indeed for defining any notion of an evolving black hole (evolving either due to accretion or Hawking radiation). The only situation in which an event horizon becomes physically observable is for the very highly idealized stationary or static black holes, when the event horizon is a Killing horizon which is degenerate with the apparent and trapping horizons, and then it is the physical observability of the apparent/trapping horizons that is fundamental—the event horizon merely comes along for the ride.

Visser, Matt

2014-12-01

147

Soil Composition  

NSDL National Science Digital Library

Soil is essential for life on Earth. It is needed for food, air, clothing and so much more. Discussion topics include the terms 'soil', 'dirt', and 'sediment', factors affecting the formation of soils, soil horizons, and the twelve orders of soils. In a hands-on activity, students will collect soil samples from three different locations, use online resources to determine texture and particle makeup, and record their observations.

Chris Fox

148

Rhizopogon Spore Longevity in Tomales Pt soil  

E-print Network

of spore banks using bioassays #12;How do we investigate spore longevity? · Innoculate grassland soil with four species of Rhizopogon and one live soil · Bury soil in non-innoculated grassland · Remove one pot #12;a Rhizopogon-free zoneTomales Point: #12;Innoculating and packaging Tomales Point soil #12;Burying

Bruns, Tom

149

FTIR spectroscopic characteristics of old surface soils as compared to those of recent surface soils to determine to historical land use  

NASA Astrophysics Data System (ADS)

The type of land use affects content and composition of soil organic matter (SOM). The aim of this study is to analyze the composition of SOM from old surface soils buried in Middle Ages and Iron Age respectively, and to compare these results with FTIR characteristics of recent forest, grassland, and arable soils. We investigate soil samples obtained from archaeological excavations at Glasow site (old soils) that are described to be former surface soils. Further recent sandy surface soils with different land use (rAp) were sampled. According to archeological data (Bork et al. 1998) the old soils are ancient surface soils from the Middle Ages (1Ap), early Middle Ages (fAh) and from the Iron Age (2Ap). SOM fractions were obtained by Na-pyrophosphate extraction and investigated by using FTIR spectroscopy. The SOM from two of the old soils (1Ap and 2Ap) show FTIR signatures similar to those found for SOM from recent arable soils. This is in accordance with archeological findings that detected for the 1Ap and 2Ap horizons traces of old ploughing procedures that were not detected for the fAh horizon.The FTIR signature of the SOM from fAh soil is similar to that found for recent surface soils that are under deciduous forest today. Assuming that the SOM composition is not changed during the last centuries due to soil processes the composition of SOM from the old soils seem to reflect the corresponding former land use. Based on these results we conclude that in the studied old surface soils the effect of land use was conserved in SOM composition.

Ellerbrock, Ruth

2010-05-01

150

Sensor system for buried waste containment sites  

DOEpatents

A sensor system is disclosed for a buried waste containment site having a bottom wall barrier and/or sidewall barriers, for containing hazardous waste. The sensor system includes one or more sensor devices disposed in one or more of the barriers for detecting a physical parameter either of the barrier itself or of the physical condition of the surrounding soils and buried waste, and for producing a signal representing the physical parameter detected. Also included is a signal processor for receiving signals produced by the sensor device and for developing information identifying the physical parameter detected, either for sounding an alarm, displaying a graphic representation of a physical parameter detected on a viewing screen and/or a hard copy printout. The sensor devices may be deployed in or adjacent the barriers at the same time the barriers are deployed and may be adapted to detect strain or cracking in the barriers, leakage of radiation through the barriers, the presence and leaking through the barriers of volatile organic compounds, or similar physical conditions.

Smith, Ann Marie (Pocatello, ID); Gardner, Bradley M. (Idaho Falls, ID); Kostelnik, Kevin M. (Idaho Falls, ID); Partin, Judy K. (Idaho Falls, ID); Lancaster, Gregory D. (Idaho Falls, ID); Pfeifer, May Catherine (Idaho Falls, ID)

2000-01-01

151

Melter development needs assessment for RWMC buried wastes  

SciTech Connect

This report presents a survey and initial assessment of the existing state-of-the-art melter technology necessary to thermally treat (stabilize) buried TRU waste, by producing a highly leach resistant glass/ceramic waste form suitable for final disposal. Buried mixed transuranic (TRU) waste at the Idaho National Engineering Laboratory (INEL) represents an environmental hazard requiring remediation. The Environmental Protection Agency (EPA) placed the INEL on the National Priorities List in 1989. Remediation of the buried TRU-contaminated waste via the CERCLA decision process is required to remove INEL from the National Priorities List. A Waste Technology Development (WTD) Preliminary Systems Design and Thermal Technologies Screening Study identified joule-heated and plasma-heated melters as the most probable thermal systems technologies capable of melting the INEL soil and waste to produce the desired final waste form (Iron-Enriched Basalt (IEB) glass/ceramic). The work reported herein then surveys the state of existing melter technology and assesses it within the context of processing INEL buried TRU wastes and contaminated soils. Necessary technology development work is recommended.

Donaldson, A.D.; Carpenedo, R.J.; Anderson, G.L.

1992-02-01

152

Melter development needs assessment for RWMC buried wastes  

SciTech Connect

This report presents a survey and initial assessment of the existing state-of-the-art melter technology necessary to thermally treat (stabilize) buried TRU waste, by producing a highly leach resistant glass/ceramic waste form suitable for final disposal. Buried mixed transuranic (TRU) waste at the Idaho National Engineering Laboratory (INEL) represents an environmental hazard requiring remediation. The Environmental Protection Agency (EPA) placed the INEL on the National Priorities List in 1989. Remediation of the buried TRU-contaminated waste via the CERCLA decision process is required to remove INEL from the National Priorities List. A Waste Technology Development (WTD) Preliminary Systems Design and Thermal Technologies Screening Study identified joule-heated and plasma-heated melters as the most probable thermal systems technologies capable of melting the INEL soil and waste to produce the desired final waste form [Iron-Enriched Basalt (IEB) glass/ceramic]. The work reported herein then surveys the state of existing melter technology and assesses it within the context of processing INEL buried TRU wastes and contaminated soils. Necessary technology development work is recommended.

Donaldson, A.D.; Carpenedo, R.J.; Anderson, G.L.

1992-02-01

153

Buried oxide layer in silicon  

DOEpatents

A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir, TN)

2001-01-01

154

Thin film buried anode battery  

DOEpatents

A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

Lee, Se-Hee (Lakewood, CO); Tracy, C. Edwin (Golden, CO); Liu, Ping (Denver, CO)

2009-12-15

155

Changes in soil properties and soil cover structure due to intensive erosion and accumulation processes in loess soils  

NASA Astrophysics Data System (ADS)

Intensive water and tillage erosion and consequent accumulation are the most important processes affecting the agroecosystems in loess regions and changing soil properties, e.g. organic carbon content, carbonate content or structure stability, and general distribution of soil units in the landscape. South Moravian loess belt, formerly covered mostly by Haplic Chernozem, is now formed by a highly diversified soil mosaic. At a morphologically heterogenous study plot (6 ha), a study on relationship between soil properties and terrain characteristics was held. DTM analysis, detailed terrain survey and laboratory analysis were the main methods adopted in the study. Three main soil units were identified: Haplic Chernozem, calcareous Regosol and Colluvial soil. The distribution of each soil unit correlates with different terrain attributes. Regosols are significatly connected to the steep slope, while their correlation with the curvature or hydrological indexes is lower. On the contrary, the Colluvial soils distribution depends mainly on values of curvature and topographical wetness index and is independent on the slope. Chernozem is related to a specific terrain position more than to any of the terrain attributes. Soil depth and humus horizon thickness vary extremelly - from 0.2 m at the erosionally exposed slopes to more than 2.5 m at the concave parts and the toeslope. Soil depth is significantly correlated with all of the tested terrain attributes except of the slope - the strongest correlation was proved in case of mean curvature, topographical wetness index and catchment area. Different degree of changes in particular soil properties results from the specificity of both erosion process and parent material character. Organic carbon content in the topsoil varies significantly. Humus is practically absent in the steepest parts of the slope where the loess is exposed. High amounts of Corg were identified in the undisturbed A horizons of the Chernozem unit. In the concave parts of the slope and at the toeslope, the Corg content in the plough layer is lower due to an admixture of non-humus material transported from the steep parts of the plot. Nevertheless, the deeper (0.7 - 2 m), buried parts of the colluvial profiles are very rich in organic carbon (up to 4 %). These horizons may represent fossil chernic horizons of former Chernozems, buried by intensive sedimentation of humic material. Similar variability was found in carbonate content values, always due to amount of loess admixture in the plough horizon. While the soil structure stability, depending strongly on humus content, was the highest in the Chernozem unit, in the eroded parts it was highly unstable. Changes in the cation exchange capacity and pH are less distinctive. CEC slightly increases in humus-rich soils and pH is higher in the eroded parts of the plot due to the loess exposition. Acknowledgement: Authors acknowledge the financial support of the Grant Agency of the Czech Republic (grant No. GA CR 526/08/0434) and the Ministry of Education, Youth and Sports of the Czech Republic (grant No. MSM 6046070901).

Zadorova, Tereza; Penizek, Vit; Jaksik, Ondrej; Kodesova, Radka; Jirku, Veronika; Fer, Miroslav

2010-05-01

156

Tracing buried pipelines using multi frequency electromagnetic  

NASA Astrophysics Data System (ADS)

In this paper the application of multi frequency electromagnetic techniques to locate buried pipelines is described. The survey site has two pipelines of SUMED, one of the world chokepoints. At desert or arid areas, regular geophysical surveys usually are difficult to carry out. EM techniques could be the best among geophysical techniques to be used for this target at these conditions. The EM survey was performed using a GEM-300 multi-frequency electromagnetic profiler. It is of handheld electromagnetic induction-type that measures in-phase and quadrature terrain conductivity without electrodes or direct soil contact. An area of 60 × 15 m was surveyed, that supposed SUMED pipeline existed. Six different frequencies, typically 2025, 2875, 4125, 5875, 8425, 12,025 Hz, have been used simultaneously. The slice maps for in-phase and conductivity distribution at each frequency could help to trace the extension of the pipeline. Two pipelines were traced successfully with 20 m spacing of each others.

El-Qady, Gad; Metwaly, Mohamed; Khozaym, Ashraf

2014-06-01

157

Common causes of material degradation in buried piping  

SciTech Connect

Buried pipe may fail for innumerable reasons. Causes can be mechanical damage/breakage, chemically initiated corrosion, or a combination. Failures may originate either internally or externally on the pipe. They may be related to flaws in the design, to excessive or unanticipated internal pressure or ground level loading, and/or to poor or uncertain installation practice. Or the pipe may simply ``wear out`` in service. Steel is strong and very forgiving in underground applications, especially with regard to backfill. However, soil support developed through densification or compaction is critical for brittle concrete and vitrified clay tile pipe, and is very important for cast iron and plastic pipe. Chemistry of the soil determines whether or not it will enhance corrosion or other types of degradation. Various causes and mechanisms for deterioration of buried pipe are indicated. Some peculiarities of the different materials of construction are characterized. Repair methods and means to circumvent special problems are described.

Jenkins, C.F.

1997-01-20

158

Preliminary observations of arthropods associated with buried carrion on oahu.  

PubMed

Several studies in Hawaii have focused on arthropod succession and decomposition patterns of surface remains, but the current research presents the first study to focus on shallow burials in this context. Three domestic pig carcasses (Sus scrofa L.) were buried at the depths of 20-40 cm in silty clay loam soil on an exposed ridge on the leeward side of the volcanically formed Koolau Mountain Range. One carcass was exhumed after 3 weeks, another after 6 weeks, and the last carcass was exhumed after 9 weeks. An inventory of arthropod taxa present on the carrion and in the surrounding soil and observations pertaining to decomposition were recorded at each exhumation. The longer the carrion was buried, the greater the diversity of arthropod species that were recovered from the remains. Biomass loss was calculated to be 49% at the 3-week interval, 56% at the 6-week interval, and 59% at the 9-week interval. PMID:25413711

Rysavy, Noel M; Goff, M Lee

2015-03-01

159

Overhead and buried conductor system  

Microsoft Academic Search

In this paper a novel computer code for the analysis of both aerial and buried system of conductors in wide frequency range is presented. A hybrid approach has been applied enabling incorporation into a single linear system both lumped circuit parameters and distributed parameters evaluated through a rigorous electromagnetic field analysis. The system of discretised conductors is replaced by a

R. Andolfato; L. Bernardi; L. Fellin

1998-01-01

160

Buried fiber optic intrusion sensor  

E-print Network

to the buried sensor induces a phase shift in light propagating along the fiber which allows for the detection and localization of intrusions. Through the use of an ultra-stable erbium-doped fiber laser and phase sensitive optical time domain reflectometry...

Maier, Eric William

2004-09-30

161

The Buried Town of Beaver.  

ERIC Educational Resources Information Center

Local history as source material for environmental education is uniquely portrayed in this resource kit. Utilizing a Winona County Historical Society publication, "The Beaver Story" and accompanied by a teacher's guide, "The Buried Town of Beaver," and other teaching aids, a case study of the area can be developed. Based on the reminiscences of…

Jostad, Karen

162

Degradation of carbohydrates and lignins in buried woods  

USGS Publications Warehouse

Spruce, alder, and oak woods deposited in coastal sediments were characterized versus their modern counterparts by quantification of individual neutral sugars and lignin-derived phenols as well as by scanning electron microscopy, 13C NMR, and elemental analysis. The buried spruce wood from a 2500 yr old deposit was unaltered whereas an alder wood from the same horizon and an oak wood from an open ocean sediment were profoundly degraded. Individual sugar and lignin phenol analyses indicate that at least 90 and 98 wt% of the initial total polysaccharides in the buried alder and oak woods, respectively, have been degraded along with 15-25 wt% of the lignin. At least 75% of the degraded biopolymer has been physically lost from these samples. This evidence is supported by the SEM, 13C NMR and elemental analyses, all of which indicate selective loss of the carbohydrate moiety. The following order of stability was observed for the major biochemical constituents of both buried hardwoods: vanillyl and p-hydroxyl lignin structural units > syringyl lignin structural units > pectin > ??-cellulose > hemicellulose. This sequence can be explained by selective preservation of the compound middle lamella regions of the wood cell walls. The magnitude and selectivity of the indicated diagenetic reactions are sufficient to cause major changes in the chemical compositions of wood-rich sedimentary organic mixtures and to provide a potentially large in situ nutrient source. ?? 1985.

Hedges, J.I.; Cowie, G.L.; Ertel, J.R.; James, Barbour R.; Hatcher, P.G.

1985-01-01

163

Test plan for buried waste containment system materials  

SciTech Connect

The objectives of the FY 1997 barrier material work at the Idaho National Engineering and Environmental Laboratory are to (1) select a waste barrier material and verify that it is compatible with the Buried Waste Containment System Process, and (2) determine if, and how, the Buried Waste Containment System emplacement process affects the material properties and performance (on proof of principle scale). This test plan describes a set of measurements and procedures used to validate a waste barrier material for the Buried Waste Containment System. A latex modified proprietary cement manufactured by CTS Cement Manufacturing Company will be tested. Emplacement properties required for the Buried Waste Containment System process are: slump between 8 and 10 in., set time between 15 and 30 minutes, compressive strength at set of 20 psi minimum, and set temperature less than 100{degrees}C. Durability properties include resistance to degradation from carbonate, sulfate, and waste-site soil leachates. A set of baseline barrier material properties will be determined to provide a data base for comparison with the barrier materials when tested in the field. The measurements include permeability, petrographic analysis to determine separation and/or segregation of mix components, and a set of mechanical properties. The measurements will be repeated on specimens from the field test material. The data will be used to determine if the Buried Waste Containment System equipment changes the material. The emplacement properties will be determined using standard laboratory procedures and instruments. Durability of the barrier material will be evaluated by determining the effect of carbonate, sulfate, and waste-site soil leachates on the compressive strength of the barrier material. The baseline properties will be determined using standard ASTM procedures. 9 refs., 1 fig., 2 tabs.

Weidner, J.; Shaw, P.

1997-03-01

164

The high water-holding capacity of petrocalcic horizons  

Technology Transfer Automated Retrieval System (TEKTRAN)

Petrocalcic soil horizons occur in most arid and semi-arid ecosystems around the world, often within the plant rooting zone. Little is known, however, about the water holding characteristic of soils indurated with calcium carbonate. We conducted a replicated experiment to define the soil-water relea...

165

KINETICS OF CHEMICAL WEATHERING IN B-HORIZON SPODOSOL FRACTION  

EPA Science Inventory

Studies on a B horizon soil from Maine have been conducted to etermine the weathering rate dependence on hydrogen ion concentration in soil solution. Effects of soil concentration and solution chemistry on chemical weathering rate were also investigated. he studies used a laborat...

166

Study of sacrificial anode cathodic protection of buried tanks: Numerical modelling  

Microsoft Academic Search

A finite element numerical model was set up to calculate the secondary distribution of potential and current density at the surface of a buried tank. The steel gas tank of interest was protected by both coating and two sacrificial anodes (magnesium alloy or zinc). The dispersion of actual soil properties was taken into account by use of three typical soils.

D. Rabiot; F. Dalard; J.-J. Rameau; J.-P. Caire; S. Boyer

1999-01-01

167

Medical technology horizon scanning  

Microsoft Academic Search

Horizon scanning is becoming particularly important in the medical industry, in the identification and evaluation of emerging\\u000a technologies. This paper examines the role biomedical engineers may have in horizon scanning new medical technologies and\\u000a considers whether this is a useful activity for biomedical engineers. A horizon scanning methodology for conducting studies\\u000a of emerging medical technologies is introduced, consisting of the

I. T. Brown; A. Smale; A. Verma; S. Momandwall

2005-01-01

168

Technology status report: In situ vitrification applied to buried wastes  

SciTech Connect

This document is a technical status report on In Situ Vitrification (ISV) as applied to buried waste; the report takes both technical and institutional concerns into perspective. The ISV process involves electrically melting such contaminated solid media as soil, sediment, sludge, and mill tailings. The resultant product is a high-quality glass-and-crystalline waste form that possesses high resistance to corrosion and leaching and is capable of long-term environmental exposure without significant degradation. The process also significantly reduces the volume of the treated solid media due to the removal of pore spaces in the soil.

Thompson, L.E. (Pacific Northwest Lab., Richland, WA (United States)); Bates, S.O. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Hansen, J.E. (Geosafe Corp., Richland, WA (United States))

1992-09-01

169

Horizon sensor accuracy improvement using earth horizon profile phenomenology  

Microsoft Academic Search

Horizon sensor system technology has developed to the point where the ultimate accuracy a horizon sensor can give depends upon the phenomenology of the horizon itself. Current horizon sensors make use of the 15 micron CO2 absorption band and find (typically) the 50-percent point on the horizon. Using this technique, accuracies of about + or - 0.70 deg in pitch

Richard A. Gontin; Kenneth A. Ward

1987-01-01

170

Laser neutralization of buried munitions  

NASA Astrophysics Data System (ADS)

This report describes the results of the first phase of a planned two-phase program to develop laser technology for rapid neutralization of buried munitions from a safe standoff distance. The primary objective of this first phase is to demonstrate, via laboratory experiments, the capabilities of a breadboard laser system to "drill" through a minimum depth of 15 cm of earthen materials to defeat a buried mine at a standoff distance greater than 20 m. In the initial phase covered by this report, results of short range laboratory testing by 3 contractors are reported. The planned second phase of this program will consist of procuring a more capable 10 kW SM laser and performing field-testing at longer standoff ranges.

Habersat, James D.; Schilling, Bradley W.; Alexander, Joe; McElhaney, Russell; Lehecka, Thomas; Nixon, Matthew D.

2011-06-01

171

Buried Water Ice on Mars  

NSDL National Science Digital Library

This product includes five classroom activities related to the discovery of water ice on Mars. In 2001, the Mars Odyssey spacecraft discovered significant amounts of water ice buried in the high latitude regions of Mars. This discovery, based upon data from the Mars Gamma Ray Spectrometer, helped motivate the development of the Mars Phoenix Lander mission, which arrived in the Martian arctic in 2008 to investigate this buried water ice. These classroom activities involve both guided and open inquiry approaches, using real data to allow students to investigate and learn about processes occurring on Mars. Each lesson includes a teacher guide and student guide. In addition, some of the lessons are accompanied by PowerPoint presentations and one extension activity uses an educational Flash animation.

2007-04-27

172

Investigation of guided waves propagation in pipe buried in sand  

SciTech Connect

The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

Leinov, Eli; Cawley, Peter; Lowe, Michael J.S. [NDE Group, Department of Mechanical Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

2014-02-18

173

Investigation of guided waves propagation in pipe buried in sand  

NASA Astrophysics Data System (ADS)

The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

Leinov, Eli; Cawley, Peter; Lowe, Michael J. S.

2014-02-01

174

Odor analysis of decomposing buried human remains  

SciTech Connect

This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the 'odor signatures' unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

Vass, Arpad Alexander [ORNL; Smith, Rob R [ORNL; Thompson, Cyril V [ORNL; Burnett, Michael N [ORNL; Dulgerian, Nishan [ORNL; Eckenrode, Brian A [ORNL

2008-01-01

175

Soil Core Sample #2  

USGS Multimedia Gallery

Soil core obtained from existing goose grazing lawn along the Smith River in the Teshekpuk Lake Special Area of the National Petroleum Reserve - Alaska.  Buried peat layer broken open.  Closer examination of the buried peat layer demonstrates that non-salt-tolerant vegetation from the past...

176

The 2010 Horizon Report  

ERIC Educational Resources Information Center

The annual "Horizon Report" describes the continuing work of the New Media Consortium's Horizon Project, a qualitative research project established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, or creative inquiry on college and university campuses within the next five years. The…

Johnson, L.; Levine, A.; Smith, R.; Stone, S.

2010-01-01

177

Ultimate IR horizon sensor  

Microsoft Academic Search

The accuracy of presently available IR horizon sensors is not sufficient to meet the stringent attitude sensing and control requirements for future remote sensing and meteorological satellites. The different sources of error in a horizon sensor are analyzed. The accuracy of the sensor is presently limited by the detector noise. Use of HgCdTe in place of an immersed bolometer detector,

Y. K. Jain; T. K. Alex; B. Kalakrishnan

1980-01-01

178

Electromagnetic response of buried cylindrical structures for line current excitation  

NASA Astrophysics Data System (ADS)

The Cylindrical-Wave Approach (CWA) rigorously solves, in the spectral domain, the electromagnetic forward scattering by a finite set of buried two-dimensional perfectly-conducting or dielectric objects [1]-[2]. In this technique, the field scattered by underground objects is represented in terms of a superposition of cylindrical waves. Use is made of the plane-wave spectrum [1] to take into account the interaction of such waves with the planar interface between air and soil, and between different layers eventually present in the ground [3]. Obstacles of general shape can be simulated through the CWA with good results, by using a suitable set of small circular-section cylinders [4]. Recently, we improved the CWA by facing the fundamental problem of losses in the ground [5]: this is of significant importance in remote-sensing applications, since real soils often have complex permittivity and conductivity, and sometimes also a complex permeability. While in previous works concerning the CWA a monochromatic or pulsed plane-wave incident field was considered, in the present work a different source of scattering is present: a cylindrical wave radiated by a line source. Such a source is more suitable to model the practical illumination field used in GPR surveys. The electric field radiated by the line current is expressed by means of a first-kind Hankel function of 0-th order. The theoretical solution to the scattering problem is developed for both dielectric and perfectly-conducting cylinders buried in a dielectric half-space. The approach is implemented in a Fortran code; an accurate numerical evaluation of the involved spectral integrals is performed, the highly-oscillating behavior of the homogeneous waves is correctly followed and evanescent contributions are taken into account. The electromagnetic field scattered in both air and ground can be obtained, in near- and far-field regions, for arbitrary radii and permittivity of the buried cylinders, as well as for arbitrary arrangements of cylinders in the soil. As future work, the presented analysis, carried out in the spectral domain, will be extended to a time-domain solution following an approach analogous to the one developed in [6] for pulsed plane-wave excitation. [1] M. Di Vico, F. Frezza, L. Pajewski, and G. Schettini, "Scattering by a Finite Set of Perfectly Conducting Cylinders Buried in a Dielectric Half-Space: a Spectral-Domain Solution," IEEE Transactions Antennas and Propagation, vol. 53(2), 719-727, 2005. [2] M. Di Vico, F. Frezza, L. Pajewski, and G. Schettini, "Scattering by Buried Dielectric Cylindrical Structures," Radio Science, vol. 40(6), RS6S18, 2005. [3] F. Frezza, L. Pajewski, C. Ponti, and G. Schettini, "Scattering by Perfectly-Conducting Cylinders Buried in a Dielectric Slab through the Cylindrical Wave Approach," IEEE Transactions Antennas and Propagation, vol. 57(4), 1208-1217, 2009. [4] F. Frezza, L. Pajewski, C. Ponti, and G. Schettini, "Accurate Wire-Grid Modeling of Buried Conducting Cylindrical Scatterers," Nondestructive Testing and Evaluation (Special Issue on "Civil Engineering Applications of Ground Penetrating Radar"), vol. 27(3), pp. 199-207, 2012. [5] F. Frezza, L. Pajewski, C. Ponti, G. Schettini, and N. Tedeschi, "Electromagnetic Scattering by a Metallic Cylinder Buried in a Lossy Medium with the Cylindrical Wave Approach," IEEE Geoscience and Remote Sensing Letters, vol. 10(1), pp. 179-183, 2013. [6] F. Frezza, P. Martinelli, L. Pajewski, and G. Schettini, "Short-Pulse Electromagnetic Scattering from Buried Perfectly-Conducting Cylinders," IEEE Geoscience and Remote Sensing Letters, vol. 4(4), pp. 611-615, 2007.

Pajewski, Lara; Ponti, Cristina

2013-04-01

179

30 CFR 823.14 - Soil replacement.  

Code of Federal Regulations, 2014 CFR

...descriptions containing soil-horizon depths, soil densities, soil pH, and other specifications such that reconstructed soils will have the capability of achieving levels of yield equal to, or higher than,...

2014-07-01

180

30 CFR 823.14 - Soil replacement.  

Code of Federal Regulations, 2013 CFR

...descriptions containing soil-horizon depths, soil densities, soil pH, and other specifications such that reconstructed soils will have the capability of achieving levels of yield equal to, or higher than,...

2013-07-01

181

30 CFR 823.14 - Soil replacement.  

Code of Federal Regulations, 2011 CFR

...descriptions containing soil-horizon depths, soil densities, soil pH, and other specifications such that reconstructed soils will have the capability of achieving levels of yield equal to, or higher than,...

2011-07-01

182

30 CFR 823.14 - Soil replacement.  

Code of Federal Regulations, 2012 CFR

...descriptions containing soil-horizon depths, soil densities, soil pH, and other specifications such that reconstructed soils will have the capability of achieving levels of yield equal to, or higher than,...

2012-07-01

183

Blast wave from buried charges  

SciTech Connect

While much airblast data are available for height-of-burst (HOB) effects, systematic airblast data for depth-of-burst (DOB) effects are more limited. It is logical to ask whether the spherical 0.5-g Nitropenta charges that, proved to be successful for HOB tests at EMI are also suitable for experiments with buried charges in the laboratory scale; preliminary studies indicated in the alternative. Of special interest is the airblast environment generated by detonations just above or below the around surface. This paper presents a brief summary of the test results.

Reichenbach, H.; Behrens, K. [Fraunhofer-Institut fuer Kurzzeitdynamik - Ernst-Mach-Institut (EMI), Freiburg im Breisgau (Germany); Kuhl, A.L. [Lawrence Livermore National Lab., El Segundo, CA (United States)

1993-08-01

184

Killing horizons and spinors  

NASA Astrophysics Data System (ADS)

We study the near-horizon geometry of generic Killing horizons constructing suitable coordinates and taking the appropriate scaling limit. We are able to show that the geometry will always show an enhancement of symmetries, and, in the extremal case, will develop a causally disconnected "throat" as expected. We analyze the implications of this to the Kerr/CFT conjecture and the attractor mechanism. We are also able to construct a set of special (pure) spinors associated with the horizon structure using their interpretation as maximally isotropic planes. The structure generalizes the usual reduced holonomy manifold in an interesting way and may be fruitful to the search of new types of compactification backgrounds.

Carneiro da Cunha, Bruno; de Queiroz, Amilcar

2014-05-01

185

Killing Horizons and Spinors  

E-print Network

We study the near horizon geometry of generic Killing horizons constructing suitable coordinates and taking the appropriate scaling limit. We are able to show that the geometry will always show an enhancement of symmetries, and, in the extremal case, will develop a causally disconnected "throat" as expected. We analyze the implications of this to the Kerr/CFT conjecture and the attractor mechanism. We are also able to construct a set of special (pure) spinors associated with the horizon structure using their interpretation as maximally isotropic planes. The structure generalizes the usual reduced holonomy manifold in an interesting way and may be fruitful to the search of new types of compactification backgrounds.

Bruno Carneiro da Cunha; Amilcar de Queiroz

2014-06-19

186

Preputial flaps to correct buried penis  

Microsoft Academic Search

The authors developed a preputial skin flap technique to correct the buried penis which was simple and practical. This simple\\u000a procedure can be applied to most boys with buried penis. In the last 3 years, we have seen 12 boys with buried penis and have\\u000a been treated by using preputial flaps. The mean age is about 5.1 (from 3 to 12).

Chih-Chun Chu; Yi-Hsin Chen; Guan-Yeu Diau; Ih-Wei Loh; Ke-Chi Chen

2007-01-01

187

Soil  

NSDL National Science Digital Library

Soil is an example of a non-living thing. Soil contains nutrients and living organisms, but the soil itself is not alive. Soil is important in plant growth because soil gives plants a place to anchor their roots and it also provides the plant with essential nutrients.

Scott Bauer (USDA-ARS; )

2006-05-23

188

Black holes: from event horizons to trapping horizons  

E-print Network

Black holes: from event horizons to trapping horizons Eric Gourgoulhon Laboratoire Univers et Th, France 10 December 2009 Eric Gourgoulhon (LUTH) Black holes: trapping horizons LATT, Toulouse, 10 December 2009 1 / 38 #12;Plan 1 Concept of black hole and event horizon 2 Local approaches to black holes 3

Gourgoulhon, Eric

189

Black holes: from event horizons to trapping horizons  

E-print Network

Black holes: from event horizons to trapping horizons Eric Gourgoulhon Laboratoire Univers et Th) Black holes: trapping horizons CERN, 17 March 2010 1 / 38 #12;Plan 1 Concept of black hole and event horizon 2 Local approaches to black holes 3 Viscous fluid analogy 4 Angular momentum and area evolution

Gourgoulhon, Eric

190

Black holes: from event horizons to trapping horizons  

E-print Network

Black holes: from event horizons to trapping horizons Eric Gourgoulhon Laboratoire Univers et Th 2009 Eric Gourgoulhon (LUTH) Black holes: trapping horizons LPT, Orsay, 14 October 2009 1 / 39 #12;Plan 1 Concept of black hole and event horizon 2 Local approaches to black holes 3 Viscous fluid analogy

Gourgoulhon, Eric

191

Black holes: from event horizons to trapping horizons  

E-print Network

Black holes: from event horizons to trapping horizons Eric Gourgoulhon Laboratoire Univers et Th April 2009 Eric Gourgoulhon (LUTH) Black holes: trapping horizons INLN, Nice, 2 April 2009 1 / 39 #12;Plan 1 Concept of black hole and event horizon 2 Local approaches to black holes 3 Viscous fluid

Gourgoulhon, Eric

192

Buried Waste Integrated Demonstration Plan  

SciTech Connect

This document presents the plan of activities for the Buried Waste Integrated Demonstration (BWID) program which supports the environmental restoration (ER) objectives of the Department of Energy (DOE) Complex. Discussed in this plan are the objectives, organization, roles and responsibilities, and the process for implementing and managing BWID. BWID is hosted at the Idaho National Engineering Laboratory (INEL), but involves participants from throughout the DOE Complex, private industry, universities, and the international community. These participants will support, demonstrate, and evaluate a suite of advanced technologies representing a comprehensive remediation system for the effective and efficient remediation of buried waste. The processes for identifying technological needs, screening candidate technologies for applicability and maturity, selecting appropriate technologies for demonstration, field demonstrating, evaluation of results and transferring technologies to environmental restoration programs are also presented. This document further describes the elements of project planning and control that apply to BWID. It addresses the management processes, operating procedures, programmatic and technical objectives, and schedules. Key functions in support of each demonstration such as regulatory coordination, safety analyses, risk evaluations, facility requirements, and data management are presented.

Kostelnik, K.M.

1991-12-01

193

Horizon 2020 Proposal Workshop  

E-print Network

Horizon 2020 Proposal Workshop "Marie Sklodowska Curie ­ Proposals for Individual fellowships" 16th Research Cooperation, University of Potsdam) 10:40 ­ 11:30 Marie Sklodowska Curie Actions ­ Individual

Potsdam, Universität

194

Chapter 3. Concepts of Basic Soil Science W. Lee Daniels  

E-print Network

Chapter 3. Concepts of Basic Soil Science W. Lee Daniels Kathryn C. Haering Department of Crop and Soil Environmental Sciences, Virginia Tech Table of Contents Soil formation and soil horizons................................................................................................................... 33 Soil composition by volume

Kaye, Jason P.

195

Xenon Isotope Releases from Buried Transuranic Waste  

NASA Astrophysics Data System (ADS)

Xenon is an inert rare gas produced as a fission product in nuclear reactors and through spontaneous fission of some transuranic isotopes. Thus, xenon will be released from buried transuranic waste. Two complementary methods are used to measure xenon isotopes: radiometric analysis for short-lived radioxenon isotopes and mass spectrometry for detection of stable xenon isotopes. Initial measurements near disposal facilities at the U.S. Department of Energy's Hanford Site show radioxenon and stable xenon isotopic signatures that are indicative of transuranic waste. Radioxenon analysis has greater sensitivity due to the lower background concentrations and indicates spontaneous fission due to the short half life of the isotopes. Stable isotope ratios may be used to distinguish irradiated fuel sources from pure spontaneous fission sources and are not as dependent on rapid release from the waste form. The release rate is dependent on the type of waste and container integrity and is the greatest unknown in application of this technique. Numerical multi-phase transport modeling of burial grounds at the Idaho National Engineering and Environmental Laboratory indicates that, under generalized conditions, the radioxenon isotopes will diffuse away from the waste and be found in the soil cap and adjacent to the burial ground at levels many orders of magnitude above the detection limit.

Dresel, P. E.; Waichler, S. R.; Kennedy, B. M.; Hayes, J. C.; McIntyre, J. I.; Giles, J. R.; Sondrup, A. J.

2004-12-01

196

Black hole horizons Eric Gourgoulhon  

E-print Network

Black hole horizons ´Eric Gourgoulhon Laboratoire Univers et Th´eories (LUTH) CNRS / Observatoire hole horizons SN2NS, Paris, 4 Feb 2014 1 / 37 #12;Outline 1 Concept of black hole and event horizon 2 Quasi-local horizons 3 Astrophysical black holes 4 The near-future observations of black holes ´Eric

Gourgoulhon, Eric

197

Detection of buried objects using reflected GNSS signals  

NASA Astrophysics Data System (ADS)

The use of reflected Global Navigation Satellite System (GNSS) signals for sensing the Earth has been growing rapidly in recent years. This technique is founded on the basic principle of detecting GNSS signals after they have been reflected off the Earth's surface and using them to determine the properties of the reflecting surface remotely. This is the so-called GNSS reflectometry (GNSS-R) technique. In this paper, a new application regarding the detection of metallic buried objects is analyzed and it is validated through several experimental campaigns. Although the penetration depth of GNSS signals into the ground is not optimal and depends on the soil moisture, GNSS signals can likely interact approximately with the first 10 cm of the ground and therefore can be reflected back by any metallic object buried on the first terrain layer. A very light and low-cost GNSS receiver prototype based on a software-defined radio approach was developed. This receiver can be used as a payload on board small drones or unmanned aerial systems to detect metallic objects (mines or other explosive devices). A signal processing tool based on an open-loop GNSS signal acquisition strategy was developed. The results of two experiments which show the possibility of using GNSS-R signals to detect buried metallic objects and to provide an estimate of their dimensions are discussed.

Notarpietro, Riccardo; De Mattia, Salvatore; Campanella, Maurizio; Pei, Yuekun; Savi, Patrizia

2014-12-01

198

Remote Excavation System technology evaluation report: Buried Waste Robotics Program  

SciTech Connect

This document describes the results from the Remote Excavation System demonstration and testing conducted at the Idaho National Engineering Laboratory during June and July 1993. The purpose of the demonstration was to ascertain the feasibility of the system for skimming soil and removing various types of buried waste in a safe manner and within all regulatory requirements, and to compare the performances of manual and remote operation of a backhoe. The procedures and goals of the demonstration were previously defined in The Remote Excavation System Test Plan, which served as a guideline for evaluating the various components of the system and discussed the procedures used to conduct the tests.

Not Available

1993-09-01

199

The influence of omnivorous elaterid larvae on the microbial carbon cycle in different forest soils  

Microsoft Academic Search

Data are presented on the influence of Athous subfuscus larvae (Coleoptera, Elateridae) on the microbial carbon cycle in the biotically most active horizons of three contrasting beech forest soils: the Ah horizon of a mull soil on limestone (Göttinger Wald, FRG), the F\\/H horizon of a moder soil on new red sandstone (Solling area, FRG) and in the F\\/H horizon

V. Wolters

1989-01-01

200

Evaluation of the graphite electrode DC arc furnace for the treatment of INEL buried wastes  

SciTech Connect

The past practices of DOE and its predecessor agencies in burying radioactive and hazardous wastes have left DOE with the responsibility of remediating large volumes of buried wastes and contaminated soils. The Buried Waste Integrated Demonstration (BWID), has chosen to evaluate treatment of buried wastes at the Idaho National Engineering Laboratory (INEL). Because of the characteristics of the buried wastes, the potential for using high-temperature thermal treatment technologies is being evaluated. The soil-waste mixture at INEL, when melted or vitrified, produces a glass/ceramic referred to as iron-enriched basalt (IEB). One potential problem with producing the IEB material is the high melting temperature of the waste and soil (1,400-1,600{degrees}C). One technology that has demonstrated capabilities to process high melting point materials is the plasma arc heated furnace. A three-party program was initiated and the program involved testing an engineering-scale DC arc furnace to gain preliminary operational and waste processibility information. It also included the design, fabrication, and evaluation of a second-generation, pilot-scale graphite electrode DC arc furnace. Widely ranging simulants of INEL buried waste were prepared and processed in the Mark I furnace. The tests included melting of soils with metals, sludges, combustibles, and simulated drums. Very promising results in terms of waste product quality, volume reduction, heating efficiency, and operational reliability and versatility were obtained. The results indicate that the graphite electrode DC arc technology would be very well suited for treating high melting point wastes such as those found at INEL. The graphite electrode DC arc furnace has been demonstrated to be very simple, yet effective, with excellent prospects for remote or semi-remote operation.

Surma, J.E.; Freeman, C.J.; Powell, T.D. [Pacific Northwest Lab., Richland, WA (United States); Cohn, D.R.; Smatlak, D.L.; Thomas, P.; Woskov, P.P. [Massachusetts Inst. of Tech., Cambridge, MA (US). Plasma Fusion Center; Hamilton, R.A.; Titus, C.H.; Wittle, J.K. [Electro-Pyrolysis, Inc., Wayne, PA (US)

1993-06-01

201

Buried Seed Banks as Indicators of Seed Output along an Altitudinal Gradient.  

ERIC Educational Resources Information Center

Study of buried seed banks (viable seeds deposited in the soil near parent plants) provides a relatively easy way of determining cumulative effects on seed production and species' altitudinal limits. Sites, methods, validity, interpretation, problems of collection on a mountain, and germination techniques are discussed. (Author/DH)

Thompson, K.

1985-01-01

202

Statistical Analyses of Field Corrosion Data for Ductile Cast Iron Pipes Buried in Sandy Marine Sediments  

Microsoft Academic Search

Field corrosion studies were conducted on bare, ductile cast iron pipes buried 17 y in sandy marine sediment classified as sandy soil and containing iron bacteria, sulfate-reducing bacteria (SRB), and other bacteria. Chemical and biochemical analyses of the sediment were performed in the laboratory. Correlation between the maximum corrosion depth (P{sub max}) and 21 environmental factors was evaluated by applying

F. Kajiyama; Y. Koyama

1997-01-01

203

Seasonal variation in parental care, offspring development, and reproductive success in the burying beetle, Nicrophorus vespillo  

Microsoft Academic Search

Beetles of the genus Nicrophorus reproduce on small vertebrate carcasses that they bury in the soil to provide the larvae with food. Usually, both parents cooperate in brood care by feeding and guarding their progeny. 2. In pairs of the common European species N. vespillo, the duration of care depended on the time of year when the beetles reproduced. Both

INGE M EIERHOFER; HORST H. S CHWARZ

204

Pore-pressure gradients in the proximity of a submarine buried pipeline  

SciTech Connect

This paper is concerned with the two-dimensional finite-element modeling of the wave-induced pore-pressure field in the proximity of a submarine pipeline buried in sandy seabed sediments subject to continuous loading of regular surface waves. Neglecting inertial forces, a linear elastic stress-strain relationship for the soil, and Darcy`s law for the flow of pore-fluid are assumed. The model takes into account the compressibility of both components (i.e., pore-fluid and soil skeleton) of the two-phase medium. The results of numerical computations are discussed with respect to the hydraulic gradient in the upper part of seabed sediments just above the buried submarine pipeline. The pore-pressure gradient is studied as a function of geometry (depth of burial) as well as soil and pore-fluid compressibility parameters where the later of which is defined in terms of soil saturation conditions.

Magda, W. [Technical Univ. of Gdansk (Poland). Marine Civil Engineering Dept.

1995-12-31

205

Numerical solutions for determining wave-induced pressure distributions around buried pipelines  

E-print Network

Committee: Dr. Richard. F. Dominguez Numerical models using both the finite difference and i'inite element technique are developed to simulate the interaction of a two-dimensional pipe-soil-wave system. The wave-induced pressure distribution in the soil... region without an embedded pipe is first studied and solutions validated by comparing with existing analy- tical and experimental results. Numerical models are then used to solve the dynamic pressure distribution around. buried pipes. Results...

Lai, Ngok-Wai

1974-01-01

206

Time as An Important Soil-Forming Factor Influencing Modern and Ancient Magnetic Susceptibility Enhancement Along the Delaware River Valley, USA  

NASA Astrophysics Data System (ADS)

Magnetic susceptibility is an increasingly popular low-cost method for rapidly assessing paleoclimate and paleoenvironmental impact on buried soils. The goal of this study is to determine the primary influence(s) on soil magnetic susceptibility along floodplain, terrace and upland soils in the middle Delaware River Valley, USA, using environmental magnetic, pedologic, and stratigraphic techniques. Two-hundred thirty samples were collected from age-constrained sandy, quartz-rich, floodplain, terrace, and upland soils (Entisols, Inceptisols). A Kruskal-Wallis (K-W) and post-hoc Tukey-Kramer (T-K) (?=0.05) multiple comparisons analysis on 176 mass-specific low-field susceptibility (Xlf) assays show that A and B horizons are magnetically enhanced compared to C and E horizons (p<0.0001). Results of descriptive soil micromorphology show that A and B horizons contain anywhere from 10-50% more amorphous organic matter and clay films along pores than do C and E horizons. Enhanced Xlf values also correlate positively (R^2=0.63) with the soil molecular weathering ratio of Alumina/Bases, suggesting that increased weathering likely results in the formation of pedogenic magnetic minerals and enhanced magnetic susceptibility signal. Additional K-W and T-K testing show that Xlf results, when grouped by floodplain-terrace designation (i.e., chronofunction) are significantly different (p<0.0001). The older T3 terrace and upland Xlf values (0.34±0.14 10^-6 m^3 kg^-1) are greater than the younger T2 terrace (0.18±0.06 10^-6 m^3 kg^-1) values, which are greater than modern floodplain (0.09±0.01 10^-6 m^3 kg^-1) Xlf values. These data suggest that longer intervals of soil formation enhance the ?lf value. This hypothesis is further supported when 159 Xlf values are plotted vs. age for the entire Holocene. A locally-weighted regression smoothing curve (LOESS) shows two distinct intervals of magnetic enhancement during previously established dry intervals, the early and late-middle Holocene. We hypothesize that prolonged drought during the early and middle Holocene reduced flood frequency and magnitude and the likelihood of soil burial, resulting in longer soil forming intervals and higher Xlf values. Although precipitation influences the Xlf signature, the results from this study suggest that the magnetic susceptibility values of well-drained buried floodplain soils along the Delaware River Valley are partly a function of time.

Stinchcomb, G. E.; Peppe, D. J.; Driese, S. G.

2011-12-01

207

Acceleration without Horizons  

E-print Network

We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} velocity or, equivalently, by an acceleration parameter and terminal velocity.

Doria, Alaric

2015-01-01

208

Acceleration without Horizons  

E-print Network

We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} velocity or, equivalently, by an acceleration parameter and terminal velocity.

Alaric Doria; Gerardo Munoz

2015-02-18

209

Optimal investment horizons  

NASA Astrophysics Data System (ADS)

In stochastic finance, one traditionally considers the return as a competitive measure of an asset, i.e., the profit generated by that asset after some fixed time span ?t, say one week or one year. This measures how well (or how bad) the asset performs over that given period of time. It has been established that the distribution of returns exhibits ``fat tails'' indicating that large returns occur more frequently than what is expected from standard Gaussian stochastic processes [1-3]. Instead of estimating this ``fat tail'' distribution of returns, we propose here an alternative approach, which is outlined by addressing the following question: What is the smallest time interval needed for an asset to cross a fixed return level of say 10%? For a particular asset, we refer to this time as the investment horizon and the corresponding distribution as the investment horizon distribution. This latter distribution complements that of returns and provides new and possibly crucial information for portfolio design and risk-management, as well as for pricing of more exotic options. By considering historical financial data, exemplified by the Dow Jones Industrial Average, we obtain a novel set of probability distributions for the investment horizons which can be used to estimate the optimal investment horizon for a stock or a future contract.

Simonsen, I.; Jensen, M. H.; Johansen, A.

2002-06-01

210

In-situ vitrification of soil  

DOEpatents

A method of vitrifying soil at or below a soil surface location. Two or more conductive electrodes are inserted into the soil for heating of the soil mass between them to a temperature above its melting temperature. Materials in the soil, such as buried waste, can thereby be effectively immobilized.

Brouns, Richard A. (Kennewick, WA); Buelt, James L. (Richland, WA); Bonner, William F. (Richland, WA)

1983-01-01

211

A Natural Seismic Isolating System: The Buried Mangrove Effects  

E-print Network

The Belleplaine test site, located in the island of Guadeloupe (French Lesser Antilles) includes a three-accelerometer vertical array, designed for liquefac- tion studies. The seismic response of the soil column at the test site is computed using three methods: the spectral ratio method using the vertical array data, a numerical method using the geotechnical properties of the soil column, and an operative fre- quency domain decomposition (FDD) modal analysis method. The Belleplaine test site is characterized by a mangrove layer overlaid by a stiff sandy deposit. This con- figuration is widely found at the border coast of the Caribbean region, which is exposed to high seismic hazard. We show that the buried mangrove layer plays the role of an isolation system equivalent to those usually employed in earthquake engineering aimed at reducing the seismic shear forces by reducing the internal stress within the structure. In our case, the flexibility of the mangrove layer reduces the distortion and the stress in the...

Gueguen, Philippe; Foray, Pierre; Rousseau, Christophe; Maury, Julie; 10.1785/0120100129

2011-01-01

212

Instability of enclosed horizons  

NASA Astrophysics Data System (ADS)

We point out that there are solutions to the scalar wave equation on dimensional Minkowski space with finite energy tails which, if they reflect off a uniformly accelerated mirror due to (say) Dirichlet boundary conditions on it, develop an infinite stress-energy tensor on the mirror's Rindler horizon. We also show that, in the presence of an image mirror in the opposite Rindler wedge, suitable compactly supported arbitrarily small initial data on a suitable initial surface will develop an arbitrarily large stress-energy scalar near where the two horizons cross. Also, while there is a regular Hartle-Hawking-Israel-like state for the quantum theory between these two mirrors, there are coherent states built on it for which there are similar singularities in the expectation value of the renormalized stress-energy tensor. We conjecture that in other situations with analogous enclosed horizons such as a (maximally extended) Schwarzschild black hole in equilibrium in a (stationary spherical) box or the (maximally extended) Schwarzschild-AdS spacetime, there will be similar stress-energy singularities and almost-singularities—leading to instability of the horizons when gravity is switched on and matter and gravity perturbations are allowed for. All this suggests it is incorrect to picture a black hole in equilibrium in a box or a Schwarzschild-AdS black hole as extending beyond the past and future horizons of a single Schwarzschild (/Schwarzschild-AdS) wedge. It would thus provide new evidence for 't Hooft's brick wall model while seeming to invalidate the picture in Maldacena's ` Eternal black holes in AdS'. It would thereby also support the validity of the author's matter-gravity entanglement hypothesis and of the paper ` Brick walls and AdS/CFT' by the author and Ortíz.

Kay, Bernard S.

2015-03-01

213

Investors' horizon and stock prices  

E-print Network

This dissertation consists of three essays on the relation between investors' trading horizon and stock prices. The first chapter explores the theoretical relation between the horizon of traders and the negative externality ...

Parsa, Sahar

2011-01-01

214

Corrosion Behavior of Ductile Cast-Iron Pipe in Soil Environments  

Microsoft Academic Search

Ductile cast-iron pipe was buried for up to fourteen years in a variety of soil environments. This final report, comparing its performance to that of carbon steel buried in the same soils, suggests the two substances corrode at nearly the same rates when encased in some soils. Different soils, however, alter the corrosion rates considerably for both materials.

W. F. Gerhold

1976-01-01

215

Spacetimes containing slowly evolving horizons  

E-print Network

Slowly evolving horizons are trapping horizons that are "almost" isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the associated mass scales, they also suggest that slowly evolving horizons are the norm rather than the exception in astrophysical processes that involve stellar-scale black holes.

W. Kavanagh; I. Booth

2006-08-29

216

Spacetimes containing slowly evolving horizons  

SciTech Connect

Slowly evolving horizons are trapping horizons that are ''almost'' isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the mass scales and orders of magnitude that arise in these calculations, we conjecture that slowly evolving horizons are the norm rather than the exception in astrophysical processes that involve stellar-scale black holes.

Kavanagh, William; Booth, Ivan [Department of Physics and Physical Oceanography, Memorial University of Newfoundland St. John's, Newfoundland and Labrador, A1B 3X7 (Canada); Department of Mathematics and Statistics, Memorial University of Newfoundland St. John's, Newfoundland and Labrador, A1C 5S7 (Canada)

2006-08-15

217

Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste  

SciTech Connect

The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting.

Allan, M.L.

1996-06-01

218

Buried Waste Integrated Demonstration. Technology summary  

SciTech Connect

The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that offer promising solutions to the problems associated with the remediation of buried waste. BWID addresses the difficult remediation problems associated with DOE complex-wide buried waste, particularly transuranic (TRU) contaminated buried waste. BWID has implemented a systems approach to the development and demonstration of technologies that will characterize, retrieve, treat, and dispose of DOE buried wastes. This approach encompasses the entire remediation process from characterization to post-monitoring. The development and demonstration of the technology is predicated on how a technology fits into the total remediation process. To address all of these technological issues, BWID has enlisted scientific expertise of individuals and groups from within the DOE Complex, as well as experts from universities and private industry. The BWID mission is to support development and demonstration of a suite of technologies that, when integrated with commercially-available technologies, forms a comprehensive, remediation system for the effective and efficient remediation of buried waste throughout the DOE Complex. BWID will evaluate and validate demonstrated technologies and transfer this information and equipment to private industry to support the Office of Environmental Restoration (ER), Office of Waste Management (WM), and Office of Facility Transition (FT) remediation planning and implementation activities.

Not Available

1994-03-01

219

TNX Burying Ground: Environmental information document  

SciTech Connect

The TNX Burying Ground, located within the TNX Area of the Savannah River Plant (SRP), was originally built to dispose of debris from an experimental evaporator explosion at TNX in 1953. This evaporator contained approximately 590 kg of uranyl nitrate. From 1980 to 1984, much of the waste material buried at TNX was excavated and sent to the SRP Radioactive Waste Burial Grounds for reburial. An estimated 27 kg of uranyl nitrate remains buried at TNX. The TNX Burying Ground consists of three sites known to contain waste and one site suspected of containing waste material. All four sites are located within the TNX security fenceline. Groundwater at the TNX Burying Ground was not evaluated because there are no groundwater monitoring wells installed in the immediate vicinity of this waste site. The closure options considered for the TNX Burying Ground are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated.

Dunaway, J.K.W.; Johnson, W.F.; Kingley, L.E.; Simmons, R.V.; Bledsoe, H.W.

1987-03-01

220

Soils âField Characterization, Collection, and Laboratory Analysis  

NSDL National Science Digital Library

Field characterization of soil profiles in coniferous and deciduous settings; sample collection of soils from different horizons; laboratory analysis of soil moisture, soil organic carbon (by loss on ignition), and grain size distribution (by sieving)

Abir Biswas

221

Decoding implicit information from the soil map of Belgium and implications for spatial modelling and soil classification  

NASA Astrophysics Data System (ADS)

A systematic soil survey of Belgium was conducted from 1948 to 1991. Field surveys were done at the detailed scale of 1:5000 with the final maps published at a 1:20,000 scale. Soil surveyors were classifying soils in the field according to physical and morphogenetic characteristics such as texture, drainage class and profile development. Mapping units are defined as a combination of these characteristics but to which modifiers can be added such as parent material, stoniness or depth to substrata. Interpretation of the map towards predicting soil properties seems straight forward. Consequently, since the soil map has been digitized, it has been used for e.g. hydrological modelling or for estimating soil organic carbon content at sub-national and national level. Besides the explicit information provided by the legend, a wealth of implicit information is embedded in the map. Based on three cases, we illustrate that by decoding this information, properties pertaining to soil drainage or soil organic carbon content can be assessed more accurately. First, the presence/absence of fragipans affects the soil hydraulic conductivity. Although a dedicated symbol exits for fragipans (suffix "...m"), it is only used explicitly in areas where fragipans are not all that common. In the Belgian Ardennes, where fragipans are common, their occurrence is implicitly implied for various soil types mentioned in explanatory booklets. Second, whenever seasonal or permanent perched water tables were observed, these were indicated by drainage class ".h." or ".i.", respectively. Stagnic properties have been under reported as typical stagnic mottling - i.e. when the surface of soil peds are lighter and/or paler than the more reddish interior - were not distinguished from mottling due to groundwater gley. Still, by combining information on topography and the occurrence of substratum layers, stagnic properties can be inferred. Thirdly, soils with deep anthropogenic enriched organic matter (Anthrosols) are distinguished for their specific profile development (code "..m"). Obviously, when assessing soil organic carbon content these soil types need particular consideration. Soils in the Campine region with anthropogenic layers only 30 to 40 cm thick, not being Anthrosols, got a specific suffix code ("…3"). Still, as these soils may have a buried Ah horizon of up to 20 cm, their soil organic carbon content can be comparable to those of Anthrosols. The buried Ah horizon is however not explicitly mapped; its presence needs to be inferred from other environmental information. In conclusion, conventional soil maps convey more information than what transpires from just the explicit legend's semantics. Although a challenge, decoding the implicit information should be particularly useful for spatial modeling. The cases also point to the importance of classifying soil characteristics explicitly, wherever possible, and in particularly when soil maps are integrated into geographical information systems.

Dondeyne, Stefaan; Legrain, Xavier; Colinet, Gilles; Van Ranst, Eric; Deckers, Jozef

2014-05-01

222

Modeling physical and biogeochemical controls over carbon accumulation in a boreal forest soil  

USGS Publications Warehouse

Boreal soils are important to the global C cycle owing to large C stocks, repeated disturbance from fire, and the potential for permafrost thaw to expose previously stable, buried C. To evaluate the primary mechanisms responsible for both short- and long-term C accumulation in boreal soils, we developed a multi-isotope (12,14C) Soil C model with dynamic soil layers that develop through time as soil organic matter burns and reaccumulates. We then evaluated the mechanisms that control organic matter turnover in boreal regions including carbon input rates, substrate recalcitrance, soil moisture and temperature, and the presence of historical permafrost to assess the importance of these factors in boreal C accumulation. Results indicate that total C accumulation is controlled by the rate of carbon input, decomposition rates, and the presence of historical permafrost. However, unlike more temperate ecosystems, one of the key mechanisms involved in C preservation in boreal soils examined here is the cooling of subsurface soil layers as soil depth increases rather than increasing recalcitrance in subsurface soils. The propagation of the 14C bomb spike into soils also illustrates the importance of historical permafrost and twentieth century warming in contemporary boreal soil respiration fluxes. Both 14C and total C simulation data also strongly suggest that boreal SOM need not be recalcitrant to accumulate; the strong role of soil temperature controls on boreal C accumulation at our modeling test site in Manitoba, Canada, indicates that carbon in the deep organic soil horizons is probably relatively labile and thus subject to perturbations that result from changing climatic conditions in the future. Copyright 2006 by the American Geophysical Union.

Carrasco, J.J.; Neff, J.C.; Harden, J.W.

2006-01-01

223

Middle Pennsylvanian pioneer plant assemblage buried in situ by volcanic ash-fall, central Bohemia, Czech Republic  

Microsoft Academic Search

Palaeoecological analysis of a single-age plant assemblage of the middle Westphalian age (Bolsovian = middle Moscovian) preserved in the tuff bed at the base of the Whetstone Horizon in the roof of the Lower Radnice Coal of the Štilec opencast mine in central Bohemia is provided. This plant assemblage represents a peat-forming phytocoenosis buried in situ by volcanic ash-fall as

Milan Libertín; Stanislav Opluštil; Josef Pšeni?ka; Ji?í Bek; Ivana Sýkorová; Ji?ina Dašková

2009-01-01

224

Behind the geon horizon  

NASA Astrophysics Data System (ADS)

We explore the Papadodimas–Raju prescription for reconstructing the region behind the horizon of one-sided black holes in AdS/CFT in the case of the {R}{{P}2} geon—a simple, analytic example of a single-sided, asymptotically AdS3 black hole, which corresponds to a pure CFT state that thermalizes at late times. We show that in this specific example, the mirror operators involved in the reconstruction of the interior have a particularly simple form: the mirror of a single trace operator at late times is just the corresponding single trace operator at early times. We use some explicit examples to explore how changes in the state modify the geometry inside the horizon.

Guica, Monica; Ross, Simon F.

2015-03-01

225

Behind the geon horizon  

E-print Network

We explore the Papadodimas-Raju prescription for reconstructing the region behind the horizon of one-sided black holes in AdS/CFT in the case of the RP^2 geon - a simple, analytic example of a single-sided, asymptotically AdS_3 black hole, which corresponds to a pure CFT state that thermalises at late times. We show that in this specific example, the mirror operators involved in the reconstruction of the interior have a particularly simple form: the mirror of a single trace operator at late times is just the corresponding single trace operator at early times. We use some explicit examples to explore how changes in the state modify the geometry inside the horizon.

Monica Guica; Simon F. Ross

2014-12-02

226

Redistribution of soil nitrogen, carbon and organic matter by mechanical disturbance during whole-tree harvesting in northern hardwoods  

USGS Publications Warehouse

To investigate whether mechanical mixing during harvesting could account for losses observed from forest floor, we measured surface disturbance on a 22 ha watershed that was whole-tree harvested. Surface soil on each 10 cm interval along 81, randomly placed transects was classified immediately after harvesting as mineral or organic, and as undisturbed, depressed, rutted, mounded, scarified, or scalped (forest floor scraped away). We quantitatively sampled these surface categories to collect soil in which preharvest forest floor might reside after harvest. Mechanically mixed mineral and organic soil horizons were readily identified. Buried forest floor under mixed mineral soil occurred in 57% of mounds with mineral surface soil. Harvesting disturbed 65% of the watershed surface and removed forest floor from 25% of the area. Mechanically mixed soil under ruts with organic or mineral surface soil, and mounds with mineral surface soil contained organic carbon and nitrogen pools significantly greater than undisturbed forest floor. Mechanical mixing into underlying mineral soil could account for the loss of forest floor observed between the preharvest condition and the second growing season after whole-tree harvesting. ?? 1992.

Ryan, D.F.; Huntington, T.G.; Wayne, Martin C.

1992-01-01

227

Receding Horizon Covariance Control  

E-print Network

: Chair of Committee, Raktim Bhattacharya Committee Members, Colleen Robles Igor Zelenko Head of Department, Dimitris Lagoudas August 2012 Major Subject: Aerospace Engineering iii ABSTRACT Receding Horizon Covariance Control. (August 2012) Eric... Bhattacharya, for his tutelage, mentorship and advice, and for introducing me to the wonderful worlds of real- time trajectory optimization and uncertainty propagation. I am also grateful to my committee members Dr. Colleen Robles and Dr. Igor Zelenko...

Wendel, Eric

2012-10-19

228

Environmental fate and transport of chemical signatures from buried landmines -- Screening model formulation and initial simulations  

SciTech Connect

The fate and transport of chemical signature molecules that emanate from buried landmines is strongly influenced by physical chemical properties and by environmental conditions of the specific chemical compounds. Published data have been evaluated as the input parameters that are used in the simulation of the fate and transport processes. A one-dimensional model developed for screening agricultural pesticides was modified and used to simulate the appearance of a surface flux above a buried landmine, estimate the subsurface total concentration, and show the phase specific concentrations at the ground surface. The physical chemical properties of TNT cause a majority of the mass released to the soil system to be bound to the solid phase soil particles. The majority of the transport occurs in the liquid phase with diffusion and evaporation driven advection of soil water as the primary mechanisms for the flux to the ground surface. The simulations provided herein should only be used for initial conceptual designs of chemical pre-concentration subsystems or complete detection systems. The physical processes modeled required necessary simplifying assumptions to allow for analytical solutions. Emerging numerical simulation tools will soon be available that should provide more realistic estimates that can be used to predict the success of landmine chemical detection surveys based on knowledge of the chemical and soil properties, and environmental conditions where the mines are buried. Additional measurements of the chemical properties in soils are also needed before a fully predictive approach can be confidently applied.

Phelan, J.M.; Webb, S.W.

1997-06-01

229

Comparison of broadband and hyperspectral thermal infrared imaging of buried threat objects  

NASA Astrophysics Data System (ADS)

Previous research by many groups has shown that broad-band thermal infrared (TIR) imagers can detect buried explosive threat devices, such as unexploded ordnance (UXO), landmines and improvised explosive devices (IEDs). Broad-band detection measures the apparent temperature - an average over the wave band of the product of the true soil surface temperature and the emissivity. Broad-band detection suffers from inconsistent performance (low signal, high clutter rates), due in part to diurnal variations, environmental and meteorological conditions, and soil surface effects. It has been suggested that hyperspectral TIR imaging might have improved performance since it can, in principle, allow extraction of the wavelength-dependent emissivity and the true soil surface temperature. This would allow the surface disturbance effects to be separated from the soil column (bulk) effects. A significant, and as yet unanswered, question is whether hyperspectral TIR images provide better detection capability (higher probability of detection and/or lower false alarm rate) than do broad-band thermal images. TIR hyperspectral image data of threat objects, buried and surface-laid in bare soil, were obtained in arid, desert-like conditions over full diurnal cycles for several days. Regions of interest containing threat objects and backgrounds were extracted throughout the time period. Simulated broad-band images were derived from the hyperspectral images. The diurnal variation of the images was studied. Hyperspectral was found to provide some advantage over broad-band imaging in detection of buried threat objects for the limited data set studied.

McFee, John E.; Achal, Steve B.; Diaz, Alejandra U.; Faust, Anthony A.

2013-06-01

230

HEGGY ET PAILLOU. 2005: PROBING BURIED CRATERS Probing Structural Elements of Small Buried Craters Using Ground-Penetrating Radar  

E-print Network

HEGGY ET PAILLOU. 2005: PROBING BURIED CRATERS Probing Structural Elements of Small Buried Craters-latitude cratered terrains in terms of crater density, size, and geomorphology. Profiles across small-buried craters BURIED CRATERS Index Terms: (0933) Remote sensing, (5420) Impact phenomena, (6022, 8136) Cratering, (5494

Paris-Sud XI, Université de

231

Secondary metabolites released by the burying beetle Nicrophorus vespilloides: chemical analyses and possible ecological functions.  

PubMed

Burying beetles of the genus Nicrophorus localize small vertebrate carcasses by emitted volatiles. The carcass that serves as reproduction and breeding site is buried in the soil by the beetles. Biparental care for offspring includes both preservation of the carrion and its preparation as diet and nursery. Buried carcasses show no signs of microbial decay, and those experimentally treated with Nicrophorus secretions are known to grow fewer bacteria and fungi. In order to investigate the chemical composition of these secretions, we used GC-MS for analysis of methanolic extracts of anal and oral secretions released by adult N. vespilloides. Furthermore, we analyzed the headspace of adult N. vespilloides by SPME-GC-MS and searched for compounds with known antimicrobial activity. We identified 34 compounds in the headspace, and anal and oral secretions, 26 of which occurred consistently. We discuss the ecological relevance of these compounds with respect to both their antimicrobial activity and ecological relevance. PMID:21667150

Degenkolb, Thomas; Düring, Rolf-Alexander; Vilcinskas, Andreas

2011-07-01

232

Holocene Fire History of an Eastern Oregon Forest Based on Soil Charcoal Radiocarbon Dates  

NASA Astrophysics Data System (ADS)

Limited research has been done on long-term forest fire histories in northeastern Oregon. As part of an investigation to determine the minimum age of a 300 ha landslide in the Blue Mountains, a pit was excavated near the toe of the slide. The pit, located in a depression between the landslide and a ridge, contains massive clays and silts, and an 8000-year sequence of forest fires recorded in 7 buried charcoal layers. Eight- thousand-year-old Mazama Ash (Crater Lake, Oregon) is common in the area, but no tephra was found in the excavation. The upper 17 cm is organic rich soil. Seven horizons of charcoal are present; the upper six are subhorizontal and occur at depths of 17, 36, 41, 46, 52, and 57 cm. The lowest charcoal horizon follows a disconformity that cuts diagonally across the pit from 85 to 125 cm below the surface; oxidation in the form of orange mottling occurs above this disconformity (interpreted to be a paleoslope) and is prominent below it. The charcoal horizons provide evidence of large-scale forest fires in the vicinity, with differing intensities represented by the amount of charcoal in each horizon. The layers vary in thickness from 2 to 6 cm. Five charcoal horizons were radiocarbon dated (AMS) and calendar calibrated. The charcoal at the base of the soil (at 17 cm) provided an age of AD 1670 to 1960; this horizon correlates with widespread fires in the Blue Mountains in AD 1855. The horizon second closest to the surface (at 36 cm) provided an age of 1310 ± 40 B.P. The thickest horizon (at 46 cm) yielded an age of 2420 ± 40 B.P. The lowest horizontal horizon (at 57 cm) provided an age of 3460 ± 40 B.P. The lowest charcoal (at the disconformity) yielded an age of 7990 ± 40 B.P. Based on radiocarbon dates, the mean rate of sedimentation in the closed depression is approximately 1.2 cm/century. Fire episodes (which correspond remarkably well with a lake core site approximately 150 km south), indicate relatively long periods (from 400 to over 4000 years) between large, stand-replacing fires, and are suggestive of changing climate and ecological conditions in this forest setting. Past fire sequences provide important clues to predicting future climate-wildfire scenarios.

Carson, R. J.; Malkemus, D.; Clifton, C. F.

2006-12-01

233

CSMRI Bagged Soil Disposal Summary Report  

E-print Network

and justification for techniques used are provided in the CSMRI Creekside Site Contaminated Soil Disposal Work Plan to identify, excavate, and dispose of contaminated soils at the Site. Fieldwork began in April 2004/metals- contaminated soil were excavated, bagged, and staged on the Site by New Horizons. At the time of New Horizons

234

Dissolved organic carbon and sulfate sorption by spodosol mineral horizons  

SciTech Connect

Carbon cycling in soils is an important process that involves the movement of large amounts of dissolved organic carbon (DOC) within the soil profile. Recent work in a variety of soils has indicated that DOC sorption properties of mineral horizons play an important role in the retention of DOC. As part of the Watershed Manipulation Project at Bear Brook Watershed in Maine (BBWM), the solubilization and movement of carbon in terrestrial and aquatic ecosystems were evaluated. For the study, the objectives were to: (1) determine the sorption properties of mineral horizons present on the BBWM watersheds for SO4 and DOC; (2) evaluate the effect of solution pH and temperature on soil DOC sorption; and (3) examine competitive sorption effects between DOC and SO4.

Vance, G.F.; David, M.B.

1992-01-01

235

Sensor System Fo4r Buried Waste Containment Sites  

DOEpatents

A sensor system for a buried waste containment site having a bottom wall barrier and/or sidewall barriers, for containing hazardous waste. The sensor system includes one or more sensor devices disposed in one or more of the barriers for detecting a physical parameter either of the barrier itself or of the physical condition of the surrounding soils and buried waste, and for producing a signal representing the physical parameter detected. Also included is a signal processor for receiving signals produced by the sensor device and for developing information identifying the physical parameter detected, either for sounding an alarm, displaying a graphic representation of a physical parameter detected on a viewing screen and/or a hard copy printout. The sensor devices may be deployed in or adjacent the barriers at the same time the barriers are deployed and may be adapted to detect strain or cracking in the barriers, leakage of radiation through the barriers, the presence and leaking through the barriers of volatile organic compounds, or similar physical conditions.

Smith, Ann Marie (Pocatello, ID); Gardner, Bradley M. (Idaho Falls, ID); Kostelnik, Kevin M. (Idaho Falls, ID); Partin, Judy K. (Idaho Falls, ID); Lancaster, Gregory D. (Idaho Falls, ID); Pfeifer, Mary Catherine (San Antonio, NM)

2005-09-27

236

Sensor System Fo4r Buried Waste Containment Sites  

DOEpatents

A sensor system for a buried waste containment site having a bottom wall barrier and sidewall barriers, for containing hazardous waste. The sensor system includes one or more sensor devices disposed in one or more of the barriers for detecting a physical parameter either of the barrier itself or of the physical condition of the surrounding soils and buried waste, and for producing a signal representing the physical parameter detected. Also included is a signal processor for receiving signals produced by the sensor device and for developing information identifying the physical parameter detected, either for sounding an alarm, displaying a graphic representation of a physical parameter detected on a viewing screen and/or a hard copy printout. The sensor devices may be deployed in or adjacent the barriers at the same time the barriers are deployed and may be adapted to detect strain or cracking in the barriers, leakage of radiation through the barriers, the presence and leaking through the barriers of volatile organic compounds, or similar physical conditions.

Smith, Ann Marie (Pocatello, ID); Gardner, Bradley M. (Idaho Falls, ID); Kostelnik, Kevin M. (Idaho Falls, ID); Partin, Judy K. (Idaho Falls, ID); Lancaster, Gregory D. (Idaho Falls, ID); Pfeifer, Mary Catherine (San Antonio, NM)

2003-11-18

237

New Horizons Web Site  

NSDL National Science Digital Library

NASA launched its New Horizons spacecraft mission on January 19, 2006. The purpose of the mission is to provide the first fly-by of the Pluto-Charon system and the first up-close exploration of the area at the edge of the solar system called the Kuyper Belt. This mission webpage provides daily updates about the location of the vehicle with graphics that show its position in relation to the planets and its planned course through the solar system from several perspectives.

NASA JHU/Applied Physics Laboratory

238

New Horizons at Pluto  

NASA Technical Reports Server (NTRS)

Artist's concept of the New Horizons spacecraft as it approaches Pluto and its largest moon, Charon, in July 2015. The craft's miniature cameras, radio science experiment, ultraviolet and infrared spectrometers and space plasma experiments will characterize the global geology and geomorphology of Pluto and Charon, map their surface compositions and temperatures, and examine Pluto's atmosphere in detail. The spacecraft's most prominent design feature is a nearly 7-foot (2.1-meter) dish antenna, through which it will communicate with Earth from as far as 4.7 billion miles (7.5 billion kilometers) away.

2007-01-01

239

DIVISION S-5--PEDOLOGY Pedogenesis of Vesicular Horizons, Cima Volcanic Field, Mojave Desert, California  

E-print Network

DIVISION S-5--PEDOLOGY Pedogenesis of Vesicular Horizons, Cima Volcanic Field, Mojave Desert vesicular soil peds. Com- Volcanic Field are underlain by a vesicular horizon with strong coarse bining no-ors have up to 40% clay and 12% CaCO3 whereas sediments adhering menclature. For example, although

Ahmad, Sajjad

240

Cold planar horizons are floppy  

NASA Astrophysics Data System (ADS)

Extremal planar black holes of four-dimensional Einstein-Maxwell theory with a negative cosmological constant have an AdS2×R2 near horizon geometry. We show that this near horizon geometry admits a deformation to a two parameter family of extremal geometries with inhomogeneous, spatially periodic horizons. At a linear level, static inhomogeneous perturbations of AdS2×R2 decay towards the horizon and thus appear irrelevant under the holographic renormalization group flow. However we have found numerically that nonlinear effects lead to inhomogeneous near horizon geometries. A consequence of these observations is that an arbitrarily small periodic deformation of the boundary theory at nonzero charge density does not flow to AdS2×R2 in the IR, but rather to an inhomogeneous horizon. These results shed light on existing numerical studies of low temperature periodically modulated black holes and also offer a new mechanism for holographic metal-insulator crossovers or transitions.

Hartnoll, Sean A.; Santos, Jorge E.

2014-06-01

241

Soil response to a 3-year increase in temperature and nitrogen deposition measured in a mature boreal forest using ion-exchange membranes.  

PubMed

The projected increase in atmospheric N deposition and air/soil temperature will likely affect soil nutrient dynamics in boreal ecosystems. The potential effects of these changes on soil ion fluxes were studied in a mature balsam fir stand (Abies balsamea [L.] Mill) in Quebec, Canada that was subjected to 3 years of experimentally increased soil temperature (+4 °C) and increased inorganic N concentration in artificial precipitation (three times the current N concentrations using NH4NO3). Soil element fluxes (NO3, NH4, PO4, K, Ca, Mg, SO4, Al, and Fe) in the organic and upper mineral horizons were monitored using buried ion-exchange membranes (PRS™ probes). While N additions did not affect soil element fluxes, 3 years of soil warming increased the cumulative fluxes of K, Mg, and SO4 in the forest floor by 43, 44, and 79 %, respectively, and Mg, SO4, and Al in the mineral horizon by 29, 66, and 23 %, respectively. We attribute these changes to increased rates of soil organic matter decomposition. Significant interactions of the heating treatment with time were observed for most elements although no clear seasonal patterns emerged. The increase in soil K and Mg in heated plots resulted in a significant but small K increase in balsam fir foliage while no change was observed for Mg. A 6-15 % decrease in foliar Ca content with soil warming could be related to the increase in soil-available Al in heated plots, as Al can interfere with the root uptake of Ca. PMID:25139238

D'Orangeville, Loïc; Houle, Daniel; Côté, Benoît; Duchesne, Louis

2014-12-01

242

Silicon on insulator with active buried regions  

DOEpatents

A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

McCarthy, Anthony M. (Menlo Park, CA)

1998-06-02

243

Silicon on insulator with active buried regions  

DOEpatents

A method is disclosed for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors. 10 figs.

McCarthy, A.M.

1996-01-30

244

Silicon on insulator with active buried regions  

DOEpatents

A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

McCarthy, Anthony M. (Menlo Park, CA)

1996-01-01

245

Silicon on insulator with active buried regions  

DOEpatents

A method is disclosed for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors. 10 figs.

McCarthy, A.M.

1998-06-02

246

Buried Waste Integrated Demonstration stakeholder involvement model  

SciTech Connect

The Buried Waste Integrated Demonstration (BWID) is a program funded by the US Department of Energy (DOE) Office of Technology Development. BWID supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. Stakeholder participation in the DOE Environmental Management decision-making process is critical to remediation efforts. Appropriate mechanisms for communication with the public, private sector, regulators, elected officials, and others are being aggressively pursued by BWID to permit informed participation. This document summarizes public outreach efforts during FY-93 and presents a strategy for expanded stakeholder involvement during FY-94.

Kaupanger, R.M.; Kostelnik, K.M.; Milam, L.M.

1994-04-01

247

Prioritization for rehabilitation of buried lifelines  

SciTech Connect

Seismic rehabilitation or retrofit is a cost-effective way to prevent pipeline damage caused by future earthquakes. In general, it is very difficult, if not impossible, to rehabilitate all buried pipelines at the same time because of limited funds and time available. The purpose of this study is to establish a priority strategy for rehabilitation of buried pipelines considering several important factors such as pipeline damage probability, rehabilitation cost, rehabilitation rate (e.g. km/day), pipeline importance and total funds available.

Wang, L.R.L.; Ishibashi, I. [Old Dominion Univ., Norfolk, VA (United States); Li, H.

1995-12-31

248

HORIZON SENSING (PROPOSAL NO.51)  

SciTech Connect

Real-time horizon sensing on continuous mining machines is becoming an industry tool. Installation and testing of production-grade Horizon Sensor (HS) systems continued this quarter at Monterey Coal Company (ExxonMobil), Mountain Coal Company West Elk Mine (Arch), and Ohio Valley Coal Company (OVC). Monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.

Larry G. Stolarczyk

2003-07-01

249

HORIZON SENSING (PROPOSAL NO.51)  

SciTech Connect

Real-time horizon sensing on continuous mining (CM) machines is becoming an industry tool. Installation and testing of production-grade Horizon Sensor (HS) systems has been ongoing this quarter at Monterey Coal Company (ExxonMobil), Mountain Coal Company West Elk Mine (Arch), Deserado Mining Company (Blue Mountain Energy), and The Ohio Valley Coal Company (TOVCC). Monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.

Larry G. Stolarczyk

2003-07-30

250

Looking beyond the horizon  

E-print Network

In this short talk we review our results from the paper hep-th/0604075 with the main stress on the issues of causality and acoustic metric in eikonal approximation. In addition we correct the formula for the redshift of sound signals from our original work. We show that, if there exists a special kind of Born-Infeld type scalar field, then one can send information from inside a black hole. This information is encoded in perturbations of the field propagating in non-trivial scalar field backgrounds, which serve as a "new ether". Although the action of the theory is manifestly Lorentz-invariant the non-trivial solutions break this symmetry spontaneously, allowing, the superluminal propagation of perturbations with respect to this "new ether". We found the stationary solution for background, which describes the accretion of the scalar field onto a black hole. Examining the propagation of small perturbations around this solution we show that the signals emitted inside the Schwarzschild horizon can reach an observer located outside the black hole. Thus the accreting field forms a hydrodynamical analog of a black hole whose horizon is inside of the gravitational black hole drawing in the scalar field.

Eugeny Babichev; Viatcheslav Mukhanov; Alexander Vikman

2007-04-25

251

Assessing bioturbation using micromorphology and biosilicate evidence: A case study of the early-Holocene Brady Soil, central Great Plains, USA  

NASA Astrophysics Data System (ADS)

The Old Wauneta Roadcut site in southwestern Nebraska exhibits a 1.2 meter-thick exposure of the Brady Soil, a buried paleosol which formed within loess during the Pleistocene-Holocene transition. Excavation of the loess-paleosol sequence has revealed considerable bioturbation by plant roots, invertebrates, and small vertebrates. Bioturbation was not restricted to a single time period, but occurred continually throughout soil development, as evidenced by differing sediment fills and crosscutting relationships. The Brady Soil is an accretionary soil within the uppermost part of the Last Glacial Maximum Peoria Loess. At the base of the solum, the Bkb horizon exhibits an increased illuvial clay and carbonate content, and contains extensive, small (~2cm width), backfilled burrows typically produced by cicada nymphs (Cicadidae) or beetle larvae. The most stable period of the Brady Soil is expressed by the dark (9.8 YR 4/1), thick Ab horizon. This is overlain by an ACb horizon, where soil formation was being extinguished by the onset of Holocene-age Bignell Loess deposition. Within the upper solum and Bignell Loess, a shift in biota activity occurs as indicated by the large burrow (6-12 cm width) and chamber (30-40 cm width) systems observed. Trace sizes suggest that a burrowing rodent, such as the prairie dog (Cynomys sp.) or ground squirrel (Spermophilus sp.), was responsible for their creation. Soil micromorphology was used to distinguish sediment-size classes, mineralogy, and clay morphology of specific loess deposits and soil horizons in order to track displacement of sediment through the profile due to bioturbation. Five block samples were taken in undisturbed sediment and soil horizons for thin-section analysis. Twelve additional samples of burrow cross-sections or bioturbated sediment were analyzed for comparison. Soil features produced by faunal and floral activity were differentiated from features produced by pedologic processes through the identification and classification of granular and spongy microstructures indicative of excrement, calcitic biospheroids, infilling, meniscate backfilling, channel microstructures, and well-oriented clay coatings. Sediment morphology, mineralogy of the infill and backfill material, and biosilicate assemblages were used to trace the material to the source sediment location providing a timeline for events of bioturbation. Defining localized versus deep-mixing events provides an assessment of the disturbance to paleoclimate proxies and age data and will allow for a more accurate paleoclimate reconstruction in this heavily bioturbated paleosol.

Woodburn, T. L.; Hasiotis, S. T.; Johnson, W. C.

2012-12-01

252

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance  

ERIC Educational Resources Information Center

Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

Seybold, C. A.; Harms, D. S.; Grossman, R. B.

2009-01-01

253

The Panther Mountain circular structure, a possible buried meteorite crater  

NASA Technical Reports Server (NTRS)

Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

1992-01-01

254

Technologies on the Horizon: Teachers Respond to the Horizon Report  

ERIC Educational Resources Information Center

The purpose of this study was to investigate teachers' beliefs regarding the integration of technologies from the 2011 K-12 edition of the "Horizon Report" into their local, public school contexts. Teachers read the "Horizon Report" and then participated in an asynchronous, threaded discussion focusing on technologies they…

Hodges, Charles B.; Prater, Alyssa H.

2014-01-01

255

Near Horizon Structure of Extremal Vanishing Horizon Black Holes  

E-print Network

We study the near horizon structure of Extremal Vanishing Horizon (EVH) black holes, extremal black holes with vanishing horizon area with a vanishing one-cycle on the horizon. We construct the most general near horizon EVH and near-EVH ansatz for the metric and other fields, like dilaton and gauge fields which may be present in the theory. We prove that (1) the near horizon EVH geometry for generic gravity theory in generic dimension has a three dimensional maximally symmetric subspace; (2) if the matter fields of the theory satisfy strong energy condition either this 3d part is AdS$_3$, or the solution is a direct product of a locally 3d flat space and a $d-3$ dimensional part; (3) these results extend to the near horizon geometry of near-EVH black holes, for which the AdS$_3$ part is replaced with BTZ geometry. We present some specific near horizon EVH geometries in 3, 4 and 5 dimensions for which there is a classification. We also briefly discuss implications of these generic results for generic (gauged) ...

Sadeghian, S; Vahidinia, M H; Yavartanoo, H

2015-01-01

256

Horizon sensor accuracy improvement using earth horizon profile phenomenology  

NASA Astrophysics Data System (ADS)

Horizon sensor system technology has developed to the point where the ultimate accuracy a horizon sensor can give depends upon the phenomenology of the horizon itself. Current horizon sensors make use of the 15 micron CO2 absorption band and find (typically) the 50-percent point on the horizon. Using this technique, accuracies of about + or - 0.70 deg in pitch are obtained in low earth polar orbit with either the static (no moving parts) Earth Sensor Assembly or with a conical scanner. Up to now this has been regarded as an 'irreducible minimum'. This paper discusses a method of data processing which can reduce errors still further, down to less than 0.015 deg pitch. This improvement results from the fact that a correlation can be established between radiance and effective tangent height (50-percent point). Methods are discussed for taking advantage of this correlation. A computer analysis is presented demonstrating that the expected improvement is actually obtained.

Gontin, Richard A.; Ward, Kenneth A.

257

COWBIRD EGG BURIED BY A NORTHERN ORIOLE  

Microsoft Academic Search

A newly constructed Northern Oriole (Icterus galbula) nest collected on 9 June 1985 contained one Brown-headed Cowbird (Molothrus ater) egg 80% buried in the 3-cm thick lining of grass and cottonwood down. The nest contained no oriole eggs. Burial as a defense by Northern Orioles against cowbird parasitism has been noted only once, despite careful checking of over 400 nests.

KEITH A. HOBSON; SPENCER G. SEALY

258

Stress Relaxation Phenomena in Buried Quantum Dots  

Microsoft Academic Search

We report on the results of experimental and theoretical investigation of mechanical stress relaxation in heterostructures with buried quantum dots. Quan- tum dot is viewed as a dilatational inclusion with eigenstrain (transformation strain) caused by crystal lattice mismatch between the dot and matrix materials. Stresses and energies for spheroid inclusions in an infinite medium, in a half-space, and in a

N. A. Bert; V. V. Chaldyshev; A. L. Kolesnikova; A. E. Romanov

259

Female-coerced monogamy in burying beetles  

Microsoft Academic Search

The reproductive interests of the sexes often do not coincide, and this fundamental conflict is believed to underlie a variety of sex-specific behavioral adaptations. Sexual conflict in burying beetles arises when a male and female secure a carcass that can support more offspring than a single female can produce. In such a situation, any male attracting a second female sires

Anne-Katrin Eggert; Scott K. Sakaluk

1995-01-01

260

THE ECOLOGY AND BEHAVIOR OF BURYING BEETLES  

Microsoft Academic Search

Burying beetles conceal small vertebrate carcasses underground and prepare them for consumption by their young. This review places their complex social behavior in an ecological context that focuses on the evolution of biparental care and communal breeding. Both males and females provide extensive parental care, and the major benefit of male assistance is to help defend the brood and carcass

Michelle Pellissier Scott

1998-01-01

261

Buried plastic pipe technology: 2nd Volume  

SciTech Connect

The goal of this symposium was to provide an update in the technology of buried plastic pipe. Papers are divided into five sections: Field testing; Design and installation; Rehabilitation; Laboratory testing; and Trenchless construction. Twelve of the papers have been processed separately for inclusion on the data base.

Eckstein, D. (ed.)

1994-01-01

262

Preputial flaps to correct buried penis.  

PubMed

The authors developed a preputial skin flap technique to correct the buried penis which was simple and practical. This simple procedure can be applied to most boys with buried penis. In the last 3 years, we have seen 12 boys with buried penis and have been treated by using preputial flaps. The mean age is about 5.1 (from 3 to 12). By making a longitudinal incision on the ventral side of penis, the tightness of the foreskin is released and leave a diamond-shaped skin defect. It allows the penile shaft to extend out. A circumferential incision is made about 5 mm proximal to the coronal sulcus. Pedicled preputial flaps are obtained leaving optimal penile skin on the dorsal side. The preputial skin flaps are rotated onto the ventral side and tailored to cover the defect. All patients are followed for at least 3 months. Edema and swelling on the flaps are common, but improves with time. None of our patients need a second operation. The preputial flaps technique is a simple technique which allows surgeons to deal with most cases of buried penis by tailoring the flaps providing good cosmetic and functional results. PMID:17828406

Chu, Chih-Chun; Chen, Yi-Hsin; Diau, Guan-Yeu; Loh, Ih-Wei; Chen, Ke-Chi

2007-11-01

263

The ability of the blowflies Calliphora vomitoria (Linnaeus), Calliphora vicina (Rob-Desvoidy) and Lucilia sericata (Meigen) (Diptera: Calliphoridae) and the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) (Diptera: Muscidae) to colonise buried remains.  

PubMed

The blowflies Calliphora vomitoria (Linnaeus), Calliphora vicina (Rob-Desvoidy) and Lucilia sericata (Meigen) exhibited a limited ability to colonise pig liver baits buried in loose soil. Calliphora vomitoria colonised baits buried at 5 cm but no deeper whilst C. vicina and L. sericata colonised remains at 10 cm but not at 20 cm. The baits were colonised by larvae hatching from eggs laid on the surface of the soil. Both C. vomitoria and L. sericata were able to develop from eggs through to adulthood on baits that were infested before being buried and the larvae developed at similar rates and pupariated at similar depths to larvae developing on baits on the soil surface. The muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) colonised remains buried in loose soil at a depth of 40 cm and even when presented with baits on the soil surface their larvae tended to remain in the soil beneath the baits. In compacted soil, M. stabulans colonised baits buried at 10 cm but M. prolapsa only colonised those buried at 5 cm. In both muscid species, the adult flies were instantly attracted to feed on fresh blood and laid eggs in the soil above buried baits within 30min of them being introduced into the cages. The adult muscid flies did not attempt to burrow into the soil and their larvae colonised the baits from eggs laid on the soil surface. This information could be useful in determining whether a body was stored above ground before being buried and/or the time since burial occurred. PMID:21071161

Gunn, Alan; Bird, Jerry

2011-04-15

264

Resolving Lifshitz Horizons  

SciTech Connect

Via the AdS/CFT correspondence, ground states of field theories at finite charge density are mapped to extremal black brane solutions. Studies of simple gravity + matter systems in this context have uncovered wide new classes of extremal geometries. The Lifshitz metrics characterizing field theories with non-trivial dynamical critical exponent z {ne} 1 emerge as one common endpoint in doped holographic toy models. However, the Lifshitz horizon exhibits mildly singular behaviour - while curvature invariants are finite, there are diverging tidal forces. Here we show that in some of the simplest contexts where Lifshitz metrics emerge, Einstein-Maxwell-dilaton theories, generic corrections lead to a replacement of the Lifshitz metric, in the deep infrared, by a re-emergent AdS{sub 2} x R{sup 2} geometry. Thus, at least in these cases, the Lifshitz scaling characterizes the physics over a wide range of energy scales, but the mild singularity is cured by quantum or stringy effects.

Harrison, Sarah; Kachru, Shamit; Wang, Huajia; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC

2012-04-24

265

The Horizon Report. 2005 Edition  

ERIC Educational Resources Information Center

This second edition of the New Media Consortium's (NMC) annual "Horizon Report" describes the continuing work of the Horizon Project, a research-oriented effort that seeks to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative expression within higher education. Drawing on an ongoing series…

New Media Consortium, 2005

2005-01-01

266

The Horizon Report. 2004 Edition  

ERIC Educational Resources Information Center

This first edition of the New Media Consortium's (NMC) annual "Horizon Report" details findings of the Horizon Project, a research-oriented effort that seeks to identify and describe emerging technologies likely to have a large impact on teaching, learning, or creative expression within higher education. Drawing on an ongoing series of interviews…

New Media Consortium, 2004

2004-01-01

267

Hawking radiation from dynamical horizons  

NASA Astrophysics Data System (ADS)

In completely local settings, we establish that a spherically symmetric, dynamically evolving black hole horizon can be assigned a Hawking temperature under a mild assumption. Moreover, we calculate the Hawking flux and show that the radius of the horizon shrinks in accordance with the amount of emitted flux.

Chatterjee, Ayan; Chatterjee, Bhramar; Ghosh, Amit

2013-04-01

268

Soil Particle Size Distribution Protocol  

NSDL National Science Digital Library

The purpose of this resource is to sure the distribution of different sizes of soil particles in each horizon of a soil profile. Using dry, sieved soil from a horizon, students mix the soil with water and a dispersing solution to completely separate the particles from each other. Students shake the mixture to fully suspend the soil in the water. The soil particles are then allowed to settle out of suspension, and the specific gravity and temperature of the suspension are measured using a hydrometer and thermometer. These measurements are taken after 2 minutes and 24 hours.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

269

Relevance of mineral-organic associations in cryoturbated permafrost soils  

NASA Astrophysics Data System (ADS)

Enhanced microbial decomposition of deep buried organic matter (OM) increase the release of CO2and CH4from high latitude ecosystems, thus being an uncertain but potentially crucial positive feedback to global warming. The role of soil minerals as stabilization agents of OM against microbial attack gain in importance as soon abiotic soil conditions will change in permafrost soils. We investigated changes in storage and turnover of soil organic carbon (OC) and total nitrogen (TN) associated with minerals in 27 cryoturbated permafrost soils from the west to the east Siberian Arctic. Furthermore, we studied the mineral composition and the potential of OM to interact with soil minerals via different binding mechanisms. Mineral-associated organic matter (MOM) was separated from particulate plant debris by density fractionation in sodium polytungstate (density cut-off 1.6 g cm-3). Their apparent 14C ages were determined by accelerator mass spectrometry and potential mineralization rates were analyzed in a 180 days incubation experiments at 5 and 15° C. The mineral composition was analyzed by X-ray diffraction and selective extractions. Desorption experiments (stepwise extraction with KCl and NaH2PO4) using the permafrost soils as well as reference soils from temperate regions (three Stagnolsols from Germany) were performed to study OM sorbed to mineral surfaces or complexed with polyvalent metal ions. The proportion of OC associated with minerals (MOC) ranged from 5.1 to 14.9 kg m-2 (average: 11.0 kg m-2), corresponding to ~55% from the total soil OC storage (average: 20.2 ± 8.0 kg m-2) in the first meter of the Cryosols. In contrast to temperate soils, where maximum MOC concentrations are present in topsoils, cambic, or spodic horizons, cryoturbation in permafrost soils leads to high MOC concentrations within the whole solum. Cryoturbated OM-rich pockets in the subsoil store 18% (2.0 ± 1.3 kg m-2) of the MOC while another 34% (3.8 ± 3.5 kg m-2) was located in the uppermost permafrost. In topsoil horizons, mineralization rates showed a similar pattern for MOM and the bulk soil controls. In contrast, even higher MOM respiration rates then the bulk control were found in the cryoturbated OM-rich pockets and permafrost horizons. These findings deviate from temperate soil environments where MOM is considered to contribute to a 'stabilized pool' with mean residence times from hundreds to thousands of years. Statistical analysis indicated that mineral-organic interactions primarily occurred with poorly crystalline Fe and Al phases and Fe/Al-OM complexes. However, the minor desorption of organic polyelectrolytes by NaH2PO4 in permafrost soils indicated that significantly lower amounts of OC were bound by ligand exchange to Fe and Al minerals or the edges of clay minerals in permafrost soils compared to the temperate reference soils. Therefore, stabilization of OM by mineral surfaces or polyvalent metal ions appears to be of minor relevance in arctic environments compared to temperate soils.

Gentsch, Norman; Mikutta, Robert; Bárta, Ji?í; ?apek, Petr; Gittel, Antje; Richter, Andreas; Šantr??ková, Hanna; Schnecker, Jörg; Shibistova, Olga; Urich, Tim; Wild, Birgit; Guggenberger, Georg

2014-05-01

270

Microscopic entropy of trapping horizon  

NASA Astrophysics Data System (ADS)

In the Carlip-Majhi-Padmanabhan approach, we calculate the microscopic entropy of the trapping (apparent) horizon of the Friedmann-Robertson-Walker metric. We solve Killing equations for the t ,r part of the metric without fixing a priori the form of the scaling factor a (t ) which is determined from the requirement of consistency of the Killing equations. Further restrictions on the form of the Killing vector follow from the requirement that the Killing vector is null at the trapping horizon at all t . The r ,t part of the Killing vector extended by zero ? and ? components forms an approximate Killing vector in the vicinity of the horizon and satisfies the Killing equations at the horizon. Applying the technique used to calculate the microscopic entropy of the Killing horizons, we calculate the microscopic entropy of the trapping horizon. Using the explicit form of the Killing vector, we verify that the identities used in the calculation of the central term of the Virasoro algebra for the Killing horizons of black holes are valid in the present case.

Iofa, Mikhail Z.

2015-01-01

271

Social pharmacology: expanding horizons.  

PubMed

In the current modern and global society, social changes are in constant evolution due to scientific progress (technology, culture, customs, and hygiene) and produce the freedom in individuals to take decisions by themselves or with their doctors toward drug consumption. In the arena of marketed drug products which includes society, individual, administration, and pharmaceutical industry, the young discipline emerged is social pharmacology or sociopharmacology. This science arises from clinical pharmacology, and deals with different parameters, which are important in creating knowledge on marketed drugs. However, the scope of "social pharmacology" is not covered by the so-called "Phase IV" alone, but it is the science that handles the postmarketing knowledge of drugs. The social pharmacology studies the "life cycle" of any marketed pharmaceutical product in the social terrain, and evaluates the effects of the real environment under circumstances totally different in the drug development process. Therefore, there are far-reaching horizons, plural, and shared predictions among health professionals and other, for beneficial use of a drug, toward maximizing the benefits of therapy, while minimizing negative social consequences. PMID:24987168

Maiti, Rituparna; Alloza, José Luis

2014-01-01

272

Social Pharmacology: Expanding horizons  

PubMed Central

In the current modern and global society, social changes are in constant evolution due to scientific progress (technology, culture, customs, and hygiene) and produce the freedom in individuals to take decisions by themselves or with their doctors toward drug consumption. In the arena of marketed drug products which includes society, individual, administration, and pharmaceutical industry, the young discipline emerged is social pharmacology or sociopharmacology. This science arises from clinical pharmacology, and deals with different parameters, which are important in creating knowledge on marketed drugs. However, the scope of “social pharmacology” is not covered by the so-called “Phase IV” alone, but it is the science that handles the postmarketing knowledge of drugs. The social pharmacology studies the “life cycle” of any marketed pharmaceutical product in the social terrain, and evaluates the effects of the real environment under circumstances totally different in the drug development process. Therefore, there are far-reaching horizons, plural, and shared predictions among health professionals and other, for beneficial use of a drug, toward maximizing the benefits of therapy, while minimizing negative social consequences. PMID:24987168

Maiti, Rituparna; Alloza, José Luis

2014-01-01

273

SOIL MOISTURE CONTROLLED SUBSURFACE DRIP IRRIGATION ON SANDY SOILS  

Microsoft Academic Search

Subsurface drip irrigation (SDI) is being adopted in areas to conserve water while maintaining economical production of crops. These systems have not been evaluated on sandy soils common to Florida. An SDI system was installed on a welldrained sandy soil for sweet corn production in Florida. SDI tubing was buried under each row (76?cm spacing) at either two depths of

M. D. Dukes; J. M. Scholberg

274

Thermodynamics of local causal horizons  

NASA Astrophysics Data System (ADS)

We propose an expression for the entropy density associated with the local causal horizons in any diffeomorphism-invariant theory of gravity. If the black-hole entropy of the theory satisfies the physical process version of the first law of thermodynamics, then our proposed entropy satisfies the Clausius relation. Thus, our study shows that the thermodynamic nature of the spacetime horizons is not restricted to the black holes; it also applies to the local causal horizons in the neighborhood of any point in the spacetime.

Mohd, Arif; Sarkar, Sudipta

2013-07-01

275

Microbial community composition shapes enzyme patterns in topsoil and subsoil horizons along a latitudinal transect in Western Siberia  

PubMed Central

Soil horizons below 30 cm depth contain about 60% of the organic carbon stored in soils. Although insight into the physical and chemical stabilization of soil organic matter (SOM) and into microbial community composition in these horizons is being gained, information on microbial functions of subsoil microbial communities and on associated microbially-mediated processes remains sparse. To identify possible controls on enzyme patterns, we correlated enzyme patterns with biotic and abiotic soil parameters, as well as with microbial community composition, estimated using phospholipid fatty acid profiles. Enzyme patterns (i.e. distance-matrixes calculated from these enzyme activities) were calculated from the activities of six extracellular enzymes (cellobiohydrolase, leucine-amino-peptidase, N-acetylglucosaminidase, chitotriosidase, phosphatase and phenoloxidase), which had been measured in soil samples from organic topsoil horizons, mineral topsoil horizons, and mineral subsoil horizons from seven ecosystems along a 1500 km latitudinal transect in Western Siberia. We found that hydrolytic enzyme activities decreased rapidly with depth, whereas oxidative enzyme activities in mineral horizons were as high as, or higher than in organic topsoil horizons. Enzyme patterns varied more strongly between ecosystems in mineral subsoil horizons than in organic topsoils. The enzyme patterns in topsoil horizons were correlated with SOM content (i.e., C and N content) and microbial community composition. In contrast, the enzyme patterns in mineral subsoil horizons were related to water content, soil pH and microbial community composition. The lack of correlation between enzyme patterns and SOM quantity in the mineral subsoils suggests that SOM chemistry, spatial separation or physical stabilization of SOM rather than SOM content might determine substrate availability for enzymatic breakdown. The correlation of microbial community composition and enzyme patterns in all horizons, suggests that microbial community composition shapes enzyme patterns and might act as a modifier for the usual dependency of decomposition rates on SOM content or C/N ratios. PMID:25859057

Schnecker, Jörg; Wild, Birgit; Takriti, Mounir; Eloy Alves, Ricardo J.; Gentsch, Norman; Gittel, Antje; Hofer, Angelika; Klaus, Karoline; Knoltsch, Anna; Lashchinskiy, Nikolay; Mikutta, Robert; Richter, Andreas

2015-01-01

276

Defect electrical conduction in SIMOX buried oxides  

Microsoft Academic Search

It is pointed out that the buried oxide (BOX) layers in SIMOX structures exhibit localized defect conduction superimposed on the background (bulk) conduction. Type I defects show a pre-breakdown quasi-linear I-V characteristic with 10-7

George A. Brown; Akos G. Revesz

1993-01-01

277

How Burying Biomass Can Contribute to CO2 Stabilization  

NASA Astrophysics Data System (ADS)

To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1), followed by temperate (3.7 GtC y-1) and boreal forests (2.1 GtC y-1). Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other environmental concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be 14/tCO2 (50/tC), lower than the typical cost for power plant CO2 capture with geological storage. The low cost for carbon sequestration with wood burial is possible because the technique uses the natural process of photosynthesis to remove carbon from the atmosphere. The technique is low tech, distributed, safe, and can be stopped at any time, thus an attractive option for large-scale implementation in a world-wide carbon market.

Cook, B.; Zeng, N.; Zaitchik, B.; Gregg, J.

2008-12-01

278

Preservation of labile organic matter in soils of drained thaw lakes in Northern Alaska  

NASA Astrophysics Data System (ADS)

A large number of studies predict changing organic matter (OM) dynamics in arctic soils due to global warming. In contrast to rather slowly altering bulk soil properties, single soil organic matter (SOM) fractions can provide a more detailed picture of the dynamics of differently preserved SOM pools in climate sensitive arctic regions. By the study of the chemical composition of such distinctive SOM fractions using nuclear magnetic resonance spectroscopy (NMR) together with radiocarbon analyses it is possible to evaluate the stability of the major OM pools. Approximately 50-75% of Alaska's Arctic Coastal Plain is covered with thaw lakes and drained thaw lakes that follow a 5,000 yr cycle of development (between creation and final drainage), thus forming a natural soil chronosequence. The drained thaw lakes offer the possibility to study SOM dynamics affected by permafrost processes over millennial timescales. In April 2010 we sampled 16 soil cores (including the active and permanent layer) reaching from young drained lakes (0-50 years since drainage) to ancient drained lakes (3000-5500 years since drainage). Air dried soil samples from soil horizons of the active and permanent layer were subjected to density fractionation in order to differentiate particulate OM and mineral associated OM. The chemical composition of the SOM fractions was analyzed by 13C CPMAS NMR spectroscopy. For a soil core of a young and an ancient drained thaw lake basin we also analyzed the 14C content. For the studied soils we can show that up to over 25 kg OC per square meter are stored mostly as labile, easily degradable organic matter rich in carbohydrates. In contrast only 10 kg OC per square meter were sequestered as presumably more stable mineral associated OC dominated by aliphatic compounds. Comparable to soils of temperate regions, we found small POM (< 20 µm) occluded in aggregated soil structures which differed in the chemical composition from larger organic particles. This was clearly shown by increased amounts of aliphatic C in these small POM fractions. As revealed by 13C CPMAS NMR, with advancing soil age increasing aliphaticity was also detected in occluded small POM fractions. By 14C dating we could show the stabilization of younger more labile OM at greater depth in buried O horizons. Additionally the study of the microscale elemental distributions, using nano-scale secondary ion mass spectrometry (NanoSIMS) showed the initial formation of aggregates and organo-mineral interfaces in the studied permafrost soils.

Mueller, Carsten W.; Rethemeyer, Janet; Kao-Kniffin, Jenny; Löppmann, Sebastian; Hinkel, Kenneth; Bockheim, James

2014-05-01

279

Information space receding horizon control.  

PubMed

In this paper, we present a receding horizon solution to the optimal sensor scheduling problem. The optimal sensor scheduling problem can be posed as a partially observed Markov decision problem whose solution is given by an information space (I-space) dynamic programming (DP) problem. We present a simulation-based stochastic optimization technique that, combined with a receding horizon approach, obviates the need to solve the computationally intractable I-space DP problem. The technique is tested on a sensor scheduling problem, in which a sensor must choose among the measurements of N dynamical systems in a manner that maximizes information regarding the aggregate system over an infinite horizon. While simple, such problems nonetheless lead to very high dimensional DP problems to which the receding horizon approach is well suited. PMID:23757584

Sunberg, Z; Chakravorty, S; Scott Erwin, R

2013-12-01

280

Acoustic horizons in nuclear fluids  

E-print Network

We consider a hydrodynamic description of the spherically symmetric outward flow of nuclear matter, accommodating dispersion in it as a very weak effect. About the resulting stationary conditions in the flow, we apply an Eulerian scheme to derive a fully nonlinear equation of a time-dependent radial perturbation. In its linearized limit, with no dispersion, this equation implies the static acoustic horizon of an analogue gravity model. We, however, show that time-dependent nonlinear effects destabilize the static horizon. We also model the perturbation as a high-frequency travelling wave, and perform a {\\it WKB} analysis, in which the effect of weak dispersion is studied iteratively. We show that even arbitrarily small values of dispersion make the horizon fully opaque to any acoustic disturbance propagating against the bulk flow, with the amplitude and the energy flux of the radial perturbation undergoing a discontinuity at the horizon, and decaying exponentially just outside it.

Niladri Sarkar; Abhik Basu; Jayanta K. Bhattacharjee; Arnab K. Ray

2014-04-13

281

Chemical Soil Physics Phenomena for Chemical Sensing of Buried UXO  

Microsoft Academic Search

Technology development efforts are under way to apply chemical sensors to discriminate inert ordnance and clutter from live munitions that remain a threat to reutilization of military ranges. However, the chemical signature is affected by multiple environmental phenomena that can enhance or reduce its presence and transport behavior, and can affect the distribution of the chemical signature in the environment.

James Phelan; Stephen W. Webb

1999-01-01

282

Mass Transport within Soils  

SciTech Connect

Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated zone with three major horizons, the saturated zone can be further divided into other zones based on hydraulic and geologic conditions. Wetland soils are a special and important class in which near-saturation conditions exist most of the time. When a contaminant is added to or formed in a soil column, there are several mechanisms by which it can be dispersed, transported out of the soil column to other parts of the environment, destroyed, or transformed into some other species. Thus, to evaluate or manage any contaminant introduced to the soil column, one must determine whether and how that substance will (1) remain or accumulate within the soil column, (2) be transported by dispersion or advection within the soil column, (3) be physically, chemically, or biologically transformed within the soil (i.e., by hydrolysis, oxidation, etc.), or (4) be transported out of the soil column to another part of the environment through a cross-media transfer (i.e., volatilization, runoff, ground water infiltration, etc.). These competing processes impact the fate of physical, chemical, or biological contaminants found in soils. In order to capture these mechanisms in mass transfer models, we must develop mass-transfer coefficients (MTCs) specific to soil layers. That is the goal of this chapter. The reader is referred to other chapters in this Handbook that address related transport processes, namely Chapter 13 on bioturbation, Chapter 15 on transport in near-surface geological formations, and Chapter 17 on soil resuspention. This chapter addresses the following issues: the nature of soil pollution, composition of soil, transport processes and transport parameters in soil, transformation processes in soil, mass-balance models, and MTCs in soils. We show that to address vertical heterogeneity in soils in is necessary to define a characteristic scaling depth and use this to establish process-based expressions for soil MTCs. The scaling depth in soil and the corresponding MTCs depend strongly on (1) the composition of the soil and physical state of the soil, (2) the chemical and physic

McKone, Thomas E.

2009-03-01

283

HORIZON SENSING (PROPOSAL No.51)  

SciTech Connect

Real-time horizon sensing on continuous mining machines is becoming an industry tool. Installation and testing of production-grade HS systems has been ongoing this quarter at Monterey Coal Company (EXXON), FMC Trona, Twentymile Coal Company (RAG America), and SASOL Coal. Detailed monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.

Larry G. Stolarczyk, Sc.D.

2002-04-30

284

Gravitational Global Monopoles with Horizons  

E-print Network

We give arguments for the existence of ``radial excitations'' of gravitational global monopoles with any number of zeros of the Higgs field and present numerical results for solutions with up to two zeros. All these solutions possess a de Sitter like cosmological horizon, outside of which they become singular. In addition we study corresponding static ``hairy'' black hole solutions, representing black holes sitting inside a global monopole core. In particular, we determine their existence domains as a function of their horizon radius rh.

Dieter Maison

1999-12-23

285

An experience in using the world reference base for soil resources for the soils of western Georgia  

NASA Astrophysics Data System (ADS)

New and previously published data on the soils of western Georgia are generalized, and traditional soil names are correlated with the units of the World Reference Base for Soil Resources. It is argued that krasnozems (red ferrallitic soils) can be attributed to the group of Nitisols (the soils characterized by intense weathering (ferralization) and having shiny ped faces in the nitic horizon); yellow and yellow-brown soils (zheltozems), to the group of Luvisols (the soils with relatively high adsorption capacity in the eluvial horizons and with the horizon of the illuvial accumulation of clay); yellow-podzolic (zheltozem-podzolic) soils, to Alisols (slightly acid soils with the low adsorption capacity, poor aggregation of the upper horizons, low-activity (kaolinite) clay, and with the horizon of clay accumulation (argic horizon)); brown forest soils, to Cambisols (the soils with the cambic horizon characterized by some alteration of the lithogenic texture and structure into the pedogenic texture and structure); and mountainous forest-meadow and meadow soils, to Umbrisols (the soils with the dark-colored unsaturated umbric horizon).

Urushadze, T. F.; Kvrivishvili, T. O.; Sanadze, E. V.

2014-08-01

286

Physics-based deformations of ground penetrating radar signals to improve the detection of buried explosives  

NASA Astrophysics Data System (ADS)

A number of recent algorithms have shown improved performance in detecting buried explosive threats by statistically modeling target responses observed in ground penetrating radar (GPR) signals. These methods extract features from known examples of target responses to train a statistical classifier. The statistical classifiers are then used to identify targets emplaced in previously unseen conditions. Due to the variation in target GPR responses caused by factors such as differing soil conditions, classifiers require training on a large, varied dataset to encompass the signal variation expected in operational conditions. These training collections generally involve burying each target type in a number of soil conditions, at a number of burial depths. The cost associated with both burying the targets, and collecting the data is extremely high. Thus, the conditions and depths sampled cover only a subset of possible scenarios. The goal of this research is to improve the ability of a classifier to generalize to new conditions by deforming target responses in accordance with the physical properties of GPR signals. These signal deformations can simulate a target response under different conditions than those represented in the data collection. This research shows that improved detection performance in previously unseen conditions can be achieved by utilizing deformations, even when the training dataset is limited.

Sakaguchi, Rayn T.; Morton, Kennth D.; Collins, Leslie M.; Torrione, Peter A.

2014-05-01

287

Soil Core Sample #1  

USGS Multimedia Gallery

Soil core obtained from existing goose grazing lawn along the Smith River in the Teshekpuk Lake Special Area of the National Petroleum Reserve - Alaska.  The buried layer of peat beneath goose grazing lawn demonstrates that vegetation change has occurred in this area....

288

The daily evaporation characteristics of deeply buried phreatic water in an extremely arid region  

NASA Astrophysics Data System (ADS)

Measurements of the daily evaporation characteristics of deeply buried phreatic water in an extremely arid area are reported. The results are used to analyze the mechanism responsible for water movement in the groundwater-soil-plant-atmosphere continuum. A closed PVC greenhouse was set up on Gobi land at the top of the Mogao Grottoes where phreatic water is more than 200 m deep. An air-conditioning unit and an automatic weighing scale were placed inside the greenhouse to condense and monitor phreatic evaporation and soil water changes in this extremely arid region. Soil temperature and humidity at various depths (0-40 cm) and other meteorological factors were also recorded on a sub-hourly basis. The relationship between evaporated water and soil water movement was analyzed by observing changes in soil weight, the condensate from the air-conditioning unit, and air moisture. The results show that phreatic water evaporation occurs from this deeply buried source in this extremely arid zone. The daily characteristics are consistent with the variation in the Sun’s radiation intensity (i.e. both show a sinusoidal behavior). In the daytime, most of the soil water does not evaporate but moves to cooler sub-layers. In the afternoon, the shallow soil layer absorbs moisture as the temperature decreases. At night, an abundance of water vapor moves upwards from the sub-layers and supplements the evaporated and downward-moving moisture of the superstratum in the daytime, but there is no evaporation. The stable, upwardly migrating vapor and film water is supported by geothermy and comes from phreatic water, the daily evaporation characteristics of which changes according to soil temperature when it reaches the ground.

Li, Hongshou; Wang, Wanfu; Liu, Benli

2014-06-01

289

ALUMINUM PRECIPITATION AND DISSOLUTION RATES IN SPODOSOL BS HORIZONS IN THE NORTHEASTERN USA  

EPA Science Inventory

The kinetics of Al precipitation/dissolution reactions in Spodosol Bs horizons from sites at Hubbard Brook, NH and Bear Brook, ME were examined. echanical vacuum extractor was employed to draw solutions through soil columns at solution/soil residence times between 0.3 and 100 h. ...

290

The effect of soil moisture on thermal properties in some typical Japanese upland soils  

Microsoft Academic Search

The effects of soil moisture on thermal properties of some typical Japanese upland soils were studied. Thermal properties which were studied here were volumetric heat capacity, thermal conductivity, and thermal diffusivity. Sample taken at various horizons of volcanic ash (Yachimata) soil, alluvial (Kiyosu) soil, and diluvial (Toyoilashi) soil were used. The results are summarized as follows. 1) Volumetric heat capacity

Tatsuaki Kasubuchi

1975-01-01

291

Soil Science Society of America Journal Soil Sci. Soc. Am. J. 78:297308  

E-print Network

, changes in soil frost regimes could ul- timately affect forest health, soil biodiversity, and water is important because losses to stream water are greatest during this period. Organic horizon soils (Oi + OeSoil Science Society of America Journal Soil Sci. Soc. Am. J. 78:297­308 doi:10.2136/sssaj2013

Templer, Pamela

292

Prehistoric Agriculture and Soil Fertility on Lava Flows in Northern Arizona, USA: Results from the San Francisco Volcanic Field REU  

NASA Astrophysics Data System (ADS)

The San Francisco Volcanic Field in northern Arizona is home to ~600 cinder cones, the youngest of which is Sunset Crater (erupted ~AD 1100). This study documents trends in available phosphate and nitrate content with time, testing whether lowered soil pH from the addition of Sunset cinders increased soil fertility and became a factor in Anasazi agricultural success. Soil fertility is examined both before and after Sunset's eruption in soils of different ages that have developed from eolian deposition on top of lava flows. An increase in phosphate and nitrate levels following acidification would suggest that the presence of Sunset cinders brought the soils to the optimal pH for mobilization of these nutrients. The combined effects of the cinder layer retaining nutrients and water, wetter climates, and increases in phosphate and nitrate (both limiting nutrients for plant growth), would have contributed to Anasazi agricultural success after Sunset's eruption. Samples for this study were taken from eolian-derived soils of different ages atop lava flows in the San Francisco Volcanic Field. OSL data from these soils on Strawberry and SP Craters' lava flows yielded age estimates of ~12.3 ka (Strawberry) and ~32.7 ka (SP), on which a soil chronosequence was based. Results from the chronosequence supported these OSL ages, indicating that soils on the SP flow are older than those on the Strawberry flow. Field descriptions, Harden Development Indices, particle size analysis, and nutrient content analysis were used for this aspect of the project. An experimental acid wash method will be used to simulate the addition of Sunset's acidic cinders, and will yield data for phosphate and nitrate content after Sunset erupted. Preliminary results indicate that phosphate and nitrate accumulate in upper, eolian-derived horizons (Av, Bw) and in more deeply buried carbonate horizons (Bk). Higher concentrations of phosphate and nitrate were found in older (SP) soils than younger (Strawberry) soils, suggesting that these nutrients increase over time with eolian deposition and soil development. Results from this study will yield information on the impact of volcanic eruptions and soil development on prehistoric agriculture and soil fertility. This study contributes to our understanding of the interactions between eruptions and human populations.

Broadman, E.; Anderson, K. C.

2013-12-01

293

Fabrication of Buried Nanochannels From Nanowire Patterns  

NASA Technical Reports Server (NTRS)

A method of fabricating channels having widths of tens of nanometers in silicon substrates and burying the channels under overlying layers of dielectric materials has been demonstrated. With further refinement, the method might be useful for fabricating nanochannels for manipulation and analysis of large biomolecules at single-molecule resolution. Unlike in prior methods, burying the channels does not involve bonding of flat wafers to the silicon substrates to cover exposed channels in the substrates. Instead, the formation and burying of the channels are accomplished in a more sophisticated process that is less vulnerable to defects in the substrates and less likely to result in clogging of, or leakage from, the channels. In this method, the first step is to establish the channel pattern by forming an array of sacrificial metal nanowires on an SiO2-on-Si substrate. In particular, the wire pattern is made by use of focused-ion-beam (FIB) lithography and a subsequent metallization/lift-off process. The pattern of metal nanowires is then transferred onto the SiO2 layer by reactive-ion etching, which yields sacrificial SiO2 nanowires covered by metal. After removal of the metal covering the SiO2 nanowires, what remains are SiO2 nanowires on an Si substrate. Plasma-enhanced chemical vapor deposition (PECVD) is used to form a layer of a dielectric material over the Si substrate and over the SiO2 wires on the surface of the substrate. FIB milling is then performed to form trenches at both ends of each SiO2 wire. The trenches serve as openings for the entry of chemicals that etch SiO2 much faster than they etch Si. Provided that the nanowires are not so long that the diffusion of the etching chemicals is blocked, the sacrificial SiO2 nanowires become etched out from between the dielectric material and the Si substrate, leaving buried channels. At the time of reporting the information for this article, channels 3 m long, 20 nm deep, and 80 nm wide (see figure) had been fabricated by this method.

Choi, Daniel; Yang, Eui-Hyeok

2007-01-01

294

Buried waste integrated demonstration configuration management plan  

SciTech Connect

This document defines plans for the configuration management requirements for the Buried Waste Integrated Demonstration (BWID) Program. Since BWID is managed programmatically by the Waste Technology Development Department (WTDD), WTDD Program Directive (PD) 1.5 (Document Preparation, Review, Approval, Publication, Management and Change Control) is to be followed for all internal EG G Idaho, Inc., BWID programmatic documentation. BWID documentation generated by organizations external to EG G Idaho is not covered by this revision of the Configuration Management Plan (CMP), but will be addressed in subsequent revisions.

Cannon, P.G.

1992-02-01

295

Buried waste integrated demonstration configuration management plan  

SciTech Connect

This document defines plans for the configuration management requirements for the Buried Waste Integrated Demonstration (BWID) Program. Since BWID is managed programmatically by the Waste Technology Development Department (WTDD), WTDD Program Directive (PD) 1.5 (Document Preparation, Review, Approval, Publication, Management and Change Control) is to be followed for all internal EG&G Idaho, Inc., BWID programmatic documentation. BWID documentation generated by organizations external to EG&G Idaho is not covered by this revision of the Configuration Management Plan (CMP), but will be addressed in subsequent revisions.

Cannon, P.G.

1992-02-01

296

Entropy from near-horizon geometries of Killing horizons  

NASA Astrophysics Data System (ADS)

We "derive" the Bekenstein-Hawking entropy for black holes based on the near-horizon symmetries of black hole space-times. To find out these symmetries we make use of an (R,T) plane close to a Killing horizon. We identify a set of vector fields that preserves this plane and forms a Witt algebra. The corresponding algebra of Hamiltonians is shown to have a nontrivial central extension. Using the Cardy formula and the central charge we obtain the Bekenstein-Hawking entropy.

Dreyer, Olaf; Ghosh, Amit; Ghosh, Avirup

2014-01-01

297

Virtual environmental applications for buried waste characterization technology evaluation report  

SciTech Connect

The project, Virtual Environment Applications for Buried Waste Characterization, was initiated in the Buried Waste Integrated Demonstration Program in fiscal year 1994. This project is a research and development effort that supports the remediation of buried waste by identifying and examining the issues, needs, and feasibility of creating virtual environments using available characterization and other data. This document describes the progress and results from this project during the past year.

NONE

1995-05-01

298

Elementary GLOBE: Getting to Know Soil  

NSDL National Science Digital Library

A learning activity for the Scoop on Soils book in the Elementary GLOBE Series. Each student will make predictions about the properties of various soil samples. Then they will examine several types of soils and record their observations. Next, they will learn about soil profiles and horizons by both examining a soil sample in a jar and by creating a soil profile flip chart. The purpose of the activity is to provide the opportunity for students to ask questions and make observations about soil and introduce students to the properties of soil and to the concept of soil profiles and horizons. After completing this activity, students will know about soil's different properties and about soil profiles. Students will know that soils have different properties including texture, color, and size. They will know that soil forms layers based on these properties.

2008-12-01

299

System and method for removal of buried objects  

DOEpatents

The present invention is a system and method for removal of buried objects. According to one embodiment of the invention, a crane with a vibrator casing driver is used to lift and suspend a large diameter steel casing over the buried object. Then the casing is driven into the ground by the vibratory driver until the casing surrounds the buried object. Then the open bottom of the casing is sealed shut by injecting grout into the ground within the casing near its bottom. When the seal has cured and hardened, the top of the casing is lifted to retrieve the casing, with the buried object inside, from the ground.

Alexander, Robert G. (Richland, WA); Crass, Dennis (Kennewick, WA); Grams, William (Kennewick, WA); Phillips, Steven J. (Sunnyside, WA); Riess, Mark (Kennewick, WA)

2008-06-03

300

Multi channel FM reflection profiler for buried pipeline surveying  

SciTech Connect

A towed multi-channel FM acoustic reflection profiler has been developed for locating and generating images of buried objects. One significant application of this sonar is buried pipeline surveying. The multi-channel reflection profiler uses 16 line arrays mounted in a towed vehicle to determine the position and burial depth of an 18 inch steel pipe filled with concrete buried under 1.5 meters of sand. This sonar will allow a survey vessel to continuously track a buried pipeline providing a continuous record of pipe burial depth and position.

Schock, S.G.; LeBlanc, L.R. [Florida Atlantic Univ., Boca Raton, FL (United States). Dept. of Ocean Engineering

1996-12-31

301

Soil Information Requirements for Humanitarian Demining: The Case for a Soil Properties Database  

Microsoft Academic Search

Landmines are buried typically in the top 30 cm of soil. A number of physical, chemical and electromagnetic properties of this near-surface layer of ground will potentially aect the wide range of technologies under de- velopment worldwide for landmine detection and neutralization. Although standard soil survey information, as related to conventional soil classication, is directed toward agricultural and environmental applications,

Y. Das; K. Russell; T. J. Katsube

302

Soil information requirements for humanitarian demining: the case for a soil properties database  

Microsoft Academic Search

Landmines are buried typically in the top 30 cm of soil. A number of physical, chemical and electromagnetic properties of this near-surface layer of ground will potentially affect the wide range of technologies under development worldwide for landmine detection and neutralization. Although standard soil survey information, as related to conventional soil classification, is directed toward agricultural and environmental applications, little

Yogadhish Das; John E. McFee; Kevin L. Russell; Guy Cross; T. John Katsube

2003-01-01

303

Buried Waste Integrated Demonstration Plan. Revision 1  

SciTech Connect

This document presents the plan of activities for the Buried Waste Integrated Demonstration (BWID) program which supports the environmental restoration (ER) objectives of the Department of Energy (DOE) Complex. Discussed in this plan are the objectives, organization, roles and responsibilities, and the process for implementing and managing BWID. BWID is hosted at the Idaho National Engineering Laboratory (INEL), but involves participants from throughout the DOE Complex, private industry, universities, and the international community. These participants will support, demonstrate, and evaluate a suite of advanced technologies representing a comprehensive remediation system for the effective and efficient remediation of buried waste. The processes for identifying technological needs, screening candidate technologies for applicability and maturity, selecting appropriate technologies for demonstration, field demonstrating, evaluation of results and transferring technologies to environmental restoration programs are also presented. This document further describes the elements of project planning and control that apply to BWID. It addresses the management processes, operating procedures, programmatic and technical objectives, and schedules. Key functions in support of each demonstration such as regulatory coordination, safety analyses, risk evaluations, facility requirements, and data management are presented.

Kostelnik, K.M.

1991-12-01

304

Enzyme leaching of surficial geochemical samples for detecting hydromorphic trace-element anomalies associated with precious-metal mineralized bedrock buried beneath glacial overburden in northern Minnesota  

USGS Publications Warehouse

One objective of the International Falls and Roseau, Minnesota, CUSMAP projects was to develop a means of conducting regional-scale geochemical surveys in areas where bedrock is buried beneath complex glacially derived overburden. Partial analysis of B-horizon soils offered hope for detecting subtle hydromorphic trace-element dispersion patterns. An enzyme-based partial leach selectively removes metals from oxide coatings on the surfaces of soil materials without attacking their matrix. Most trace-element concentrations in the resulting solutions are in the part-per-trillion to low part-per-billion range, necessitating determinations by inductively coupled plasma/mass spectrometry. The resulting data show greater contrasts for many trace elements than with other techniques tested. Spatially, many trace metal anomalies are locally discontinuous, but anomalous trends within larger areas are apparent. In many instances, the source for an anomaly seems to be either basal till or bedrock. Ground water flow is probably the most important mechanism for transporting metals toward the surface, although ionic diffusion, electrochemical gradients, and capillary action may play a role in anomaly dispersal. Sample sites near the Rainy Lake-Seine River fault zone, a regional shear zone, often have anomalous concentrations of a variety of metals, commonly including Zn and/or one or more metals which substitute for Zn in sphalerite (Cd, Ge, Ga, and Sn). Shifts in background concentrations of Bi, Sb, and As show a trend across the area indicating a possible regional zoning of lode-Au mineralization. Soil anomalies of Ag, Co, and Tl parallel basement structures, suggesting areas that may have potential for Cobalt/Thunder Baytype silver viens. An area around Baudette, Minnesota, which is underlain by quartz-chlorite-carbonate-altered shear zones, is anomalous in Ag, As, Bi, Co, Mo, Te, Tl, and W. Anomalies of Ag, As, Bi, Te, and W tend to follow the fault zones, suggesting potential for lode-Au deposits. Soil anomalies of Co, Mo, and Tl appear to follow northwest-striking structures that cross the shear zones, suggesting that Thunder Bay-type mineralization may have overprinted earlier mineralization along the shear zones.

Clark, Robert J.; Meier, A.L.; Riddle, G.

1990-01-01

305

Butterflies on the Stretched Horizon  

E-print Network

In this paper I return to the question of what kind of perturbations on Alice's side of an Einstein-Rosen bridge can send messages to Bob as he enters the horizon at the other end. By definition "easy" operators do not activate messages and "hard" operators do, but there are no clear criteria to identify the difference between easy and hard. In this paper I argue that the difference is related to the time evolution of a certain measure of computational complexity, associated with the stretched horizon of Alice's black hole. The arguments suggest that the AMPSS commutator argument is more connected with butterflies than with firewalls.

Susskind, Leonard

2013-01-01

306

Butterflies on the Stretched Horizon  

E-print Network

In this paper I return to the question of what kind of perturbations on Alice's side of an Einstein-Rosen bridge can send messages to Bob as he enters the horizon at the other end. By definition "easy" operators do not activate messages and "hard" operators do, but there are no clear criteria to identify the difference between easy and hard. In this paper I argue that the difference is related to the time evolution of a certain measure of computational complexity, associated with the stretched horizon of Alice's black hole. The arguments suggest that the AMPSS commutator argument is more connected with butterflies than with firewalls.

Leonard Susskind

2013-12-07

307

Deepwater Horizon Situation Report #5  

SciTech Connect

At approximately 11:00 pm EDT April 20, 2010 an explosion occurred aboard the Deepwater Horizon mobile offshore drilling unit (MODU) located 52 miles Southeast of Venice, LA and 130 miles southeast of New Orleans, LA. The MODU was drilling an exploratory well and was not producing oil at the time of the incident. The Deepwater Horizon MODU sank 1,500 feet northwest of the well site. Detailed information on response and recovery operations can be found at: http://www.deepwaterhorizonresponse.com/go/site/2931/

none,

2010-06-10

308

Thermal processing system concepts and considerations for RWMC buried waste  

SciTech Connect

This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided.

Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

1992-02-01

309

Benghal dayflower (Commelina benghalensis) seed viability in soil  

Technology Transfer Automated Retrieval System (TEKTRAN)

Benghal dayflower is a challenging weed to manage in agricultural settings. Research was conducted in North Carolina, Georgia, and Florida to evaluate the longevity of buried Benghal dayflower seeds. Seeds were buried for 2 to 60 months at a depth of 20 cm in mesh bags containing soil native to eac...

310

Deepwater Horizon Controlled Oil Burn  

USGS Multimedia Gallery

OFF THE LOUISIANA COAST — A controlled burn of oil from the Deepwater Horizon/BP oil spill sends towers of fire hundreds of feet into the air over the Gulf of Mexico. U.S. Coast Guard Photo by Petty Officer First Class John Masson....

311

NIF featured on BBC "Horizon"  

ScienceCinema

The National Ignition Facility, the world's largest laser system, located at Lawrence Livermore National Laboratory, was featured in the BBC broadcast "Horizon" hosted by physicist Brian Cox. Here is the NIF portion of the program, which was entitled "Can We Make A Star On Earth?" This video is used with the express permission of the BBC.

Brian Cox

2010-09-01

312

Evolutionary Robotics: Exploring New Horizons  

E-print Network

Chapter 1 Evolutionary Robotics: Exploring New Horizons St´ephane Doncieux, Jean-Baptiste Mouret, Nicolas Bredeche, and Vincent Padois Abstract. This paper considers the field of Evolutionary Robotics (ER of research is discussed, as well as the potential use of ER in a robot design process. Four main aspects

Paris-Sud XI, Université de

313

Return to Flight New Horizons  

E-print Network

Return to Flight Pg 3 New Horizons Pg 5 Goes-N: Keeping Watch From Above Pg 5 GoddardView NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Goddard Space Flight Center Explore. Discover. Understand #12;02 Tableof and indispensable tool that allows us to keep up with activi- ties at the Goddard Space Flight Center. If you have

Christian, Eric

314

Baseline tests for arc melter vitrification of INEL buried wastes. Volume II: Baseline test data appendices  

SciTech Connect

This report presents field results and raw data from the Buried Waste Integrated Demonstration (BWID) Arc Melter Vitrification Project Phase 1 baseline test series conducted by the Idaho National Engineering Laboratory (INEL) in cooperation with the U.S. Bureau of Mines (USBM). The baseline test series was conducted using the electric arc melter facility at the USBM Albany Research Center in Albany, Oregon. Five different surrogate waste feed mixtures were tested that simulated thermally-oxidized, buried, TRU-contaminated, mixed wastes and soils present at the INEL. The USBM Arc Furnace Integrated Waste Processing Test Facility includes a continuous feed system, the arc melting furnace, an offgas control system, and utilities. The melter is a sealed, 3-phase alternating current (ac) furnace approximately 2 m high and 1.3 m wide. The furnace has a capacity of 1 metric ton of steel and can process as much as 1,500 lb/h of soil-type waste materials. The surrogate feed materials included five mixtures designed to simulate incinerated TRU-contaminated buried waste materials mixed with INEL soil. Process samples, melter system operations data and offgas composition data were obtained during the baseline tests to evaluate the melter performance and meet test objectives. Samples and data gathered during this program included (a) automatically and manually logged melter systems operations data, (b) process samples of slag, metal and fume solids, and (c) offgas composition, temperature, velocity, flowrate, moisture content, particulate loading and metals content. This report consists of 2 volumes: Volume I summarizes the baseline test operations. It includes an executive summary, system and facility description, review of the surrogate waste mixtures, and a description of the baseline test activities, measurements, and sample collection. Volume II contains the raw test data and sample analyses from samples collected during the baseline tests.

Oden, L.L.; O`Conner, W.K.; Turner, P.C.; Soelberg, N.R.; Anderson, G.L.

1993-11-19

315

Mechanics of buried chilled gas pipelines  

SciTech Connect

This paper examines the factors influencing the modelling of soil-pipeline interaction for a pipeline which is used to transport chilled gas. The soil-pipeline interaction is induced by the generation of discontinuous frost heave at a boundary between soils with differing frost susceptibility. The three-dimensional modelling takes into consideration the time-dependent evolution of frost heave due to moisture migration, the creep and elastic behavior of the frozen soil and flexural behavior of the embedded pipeline. The results of the computational model are compared with experimental results obtained from the frost heave induced soil-pipeline interaction test performed at the full scale test facilities in Caen, France.

Selvadurai, A.P.S.; Hu, J. [McGill Univ., Montreal, Quebec (Canada). Dept. of Civil Engineering and Applied Mechanics

1996-12-31

316

Buffer capacities of podzolic and peat gleyic podzolic soils to sulfuric and nitric acids  

Microsoft Academic Search

Soil samples from the main genetic horizons of pale podzolic and peat gleyic podzolic soils from the Central Forest Reserve\\u000a were subjected to a continuous potentiometric titration by sulfuric and nitric acids. The sulfate sorption capacity was determined\\u000a in soil mineral horizons. The buffer capacity of mineral horizons of both soils to sulfuric acid was found to be higher than

N. B. Kuznetsov; S. A. Alekseeva; G. V. Shashkova; T. Ya. Dronova; T. A. Sokolova

2007-01-01

317

Introduction Interest in buried glacial ice has gained considerable  

E-print Network

the range of climate conditions necessary to preserve the buried ice for millions of years. Our approachIntroduction Interest in buried glacial ice has gained considerable attention in recent years due to its potential as an archive for long-term climate change. Geochemical analyses of ice stored

Marchant, David R.

318

Buried Oxide Densification for Low Power, Low Voltage CMOS Applications  

NASA Technical Reports Server (NTRS)

Special technology and circuit architecture are of growing interest for implementation of circuits which operate at low supply voltages and consume low power levels without sacrificing performance[1]. Use of thin buried oxide SOI substrates is a primary approach to simultaneously achieve these goals. A significant aspect regarding SIMOX SOI for low voltage, low power applications is the reliability and performance of the thin buried oxide. In addition, when subjected to high total dose irradiation, the silicon islands within the BOX layer of SIMOX can store charges and significantly effect the back channel threshold voltages of devices. Thus, elimination of the islands within the buried oxide (BOX) layer is preferred in order to prevent leakage through these conductive islands and charge build-up within the buried oxide layer. A differential (2-step) ramp rate as applied to full and 100 nm BOX SIMOX was previously reported to play a significant role in the stoichiometry and island formation within the buried layer[2]. This paper focus is on the properties of a thin (120nm) buried oxide as a function of the anneal ramp rate and the temperature of anneal. In this research, we have found an improvement in the buried oxide stoichiometry with the use of a slower, singular ramp rate for specified thin buried oxides, with slower ramp rates and higher temperatures of anneal suggested for reducing the presence of Si islands within the BOX layer.

Allen, L. P.; Anc, M. J.; Dolan, B.; Jiao, J.; Guss, B.; Seraphin, S.; Liu, S. T.; Jenkins, W.

1998-01-01

319

A Simplified Preputial Covering Technique to Correct Buried Penis  

Microsoft Academic Search

Objective: We report on refinements of a technique for preputial covering to prevent complications of redundant prepuce, possibly caused by inadequate surgery for buried penis. Patients and Methods: From July 2006 to July 2008, 20 consecutive patients (mean age 4.3 years) underwent surgery for buried penis. The surgical techniques consisted of complete unfurling of the penile shaft, fixation of the

Ta-Min Wang; Hsiao-Wen Chen; Yang-Jen Chiang; Sheng-Hsien Chu; Kuan-Lin Liu; Hsu-Han Wang

2010-01-01

320

Phosphatase activity in relation to key litter and soil properties in mature subtropical forests in China.  

PubMed

Phosphatase-mediated phosphorus (P) mineralization is one of the critical processes in biogeochemical cycling of P and determines soil P availability in forest ecosystems; however, the regulation of soil phosphatase activity remains elusive. This study investigated the potential extracellular activities of acid phosphomonoesterase (AcPME) and phosphodiesterase (PDE) and how they were related to key edaphic properties in the L horizon (undecomposed litter) and F/H horizon (fermented and humified litter) and the underlying mineral soil at the 0-15cm depth in eight mature subtropical forests in China. AcPME activity decreased significantly in the order of F/H horizon>L horizon>mineral soil horizon, while the order for PDE activity was L horizon=F/H horizon>mineral soil horizon. AcPME (X axis) and PDE (Y axis) activities were positively correlated in all horizons with significantly higher slope in the L and F/H horizons than in the mineral soil horizon. Both AcPME and PDE activities were positively related to microbial biomass C, moisture content and water-holding capacity in the L horizon, and were positively related to soil C:P, N:P and C:N ratios and fine root (diameter?2mm) biomass in the mineral soil horizon. Both enzyme activities were also interactively affected by forest and horizon, partly due to the interactive effect of forest and horizon on microbial biomass. Our results suggest that modulator(s) of the potential extracellular activity of phosphatases vary with horizon, depending on the relative C, P and water availability of the horizon. PMID:25700362

Hou, Enqing; Chen, Chengrong; Wen, Dazhi; Liu, Xian

2015-05-15

321

The ecology and behavior of burying beetles.  

PubMed

Burying beetles conceal small vertebrate carcasses underground and prepare them for consumption by their young. This review places their complex social behavior in an ecological context that focuses on the evolution of biparental care and communal breeding. Both males and females provide extensive parental care, and the major benefit of male assistance is to help defend the brood and carcass from competitors. As intensity and type of competition vary, so do the effectiveness and duration of male care. In many species, a single brood may be reared on large carcasses by more than one male and/or female. Limited reproductive opportunities, the greater effectiveness of groups in preventing the probability of brood failure (especially that caused by competing flies), and the superabundance of food on large carcasses have contributed to the evolution of this cooperative behavior. PMID:15012399

Scott, M P

1998-01-01

322

Buried waste integrated demonstration technology integration process  

SciTech Connect

A Technology integration Process was developed for the Idaho National Energy Laboratories (INEL) Buried Waste Integrated Demonstration (BWID) Program to facilitate the transfer of technology and knowledge from industry, universities, and other Federal agencies into the BWID; to successfully transfer demonstrated technology and knowledge from the BWID to industry, universities, and other Federal agencies; and to share demonstrated technologies and knowledge between Integrated Demonstrations and other Department of Energy (DOE) spread throughout the DOE Complex. This document also details specific methods and tools for integrating and transferring technologies into or out of the BWID program. The document provides background on the BWID program and technology development needs, demonstrates the direction of technology transfer, illustrates current processes for this transfer, and lists points of contact for prospective participants in the BWID technology transfer efforts. The Technology Integration Process was prepared to ensure compliance with the requirements of DOE`s Office of Technology Development (OTD).

Ferguson, J.S.; Ferguson, J.E.

1992-04-01

323

Buried waste integrated demonstration technology integration process  

SciTech Connect

A Technology integration Process was developed for the Idaho National Energy Laboratories (INEL) Buried Waste Integrated Demonstration (BWID) Program to facilitate the transfer of technology and knowledge from industry, universities, and other Federal agencies into the BWID; to successfully transfer demonstrated technology and knowledge from the BWID to industry, universities, and other Federal agencies; and to share demonstrated technologies and knowledge between Integrated Demonstrations and other Department of Energy (DOE) spread throughout the DOE Complex. This document also details specific methods and tools for integrating and transferring technologies into or out of the BWID program. The document provides background on the BWID program and technology development needs, demonstrates the direction of technology transfer, illustrates current processes for this transfer, and lists points of contact for prospective participants in the BWID technology transfer efforts. The Technology Integration Process was prepared to ensure compliance with the requirements of DOE's Office of Technology Development (OTD).

Ferguson, J.S.; Ferguson, J.E.

1992-04-01

324

Landslide Buries Valley of the Geysers  

NASA Technical Reports Server (NTRS)

Geysers are a rare natural phenomena found only in a few places, such as New Zealand, Iceland, the United States (Yellowstone National Park), and on Russia's far eastern Kamchatka Peninsula. On June 3, 2007, one of these rare geyser fields was severely damaged when a landslide rolled through Russia's Valley of the Geysers. The landslide--a mix of mud, melting snow, trees, and boulders--tore a scar on the land and buried a number of geysers, thermal pools, and waterfalls in the valley. It also blocked the Geyser River, causing a new thermal lake to pool upstream. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this infrared-enhanced image on June 11, 2007, a week after the slide. The image shows the valley, the landslide, and the new thermal lake. Even in mid-June, just days from the start of summer, the landscape is generally covered in snow, though the geologically heated valley is relatively snow free. The tree-covered hills are red (the color of vegetation in this false-color treatment), providing a strong contrast to the aquamarine water and the gray-brown slide. According to the Russian News and Information Agency (RIA) [English language], the slide left a path roughly a kilometer and a half (one mile) long and 200 meters (600 feet) wide. Within hours of the landslide, the water in the new lake inundated a number of additional geysers. The geysers directly buried under the landslide now lie under as much as 60 meters (180 feet) of material, according to RIA reports. It is unlikely that the geysers will be able to force a new opening through this thick layer, adds RIA. Among those directly buried is Pervenets (Firstborn), the first geyser found in the valley, in 1941. Other geysers, such as the Bolshoi (Greater) and Maly (Lesser) Geysers, were silenced when buried by water building up behind the new natural dam. According to Vladimir and Andrei Leonov of the Russian Federation Institute of Volcanology and Seismology, the new lake appears to be stable and draining gradually through the earthen dam, alleviating fears of a catastrophic flood. Should the new lake drain enough, many of the inundated geysers may restart. Initial reports from the Volcanology and Seismology Institute state this has already happened for some geysers. Geysers outside of the slide region, including the Velikan (Giant) Geyser and a major section of the geyser field known as Vitrazh (Stained Glass) appear to have escaped damage. In addition to destroying a number of geysers, the landslide may have damaged habitats in the Valley of the Geysers. The thermal waters and heated steam jets made this valley warmer than the surrounding landscape, and the warmth supported a unique ecosystem. The loss of a large part of its heat source may alter the ecosystem, but it is not clear what additional longer-term changes might occur. For example, salmon that spawn in the Geyser River will be confined to the lower reaches of the river, and bears, which depended on salmon, will need to shift feeding grounds correspondingly. Thanks to Sergey Chernomorets and Boris Yurchak for information and translation. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

2007-01-01

325

Detection of Microbial sulfate-reduction associated with buried stainless steel coupons  

SciTech Connect

The objective of this study was to demonstrate applicability of an innovative radioactive isotope method for imaging microbial activity in geological materials to a comprehensive study of metal corrosion. The method was tested on a sample of stainless steel coupons that had been buried as part of a corrosion study initiated by the National Institute of Standards and Testing or NIST (known as National Bureau of Standards prior to 1988) in 1970. The images showed evidence of microbial activity that could be mapped on a millimeter scale to coupon surfaces. A second more conventional isotope tracer method was also used to provide a quantitative measure of the same type of microbial activity in soil proximal to the buried coupons. Together the techniques offer a method for evaluating low metabolic levels of activity that have the potential for significant cumulative corrosion effects. The methods are powerful tools for evaluation of potential for microbial induced corrosion to buried steel components used on pipelines, in the power and communications infrastructure, and in nuclear waste repository containers.

Mark E. Delwiche; M. Kay Adler Flitton; Alicia Olson

2007-03-01

326

Integrated test schedule for buried waste integrated demonstration  

SciTech Connect

The Integrated Test Schedule incorporates the various schedules the Buried Waste Integrated Demonstration (BWID) supports into one document. This document contains the Federal Facilities Agreement and Consent Order schedules for the Idaho National Engineering Laboratory, Hanford Reservation, Oak Ridge Reservation, and Fernald Environmental Materials Center. Included in the Integrated Test Schedule is the Buried Waste Integrated Demonstration ``windows of opportunity`` schedule. The ``windows of opportunity`` schedule shows periods of time in which Buried Waste Integrated Demonstration Program-sponsored technology demonstrations could support key decisions in the Federal Facilities Agreement and Consent Order. Schedules for the Buried Waste Integrated Demonstration-sponsored technology task plans are categorized by technology area and divided by current fiscal year and out-year. Total estimated costs for Buried Waste Integrated Demonstration-sponsored Technology Task Plans for FY-92 through FY-97 are $74.756M.

Brown, J.T.; McDonald, J.K.

1992-05-01

327

Integrated test schedule for buried waste integrated demonstration  

SciTech Connect

The Integrated Test Schedule incorporates the various schedules the Buried Waste Integrated Demonstration (BWID) supports into one document. This document contains the Federal Facilities Agreement and Consent Order schedules for the Idaho National Engineering Laboratory, Hanford Reservation, Oak Ridge Reservation, and Fernald Environmental Materials Center. Included in the Integrated Test Schedule is the Buried Waste Integrated Demonstration windows of opportunity'' schedule. The windows of opportunity'' schedule shows periods of time in which Buried Waste Integrated Demonstration Program-sponsored technology demonstrations could support key decisions in the Federal Facilities Agreement and Consent Order. Schedules for the Buried Waste Integrated Demonstration-sponsored technology task plans are categorized by technology area and divided by current fiscal year and out-year. Total estimated costs for Buried Waste Integrated Demonstration-sponsored Technology Task Plans for FY-92 through FY-97 are $74.756M.

Brown, J.T.; McDonald, J.K.

1992-05-01

328

Spectroscopy of a weakly isolated horizon  

E-print Network

The spectroscopy of a weakly isolated horizon (WIH) has been investigated. We obtain an equally spaced entropy spectrum with its quantum equal to the one given by Bekenstein [5]. We demonstrate that the quantization of entropy and area is a generic property of horizon, and the results exit in a wide class of spacetimes admitting weakly isolated horizons. Our results also indicate that the entropy quantum of the black hole horizon is closely related to Hawking temperature.

Ge-Rui Chen; Yong-Chang Huang

2015-02-12

329

Parametric Study of Transient Electromagnetic Fields Due to Overhead Transmission Lines and Buried Cables in the Vicinity of Lossy Ground  

Microsoft Academic Search

In this paper, the problem of calculating transient electromagnetic fields due to frequency-dependent multicon- ductor overhead transmission lines above lossy ground and underground cables buried in lossy soil is studied by decomposing the transmission line into a number of small segments. A modified finite-difference time-domain technique is applied to find the current passing through each segment of the excited transmis-

Pooya Taheri; Behzad Kordi; Aniruddha M. Gole

2011-01-01

330

Spin and its relation to the Horizon  

Microsoft Academic Search

The author had previously suggested the the CMBR was not necessarily the result of just the big-bang, but may in fact be the Horizon of the Universe. This conclusion was reached by noting the fact that Horizons of curved surfaces, unlike flat surfaces are non-magnifiable. If one looks at the Horizon of the earth, say on a beach by the

Richard Kriske

2010-01-01

331

A study on the use of passive microwave radiometry for the detection of buried objects and their associated hydrological changes  

NASA Astrophysics Data System (ADS)

The detection of buried objects with remote sensing techniques mainly relies on thermal infrared, ground penetrating radar, and metal detectors. However, nowadays people also start to use low frequency passive microwave radiometry for the same purpose. The detection performance of passive microwave radiometry is influenced by the depth and size of the object, environmental factors, and soil properties. Soil moisture is a key variable here, due to its strong influence on the observed dielectric constant. Through digging activities will the hydrological conditions of the soil change significantly that can be detected by remotely sensing systems. A study was designed to examine the influence of the hydrological changes caused by the direct placement of an object in the ground. Simulations in a soil moisture model and field observations revealed the development of a wetter part above and a drier part underneath an object. The observations were converted to brightness temperatures with a coherent model in combination with a dielectric mixing model. Development of a drier area underneath an object generally increases the brightness temperature after a precipitation event. As a results are brightness temperature anomalies of low dielectric constant objects raised during the first 36 hours after a rain event. Ground observations of soil moisture and porosity revealed an increase in porosity and loss in soil moisture for the part that was excavated. Knowledge of past weather conditions could therefore improve buried object detection by passive microwave sensors.

van de Ven, Robbert; de Jeu, Richard; Haarbrink, Roland

2014-10-01

332

Soil Fertility Protocol  

NSDL National Science Digital Library

The purpose of this resource is to measure the amounts of nitrogen, phosphorous and potassium in each horizon in a soil profile. Using a NPK test kit, students mix a dry, sieved soil sample into a solution and chemically extract the N, P, and K as nitrate, phosphate, and potassium. The N, P, and K amounts in the sample are determined by comparing the solution to a color chart. Students describe the N, P, K amounts as high, medium, low, or none. These measurements are conducted three times for each horizon.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

333

A laboratory-scale buried charge simulator G.J. McShane, V.S. Deshpande, N.A. Fleck  

E-print Network

phase of high pressure (attributed to wave propagation effects in the impacting sand), followed. Important parameters include the size and shape of the explosive charge, the properties of the soilA laboratory-scale buried charge simulator G.J. McShane, V.S. Deshpande, N.A. Fleck Department

Fleck, Norman A.

334

Evaluation of Xenon Gas Detection as a Means for Identifying Buried Transuranic Waste at the Radioactive Waste Management Complex, Idaho National Environmental and Engineering Laboratory  

Microsoft Academic Search

Xenon is produced as a fission product in nuclear reactors and through spontaneous fission of some transuranic (TRU) isotopes. Xenon gas is nearly inert and will be released from buried TRU waste. This document describes and evaluates the potential for analyzing xenon isotopes in soil gas to detect TRU waste in the subsurface at the Idaho National Environmental and Engineering

P Evan Dresel; Scott R. Waichler

2004-01-01

335

The effects of vegetation and burning on the chemical composition of soil organic matter in a volcanic ash soil as shown by 13C NMR spectroscopy. I. Whole soil and humic acid fraction  

Microsoft Academic Search

Soil samples were collected from the surface mineral horizon (Ah horizon) of four adjacent soils (sites I, II, III, IV) and one remote soil (site V) derived from volcanic ash in Japan. The four adjacent sites were managed as Miscanthus sinensis grassland for several hundred years by the use of annual burning to prevent the regrowth of native forest species.

A. Golchin; P. Clarke; J. A. Baldock; T. Higashi; J. O. Skjemstad; J. M. Oades

1997-01-01

336

Chemical Sensing for Buried Landmines - Fundamental Processes Influencing Trace Chemical Detection  

SciTech Connect

Mine detection dogs have a demonstrated capability to locate hidden objects by trace chemical detection. Because of this capability, demining activities frequently employ mine detection dogs to locate individual buried landmines or for area reduction. The conditions appropriate for use of mine detection dogs are only beginning to emerge through diligent research that combines dog selection/training, the environmental conditions that impact landmine signature chemical vapors, and vapor sensing performance capability and reliability. This report seeks to address the fundamental soil-chemical interactions, driven by local weather history, that influence the availability of chemical for trace chemical detection. The processes evaluated include: landmine chemical emissions to the soil, chemical distribution in soils, chemical degradation in soils, and weather and chemical transport in soils. Simulation modeling is presented as a method to evaluate the complex interdependencies among these various processes and to establish conditions appropriate for trace chemical detection. Results from chemical analyses on soil samples obtained adjacent to landmines are presented and demonstrate the ultra-trace nature of these residues. Lastly, initial measurements of the vapor sensing performance of mine detection dogs demonstrates the extreme sensitivity of dogs in sensing landmine signature chemicals; however, reliability at these ultra-trace vapor concentrations still needs to be determined. Through this compilation, additional work is suggested that will fill in data gaps to improve the utility of trace chemical detection.

PHELAN, JAMES M.

2002-05-01

337

Dynamics of decadally cycling carbon in subsurface soils  

E-print Network

of Soil, Water and Environmental Science, University ofsoil carbon and atmospheric carbon dioxide driven by temperature change, Science,soil (surface horizons, nominally the A or Ap Department of Earth System Science,

Koarashi, Jun; Hockaday, William C; Masiello, Caroline A; Trumbore, Susan E

2012-01-01

338

Using soil properties as a tool to differentiate landslide generations and constrain their ages - Rogowiec landslide, Sudetes (SW Poland)  

NASA Astrophysics Data System (ADS)

The Sudetes, at the border of Poland and the Czech Republic, are generally considered as a mountain range where landslides play a marginal geomorphic role. Only a few larger landslides have been recorded during historical times, mainly on steep valley sides undercut by rivers. Forested slopes, which dominate in the Sudetes, are usually inferred to be stable, except for near-surface bioturbation and localized accelerated surface erosion at sites subject to strong human impact. Large, apparently relict landslides in the Kamienne Mountains, Middle Sudetes, pose a considerable challenge to this view and two interpretations are possible. First, they may be indeed relict, pre-Holocene features that formed under different environmental conditions and have been completely stabilized since the origin. Second, they may be rare components of the contemporary (Holocene) geomorphic system but their frequency of occurrence is low and this is why none has been reported in written or oral records. If the second scenario captures the reality adequately, this would have significant implications for hazard and risk assessment. To address this issue, an extensive soil survey was carried out on the large landslide of Rogowiec, likely of complex flow nature as suggested by landform mapping. The rationale of the study involved an assumption that soil formation time in the area is limited to the Holocene, since harsh periglacial conditions typified the late Pleistocene. 15 soil pits were excavated within landslide terrain and on adjacent reference slopes which do not bear any evident traces of significant displacements. Despite the small area under investigation, the soil profiles are very diverse in terms of depth, horizonation, organic matter content, development of soil structure, as well as the content and lithology of coarse fragments. A great deal of this diversity can be explained by different duration of pedogenesis controlled by geomorphic processes. Very weakly developed soil profiles in the landslide body do not show evidence of protracted soil evolution under contemporary climate and hence, are interpreted as having been formed during a fraction of the Holocene. This implies a Holocene age of the landslide. In addition, an older shallow translational landslide has been recognized on the valley side, with the toe buried by the main Rogowiec landslide. The depletion area was identified through the occurrence of thin, truncated soils (compared to the neighbouring slopes). This and the occurrence of weakly horizonated and poorly structural soils in the landslide body itself suggest that this valley-side landslide is of the Holocene age too. Thus, soils proved a powerful tool to establish the relative chronology of landslides and give strong evidence of their Holocene age. Soil research is recommended as a part of landslide hazard and risk assessment for landslides of unknown age.

Kacprzak, Andrzej; Migo?, Piotr

2013-04-01

339

Is life a thermal horizon ?  

E-print Network

This talk aims at questioning the vanishing of Unruh temperature for an inertial observer in Minkovski spacetime with finite lifetime, arguing that in the non eternal case the existence of a causal horizon is not linked to the non-vanishing of the acceleration. This is illustrated by a previous result, the diamonds temperature, that adapts the algebraic approach of Unruh effect to the finite case.

Pierre Martinetti

2007-07-26

340

Penrose inequality and apparent horizons  

SciTech Connect

A spherically symmetric spacetime is presented with an initial data set that is asymptotically flat, satisfies the dominant energy condition, and such that on this initial data M<{radical}(A/16{pi}), where M is the total mass and A is the area of the apparent horizon. This provides a counterexample to a commonly stated version of the Penrose inequality, though it does not contradict the true Penrose inequality.

Ben-Dov, Ishai [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637-1433 (United States)

2004-12-15

341

Horizon universality and anomalous conductivities  

E-print Network

We show that the value of chiral conductivities associated with anomalous transport is universal in a general class of strongly coupled quantum field theories. Our result applies to theories with no dynamical gluon fields and admitting a gravitational holographic dual in the large N limit. On the gravity side the result follows from near horizon universality of the fluctuation equations, similar to the holographic calculation of the shear viscosity.

Umut Gursoy; Javier Tarrio

2014-10-06

342

Horizons cannot save the Landscape  

E-print Network

Solutions with anti-D3 branes in a Klebanov-Strassler geometry with positive charge dissolved in fluxes have a certain singularity corresponding to a diverging energy density of the RR and NS-NS three-form fluxes. There are many hopes and arguments for and against this singularity, and we attempt to settle the issue by examining whether this singularity can be cloaked by a regular event horizon. This is equivalent to the existence of asymptotically Klebanov-Tseytlin or Klebanov-Strassler black holes whose charge measured at the horizon has the opposite sign to the asymptotic charge. We find that no such KT solution exists. Furthermore, for a large class of KS black holes we considered, the charge at the horizon must also have the same sign as the asymptotic charge, and is completely determined by the temperature, the number of fractional branes and the gaugino masses of the dual gauge theory. Our result suggests that antibrane singularities in backgrounds with charge in the fluxes are unphysical, which in turn raises the question as to whether antibranes can be used to uplift AdS vacua to deSitter ones. Our results also point out to a possible instability mechanism for the antibranes.

Iosif Bena; Alex Buchel; Oscar J. C. Dias

2012-12-20

343

Radioisotopic battery for long-life, buried autonomous power  

NASA Astrophysics Data System (ADS)

Indirect conversion radioisotopic batteries (ICRBs) are investigated for use as long-life power source for autonomous buried applications. As part of this work the optimum configuration of this class of battery has been experimentally investigated. An ICRB was buried at a depth of 90cm for two months during which time its voltage was monitored, with these results presented. The ICRB successfully demonstrated the buried operation of this class of battery and suggested that the power of the device halves at twice the half-life of the radioisotope used.

Walton, R.; Anthony, C.; Chapman, D.; Metje, N.; Ward, M.

2013-12-01

344

Designable buried waveguides in sapphire by proton implantation  

SciTech Connect

Buried and stacked planar as well as buried single and parallel channel waveguides are fabricated in sapphire by proton implantation. Good control of the implantation parameters provides excellent confinement of the guided light in each structure. Low propagation losses are obtained in fundamental-mode, buried channel waveguides without postimplantation annealing. Choice of the implantation parameters allows one to design mode shapes with different ellipticity and/or mode asymmetry in each orthogonal direction, thus demonstrating the versatility of the fabrication method. Horizontal and vertical parallelization is demonstrated for the design of one- or two-dimensional waveguide arrays in hard crystalline materials.

Laversenne, L.; Hoffmann, P.; Pollnau, M.; Moretti, P.; Mugnier, J. [Advanced Photonics Laboratory, Institute of Imaging and Applied Optics, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland); Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR 5620 CNRS, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne (France)

2004-11-29

345

Soil Science Education Homepage  

NSDL National Science Digital Library

This site covers numerous aspects of soil science and addresses many soil related issues at a level that can be presented to school age children. Several sections are devoted to the relationship between humans and soil in terms of agriculture, society, ecosystems, and why soil should be studied. Also included are photographs of different soil types or soil horizons with descriptions that explain what is being seen and what processes may have contributed to the soil characteristics. There are a host of activities that can be performed in the classroom or out in the field. The features of this site appear to be updated frequently and present different issues, activities, and discussions relating to soil.

2002-03-19

346

New Horizons Launch Contingency Effort  

NASA Astrophysics Data System (ADS)

On 19 January 2006 at 2:00 PM EST, the NASA New Horizons spacecraft (SC) was launched from the Cape Canaveral Air Force Station (CCAFS), FL, onboard an Atlas V 551/Centaur/STAR™ 48B launch vehicle (LV) on a mission to explore the Pluto Charon planetary system and possibly other Kuiper Belt Objects. It carried a single Radioisotope Thermoelectric Generator (RTG). As part of the joint NASA/US Department of Energy (DOE) safety effort, contingency plans were prepared to address the unlikely events of launch accidents leading to a near-pad impact, a suborbital reentry, an orbital reentry, or a heliocentric orbit. As the implementing organization. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had expanded roles in the New Horizons launch contingency effort over those for the Cassini mission and Mars Exploration Rovers missions. The expanded tasks included participation in the Radiological Control Center (RADCC) at the Kennedy Space Center (KSC), preparation of contingency plans, coordination of space tracking assets, improved aerodynamics characterization of the RTG's 18 General Purpose Heat Source (GPHS) modules, and development of spacecraft and RTG reentry breakup analysis tools. Other JHU/APL tasks were prediction of the Earth impact footprints (ElFs) for the GPHS modules released during the atmospheric reentry (for purposes of notification and recovery), prediction of the time of SC reentry from a potential orbital decay, pre-launch dissemination of ballistic coefficients of various possible reentry configurations, and launch support of an Emergency Operations Center (EOC) on the JHU/APL campus. For the New Horizons launch, JHU/APL personnel at the RADCC and at the EOC were ready to implement any real-time launch contingency activities. A successful New Horizons launch and interplanetary injection precluded any further contingency actions. The New Horizons launch contingency was an interagency effort by several organizations. This paper describes JHU/APL's roles and responsibilities in the launch contingency effort, and the specific tasks to fulfill those responsibilities. The overall effort contributed to mission safety and demonstrated successful cooperation between several agencies.

Chang, Yale; Lear, Matthew H.; McGrath, Brian E.; Heyler, Gene A.; Takashima, Naruhisa; Owings, W. Donald

2007-01-01

347

Moisture Effects in Soils Using a Frequency Domain Metal Detector  

Microsoft Academic Search

It is reported by experienced deminers that the existence of moisture in soils complicates the detection of buried land mines. In this work we examine the influence of water in two different sample soil types (sand and clay soil) on the magnetic field induced by a mine surrogate and thus on the quality of the detector's audible signal when using

B. R. Vales; S. Harneit; M. Reuter; V. Skorupskaite

2006-01-01

348

Buried nanoantenna arrays: versatile antireflection coating.  

PubMed

Reflection is usually a detrimental phenomenon in many applications such as flat-panel-displays, solar cells, photodetectors, infrared sensors, and lenses. Thus far, to control and suppress the reflection from a substrate, numerous techniques including dielectric interference coatings, surface texturing, adiabatic index matching, and scattering from plasmonic nanoparticles have been investigated. A new technique is demonstrated to manage and suppress reflection from lossless and lossy substrates. It provides a wider flexibility in design versus previous methods. Reflection from a surface can be suppressed over a narrowband, wideband, or multiband frequency range. The antireflection can be dependent or independent of the incident wave polarization. Moreover, antireflection at a very wide incidence angle can be attained. The reflection from a substrate is controlled by a buried nanoantenna array, a structure composed of (1) a subwavelength metallic array and (2) a dielectric cover layer referred to as a superstrate. The material properties and thickness of the superstrate and nanoantennas' geometry and periodicity control the phase and intensity of the wave circulating inside the superstrate cavity. A minimum reflectance of 0.02% is achieved in various experiments in the mid-infrared from a silicon substrate. The design can be integrated in straightforward way in optical devices. The proposed structure is a versatile AR coating to optically impedance matches any substrate to free space in selected any narrow and broadband spectral response across the entire visible and infrared spectrum. PMID:24266700

Kabiri, Ali; Girgis, Emad; Capasso, Federico

2013-01-01

349

ISV technology development plan for buried waste  

SciTech Connect

This report identifies the main technical issues facing the in situ vitrification (ISV) application to buried waste, and presents a plan showing the top-level schedule and projected resources needed to develop and demonstrate the technology for meeting Environmental Restoration Department (ERD) needs. The plan also proposes a model strategy for the technology transfer from the Department of Energy's Office of Technology Development (DOE-OTD) to the Office of Environmental Restoration (DOE-ER) as the technology proceeds from issues resolution (development) to demonstration and remedial readiness. Implementation of the plan would require $34,91 1K in total funding to be spread in the years FY-93 through FY-98. Of this amount, $10,183K is planned to be funded by DOE-OTD through the ISV Integrated Program. The remaining amount, $24,728K, is recommended to be split between the Department of Energy (DOE) Office of Technology Development ($6,670K) and DOE Office of Environmental Restoration ($18,058K).

Nickelson, D.F.; Callow, R.A. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Luey, J.K. (Pacific Northwest Lab., Richland, WA (United States))

1992-07-01

350

ISV technology development plan for buried waste  

SciTech Connect

This report identifies the main technical issues facing the in situ vitrification (ISV) application to buried waste, and presents a plan showing the top-level schedule and projected resources needed to develop and demonstrate the technology for meeting Environmental Restoration Department (ERD) needs. The plan also proposes a model strategy for the technology transfer from the Department of Energy`s Office of Technology Development (DOE-OTD) to the Office of Environmental Restoration (DOE-ER) as the technology proceeds from issues resolution (development) to demonstration and remedial readiness. Implementation of the plan would require $34,91 1K in total funding to be spread in the years FY-93 through FY-98. Of this amount, $10,183K is planned to be funded by DOE-OTD through the ISV Integrated Program. The remaining amount, $24,728K, is recommended to be split between the Department of Energy (DOE) Office of Technology Development ($6,670K) and DOE Office of Environmental Restoration ($18,058K).

Nickelson, D.F.; Callow, R.A. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Luey, J.K. [Pacific Northwest Lab., Richland, WA (United States)

1992-07-01

351

Buried waste containment system materials. Final Report  

SciTech Connect

This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers.

Weidner, J.R.; Shaw, P.G.

1997-10-01

352

In situ vitrification application to buried waste: Final report of intermediate field tests at Idaho National Engineering Laboratory  

SciTech Connect

This report describes two in situ vitrification field tests conducted on simulated buried waste pits during June and July 1990 at the Idaho National Engineering Laboratory. In situ vitrification, an emerging technology for in place conversion of contaminated soils into a durable glass and crystalline waste form, is being investigated as a potential remediation technology for buried waste. The overall objective of the two tests was to access the general suitability of the process to remediate waste structures representative of buried waste found at Idaho National Engineering Laboratory. In particular, these tests, as part of a treatability study, were designed to provide essential information on the field performance of the process under conditions of significant combustible and metal wastes and to test a newly developed electrode feed technology. The tests were successfully completed, and the electrode feed technology successfully processed the high metal content waste. Test results indicate the process is a feasible technology for application to buried waste. 33 refs., 109 figs., 39 tabs.

Callow, R.A.; Weidner, J.R.; Loehr, C.A.; Bates, S.O. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Thompson, L.E.; McGrail, B.P. (Pacific Northwest Lab., Richland, WA (United States))

1991-08-01

353

Study of near-source earthquake effects on flexible buried pipes  

NASA Astrophysics Data System (ADS)

An investigation is carried out, using strong ground motion recordings, field measurements, and new analytical models, on large diameter flexible buried pipes shaken in the 1994 Northridge earthquake near field. Case studies are presented for corrugated metal pipes (CMP) in the Van Norman Complex (VNC) vicinity in Los Angeles, California. In 1994 the VNC yielded an unprecedented number of strong motion recordings with high acceleration and velocity. These recordings contain forward directivity pulses and provided the largest velocity ever instrumentally recorded (180 cm/s). The recorded motions were significantly different in the longitudinal and transverse directions and had approximately half the amplitude at the VNC center than on the north and south ends. The seismic performances of 61 underground CMPs are presented, beginning with detailed studies of a 2.4 m diameter pipe that suffered complete lateral buckling collapse at the Lower San Fernando Dam (LSFD). The case histories identify factors controlling large diameter CMP seismic performances that are incorporated into several newly developed models for the analysis and design of buried structures. Each model progressively improves the understanding of buried pipe behavior. Simple acceleration- and strain-based pseudo-static models are initially developed to identify main causes for CMP damage. Elasto-dynamic models for transverse SV waves are later used to understand flexible pipe response in the frequency and time domains and are compared with existing solutions. Finally, pseudo-static models, which analyze pipe responses in terms of free-field strains, are formulated to account for dynamic amplification, non-vertical wave incidence, soil layering, and trench backfill soil stiffness. The elastic models are used to investigate soil-pipe interface shear stress and non-linear soil behavior and show that the maximum pipe hoop force is best characterized by assuming no interface slippage. The models explain the observed CMP performance during the 1994 earthquake and show that peak velocity is a more reliable index of flexible pipe damage than acceleration and that large seismic stresses, modulus reduction, and pore pressure increases in the embedding soils damaged the LSFD and other CMPs. Results of the field investigations and companion analyses are useful for the seismic design and strengthening of underground structures.

Davis, Craig Alan

2000-10-01

354

Probabilistic Modeling of Landfill Subsidence Introduced by Buried Structure Collapse - 13229  

SciTech Connect

The long-term reliability of land disposal facility final cover systems - and therefore the overall waste containment - depends on the distortions imposed on these systems by differential settlement/subsidence. The evaluation of differential settlement is challenging because of the heterogeneity of the waste mass and buried structure placement. Deterministic approaches to long-term final cover settlement prediction are not able to capture the spatial variability in the waste mass and sub-grade properties, especially discontinuous inclusions, which control differential settlement. An alternative is to use a probabilistic model to capture the non-uniform collapse of cover soils and buried structures and the subsequent effect of that collapse on the final cover system. Both techniques are applied to the problem of two side-by-side waste trenches with collapsible voids. The results show how this analytical technique can be used to connect a metric of final cover performance (inundation area) to the susceptibility of the sub-grade to collapse and the effective thickness of the cover soils. This approach allows designers to specify cover thickness, reinforcement, and slope to meet the demands imposed by the settlement of the underlying waste trenches. (authors)

Foye, Kevin; Soong, Te-Yang [CTI and Associates, Inc., 51331 W. Pontiac Trail, Wixom, MI 48393 (United States)] [CTI and Associates, Inc., 51331 W. Pontiac Trail, Wixom, MI 48393 (United States)

2013-07-01

355

Implications of the sedimentology and isotope geochemistry of calcic horizons in the Pliocene-Early Pleistocene St. David Fm. , Arizona  

SciTech Connect

Two types of calcic horizons occur in pedogenically modified alluvial mudstones of the Plio-Pleistocene St. David Fm.: (1) nodular-carbonate zones (stage 2 morphology) with downward decreasing carbonate abundance, located below leached red muds; (2) massive to nodular zones (stage 3) with sharp bases, upward decrease in carbonate abundance, associated with variably leached muds typically exhibiting green mottles. Type 1 horizons are traceable for hundreds of meters; type 2 horizons vary in thickness and carbonate content over distances as short at 15 m. and are laterally contiguous with pond deposits. Type 1 horizons are interpreted as vadose aridosol calcic horizons, whereas type 2 horizons are partly gleyed hydromorphic soils with calcite derived from groundwater as well as from leaching within the soil. O and C isotopic compositions of age-equivalent 1 and 2 carbonates are similar suggesting that type 2 calcite formed in the unsaturated zone, probably in the capillary fringe above the water table. These latter horizons define a limited time of elevated water table, which corresponds to a cooler/wetter climate and higher sedimentation rates. If the distinction between these two soil types was not made, the greater morphological maturity'' of type 2 horizons would lead to misinterpretation of more arid climatic conditions or lower sedimentation rates. Type 1 horizons occur within parallel piedmont-facies belts representing channel/channel margin and floodplain deposition. Paleosols are morphologically similar, although floodplain soils are more clay rich. C-isotope analyses suggest, however, different vegetational histories for the two depositional tracts that reflect different responses of channel-margin and floodplain settings to increasing seasonality of precipitation during the late Pliocene.

Smith, G.A. (Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Earth and Planetary Science); Wang, Y.; Cerling, T.E. (Univ. of Utah, Salt Lake City, UT (United States))

1992-01-01

356

49 CFR 195.248 - Cover over buried pipeline.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

2011-10-01

357

49 CFR 195.248 - Cover over buried pipeline.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

2014-10-01

358

49 CFR 195.248 - Cover over buried pipeline.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

2012-10-01

359

49 CFR 195.248 - Cover over buried pipeline.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION...DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF...

2013-10-01

360

Stability analysis of buried flexible pipes: a biaxial buckling equation  

E-print Network

STABILITY ANALYSIS OF BURIED FLEXIBLE PIPES: A BIAXIAL BUCKLING EQUATION A Thesis by MELISSA TUYET-MAI CHAU Submitted to the Office of Graduate Studies of Texas AkM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1990 Major Subject: Civil Engineering STABLILITY ANALYSIS OF BURIED FLEXIBLE PIPES: A BIAXIAL BUCKLING EQUATION A Thesis by MELISSA TUYET-MAI CHAU Approved as to style and content by: r. obert L. Lytt n (Chair of Committee...

Chau, Melissa Tuyet-Mai

1990-01-01

361

Soil Field Descriptions and Soil Forming Processes  

NSDL National Science Digital Library

In this field activity students break into small groups and dig soil pits. The pits are distributed among different vegetative covers and topographic positions allowing comparisons of soil profiles under different soil forming processes. Each group prepares a field description of their soil using a shortened version of the NRCS Field Book for Describing and Sampling Soils (2002). Before leaving the field the class takes a tour of the pits and each group gives a brief oral presentation of their profile. Samples from each horizon are later analyzed in the lab to determine the % soil moisture and organic matter. Data from each group is compiled on a share drive which is then utilized by the rest of the class for comparison. Designed for a geomorphology course

Jeff Clark

362

Leaf litter is an important mediator of soil respiration in an oak-dominated forest  

Microsoft Academic Search

The contribution of the organic (O) horizon to total soil respiration is poorly understood even though it can represent a large source of uncertainty due to seasonal changes in microclimate and O horizon properties due to plant phenology. Our objectives were to partition the CO2 effluxes of litter layer and mineral soil from total soil respiration (SR) and determine the

Jared L. Deforest; Jiquan Chen; Steve G. McNulty

2009-01-01

363

Chemical and mineral composition of ectomycorrhizosphere soils of subalpine fir (Abies  

E-print Network

Chemical and mineral composition of ectomycorrhizosphere soils of subalpine fir (Abies lasiocarpa- zosphere soils of subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in the Ae horizon of a Luvisol. Can. J'ectomycorhi- zosphère sous sapin subalpin (Abies lasiocarpa (Hook.) Nutt.) dans l'horizon Ae d'un luvisol. Can. J. Soil

Massicotte, Hugues

364

The Q 10 relationship of microbial respiration in a temperate forest soil  

Microsoft Academic Search

Our objective was to study the effect of temperature on rates of soil respiration in the A-, E- and B-horizons of a temperate forest (Durham, North Carolina, USA). Soil samples were incubated for several months at 4, 15, 22 and 38°C and respiration was measured frequently during incubation. For each soil horizon, rates of CO2 evolution varied significantly with time

Julia Palmer Winkler; Robert S. Cherry; William H. Schlesinger

1996-01-01

365

Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet)  

SciTech Connect

Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation. There are three possible combinations of BED strategies: (1) buried ducts; (2) encapsulated ducts (with ccSPF); and (3) buried and encapsulated ducts. The best solution for each situation depends on the climate, age of the house, and the configuration of the HVAC system and attic. For new construction projects, the team recommends that ducts be both encapsulated and buried as the minimal planning and costs required for this will yield optimal energy savings. The encapsulated/buried duct strategy, which utilizes ccSPF to address condensation concerns, is an approach that was developed specifically for humid climates.

Not Available

2013-11-01

366

How small is pedogenic magnetite? Size estimates for loessic soils based on remanence and hysteresis measurements.  

NASA Astrophysics Data System (ADS)

Pedogenic magnetite (or maghemite) is generally believed to be fine-grained, consisting mainly of superparamagnetic (SP) and single-domain (SD) particles. These grain size estimates are based on increased values of ARM/IRM or frequency dependent susceptibility (?FD) in the magnetically enhanced horizons. However, these changes in grain size dependent parameters are generally quite small, compared to the often large increase in concentration dependent parameters, such as low field susceptibility, saturation magnetization (J_S), or various remanence parameters (RM). In addition, a recent study by Dunlop (2002b) suggested that hysteresis properties of several Chinese soils (modern and buried) do not suggest a fining of the magnetic component in the magnetically enhanced soil horizons. We used the model of Dunlop (2002a)to analyze hysteresis data from twenty modern soil profiles from the Midwestern United States. In contrast to the data analyzed by Dunlop (2002b), our data can be modeled equally well with binary mixtures of SD-MD and SD-SP particles. To complement the ambiguous hysteresis data we generated a simple mixing model to constrain the size distribution of pedogenic magnetite. Our model assumes remanence acquisition efficiencies f = RM / J_S for coarse (MD - PSD) and fine (SD-SP) magnetite for ARM and IRM. It then uses ARM/IRM ratios to estimate the relative abundances of coarse and fine magnetite. The validity of our grain size distribution estimates can be checked by comparing measured J_S values to J_S calculated from our model output and measured values of IRM (or ARM). A comparison of our ARM/IRM modeling and hysteresis data shows that the magnetic properties of magnetically enhanced soil horizons can be explained with the addition of a fine grained magnetite component. This component, however, has a wide grain size distribution which includes SP, SD and likely PSD particles. Dunlop, D. J. (2002a). Theory and application of the Day plot (Mrs/M_s versus Hcr/H_c) 1. Theoretical curves and tests using titanomagnetite data. Journal of Geophysical Research 107, 10.1029/2001JB000486. Dunlop, D. J. (2002b). Theory and application of the Day plot (Mrs/M_s versus Hcr/H_c) 2. Application to data for rocks, sediments and soils. Journal of Geophysical Research 107, 10.1029/2001JB000487.

Geiss, C. E.; Machac, T.

2005-12-01

367

Influence of soil surface characteristics and water repellence on soil infiltration and soil loss of Andisols (Canary Islands, Spain)  

NASA Astrophysics Data System (ADS)

Infiltration is a crucial process in the hydrological cycle, since it controls - among other things - the generation of run-off, erosion and aquifer recharge. Undisturbed Andisols are considered resistant to water erosion; a characteristic closely associated with their high porosity that permits a rapid rainfall infiltration and high structural stability. In spite of that, the high content of organic C on this type of soils, and the positive relation between this property and water repellence, could allow the presence of some soil surface characteristics that may change this behaviour. The aim of this work was to study the influence of these hydrophobic layers on water infiltration and soil loss on Andisols of Tenerife. Twelve sites were chosen, all of which are located on the northern side of the island of Tenerife (Canary Islands, Spain), between 825-1400 m.a.s.l. The soils are allophanic Andisols (Typic/Lithic Hapludands and Typic Haplustands) and vitric Andisols (Typic Udivitrands) under pine forest. In each site, soil surface features with potential hydrological implications were described. To determine infiltration, a rainfall simulator with the following characteristics was used: 35 x 25 x 30 cm metal box with nozzles in the bottom, 2.5 cm apart (diameter of drops = 2-3 mm). The 4 box adjustable legs were set at 2 m height. Prior to installing the rainfall simulator, study zones were marked out using 30 cm-tall metal sheets. Each area measured approximately 875 cm2 and measurements were taken for slopes of 10 and 30% when it was possible. At the end of the slope a 25 cm-wide collector was semi-buried to collect runoff and sediment. Rainfall of variable intensity between 50-70 mmh-1 was simulated for periods of 30-45 minutes. Time to runoff (TR), volume to runoff (VR), steady-state infiltration rate (IR), runoff/rainfall ratio (RR), soil loss rate (SED) and sediment concentration (CSED) were measured. For some of the studied soils, the formation of horizons made up with pine needles embedded with fungi mycelia was observed. These layers were highly water-repellent and could be easily detached from the underlying soil. When comparing the soils in which these are present with those devoid of them, the former showed an average decrease of 40% in TR and VR for both slopes. The IR suffered a decrease of nearly 40% and 30%, and the RR an increase of 40% and 20% for slopes of 10 and 30% respectively. Contradictory, soil loss showed a decrease in sites where this layer was present, 20% and 40% in SED, and 15% and 50% in CSED for slopes of 10% and 30% respectively. As a conclusion, despite the reduction in IR and the increase in RR, the presence of this layer in soils seems to provide them with a high resistance to drop impact, and a modification of water dynamics leading to a decrease of soil loss.

Concepción, Jiménez; Jonay, Neris; Josué, Fuentes; Marisa, Tejedor

2010-05-01

368

Topological deformation of isolated horizons  

SciTech Connect

We show that the Gauss-Bonnet term can have physical effects in four dimensions. Specifically, the entropy of a black hole acquires a correction term that is proportional to the Euler characteristic of the cross sections of the horizon. While this term is constant for a single black hole, it will be a nontrivial function for a system with dynamical topologies such as black-hole mergers: it is shown that for certain values of the Gauss-Bonnet parameter, the second law of black-hole mechanics can be violated.

Liko, Tomas [Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X7 (Canada)

2008-03-15

369

SOIL AIR CARBON DIOXIDE CONCENTRATIONS IN A NEW ENGLAND SPRUCE-FIR FORESTS  

EPA Science Inventory

Research and modeling efforts to evaluate soil-soil solution chemical interactions must take into account solution equilibria with soil air CO2. Measurements of soil air CO2 and soil temperature were made in the major horizons of a forest soil in eastern Maine through the 1985 gr...

370

Decomposition of forest products buried in landfills.  

PubMed

The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C+H) loss of up to 38%, while loss for the other wood types was 0-10% in most samples. The C+H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27gOCg(-1) dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported. PMID:23942265

Wang, Xiaoming; Padgett, Jennifer M; Powell, John S; Barlaz, Morton A

2013-11-01

371

Record Blizzard Buries U.S. Northeast  

NASA Technical Reports Server (NTRS)

After two days of blustery weather, the skies cleared over Massachusetts on January 24, 2005. Along with other northeastern U.S. states, Massachusetts was slammed with a powerful blizzard on January 22 and 23 that shut down travel and businesses and extinguished power. The storm brought record snow to many places, but Massachusetts topped the list. The cities of Salem and Plymouth were buried in 38 inches (96.5 cm) of snow, and strong winds created drifts up to seven feet (2 meters) high, according to the National Weather Service. For Boston, the storm was the fifth worst blizzard to hit the city since 1892, dumping 22.5 inches (57 cm) of snow in two days. Of that, 13.4 inches (34 cm) fell on January 23' the most snow to fall on the city in a single day since records began. These totals gave Boston nearly twice its average snowfall for January (the average is 13.5 inches, 34.3 cm), and over half its annual average snow of 41.8 inches (106 cm). This Moderate Resolution Imaging Spectroradiometer (MODIS) image, taken on January 24 by NASA's Terra satellite, shows the effects of the storm on Massachusetts and its southern neighbors, Connecticut (left) and Rhode Island (right). New York's Long Island is in the lower left corner of the image. The entire region is coated with snow, though clouds obscure the ground on the left side of the image. The snow was accompanied by powerful hurricane-force winds that helped create white-out conditions and large snowdrifts. The wind also churned ocean waters around Cape Cod, leaving them milky with sediment. NASA image courtesy the MODIS Rapid Response Team at NASA GSFC.

2005-01-01

372

Airblast environments from buried HE charges  

SciTech Connect

Laboratory experiments were conducted to measure the airblast environment generated by the detonation of buried HE charges. Spherical 0.5-g charges of Nitropenta were used as the HE source. Three ground materials were used: (1) a porous, crushable grout (YTONG, {rho} = 0.4 g/cm{sup 3}); (2) a water-saturated grout ({rho} {approx_equal} 0.7 g/Cm{sup 3}) to investigate the effects of density increase; and (3) a clay-loam material ({rho} {approx_equal} 1.8 g/cm{sup 3}) to simulate some of the previous field tests conducted in clay. Diagnostics consisted of 13 flush-mounted pressure gauges, and single-frame schlieren photography. A special shock isolation system was used to eliminate the acceleration effects on the gauges that were induced by the cratering process. Analysis of the pressure measurements resulted in an experimental definition of the airblast environment as a function of ground range (GR) and depth-of-burst (DOB). Synthesis of these results allowed one to construct airblast DOB curves, similar to the airblast height-of-burst curves that we published previously for Nitropenta charges. Variables analyzed were: peak pressure, arrival time, positive phase duration and impulse. As in field tests, we found that the airblast waveforms changed character with increasing DOB. The crater characteristics (e.a., depth, radius and volume) were also measured. The cube-root-scaled crater volume was in qualitative agreement with data from field tests (e.g., charge weights up to 10{sup 4} lbs.). Since the present scaled results compare well with data from large-scale HE tests, we conclude that the present experimental technique provides a useful tool for parametric investigations of explosion effects in the laboratory.

Reichenbach, H.; Behrens, K. [Fraunhofer-Institut fuer Kurzzeitdynamik - Ernst-Mach-Institut (EMI), Freiburg im Breisgau (Germany); Kuhl, A. [Lawrence Livermore National Lab., El Segundo, CA (United States)

1993-01-01

373

Decomposition of forest products buried in landfills  

SciTech Connect

Highlights: • This study tracked chemical changes of wood and paper in landfills. • A decomposition index was developed to quantify carbohydrate biodegradation. • Newsprint biodegradation as measured here is greater than previous reports. • The field results correlate well with previous laboratory measurements. - Abstract: The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g{sup ?1} dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported.

Wang, Xiaoming, E-mail: xwang25@ncsu.edu [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Padgett, Jennifer M. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Powell, John S. [Department of Chemical and Biomolecular Engineering, Campus Box 7905, North Carolina State University, Raleigh, NC 27695-7905 (United States); Barlaz, Morton A. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States)

2013-11-15

374

CROP MANAGEMENT IMPACTS ON CLAYPAN SOIL QUALITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

A high clay-content argillic horizon occurring 10 to 100 cm below the surface restricts soil water movement and reduces nutrient efficiency of claypan soils, which affect soil quality related to production and environmental buffering. The objective of this study was to determine the impacts of long-...

375

Surfactant effects on soil aggregate tensile strength  

Technology Transfer Automated Retrieval System (TEKTRAN)

Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

376

The beginnings of black hole horizons  

NASA Astrophysics Data System (ADS)

The beginning of a black hole horizon is the set of points where generators enter the horizon. Several properties of this "entry set" and the early horizon near it are shown: It is the locus of the horizon's self-intersections, and it is spacelike of dimension zero, one or two, where this is defined. It is connected but can bifurcate in possibly complicated ways. On spacelike surfaces the entry of generators manifests itself in a kink in the horizon. The kinks propagate at superluminal speed until they "run out of steam," slow down to light speed and disappear. Kinks generally run from the main collapse region to secondary collapse events until no more new generators enter the horizon. This is illustrated by collapse of two mass concentrations, and by the case of a large number of particles.

Brill, Dieter

2011-04-01

377

Variable horizon in a peridynamic medium.  

SciTech Connect

A notion of material homogeneity is proposed for peridynamic bodies with vari- able horizon but constant bulk properties. A relation is derived that scales the force state according to the position-dependent horizon while keeping the bulk properties un- changed. Using this scaling relation, if the horizon depends on position, artifacts called ghost forces may arise in a body under homogeneous deformation. These artifacts de- pend on the second derivative of horizon and can be reduced by use of a modified equilibrium equation using a new quantity called the partial stress . Bodies with piece- wise constant horizon can be modeled without ghost forces by using a technique called a splice between the regions. As a limiting case of zero horizon, both partial stress and splice techniques can be used to achieve local-nonlocal coupling. Computational examples, including dynamic fracture in a one-dimensional model with local-nonlocal coupling, illustrate the methods.

Silling, Stewart A.; Littlewood, David John; Seleson, Pablo

2014-10-01

378

Hall Scrambling on Black Hole Horizon  

E-print Network

We explore the effect of the electrodynamics $\\theta$-angle on the macroscopic properties of black hole horizons. Using only classical Einstein-Maxwell-Chern-Simons theory in (3+1)-dimensions, in the form of the membrane paradigm, we show that in the presence of the $\\theta$-term, a black hole horizon behaves as a Hall conductor, for an observer hovering outside. We study how localized perturbations created on the stretched horizon scramble on the horizon by dropping a charged particle. We show that the $\\theta$-angle affects the way perturbations scramble on the horizon, in particular, it introduces vortices without changing the scrambling time. This Hall scrambling of information is also expected to occur on cosmological horizons.

Willy Fischler; Sandipan Kundu

2015-01-06

379

Holography beyond the horizon and cosmic censorship  

E-print Network

We investigate the description of the region behind the event horizon in rotating black holes in the AdS/CFT correspondence, using the rotating BTZ black hole as a concrete example. We extend a technique introduced by Kraus, Ooguri and Shenker [hep-th/0212277], based on analytically continuing amplitudes defined in a Euclidean space, to include rotation. In the rotating case, boundary amplitudes again have two different bulk descriptions, involving either integration only over the regions outside the black holes' event horizon, or integration over this region and the region between the event horizon and the Cauchy horizon (inner horizon). We argue that generally, the holographic map will relate the field theory to the region bounded by the Cauchy horizons in spacetime. We also argue that these results suggest that the holographic description of black holes will satisfy strong cosmic censorship.

Thomas S. Levi; Simon F. Ross

2003-05-09

380

Mechanical laws of the Rindler horizon  

NASA Astrophysics Data System (ADS)

Gravitational perturbations of flat Minkowski space make the Rindler horizon dynamical: the horizon satisfies mechanical laws analogous to the ones followed by black holes. We describe the gravitational perturbation of Minkowski space using perturbative field-theoretical methods. The change in the area of the Rindler horizon is described in terms of the deflection of light rays by the gravitational field. The difference between the area of the perturbed and the unperturbed horizon is related to the energy of matter crossing the horizon. We derive consistency conditions for the validity of our approximations and compare our results to similar ones present in the literature. Finally, we discuss how this setting can be used in perturbative quantum gravity to extend the classical mechanical laws to thermodynamic laws, with the entanglement of field modes across the Rindler horizon providing a notion of thermodynamic entropy.

Bianchi, Eugenio; Satz, Alejandro

2013-06-01

381

Organic and inorganic sulfur constituents of a forest soil and their relationship to microbial activity  

Microsoft Academic Search

Sulfur (S) constituents, microbial biomass, and sulfohydrolase activity were determined for each soil horizon at both hardwood and conifer sites in a Becket soil (Adirondack Mountains, New York). Drying of soil before analysis altered the S constituents. There was a threefold increase (p<0.05) in sulfate in the organic horizons. Total S was greatest in the O horizons with 2,010 and

M. B. David; M. J. Mitchell; J. P. Nakas

1982-01-01

382

ACIDIFICATION AND RECOVERY OF A SPODOSOL BS HORIZON FROM ACIDIC DEPOSITION  

EPA Science Inventory

A laboratory study was conducted to examine acidification and recovery of a Spodosol Bs horizon from acidic deposition in the Bear Brook Watershed (BBW) in central Maine. echanical vacuum extractor was used to draw solutions through a soil column at three treatments containing 40...

383

EFFECT OF ACID TREATMENT ON DISSOLVED ORGANIC CARBON RETENTION BY A SPODIC HORIZON  

EPA Science Inventory

Processes involving the movement of organic substances in forest soils are not well understood. This study was conducted to examine the role of acidic inputs on dissolved organic carbon (DOC) mobility, processes affecting the retention of DOV by a B horizon, and SO2-4 adsorption....

384

Extremality conditions for isolated and dynamical horizons  

SciTech Connect

A maximally rotating Kerr black hole is said to be extremal. In this paper we introduce the corresponding restrictions for isolated and dynamical horizons. These reduce to the standard notions for Kerr but in general do not require the horizon to be either stationary or rotationally symmetric. We consider physical implications and applications of these results. In particular we introduce a parameter e which characterizes how close a horizon is to extremality and should be calculable in numerical simulations.

Booth, Ivan; Fairhurst, Stephen [Department of Mathematics and Statistics, Memorial University of Newfoundland St. John's, Newfoundland and Labrador, A1C 5S7 (Canada); Department of Physics, University of Wisconsin-Milwaukee Milwaukee, Wisconsin, 53201 (United States); LIGO-California Institute of Technology, Pasadena, California 91125 (United States); School of Physics and Astronomy, Cardiff University, Cardiff, CF2 3YB (United Kingdom)

2008-04-15

385

Soil bioturbation. A commentary  

NASA Astrophysics Data System (ADS)

Organisms such as trees, ants, earthworms, termites are important components of the earth systems that have dominantly been thought of as abiotic. Despite an early focus on soil bioturbation by heavy-weights such as Charles Darwin and Nathanial Shaler in the late 19th century, sporadic attention to this theme has subsequently followed. Recent compilations demonstrate that soil bioturbation by fauna and flora is widespread across Earths terrestrial surface, and operates at geologically rapid rates that warrant further attention. Such biotic activity contributes to soil creep, soil carbon dynamics, and is critical in engineering the medium through which ecosystems draw their abiotic requirements. Soil and its biota are fundamental components of the Earth System. However, soil scientist focussed on the dominant paradigm of landscape evolution, and bioturbation was relegated. In fact, bioturbation is still not widely appreciated within the soil and earth system research community. Nevertheless, within the last decade a review of the impact of bioturbation was launched by authors such as Geoff S. Humphreys. Bioturbation is a complex process as new soil is formed, mounds are developed, soil is buried and a downslope transport of material is done. Bioturbation modify the soil texture and porosity, increase the nutrients and encourage the soil creep flux. A review of the State-of-the-Art of Bioturbation will be presented.

Cerdà, Artemi; Wilkinson, Marshall

2010-05-01

386

Horizon entropy with loop quantum gravity methods  

E-print Network

We show that the spherically symmetric isolated horizon can be described in terms of an SU(2) connection and a su(2) valued one form, obeying certain constraints. The horizon symplectic structure is precisely the one of 3d gravity in a first order formulation. We quantize the horizon degrees of freedom in the framework of loop quantum gravity, with methods recently developed for 3d gravity with non-vanishing cosmological constant. Bulk excitations ending on the horizon act very similar to particles in 3d gravity. The Bekenstein-Hawking law is recovered in the limit of imaginary Barbero-Immirzi parameter. Alternative methods of quantization are also discussed.

Daniele Pranzetti; Hanno Sahlmann

2014-12-23

387

Apparent horizon in fluid-gravity duality  

SciTech Connect

This article develops a computational framework for determining the location of boundary-covariant apparent horizons in the geometry of conformal fluid-gravity duality in arbitrary dimensions. In particular, it is shown up to second order and conjectured to hold to all orders in the gradient expansion that there is a unique apparent horizon which is covariantly expressible in terms of fluid velocity, temperature, and boundary metric. This leads to the first explicit example of an entropy current defined by an apparent horizon and opens the possibility that in the near-equilibrium regime there is preferred foliation of apparent horizons for black holes in asymptotically anti-de Sitter spacetimes.

Booth, Ivan; Heller, Michal P.; Plewa, Grzegorz; Spalinski, Michal [Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, A1C 5S7 (Canada); Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland) and Physics Department, University of Bialystok, 15-424 Bialystok (Poland)

2011-05-15

388

Electrogeochemical sampling with NEOCHIM - results of tests over buried gold deposits  

USGS Publications Warehouse

Electrogeochemical extraction methods are based on the migration of ions in an electric field. Ions present in soil moisture are transported by an applied current into fluids contained in special electrodes placed on the soil. The fluids are then collected and analyzed. Extractions are governed by Faraday's and Ohm's laws and are modeled by the operation of a simple Hittord transference apparatus. Calculations show that the volume of soil sampled in an ideal electrogeochemical extraction can be orders of magnitude greater than the volumes used in more popular geochemical extraction methods, although this has not been verified experimentally. CHIM is a method of in-situ electrogeochemical extraction that was developed in the former Soviet Union and has been tested and applied internationally to exploration for buried mineral deposits. Tests carried out at the US Geological Survey (USGS) indicated that there were problems inherent in the use of CHIM technology. The cause of the problems was determined to be the diffusion of acid from the conventional electrode into the soil. The NEOCHIM electrode incorporates two compartments and a salt bridge in a design that inhibits diffusion of acid and enables the collection of anions or cations. Tests over a gold-enriched vein in Colorado and over buried, Carlin-type, disseminated gold deposits in northern Nevada show that there are similarities and differences between NEOCHIM results and those by partial extractions of soils which include simple extractions with water, dilute acids and solutions of salts used as collector fluids in the electrodes. Results of both differ from the results obtained by total chemical digestion. The results indicate that NEOCHIM responds to mineralized faults associated with disseminated gold deposits whereas partial and total chemical extraction methods do not. This suggests that faults are favored channels for the upward migration of metals and that NEOCHIM may be more effective in exploration for the deposits. It defines anomalies that are often narrow and intense, an observation previously made by CHIM researchers. The field tests show that NEOCHIM is less affected by surface contamination. A test over the Mike disseminated gold deposit indicates that the method may not be effective for locating deposits with impermeable cover. Faradaic extraction efficiencies of 20-30%, or more, are frequently achieved with NEOCHIM and the method generally shows good reproducibility, especially in extraction of major cations. However, ions of other metals that are useful in exploration, including Au and As, may be collected in low and temporally variable concentrations. The reason for this variability is unclear and requires further investigation.CHIM is a method of in-situ electrogeochemical extraction developed for the exploration of buried mineral deposits. However, electrode problems like diffusion of acid into the soil were encountered during the use of CHIM. The NEOCHIM electrode was developed to inhibit the diffusion of acid and enable collection of anions or cations. Tests over buried gold deposits showed that NEOCHIM responds to mineralized faults associated with disseminated gold deposits whereas partial and total chemical extraction methods do not. This suggests that faults are favored channels for the upward migration of metals and NEOCHIM may be effective in exploration for the deposits. But ions of metals may be collected in low and variable concentration.

Leinz, R.W.; Hoover, D.B.; Fey, D.L.; Smith, D.B.; Patterson, T.

1998-01-01

389

Buried object remote detection technology for law enforcement  

NASA Astrophysics Data System (ADS)

A precise airborne temperature-sensing technology to detect buried objects for use by law enforcement is developed. Demonstrations have imaged the sites of buried foundations, walls and trenches; mapped underground waterways and aquifers; and been used to locate underground military objects. The methodology is incorporated in a commercially available, high signal-to-noise, dual-band infrared scanner with real-time, 12-bit digital image processing software and display. The method creates color-coded images based on surface temperature variations of 0.2 degree(s)C. Unlike other less-sensitive methods, it maps true (corrected) temperatures by removing the (decoupled) surface emissivity mask equivalent to 1 degree(s)C or 2 degree(s)C; this mask hinders interpretation of apparent (blackbody) temperatures. Once removed, it is possible to identify surface temperature patterns from small diffusivity changes at buried object sites which heat and cool differently from their surroundings. Objects made of different materials and buried at different depths are identified by their unique spectral, spatial, thermal, temporal, emissivity and diffusivity signatures. The authors have successfully located the sites of buried (inert) simulated land mines 0.1 to 0.2 m deep; sod-covered rock pathways alongside dry ditches, deeper than 0.2 m; pavement covered burial trenches and cemetery structures as deep as 0.8 m; and aquifers more than 6 m and less than 60 m deep. The technology could be adapted for drug interdiction and pollution control. For the former, buried tunnels, underground structures built beneath typical surface structures, roof-tops disguised by jungle canopies, and covered containers used for contraband would be located. For the latter, buried waste containers, sludge migration pathways from faulty containers, and the juxtaposition of groundwater channels, if present, nearby, would be depicted. The precise airborne temperature-sensing technology has a promising potential to detect underground epicenters of smuggling and pollution.

del Grande, Nancy K.; Clark, Gregory A.; Durbin, Philip F.; Fields, David J.; Hernandez, Jose E.; Sherwood, Robert J.

1991-08-01

390

Temperature dependence of nitrogen mineralization and microbial status in O H horizon of a temperate forest ecosystem  

Microsoft Academic Search

It was hypothesized that increasing air and\\/or soil temperature would increase rates of microbial processes including litter\\u000a decomposition and net N mineralization, resulting in greater sequestration of carbon and nitrogen in humus, and consequently\\u000a development in OH horizon (humus horizon). To quantify the effect of temperature on biochemical processes controlling the rate of OH layer development three adjacent forest floors

Ali Bagherzadeh; Rainer Brumme; Friedrich Beese

2008-01-01

391

Albert Munsell and His Impact on Soil Science and  

E-print Network

Albert Munsell and His Impact on Soil Science and Other Natural Disciplines Edward Landa Research recognition in soil science, where color description of soil horizons is a critical step in classification.P.H. in radiological health, and an M.S. and Ph.D. in soil science from the University of Minnesota. His research has

Zanibbi, Richard

392

Ferromanganese crusts from Necker Ridge, Horizon Guyot and S.P. Lee Guyot: Geological considerations  

USGS Publications Warehouse

Necker Ridge, Horizon Guyot and S.P. Lee Guyot in the Central Pacific were sampled, seismically surveyed, and photographed by bottom cameras in order to better understand the distribution, origin, and evolution of ferromanganese crusts. Necker Ridge is over 600 km long with a rugged crest, pods of sediment to 146 m thick, slopes that average 12?? to 20??, and debris aprons that cover some of the lower flanks. Substrate lithologies are mostly hyaloclastite, volcaniclastic breccia, and minor alkalic basalt. Horizon Guyot, 300 km long and 75 km wide, is capped by at least 160 m of sediment, which buries stepped terraces. Substrate lithologies are similar to those on Necker Ridge, although previous workers sampled much tholeiitic basalt on Horizon. S.P. Lee Guyot, 125 km long and 80 km wide, is capped by at least 300 m of sediment, and contains talus aprons along its lower flanks. Ferromanganese-encrusted rocks were recovered in every dredge and are thickest on Necker Ridge. Crust thicknesses average about 2.5, 1.5, and 0.8 cm for Necker, Horizon, and S.P. Lee, respectively. Crusts range from smooth or porous surfaces to knobby and botryoidal. The entire crust is laminated, however, two distinct layers commonly exist, separated by a paper-thin layer of phosphorite. The dominant mineral of all crusts is vernadite (??-MnO2), while quartz, feldspar, apatite, and, in three rocks todorokite, are minor phases. Quartz and feldspar decrease with decreasing latitude of occurrence, and is suggested to be related to eolian input. On the average, apatite also increases within the crusts with decreasing latitude of occurrence, which may be related to high biological productivity in the zone of equatorial upwelling. Phosphorite substrates are more abundant on Necker Ridge and S.P. Lee Guyot than they are on Horizon Guyot. Seamount ferromanganese nodules are distinct from abyssal nodules in their chemistry and internal structure. ?? 1985.

Hein, J.R.; Manheim, F. T.; Schwab, W.C.; Davis, A.S.

1985-01-01

393

Optical geometry across the horizon  

E-print Network

In a companion paper (Jonsson and Westman, Class. Quantum Grav. 23 (2006) 61), a generalization of optical geometry, assuming a non-shearing reference congruence, is discussed. Here we illustrate that this formalism can be applied to a finite four-volume of any spherically symmetric spacetime. In particular we apply the formalism, using a non-static reference congruence, to do optical geometry across the horizon of a static black hole. While the resulting geometry in principle is time dependent, we can choose the reference congruence in such a manner that an embedding of the geometry always looks the same. Relative to the embedded geometry the reference points are then moving. We discuss the motion of photons, inertial forces and gyroscope precession in this framework.

Rickard Jonsson

2007-08-19

394

Experimental investigation of buried tritium in plant and animal tissues  

SciTech Connect

Buried exchangeable tritium appears as part of organically bound tritium (OBT) in the traditional experimental determination of OBT. Since buried tritium quickly exchanges with hydrogen atoms in the body following ingestion, assuming that it is part of OBT rather than part of tritiated water (HTO) could result in a significant overestimate of the ingestion dose. This paper documents an experimental investigation into the existence, amount and significance of buried tritium in plant and fish samples. OBT concentrations in the samples were determined in the traditional way and also following denaturing with five chemical solutions that break down large molecules and expose buried tritium to exchange with free hydrogen atoms. A comparison of the OBT concentrations before and after denaturing, together with the concentration of HTO in the supernatant obtained after denaturing, suggests that buried OBT may exist but makes up less than 5% of the OBT concentration in plants and at most 20% of the OBT concentration in fish. The effects of rinse time and rinse water volumes were investigated to optimize the removal of exchangeable OBT from the samples. (authors)

Kim, S. B.; Workman, W. J. G.; Davis, P. A. [AECL, Chalk River Laboratories, Environmental Technologies Branch, Chalk River, ON K0J 1J0 (Canada)

2008-07-15

395

Buried waste remediation: A new application for in situ vitrification  

SciTech Connect

Buried wastes represent a significant environmental concern and a major financial and technological challenge facing many private firms, local and state governments, and federal agencies. Numerous radioactive and hazardous mixed buried waste sites managed by the US Department of Energy (DOE) require timely clean up to comply with state or federal environmental regulations. Hazardous wastes, biomedical wastes, and common household wastes disposed at many municipal landfills represent a significant environmental health concern. New programs and regulations that result in a greater reduction of waste via recycling and stricter controls regarding generation and disposal of many wastes will help to stem the environmental consequences of wastes currently being generated. Groundwater contamination, methane generation, and potential exposures to biohazards and chemically hazardous materials from inadvertent intrusion will continue to be potential environmental health consequences until effective and permanent closure is achieved. In situ vitrification (ISV) is being considered by the DOE as a permanent closure option for radioactive buried waste sites. The results of several ISV tests on simulated and actual buried wastes conducted during 1990 are presented here. The test results illustrate the feasibility of the ISV process for permanent remediation and closure of buried waste sites in commercial landfills. The tests were successful in immobilizing or destroying hazardous and radioactive contaminants while providing up to 75 vol % waste reduction. 6 refs., 7 figs., 5 tabs.

Kindle, C.H.; Thompson, L.E.

1991-04-01

396

The Path to Disaster The Deepwater Horizon  

E-print Network

21/08/2013 1 The Path to Disaster The Deepwater Horizon BP's disaster in the Gulf of Mexico Professor Patrick Hudson & Tim Hudson Hudson Global Consulting 4th Annual Plexus Industrial Safety Lecture Industrial Psychology Research Centre 14th August, 2013 Transocean Deepwater Horizon #12;21/08/2013 2

Pym, David J.

397

Expanding your horizons in science and mathematics  

NASA Technical Reports Server (NTRS)

The purpose of the 'Expanding Your Horizons in Science and Mathematics' program is to interest young women in grades six through twelve in a variety of careers where mathematics and science are important. Progress in encouraging young women to take courses in mathematics, science, and technological subjects is discussed. Also included are adult, student, and organizational information packets used for 'Expanding Your Horizons' conferences.

Palmer, Cynthia E. A.

1995-01-01

398

Black holes as trapping horizons Eric Gourgoulhon  

E-print Network

Black holes as trapping horizons Eric Gourgoulhon Laboratoire Univers et Th´eories (LUTH) CNRS://www.luth.obspm.fr/~luthier/gourgoulhon/ Centrum Astronomiczne im. M. Kopernika Warsaw, Poland 17 November 2008 Eric Gourgoulhon (LUTH) Black holes as trapping horizons CAMK, Warsaw, 17 Nov. 2008 1 / 36 #12;Plan 1 Local approaches to black holes 2 Viscous

Gourgoulhon, Eric

399

Horizon Report: 2009 Economic Development Edition  

ERIC Educational Resources Information Center

The New Media Consortium's Horizon Project is an ongoing research project that seeks to identify and describe emerging technologies likely to have a large impact in education and other industries around the world over a five-year time period. The chief products of the project are the "Horizon Reports", an annual series of publications that…

Johnson, L.; Levine, A.; Scott, C.; Smith, R.; Stone, S.

2009-01-01

400

Code generation for receding horizon control  

Microsoft Academic Search

Receding horizon control (RHC), also known as model predictive control (MPC), is a general purpose control scheme that involves repeatedly solving a constrained optimization problem, using predictions of future costs, disturbances, and constraints over a moving time horizon to choose the control action. RHC handles constraints, such as limits on control variables, in a direct and natural way, and generates

Jacob Mattingley; Yang Wang; Stephen Boyd

2010-01-01

401

Deepwater Horizon Disaster Professor Satish Nagarajaiah  

E-print Network

Impact of the Oil Spill Oil Spill Response and Containment Measures Ongoing Investigationsg g g;Collapse / Oil Spill Offshore and Marine Systems Research @ Rice Source: NYT/AP/flickr #12;Horizon Before Systems Research @ Rice Source: MMS and BP #12;April 20, 2010 At approximately 10 pm Horizon Rig disaster

Nagarajaiah, Satish

402

Battling Blaze on Deepwater Horizon Oilrig  

USGS Multimedia Gallery

NEW ORLEANS — Fire boat response crews battle the blazing remnants of the off shore oilrig Deepwater Horizon. A Coast Guard MH-65C dolphin rescue helicopter and crew document the fire aboard the mobile offshore drilling unit Deepwater Horizon, while searching for survivors. Multiple Coast Guar...

403

HORIZON 2020 WORK PROGRAMME 2014 2015  

E-print Network

HORIZON 2020 WORK PROGRAMME 2014 ­ 2015 3. Marie Sklodowska-Curie Actions Important Notice (2013)8631 of 10 December 2013) #12;HORIZON 2020 ­ WORK PROGRAMME 2014-2015 Marie Sklodowska-Curie................................................................................................................................ 3 2014 Call for Marie Sklodowska-Curie Innovative Training Networks (ITN

Erdem, Erkut

404

Assessing the impact of soil salinity on manganese distribution in sierozem soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plant availability of heavy metals from soil depends on factors such as soil type, organic matter, base saturation, texture, and salinity. Plant availability of mobile manganese (Mn) was accessed from various horizons of non-saline, medium saline, and highly saline sieriozem soils and a pasture. Man...

405

The tri-soil experiment: do plants discriminate among vegetation soil types?  

Technology Transfer Automated Retrieval System (TEKTRAN)

We tested if rooting mass and root nutrient uptake of cheatgrass (Bromus tectorum) or creeping wildrye (Leymus triticoides) were influenced by vegetation soil type. Three soil types (A horizons), similar in gross physical and chemical properties, were freshly-collected. The soils varied in the veget...

406

Mobile aluminum compounds in soils of the southern taiga (soils of the central forest reserve as an example)  

NASA Astrophysics Data System (ADS)

The profile distributions of aluminum extracted by the Tamm and Bascomb reagents and of the exchangeable aluminum were studied in soils of automorphic, transitive, and accumulative positions in the landscapes of the southern taiga. In the mineral horizons of the gleyic peaty-podzolic soils developed on poorly drained flat surfaces and in the floodplain soils, the distribution of oxalate- and pyrophosphate-soluble aluminum has a strongly pronounced accumulative character. In the podzolic soils of the automorphic positions and slopes, an eluvial-illuvial distribution was characteristic with the maximal aluminum content in the podzolic horizons. The strong differentiation of the upper part of the profile in the automorphic podzolic soils in terms of the Al content in the Tamm and Bascomb extracts is mainly related to an increase of the pedogenic chlorite content upon the transition from the AE to the E horizon. In the podzolic horizons of these soils, aluminum can accumulate in the form of proto-imogolite structures. The exchangeable aluminum displays an accumulative type of distribution. On the basis of calculating the reserves of the different aluminum compounds, two main accumulative zones for the mobile compounds of this element were recorded in the soils of the landscapes studied: the E horizon in the automorphic podzolic soils, where Al accumulates as soil chlorite or, probably, as proto-imogolite, and the A1 horizon of the floodplain soils, where Al accumulates in aluminoorganic complexes.

Tolpeshta, I. I.; Sokolova, T. A.

2010-08-01

407

Can matter really cross a horizon?  

NASA Astrophysics Data System (ADS)

It has been taken as a truth that collapsing matter can eventually cross the horizon and enter into the interior of a black hole in a finite proper time. However, the Rindler/tachyon dual description we suggested recently implies that this should not be the case. A test particle falling towards the event horizon of a nonextreme black hole can actually be viewed as an unstable particle, whose dynamics is described by the tachyon field theory. This means that the collapsing process of a free particle in Rindler space is essentially a tachyon condensation process. In terms of the results in tachyon condensation, we learn that the infalling particle should strongly couple to bulk gravitational modes and should decay completely into something like gravitons before reaching the horizon. Hence, there should be no matter that can cross a horizon as still matter. The matter will get "dissolved" into spacetime when approaching the horizon.

Li, Huiquan

2014-10-01

408

Occurrence of perched saturation and interflow over an argillic horizon in a low relief hillslope.  

SciTech Connect

Abstract. Many of the soils in the south-eastern US are characterized by an argillic, or clay horizon, that largely parallels the soil surface at depths ranging from a few centimeters to 100 cen-timeters. The degree to which these argillic horizons alter subsurface movement of infiltrated water is not well known. Interflow, or throughflow, is shallow lateral subsurface flow that moves over a horizon that restricts percolation. This research investigates how often and under what conditions a relatively deep (20-150+cm) argillic horizon on low slope (2-6%) hillsides causes interflow to oc-cur. Research is being conducted at the Savannah River Site, Aiken, South Carolina, on a small zero-order watershed. In the first phase of this research, a high resolution topographic map of the clay layer was developed. This map will be used to instrument designated “low” spots with max rise piezo-meters in order to determine if there is channelized subsurface flow. In situ conductivities of the clay layer and the surface horizons were measured using an Amoozegar meter, and bulk density samples were taken and measured. Along with soil topographic measurements, data-logging piezometers have been installed to measure the piezometric head above, in, and below the argillic horizon to further investigate interflow as a potential hydraulic routing mechanism. The stream that drains the catchment was instrumented with a 2’ H flume and data-logging pressure transducer to measure stream flow. Climate data including precipitation, barometric pressure and temperature, are being continuously collected in an open area approximately ¼ mile from the study site. Combining the shallow surface and subsurface piezometric heads with stream flow rates, we should be able to determine if and when the clay layer is contributing to inter-flow.

Greco, James; Jackson, Rhett, C.

2009-03-01

409

The Changing Model of Soil  

NASA Astrophysics Data System (ADS)

The contemporary genetic model of soil is changing rapidly in response to advances in soil science and to human and environmental forcings in the 21st century (Richter and Yaalon, 2012). Three ongoing changes in the model of soil include that: (1) lower soil boundaries are much deeper than the solum, historically the O to B horizons, (2) most soils are polygenetic paleosols, products of soil-forming processes that have ranged widely over soils' lifetimes, and (3) soils are globally human-natural bodies, no longer natural bodies. Together, these changes in the model of soil mean that human forcings are a global wave of soil polygenesis altering fluxes of matter and energy and transforming soil thermodynamics as potentially very deep systems. Because soils are non-linear systems resulting from high-order interactions of physics, chemistry, and biology, trajectories of how human forcings alter soils over decades are not readily predictable and require long-term soil observations. There is much to learn about how soils are changing internally as central components of management systems and externally in relation to wider environments. To be critical, research has been remarkably superficial in studies of soil, reductionist in approach, and lacking in time-series observations of responses to soil management. While this criticism may sound negative, it creates significant opportunities for contemporary soil scientists.

Richter, D. D.; Yaalon, D.

2012-12-01

410

An investigation into the persistence of textile fibres on buried carcasses.  

PubMed

A significant amount of research has been carried out on fibres to aid the forensic scientist in determining the significance of these when found on a victim or suspect. This work has focused on open-air environments, and as such no research has been undertaken to examine the persistence of fibres on bodies in the burial environment. Wool and cotton fibres, known to fluoresce under ultraviolet (UV) light, were transferred onto the skin of four porcine (Sus scrofa) carcasses (two carcasses per fibre type). The number of fibres transferred was recorded from images taken under UV light. The remains were subsequently placed in four burial sites and left interred for 14 days. After this period the carcasses were excavated and lightly brushed down to remove the soil layer that had adhered to the skin. Once again photography under UV light was used to record the number of fibres which persisted on the skin. Results showed that after 14 days, wool and cotton fibres remain on the surface of the buried carcasses. In no circumstance was there a total loss of fibres suggesting that in such scenarios, the likelihood of finding fibres is high but the initial number of fibres transferred would be strongly diminished. This has important implications for both the excavation protocol for buried remains and the subsequent analysis for physical evidence. PMID:25002046

DeBattista, Roslyn; Tidy, Helen; Thompson, Tim J U; Robertson, Peter

2014-07-01

411

Closure report for CAU Number 430: Buried Depleted Uranium Artillery Round Number 1, Tonopah Test Range  

SciTech Connect

Corrective Action Unit (CAU) 430 consists of the Buried Depleted Uranium (DU) Artillery Round No. 1. This Closure Report presents the information obtained from investigate actions performed to justify the decision for clean closure of CAU 430 through ``No Further Action``. The site was thought to consist of a potentially unexploded W-79 Joint Test Assembly (JTA) test artillery projectile with high explosives (HE) and DU. The DU was substituted for Special Nuclear Materials to prevent a nuclear explosion and yet retain the physical characteristics of uranium for ballistic and other mechanical tests. The projectile was reportedly buried in one pit, approximately 5 to 10 feet (ft) deep. The objectives of the activities were to prepare the site for closure through locating and identifying the projectile, destroying the projectile and any remaining components, collecting soil samples to detect residual contamination resulting from projectile destruction, and finally, remediating residual contamination. This report contains the following five sections. Section 1.0 introduces the CAU and scope of work. Section 2.0 of this report presents the closure activities performed as part of this investigation. Waste disposition is discussed in Section 3.0. Closure investigation results are presented in Section 4.0, and references are presented in Section 5.0.

NONE

1997-02-01

412

End effectors and attachments for buried waste excavation equipment  

SciTech Connect

The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. Their efforts are identified and coordinated in support of the U.S. Department of Energy (DOE), Environmental Restoration and Waste Management (ER&WM) Department`s needs and objectives. The present focus of BWID is to support retrieval and ex-situ treatment configuration options. Future activities will explore and support containment, and stabilization efforts in addition to the retrieval/ex situ treatment options. This report presents a literature search on the state-of-the-art in end effectors and attachments in support of excavator of buried transuranic waste. Included in the report are excavator platforms and a discussion of the various attachments. Also included is it list of vendors and specifications.

King, R.H.

1993-09-01

413

Porosity determinations in buried and surface layers of porous silicon  

SciTech Connect

Gravimetric techniques offer a convenient and accurate method of determining surface layer porosity in both n- and p-type porous silicon (PS). Porosity of the PS affects its volume expansion on oxidation and the insulating properties of the resulting oxide. Optimal porosity (ca. 55%) yields fully dense, insulating oxides with minimal expansion-induced stresses. Two factors affect the porosity: chemical dissolution of PS by the anodization electrolyte, and oxidation of the PS to produce a native oxide on the surface. Buried layer porosities cannot normally be measured by gravimetric techniques unless the volume of the buried layer is large enough to yield a measurable weight change on anodization. We therefore used a form of Faraday's Law to determine buried layer porosities and determined that they can be correlated with porosities of surface layers formed under identical conditions. 9 refs., 4 figs.

Guilinger, T.R.; Kelly, M.J.; Tsao, S.S.

1987-01-01

414

Operation Hardtack. Project 1. 9. Loading on buried simulated structures in high-overpressure regions. Report for April-October 1958  

SciTech Connect

The objective of this project was to study some of the factors affecting the transmission of air-blast-induced pressure through soil and the loading produced on buried structures by such pressures in the high-pressure region (approximately 250 psi). Factors studied were: (1) the attenuation of pressure in a sand deposit when the water table is a few feet below the ground surface; (2) the effect of duration of positive phase of blast on the pressure transmitted through such a soil; (3) the effect of structure flexibility on the pressure acting on structures buried in such a soil; and (4) the relationship between horizontal and vertical pressures in such a soil. The project employed 43 devices, each a rigid cylinder having one rigid end and one deformable-diaphragm end. The devices were buried at depths ranging from 0 to 20 feet at each of two locations at the Eniwetok Proving Ground. The locations were chosen to give a predicted ground surface overpressure of about 250 psi from each of two shots, Cactus and Koa.

Bultmann, E.H.; McDonough, G.F.; Sinnamon, G.K.

1984-10-31

415

WEATHERING OF IRONBEARING MINERALS IN SOILS AND SAPROLITE ON THE NORTH CAROLINA BLUE RIDGE FRONT: II. CLAY MINERALOGY  

Microsoft Academic Search

The mineralogy of the clay fraction was studied for soils and saprolite on two Blue Ridge Front mountain slopes. The clay fraction contained the weathering products of primary minerals in the mica gneiss and schist parent rocks. Gibbsite is most abundant in the saprolite and residual soil horizons, where only chemical weathering has been operable. In colluvial soil horizons, where

D. D. AMARASIRIWARDENA; S. W. BUOL

416

Soils - Part 1: The Origin and Development of Soil(How Soil Gets a Life and a Name)  

NSDL National Science Digital Library

In this lesson, you will gain an understanding of the five soil forming factors and will be able to describe how each influences soil development. You will learn to identify common parent materials, determine the age of a soil, identify the types of native vegetation associated with different soils in Nebraska and define soil horizons.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

417

Taking into account the heterogeneity and the temporal variability of the soil structure to implement relevant soil hydraulic properties  

NASA Astrophysics Data System (ADS)

Due to its position at the interface between the atmosphere and the vadose zone, the soil significantly contributes to the partitioning of rainfall into infiltration and overland flow, and, as a consequence, to the water feeding to plants and to the water aquifer level. The characteristics of the soil are usually described at the scale of the horizon, the latter being considered as the elementary component of the pedological maps and soil databases. As far as hydraulic properties are concerned - the water retention curve and the unsaturated hydraulic conductivity, the two essential soil characteristics for the description of soil water transfers -, their estimation at the horizon scale is then of major interest. Nevertheless, even at this scale, the horizon can usually not be considered neither as a homogeneous volume, nor as a time-stable system. As a consequence, methodologies have to be developed to characterize i) the degree of heterogeneity of the soil structure, ii) the evolution of the structure with time, and iii) if possible, the equivalent properties of such heterogeneous horizons. The surface horizons and the stony horizons can be considered as representative models of soil horizons to test these methodologies: the first ones because their fine structure evolves rapidly, under the effect of human agricultural activities - compaction by wheeling, fragmentation by tillage - of climate, or of faunal and vegetal actions; the second ones because the strong difference in material and in bulk density between fine earth and rock fragments lead to complex hydric behaviors. Based on several examples, the objectives of this presentation will then be i) to describe the temporal evolution of soil hydraulic properties in cultivated horizons, ii) to present methodologies for the estimation of equivalent soil hydraulic properties in stony horizons, and iii) to discuss the contribution of this new methodologies compared to old ones to better estimate the soil hydric functioning at the local or regional scales.

Cousin, Isabelle; Tetegan, Marion; Chabbi, Abad; Korboulewski, Nathalie

2013-04-01

418

Surface Localization of Buried III-V Semiconductor Nanostructures.  

PubMed

In this work, we study the top surface localization of InAs quantum dots once capped by a GaAs layer grown by molecular beam epitaxy. At the used growth conditions, the underneath nanostructures are revealed at the top surface as mounding features that match their density with independence of the cap layer thickness explored (from 25 to 100 nm). The correspondence between these mounds and the buried nanostructures is confirmed by posterior selective strain-driven formation of new nanostructures on top of them, when the distance between the buried and the superficial nanostructures is short enough (d = 25 nm). PMID:20596455

Alonso-González, P; González, L; Fuster, D; Martín-Sánchez, J; González, Yolanda

2009-01-01

419

Method of forming buried oxide layers in silicon  

DOEpatents

A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir City, TN)

2000-01-01

420

Buried wire gage for wall shear stress measurements  

NASA Technical Reports Server (NTRS)

A buried wire gage for measuring wall shear stress in fluid flow was studied and further developed. Several methods of making this relatively new type of gage were examined to arrive at a successful technique that is well-suited for wind-tunnel testing. A series of measurements was made to demonstrate the adequacy of a two-point calibration procedure for these gages. The buried wire gage is also demonstrated to be ideally suited for quantitative measurement of wall shear stress in wind-tunnel testing.

Murthy, V. S.; Rose, W. C.

1978-01-01

421

A study of different horizons in inhomogeneous LTB cosmological model  

E-print Network

This work deals with a detailed study of the dynamics of the apparent, event and particle horizons in the background of the inhomogeneous LTB spacetime. The comparative study among these horizons shows a distinct character for apparent horizon compared to the other horizons. The apparent horizon will be a trapping horizon if its acceleration is positive. The Kodama vector is also defined and its causal character is found to be similar to that in the FRW model.

Subenoy Chakraborty; Subhajit Saha

2015-03-04

422

A study of different horizons in inhomogeneous LTB cosmological model  

NASA Astrophysics Data System (ADS)

This work deals with a detailed study of the dynamics of the apparent, event and particle horizons in the background of the inhomogeneous LTB spacetime. The comparative study among these horizons shows a distinct character for apparent horizon compared to the other horizons. The apparent horizon will be a trapping horizon if its acceleration is positive. The Kodama vector is also defined and its causal character is found to be similar to that in the FRW model.

Chakraborty, Subenoy; Saha, Subhajit

2015-02-01

423

Proton surface charge determination in Spodosol horizons with organically bound aluminum  

NASA Astrophysics Data System (ADS)

Net proton surface charge densities were determined in O, E, Bh, and Bs horizons of a sandy till, Spodosol from Denmark, by means of acid-base titration combined with ion adsorption in 0.005 M Ca(NO 3) 2 and independent permanent charge determination. The release of organic anions exceeded the adsorption of NO 3-, resulting in a desorption of anions in all horizons. Data were found to obey the law of balance between surface charges and adsorbed ions only when charges pertaining to Al and organic anions released during the titration experiments were accounted for, in addition to charges pertaining the potential determining ions (PDI) H + and OH - and the index ions Ca 2+ and NO 3-. It was furthermore shown that the point of zero net proton charge (PZNPC) in soils highly depends on the concentration of organically bound Al. Approaches previously used in soils, in which adsorbed Al n+ has been ignored (i.e., considered equivalent to nH + as a PDI), resulted in a PZNPC of 4.1 in the Bs horizon. If instead organically bound Al was accounted for as a counter-ion similar to 3/2Ca 2+, a PZNPC of 2.9 was obtained for the same Bs horizon. Based on PZNPC values estimated by the latter approach, combined with a weak-acid analog, it was shown that organic proton surface charges buffered pH with a similar intensity in the O, E, Bh, and Bs horizons of this study. Because the acidity of Al adsorbed to conjugate bases of soil organic acids is substantially weaker than the acidity of the corresponding protonated form of the organic acids, the point of zero net proton charge (PZNPC) will increase if the concentration of organically adsorbed Al increases at the expense of adsorbed H. This means that PZNPC values determined for soils with unknown concentrations of organically adsorbed Al are highly operational and not very meaningful as references.

Skyllberg, Ulf; Borggaard, Ole K.

1998-05-01

424

A comparison of soil moisture characteristics predicted by the Arya-Paris model with laboratory-measured data  

NASA Technical Reports Server (NTRS)

Soil moisture characteristics predicted by the Arya-Paris model were compared with the laboratory measured data for 181 New Jersey soil horizons. For a number of soil horizons, the predicted and the measured moisture characteristic curves are almost coincident; for a large number of other horizons, despite some disparity, their shapes are strikingly similar. Uncertainties in the model input and laboratory measurement of the moisture characteristic are indicated, and recommendations for additional experimentation and testing are made.

Arya, L. M.; Richter, J. C.; Davidson, S. A. (principal investigators)

1982-01-01

425

Training requirements and responsibilities for the Buried Waste Integrated Demonstration at the Radioactive Waste Management Complex  

SciTech Connect

The Buried Waste Integrated Demonstration (BWID) is scheduled to conduct intrusive (hydropunch screening tests, bore hole installation, soil sampling, etc.) and nonintrusive (geophysical surveys) studies at the Radioactive Waste Management Complex (RWMC). These studies and activities will be limited to specific locations at the RWMC. The duration of these activities will vary, but most tasks are not expected to exceed 90 days. The BWID personnel requested that the Waste Management Operational Support Group establish the training requirements and training responsibilities for BWID personnel and BWID subcontractor personnel. This document specifies these training requirements and responsibilities. While the responsibilities of BWID and the RWMC are, in general, defined in the interface agreement, the training elements are based on regulatory requirements, DOE orders, DOE-ID guidance, state law, and the nature of the work to be performed.

Vega, H.G.; French, S.B.; Rick, D.L.

1992-09-01

426

Universal horizons in maximally symmetric spaces  

E-print Network

Universal horizons in Ho\\v{r}ava-Lifshitz gravity and Einstein-{\\ae}ther theory are the equivalent of causal horizons in general relativity and appear to have many of the same properties, including a first law of horizon thermodynamics and thermal radiation. Since universal horizons are infrared solutions of a putative power counting renormalizable quantum gravitational theory, fully understanding their thermodynamics will shed light on the interplay between black hole thermodynamics and quantum gravity. In this paper, we provide a complete classification, including asymptotic charges, of all four dimensional static and spherically symmetric universal horizon solutions with maximally symmetric asymptotics -- the equivalents of the Schwarzschild, Schwarzschild de Sitter or Schwarzschild anti-de Sitter spacetimes. Additionally we derive the associated first laws for the universal horizon solutions. Finally we prove that independent of asymptotic boundary conditions, any spherically symmetric solution in Ho\\v{r}ava-Lifshitz gravity with a universal horizon is also a solution of Einstein-{\\ae}ther theory, thereby broadening and complementing the known equivalence region of the solution spaces.

Jishnu Bhattacharyya; David Mattingly

2014-08-27