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1

Carbon cycle: Sequestration in buried soils  

NASA Astrophysics Data System (ADS)

Rapid deposition of wind-borne silt after the end of the last glacial period buried a large reservoir of organic carbon in the deep soil. Geochemical analyses suggest that this sequestered soil carbon could be released to the atmosphere if exposed to decomposition.

Johnson, William C.

2014-06-01

2

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

3

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

4

Soil organic matter stabilization in buried paleosols of the Great Plains  

NASA Astrophysics Data System (ADS)

Understanding the mechanisms that control soil organic matter (SOM) stabilization is important for understanding how soil carbon is sequestered over millennia, and for predicting how future disturbances may affect soil carbon stocks. We are studying the mechanisms controlling SOM stabilization in the Brady Soil, a buried paleosol in Holocene loess deposits spanning much of the central Great Plains of the United States. The Brady Soil developed 9,000-13,500 years ago during a time of warming and drying that resulted in a shift from C3 to C4 dominated plants. The Brady soil is unusual in that it has very dark coloring, although it contains less than <1 % organic C. Although the Brady Soil has low C concentrations, it contains significant carbon stocks due to its thickness (~1 m) and wide geographic extent. We sampled the modern surface A horizon and multiple buried paleosol horizons from two roadcuts near Wauneta in southwestern Nebraska. We are using isotopic, spectroscopic, and geochemical techniques to examine what plant and microbially-derived compounds are have been preserved in the Brady Soil. We used a combined physical density and particle size fractionation method to separate particulate organic matter associated with minerals from that within and outside of soil aggregates. We found the largest and darkest amounts of organic C in aggregate-protected SOM greater than 20 µm in diameter. Density and textural fractionation revealed that much of the SOM is bound within aggregates, indicating that protection within aggregates is a major contributor to SOM- stabilization in the Brady Soil. We are conducting a long-term lab soil incubation with soils collected from the modern A horizon and the Brady Soil to determine if the buried SOM becomes microbially available when exposed to the modern atmosphere. We are measuring potential rates of respiration and production of CH4 and N2O. Results so far show respiration rates at field moisture for both modern and buried horizons are limited by water, suggesting dry environmental conditions may have helped to preserve SOM in the Brady Soil. We are investigating the potential for chemical stabilization of the dark SOM preserved in the buried paleosol by characterizing C chemistry using solid-state 13C-NMR spectroscopy. Furthermore, we plan to use lipid analyses and pyrolysis GC/MS to determine likely sources for the SOM: microbial vs plant. Combining information on the physical location of SOM in the soil, its chemical composition, decomposability, and radiocarbon based mean residence time estimates will allow us to determine (a) the source of the dark coloration in the Brady soil, (b) the mechanisms that have contributed to its preservation for the last 10,000 years, and (c) the likelihood this large soil C stock will be lost to the atmosphere if exposed during disturbance.

Chaopricha, N. T.; Marin-Spiotta, E.; Mason, J. A.; Mueller, C. W.

2010-12-01

5

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

6

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

2003-01-01

7

Soil Load Mobilization in Axially Loaded Buried Polyethylene Pipes  

Microsoft Academic Search

The performance evaluation of buried polyethylene (PE) pipelines in areas prone to ground movement is a key consideration in natural gas distribution systems. Considering the relatively smaller deformation stiffness and nonlinear stress-strain response of PE pipe material, understanding the basic pipe-soil interaction mechanisms both under small and large strain levels forms a critical part in these evaluations. In determining the

D. Wijewickreme; L. Weerasekara; G. Johnson

8

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

9

The humus status of modern and buried volcanic soils in Mexico and its role in the paleogeographic interpretation of tephra-paleosol sequences  

Microsoft Academic Search

Chemical and optical characteristics of soil humus have been analyzed as “memory” components of the Pleistocene volcanic paleosols\\u000a in Mexico. We have studied the A1 horizons of buried Andosols of the Nevado de Toluca series and of the modern Andosols formed\\u000a under different bioclimatic conditions. Data on the organic matter of buried paleosols suggest that Andosols of the Nevado\\u000a de

O. S. Yakimenko; S. N. Sedov; E. Solleiro

2007-01-01

10

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

11

Response of buried steel pipelines subjected to relative axial soil movement  

Microsoft Academic Search

The performance of buried steel pipelines subjected to relative soil movements in the axial direction was inves- tigated using full-scale pullout testing in a soil chamber. Measured axial soil loads from pullout testing of pipes buried in loose dry sand were comparable to those predicted using guidelines commonly used in practice. The peak values of axial pullout resistance observed on

Dharma Wijewickreme; Hamid Karimian; Douglas Honegger

2009-01-01

12

Weakly nonlinear oscillations of a compliant object buried in soil.  

PubMed

A nonlinear model equation in Rayleigh-Plesset form is developed for volume oscillations of a compliant object buried close to the surface in soil. The equation takes into account the stress-free boundary condition on the surface of the ground. The model is fully nonlinear given exact relations for the elastic potential energy stored in deformation of the object and the soil. Expansions of the potential energies for weak nonlinearity are provided in terms of elastic constants that can be determined experimentally. When the shear modulus is allowed to increase with depth below the surface, the natural frequency predicted by the model first decreases and thereafter increases with burial depth, in agreement with reported observations. Perturbation solutions are derived for the displacements on the surface of the ground at the second harmonic and difference frequency due to the nonlinear response of the object to acoustic excitation. PMID:19354379

Zabolotskaya, Evgenia A; Ilinskii, Yurii A; Hamilton, Mark F

2009-04-01

13

Soil Texture Involvement in Germination and Emergence of Buried Weed Seeds  

Microsoft Academic Search

studied in an ecological perspective to identify the physi- ological causes that prevent deeply buried seed from Laboratory trials were performed to test germination and emer- germinating; results obtained so far suggest this is partly gence characteristics of jimsonweed (Datura stramonium L.) seeds buried in 10 different soil types (with or without the control of soil due to the lack

Stefano Benvenuti

2003-01-01

14

Molecular Identification of Ectomycorrhizal Mycelium in Soil Horizons  

PubMed Central

Molecular identification techniques based on total DNA extraction provide a unique tool for identification of mycelium in soil. Using molecular identification techniques, the ectomycorrhizal (EM) fungal community under coniferous vegetation was analyzed. Soil samples were taken at different depths from four horizons of a podzol profile. A basidiomycete-specific primer pair (ITS1F-ITS4B) was used to amplify fungal internal transcribed spacer (ITS) sequences from total DNA extracts of the soil horizons. Amplified basidiomycete DNA was cloned and sequenced, and a selection of the obtained clones was analyzed phylogenetically. Based on sequence similarity, the fungal clone sequences were sorted into 25 different fungal groups, or operational taxonomic units (OTUs). Out of 25 basidiomycete OTUs, 7 OTUs showed high nucleotide homology (?99%) with known EM fungal sequences and 16 were found exclusively in the mineral soil. The taxonomic positions of six OTUs remained unclear. OTU sequences were compared to sequences from morphotyped EM root tips collected from the same sites. Of the 25 OTUs, 10 OTUs had ?98% sequence similarity with these EM root tip sequences. The present study demonstrates the use of molecular techniques to identify EM hyphae in various soil types. This approach differs from the conventional method of EM root tip identification and provides a novel approach to examine EM fungal communities in soil.

Landeweert, Renske; Leeflang, Paula; Kuyper, Thom W.; Hoffland, Ellis; Rosling, Anna; Wernars, Karel; Smit, Eric

2003-01-01

15

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

16

Impact of varying soil structure on transport processes in different diagnostic horizons of three soil types.  

PubMed

When soil structure varies in different soil types and the horizons of these soil types, it has a significant impact on water flow and contaminant transport in soils. This paper focuses on the effect of soil structure variations on the transport of pesticides in the soil above the water table. Transport of a pesticide (chlorotoluron) initially applied on soil columns taken from various horizons of three different soil types (Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol) was studied using two scenarios of ponding infiltration. The highest infiltration rate and pesticide mobility were observed for the Bt(1) horizon of Haplic Luvisol that exhibited a well-developed prismatic structure. The lowest infiltration rate was measured for the Bw horizon of Haplic Cambisol, which had a poorly developed soil structure and a low fraction of large capillary pores and gravitational pores. Water infiltration rates were reduced during the experiments by a soil structure breakdown, swelling of clay and/or air entrapped in soil samples. The largest soil structure breakdown and infiltration decrease was observed for the Ap horizon of Haplic Luvisol due to the low aggregate stability of the initially well-aggregated soil. Single-porosity and dual-permeability (with matrix and macropore domains) flow models in HYDRUS-1D were used to estimate soil hydraulic parameters via numerical inversion using data from the first infiltration experiment. A fraction of the macropore domain in the dual-permeability model was estimated using the micro-morphological images. Final soil hydraulic parameters determined using the single-porosity and dual-permeability models were subsequently used to optimize solute transport parameters. To improve numerical inversion results, the two-site sorption model was also applied. Although structural changes observed during the experiment affected water flow and solute transport, the dual-permeability model together with the two-site sorption model proved to be able to approximate experimental data. PMID:19062128

Kodesová, Radka; Vignozzi, Nadia; Rohosková, Marcela; Hájková, Tereza; Kocárek, Martin; Pagliai, Marcello; Kozák, Josef; Sim?nek, Jirka

2009-02-16

17

Soil organic matter stabilization in buried paleosols of the Great Plains  

Microsoft Academic Search

Understanding the mechanisms that control soil organic matter (SOM) stabilization is important for understanding how soil carbon is sequestered over millennia, and for predicting how future disturbances may affect soil carbon stocks. We are studying the mechanisms controlling SOM stabilization in the Brady Soil, a buried paleosol in Holocene loess deposits spanning much of the central Great Plains of the

N. T. Chaopricha; E. Marin-Spiotta; J. A. Mason; C. W. Mueller

2010-01-01

18

Seismic analysis of buried pipeline in a 3D soil continuum  

Microsoft Academic Search

An efficient numerical approach based on both boundary and finite element methods is developed in this work. This development is capable of realistic three dimensional analyses of soil-structure interaction problems in the real time domain and is specifically tailored to buried lifelines. In particular, boundary elements are used in a surface-only representation of the buried cavity problem for determining influence

G. D. Manolis; P. I. Tetepoulidis; D. G. Talaslidis; G. Apostolidis

1995-01-01

19

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

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

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

22

PH BUFFERING IN FOREST SOIL ORGANIC HORIZONS: RELEVANCE TO ACID PRECIPITATION  

EPA Science Inventory

Samples of organic surface horizons (Oi, Oe, Oa) from New York State forest soils were equilibrated with 0 to 20 cmol HNO3 Kg(-1) soil in the laboratory by a batch technique designed to simulate reactions of acid precipitation with forest floors. Each organic horizon retained a c...

23

Wave-induced pore pressure around a buried pipeline in Gibson soil: finite element analysis  

Microsoft Academic Search

The water wave-induced pore pressure on a pipeline buried in a porous seabed is investigated. Unlike conventional investigations, shear modulus of the seabed is considered to vary with soil depth in this study. The boundary value problem describing soil stresses as well as pore water pressure under periodical wave loading is solved numerically by using a Finite Element Method. Employing

D. S. Jeng; Y. S. Lin

1999-01-01

24

3D Numerical Analyses of the Soil Variability Impact on Longitudinal Behaviour of Buried Pipes  

Microsoft Academic Search

The longitudinal bending of buried pipes is responsible for a significant amount of the pipe failures observed during CCTV inspections. However, compared to the circumferential pipe behaviour, little work is done to investigate this aspect of the pipe-soil interaction. The longitudinal bending is closely related to heterogeneities of the trench backfill especially uneven compaction of the soil surrounding the pipe.

J. Buco; F. Emeriault; R. Kastner

25

Predicting Performance of Pipe Culverts Buried in Soil.  

National Technical Information Service (NTIS)

An analytical tool based on the finite element method has been developed to analyze buried culvert problems in a realistic fashion. Segments of a curved bar with three degrees of freedom (normal, tangential and rotational) at each end have been used to si...

G. A. Leonards M. B. Roy

1976-01-01

26

The pedogeochemical segregation a few horizons in soils from glass houses  

NASA Astrophysics Data System (ADS)

Our studies have focused the apparition and manifestation conditions of pedogeochemical segregation phenomena in case of soils from Copou - Ia?i, Bac?u and Bârlad (Romania) glass house, and the effects of this on the pedogeochemical and agrochemical characteristics of soils from glass houses cultivated with vegetables. The utilization of intensive cultivation technologies of vegetables in glass houses determined the degradation of morphological, physical and chemical characteristics of soils, by rapid evolution of salted processes (salinization and / or sodization), compaction, carbonatation, eluviation-illuviation, frangipane formation, stagnogleization, gleization etc. Under these conditions, at depth of 30-40 cm is formed a compact and impenetrable horizon - Ahok(x) horizon. In function of exploitation conditions and by the chemical-mineralogical characteristics of soils from glasshouses, the Ahok horizons can have frangipane properties, expressed more or less. These horizons determined a geochemical segregation of soils from glass houses: (i) superior horizons, above Ahok(x) horizon evolve in weak oxidative conditions, weak alkaline pH, higher salinity, humidity and temperature; (ii) inferior horizons, below Ahok(x) horizon evolve in weak reducing conditions weak acid pH, lower salinity, humidity and temperature. Concomitant with the development of Ahok(x) horizons, the rapid degradation of the properties of soils from glasshouses is observed. The aspects about the formation of frangipane horizon in soils from glasshouses are not yet sufficiently know. Whatever of the formation processes, the frangipane horizons determined a sever segregation in pedogeochemical evolution of soils from glass houses, with very important consequences on the agrochemical quality of these soils. The segregation effects are manifested in the differential dynamics of pedogeochemical processes from superior horizons (situated above the segregation horizon), in comparison with the inferior horizons (situated below the segregation horizon), and in global evolution of degradation processes of soils from glasshouses. The results obtained by as have shown that together by mobile forms of Si, Al and Fe, at the formation of segregation horizons (frangipane), an important role has the phosphorus (organic. in special) and the organic-mineral complexes, respectively. The experimental results indicate a strong accumulation tendency, at the level of pedogeochemical segregation horizons - Ahok(x) horizons, of fin grain-size fractions and of amorphous forms of mineral components. Also, was observed that in the composition of soil aggregates from frangipane horizon, and important weight have the smectites, amorphous iron oxides and oxy-hydroxides, amorphous silica and organic matter. The particularity of pedogeochemical segregation horizon (frangipane) from Copou-Ia?i glass house is given by the relatively high contents of: (i) phosphorus - organic, in special, as inositol-phosphoric esters; (ii) fulvic acids; (iii) organic-mineral complexes - with special composition and structure, and (iv) poly-metha-phosphate associated with aluminosilicated gel - from chemical point of view has the characteristics of a pseudo-solid solution by (SiO2)x(Al2O3)y(PO4)z type, where x / z = (10-16) / 1, and y / z = (3-5) / 1); this appear as nodular depositions (? = 3-5 mm) covered with thin iron-carbonated crust. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51-045/07).

Bulgariu, Dumitru; Rusu, Constantin; Filipov, Feodor; Buzgar, Nicolae; Bulgariu, Laura

2010-05-01

27

The distribution of volatile isoprenoids in the soil horizons around Pinus halepensis trees  

Microsoft Academic Search

We measured the terpene concentration in pentane and water extracts from soil horizons (litter, organic, top and low mineral) and from roots growing in top and low mineral horizons on a distance gradient from Pinus halepensis L. trees growing alone on a grassland. Terpene concentrations in pentane were higher than in water extracts, although ?-caryophyllene showed relatively high solubility in

Dolores Asensio; Susan M. Owen; Joan Llusià; Josep Peñuelas

2008-01-01

28

What Lies Within: Contributions of the Organic Horizon to Forest Soil Respiration  

Microsoft Academic Search

Soil respiration rates can exhibit tremendous spatial variability, making it difficult to ascertain the proximal causes of CO2 production. In coniferous forest soils, a large proportion of CO2 is produced in the organic layer, and better characterizing the organisms and chemical composition of this heterogeneous horizon may contribute to a predictive understanding of soil respiration rates. In this study we

P. Julia; C. L. Phillips; B. J. Bond

2008-01-01

29

Project Ostrich a Feasibility Study: Detecting Buried Mines in Dry Soils Using Synthetic Aperture Radar.  

National Technical Information Service (NTIS)

Metallic and nonmetallic mines were utilized to construct a minefield in arid soil at Twentynine Palms, California to assess the extent to which long-wavelength radar could be used to detect buried mines by remote sensing. Surface and subsurface mines wer...

J. V. Hansen J. Ehlen T. D. Evans R. A. Hevenor

1993-01-01

30

Mechanical Energy Propagation and Backscattering in Nominally Dry Soil: Imaging Buried Land Mines  

NASA Astrophysics Data System (ADS)

The imaging of shallow buried objects in a complex medium, e.g., nominally dry sand, is an outstanding challenge. Such imaging is of relevance in connection with the detection and subsequent imaging of buried non-metallic anti-personnel land mines and in other applications. It has been shown that gentle mechanical impulses and low frequency sound waves with frequencies roughly between 150-350 Hz or so can penetrate distances of up to a foot in sand. Hence, such signals can potentially be useful in the detection and perhaps in the imaging of shallow buried objects. It is presently unclear whether high frequency signals can be effectively used to image shallow buried objects. Impulses can typically penetrate larger distances into sand and soil. Both impulses and continuous sound waves can be used for imaging shallow buried objects. The talk shall briefly review the state-of-the-art in low frequency sound propagation in soil and shall discuss the current understanding of impulse propagation and backscattering in nominally dry sand beds. It will be argued that impulse based imaging may have the potential to be a simple and fast way to detect and image small non-metallic mines. Research supported by the National Science Foundation Grant No. NSF-CMS 0070055.

Sen, Surajit

2003-04-01

31

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

32

pH Buffering in Forest Soil Organic Horizons: Relevance to Acid Precipitation.  

National Technical Information Service (NTIS)

Samples of organic surface horizons (Oi, Oe, Oa) from New York State forest soils were equilibrated with 0 to 20 cmol HNO3 Kg(-1) soil in the laboratory by a batch technique designed to simulate reactions of acid precipitation with forest floors. Each org...

B. R. James S. J. Riha

1986-01-01

33

A warmer climate induces greater temperature sensitivity in boreal forest organic horizon soil respiration  

NASA Astrophysics Data System (ADS)

To predict the impact of climate warming on the global carbon (C) cycle, we must address the dynamics of soil organic matter (SOM), particularly in high latitude ecosystems where >31% of Earth's soil organic C reservoir resides. Previous studies have demonstrated the role of substrate usage on the temperature sensitivity of soil C mineralization (C Quality-Temperature Hypothesis). Few studies, however, have addressed the role of in situ climate warming in regulating the temperature sensitivity of distinct soil C pools. Does a warmer climate history yield SOM pools whose degradation is more temperature sensitive, and are the response of these pools able to predict those of more intact soils? In this study, we conducted two parallel experiments using podzolic boreal forest soils collected from two regions generally similar except in mean annual temperature (difference of 5°C). We incubated a reconstructed O-horizon to test the influence of climate history (warmer versus cooler regions) on these soils' respiratory responses to temperatures at 5, 10 and 15°C for 450 days. Cumulative respiration was greater in the cooler region relative to the warmer region, regardless of incubation temperature. However, the mean temperature sensitivity of CO2 production was 31% higher in the warmer (Q10=4.6) versus cooler region (Q10=3.5). In a parallel experiment, we incubated the separate sub-horizons (L, F, H) that demonstrated no difference in Q10 by region (no climate history effect). We compared the weighted sum of cumulative respiration from the sub-horizons (L+F+H) to that of the reconstructed O-horizon incubations. As was the case for the separate sub-horizons, the summed cumulative respiration was greater in the cooler vs. warmer region soils at all temperatures and Q10 was not affected by soil climate history. Results indicate that temperature sensitivity can be influenced by how the sample incubated and, though not confirmed in this study, suggests that microbes' access to different soil C pools may regulate such temperature sensitivity. The elevated temperature sensitivity of the reconstructed O-horizon soil from the warmer region observed here suggests the potential for positive feedbacks associated with these soils in a warmer climate. Given that the individual sub-horizon incubations could not predict the same effects suggests the factors regulating this climate history effect are more complex then the increase in the temperature sensitivity of individual soil C pools. Further investigations are required to determine the role that shifts in microbial substrate choice may play in regulating the temperature sensitivity of soil C pool respiration.

Podrebarac, F. A.; Laganiere, J.; Billings, S. A.; Edwards, K.; Ziegler, S. E.

2013-12-01

34

Effect of Biostimulation and Bioaugmentation on Degradation of Polyurethane Buried in Soil?  

PubMed Central

This work investigated biostimulation and bioaugmentation as strategies for removing polyurethane (PU) waste in soil. Soil microcosms were biostimulated with the PU dispersion agent “Impranil” and/or yeast extract or were bioaugmented with PU-degrading fungi, and the degradation of subsequently buried PU was determined. Fungal communities in the soil and colonizing buried PU were enumerated on solid media and were analyzed using denaturing gradient gel electrophoresis (DGGE). Biostimulation with yeast extract alone or in conjunction with Impranil increased PU degradation 62% compared to the degradation in untreated control soil and was associated with a 45% increase in putative PU degraders colonizing PU. Specific fungi were enriched in soil following biostimulation; however, few of these fungi colonized the surface of buried PU. Fungi used for soil bioaugmentation were cultivated on the surface of sterile wheat to form a mycelium-rich inoculum. Wheat, when added alone to soil, increased PU degradation by 28%, suggesting that wheat biomass had a biostimulating effect. Addition of wheat colonized with Nectria haematococca, Penicillium viridicatum, Penicillium ochrochloron, or an unidentified Mucormycotina sp. increased PU degradation a further 30 to 70%, suggesting that biostimulation and bioaugmentation were operating in concert to enhance PU degradation. Interestingly, few of the inoculated fungi could be detected by DGGE in the soil or on the surface of the PU 4 weeks after inoculation. Bioaugmentation did, however, increase the numbers of indigenous PU-degrading fungi and caused an inoculum-dependent change in the composition of the native fungal populations, which may explain the increased degradation observed. These results demonstrate that both biostimulation and bioaugmentation may be viable tools for the remediation of environments contaminated with polyurethane waste.

Cosgrove, L.; McGeechan, P. L.; Handley, P. S.; Robson, G. D.

2010-01-01

35

Some features of technogenic soil layers and horizons in the zones of underground gas storages  

Microsoft Academic Search

Technogenic soils in underground gas storage areas are formed under the combined impact of natural and technogenic soil-forming\\u000a factors (pipelining, gas well drilling and exploitation). New layers and horizons appear in the soil profiles. Technogenic\\u000a layers (drilling technogenic layer (TSd), a chemically polluted loamy layer formed during the period of gas well drilling\\u000a and exploitation; technogenic layer (TS..), a periodically

N. V. Mozharova; T. V. Gol’tsova

2008-01-01

36

Thermal analysis of soil-buried oxo-biodegradable polyethylene based blends  

Microsoft Academic Search

Low-density polyethylene (LDPE) blended with poly(3-hydroxybutyrate) (PHB) and additivated with pro-oxidant were soil buried\\u000a for 180 days and characterized using thermogravimetry (TG) and differential scanning calorimetry (DSC). TG data showed that\\u000a both onset and maximum rate degradation temperatures decreased as a function of biodegradation time. Apparent activation energies\\u000a (E\\u000a a) using the Broido integral method decreased with the burial time increasing.

Sílvia Maria Martelli; Elizabeth Grillo Fernandes; Emo Chiellini

2009-01-01

37

Discordant 14C ages from buried tidal-marsh soils in the Cascadia subduction zone, southern Oregon coast  

USGS Publications Warehouse

Peaty, tidal-marsh soils interbedded with estuarine mud in late Holocene stratigraphic sequences near Coos Bay, Oregon, may have been submerged and buried during great (M > 8) subduction earthquakes, smaller localized earthquakes, or by nontectonic processes. Radiocarbon dating might help distinguish among these alternatives by showing that soils at different sites were submerged at different times along this part of the Cascadia subduction zone. But comparison of conventional 14C ages for different materials from the same buried soils shows that they contain materials that differ in age by many hundreds of years. Errors in calibrated soil ages represent about the same length of time as recurrence times for submergence events (150-500 yr)-this similarity precludes using conventional 14C ages to distinguish buried soils along the southern Oregon coast. Accelerator mass spectrometer 14C ages of carefully selected macrofossils from the tops of peaty soils should provide more precise estimates of the times of submergence events. ?? 1992.

Nelson, A. R.

1992-01-01

38

Failure mechanisms of buried pipelines under fault movement and soil liquefaction  

SciTech Connect

Lifelines, such as oil and gas transmission lines and water and sewer pipelines, have been damaged heavily in recent earthquakes. The damages of these lifelines have caused major, catastrophic disruption of essential service to human needs. Two seismic hazards are a) fault movement and b) soil liquefaction. In the investigation of fault movement, a non-linear analysis for a buried pipeline subjected to tensile strike-slip fault is proposed with following conditions: 1) the conditions of using elastic foundation for the far end of the pipe and the ultimate passive soil pressure near the fault are used to derive the basic equations of a pipeline crossing an active fault; and 2) an iterative method is used to solve the non-linear equations induced from the non-linearity of material and soil characteristics and large displacement. This study also discusses the design criteria for buried pipelines subjected to various fault movement and other design parameters. An initial research effort to investigate the performance of a pipeline in a soil liquefaction environment during earthquakes is described. The pipeline is subjected to longitudinal wave propagation at the time of liquefaction of soil deposits. A simplified pipe model on a time dependent elastic foundation is proposed to stimulate a liquefaction situation of a liquefiable zone during earthquakes and the finite difference technique coupled with a time-increment computer solution is employed to determine the dynamic responses of the proposed model numerically.

Yeh, Y.H.

1983-01-01

39

A Receding Horizon Control algorithm for adaptive management of soil moisture and chemical levels during irrigation  

Microsoft Academic Search

The capacity to adaptively manage irrigation and associated contaminant transport is desirable from the perspectives of water conservation, groundwater quality protection, and other concerns. This paper introduces the application of a feedback-control strategy known as Receding Horizon Control (RHC) to the problem of irrigation management. The RHC method incorporates sensor measurements, predictive models, and optimization algorithms to maintain soil moisture

Jeff S. Shamma; Thomas C. Harmon

2009-01-01

40

Bacterial, archaeal and eukaryal community structures throughout soil horizons of harvested and naturally disturbed forest stands.  

PubMed

Disturbances caused by timber harvesting have critical long-term effects on the forest soil microbiota and alter fundamental ecosystem services provided by these communities. This study assessed the effects of organic matter removal and soil compaction on microbial community structures in different soil horizons 13 years after timber harvesting at the long-term soil productivity site at Skulow Lake, British Columbia. A harvested stand was compared with an unmanaged forest stand. Ribosomal intergenic spacer profiles of bacteria, archaea and eukarya indicated significantly different community structures in the upper three soil horizons of the two stands, with differences decreasing with depth. Large-scale sequencing of the ribosomal intergenic spacers coupled to small-subunit ribosomal RNA genes allowed taxonomic identification of major microbial phylotypes affected by harvesting or varying among soil horizons. Actinobacteria and Gemmatimonadetes were the predominant phylotypes in the bacterial profiles, with the relative abundance of these groups highest in the unmanaged stand, particularly in the deeper soil horizons. Predominant eukaryal phylotypes were mainly assigned to known mycorrhizal and saprotrophic species of Basidiomycetes and Ascomycetes. Harvesting affected Basidiomycetes to a minor degree but had stronger effects on some Ascomycetes. Archaeal profiles had low diversity with only a few predominant crenarchaeal phylotypes whose abundance appeared to increase with depth. Detection of these effects 13 years after harvesting may indicate a long-term change in processes mediated by the microbial community with important consequences for forest productivity. These effects warrant more comprehensive investigation of the effects of harvesting on the structure of forest soil microbial communities and the functional consequences. PMID:19659501

Hartmann, Martin; Lee, Sangwon; Hallam, Steven J; Mohn, William W

2009-12-01

41

Wave-induced pore pressure around a buried pipeline in Gibson soil: finite element analysis  

NASA Astrophysics Data System (ADS)

The water wave-induced pore pressure on a pipeline buried in a porous seabed is investigated. Unlike conventional investigations, shear modulus of the seabed is considered to vary with soil depth in this study. The boundary value problem describing soil stresses as well as pore water pressure under periodical wave loading is solved numerically by using a Finite Element Method. Employing the principle of repeatability, the lateral boundary conditions are obtained first and verified with previous analytical solutions. Then, the wave-sealed-pipe interaction problem can be solved to obtain the wave-induced soil response. The effects of variable shear modulus, geometry of the pipe and the degree of saturation on the wave-induced pore pressure are found to be significant.

Jeng, D. S.; Lin, Y. S.

1999-11-01

42

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

43

The reasons for the formation of light-colored acid eluvial horizons in the soil profile  

NASA Astrophysics Data System (ADS)

Concepts concerning the origin of light-colored acid eluvial horizons within the soil profiles are considered. In Russia, the current concept is related to the polygenetic origin of these horizons indicating that their formation is affected by acidic hydrolysis, lessivage, and gleying. The acidic hydrolysis under aerobic conditions was shown not to provide the reduction of Fe (III) to Fe(II) and its transfer to soil solution. Lessivage is not an obligatory factor that controls the formation of light-colored acid eluvial horizons, since its signs are often absent in the profile of soils. The only process responsible for the eluviation of Fe, Mn, and Al; the removal of hydroxide and oxide iron coatings from mineral grains; increasing the relative Si content; and the appearance of the whitish color is gleying under conditions of a stagnant-percolative water regime. Precisely this factor is the single reason for the formation of light-colored acid eluvial (podzolic) horizons. Therefore, they are monogenetic in origin.

Zaidel'Man, F. R.

2007-10-01

44

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

45

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

Microsoft Academic Search

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.

Thomas C. Harmon

2011-01-01

46

Functional Assays and Metagenomic Analyses Reveals Differences between the Microbial Communities Inhabiting the Soil Horizons of a Norway Spruce Plantation  

PubMed Central

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.

Uroz, Stephane; Ioannidis, Panos; Lengelle, Juliette; Cebron, Aurelie; Morin, Emmanuelle; Buee, Marc; Martin, Francis

2013-01-01

47

Modeling the effects of fire severity on soil organic horizons and forest composition in Interior Alaska  

NASA Astrophysics Data System (ADS)

The fire regime in the boreal region of interior Alaska has been intensifying in terms of both area burned and severity over the last three decades. Based on projections of climate change, this trend is expected to continue throughout the 21st century. Fire causes abrupt changes in energy, nutrient and water balances influencing habitat and vegetation composition. An important factor influencing these changes is the reduction of the soil organic horizon because of differential regeneration capabilities of conifer and evergreen shrubs vs. deciduous and herbaceous vegetation on organic vs. mineral soils. The goal of this study is to develop a prognostic model to simulate the effects of fire severity on soil organic horizons and to evaluate its long-term consequences on forest composition in interior Alaska. Existing field observations were analyzed to build a predictive model of the depth of burning of soil organic horizon after a fire. The model is driven by data sets of fire occurrence, climate, and topography. Post-fire vegetation succession was simulated as a function of post-fire organic horizon depth. The fire severity and post-fire vegetation succession models were then implemented within a biogeochemistry model, the process-based Terrestrial Ecosystem Model. Simulations for 21st century climate scenarios at a 1 by 1km resolution for the Alaska Yukon River Basin were conducted to evaluate the effects of considering vs. ignoring post-fire vegetation succession on carbon dynamics. The results of these simulations indicate that it is important for ecosystem models to represent the influence of fire severity on post-fire vegetation succession in order to fully understand the consequences of changes in climate and disturbance regimes on boreal ecosystems.

Genet, H.; Barrett, K. M.; Johnstone, J. F.; McGuire, A. D.; Yuan, F.; Euskirchen, E. S.; Kasischke, E. S.; Rupp, S. T.; Turetsky, M. R.

2012-12-01

48

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.

49

Comparison of 3He and BF3 neutron detectors used to detect hydrogenous material buried in soil  

NASA Astrophysics Data System (ADS)

Thermal neutrons detectors have been used for a long time and continue to be used to detect hydrogenous material. In this work, BF3 and 3He detectors ability have been compared with each other to detect Polyethylene (PE) sample that was buried in soil. It was found that neither BF3 nor 3He could detect PE sample without shields. This research shows that a thickness of 5 cm graphite is suitable shield for 3He detector that has been used to detect buried PE sample.

Rezaei-Ochbelagh, D.

2012-04-01

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

Fungal colonization of soil-buried plasticized polyvinyl chloride (pPVC) and the impact of incorporated biocides.  

PubMed

Plasticized polyvinyl chloride (pPVC) with or without incorporated biocides was buried in grassland and forest soil for up to 10 months. The change with time in viable counts of fungi on the plastic surface was followed, together with the percentage capable of clearing the two plasticizers dioctyl adipate (DOA) and dioctyl phthalate (DOP). With time fungal total viable counts (TVC) on control pPVC increased and the fraction able to clear DOA was considerably higher than the average estimated in both soil types. A total of 92 fungal morphotypes were isolated from grassland soil and 42 from forest soil with the greatest variety of fungal isolates observed on control pPVC. The incorporation of biocides into pPVC affected both fungal TVC and the richness of species isolated. The biocides NCMP [n-(trichloromethylthio)phthalimide], OBPA (10,10'-oxybisphenoxarsine) and OIT (2-n-octyl-4-isothiazolin-3-one) were the most effective in grassland soil, and TCMP [2,3,5,6-tetrachloro-4-(methylsulphonyl)pyridine] and NCMP the most effective in forest soil. In grassland soil, Penicillium janthinellum established as a principal colonizer and was recovered from all pPVC types. DOP clearers were found at much lower levels than DOA clearers, with Doratomyces spp. being the most efficient. At the end of 10 months the physical properties of the pPVC were altered; changes in stiffness were the most significant for heavily colonized grassland-buried pPVC samples, whereas in forest soil, the extensibility of the pPVC was affected more than the stiffness. These results suggest that fungi are important colonizers of pPVC buried in soil and that enrichment of soil fungi capable of clearing DOA occurs during colonization of the plastic surface. The results also demonstrate that incorporated biocides have a marked impact on the richness of species colonizing the pPVC surface. PMID:16735736

Sabev, H A; Handley, P S; Robson, G D

2006-06-01

52

Stabilization of ancient organic matter in deep buried paleosols  

NASA Astrophysics Data System (ADS)

Buried soils representing ancient surface horizons can contain large organic carbon reservoirs that may interact with the atmosphere if exposed by erosion, road construction, or strip mining. Paleosols in long-term depositional sites provide a unique opportunity for studying the importance of different mechanisms on the persistence of organic matter (OM) over millennial time-scales. We report on the chemistry and bioavailability of OM stored in the Brady soil, a deeply buried (7 m) paleosol in loess deposits of southwestern Nebraska, USA. The Brady Soil developed 9,000-13,500 years ago during a time of warming and drying. The Brady soil represents a dark brown horizon enriched in C relative to loess immediately above and below. Spanning much of the central Great Plains, this buried soil contains large C stocks due to the thickness of its A horizon (0.5 to 1 m) and wide geographic extent. Our research provides a unique perspective on long-term OM stabilization in deep soils using multiple analytical approaches. Soils were collected from the Brady soil A horizon (at 7 m depth) and modern surface A horizons (0-15 cm) at two sites for comparison. Soils were separated by density fractionation using 1.85 g ml-1 sodium polytungstate into: free particulate organic matter (fPOM) and aggregate-occluded (oPOM) of two size classes (large: >20 ?m, and small: < 20 ?m). The remaining dense fraction was separated into sand, silt, and clay size fractions. The distribution and age of C among density and particle-size fractions differed between surface and Brady soils. We isolated the source of the characteristic dark coloring of the Brady soil to the oPOM-small fraction, which also contained 20% of the total organic C pool in the Brady soil. The oPOM-small fraction and the bulk soil in the middle of the Brady A horizon had 14C ages of 10,500-12,400 cal yr BP, within the time that the soil was actively forming at the land surface. Surface soils showed modern ages. Lipid analyses of the Brady soil indicate a predominance of terrestrial vegetation biomarkers. The strong presence of vascular plant-derived terpenoids and long-chain n-alkyl lipids suggest a grassland origin. Respiration rates of the buried soil in a laboratory incubation were negligible compared to modern surface A and B horizons, and responded little to wetting. These results suggest that moisture alone does not limit decomposition in the buried soil, at least over the 120-day incubation. Solid-state 13C-NMR spectroscopy reveals that the Brady soil is enriched in aromatic C, with high contributions of char, especially in the oPOM-small fraction. Thermal analysis showed high thermal stability of oPOM-small and bulk soils in the Brady soil compared to modern surface horizons. Radiocarbon ages and chemical composition of OM isolated from a deep paleosol suggest little modification since burial and may indicate rapid stabilization of plant-derived organic C by burial. The accumulation of char in the aggregate-protected fraction of the Brady soil provides additional evidence for warming and drying conditions during the time of loess deposition at this site. Developing a better understanding of the mechanisms that control long-term SOM stabilization is important for understanding how soil C is sequestered over millennia and for predicting how future disturbances may affect deep soil C.

Marin-Spiotta, E.; Chaopricha, N. T.; Mueller, C.; Diefendorf, A. F.; Plante, A. F.; Grandy, S.; Mason, J. A.

2012-12-01

53

Carbon delivery to deep mineral horizons in Hawaiian rain forest soils  

NASA Astrophysics Data System (ADS)

This study aimed to better understand the mechanisms for soil organic matter delivery to and accumulation in mineral horizons of tropical rain forest, volcanic soils. We used soil morphology, lysimetry, isotopes, and spectroscopy to investigate the role of preferential flow paths in the delivery of carbon (C) to the subsoil. High rainfall, high primary productivity, and the dominance of highly reactive, short-range-order minerals combine to sequester substantial stocks of soil C with long mean residence times. The soils have large peds, separated by wide cracks, which form a network of channels propagating downward through the top 40 to 60 cm, facilitating macropore flow. The channel infillings and crack surfaces were enriched in organic material (OM) with lower C:N ratios, and had higher ammonium oxalate-extractable Al, and lower ammonium oxalate-extractable Fe than the adjacent mineral bulk soil. CP MAS 13C-NMR spectra of OM accumulating at depth showed strong signal intensities in the carboxyl and carbonyl C regions, indicative of organic acids, while decaying roots showed greater contributions of aromatic and O-alkyl C. The ratios of alkyl-to-O-alkyl C in the organic infillings were more similar to those of the bulk Bh and to dissolved organic matter than to those of decaying roots. Radiocarbon-based ages of OM infillings at >50 cm depth were significantly younger than the mineral soil (2000 years versus 7000 years). Respired CO2 from incubated soils showed that OM accumulating at depth is a mixture of modern and much older C, providing further evidence for the downward movement of fresh C.

Marin-Spiotta, Erika; Chadwick, Oliver A.; Kramer, Marc; Carbone, Mariah S.

2011-09-01

54

Defense Waste Management Plan for Buried Transuranic-Contaminated Waste, Transuranic-Contaminated Soil, and Difficult-to-Certify Transuranic Waste.  

National Technical Information Service (NTIS)

GAO recommended that DOE provide specific plans for permanent disposal of buried TRU-contaminated waste, TRU-contaminated soil, and difficult-to-certify TRU waste; cost estimates for permanent disposal of all TRU waste, including the options for the burie...

1987-01-01

55

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

56

Estimating the effect of tree uprooting on variation of soil horizon depth by confronting pedogenetic simulations to measurements in a Belgian loess area  

NASA Astrophysics Data System (ADS)

patterns of soil often do not reflect those of topographic controls. We attempted to identify possible causes of this by comparing observed and simulated soil horizon depths. Observed depths of E, Bt, BC, C1, and C2 horizons in loess-derived soils in Belgium showed a weak to absent relation to terrain attributes in a sloping area. We applied the soil genesis model SoilGen2.16 onto 108 1 × 1 m2 locations in a 1329 ha area to find possible causes. Two scenarios were simulated. Model 1 simulated soil development under undisturbed conditions, taking slope, aspect, and loess thickness as the only sources of variations. Model 2 additionally included a stochastic submodel to generate tree-uprooting events based on the exposure of trees to the wind. Outputs of both models were converted to depths of transitions between horizons, using an algorithm calibrated to horizon depths observed in the field. Model 1 showed strong correlations between terrain attributes and depths for all horizons, although surprisingly, regression kriging was not able to model all variations. Model 2 showed a weak to absent correlation for the upper horizons but still a strong correlation for the deeper horizons BC, C1, and C2. For the upper horizons the spatial variation strongly resembled that of the measurements. This is a strong indication that bioturbation in the course of soil formation due to treefalls influences spatial patterns of horizon depths.

Finke, P. A.; Vanwalleghem, T.; Opolot, E.; Poesen, J.; Deckers, J.

2013-12-01

57

Conservation of soil organic matter through cryoturbation in arctic soils in Siberia  

NASA Astrophysics Data System (ADS)

Cryoturbation (mixing of soil layers due to repeated freeze-thaw processes) is a major soil forming process in arctic regions, which may contribute to long-term storage of C in soils of northern latitudes. Our goal was to determine the effect of subduction of organic matter by cryoturbation on microbial decomposition processes in tundra soils. Buried layers were situated at 30-60 cm depth, between Bg and B horizons, but exhibited a C and N content highly similar to present-day A horizons. Radiocarbon dating revealed, however, that the mean age of C in the buried layer was three times higher (˜1300 years BP) than in the A horizon (˜400 years BP), suggesting that decomposition rates in the buried layer were delayed. The observed microbial processes support this result: gross C and N mineralization rates were substantially lower in the buried layers than in the respective A horizons. The amount of C stored in the buried layer still doubles the amount of C stored in topsoil horizons (O and A). Assuming that the buried layer originates from both O and A horizons, this indicates that O and A horizon at time of burying (800-1300 years BP) must have been significantly thicker and present-day O and A horizon at this site may still have the capacity to accumulate additional C. Cryoturbation therefore may lead to additional long-term storage of carbon in the system by (1) retarding decomposition processes of buried organic material and (2) enabling the soil to restart C accumulation in topsoil layers.

Kaiser, Christina; Meyer, Hildegard; Biasi, Christina; Rusalimova, Olga; Barsukov, Pavel; Richter, Andreas

2007-06-01

58

Investigating priming of soil organic matter decomposition with litter extract in genetic horizons of two harvested red spruce podzols  

NASA Astrophysics Data System (ADS)

Soil organic matter (SOM) represents a significant store of carbon (C), and factors that influence its stability are essential to understand, particularly since rising greenhouse gases such as CO2 play an important role in exacerbating climate change. Several studies have documented losses of SOM as a result of forest harvesting, particularly in mineral soils below 20 cm, but the specific mechanism for this loss has not been identified. Priming of SOM decomposition has been observed in some soils with the addition of labile C sources, so it is important to consider whether leaching of organic matter from litter through soil profiles is a mechanism that might explain these observed harvesting-related losses. Here we present preliminary results of a study whose objective is to quantify changes in respiration rates from paired soils differing only in their harvest history, through depth and under C amendment conditions that closely mimic those found in the field setting. Composite field moist soil samples from Ae, Bf and BC (transitional) horizons were incubated to assess respiration rates (2.5 g dry weight, in triplicate) at 15 C for paired sites representing 110 yr and 35 yr post-harvest temperate forest soils. The approach combined descriptive measurements (elemental composition and C and N stable isotope ratios), with soil headspace CO2 and ?13C-CO2 measurements for soils experiencing additions of litter extract or deionized water over a 28 day period. Results indicate an order of magnitude difference in CO2 evolution rates between the shallow horizons (Ae and Bf) and the deeper soil (BC). The respired 13C-CO2 ratio was higher in the 110 yr old site soils, with a more depleted signature released from the 35 yr old site soils. The stable isotope signature of respired CO2 matched that of the bulk soil in the Ae horizon, but signatures that emerged from the Bf horizon did not necessarily follow that trend. Litter extracts produced variable results between sites, yielding insight into the role a labile C source derived from the upper profile may play in the stability of C in the profiles of harvested soils. Studies of this nature have important implications for understanding key processes governing SOM stability.

Gabriel, C.; Kellman, L. M.

2012-12-01

59

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

60

Feasibility of fast neutron analysis for the detection of explosives buried in soil  

NASA Astrophysics Data System (ADS)

A commercialized thermal neutron analysis (TNA) sensor has been developed to confirm the presence of buried bulk explosives as part of a multi-sensor anti-tank landmine detection system. Continuing improvements to the TNA system have included the use of an electronic pulsed neutron generator that offers the possibility of applying fast neutron analysis (FNA) methods to improve the system's detection capability. This paper describes an investigation into the use of FNA as a complementary component in such a TNA system. The results of a modeling study using simple geometries and a full model of the TNA sensor head are presented, as well as preliminary results from an experimental associated particle imaging (API) system that supports the modeling study results. The investigation has concluded that the pulsed beam FNA approach would not improve the detection performance of a TNA system for landmine or buried IED detection in a confirmation role, and could not be made into a practical stand-alone detection system for buried anti-tank landmines. Detection of buried landmines and IEDs by FNA remains a possibility, however, through the use of the API technique.

Faust, A. A.; McFee, J. E.; Bowman, C. L.; Mosquera, C.; Andrews, H. R.; Kovaltchouk, V. D.; Ing, H.

2011-12-01

61

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

62

Chemical Composition of Soil Horizons and Aggregate Size Fractions Under the Hawaiian Fern Dicranopteris and Angiosperm Cheirodendrom  

NASA Astrophysics Data System (ADS)

Soil organic matter (SOM) inherits much of its chemical nature from the dominant vegetation, including phenolic (lignin-derived), aromatic, and aliphatic (cutin and wax-derived) compounds. However, relatively stable recalcitrant compounds may also be formed as a result of condensation and complexation reactions through decomposition and protected with association with mineral particles. The Hawaiian fern species Dicranopteris decomposes more slowly than the angiosperm, Cheirodendrom due to high concentrations of recalcitrant C compounds. These aliphatic fern leaf waxes are well-preserved and may comprise a large portion of the recalcitrant organic matter in these soils. Our objective was to determine the chemical composition of the SOM under the O- (litter-dominated) and the A- (mineral) horizons formed under fern and angiosperm vegetation. To determine the effect of mineral-association, we fractioned the soil into four size classes; 850-590 ?m, 590-180 ?m, 180-53 ?m and <53 ?m and characterized the SOM via pyrolysis-gas chromatography-mass spectrometry (py-GC/MS). As the soils developed from the O- to the A-horizon, there was a decrease of lignin-derived phenolic compounds and an increase in more recalcitrant, aromatic and aliphatic C. Soils under ferns had greater relative concentrations of phenolic compounds, while the angiosperms had greater concentrations of fatty-acid methyl esters and furans (some polysaccharide-derived). Differences between size fractions were most evident in the O-horizon of both species. Recalcitrant fern-derived cutin and leaf waxes (alkene and alkanes structures) occurred in the 180-53 ?m fraction, which has been shown to be the most stable of the aggregate-size fractions. Soils developed under fern versus angiosperm vegetation have distinct chemical signatures, which likely determine the recalcitrance of the SOM.

Stewart, C. E.; Amatangelo, K.; Neff, J.

2007-12-01

63

Effects of Future Warming and Fire Regime Change on Boreal Soil Organic Horizons and Permafrost Dynamics in Interior Alaska  

NASA Astrophysics Data System (ADS)

There is evidence that ongoing climate change is affecting fire frequency, extent, and severity in the interior boreal region of Alaska, and these changes are likely to continue into the future. In this study we couple a landscape fire dynamics model with an ecosystem model in an application to evaluate the long term effects of changes in climate and fire regime on soil organic horizons and permafrost dynamics in interior Alaska. Changes in fire regime were simulated by the Alaska Frame-based Ecosystem Code (ALFRESCO) model driven by downscaled GCM climate outputs from CCCMA-CGCM3.1 and MPI ECHAM5 models using the A1B scenario at 1km x 1 km resolution for the Yukon River Basin in Alaska. The outputs of ALFRESCO were used to drive the dynamic organic soil version of the Terrestrial Ecosystem Model (DOS-TEM). ALFRESCO simulated fire activity would be enhanced through the middle of the 21st Century, after which fire activity would revert to pre-1990 levels because of a shift in forest composition (i.e., fuels) to a greater fraction of deciduous forest. The model framework estimated that the fibrous organic horizon would lose C through the middle of the 21st Century for the warmer ECHAM5 scenario, but would gain C throughout the 21st Century for the CCCMA scenario. The amorphous organic horizon lost C through the 21st Century for both scenarios. The active layer deepened across the basin from about 1 m to between 1.6 and 1.8 m by the middle of the century and then returned to current depth by the end of the 21st Century. These results suggest that it is important to couple changes in the soil organic horizons of boreal ecosystems to permafrost dynamics in order to fully understand the effects of changes in climate and fire regime on regional boreal ecosystem C storage.

Yuan, F.; McGuire, A. D.; Yi, S.; Euskirchen, E. S.; Rupp, T. S.; Breen, A. L.; Kurkowski, T.; Kasischke, E. S.; Harden, J. W.

2011-12-01

64

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

65

Contamination of the O2 soil horizon by zinc smelting and its effect on woodlouse survival  

USGS Publications Warehouse

Samples of litter from the 02 horizon of Dekalb soil (loamyskeletal, mixed, mesic Typic Dystrochrept) were collected from 18 ridgetop sites on a transect that ran by two Zn smelters in Palmerton, Pa. Metal concentrations increased by regular gradations from a minimum at a site 105 km west of the smelters (67 mg/kg Zn, 0.85 mg/kg Cd, 150 mg/kg Pb, 11 mg/kg Cu) to a maximum 1.2 km east of the smelters (35,000 mg/kg Zn, 1300 mg/kg Cd, 3200 mg/kg Pb, 280 mg/kg Cu), and then decreased until they reached an eastern minimum at the easternmost site, 19 km from the smelters. An increase in the P concentrations near the smelters showed that the emissions were disrupting nutrient flow through the ecosystem. An increase in the pH near the smelters was attributed to the high concentrations of Zn. The log of the distance of the sites from the smelters was significantly correlated (r = - 0.80, p < 0.05) with the mortality of woodlice (Porcellio scaber Latreille} fed samples of the litter during an 8-week test. There was substantial mortality of woodlice observed even in the 02 litter collected 19 km east of the smelters. Zinc, cadmium, lead, copper, and sulfur were experimentally added, alone or in combination, to 02 litter collected far from any known source of metal emissions. The highest concentration of Zn added (20,000 mg/kg) was toxic enough to account for the mortality observed in the earlier test. A lower concentration of Zn (5000 mg/kg) as well as the concentration of Cd (500 mg/kg) tested also significantly (p < 0.05) increased the mortality of woodlice.

Beyer, W.N.; Miller, G.W.; Cromartie, E.J.

1984-01-01

66

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

67

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

68

Incubation of air-pollution-control residues from secondary Pb smelter in deciduous and coniferous organic soil horizons: leachability of lead, cadmium and zinc.  

PubMed

The leachability of air-pollution-control (APC) residues from a secondary lead smelter in organic soil horizons (F and H) from a deciduous and a coniferous forest during incubation periods of 0, 3 and 6 months were compared in this work. While the concentration of Pb, Zn and Cd associated with the exchangeable/acid extractable fraction in the horizon F from the coniferous forest was higher compared to the deciduous, significantly lower concentrations in the humified horizon H was found. It is suggested that lower pH and a higher share of fulvic acids fraction (FAs) of solid phase soil organic matter (SOM) in the humified soil horizon H from the coniferous compared to the deciduous forest is responsible for a higher metal association with solid phase SOM and therefore a lower metal leaching in a soil system. From this point of view, the humified soil horizon H from the deciduous forest represents a soil system more vulnerable to Pb, Zn and Cd leaching from APC residues. PMID:22277334

Chrastný, Vladislav; Van?k, Aleš; Komárek, Michael; Farkaš, Juraj; Drábek, Ond?ej; Vokurková, Petra; N?mcová, Jana

2012-03-30

69

SOIL-PIPE INTERACTION OF FAULT CROSSING SEGMENTED BURIED DUCTILE IRON PIPELINES SUBJECTED TO DIP FAULTINGS  

NASA Astrophysics Data System (ADS)

This study investigates the necessity of considering different soil resistance against pipeline relative movement in upward and downward directions. In this way, results of FEM analyses are verified by experimental tests on a segmented ductile iron pipeline with 93mm diameter and 15m length installed at a 60cm depth from the ground surface in the moderate dense sand backfill condition. Fault movement, totally 35cm, has three same steps occurring in reverse way and intersection angle of 60 degrees with the pipe. This study demonstrates how assuming same resistance for soil against both upward and downward relative movements of pipeline, as suggested in JGA guideline, eventuates in imprecise FEM models.

Erami, Mohammad Hossein; Miyajima, Masakatsu; Kaneko, Shougo

70

Alluvial sediment or playas: What is the dominant source of sand and silt in desert soil vesicular A horizons, southwest USA  

NASA Astrophysics Data System (ADS)

Vesicular A (Av) soil horizons form beneath desert pavements from the accretion of aeolian sediment (dust) commonly thought to be derived primarily from desiccating pluvial lakes and playas, with contributions from ephemeral washes and alluvial fans. Particle size distributions of Av horizons are typically bimodal with primary modes of very fine silt and fine sand, suggesting that the horizon matrix is derived from multiple sources. Here we conduct detailed chemical and physical analysis of both Av horizon soil samples and potential sources of aeolian sediment to better constrain the relative contributions of dust associated with the development of Av horizons. Geochemical data from both sand (125-250 µm) and silt (2-32 µm) fractions in Av horizons and potential dust sources in the eastern Mojave Desert and western Sonora Desert, USA, point to large contributions from nearby sources including distal alluvial fans and washes, and comparably lower contributions from regional sources such as playas. The silt mode is derived from suspension transport of dust, and the fine sand mode is derived from saltating sand. The desiccation of pluvial lakes in the Mojave Desert is commonly believed to have driven episodes of aeolian activity, contributing to sand dunes and Av horizon formation. We propose that alluvial fans and washes are underappreciated as desert dust sources and that pulses of dust from late Pleistocene and Holocene alluvial fans dwarfed pulses of dust from desiccating pluvial lakes in the eastern Mojave Desert.

Sweeney, Mark R.; McDonald, Eric V.; Markley, Christopher E.

2013-03-01

71

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

72

The semi-analytic mode matching (SAMM) algorithm for efficient computation of scattered near fields from 3D dielectric targets buried in lossy soil  

Microsoft Academic Search

The 3D semi-analytic mode matching (SAMM) algorithm is used to determine the nearfield scattering from spherical, prolate spheroidal and oblate spheroidal targets buried in lossy soil. Scattering is described by moderately low-order superpositions of spherical modes originating at user-specified coordinate scattering centers (CSCs); the mode coefficients are found numerically by least-squares fitting all boundary conditions at discrete points along the

A. W. Morgenthaler; C. M. Rappaport

2005-01-01

73

Bury Your Trash  

NSDL National Science Digital Library

This activity will allow students to bury various pieces of trash in a plotted area of land outside. After approximately two to three months, the trash will be uncovered to allow the students to investigate what types of materials biodegrade in soil.

Engineering K-Ph.D. Program, Pratt School of Engineering, Duke University

2012-04-21

74

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...

75

Laboratory Load Tests on Buried Flexible Pipe.  

National Technical Information Service (NTIS)

As part of a study on soil factors affecting the behavior of buried pipe, research is being conducted on the soil-structure interaction of buried flexible pipe; earlier tests dealt with rigid pipe. The main items of investigation on flexible pipe are soil...

A. K. Howard

1968-01-01

76

Prestressing buried pipelines by heating with air  

Microsoft Academic Search

Buried pipelines operating at elevated temperatures experience high longitudinal compressive stresses because the surrounding soil prevents thermal expansion. At high operating temperatures, buried pipelines can push through the soil at bends and buckle catastrophically. In soft soils they can lose lateral stability, and they can develop plastic failures. Thermally induced problems can be prevented with varying degrees of success by

G. King

1993-01-01

77

Short-term increases in relative nitrification rates due to trenching in forest floor and mineral soil horizons of different forest types  

Microsoft Academic Search

The representation of NO3- dynamics within forest growth simulation models could improve forest management. An extensive literature review revealed an 88% probability of measuring a higher relative nitrification index (i.e. RNI = [NO3-] ÷ [NO3- + NH4+]) in mineral soil horizons than in forest floors, across a wide range of conifer and hardwood ecosystems. We then hypothesised that humus form

Martin Lavoie; Robert L. Bradley

2003-01-01

78

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

79

Boron isotopes in soils: investigation of horizon reactivity and vegetation cycling  

NASA Astrophysics Data System (ADS)

Investigating the soil/plant coupling requires the development of specific approaches being unambiguously sensitive to mineral- and biology-derived reactions. Boron presents chemical properties that, a priori, well meet the conditions for tracing bio-geochemical reactions. In particular, it is present in moderate to high concentrations in minerals; it is very sensitive to water/rock interactions during which it is partitioned between solid and liquid phases and undergoes a great isotopic fractionation and, finally, it is an essential nutrient for plants. Here, we present an extensive study on B isotopes in two distinct soil/tree systems from the well-characterized Strengbach basin (http://ohge.u-strasbg.fr/indexuk.html). Both bulk soil samples and granulometric fractions were analyzed. Soil solutions (down to 60 cm depth) were monitored every 6 weeks over two years (2005-2006). Tree samples (spruce needles and beech leaves) punctually sampled during this period. A Mass budget based on B concentration and hydrology model clearly first indicates that trees largely control the distribution of B in soil uppermost layers by yearly mobilizing 4 times more B than it is drained by soil solutions below 60 cm depth. B isotopes in soil solution depth profile highlight the presence of a highly reactive layer a 10 cm depth, which is interpreted as resulting from seasonal chemical oscillations caused by the biology and hydrology cycles. Isotopic budget indicates that this layer is not at steady state and accumulates B over years. The increasing contribution with depth of the weathering-derived B flux is clearly observable by a shift of the ?11B values towards low values. At the soil scale, mass and isotopic budgets help distinguishing both the B fluxes related to the mineral weathering reactions and the vegetation cycling and even show a strong correlation between them. Detailed analyses of granulometric fractions permit the determination of the B-carrier phases in these two soils and help understanding the long-term B geochemical cycle in forest soils. This approach evidences the transfer of B from the coarse (primary) fractions at greater depth to the finest (secondary) fractions in uppermost layers. Investigation of B isotopes in the bulk soil samples shows opposite weathering regime with respect to the soil type. The brown acidic (dystrochrept) soil developed on an hydrothermally altered granite and under spruce trees shows a dominant dissolving behavior with little precipitation of secondary phases whereas the ochreous podzolic (Haplorthod) soil developed on the less hydrothermally altered granite and under beech trees shows an increasing contribution on the B isotopic signature of secondary minerals with decreasing depth. These observations bring conceptual basics on the use of B isotopes in investigating bio-geochemical reactions and further help to quantify the mass budget of the dissolution/precipitation reactions in forest soils as well as to identify with more details the soil layers being presently the most reactive.

Cividini, D.; Lemarchand, D.; Chabaux, F. J.; Turpault, M.; Viville, D.; Stille, P.; Pierret, M.

2009-12-01

80

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

81

Early season nitrogen limitation of microbial respiration in the organic horizon of tussock tundra soils  

NASA Astrophysics Data System (ADS)

Low nitrogen (N) availability is a key constraint to decomposition of organic matter in arctic ecosystems. In tussock tundra soils, we have previously observed relatively high N availability early in the growing season followed by a crash in N availability later in the season. This crash led us to hypothesize that N is less limiting to microbial respiration early in the season and more limiting later in the season. To test this hypothesis, we incubated tussock tundra soils for one week in mason jars at three temperatures (5,10,15°C) with either ambient N levels or additional N (112.5 ug N g-1 dry soil). We made early season measurements at the beginning of June and late season measurements at the end of July in both 2010 and 2011. Contrary to our hypothesis, the laboratory incubations suggest that soil respiration is N-limited at both times of the season. The size of the limitation varied with temperature, with the most consistent effect of added N observed at 10°C. Reductions in the C:N ratio of the microbial biomass shows that they readily took up the added N in both the early and late season. We also saw that more carbon overall was respired in the warmer treatments in 2011. Rapid reductions in the respiration rate over the course of the one week incubation, particularly in 2011, suggest that labile carbon is also strongly limiting to microbial respiration in these soils. These data suggest that both carbon and nitrogen limitation to decomposition can occur very early in the growing season, even shortly after the onset of soil thaw. The results of this study reinforce the role of nutrient limitation as an important constraint on the loss of large stocks of carbon from the organic-rich upper layers of tussock tundra soils.

Darrouzet-Nardi, A.; Wallenstein, M. D.; Steltzer, H.; Sullivan, P.; Melle, C.; Segal, A. D.; Weintraub, M. N.

2011-12-01

82

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

83

Buried Bones  

NSDL National Science Digital Library

This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they learn about paleontology with a hands-on activity. The activity opens with an explanation covering how fossilized bones are usually very delicate and buried deeply in rock fossils. Students are then given step-by-step directions for working with a friend to create two make-believe dig sites by burying bones in plaster of Paris. The activity ends with three discussion questions: What was surprising about excavating the bones? What strategies did you find worked well for removing the plaster? How would you have worked differently if you had no idea what was buried inside? Adult supervision is recommended.

84

Preliminary systems design study assessment report. [Evaluation of using specific technologies and system concepts for testing 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. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Feizollahi, F. (Bechtel National, Inc., San Francisco, CA (United States)); Del Signore, J.C. (Ebasco Environmental, Richland, WA (United States))

1991-09-01

85

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

86

Soil Taxonomy and Soil Properties.  

National Technical Information Service (NTIS)

The 16 papers in this report deal with the following areas: soil taxonomy; an overview; diagnostic soil horizons in soil taxonomy; soil moisture and temperature regimes in soil taxonomy; particle size and mineralogy in soil taxonomy; soil series and soil ...

1977-01-01

87

Laboratory Load Tests on Buried Flexible Pipe.  

National Technical Information Service (NTIS)

In an effort to lower construction costs of closed conduit systems, the Bureau of Reclamation has been investigating the soil-structure interaction of buried flexible pipe. The test pipes are buried in a large container by placing a lean clay soil at opti...

A. K. Howard

1970-01-01

88

Development of a feldspar weathering index and its application to a buried soil chronosequence in southeastern England  

Microsoft Academic Search

An index of feldspar weathering (IFW) has been developed, based upon the assignment of individual grains to weathering classes defined in terms of progressive changes in surface morphology identifiable under a polarising microscope. The index was used to test the hypothesis that profiles of a (buried) paleosol developed on the higher terraces of the River Thames in southeastern England are

Glynis Read; Rob A. Kemp; James Rose

1996-01-01

89

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

90

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.

History, American M.

2012-06-26

91

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

92

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

Microsoft Academic Search

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,

J. E. Surma; C. J. Freeman; T. D. Powell; D. R. Cohn; D. L. Smatlak; P. Thomas; P. P. Woskov; R. A. Hamilton; C. H. Titus; J. K. Wittle

1993-01-01

93

Zn speciation in the organic horizon of a contaminated soil by micro-X-ray fluorescence, micro- and powder-EXAFS spectroscopy, and isotopic dilution.  

PubMed

Soils that have been acutely contaminated by heavy metals show distinct characteristics, such as colonization by metal-tolerant plant species and topsoil enrichment in weakly degraded plant debris, because biodegradation processes are strongly inhibited by contamination. Such an organic topsoil, located downwind of an active zinc smelter and extremely rich in Zn (approximately 2%, dry weight), was investigated by X-ray diffraction, synchrotron-based X-ray microfluorescence, and powder- and micro-extended X-ray absorption fine structure (EXAFS) spectroscopy for Zn speciation and by isotopic dilution for Zn lability. EXAFS spectra recorded on size fractions and on selected spots of thin sections were analyzed by principal component analysis and linear combination fits. Although Zn primary minerals (franklinite, sphalerite, and willemite) are still present (approximately 15% of total Zn) in the bulk soil, Zn was found to be predominantly speciated as Zn-organic matter complexes (approximately 45%), outer-sphere complexes (approximately 20%), Zn-sorbed phosphate (approximately 10%), and Zn-sorbed iron oxyhydroxides (approximately 10%). The bioaccumulated Zn fraction is likely complexed to soil organic matter after the plants' death. The proportion of labile Zn ranges from 54 to 92%, depending on the soil fraction, in agreement with the high proportion of organically bound Zn. Despite its marked lability, Zn seems to be retained in the topsoil thanks to the huge content of organic matter, which confers to this horizon a high sorption capacity. The speciation of Zn in this organic soil horizon is compared with that found in other types of soils. PMID:15212252

Sarret, Géraldine; Balesdent, Jérome; Bouziri, Lamia; Garnier, Jean-Marie; Marcus, Matthew A; Geoffroy, Nicolas; Panfili, Frédéric; Manceau, Alain

2004-05-15

94

Modeling of buried explosions  

SciTech Connect

Los Alamos National Laboratory has been and continues developing techniques for modeling buried explosions using a large geotechnical centrifuge. When fully developed, the techniques should permit the accurate modeling of large explosions in complex geometries. Our intentional application is to study the phenomena of explosive cavity formation and collapse. However, the same methods should also be applicable to simulation of bursts shallow enough to produce craters, and perhaps even of airbursts in situations where soil overburden is important. We have placed primary emphasis on test bed construction methods and on accurate measurement of the ground shock produced by the explosions. 8 refs., 7 figs.

Gaffney, E.S.; Wohletz, K.H.; House, J.W.; Brown, J.A.

1987-01-01

95

The chronological position of the Lohne Soil in the Nussloch loess section - re-evaluation for a European loess-marker horizon  

NASA Astrophysics Data System (ADS)

The loess section of Nussloch in southwestern Germany is a key profile for the reconstruction of the terrestrial palaeo-environment of central Europe at the time of the Last Glacial and Interglacial. Recently, the significance of the site for palaeo-environmental and geoarchaeological research increased additionally, with the discovery of unique Palaeolithic cultural remains from anatomically and culturally modern humans that invaded southwestern Germany during the Weichselian (Würmian) Pleniglacial period. At Nussloch, a chrono-stratigraphical key position is taken by a Middle Pleniglacial Cambisol remain which, under the designation Lohne Soil, serves as an important pedostratigraphic marker horizon for the greater area. Repeatedly, Greenland interstadial (GIS) 8 was suggested as a likely period of soil formation for the Lohne Soil. This interpretation is yet not justified on the basis of published chronometric data. Critical assessment of the data points to a later period of soil formation, likely during GIS7 to GIS5. This conclusion is supported by a new set of radiocarbon ages for the Nussloch site which are presented here for the first time. Consequences of a revised chronology for correlations of Pleniglacial Cryosols below and above the Lohne Soil with Greenland interstadials are discussed. The implications are important for European loess research as the Nussloch section serves as a reference base for loess sections throughout Europe.

Kadereit, Annette; Kind, Claus-Joachim; Wagner, Günther A.

2013-01-01

96

The soil moisture and its effect on the detection of buried hydrogenous material by neutron backscattering technique  

Microsoft Academic Search

Among the available nuclear techniques, the neutron backscattering technique, based on the detection of the produced thermal neutrons, is thought to be the most promising for landmine detections. The results obtained from Monte Carlo simulation were used for selection of BF3 detector and Am-Be neutron source shielding. In addition, soil moisture was discussed as a limitation of the neutron backscattering

D. Rezaei Ochbelagh; H. Miri Hakimabad; R. Izadi Najafabadi

2009-01-01

97

Enhanced horizons  

NASA Astrophysics Data System (ADS)

Half-supersymmetric geometries of N = 2 five-dimensional gauged supergravity have recently been fully classified using spinorial geometry techniques. We use this classification to determine all possible regular half-supersymmetric near-horizon geometries, assuming that all of the gauge-invariant spinor bilinears are regular at the horizon. Four geometries are found, two of which have been found previously in Kunduri and Lucietti (2007 J. High Energy Phys. JHEP02(2007)026), and Kunduri and Lucietti (2007 J. High Energy Phys. JHEP12(2007)015).

Gutowski, J. B.; Sabra, W. A.

2010-12-01

98

The soil moisture and its effect on the detection of buried hydrogenous material by neutron backscattering technique  

Microsoft Academic Search

Among the available nuclear techniques, the neutron backscattering technique, based on the detection of the produced thermal neutrons, is thought to be the most promising for landmine detections.The results obtained from Monte Carlo simulation were used for selection of BF3 detector and Am–Be neutron source shielding. In addition, soil moisture was discussed as a limitation of the neutron backscattering technique.

D. Rezaei Ochbelagh; H. Miri Hakimabad; R. Izadi Najafabadi

2009-01-01

99

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.

100

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

101

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 for the remediation of hazardous and transuranic waste stored at 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. This volume contains introduction section containing a brief SDS background and lists the general assumptions and considerations used during the development of the system concepts. The introduction section is followed by sections describing two system concepts that produce a waste form in compliance with the Waste Isolation Pilot Plant (WIPP) Waste Acceptance Criteria (WAC) and transportation package (TRAMPAC) requirements. This system concept category is referred to as Waste Form 4, WIPP and TRAMPAC Acceptable.'' The following two system concepts are under this category: Sort, Treat, and Repackage System (4-BE-2); Volume Reduction and Packaging System (4-BE-4).

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

1992-01-01

102

Selected kinetic parameters of soil microbial respiration in the A horizon of differently managed mountain forests and meadows of Moravian-Silesian Beskids Mts.  

NASA Astrophysics Data System (ADS)

The aim of this study was to find out the effect of intensity of thinning (FD-dense stand = 2044 trees/ha; FS-open stand = 1652 trees/ha) performed in young forest stands (99% spruce, 1% fir) in Moravian-Silesian Beskids Mts. (908 m a.s.l.; 49°30'10? N, 18°32'20? E) on V DS (C mineralization rate immediately after drying and re-wetting of soil), V BR (basal soil respiration at 60% w/w soil water content measured 5th day after rewetting of dry soil), V MAX (maximum respiration rate after glucose addition measured from 6th day after rewetting of dry soil), V DS/ V MAX (heterotrophic respiratory potential) and ACDS/ACBR (the potential flush of biologically available C) in Ae horizon of Haplic and Entic Podzols. The ACDS/ACBR was calculated from three 24-hour respirations of 7-day incubation according to the equation ACDS/ACBR= V DS V MAX/(2 V BR( V MAX- V DS)). The aim of the work was also to find the effect of circa 11-year abandonment of a mountain meadow in the locality (825-860 m a.s.l.; 49°30'17? N, 18°32'28? E) on the same parameters in Ah horizon of Gleyic Luvisol. The studied parameters were measured in the course of the vegetation season 2004 (May-September) at 30-day intervals. The higher intensity of thinning caused alternately higher or lower or very similar values of V DS, V BR, V MAX, V DS/ V MAX and ACDS/ACBR in the course of the season. The abandonment of the meadow increased V DS, V BR, V MAX throughout the whole experiment. V DS/ V MAX increased due to the abandonment except for the last sampling in September. Alternately higher or lower or very similar values of ACDS/ACBR in course of the season appeared on abandoned or moderately mown meadows. The lower intensity of thinning or abandonment of the meadow were connected with increasing number of significant ( P < 0.05) correlations between the studied properties.

Vranová, V.; Formánek, P.; Rejšek, K.; Kisza, L.

2009-03-01

103

Buried late holocene paleosols of the nienshants cultural-historical monument in St. Petersburg  

NASA Astrophysics Data System (ADS)

Buried Late Holocene paleosols of the Nienshants historical monument at the junction of the Neva and Okhta rivers (St. Petersburg) have been studied. These soils developed from estuary deposits of the Littorina basin with abundant artifacts of the Neolithic and Early Iron ages (7-2 ka BP). The soil cover of the area consists of the mature dark-humus profile-gleyed soils on elevated elements of the mesotopography (3.0-3.5 a.s.l.) and dark-humus gley soils in the local depressions (2.0-2.6 m a.s.l.). The soils are characterized by the low to moderate content of humus of the fulvate-humate type. The beginning of humus formation in the dark-humus gley soil on the slope facing the Neva River is estimated at about 2600 yrs ago; for the darkhumus profile-gleyed soils of the studied paleocatena, at about 2000 and 1780 yrs ago; and for the darkhumus gley soil, at about 1440 years ago. Judging from the spore-pollen spectra, the development of these soils took place in the Subatlantic period under birch and pine-birch forests with the admixture of spruce and alder trees. The gleyed horizons of the buried soil at the depth of 1.6-1.2 m on the Neva-facing slope date back to the Late Subboreal period (2500-2600 yrs ago), when pine-birch-spruce forests were widespread in the area. The new data contribute to our knowledge of the environmental conditions during the Neolithic and Iron ages.

Rusakov, A. V.; Nikonov, A. A.; Savelieva, L. A.; Pinakhina, D. V.

2013-01-01

104

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

105

Dynamics of the dispersity of model soddy-podzolic soils in a long-term lysimetric experiment  

NASA Astrophysics Data System (ADS)

Changes in the particle-size composition and specific surface area were considered for soddy-podzolic soils in large lysimeters of the Soil Research Station of Moscow State University, which simulated anthropogenically modified soils with different sequences of genetic horizons in a long-term (1961 2002) experiment. Changes were detected in the degree of dispersion of the soil horizons occurring under conditions inadequate for their genesis: a decrease in the clay content by 7% and in the external specific surface area from 28.9 to 7.4% in the illuvial horizon placed on the surface and the accumulation of colloidal mineral fractions in the Ap horizon buried at a depth of 80 100 cm. The degree of change depended on the occurrence depth of the buried horizons and increased with approaching the surface. The changes in the dispersity of the model soddypodzolic soils in the lysimetric experiment were primarily due to the translocation of the fine fractions with vertical water flows. The long-term experiment carried out under completely controlled conditions showed that, at the initial functioning stages of the soils with anthropogenically modified profiles, this process was well detectable and significant for the monitoring studies.

Umarova, A. B.; Ivanova, T. V.

2008-05-01

106

Junction stresses in buried jointed pipelines  

Microsoft Academic Search

An analytical and experimental investigation on the effects of placing flexible joints in the vicinity of buried pipeline junctions evaluated the following important variables: (1) flexibility of rubber-gasketed pipeline joints, (2) bending and axial stiffness of cast-iron pipe barrels and joints, (3) modulus of soil foundation and direct soil shear effects, and (4) variations in the network topology of intersecting

A. C. Singhal; Chian-Lee Meng

1983-01-01

107

Frost heave induced mechanics of buried pipelines  

Microsoft Academic Search

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

A. P. S. Selvadurai; S. B. Shinde

1993-01-01

108

Ionic charge, radius, and potential control root/soil concentration ratios of fifty cationic elements in the organic horizon of a beech (Fagus sylvatica) forest podzol.  

PubMed

The root/organic soil concentration ratio; R/S) of 50 cationic mineral elements was related to their ionic properties, including ionic radius (r), ionic charge (z), and ionic potential (z/r or z2/r). The materials studied were ectomycorrhizal beech (Fagus sylvatica L.) roots and their almost purely organic soil substrate, the O-horizon (mor; raw humus) of a Podzol in South Sweden, developed in a site which has been untouched by forestry or other mechanical disturbance since at least 50 years and located in an area with no local sources of pollution. Elements determined by ICP-AES were aluminium, barium, calcium, iron, potassium, magnesium, manganese, sodium and strontium. Determined by ICP-MS were silver, beryllium, bismuth, cadmium, cerium, cobalt, chromium, caesium, copper, dysprosium, erbium, europium, gallium, gadolinium, hafnium, mercury, holmium, indium, lanthanum, lithium, lutetium, niobium, neodymium, nickel, lead, praseodymium, rubidium, scandium, samarium, tin, terbium, thorium, titanium, thallium, thulium, uranium, vanadium, yttrium, ytterbium, zinc and zirconium. The R/S ratios were most clearly related to the ionic potential of the cationic elements studied, which accounted for approximately 60% of the variability in R/S among elements. The ionic charge of an element was more important than the ionic radius. Elements with high ionic charge had low R/S ratios and vice versa. No clear differences in R/S between essential and non-essential plant nutrients were observed, especially when ions of similar charge were compared. PMID:15262169

Tyler, Germund

2004-08-15

109

Effect of litters on the mobility of zinc, copper, manganese, and iron in the upper horizons of podzolic soils  

Microsoft Academic Search

The concentrations of water-soluble Cu, Zn, Mn, and Fe in the litters of the peaty-podzolic-gleyic and pale-podzolic soils\\u000a of the Central Forest State Biosphere Reserve are inversely proportional to the pH and directly proportional to the total\\u000a titratable acidity of the extracts and the content of the water-soluble organic matter (WSOM). During the interaction of the\\u000a litter solutions with the

E. I. Karavanova; L. A. Belyanina; A. D. Shapiro; A. A. Stepanov

2006-01-01

110

Variability of organic material in surface horizons of the hyper-arid Mars-like soils of the Atacama Desert  

NASA Astrophysics Data System (ADS)

The objective of this work was to investigate the variability of surface organic carbon within the hyper-arid Yungay region of the Atacama Desert. The fraction of Labile Organic Carbon (LOC) in these samples varied from 2 to 73 ?g per gram of soil with a bi-modal distribution with average content of 17 ± 9 ?g LOC and 69 ± 3 ?g LOC for "low" and "high" samples, respectively. Interestingly, there was no relation between organic levels and geomorphologic shapes. While organics are deposited and distributed in these soils via eolic processes, it is suggested that fog is the dynamic mechanism that is responsible for the variability and peaks in organic carbon throughout the area, where a "high" LOC content sample could be indicative of a biological process. It was determined that there was no significant difference between topological feature or geographical position within the hyper-arid samples and LOC. This very curious result has implications for the investigation of run-off gullies on the planet Mars as our work suggests a need for careful consideration of the expectation of increases in concentrations of organic materials associated with following aqueous altered topology.

Fletcher, Lauren E.; Valdivia-Silva, Julio E.; Perez-Montaño, Saul; Condori-Apaza, Renee M.; Conley, Catharine A.; McKay, Christopher P.

2012-01-01

111

Temporal change in molecular weight distribution of hot-water extractable organic nitrogen from cattle manure compost buried in soil using high-performance size exclusion chromatography with chemiluminescent nitrogen detection  

NASA Astrophysics Data System (ADS)

The application of compost can improve the fertility of the agricultural soils. The compost organic nitrogen is absorbed by plants after degradation and mineralization. To investigate the degradation process of compost organic nitrogen in soil, we conducted soil burial test of compost and observed the molecular weight distribution of hot-water extractable organic nitrogen from the compost. The cattle manure compost (1g) was mixed with soil (25g), put into glass fiber-filter paper bag and buried in 15 cm under surface of the ground for 6 months. The soils used were Andosol, Gray Lowland soil, and Yellow soil without organic matter application for 25 years in Tsukuba, Japan. Organic matter was extracted from the buried sample with 80° C of water for 16 hours. The molecular weight distribution of the hot-water extractable organic matter (HWEOM) was measured by high-performance size exclusion chromatography and chemiluminescent nitrogen detection (HPSEC/CLND). In this system, N-containing compound eluted from a SEC column was introduced into a furnace at 1050° C, and N in the compound was oxidized to nitric oxide and then detected using a chemiluminescent reaction with ozone. The N chromatogram showed that N in the HWEOM from the soil with compost had various molecular weights ranging from 0.1 to 100 kDa. A void peak (>100 kDa), a broad peak around 30 kDa, and several sharp peaks less than 30 kDa were observed in the chromatogram. The broad peak (~ 30kDa) was likely to be derived from the compost, because it was not observed in the chromatogram of HWEOM from soil alone. The N intensities of all peaks decreased with burial time, especially, the broad peak (~30 kDa) intensity rapidly decreased by 10 - 50 % in only first 2 months. The decreasing rates of the broad peak were higher than that of the sharp peaks, indicating that the organic nitrogen with a larger molecular weight decomposed faster. The broad peak (~ 30 kDa) had visible (420nm) absorption and less fulvic acid like florescence (Ex340nm, Em440 nm). The several sharp peaks had small visible absorption and intense florescence. Further studies are needed to assign the chemical forms for each peak.

Moriizumi, M.; Mutsunaga, T.

2012-04-01

112

Soils and cultural layers in Velikii Novgorod  

NASA Astrophysics Data System (ADS)

Urban pedosediments (cultural layers) dating back to the 10th-11th centuries AD and soddypodzolic soils buried under them were studied in two archaeological excavations in Velikii Novgorod. Stages of their development were described. It was found that the buried soddy-podzolic soils at the latest stages of their development were cultivated or were formed under meadow vegetation. Weakly developed garden soils were described in the thickness of urban pedosediments. The lowermost organic cultural layers in Velikii Novgorod were waterlogged and represented peatlike mass with well-preserved wood remains. The oxidation of organic matter, gleyzation, and vivianite formation were described in them. The upper mineral layers were enriched in brick debris and building lime. The processes of organic matter mineralization, alkalization, calcification, zoogenic turbation, and biogenic structuring were clearly manifested in this part. Soil solutions infiltrated from the cultural layers caused some alkalization of the buried soddy-podzolic soil. Diagenetic carbonates and vivianite appeared in some loci within the eluvial and the upper part of the illuvial horizon of this soil. The entire cultural layer was subjected to contamination with heavy metals.

Dolgikh, A. V.; Aleksandrovskii, A. L.

2010-05-01

113

Age and origin of Terra Rossa soils in the Coonawarra area of South Australia  

NASA Astrophysics Data System (ADS)

The famous Terra Rossa soil in the Coonawarra area, South Australia, is dominated by locally derived aeolian detritus, which probably accumulated over the last 120-130 ka. Four soil profiles and associated limestone and lunette deposits were investigated using the following methods: mass balance geochemistry of bulk soil samples (major and trace elements), quantitative X-ray diffraction (XRD) mineralogy, strontium isotopes (87/86), as well as grain-size analysis and cation exchange capacity. These data show that the Terra Rossa soil from the Coonawarra has a thick, clayey B-horizon which is geochemically homogeneous and dominated by smectite and kaolinite. Mass-balance calculations show unrealistic weathering scenarios when plotted using silicate residuum from the underlying limestone as parent. Realistic weathering scenarios are produced with fine-grained silicate material from local lunette deposits as parent. Strontium isotopes of silicate residuum from Gambier Limestone (0.78) contrast strongly with the clayey B-horizon (0.726). Strontium isotope ratios of silicate material from a local lunette (0.725) are similar to the B-horizon soil values. Strontium isotope ratios from regional geological units indicate that the strontium signature in the lunette and soil B-horizon is dominated by weathering products from the Palaeozoic Kanmantoo shales, extensively exposed upwind to the west on Kangaroo Island and the Fleurieu Peninsula. Optical (optically stimulated luminescence, OSL) dating of 61 individual quartz grains (single aliquot) from three samples in the Coonawarra soil profile (one from the A-horizon and two from the B-horizon) shows that most of the quartz sand grains have been buried for only a few thousand years. Many of the grains, however, have been buried for tens of thousands of years with three grains having exposure ages of between 105 and 109 ka. The large population of young exposure dates represents quartz sands recently exposed in the A-horizon and which have been translocated down to the B-horizon. The older exposure dates are interpreted as representing grains that were buried during or soon after the accumulation of wind-blown silt and clay. Our current model concerning the timing and conditions of aeolian deposition of the Coonawarra soil is that much of it accumulated during the relatively wet, last interglacial period around 120-130 ka. During that time span, it is thought that the playa-lunette systems in the low-lying areas to the west were particularly active and generated a significant local dust flux.

Mee, Aija C.; Bestland, Erick A.; Spooner, Nigel A.

2004-03-01

114

Analysis of Longitudinal Behaviour of Buried Pipes.  

National Technical Information Service (NTIS)

The longitudinal behavior of a buried pipeline is analyzed in relation to two cases: a pipeline beneath a load area, and a pipeline situated in a swelling or shrinking soil. The effects of various factors such as the relative flexibility of the pipe, the ...

H. G. Poulos

1973-01-01

115

Security of Shallow-buried Oil-pipeline in the freeze-thaw processes of frost-soil bed in cold-region  

Microsoft Academic Search

According to the particularity of cold-region for its geographical and climatic environments where the oil-pipeline is laid, the author adopts suitably physical parameters and mathematical-physical models involved in the oil-pipeline system, to simulate the boundary conditions of ground surfaces and the region where oil-pipeline is located, constructing finite element (FE) analysis models of the coupled freezing process of shallow buried

Nansheng Li; Yu Wang

2011-01-01

116

Longitudinal Permanent Ground Deformation Effects on Buried Continuous Pipelines.  

National Technical Information Service (NTIS)

The response of buried steel pipelines to permanent ground displacement is investigated. Specifically, pipeline response to four different idealized patterns of longitudinal permanent ground deformation, wherein the non-recoverable soil movement is parall...

M. J. O'Rourke C. Nordberg

1992-01-01

117

Prestressing buried pipelines by heating with air  

SciTech Connect

Buried pipelines operating at elevated temperatures experience high longitudinal compressive stresses because the surrounding soil prevents thermal expansion. At high operating temperatures, buried pipelines can push through the soil at bends and buckle catastrophically. In soft soils they can lose lateral stability, and they can develop plastic failures. Thermally induced problems can be prevented with varying degrees of success by using thicker wall pipe, higher strength prevented with varying degrees of success by using thicker wall pipe, higher strength steel, longer radius bends, deeper burial, better backfill compaction, and/or prestressing during construction. Prestressing is most appropriate for pipelines operating at temperatures more than 80 C above ambient. One technique for prestressing a buried pipeline, that has been found to be both easy and economical for a liquid sulfur pipeline in Alberta, is to heat it with hot air and bury it while it is still hot. Pipe diameter and prestressing temperature both have a significant impact on the kind of heating equipment that is required.

King, G. (SNC--Lavalin, Calgary, Alberta (Canada))

1993-11-01

118

Infrared Horizon Sensors.  

National Technical Information Service (NTIS)

More than 25 different infrared horizon-sensing instruments are described in this report. Particular attention is paid to their optical and electronic characteristics. Atmospheric properties which pertain to horizon detection are reviewed, and error analy...

J. Duncan W. Wolfe G. Oppel J. Burn

1965-01-01

119

Spherically symmetric quantum horizons  

Microsoft Academic Search

Isolated horizon conditions specialized to spherical symmetry can be imposed directly at the quantum level. This answers several questions concerning horizon degrees of freedom, which are seen to be related to orientation, and its fluctuations at the kinematical as well as dynamical level. In particular, in the absence of scalar or fermionic matter the horizon area is an approximate quantum

Martin Bojowald; Rafal Swiderski

2005-01-01

120

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

121

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

122

Distance to Horizon  

NSDL National Science Digital Library

This applet allows students to explore the relationship between their height above the Earth and the distance they can see to the horizon. Learners can change the height above sea level by dragging the point labeled Height. Based on the height, the distance to the horizon is automatically calculated. Students are challenged to find a relationship between the height of a person above sea level and the distance he/she can see to the horizon.

Illuminations, Nctm

2000-01-01

123

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

124

Sensor feature fusion for detecting buried objects  

SciTech Connect

Given multiple registered images of the earth`s surface from dual-band sensors, our system fuses information from the sensors to reduce the effects of clutter and improve the ability to detect buried or surface target sites. The sensor suite currently includes two sensors (5 micron and 10 micron wavelengths) and one ground penetrating radar (GPR) of the wide-band pulsed synthetic aperture type. We use a supervised teaming pattern recognition approach to detect metal and plastic land mines buried in soil. The overall process consists of four main parts: Preprocessing, feature extraction, feature selection, and classification. These parts are used in a two step process to classify a subimage. Thee first step, referred to as feature selection, determines the features of sub-images which result in the greatest separability among the classes. The second step, image labeling, uses the selected features and the decisions from a pattern classifier to label the regions in the image which are likely to correspond to buried mines. We extract features from the images, and use feature selection algorithms to select only the most important features according to their contribution to correct detections. This allows us to save computational complexity and determine which of the sensors add value to the detection system. The most important features from the various sensors are fused using supervised teaming pattern classifiers (including neural networks). We present results of experiments to detect buried land mines from real data, and evaluate the usefulness of fusing feature information from multiple sensor types, including dual-band infrared and ground penetrating radar. The novelty of the work lies mostly in the combination of the algorithms and their application to the very important and currently unsolved operational problem of detecting buried land mines from an airborne standoff platform.

Clark, G.A.; Sengupta, S.K.; Sherwood, R.J.; Hernandez, J.E.; Buhl, M.R.; Schaich, P.C.; Kane, R.J.; Barth, M.J.; DelGrande, N.K.

1993-04-01

125

Saturated hydraulic conductivity of soils in the Southern Piedmont of Georgia, USA: Field evaluation and relation to horizon and landscape properties  

Microsoft Academic Search

Saturated hydraulic conductivity (Ks) is one of the soil properties used most often to predict soil behavior and suitability for a variety of uses. Because of the difficulty in Ks measurement and its variability with depth and across the landscape, Ks is commonly predicted from other more easily evaluated properties including texture, clay mineralogy, bulk density, pedogenic structure and cementation.

L. T. West; M. A. Abreu; J. P. Bishop

2008-01-01

126

Laboratory Load Tests on Buried Flexible Pipe. Progress Report No. 5. Fiberglass Reinforced Plastic (FRP), Polyethylene (PE), and Polyvinyl Chloride (PVC) Pipe.  

National Technical Information Service (NTIS)

Laboratory tests were conducted to investigate the behavior of buried flexible pipes. Kinds of pipe tested were fiberglass reinforced plastic (FRP), polyvinyl chloride (PVC), and polyethylene (PE). The pipes were buried in a large, steel, soil container i...

A. K. Howard

1973-01-01

127

Spherically symmetric quantum horizons  

SciTech Connect

Isolated horizon conditions specialized to spherical symmetry can be imposed directly at the quantum level. This answers several questions concerning horizon degrees of freedom, which are seen to be related to orientation, and its fluctuations at the kinematical as well as dynamical level. In particular, in the absence of scalar or fermionic matter the horizon area is an approximate quantum observable. Including different kinds of matter fields allows to probe several aspects of the Hamiltonian constraint of quantum geometry that are important in inhomogeneous situations.

Bojowald, Martin; Swiderski, Rafal [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, D-14476 Potsdam (Germany); Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, D-14476 Potsdam (Germany)

2005-04-15

128

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

129

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

130

Mineralogical analysis of clays in hardsetting soil horizons, by X-ray fluorescence and X-ray diffraction using Rietveld method  

NASA Astrophysics Data System (ADS)

Diffraction and spectroscopic techniques have been shown to be suitable for obtaining physical and mineralogical properties in polycrystalline soil samples, and also in their precursor compounds. For instance, the X-ray fluorescence (XRF) spectroscopy allows obtaining the elemental composition of an investigated sample, while the X-ray diffraction (XRD) technique permits obtaining qualitative and quantitative composition of the soil minerals through the Rietveld method (RM). In this study Yellow Latosol (Oxisol), Yellow Argisol (Ultisol) and Gray Argisol (Ultisol) soil samples, classified as "hardsetting soils", extracted from areas located at Northeast and Southeast of Brazilian coast were investigated. The soils and their fractions were analyzed in an EDX-700 and an XRD-6000 (Cu K? radiation). XRF results indicate high percentages of Si and Al, and small percentage of Fe and Ti in the investigated samples. The DRX data and RM indicate that there was a predominance of kaolinite and halloysite minerals (kaolin group minerals) in the clay fractions, which are presumably responsible for the formation of kaolinitic plasma in these soils. Also, the obtained results showed that the XRF, XRD techniques and RM were very helpful for investigating the mineralogical composition of a hardsetting soil.

Prandel, L. V.; Saab, S. C.; Brinatti, A. M.; Giarola, N. F. B.; Leite, W. C.; Cassaro, F. A. M.

2014-02-01

131

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

132

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

133

Liquefaction hazards and their effects on buried pipelines. Technical report  

SciTech Connect

This research involves the evaluation of liquefaction-induced ground movements and their effects on buried pipelines. The work is divided into three components: review of liquefaction phenomena and associated ground displacements; characterization of liquefaction-induced lateral spreading through observations and measurements of lateral spread deformations during past earthquakes; parametric study to evaluate buried pipeline response as a function of soil properties and geometric characteristics of lateral spreads. Case studies of four earthquakes were reviewed in which occurrences of lateral spreading have been reported. The results of the case studies indicate a close relationship between geologic and morphologic conditions and the occurrence and pattern of lateral spreading. The parametric study demonstrates the strong influence of geometric characteristics of the soil displacements on buried pipeline response. The delineation of zones of potentially large ground movement and the estimation of displacement patterns can be useful in the design of future pipeline systems, and the modification of existing ones, to limit earthquake damage.

O'Rourke, T.D.; Lane, P.A.

1989-02-01

134

Seismic risk analysis of buried pipelines--  

SciTech Connect

A procedure is described for the seismic risk analysis of buried pipelines that provides an estimation of the annual probability of occurrence of different damage states, called damage indexes, in a component segment of the general network system of buried pipelines. The damage indexes are obtained by combining a damage probability matrix (DPM) with the annual probability of occurrence of different levels of earthquake intensity. The DPM is obtained by finding the probabilities of different damage states, defined with respect to some criterion, due to different levels of earthquake intensity. The expected peak values of stresses at the critical sections of the buried pipeline for each level of earthquake intensity are determined using a random vibration analysis with discrete lumped mass model. The pipe responses are calculated by spectral approach, in which the PSDFs of ground accelerations are defined as functions of earthquake intensity in Modified Mercalli Intensity (MMI) scale. The analysis considers two component earthquake having an angle of incidence with respect to global axes of reference. A numerical study conducted with the help of proposed procedure shows that the pipe end conditions, the types of pipe intersections, the pipe radius, the angle of incidence of earthquake wave, the angle of intersection of pipes, and the type of soil have considerable influences on the damage indexes.

Mashaly, E.-S.A. (Dept. of Civ. Engrg., Alexandria Univ., Alexandria (EG)); Datta, T.K. (Dept. of Civ. Engrg., Indian Inst. of Tech., Delhi, Hauz Khas 110016 New Delhi (IN))

1989-05-01

135

Mt. Blanco revisited: soil-geomorphic implications for the ages of the upper Cenozoic Blanco and Blackwater Draw Formations  

SciTech Connect

Mt. Blanco, on the eastern edge of the Southern High Plains of Texas, contains stratigraphic features significant in interpreting the late Cenozoic history of the region and the vertebrate paleontology of the Great Plains; however, the stratigraphic relations are confused in the literature or are unreported. Mt. Blanco is the type locality for the Blanco Formation and the Blanco Local Fauna, which occurs throughout North America and is the type fauna for the Blancan Land Mammal Age in North America. Here also occur exposures of the Blackwater Draw Formation, an extensive (120,000 km/sup 2/) eolian sheet that is the surficial cover of the region and contains the 1.4 Ma Guaje Ash and several buried soils. A reexamination of the section shows that (1) the Blackwater Draw Formation, an eolian deposit, contains three well-expressed buried soils (5 YR hues, argillic horizons greater than or equal to 1 m thick, Stages III and IV calcic horizons) and the similar regional surface soil (Paleustalf); (2) the Guaje Ash is within the lower Blackwater Draw Formation but is separated from the Blanco Formation, a lacustrine unit, by about 1 m of sediment, including the lowest buried soil; and (3) the lowest buried soil shows a Stage IV calcrete formed at the top of the Blanco Formation and the base of the Blackwater Draw Formation and probably took about 200 ka to form. These new data suggested that deposition of the type Blanco sediments may have ended by about 1.6 Ma or earlier. Since that time, the Blackwater Draw Formation has accumulated episodically; periods of nondeposition are characterized by landscape stability and pedogenesis.

Holliday, V.T.

1988-06-01

136

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

137

Chemical composition of solutions in macro- and micropores in the upper horizons of soils in the Central Forest State Biosphere Reserve  

NASA Astrophysics Data System (ADS)

The average concentrations of Al, Si, Fe, Mn, Pb, Ni, V, Ba, and other elements were 1.5-3.5 times lower (in some cases, up to 60 times) in the macropores than in the micropores. The regularities found agreed with the rules of selective absorption of ions and their capability for the formation of complexes with the components of the soil solids. The behavior of Fe and Mn can be explained by the differences in the redox conditions in the pores of different sizes. The degree of the relationships between the soil solution and the solid phase of the matrix in the macro- and micropores differed by several orders of magnitude (within a pF range up to 4). This fact determined the different mobilization of the elements in the solutions of the macro- and micropores. The reserves of the elements were proportional not only to their concentrations but also to the amount of solution in the appropriate pores.

Karavanova, E. I.; Timofeeva, E. A.

2009-12-01

138

Torsion and Particle Horizons  

NASA Astrophysics Data System (ADS)

Inthe present work we show that the existence of non-vanishing torsion field may solve, at least, one of the problems FRW-cosmology, the particle horizons problem. The field equations of general relativity (GR) are written in a space having non-vanishing torsion, the absolute parallelism (AP) space. An AP-Structure, satisfying the cosmological principle, is used to construct a world model. Energy density and pressure, purely induced by torsion, are defined from the building blocks of the AP-geometry using GR. When these quantities are used in the FRW-dynamical equations, we get a world model free from particle horizons.

Wanas, M. I.; Hassan, H. A.

2014-04-01

139

Variable horizon predictor  

Microsoft Academic Search

Variable horizon predictor (VHP) background and design are discussed. VHP is designed to work in feedback control loops with various control algorithms, especially with processes featuring significant time delays. Disturbances are included into prediction, so there is no need to incorporate feedforward into feedback algorithms. PID and fuzzy logic controllers were tested with VHP and compared with simple predictive algorithm,

W. K. Wojsnis

1994-01-01

140

Un horizon conjoncturel dégagé  

Microsoft Academic Search

[eng] A cleared short term horizon Division modèle trimestriel Mosaïque Most Western economies experience sustained growth rates, but business conditions still widely differ. Optimism on the real economy gees with a large financial turmoil : exchange rates markets are upset by trade imbalances ; long term interest rates have sharply risen everywhere, fearing, first, the U.S. inflation, then acknowledging the

Françoise Milewski; Hervé Péléraux; Olivier Passet; Christine Rifflart; Bruno Coquet

1994-01-01

141

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

142

Performance of Buried Flexible Conduits.  

National Technical Information Service (NTIS)

An extensive review was made of the performance of buried flexible culverts, with special emphasis on buckling failure modes. All known theories on elastic buckling of rings and cylinders with radial support subjected to external radial pressures were ana...

G. A. Leonards R. A. Stetkar

1978-01-01

143

Numerical Modeling for Impact-resistant Pipes Buried at Shallow Depth  

NASA Astrophysics Data System (ADS)

The plastic pipes buried at shallow depth are popular for underground telecommunication lines. To assess their impact-worthiness under loads from heavy traffics, the study establishes a numerical model to correlate with field data. Field impact tests were carried out where a 50-kg mass free-falling at 2.2 m height was dropped onto the soil backfill directly above a buried pipe. A contact-impact model incorporating finite elements of disjoined material regions is developed to simulate the phenomena of mass-soil-pipe interaction and soil dent. Plastic soil deformations are accounted for. Also implemented is a new erosion scheme for dealing with numerical instability caused by crumpled elements during heavy impact. Reasonable agreements can be observed between the analyzed and measured soil dent. This model is versatile in making design evaluations for buried pipes to withstand impact loads. It has potential applications to cemented soil fills and blast loads.

Wang, Ching-Jong; Hsu, Jung-Fu

2010-05-01

144

System design for buried high-pressure/high-temperature pipelines  

SciTech Connect

A pipeline expands or contracts when temperatures or pressures vary from the conditions at the time the pipeline was installed. Buried pipelines operating at high temperatures and pressures experience extreme compressive loads. Because radial expansion is limited by soil restraint, buried pipelines expand axially. High axial forces combined with imperfections in the seabed may overstress the pipeline or result in upheaval buckling. Methods to control expansion and upheaval buckling were investigated for the design of a buried high-pressure/high temperature (HP/HT) sour-gas flowline in Mobile Bay, Alabama. After investigating conventional and unconventional methods, the decision was made to use expansion loops over the length of the pipeline to protect the risers and reduce axial force in the middle of the pipeline. Expansion loops and doglegs act as springs to absorb pipeline expansion. Methods were investigated to prevent soil from accumulating around the buried expansion loops. Commercially available concrete dog houses used to protect pipelines and expansion loops from dropped objects were not suitable for burial, and fabrication of custom concrete housing was expensive. Fabrication of a steel enclosure was the solution chosen. A mathematical model based on internal-design guidelines and ultimate soil friction was used to determine placement and size of the expansion loops.

NONE

1998-06-01

145

Dissolution of microcline and labradorite in a forest O horizon extract: the effect of naturally occurring organic acids  

Microsoft Academic Search

Water extracts of O horizon soil (mor) containing realistic soil solution levels of organic acids and cations were used to dissolve microcline, labradorite and a natural soil (C-horizon) in fluidized bed reactors. Experiments were also conducted with inorganic solutions containing the same concentration of cations (inorganic eluent) as in the mor extract until reaction rates were stabilized. All experiments were

P. A. W van Hees; C.-M Mörth

2002-01-01

146

Refraction near the horizon  

NASA Technical Reports Server (NTRS)

Variations in astronomical refraction near the horizon are examined. Sunset timings, a sextant mounted on a tripod, and a temperature profile are utilized to derive the variations in refraction data, collected from 7 locations. It is determined that the refraction ranges from 0.234 to 1.678 deg with an rms deviation of 0.16, and it is observed that the variation is larger than previously supposed. Some applications for the variation of refraction value are discussed.

Schaefer, Bradley E.; Liller, William

1990-01-01

147

Cosmological apparent and trapping horizons  

NASA Astrophysics Data System (ADS)

The dynamics of particle, event, and apparent horizons in Friedmann-Lemaitre-Robertson-Walker space are discussed. The apparent horizon is trapping when the Ricci curvature is positive. This simple criterion coincides with the condition for the Kodama-Hayward apparent horizon temperature to be positive and also discriminates between the timelike and spacelike character of the apparent horizon. We discuss also the entropy of apparent cosmological horizons in extended theories of gravity and we use the generalized 2nd law to discard an exact solution of Brans-Dicke gravity as unphysical.

Faraoni, Valerio

2011-07-01

148

Organic matter accumulating in Aeh and Bh horizons of a Podzol — chemical characterization in primary organo-mineral associations  

Microsoft Academic Search

The chemical structure of soil organic matter from the eluvial (Aeh) and (illuvial) Bh horizon of a Podzol was studied in primary organo-mineral associations by 13C CPMAS NMR spectroscopy and acid hydrolysis. In Podzols, organic matter is leached from the forest floor and Aeh horizons into the Bh horizon, where it is intimately associated with the mineral phase. In the

Michael W. I. Schmidt; Heike Knicker; Ingrid Kögel-Knabner

2000-01-01

149

Sensor system for buried waste containment sites  

SciTech Connect

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, A.M.; Gardner, B.M.; Kostelnik, K.M.; Partin, J.K.; Lancaster, G.D.; Pfeifer, M.C.

2000-01-25

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

Modeling the electromagnetic detection of buried cylindrical conductors  

SciTech Connect

The remote detection of buried structures and tunnels is important to the mining, construction, and defense industries. It is often desirable to identify underground power lines, pipe lines, and utility tunnels which have unique electromagnetic cross sections. A computational model for the electromagnetic detection of buried conducting cylinders is described in this paper. The source of electromagnetic radiation is either current injection into the soil or a surface based magnetic dipole with possible extensions to airborne platforms. Frequency ranges from a few kHz to 100 kHz are considered. The target conductor is a cylinder buried directly in the soil or placed inside an insulating pipe. The receiver is a magnetic gradiometer held 1m above the ground, separate from the transmitter. Data are taken widely over the terrain under investigation. Cases where the target conductor is grounded at both ends, one end, or not at all are modeled. The scattered field and field gradient are computed at or above ground level and compared in magnitude and phase with the transmitted signal. Calculated results are compared with experimental tests done to detect a buried wire at Sandia National Laboratory and a tunnel at Yucca Mountain. Essential factors affecting detection performance are frequency optimization, dynamic range of reception and proper data processing.

Moses, R.W.; Kelly, R.E.; Mack, J.M.

1996-05-01

152

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

153

Degradation of carbohydrates and lignins in buried woods  

NASA Astrophysics Data System (ADS)

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.

Hedges, John I.; Cowie, Gregory L.; Ertel, John R.; James Barbour, R.; Hatcher, Patrick G.

1985-03-01

154

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

155

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

156

Entomofauna of buried bodies in northern France.  

PubMed

Autopsies of exhumed cadavers can reveal important evidence for clarification of medical insurance and social issues. This study concerns insects sampled on 22 exhumed cadavers in the Lille area. For each corpse, the species and the stages of development were noted, as well as the time elapsed after burial, the location of the cemetery, the stage of decay and possible preservation treatment. A total of eight Diptera and two Coleoptera species were sampled on the corpses. The relationships between entomofauna and conditions of burial are discussed. Three species were regularly found because of their preference for underground environments or closed environments: Conicera tibialis, typically associated with buried bodies, Leptocera caenosa which is known to be associated with human faeces, water closets, caves and cracked soil pipes, and Ophyra capensis, sometimes found on human bodies kept indoors for several months, where blowflies have not had access. Triphleba hyalinata, which is associated with human bodies in wooden coffins, was found only twice. PMID:15114486

Bourel, Benoit; Tournel, Gilles; Hédouin, Valéry; Gosset, Didier

2004-08-01

157

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.

Laboratory, Nasa J.; Nasa

158

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

159

Fungal communities in the soils of early medieval settlements in the taiga zone  

NASA Astrophysics Data System (ADS)

The difference between the mycobiota in anthropogenically transformed soils of the settlements of the 9th 14th centuries and in the background zonal Podzols and umbric Albeluvisols of the middle and southern taiga subzones in the European part of Russia is demonstrated. The mycological specificity of anthropogenically transformed soils with a cultural layer (CL) in comparison with the background soils is similar for all the studied objects. Its characteristic features are as follows: (1) the redistribution of the fungal biomass in the profile of anthropogenically transformed soils in comparison with zonal soils, (2) the lower amount of fungal mycelium in the CL with the accumulation of fungal spores in this layer, (3) the increased species diversity of fungal communities in the CL manifested by the greater morphological diversity of the spore pool and by the greater diversity of the fungi grown on nutrient media, (4) the change in the composition and species structure of fungal communities in the CL, (5) the replacement of dominant species typical of the zonal soils by eurytopic species, and (6) the significant difference between the fungal communities in the CL and in the above-and lower-lying horizons and buried soils of the same age. Most of the mycological properties of the soils of ancient settlements are also typical of modern urban soils. Thus, the mycological properties of soils can be considered informative carriers of soil memory about ancient anthropogenic impacts.

Marfenina, O. E.; Ivanova, A. E.; Kislova, E. E.; Zazovskaya, E. P.; Chernov, I. Yu.

2008-07-01

160

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

161

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

162

Locating a Buried Magnetic Dipole  

Microsoft Academic Search

Five measurements of the magnetic-field vector near the surface of the earth are shown to be sufficient to determine the orientation and location of a buried magnetic dipole. A discussion of field experiments which demonstrate the location concept is included.

Thurlow W. H. Caffey; Louis Romero

1982-01-01

163

Predicting Performance of Buried Conduits.  

National Technical Information Service (NTIS)

The capabilities of finite element computer codes FINLIN, CANDE, SSTIP and NLSSIP were evaluated. CANDE was judged to be the best over-all code for predicting performance of buried conduits. A number of improvements to this code were made. Example solutio...

C. H. Juang G. A. Leonards T. H. Wu

1982-01-01

164

7 CFR 1755.505 - Buried services.  

Code of Federal Regulations, 2011 CFR

...filled terminal blocks in accordance with the applicable paragraphs of § 1755.200, RUS standard for splicing copper and fiber optic cables. (d) Buried service wire or cable shall be identified at buried plant housings in accordance with construction...

2014-01-01

165

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

166

Numerical Modeling for Impact-resistant Pipes Buried at Shallow Depth  

Microsoft Academic Search

The plastic pipes buried at shallow depth are popular for underground telecommunication lines. To assess their impact-worthiness under loads from heavy traffics, the study establishes a numerical model to correlate with field data. Field impact tests were carried out where a 50-kg mass free-falling at 2.2 m height was dropped onto the soil backfill directly above a buried pipe. A

Ching-Jong Wang; Jung-Fu Hsu

2010-01-01

167

Load-displacement characteristics of a buried pipe affected by permanent earthquake ground movements  

Microsoft Academic Search

Earthquakes cause permanent ground movements that develop soil forces against buried pipelines, thereby causing substantial axial and bending strains. In this study, the force-displacement behavior of buried pipe, subjected to movements consistent with earthquake-induced ground failure, is reported for diameters and depths typical of gas and water utility practice. Using a field-scale test facility, 102-mm-diameter and 324-mm-diameter pipes were displaced

C. H. Trautmann; T. D. ORourke

1983-01-01

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

Cauchy horizons in Gowdy spacetimes  

NASA Astrophysics Data System (ADS)

We analyse exhaustively the structure of non-degenerate Cauchy horizons in Gowdy spacetimes, and we establish existence of a large class of non-polarized Gowdy spacetimes with such horizons. Our results here, together with the deep new results of Ringström, establish strong cosmic censorship in (toroidal) Gowdy spacetimes.

Chrusciel, Piotr T.; Lake, Kayll

2004-02-01

170

The Horizon Report. 2007 Edition  

ERIC Educational Resources Information Center

This fourth 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 ongoing…

New Media Consortium, 2007

2007-01-01

171

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

172

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

173

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

174

The Dirt on Soil  

NSDL National Science Digital Library

This page is from Discoveryschool.com. It has three sections. The first one, Down and Dirty, describes the various soil horizons. The second section, Field Guide, identifies some soil organisms and the third section, Soil Safari, is an animated tour of the soil beneath your feet.

2008-01-01

175

Functional substrate biodiversity of cultivated and uncultivated A horizons of vertisols in NW New South Wales  

Microsoft Academic Search

Concern over the effects of anthropogenic activities on soil ‘quality’ has fuelled efforts to identify and measure those factors that affect soil quality. Soil microbial diversity is one of many possible factors. Our objective was to compare the functional diversity of microbial communities in the A horizons of cultivated and uncultivated vertisols in NW New South Wales. Samples from two

F. Yan; A. B. McBratney; L. Copeland

2000-01-01

176

Dualities near the horizon  

NASA Astrophysics Data System (ADS)

In 4-dimensional supergravity theories, covariant under symplectic electricmagnetic duality rotations, a significant role is played by the symplectic matrix ( ?), related to the coupling of scalars ? to vector field-strengths. In particular, this matrix enters the twisted self-duality condition for 2-form field strengths in the symplectic formulation of generalized Maxwell equations in the presence of scalar fields. In this investigation, we compute several properties of this matrix in relation to the attractor mechanism of extremal (asymptotically flat) black holes. At the attractor points with no flat directions (as in the = 2 BPS case), this matrix enjoys a universal form in terms of the dyonic charge vector and the invariants of the corresponding symplectic representation of the duality group G, whenever the scalar manifold is a symmetric space with G simple and non-degenerate of type E7. At attractors with flat directions, still depends on flat directions, but not , defining the so-called Freudenthal dual of itself. This allows for a universal expression of the symplectic vector field strengths in terms of , in the near-horizon Bertotti-Robinson black hole geometry.

Ferrara, Sergio; Marrani, Alessio; Orazi, Emanuele; Trigiante, Mario

2013-11-01

177

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.

Maiti, Rituparna; Alloza, Jose Luis

2014-01-01

178

In situ grouting of buried transuranic waste with polyacrylamide  

SciTech Connect

This project is a demonstration and evaluation of the in situ hydrologic stabilization of buried transuranic waste at a humid site via grout injection. Two small trenches, containing buried transuranic waste, were filled with 34.000 L of polyacrylamide grout. Initial field results have indicated that voids within the trenches were totally filled by the grout and that the intratrench hydraulic conductivity was reduced to below field-measurable values. No evidence of grout constituents were observed in twelve perimeter groundwater monitoring wells indicating that grout was contained completely within the two trenches. Polyacrylamide grout was selected for field demonstration over the polyacrylate grout due to its superior performance in laboratory degradation studies. Also supporting the selection of polyacrylamide was the difficulty in controlling the set time of the acrylate polymerization. Based on preliminary degradation monitoring, the polyacrylamide was estimated to have a microbiological half-life of 362 years in the test soil. 15 refs., 9 figs., 12 tabs.

Spalding, B.P.; Lee, S.Y.; Farmer, C.D.; Hyder, L.K.; Supaokit, P.

1987-01-01

179

Centrifuge modeling of PGD response of buried pipe  

NASA Astrophysics Data System (ADS)

A new centrifuge based method for determining the response of continuous buried pipe to PGD is presented. The physical characteristics of the RPI's 100 g-ton geotechnical centrifuge and the current lifeline experiment split-box are described: The split-box contains the model pipeline and surrounding soil and is manufactured such that half can be offset, in flight, simulating PGD. In addition, governing similitude relations which allow one to determine the physical characteristics, (diameter, wall thickness and material modulus of elasticity) of the model pipeline are presented. Finally, recorded strains induced in two buried pipes with prototype diameters of 0.63 m and 0.95 m (24 and 36 inch) subject to 0.6 and 2.0 meters (2 and 6 feet) of full scale fault offsets and presented and compared to corresponding FE results.

O'Rourke, Michael; Gadicherla, Vikram; Abdoun, Tarek

2005-06-01

180

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

181

Buried-Dielectric-Microstrip Network  

NASA Technical Reports Server (NTRS)

Problem of obtaining very-broadband frequency response resolved with buried-dielectric-microstrip matching network incorporated into infraredwaveguide structure. Waveguide modulator structure represents state-of-the-art of integrated optical devices: Has three-dimensional shape to accommodate three quarter-wavelength-transformers for microwave impendance matching at both input and output terminals. Microwave network, along with microstrip line designed with aid of computer, integrated with optical waveguide and used to tune line-selectable CO2 laser that provides total tuning range of 30 GHz in two sidebands.

Cheo, P. K.; Wagner, R. A.; Gilden, M.

1986-01-01

182

A study of the effect of buried biomass on ground-penetrating radar performance  

NASA Astrophysics Data System (ADS)

It is widely acknowledged that tree roots and other forms of buried biomass have an adverse effect on the performance of ground-penetrating radars (GPRs). In this work we present experimental and theoretical work that quantifies that effect. Test sites containing extensive root infiltration at Eglin Air Force Base, FL were probed with a GPR. After completing the measurements, the sites were excavated, and the root structure and soil were thoroughly characterized. Supplemental GPR measurements of simple cylindrical objects in a laboratory setting were performed to investigate basic scattering behavior of buried roots. A numerical simulator based on the Discrete Dipole Approximation (DDA), an integral-equation-based method, was developed, validated and subsequently used to compute scattering from root structures modeled by an ensemble of buried cylinders. A comparison of the measurements and numerical calculations is presented that quantifies the potential for false alarms and increased clutter due to buried roots.

Niltawach, Nakasit; Chen, Chi-Chih; Johnson, Joel T.; Baertlein, Brian A.

2003-08-01

183

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

184

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

185

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

NASA Astrophysics Data System (ADS)

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.

Carrasco, Jonathan J.; Neff, Jason C.; Harden, Jennifer W.

2006-06-01

186

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

187

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

188

Stress State of Bent Buried Pipelines  

Microsoft Academic Search

The authors consider edge effects in buried pipelines that occur in the region of joining of a straight buried pipe and a bent insert (factory bend, elbow, or an elastically bent segment). The action of those effects results in the appearance of additional bending moments, which are proportional to the difference between the axial force in an infinite straight pipeline

I. V. Orynyak; S. A. Radchenko

2003-01-01

189

Mining metrics for buried treasure  

NASA Astrophysics Data System (ADS)

The same but different: That might describe two metrics. On the surface CLASSI may show two metrics are locally equivalent, but buried beneath may be a wealth of further structure. This was beautifully described in a paper by Malcolm MacCallum in 1998. Here I will illustrate the effect with two flat metrics — one describing ordinary Minkowski spacetime and the other describing a threeparameter family of Gal'tsov-Letelier-Tod spacetimes. I will dig out the beautiful hidden classical singularity structure of the latter (a structure first noticed by Tod in 1994) and then show how quantum considerations can illuminate the riches. I will then discuss how quantum structure can help us understand classical singularities and metric parameters in a variety of exact solutions mined from the Exact Solutions book.

Konkowski, D. A.; Helliwell, T. M.

2006-06-01

190

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

191

Horizon-entropy increase laws for spherically symmetric horizons in Brans-Dicke theory  

NASA Astrophysics Data System (ADS)

We derive the horizon-entropy increase law for spherically symmetric quasi-local horizons in Brans-Dicke theory. The quasi-local horizons used do not marginally trap null rays, and hence are not apparent horizons or foliated by marginally trapped surfaces, but instead have instantaneously constant gravitational entropy in the outgoing null direction. The relation derived has a very direct comparison with the horizon-entropy increase law for event horizons.

Nielsen, Alex B.

2011-09-01

192

Using the ARP-03 for high-resolution mapping of calcic horizons  

NASA Astrophysics Data System (ADS)

The aim of this work is to present a fast and cheap method for high-resolutionmapping of calcic horizons in vineyards based on geoelectrical proximal sensing. The study area, 45 ha located in southern Sicily (Italy), was characterized by an old, partially dismantled marine terrace and soils with a calcic horizon at different depths. The geoelectrical investigation consisted of a survey of the soil electrical resistivity recorded with the Automatic Resistivity Profiling-03 sensor. The electrical resistivity values at three pseudo-depths, 0-50, 0-100 and 0-170 cm, were spatialized by means of ordinary kriging. A principal component analysis of the three electrical resistivity maps was carried out. During the survey, 18 boreholes, located at different electrical resistivity values, were made for soil description and sampling. The depth to the calcic horizon showed a strong correlation with electrical resistivity. The regression model between calcic horizon and the principal component analysis factors with the highest correlation coefficients was selected to spatialise the calcic horizon values. An Normalized Difference Vegetation Index map was used to validate the calcic horizon map in terms of crop response to different soil rooting depths. The strengths of this method are the quick, non-invasive kind of survey, the relevance for vine vigour, and the high spatial resolution of the final map.

Priori, S.; Fantappi?, M.; Magini, S.; Costantini, E. A. C.

2013-09-01

193

Ultrasonic displacement sensor for the seismic detection of buried land mines  

Microsoft Academic Search

A system is under development that uses seismic surface waves to detect and image buried landmines. The system, which has been previously reported in the literature, requires a sensor that does not contact the soil surface. Thus, the seismic signal can be evaluated directly above a candidate mine location. The system can then utilize small amplitude and non-propagating components of

James S. Martin; Douglas J. Fenneman; Fabien T. Codron; Peter H. Rogers; Waymond R. Scott; Gregg D. Larson; George S. McCall

2002-01-01

194

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

195

Shaking table tests on the lateral response of a pile buried in liquefied sand  

Microsoft Academic Search

This paper presents an experimental study on the lateral resistance of a pile subjected to liquefaction-induced lateral flow. To observe the soil surrounding the pile during liquefaction, it was modeled as a buried cylinder that corresponded to a sectional model of the prototype pile at a certain depth in the subsoil. In order to create a realistic stress condition in

J. R. Dungca; J. Kuwano; A. Takahashi; T. Saruwatari; J. Izawa; H. Suzuki; K. Tokimatsu

2006-01-01

196

Experimental study on the behavior of segmented buried concrete pipelines subject to ground movements  

Microsoft Academic Search

Seismic damage to buried pipelines is mainly caused by permanent ground displacements, typically concentrated in the vicinity of the fault line in the soil. In particular, a pipeline crossing the fault plane is subjected to significant bending, shear, and axial forces. While researchers have explored the behavior of segmented metallic pipelines under permanent ground displacement, comparatively less experimental work has

Junhee Kim; Jerome P. Lynch; Radoslaw L. Michalowski; Russell A. Green; Mohammed Pour-Ghaz; W. Jason Weiss; Aaron Bradshaw

2009-01-01

197

Data analysis and laboratory investigation of the behaviour of pipes buried in reactive clay  

Microsoft Academic Search

Buried pipe failures due to ground movement is a common problem which leads to the loss of water or gas supply in urban areas. Statistical analysis of pipe asset data indicates that pipe failure is correlated to ground movement caused by the shrinking and swelling of reactive soils due to seasonal climatic variations. This problem was studied in a large

Derek Chan

198

Finite element analysis of buried steel pipelines under strike-slip fault displacements  

Microsoft Academic Search

The present paper investigates the mechanical behavior of buried steel pipelines, crossing an active strike-slip tectonic fault. The fault is normal to the pipeline direction and moves in the horizontal direction, causing stress and deformation in the pipeline. The interacting soil–pipeline system is modelled rigorously through finite elements, which account for large strains and displacements, nonlinear material behavior and special

Polynikis Vazouras; Spyros A. Karamanos; Panos Dakoulas

2010-01-01

199

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

200

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

201

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

202

Radiance of the Ocean Horizon.  

National Technical Information Service (NTIS)

Cox and Munk (1954) proposed that the fluctuating surface of the open ocean could be accurately represented by many small mirror-like facets, each of which is randomly tilted with respect to the local horizon. Through aerial photographs of sun glint, they...

C. R. Zeisse

1994-01-01

203

New Horizons Mission to Pluto  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the trajectory that will take the New Horizons Mission to Pluto. Included are photographs of the spacecraft, the launch vehicle, the assembled vehicle as it is being moved to the launch pad and the launch. Also shown are diagrams of the assembled parts with identifying part names.

Delgado, Luis G.

2011-01-01

204

New Horizons in Education, 2000.  

ERIC Educational Resources Information Center

This document contains the May and November 2000 issues of "New Horizons in Education," with articles in English and Chinese. The May issue includes the following articles: "A Key to Successful Environmental Education: Teacher Trainees' Attitude, Behaviour, and Knowledge" (Kevin Chung Wai Lui, Eric Po Keung Tsang, Sing Lai Chan); "Critical…

Ho, Kwok Keung, Ed.

2000-01-01

205

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

206

Radiance of the Ocean Horizon.  

National Technical Information Service (NTIS)

Cox and Munk used aerial photographs of sun glint to determine the statistical distribution of ocean capillary wave slopes as a function of wind velocity. When their equation connecting the slope distribution with sun glint is used on the horizon, however...

C. R. Zeisse

1995-01-01

207

NIF featured on BBC "Horizon"  

SciTech Connect

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

2010-01-12

208

Distribution of Active Ectomycorrhizal Short Roots in Forest Soils of the Inland Northwest: Effects of Site and Disturbance.  

National Technical Information Service (NTIS)

Approximately 75 percent of ectomycorrhizal activities that occurred in soils from eight undisturbed and six variously disturbed sites occurred in shallow organic horizons. These horizons represented only the first 4 cm of soil depth. This disproportionat...

A. E. Harvey M. F. Jurgensen M. J. Larsen J. A. Schlieter

1986-01-01

209

Seasonal factors influencing the failure of buried water reticulation pipes.  

PubMed

While the use of environmental factors in the analysis and prediction of failures of buried reticulation pipes in cold environments has been the focus of extensive work, the same cannot be said for failures occurring on pipes in other (non-freezing) environments. A novel analysis of pipe failures in such an environment is the subject of this paper. An exploratory statistical analysis was undertaken, identifying a peak in failure rates during mid to late summer. This peak was found to correspond to a peak in the rate of circumferential failures, whilst the rate of longitudinal failures remained constant. Investigation into the effect of climate on failure rates revealed that the peak in failure rates occurs due to differential soil movement as the result of shrinkage in expansive soils. PMID:22049766

Gould, S J F; Boulaire, F A; Burn, S; Zhao, X L; Kodikara, J K

2011-01-01

210

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

211

Seismic Design of Buried and Offshore Pipelines.  

National Technical Information Service (NTIS)

The monograph reviews the behavior of buried pipeline components subject to permanent ground deformation and wave propagation hazards, as well as existing methods to quantify the response. To the extent possible and where appropriate, the review focuses o...

M. J. O'Rourke X. Liu

2012-01-01

212

Implementation of the buried waste integrated demonstration  

SciTech Connect

The Department of Energy (DOE), Office of Technology Development (OTD) has initiated the Buried Waste Integrated Demonstration (BWID) to resolve technological deficiencies associated with the remediation of radioactive and hazardous buried waste. The BWID mission is to identify, demonstrate, and transfer innovative technologies for the remediation of DOE buried waste. To accomplish the mission, BWID is using a systems approach which supports the development of a suite of advanced and innovative technologies for the effective and efficient remediation of buried waste. This systems approach includes technologies for theentire remediation cycle. Specifically, BWID sponsors technology development in the following technology categories: site and waste characterization, retrieval, preprocessing, ex situ treatment, packaging, transportation, storage, disposal, and post-disposal monitoring.

Kostelnik, K.M.; Merrill, S.K.

1992-01-01

213

Implementation of the buried waste integrated demonstration  

SciTech Connect

The Department of Energy (DOE), Office of Technology Development (OTD) has initiated the Buried Waste Integrated Demonstration (BWID) to resolve technological deficiencies associated with the remediation of radioactive and hazardous buried waste. The BWID mission is to identify, demonstrate, and transfer innovative technologies for the remediation of DOE buried waste. To accomplish the mission, BWID is using a systems approach which supports the development of a suite of advanced and innovative technologies for the effective and efficient remediation of buried waste. This systems approach includes technologies for theentire remediation cycle. Specifically, BWID sponsors technology development in the following technology categories: site and waste characterization, retrieval, preprocessing, ex situ treatment, packaging, transportation, storage, disposal, and post-disposal monitoring.

Kostelnik, K.M.; Merrill, S.K.

1992-09-01

214

Electromagnetic Scattering by Buried Complex Objects.  

National Technical Information Service (NTIS)

The solution of scattering problem of buried complex bodies needs to not only consider the scattering from the complex bodies, but also apply the boundary conditions in two different types of coordinate systems. This paper applys the conversion technique ...

P. G. Xu M. Chang H. Kang S. Lu

1995-01-01

215

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

216

Study on leak location technology for buried gas pipeline  

Microsoft Academic Search

This paper discusses the leak location technology for buried gas pipeline. In the paper the leak model of buried gas pipeline is built, the leak location algorithm based correlation theory is designed, and the buried gas pipeline is tested in experiment site. Experimental results show that the method is effective on leak identification and leak location for the buried gas

Yang Jiao; Guang-Hai Li; Guang-Kai Sun; Ying-Kui Zhu; Yu-Bo Zhao

2009-01-01

217

Horizons of knowledge in cosmology.  

NASA Astrophysics Data System (ADS)

In cosmology one faces the problem that the observer is part of the system, the universe, and that the system cannot be altered to test physical theory. In the big bang cosmology the universe becomes opaque to radiation early on, the images of extended distant galaxies merge and in order to measure the distance of a remote galaxy one has to disperse its light to form a spectrum which would cause confusion with other background galaxies. For these and other reasons, one encounters horizons of knowledge in the universe. Since the early universe should be described in quantum terms, it follows that non-locality in the universe is not an a-priori requirement but the outcome of the observing process itself. As such, the flatness and horizon problems may not be preconditions on theoretical models.

Kafatos, M.

218

Decomposition and stabilization of root litter in top- and subsoil horizons: what is the difference?  

Microsoft Academic Search

Mechanisms leading to high mean residence times of organic matter in subsoil horizons are poorly understood. In lower parts\\u000a of the soil profile root material contributes greatly to soil organic matter (SOM). The objective of this study was to elucidate\\u000a the decomposition dynamics of root-derived C and N in different soil depths during a 3 year field experiment and to examine

Muhammad Sanaullah; Abad Chabbi; Jens Leifeld; Gerard Bardoux; Daniel Billou; Cornelia Rumpel

2011-01-01

219

Periglacial morphogenesis in the Paris basin: insight from geophysical survey and consequences for the fate of soil pollution  

NASA Astrophysics Data System (ADS)

Geophysical survey by Automatic Resistivity Profiling (ARP©) system of the Pierrelaye-Bessancourt area revealed remarkable conductive polygon patterns of 20- to 30-m diameter detected between 0.5- and 1.7-m depth. Trenches dug down to the limestone substrate allowed detailing of the pedological and lithological units that compose such polygonal features. The patterns are formed by greenish glauconite and carbonated sand hollows where clay-rich pedological horizons bend downward, forming narrow tongs extending up to 2- to 3-m depth. Such structures were interpreted as a buried polygonal ice-wedge network (thermokarst depressions). Geometrical relationships between the lithological units and consecutive erosional surfaces allowed the identification of successive landscape events and a landscape chronology. The sequence started during the Saalian glaciation with (1) the development of patterned grounds by thermokarstic cryoturbation; (2) the consecutive deflation/erosion during post-permafrost aridity; (3) the loess and eolian sand deposits; (4) the weathering of the former deposits with development of pedogenic horizons during the Eemian interglacial; (5) the recurrent cryoturbation and thermal cracking leading to infolding of the pedogenic horizons during the Pleniglacial optimum (Weichselian); and finally (5) the erosion that levelled the periglacial microreliefs, most probably during the last glacial stage (Weichselian), leading to the modern landscape. In this agricultural area, urban waste water has been spread for more than 100 years by flooding irrigation for food crop production and has led to high levels of metal pollution in the surface horizons of the soils. The polygonal cryogenic structures have major impacts on soil hydrology and dispersion/distribution of heavy metals toward the geological substrate. Such structures are essential to consider when conceiving proposals for future soil management of this polluted area.

Thiry, Médard; van Oort, Folkert; Thiesson, Julien; Van Vliet-Lanoe, Brigitte

2013-09-01

220

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

221

Horizons cannot save the landscape  

NASA Astrophysics Data System (ADS)

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 Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz 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 Klebanov-Tseytlin solution exists. Furthermore, for a large class of Klebanov-Strassler 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 anti-de Sitter vacua to deSitter ones. Our results also point to a possible instability mechanism for the antibranes.

Bena, Iosif; Buchel, Alex; Dias, Óscar J. C.

2013-03-01

222

How does a black hole horizon start?  

NASA Astrophysics Data System (ADS)

When a black hole is created by gravitational collapse, there is a region of spacetime before the collapse where there is no horizon. Before the matter can fall through the horizon and create a black hole, the horizon has to start and expand to meet the matter. The starting point or points is where the generators enter the horizon. This set is a lower-dimensional, connected subset of a spacelike surface. By way of examples we will discuss the early configuration of the horizon to the time that matter enters. )

Brill, Dieter

2010-02-01

223

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

224

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

225

Radar detection of simulant mines buried in frozen ground  

NASA Astrophysics Data System (ADS)

We are investigating the environmental effects on radar detection of simulant mines (SIMs). SIMs are standard test targets developed by the US Army Project Manager-Mines, Countermine and Demolitions, and VSE Corporation for testing and evaluation of mine detection equipment. These test targets are filed with RTV silicone rubber, which has similar dielectric properties as TNT and Composition B. Therefore, they interact with radar sensors in a way representative of live mines. We are using broadband frequency modulated continuous wave (FMCW) and impulse radars to obtain signatures of SIMs buried under controlled laboratory conditions and at a test site instrumented with sensors to monitor the state of the ground. We find that anti-tank SIMs buried in frozen soil, in our case a common, silty sand are easy to detect. The dominant resonances included within SIMs by a broadbeam, 1.5 GHz impulse radar are of-nadir responses that appear unique and not predictable by simple ray theories of diffraction. A narrow beam, 2-6 GHz bandwidth FMCW radar induced reflections from the top and bottom of SIMs that were clearly resolved due to the broad bandwidth of the FMCW radar.

Koh, Gary; Arcone, Steven A.

1999-08-01

226

Centrifuge modeling of buried continuous pipelines subjected to normal faulting  

NASA Astrophysics Data System (ADS)

Seismic ground faulting is the greatest hazard for continuous buried pipelines. Over the years, researchers have attempted to understand pipeline behavior mostly via numerical modeling such as the finite element method. The lack of well-documented field case histories of pipeline failure from seismic ground faulting and the cost and complicated facilities needed for full-scale experimental simulation mean that a centrifuge-based method to determine the behavior of pipelines subjected to faulting is best to verify numerical approaches. This paper presents results from three centrifuge tests designed to investigate continuous buried steel pipeline behavior subjected to normal faulting. The experimental setup and procedure are described and the recorded axial and bending strains induced in a pipeline are presented and compared to those obtained via analytical methods. The influence of factors such as faulting offset, burial depth and pipe diameter on the axial and bending strains of pipes and on ground soil failure and pipeline deformation patterns are also investigated. Finally, the tensile rupture of a pipeline due to normal faulting is investigated.

Moradi, Majid; Rojhani, Mahdi; Galandarzadeh, Abbas; Takada, Shiro

2013-03-01

227

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

228

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

229

Geochemical characterization of loess-soil complexes on the Terek-Kuma Plain and the Azov-Kuban' Lowland  

NASA Astrophysics Data System (ADS)

The changes in the material composition of the buried soils and loesses in relation to the dynamics of the climate and sediment accumulation were studied for revealing the pedogenetic features and assessing the natural conditions in the steppe zone of the southern Russian Plain. A comparative analysis of the chemical compositions of the different-aged Pleistocene loess-soil complexes (the Otkaznoe, Port-Katon, and Shabel'skoe profiles) on the Terek-Kuma Plain and the Azov-Kuban' Lowland was performed. An increase in the concentrations of Fe and Mn, which are intensively involved in the biological cycle, and Rb, which is accumulated due to the activation of weathering processes, was observed in the paleosols that developed in interglacial periods of activation of pedogenesis. Increased coefficients of weathering (chemical index of alteration (CIA)) = [Al/(Al + Ca + Na + K)] 100, Al/(Al + Ca + Na + Mg), Rb/Sr, and Mn/Sr), leaching (Ba/Sr), and biological activity and bioproductivity (Mn/Fe, Mn/Al) were also noted for the paleosol horizons as compared with the loess horizons. It is argued that geochemical coefficients can be used as an efficient tool in the soil and paleogeographic studies aimed at the reconstruction and refinement of the schemes of changes in the bioclimatic conditions during the Pleistocene.

Kalinin, P. I.; Alekseev, A. O.

2011-12-01

230

Gravitational radiations of generic isolated horizons and nonrotating dynamical horizons from asymptotic expansions  

SciTech Connect

Instead of using a three-dimensional analysis on quasilocal horizons, we adopt a four-dimensional asymptotic expansion analysis to study the next order contributions from the nonlinearity of general relativity. From the similarity between null infinity and horizons, the proper reference frames are chosen from the compatible constant spinors for an observer to measure the energy-momentum and flux near quasilocal horizons. In particular, we focus on the similarity of Bondi-Sachs gravitational radiation for the quasilocal horizons and compare our results with Ashtekar-Kirshnan flux formula. The quasilocal energy-momentum and flux of generic isolated horizons and nonrotating dynamical horizons are discussed in this paper.

Wu, Y.-H.; Wang, C.-H. [Center for Mathematics and Theoretical Physics, National Central University and Department of Physics, National Central University, Chungli, 320, Taiwan (China); Department of Physics, National Central University, Chungli, 320, Taiwan (China)

2009-09-15

231

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

232

Horizon dynamics of distorted rotating black holes  

SciTech Connect

We present numerical simulations of a rotating black hole distorted by a pulse of ingoing gravitational radiation. For strong pulses, we find up to five concentric marginally outer trapped surfaces. These trapped surfaces appear and disappear in pairs, so that the total number of such surfaces at any given time is odd. The world tubes traced out by the marginally outer trapped surfaces are found to be spacelike during the highly dynamical regime, approaching a null hypersurface at early and late times. We analyze the structure of these marginally trapped tubes in the context of the dynamical horizon formalism, computing the expansion of outgoing and incoming null geodesics, as well as evaluating the dynamical horizon flux law and the angular momentum flux law. Finally, we compute the event horizon. The event horizon is well-behaved and approaches the apparent horizon before and after the highly dynamical regime. No new generators enter the event horizon during the simulation.

Chu, Tony; Cohen, Michael I. [Theoretical Astrophysics 350-17, California Institute of Technology, Pasadena, California 91125 (United States); Pfeiffer, Harald P. [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada)

2011-05-15

233

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

234

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

235

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

236

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

237

Buried Waste Integrated Demonstration test objectives  

SciTech Connect

The mission of the Buried Waste Integrated Demonstration Program (BWID) is to support the development and demonstration of a suite of technologies that when integrated with commercially available baseline technologies form a comprehensive system for the effective and efficient remediation of buried waste throughout the US Department of Energy complex. To accomplish this mission of identifying technology solutions for remediation deficiencies, the Office of Technology Development initiated the BWID at the Idaho National Engineering Laboratory in fiscal year (FY) 1991. This document provides the test objectives against which the demonstrations will be tested during FY-93.

Morrison, J.L.; Heard, R.E.

1993-05-01

238

In-situ vitrification of soil. [Patent application  

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, R.A.; Buelt, J.L.; Bonner, W.F.

1981-04-06

239

Opportunity's Heatshield on the Horizon  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for Opportunity's Heatshield on the Horizon (QTVR)

This image mosaic from the panoramic camera on the Mars Exploration Rover Opportunity shows the distant horizon from Opportunity's position inside a small crater at Meridiani Planum, Mars. To the left is a large crater about 700 meters (2,296 feet) away from the landing site and approximately 200 meters (656 feet) in diameter. In the center, Opportunity's heatshield and its impact mark can be seen at a distance of approximately 875 meters (one-half mile) from the landing site. To the right, a string of bounce marks left by the rover's airbags is visible. Near the mark just outside the landing site crater's rim is the largest rock in the area. This rock is about 40 centimeters (16 inches) across and 50 meters (164 feet) from the rover's position. The image is an enhanced color composite acquired on the 35th and 36th martian days, or sols, of Opportunity's journey, using three different wavelength filters.

2004-01-01

240

Event Horizons from black-hole rings  

NASA Astrophysics Data System (ADS)

We construct and evolve non-rotating vacuum initial data with a ring singularity, based on a simple extension of the standard Brill-Lindquist multiple black-hole initial data, and search for event horizon with spatial slices that are topologically tori. We find, that it is not possible to produce a finite-sized toroidal horizon, which only occurs in a singular limit where the horizon width has zero size, indicating the presence of a naked singularity.

Ponce, Marcelo; Lousto, Carlos; Zlochower, Yosef

2011-04-01

241

Surface acoustic wave devices as passive buried sensors  

NASA Astrophysics Data System (ADS)

Surface acoustic wave (SAW) devices are currently used as passive remote-controlled sensors for measuring various physical quantities through a wireless link. Among the two main classes of designs-resonator and delay line-the former has the advantage of providing narrow-band spectrum informations and hence appears compatible with an interrogation strategy complying with Industry-Scientific-Medical regulations in radio-frequency (rf) bands centered around 434, 866, or 915 MHz. Delay-line based sensors require larger bandwidths as they consists of a few interdigitated electrodes excited by short rf pulses with large instantaneous energy and short response delays but is compatible with existing equipment such as ground penetrating radar (GPR). We here demonstrate the measurement of temperature using the two configurations, particularly for long term monitoring using sensors buried in soil. Although we have demonstrated long term stability and robustness of packaged resonators and signal to noise ratio compatible with the expected application, the interrogation range (maximum 80 cm) is insufficient for most geology or geophysical purposes. We then focus on the use of delay lines, as the corresponding interrogation method is similar to the one used by GPR which allows for rf penetration distances ranging from a few meters to tens of meters and which operates in the lower rf range, depending on soil water content, permittivity, and conductivity. Assuming propagation losses in a pure dielectric medium with negligible conductivity (snow or ice), an interrogation distance of about 40 m is predicted, which overcomes the observed limits met when using interrogation methods specifically developed for wireless SAW sensors, and could partly comply with the above-mentioned applications. Although quite optimistic, this estimate is consistent with the signal to noise ratio observed during an experimental demonstration of the interrogation of a delay line buried at a depth of 5 m in snow.

Friedt, J.-M.; Rétornaz, T.; Alzuaga, S.; Baron, T.; Martin, G.; Laroche, T.; Ballandras, S.; Griselin, M.; Simonnet, J.-P.

2011-02-01

242

Boreal Forest Organic Soil Properties: Variation Within Soil Profiles and Across Landscapes  

NASA Astrophysics Data System (ADS)

Organic soils play an important role in boreal ecosystem function by influencing temperature, hydrology, decomposition rates, fire dynamics, and species composition. Understanding the variability in soil properties both across a landscape and within a soil profile is very important given that relatively few soil descriptions exist in this region. Modeling studies, in particular, require a better understanding of the inherent variability in the boreal landscape. To help characterize organic soils of the boreal region we collected over 250 soil cores from mature and young black spruce (Picea mariana) stands located in both wet and dry ecosystems and stratified the soils by horizon type (moss, fibric, mesic, humic horizons). We investigated the porosity, bulk density, and carbon fraction of each horizon within the organic soil profile. Our results suggest that these properties vary by both horizon type and drainage class. We also found that a simple model including horizon type directly above the mineral soil and organic soil thickness can be used to accurately predict C stocks of organic soil profile. This relationship can be used to estimate C stocks (g/m2) for sites where horizons were described but sampling efforts did not occur, allowing more spatial representation of C storage across the boreal forest. We also present relationships between C density (g/m3) and height above mineral soil for both the dry and wet drainages, so that these values can be used in modeling studies of organic layer dynamics.

Manies, K.; Yi, S.; Harden, J.; McGuire, A.

2008-12-01

243

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

244

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

245

Backyard bolides: finding a buried impact crater  

Microsoft Academic Search

The author reports the scientific activities that led to his discovery of a huge submerged impact crater in Chesapeake Bay, some 140 km east of Atlantic City, New Jersey. This crater, buried under 350 m of sediment is 80 km wide and almost 1 km deep. Microfossil evidence shows that the crater is approximately 35 million years old. The author

C. W. Poag

1998-01-01

246

Buried object detection - EMI and IR sensors  

Microsoft Academic Search

Several sensors have been used to detect buried objects, such as GPR (ground penetrating radar) and EMI (electromagnetic induction) sensors. IR (infrared) and acoustic sensors are supportive sensors which are used with an EMI sensor or GPR. The paper focuses mainly on two sensors, a main EMI sensor and a support IR sensor. The EMI sensor's output signal and IR

S. Akgun; M. D. Azak; S. Samedov; R. Caputcu

2004-01-01

247

Computer vision for locating buried objects.  

National Technical Information Service (NTIS)

Given two registered images of the earth, measured with aerial dual-band infrared (IR) sensors, we use advanced computer vision/automatic target recognition techniques to estimate the positions of buried land mines. The images are very difficult to interp...

G. A. Clark J. E. Hernandez N. K. DelGrande R. J. Sherwood S. Y. Lu

1991-01-01

248

Time domain processing of frequency domain GPR signatures for buried land mine detection  

Microsoft Academic Search

This paper investigates the feasibility of detecting plastic antipersonnel land mines buried in lossy, dispersive, rough soils using a stepped-frequency ultra wideband (WB) ground-penetrating radar (GPR). Realistic land mine scenarios were modeled using a two-dimensional (2D) finite difference frequency domain (FDFD) technique. Assuming normal incidence plane wave excitation, the scattered fields were generated over a large frequency bandwidth (.5 to

Audrey Dumanian; Carey M. Rappaport; Ann W. Morgenthaler

2002-01-01

249

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

250

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

251

49 CFR 195.248 - Cover over buried pipeline.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.248 Cover over buried pipeline. (a) Unless specifically...

2010-10-01

252

49 CFR 195.248 - Cover over buried pipeline.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.248 Cover over buried pipeline. (a) Unless specifically...

2009-10-01

253

Detection of buried land mines using a dual-band LWIR\\/LWIR QWIP focal plane array  

Microsoft Academic Search

We report on the development and testing of a new dual-band infrared focal plane array (FPA) specifically designed to detect buried land mines. The detector response spectra were tailored to take advantage of the sharp spectral features associated with disturbed soils. The goal was to have a “blue” channel with peak response near 9.2 ?m and a “red” channel with

Arnold Goldberg; Parvez N Uppal; Michael Winn

2003-01-01

254

Laboratory Load Tests on Buried Flexible Pipe. Progress Report No. 6. Steel and Fiberglass Reinforced Resin Pipe in Sand Backfill.  

National Technical Information Service (NTIS)

Two steel pipe, one reinforced plastic mortar, and one fiberglass reinforced plastic pipe, each about 18 inches (46 centimeters) in diameter and 71 inches long were load-tested in a laboratory soil container. All pipe were buried in a sand backfill. Incre...

A. K. Howard

1973-01-01

255

Maximal Indecomposable Past Sets and Event Horizons  

NASA Astrophysics Data System (ADS)

The existence of maximal indecomposable past sets MIPs is demonstrated using the Kuratowski-Zorn lemma. A criterion for the existence of an absolute event horizon in space-time is given in terms of MIPs and a relation to black hole event horizon is shown.

Królak, Andrzej

1984-02-01

256

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

257

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

258

Horizon Report: 2010 K-12 Edition  

ERIC Educational Resources Information Center

The "Horizon Report" series is the most visible outcome of the New Media Consortium's Horizon Project, an ongoing research effort established in 2002 that identifies and describes emerging technologies likely to have a large impact on teaching, learning, research, or creative expression within education around the globe. This volume, the "2010…

Johnson, L.; Smith, R.; Levine, A.; Haywood, K.

2010-01-01

259

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

260

Surveyor observations of lunar horizon-glow  

Microsoft Academic Search

Each of the Surveyor 7, 6, and 5 spacecraft observed a line of light along its western lunar horizon following local sunset. It has been suggested that this horizon-glow (HG) is sunlight, which is forward-scattered by dust grains (~ 10µ in diam, ~ 50 grains cm-2) present in a tenuous cloud formed temporarily (? 3 h duration) just above sharp

J. J. Rennilson; D. R. Criswell

1974-01-01

261

Moving horizon estimation for hybrid systems  

Microsoft Academic Search

In this paper, by exploiting the equivalence between hybrid systems modeled in the mixed logic dynamical form and piecewise affine systems, we propose a state smoothing algorithm based on moving horizon estimation (MHE). We provide sufficient conditions on the time horizon and the initial penalties to guarantee asymptotic convergence of the MHE scheme. Moreover we propose an algorithm for the

Giancarlo Ferrari-Trecate; Domenico Mignone; Manfred Morari

2000-01-01

262

Cosmological event horizons, thermodynamics, and particle creation  

Microsoft Academic Search

It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological constant. An observer in these models will have an event horizon whose area can be interpreted as the entropy or lack of information of the observer about the

G. W. Gibbons; S. W. Hawking

1977-01-01

263

Reconceptualizing Knowledge at the Mathematical Horizon  

ERIC Educational Resources Information Center

This article extends the notion of "knowledge at the mathematical horizon" or "horizon knowledge" introduced by Ball and colleagues as a part of teachers' subject matter knowledge. Our focus is on teachers' mathematical knowledge beyond the school curriculum, that is, on mathematics learnt during undergraduate college or university studies. We…

Zazkis, Rina; Mamolo, Ami

2011-01-01

264

Particle filtering and moving horizon estimation  

Microsoft Academic Search

This paper provides an overview of currently available methods for state estimation of linear, constrained and nonlinear systems. The following methods are discussed: Kalman filtering, extended Kalman filtering, unscented Kalman filtering, particle filtering, and moving horizon estimation. The current research literature on particle filtering and moving horizon estimation is reviewed, and the advantages and disadvantages of these methods are presented.

James B. Rawlings; Bhavik R. Bakshi

2006-01-01

265

Contributions of Oi, Oe and Oa horizons to dissolved organic matter in forest floor leachates  

Microsoft Academic Search

The aim of this study was to identify the role of organic matter of the Oi, Oe and Oa layers for leaching of dissolved organic matter (DOM) from the O horizon in a podsolised forest soil in southern Sweden. Solid state 13C cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy and 14C measurements were used to analyse

Mats Fröberg; Dan Berggren; Bo Bergkvist; Charlotte Bryant; Heike Knicker

2003-01-01

266

First Results in the Autonomous Retrieval of Buried Objects  

Microsoft Academic Search

We have developed an autonomous system for the retrieval of buried objects. It is designed to detect, locate and retrieve buried objects. The system is equipped with a hydraulic robot, laser range finder and a subsurface sensor. First, subsurface sensing is used to detect and locate buried objects. If an object can be reached with one dig, the excavator retrieves

Herman Herman; Sanjiv Singh

1994-01-01

267

History of a black hole horizon  

NASA Astrophysics Data System (ADS)

The horizon of a general (non-eternal) black hole is initially much more complicated than in the well-known case of a spherically symmetric spacetime; but finally it becomes simple and acquires an asymptotic ``no hair'' state. It is therefore simplest to evolve the horizon backwards in time from the final condition, by following its congruence of null geodesic generators. During the evolution, significant events occur when generators cross and exit the horizon, leaving behind a spacelike crease. This happens typically when matter crosses the horizon, but the crossing is not causally related to the crease. The crease set (if it were a priori known) can be an initial condition for horizon development forward in time. Examples will be given in 3- and 4-dimensional spacetimes.

Brill, Dieter

2013-04-01

268

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

269

Speciation and distribution of cadmium and lead in salinized horizons of antrosols  

NASA Astrophysics Data System (ADS)

The utilization of intensive technologies for the vegetable cultivation in glass houses by the administration of high doses of organic fertilizes, the supra-dimensional irrigation and the maintaining of soil at high humidity state, in special in case of vicious drainage have as result the rapid degradation of morphological, chemical and physical characteristics of soils, concretized by: (i) decrease of structural aggregates stability; (ii) more dense packing of soil; (iii) accumulation of easy soluble salts (in special at superior horizons level); (iv) limitation of organic compounds and micro-elements biodisponibility. All these determined a significant reduction of productivity and of exploitation duration of soils from glass houses. These phenomena modified continuously the dynamic of speciation processes and inter-phases distribution, of heavy metals in soils from glass houses, and can determined a non-controlled accumulation of heavy metals, in special as mobile forms with high biodisponibility. Ours studied have been performed using soil profiles drawing from Copou-glass house, Iasi (Romania). Has been followed the modification of distribution for speciation forms of cadmium and lead (two heavy metals with high toxicity degree), between hortic antrosol horizons, and between chemical-mineralogical components of this, with the progressive salinization of superior horizons, in 2007-2008 period. The separation, differentiation and determination of cadmium and lead speciation forms was done by combined solid-liquid sequential extraction (SPE) and extraction in aqueous polymer-inorganic salt two-phase systems (ABS) procedure, presented in some of ours previous studies. After extraction, the total contents of the two heavy metals and fractions from these differential bonded by mineral and organic components of hortic antrosol have been determined by atomic absorption spectrometry. The specific interaction mechanisms of Cd and Pb with organic-mineral components of soils have been estimated on the basis of Raman and FT-IR spectra, recorded for fractions obtained after each extraction step. These data were correlated with those obtained by chemical analysis and UV-VIS spectrometry, and were used for to establish the type and weight of Cd and Pb speciation forms in studied antrosol. Our studies have been show that in medium and inferior horizons of hortic antrosols, the heavy metals have a general accumulation tendency, preferential by binding on organic matter and organic-mineral complexes, components with higher abundance in such type of soils. The selectivity and complexation mechanisms are controlled by speciation forms of the two metals. This phenomenon has two important consequences, the strong fixation of heavy metals in hortic antrosol and significant modification of structure and conformation of organic macromolecules. A specific phenomenon of hortic antrosols is that the accumulation rate of heavy metals is higher than levigation rate, and the mobile forms of these have a higher biodisponibility, being relative easy assimilated by plants. The progressive salinization of superior horizons of soils from glass houses, determined a sever perturbation of equilibrium between Cd and Pb speciation forms. In consequence these will have an accentuated migration tendency in superior horizons, as complexes with inorganic ligands, with a high mobility and biodsiponibility. The accumulation of soluble salts in superior horizons, and the formation of frangipane horizon (horizon of geochemical segregation of hortic antrosols) modified the ionic strength from soil solution and the thermodynamic activity of cadmium and lead species. Under these conditions, the levigation rate of cadmium and lead is higher than the accumulation rate, which means that the migration of these metals in soil solution occurs fast and in high concentrations. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07 an Project PNCDI 2-D5 no. 52141 / 08).

Bulgariu, D.; Bulgariu, L.; Astefanei, D.

2009-04-01

270

Buried junction enhanced Schottky barrier device  

NASA Astrophysics Data System (ADS)

The present invention contemplates a completely submersed Schottky barrier junction in order to enhance collection efficiency of photogenerated carriers. Using a buried active back-to-back thin junction allows collection of carriers generated with momentum vectors in both the forward and reverse directions. Thus, the quantum efficiency and sensitivity of the infrared detector is substantially enhanced. In addition, thicker Schottky metallizations can be used to enhance spectral absorption of incident infrared lights.

Skolnik, L. H.

1984-08-01

271

Burying by rats in response to aversive and nonaversive stimuli  

PubMed Central

Previous investigations have shown that rats bury a variety of conditioned and unconditioned aversive stimuli. Such burying has been considered as a species-typical defensive reaction. In the present studies, rats buried spouts filled with Tabasco sauce, or condensed milk to which a taste aversion was conditioned, but did not bury water-filled spouts or spouts filled with a palatable novel food (apple juice) to which a taste aversion was not conditioned. However, in other experiments rats consistently and repeatedly buried Purina Rat Chow, Purina Rat Chow coated with quinine, and glass marbles. This indicates that a variety of stimuli, not all aversive or novel, evoke burying by rats. Whereas the behavior may reasonably be considered as a species-typical defensive behavior in some situations, the wide range of conditions that occasion burying suggests that the behavior has no single biological function.

Poling, Alan; Cleary, James; Monaghan, Michael

1981-01-01

272

[Visual illusions and moving horizon].  

PubMed

Results of psychological "additional investigation" of the crash of Boeing-737, "Aeroflot-Nord" on 14.09.2008 near Perm are presented. 37 pilots from the one of the leading airline companies sensed the attitude and rolling out the aircraft to the forward flight under the moving horizon with straight display of bank and tangage (view from the aircraft to the ground) in model conditions. 29 pilots (78.4%) made a mistake at determining the roll direction and tangage, they made a mistake at determining the roll direction 61 times (16.4%) and 44 times at determining the tangage direction, in other words they confused left and right bank and also nose-up and nose-down. Visual illusions of mobility of space and handling of ground (instead of aircraft) during the flight were revealed in pilots. These illusions may be the important cause of the following crashes. The necessity of "back" faultless display of bank in all aircrafts of civil aviation and development of computer complex for training of visual spatial orientation is proved. PMID:23156114

Zhdan'ko, I M; Chulaevski?, A O; Kovalenko, P A

2012-09-01

273

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

274

Black Hole Entropy and Isolated Horizons Thermodynamics  

NASA Astrophysics Data System (ADS)

We present a statistical mechanical calculation of the thermodynamical properties of (nonrotating) isolated horizons. The introduction of the Planck scale allows for the definition of a universal horizon temperature (independent of the mass of the black hole) and a well-defined notion of energy (as measured by suitable local observers) proportional to the horizon area in Planck units. The microcanonical and canonical ensembles associated with the system are introduced. Black hole entropy and other thermodynamical quantities can be consistently computed in both ensembles and results are in agreement with Hawking’s semiclassical analysis for all values of the Immirzi parameter.

Ghosh, Amit; Perez, Alejandro

2011-12-01

275

Black hole entropy and isolated horizons thermodynamics.  

PubMed

We present a statistical mechanical calculation of the thermodynamical properties of (nonrotating) isolated horizons. The introduction of the Planck scale allows for the definition of a universal horizon temperature (independent of the mass of the black hole) and a well-defined notion of energy (as measured by suitable local observers) proportional to the horizon area in Planck units. The microcanonical and canonical ensembles associated with the system are introduced. Black hole entropy and other thermodynamical quantities can be consistently computed in both ensembles and results are in agreement with Hawking's semiclassical analysis for all values of the Immirzi parameter. PMID:22242986

Ghosh, Amit; Perez, Alejandro

2011-12-01

276

Hydrogen soil dynamics in northern boreal and subarctic Sweden  

NASA Astrophysics Data System (ADS)

Wetland ecosystems store a large amount of organic carbon in the form of peat and are the largest natural source of CH4. Thawing of northern wetland permafrost results in an increase in the pool of soil carbon that is made available for decomposition processes and CH4 production. Some subarctic mire sites are also getting wetter as the climate warms. An increase in inundated areas in conjunction with increased amounts of organic matter could give rise to potential feedbacks to warming temperatures via increased emissions of reduced trace gases, such as CH4 and H2, to the atmosphere. H2 soil dynamics in peatlands and forests are complex because of the many microbial-mediated reactions driving H2 production and consumption. H2 couples oxidative and reductive processes in anaerobic environments. The aim of this project was to determine if high-latitude boreal and subarctic soils can change from a sink to a source of H2 to the atmosphere by identifying the microbial processes controlling the production and consumption of H2. Does H2 production and emissions to the atmosphere occur under temporary anoxia in organic -rich soils and soil horizons and do episodic weather events, particularly rain and freeze-thaw cycles, drive H2 production and release from natural soils due to the release of labile organic material and anaerobic conditions. Porewater soil gas profiles from different sub-habitats were determined in Stordalen mire in subarctic Sweden using buried ePTFE tubing and samples manually obtained using a stainless steel sipper. Trends in H2 concentration between the microporous tubing and sipper samples generally agree. The H2 concentration is higher in the tubing possibly due to preferential diffusion into the air-filled tubing by H2, which has a low solubility in water. The wettest site dominated by Eriophorum had the highest concentration of H2 with a maximum of 39.3 ppmv H2 at a depth of 30 cm. A mesic site dominated by Sphagnum had the next highest H2 concentration with 37.6 ppmv H2 at 20 cm below the ground surface. A Carex-dominated site also had increasing H2 concentration with depth. The concentrations of soil H2 in the dry palsa site were lower than ambient air indicating consumption at this site. Soil H2 was also measured in boreal forest soils, which typically act as a sink of atmospheric H2. Manual field sampling revealed that H2 concentrations were higher above the surface of the ground than at the base of the O horizon suggesting H2 deposition. An incubation experiment designed to test the interactions between soil moisture, temperature, and substrate addition indicated that warm, dry forest soils with added glucose are the highest consumers of H2 while warm, dry forest soils with no substrate addition produce the most H2. With the exception of the soil with the greatest glucose addition, the soils incubated at 20°C produced more H2 than soils at 12°C and 4°C.

Steele, K. J.; Crill, P. M.; Oquist, M. G.; Varner, R. K.

2011-12-01

277

Evaluation of simple transmission line oscillators for soil moisture measurement  

Microsoft Academic Search

Time domain reflectometry (TDR) measures water content in soil by measuring the travel time of an electrical pulse in a transmission line which is buried in the soil. Travel time is determined, in part, by the dielectric constant of the soil. The large dielectric constant of water, relative to soil minerals and air, assures that TDR measurements can register small

Gaylon S Campbell; Russell Y Anderson

1998-01-01

278

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

279

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

280

Horizon 2000 and European national programmes  

NASA Astrophysics Data System (ADS)

A review on ESA's science program is presented. Five missions still in orbit are outlined: IUE, Giotto, Hipparcos, Hubble Space Telescope, and Ulysses. Objectives of the Horizon 2000 program are described. Solar system exploration in Horizon 2000 concerns: the SOHO (Solar and Heliospheric Observatory) and Cluster missions, Cassini/Huygens to Saturn and Titan, and the Rosetta Comet Nucleus Sample Return (CNSR). Astronomy in Horizon 2000 concerns ISO (Infrared Space Observatory), the X-ray Multimirror Mission (XMM) and FIRST (Far Infrared and Submillimeter Space Telescope). Medium sized missions of Horizon 2000 include INTEGRAL (International Gamma Ray Astrophysical Laboratory), MARSNET (a network of lander modules in Mars), and STEP (Satellite Test of the (weak) Equivalent Principle). Small missions include extension of Giotto and instruments to fly on Eureca, the Columbus Space Station, and the Polar Platform.

Bonnet, R. M.

1992-07-01

281

Lessons Learned from the Deepwater Horizon Response.  

National Technical Information Service (NTIS)

Following the unprecedented federal response to the Deepwater Horizon (DWH) disaster, the National Institute for Occupational Safety and Health (NIOSH) conducted a review of the Institute's response activities. The purpose of this report is to evaluate th...

A. Tepper B. Bernard B. King D. Reissman G. DeBord J. Decker J. Gibbins J. Spahr L. Delaney M. Kitt M. H. Sweeney R. Funk T. Seitz V. Castranova

2011-01-01

282

Information Horizons in Complex Networks  

NASA Astrophysics Data System (ADS)

We investigate how the structure constrain specific communication in social-, man-made and biological networks. We find that human networks of governance and collaboration are predictable on teat-a-teat level, reflecting well defined pathways, but globally inefficient (1). In contrast, the Internet tends to have better overall communication abilities, more alternative pathways, and is therefore more robust. Between these extremes are the molecular network of living organisms. Further, for most real world networks we find that communication ability is favored by topology on small distances, but disfavored at larger distances (2,3,4). We discuss the topological implications in terms of modularity and the positioning of hubs in the networks (5,6). Finally we introduce some simple models which demonstarte how communication may shape the structure of in particular man made networks (7,8). 1) K. Sneppen, A. Trusina, M. Rosvall (2004). Hide and seek on complex networks [cond-mat/0407055] 2) M. Rosvall, A. Trusina, P. Minnhagen and K. Sneppen (2004). Networks and Cities: An Information Perspective [cond-mat/0407054]. In PRL. 3) A. Trusina, M. Rosvall, K. Sneppen (2004). Information Horizons in Networks. [cond-mat/0412064] 4) M. Rosvall, P. Minnhagen, K. Sneppen (2004). Navigating Networks with Limited Information. [cond-mat/0412051] 5) S. Maslov and K. Sneppen (2002). Specificity and stability in topology of protein networks Science 296, 910-913 [cond-mat/0205380]. 6) A. Trusina, S. Maslov, P. Minnhagen, K. Sneppen Hierarchy Measures in Complex Networks. Phys. Rev. Lett. 92, 178702 [cond-mat/0308339]. 7) M. Rosvall and K. Sneppen (2003). Modeling Dynamics of Information Networks. Phys. Rev. Lett. 91, 178701 [cond-mat/0308399]. 8) B-J. Kim, A. Trusina, P. Minnhagen, K. Sneppen (2003). Self Organized Scale-Free Networks from Merging and Regeneration. nlin.AO/0403006. In European Journal of Physics.

Sneppen, Kim

2005-03-01

283

Emergent symmetry on black hole horizons  

NASA Astrophysics Data System (ADS)

For a stationary and axisymmetric black hole, there is a natural way to split the fields into a probe sector and a background sector. The equations of motion for the probe sector enjoy a significantly enhanced symmetry on the black hole horizon. The extended symmetry is conformal in four dimensions, while in higher dimensions it is much bigger. This puts conformal symmetry at the bottom of the ladder of symmetries that can arise on black hole horizons in generic dimensions.

Mei, Jianwei

2014-03-01

284

Fast scramblers and ultrametric black hole horizons  

NASA Astrophysics Data System (ADS)

We propose that fast scrambling on finite-entropy stretched horizons can be modeled by a diffusion process on an effective ultrametric geometry. A scrambling time scaling logarithmically with the entropy is obtained when the elementary transition rates saturate causality bounds on the stretched horizon. The so-defined ultrametric diffusion becomes unstable in the infinite-entropy limit. A formally regularized version can be shown to follow a particular case of the Kohlrausch law.

Barbón, José L. F.; Magán, Javier M.

2013-11-01

285

Soil properties influencing the denitrification potential of Flemish agricultural soils  

Microsoft Academic Search

The denitrification potential of the soil horizons between 0- and 90-cm depth of 20 agricultural fields, representative of the most frequent combinations of agricultural crops and soil textures in Flanders (Belgium), and the factors affecting the denitrification potential were studied in the laboratory under controlled conditions. The denitrification potential in the presence of an added soluble C and N source

Karoline D'Haene; Edwin Moreels; Stefaan De Neve; Barbara Chaves Daguilar; Pascal Boeckx; Georges Hofman; Oswald Van Cleemput

2003-01-01

286

Study of the influence of the plastic casing on the electromagnetic induction response of a buried landmine  

NASA Astrophysics Data System (ADS)

Most studies of the electromagnetic induction (EMI) response of a low-metal landmine buried in soil ignore any influence that the plastic casing may have on such response. In most cases such treatment is adequate since only the metal components of a landmine are expected to contribute to such a response. However, when the landmine is buried in a soil that has significant conductivity and/or magnetic susceptibility, the electromagnetic void created by the casing may have an influence on the EMI response of the landmine. That possibility is investigated using a simple analytical model and an experiment. A sphere is chosen as a simple prototype for the small metal parts in low-metal landmines, and a concentric spherical shell, made of foamed polystyrene, encasing the sphere is used to represent the plastic landmine body. The time-domain EMI response is measured using a purpose-designed system based on a modified Schiebel AN19/2 metal detector. Responses of the metallic sphere, the polystyrene shell and the metal-polystyrene composite target are measured with the targets buried in magnetic soil half-spaces. The particular soil type for which data are presented in this paper is Cambodian "laterite" with dispersive magnetic susceptibility, which serves as a good model for soils that are known to affect the performance of metal detectors. The metal sphere used has a diameter of 0.0254 m and is made of 6061-T6 aluminum, and the polystyrene shell has an outer diameter of 0.15 m. For the specific soil and targets used, theoretical results show that a small effect on the time-domain response is expected from the presence of the polystyrene casing. Experimental results confirm this for the case of the buried polystyrene shell. However the small difference in the example of the composite target is masked by experimental errors.

Das, Y.

2008-05-01

287

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

288

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

289

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

290

Investigation of Buried Domes. Phase IV. Static Response of Flexible Domes Buried in Sand.  

National Technical Information Service (NTIS)

A series of tests was conducted on three 12-inch-diameter hemispherical domes buried in 20-30 Ottawa sand. The domes were constructed of Plexiglas and had radius-to-thickness ratios ranging from 60 to 150. They were supported on a rigid layer with 12 inch...

R. B. McPherson

1968-01-01

291

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...

292

Soil Air Carbon Dioxide Concentrations in a New England Spruce-Fir Forests.  

National Technical Information Service (NTIS)

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 ...

I. J. Fernandex P. A. Kosian

1987-01-01

293

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

2008-06-03

294

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

295

Effect of imperfect bonding on the axisymmetric dynamic response of buried orthotropic cylindrical shells  

NASA Astrophysics Data System (ADS)

This paper deals with the dynamic response of an imperfectly bonded buried orthotropic pipeline subjected to p-wave excitation. An infinite cylindrical shell model, including the rotary inertia and shear deformation effects, has been used for the pipeline. Only the axisymmetric response due to an incident compressional wave has been investigated. Effects of imperfect bond between the pipe and the soil have been included by considering a layer of infinitesimally small thickness between the pipe and the soil. The layer possesse stiffness and damping properties against any axial or radial movement. The ddgree of imperfection or the looseness of the bond is incorporated by varying the stiffness and the damping parameters of the layer. Effects of the imperfect bond on the radial and the axial displacement of the shell have been studied in different soil conditions. These effects have been compared with the effects due to changes in the orthotropic parameters of the pipe.

Dwivedi, J. P.; Upadhyay, P. C.

1989-12-01

296

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

297

Biochar reduces short-term nitrate leaching from a horizon in an apple orchard.  

PubMed

Nitrogen leaching in croplands is a worldwide problem with implications both on human health and on the environment. Efforts should be taken to increase nutrient use efficiency and minimize N losses from terrestrial to water ecosystems. Soil-applied biochar has been reported to increase soil fertility and decrease nutrient leaching in tropical soils and under laboratory conditions. Our objective was to evaluate the effect of biochar addition on short-term N leaching from A soil horizon in a mature apple orchard growing on subalkaline soils located in the Po Valley (Italy). In spring 2009, 10 Mg of biochar per hectare was incorporated into the surface 20-cm soil layer by soil plowing. Cumulative nitrate (NO) and ammonium (NH) leaching was measured in treated and control plots 4 mo after the addition of biochar and the following year by using ion-exchange resin lysimeters installed below the plowed soil layer. Cumulative NO leaching was not affected by biochar after 4 mo, whereas in the following year it was significantly ( < 0.05) reduced by 75% over the control (from 5.5 to 1.4 kg ha). Conversely, NH leaching was very low and unaffected by soil biochar treatment. The present study shows that soil biochar addition can significantly decrease short-term nitrate leaching from the surface layer of a subalkaline soil under temperate climatic conditions. PMID:23673741

Ventura, M; Sorrenti, G; Panzacchi, P; George, E; Tonon, G

2013-01-01

298

Digital Horizons: A Plains Media Resource  

NSDL National Science Digital Library

The Digital Horizons website "provides, maintains, and preserves a wide range of historical and significant content related specifically to Fargo-Moorhead and broadly to North Dakota and Minnesota." In the "About Digital Horizons" link, visitors can read the foregoing purpose of the project, as well as the vision statement. The goals of the project, the audiences it's intended for--students, educators, internal staff, commercial users; and how to become a member of the project, are also in the "About Digital Horizons" link. The homepage has sections on "Managing Your Collection", about preserving or donating the photos, film, audio and textual materials one might have in one's home, and "Contributing Organizations", the list of which institutions have contributed to the project, which include Concordia College Archives, Prairie Public Broadcasting and the State Historical Society of North Dakota. Visitors can browse by "General Subject", "Collection", or "Popular Searches", via the homepage or the right hand side of any other main page.

299

Experimental study on the behavior of segmented buried concrete pipelines subject to ground movements  

NASA Astrophysics Data System (ADS)

Seismic damage to buried pipelines is mainly caused by permanent ground displacements, typically concentrated in the vicinity of the fault line in the soil. In particular, a pipeline crossing the fault plane is subjected to significant bending, shear, and axial forces. While researchers have explored the behavior of segmented metallic pipelines under permanent ground displacement, comparatively less experimental work has been conducted on the performance of segmented concrete pipelines. In this study, a large-scale test is conducted on a segmented concrete pipeline using the unique capabilities of the NEES Lifeline Experimental and Testing Facilities at Cornell University. A total of 13 partial-scale concrete pressure pipes (19 cm diameter and 86 cm long) are assembled into a continuous pipeline and buried in a loose granular soil. Permanent ground displacement that places the segmented concrete pipeline in compression is simulated through the translation of half of the soil test basin. A dense array of sensors including linear variable differential transducers, strain gauges, and load cells are installed along the length of the pipeline to measure its response to ground displacement. Response data collected from the pipe suggests that significant damage localization occurs at the ends of the segment crossing the fault plane, resulting in rapid catastrophic failure of the pipeline.

Kim, Junhee; Lynch, Jerome P.; Michalowski, Radoslaw L.; Green, Russell A.; Pour-Ghaz, Mohammed; Weiss, W. Jason; Bradshaw, Aaron

2009-03-01

300

Ultra wide band radar holographic imaging of buried waste at DOE sites  

SciTech Connect

Ultra wideband linear array holography is a unique real-time imaging technique for in-situ inspection of buried waste at various DOE sites. The array can be mounted on various platforms such as crane booms, pickup trucks, ATVs, and scanned generating ``3-D`` subsurface images in real time. Inspection speeds are 0.5 to 2 meters/sec, if the image is viewed in real time, greater for off-line processing. The Ground Penetrating Holographic (GPH) system developed for inspection of DOE sites employs two 32element arrays of tapered-slot antenna operating at 5-GHz and 2.5-GHz center frequencies. The GPH system, which is mounted on a small trailer with a computer image processor, display, and power supply, is capable of imaging a wide swath (1 to 2 meters) with its linear arrays. The lower frequency array will be used at INEL (for greater depth penetration) because of high soil attenuation. Recent holographic ``3-D`` images of buried waste container lids and dielectrics obtained in Hanford sand and INEL soils at various depths graphically illustrate the unique image resolution capabilities of the system. Experimental results using the 5-GHz array will be presented showing the excellent holographic image quality of various subsurface targets in sand and INEL soil.

Collins, H.D.; Gribble, R.P.; Hall, T.E.; Lechelt, W.M.

1995-04-01

301

Evidence for a sedimentary siloxane horizon  

SciTech Connect

Selected samples from two Puget Sound sediment cores have been analyzed for poly(organo)siloxanes(silicones). One core was 60 years old at 30-cm depth (ages by lead-210 dating) and showed no evidence for silicones there. The second, 15 years old at depth, exhibited silicones at depth. Clearly shown is evidence for a siloxane horizon in theses two cores, with the presence of the horizon directly related to the fact that silicones have been in widespread use only since World War II. All samples were analyzed by solvent extraction and diffuse reflectance Fourier transform infrared spectrometry. 10 references, 2 figures, 1 table.

Pellenbarg, R.E.; Tevault, D.E.

1986-07-01

302

Are quantization rules for horizon areas universal?  

NASA Astrophysics Data System (ADS)

Doubts have been expressed on the universality of holographic/string-inspired quantization rules for the horizon areas of stationary black holes, or the products of their radii, already in 4-dimensional general relativity. Realistic black holes are not stationary but time-dependent. We produce three examples of 4-dimensional general-relativistic spacetimes containing dynamical black holes for at least part of the time, and we show that the quantization rules (even counting virtual horizons) cannot hold, except possibly at isolated instants of time, and do not seem to be universal.

Faraoni, Valerio; Moreno, Andres F. Zambrano

2013-08-01

303

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

304

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

305

Geophysical investigation of buried Pleistocene subglacial valleys in Northern Germany  

Microsoft Academic Search

Buried Pleistocene subglacial valleys are extensively used as groundwater reservoirs by waterworks in northern Germany, although little is known about the locations and size of these valleys and the internal structure of the sediment fill. This lack of knowledge about important groundwater reservoirs is a challenge for geophysics.This paper summarizes the geophysical investigation of two buried Pleistocene subglacial valleys in

Gerald Gabriel; Reinhard Kirsch; Bernhard Siemon; Helga Wiederhold

2003-01-01

306

First Results in Autonomous Mapping and Retrieval of Buried Objects  

Microsoft Academic Search

We are developing the means to autonomously retrieve buried objects. The most immediate application of this tech-nology is to cleanup operations at sites where toxic and nuclear wastes have been improperly stored. Many cleanup efforts are progressing slowly because they expose human workers to substantial risk. There is also substantial interest in the autonomous retrieval of buried unexploded ordnance at

Herman Herman; Sanjiv Singh

307

Diver-Portable Multi-Sensor Buried Mine-Hunter.  

National Technical Information Service (NTIS)

The long-term goal of this task is to identify and develop technology that will permit a diver to detect and localize fully buried mines as well as to detect, classify, and localize volume and partially buried mines. This task seeks to identify and develo...

D. L. Folds J. L. Lopes R. Marciniak

1998-01-01

308

Information processing in buried pipeline leak detection system  

Microsoft Academic Search

Detecting leak noises of buried pipelines is the most effective method of pinpointing a leak or leaks in buried pipelines. However, the acquired leak signals are usually blurred with ambient noises and therefore they have low signal-to-noise ratio. It is essential to use appropriate information processing scheme in order to acquire the leak signatures. The sensors are positioned on either

Yumei Wen; Ping Li; Jin Yang; Zhangmin Zhou

2004-01-01

309

Magnetic gradiometer on an AUV for buried object detection  

Microsoft Academic Search

Magnetic detection is an effective way for underwater buried target detection especially man-made objects which will contain some amount of permeable materials. Magnetic sensing can augment acoustic means of detection, effectively reduce false alarms. The advances in Autonomous Underwater Vehicle (AUV) technology enabled the integration of magnetic gradiometer onboard for underwater buried object detection. In this paper, the design considerations

Y. H. Pei; H. G. Yeo; X. Y. Kang; S. L. Pua; John Tan

2010-01-01

310

Littoral Assessment of Mine Burial Signatures (LAMBS) buried land mine/background spectral signature analyses  

USGS Publications Warehouse

The objective of the Office of Naval Research (ONR) Rapid Overt Reconnaissance (ROR) program and the Airborne Littoral Reconnaissance Technologies (ALRT) project's LAMBS effort is to determine if electro-optical spectral discriminants exist that are useful for the detection of land mines in littoral regions. Statistically significant buried mine overburden and background signature data were collected over a wide spectral range (0.35 to 14 ??m) to identify robust spectral features that might serve as discriminants for new airborne sensor concepts. LAMBS has expanded previously collected databases to littoral areas - primarily dry and wet sandy soils - where tidal, surf, and wind conditions can severely modify spectral signatures. At AeroSense 2003, we reported completion of three buried mine collections at an inland bay, Atlantic and Gulf of Mexico beach sites.1 We now report LAMBS spectral database analyses results using metrics which characterize the detection performance of general types of spectral detection algorithms. These metrics include mean contrast, spectral signal-to-clutter, covariance, information content, and spectral matched filter analyses. Detection performance of the buried land mines was analyzed with regard to burial age, background type, and environmental conditions. These analyses considered features observed due to particle size differences, surface roughness, surface moisture, and compositional differences.

Kenton, A. C.; Geci, D. M.; Ray, K. J.; Thomas, C. M.; Salisbury, J. W.; Mars, J. C.; Crowley, J. K.; Witherspoon, N. H.; Holloway, Jr. , J. H.

2004-01-01

311

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

312

Ge atom distribution in buried dome islands  

SciTech Connect

Laser-assisted atom probe tomography microscopy is used to provide direct and quantitative compositional measurements of tri-dimensional Ge distribution in Ge dome islands buried by Si. Sub-nanometer spatial resolution 3D imaging shows that islands keep their facets after deposition of the Si cap, and that the island/substrate/Si cap interfaces are abrupt. The core of the domes contains 55% of Ge, while the island shell exhibits a constant composition of 15% of Ge. The {l_brace}113{r_brace} facets of the islands present a Ge enrichment up to 35%. The wetting layer composition is not homogeneous, varying from 9.5% to 30% of Ge.

Portavoce, A.; Berbezier, I.; Ronda, A.; Mangelinck, D. [CNRS, IM2NP, Case 142, 13397 Marseille Cedex 20 (France); Hoummada, K. [Aix-Marseille Universite, IM2NP, Case 142, 13397 Marseille Cedex 20 (France)

2012-04-16

313

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

314

Backyard bolides: finding a buried impact crater.  

NASA Astrophysics Data System (ADS)

The author reports the scientific activities that led to his discovery of a huge submerged impact crater in Chesapeake Bay, some 140 km east of Atlantic City, New Jersey. This crater, buried under 350 m of sediment is 80 km wide and almost 1 km deep. Microfossil evidence shows that the crater is approximately 35 million years old. The author futher identified 14 small secondary craters with diamters of 0.4 to 0.5 km diameter within 60 km of the primary crater. These were caused by the impact of huge blocks of material ejected by the primary impact event. In addition, the author identified an intermediate-size primary crater (19 km diameter) in Toms Canyon, some 300 km from the Chesapeake crater and, again from microfossil evidence, identical in age.

Poag, C. W.

1998-10-01

315

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

316

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

317

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

318

Model Assessment of Alternatives for Reducing Seepage from Buried Uranium Mill Talings at the Morton Ranch Site in Central Wyoming  

SciTech Connect

The purpose of this study is to examine potential ground water contamination by seepage from buried tailings under four alternatives of clay liners and tailings placement, which have been proposed for possible use at the Morton Ranch Site. To accomplish this comparison of alternatives, laboratory work and numerous measurements were made on materials typical of the Morton Ranch Site. These measurements provide the soil characteristics necessary for input to the hydrologic flow and transport models.

Nelson, R. W.; Reisenauer, A. E.; Gee, G. W.

1980-06-01

319

Failure analysis of natural gas buried X65 steel pipeline under deflection load using finite element method  

Microsoft Academic Search

A 3D parametric finite element model of the pipeline and soil is established using finite element method to perform the failure analysis of natural gas buried X65 steel pipeline under deflection load. The pipeline is assumed to be loaded in a parabolic deflection displacement along the axial direction. Based on the true stress–strain constitutive relationship of X65 steel, the elastic–plastic

P. F. Liu; J. Y. Zheng; B. J. Zhang; P. Shi

2010-01-01

320

Eolian sedimentation and soil development on a semiarid to subhumid grassland, Tertiary Ogallala and Quaternary Blackwater Draw Formations, Texas and New Mexico High Plains  

SciTech Connect

Eolian sediments have accumulated as non-glacigenic loess and thin sand sheets on the Central and Southern High Plains grasslands of Texas and new mexico since the late Miocene. Locally as much as 110 m of eolian sediments with numerous paleosols are preserved in the Quaternary Blackwater Draw formation and the upper part of the Miocene-Pleiocene Ogallala formation. These sediments and paleosols, which cover more than 130,000 km{sup 2}, are similar to recent surface sediments and soils and record a long period of episodic eolian transport and sedimentation, and pedogenesis on a stable low-relief grass-covered landscape. Eolian sections, which comprise the fine sand to coarse silt lithofacies of the Ogallala formation, and the very fine to fine sand and sandy mud lithofacies of the Blackwater Draw formation, generally lack primary sedimentary structures. Grain size of Ogallala sediments decreases from west to east and grain size of Blackwater Draw sediments decreases from southwest to northeast. Soil horizonation is well developed in most sections, and buried calcic and argillic horizons are common. Calcic horizons are characterized by sharply increased CaCO{sub 3} content in the form of filaments, nodules, and petrocalcic horizons (calcretes). Argillic horizons are characterized by increased illuvial clay, pedogenic structure, and darker reddish hues. Rhizocretions are common locally. Open root tubules, which are typically less than 1 mm in diameter and characteristic of small plants like grasses, are present in all Ogallala and Blackwater Draw eolian sediments. Paleosols preserved in eolian sediments of the High Plains reflect periods of sedimentation followed by episodes of landscape stability and pedogenesis, and negligible sedimentation. Episodes of sedimentation and soil development likely resulted from cyclic decreases and increases in available moisture and vegetative cover. Eolian sediments were eroded and transported eastward during dry periods when vegetation was sparse in source areas, such as the western High Plains and the Pecos Valley. During humid periods more abundant vegetation probably protected source areas from deflation, and resulted in landscape stability across the High Plains.

Gustavson, T.C. [Univ. of Texas, Austin, TX (United States). Texas Archeological Research Lab.; Holliday, V.T. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Geography

1999-05-01

321

49 CFR 195.569 - Do I have to examine exposed portions of buried pipelines?  

Code of Federal Regulations, 2010 CFR

...to examine exposed portions of buried pipelines? 195.569 Section 195...to examine exposed portions of buried pipelines? Whenever you have knowledge that any portion of a buried pipeline is exposed, you must...

2010-10-01

322

49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.  

Code of Federal Regulations, 2010 CFR

...corrosion control: Examination of buried pipeline when exposed. 192.459 ...corrosion control: Examination of buried pipeline when exposed. Whenever an...knowledge that any portion of a buried pipeline is exposed, the...

2010-10-01

323

49 CFR 195.569 - Do I have to examine exposed portions of buried pipelines?  

Code of Federal Regulations, 2010 CFR

...to examine exposed portions of buried pipelines? 195.569 Section 195...to examine exposed portions of buried pipelines? Whenever you have knowledge that any portion of a buried pipeline is exposed, you must...

2009-10-01

324

49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.  

Code of Federal Regulations, 2010 CFR

...corrosion control: Examination of buried pipeline when exposed. 192.459 ...corrosion control: Examination of buried pipeline when exposed. Whenever an...knowledge that any portion of a buried pipeline is exposed, the...

2009-10-01

325

Hair from the Isolated Horizon Perspective  

Microsoft Academic Search

The recently introduced Isolated Horizons (IH) formalism has become a powerful tool for realistic black hole physics. In particular, it generalizes the zeroth and first laws of black hole mechanics in terms of quasi-local quantities and serves as a starting point for quantum entropy calculations. In this note we consider theories which admit hair, and analyze some new results that

Alejandro Corichi; Daniel Sudarsky

2000-01-01

326

An Albedo Horizon Sensor Using Hybrid Circuitry.  

National Technical Information Service (NTIS)

Successful operation of an albedo horizon sensor using hybrid circuitry was demonstrated in the flight of Skylark SL 904. Two sensors were flown, each having an array of 16 detector elements and the vehicle roll angle was measured over a 60 degree range t...

A. K. Brookman

1971-01-01

327

Three Dimensional Receding Horizon Control for UAVs  

Microsoft Academic Search

This paper presents a receding horizon controller (RHC) that can be used to design trajectories for an aerial vehicle flying through a three dimensional terrain with obstacles and no-fly zones. To avoid exposure to threats, the paths are chosen to stay as close to the terrain as possible, but the vehicle can choose to pop-up over the obstacles if neces-

Yoshiaki Kuwata

2004-01-01

328

NIOSH Deepwater Horizon Roster Summary Report.  

National Technical Information Service (NTIS)

The explosion on the Deepwater Horizon oil rig on April 20, 2010, resulted in the deaths of 11 workers and injuries to another 17 workers. In the weeks and months afterward, large amounts of crude oil were emitted from the Macondo Well. As a result, tens ...

2011-01-01

329

Trading horizons and the value of money  

Microsoft Academic Search

This paper shows that fiat money can be feasible and essential even if the trading horizon is finite and deterministic. The result hinges on two features of our model. First, individual actions can affect the future availability of productive resources. So, agents may be willing to sell for money, even if on that date they have no reason to accept

Gabriele Camera; Filip Vesely

2007-01-01

330

Adaptive Receding Horizon Control of Tubular Bioreactors  

Microsoft Academic Search

This paper presents a case study of application of an adaptive nonlinear predictive control algorithm to tubular bioreactors. According to the control strategy proposed, the system of PDEs describing the reactor is approximated by a lumped parameter model obtained using the Orthogonal Collocation Method. An adaptive receding horizon controller is then designed using Control Lyapunov Function methods. The design procedure

J. M. Igreja; J. M. Lemos; R. N. Silva

2005-01-01

331

Expanding Your Horizons in Science and Mathematics.  

National Technical Information Service (NTIS)

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 course...

C. E. A. Palmer

1995-01-01

332

Phosphorus fertilization by active dust deposition in a super-humid, temperate environment—Soil phosphorus fractionation and accession processes  

NASA Astrophysics Data System (ADS)

The inventory of soil phosphorus (P) is subject to significant changes over time. The main primary form, bedrock-derived apatite P, becomes progressively lost through leaching, or transformed into more immobile and less plant-accessible, secondary organic and mineral forms. Here we studied the rejuvenating effect of dust deposition on soil P along an active dust flux gradient downwind of a braided river. Along the gradient, we measured soil P fractions to 50 cm depth of six Spodosols and one Inceptisol, supplemented by tree foliage P concentrations. While an increasing dust flux correlates with a twofold increase of foliar P and soil organic P along the gradient, apatite P declines from ~50 to 3 g m-2 and total P shows no response. Compared to dust-unaffected Spodosols, depth distribution of total P becomes increasingly uniform and organic P propagates deeper into the soil under dust flux. Further, the effect of topsoil P eluviation attenuates due to higher organic P content and the zone of high apatite P concentrations associated with un-weathered subsoil becomes progressively removed from the upper 50 cm. We interpret these patterns as being consistent with upbuilding pedogenesi and conclude that dust-derived mineral P is assimilated in the organic surface horizon and does not reach the mineral soil. Dust-derived mineral P is temporarily stored in the living biomass and returns to the soil with plant and microbial detritus as organic P, which is subsequently buried by further dust increments. We further conclude that (1) the efficiency of P fertilization of the ecosystem by dust accession is higher than through P advection in dust-unaffected Spodosols and (2) organic P may serve as an important source of labile P in a high-leaching environment.

Eger, Andre; Almond, Peter C.; Condron, Leo M.

2013-01-01

333

Laboratory Load Tests on Buried Flexible Pipe-Progress Report No. 6. Steel and Fiberglass Reinforced Resin Pipe in Sand Backfill.  

National Technical Information Service (NTIS)

Two steel pipe, one reinforced plastic mortar, and one fiberglass reinforced plastic pipe, each about 18 inches (46 centimeters) in diameter and 71 inches long were load-tested in a laboratory soil container. All pipe were buried in a sand backfill. Incre...

A. K. Howard

1973-01-01

334

What happens at the horizon(s) of an extreme black hole?  

NASA Astrophysics Data System (ADS)

A massless scalar field exhibits an instability at the event horizon of an extreme black hole. We study numerically the nonlinear evolution of this instability for spherically symmetric perturbations of an extreme Reissner-Nordstrom (RN) black hole. We find that generically the endpoint of the instability is a non-extreme RN solution. However, there exist fine-tuned initial perturbations for which the instability never decays. In this case, the perturbed spacetime describes a time-dependent extreme black hole. Such solutions settle down to extreme RN outside, but not on, the event horizon. The event horizon remains smooth but certain observers who cross it at late time experience large gradients there. Our results indicate that these dynamical extreme black holes admit a C1 extension across an inner (Cauchy) horizon.

Murata, Keiju; Reall, Harvey S.; Tanahashi, Norihiro

2013-12-01

335

Geomorphic Analysis of Soils  

NSDL National Science Digital Library

Students are taken to a former plantation along a tidal river near Charleston, SC. The students are then shown how to sample and describe soils using an push-auger sampler, similar to those used in industry. After the demonstration, the students are taken to various locations on the plantation, including upland areas, wetlands, former agricultural areas, lowlands, and tidal marshes, to sample and make field descriptions of the various soils encountered. Students describe depths to horizons, soil color using Munsell Color Charts, soil texture, and any other pertinent properties. Students then prepare a formal technical write-up on the soils, their distribution, and how their sampling results compare to published soil data for the area. Designed for a geomorphology course Uses online and/or real-time data

Doyle, Briget

336

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.

337

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

338

Soil warming and carbon loss from a lake states Spodosol  

SciTech Connect

Elevated soil temperatures may increase C loss from soils by accelerating microbial respiration and dissolved organic C leaching. The authors evaluated the effect of elevated soil temperatures on C losses from a forest Spodosol by incubating soil cores from surface (Oa + A + E) and subsurface (Bhs) horizons at two seasonal temperature regimes. One regime simulated the normal course of soil temperatures in northern lower Michigan, and the other simulated soil temperatures representing an amount of warming the might occur under some global warming theory calculations. The authors measured the amounts of CO{sub 2}-C respired and dissolved organic C leached from the soil cores during a 33-wk period. Microbial respiration rates, after adjustment for variation in initial rates, were significantly increased by soil warming and were greater in surface than in subsurface horizons. Warming significantly increased cumulative C respired, with greater losses from surface soils as compared with subsurface soils. Mean quantities of dissolved organic C leached, ranging from 2.3 to 3.2 mg C g{sup {minus}1} C, did not differ significantly by soil horizon or temperature regime. Increased microbial respiration in surface soil horizons was the process most responsive to soil warming in the Spodosol samples examined. Whether this is a short-term effect that would disappear once pools of labile C are exhausted, or represents a long-term response to soil warming, remains uncertain.

MacDonald, N.W. [Grand Valley State Univ., Allendale, MI (United States). Dept. of Biology; Randlett, D.L.; Zak, D.R. [Univ. of Michigan, Ann Arbor, MI (United States). School of Natural Resources and Environment

1999-01-01

339

Protocol-based conflict resolution for finite information horizon  

Microsoft Academic Search

Proposes a protocol-based multiple aircraft conflict resolution for a finite information horizon, in which the communication range of an aircraft is finite. A protocol for multiple aircraft conflict resolution for an infinite information horizon is presented and then this protocol is extended to a finite information horizon problem using graph theory. Communication topology among aircraft is important for the finite

Inseok Hwang; Claire Tomlin

2002-01-01

340

Gravitational anomaly and Hawking radiation near a weakly isolated horizon  

Microsoft Academic Search

Based on the idea of the work by Wilczek and his collaborators, we consider the gravitational anomaly near a weakly isolated horizon. We find that there exists a universal choice of tortoise coordinate for any weakly isolated horizon. Under this coordinate, the leading behavior of a quite arbitrary scalar field near a horizon is a 2-dimensional chiral scalar field. This

Wu Xiaoning; Huang Chaoguang; Sun Jiarui

2008-01-01

341

A note on the receding-horizon control method  

Microsoft Academic Search

In this correspondence, the relation of receding-horizon control method with the state deadbeat control is brought out. It is shown for single-input systems that the receding-horizon control is a state deadbeat control if the horizon length is taken to be equal to the state dimension.

ENGIN YAZ; HASAN SELBUZ

1984-01-01

342

Complications of a buried penis in an extremely obese patient.  

PubMed

The buried penis syndrome in adults is a rare condition of different aetiologies. Today extreme obesity is considered as a major contributor. We present a case of a 30-year-old extremely obese patient (BMI 65 kg/m(2)) with purulent infection of the penile cavity, a phlegmon of the mons pubis and urinary retention due to a buried penis. Whereas acute complications of a buried penis in obese patients include local infection and urinary retention, chronic problems are undirected voiding, disturbed vaginal penetration and erectile dysfunction. Even though several surgical techniques are described, weight reduction should be primarily preferred. PMID:21762192

Mattsson, B; Vollmer, C; Schwab, C; Padevit, C; Horton, K; John, H; Horstmann, M

2012-05-01

343

Computer vision and sensor fusion for detecting buried objects  

SciTech Connect

Given multiple images of the surface of the earth from dual-band infrared sensors, our system fuses information from the sensors to reduce the effects of clutter and improve the ability to detect buried or surface target sites. Supervised learning pattern classifiers (including neural networks,) are used. We present results of experiments to detect buried land mines from real data, and evaluate the usefulness of fusing information from multiple sensor types. The novelty of the work lies mostly in the combination of the algorithms and their application to the very important and currently unsolved problem of detecting buried land mines from an airborne standoff platform.

Clark, G.A.; Hernandez, J.E.; Sengupta, S.K.; Sherwood, R.J.; Schaich, P.C.; Buhl, M.R.; Kane, R.J.; DelGrande, N.K.

1992-10-01

344

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

345

DISTRIBUTION PATTERN OF SOME HEAVY METALS IN SOIL AND PLANTS ALONG EL-MOUKATTAM HIGHWAY  

Microsoft Academic Search

Generally very wide variations are not noticed in the distribution of lead (Pb) between the different horizons of soil profiles. However, Pb contents vary more or less, in relation to humus and organic matter concentrations. Most of the time, an accumulation of Pb is observed in the upper soil horizons. The mobilization patterns of cadmium (Cd) indicate that ion exchange

Ibrahim M El-Gamal

346

Quantitative Relationships Between Net Volume Change and Fabric Properties During Soil Evolution  

NASA Technical Reports Server (NTRS)

The state of soil evolution can be charted by net long-term volume and elemental mass changes for individual horizons compared with parent material. Volume collapse or dilation depends on relative elemental mass fluxes associated with losses form or additions to soil horizons.

Chadwick, O. A.; Nettleton, W. D.

1993-01-01

347

Fate and Speciation of Gasoline-Derived Lead in Organic Horizons of the Northeastern USA  

SciTech Connect

Although legislation in the late 1970s significantly reduced atmospheric lead (Pb) inputs to ecosystems in North America, organic (O) horizons in forests of the northeastern USA still contain up to 30 kg of gasoline-derived Pb ha{sup -1}. The residence time, geochemical behavior, and fate of this contaminant Pb in soils is poorly understood. Here we use forest floor time series data and synchrotron-based X-ray techniques to examine the mobility and speciation of Pb in O horizons collected from remote sites across the northeastern USA. At high elevation (>800 m) sites in Vermont and New York, samples collected from similar locations in 1980, 1990, and early 2000 had indistinguishable Pb contents, ranging ({+-}1{sigma}) from 11 to 29 kg Pb ha{sup -1}. However, at lower elevation and lower latitude sites with mixed vegetation, significant decreases in Pb amount were observed during the two-decade study period. Lower elevation sites ranged from 10 to 20 kg Pb ha{sup -1} in 1980, and from 2 to 10 kg Pb ha{sup -1} 20 yr later. Lead-enriched soil grains were determined to be amorphous with microfocused X-ray diffraction, and Pb concentrations correlated well with Fe on maps generated via microfocused X-ray fluorescence. Bulk Pb L{sub III}-edge X-ray absorption spectroscopy of coniferous O horizon samples indicate that Pb is binding to iron-rich soil particles by inner-sphere complexes, most likely to amorphous Fe oxides. Based on our paired regional and microscopic observations, we conclude that Pb is strongly retained in well-drained O horizons, and mobility is governed by decomposition and colloidal transport.

Kaste,J.; Bostick, B.; Friedland, A.; Schroth, A.; Siccama, T.

2006-01-01

348

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

349

Soil hydraulic and physico-chemical properties of Ultisols and Inceptisols in south-eastern Nigeria  

Microsoft Academic Search

Understanding soil water dynamics and storage is important to avoid crop failure on highly weathered, porous and leached soils. The aim of the study was to relate soil moisture characteristics to particle-size distributions and chemical properties. On average, Atterberg limits were below 25% in the A-horizon and not more than26.56% in the B-horizon, whereas soil bulk density was between 1.27

Charles A. Igwe; Mehdi Zarei; Karl Stahr

2012-01-01

350

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

351

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

352

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

353

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

2013-12-11

354

A diphtheria outbreak in Buri Ram, Thailand.  

PubMed

In May 1996 there was an outbreak of diphtheria in Buri Ram, Thailand which infected 31 patients, 8 males and 23 females. The mean age of the patients was 8 +/- 5 years. Seventy-four percent had a history of childhood vaccinations. Common signs and symptoms included fever (100%) which was low grade in 61%, sore throat (90%), upper airway obstruction (3%), and hoarseness (10%). Pseudomembranes (seen in 100%) were located on the tonsils (71%), pharynx (22%), larynx (9.6%), and uvula (6%). The mean duration of symptoms prior to admission was 2 days with a range of 1 to 5 days. Complications included upper airway obstruction (10%) and cardiac complications (10%). There were no neurological complication or deaths. There were negative associations between cardiac complications, severity of disease and previous diphtheria vaccination. The ages varied from children to adults. Early recognition and prompt treatment decreased complications and mortality in this group of patients when compared with Chiang Mai and Queen Sirikit National Institute of Child Health (QSNICH) studies. PMID:19058607

Pantukosit, Pantavee; Arpornsuwan, Manote; Sookananta, Kanokporn

2008-07-01

355

Experimental study of near-surface radar imaging of buried objects with adaptive focused synthetic aperture processing  

NASA Astrophysics Data System (ADS)

This paper deals with the application of stepped frequency radar to subsurface imaging of buried targets with a final aim of object imaging and identification. The applications are mainly mines or UXO detection but also buried pipes. The depths considered here are a few cm to 15 cm under the surface (from the top of the object). It is necessary to use a UWB radar in order to separate the soil interface from the top of the object. A versatile system has been built that can be brought outdoor. It is used to find the best parameters for a future optimal radar. Special antennas have been realized that cover the 500 MHz to 8 GHz frequency range. The antenna pair (T/R) moves at a given height over the soil surface along a rail. Radar returns are then processed on a PC in order to deliver in a few seconds a 2D vertical profile of the soil. A special algorithm for near field synthetic focusing aperture has been developed for this task. It takes into account the wave propagation in the soil. Tomographic images are presented for different objects in different soils (.5 to 5 GHz and 2 to 8 GHz bandwidths) that show the quality of the results delivered by this improved technique. Conclusion are drawn on the potentialities and the limitations of the method and future perspectives like 3D imaging.

Millot, Patrick; Bureau, J. C.; Borderies, P.; Bachelier, E.; Pichot, Christian; Le Brusq, E.; Guillanton, E.; Dauvignac, J. Y.

2000-07-01

356

Horizon spectroscopy in and beyond general relativity  

NASA Astrophysics Data System (ADS)

In this work we generalize the results for the entropy spectra typically derived for black holes in general relativity to a generic horizon within the spherically symmetric (asymptotically flat and nonflat) space-times of more general theories of gravity. We use all the standard approaches—Bekenstein's universal lower bound on the entropy transition, the highly damped quasinormal modes and reduced phase-space quantization—to derive the spectra. In particular, the three approaches show that the Bekenstein-like spectra for the horizon entropy is a robust result. Our results confirm the suggestion made relatively recently by an independent fourth argument by Kothawala et al. [Phys. Rev. D 78, 104018 (2008)].

Skákala, Jozef; Shankaranarayanan, S.

2014-02-01

357

Horizon ratio bound for inflationary fluctuations.  

PubMed

We demonstrate that the gravity wave background amplitude implies a robust upper bound on the wavelength-to-horizon ratio at the end of inflation: lambda/H(-1) less than or approximately equal e(60), as long as the cosmic energy density does not drop faster than radiation subsequent to inflation. This limit implies that N, the number of e-folds between horizon exit and the end of inflation for wave modes of interest, is less, similar 60 plus a model-dependent factor-for vast classes of slow-roll models, N less than or approximately equal 67. As an example, this bound solidifies the tension between observations of the cosmic microwave background anisotropies and chaotic inflation with a phi(4) potential by closing the escape hatch of large N (<62). PMID:14525296

Dodelson, Scott; Hui, Lam

2003-09-26

358

Noether current, horizon Virasoro algebra, and entropy  

NASA Astrophysics Data System (ADS)

We provide a simple and straightforward procedure for defining a Virasoro algebra based on the diffeomorphisms near a null surface in a space-time and obtain the entropy density of the null surface from its central charge. We use the off-shell Noether current corresponding to the diffeomorphism invariance of a gravitational Lagrangian L(gab,Rabcd) and define the Virasoro algebra from its variation. This allows us to identify the central charge and the zero-mode eigenvalue with which we obtain the entropy density of the Killing horizon. Our approach works for all Lanczos-Lovelock models and reproduces the correct Wald entropy. The entire analysis is done off-shell without using the field equations and allows us to define an entropy density for any null surface which acts as a local Rindler horizon for a particular class of observers.

Majhi, Bibhas Ranjan; Padmanabhan, T.

2012-04-01

359

Polarimetry with the Event Horizon Telescope  

NASA Astrophysics Data System (ADS)

The Event Horizon Telescope (EHT) is an effort to develop millimeter and submillimeter VLBI to image nearby black holes at resolutions comparable to their event horizons. Past work with the EHT has measured compact emission on such scales for Sgr A* and M87, and has also measured sub-parsec structure in more distant quasars. Polarimetry with the EHT enables a powerful extension of this work, mapping magnetic field structures via the highly polarized synchrotron emission. Polarization is also an excellent probe of rapid variability, especially for Sgr A*, and can convey rich astrometric information even with incomplete imaging. We report on results from our 2013 campaign, which demonstrate a sharp increase in the linear polarization fraction and variability with increasing baseline, and we demonstrate that current EHT data can potentially achieve microarcsecond relative astrometry of flaring regions on timescales of minutes.

Johnson, Michael; Doeleman, Sheperd; Fish, Vincent L.; Plambeck, Richard L.; Marrone, Daniel P.; Kosowsky, Michael; Wardle, John F. C.; Lu, Rusen

2014-06-01

360

Identification of buried structures (aerial surveillance and analysis of buried waste) long-range project plan  

SciTech Connect

This long-range plan presents the plan (i.e., budget, schedule, justification, and plans for technology deployment) for implementation of the Identification of Buried Structures project. Two subcontractors will test and demonstrate their technologies at the Idaho National Engineering Laboratory during October and November 1991, and will analyze their data and submit final reports to EG G Idaho, Inc., by the end of December 1991. By February 21, 1992, EG G Idaho will present a final report to the Department of Energy, assessing the subcontractor's results and recommending further action.

Williams, K.L.

1991-11-01

361

Identification of buried structures (aerial surveillance and analysis of buried waste) long-range project plan  

SciTech Connect

This long-range plan presents the plan (i.e., budget, schedule, justification, and plans for technology deployment) for implementation of the Identification of Buried Structures project. Two subcontractors will test and demonstrate their technologies at the Idaho National Engineering Laboratory during October and November 1991, and will analyze their data and submit final reports to EG&G Idaho, Inc., by the end of December 1991. By February 21, 1992, EG&G Idaho will present a final report to the Department of Energy, assessing the subcontractor`s results and recommending further action.

Williams, K.L.

1991-11-01

362

Carbon Stabilization in Wet Tropical Forest Volcanic Soils  

NASA Astrophysics Data System (ADS)

Volcanic soils, particularly Andisols, have high carbon storage capacities due to the accumulation of highly reactive, non-crystalline minerals. Previous research along a pedogenic chronosequence on volcanic lava in Hawai'i found that soils in the intermediate weathering stage, dominated by allophane, contained the largest soil C stocks with slowest turnover rates. Potential mechanisms for long-term soil C stabilization include an accumulation of chemically recalcitrant C, microenvironmental conditions unfavorable for decomposition, and strong sorption of soluble and otherwise labile C to mineral and/or metals. In well-drained soils in wet climates, dissolved organic matter (DOM) is a likely main pathway for the transport of C from the zones of highest microbial activity to deeper mineral horizons. To address the production, transformation, and fate of dissolved organic matter (DOM), we have installed tension and zero tension lysimeters throughout sequentially deeper organic and mineral horizons in an intermediate aged soil (ca. 350k years) under wet (ca. 3000 mm mean annual rainfall) native tropical forest in Hawai'i. The soils are characterized by thick O horizons and Bh horizons 20-30 cm deep, followed by mineral horizons showing redoximorphic features. Bulk soil carbon to nitrogen ratios increase with soil depth, matching that of DOM in the surface organic horizons at 40-50 cm depth. Low pH does not seem to explain this accumulation of C-rich, N-depleted OM, as soils become less acidic with depth. Soil C:N are positively correlated with alumina, oxalate-extractable Al, and dithionite citrate-extractable Al. The greatest source of DOC is the forest floor (Oie), followed by the Oa horizon, and concentrations decrease significantly in the mineral horizons. DOC concentrations increase with total dissolved Al and Fe in the Oie horizon, and with total Fe in solution in the Bg horizon. In the Bh horizon, DOM C:N are negatively correlated with total Al and Fe in solution. Metals appear to be implicated in the mobilization of C in solution and its stabilization in mineral horizons. The formation of cracks along large peds facilitates macropore flow and downward delivery of carbon.

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

2008-12-01

363

Super-horizon cosmic string correlations  

Microsoft Academic Search

When gauged cosmic strings form in a symmetry-breaking phase transition, the gauge field configuration at the time becomes imprinted in the spatial string distribution by the flux trapping mechanism. Causality and flux conservation suggest that quantum and thermal gauge field fluctuations give rise to long-range super-horizon correlations in the string network. Classical field theory simulations in the Abelian Higgs model

Rajantie; Arttu

2009-01-01

364

Astrophysical Evidence for Black Hole Event Horizons  

Microsoft Academic Search

Astronomers have discovered many potential black holes in X-ray binaries and\\u000agalactic nuclei. These black holes are usually identified by the fact that they\\u000aare too massive to be neutron stars. Until recently, however, there was no\\u000aconvincing evidence that the objects identified as black hole candidates\\u000aactually have event horizons. This has changed with extensive applications of a\\u000aclass

Kristen Menou; Eliot Quataert; Ramesh Narayan

1998-01-01

365

The New Horizons Radio Science Experiment (REX)  

Microsoft Academic Search

The New Horizons (NH) Radio Science Experiment, REX, is designed to determine the atmospheric state at the surface of Pluto\\u000a and in the lowest few scale heights. Expected absolute accuracies in n, p, and T at the surface are 4?1019 m?3, 0.1 Pa, and 3 K, respectively, obtained by radio occultation of a 4.2 cm-? signal transmitted from Earth at 10–30 kW and received

G. L. Tyler; I. R. Linscott; M. K. Bird; D. P. Hinson; D. F. Strobel; M. Pätzold; M. E. Summers; K. Sivaramakrishnan

2008-01-01

366

Accurate, reliable prototype earth horizon sensor head  

NASA Technical Reports Server (NTRS)

The design and performance is described of an accurate and reliable prototype earth sensor head (ARPESH). The ARPESH employs a detection logic 'locator' concept and horizon sensor mechanization which should lead to high accuracy horizon sensing that is minimally degraded by spatial or temporal variations in sensing attitude from a satellite in orbit around the earth at altitudes in the 500 km environ 1,2. An accuracy of horizon location to within 0.7 km has been predicted, independent of meteorological conditions. This corresponds to an error of 0.015 deg-at 500 km altitude. Laboratory evaluation of the sensor indicates that this accuracy is achieved. First, the basic operating principles of ARPESH are described; next, detailed design and construction data is presented and then performance of the sensor under laboratory conditions in which the sensor is installed in a simulator that permits it to scan over a blackbody source against background representing the earth space interface for various equivalent plant temperatures.

Schwarz, F.; Cohen, H.

1973-01-01

367

Finding KBO flyby targets for New Horizons  

NASA Astrophysics Data System (ADS)

We propose to continue the search for Kuiper Belt Objects (KBOs) that can be reached by the New Horizons spacecraft after its 2015 Pluto flyby. This first flyby of a small (~50 km) KBO would revolutionize our understanding of KBOs, providing information that can be extrapolated to hundreds of thousands of similar KBOs. Our 2011 search discovered three objects that could be targeted with only about twice the fuel that New Horizons has available during excellent seeing, but seeing was insufficient to achieve this depth over the entire search area in 2012 or 2013. Deepening the search in 2014, taking advantage of lower star density and the shrinking search area, has a good chance of finding a targetable object given sufficiently good seeing, especially with Hyper Suprime Cam. We expect about 2.5 targetable objects with R less 26.0 in the HSC field of view. We will also refine the orbits of previously discovered objects, including ones that can be observed from a distance by New Horizons on its passage through the Kuiper Belt.

Spencer, John; Trilling, David; Buie, Marc; Parker, Alex; Tholen, David; Stern, S. Alan

2014-02-01

368

Finding KBO flyby targets for New Horizons  

NASA Astrophysics Data System (ADS)

We propose to continue the search for Kuiper Belt Objects (KBOs) that can be reached by the New Horizons spacecraft after its 2015 Pluto flyby, by following up on KBOs discovered in 2014A. The first flyby of a small (~50 km) KBO would revolutionize our understanding of KBOs, providing information that can be extrapolated to hundreds of thousands of similar KBOs. Our 2011 search discovered two objects that could be targeted with less than twice the fuel that New Horizons has available, during excellent seeing, but seeing was insufficient to achieve this depth over the entire search area in 2012 or 2013. Deepening the search with time allocated in 2014A, taking advantage of lower star density and the shrinking search area, has a chance of finding a targetable object given sufficiently good seeing, especially with Hyper Suprime Cam. 2014B follow-up is essential to produce orbits good enough to determine targetability, and allow recovery in 2015. We will also continue to refine the orbits of other previously discovered objects, including ones that can be observed from a distance by New Horizons on its passage through the Kuiper Belt.

Spencer, John; Trilling, David; Buie, Marc; Parker, Alex; Tholen, David; Stern, S. Alan

2014-08-01

369

Index theory and supersymmetry of 5D horizons  

NASA Astrophysics Data System (ADS)

We prove that the near-horizon geometries of minimal gauged five-dimensional supergravity preserve at least half of the supersymmetry. If the near-horizon geometries preserve a larger fraction, then they are locally isometric to AdS 5. Our proof is based on Lichnerowicz type theorems for two horizon Dirac operators constructed from the supercovariant connection restricted to the horizon sections, and on an application of the index theorem. An application is that all half-supersymmetric five-dimensional horizons admit an sl(2 , ) symmetry subalgebra.

Grover, J.; Gutowski, J.; Papadopoulos, G.; Sabra, W. A.

2014-06-01

370

Applied Geophysics and the Detection of Buried Munitions.  

National Technical Information Service (NTIS)

Buried military munitions, such as bombs, artillery projectiles, rockets and landmines can present serious safety hazards. Geophysical investigations are often used to detect such munitions so that they can be safely recovered and destroyed. However, diff...

L. Helms R. Young

1996-01-01

371

Liquefaction Hazards and Their Effects on Buried Pipelines.  

National Technical Information Service (NTIS)

The research described involves the evaluation of liquefaction-induced ground movements and their effects on buried pipelines. The work is divided into three components: review of liquefaction phenomena and associated ground displacements; characterizatio...

T. D. O'Rourke P. A. Lane

1989-01-01

372

Development of Coating Defect Inspection Technique for Buried Steel Pipelines.  

National Technical Information Service (NTIS)

Coating defect inspection system (Super Coating Defect Inspection System-SUPER CODINS) which can detect defects in the coating of buried steel pipelines from the ground surface has been developed. The system consists of a transmitter for passing the leaka...

M. Kawakami Y. Kuroda K. Kawabata N. Sasaki N. Fujii

1989-01-01

373

Experiment on Performance of Buried Pipelines Across San Andreas Fault.  

National Technical Information Service (NTIS)

A field experiment designed to investigate the performance of buried pipelines at a fault crossing has been constructed near Parkfield, CA. The site was chosen to capitalize on the predicted recurrence of the 1966 Parkfield-Cholame earthquake sequence. Mo...

J. Isenberg E. Richardson T. D. O'Rourke

1989-01-01

374

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

375

Seismic Design Criteria for Buried Water Pipeline in Puerto Rico.  

National Technical Information Service (NTIS)

The primary objective of this report was to determine the effect of earthquakes on buried water pipelines constructed in Puerto Rico. The work established the design earthquake parameters required together with a simplified dynamic analysis technique that...

R. Jimenez-Perez

1983-01-01

376

Detection of Buried Mines and Unexploded Ordnance (UXO).  

National Technical Information Service (NTIS)

Most military and commercial detectors sense the presence of metal casings or components of buried mines or explosive ordnance; however, this traditional approach to mine and unexploded ordnance (UXO) detection is prone to high false alarm rates. Explosiv...

B. Balko D. Heberlein I. Chappell J. Biddle

2007-01-01

377

Finite Element Analysis of a Large Diameter Buried Steel Pipeline.  

National Technical Information Service (NTIS)

In a buried pipe, the stresses and displacements produced during placement and compaction of the backfill are difficult to predict theoretically because their values are strongly influenced by the construction procedures employed on site. However, the dis...

P. Nath

1977-01-01

378

Corrosion and Corrosion Prevention in Buried Pipelines and Containers.  

National Technical Information Service (NTIS)

Summaries are presented of papers on the underground corrosion behavior of metals and methods for prevention of corrosion in buried pipes and containers. The summaries included are: corrosion behavior of metallic materials; corrosion behavior of copper an...

1979-01-01

379

Seismic and DC resistivity imaging of a buried channel, NW Alberta, Canada  

NASA Astrophysics Data System (ADS)

Buried channels are often filled with a variety of porous and permeable sediments which can act as water and hydrocarbons reservoirs. Shallow methane deposits within these channels (less than 50-m deep) represent a significant drilling hazard in some areas. A joint high resolution seismic reflection and DC resistivity 10 km long profiles were acquired in northwest Alberta to define the position and geological setting of a buried channel. Due to the near surface nature (50-m to 300-m) of the target, a high spatial and temporal resolution seismic profile was collected using a 240 channel semi-distributed seismic acquisition system recording 40 Hz geophones placed at a 4-m spacing. A high-frequency seismic vibrator provided a 20-250 Hz source sweep. Electrical resistivity tomography (ERT) data was acquired using a 15-m electrode spacing. At its deepest point, the channel cuts through more than 300-m of Cretaceous sands and shales through a regional unconformity into higher velocity carbonates. The channel fill materials have generally lower seismic velocities and are more resistive than the flanking undisturbed Cretaceous formations. These contrasts allow the channel to be detected on the basis of both refraction and resistivity analysis, which is in good agreement with geology. The resistivity profile further shows highly resistive zones that may be indicative of shallow gas which correspond to a known producing horizon. These filled incised valley sediments were may have been deposited during different periods of glaciation. Geochemical analyses of shallow gas from wells within the channel indicates a thermogenic origin and suggests that the channel both breeches the source zone and serves as a conduit for escaping methane.

Ahmad, J.; Schmitt, D. R.; Rokosh, C. D.; Pawlowicz, J.; Plouffe, A.

2005-12-01

380

Detection of buried objects beneath a rough surface  

Microsoft Academic Search

This paper deals with the detection of a buried object beneath a rough surface in a two-dimensional configuration. A new method for detecting buried objects from wide-band, near-field, multi-static data is suggested. The so-called near-field configuration corresponds to a set of transmitters and receivers located along a line segment in the vicinity of the surface. The detection method proposed here

O. Cmielewski; M. Saillard; H. Tortel

2006-01-01

381

User performance testing of the Perimitrax buried cable sensor  

Microsoft Academic Search

Beginning in the 1970's buried cable sensors have been used extensively to provide perimeter intrusion detection for a wide range of military, government and industrial facilities around the world. In 1998, the U.S. Army Engineer Research and Development Center (USAERDC), in partnership with Senstar-Stellar Corporation, conducted testing of the Perimitrax buried cable sensor. Perimitrax is a new product manufactured by

M. Maki; C. Hill; C. R. Malone

1999-01-01

382

Wireless Power Transmission to a Buried Sensor in Concrete  

Microsoft Academic Search

The feasibility of sending wireless power to a buried sensor antenna within concrete was studied. A receive patch rectenna with 75.8% conversion efficiency was designed for operation at 5.7 GHz. The received DC power at the rectenna was measured within dry and wet concrete samples with various cover thicknesses and air-gaps. For the rectenna buried within 30 mm of the

Khan M. Z. Shams; Mohammod Ali

2007-01-01

383

Imaging of buried objects by low frequency SAS  

Microsoft Academic Search

Search for buried objects are normally done by normal incidence sonar, working with wide-band low frequency signals. Especially the parametric sonar has proven to be a reliable tool to detect buried objects, as well as for mapping of internal stratification in sub-bottom layers. However, due to the small foot-print searching with normal incidence sonar is tedious. Also, in a mine

M. Jonsson; Jorgen Pihl; M. Aklint

2005-01-01

384

Data fusion for the detection of buried land mines  

SciTech Connect

The authors conducted experiments to demonstrate the enhanced delectability of buried land mines using sensor fusion techniques. Multiple sensors, including imagery, infrared imagery, and ground penetrating radar, have been used to acquire data on a number of buried mines and mine surrogates. The authors present this data along with a discussion of the application of sensor fusion techniques for this particular detection problem. The authors describe the data fusion architecture and discuss some relevant results of these classification methods.

Clark, G.A.; Sengupta, S.K.; Schaich, P.C.; Sherwood, R.J.; Buhl, M.R.; Hernandez, J.E.; Kane, R.J.; Barth, M.J.; Fields, D.J.; Carter, M.R.

1993-10-01

385

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

386

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

387

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

388

Centrifugal and numerical modeling of buried structures. Volume 3. A centrifuge study of the behavior of buried conduits under airblast loads. Final report  

SciTech Connect

The principal object of the research was to provide a better understanding of the behavior of the soil-structure interaction phenomena associated with buried conduits subjected to airblast loads. A parametric study was performed to experimentally determine the effects of airblast loads on 4-in-diameter micro-concrete pipes, embedded horizontally in a dry sand. The parameters varied in the study included the gravity level, the applied airblast pressure level, the relative density of the dry sand, burial depth of the structure, and the relative stiffness between the structure and the soil. A geotechnical centrifuge was used to create the proper in-situ stress conditions in the sample during each test. Dynamic stress gages were utilized to measure the applied airblast on the sample surface, the normal stresses acting at the soil-pipe interface, and in the free-field conditions. Proximitors positioned inside of the structures were used to measure the resulting deflections. The results of the experimental study verified the importance of testing models at increased gravity levels, and determined the feasibility of the dynamic stress gages for measurement of contact and free-field stresses. Interesting trends in contact stresses around the circumference of the pipe; variations of 20% in relative density of the sand produced no significant changes in contact stress levels.

Whittaker, J.P.

1987-07-14

389

Using atmospheric fallout to date organic horizon layers and quantify metal dynamics during decomposition  

NASA Astrophysics Data System (ADS)

High concentrations of metals in organic matter can inhibit decomposition and limit nutrient availability in ecosystems, but the long-term fate of metals bound to forest litter is poorly understood. Controlled experiments indicate that during the first few years of litter decay, Al, Fe, Pb, and other metals that form stable complexes with organic matter are naturally enriched by several hundred percent as carbon is oxidized. The transformation of fresh litter to humus takes decades, however, such that current datasets describing the accumulation and release of metals in decomposing organic matter are timescale limited. Here we use atmospheric 210Pb to quantify the fate of metals in canopy-derived litter during burial and decay in coniferous forests in New England and Norway where decomposition rates are slow and physical soil mixing is minimal. We measure 210Pb inventories in the O horizon and mineral soil and calculate a 60-630 year timescale for the production of mobile organo-metallic colloids from the decomposition of fresh forest detritus. This production rate is slowest at our highest elevation (˜1000 m) and highest latitude sites (>63°N) where decomposition rates are expected to be low. We calculate soil layer ages by assuming a constant supply of atmospheric 210Pb and find that they are consistent with the distribution of geochemical tracers from weapons fallout, air pollution, and a direct 207Pb application at one site. By quantifying a gradient of organic matter ages with depth in the O horizon, we describe the accumulation and loss of metals in the soil profile as organic matter transforms from fresh litter to humus. While decomposition experiments predict that Al and Fe concentrations increase during the initial few years of decay, we show here that these metals continue to accumulate in humus for decades, and that enrichment occurs at a rate higher than can be explained by quantitative retention during decomposition alone. Acid extractable Al and Fe concentrations are higher in the humus layer of the O horizon than in the mineral soil immediately beneath this layer: it is therefore unlikely that physical soil mixing introduces significant Al and Fe to humus. This continuous enrichment of Al and Fe over time may best be explained by the recent suggestion that metals are mined from deeper horizons and brought into the O horizon via mycorrhizal plants. In sharp contrast to Al and Fe, we find that Mn concentrations in decomposing litter layers decrease exponentially with age, presumably because of leaching or rapid uptake, which may explain the low levels of acid extractable Mn in the mineral soil. This study quantifies how metals are enriched and lost in decomposing organic matter over a longer timescale than previous studies have been able to characterize. We also put new limits on the rate at which metals in litter become mobile organo-metallic complexes that can migrate to deeper soil horizons or surface waters.

Kaste, James M.; Bostick, Benjamin C.; Heimsath, Arjun M.; Steinnes, Eiliv; Friedland, Andrew J.

2011-03-01

390

Hydrologic characteristics of Nebraska soils  

USGS Publications Warehouse

The influence of the physical characteristics of soil on hydrology is frequently neglected. In this report, the effects of five characteristics on the hydrologic responses of soils in Nebraska are evaluated quantitatively, soils are grouped through use of a simplified coding system according to similarities in hydrologic responses, and are mapped according to these responses. General soils maps of the U.S. Department of Agriculture Soil Conservation Service and data for the physical properties of the soils proved well-suited to hydrologic interpretation. This interpretation of the maps and data led to the selection of three characteristics as classification variables: Average permeability of the 60-inch soil profile, average maximum soil slope, and depth to the seasonal high water table. Permeability of the least permeable horizon and available water capacity, although not needed as classification variables, are useful in explaining some of the hydrologic responses of soils. The primary soil units used in groupings and interpretation of the soils for this study are the soil associations. A computer program is presented that sorts the soils into groups and calculates statistics for each group. The 147 soil associations in Nebraska were thus sorted into 29 hydrologic soil groups. The location and extent of these hydrologic soil groups are shown on maps at scales of 1:750,000 and 1:250,000 for the State.

Dugan, Jack T.

1984-01-01

391

Influence of soil ph on aluminum availability in the soil and aluminum in tea leaves  

Microsoft Academic Search

Soils and tea leaves from thirteen tea gardens located in east China were collected to investigate the effect of soil pH on the availability of aluminum (Al) and its uptake by tea plants. The soil samples were obtained from two horizons, i.e., 0–20 cm and 20–40 cm, with pH ranging from 4.05 to 7.11. Solubility of Al in soils, and

Deming Dong; Zhonglei Xie; Yaoguo Du; Chunming Liu; Shengtian Wang

1999-01-01

392

Evaluation of fluoride-induced metal mobilization in soil columns  

Microsoft Academic Search

Fluoride in soil solution may cause substantially increased leaching of dissolved organic carbon (DOC), Al, and heavy metals from soils. The authors objective was to examine whether increased metal solubility is attributable to formation of fluoro- or organo-complexes. The A horizon of a Slovak soil contaminated with heavy metals and F by Al smelter emissions was used to conduct two

Kai Uwe Totsche; Wolfgang Wilcke; M. Koerber; Jozef Kobza; Wolfgang Zech

2000-01-01

393

Soil macroaggregate dynamics in a mountain spatial climate gradient  

Microsoft Academic Search

We investigated the response of soil macroaggregate dynamics to soil temperature modification along a spatial gradient located\\u000a on a forested north-facing slope in the southern French Alps, simulating long-term adjustment of soil–plant interactions to\\u000a absence or occurrence of soil frost. Soil macroaggregate (>250 ?m) content of Ah horizons was strongly depleted (72%) in colder\\u000a plots affected by freeze-thaw events, compared to

Lauric Cécillon; Nilvania A. de Mello; Sébastien De Danieli; Jean-Jacques Brun

2010-01-01

394

Buried Alive in the Coronal Graveyard  

NASA Astrophysics Data System (ADS)

We have used the High Resolution Camera (HRC-I) of the Chandra X-Ray Observatory to search for coronal (T~106 K) emission from the archetype ``noncoronal'' red giants Arcturus (? Bootis=HD 124897, K1 III) and Aldebaran (? Tauri=HD 29139, K5 III). Our program follows up previous detections of ultraviolet coronal proxies such as C IV ?1548 (T~1×105 K) and O VI ?1031 (T~3×105 K). The deep (~19 ks) HRC-I pointings obtained a tentative 3 ? detection of Arcturus, with fX(0.2-2keV)=1.0+1.8-0.8×10-15 ergs cm-2 s-1 (95% confidence limits [CLs]), but failed to record Aldebaran, with an upper limit of <~1.5×10-15 ergs cm-2 s-1 (also at 95% CL). The corresponding LX/Lbol ratios are a factor of ten thousand less than the Sun, a low-activity coronal dwarf. At the same time, Hubble Space Telescope Imaging Spectrograph far-ultraviolet spectra suggest the presence of a ``cool absorber,'' probably near the base of the red giant chromosphere, imprinting discrete low-excitation absorptions on top of highly ionized features such as Si IV ?1393. The hot emission zones thus are at least partially buried under a large column of chromospheric material, which would severely attenuate any soft X-rays that might be emitted. The submerged hot structures presumably are magnetic because of their high temperatures and broad C IV profiles (FWHM~130 km s-1). Perhaps these structures are analogous to small-scale ephemeral bipolar regions seen ubiquitously on the Sun throughout the sunspot cycle and thought to be of direct convective origin. If small-scale magnetic fields indeed are present in the lower atmospheres of red giants such as Arcturus and Aldebaran, they might play a role in initiating the cool winds of such stars, perhaps through a mechanism similar to solar spicules.

Ayres, Thomas R.; Brown, Alexander; Harper, Graham M.

2003-11-01

395

Buried Alive in the Coronal Graveyard  

NASA Astrophysics Data System (ADS)

We have used the highly sensitive ``solar-blind'' Chandra High Resolution Camera (HRC-I) to search for 0.2--10 keV coronal X-ray emission from the key ``noncoronal'' red giants Arcturus (? Boo: K1 III) and Aldebaran (? Tauri: K5 III). Our program follows up previous detections of subcoronal (T ~ 105 K) emission lines, such as C 4 ? 1548, by HST STIS, and its predecessor GHRS. The two deep (19 ks) HRC-I pointings failed to detect either red giant, however, with 3 ? upper limits of 1x 10-4 cnts s-1 and 2x 10-4 cnts s-1 for Arcturus and Aldebaran, respectively. The corresponding 0.2--2.0 keV L X/L bol levels are a factor of a thousand lower than the Sun (itself already an inconspicuous coronal object), establishing new limits of coronal futility among late-type stars. At the same time, STIS far-ultraviolet spectra suggest the presence of a ``cool absorber'' in the red giant atmosphere capable of selectively extinguishing the subcoronal spectrum shortward of ~ 1500 Å. The cool absorber must lie beneath the extensive chromospheric (T ~ 7000 K) envelope, because the chromospheric lines lack absorption signatures from the cool layer. As a result, the hot-line structures must be doubly buried under a large column of neutral hydrogen, undoubtedly smothering any soft X-ray emission that might be present. If small-scale magnetic active regions indeed exist in the lower atmospheres of red giants like Arcturus and Aldebaran, they might in some way be responsible for initiating and sustaining the cool outflows of such stars. The source of the near surface magnetism could be analogous to that of the small-scale ephemeral bipolar regions seen ubiquitously on the Sun throughout the sunspot cycle, and thought to be of direct convective origin. [-3mm] This work was supported by Chandra grant G02-3014X and HST grant GO-09273.01--A to the University of Colorado.

Ayres, T. R.; Brown, A.; Harper, G. M.

2002-12-01

396

Carbon stock and organic carbon dynamics in soils of Rajasthan, India  

Microsoft Academic Search

Soil carbon stock (CS), was estimated in the 0–25 and 0–100cm soil depths of arid and semi-arid regions of Rajasthan. Carbon stock was 2.13Pg in the 0–100cm soil depth, of which 1.23Pg was soil organic carbon and 0.90Pg was soil inorganic carbon. The surface horizon (0–25cm) stored 31% of the soil carbon stock. Soil carbon stocks were higher in Entisols

S. K. Singh; A. K. Singh; B. K. Sharma; J. C. Tarafdar

2007-01-01

397

Red Maple ('Acer Rubrum' L.) Growth and Foliar Nutrient Responses to Soil Fertility Level and Water Regime.  

National Technical Information Service (NTIS)

Red maple (Acer rubrum) seedlings were grown in a greenhouse using three treatments: two soil horizons, two soil moisture regimes, and three nutrient levels. Fertilization increased growth under moist conditions on the more fertile topsoil. Under dry cond...

C. H. Pham H. G. Halverson G. M. Heisler

1978-01-01

398

Pair production close to black hole horizon  

NASA Astrophysics Data System (ADS)

Accreting stellar-mass black holes in Galactic binaries exhibit a ``bi-modal" spectral behavior - namely the so called high-soft and low-hard spectral states. An increase in the soft blackbody luminosity component leads to the appearance of an extended power law. An important observational fact is that this effect is seen as a persistent phenomenon only in BH candidates, and thus it is apparently a unique black hole signature. Although similar power law components are detected in the intermediate stages in neutron star systems, they are of a transient nature, i.e. disappearing with increasing luminosity. It thus seems a reasonable assumption that the unique spectral signature of the soft state of BH binaries is directly tied to the black hole event horizon. This is the primary motivation for the Bulk Motion Comptonization Model, introduced in several previous papers, and recently applied with striking success to a substantial body of observational data. We argued that the BH X-ray spectrum in the high-soft state is formed in the relatively cold accretion flow with a subrelativistic bulk velocity close to c and a temperature of a few keV. In such a flow the effect of the bulk Comptonization is indeed much stronger than the effect of the thermal ones. Another property of these accreted flow, that we will explore during this talk, is that, very close to horizon, X-ray photons may be upscattered by bulk electrons to MeV energy. Most of these photons fall down then in the black hole, but some of them anyway have time to interact with another X-ray photon by the photon-photon process to make an electron-positron pairs. We will then explore in details the consequences of this pair creation process close to horizon and what can be the observational evidences of this effect.

Laurent, Philippe; Titarchuk, Lev

2012-07-01

399

Super-horizon cosmic string correlations  

SciTech Connect

When gauged cosmic strings form in a symmetry-breaking phase transition, the gauge field configuration at the time becomes imprinted in the spatial string distribution by the flux trapping mechanism. Causality and flux conservation suggest that quantum and thermal gauge field fluctuations give rise to long-range super-horizon correlations in the string network. Classical field theory simulations in the Abelian Higgs model confirm this finding. In contrast, the Kibble-Zurek mechanism, which most cosmic string studies are based on, only gives rise to short-distance, subhorizon correlations. These results may have implications for cosmology, and it may also be possible to test them in superconductor experiments.

Rajantie, Arttu [Department of Physics, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom)

2009-02-15

400

Black hole thermodynamics from Euclidean horizon constraints.  

PubMed

To explain black hole thermodynamics in quantum gravity, one must introduce constraints to ensure that a black hole is actually present. I show that for a large class of black holes, such "horizon constraints" allow the use of conformal field theory techniques to compute the density of states, reproducing the Bekenstein-Hawking entropy in a nearly model-independent manner. One standard string theory approach to black hole entropy arises as a special case, lending support to the claim that the mechanism may be "universal." I argue that the relevant degrees of freedom are Goldstone-boson-like excitations arising from the weak breaking of symmetry by the constraints. PMID:17678209

Carlip, S

2007-07-13

401

Time Horizon and Social Scale in Communication  

NASA Astrophysics Data System (ADS)

In 2009 our center (CRED) published a first version of The Psychology of Climate Change Communication. In it, we attempted to summarize facts and concepts from psychological research that could help guide communication. While this work focused on climate change, most of the ideas are at least partly applicable for communication about a variety of natural hazards. Of the many examples in this guide, I mention three. Single-action bias is the human tendency to stop considering further actions that might be needed to deal with a given hazard, once a single action has been taken. Another example is the importance of group affiliation in motivating voluntary contributions to joint action. A third concerns the finding that group participation enhances understanding of probabilistic concepts and promotes action in the face of uncertainty. One current research direction, which goes beyond those included in the above publication, focuses on how time horizons arise in the thinking of individuals and groups, and how these time horizons might influence hazard preparedness. On the one hand, individuals sometimes appear impatient, organizations look for immediate results, and officials fail to look beyond the next election cycle. Yet under some laboratory conditions and in some subcultures, a longer time horizon is adopted. We are interested in how time horizon is influenced by group identity and by the very architecture of planning and decision making. Institutional changes, involving long-term contractual relationships among communities, developers, insurers, and governments, could greatly increase resilience in the face of natural hazards. Communication about hazards, in the context of such long-term contractual relationships might look very different from communication that is first initiated by immediate threat. Another new direction concerns the social scale of institutions and of communication about hazards. Traditionally, insurance contracts share risk among a large number of insurees: each contributes a small premium toward a fund that is adequate to cover the large losses that occasionally occur. Participatory processes are needed that extend risk sharing to larger social scales and that reduce adversarial relationships between insurers, insurees, insurance regulators, and governments that intervene or fail to intervene on an ad hoc rather than a contractual basis.

Krantz, D. H.

2010-12-01

402

A global data set of soil particle size properties  

NASA Technical Reports Server (NTRS)

A standardized global data set of soil horizon thicknesses and textures (particle size distributions) was compiled. This data set will be used by the improved ground hydrology parameterization designed for the Goddard Institute for Space Studies General Circulation Model (GISS GCM) Model 3. The data set specifies the top and bottom depths and the percent abundance of sand, silt, and clay of individual soil horizons in each of the 106 soil types cataloged for nine continental divisions. When combined with the World Soil Data File, the result is a global data set of variations in physical properties throughout the soil profile. These properties are important in the determination of water storage in individual soil horizons and exchange of water with the lower atmosphere. The incorporation of this data set into the GISS GCM should improve model performance by including more realistic variability in land-surface properties.

Webb, Robert S.; Rosenzweig, Cynthia E.; Levine, Elissa R.

1991-01-01

403

Frost features in soil thin sections as a tool for Holocene reconstruction: a study case from the Northern Apennines  

NASA Astrophysics Data System (ADS)

The study of Holocene paleosols can be difficult in many cases, since soil features are usually much less expressed than in older paleosols and the ability to detect single genetic phases is much impaired. Frost action, a key diagnostic feature in past climate reconstructions, is not exempt to this rule, and can sometimes remain undetected at the macroscopic scale. In such cases micromorphology can be one of great use, since it raises the resolution of our observations allowing us to identify some of the less visible features. The northern slope of Mt. Cusna (2121 m a.s.l.) in the Northern Apennines is characterized by the presence of a paleosurface formed since the end of the last glacial period. Four soil profiles related to a morphologically flat area inside the paleosurface (at around 1760 m a.s.l.) were described and sampled for bulk and micromorphological analyses. Field descriptions and bulk analyses indicated the presence of two main soil units. The upper unit showed the structure of a colluvial deposit interested by a weak pedogenesis. The lower unit was composed by a truncated paleosol with strong evidence of clay illuviation. At the top of the lower unit, a blackish organic horizon poor in coarse particles and without apparent structure was found. At the microscopic level the microstructure of this blackish horizon, composed by fine (40-80 ?m) rounded granules, was interested by a pattern of parallel-perpendicular planar voids, which can be interpreted as the result of frost action. Moreover, in one profile they were expressed enough to form a secondary angular blocky structure, and in another profile a series of vertical fissures a few millimeters wide was also found at the top of the blackish horizon. These features weren't identified in any of the other horizons of the four described profiles. The micromorphological characteristics of these buried organic levels, coupled with the paleoenvironmental context of the profiles, allowed to interpret these horizons as the results of an independent pedogenetic phase. In fact, in mountain environments accumulation of organic matter at the soil surface without significant development is a likely sign of a period of climatic recrudescence. The presence of frost features clearly confirms this hypothesis. The absence of frost features both in the deeper paleosol unit and in the colluvium above suggests two things: first, that this period can be viewed as a climatic recrudescence of the previous one, during which a temperate forest paleosol was formed. Second, that temperatures were probably also colder than present, which implies a successive warming. Radiocarbon dating from one of the profiles puts the formation of the blackish horizon, and thus the period of climatic recrudescence, somewhere between the boundary Middle-Late Holocene and the Little Ice Age. This is consistent with the Holocene climatic fluctuations attested for Northern Italy, which describe the Late Holocene as an unstable phase of colder periods.

Stefano Mariani, Guido; Compostella, Chiara; Trombino, Luca

2014-05-01

404

Two-dimensional detection of underground contamination and buried objects using cross-well radar  

NASA Astrophysics Data System (ADS)

Traditional approaches for locating and characterizing contaminated sites rely on invasive techniques which require drilling, testing, and sampling. These techniques provide the most direct access to the subsurface, but they are generally expensive and only provide measurements at points in a three dimensional surface. Furthermore, invasive techniques in polluted areas can promote further spread of contaminants. Development of non-invasive techniques that offer rapid and relatively inexpensive characterization is, therefore, necessary to detect and monitor plumes and sources of contaminants. Non-invasive techniques are also required for locating buried objects, such as landmines and unexploded ordnances. The use of cross well radar (CWR) as a non-invasive technique that has proven to be a reliable technology for detection of target objects that exhibit significant contrast of dielectric properties in saturated soils. Its application to detection of heterogeneously distributed phases in unsaturated soils under variable flow conditions has yet to be developed. This paper addresses the development of 2D flow and electromagnetic (EM) soilBed setup to further assess and enhance CWR technology for the detection of Dense Non-Aqueous Phase Liquids (DNAPLs) contamination and other target elements in variably-saturated soils subjected to transient flow conditions. Loop antennas have been developed and tested for this purpose. Transmission and reflection measurements are evaluated to determine the antenna's reliability and optimize their performance in the 2D electromagnetic field. The measurements indicate that a 2D EM boundary condition may be imposed by placing two parallel perfectly-reflecting metal plates along one of the dimensions of the soilBed setup. Transmission and reflection characteristics of the antennas vary with their method of construction. Results show a reliable and reproducible response from the loop antennas, but suggest some wave leakage and indicate that their design must be optimized. Measured variations in the transmission, reflection and impedance in the presence and absence of a buried object suggest that the 2D EM soilBed setup using loop antennas can be aplied to detect target elements in subsurface environments subjected to flow conditions. Future work addresses the assessment of CWR technology as a non-invasive method for detection and monitoring of heterogeneously-distributed target objects in subsurface environments.

Serrano-Guzmán, Maria F.; Padilla, Ingrid; Rodriguez, Rafael

2006-06-01

405

Fertigation of apples with nitrate or ammonium nitrogen under drip irrigation. II. Nutrient distribution in the soil  

Microsoft Academic Search

Nutrient distribution in the soil under drip irrigation was monitored by soil sampling and analysis of soil solution collected by vacuum suction through ceramic cups buried in the soil near the drippers. Concentration of ammonium and nitrate nitrogen, phosphate and potassium, and the pH were monitored in three fertigation treatments with N fertilizers containing 0, 50 or 100% NH4 .

Isaac Klein; Gideon Spieler

1987-01-01

406

Soils, time, and primate paleoenvironments  

USGS Publications Warehouse

Soils are the skin of the earth. From both poles to the equator, wherever rocks or sediment are exposed at the surface, soils are forming through the physical and chemical action of climate and living organisms. The physical attributes (color, texture, thickness) and chemical makeup of soils vary considerably, depending on the composition of the parent material and other variables: temperature, rainfall and soil moisture, vegetation, soil fauna, and the length of time that soil-forming processes have been at work. United States soil scientists1 have classified modern soils into ten major groups and numerous subgroups, each reflecting the composition and architecture of the soils and, to some extent, the processes that led to their formation. The physical and chemical processes of soil formation have been active throughout geologic time; the organic processes have been active at least since the Ordovician.2 Consequently, nearly all sedimentary rocks that were deposited in nonmarine settings and exposed to the elements contain a record of ancient, buried soils or paleosols. A sequence of these rocks, such as most ancient fluvial (stream) deposits, provides a record of soil paleoenvironments through time. Paleosols are also repositories of the fossils of organisms (body fossils) and the traces of those organisms burrowing, food-seeking, and dwelling activities (ichnofossils). Indeed, most fossil primates are found in paleosols. Careful study of ancient soils gives new, valuable insights into the correct temporal reconstruction of the primate fossil record and the nature of primate paleoenvironments. ?? 1993 Wiley-Liss, Inc.

Bown, T. M.; Kraus, M. J.

1993-01-01

407

Oil sheen weathering post Deepwater Horizon  

NASA Astrophysics Data System (ADS)

A recently published study identified the source of the reoccurred oil sheens close to the Deepwater Horizon (DWH) disaster site as a finite contamination most likely derived from tanks and pits on the DWH wreckage itself. Here we use geochemical fingerprinting and microbial community analysis to better understand the fate and weathering processes affecting these surface oils. Both, alkanes and polycyclic aromatic hydrocarbons (PAHs) are shown to reflect a linear decrease of hydrocarbon compounds with increasing distance to the DWH wreckage site (equivalent to exposure time on the sea surface). These results indicate that in the early stage of weathering the combined effects of dissolution and evaporation dominate the degradation of these surface oils. Sheen microbial communities were dominated by Cyanobacteria, Planctomycetes, Verrucomicrobia, Flavobacteria, Alphaproteobacteria, and Deltaproteobacteria, with low relative abundances of Gammaproteobacteria likely to be hydrocarbon degraders (no more than 15% of sequences in each sample). However, some of these Gammaproteobacteria were closely related to putative hydrocarbon degraders observed in abundance in deep water plumes during the primary Deepwater Horizon spill, suggesting that very low levels of biodegradation may be also occurring. This in situ weathering experiment provides new insights in hydrocarbon weathering dynamics and shows how chemical and biological changes can potentially be masked by large evaporative losses of compounds smaller than C18 n-alkanes.

Kellermann, M. Y.; Redmond, M. C.; Reddy, C. M.; Aeppli, C.; Nelson, R. K.; Valentine, D. L.

2013-12-01

408

Effects of compaction and wetting of laterite cover soil on development and survival of Musca domestica (Diptera: Muscidae) immatures.  

PubMed

Effects of laterite cover soil with different characteristics on survival of buried eggs, third instar larvae, and pupae of Musca domestica (L.) were studied experimentally. Soil treatments were loose dry soil, loose wet soil, compacted dry soil, and compacted wet soil (CWS). Eggs, third instar larvae, and pupae were buried under 30 cm of the different soil treatments and placed under field conditions until adults emerged. Rearing medium was provided for eggs and larvae, and control treatments of all stages were unburied immatures placed on soil surface. Egg and pupal survival to adult were significantly affected by the cover soil treatments, but third instars were more resilient. Wet soil treatments (loose wet soil and CWS) resulted in significantly reduced pupal survival, but increased survival of eggs. However, CWS significantly reduced adult emergence from buried eggs. Though emergence of house flies buried as eggs was significantly reduced, some were able to hatch and emerging first instar larvae developed to pupation. Although cover soil does not completely prevent fly emergence, it did limit development and emergence of buried house flies. PMID:24180104

Abu Tahir, Nurita; Ahmad, Abu Hassan

2013-09-01

409

Cosmic censorship: Formation of a shielding horizon around a fragile horizon  

NASA Astrophysics Data System (ADS)

The weak cosmic censorship conjecture asserts that spacetime singularities that arise in gravitational collapse are always hidden inside of black holes, invisible to distant observers. This conjecture, put forward by Penrose more than four decades ago, is widely believed to be one of the basic principles of nature. However, a complete proof of this hypothesis is still lacking and the validity of the conjecture has therefore remained one of the most important open questions in general relativity. In this study we analyze a gedanken experiment that is designed to challenge cosmic censorship by trying to overcharge a Reissner-Nordström black hole: a charged shell is lowered adiabatically into the charged black hole. The mass energy delivered to the black hole can be redshifted by letting the dropping point of the shell approach the black-hole horizon. On the other hand, the electric charge of the shell is not redshifted by the gravitational field of the black hole. It therefore seems, at first sight, that the charged shell is not hindered from entering the black hole, overcharging it and removing its horizon. However, in the present study we prove that the exposure of a naked singularity to distant observers is actually excluded due to the formation of a new (and larger) horizon around the original black hole. Moreover, we shall prove that this new horizon is already formed before the charged shell crosses the original black-hole horizon. This result, which seems to have been previously overlooked, guarantees the validity of the weak cosmic censorship conjecture in this type of gedanken experiments.

Hod, Shahar

2013-01-01

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 14days. 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 14days, 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

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

412

Horizons versus singularities in spherically symmetric space-times  

SciTech Connect

We discuss different kinds of Killing horizons possible in static, spherically symmetric configurations and recently classified as 'usual', 'naked', and 'truly naked' ones depending on the near-horizon behavior of transverse tidal forces acting on an extended body. We obtain the necessary conditions for the metric to be extensible beyond a horizon in terms of an arbitrary radial coordinate and show that all truly naked horizons, as well as many of those previously characterized as naked and even usual ones, do not admit an extension and therefore must be considered as singularities. Some examples are given, showing which kinds of matter are able to create specific space-times with different kinds of horizons, including truly naked ones. Among them are fluids with negative pressure and scalar fields with a particular behavior of the potential. We also discuss horizons and singularities in Kantowski-Sachs spherically symmetric cosmologies and present horizon regularity conditions in terms of an arbitrary time coordinate and proper (synchronous) time. It turns out that horizons of orders 2 and higher occur in infinite proper times in the past or future, but one-way communication with regions beyond such horizons is still possible.

Bronnikov, K. A.; Elizalde, E.; Odintsov, S. D.; Zaslavskii, O. B. [Center for Gravitation and Fundamental Metrology, VNIIMS, 46 Ozyornaya Street, Moscow 119361 (Russian Federation) and Institute of Gravitation and Cosmology, PFUR, 6 Miklukho-Maklaya Street, Moscow 117198 (Russian Federation) and Consejo Superior de Investigaciones Cientificas ICE/CSIC-IEEC, Campus UAB, Facultat de Ciencies, Torre C5-Parell-2a pl, E-08193 Bellaterra (Barcelona) (Spain); Institucio Catalana de Recerca i Estudis Avancats (ICREA) and Institut de Ciencies de l'Espai (IEEC-CSIC), Campus UAB, Facultat de Ciencies, Torre C5-Parell-2a pl, E-08193 Bellaterra, Barcelona (Spain) and Laboratory for Fundamental Studies, Tomsk State Pedagogical University, Tomsk (Russian Federation); Astronomical Institute of Kharkov V.N. Karazin National University, 35 Sumskaya Street, Kharkov, 61022 (Ukraine)

2008-09-15

413

Numerical examination of an evolving black string horizon  

NASA Astrophysics Data System (ADS)

We use the numerical solution describing the evolution of a perturbed black string presented by M. Choptuik, L. Lehner, I. Olabarrieta, R. Petryk, F. Pretorius, and H. Villegas [Phys. Rev. D 68, 044001 (2003)] to elucidate the intrinsic behavior of the horizon. It is found that by the end of the simulation, the affine parameter on the horizon has become very large and the expansion and shear of the horizon in turn very small. This suggests the possibility that the horizon might pinch off in infinite affine parameter.

Garfinkle, David; Lehner, Luis; Pretorius, Frans

2005-03-01

414

Horizons versus singularities in spherically symmetric space-times  

NASA Astrophysics Data System (ADS)

We discuss different kinds of Killing horizons possible in static, spherically symmetric configurations and recently classified as “usual,” “naked,” and “truly naked” ones depending on the near-horizon behavior of transverse tidal forces acting on an extended body. We obtain the necessary conditions for the metric to be extensible beyond a horizon in terms of an arbitrary radial coordinate and show that all truly naked horizons, as well as many of those previously characterized as naked and even usual ones, do not admit an extension and therefore must be considered as singularities. Some examples are given, showing which kinds of matter are able to create specific space-times with different kinds of horizons, including truly naked ones. Among them are fluids with negative pressure and scalar fields with a particular behavior of the potential. We also discuss horizons and singularities in Kantowski-Sachs spherically symmetric cosmologies and present horizon regularity conditions in terms of an arbitrary time coordinate and proper (synchronous) time. It turns out that horizons of orders 2 and higher occur in infinite proper times in the past or future, but one-way communication with regions beyond such horizons is still possible.

Bronnikov, K. A.; Elizalde, E.; Odintsov, S. D.; Zaslavskii, O. B.

2008-09-01

415

Dynamics of diffeomorphism degrees of freedom at a horizon  

SciTech Connect

We define a set of boundary conditions that ensure the presence of a null hypersurface with the essential characteristics of a horizon, using the formalism of weakly isolated horizons as a guide. We then determine the diffeomorphisms that preserve these boundary conditions, and derive a dynamical action for these diffeomorphisms in a neighborhood of the horizon. The action is similar to that of the Liouville theory, and the equation of motion of the gravitational degrees of freedom approaches that of a free two-dimensional conformal field in the near-horizon region.

Chung, Hyeyoun [Jefferson Physical Laboratory, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138 (United States)

2011-04-15

416

SPATIAL RELATIONSHIPS AMONG SOIL PHYSICAL PROPERTIES IN A GRASS-ALFALFA HAY FIELD  

Microsoft Academic Search

Knowledge of the spatial variability of soil physical properties is important for site-specific soil management. The objectives of this study were to characterize the field-scale spatial variability of cone index (CI), soil bulk density (Db), moisture content (Kv), and sand and clay contents in the A horizon of a Lihen sandy loamy soil (sandy, mixed, frigid Entic Haplustoll), and to

Jay D. Jabro; Bart W. Stevens; Robert G. Evans

2006-01-01

417

Impacts of Deforestation and Land Cover Change on Mountain Soils in Hrazdan, Armenia  

Microsoft Academic Search

The impacts of deforestation and land cover change upon underlying soils were examined on one hillside in central Armenia. Soil characteristics in three land cover areas—forest, coppice, and pasture—were recorded and soil samples were analyzed. Deforestation and land cover change were found to increase erosion rates. From soil horizon and structural characteristics, it can be estimated that 40 cm of

Jason L. Rhoades; Michael Scott Demyan; Blair Orr

2011-01-01

418

Corrosion of underground water pipes due to acidification of soil and groundwater.  

National Technical Information Service (NTIS)

The anthropogenic acidification creates changes of soil and groundwater that may contribute to increased corrosion of water pipe systems, buried in the ground. Investigations on the influence of acidification on corrosion of underground water pipes are be...

E. Levlin

1992-01-01

419