Science.gov

Sample records for influences governing subsurface

  1. Influence of groundwater composition on subsurface iron and arsenic removal.

    PubMed

    Moed, D H; van Halem, D; Verberk, J Q J C; Amy, G L; van Dijk, J C

    2012-01-01

    Subsurface arsenic and iron removal (SAR/SIR) is a novel technology to remove arsenic, iron and other groundwater components by using the subsoil. This research project investigated the influence of the groundwater composition on subsurface treatment. In anoxic sand column experiments, with synthetic groundwater and virgin sand, it was found that several dissolved substances in groundwater compete for adsorption sites with arsenic and iron. The presence of 0.01 mmol L(-1) phosphate, 0.2 mmol L(-1) silicate, and 1 mmol L(-1) nitrate greatly reduced the efficiency of SAR, illustrating the vulnerability of this technology in diverse geochemical settings. SIR was not as sensitive to other inorganic groundwater compounds, though iron retardation was limited by 1.2 mmol L(-1) calcium and 0.06 mmol L(-1) manganese. PMID:22678215

  2. RESEARCH ACTIVITIES AT U.S. GOVERNMENT AGENCIES IN SUBSURFACE REACTIVE TRANSPORT MODELING

    EPA Science Inventory

    The fate of contaminants in the environment is controlled by both chemical reactions and transport phenomena in the subsurface. Our ability to understand the significance of these processes over time requires an accurate conceptual model that incorporates the various mechanisms ...

  3. The Influence of Plant Root Systems on Subsurface Flow: Implications for Slope Stability

    EPA Science Inventory

    Although research has explained how plant roots mechanically stabilize soils, in this article we explore how root systems create networks of preferential flow and thus influence water pressures in soils to trigger landslides. Root systems may alter subsurface flow: Hydrological m...

  4. INFLUENCE OF COUPLED PROCESSES ON CONTAMINANT FATE AND TRANSPORT IN SUBSURFACE ENVIRONMENTS

    SciTech Connect

    Jardine, Philip M

    2008-01-01

    The following chapter emphasizes subsurface environmental research investigations over the past 10 to 15 years that couple hydrological, geochemical, and biological processes as related to contaminant fate and transport. An attempt is made to focus on field-scale studies with possible reference to laboratory-scale endeavors. Much of the research discussed reflects investigations of the influence of coupled processes on the fate and transport of inorganic, radionuclide, and organic contaminants in subsurface environments as a result of natural processes or energy and weapons production endeavors that required waste disposal. The chapter provides on overview of the interaction between hydro-bio-geochemical processes in structured, heterogeneous subsurface environments and how these interactions control contaminant fate and transport, followed by experimental and numerical subsurface science research and case studies involving specific classes of inorganic and organic contaminants. Lastly, thought provoking insights are highlighted on why the study of subsurface coupled processes is paramount to understanding potential future contaminant fate and transport issues of global concern.

  5. Influence of soil spatial variability on surface and subsurface flow at a vegetative buffer strip scale.

    NASA Astrophysics Data System (ADS)

    Gatel, Laura; Lauvernet, Claire; Carluer, Nadia; Paniconi, Claudio; Leblois, Etienne

    2015-04-01

    The objective of this study is to evaluate the influence of soil hydrodynamic characteristics variability on surface and subsurface flow at a vegetative buffer strip scale, using mecanistic modeling. Cathy (CATchment HYdrology, Camporese et al. 2010) is a research physically based model able to simulate coupled surface/subsurface flow. The evaluation of soil hydrodynamic characteristics variability is based essentially on saturated hydraulic conductivity because of its large spatial variability in the 3 dimensions and its important influence on flow pathways, as well as its high influence on the model output variables. After testing the model sensitivity to some input variables, to the boundary conditions and to the mesh definition, the work focuses on hydraulic conductivity parametrization. The study was first conducted with uniform (by horizons) conductivity domains based on field measurements. In a second step, heterogeneous fields were generated by a statistical tool which allows the user to choose the statistical law (in this case, lognormal or Gauss), the hydraulic conductivity auto-correlation length and the possibility to condition the fields with measured points. With all these different ways to represent spatial variability of hydraulic conductivity, model simulated surface and subsurface fluxes consistent with datasets from artificial run-off experiments on an French wineyard hillslope (Morcille catchment, Beaujolais, France). Model simulations are evaluated and compared to observations on several criteria : consistency, stability, interaction with water table, etc...

  6. Factors governing selection of operating frequency for subsurface- imaging synthetic-aperture radar

    SciTech Connect

    Brock, B.C.; Patitz, W.E.

    1993-12-31

    A subsurface-imaging synthetic-aperture radar (SISAR) has potential for application in areas as diverse as non-proliferation programs for nuclear weapons to environmental monitoring. However, subsurface imaging is complicated by propagation loss in the soil and surface-clutter response. Both the loss and surface-clutter response depend on the operating frequency. This paper examines several factors which provide a basis for determining optimum frequencies and frequency ranges which will allow synthetic-aperture imaging of buried targets. No distinction can be made between objects at different heights when viewed with a conventional imaging radar (which uses a one-dimensional synthetic aperture), and the return from a buried object must compete with the return from the surface clutter. Thus, the signal-to-clutter ratio is an appropriate measure of performance for a SISAR. A parameter-based modeling approach is used to model the complex dielectric constant of the soil from measured data obtained from the literature. Theoretical random-surface scattering models, based on statistical solutions to Maxwell`s equations, are used to model the clutter. These models are combined to estimate the signal-to-clutter ratio for canonical targets buried in several soil configurations. Results indicate that the HF spectrum (3--30), although it could be used to detect certain targets under some conditions, has limited practical value for use with SISAR, while the upper VIHF through UHF spectrum ({approximately}100 MHz - 1 GHz) shows the most promise for a general purpose SISAR system. Recommendations are included for additional research.

  7. Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

    PubMed

    Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

    2015-12-01

    Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm. PMID:26452371

  8. Influence of Subsurface Structure on the Linear Reciprocating Sliding Wear Behavior of Steels with Different Microstructures

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sangal, S.; Mondal, K.

    2014-09-01

    The present work investigates the influence of subsurface microstructure on the linear reciprocating sliding wear behavior of a number of steels with ferrite-pearlitic, pearlitic, bainitic, and martensitic microstructures under dry unlubricated condition. The change in the underlying microstructure with depth from worn-out surface of steel sample intimately relates to the associated hardness variation and wear volume. The present paper is not about comparison of wear resistance of steels with different structures; rather it is on mutual influence of wear and substructure for individual microstructure. Inherent toughness of the matrix and ability of microstructural components to get deformed under the reciprocating action of the ball decide the wear resistance of the steels. Bainite has good amount of stability to plastic deformation. Ferrite shows severe banding due to wear action. Work hardening renders pearlite to be wear resistant. Temperature rise and associated tempering of martensite are observed during wear.

  9. Influence of Subsurface Structure on the Linear Reciprocating Sliding Wear Behavior of Steels with Different Microstructures

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sangal, S.; Mondal, K.

    2014-12-01

    The present work investigates the influence of subsurface microstructure on the linear reciprocating sliding wear behavior of a number of steels with ferrite-pearlitic, pearlitic, bainitic, and martensitic microstructures under dry unlubricated condition. The change in the underlying microstructure with depth from worn-out surface of steel sample intimately relates to the associated hardness variation and wear volume. The present paper is not about comparison of wear resistance of steels with different structures; rather it is on mutual influence of wear and substructure for individual microstructure. Inherent toughness of the matrix and ability of microstructural components to get deformed under the reciprocating action of the ball decide the wear resistance of the steels. Bainite has good amount of stability to plastic deformation. Ferrite shows severe banding due to wear action. Work hardening renders pearlite to be wear resistant. Temperature rise and associated tempering of martensite are observed during wear.

  10. Influences of Peat, Surface and Subsurface Water, and Snow on Active Layer Thickness

    SciTech Connect

    Atchley, Adam; Coon, Ethan T.; Painter, Scott L; Harp, Dylan; Wilson, Cathy

    2016-01-01

    The effect of three environmental conditions: 1) thickness of organic soil, 2) snow depth, and 3) soil moisture content or water table height above and below the soil surface, on active layer thickness (ALT) are investigated using an ensemble of 1D thermal hydrology models. Sensitivity analyses of the ensemble exposed the isolated influence of each environmental condition on ALT and their multivariate interactions. The primary and interactive influences are illustrated in the form of color maps of ALT change. Results show that organic layer acts as a strong insulator, and its thickness is the dominant control of ALT, but the strength of the effect of organic layer thickness is dependent on the saturation state. Snow depth, subsurface saturation, and ponded water depth are strongly codependent and positively correlated to ALT.

  11. Influences of Peat, Surface and Subsurface Water, and Snow on Active Layer Thickness

    DOE PAGESBeta

    Atchley, Adam; Coon, Ethan T.; Painter, Scott L; Harp, Dylan; Wilson, Cathy

    2016-01-01

    The effect of three environmental conditions: 1) thickness of organic soil, 2) snow depth, and 3) soil moisture content or water table height above and below the soil surface, on active layer thickness (ALT) are investigated using an ensemble of 1D thermal hydrology models. Sensitivity analyses of the ensemble exposed the isolated influence of each environmental condition on ALT and their multivariate interactions. The primary and interactive influences are illustrated in the form of color maps of ALT change. Results show that organic layer acts as a strong insulator, and its thickness is the dominant control of ALT, but themore » strength of the effect of organic layer thickness is dependent on the saturation state. Snow depth, subsurface saturation, and ponded water depth are strongly codependent and positively correlated to ALT.« less

  12. Technical geothermal potential of urban subsurface influenced by land surface effects

    NASA Astrophysics Data System (ADS)

    Rivera, Jaime A.; Blum, Philipp; Bayer, Peter

    2016-04-01

    Changes in land use are probably one of the most notorious anthropogenic perturbations in urban environments. They significantly change the coupled thermal regime at the ground surface leading in most cases to increased ground surface temperatures (GST). The associated elevated vertical heat fluxes act at different scales and can influence the thermal conditions in several tens of meters in the subsurface. Urban subsurface thus often stores a higher amount of heat than less affected rural surroundings. The stored heat is regarded as a potential source of low-enthalpy geothermal energy to supply the heating energy demands in urban areas. In this work, we explore the technical geothermal potential of urban subsurface via ground coupled heat pumps with borehole heat exchangers (BHE). This is tackled by semi-analytical line-source equations. The commonly used response factors or g-functions are modified to include transient land surface effects. By including this additional source of heat, the new formulation allows to analyse the effect of pre-existing urban warming as well as different exploitation schemes fulfilling standard renewable and sustainable criteria. In our generalized reference scenario, it is demonstrated that energy gains for a single BHE may be up to 40 % when compared to non-urbanized conditions. For a scenario including the interaction of multiple BHEs, results indicate that it would be possible to supply between 6 % and 27 % of the heating demands in Central European urban settlements in a renewable way. The methodology is also applied to a study case of the city of Zurich, Switzerland, where the detailed evolution of land use is available.

  13. Subsurface storage capacity influences climate-evapotranspiration interactions in three western United States catchments

    NASA Astrophysics Data System (ADS)

    Garcia, E. S.; Tague, C. L.

    2015-12-01

    In the winter-wet, summer-dry forests of the western United States, total annual evapotranspiration (ET) varies with precipitation and temperature. Geologically mediated drainage and storage properties, however, may strongly influence these relationships between climate and ET. We use a physically based process model to evaluate how plant accessible water storage capacity (AWC) and rates of drainage influence model estimates of ET-climate relationships for three snow-dominated, mountainous catchments with differing precipitation regimes. Model estimates show that total annual precipitation is a primary control on inter-annual variation in ET across all catchments and that the timing of recharge is a second-order control. Low AWC, however, increases the sensitivity of annual ET to these climate drivers by 3 to 5 times in our two study basins with drier summers. ET-climate relationships in our Colorado basin receiving summer precipitation are more stable across subsurface drainage and storage characteristics. Climate driver-ET relationships are most sensitive to subsurface storage (AWC) and drainage parameters related to lateral redistribution in the relatively dry Sierra site that receives little summer precipitation. Our results demonstrate that uncertainty in geophysically mediated storage and drainage properties can strongly influence model estimates of watershed-scale ET responses to climate variation and climate change. This sensitivity to uncertainty in geophysical properties is particularly true for sites receiving little summer precipitation. A parallel interpretation of this parameter sensitivity is that spatial variation in storage and drainage properties are likely to lead to substantial within-watershed plot-scale differences in forest water use and drought stress.

  14. The Influence of Subsurface Karst Terrain on Hydrology and Hydrogeology in Southwestern Victoria, Australia

    NASA Astrophysics Data System (ADS)

    Perveen, F.; Webb, J.; Dresel, E.; Hekmeijer, P.; Zydor, H.

    2012-12-01

    A detailed study, in collaboration with Department of Primary Industries (DPI), Victoria, has been carried out in three small subcatchments of southwestern Victoria (total area 8.4 km2), which are characterised by varying degrees of influence of a subsurface karst terrain. Lithological logs and downhole geophysics (gamma and bulk conductivity - EM39) on 15 bores within the catchments were supplemented by 2D electrical resistivity vertical profiling, and showed that the middle to late Miocene Port Campbell Limestone is present at shallow depths (~5 m) in two catchments, and somewhat deeper (>70 m) in the third catchment. The limestone is overlain by early Pliocene clay-rich Dorodong Sands. The topography of the third catchment is characterised by shallow closed depressions. Detailed hydrogeological cross-sections using groundwater levels in the bores show closed depressions within the potentiometric surface, that are attributed to the presence of subsurface conduits within the highly permeable limestone, verified by the variable hydraulic conductivity values ( 0.005 - 0.545m/day) obtained from single borehole recovery tests. Stream hydrographs reveal that there is virtually no surface runoff from one subcatchment, due to leakage into a conduit in the underlying limestone. A perched water table is also found in the same area. Thus the study area shows the typical karst features of a highly heterogeneous terrain with massive connectivity between surface water and groundwater regimes, despite the fact that the limestone is overlain by the clay-rich Dorodong Sands.

  15. Influence of subsurface drainage on quantity and quality of dissolved organic matter export from agricultural landscapes

    NASA Astrophysics Data System (ADS)

    Dalzell, Brent J.; King, Jennifer Y.; Mulla, David J.; Finlay, Jacques C.; Sands, Gary R.

    2011-06-01

    Despite its importance for aquatic ecosystem function and watershed carbon budgets, little is known about how land use influences dissolved organic matter (DOM) export. We investigated the influence of subsurface soil drainage, widespread in the Midwestern United States, on DOM export from agricultural fields designed to drain water at either 13 mm d-1 (conventional) or 51 mm d-1 (intense). Intense drainage exported 55% (±22%) more dissolved organic carbon (DOC) per year than conventional drainage due to both increased concentration and water yield. DOC export from plots was strongly dependent on precipitation and showed considerable interannual variability. Mean DOC concentrations in drainage water were low (1.62 and 1.87 mg L-1 for conventional and intense treatments), and fluorescence index (FI) measurements showed that it had a microbial source with little evidence of terrestrially derived material, suggesting that flow through deeper, organic-poor soil horizons is important in regulating DOC export from these plots. We compared DOM in subsurface drains with downstream ditch and stream sites. Increases in DOC concentration and molecular weight accompanied by decreasing FI values at downstream sites showed that streams gain a large amount of terrestrially derived DOM during base flow transport through agricultural landscapes, probably from riparian zones. These results show that DOM compositional characteristics change with catchment area and that the relevant observation scale for DOM dynamics is likely to vary among watersheds. This study also demonstrates that land management practices can directly affect DOC via changes to water flow paths. These results are critical for improving model estimates of DOM export from agricultural landscapes as well as predicting how DOC export will respond to changing land use and climate.

  16. Influence of Composition and Hot Rolling on the Subsurface Microstructure and Bendability of Ultrahigh-Strength Strip

    NASA Astrophysics Data System (ADS)

    Kaijalainen, Antti Juhani; Liimatainen, Mia; Kesti, Vili; Heikkala, Jouko; Liimatainen, Tommi; Porter, David A.

    2016-08-01

    The effect of subsurface microstructure on the bendability of three 8-mm-thick low-alloyed hot-rolled and direct-quenched ultrahigh-strength strip steels with yield strengths in the range 800 to 1100 MPa has been investigated. Rolling to lower finish rolling temperatures increased austenite pancaking, leading to the formation of ferritic/granular bainitic subsurface microstructures that are softer than the upper bainitic microstructures found with higher finish rolling temperature. In addition, increased austenite pancaking was found to increase the intensities of {112}<111>α and {110}<112>α to {110}<111>α texture components in the surface layers, especially in upper bainitic microstructures. It is shown that the bendability of ultrahigh-strength steels is governed by subsurface hardness and crystallographic texture. Bendability was found to be related to mean microhardness 0.1 to 0.4 mm below the surface, such that excellent bendability was achieved with a relatively soft subsurface layer down to a depth of 0.4 mm, i.e., 5 pct of the sheet thickness. Intense {112}<111>α texture combined with upper bainite containing MA islands in the subsurface region is shown to be detrimental to bendability when the bend axis is perpendicular to the rolling direction probably as a result of geometrical softening combined with high hardness.

  17. Influence of Composition and Hot Rolling on the Subsurface Microstructure and Bendability of Ultrahigh-Strength Strip

    NASA Astrophysics Data System (ADS)

    Kaijalainen, Antti Juhani; Liimatainen, Mia; Kesti, Vili; Heikkala, Jouko; Liimatainen, Tommi; Porter, David A.

    2016-06-01

    The effect of subsurface microstructure on the bendability of three 8-mm-thick low-alloyed hot-rolled and direct-quenched ultrahigh-strength strip steels with yield strengths in the range 800 to 1100 MPa has been investigated. Rolling to lower finish rolling temperatures increased austenite pancaking, leading to the formation of ferritic/granular bainitic subsurface microstructures that are softer than the upper bainitic microstructures found with higher finish rolling temperature. In addition, increased austenite pancaking was found to increase the intensities of {112}<111>α and {110}<112>α to {110}<111>α texture components in the surface layers, especially in upper bainitic microstructures. It is shown that the bendability of ultrahigh-strength steels is governed by subsurface hardness and crystallographic texture. Bendability was found to be related to mean microhardness 0.1 to 0.4 mm below the surface, such that excellent bendability was achieved with a relatively soft subsurface layer down to a depth of 0.4 mm, i.e., 5 pct of the sheet thickness. Intense {112}<111>α texture combined with upper bainite containing MA islands in the subsurface region is shown to be detrimental to bendability when the bend axis is perpendicular to the rolling direction probably as a result of geometrical softening combined with high hardness.

  18. INFLUENCE OF INORGANIC AND ORGANIC NUTRIENTS ON AEROBIC BIODEGRADATION AND ON THE ADAPTATION RESPONSE OF SUBSURFACE MICROBIAL COMMUNITIES

    EPA Science Inventory

    The influence of inorganic and organic amendments on the mineralization of ethylene dibromide, p-nitrophenol, phenol, and toluene was examined in subsurface soil samples from a pristine aquifer near Lula, Okla. The responses indicate that the metabolic abilities and nutrient requ...

  19. Influence of chlorothalonil on the removal of organic matter in horizontal subsurface flow constructed wetlands.

    PubMed

    Casas-Zapata, Juan C; Ríos, Karina; Florville-Alejandre, Tomás R; Morató, Jordi; Peñuela, Gustavo

    2013-01-01

    This study investigates the effects of chlorothalonil (CLT) on chemical oxygen demand (COD) and dissolved organic carbon (DOC) in pilot-scale horizontal subsurface flow constructed wetlands (HSSFCW) planted with Phragmites australis. Physicochemical parameters of influent and effluent water samples, microbial population counting methods and statistical analysis were used to evaluate the influence of CLT on organic matter removal efficiency. The experiments were conducted on four planted replicate wetlands (HSSFCW-Pa) and one unplanted control wetland (HSSFCW-NPa). The wetlands exhibited high average organic matter removal efficiencies (HSSFCW-Pa: 80.6% DOC, 98.0% COD; HSSFCW-NPa: 93.2% DOC, 98.4% COD). The addition of CLT did not influence organic removal parameters. In all cases CLT concentrations in the effluent occurred in concentrations lower than the detection limit of the analytical method. Microbial population counts from HSSFCW-Pa showed significant correlations among different microbial groups and with different physicochemical variables. The apparent independence of organic matter removal and CLT inputs, along with the CLT depletion observed in effluent samples demonstrated that HSSFCW are a viable technology for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT. PMID:23305280

  20. An Analysis of the Treatment of Corporate Influence on Government by United States History and American Government High School Textbooks

    ERIC Educational Resources Information Center

    Neumann, Richard

    2014-01-01

    This article reports on an investigation to explore the possibility that ideology might be expressed in the treatment of corporate influence on federal government by social studies textbooks. Two textbooks were examined in the study--United States history and American government. Corporate influence involves activities that affect election and…

  1. Microbial and chemical factors influencing methane production in laboratory incubations of low-rank subsurface coals

    USGS Publications Warehouse

    Harris, Stephen H.; Smith, Richard L.; Barker, Charles E.

    2008-01-01

    Lignite and subbituminous coals were investigated for their ability to support microbial methane production in laboratory incubations. Results show that naturally-occurring microorganisms associated with the coals produced substantial quantities of methane, although the factors influencing this process were variable among different samples tested. Methanogenic microbes in two coals from the Powder River Basin, Wyoming, USA, produced 140.5-374.6 mL CH4/kg ((4.5-12.0 standard cubic feet (scf)/ton) in response to an amendment of H2/CO2. The addition of high concentrations (5-10 mM) of acetate did not support substantive methane production under the laboratory conditions. However, acetate accumulated in control incubations where methanogenesis was inhibited, indicating that acetate was produced and consumed during the course of methane production. Acetogenesis from H2/CO2 was evident in these incubations and may serve as a competing metabolic mode influencing the cumulative amount of methane produced in coal. Two low-rank (lignite A) coals from Fort Yukon, Alaska, USA, demonstrated a comparable level of methane production (131.1-284.0 mL CH4/kg (4.2-9.1 scf/ton)) in the presence of an inorganic nutrient amendment, indicating that the source of energy and organic carbon was derived from the coal. The concentration of chloroform-extractable organic matter varied by almost three orders of magnitude among all the coals tested, and appeared to be related to methane production potential. These results indicate that substrate availability within the coal matrix and competition between different groups of microorganisms are two factors that may exert a profound influence on methanogenesis in subsurface coal beds.

  2. Influencing and impacting the profession through governance opportunities.

    PubMed

    Drenkard, Karen N

    2015-01-01

    In addition to board leadership of health care organizations and corporations, there are strategic opportunities for nurses to participate in professional association boards and commissions and expert panels. These boards have specific and unique challenges and opportunities, and it is important for nurse leaders to serve in shaping the direction of the profession. Nursing as a profession has an opening to solve many of the care delivery issues that face the country. A strategic contribution to association boards and commissions can influence the health care delivery system changes needed to improve quality of care, access to care, and reducing costs. This article describes similarities and differences of service on association boards and commissions compared with organizational and corporate boards. Through these leadership roles, the larger community can observe influential nurses in an essential role. These leadership opportunities, including membership boards, commissions, and content expert panels, call for a special understanding of those governance structures and the contributions that nurse leaders can make to impact health care. Association and membership organizations have undergone many changes in the past 10 years, and new models of governance and leadership have been called into play. There are challenges and opportunities in serving on these boards and commissions. Maximizing the leadership and governance roles of this type of service is a critical contribution that nurses can make to impact the profession of nursing and the greater health care system. PMID:25474665

  3. Corroboration for the influence of a component of solar irradiance on subsurface radon signals

    NASA Astrophysics Data System (ADS)

    Steinitz, G.; Piatibratova, O.; Kotlarsky, P.; Sturrock, P.; Maritn, C.

    2012-04-01

    Rn-222 occurs at highly varying levels as a trace component in subsurface air (geogas). This high variability is traced by alpha and gamma activity due to the decay of radon and its progeny. Nuclear radiation from radon in geogas and in experiments using air+radon within a confined volume exhibits systematic temporal variations. These variations are composed of periodic and non-periodic signals spanning several orders of magnitude in time - from annual to daily and sub-daily durations. Analysis of extensive data sets from three key sites 200 km apart in the arid desert of southern Israel [1-3] and from a 5-year experiment using alpha and gamma detectors [4] demonstrate that the periodic variations, observed to a depth of >100 meters, are related to an above surface driver probably due to a component of solar irradiance. Insight was also derived from the long term variations in the geological and the experimental time series [5], indicated by the occurrence of multi-year variations, and clear semiannual and ternary annual signals which are in addition to the annual periodicity. New confirmations are based on recognizing further cyclic phenomena, some of which are not linked with Earth related periodicities. A likehood analysis of the alpha and gamma time series in a long-term experiment is performed. A Combined Power Statistic formed from the gamma, alpha-H and alpha-L sensors inside the experimental tank shows that the time series of the gamma radiation contains an annual periodicity as well as a clear semi-annual and possibly a ternary-annual periodicity. The same analysis also resolves additional periodicities in the frequency range of 10-15 yr-1 in the gamma time series which are indicative of a relationship to rotation of the sun around its axis [6]. Observation of solar periodicities in the temporal pattern of the nuclear radiation of radon is a significant independent substantiation for the notion of the influence of a component in solar irradiance. An

  4. Investigating the influence of subsurface heterogeneity on chemical weathering in the critical zone using high resolution reactive transport models

    NASA Astrophysics Data System (ADS)

    Pandey, S.; Rajaram, H.

    2014-12-01

    The critical zone (CZ) represents a major life-sustaining realm of the terrestrial surface. The processes controlling the development and transformation of the CZ are important to continued health of the planet as human influence continues to grow. The CZ encompasses the shallow subsurface, a region of reaction, unsaturated flow, and transport. Chemical weathering in the subsurface is one of the important processes involved in the formation and functioning of the CZ. We present two case studies of reactive transport modeling to investigate the influence of subsurface heterogeneity and unsaturated flow on chemical weathering processes in the CZ. The model is implemented using the reactive transport code PFLOTRAN. Heterogeneity in subsurface flow is represented using multiple realizations of conductive fracture networks in a hillslope cross-section. The first case study is motivated by observations at the Boulder Creek Critical Zone Observatory (BCCZO) including extensive hydrologic and geochemical datasets. The simulations show that fractures greatly enhance weathering as compared to a homogeneous porous medium. Simulations of north-facing slope hydrology with prolonged snowmelt pulses also increases weathering rates, showing the importance of slope aspect on weathering intensity. Recent work elucidates deteriorating water quality caused by climate change in the CZ of watersheds where acid rock drainage (ARD) occurs. The more complex reactions of ARD require a customized kinetic reaction module with PFLOTRAN. The second case study explores the mechanisms by which changes in hydrologic forcing, air and ground temperatures, and water table elevations influence ARD. For instance, unreacted pyrite exposed by a water table drop was shown to produce a 125% increase in annual pyrite oxidization rate, which provides one explanation for increased ARD.

  5. Evaluating the Competitive Use of the Subsurface: The Influence of Energy Storage and Production in Groundwater

    NASA Astrophysics Data System (ADS)

    Helmig, R.; Becker, B.; Flemisch, B.

    2015-12-01

    The natural subsurface is gaining in importance for a variety of engineering applications related to energy supply. At the same time it is already utilized in many ways. On the one hand, the subsurface with its groundwater system represents the most important source of drinking water; on the other hand, it contains natural resources such as petroleum, natural gas and coal. In recent years, the subsurface has been gaining importance as a resource of energy and as an energy and waste repository. It can serve as a short-, medium- or long-term storage medium for energy in various forms, e.g. in the form of methane (CH4), hydrogen (H2) or compressed air. The subsurface is also attracting increasing interest as a natural source of energy, regarding, for instance, the extraction of fossil methane by hydraulic fracturing or the utilization of geothermal energy as a renewable energy source. As a result, with increasing exploitation, resource conflicts are becoming more and more common and complex. Modeling concepts for simulating multiphase flow that can reproduce the high complexity of the underlying processes in an efficient way need to be developed. The application of these model concepts is of great importance with respect to feasibility, risk analysis, storage capacity and sensitivity issues. This talk will give an overview on possible utilization conflicts in subsurface systems and how the groundwater is affected. It will focus on presenting fundamental properties and functions of a compositional multiphase system in a porous medium and introduce basic multiscale and multiphysics concepts as well as formulate conser­vation laws for simulating energy storage in the subsurface. Large-scale simulations that show the general applicability of the modeling concepts of such complicated natural systems, especially the impact on the groundwater of simultaneously using geothermal energy and storing chemical and thermal energy, and how such real large-scale systems provide a

  6. Influence of subsurface heterogeneity on observed borehole temperatures at a mountain permafrost site in the Upper Engadine, Swiss Alps

    NASA Astrophysics Data System (ADS)

    Schneider, S.; Hoelzle, M.; Hauck, C.

    2012-04-01

    Permafrost in high mountain areas occurs in a large variety of surface and subsurface material within short distances. This work presents a nine-year (2002 - 2011) data set of borehole temperatures for five different (sub-) surface materials from the high alpine permafrost area, Murtèl-Corvatsch, Switzerland (Haeberli et al. (1988) and Hanson & Hoelzle (2005)). The influence of the material on the thermal regime was investigated by borehole temperature data, the temperature at the top of the permafrost (TTOP-concept) and the apparent thermal diffusivity (ATD). The results show no consistent subsurface temperature trends since 2002 within the uppermost 6 meters. Rather, the thermal regime is predominantly influenced by the composition of the subsurface material and the thickness and duration of the snow cover. At all sites the subsurface temperatures were the lowest when the snow thickness was less than 1m. As pointed out in Luetschg et al. (2008), it could be confirmed, that the longer the non-insulating snow cover lasts in autumn, the colder is the ground surface temperature (GST) through the entire year. At all sites the cooling during autumn/ winter and the duration of the zero curtain in spring had a stronger influence on the interannual variability of the thermal regime than the temperature increase during summer. At coarse blocky, ice-rich sites no changes in active layer depth were observed. Rather, the ATD values of the active layer and the high temperature transport rate of 5.6 K m-1 d-1 confirm a high thermal response of the active layer. Within coarse blocky material, the air ventilation (as described in Wakonigg (1996)) and the seasonal production of ice seem to be the main factors for permafrost occurrence in high alpine regions. While temperatures within the talus slope are close to 0 °C and a stable permafrost regime is observed, the subsurface of the fine-grained site (where convective and advective airflow can be neglected) showed positive

  7. Influence of lateral subsurface flow and connectivity on soil water storage in land surface modeling

    NASA Astrophysics Data System (ADS)

    Kim, Jonggun; Mohanty, Binayak P.

    2016-01-01

    Lateral surface/subsurface flow and their connectivity play a significant role in redistributing soil water, which has a direct effect on biological, chemical, and geomorphological processes in the root zone (~1 m). However, most of the land surface models neglect the horizontal exchanges of water at the grid or subgrid scales, focusing only on the vertical exchanges of water as one-dimensional process. To develop better hydrologic understanding and modeling capability in complex landscapes, in this study we added connectivity-based lateral subsurface flow algorithms in the Community Land Model. To demonstrate the impact of lateral flow and connectivity on soil water storage we designed three cases including the following: (1) with complex surface topography only, (2) with complex surface topography in upper soil layers and soil hydraulic properties with uniform anisotropy. and (3) with complex surface topography and soil hydraulic properties with spatially varying anisotropy. The connectivity was considered as an indicator for the variation of anisotropy in the case 3, which was created by wetness conditions or geophysical controls (e.g., soil type, normalized difference vegetation index, and topographic index). These cases were tested in two study sites (ER 5 field and ER-sub watershed in Oklahoma) comparing to the field (gravimetric and remote sensing) soil moisture observations. Through the analysis of spatial patterns and temporal dynamics of soil moisture predictions from the study cases, surface topography was found to be a crucial control in demonstrating the variation of near surface soil moisture, but not significantly affected the subsurface flow in deeper soil layers. In addition, we observed the best performance in case 3 representing that the lateral connectivity can contribute effectively to quantify the anisotropy and redistributing soil water in the root zone. Hence, the approach with connectivity-based lateral subsurface flow was able to better

  8. Governance.

    ERIC Educational Resources Information Center

    Academe, 1989

    1989-01-01

    Over the last 75 years the AAUP has made progress in specifying its standards of governance and in reconciling traditional governance with collective bargaining. Excerpts from the "Joint Statement on Government of Colleges and Universities" and the "Statement on Academic Government for Institutions Engaged in Collective Bargaining" are presented.…

  9. Tetracycline Resistance in the Subsurface of a Poultry Farm: Influence of Poultry Wastes

    NASA Astrophysics Data System (ADS)

    You, Y.; Ball, W. P.; Ward, M. J.; Hilpert, M.

    2007-12-01

    Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoir of antibiotic resistant bacteria. Using the electromagnetic induction (EMI) method of geophysical characterization, we measured the apparent subsurface electrical conductivity (ECa) at a CAFO site in order to assess the movement of pollutants associated with animal waste. The map of ECa and other available data suggest that (1) soil surrounding a poultry litter storage shed is contaminated by poultry waste, (2) a contamination plume in the subsurface emanates from that shed, and (3) the development of that plume is due to groundwater flow. We focused on understanding the spread of tetracycline resistance (Tc\\tiny R), because tetracycline is one of the most frequently used antibiotics in food animal production and therefore probably used at our field site. Microbiological experiments show the presence of Tc\\tiny R bacteria in the subsurface and indicate higher concentrations in the top soil than in the aquifer. Environmental DNA was extracted to identify CAFO- associated Tc\\tiny R genes and to explore a link between the presence of Tc\\tiny R and CAFO practices. A "shot-gun" cloning approach is under development to target the most prevalent Tc\\tiny R gene. This gene will be monitored in future experiments, in which we will study the transmission of Tc\\tiny R to naive E.~coli under selective pressure of Tc. Experimental results will be used to develop a mathematical/numerical model in order to describe the transmission process and to subsequently make estimates regarding the large-scale spread of antibiotic resistance.

  10. Government Influence and Community Involvement on Abstinence-Only Programs in 1999 and 2003

    ERIC Educational Resources Information Center

    Gusrang, Jamie L.; Cheng, Simon

    2010-01-01

    In this study, we compare federal government influence on abstinence-only programs in 1999 and 2003 to better see how shifts in the federal government's sex education polices impacted other government and community actors. Using data from the Sex Education in America Surveys (SEAS), we find that changes in federal policy, particularly after the…

  11. Influence of inorganic and organic nutrients on aerobic biodegradation and on the adaptation response of subsurface microbial communities.

    PubMed

    Swindoll, C M; Aelion, C M; Pfaender, F K

    1988-01-01

    The influence of inorganic and organic amendments on the mineralization of ethylene dibromide, p-nitrophenol, phenol, and toluene was examined in subsurface soil samples from a pristine aquifer near Lula, Okla. The responses indicate that the metabolic abilities and nutrient requirements of groundwater microorganisms vary substantially within an aquifer. In some samples, additions of inorganic nutrients resulted in a more rapid adaptation to the test substrate and a higher rate of metabolism, indicating that metabolism may have been limited by these nutrients. In other samples from the same aquifer layer, inorganic amendments had little or no influence on mineralization. In general, the addition of multiple inorganic nutrients resulted in a greater enhancement of degradation than did the addition of single substances. Additions of alternate carbon sources, such as glucose or amino acids, inhibited the mineralization of the xenobiotic substrates. This inhibition appears to be the result of the preferential utilization of the more easily degradable carbon amendments. PMID:3125792

  12. Influence of frozen storage on herbicide degradation capacity in surface and subsurface sandy soils.

    PubMed

    Mortensen, Sarah K; Jacobsen, Carsten S

    2004-12-15

    The degradation of MCPA and metribuzin was investigated in laboratory batch experiments using fresh and frozen-stored soil samples from the unsaturated zone of a sandy soil. Mineralization potentials measured in fresh and frozen-stored soils were similar, and mineralization kinetics in surface and subsurface soils could be fitted using the same kinetic models. MCPA mineralization data from all three horizons were best described with the exponential growth form of the three-half-order model. During the mineralization of MCPA, growth in MCPA-degrading microbial populations was confirmed by increases in the abundance of tfdA genes following MCPA exposure. In contrast to MCPA, metribuzin mineralization followed zero-order kinetics, and very little metribuzin was mineralized (<1%) in all three of the investigated soil horizons. In addition, metribuzin dissipation and metabolite formation were also measured in surface and subsurface soils using LC-MS/MS. Differences in metribuzin dissipation were observed in the A-horizon at the beginning of the experiment and resulted in substantially different 50% disappearance time, DT50, values for frozen-stored (36 days) and fresh (<15 days) soil samples. However, the % of metribuzin remaining in fresh and frozen-stored surface soils was comparable from day 37 and thereafter. PMID:15669321

  13. Sub-surface alloying largely influences graphene nucleation and growth over transition metal substrates.

    PubMed

    Zhang, Liying; Zhao, Xingju; Xue, Xinlian; Shi, Jinlei; Li, Chong; Ren, Xiaoyan; Niu, Chunyao; Jia, Yu; Guo, Zhengxiao; Li, Shunfang

    2015-11-11

    Sub-surface alloying (SSA) can be an effective approach to tuning surface functionalities. Focusing on Rh(111) as a typical substrate for graphene nucleation, we show strong modulation by SSA atoms of both the energetics and kinetics of graphene nucleation simulated by first-principles calculations. Counter-intuitively, when the sub-surface atoms are replaced by more active solute metal elements to the left of Rh in the periodic table, such as the early transition metals (TMs), Ru and Tc, the binding between a C atom and the substrate is weakened and two C atoms favor dimerization. Alternatively, when the alloying elements are the late TMs to the right of Rh, such as the relatively inert Pd and Ag, the repulsion between the two C atoms is enhanced. Such distinct results can be well addressed by the delicately modulated activities of the surface host atoms in the framework of the d-band theory. More specifically, we establish a very simple selection rule for optimizing the metal substrate for high quality graphene growth: the introduction of an early (late) solute TM in the SSA lowers (raises) the d-band center and the activity of the top-most host metal atoms, weakening (strengthening) the C-substrate binding, meanwhile both energetically and kinetically facilitating (hindering) the graphene nucleation, and simultaneously promoting (suppressing) the orientation disordering the graphene domains. Importantly, our preliminary theoretical results also show that such a simple rule is also proposed to be operative for graphene growth on the widely invoked Cu(111) catalytic substrate. PMID:26257125

  14. Influences on corporate executive decision behavior in government acquisitions

    NASA Technical Reports Server (NTRS)

    Wetherington, J. R.

    1986-01-01

    This paper presents extensive exploratory research which had as its primary objective, the discovery and determination of major areas of concern exhibited by U.S. corporate executives in the preparation and submittal of proposals and bids to the Federal government. The existence of numerous unique concerns inherent in corporate strategies within the government market environment was established. A determination of the relationship of these concerns to each other was accomplished utilizing statistical factor analysis techniques resulting in the identification of major groupings of management concerns. Finally, using analysis of variance, an analysis and discovery of the interrelationship of the factors to corporate demographics was accomplished. The existence of separate and distinct concerns exhibited by corporate executives when contemplating sales and operations in the government marketplace was established. It was also demonstrated that quantifiable relationships exist between such variables and that the decision behavior exhibited by the responsible executives has an interrelationship to their company's demographics.

  15. Influence of lowland forests on subsurface salt accumulation in shallow groundwater areas.

    PubMed

    Tóth, Tibor; Balog, Kitti; Szabó, András; Pásztor, László; Jobbágy, Esteban G; Nosetto, Marcelo D; Gribovszki, Zoltán

    2014-01-01

    In flat sedimentary plains in areas with a sub-humid climate, tree planting on grasslands and arable lands creates strong hydrological shifts. As a result of deep rooting and high water uptake of trees, groundwater levels drop and subsurface salt accumulation increases. Tree planting has expanded globally and in Hungary it reached rates of 15 000 ha year(-1), being focused mainly in the Great Hungarian Plain where forests replace grasslands and crops in a region with widespread shallow groundwater. We performed soil and groundwater observations in 31 pairs of forest and control plots in the region, including gradients of initial water table depth and salinity, soil layering, and tree species and age. Accumulated tree biomass was positively correlated with soil salinization rates following tree planting, being also affected by species (poplar > common oak > black locust) and stand age. Differences among tree species effects appeared to be related to their growth rates. Due to downward deep percolation and salt leaching episodes during the Hungarian winters, the observed salt accumulation rates were lower than those described under similar settings in the warmer Argentine Pampas. PMID:25228311

  16. Influence of the mole penetrator on measurements of heat flow in lunar subsurface layers

    NASA Astrophysics Data System (ADS)

    Wawrzaszek, Roman; Drogosz, Michal; Seweryn, Karol; Banaszkiewicz, Marek; Grygorczuk, Jerzy

    Measuring the thermal gradient in subsurface layers is a basic method of determination the heat flux from the interior of a planetary body to its surface. In case of the Moon, such measurements complemented with the results of theoretical analysis and modeling can significantly improve our understanding of the thermal and geological evolution of the Moon. In practice, temperature gradient measurements are performed by at least two sensors located at different depths under the surface. These sensors will be attached to a penetrator [1] or to a cable pulled behind the penetrator. In both cases the object that carries the sensors, e.g. penetrator, perturb temperature measurements. In our study we analyze a case of two thermal sensors attached to the ends of 350mm long penetrator made of a composite material. In agreement with the studies of other authors we have found that the penetrator should be placed at the depth of 2-3 meters, where periodic changes of the temperature due to variation of solar flux at the surface are significantly smaller than the error of temperature measurement. The most important result of our analysis is to show how to deconvolve the real gradient of the temperature from the measurements perturbed by the penetrator body. In this way it will be possible to more accurately determine heat flux in the lunar regolith. [1] Grygorczuk J., Seweryn K., Wawrzaszek R., Banaszkiewicz M., Insertion of a Mole Pene-trator -Experimental Results, /39th Lunar and Planetary Science Conference /League City, Texas 2008

  17. Influence of lowland forests on subsurface salt accumulation in shallow groundwater areas

    PubMed Central

    Tóth, Tibor; Balog, Kitti; Szabó, András; Pásztor, László; Jobbágy, Esteban G.; Nosetto, Marcelo D.; Gribovszki, Zoltán

    2013-01-01

    In flat sedimentary plains in areas with a sub-humid climate, tree planting on grasslands and arable lands creates strong hydrological shifts. As a result of deep rooting and high water uptake of trees, groundwater levels drop and subsurface salt accumulation increases. Tree planting has expanded globally and in Hungary it reached rates of 15 000 ha year−1, being focused mainly in the Great Hungarian Plain where forests replace grasslands and crops in a region with widespread shallow groundwater. We performed soil and groundwater observations in 31 pairs of forest and control plots in the region, including gradients of initial water table depth and salinity, soil layering, and tree species and age. Accumulated tree biomass was positively correlated with soil salinization rates following tree planting, being also affected by species (poplar > common oak > black locust) and stand age. Differences among tree species effects appeared to be related to their growth rates. Due to downward deep percolation and salt leaching episodes during the Hungarian winters, the observed salt accumulation rates were lower than those described under similar settings in the warmer Argentine Pampas. PMID:25228311

  18. Clogging influence on metals migration and removal in sub-surface flow constructed wetlands

    NASA Astrophysics Data System (ADS)

    Ranieri, Ezio; Young, Thomas M.

    2012-03-01

    Chromium (Cr) and Nickel (Ni) removal from secondary effluent has been evaluated in a four year research program to determine the effectiveness of Sub-Surface Flow (SSF) Constructed Wetlands (cws). Tests were performed in small scale (10 l/h) and full scale (150 m3/d) SSF cws. Metals removal was also assessed as a function of increased clogging that occurred in the cws over the course of the study. Cr and Ni content were evaluated in sediments at various locations along the flow path and in plant tissues by sampling Phragmites australis roots, stems and leaves. Clogging was evaluated by measuring hydraulic conductivity at the same sampling locations at the beginning and at the end of the experiment. Residence Time Distribution (RTD) curves were also assessed at the beginning and after 48 months; the skewness of the RTDs increased over this period. Proportionality between increasing clogging and sediment accumulation of metals was observed, especially for Ni. Adsorption to the original matrix and the accumulated sediment is a removal mechanism consistent with available data.

  19. Influence of acidic and alkaline waste solution properties on uranium migration in subsurface sediments.

    PubMed

    Szecsody, Jim E; Truex, Mike J; Qafoku, Nikolla P; Wellman, Dawn M; Resch, Tom; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments have significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100 s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH2) resulted in a rapid (<10 h) increase in aqueous carbonate (with Ca(2+), Mg(2+)) and phosphate and a slow (100 s of hours) increase in silica, Al(3+), and K(+), likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH13) resulted in a rapid (<10h) increase in carbonate, followed by a slow (10 s to 100 s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in not only uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity. PMID:23851265

  20. Seasonal influence on sulfate reduction and zinc sequestration in subsurface treatment wetlands.

    PubMed

    Stein, Otto R; Borden-Stewart, Deborah J; Hook, Paul B; Jones, Warren L

    2007-08-01

    To characterize the effects of season, temperature, plant species, and chemical oxygen demand (COD) loading on sulfate reduction and metals removal in treatment wetlands we measured pore water redox potentials and concentrations of sulfate, sulfide, zinc and COD in subsurface wetland microcosms. Two batch incubations of 20 day duration were conducted in each of four seasons defined by temperature and daylight duration. Four treatments were compared: unplanted controls, Typha latifolia (broadleaf cattail), and Schoenoplectus acutus (hardstem bulrush), all at low COD loading (267 mg/L), plus bulrush at high COD loading (534 mg/L). Initial SO4-S and zinc concentrations were 67 and 24 mg/L, respectively. For all treatments, sulfate removal was least in winter (4 degrees C, plant dormancy) greatest in summer (24 degrees C, active plant growth) and intermediate in spring and fall (14 degrees C), but seasonal variation was greater in cattail, and especially, bulrush treatments. Redox measurements indicated that, in winter, plant-mediated oxygen transfer inhibited activity of sulfate reducing bacteria, exacerbating the reduction in sulfate removal due to temperature. Doubling the COD load in bulrush treatments increased sulfate removal by only 20-30% when averaged over all seasons and did not alter the basic pattern of seasonal variation, despite tempering the wintertime increase in redox potential. Seasonal and treatment effects on zinc removal were broadly consistent with sulfate removal and presumably reflected zinc-sulfide precipitation. Results strongly suggest that interactive effects of COD loading rate, temperature, season, and plant species control not only sulfate reduction and zinc sequestration, but also the balance of competition between various microbial consortia responsible for water treatment in constructed wetlands. PMID:17599383

  1. Influence of acidic and alkaline waste solution properties on uranium migration in subsurface sediments

    NASA Astrophysics Data System (ADS)

    Szecsody, Jim E.; Truex, Mike J.; Qafoku, Nikolla P.; Wellman, Dawn M.; Resch, Tom; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments have significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100 s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH 2) resulted in a rapid (< 10 h) increase in aqueous carbonate (with Ca2 +, Mg2 +) and phosphate and a slow (100 s of hours) increase in silica, Al3 +, and K+, likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH 13) resulted in a rapid (< 10 h) increase in carbonate, followed by a slow (10 s to 100 s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in not only uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity.

  2. Influence of Acidic and Alkaline Waste Solution Properties on Uranium Migration in Subsurface Sediments

    SciTech Connect

    Szecsody, James E.; Truex, Michael J.; Qafoku, Nikolla; Wellman, Dawn M.; Resch, Charles T.; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments has significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH 2) resulted in a rapid (< 10 h) increase in aqueous carbonate (with Ca2+, Mg2+) and phosphate and a slow (100s of hours) increase in silica, Al3+, and K+, likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH 13) resulted in a rapid (< 10 h) increase in carbonate, followed by a slow (10s to 100s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity.

  3. The Growing Influence of the Government on the Affairs of the University. A Self Study.

    ERIC Educational Resources Information Center

    George Washington Univ., Washington, DC.

    A self-study conducted by George Washington University on the influence of the government on university affairs considered the following areas: (1) civil rights legislation and compliance; (2) legislation other than civil rights requiring compliance (e.g., occupational safety); (3) government program funding priorities; and (4) funds…

  4. Governance.

    ERIC Educational Resources Information Center

    Moran, K. D.

    The author notes that two trends appear to be developing in litigation over the governance of the public schools. One trend is increasing participation of organized groups in suits against the schools. The other is a greater volume of litigation dealing with open meeting laws and freedom of information acts. Reflecting the second trend, the…

  5. Influence of dissimilatory metal reduction on fate of organic and metal contaminants in the subsurface

    NASA Astrophysics Data System (ADS)

    Lovley, Derek R.; Anderson, Robert T.

    Dissimilatory Fe(III)-reducing microorganisms have the ability to destroy organic contaminants under anaerobic conditions by oxidizing them to carbon dioxide. Some Fe(III)-reducing microorganisms can also reductively dechlorinate chlorinated contaminants. Fe(III)-reducing microorganisms can reduce a variety of contaminant metals and convert them from soluble forms to forms that are likely to be immobilized in the subsurface. Studies in petroleum-contaminated aquifers have demonstrated that Fe(III)-reducing microorganisms can be effective agents in removing aromatic hydrocarbons from groundwater under anaerobic conditions. Laboratory studies have demonstrated the potential for Fe(III)-reducing microorganisms to remove uranium from contaminated groundwaters. The activity of Fe(III)-reducing microorganisms can be stimulated in several ways to enhance organic contaminant oxidation and metal reduction. Molecular analyses in both field and laboratory studies have demonstrated that microorganisms of the genus Geobacter become dominant members of the microbial community when Fe(III)-reducing conditions develop as the result of organic contamination, or when Fe(III) reduction is artificially stimulated. These results suggest that further understanding of the ecophysiology of Geobacter species would aid in better prediction of the natural attenuation of organic contaminants under anaerobic conditions and in the design of strategies for the bioremediation of subsurface metal contamination. Des micro-organismes simulant la réduction du fer ont la capacité de détruire des polluants organiques dans des conditions anérobies en les oxydant en dioxyde de carbone. Certains micro-organismes réducteurs de fer peuvent aussi dé-chlorer par réduction des polluants chlorés. Des micro-organismes réducteurs de fer peuvent réduire tout un ensemble de métaux polluants et les faire passer de formes solubles à des formes qui sont susceptibles d'être immobilisées dans le milieu

  6. Influence of dissimilatory metal reduction on fate of organic and metal contaminants in the subsurface

    NASA Astrophysics Data System (ADS)

    Lovley, Derek R.; Anderson, Robert T.

    Dissimilatory Fe(III)-reducing microorganisms have the ability to destroy organic contaminants under anaerobic conditions by oxidizing them to carbon dioxide. Some Fe(III)-reducing microorganisms can also reductively dechlorinate chlorinated contaminants. Fe(III)-reducing microorganisms can reduce a variety of contaminant metals and convert them from soluble forms to forms that are likely to be immobilized in the subsurface. Studies in petroleum-contaminated aquifers have demonstrated that Fe(III)-reducing microorganisms can be effective agents in removing aromatic hydrocarbons from groundwater under anaerobic conditions. Laboratory studies have demonstrated the potential for Fe(III)-reducing microorganisms to remove uranium from contaminated groundwaters. The activity of Fe(III)-reducing microorganisms can be stimulated in several ways to enhance organic contaminant oxidation and metal reduction. Molecular analyses in both field and laboratory studies have demonstrated that microorganisms of the genus Geobacter become dominant members of the microbial community when Fe(III)-reducing conditions develop as the result of organic contamination, or when Fe(III) reduction is artificially stimulated. These results suggest that further understanding of the ecophysiology of Geobacter species would aid in better prediction of the natural attenuation of organic contaminants under anaerobic conditions and in the design of strategies for the bioremediation of subsurface metal contamination. Des micro-organismes simulant la réduction du fer ont la capacité de détruire des polluants organiques dans des conditions anérobies en les oxydant en dioxyde de carbone. Certains micro-organismes réducteurs de fer peuvent aussi dé-chlorer par réduction des polluants chlorés. Des micro-organismes réducteurs de fer peuvent réduire tout un ensemble de métaux polluants et les faire passer de formes solubles à des formes qui sont susceptibles d'être immobilisées dans le milieu

  7. Computer modeling of pesticide fate at the hillslope scale. Influence of vegetated filter strips on surface runoff pesticides transfer and partitioning between surface and subsurface fluxes

    NASA Astrophysics Data System (ADS)

    Djabelkhir, K.; Carluer, N.; Lauvernet, C.

    2012-04-01

    In France, agriculture uses large quantities of fertilizer and pesticides. Water contamination by pesticides is highlighted by monitoring networks, at local and national levels. Control and reduction of contamination are major issues, for the protection of drinking water resources and aquatic ecosystems. Thus, understanding and quantifying the mechanisms involved in mobilization, transfer and dissipation of these substances can help to perform risk of water contamination diagnosis, and to estimate the effectiveness of corrective solutions. In this context, landscape elements, like buffer zones, can be an effective way to reduce diffuse contamination of pesticides carried by surface runoff. They protect the water ressources of the drift of the products applied to crops and contribute to the reduction of the transfer of pesticides in surface runoff from the plots to the river. We are interested in our study to the vegetative filter strips. The main objective of this thesis is to develop a model simulating the processes governing the transfer and dissipation of pesticides from plots to surface water, on surface and subsurface, along a slope. This will be done by taking into account the influence of vegetative filter strips between plots and rivers on the transfer, by changing the flow paths and retention time of these products via several mechanisms (infiltration, filtration of runoff -sedimentation of MES-, adsorption and degradation of products on the surface of the vegetative filter strips or infiltrated). Several models describing the mechanisms of transfer of water and solutes (sometimes) at a hillslope scale exist, in particular : POLA (Pinheiro and al., 1995), Openfluid (LISAH), J2000-JAMS (Krause and al., 2006), CatFlow (Zehe and al., 2000), tRIBS (Ivanov and al., 2004), Cathy 3D (Bixio and al., 2000) and CMF (Kraft and al., 2011). It was decided to choose a spatially distributed and object-oriented model, allowing to couple hydrological processes occuring

  8. Sociopolitical Influences on Federal Government Funding of Gifted and Talented and Bilingual Education Programs.

    ERIC Educational Resources Information Center

    Casanova, Ursula; Chavez, Sheila

    1992-01-01

    Examines the influence of various sociopolitical factors on government policies in two federal programs, those for the gifted and talented and those for bilingual education. Traces the evolution of these programs and compares their backgrounds to determine the influences shaping federal funding and program implementation. (GLR)

  9. Indications for solar influence on radon signal in the subsurface of Tenerife (Canary Islands, Spain)

    NASA Astrophysics Data System (ADS)

    Steinitz, G.; Martin-Luis, M. C.; Piatibratova, O.

    2015-05-01

    Radon at two locations in Tenerife is investigated. The MM-0 site is located in a bunker near Teide volcano. Daily radon (DR) signals are dominated by a 12-hour (S2) periodicity. Continuous wavelet transform (CWT) analysis of day-time and night-time series results in a day-night differentiation, which does not occur in the coeval temperature and pressure. This indicates that the radon system is directly affected by rotation of Earth around its axis, and not via the pressure and/or temperature pattern. San Fernando sites are in an underground gallery, located at 2.1 and 3 km from the entrance. Alpha and gamma time series show DR signals having an S1 and a strong S2 periodicity. Sidebands occur around the S1 periodicity. The lower sideband is close to 0.9972696 cycles per day (CPD; = sidereal frequency) and the upper sideband at a symmetric frequency above. They reflect a driver containing two waveforms having periodicities of rotation of Earth around its axis and around the Sun that influences radon in a non-linear fashion, leading to the sidebands around the S1 periodicity. Observation in Tenerife of sidebands and day-night phenomena substantiates the notion that the periodic components in the diurnal and annual frequency band of radon time series are due to the influence of a component in solar radiation.

  10. Influence of flow velocity on the removal of faecal coliforms in horizontal subsurface flow constructed wetland.

    PubMed

    Lohay, W S; Lyimo, T J; Njau, K N

    2012-01-01

    In order to determine the influence of flow velocity on the removal of faecal coliforms (FC) in constructed wetlands (CWs), removal rate constants of FC (k(FC)) were studied at various flow velocities (u). Membrane filtration technique was used during analysis. Values of k(FC) were determined using Reed's equation of pathogen removal; the results were compared with the plug flow equation. According to Reed's equation, k(FC) values ranged from 1.6 day⁻¹ at a velocity of 4 m/day to 34.5 day⁻¹ at a velocity of 42.9 m/day. The removal rates correlated positively with flow velocity (r = 0.84, p < 0.05). On assuming a plug flow equation, removal rates constants ranged from 0.77 to 11.69 day⁻¹; a more positive correlation (r = 0.93, p < 0.05) was observed. Optimum removal rate constants were observed for the velocity ranging 36 to 43 m/day. Generally, the increase of flow velocity improved FC removal rate constants: implying that pathogen removals are influenced by diffusion of the microorganisms into the biofilms on CW media. The velocity dependent approach together with the plug flow equation is therefore proposed for incorporation in the design of CW in a tropical climate where temperature variations are minor. PMID:23109602

  11. Subsurface damage of optical components and the influence on scattering properties

    NASA Astrophysics Data System (ADS)

    Draheim, Falk; Harnisch, Bernd; Weigel, Thomas

    1994-09-01

    The influence ofsurface damage under smooth optical surfaces on the scattering properties was investigated. Usually thissurface damage is filled and covered by a polishing layer. Thereforesurface damage does not contribute to the micro roughness of the surface. Three glasses, SF3, BK7, and SUPRASIL, with different Knoop hardness and related differentsurface damage density were chosen for the measurements. Three samples of each glass were polished with increasing polishing time in order to reduce the layer which contains thesurface damage. Beside the extensive measurements of the scatter behavior the samples were also investigated by means of microscopy (Nomarski, darkfield, cross polarization) and optical profilometry. The stray light was detected in the case of reflection (back scatter), transmission (forward scatter) and total reflection. In the case of totalreflection the scattered light behind the reflection surface was investigated. The detected scatter light was integrated over the measurement range and the resulting value was compared with the polishing time. Additional investigations were carried out to determine the influence on the light polarization.

  12. Influence of Microbial Iron and Nitrate Reduction on Subsurface Iron Biogeochemistry and Contaminant Metal Mobilization

    SciTech Connect

    Flynn Picardal

    2002-04-14

    Although toxic metal and radionuclide contaminants can not be destroyed, their toxicity and mobility can be dramatically altered by microbial activity. In addition to toxic metals, many contaminated sites contain both iron-containing minerals and co-contaminants such as nitrate (NO3-). Successful implementation of metal and radionuclide bioremediation strategies in such environments requires an understanding of the complex microbial and geochemical interactions that influence the redox speciation and mobility of toxic metals. Our specific objectives have been to (1) determine the effect of iron oxide mineral reduction on the mobility of sorbed, representative toxic metals (Zn2+), (2) study the biogeochemical interactions that may occur during microbial reduction of NO3- and iron oxide minerals, and (3) evaluate the kinetics of NO3--dependent, microbial oxidation of ferrous iron (Fe2+).

  13. Influence of Microbial Iron and Nitrate Reduction on Subsurface Iron Biogeochemistry and Contaminant Metal Mobilization

    SciTech Connect

    Flynn W. Picardal

    2002-04-10

    Although toxic metal and radionuclide contaminants can not be destroyed, their toxicity and mobility can be dramatically altered by microbial activity. In addition to toxic metals, many contaminated sites contain both iron-containing minerals and co-contaminants such as nitrate NO{sub 3}{sup -}. Successful implementation of metal and radionuclide bioremediation strategies in such environments requires an understanding of the complex microbial and geochemical interactions that influence the redox speciation and mobility of toxic metals. Our specific objectives have been to (1) determine the effect of iron oxide mineral reduction on the mobility of sorbed, representative toxic metals (Zn{sup 2+}), (2) study the biogeochemical interactions that may occur during microbial reduction of NO{sub 3}{sup -} and iron oxide minerals, and (3) evaluate the kinetics of NO{sub 3}{sup -}-dependent, microbial oxidation of ferrous iron (Fe{sup 2+}).

  14. Influences of specific ions in groundwater on concrete degradation in subsurface engineered barrier system.

    PubMed

    Lin, Wen-Sheng; Liu, Chen-Wuing; Li, Ming-Hsu

    2016-01-01

    Many disposal concepts currently show that concrete is an effective confinement material used in engineered barrier systems (EBS) at a number of low-level radioactive waste (LLW) disposal sites. Cement-based materials have properties for the encapsulation, isolation, or retardation of a variety of hazardous contaminants. The reactive chemical transport model of HYDROGEOCHEM 5.0 was applied to simulate the effect of hydrogeochemical processes on concrete barrier degradation in an EBS which has been proposed to use in the LLW disposal site in Taiwan. The simulated results indicated that the main processes that are responsible for concrete degradation are the species induced from hydrogen ion, sulfate, and chloride. The EBS with the side ditch drainage system effectively discharges the infiltrated water and lowers the solute concentrations that may induce concrete degradation. The redox processes markedly influence the formations of the degradation materials. The reductive environment in the EBS reduces the formation of ettringite in concrete degradation processes. Moreover, the chemical conditions in the concrete barriers maintain an alkaline condition after 300 years in the proposed LLW repository. This study provides a detailed picture of the long-term evolution of the hydrogeochemical environment in the proposed LLW disposal site in Taiwan. PMID:27376013

  15. Influence of calcite and dissolved calcium on uranium(VI) sorption to a hanford subsurface sediment.

    PubMed

    Dong, Wenming; Ball, William P; Liu, Chongxuan; Wang, Zheming; Stone, Alan T; Bai, Jing; Zachara, John M

    2005-10-15

    The influence of calcite and dissolved calcium on U(VI) adsorption was investigated using a calcite-containing sandy silt/clay sediment from the U. S. Department of Energy Hanford site. U(VI) adsorption to sediment, treated sediment, and sediment size fractions was studied in solutions that both had and had not been preequilibrated with calcite, at initial [U(VI)] = 10(-7)-10(-5) mol/L and final pH = 6.0-10.0. Kinetic and reversibility studies (pH 8.4) showed rapid sorption (30 min), with reasonable reversibility in the 3-day reaction time. Sorption from solutions equilibrated with calcite showed maximum U(VI) adsorption at pH 8.4 +/- 0.1. In contrast, calcium-free systems showed the greatest adsorption at pH 6.0-7.2. At pH > 8.4, U(VI) adsorption was identical from calcium-free and calcium-containing solutions. For calcite-presaturated systems, both speciation calculations and laser-induced fluorescence spectroscopic analyses indicated that aqueous U(VI) was increasingly dominated by Ca2UO2(CO3)3(0)(aq) at pH < 8.4 and thatformation of Ca2UO2(CO3)3(0)(aq) is what suppresses U(VI) adsorption. Above pH 8.4, aqueous U(VI) speciation was dominated by UO2(CO3)3(4-) in all solutions. Finally, results also showed that U(VI) adsorption was additive in regard to size fraction but not in regard to mineral mass: Carbonate minerals may have blocked U(VI) access to surfaces of higher sorption affinity. PMID:16295860

  16. Influence of Calcite and Dissolved Calcium on Uranium(VI) Sorption to a Hanford Subsurface Sediment

    SciTech Connect

    Dong, Wenming; Ball, William P.; Liu, Chongxuan; Wang, Zheming; Stone, Alan T.; Bai, Jing; Zachara, John M.

    2005-10-15

    The influence of calcite and dissolved calcium on U(VI) adsorption was investigated using a calcite-containing sandy silt/clay sediment from the U. S. Department of Energy Hanford site. U(VI) adsorption to sediment, treated sediment, and sediment size fractions was studied in solutions that both had and had not been preequilibrated with calcite, at initial [U(VI)] - 10-7-10-5 mol/L and final pH - 6.0-10.0. Kinetic and reversibility studies (pH 8.4) showed rapid sorption (30 min), with reasonable reversibility in the 3-day reaction time. Sorption from solutions equilibrated with calcite showed maximum U(VI) adsorption at pH 8.4-0.1. In contrast, calcium-free systems showed the greatest adsorption at pH 6.0-7.2. At pH > 8.4, U(VI) adsorption was identical from calcium-free and calcium-containing solutions. For calcite-presaturated systems, both speciation calculations and laser-induced fluorescence spectroscopic analyses indicated that aqueous U(VI) was increasingly dominated by Ca2UO2(CO3)3 0(aq) at pH<8.4 and that formation of Ca2UO2(CO3)3 0(aq) is what suppresses U(VI) adsorption. Above pH 8.4, aqueous U(VI) speciation was dominated by UO2(CO3)3 4- in all solutions. Finally, results also showed that U(VI) adsorption was additive in regard to size fraction but not in regard to mineral mass: Carbonate minerals may have blocked U(VI) access to surfaces of higher sorption affinity.

  17. Three essays in corporate finance: Examining the influence of government ownership and evaluating crude oil arbitrage

    NASA Astrophysics Data System (ADS)

    Holland, Kateryna

    The aim of this dissertation is twofold: first, to evaluate how governments influence firms in which they invest (chapters one and two), and second, to examine arbitrage in the crude oil market by investigating the relationship between crude oil inventories, physical prices, and financial prices (chapter three). In the first chapter (The Wealth Effects of Government Investment in Publicly Traded Firms), I study how government share ownership affects shareholder wealth. I find that government investments with higher likelihood of political interference have a negative influence on shareholder wealth, while the opposite is true for government investments with economic objectives. In the second chapter (Government Ownership and the Cost of Debt: Evidence form Government Investment in Publicly Traded Firms), I investigate how government share ownership affects the cost of debt of publicly traded firms. I find that government ownership generally leads to a higher cost of debt, except for times of economic and firm distress, when the value of the implicit government guarantee is associated with a reduction in the cost of debt. In the third chapter (Financial Trading, Spot Oil Prices, and Inventory: Evidence from the U.S. Crude Oil Market), I confirm the existence of an active cash and carry market in crude oil in Cushing, OK, the main U.S. crude oil futures settlement location. In other words, crude oil inventories in Cushing, but not in any other U.S. crude oil storage locations, are explained by the spread between the financial and the physical price of oil in addition to operational factors.

  18. Influence of Assimilation of Subsurface Temperature Measurements on Simulations of Equatorial Undercurrent and South Equatorial Current Along the Pacific Equator

    NASA Technical Reports Server (NTRS)

    Halpern, David; Leetmaan, Ants; Reynolds, Richard W.; Ji, Ming

    1997-01-01

    Equatorial Pacific current and temperature fields were simulated with and without assimilation of subsurface temperature measurements for April 1992 - March 1995, and compared with moored bouy and research vessel current measurements.

  19. Deep subsurface microbial processes

    USGS Publications Warehouse

    Lovley, D.R.; Chapelle, F.H.

    1995-01-01

    Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

  20. Agency Governance and Enforcement: The Influence of Mission on Environmental Decisionmaking

    ERIC Educational Resources Information Center

    Firestone, Jeremy

    2002-01-01

    Administrative agencies seeking to impose sanctions for regulatory violations can handle matters internally or through civil or criminal courts. Organizational culture, legal constraints, and political and private actors may influence governance and hence choice of enforcement venue. An enforcement behavior model is constructed and tested…

  1. Assessment of Groups Influence on Management Style as Related to University Governance

    ERIC Educational Resources Information Center

    Irtwange, S. V.; Orsaah, S.

    2010-01-01

    The study was undertaken with the objective of assessing groups influence on management style as related to University governance with University of Agriculture, Makurdi as a case study from academic staff perspective. The management style of the Vice Chancellor of the University of Agriculture, Makurdi between the period September 3, 1996 to…

  2. Factors Influencing the Design, Establishment, Administration, and Governance of Correctional Education for Females

    ERIC Educational Resources Information Center

    Ellis, Johnica; McFadden, Cheryl; Colaric, Susan

    2008-01-01

    This article summarizes the results of a study conducted to investigate factors influencing the organizational design, establishment, administration, and governance of correctional education for females. The research involved interviews with correctional and community college administrators and practitioners representing North Carolina female…

  3. Switching between hydrophobic and wettable conditions in soil: experiments to assess the influence of cracks, roots and subsurface drainage impedance

    NASA Astrophysics Data System (ADS)

    Urbanek, E.; Walsh, R. P. D.; Shakesby, R. A.

    2012-04-01

    Although much is known about soil hydrophobicity, assessments of the overall hydrological and erosional significance of the soil property in areas affected by it are greatly hampered by a lack of knowledge on switching between hydrophobic and hydrophilic states. This arises mainly because of (1) the destructive nature of methods of assessing hydrophobicity, (2) its often high local spatial variability and (3) difficulties of relating hydrophobicity results to meaningful soil moisture values. Also, very little is known about the influence which cracks and holes through hydrophobic soil and the presence or absence of subsurface impeding layers have on the 3D pattern and speed of hydrophobicity change during wetting and drying cycles. These issues form the focus of the present paper, which was carried out as part of the EU DESIRE Project. A laboratory experimental approach was adopted. Three different soils of equal initial hydrophibicity class when dry (18 % MED), but of contrasting texture and total carbon content, were investigated: (1) from the scrub-covered (dominated by Erica umbellata, Calluna vulgaris and Pterospartum tridentatum) Vale Torto catchment in Gois municipality, central Portugal (an area where the impacts of prescribed fire were being assessed); (2) soil around a Chamaecyparis lawsonia tree in South Wales; and (3) a vegetated coastal sand-dune location at Nicholaston, Gower Peninsula, South Wales. For the experiments, 106 samples of sieved (< 2 mm), dried soil were placed to a depth of 10 cm in standardized transparent pots (16.5 cm high, top diameter 16 cm, basal diameter 11 cm). Equal numbers of samples were prepared with either (i) five simulated holes, (ii) two simulated linear cracks (in both cases extending downwards to the sample base) and (iii) control soil samples without cracks or holes). Samples were also either (i) sealed at the base to create subsurface impeded drainage or (ii) provided with unimpeded basal drainage by insertion of

  4. Limiting the influence of pharmaceutical industry gifts on physicians: self-regulation or government intervention?

    PubMed

    Grande, David

    2010-01-01

    Concerns over the influence of pharmaceutical gifts on physicians have surged in recent years. This has prompted wide ranging legislative proposals in numerous states and in the federal government as well as stepped up efforts at self-regulation by the pharmaceutical industry and the medical profession. Policymakers face the decision of whether to defer to self-regulation or support government intervention. This commentary describes efforts at self-regulation by the pharmaceutical industry and the medical profession. The author examines and critiques the wide ranging legislative strategies pursued to limit the influence of pharmaceutical gifts on physicians and concludes with suggestions for policymakers and the profession to limit influence and preserve public trust. PMID:19756874

  5. Limiting the Influence of Pharmaceutical Industry Gifts on Physicians: Self-Regulation or Government Intervention?

    PubMed Central

    2009-01-01

    Concerns over the influence of pharmaceutical gifts on physicians have surged in recent years. This has prompted wide ranging legislative proposals in numerous states and in the federal government as well as stepped up efforts at self-regulation by the pharmaceutical industry and the medical profession. Policymakers face the decision of whether to defer to self-regulation or support government intervention. This commentary describes efforts at self-regulation by the pharmaceutical industry and the medical profession. The author examines and critiques the wide ranging legislative strategies pursued to limit the influence of pharmaceutical gifts on physicians and concludes with suggestions for policymakers and the profession to limit influence and preserve public trust. PMID:19756874

  6. Testing a model of county government influence on health care safety-nets.

    PubMed

    Knepper, Hillary

    2012-01-01

    In the United States, health care is not equitably distributed. As indicated in the literature, age, income, and other socio-economic indicators contribute to substantial differences in the variety and scope of health services. The 2010 Affordable Care Act illustrates the United States' effort to bring balance and equity to the health care system. In the meantime, county governments are struggling with rising health care costs on their budgets (Eaton, 2009; Phaup, 2009; Clark, 2003), particularly health care for low-income residents (Benton, Byers, Cigler, Klase, Menzel, Salant, Streib, Svara, & Waugh, 2008). However, as learned in this study, county governments across the country continue to address the health care needs of uninsured and underinsured citizens through participation in health care safety nets. This research identifies possible county government influences on health care safety-nets. This study analyzed 123 responses from county government administrators and elected officials along with secondary data from the U.S. Census Bureau and the International City/County Manager Association using a variety of statistical techniques, culminating in structural equation modeling. These analyses provided reasonable explanation for the variation among the variables leading to network performance improvement in meeting the health care needs of uninsured and underinsured people as well as the significant influence of county government involvement. PMID:22838054

  7. Influence of environmental parameters on the concentration of subsurface dissolved methane in two hydroelectric power plants in Brazil

    NASA Astrophysics Data System (ADS)

    Silva, M. G.; Marani, L.; Alvala, P. C.

    2013-12-01

    Methane (CH4) is a trace gas in the atmosphere of great importance for atmospheric chemistry as one of the main greenhouse gases. There are different sources with the largest individual production associated with the degradation of organic matter submerged in flooded areas. The amount of dissolved methane that reaches the surface depends on the production in the sediments and consumption in the water column. Both processes are associated with microbial activity and consequently dependent on the physico-chemical environmental conditions. The construction of hydroelectric dams cause flooding of areas near the river that can change the characteristics of the environment and cause changes in subsurface methane concentration. In this work, we studied two hydroelectric plants located in Brazil: Batalha (17°20'39.52"S, 47°29'34.29"W), under construction when the samples were take, and Itaipu (25°24'45.00"S, 54°35'39.00"W) which has been floated over 30 years ago. The water samples to determine dissolved methane were collected approximately 5 cm near the surface. In each collection point was measured depth, water temperature, pH and redox potential. The range of dissolved methane between the two dams was similar: 0.07-10.33 μg/l (Batalha) and 0.15-10.93 μg/l (Itaipu). However, the Batalha's average (4.04 × 3.43 μg/l; median = 3.66 μg/l) was higher than that observed in Itaipu (2.15 × 1.59 μg/l; median = 2.53 μg/l). The influence of environmental parameters on the concentration of dissolved methane was evaluated by multivariate statistical techniques (Principal Component Analysis - PCA). All of the parameters had some correlation with dissolved methane, however, the greatest contribution in Batalha was associated with pH while in Itaipu was the depth. The pH variation of the various points studied in Batalha may be associated with periods of drought and flooding of the river and hence the incorporation of organic matter in the environment. The organisms

  8. Subsurface Band Application of Poultry Litter and Its Influence on Phosphorus Concentration and Retention after Runoff from Permanent Pastures.

    PubMed

    Watts, Dexter B; Way, Thomas R; Torbert, H Allen; Armstrong, Shalamar D

    2015-11-01

    Excessive phosphorus (P) loss from agricultural fields is a major cause of eutrophication to rivers, lakes, and streams. To mitigate P loss after poultry litter (PL) applications, technology is being developed to apply litter below the soil surface. Thus, research was conducted to evaluate the effects of subsurface PL banding on soil P under pasture management. Treatments consisted of surface-broadcasted or subsurface-banded PL (38 cm apart) at 9 Mg ha, surface-broadcasted commercial fertilizer (CF; urea and triple superphosphate blend) at N (330 kg N ha) and P (315 kg N ha) application rates equivalent to PL, and a nonfertilized control. Runoff events lasting 40 min were simulated in bermudagrass ( L.) pastures on common soil types of the Coastal Plain and Piedmont regions. One day later, Mehlich-1 and water-soluble P concentrations in soil were measured at depths of 0 to 5 cm and 5 to 10 cm to determine P distribution and movement. The greatest P concentrations were observed at the shallow depth for all treatments. Phosphorus measurements at the point of application for PL bands were greater than for the surface-applied treatments (PL and CF) and control. Measurements between subsurface PL bands were slightly higher than the control but were statistically similar, suggesting that this application method can abate short-term P movement. Results obtained from this study show that subsurface band applying PL could increase P retention and reduce movement by precluding contact between surface water and litter nutrients. PMID:26641345

  9. Subsurface application of poultry litter and its influence on nutrient losses in runoff water from permanent pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental pressure to reduce nutrient losses from agricultural fields has increased in recent years. To abate this nutrient loss to the environment, better management practices and new technologies need to be developed. Thus, research was conducted to evaluate if subsurface banding poultry lit...

  10. Subsurface band application of poultry litter and its influence on Phosphorus concentration and retention after runoff from permanent pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive P loss from agricultural fields has been identified as a major cause of eutrophication to river, lakes, and streams. To minimize and mitigate P loss from poultry litter (PL) applications, new technology is being developed for subsurface band application of litter below the soil surface. Th...

  11. Subsurface application of poultry litter and its influence on nutrient losses in runoff water from permanent pastures.

    PubMed

    Watts, D B; Way, T R; Torbert, H A

    2011-01-01

    Environmental pressure to reduce nutrient losses from agricultural fields has increased in recent years. To abate this nutrient loss to the environment, better management practices and new technologies need to be developed. Thus, research was conducted to evaluate if subsurface banding poultry litter (PL) would reduce nitrogen (N) and phosphorus (P) loss in surface water runoff using a four-row prototype implement. Rainfall simulations were conducted to create a 40-min runoff event in an established bermudagrass (Cynodon dactylon L.) pasture on soil types common to the Coastal Plain and Piedmont regions. The Coastal Plain soil type was a Marvyn loamy sand (fine-loamy, kaolinitic, thermic Typic Kanhapludults) and the Piedmont soil type was a Hard Labor loamy sand (fine, kaolinitic, thermic Oxyaquic Kanhapludults). Treatments consisted of surface- and subsurface-applied PL at a rate of 9 Mg ha(-1), surface broadcast-applied commercial fertilizer (CF; urea and triple superphosphate blend) at the equivalent N (330 kg N ha(-1)) and P (315 kg N ha(-1)) content of PL, and a nonfertilized control. The greatest loss for inorganic N, total N, dissolved reactive P (DRP), and total P occurred with the surface broadcast treatments, with CF contributing to the greatest loss. Nutrient losses from the subsurface banded treatment reduced N and P in surface water runoff to levels of the control. Subsurface banding of PL reduced concentrations of inorganic N 91%, total N 90%, DRP 86%, and total P 86% in runoff water compared with surface broadcasted PL. These results show that subsurface band-applied PL can greatly reduce the impact of N and P loss to the environment compared with conventional surface-applied PL and CF practices. PMID:21520749

  12. Modeling the influence of exopolymeric substances (EPS) extracted from Pseudomonas bacteria on chromium (III) sorption and transport in heterogeneous subsurface soils

    NASA Astrophysics Data System (ADS)

    Kantar, C.; Demiray, H.; Koleli, N.; Mercan, N.

    2009-04-01

    In situ remediation of soils contaminated with Cr(VI) is usually accomplished through microbial reduction of Cr(VI) to Cr(III) by soil microorganisms including Pseudomonas bacteria. Cr(VI) is a toxic substance that may stimulate the production of exopolymeric substances (EPS) by soil bacteria. Natural organic ligands such as EPS may have a pronounced impact on Cr(III) solubility, sorption, transport and bioavailability in subsurface systems. In this study, laboratory sorption and column experiments were performed to investigate the influence of exopolymeric substances (EPS) extracted from Pseudomonas aeruginosa P16, Pseudomonas putida P18 and Pseudomonas stutzeri P40 on chromium (III) sorption and transport in heterogeneous subsurface soils. The results from laboratory experiments indicate that microbial EPS enhanced Cr(III) solubility, which, in turn, led to an increase in Cr(III) transport through columns packed with subsurface soils under slightly acidic to alkaline pH conditions. A reactive transport code that includes a semi-empirical surface complexation model (SCM) to describe chemical processes e.g., sorption was used to simulate bench-scale column data for Cr(III) transport in the presence of EPS. Our transport simulations suggest that for an accurate simulation of Cr(III) transport in the presence of microbial EPS, the following processes and/or interactions need to be explicitly considered: 1) Cr(III)-EPS interactions; 2) binary soil/Cr and soil/EPS surface complexes; and 3) ternary soil/Cr/EPS complexes.

  13. Subsurface sounders

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Airborne or spaceborne electromagnetic systems used to detect subsurface features are discussed. Data are given as a function of resistivity of ground material, magnetic permeability of free space, and angular frequency. It was noted that resistivities vary with the water content and temperature.

  14. Subsurface Mapping

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Target areas for sinking base holes, underground pipelines, etc., can be identified with the assistance of NASA Ames developed technology, by Airborne Pipeline Services, Inc. Subsurface features are computer processed; the system can cover 250 miles a day and was first developed by Applied Science, Inc.

  15. Influence of humic substances on Co[sup 2+] sorption by a subsurface mineral separate and its mineralogic components

    SciTech Connect

    Zachara, J.M.; Resch, C.T.; Smith, S.C. )

    1994-01-01

    The sorption of Co[sup 2+] (10[sup [minus]6] mol/L) was measured on subsurface mineral materials in the absence and presence of a sorbed leonardite humic acid (LHA) to (1) evaluate the sorptive role of mineral-bound humic substances, and (2) establish approaches to model metal ion binding in composite materials. The subsurface materials were a <2.0 [mu]m size fraction of an ultisol saprolite (CP) and this same material treated with dithonite-citrate-bicarbonate (DCB) to remove Fe-oxides (DCP). Comparable experiments (with and without LHA) were also performed with mineral sorbents representing dominant phases in the CP separate (gibbsite, Al-geothite, and kalonite) to evaluate their potential contributions to Co sorption. The mineral-bound LHA ranged in concentration between 0.1-0.4 mg-C/m[sup 2], representing approximately 0.7% of the subsurface isolate by mass. In solid-free suspensions, the affinity of LHA for Co increased with pH and decreasing I (K[sub d] ranging 20-450 L/g). Mineral-bound LHA increased Co sorption on all the sorbents by factors of 10-60%, with the greatest augmentation noted at pH values (4.5-6.5) where (1) maximum LHA sorption occurred, and (2) Co sorption to the mineral phase was weak and dominated by ion exchange. The LHA appeared simply to augment, rather than to change the intrinsic adsorption behavior of the mineral sorbents. Accordingly, predictions of the K[sub d] for Co on the LHA-coated subsurface materials (DCP, CP) based on a linear additivity model agreed well with the experimental data, suggesting that the complex humic-mineral association acted as a noninterative sorbent mixture at low aqueous Co concentrations.

  16. Influence of humic substances on Co 2+ sorption by a subsurface mineral separate and its mineralogic components

    NASA Astrophysics Data System (ADS)

    Zachara, J. M.; Resch, C. T.; Smith, S. C.

    1994-01-01

    The sorption of Co 2+ (10 -6 mol/L) was measured on subsurface mineral materials in the absence and presence of a sorbed leonardite humic acid (LHA) to (1) evaluate the sorptive role of mineral-bound humic substances, and (2) establish approaches to model metal ion binding in composite materials. The subsurface materials were a < 2.0 μm size fraction of an ultisol saprolite (CP) and this same material treated with dithionite-citrate-bicarbonate (DCB) to remove Fe-oxides (DCP). Comparable experiments (with and without LHA) were also performed with mineral sorbents representing dominant phases in the CP separate (gibbsite, Al-goethite, and kaolinite) to evaluate their potential contributions to Co sorption. The mineral-bound LHA ranged in concentration between 0.1-0.4 mg-C/m 2, representing approximately 0.7% of the subsurface isolate by mass. The sorption-desorption of LHA on the mineral surfaces, and its affinity for Co as a aqueous phase complexant were also determined. Batch measurements were employed (sorbents at 20-90 m 2/L; LHA-DOC at ≈11 mg-C/L) over a range in pH and ionic strength ( I) at I = 0.01 and 0.1 in NaClO 4. The LHA strongly sorbed to the subsurface mineral isolates (CP and DCP), and to all the specimen sorbents except kaolinite. Maximum sorption of LHA occurred at lower pH (≈4.5). In solid-free suspensions, the affinity of LHA for Co increased with pH and decreasing I ( Kd ranging 20-450 L/g). Mineral-bound LHA increased Co sorption on all the sorbents by factors of 10-60 %, with the greatest augmentation noted at pH values (4.5-6.5) where (1) maximum LHA sorption occurred, and (2) Co sorption to the mineral phase was weak and dominated by ion exchange. The LHA appeared simply to augment, rather than to change the intrinsic adsorption behavior of the mineral sorbents. Accordingly, predictions of the Kd for Co on the LHA-coated subsurface materials (DCP, CP) based on a linear additivity model agreed well with the experimental data, suggesting

  17. Increasing a Community College Governing Board's Engagement in Accountability for Student Success: What Are the Principal Influences?

    ERIC Educational Resources Information Center

    Welsh, Linda Susan Anderson

    2010-01-01

    Understanding the factors that influence a community college governing board to increase its engagement in accountability for student success was the purpose of this grounded theory case study. A further aim was to develop a model that described how these factors interact. A highly engaged community college governing board, as defined by a focus,…

  18. Subsurface geometry of the San Andreas-Calaveras fault junction: influence of serpentinite and the Coast Range Ophiolite

    USGS Publications Warehouse

    Watt, Janet Tilden; Ponce, David A.; Graymer, Russell W.; Jachens, Robert C.; Simpson, Robert W.

    2014-01-01

    While an enormous amount of research has been focused on trying to understand the geologic history and neotectonics of the San Andreas-Calaveras fault (SAF-CF) junction, fundamental questions concerning fault geometry and mechanisms for slip transfer through the junction remain. We use potential-field, geologic, geodetic, and seismicity data to investigate the 3-D geologic framework of the SAF-CF junction and identify potential slip-transferring structures within the junction. Geophysical evidence suggests that the San Andreas and Calaveras fault zones dip away from each other within the northern portion of the junction, bounding a triangular-shaped wedge of crust in cross section. This wedge changes shape to the south as fault geometries change and fault activity shifts between fault strands, particularly along the Calaveras fault zone (CFZ). Potential-field modeling and relocated seismicity suggest that the Paicines and San Benito strands of the CFZ dip 65° to 70° NE and form the southwest boundary of a folded 1 to 3 km thick tabular body of Coast Range Ophiolite (CRO) within the Vallecitos syncline. We identify and characterize two steeply dipping, seismically active cross structures within the junction that are associated with serpentinite in the subsurface. The architecture of the SAF-CF junction presented in this study may help explain fault-normal motions currently observed in geodetic data and help constrain the seismic hazard. The abundance of serpentinite and related CRO in the subsurface is a significant discovery that not only helps constrain the geometry of structures but may also help explain fault behavior and the tectonic evolution of the SAF-CF junction.

  19. Influence of surface and subsurface tillage on soil physical properties and soil/plant relationships of planted loblolly pine

    SciTech Connect

    D. L. Kelting; H. L. Allen

    2000-05-01

    Soil tillage can improve tree survival and growth by reducing competing vegetation, increasing nutrient availability, improving planting quality, and improving soil physical properties. The authors conducted a tillage study with competition control and nutrient amendments to isolate the physical effects of tillage on tree growth. The objectives of this study were to understand: (1) how tillage affects soil physical properties; (2) the relationships between these properties and root growth; (3) linkages between root growth response and aboveground growth; and (4) tillage effects on aboveground growth. Four replicates of a 2x2 factorial combination of surface (disking) and subsurface (subsoiling) were installed on a well-drained, clay-textured subsoil, soil located on the Piedmont of North Carolina. Disking improved soil physical properties (reduced bulk density and increased aeration porosity) in the surface 20-cm of soil. Subsoiling improved soil physical properties at all depths in the planting row, with improvements still noted at 60-cm from the planting row in the surface 10-cm of soil. Rooting patterns followed the changes in soil physical properties. Despite improvements in soil physical properties and changes in rooting patterns, aboveground tree growth was not affected by tillage. The results of this study point to the need for better diagnostics for identifying sites were tillage is appropriate in situations where fertilization and vegetation control are planned. Potential factors to consider are presence and abundance of old root channels, soil shrink/swell capacity, soil structure, presence and depth to root restricting layers, and historical precipitation records.

  20. Stochastic and Deterministic Assembly Processes in Subsurface Microbial Communities

    SciTech Connect

    Stegen, James C.; Lin, Xueju; Konopka, Allan; Fredrickson, Jim K.

    2012-03-29

    A major goal of microbial community ecology is to understand the forces that structure community composition. Deterministic selection by specific environmental factors is sometimes important, but in other cases stochastic or ecologically neutral processes dominate. Lacking is a unified conceptual framework aiming to understand why deterministic processes dominate in some contexts but not others. Here we work towards such a framework. By testing predictions derived from general ecological theory we aim to uncover factors that govern the relative influences of deterministic and stochastic processes. We couple spatiotemporal data on subsurface microbial communities and environmental parameters with metrics and null models of within and between community phylogenetic composition. Testing for phylogenetic signal in organismal niches showed that more closely related taxa have more similar habitat associations. Community phylogenetic analyses further showed that ecologically similar taxa coexist to a greater degree than expected by chance. Environmental filtering thus deterministically governs subsurface microbial community composition. More importantly, the influence of deterministic environmental filtering relative to stochastic factors was maximized at both ends of an environmental variation gradient. A stronger role of stochastic factors was, however, supported through analyses of phylogenetic temporal turnover. While phylogenetic turnover was on average faster than expected, most pairwise comparisons were not themselves significantly non-random. The relative influence of deterministic environmental filtering over community dynamics was elevated, however, in the most temporally and spatially variable environments. Our results point to general rules governing the relative influences of stochastic and deterministic processes across micro- and macro-organisms.

  1. Influence of substrate heterogeneity on the hydraulic residence time and removal efficiency of horizontal subsurface flow constructed wetlands

    NASA Astrophysics Data System (ADS)

    Carranza-Diaz, O.; Brovelli, A.; Rossi, L.; Barry, D. A.

    2009-04-01

    Horizontal, subsurface flow constructed wetlands are wastewater treatment devices. The influent polluted water flows through a porous substrate where the contaminants are removed, for example by microbial oxidation, surface adsorption and mineral precipitation. These systems are widely used with varying degrees of success to treat municipal and agricultural contaminated waters and remove the organic carbon and nutrient load. Constructed wetlands are an appealing and promising technology, because they (i) are potentially very efficient in removing the pollutants, (ii) require only a small external energy input and (iii) require low maintenance. However, practical experience has shown that the observed purification rate is highly variable and is often much smaller than expected. One of the numerous reasons proposed to explain the variable efficiency of constructed wetlands is the existence of highly conductive zones within the porous substrate, which produce a dramatic reduction of the hydraulic residence time and therefore directly decreases the overall water purification rate. This work aims to understand quantitatively the relationship between the spatial variability in the hydraulic properties of the substrate and the effective residence time in constructed wetlands. We conducted two suites of stochastic numerical simulations, modelling the transport of a conservative tracer in a three-dimensional simulated constructed wetland in one case, and the microbial oxidation of a carbon source in the other. Within each group of simulations, different hydraulic conductivity fields were tested. These were based on a log-normal, spatially correlated random field (with exponential spatial correlation). The amount of heterogeneity was varied by changing the variance correlation length in the three directions. For each set of parameters, different realizations are considered to deduce both the expected residence time for a certain amount of heterogeneity, and its range of

  2. Catchment-scale stream temperature response to land disturbance by wildfire governed by surface-subsurface energy exchange and atmospheric controls

    NASA Astrophysics Data System (ADS)

    Wagner, Michael J.; Bladon, Kevin D.; Silins, Uldis; Williams, Chris H. S.; Martens, Amanda M.; Boon, Sarah; MacDonald, Ryan J.; Stone, Micheal; Emelko, Monica B.; Anderson, Axel

    2014-09-01

    In 2003, the Lost Creek wildfire severely burned 21,000 hectares of forest on the eastern slopes of the Canadian Rocky Mountains. Seven headwater catchments with varying levels of disturbance (burned, post-fire salvage logged, and unburned) were instrumented as part of the Southern Rockies Watershed Project to measure streamflow, stream temperature, and meteorological conditions. From 2004 to 2010 mean annual stream temperature (Ts) was elevated 0.8-2.1 °C in the burned and post-fire salvage logged streams compared to the unburned streams. Mean daily maximum Ts was 1.0-3.0 °C warmer and mean daily minimum Ts was 0.9-2.8 °C warmer in the burned and post-fire salvage logged streams compared to the unburned catchments. The effects of wildfire on the thermal regime of the burned catchments were persistent and trend analysis showed no apparent recovery during the study period. Temporal patterns of Ts were strongly associated with seasonal variability of surface and groundwater interactions and air temperature. Advective heat fluxes between groundwater and surface water were likely the dominant controls on Ts, though the strength of these advective controls varied among catchments highlighting the importance of simultaneous catchment-scale and process-focused research to better elucidate the physical drivers influencing Ts response to disturbance.

  3. Subsurface environment database for application of ground heat exchanger system

    NASA Astrophysics Data System (ADS)

    Hamamoto, H.; Hachinohe, S.; Shiraishi, H.; Takashi, I.; Sasaka, K.; Miyakoshi, A.; Goto, S.

    2010-12-01

    Ground heat exchanger system is economical and environmentally friendly technology and widely used in Europe and North America, while it is rarely used in Japan. One of the causes is relatively complex topography and geological structure in Japan in comparison with those in Europe and North America. Complex structures produce regional differences in subsurface thermal properties and temperature structure, leading to regional variation in efficiency of heat exchanger system. It is thus important to evaluate available subsurface heat energy through thermal response tests and/or numerical simulation and to design appropriate systems (depth and number of boreholes for heat exchange). Information on subsurface environment in target areas is necessary for evaluation of potential subsurface heat energy, but little information has been published. Center for Environmental Science in Saitama is a research institute established by a local government, Saitama prefecture, which is located on the north of Tokyo and has a population of over seven million. We have been collecting various subsurface environmental data in Saitama (e.g., lithological column data on over 10,000 boreholes). We have compiled the accumulated data and obtained new data (geological information, subsurface temperature distribution, and hydrogeological properties) to construct a database for application of ground heat exchanger systems in Saitama. It is important to estimate demand for heat energy in the target areas as well as available subsurface heat energy. We therefore compile meteorological data (air temperature and solar radiation) necessary for estimation for the demand and investigate regional variation in meteorological condition. We intend to disclose the database and research products using web GIS (geographic information system) in the future. It will assist spread of ground heat exchanger systems in the target areas. Investigation methods of subsurface environment survey and database

  4. Biodegradation of subsurface oil in a tidally influenced sand beach: Impact of hydraulics and interaction with pore water chemistry

    NASA Astrophysics Data System (ADS)

    Geng, Xiaolong; Boufadel, Michel C.; Lee, Kenneth; Abrams, Stewart; Suidan, Makram

    2015-05-01

    The aerobic biodegradation of oil in tidally influenced beaches was investigated numerically in this work using realistic beach and tide conditions. A numerical model BIOMARUN, coupling a multiple-Monod kinetic model BIOB to a density-dependent variably saturated groundwater flow model 2-D MARUN, was used to simulate the biodegradation of low-solubility hydrocarbon and transport processes of associated solute species (i.e., oxygen and nitrogen) in a tidally influenced beach environment. It was found that different limiting factors affect different portions of the beach. In the upper intertidal zone, where the inland incoming nutrient concentration was large (1.2 mg N/L), oil biodegradation occurred deeper in the beach (i.e., 0.3 m below the surface). In the midintertidal zone, a reversal was noted where the biodegradation was fast at shallow locations (i.e., 0.1 m below the surface), and it was due to the decrease of oxygen with depth due to consumption, which made oxygen the limiting factor for biodegradation. Oxygen concentration in the midintertidal zone exhibited two peaks as a function of time. One peak was associated with the high tide, when dissolved oxygen laden seawater filled the beach and a second oxygen peak was observed during low tides, and it was due to pore oxygen replenishment from the atmosphere. The effect of the capillary fringe (CF) height was investigated, and it was found that there is an optimal CF for the maximum biodegradation of oil in the beach. Too large a CF (i.e., very fine material) would attenuate oxygen replenishment (either from seawater or the atmosphere), while too small a CF (i.e., very coarse material) would reduce the interaction between microorganisms and oil in the upper intertidal zone due to rapid reduction in the soil moisture at low tide. This article was corrected on 22 JUN 2015. See the end of the full text for details.

  5. Influence of Environmental Governance on Deforestation in Municipalities of the Brazilian Amazon

    PubMed Central

    Dias, Lilian Fernandes Oliveira; Dias, David Valentim; Magnusson, William Ernest

    2015-01-01

    It has been argued that measuring governance at scales smaller than global could be an important management tool. However, current studies are conducted on a global scale and use expensive methods. In the present study, we assess whether the reported governance of Amazonian municipalities is related to reductions in deforestation. Economic activity (EA) affected general governance (G) positively (G = 0.81 +1.19 * EA, F1, 98 = 77.36, p < 0.001). Environmental governance (EG) was not affected significantly (p = 0.43) by deforestation before 2000 (PD), but increased significantly (p < 0.001) with general governance (G) (EG = -0.29 + 0.04 PD+0.98*OG, F2,97 = 42.6, p <0.001). Deforestation was not significantly related to environmental governance (p = 0.82). The only indirect effect of significant magnitude was the effect of the density of forest reserves on recent deforestation through deforestation before 2000, which was strongly negative (-0.49). It is possible to assess reported actions to promote municipal governance through official data. However, it is not enough to assume that general governance or environmental governance at the municipal level, as reflected in the official statistics, benefits environmental conservation. In fact, even at the level of nation states, at which most quantification of governance has been undertaken, it seems that the relationship between governance and environmental preservation is only an assumption, because we are aware of no study that supports that hypothesis quantitatively. PMID:26208282

  6. Influence of Environmental Governance on Deforestation in Municipalities of the Brazilian Amazon.

    PubMed

    Dias, Lilian Fernandes Oliveira; Dias, David Valentim; Magnusson, William Ernest

    2015-01-01

    It has been argued that measuring governance at scales smaller than global could be an important management tool. However, current studies are conducted on a global scale and use expensive methods. In the present study, we assess whether the reported governance of Amazonian municipalities is related to reductions in deforestation. Economic activity (EA) affected general governance (G) positively (G = 0.81 +1.19 * EA, F1, 98 = 77.36, p < 0.001). Environmental governance (EG) was not affected significantly (p = 0.43) by deforestation before 2000 (PD), but increased significantly (p < 0.001) with general governance (G) (EG = -0.29 + 0.04 PD+0.98*OG, F2,97 = 42.6, p <0.001). Deforestation was not significantly related to environmental governance (p = 0.82). The only indirect effect of significant magnitude was the effect of the density of forest reserves on recent deforestation through deforestation before 2000, which was strongly negative (-0.49). It is possible to assess reported actions to promote municipal governance through official data. However, it is not enough to assume that general governance or environmental governance at the municipal level, as reflected in the official statistics, benefits environmental conservation. In fact, even at the level of nation states, at which most quantification of governance has been undertaken, it seems that the relationship between governance and environmental preservation is only an assumption, because we are aware of no study that supports that hypothesis quantitatively. PMID:26208282

  7. Factors Influencing Low Level of Women Participation in Literacy Programme in Maiha Local Government Area of Adamawa State

    ERIC Educational Resources Information Center

    Daniel, Aminchi

    2015-01-01

    This study was designed to determine the extent to which poverty, gender stereotype, socio-cultural belief and lack of awareness influence low level of women participation in literacy programme in Maiha Local Government Area of Adamawa State. Survey designed was adopted for the study and a sample consisting of three hundred (300) women who were…

  8. Home Influences on the Academic Performance of Agricultural Science Students in Ikwuano Local Government Area of Abia State, Nigeria

    ERIC Educational Resources Information Center

    Ndirika, Maryann C.; Njoku, U. J.

    2012-01-01

    This study was conducted to investigate the home influences on the academic performance of agricultural science secondary school students in Ikwuano Local Government Area of Abia State. The instrument used in data collection was a validated questionnaire structured on a two point rating scale. Simple random sampling technique was used to select…

  9. Influence of oxidation states on plutonium mobility during long-term transport through an unsaturated subsurface environment.

    PubMed

    Kaplan, Daniel I; Powell, Brian A; Demirkanli, Deniz I; Fjeld, Robert A; Molz, Fred J; Serkiz, Steven M; Coates, John T

    2004-10-01

    Lysimeter and laboratory studies were conducted to identify the controlling chemical processes influencing Pu(IV) mobility through the vadose zone. A 52-L lysimeter containing sediment from the Savannah River Site, South Carolina and solid PuIV(NO3)4 was left exposed to natural wetting and drying cycles for 11 years before the lysimeter sediment was sampled. Pu had traveled 10 cm, with >95% of the Pu remaining within 1.25 cm of the source. Laboratory studies showed that the sediment quickly reduced Pu(V) to Pu(IV) (the pseudo-first-order reduction rate constant, Kobs, was 0.11 h(-1)). Of particular interest was that this same sediment could be induced to release very low concentrations of sorbed Pu under oxidizing conditions, presumably by oxidation of sorbed Pu(IV) to the more mobile Pu(V) species. Transport modeling supported the postulation that Pu oxidation occurred in the lysimeter sediment; the inclusion of an oxidation term in the model produced simulations that capture the Pu depth profile data. By not including the oxidation process in the model, Pu mobility was grossly underestimated by a factor of 3.5. It is concluded that both oxidation and reduction mechanisms can play an important role in Pu transportthrough the vadose zone and should be considered when evaluating disposal of Pu-bearing wastes. PMID:15506198

  10. Influence of intraparticle diffusion on the desorption of radiocesium from the subsurface sediments at Hanford site, USA

    NASA Astrophysics Data System (ADS)

    Liu, C.; Zachara, J.; Smith, S.; McKinley, J.

    2002-12-01

    The desorption of 137Cs was investigated on sediments from the United States Hanford site. Pristine sediments and ones that were contaminated by the accidental release of alkaline 137Cs-containing high level nuclear wastes (HLW) were studied. The desorption of 137Cs was measured in Na+, K+, Rb+, and NH4+ electrolytes of variable concentration and pH, and in presence of a strong Cs-specific sorbent (self-assembled monolayer on a mesoporous support, SAMMS). 137Cs desorption from the HLW-contaminated Hanford sediments exhibited two distinct phases: an initial instantaneous release followed by a slow kinetic process. The first phase was driven by the equilibrium ion exchange of Cs located on the mica edges and its release extent followed the respective selectivities of the sediment for exchanging cations. The kinetic process was controlled by the intraparticle diffusion. X-ray microprobe analyses of Cs-sorbed micas showed that the 137Cs distributed not only on mica edges, but also within internal channels parallel to the basal plane. The diffusion rate was influenced by surface armoring and edge-channel collapse in solutions containing K+, Rb+, or NH4+. Scanning electron microscopic analysis revealed HLW-induced precipitation of secondary alumino-silicates on the edges of micaceous minerals. The removal of these precipitates by acidified ammonium oxalate extraction significantly increased the desorption rate and extent. Controlled desorption experiments using Cs-spiked pristine sediment indicated that the 137Cs diffusion rate was fast in Na-electrolyte, but much slower in the presence of K or Rb, suggesting an effect of edge-channel collapse. Model simulation using an intraparticle diffusion coupled with a cation exchange suggested that about 40 percent of total sorbed 137Cs in the contaminated Hanford sediment was exchangeable, including equilibrium and diffusive desorbable pools. This ratio increased to 60-80 percent after the removal of secondary precipitates. The

  11. "AGB Statement on Institutional Governance" and "Governing in the Public Trust: External Influences on Colleges and Universities." The Fundamentals. Board Basics.

    ERIC Educational Resources Information Center

    Association of Governing Boards of Universities and Colleges, 2001

    2001-01-01

    This booklet contains two statements from the Association of Governing Boards of Universities and Colleges (AGB). The "Statement on Institutional Governance" encourages all governing boards and chief executives to examine the clarity, coherence, and appropriateness of their institutions' governance structures, policies, and practices. It presents…

  12. Government regulations and other influences on the medical use of computers.

    PubMed

    Mishelevich, D J; Grams, R R; Mize, S G; Smith, J P

    1979-01-01

    This paper presents points brought out in a panel discussion held at the 12th Hawaiian International Conference on System Sciences, January 1979. The session was attended by approximately two dozen interested parties from various segments of the academic, government, and health care communities. The broad categories covered include the specific problems of government regulations and their impact on specific clinical information systems installed at The University of Texas Health Science Center at Dallas, opportunities in a regulated environment, problems in a regulated environment, vendor-related issues in the marketing and manufacture of computer-based information systems, rational approaches to government control, and specific issues related to medical computer science. PMID:548568

  13. An Exploration of the Factors Influencing the Adoption of an IS Governance Framework

    ERIC Educational Resources Information Center

    Parker, Sharon L.

    2013-01-01

    This research explored IT governance framework adoption, leveraging established IS theories. It applied both the technology acceptance model (TAM) and the technology, organization, environment (TOE) models. The study consisted of developing a model utilizing TOE and TAM, deriving relevant hypotheses. Interviews with a group of practitioners…

  14. Governing in the Public Trust: External Influences on Colleges and Universities.

    ERIC Educational Resources Information Center

    Association of Governing Boards of Universities and Colleges, 2001

    2001-01-01

    This statement responds to the need for all higher education leaders to consider the perspectives of external voices while resisting purely political or ideological agendas. Long-standing and recent external challenges to the traditions of citizen governing boards of colleges and universities make it necessary to distinguish between broad, often…

  15. The Stem Advisory Forum: A Means of Allowing People to Influence the Government's STEM Initiatives

    ERIC Educational Resources Information Center

    Onion, Alice; Follett, Brian

    2011-01-01

    This paper gives a short overview of the UK government's STEM agenda and then considers one aspect in depth--the STEM Advisory Forum. It explains how the Forum operates to draw together views from across the STEM community through online discussions and face-to-face events. Four examples are given of topics that have been dealt with by the Forum.…

  16. Influence of Sub-Surface Irrigation on Soil Conditions and Water Irrigation Efficiency in a Cherry Orchard in a Hilly Semi-Arid Area of Northern China

    PubMed Central

    Peng, Gao; Bing, Wang; Guangcan, Zhang

    2013-01-01

    Sub-surface irrigation (SUI) is a new water-saving irrigation technology. To explore the influence of SUI on soil conditions in a cherry orchard and its water-saving efficiency, experiments were conducted from 2009 to 2010 using both SUI and flood irrigation (FLI) and different SUI quotas in hilly semi-arid area of northern China. The results demonstrated the following: 1) The bulk density of the soil under SUI was 6.8% lower than that of soil under FLI (P<0.01). The total soil porosity, capillary porosity and non-capillary porosity of soils using SUI were 11.7% (P<0.01), 8.7% (P<0.01) and 43.8% (P<0.01) higher than for soils using FLI. 2) The average soil temperatures at 0, 5, 10, 15 and 20 cm of soil depth using SUI were 1.7, 1.1, 0.7, 0.4 and 0.3°C higher than those for FLI, specifically, the differences between the surface soil layers were more significant. 3) Compared with FLI, the average water-saving efficiency of SUI was 55.6%, and SUI increased the irrigation productivity by 7.9-12.3 kg m-3 ha-1. 4) The soil moisture of different soil layers using SUI increased with increases in the irrigation quotas, and the soil moisture contents under SUI were significantly higher in the 0-20 cm layer and in the 21-50 cm layer than those under FLI (P<0.01). 5) The average yields of cherries under SUI with irrigation quotas of 80-320 m3 ha-1 were 8.7%-34.9% higher than those in soil with no irrigation (CK2). The average yields of cherries from soils using SUI were 4.5%-12.2% higher than using FLI. It is appropriate to irrigate 2-3 times with 230 m3 ha-1 per application using SUI in a year with normal rainfall. Our findings indicated that SUI could maintain the physical properties, greatly improve irrigation water use efficiency, and significantly increase fruit yields in hilly semi-arid areas of northern China. PMID:24039986

  17. Stakeholder Perceptions of Governance: Factors Influencing Presidential Perceptions of Board Effectiveness

    ERIC Educational Resources Information Center

    Proper, Eve; Willmer, Wesley K.; Hartley, Harold V., III; Caboni, Timothy C.

    2009-01-01

    This article examines the factors that influence presidents' perceptions of board effectiveness in relation to their boards' fundraising role. Data from a survey of small college presidents are used to see what factors influence each of four areas of satisfaction: deciding policy, making financial contributions, referring donor prospects and…

  18. What influences government adoption of vaccines in developing countries? A policy process analysis.

    PubMed

    Munira, Syarifah Liza; Fritzen, Scott A

    2007-10-01

    This paper proposes a framework for examining the process by which government consideration and adoption of new vaccines takes place, with specific reference to developing country settings. The cases of early Hepatitis B vaccine adoption in Taiwan and Thailand are used to explore the relevance of explanatory factors identified in the literature as well as the need to go beyond a variable-centric focus by highlighting the role of policy context and process in determining the pace and extent of adoption. The cases suggest the feasibility and importance of modeling 'causal diversity'-the complex set of necessary and sufficient conditions leading to particular decisional outcomes-in a broad range of country contexts. A better understanding of the lenses through which government decision-makers filter information, and of the arenas in which critical decisions are shaped and taken, may assist both analysts (in predicting institutionalization of new vaccines) and advocates (in crafting targeted strategies to accelerate their diffusion). PMID:17644230

  19. Governance regime and location influence avoided deforestation success of protected areas in the Brazilian Amazon

    PubMed Central

    Nolte, Christoph; Agrawal, Arun; Silvius, Kirsten M.; Soares-Filho, Britaldo S.

    2013-01-01

    Protected areas in tropical countries are managed under different governance regimes, the relative effectiveness of which in avoiding deforestation has been the subject of recent debates. Participants in these debates answer appeals for more strict protection with the argument that sustainable use areas and indigenous lands can balance deforestation pressures by leveraging local support to create and enforce protective regulations. Which protection strategy is more effective can also depend on (i) the level of deforestation pressures to which an area is exposed and (ii) the intensity of government enforcement. We examine this relationship empirically, using data from 292 protected areas in the Brazilian Amazon. We show that, for any given level of deforestation pressure, strictly protected areas consistently avoided more deforestation than sustainable use areas. Indigenous lands were particularly effective at avoiding deforestation in locations with high deforestation pressure. Findings were stable across two time periods featuring major shifts in the intensity of government enforcement. We also observed shifting trends in the location of protected areas, documenting that between 2000 and 2005 strictly protected areas were more likely to be established in high-pressure locations than in sustainable use areas and indigenous lands. Our findings confirm that all protection regimes helped reduce deforestation in the Brazilian Amazon. PMID:23479648

  20. SOME CONCEPTS PERTAINING TO INVESTIGATIVE METHODOLOGY FOR SUBSURFACE PROCESS RESEARCH

    EPA Science Inventory

    Problems of investigative methodology comprise a critical and often preponderant element of research to delineate and quantitate processes which govern the transport and fate of pollutants in subsurface environments. Examination of several recent research studies illustrates that...

  1. Reported Pain During Labour – A Qualitative Study of Influencing Factors among Parturient During Confinement in Private or Government Hospital

    PubMed Central

    Ravishankar, M.; Hemanthkumar, V.R.

    2016-01-01

    Introduction Labour pain is distressing and it produces undue side effects both to the mother and the baby. The incidence is high in developing countries like India where the awareness about labour analgesia is still lacking. Aim It is to find out the incidence of labour pain and the influence of various described factors on pain with a comparison between patients admitted in a government set up with a private set up in a south Indian semi-urban area. Materials and Methods Two hundred continuous uneventful normal deliveries each in a Government (group G) and a private hospital (group P) were enrolled for the study. The reported pain during labour was noted 6-7 hours after delivery by interacting with the patient. The factors like age of the mother, sex and weight of the baby, literacy, socioeconomic status, the use of oxytocics and analgesia were evaluated. Results The incidence of severe pain was more in group G (43.5%) than group P (12%). There was no analgesic intervention in 68.5% in group G while it was 13.5% (27/200) in group P. Even among these 27 patients who did not receive analgesics, only three parturients reported severe pain. Even administration of analgesics in a Government set up did not decrease pain to a significant extent. There were richer and more literate patients in group P. Booked cases were less in group G. Logistic regression analyses to find out factors which influenced pain in either group was used. Gravida, analgesic intervention and admission in a Govt. hospital influenced the pain experience of the parturient. There was minimal antenatal preparation in both the groups. There were no post partum complications. Conclusion Mothers suffered from labour pain to a significant extent and there is an urgent need for awareness about labour analgesia. Primigravida, admission in a Govt. set up and analgesic interventions were the factors which influenced pain than others. Patients admitted in Govt. hospitals suffered more pain with less analgesic

  2. Spatially distributed influence of agro-environmental factors governing nitrate fate and transport in an irrigated stream-aquifer system

    NASA Astrophysics Data System (ADS)

    Bailey, R. T.; Ahmadi, M.; Gates, T. K.; Arabi, M.

    2015-12-01

    Elevated levels of nitrate (NO3) in groundwater systems pose a serious risk to human populations and natural ecosystems. As part of an effort to remediate NO3 contamination in irrigated stream-aquifer systems, this study elucidates agricultural and environmental parameters and processes that govern NO3 fate and transport at the regional (500 km2), local (50 km2), and field scales (< 1 km2). Specifically, the revised Morris sensitivity analysis method was applied to a finite-difference nitrogen cycling and reactive transport model of a regional-scale study site in the lower Arkansas River valley in southeastern Colorado. The method was used to rank the influence of anthropogenic activities and natural chemical processes on NO3 groundwater concentration, NO3 mass leaching, and NO3 mass loading to the Arkansas River from the aquifer. Sensitivity indices were computed for the entire study area in aggregate as well as each canal command area, crop type, and individual grid cells. Results suggest that fertilizer loading, crop uptake, and heterotrophic denitrification govern NO3 fate and transport for the majority of the study area, although their order of influence on NO3 groundwater concentration and mass leaching varies according to crop type and command area. Canal NO3 concentration and rates of autotrophic denitrification, nitrification, and humus decomposition also dominate or partially dominate in other locations. Each factor, with the exception of O2 reduction rate, is the dominating influence on NO3 groundwater concentration at one or more locations within the study area. Results can be used to determine critical processes and key management actions for future data collection and remediation strategies, with efforts able to be focused on localized areas.

  3. Outrage Factors in Government Press Releases of Food Risk and Their Influence on News Media Coverage.

    PubMed

    Ju, Youngkee; Lim, Jeongsub; Shim, Minsun; You, Myoungsoon

    2015-08-01

    An appropriate level of risk perception should be a critical issue in modern "risk society." There have been many studies on the influences on risk perception. This study investigates whether risk communication scholar Dr. Peter Sandman's outrage factors intensify journalistic attention to health risks from food consumption. A content analysis of a health institution's press releases was conducted to examine 15 outrage factors of food risks conveyed in the governmental risk communication. In addition, the news stories covering the food risks informed by the press releases were calculated to evaluate the relation between outrage factors of a risk and the number of news stories covering the risk. Results showed that controllability was the most salient outrage factor, followed by trust, voluntariness, familiarity, and human origin; the greater the outrage score of a risk, the more news stories of the risk. For individual outrage factors, a risk with an implication of catastrophic potential was associated with an increase of news stories. Food providers' distrustful behaviors also influenced journalistic attention to the food risks. The implication of the findings to health message designers is discussed. PMID:26065830

  4. Influence of surface wettability on transport mechanisms governing water droplet evaporation.

    PubMed

    Pan, Zhenhai; Weibel, Justin A; Garimella, Suresh V

    2014-08-19

    Prediction and manipulation of the evaporation of small droplets is a fundamental problem with importance in a variety of microfluidic, microfabrication, and biomedical applications. A vapor-diffusion-based model has been widely employed to predict the interfacial evaporation rate; however, its scope of applicability is limited due to incorporation of a number of simplifying assumptions of the physical behavior. Two key transport mechanisms besides vapor diffusion-evaporative cooling and natural convection in the surrounding gas-are investigated here as a function of the substrate wettability using an augmented droplet evaporation model. Three regimes are distinguished by the instantaneous contact angle (CA). In Regime I (CA ≲ 60°), the flat droplet shape results in a small thermal resistance between the liquid-vapor interface and substrate, which mitigates the effect of evaporative cooling; upward gas-phase natural convection enhances evaporation. In Regime II (60 ≲ CA ≲ 90°), evaporative cooling at the interface suppresses evaporation with increasing contact angle and counterbalances the gas-phase convection enhancement. Because effects of the evaporative cooling and gas-phase convection mechanisms largely neutralize each other, the vapor-diffusion-based model can predict the overall evaporation rates in this regime. In Regime III (CA ≳ 90°), evaporative cooling suppresses the evaporation rate significantly and reverses entirely the direction of natural convection induced by vapor concentration gradients in the gas phase. Delineation of these counteracting mechanisms reconciles previous debate (founded on single-surface experiments or models that consider only a subset of the governing transport mechanisms) regarding the applicability of the classic vapor-diffusion model. The vapor diffusion-based model cannot predict the local evaporation flux along the interface for high contact angle (CA ≥ 90°) when evaporative cooling is strong and the

  5. Ceramic subsurface marker prototypes

    SciTech Connect

    Lukens, C.E.

    1985-05-02

    The client submitted 5 sets of porcelain and stoneware subsurface (radioactive site) marker prototypes (31 markers each set). The following were determined: compressive strength, thermal shock resistance, thermal crazing resistance, alkali resistance, color retention, and chemical resistance.

  6. Subsurface Microbiology and Biogeochemistry

    SciTech Connect

    Fredrickson, Jim K.; Fletcher, Madilyn

    2001-05-01

    Jim contributed a chapter to this book, in addition to co-editing it with Madilyn Fletcher. Fredrickson, J. K., and M. Fletcher. (eds.) 2001 Subsurface Microbiology and Biogeochemistry. Wiley-Liss, Inc., New York.

  7. Emergency contraception in Peru: shifting government and donor policies and influences.

    PubMed

    Chávez, Susana; Coe, Anna-Britt

    2007-05-01

    Inclusion of emergency contraception in national family planning programmes is consistent with international agreements that countries should strive to ensure access to a wide range of contraceptive methods and promote voluntary, informed choice. Yet in 2005, USAID/Peru requested that its NGO grantees in Peru take a "neutral" position on emergency contraception in activities or materials that involve its funds. For many decades, donor countries have viewed conservative religious forces in low-income countries as an obstacle to expanding family planning programmes. Today, however, far-right organisations in the United States are having an unprecedented influence on US public policy, including in countries such as Peru. This article analyses shifts in USAID/Peru's policy on emergency contraception in Peru since 1992. In Peru today, there is widespread official and public support for making emergency contraception available. Given USAID's long support for family planning internationally and in Peru, the current policy appears to be the result of attacks by US far-right organisations carried out in synergy with sympathetic US public officials and anti-choice Peruvian allies. PMID:17512385

  8. Subsurface Contamination Control

    SciTech Connect

    Y. Yuan

    2001-12-12

    There are two objectives of this report, ''Subsurface Contamination Control''. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second is to provide an evaluation of the magnitude of potential releases from a defective WP and the detectability of the released contents. The technical basis for deriving LRCL has been established in ''Retrieval Equipment and Strategy for Wp on Pallet'' (CRWMS M and O 2000g, 6.3.1). This report updates the derivation by incorporating the latest design information of the subsurface repository for site recommendation. The derived LRCL on the external surface of WPs, therefore, supercede that described in CRWMS M and O 2000g. The derived LRCL represent the average concentrations of contamination on the external surfaces of each WP that must not be exceeded before the WP is to be transported to the subsurface facility for emplacement. The evaluation of potential releases is necessary to control the potential contamination of the subsurface repository and to detect prematurely failed WPs. The detection of failed WPs is required in order to provide reasonable assurance that the integrity of each WP is intact prior to MGR closure. An emplaced WP may become breached due to manufacturing defects or improper weld combined with failure to detect the defect, by corrosion, or by mechanical penetration due to accidents or rockfall conditions. The breached WP may release its gaseous and volatile radionuclide content to the subsurface environment and result in contaminating the subsurface facility. The scope of this analysis is limited to radioactive contaminants resulting from breached WPs during the preclosure period of the subsurface repository. This report: (1) documents a method for deriving LRCL on the external surfaces of WP for acceptance into the subsurface repository; (2) provides a

  9. FACTORS INFLUENCING THE CHOICE OF HEALTH CARE PROVIDING FACILITY AMONG WORKERS IN A LOCAL GOVERNMENT SECRETARIAT IN SOUTH WESTERN NIGERIA

    PubMed Central

    Uchendu, O.C.; Ilesanmi, O.S.; Olumide, A.E.

    2013-01-01

    Background: There is increasing interest in the choice of health care providing facility in Nigeria. Objectives: This study aimed to assess the factors influencing choice and satisfaction with health service providers among local government staff. Methods: A cross sectional survey of all 312 workers in a Local Government Secretariat in South West Nigeria was done. Chi Square and logistic regression analysis was done. Results: The mean age was 38.6 ± 7.5 years, 55% were females and 71.7% had tertiary education. The median monthly family income of the respondents was N 28, 000 (N3,000 – N500,000), with 24.4% earning a monthly income of N21, 000 to N30, 000. Many (72.3%) utilized public health facilities attributing the choice to the low cost of services. Respondents who are satisfied with their usual care providing facilities are 12.2 times more likely to have used public facilities than private facilities (95%, CI 3.431 – 43.114). Respondents who described the quality with ease of getting care/short waiting times as being good are 3.9 times more likely to have private facilities as their chosen health care providing facility (95%, CI 1.755 – 8.742). Cost/payment for service is 2.9 times more likely to predict the use of public health facility as the usual health care provider. Conclusion: Private facilities though costlier do not appear to be providing better services than public facilities. To increase access to health care the cost of services and the waiting time are important factors to address. PMID:25161426

  10. Renewing governance.

    PubMed

    Loos, Gregory P

    2003-01-01

    Globalization's profound influence on social and political institutions need not be negative. Critics of globalization have often referred to the "Impossible Trinity" because decision-making must 1. respect national sovereignty, 2. develop and implement firm regulation, and 3. allow capital markets to be as free as possible. To many, such goals are mutually exclusive because history conditions us to view policy-making and governance in traditional molds. Thus, transnational governance merely appears impossible because current forms of governance were not designed to provide it. The world needs new tools for governing, and its citizens must seize the opportunity to help develop them. The rise of a global society requires a greater level of generality and inclusion than is found in most policy bodies today. Politicians need to re-examine key assumptions about government. States must develop ways to discharge their regulatory responsibilities across borders and collaborate with neighboring jurisdictions, multilateral bodies, and business. Concepts such as multilateralism and tripartism show great promise. Governments must engage civil society in the spirit of shared responsibility and democratic decision-making. Such changes will result in a renewal of the state's purpose and better use of international resources and expertise in governance. PMID:17208717

  11. Best Practice -- Subsurface Investigations

    SciTech Connect

    Clark Scott

    2010-03-01

    These best practices for Subsurface Survey processes were developed at the Idaho National Laboratory (INL) and later shared and formalized by a sub-committee, under the Electrical Safety Committee of EFCOG. The developed best practice is best characterized as a Tier II (enhanced) survey process for subsurface investigations. A result of this process has been an increase in the safety and lowering of overall cost, when utility hits and their related costs are factored in. The process involves improving the methodology and thoroughness of the survey and reporting processes; or improvement in tool use rather than in the tools themselves. It is hoped that the process described here can be implemented at other sites seeking to improve their Subsurface Investigation results with little upheaval to their existing system.

  12. The Serpentinite Subsurface Microbiome

    NASA Astrophysics Data System (ADS)

    Schrenk, M. O.; Nelson, B. Y.; Brazelton, W. J.

    2011-12-01

    Microbial habitats hosted in ultramafic rocks constitute substantial, globally-distributed portions of the subsurface biosphere, occurring both on the continents and beneath the seafloor. The aqueous alteration of ultramafics, in a process known as serpentinization, creates energy rich, high pH conditions, with low concentrations of inorganic carbon which place fundamental constraints upon microbial metabolism and physiology. Despite their importance, very few studies have attempted to directly access and quantify microbial activities and distributions in the serpentinite subsurface microbiome. We have initiated microbiological studies of subsurface seeps and rocks at three separate continental sites of serpentinization in Newfoundland, Italy, and California and compared these results to previous analyses of the Lost City field, near the Mid-Atlantic Ridge. In all cases, microbial cell densities in seep fluids are extremely low, ranging from approximately 100,000 to less than 1,000 cells per milliliter. Culture-independent analyses of 16S rRNA genes revealed low-diversity microbial communities related to Gram-positive Firmicutes and hydrogen-oxidizing bacteria. Interestingly, unlike Lost City, there has been little evidence for significant archaeal populations in the continental subsurface to date. Culturing studies at the sites yielded numerous alkaliphilic isolates on nutrient-rich agar and putative iron-reducing bacteria in anaerobic incubations, many of which are related to known alkaliphilic and subsurface isolates. Finally, metagenomic data reinforce the culturing results, indicating the presence of genes associated with organotrophy, hydrogen oxidation, and iron reduction in seep fluid samples. Our data provide insight into the lifestyles of serpentinite subsurface microbial populations and targets for future quantitative exploration using both biochemical and geochemical approaches.

  13. Subsurface connection methods for subsurface heaters

    DOEpatents

    Vinegar, Harold J.; Bass, Ronald Marshall; Kim, Dong Sub; Mason, Stanley Leroy; Stegemeier, George Leo; Keltner, Thomas Joseph; Carl, Jr., Frederick Gordon

    2010-12-28

    A system for heating a subsurface formation is described. The system includes a first elongated heater in a first opening in the formation. The first elongated heater includes an exposed metal section in a portion of the first opening. The portion is below a layer of the formation to be heated. The exposed metal section is exposed to the formation. A second elongated heater is in a second opening in the formation. The second opening connects to the first opening at or near the portion of the first opening below the layer to be heated. At least a portion of an exposed metal section of the second elongated heater is electrically coupled to at least a portion of the exposed metal section of the first elongated heater in the portion of the first opening below the layer to be heated.

  14. Modeling microorganism transport and survival in the subsurface

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An understanding of microbial transport and survival in the subsurface is needed for public health, environmental applications, and industrial processes. Much research has therefore been directed to quantify mechanisms influencing microbial fate, and the results demonstrate a complex coupling among ...

  15. The influence of surface low-salinity waters and cold subsurface water masses on picoplankton and ultraplankton distribution in the continental shelf off Rio de Janeiro, SE Brazil

    NASA Astrophysics Data System (ADS)

    Moser, G. A. O.; Castro, N. O.; Takanohashi, R. A.; Fernandes, A. M.; Pollery, R. C. G.; Tenenbaum, D. R.; Varela-Guerra, J.; Barrera-Alba, J. J.; Ciotti, A. M.

    2016-06-01

    The smallest phytoplankton groups named picoplankton and ultraplankton can be responsible for about 50-80% of the primary production rates in oligotrophic waters, due to their high surface/volume ratios that enables them for competitive growth rates relative to bigger cells under low light and low nutrient availability. The role of picoplankton and ultraplankton in coastal dynamic regions is less clear. This work relates the spatial distribution of autotrophic and heterotrophic components of these communities to the different properties of the water masses in the Southeastern Brazilian Continental Shelf, generally considered oligotrophic. Picoplankton and ultraplankton communities were related to nutrients present in the subsurface South Atlantic Central Water and waters with salinities below 35.5 originated from different estuarine systems. The enhance of autotrophs were also associated with a near shore feature related to topographic effects of São Sebastião Island to the local currents, first reported in this article. A core of higher chlorophyll a concentration, associated with the northeastward current flow at approximately 21 m depth below the surface, was identified as a dome-like shape. This core dissipated in the subsequent days suggesting that the flow towards NE was no longer a permanent feature two days after its observation. Locally enhancement of the contribution of picoplanktonic and ultraplanktonic autotrophs was observed in the surface and at the deep chlorophyll maximum depth associated with the chlorophyll core. Heterotrophs were more abundant inside and at the mouth of Guanabara Bay as well as inside Sepetiba Bay where light levels were low.

  16. A Comparative Case Study of the Influence of Educational Governance Team Decision-Making Processes on District Climate and Student Achievement

    ERIC Educational Resources Information Center

    Thompson, Debra A.

    2010-01-01

    This study explored how the educational governance team, composed of the superintendent and school board, can, in their collaborative efforts and decision-making processes, influence school district climate and impact student achievement. Though in form and function, school boards have not changed much in their almost 200 years of existence,…

  17. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  18. INEEL Subregional Conceptual Model Report Volume 2: Summary of Existing Knowledge of Geochemical Influences on the Fate and Transport of Contaminants in the Subsurface at the INEEL

    SciTech Connect

    Paul L. Wichlacz; Robert C. Starr; Brennon Orr

    2003-09-01

    . The documents that appeared to be the most pertinent were selected from further review. These documents are tabulated in the citation list. This report summarizes existing geochemical conceptual models, but does not attempt to generate a new conceptual model or select the ''right'' model. This document is organized as follows. Geochemical models are described in general in Section 2. Geochemical processes that control the transport and fate of contaminants introduced into groundwater are described in Section 3. The natural geochemistry of the Eastern Snake River Plain Aquifer (SRPA) is described in Section 4. The effect of waste disposal on the INEEL subsurface is described in Section 5. The geochemical behavior of the major contaminants is described in Section 6. Section 7 describes the site-specific geochemical models developed for various INEEL facilities.

  19. Quantifying the influence of the tobacco industry on EU governance: automated content analysis of the EU Tobacco Products Directive

    PubMed Central

    Costa, Hélia; Gilmore, Anna B; Peeters, Silvy; McKee, Martin; Stuckler, David

    2014-01-01

    Objective The tobacco industry spends large sums lobbying the European Union (EU) institutions, yet whether such lobbying significantly affects tobacco policy is not well understood. We used novel quantitative text mining techniques to evaluate the impact of industry pressure on the contested EU Tobacco Products Directive revision. Design Policy positions of 18 stakeholders including the tobacco industry, health NGOs and tobacco retailers were evaluated using their text submissions to EU consultations and impact assessments. Using Wordscores to calculate word frequencies, we developed a scale ranging from 0–tobacco industry to 1–public health organisations, which was then used to track changes in the policy position of the European Commission's 2010 consultation document, its 2012 final proposal and the European Parliament and Council's approved legislation in March 2014. Results Several stakeholders’ positions were closer to the tobacco industry than that of health NGOs, including retailers (ω=0.35), trade unions (ω=0.34) and publishers (ω=0.33 and ω=0.40). Over time the European Commission's position shifted towards the tobacco industry from ω=0.52 (95% CI 0.50 to 0.54) to ω=0.40 (95% CI 0.39 to 0.42). This transition reflected an increasing use of words pertaining to business and the economy in the Commission's document. Our findings were robust to alternative methods of scoring policy positions in EU documents. Conclusions Using quantitative text mining techniques, we observed that tobacco industry lobbying activity at the EU was associated with significant policy shifts in the EU Tobacco Products Directive legislation towards the tobacco industry's submissions. In the light of the Framework Convention on Tobacco Control, additional governance strategies are needed to prevent undue influence of the tobacco industry on EU policy making. PMID:25124165

  20. Subsurface contaminants focus area

    SciTech Connect

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

  1. Applications of subsurface microscopy.

    PubMed

    Tetard, Laurene; Passian, Ali; Farahi, Rubye H; Voy, Brynn H; Thundat, Thomas

    2012-01-01

    Exploring the interior of a cell is of tremendous importance in order to assess the effects of nanomaterials on biological systems. Outside of a controlled laboratory environment, nanomaterials will most likely not be conveniently labeled or tagged so that their translocation within a biological system cannot be easily identified and quantified. Ideally, the characterization of nanomaterials within a cell requires a nondestructive, label-free, and subsurface approach. Subsurface nanoscale imaging represents a real challenge for instrumentation. Indeed the tools available for high resolution characterization, including optical, electron or scanning probe microscopies, mainly provide topography images or require taggants that fluoresce. Although the intercellular environment holds a great deal of information, subsurface visualization remains a poorly explored area. Recently, it was discovered that by mechanically perturbing a sample, it was possible to observe its response in time with nanoscale resolution by probing the surface with a micro-resonator such as a microcantilever probe. Microcantilevers are used as the force-sensing probes in atomic force microscopy (AFM), where the nanometer-scale probe tip on the microcantilever interacts with the sample in a highly controlled manner to produce high-resolution raster-scanned information of the sample surface. Taking advantage of the existing capabilities of AFM, we present a novel technique, mode synthesizing atomic force microscopy (MSAFM), which has the ability to probe subsurface structures such as non-labeled nanoparticles embedded in a cell. In MSAFM mechanical actuators (PZTs) excite the probe and the sample at different frequencies as depicted in the first figure of this chapter. The nonlinear nature of the tip-sample interaction, at the point of contact of the probe and the surface of the sample, in the contact mode AFM configuration permits the mixing of the elastic waves. The new dynamic system comprises new

  2. Influence of Gas Composition and Exposure Cycle on the Formation of Surface and Subsurface Oxides in Iron-Aluminum-Based Alloys at High Temperatures

    NASA Astrophysics Data System (ADS)

    Bott, June H.; Yin, Hogbin; Sridhar, Seetharaman; Auinger, Michael

    2016-04-01

    The slab reheating process of binary iron-aluminum alloys and an industrial TRIP steel grade has been investigated in both dry and wet atmospheres. The presence of water vapor has a significant effect on the overall scale growth and internal corrosion depth. Heating rate greatly influences the porosity of the surface oxide layer with the surface getting more porous at faster heating rates. Nitride formation could be suppressed in the presence of water vapor, leading to a reduction of internal corrosion depth and a better formability of the final material. Experimental results were compared to thermodynamic predictions and critically discussed.

  3. Influence of Gas Composition and Exposure Cycle on the Formation of Surface and Subsurface Oxides in Iron-Aluminum-Based Alloys at High Temperatures

    NASA Astrophysics Data System (ADS)

    Bott, June H.; Yin, Hogbin; Sridhar, Seetharaman; Auinger, Michael

    2016-08-01

    The slab reheating process of binary iron-aluminum alloys and an industrial TRIP steel grade has been investigated in both dry and wet atmospheres. The presence of water vapor has a significant effect on the overall scale growth and internal corrosion depth. Heating rate greatly influences the porosity of the surface oxide layer with the surface getting more porous at faster heating rates. Nitride formation could be suppressed in the presence of water vapor, leading to a reduction of internal corrosion depth and a better formability of the final material. Experimental results were compared to thermodynamic predictions and critically discussed.

  4. The Influences of Interfacial Characteristics and Subsurface Microstructural Evolution on Wear Behavior of Al/A206-5 Pct Alumina Micro/Nano-Composites

    NASA Astrophysics Data System (ADS)

    Tahamtan, Saleh; Halvaee, Ayyoub; Emamy, Masoud

    2015-03-01

    Al206-5 pct aluminap cast composites were fabricated by the injection of (i) the as-received alumina particles and (ii) milled mixture of alumina with Al and Mg powders [composite powder (CP)] into semi-solid Al alloy. The influences of interfacial characteristics as well as microstructural evolution on wear properties were then explored. Microstructures of the composite, worn surfaces, and worn surface side views were characterized by field emission scanning electron microscopy and transmission electron microscopy, and interfacial failure loads were evaluated by high load nano-indentation test. Obtained results revealed augmented wear resistance in the composites fabricated via CP injection into the semi-solid alloy. Improvement in wear resistance was ascribed to lower thickness and higher bonding strength of alumina/matrix interface as well as uniform distribution of grains as a consequence of recrystallization beneath the worn surface.

  5. Factors Influencing the Selection of the Systems Integration Organizational Model Type for Planning and Implementing Government High-Technology Programs

    NASA Technical Reports Server (NTRS)

    Thomas, Leann; Utley, Dawn

    2006-01-01

    While there has been extensive research in defining project organizational structures for traditional projects, little research exists to support high technology government project s organizational structure definition. High-Technology Government projects differ from traditional projects in that they are non-profit, span across Government-Industry organizations, typically require significant integration effort, and are strongly susceptible to a volatile external environment. Systems Integration implementation has been identified as a major contributor to both project success and failure. The literature research bridges program management organizational planning, systems integration, organizational theory, and independent project reports, in order to assess Systems Integration (SI) organizational structure selection for improving the high-technology government project s probability of success. This paper will describe the methodology used to 1) Identify and assess SI organizational structures and their success rate, and 2) Identify key factors to be used in the selection of these SI organizational structures during the acquisition strategy process.

  6. Subsurface Flow and Contaminant Transport

    Energy Science and Technology Software Center (ESTSC)

    2000-09-19

    FACT is a transient three-dimensional, finite element code for simulating isothermal groundwater flow, moisture movement, and solute transport in variably and/or fully saturated subsurface porous media. Both single and dual-domain transport formulations are available. Transport mechanisms considered include advection, hydrodynamic dispersion, linear adsorption, mobile/immobile mass transfer and first-order degradation. A wide range of acquifier conditions and remediation systems commonly encountered in the field can be simulated. Notable boundary condition (BC) options include, a combined rechargemore » and drain BC for simulating recirculation wells, and a head dependent well BC that computes flow based on specified drawdown. The code is designed to handle highly heterogenous, multi-layer, acquifer systems in a numerically efficient manner. Subsurface structure is represented with vertically distorted rectangular brick elements in a Cartesian system. The groundwater flow equation is approximated using the Bubnov-Galerkin finite element method in conjunction with an efficient symmetric Preconditioned Conjugate Gradient (PCG) ICCG matrix solver. The solute transport equation is approximated using an upstream weighted residual finite element method designed to alleviate numerical oscillation. An efficient asymmetric PCG (ORTHOMIN) matrix solver is employed for transport. For both the flow and transport equations, element matrices are computed from either influence coefficient formulas for speed, or two point Gauss-Legendre quadrature for accuracy. Non-linear flow problems can be solved using either Newton-Ralphson linearization or Picard iteration, with under-relaxation formulas to further enhance convergence. Dynamic memory allocation is implemented using Fortran 90 constructs. FACT coding is clean and modular.« less

  7. Governance in Strategic Context

    ERIC Educational Resources Information Center

    Alfred, Richard L.

    2008-01-01

    This chapter begins with a retrospective look at governance in community colleges based on a working understanding of governance as a correlate of decision making. In its simplest form, governance is "a process for distributing authority, power, and influence in decision making among constituencies" (Alfred and Smydra, 1985, pp. 201-202). What…

  8. U. S. Government Factors Influencing an Expansion of Study Abroad in the Middle East/North Africa

    ERIC Educational Resources Information Center

    Lane-Toomey, Cara

    2014-01-01

    As the United States continued to grow as a world power throughout the later part of the twentieth century, government funding for international education grew more closely connected to its national security needs. Federal funds have contributed to the growth of Area Studies and studying Less Commonly Taught Languages (LCTLs). Within the last ten…

  9. Understanding the Programmatic and Contextual Forces That Influence Participation in a Government-Sponsored International Student-Mobility Program

    ERIC Educational Resources Information Center

    Perna, Laura W.; Orosz, Kata; Jumakulov, Zakir; Kishkentayeva, Marina; Ashirbekov, Adil

    2015-01-01

    Although prior research establishes the forces that "push" and "pull" students to participate in foreign study, the transferability of findings from earlier studies is limited by the absence of theoretical grounding. In addition, relatively little is known about how a government-sponsored student mobility program promotes…

  10. The influence of government actions on innovative activities in the development of environmental technologies to control sulfur dioxide emissions from stationary sources

    NASA Astrophysics Data System (ADS)

    Taylor, Margaret R.

    2001-12-01

    A better understanding of the influence of government actions on innovation is needed to inform future policy endeavors in areas ranging from industrial competitiveness to environmentally sustainable growth. Environmental control technology is a rich area for the study of this influence, since government has stronger incentives to promote innovation in these technologies than does the private sector. This dissertation investigated the case of sulfur dioxide (SO2) control technologies for electric power plants. In studying innovation in these technologies, it was very important to understand the details of these technologies as well as their long organizational history. These technologies have been affected by government actions ranging from government-sponsored research and technology transfer mechanisms to national regulatory events. The dissertation integrated insights from several complementary and repeatable innovation evaluation methods; this approach supported a fuller understanding of innovation while it structured the research results for potential future comparative analysis. Innovative activities were investigated through: patent activity analysis; technical content analysis and researcher co-authorship network analysis in a conference held for over twenty years; learning curve analysis for eighty-eight U.S. power plants; and a dozen expert interviews from a variety of innovative actors. Innovative outcomes were investigated through: analysis of observed improvements in newly installed technologies over time; evaluation of historic cost studies on standardized systems; and expert interviews. Several policy-relevant findings resulted from this dissertation. (1) The existence of national government regulation stimulated inventive activity more than government research support alone. (2) The existence and the anticipation of government regulation appeared to spur inventive activity, while regulatory stringency appeared to drive inventive activity and the

  11. Containment of subsurface contaminants

    DOEpatents

    Corey, John C.

    1994-01-01

    A barrier for reducing the spread of a plume of subsurface contaminants. The apparatus includes a well system for injecting a fluid, such as air, just outside and below the periphery of the plume. The fluid is injected at a pressure sufficient to lower the hydraulic conductivity of the soil from the point of injection to the surface thus establishing a curtain-like barrier to groundwater movement. The barrier is established upgradient of the plume to divert groundwater away, or preferably completely around the plume to reduce the flow of groundwater into or out of the plume. The barrier enables the remediation of the confined contamination and then, when the injection of the fluid is halted, the barrier quickly dissipates.

  12. Nonintrusive subsurface surveying capability

    SciTech Connect

    Tunnell, T.W.; Cave, S.P.

    1994-06-01

    This presentation describes the capabilities of a ground-pentrating radar (GPR) system developed by EG&G Energy Measurements (EM), a prime contractor to the Department of Energy (DOE). The focus of the presentation will be on the subsurface survey of DOE site TA-21 in Los Alamos, New Mexico. EG&G EM developed the system for the Department of Defense. The system is owned by the Department of the Army and currently resides at KO in Albuquerque. EM is pursuing efforts to transfer this technology to environmental applications such as waste-site characterization with DOE encouragement. The Army has already granted permission to use the system for the waste-site characterization activities.

  13. Containment of subsurface contaminants

    DOEpatents

    Corey, J.C.

    1994-09-06

    A barrier is disclosed for reducing the spread of a plume of subsurface contaminants. The apparatus includes a well system for injecting a fluid, such as air, just outside and below the periphery of the plume. The fluid is injected at a pressure sufficient to lower the hydraulic conductivity of the soil from the point of injection to the surface thus establishing a curtain-like barrier to groundwater movement. The barrier is established upgradient of the plume to divert groundwater away, or preferably completely around the plume to reduce the flow of groundwater into or out of the plume. The barrier enables the remediation of the confined contamination and then, when the injection of the fluid is halted, the barrier quickly dissipates. 5 figs.

  14. SUBSURFACE FACILITY WORKER DOES ASSESSMENT

    SciTech Connect

    V. Arakali; E. Faillace; A. Linden

    2004-02-27

    The purpose of this design calculation is to estimate radiation doses received by personnel working in the subsurface facility of the repository performing emplacement, maintenance, and retrieval operations under normal conditions. The results of this calculation will be used to support the design of the subsurface facilities and provide occupational dose estimates for the License Application.

  15. Subsurface Ventilation System Description Document

    SciTech Connect

    Eric Loros

    2001-07-25

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  16. Subsurface Ventilation System Description Document

    SciTech Connect

    2000-10-12

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  17. Subsurface Facility System Description Document

    SciTech Connect

    Eric Loros

    2001-07-31

    The Subsurface Facility System encompasses the location, arrangement, size, and spacing of the underground openings. This subsurface system includes accesses, alcoves, and drifts. This system provides access to the underground, provides for the emplacement of waste packages, provides openings to allow safe and secure work conditions, and interfaces with the natural barrier. This system includes what is now the Exploratory Studies Facility. The Subsurface Facility System physical location and general arrangement help support the long-term waste isolation objectives of the repository. The Subsurface Facility System locates the repository openings away from main traces of major faults, away from exposure to erosion, above the probable maximum flood elevation, and above the water table. The general arrangement, size, and spacing of the emplacement drifts support disposal of the entire inventory of waste packages based on the emplacement strategy. The Subsurface Facility System provides access ramps to safely facilitate development and emplacement operations. The Subsurface Facility System supports the development and emplacement operations by providing subsurface space for such systems as ventilation, utilities, safety, monitoring, and transportation.

  18. Government Should Subsidize, Not Tax, Marriage: Social Policies Have Influenced the Rate of Growth in Single-Parent Families

    ERIC Educational Resources Information Center

    Peterson, Paul E.

    2015-01-01

    Based upon reflections from the Moynihan report of 1965, this author notes that the root causes of the growth in single-parent families have yet to be well identified, making it difficult to figure out where to go next. However, from 1965 onward, social policies have influenced the rate of growth in single-parent families. What is needed is a…

  19. Interphase mass transfer between fluids in subsurface formations: A review

    NASA Astrophysics Data System (ADS)

    Agaoglu, Berken; Copty, Nadim K.; Scheytt, Traugott; Hinkelmann, Reinhard

    2015-05-01

    This paper presents a review of the state-of-the-art on interphase mass transfer between immiscible fluids in porous media with focus on the factors that have significant influence on this process. In total close to 300 papers were reviewed focusing to a large extent on the literature relating to NAPL contamination of the subsurface. The large body of work available on this topic was organized according to the length scale of the conducted studies, namely the pore, meso and field scales. The interrelation of interphase mass transfer at these different scales is highlighted. To gain further insight into interphase mass transfer, published studies were discussed and evaluated in terms of the governing flow configurations defined in terms of the wettability and mobility of the different phases. Such organization of the existing literature enables the identification of the interfacial domains that would have significant impact on interphase mass transfer. Available modeling approaches at the various length scales are discussed with regard to current knowledge on the physics of this process. Future research directions are also suggested.

  20. Adverse possession of subsurface minerals

    SciTech Connect

    Bowles, P.N.

    1983-01-01

    Concepts applicable to adverse possession of subsurface minerals are generally the same as those that apply to adverse possession of all real estate. However, special requirements must be satisfied in order to perfect title to subsurface minerals by adverse possession, particularly when there has been a severance of the true title between surface and subsurface minerals. In those jurisdictions where senior and junior grants came from the state or commonwealth covering the same or some of the same land and in those areas where descriptions of land were vague or not carefully drawn, adverse possession serves to solidify land and mineral ownership. There may be some public, social, and economic justification in rewarding, with good title, those who take possession and use real estate for its intended use, including the extraction of subsurface minerals. 96 refernces.

  1. Subsurface plankton layers in the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Churnside, James H.; Marchbanks, Richard D.

    2015-06-01

    The first synoptic measurements of subsurface plankton layers were made in the western Arctic Ocean in July 2014 using airborne lidar. Layers were detected in open water and in pack ice where up to 90% of the surface was covered by ice. Layers under the ice were less prevalent, weaker, and shallower than those in open water. Layers were more prevalent in the Chukchi Sea than in the Beaufort Sea. Three quarters of the layers observed were thinner than 5 m. The presence of these layers, which are not adequately captured in satellite data, will influence primary productivity, secondary productivity, fisheries recruitment, and carbon export to the benthos.

  2. Estimating and mapping ecological processes influencing microbial community assembly

    SciTech Connect

    Stegen, James C.; Lin, Xueju; Fredrickson, Jim K.; Konopka, Allan E.

    2015-05-01

    Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recently developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth.

  3. Estimating and mapping ecological processes influencing microbial community assembly

    PubMed Central

    Stegen, James C.; Lin, Xueju; Fredrickson, Jim K.; Konopka, Allan E.

    2015-01-01

    Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recently developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth. PMID:25983725

  4. Estimating and mapping ecological processes influencing microbial community assembly

    DOE PAGESBeta

    Stegen, James C.; Lin, Xueju; Fredrickson, Jim K.; Konopka, Allan E.

    2015-05-01

    Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recentlymore » developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth.« less

  5. Subsurface Geotechnical Parameters Report

    SciTech Connect

    D. Rigby; M. Mrugala; G. Shideler; T. Davidsavor; J. Leem; D. Buesch; Y. Sun; D. Potyondy; M. Christianson

    2003-12-17

    The Yucca Mountain Project is entering a the license application (LA) stage in its mission to develop the nation's first underground nuclear waste repository. After a number of years of gathering data related to site characterization, including activities ranging from laboratory and site investigations, to numerical modeling of processes associated with conditions to be encountered in the future repository, the Project is realigning its activities towards the License Application preparation. At the current stage, the major efforts are directed at translating the results of scientific investigations into sets of data needed to support the design, and to fulfill the licensing requirements and the repository design activities. This document addresses the program need to address specific technical questions so that an assessment can be made about the suitability and adequacy of data to license and construct a repository at the Yucca Mountain Site. In July 2002, the U.S. Nuclear Regulatory Commission (NRC) published an Integrated Issue Resolution Status Report (NRC 2002). Included in this report were the Repository Design and Thermal-Mechanical Effects (RDTME) Key Technical Issues (KTI). Geotechnical agreements were formulated to resolve a number of KTI subissues, in particular, RDTME KTIs 3.04, 3.05, 3.07, and 3.19 relate to the physical, thermal and mechanical properties of the host rock (NRC 2002, pp. 2.1.1-28, 2.1.7-10 to 2.1.7-21, A-17, A-18, and A-20). The purpose of the Subsurface Geotechnical Parameters Report is to present an accounting of current geotechnical information that will help resolve KTI subissues and some other project needs. The report analyzes and summarizes available qualified geotechnical data. It evaluates the sufficiency and quality of existing data to support engineering design and performance assessment. In addition, the corroborative data obtained from tests performed by a number of research organizations is presented to reinforce

  6. Improving subsurface hydrology in Earth System Models

    NASA Astrophysics Data System (ADS)

    Volk, J. M.; Clark, M. P.; Swenson, S. C.; Lawrence, D. M.; Tyler, S. W.

    2015-12-01

    Hydrologic processes that govern storage and transport of soil water and groundwater can have strong dynamic relationships with biogeochemical and atmospheric processes. This understanding has lead to a push to improve subsurface hydrologic parametrization in Earth System Models. Here we present results related to improving the implementation of soil moisture distribution, groundwater recharge/discharge, and subsurface drainage in the Community Land Model (CLM) which is the land surface model in the Community Earth System Model. First we identified geo-climatically different locations around the world to develop test cases. For each case we compare the vertical soil moisture distribution from the different implementations of 1D Richards equation, considering the boundary conditions, the treatment of the groundwater sink term, the vertical discretization, and the time stepping schemes. Generally, large errors in the hydrologic mass balance within the soil column occur when there is a large vertical gradient in soil moisture or when there is a shallow water table within a soil column. We then test the sensitivity of the algorithmic parameters that control temporal discretization and error tolerance of the adaptive time-stepping scheme to help optimize its computational efficiency. In addition, we vary the spatial discretization of soil layers (i.e. quantity of layers and their thicknesses) to better understand the sensitivity of vertical discretization of soil columns on soil moisture variability in ESMs. We present multivariate and multi-scale evaluation for the different model options and suggest ways to move forward with future model improvements.

  7. Armored Enzyme Nanoparticles for Remediation of Subsurface

    SciTech Connect

    Grate, Jay W.

    2005-09-01

    The remediation of subsurface contaminants is a critical problem for the Department of Energy, other government agencies, and our nation. Severe contamination of soil and groundwater exists at several DOE sites due to various methods of intentional and unintentional release. Given the difficulties involved in conventional removal or separation processes, it is vital to develop methods to transform contaminants and contaminated earth/water to reduce risks to human health and the environment. Transformation of the contaminants themselves may involve conversion to other immobile species that do not migrate into well water or surface waters, as is proposed for metals and radionuclides; or degradation to harmless molecules, as is desired for organic contaminants. Transformation of contaminated earth (as opposed to the contaminants themselves) may entail reductions in volume or release of bound contaminants for remediation.

  8. Spatially-distributed influence of agro-environmental factors governing nitrate fate and transport in an irrigated stream-aquifer system

    NASA Astrophysics Data System (ADS)

    Bailey, R. T.; Ahmadi, M.; Gates, T. K.; Arabi, M.

    2015-02-01

    Elevated levels of nitrate (NO3) in groundwater systems pose a serious risk to human populations and natural ecosystems. As part of an effort to remediate NO3 contamination in irrigated stream-aquifer systems, this study elucidates agricultural and environmental parameters and processes that govern NO3 fate and transport at the regional (500 km2), local (50 km2), and field scales (< 1 km2). Specifically, the revised Morris sensitivity analysis method was applied to a finite-difference nitrogen cycling and reactive transport model of a regional-scale study site in the Lower Arkansas River Valley in southeastern Colorado. The method was used to rank the influence of anthropogenic activities and natural chemical processes on NO3 groundwater concentration, NO3 mass leaching, and NO3 mass loading to the Arkansas River from the aquifer. Sensitivity indices were computed for the entire study area in aggregate as well as each canal command area, crop type, and individual grid cells. Results suggest that fertilizer loading, crop uptake, and heterotrophic denitrification govern NO3 fate and transport for the majority of the study area, while canal NO3 concentration and rates of autotrophic denitrification, nitrification, and humus decomposition dominate or partially dominate in several canal command areas. Also, NO3 leaching and groundwater concentration in adjacent cultivated fields often are governed by different processes and mass inputs/outputs. Results can be used to determine critical processes and key management actions for future data collection and remediation strategies, with efforts able to be focused on localized areas.

  9. Global Health Governance and the Commercial Sector: A Documentary Analysis of Tobacco Company Strategies to Influence the WHO Framework Convention on Tobacco Control

    PubMed Central

    Weishaar, Heide; Collin, Jeff; Smith, Katherine; Grüning, Thilo; Mandal, Sema; Gilmore, Anna

    2012-01-01

    Background In successfully negotiating the Framework Convention on Tobacco Control (FCTC), the World Health Organization (WHO) has led a significant innovation in global health governance, helping to transform international tobacco control. This article provides the first comprehensive review of the diverse campaign initiated by transnational tobacco corporations (TTCs) to try to undermine the proposed convention. Methods and Findings The article is primarily based on an analysis of internal tobacco industry documents made public through litigation, triangulated with data from official documentation relating to the FCTC process and websites of relevant organisations. It is also informed by a comprehensive review of previous studies concerning tobacco industry efforts to influence the FCTC. The findings demonstrate that the industry's strategic response to the proposed WHO convention was two-fold. First, arguments and frames were developed to challenge the FCTC, including: claiming there would be damaging economic consequences; depicting tobacco control as an agenda promoted by high-income countries; alleging the treaty conflicted with trade agreements, “good governance,” and national sovereignty; questioning WHO's mandate; claiming the FCTC would set a precedent for issues beyond tobacco; and presenting corporate social responsibility (CSR) as an alternative. Second, multiple tactics were employed to promote and increase the impact of these arguments, including: directly targeting FCTC delegations and relevant political actors, enlisting diverse allies (e.g., mass media outlets and scientists), and using stakeholder consultation to delay decisions and secure industry participation. Conclusions TTCs' efforts to undermine the FCTC were comprehensive, demonstrating the global application of tactics that TTCs have previously been found to have employed nationally and further included arguments against the FCTC as a key initiative in global health governance

  10. Tangible Exploration of Subsurface Data

    NASA Astrophysics Data System (ADS)

    Petrasova, A.; Harmon, B.; Mitasova, H.; White, J.

    2014-12-01

    Since traditional subsurface visualizations using 2D maps, profiles or charts can be difficult to interpret and often do not convey information in an engaging form, scientists are interested in developing alternative visualization techniques which would help them communicate the subsurface volume data with students and general public. We would like to present new technique for interactive visualization of subsurface using Tangible geospatial modeling and visualization system (Tangeoms). It couples a physical, three-dimensional model with geospatial modeling and analysis through a cycle of scanning and projection. Previous applications of Tangeoms were exploring the impact of terrain modifications on surface-based geophysical processes, such as overland water flow, sediment transport, and also on viewsheds, cast shadows or solar energy potential. However, Tangeoms can serve as a tool for exploring subsurface as well. By creating a physical sand model of a study area, removing the sand from different parts of the model and projecting the computed cross-sections, we can look under the ground as if we were at an excavation site, and see the actual data represented as a 3D raster in that particular part of the model. Depending on data availability, we can also incorporate temporal dimension. Our method is an intuitive and natural way of exploring subsurface data and for users, it represents an alternative to more abstract 3D computer visualization tools, by offering direct, tangible interface.

  11. Endoscopic subsurface imaging in tissues

    SciTech Connect

    Demos, S G; Staggs, M; Radousky, H B

    2001-02-12

    The objective of this work is to develop endoscopic subsurface optical imaging technology that will be able to image different tissue components located underneath the surface of the tissue at an imaging depth of up to 1 centimeter. This effort is based on the utilization of existing technology and components developed for medical endoscopes with the incorporation of the appropriate modifications to implement the spectral and polarization difference imaging technique. This subsurface imaging technique employs polarization and spectral light discrimination in combination with image processing to remove a large portion of the image information from the outer layers of the tissue which leads to enhancement of the contrast and image quality of subsurface tissue structures.

  12. Subsurface microbial habitats on Mars

    NASA Technical Reports Server (NTRS)

    Boston, P. J.; Mckay, C. P.

    1991-01-01

    We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

  13. Colloids in groundwater: Their mobilization, subsurface transport, and sorption affinity for toxic chemicals

    SciTech Connect

    Not Available

    1991-01-01

    During the initial project period, we have pursued several activities with the overall goal of characterizing the roles of colloid in groundwater. First, we have collected soil cores from a site where we have previously found large quantities of kaolinite colloids in the groundwater. We have intensely investigated these cores to test our hypothesis that the colloids have been mobilized as a result of iron oxide dissolution. Next, we have constructed a soil core system in our laboratory with which we are attempting to mimic the factors that we think are governing colloid transport in the subsurface. Finally, we have pursued the issue of how well organic chemicals bind to the kinds of colloids that we are seeing at field sites. Together, with our knowledge of colloid mobility, we anticipate that this sorption data will enable us to predict the influence of groundwater colloids on contaminant fates in the subsurface. Our progress in each of these activities is described in this report. 7 refs., 12 figs.

  14. Towed Subsurface Optical Communications Buoy

    NASA Technical Reports Server (NTRS)

    Stirbl, Robert C.; Farr, William H.

    2013-01-01

    The innovation allows critical, high-bandwidth submarine communications at speed and depth. This reported innovation is a subsurface optical communications buoy, with active neutral buoyancy and streamlined flow surface veins for depth control. This novel subsurface positioning for the towed communications buoy enables substantial reduction in water-absorption and increased optical transmission by eliminating the intervening water absorption and dispersion, as well as by reducing or eliminating the beam spread and the pulse spreading that is associated with submarine-launched optical beams.

  15. Student Government.

    ERIC Educational Resources Information Center

    Morrow, Joyce

    Materials for running a student government program at the junior high school level are provided in three general sections. Section 1 is a description of student government operations. Topics covered include student government responsibilities and activities, student council meeting procedures, parliamentary rules, responsibilities of the…

  16. Scenario simulation based assessment of subsurface energy storage

    NASA Astrophysics Data System (ADS)

    Beyer, C.; Bauer, S.; Dahmke, A.

    2014-12-01

    -processes, mutual effects and influences on protected entities. The scenario analyses allow the deduction of monitoring concepts as well as a first methodology for large scale spatial planning of the geological subsurface. This concept is illustrated for different storage options and their impacts in space and time.

  17. Soil Carbon Dioxide Production and Surface Fluxes: Subsurface Physical Controls

    NASA Astrophysics Data System (ADS)

    Risk, D.; Kellman, L.; Beltrami, H.

    Soil respiration is a critical determinant of landscape carbon balance. Variations in soil temperature and moisture patterns are important physical processes controlling soil respiration which need to be better understood. Relationships between soil respi- ration and physical controls are typically addressed using only surface flux data but other methods also exist which permit more rigorous interpretation of soil respira- tion processes. Here we use a combination of subsurface CO_{2} concentrations, surface CO_{2} fluxes and detailed physical monitoring of the subsurface envi- ronment to examine physical controls on soil CO_{2} production at four climate observatories in Eastern Canada. Results indicate that subsurface CO_{2} produc- tion is more strongly correlated to the subsurface thermal environment than the surface CO_{2} flux. Soil moisture was also found to have an important influence on sub- surface CO_{2} production, particularly in relation to the soil moisture - soil profile diffusivity relationship. Non-diffusive profile CO_{2} transport appears to be im- portant at these sites, resulting in a de-coupling of summertime surface fluxes from subsurface processes and violating assumptions that surface CO_{2} emissions are the result solely of diffusion. These results have implications for the study of soil respiration across a broad range of terrestrial environments.

  18. Pattern formation during the CO-oxidation involving subsurface oxygen

    NASA Astrophysics Data System (ADS)

    Rotermund, Harm Hinrich; Pollmann, Michael; Kevrekidis, Ioannis G.

    2002-03-01

    This paper focuses on subsurface oxygen and its influence on pattern formation during CO-oxidation on platinum surfaces. For the observation of spatiotemporal pattern formation during catalytic reactions the photoelectron emission microscope (PEEM) has proven to be an excellent real-time imaging instrument, capable of tracking local work function changes. The existence of subsurface oxygen on platinumlike surfaces has been extensively discussed and for palladium its presence has been clearly established during rate oscillations. Subsurface oxygen is defined at this point as an atomic O species located directly underneath the uppermost metal crystal layer; its dipole moment therefore considerably lowers the work function of the surface. Here we review some of the investigations involving subsurface oxygen, focusing on the role subsurface oxygen might play in pattern formation during CO-oxidation on platinum. We will also present some new results, where this species clearly interacts with chemisorbed oxygen under restrictions by boundary conditions on the Pt(110) single crystal. These previously (through microlithography) constructed domain boundaries on the surface are made out of Rh or Pd, and they are acting as an additional source of CO molecules for the Pt surface.

  19. SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

    SciTech Connect

    D.W. Markman

    2001-08-06

    The ''Subsurface Fire Hazard Analysis'' (CRWMS M&O 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M&O 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree of

  20. Subsurface damage on ground fused silica surfaces

    NASA Astrophysics Data System (ADS)

    Xu, Jiafeng; Xu, Xueke; Gao, Wenlan; Wei, Chaoyang; Yang, Minghong; Shao, Jianda

    2014-08-01

    The low surface laser damage threshold of fused silica components in high power laser systems such as NIF restricts the improvement of the output fluence of those systems. Once damage is initiated and grows under subsequent laser shots, the components will go unusable. Subsurface damage (SSD) introduced during manufacturing has been identified as a main damage initiator. A good knowledge of SSD and how manufacturing influences it is essential to optimize manufacturing processes for damage free optics. Using the magneto-rheological finishing (MRF) wedge technique of better accuracy attributed to a tip, we have characterized the subsurface damage on fused silica optical surfaces ground with loose Al2O3 abrasives of different sizes. Larger abrasives generates longer cracks and the number density of cracks decreases sharply with the depth for each size. Rogue particles account for the occurrence of trailing indent scratches. Addition of rogue abrasives into relatively small base abrasive extends SSD more deeply than that induced by rogue abrasives alone. The linear model, with the proportional coefficient 3.511, fits the relationship between SSD depth and surface roughness (SR) better than the quadratic polynomial one. We believe SSD depth relates to SR more statistically than following some specified physical law. The linear relationship between SSD depth and the abrasive size was also established. The abrasive size turned out not to be as a good indictor of SSD depth as SR.

  1. Modeling the Subsurface Structure of Sunspots

    NASA Astrophysics Data System (ADS)

    Moradi, H.; Baldner, C.; Birch, A. C.; Braun, D. C.; Cameron, R. H.; Duvall, T. L.; Gizon, L.; Haber, D.; Hanasoge, S. M.; Hindman, B. W.; Jackiewicz, J.; Khomenko, E.; Komm, R.; Rajaguru, P.; Rempel, M.; Roth, M.; Schlichenmaier, R.; Schunker, H.; Spruit, H. C.; Strassmeier, K. G.; Thompson, M. J.; Zharkov, S.

    2010-11-01

    While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There are two main hypotheses for the subsurface structure of sunspots: the monolithic model and the cluster model. Local helioseismology is the only means by which we can investigate subphotospheric structure. However, as current linear inversion techniques do not yet allow helioseismology to probe the internal structure with sufficient confidence to distinguish between the monolith and cluster models, the development of physically realistic sunspot models are a priority for helioseismologists. This is because they are not only important indicators of the variety of physical effects that may influence helioseismic inferences in active regions, but they also enable detailed assessments of the validity of helioseismic interpretations through numerical forward modeling. In this article, we provide a critical review of the existing sunspot models and an overview of numerical methods employed to model wave propagation through model sunspots. We then carry out a helioseismic analysis of the sunspot in Active Region 9787 and address the serious inconsistencies uncovered by Gizon et al. (2009a, 2009). We find that this sunspot is most probably associated with a shallow, positive wave-speed perturbation (unlike the traditional two-layer model) and that travel-time measurements are consistent with a horizontal outflow in the surrounding moat.

  2. Partnering to proceed: scaling up adolescent sexual reproductive health programmes in Tanzania. Operational research into the factors that influenced local government uptake and implementation

    PubMed Central

    2010-01-01

    Background Little is known about how to implement promising small-scale projects to reduce reproductive ill health and HIV vulnerability in young people on a large scale. This evaluation documents and explains how a partnership between a non-governmental organization (NGO) and local government authorities (LGAs) influenced the LGA-led scale-up of an innovative NGO programme in the wider context of a new national multisectoral AIDS strategy. Methods Four rounds of semi-structured interviews with 82 key informants, 8 group discussions with 49 district trainers and supervisors (DTS), 8 participatory workshops involving 52 DTS, and participant observations of 80% of LGA-led and 100% of NGO-led meetings were conducted, to ascertain views on project components, flow of communication and decision-making and amount of time DTS utilized undertaking project activities. Results Despite a successful ten-fold scale-up of intervention activities in three years, full integration into LGA systems did not materialize. LGAs contributed significant human resources but limited finances; the NGO retained control over finances and decision-making and LGAs largely continued to view activities as NGO driven. Embedding of technical assistants (TAs) in the LGAs contributed to capacity building among district implementers, but may paradoxically have hindered project integration, because TAs were unable to effectively transition from an implementing to a facilitating role. Operation of NGO administration and financial mechanisms also hindered integration into district systems. Conclusions Sustainable intervention scale-up requires operational, financial and psychological integration into local government mechanisms. This must include substantial time for district systems to try out implementation with only minimal NGO support and modest output targets. It must therefore go beyond the typical three- to four-year project cycles. Scale-up of NGO pilot projects of this nature also need NGOs to be

  3. INEEL Subregional Conceptual Model Report; Volume 1 - Summary of Existing Knowledge of Natural and Anthropogenic Influences Governing Subsurface Contaminant Transport in the INEEL Subregion of the Eastern Snake River Plain

    SciTech Connect

    Wichlacz, Paul Louis; Orr, Brennan

    2002-08-01

    The National Research Council has defined a conceptual model as ''an evolving hypothesis identifying the important features, processes, and events controlling fluid flow and contaminant transport of consequence at a specific field site in the context of a recognized problem''. Presently, several subregional conceptual models are under development at the Idaho National Engineering and Environmental Laboratory (INEEL). Additionally, facility-specific conceptual models have been described as part of INEEL environmental restoration activities. Compilation of these models is required to develop a comprehensive conceptual model that can be used to strategically plan for future groundwater research activities at the INEEL. Conceptual models of groundwater flow and contaminant transport at the INEEL include the description of the geologic framework, matrix hydraulic properties, and inflows and outflows. They also include definitions of the contaminant source term and contaminant transport mechanisms. The geologic framework of the INEEL subregion is described by the geometry of the system, stratigraphic units within the system, and structural features that affect groundwater flow and contaminant transport. These elements define geohydrologic units that make up the Snake River Plain Aquifer (SRPA). The United States Geological Survey (USGS) conceptual model encompasses approximately 1,920 mi2 of the eastern Snake River Plain. The Waste Area Group (WAG)-10 model includes the USGS area and additional areas to the northeast and southeast. Both conceptual models are bounded to the northwest by the Pioneer Mountains, Lost River Range, and Lemhi Mountains. They are bounded to the southeast by groundwater flow paths determined from aquifer water-level contours. The upgradient extent of the USGS model is a water-level contour that includes the northeastern boundary of the INEEL. The WAG-10 model includes more of the Mud Lake area to utilize previous estimates of underflow into the subregion. Both conceptual models extend approximately 25 miles to the southwest of the INEEL, a distance sufficient to include known concentrations of contaminant tracers. Several hypotheses have been developed concerning the effective thickness of the SRPA at the INEEL. The USGS model has defined the effective thickness from electrical resistivity and borehole data to be as much as 2,500 ft in the eastern part of the subregion and as much as 4,000 ft in the southwestern part. The WAG-10 model has developed two alternatives using aquifer-temperature and electrical resistivity data. The ''thick'' aquifer interpretation utilizes colder temperature data and includes a northtrending zone in which the thickness exceeds 1,300 ft and with a maximum thickness of 1,700 ft. The ''thin'' aquifer interpretation minimizes aquifer thickness, with thickness ranging from 328 to 1,300 ft. Facility-specific models generally have focused efforts on the upper 250 ft of saturation. Conceptual models have utilized a stratigraphic data set to define geohydrologic units within the INEEL subregion. This data set, compiled from geophysical logs and cores from boreholes, correlates the thick, complex stack of basalt flows across the subregion. Conceptual models generally concur that the upper geohydrologic unit consists of a section of highly fractured, multiple, thin basalt flows and sedimentary interbeds. Beneath this unit is an areally extensive, thick, unfractured basalt flow that rises above the water table southwest of the INEEL. The bottom unit consists of a thick section of slightly- to moderately-altered basalt. A key objective of the DOE water-integration project at the INEEL is to coordinate development of a subregional conceptual model of groundwater flow and contaminant transport that is based on the best available understanding of geologic and hydrologic features. The first step in this process is to compile and summarize the current conceptual models of groundwater flow and contaminant transport at the INEEL that have been developed from extensive geohydrologic studies con

  4. Robust Representation of Integrated Surface-subsurface Hydrology at Watershed Scales

    NASA Astrophysics Data System (ADS)

    Painter, S. L.; Tang, G.; Collier, N.; Jan, A.; Karra, S.

    2015-12-01

    A representation of integrated surface-subsurface hydrology is the central component to process-rich watershed models that are emerging as alternatives to traditional reduced complexity models. These physically based systems are important for assessing potential impacts of climate change and human activities on groundwater-dependent ecosystems and water supply and quality. Integrated surface-subsurface models typically couple three-dimensional solutions for variably saturated flow in the subsurface with the kinematic- or diffusion-wave equation for surface flows. The computational scheme for coupling the surface and subsurface systems is key to the robustness, computational performance, and ease-of-implementation of the integrated system. A new, robust approach for coupling the subsurface and surface systems is developed from the assumption that the vertical gradient in head is negligible at the surface. This tight-coupling assumption allows the surface flow system to be incorporated directly into the subsurface system; effects of surface flow and surface water accumulation are represented as modifications to the subsurface flow and accumulation terms but are not triggered until the subsurface pressure reaches a threshold value corresponding to the appearance of water on the surface. The new approach has been implemented in the highly parallel PFLOTRAN (www.pflotran.org) code. Several synthetic examples and three-dimensional examples from the Walker Branch Watershed in Oak Ridge TN demonstrate the utility and robustness of the new approach using unstructured computational meshes. Representation of solute transport in the new approach is also discussed. Notice: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid

  5. Arabidopsis MYB-Related HHO2 Exerts a Regulatory Influence on a Subset of Root Traits and Genes Governing Phosphate Homeostasis.

    PubMed

    Nagarajan, Vinay K; Satheesh, Viswanathan; Poling, Michael D; Raghothama, Kashchandra G; Jain, Ajay

    2016-06-01

    Phosphate (Pi), an essential macronutrient required for growth and development of plants, is often limiting in soils. Pi deficiency modulates the expression of Pi starvation-responsive (PSR) genes including transcription factors (TFs). Here, we elucidated the role of the MYB-related TF HYPERSENSITIVITY TO LOW PHOSPHATE-ELICITED PRIMARY ROOT SHORTENING1 HOMOLOG2 (HHO2, At1g68670) in regulating Pi acquisition and signaling in Arabidopsis thaliana HHO2 was specifically and significantly induced in different tissues in response to Pi deprivation. Transgenic seedlings expressing 35S::GFP::HHO2 confirmed the localization of HHO2 to the nucleus. Knockout mutants of HHO2 showed significant reduction in number and length of first- and higher-order lateral roots and Pi content of different tissues compared with the wild-type irrespective of the Pi regime. In contrast, HHO2-overexpressing lines exhibited augmented lateral root development, enhanced Pi uptake rate and higher Pi content in leaf compared with the wild-type. Expression levels of PSR genes involved in Pi sensing and signaling in mutants and overexpressors were differentially regulated as compared with the wild-type. Attenuation in the expression of HHO2 in the phr1 mutant suggested a likely influence of PHR1 in HHO2-mediated regulation of a subset of traits governing Pi homeostasis. PMID:27016098

  6. Method of installing subsurface barrier

    DOEpatents

    Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.

    2007-10-09

    Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.

  7. Reinventing Government.

    ERIC Educational Resources Information Center

    Osborne, David T.

    1993-01-01

    Throughout all levels of American government, a shift is taking place from the rigid, wasteful, centralized bureaucracies of the industrial era to the more flexible, entrepreneurial, decentralized government needed to succeed in today's world. This shift has been brought about by an unprecedented, ongoing fiscal crisis that has created a sudden…

  8. Remaking Governance.

    ERIC Educational Resources Information Center

    Carver, John

    2000-01-01

    The Policy Governance model's philosophical foundations lie in Rousseau's social contract, Greenleaf's servant-leadership, and modern management theory. Policy Governance stresses primacy of the owner-representative role; full-board authority; superintendents as chief executive officers; authoritative prescription of "ends," bounded freedom for…

  9. Geophysical characterization of subsurface barriers

    SciTech Connect

    Borns, D.J.

    1995-08-01

    An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier.

  10. INL Subsurface Wireless Sensor Platform

    SciTech Connect

    Dennis C. Kunerth; John M. Svoboda; James T. Johnson

    2005-10-01

    The Idaho National Laboratory is developing a versatile micro-power sensor interface platform for periodic subsurface sensing of environmental variables important to waste disposal sites such as volumetric moisture, water potential, and temperature. The key characteristics of the platform architecture are that the platform is passive until externally energized --no internal power source is required -- and that it communicates with a "reader" via short-range telemetry - no wires penetrate the subsurface. Other significant attributes include the potential for a long service life and a compact size that makes it well suited for retrofitting existing landfill structures. Functionally, the sensor package is "read" by a short-range induction coil that activates and powers the sensor platform as well as detects the sensor output via a radio frequency signal generated by the onboard programmable interface controller microchip. As a result, the platform has a functional subsurface communication range of approximately 10 to 12 ft. and can only accept sensors that require low power to operate.

  11. Surface/subsurface observation and removal mechanisms of ground reaction bonded silicon carbide

    NASA Astrophysics Data System (ADS)

    Yao, Wang; Zhang, Yu-Min; Han, Jie-cai; Zhang, Yun-long; Zhang, Jian-han; Zhou, Yu-feng; Han, Yuan-yuan

    2006-01-01

    Reaction Bonded Silicon Carbide (RBSiC) has long been recognized as a promising material for optical applications because of its unique combination of favorable properties and low-cost fabrication. Grinding of silicon carbide is difficult because of its high hardness and brittleness. Grinding often induces surface and subsurface damage, residual stress and other types of damage, which have great influence on the ceramic components for optical application. In this paper, surface integrity, subsurface damage and material removal mechanisms of RBSiC ground using diamond grinding wheel on creep-feed surface grinding machine are investigated. The surface and subsurface are studied with scanning electron microscopy (SEM) and optical microscopy. The effects of grinding conditions on surface and subsurface damage are discussed. This research links the surface roughness, surface and subsurface cracks to grinding parameters and provides valuable insights into the material removal mechanism and the dependence of grind induced damage on grinding conditions.

  12. Shallow subsurface storm flow in a forested headwater catchment: Observations and modeling using a modified TOPMODEL

    NASA Astrophysics Data System (ADS)

    Scanlon, Todd M.; Raffensperger, Jeff P.; Hornberger, George M.; Clapp, Roger B.

    2000-09-01

    Transient, perched water tables in the shallow subsurface are observed at the South Fork Brokenback Run catchment in Shenandoah National Park, Virginia. Crest piezometers installed along a hillslope transect show that the development of saturated conditions in the upper 1.5 m of the subsurface is controlled by total precipitation and antecedent conditions, not precipitation intensity, although soil heterogeneities strongly influence local response. The macroporous subsurface storm flow zone provides a hydrological pathway for rapid runoff generation apart from the underlying groundwater zone, a conceptualization supported by the two-storage system exhibited by hydrograph recession analysis. A modified version of TOPMODEL is used to simulate the observed catchment dynamics. In this model, generalized topographic index theory is applied to the subsurface storm flow zone to account for logarithmic storm flow recessions, indicative of linearly decreasing transmissivity with depth. Vertical drainage to the groundwater zone is required, and both subsurface reservoirs are considered to contribute to surface saturation.

  13. Shallow subsurface storm flow in a forested headwater catchment: Observations and modeling using a modified TOPMODEL

    USGS Publications Warehouse

    Scanlon, T.M.; Raffensperger, J.P.; Hornberger, G.M.; Clapp, R.B.

    2000-01-01

    Transient, perched water tables in the shallow subsurface are observed at the South Fork Brokenback Run catchment in Shenandoah National Park, Virginia. Crest piezometers installed along a hillslope transect show that the development of saturated conditions in the upper 1.5 m of the subsurface is controlled by total precipitation and antecedent conditions, not precipitation intensity, although soil heterogeneities strongly influence local response. The macroporous subsurface storm flow zone provides a hydrological pathway for rapid runoff generation apart from the underlying groundwater zone, a conceptualization supported by the two-storage system exhibited by hydrograph recession analysis. A modified version of TOPMODEL is used to simulate the observed catchment dynamics. In this model, generalized topographic index theory is applied to the subsurface storm flow zone to account for logarithmic storm flow recessions, indicative of linearly decreasing transmissivity with depth. Vertical drainage to the groundwater zone is required, and both subsurface reservoirs are considered to contribute to surface saturation.

  14. Subsurface Flow and Contaminant Transport Documentation and User's Guide

    SciTech Connect

    Aleman, S.E.

    1999-07-28

    This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media. The code is designed specifically to handle complex multi-layer and/or heterogeneous aquifer systems in an efficient manner and accommodates a wide range of boundary conditions. Additionally, 1-D and 2-D (in Cartesian coordinates) problems are handled in FACT by simply limiting the number of elements in a particular direction(s) to one. The governing equations in FACT are formulated only in Cartesian coordinates.

  15. A technical investigation on tools and concepts for sustainable management of the subsurface in The Netherlands.

    PubMed

    Griffioen, Jasper; van Wensem, Joke; Oomes, Justine L M; Barends, Frans; Breunese, Jaap; Bruining, Hans; Olsthoorn, Theo; Stams, Alfons J M; van der Stoel, Almer E C

    2014-07-01

    In response to increasing use of the subsurface, there is a need to modernise policies on sustainable use of the subsurface. This holds in particular for the densely populated Netherlands. We aimed to analyse current practice of subsurface management and the associated pressure points and to establish a conceptual overview of the technical issues related to sustainable management of the subsurface. Case studies on the exploitation of subsurface resources (including spatial use of the subsurface) were analysed, examining social relevance, environmental impact, pressure points and management solutions. The case studies ranged from constructing underground garages to geothermal exploitation. The following issues were identified for the technological/scientific aspects: site investigation, suitability, risk assessment, monitoring and measures in the event of failure. Additionally, the following general issues were identified for the administrative aspects: spatial planning, option assessment, precaution, transparency, responsibility and liability. These issues were explored on their technological implications within the framework of sustainable management of the subsurface. This resulted into the following key aspects: (1) sustainability assessment, (2) dealing with uncertainty and (3) policy instruments and governance. For all three aspects, different options were identified which might have a legal, economic or ethical background. The technological implications of these backgrounds have been identified. A set of recommendations for sustainable management of the subsurface resources (incl. space) was established: (1) management should be driven by scarcity, (2) always implement closed loop monitoring when the subsurface activities are high-risk, (3) when dealing with unknown features and heterogeneity, apply the precautionary principle, (4) responsibility and liability for damage must be set out in legislation and (5) sustainability should be incorporated in all

  16. Link between Surface and Subsurface Urban Heat Islands

    NASA Astrophysics Data System (ADS)

    Benz, Susanne; Bayer, Peter; Olesen, Folke; Goettsche, Frank; Blum, Philipp

    2016-04-01

    Urban heat islands exist in all diverse layers of modern cities, such as surface and subsurface. While both layers are typically investigated separately, the coupling of surface and subsurface urban heat islands is insufficiently understood. Hence, this study focuses on the interrelation of both zones and the influence of additional underground heat sources, such as heated basements, on this interaction. Using satellite derived land surface temperatures and interpolated groundwater temperature measurements the spatial properties of both heat islands are compared. Significant correlations of 0.5 up to more than 0.8 are found between surface and subsurface urban heat islands. If groundwater flow is considered this correlation increases by approximately 10%. Next we analyzed the dissimilarities between both heat islands in order to understand the interaction between the urban surface and subsurface. We find that local groundwater hotspots under the city center and industrial areas are not revealed in satellite derived land surface temperatures. Overall groundwater temperatures are higher than land surface temperatures in 95% of the analyzed area due to the influence of below ground anthropogenic heat sources such as sewage systems, district heating systems, and especially elevated basement temperatures. Thus, an estimation method is proposed that relates groundwater temperatures to mean annual land surface temperatures, building density, and elevated basement temperatures. Using this method regional groundwater temperatures can be accurately estimated with a mean absolute error of 0.9 K. Since land surface temperatures and building densities are available from remote sensing, this method has the potential for a large scale estimations of urban groundwater temperatures. Thus, it is feasible to detect subsurface urban heat islands on a global level and to investigate sustainable geothermal potentials using satellite derived data.

  17. Student and University Governance.

    ERIC Educational Resources Information Center

    Shoben, Edward Joseph, Jr.

    It is necessary to provide organizational and political bases from which genuine student influence can be exercised if we assume that (1) extensive and meaningful participation by students in university governance is likely to be a permanent feature of academic life; (2) participation legitimately represents serious student concerns and provides a…

  18. Sulfur and iron cycling in deep-subsurface, coal bed-containing sediments off Shimokita (Japan)

    NASA Astrophysics Data System (ADS)

    Riedinger, N.; Smirnoff, M. N.; Gilhooly, W.; Phillips, S. C.; Lyons, T. W.; 337 Scientific Party, I.

    2013-12-01

    The main goal of IODP Expedition 337 was the identification and characterization of the deep coal bed biosphere and hydrocarbon system off the Shimokita Peninsula (Japan) in the northwestern Pacific using the D/V Chikyu. To accomplish this scientific objective, it was also necessary to investigate the inorganic biogeochemistry in order to identify possible electron acceptors and bio-essential nutrients. These biogeochemical parameters greatly influence both, the composition and abundance of microbial communities as well as the organic carbon cycle. In turn, the microbially mediated carbon cycle influences the diagenetic reactions in the subsurface, thus, altering geochemical and physical characteristics of the material. Here we present results from metal and sulfur geochemical analyses from the deep-subsurface sediments (about 1250 to 2466 mbsf) at Site C0020 off Shimokita. The measured concentrations of acid volatile sulfur (AVS) as well as chromium reducible sulfur (CRS) reflect the alteration of iron oxides to iron sulfides and indicate that the main sulfur-bearing phase in the investigated sediments is pyrite. Concentrations of intermediate sulfur species are minor and occur mainly in the coal-bearing interval. Our data show that the uppermost sediments contain higher amounts of pyrite (up to 1.2 wt.%) with an average of 0.5 wt.% compared to the deeper deposits (below about 1800 mbsf), which show an average of 0.16 wt.%. In contrast, iron oxide concentrations are highest in the deeper sediment sections (up to 0.4%), where pyrite concentrations are low. The alteration of iron oxides to sulfides in theses lower section was probably governed by the amount of available sulfide in the pore water. The occurrence of (bio-)reactive iron phases in these deeply buried sediments has implications for the deep biosphere as those minerals have the potential to serve as electron acceptors during burial, including reactions involving deep sourced electron donors, such as

  19. Interaction of surface and subsurface waters in the system

    NASA Astrophysics Data System (ADS)

    Mazukhina, Svetlana; Masloboev, Vladimir; Chudnenko, Konstantin; Bychinski, Valerii; Sandimirov, Sergey

    2010-05-01

    Purpose of the study - to assess the influence of the Khibiny massif on the formation of the chemical composition of surface and subsurface waters, generated within its boundaries using physical-chemical modeling ("Selector" software package). Objects of monitoring - rivers with sources in the upper reaches of the Khibiny massif (surface waters), and boreholes, located in these rivers' valleys (subsurface waters) have been chosen as objects of monitoring. Processes of formation of surface and subsurface waters, generated within the boundaries of the Khibiny massif, have been considered within the framework of a unified system "water-rock-atmosphere-carbon". The initial data of the model: chemical compositions of the Khibiny massif rocks and chemical analyses of atmospheric and surface waters. Besides, there have been considered Clarke concentrations S, Cl, F, C, their influence on the formation of chemical composition of water solutions; geochemical mobility of chemical elements. The previously developed model has been improved with the purpose of assessment of the influence of organic substance, either liquid or solid, on the formation of the chemical composition of water. The record of the base model of the multisystem includes 24 independent components (Al-B-Br-Ar-He-Ne-C-Ca-Cl-F-K-Mg-Mn-N-Na-P-S-Si-Sr-Cu-Zn-H-O-e), 872 dependent components, including, in a water solution - 295, in a gas phase - 76, liquid hydrocarbons - 111, solid phases, organic and mineral substances - 390. The record of solid phases of multisystem is made with consideration of the mineral composition of the Khibiny massif. Using the created model, the physical-chemical modeling of surface and subsurface water generation has been carried out: 1. The system "water-rock-atmosphere" has been studied, depending on the interaction degree (ksi) of rock with water. A model like this allowed investigating the interactions of surface waters (rivers and lakes) with rocks that form the Khibiny massif. 2

  20. Phylogenetic relationships among subsurface microorganisms

    SciTech Connect

    Nierzwicki-Bauer, S.A.

    1991-01-01

    This project involves the development of group specific 16S ribosomal RNA-targeted oligonucleotide hybridization probes for the rapid detection of specific types of subsurface organisms (e.g., groups of microbes that share certain physiological traits). Major accomplishments for the period of 6/91 to 12/1/91 are described. Nine new probes have been synthesized on the basis of published 16S rRNA sequence data from the Ribosomal Database Project. We have initiated rapid screening of many of the subsurface microbial isolates obtained from the P24 borehole at the Savannah River Site. To date, we have screened approximately 50% of the isolates from P24. We have optimized our {und in situ} hybridization technique, and have developed a cell blot hybridization technique to screen 96 samples on a single blot. This is much faster than reading 96 individual slides. Preliminary experiments have been carried out which indicate specific nutrients can be used to amplify rRNA only in those organisms capable of metabolizing those nutrients. 1 tab., 2 figs.

  1. Introduction: energy and the subsurface.

    PubMed

    Christov, Ivan C; Viswanathan, Hari S

    2016-10-13

    This theme issue covers topics at the forefront of scientific research on energy and the subsurface, ranging from carbon dioxide (CO2) sequestration to the recovery of unconventional shale oil and gas resources through hydraulic fracturing. As such, the goal of this theme issue is to have an impact on the scientific community, broadly, by providing a self-contained collection of articles contributing to and reviewing the state-of-the-art of the field. This collection of articles could be used, for example, to set the next generation of research directions, while also being useful as a self-study guide for those interested in entering the field. Review articles are included on the topics of hydraulic fracturing as a multiscale problem, numerical modelling of hydraulic fracture propagation, the role of computational sciences in the upstream oil and gas industry and chemohydrodynamic patterns in porous media. Complementing the reviews is a set of original research papers covering growth models for branched hydraulic crack systems, fluid-driven crack propagation in elastic matrices, elastic and inelastic deformation of fluid-saturated rock, reaction front propagation in fracture matrices, the effects of rock mineralogy and pore structure on stress-dependent permeability of shales, topographic viscous fingering and plume dynamics in porous media convection.This article is part of the themed issue 'Energy and the subsurface'. PMID:27597784

  2. Key aspects governing induced seismicity

    NASA Astrophysics Data System (ADS)

    Buijze, Loes; Wassing, Brecht; Fokker, Peter

    2013-04-01

    In the past decades numerous examples of earthquakes induced by human-induced changes in subsurface fluid pressures have been reported. This poses a major threat to the future development of some of these operations and calls for an understanding and quantification of the seismicity generated. From geomechanical considerations and insights from laboratory experiments the factors controlling induced seismicity may be grouped into 4 categories; the magnitude of the stress disturbance, the pre-existing stress conditions, the reservoir/fault rock properties and the local geometry. We investigated whether the (relative) contributions of these factors and their influence on magnitudes generated could be recognized by looking at the entire dataset of reported cases of induced seismicity as a whole, and what this might imply for future developments. An extensive database has been built out of over a 160 known cases of induced seismicity worldwide, incorporating the relevant geological, seismological and fluid-related parameters. The cases studied include hydrocarbon depletion and secondary recovery, waste water injection, (enhanced) geothermal systems and hydraulic fracturing with observed magnitudes ranging from less than -1.5 to 7. The parameters taken into account were based on the theoretical background of the mechanisms of induced seismicity and include the injection/depletion-related parameters, (spatial) characteristics of seismicity, lithological properties and the local stress situation. Correlations between the seismic response and the geological/geomechanical characteristics of the various sites were investigated. The injected/depleted volumes and the scale of the activities are major controlling factors on the maximum magnitudes generated. Spatial signatures of seismicity such as the depth and lateral spread of the seismicity were observed to be distinct for different activities, which is useful when considering future operations. Where available the local

  3. Calculation notes that support accident scenario and consequence development for the subsurface leak remaining subsurface accident

    SciTech Connect

    Ryan, G.W., Westinghouse Hanford

    1996-07-12

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Subsurface Leak Remaining Subsurface. The calculations needed to quantify the risk associated with this accident scenario are included within.

  4. Calculation notes that support accident scenario and consequence development for the subsurface leak remaining subsurface accident

    SciTech Connect

    Ryan, G.W., Westinghouse Hanford

    1996-09-19

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Subsurface Leak Remaining Subsurface. The calculations needed to quantify the risk associated with this accident scenario are included within.

  5. Government Regulatory

    NASA Astrophysics Data System (ADS)

    Becker, Katie

    Government regulation of food products, food processing, and food preparation is imperative in bringing an unadulterated, nonmisleading, and safe food product to market and is relevant to all areas of food science, including engineering, processing, chemistry, and microbiology. The liability associated with providing consumers with an adulterated or substandard product cannot only tarnish a company's name and reputation, but also impose substantial financial repercussions on the company and those individuals who play an active role in the violation. In order for a company to fully comply with the relevant food laws (both federal and state), an intimate knowledge of food science is required. Individuals knowledgeable in food science play an integral role not only in implementing and counseling food companies/processors to ensure compliance with government regulations, but these individuals are also necessary to the state and federal governments that make and enforce the relevant laws and regulators.

  6. STOMP, Subsurface Transport Over Multiple Phases, theory guide

    SciTech Connect

    White, M.D.; Oostrom, M.

    1996-10-01

    This guide describes the simulator`s governing equations, constitutive functions and numerical solution algorithms of the STOMP (Subsurface Transport Over Multiple Phases) simulator, a scientific tool for analyzing multiple phase subsurface flow and transport. The STOMP simulator`s fundamental purpose is to produce numerical predictions of thermal and hydrologic flow and transport phenomena in variably saturated subsurface environments, which are contaminated with volatile or nonvolatile organic compounds. Auxiliary applications include numerical predictions of solute transport processes including radioactive chain decay processes. In writing these guides for the STOMP simulator, the authors have assumed that the reader comprehends concepts and theories associated with multiple-phase hydrology, heat transfer, thermodynamics, radioactive chain decay, and nonhysteretic relative permeability, saturation-capillary pressure constitutive functions. The authors further assume that the reader is familiar with the computing environment on which they plan to compile and execute the STOMP simulator. The STOMP simulator requires an ANSI FORTRAN 77 compiler to generate an executable code. The memory requirements for executing the simulator are dependent on the complexity of physical system to be modeled and the size and dimensionality of the computational domain. Likewise execution speed depends on the problem complexity, size and dimensionality of the computational domain, and computer performance. One-dimensional problems of moderate complexity can be solved on conventional desktop computers, but multidimensional problems involving complex flow and transport phenomena typically require the power and memory capabilities of workstation or mainframe type computer systems.

  7. Mars Subsurface Exploration Using Schumann Resonance

    NASA Astrophysics Data System (ADS)

    Kozakiewicz, Joanna; Kulak, Andrzej; Mlynarczyk, Janusz

    2014-05-01

    In a planetary environment, an electrically conductive ionosphere and ground create a spherical electromagnetic cavity. In this cavity, extremely low frequency (ELF, 3-3000 Hz) electromagnetic waves are weakly attenuated and can propagate around the globe producing global resonance. The extremely low frequency waves are generated by electrical discharges in planetary atmospheres. We have developed an analytical method that enables taking into account not only the electrical properties of the Martian ionosphere but also the Martian ground. This method allowed us to obtain the Schumann resonance frequencies and Q factors and analyze how they depend on the Martian environmental properties. We compared the results from our analytical model with previously published results from numerical modeling. In this work, we show that the Martian ground has a significant influence on the Schumann resonance parameters. Therefore, Schumann resonance can be used us a tool to study, not only the properties of the Martian atmosphere, but also the properties of the subsurface layers. It can be particularly useful in groundwater exploration. In order to study the influence of water on the Schumann resonance parameters on Mars, we assumed two cases of the Martian ground containing aquifers. In both cases, we considered the upper part of the Martian crust composed of porous basaltic rocks containing ice. Beneath this layer, we implemented water-bearing basalts. We assumed that ice and water contains some NaCl impurities or solutions. In the first case, we considered the low concentration of salts in ice and low-salinity water. In the second case, we assumed some high-impurity ice and brines. In order to compare the results of the above-mentioned cases with a situation in which the subsurface of Mars does not contain any water, we introduced the model of the Martian crust composed only of dry basaltic rocks. There are clear differences in the Schumann resonance parameters for the different

  8. Surface expressions of subsurface structures in parts of the Michigan and Illinois basins

    SciTech Connect

    Herman, J.D. )

    1991-08-01

    Study of glacial geology, stream drainage, bedrock topography, and subsurface structure maps in Isabella, Midland, Arenac, Gladwin, Clare, Ogemaw, Iosco, Mecosta, and Montcalm counties in Michigan revealed distinct correlations between patterns and types of glacial deposits and subsurface structures. Anticlinal structures associated with the Mt. Pleasant, North Buckeye, and South Buckeye, Hamilton, Deep River, Clayton, Logan, Six Lakes, and West Branch oil and gas fields occur along areas where northeast-trending glacial moraines and truncated, attenuated, or deviated. Furthermore, these anticlinal structures are associated with lacustrine sands and gravels and glacial outwash deposits nearly surrounded by glacial tills or lacustrine sands and clays. All of the anticlinal structures are associated with bedrock topography highs and alignment of streams parallel to the trends of the structures. Comparison of images of subsurface structure and surface elevation data covering the northern part of the illinois basin showed distinct correlations between glacial moraine patterns and subsurface structural trends. The Pesotum and Arcola end moraines bracket the major anticlinal structure at the Hayes oil field. The Westfield, Nevins, and Paris moraines are truncated or attenuated where they intersect the surface projections of the subsurface LaSalle anticlinal belt and the anticlinal structure associated with the Mattoon oil field. These correlations among subsurface structure, bedrock topography, and surface glacial features indicate that the subsurface structural configuration influenced glacial depositional patterns in detectable and predictable ways, even in areas blanketed by over 100 ft of Wisconsin glacial drift.

  9. Amino acid synthesis in Europa's subsurface environment

    NASA Astrophysics Data System (ADS)

    Abbas, Sam H.; Schulze-Makuch, Dirk

    2008-10-01

    It has been suggested that Europa's subsurface environment may provide a haven for prebiotic evolution and the development of exotic biotic systems. The detection of hydrogen peroxide, sulfuric acid, water, hydrates and related species on the surface, coupled with observed mobility of icebergs, suggests the presence of a substantial subsurface liquid reservoir that actively exchanges materials with the surface environment. The atmospheric, surface and subsurface environments are described with their known chemistry. Three synthetic schemes using hydrogen peroxide, sulfuric acid and hydrocyanic acid leading to the production of larger biologically important molecules such as amino acids are described. Metabolic pathways based on properties of the subsurface ocean environment are detailed. Tidal heating, osmotic gradients, chemical cycling, as well as hydrothermal vents, provide energy and materials that may support a course of prebiotic evolution leading to the development or sustenance of simple biotic systems. Putative organisms may employ metabolic pathways based on chemical oxidation reduction cycles occurring in the putative subsurface ocean environment.

  10. Reinventing government

    SciTech Connect

    Hanson, D.J.; Lepkowski, W.; Long, J.R.; Zurer, P.S.

    1993-10-11

    Both Clinton and Vice President Al Gore are committed to reinventing the federal government. To do so they will need more than a little help from Congress. But, if they succeed in turning the report's recommendations into reality, substantial change will occur in the way the federal government interacts with the chemical community in areas such as environmental and safety and health regulation, science and technology policy, education, and research priority setting. The report is the result of a six-month effort by the National Performance Review (NPR), a group led by Gore. It contains some 400 specific recommendations for changing the ways the federal government operates. These recommendations, if enacted the report claims, would produced savings of $108 billion over five years and reduce the size of the civilian, nonpostal work force by 12%, 252 positions, over the same period. The Department of Energy is the target of eight NPR recommendations. But the one with the most direct relevance to R and D calls for directing its national laboratories to pursue post-Cold War research priorities. Efforts to shift the labs away from their defense orientation began during the Carter presidency, when all of the labs began establishing stronger research programs in environmental science and technology and biology.

  11. Phosphorus Release to Floodwater from Calcareous Surface Soils and Their Corresponding Subsurface Soils under Anaerobic Conditions.

    PubMed

    Jayarathne, P D K D; Kumaragamage, D; Indraratne, S; Flaten, D; Goltz, D

    2016-07-01

    Enhanced phosphorus (P) release from soils to overlying water under flooded, anaerobic conditions has been well documented for noncalcareous and surface soils, but little information is available for calcareous and subsurface soils. We compared the magnitude of P released from 12 calcareous surface soils and corresponding subsurface soils to overlying water under flooded, anaerobic conditions and examined the reasons for the differences. Surface (0-15 cm) and subsurface (15-30 cm) soils were packed into vessels and flooded for 8 wk. Soil redox potential and concentrations of dissolved reactive phosphorus (DRP) and total dissolved Ca, Mg, Fe, and Mn in floodwater and pore water were measured weekly. Soil test P was significantly smaller in subsurface soils than in corresponding surface soils; thus, the P release to floodwater from subsurface soils was significantly less than from corresponding surface soils. Under anaerobic conditions, floodwater DRP concentration significantly increased in >80% of calcareous surface soils and in about 40% of subsurface soils. The increase in floodwater DRP concentration was 2- to 17-fold in surface soils but only 4- to 7-fold in subsurface soils. With time of flooding, molar ratios of Ca/P and Mg/P in floodwater increased, whereas Fe/P and Mn/P decreased, suggesting that resorption and/or reprecipitation of P took place involving Fe and Mn. Results indicate that P release to floodwater under anaerobic conditions was enhanced in most calcareous soils. Surface and subsurface calcareous soils in general behaved similarly in releasing P under flooded, anaerobic conditions, with concentrations released mainly governed by initial soil P concentrations. PMID:27380087

  12. Detecting NAPLs Heterogeneously Distributed in the Subsurface

    NASA Astrophysics Data System (ADS)

    Imhoff, P. T.; Pirestani, K.

    2004-12-01

    A particularly difficult task facing engineers and managers concerned with subsurface spills of nonaqueous phase liquids (NAPLs) is determining where the NAPL is and how much is there. Borrowing from past work in petroleum reservoir engineering, partitioning interwell tracer tests (PITT) were developed for characterizing the NAPL source zone and assessing the performance of remediation technologies. PITTs have been used to determine domain-average NAPL saturations as well as the spatial distribution of the NAPL. While these tracer tests work well when the NAPL is distributed uniformly throughout the domain, if NAPL is located nonuniformly, either as millimeter-scale ganglia or pools that are centimeter-scale and larger, the flow paths of the injected tracer solution may bypass NAPL-contaminated zones. In this case, the transfer of tracer mass from the main flow paths to the NAPL may be slow, resulting in extensive tailing of tracer breakthrough curves and underestimation of NAPL mass. In this work we examined the influence of nonuniform NAPL distribution and local-scale mass transfer resistance on the accuracy of measured NAPL saturations using PITTs. Two mathematical models were used along with laboratory column experiments to explore the influence of tracer partition coefficient, tracer detection limit, and injected tracer mass on NAPL measurement when the NAPL was distributed nonuniformly. When dimensionless mass transfer coefficients were small, NAPL measurement errors decreased with decreasing tracer partition coefficient, decreasing tracer detection limit, and increasing injected tracer mass. Extrapolating breakthrough curves exponentially reduced but did not eliminate systematic errors in NAPL measurement. Although transport in a single stream tube was used in the mathematical models and laboratory experiments, the results from this simplified domain were supported by data taken from a three-dimensional computational experiment, where the NAPL resided as

  13. Subsurface Explosions in Granular Media

    NASA Astrophysics Data System (ADS)

    Lai, Shuyue; Houim, Ryan; Oran, Elaine

    2015-11-01

    Numerical simulations of coupled gas-granular flows are used to study properties of shock formation and propagation in media, such as sand or regolith on the moon, asteroids, or comets. The simulations were performed with a multidimensional fully compressible model, GRAF, which solves two sets of coupled Navier-Stokes equations, one for the gas and one for the granular medium. The specific case discussed here is for a subsurface explosion in a granular medium initiated by an equivalent of 200g of TNT in depths ranging from 0.1m to 3m. The background conditions of 100K, 10 Pa and loose initial particle volume fraction of 25% are consistent with an event on a comet. The initial blast creates a cavity as a granular shock expands outwards. Since the gas-phase shock propagates faster than the granular shock in loose, granular material, some gas and particles are ejected before the granular shock arrives. When the granular shock reaches the surface, a cap-like structure forms. This cap breaks and may fall back on the surface and in this process, relatively dense particle clusters form. At lower temperatures, the explosion timescales are increased and entrained particles are more densely packed.

  14. Uranium Biomineralization By Natural Microbial Phosphatase Activities in the Subsurface

    SciTech Connect

    Taillefert, Martial

    2015-04-01

    This project investigated the geochemical and microbial processes associated with the biomineralization of radionuclides in subsurface soils. During this study, it was determined that microbial communities from the Oak Ridge Field Research subsurface are able to express phosphatase activities that hydrolyze exogenous organophosphate compounds and result in the non-reductive bioimmobilization of U(VI) phosphate minerals in both aerobic and anaerobic conditions. The changes of the microbial community structure associated with the biomineralization of U(VI) was determined to identify the main organisms involved in the biomineralization process, and the complete genome of two isolates was sequenced. In addition, it was determined that both phytate, the main source of natural organophosphate compounds in natural environments, and polyphosphate accumulated in cells could also be hydrolyzed by native microbial population to liberate enough orthophosphate and precipitate uranium phosphate minerals. Finally, the minerals produced during this process are stable in low pH conditions or environments where the production of dissolved inorganic carbon is moderate. These findings suggest that the biomineralization of U(VI) phosphate minerals is an attractive bioremediation strategy to uranium bioreduction in low pH uranium-contaminated environments. These efforts support the goals of the SBR long-term performance measure by providing key information on "biological processes influencing the form and mobility of DOE contaminants in the subsurface".

  15. Subsurface Biogeochemical Research FY11 Second Quarter Performance Measure

    SciTech Connect

    Scheibe, Timothy D.

    2011-03-31

    The Subsurface Biogeochemical Research (SBR) Long Term Measure for 2011 under the Performance Assessment Rating Tool (PART) measure is to "Refine subsurface transport models by developing computational methods to link important processes impacting contaminant transport at smaller scales to the field scale." The second quarter performance measure is to "Provide a report on computational methods linking genome-enabled understanding of microbial metabolism with reactive transport models to describe processes impacting contaminant transport in the subsurface." Microorganisms such as bacteria are by definition small (typically on the order of a micron in size), and their behavior is controlled by their local biogeochemical environment (typically within a single pore or a biofilm on a grain surface, on the order of tens of microns in size). However, their metabolic activity exerts strong influence on the transport and fate of groundwater contaminants of significant concern at DOE sites, in contaminant plumes with spatial extents of meters to kilometers. This report describes progress and key findings from research aimed at integrating models of microbial metabolism based on genomic information (small scale) with models of contaminant fate and transport in aquifers (field scale).

  16. Understanding fast heat transfer in the shallow subsurface

    NASA Astrophysics Data System (ADS)

    Rutten, Martine; Steele-Dunne, Susan; Judge, Jasmeet; van de Giesen, Nick

    2010-05-01

    Understanding the temperature profile of the shallow subsurface is of great importance for interpreting remote sensing observations and modeling land-atmosphere interaction. Remote sensing observations are translated to surface characteristics, such as vegetation and soil moisture, using radiative transfer schemes that are sensitive to skin temperature estimation. The surface temperature is also a key variable in the heat partitioning of net radiation into sensible, latent and soil heat flux at the interface between land and atmosphere. The temperature profile of the soil is determined by the processes of radiative, convective and conductive heat transfer. Whereas radiative and convective heat transfer are dominant at the soil-air interface, heat transfer within the soil is typically assumed to be governed by conduction and as such is described with a diffusion model. The thermal diffusivity of the soil depends mainly on mineral composition and moisture content and is described in many empirical models. Using temperature data from experiments conducted in Florida (MicroWex 2) and the Netherlands (Monster), we show that diffusion cannot describe heat transfer within approximately the upper ten centimeters of the soil. The heat transfer is significantly faster than would be predicted with a diffusion equation. Diffusivity values, estimated using an inversion approach to the diffusion equation, fall outside the physically reasonable range, which is defined by available soil diffusivity models. The extent of this strongly thermally active layer depends on vegetation conditions, and possibly moisture conditions. We investigate mechanisms that may explain the fast heat transfer in the shallow subsurface. Possible mechanisms include heat transfer by convective heat transfer processes such as latent heat formation and heat transfer due to water percolation. We estimated the size of the heat sink-source at depth and compared these to observations of latent heat and

  17. The role of subsurface soil temperature feedbacks in summer surface air temperature variability over East Asia

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2012-12-01

    Soil temperature, an important component of land surface, can influence the climate through its effects on surface energy and water budgets and resulted changes in regional atmospheric circulation. However, the effects of soil temperature on climate variations have been less discussed. This study investigates the role of subsurface soil temperature feedbacks in influencing summer surface air temperature variability over East Asia by means of regional climate model (RCM) simulations. For this aim, two long-term simulations with and without subsurface soil temperature feedbacks are performed with the Weather Research and Forecasting (WRF) model. From our investigation, it is evident that subsurface soil temperature feedbacks make a dominant contribution to amplifying summer surface air temperature variability over the arid/semi-arid regions. Further analysis reveals that subsurface soil temperature exhibits an asymmetric effect on summer daytime and nighttime surface air temperature variability, with a stronger effect on daily minimum temperature variability than that of daily maximum temperature variability. This study provides the first RCM-based demonstration that subsurface soil temperature feedbacks play an important role in influencing climate variability over East Asia, such as summer surface air temperature. In the meanwhile, the model bias should be recognized. The results achieved by this study thus need to be further confirmed in a multi-model framework to eliminate the model dependence.

  18. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    SciTech Connect

    D.C. Randle

    2000-01-07

    The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I&C) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I&C and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I&C systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I&C systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored, controlled, and

  19. DOE UST interim subsurface barrier technologies workshop

    SciTech Connect

    1992-09-01

    This document contains information which was presented at a workshop regarding interim subsurface barrier technologies that could be used for underground storage tanks, particularly the tank 241-C-106 at the Hanford Reservation.

  20. Plants as ecosystem engineers in subsurface-flow treatment wetlands.

    PubMed

    Tanner, C C

    2001-01-01

    Mass balance performance data from side by side studies of planted and unplanted gravel-bed treatment wetlands with horizontal subsurface-flow are compared. Planted systems showed enhanced nitrogen and initial phosphorus removal, but only small improvements in disinfection, BOD, COD and suspended solids removal. Direct nutrient uptake by plants was insufficient to account for more than a fraction of the improved removal shown by planted systems. Roles of plants as ecosystem engineers are summarised, with organic matter production and root-zone oxygen release identified as key factors influencing nutrient transformation and sequestration. PMID:11804163

  1. Phylogenetic relationships among subsurface microorganisms

    SciTech Connect

    Nierzwicki-Bauer, S.A.

    1991-01-01

    This report summarizes the progress made from 6/90--3/91 toward completion of our project, Phylogenetic Relationships among subsurface microorganisms. 16S rRNA was sequenced, and based on the sequence the SMCC isolates were assigned to preliminary groups. Microorganisms were obtained at various depths at the Savannah River Site, including the Surface (0 m), Congaree (91 m), and Middendorf (244 m, 259 m, 265 m). Sequence data from four isolates from the Congaree formation indicate these microorganisms can be divided into Pseudomonas spp. or Acinetobacter spp. Three 16S rRNA probes were synthesized based on sequence data. The synthesized probes were tested through in situ hybridization. Optimal conditions for in situ hybridization were determined. Because stability of RNA-DNA hybrids is dependent on hybridization stringency, related organisms can be differentiated using a single probe under different strigencies. The results of these hybridizations agree with results obtained by Balkwill and Reeves using restriction fragment length polymorphism analysis. The RNA content of a cell reflects its metabolic state. Cells which are starved for four days are not detectable with the homologous 16S rRNA probe. However, within 15 minutes of refeeding, detectable rRNA appeared. This suggests that organisms which are undetectable in environmental samples due to starvation may be detectable after addition of nutrients. Stepwise addition of specific nutrients could indicate which nutrients are rate limiting for growth. Preliminary experiments with soil samples from the Hanford Site indicate indigenous microorganisms can be detected by oligionucleotide probes. Further, using multiple probes based on universal sequences increases the number of organisms detected. Double label experiments, using a rhodamine-labelled oligionucleotide probe with free coumarin succinimidyl ester will allow simultaneous detection of total bacteria and specific 16S rRNA containing bacteria. 4 tabs. (MHB)

  2. Floating insulated conductors for heating subsurface formations

    SciTech Connect

    Burns, David; Goodwin, Charles R.

    2014-07-29

    A heating system for a subsurface formation includes a conduit located in a first opening in the subsurface formation. Three electrical conductors are located in the conduit. A return conductor is located inside the conduit. The return conductor is electrically coupled to the ends of the electrical conductors distal from the surface of the formation. Insulation is located inside the conduit. The insulation electrically insulates the three electrical conductors, the return conductor, and the conduit from each other.

  3. Microbial life in the deep terrestrial subsurface

    SciTech Connect

    Fliermans, C.B.; Balkwill, D.L.; Beeman, R.E.

    1988-12-31

    The distribution and function of microorganisms is a vital issue in microbial ecology. The US Department of Energy`s Program, ``Microbiology of the Deep Subsurface,`` concentrates on establishing fundamental scientific information about organisms at depth, and the use of these organisms for remediation of contaminants in deep vadose zone and groundwater environments. This investigation effectively extends the Biosphere hundreds of meters into the Geosphere and has implications to a variety of subsurface activities.

  4. Revisiting subsurface chlorophyll and phytoplankton distributions

    NASA Astrophysics Data System (ADS)

    Hense, I.; Beckmann, A.

    2008-09-01

    Vertical profiles of chlorophyll concentration and phytoplankton biomass at ALOHA (HOT) are analyzed for the time period 1988 to 2004. Two different methods are applied: in the standard approach the data are averaged over depth horizons and in the alternative approach the profiles are shifted to the depth of the deepest subsurface maximum before averaging. The results show that the latter is the only meaningful way to look at vertical distribution patterns of both chlorophyll and phytoplankton in the oligotrophic ocean. In particular, a pronounced subsurface maximum of phytoplankton biomass appears only if this depth-adjustment method is used. Otherwise the vertical displacement of the subsurface biomass due to changes in the subsurface light field masks the actual signal: the thickness of the subsurface maximum is overestimated and the maximum is reduced. The results of this study have far-reaching consequences for the interpretation of the large number of profiles of chlorophyll and phytoplankton in the oligotrophic ocean. The absence of a subsurface biomass maximum might not be necessarily a result of photoacclimation but of inadequate analyses combined with coarse vertical resolution.

  5. An exploration of coupled surface-subsurface solute transport in a fully integrated catchment model

    NASA Astrophysics Data System (ADS)

    Liggett, Jessica E.; Partington, Daniel; Frei, Sven; Werner, Adrian D.; Simmons, Craig T.; Fleckenstein, Jan H.

    2015-10-01

    Coupling surface and subsurface water flow in fully integrated hydrological codes is becoming common in hydrological research; however, the coupling of surface-subsurface solute transport has received much less attention. Previous studies on fully integrated solute transport focus on small scales, simple geometric domains, and have not utilised many different field data sources. The objective of this study is to demonstrate the inclusion of both flow and solute transport in a 3D, fully integrated catchment model, utilising high resolution observations of dissolved organic carbon (DOC) export from a wetland complex during a rainfall event. A sensitivity analysis is performed to span a range of transport conditions for the surface-subsurface boundary (e.g. advective exchange only, advection plus diffusion, advection plus full mechanical dispersion) and subsurface dispersivities. The catchment model captures some aspects of observed catchment behaviour (e.g. solute discharge at the catchment outlet, increasing discharge from wetlands with increased stream discharge, and counter-clockwise concentration-discharge relationships), although other known behaviours are not well represented in the model (e.g. slope of concentration-discharge plots). Including surface-subsurface solute transport aids in evaluating internal model processes, however there are challenges related to the influence of dispersion across the surface-subsurface interface, and non-uniqueness of the solute transport solution. This highlights that obtaining solute field data is especially important for constraining integrated models of solute transport.

  6. Mediterranean subsurface circulation estimated from Argo data in 2003-2009

    NASA Astrophysics Data System (ADS)

    Menna, M.; Poulain, P. M.

    2009-11-01

    Data from 38 Argo profiling floats are used to describe the subsurface Mediterranean currents for the period 2003-2009. These floats were programmed to execute 5-day cycles, to drift at a neutral parking depth of 350 m and measure temperature and salinity profiles from either 700 or 2000 m up to the surface. At the end of each cycle the floats remained at the sea surface for about 6 h, enough time to be localised and transmit the data to the Argos satellite system. The Argos positions were used to determine the float surface and subsurface displacements. At the surface, the float motion was approximated by a linear displacement and inertial motion. Subsurface velocities estimates were used to investigate the Mediterranean circulation at 350 m, to compute the pseudo-Eulerian statistics and to study the influence of bathymetry on the subsurface currents. Maximum speeds, as large as 33 cm/s, were found northeast of the Balearic Islands (Western basin) and in the Ierapetra eddy (Eastern basin). Typical speeds in the main along-slope currents (Liguro-Provençal-Catalan, Algerian and Libyo-Egyptian Currents) were ~20 cm/s. In the best sampled regions, the pseudo-Eulerian statistics show typical subsurface circulation pathways which can be related to the motion of Levantine Intermediate Water. In general our results agree with the qualitative subsurface circulation schemes proposed in the literature, except in the southern Ionian where we found westward-flowing subsurface currents. Fluctuating currents appeared to be usually larger than the mean flow. Subsurface currents were found to be essentially parallel to the isobaths over most of the areas characterized by strong bathymetry gradients, in particular, in the vicinity of the continental slopes.

  7. The Mexican Coastal Current: A subsurface seasonal bridge that connects the tropical and subtropical Northeastern Pacific

    NASA Astrophysics Data System (ADS)

    Gómez-Valdivia, F.; Parés-Sierra, A.; Flores-Morales, A. L.

    2015-11-01

    We used a three-dimensional numerical model to analyze the seasonal variability of the coastal circulation off SW Mexico. In agreement with previous research, our model reproduced a Mexican Coastal Current (MCC) that dominates the regional poleward circulation. The modeled dynamics evidenced an energetic semiannual component that governed the subsurface seasonal variability of this poleward flow. Below the thermocline the MCC was stronger during spring and fall, when it reached subsurface seasonal-averaged velocities of ∼10 cms-1 and flowed continuously from the Gulf of Tehuantepec to the entrance of the Gulf of California. There, the subsurface MCC bifurcated in one branch that continued along the coast of mainland Mexico and a second branch that crossed the gulf and joined the California Undercurrent. Instead of the local wind, the semiannual MCC variability was induced by the transit of equatorial Kelvin waves whose upwelling (downwelling) phase propagation strengthen (weakened) the subsurface poleward circulation along the Tropical Pacific off Mexico. The MCC dynamics reported in this study accounts for the, previously reported, semiannual variability of the alongshore transport and salinity content in the southern Gulf of California. Moreover, the subsurface bridge between the MCC and the California Current System represents an external source of momentum that helps to explain the intensification of the California Undercurrent during spring and fall.

  8. Geophysical subsurface imaging and interface identification.

    SciTech Connect

    Pendley, Kevin; Bochev, Pavel Blagoveston; Day, David Minot; Robinson, Allen Conrad; Weiss, Chester Joseph

    2005-09-01

    Electromagnetic induction is a classic geophysical exploration method designed for subsurface characterization--in particular, sensing the presence of geologic heterogeneities and fluids such as groundwater and hydrocarbons. Several approaches to the computational problems associated with predicting and interpreting electromagnetic phenomena in and around the earth are addressed herein. Publications resulting from the project include [31]. To obtain accurate and physically meaningful numerical simulations of natural phenomena, computational algorithms should operate in discrete settings that reflect the structure of governing mathematical models. In section 2, the extension of algebraic multigrid methods for the time domain eddy current equations to the frequency domain problem is discussed. Software was developed and is available in Trilinos ML package. In section 3 we consider finite element approximations of De Rham's complex. We describe how to develop a family of finite element spaces that forms an exact sequence on hexahedral grids. The ensuing family of non-affine finite elements is called a van Welij complex, after the work [37] of van Welij who first proposed a general method for developing tangentially and normally continuous vector fields on hexahedral elements. The use of this complex is illustrated for the eddy current equations and a conservation law problem. Software was developed and is available in the Ptenos finite element package. The more popular methods of geophysical inversion seek solutions to an unconstrained optimization problem by imposing stabilizing constraints in the form of smoothing operators on some enormous set of model parameters (i.e. ''over-parametrize and regularize''). In contrast we investigate an alternative approach whereby sharp jumps in material properties are preserved in the solution by choosing as model parameters a modest set of variables which describe an interface between adjacent regions in physical space. While

  9. The Influence of E-Learning on Individual and Collective Empowerment in the Public Sector: An Empirical Study of Korean Government Employees

    ERIC Educational Resources Information Center

    Hur, Mann Hyung; Im, Yeonwook

    2013-01-01

    Our study explores the influence of e-learning on individual and collective empowerment by using data collected from e-learning class participants of Korea's Cyber-Education Center. For the survey, a questionnaire was sent to each of the 41 central ministries' education and training officers (ETO) via email. The ETOs distributed the…

  10. Factors Influencing the Use of Information and Communication Technology (ICT) in Teaching and Learning Computer Studies in Ohaukwu Local Government Area of Ebonyi State-Nigeria

    ERIC Educational Resources Information Center

    Agbo, Igwe Sylvester

    2015-01-01

    Research studies in the past years show that Information and Communication Technology is an effective means for boasting educational opportunities, but most teachers neither use this technology as an instructional delivery system nor integrate technology into their curriculum. Studies reveal a number of factors influencing teachers' decisions to…

  11. CSMOS GROUNDWATER MODELING SOFTWARE (CENTER FOR SUBSURFACE MODELING SUPPORT, SUBSURFACE PROTECTION AND REMEDIATION DIVISION, NRMRL)

    EPA Science Inventory

    The Center for Subsurface Modeling Support (CSMoS), which is part of NRMRL's Subsurface Protection and Remediation Division, distributes various public domain groundwater and vadose zone models. A short decription of each model is available. You can obtain both models and manuals...

  12. QUANTIFYING SUBSURFACE HYDROLOGY WITH GROUND PENETRATING RADAR AND AGRICULTURAL MONITORING DATA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrology, especially subsurface-water flow can influence crop growth patterns within a production field as well as the fate of surface-applied fertilizers and pesticides migrating thru agricultural land. Ground-penetrating radar (GPR) and digital elevation maps (DEM) were used to locate and quanti...

  13. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    SciTech Connect

    C.J. Fernado

    1998-09-17

    The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I&C) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I&C and will typically be integrated over a data communication network. The subsurface I&C systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures that

  14. Wave-Based Subsurface Guide Star

    SciTech Connect

    Lehman, S K

    2011-07-26

    Astronomical or optical guide stars are either natural or artificial point sources located above the Earth's atmosphere. When imaged from ground-based telescopes, they are distorted by atmospheric effects. Knowing the guide star is a point source, the atmospheric distortions may be estimated and, deconvolved or mitigated in subsequent imagery. Extending the guide star concept to wave-based measurement systems to include acoustic, seismo-acoustic, ultrasonic, and radar, a strong artificial scatterer (either acoustic or electromagnetic) may be buried or inserted, or a pre-existing or natural sub-surface point scatterer may be identified, imaged, and used as a guide star to determine properties of the sub-surface volume. That is, a data collection is performed on the guide star and the sub-surface environment reconstructed or imaged using an optimizer assuming the guide star is a point scatterer. The optimization parameters are the transceiver height and bulk sub-surface background refractive index. Once identified, the refractive index may be used in subsequent reconstructions of sub-surface measurements. The wave-base guide star description presented in this document is for a multimonostatic ground penetrating radar (GPR) but is applicable to acoustic, seismo-acoustic, and ultrasonic measurement systems operating in multimonostatic, multistatic, multibistatic, etc., modes.

  15. Subsurface Shielding Source Term Specification Calculation

    SciTech Connect

    S.Su

    2001-04-12

    The purpose of this calculation is to establish appropriate and defensible waste-package radiation source terms for use in repository subsurface shielding design. This calculation supports the shielding design for the waste emplacement and retrieval system, and subsurface facility system. The objective is to identify the limiting waste package and specify its associated source terms including source strengths and energy spectra. Consistent with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001, p. 15), the scope of work includes the following: (1) Review source terms generated by the Waste Package Department (WPD) for various waste forms and waste package types, and compile them for shielding-specific applications. (2) Determine acceptable waste package specific source terms for use in subsurface shielding design, using a reasonable and defensible methodology that is not unduly conservative. This calculation is associated with the engineering and design activity for the waste emplacement and retrieval system, and subsurface facility system. The technical work plan for this calculation is provided in CRWMS M&O 2001. Development and performance of this calculation conforms to the procedure, AP-3.12Q, Calculations.

  16. DWH MC 252: Subsurface Oil Transport

    NASA Astrophysics Data System (ADS)

    Beegle-Krause, C. J.; Boyer, T.; Murray, D.

    2010-12-01

    Before reaching the ocean surface, the oil and gas released from the DWH MC 252 blowout at 1500 m moves as a buoyant plume until the trapping depth and plume transition point are reached (Zheng et al 2002). At the transition point, the oil droplets and bubbles move independently of each other, and rise at a rate related to their diameter. The oil density, droplet size distribution and currents primarily determine the distribution of the oil between: Large droplets that rise quickly and create a surface expression of the oil. Moderate size droplets that rise over the course of days, and so spread out quite differently than the surface oil, and commonly do not reach the surface in large enough quantities to create a surface sheen. These droplets separate in the currents, particularly in the strong current shear in upper 500 m currents. Very tiny droplets that rise very slowly, over the course or weeks to months, and may be removed by dissolution, biodegradation or marine snow before ever reaching the surface. Modeling and observations (Joint Analysis Group, 2010) confirm the presence of a deep layer of oil and gas between approximately 1100 and 1300 m over the release location and spreading out along the isopycnal surfaces. Later in the event, a small oxygen depression was a proxy for where oil and gas had been. The DWH MC252 well is located at intermediate depth in the Gulf of Mexico (GoM). The water mass is Antarctic Intermediate Water, which enters and exits the GoM through the Yucatan Straits. Surface influences, such as Loop Current Frontal Eddies (e.g. Berger et al 2000) can reach down to these depths, and alter the flow within De Soto Canyon. The water mass containing the deep layer of oil droplets changes depth within the GoM, but does not reach above a depth of about 900 m. There are no physical processes that could cause this deep layer of oil to reach the continental shelf or the Florida Straits. Observed and historical hydrographic data, observations

  17. Linking subsurface temperature and hillslope processes through geologic time

    NASA Astrophysics Data System (ADS)

    Barnhart, Katherine; Anderson, Robert

    2015-04-01

    Many periglacial hillslope processes - physical, chemical, and biological - depend on subsurface temperature and water availability. As the subsurface temperature field varies both in space and through time over many scales up to climate cycles, the dominant processes of mobile regolith production and transport and the rate at which they act will vary. These processes include the chemical weathering of minerals, cracking of rocks through frost action and tree roots, presence and impact of vegetation on soil cohesion, location and activity of burrowing and trampling animals, frost creep, and solifluction. In order to explore the interplay between these processes across a landscape over the geologic timescales on which such landscapes evolve, we explore the effects of slope, aspect, latitude, atmosphere, and time before present on the expected energy balance at the surface of the earth and the resulting subsurface temperature field. We begin by calculating top-of-atmosphere insolation at any time in the Quaternary, honoring the variations in orbit over Milankovitch timescales. We then incorporate spatial and temporal variations in incoming short-wave radiation on sub-daily timescales due to elevation, latitude, aspect, and shading. Outgoing long-wave radiation is taken to depend on the surface temperature and may be modified by allowing back-radiation from the atmosphere. We then solve for the subsurface temperature field using a numerical model that acknowledges depth-varying material properties, water content, and phase change. With these tools we target variations in regolith production and motion over the long timescales on which periglacial hillslopes evolve. We implement a basic parameterization of temperature-dependent chemical and physical weathering linked to mobile regolith generation. We incorporate multiple regolith transport processes including frost heave and creep. Our intention is not to parameterize all operative processes, but to include sufficient

  18. Survival and Phospholipid Fatty Acid Profiles of Surface and Subsurface Bacteria in Natural Sediment Microcosms

    PubMed Central

    Kieft, T. L.; Wilch, E.; O'Connor, K.; Ringelberg, D. B.; White, D. C.

    1997-01-01

    Although starvation survival has been characterized for many bacteria, few subsurface bacteria have been tested, and few if any have been tested in natural subsurface porous media. We hypothesized that subsurface bacteria may be uniquely adapted for long-term survival in situ. We further hypothesized that subsurface conditions (sediment type and moisture content) would influence microbial survival. We compared starvation survival capabilities of surface and subsurface strains of Pseudomonas fluorescens and a novel Arthrobacter sp. in microcosms composed of natural sediments. Bacteria were incubated for up to 64 weeks under saturated and unsaturated conditions in sterilized microcosms containing either a silty sand paleosol (buried soil) or a sandy silt nonpaleosol sediment. Direct counts, plate counts, and cell sizes were measured. Membrane phospholipid fatty acid (PLFA) profiles were quantified to determine temporal patterns of PLFA stress signatures and differences in PLFAs among strains and treatments. The Arthrobacter strains survived better than the P. fluorescens strains; however, differences in survival between surface and subsurface strains of each genus were not significant. Bacteria survived better in the paleosol than in the nonpaleosol and survived better under saturated conditions than under unsaturated conditions. Cell volumes of all strains decreased; however, sediment type and moisture did not influence rates of miniaturization. Both P. fluorescens strains showed PLFA stress signatures typical for gram-negative bacteria: increased ratios of saturated to unsaturated fatty acids, increased ratios of trans- to cis-monoenoic fatty acids, and increased ratios of cyclopropyl to monoenoic precursor fatty acids. The Arthrobacter strains showed few changes in PLFAs. Environmental conditions strongly influenced PLFA profiles. PMID:16535578

  19. Survival and phospholipid fatty acid profiles of surface and subsurface bacteria in natural sediment microcosms

    SciTech Connect

    Kieft, T.L.; Wilch, E.; O`Connor, K.

    1997-04-01

    Although starvation survival has been characterized for many bacteria, few subsurface bacteria have been tested, and few if any have been tested in natural subsurface porous media. We hypothesized that subsurface bacteria may be uniquely adapted for long-term survival in situ. We further hypothesized that subsurface conditions (sediment type and moisture content) would influence microbial survival. We compared starvation survival capabilities of surface and subsurface strains of Pseudomonas fluorescens and a novel Arthrobacter sp. in microcosms composed of natural sediments. Bacteria were incubated for up to 64 weeks under saturated and unsaturated conditions in sterilized microcosms containing either a silty sand paleosol (buried soil) or a sandy silt nonpaleosol sediment. Direct counts, plate counts, and cell sizes were measured. Membrane phospholipid fatty acid (PLFA) profiles were quantified to determine temporal patterns of PLFA stress signatures and differences in PLFAs among strains and treatments. The Arthrobacter strains survived better than the P. fluorescens strains; however, differences in survival between surface and subsurface strains of each genus were not significant. Bacteria survived better in the paleosol than in the nonpaleosol and survived better under saturated conditions than under unsaturated conditions. Cell volumes of all strains decreased; however, sediment type and moisture did not influence rates of miniaturization. Both P.fluorescens strains showed PLFA stress signatures typical for gram-negative bacteria: increased ratios of saturated to unsaturated fatty acids, increased ratios of trans- to cis-monoenoic fatty acids, and increased ratios of cyclopropyl to monoenoic precursor fatty acids. The Arthrobacter strains showed few changes in PLFAs. Environmental conditions strongly influenced PLFA profiles. 40 refs., 7 figs.

  20. Urban heat island in the subsurface

    NASA Astrophysics Data System (ADS)

    Ferguson, Grant; Woodbury, Allan D.

    2007-12-01

    The urban heat island effect has received significant attention in recent years due to the possible effect on long-term meteorological records. Recent studies of this phenomenon have suggested that this may not be important to estimates of regional climate change once data are properly corrected. However, surface air temperatures within urban environments have significant variation, making correction difficult. In the current study, we examine subsurface temperatures in an urban environment and the surrounding rural area to help characterize the nature of this variability. The results of our study indicate that subsurface temperatures are linked to land-use and supports previous work indicating that the urban heat island effect has significant and complex spatial variability. In most situations, the relationship between subsurface and surface processes cannot be easily determined, indicating that previous studies that relying on such a linkage may require further examination.

  1. Tidal response of Europa's subsurface ocean

    NASA Astrophysics Data System (ADS)

    Karatekin, Özgür; Comblen, Richard; Toubeau, Jonathan; Deleersnijder, Eric; van Hoolst, Tim; Dehant, Veronique

    2010-05-01

    Observations of Cassini and Galileo spacecrafts suggest the presence of subsurface global water oceans under the icy shells of several satellites of Jupiter and Saturn. Previous studies have shown that in the presence of subsurface oceans, time-variable tides cause large periodic surface displacements and that tidal dissipation in the icy shell becomes a major energy source that can affect long-term orbital evolution. However, in most studies so far, the dynamics of these satellite oceans have been neglected. In the present study, we investigate the tidal response of the subsurface ocean of Europa to a time-varying potential. Two-dimensional nonlinear shallow water equations are solved on a sphere by means of a finite element code. The resulting ocean tidal flow velocities and surface displacements will be presented.

  2. Subsurface Contaminants Focus Area annual report 1997

    SciTech Connect

    1997-12-31

    In support of its vision for technological excellence, the Subsurface Contaminants Focus Area (SCFA) has identified three strategic goals. The three goals of the SCFA are: Contain and/or stabilize contamination sources that pose an imminent threat to surface and ground waters; Delineate DNAPL contamination in the subsurface and remediate DNAPL-contaminated soils and ground water; and Remove a full range of metal and radionuclide contamination in soils and ground water. To meet the challenges of remediating subsurface contaminants in soils and ground water, SCFA funded more than 40 technologies in fiscal year 1997. These technologies are grouped according to the following product lines: Dense Nonaqueous-Phase Liquids; Metals and Radionuclides; Source Term Containment; and Source Term Remediation. This report briefly describes the SCFA 1997 technologies and showcases a few key technologies in each product line.

  3. Autonomous microexplosives subsurface tracing system final report.

    SciTech Connect

    Engler, Bruce Phillip; Nogan, John; Melof, Brian Matthew; Uhl, James Eugene; Dulleck, George R., Jr.; Ingram, Brian V.; Grubelich, Mark Charles; Rivas, Raul R.; Cooper, Paul W.; Warpinski, Norman Raymond; Kravitz, Stanley H.

    2004-04-01

    The objective of the autonomous micro-explosive subsurface tracing system is to image the location and geometry of hydraulically induced fractures in subsurface petroleum reservoirs. This system is based on the insertion of a swarm of autonomous micro-explosive packages during the fracturing process, with subsequent triggering of the energetic material to create an array of micro-seismic sources that can be detected and analyzed using existing seismic receiver arrays and analysis software. The project included investigations of energetic mixtures, triggering systems, package size and shape, and seismic output. Given the current absence of any technology capable of such high resolution mapping of subsurface structures, this technology has the potential for major impact on petroleum industry, which spends approximately $1 billion dollar per year on hydraulic fracturing operations in the United States alone.

  4. Complete Subsurface Elemental Composition Measurements With PING

    NASA Technical Reports Server (NTRS)

    Parsons, A. M.

    2012-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument will measure the complete bulk elemental composition of the subsurface of Mars as well as any other solid planetary body. PING can thus be a highly effective tool for both detailed local geochemistry science investigations and precision measurements of Mars subsurface reSOurces in preparation for future human exploration. As such, PING is thus fully capable of meeting a majority of both ncar and far term elements in Challenge #1 presented for this conference. Measuring the ncar subsurface composition of Mars will enable many of the MEPAG science goals and will be key to filling an important Strategic Knowledge Gap with regard to In situ Resources Utilization (ISRU) needs for human exploration. [1, 2] PING will thus fill an important niche in the Mars Exploration Program.

  5. Microbial activities in deep subsurface environments

    SciTech Connect

    Phelps, T.J.; Raione, E.G.; White, D.C. |; Fliermans, C.B.

    1988-12-31

    Activities of microorganisms residing in terrestrial deep subsurface sediments were examined in forty-six sediment samples from three aseptically sampled boreholes. Radiolabeled time course experiments assessing in situ microbial activities were initiated within 30 minutes of core recovery. [{sup 14}C-1-] Acetate incorporation into lipids. [methyl-{sup 3}H-]thymidine incorporation into DNA, [{sup 14}C-2-]acetate and [{sup 14}C-U-]glucose mineralization in addition to microbial enrichment and enumeration studies were examined in surface and subsurface sediments. Surface soils contained the greatest biomass and activities followed by the shallow aquifer zones. Water saturated subsurface sediments exhibited three to four orders of magnitude greater activity and culturable microorganisms than the dense clay zones. Regardless of depth, sediments which contained more than 20% clays exhibited the lowest activities and culturable microorganisms.

  6. Improving the biodegradative capacity of subsurface bacteria

    SciTech Connect

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  7. MSTS - Multiphase Subsurface Transport Simulator theory manual

    SciTech Connect

    White, M.D.; Nichols, W.E.

    1993-05-01

    The US Department of Energy, through the Yucca Mountain Site Characterization Project Office, has designated the Yucca Mountain site in Nevada for detailed study as the candidate US geologic repository for spent nuclear fuel and high-level radioactive waste. Site characterization will determine the suitability of the Yucca Mountain site for the potential waste repository. If the site is determined suitable, subsequent studies and characterization will be conducted to obtain authorization from the Nuclear Regulatory Commission to construct the potential waste repository. A principal component of the characterization and licensing processes involves numerically predicting the thermal and hydrologic response of the subsurface environment of the Yucca Mountain site to the potential repository over a 10,000-year period. The thermal and hydrologic response of the subsurface environment to the repository is anticipated to include complex processes of countercurrent vapor and liquid migration, multiple-phase heat transfer, multiple-phase transport, and geochemical reactions. Numerical simulators based on mathematical descriptions of these subsurface phenomena are required to make numerical predictions of the thermal and hydrologic response of the Yucca Mountain subsurface environment The engineering simulator called the Multiphase Subsurface Transport Simulator (MSTS) was developed at the request of the Yucca Mountain Site Characterization Project Office to produce numerical predictions of subsurface flow and transport phenomena at the potential Yucca Mountain site. This document delineates the design architecture and describes the specific computational algorithms that compose MSTS. Details for using MSTS and sample problems are given in the {open_quotes}User`s Guide and Reference{close_quotes} companion document.

  8. Radar Soundings of the Subsurface of Mars

    NASA Technical Reports Server (NTRS)

    Picardi, Giovanni; Plaut, Jeffrey J.; Biccari, Daniela; Bombaci, Ornella; Calabrese, Diego; Cartacci, Marco; Cicchetti, Andrea; Clifford, Stephen M.; Edenhofer, Peter; Farrell, William M.; Federico, Costanzo; Frigeri, Alessandro; Gurnett, Donald A.; Hagfors, Tor; Heggy, Essam; Herique, Alain; Huff, Richard L.; Ivanov, Anton B.; Johnson, William T. K.; Jordan, Rolando L.; Kirchner, Donald L.; Kofman, Wlodek; Leuschen, Carlton J.; Nielsen, Erling; Orosei, Roberto

    2005-01-01

    The martian subsurface has been probed to kilometer depths by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument aboard the Mars Express orbiter. Signals penetrate the polar layered deposits, probably imaging the base of the deposits. Data from the northern lowlands of Chryse Planitia have revealed a shallowly buried quasi-circular structure about 250 kilometers in diameter that is interpreted to be an impact basin. In addition, a planar reflector associated with the basin structure may indicate the presence of a low-loss deposit that is more than 1 kilometer thick.

  9. Subsurface Microbes Expanding the Tree of Life

    SciTech Connect

    Banfield, Jillian

    2015-05-11

    Jillian Banfield, Ph.D., UC Berkeley Professor and Berkeley Lab Earth Sciences Division staff scientist and long-time user of the DOE Joint Genome Institute’s resources shares her perspective on how the DOE JGI helps advance her research addressing knowledge gaps related to the roles of subsurface microbial communities in biogeochemical cycling. The video was filmed near the town of Rifle, Colorado at the primary field site for Phase I of the Subsurface Systems Scientific Focus Area 2.0 sponsored by the DOE Office of Biological and Environmental Research.

  10. Induction heaters used to heat subsurface formations

    DOEpatents

    Nguyen, Scott Vinh; Bass, Ronald M.

    2012-04-24

    A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300.degree. C.

  11. Apparatus for passive removal of subsurface contaminants

    DOEpatents

    Pemberton, Bradley E.; May, Christopher P.; Rossabi, Joseph

    1997-01-01

    An apparatus is provided which passively removes contaminated gases from a subsurface. The apparatus includes a riser pipe extending into a subsurface which has an exterior end in fluid communication with a valve. When well pressure is greater than atmospheric pressure, the valve opens to release contaminants into the atmosphere, and when well pressure is less than atmospheric pressure, the valve closes to prevent flow of air into the well. The valve assembly of the invention comprises a lightweight ball which is lifted from its valve seat with a slight pressure drop between the well and the atmosphere.

  12. Heating systems for heating subsurface formations

    DOEpatents

    Nguyen, Scott Vinh; Vinegar, Harold J.

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  13. Apparatus for passive removal of subsurface contaminants

    DOEpatents

    Pemberton, B.E.; May, C.P.; Rossabi, J.

    1997-06-24

    An apparatus is provided which passively removes contaminated gases from a subsurface. The apparatus includes a riser pipe extending into a subsurface which has an exterior end in fluid communication with a valve. When well pressure is greater than atmospheric pressure, the valve opens to release contaminants into the atmosphere, and when well pressure is less than atmospheric pressure, the valve closes to prevent flow of air into the well. The valve assembly of the invention comprises a lightweight ball which is lifted from its valve seat with a slight pressure drop between the well and the atmosphere. 7 figs.

  14. Subsurface clade of Geobacteraceae that predominates in a diversity of Fe(III)-reducing subsurface environments

    SciTech Connect

    Holmes, Dawn; O'Neil, Regina; Vrionis, Helen A.; N'guessan, Lucie A.; Ortiz-Bernad, Irene; Larrahondo, Maria J.; Adams, Lorrie A.; Ward, Joy A.; Nicoll, Julie S.; Nevin, Kelly P.; Chavan, Milind A.; Johnson, Jessica P.; Long, Philip E.; Lovely, Derek R.

    2007-12-01

    There are distinct differences in the physiology of Geobacter species available in pure culture. Therefore, to understand the ecology of Geobacter species in subsurface environments, it is important to know which species predominate. Clone libraries were assembled with 16S rRNA genes and transcripts amplified from three subsurface environments in which Geobacter species are known to be important members of the microbial community: (1) a uranium-contaminated aquifer located in Rifle, CO, USA undergoing in situ bioremediation; (2) an acetate-impacted aquifer that serves as an analog for the long-term acetate amendments proposed for in situ uranium bioremediation and (3) a petroleum-contaminated aquifer in which Geobacter species play a role in the oxidation of aromatic hydrocarbons coupled with the reduction of Fe(III). The majority of Geobacteraceae 16S rRNA sequences found in these environments clustered in a phylogenetically coherent subsurface clade, which also contains a number of Geobacter species isolated from subsurface environments. Concatamers constructed with 43 Geobacter genes amplified from these sites also clustered within this subsurface clade. 16S rRNA transcript and gene sequences in the sediments and groundwater at the Rifle site were highly similar, suggesting that sampling groundwater via monitoring wells can recover the most active Geobacter species. These results suggest that further study of Geobacter species in the subsurface clade is necessary to accurately model the behavior of Geobacter species during subsurface bioremediation of metal and organic contaminants

  15. Quantifying induced effects of subsurface renewable energy storage

    NASA Astrophysics Data System (ADS)

    Bauer, Sebastian; Beyer, Christof; Pfeiffer, Tilmann; Boockmeyer, Anke; Popp, Steffi; Delfs, Jens-Olaf; Wang, Bo; Li, Dedong; Dethlefsen, Frank; Dahmke, Andreas

    2015-04-01

    New methods and technologies for energy storage are required for the transition to renewable energy sources. Subsurface energy storage systems such as salt caverns or porous formations offer the possibility of hosting large amounts of energy or substance. When employing these systems, an adequate system and process understanding is required in order to assess the feasibility of the individual storage option at the respective site and to predict the complex and interacting effects induced. This understanding is the basis for assessing the potential as well as the risks connected with a sustainable usage of these storage options, especially when considering possible mutual influences. For achieving this aim, in this work synthetic scenarios for the use of the geological underground as an energy storage system are developed and parameterized. The scenarios are designed to represent typical conditions in North Germany. The types of subsurface use investigated here include gas storage and heat storage in porous formations. The scenarios are numerically simulated and interpreted with regard to risk analysis and effect forecasting. For this, the numerical simulators Eclipse and OpenGeoSys are used. The latter is enhanced to include the required coupled hydraulic, thermal, geomechanical and geochemical processes. Using the simulated and interpreted scenarios, the induced effects are quantified individually and monitoring concepts for observing these effects are derived. This presentation will detail the general investigation concept used and analyze the parameter availability for this type of model applications. Then the process implementation and numerical methods required and applied for simulating the induced effects of subsurface storage are detailed and explained. Application examples show the developed methods and quantify induced effects and storage sizes for the typical settings parameterized. This work is part of the ANGUS+ project, funded by the German Ministry

  16. Progression of methanogenic degradation of crude oil in the subsurface

    USGS Publications Warehouse

    Bekins, B.A.; Hostettler, F.D.; Herkelrath, W.N.; Delin, G.N.; Warren, E.; Essaid, H.I.

    2005-01-01

    Our results show that subsurface crude-oil degradation rates at a long-term research site were strongly influenced by small-scale variations in hydrologic conditions. The site is a shallow glacial outwash aquifer located near Bemidji in northern Minnesota that became contaminated when oil spilled from a broken pipeline in August 1979. In the study area, separate-phase oil forms a subsurface oil body extending from land surface to about 1 m (3.3 ft) below the 6-8-m (20-26 ft)-deep water table. Oil saturation in the sediments ranges from 10-20% in the vadose zone to 30-70% near the water table. At depths below 2 m (6.6 ft), degradation of the separate-phase crude oil occurs under methanogenic conditions. The sequence of methanogenic alkane degradation depletes the longer chain n-alkanes before the shorter chain n-alkanes, which is opposite to the better known aerobic sequence. The rates of degradation vary significantly with location in the subsurface. Oil-coated soils within 1.5 m (5 ft) of land surface have experienced little degradation where soil water saturation is less than 20%. Oil located 2-8 m (6.6-26 ft) below land surface in areas of higher recharge has been substantially degraded. The best explanation for the association between recharge and enhanced degradation seems to be increased downward transport of microbial growth nutrients to the oil body. This is supported by observations of greater microbial numbers at higher elevations in the oil body and significant decreases with depth in nutrient concentrations, especially phosphorus. Our results suggest that environmental effects may cause widely diverging degradation rates in the same spill, calling into question dating methods based on degradation state. Copyright ?? 2005. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  17. Smouldering Subsurface Fires in the Earth System

    NASA Astrophysics Data System (ADS)

    Rein, Guillermo

    2010-05-01

    Smouldering fires, the slow, low-temperature, flameless form of combustion, are an important phenomena in the Earth system. These fires propagate slowly through organic layers of the forest ground and are responsible for 50% or more of the total biomass consumed during wildfires. Only after the 2002 study of the 1997 extreme haze event in South-East Asia, the scientific community recognised the environmental and economic threats posed by subsurface fires. This was caused by the spread of vast biomass fires in Indonesia, burning below the surface for months during the El Niño climate event. It has been calculated that these fires released between 0.81 and 2.57 Gton of carbon gases (13-40% of global emissions). Large smouldering fires are rare events at the local scale but occur regularly at a global scale. Once ignited, they are particularly difficult to extinguish despite extensive rains or fire-fighting attempts and can persist for long periods of time (months, years) spreading over very extensive areas of forest and deep into the soil. Indeed, these are the oldest continuously burning fires on Earth. Earth scientists are interested in smouldering fires because they destroy large amounts of biomass and cause greater damage to the soil ecosystem than flaming fires do. Moreover, these fires cannot be detected with current satellite remote sensing technologies causing inconsistencies between emission inventories and model predictions. Organic soils sustain smouldering fire (hummus, duff, peat and coal) which total carbon pool exceeds that of the world's forests or the atmosphere. This have important implications for climate change. Warmer temperatures at high latitudes are resulting in unprecedented permafrost thaw that is leaving large soil carbon pools exposed to fires. Because the CO2 flux from peat fires has been measured to be about 3000 times larger that the natural degradation flux, permafrost thaw is a risk for greater carbon release by fire and subsequently

  18. Governance of Governance in Higher Education: Practices and Lessons Drawn from the Portuguese Case

    ERIC Educational Resources Information Center

    Magalhaes, Antonio; Veiga, Amelia; Amaral, Alberto; Sousa, Sofia; Ribeiro, Filipa

    2013-01-01

    The implementation of the governance reform of Portuguese higher education has been developed under the influence of "new public management" resulting in the loss of collegial governance. Additionally, the need for meta-governance of the higher education system and institutions to monitor institutional performance against policy…

  19. Subsurface microbial community structure correlates with uranium redox phases during in situ field manipulation in a contaminated aquifer

    SciTech Connect

    Kostka, Joel; Green, Stefan; Wu, Wei-min; Criddle, Craig; Watson, David B; Jardine, Philip M

    2009-07-01

    Long-term field manipulation experiments investigating the effects of subsurface redox conditions on the fate and transport of soluble uranium(VI) were conducted over a 3 year period at the Oak Ridge Integrated Field Research Center (OR-IFRC) in Oak Ridge, TN. In the highly contaminated source zone, introduction of ethanol to the subsurface stimulated native denitrifying, sulfate-reducing, iron-reducing and fermentative microorganisms and reduced U to below 0.03 mg/L. Subsequently, oxygen and nitrate were experimentally re-introduced into the subsurface to examine the potential for re-oxidation and re-mobilization of U(IV). Introduction of oxygen or nitrate caused changes in subsurface geochemistry and re-oxidation of U. After reoxidation, the subsurface experienced several months of starvation conditions before ethanol injection was restored to reduce the treatment zone. Subsurface microorganisms were characterized by community fingerprinting, targeted population analyses, and quantitative PCR of key functional groups in 50 samples taken during multiple phases of field manipulation. Statistical analysis confirmed the hypothesis that the microbial community would co-vary with the shifts in the subsurface geochemistry. The level of hydraulic connectivity of sampling wells to the injection well was readily tracked by microbial community analysis. We demonstrate quantitatively that specific populations, especially Desulfosporosinus, are heavily influenced by geochemical conditions and positively correlate with the immobilization of uranium. Following nitrate reoxidation, populations of Fe(II)-oxidizing, nitrate reducing organisms (Thiobacillus) showed an increase in relative abundance.

  20. Is the Genetic Landscape of the Deep Subsurface Biosphere Affected by Viruses?

    PubMed Central

    Anderson, Rika E.; Brazelton, William J.; Baross, John A.

    2011-01-01

    Viruses are powerful manipulators of microbial diversity, biogeochemistry, and evolution in the marine environment. Viruses can directly influence the genetic capabilities and the fitness of their hosts through the use of fitness factors and through horizontal gene transfer. However, the impact of viruses on microbial ecology and evolution is often overlooked in studies of the deep subsurface biosphere. Subsurface habitats connected to hydrothermal vent systems are characterized by constant fluid flux, dynamic environmental variability, and high microbial diversity. In such conditions, high adaptability would be an evolutionary asset, and the potential for frequent host–virus interactions would be high, increasing the likelihood that cellular hosts could acquire novel functions. Here, we review evidence supporting this hypothesis, including data indicating that microbial communities in subsurface hydrothermal fluids are exposed to a high rate of viral infection, as well as viral metagenomic data suggesting that the vent viral assemblage is particularly enriched in genes that facilitate horizontal gene transfer and host adaptability. Therefore, viruses are likely to play a crucial role in facilitating adaptability to the extreme conditions of these regions of the deep subsurface biosphere. We also discuss how these results might apply to other regions of the deep subsurface, where the nature of virus–host interactions would be altered, but possibly no less important, compared to more energetic hydrothermal systems. PMID:22084639

  1. Sub-surface imaging of carbon nanotube-polymer composites using dynamic AFM methods.

    PubMed

    Cadena, Maria J; Misiego, Rocio; Smith, Kyle C; Avila, Alba; Pipes, Byron; Reifenberger, Ron; Raman, Arvind

    2013-04-01

    High-resolution sub-surface imaging of carbon nanotube (CNT) networks within polymer nanocomposites is demonstrated through electrical characterization techniques based on dynamic atomic force microscopy (AFM). We compare three techniques implemented in the single-pass configuration: DC-biased amplitude modulated AFM (AM-AFM), electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM) in terms of the physics of sub-surface image formation and experimental robustness. The methods were applied to study the dispersion of sub-surface networks of single-walled nanotubes (SWNTs) in a polyimide (PI) matrix. We conclude that among these methods, the KPFM channel, which measures the capacitance gradient (∂C/∂d) at the second harmonic of electrical excitation, is the best channel to obtain high-contrast images of the CNT network embedded in the polymer matrix, without the influence of surface conditions. Additionally, we propose an analysis of the ∂C/∂d images as a tool to characterize the dispersion and connectivity of the CNTs. Through the analysis we demonstrate that these AFM-based sub-surface methods probe sufficiently deep within the SWNT composites, to resolve clustered networks that likely play a role in conductivity percolation. This opens up the possibility of dynamic AFM-based characterization of sub-surface dispersion and connectivity in nanostructured composites, two critical parameters for nanocomposite applications in sensors and energy storage devices. PMID:23478510

  2. Simulation for ground penetrating radar (GPR) study of the subsurface structure of the Moon

    NASA Astrophysics Data System (ADS)

    Fa, Wenzhe

    2013-12-01

    Ground penetrating radar (GPR) is currently within the scope of China's Chang-E 3 lunar mission, to study the shallow subsurface of the Moon. In this study, key factors that could affect a lunar GPR performance, such as frequency, range resolution, and antenna directivity, are discussed firstly. Geometrical optics and ray tracing techniques are used to model GPR echoes, considering the transmission, attenuation, reflection, geometrical spreading of radar waves, and the antenna directivity. The influence on A-scope GPR echoes and on the simulated radargrams for the Sinus Iridum region by surface and subsurface roughness, dielectric loss of the lunar regolith, radar frequency and bandwidth, and the distance between the transmit and receive antennas are discussed. Finally, potential scientific return about lunar subsurface properties from GPR echoes is also discussed. Simulation results suggest that subsurface structure from several to hundreds of meters can be studied from GPR echoes at P and VHF bands, and information about dielectric permittivity and thickness of subsurface layers can be estimated from GPR echoes in combination with regolith composition data.

  3. Subsurface Sensors to Manage Cattle Feedlot Waste

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subsurface sensing tools were used to aid collection of biosolids from feedlot surfaces to be utilized by crops, for control and utilization of nutrient laden liquid runoff, and to enhance feedlot surface management to reduce nutrient losses and gaseous emissions. The work described here was all co...

  4. Subsurface processes affecting cold season streamflow generation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amount and timing of snowmelt-generated streamflow greatly affects the management of water resources in the western USA and Canada. Subsurface processes that deliver water to streams during snowmelt are somewhat different from those that occur during rainfall. In this study we document some of ...

  5. SEQUESTRATION OF SUBSURFACE ELEMENTAL MERCURY (HG0)

    EPA Science Inventory

    Elemental mercury (Hg0) is a metal with a number of atypical properties, which has resulted in its use in myriad anthropogenic processes. However, these same properties have also led to severe local subsurface contamination at many places where it has been used. As...

  6. Lateral gene transfer in the subsurface

    SciTech Connect

    Barkay, Tamar; Sobecky, Patricia

    2007-08-27

    Lateral gene transfer (LGT) is an important adaptive mechanism among prokaryotic organisms. This mechanism is particularly important for the response of microorganisms to changing environmental conditions because it facilitates the transfer of a large number of genes and their rapid expression. Together the transferred genes promote rapid genetic and metabolic changes that may enhance survival to newly established and sometimes hostile environmental conditions. The goal of our project was to examine if and how LGT enhances microbial adaptation to toxic heavy metals in subsurface environments that had been contaminated by mixed wastes due to activities associated with the production of nuclear energy and weapons. This task has been accomplished by dividing the project to several sub-tasks. Thus, we: (1) Determined the level of resistance of subsurface bacterial isolates to several toxic metals, all identified as pollutants of concern in subsurface environments; (2) Designed, tested, and applied, a molecular approach that determined whether metal resistance genes had evolved by LGT among subsurface bacteria; and (3) Developed a DNA hybridization array for the identification of broad host range plasmids and of metal resistance plasmids. The results are briefly summarized below with references to published papers and manuscripts in preparation where details about our research can be found. Additional information may be found in copies of our published manuscripts and conference proceedings, and our yearly reports that were submitted through the RIMS system.

  7. OVERVIEW -- SUBSURFACE PROTECTION AND REMEDIATION DIVISION

    EPA Science Inventory

    NRMRL's Subsurface Protection and Remediation Division located in Ada, Oklahoma, conducts EPA-investigator led laboratory and field research to provide the scientific basis to support the development of strategies and technologies to protect and restore ground and surface water q...

  8. Is Europa's Subsurface Water Ocean Warm?

    NASA Technical Reports Server (NTRS)

    Melosh, H. J.; Ekholm, A. G.; Showman, A. P.; Lorenz, R. D.

    2002-01-01

    Europa's subsurface water ocean may be warm: that is, at the temperature of water's maximum density. This provides a natural explanation of chaos melt-through events and leads to a correct estimate of the age of its surface. Additional information is contained in the original extended abstract.

  9. Molecular analysis of deep-subsurface bacteria

    SciTech Connect

    Jimenez, L. )

    1990-07-01

    Bacterial isolates from deep-sediment samples from three sites at the Savannah River site, near Aiken, S.C., were studied to determine their microbial community composition and DNA structure by using total DNA hybridization and moles percent G+C. Standard phenotypic identification underestimated the bacterial diversity at the three sites, since isolates with the same phenotype had different DNA structures in terms of moles percent G+C and DNA homology. The G+C content of deep-subsurface bacteria ranged from 20 to 77 mol%. More than 60% of the isolates tested had G+C values similar to those of Pseudomonas spp., and 12% had values similar to those of Acinetobacter spp. No isolates from deeper formations showed the same DNA composition as isolates from upper formations. Total-DNA hybridization and DNA base composition analysis provided a better resolution than phenotypic tests for the understanding of the diversity and structure of deep-subsurface bacterial communities. On the basis of the moles percent G+C values, deep-subsurface isolates tested seemed to belong to the families Pseudomonadaceae and Neisseriaceae, which might reflect a long period of adaptation to the environmental conditions of the deep subsurface.

  10. Subsurface manure application to reduce ammonia emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporation into soil is generally recommended to reduce ammonia volatilization and nutrient runoff following land application of manures. A range of subsurface applicators are available for manure incorporation with minimal soil disturbance in reduced tillage systems, but none have been widely a...