Science.gov

Sample records for 3-d ground water

  1. Modeling 3-D Slope Stability of Coastal Bluffs Using 3-D Ground-Water Flow, Southwestern Seattle, Washington

    USGS Publications Warehouse

    Brien, Dianne L.; Reid, Mark E.

    2007-01-01

    Landslides are a common problem on coastal bluffs throughout the world. Along the coastal bluffs of the Puget Sound in Seattle, Washington, landslides range from small, shallow failures to large, deep-seated landslides. Landslides of all types can pose hazards to human lives and property, but deep-seated landslides are of significant concern because their large areal extent can cause extensive property damage. Although many geomorphic processes shape the coastal bluffs of Seattle, we focus on large (greater than 3,000 m3), deepseated, rotational landslides that occur on the steep bluffs along Puget Sound. Many of these larger failures occur in advance outwash deposits of the Vashon Drift (Qva); some failures extend into the underlying Lawton Clay Member of the Vashon Drift (Qvlc). The slope stability of coastal bluffs is controlled by the interplay of three-dimensional (3-D) variations in gravitational stress, strength, and pore-water pressure. We assess 3-D slope-stability using SCOOPS (Reid and others, 2000), a computer program that allows us to search a high-resolution digital-elevation model (DEM) to quantify the relative stability of all parts of the landscape by computing the stability and volume of thousands of potential spherical failures. SCOOPS incorporates topography, 3-D strength variations, and 3-D pore pressures. Initially, we use our 3-D analysis methods to examine the effects of topography and geology by using heterogeneous material properties, as defined by stratigraphy, without pore pressures. In this scenario, the least-stable areas are located on the steepest slopes, commonly in Qva or Qvlc. However, these locations do not agree well with observations of deep-seated landslides. Historically, both shallow colluvial landslides and deep-seated landslides have been observed near the contact between Qva and Qvlc, and commonly occur in Qva. The low hydraulic conductivity of Qvlc impedes ground-water flow, resulting in elevated pore pressures at the

  2. Age, double porosity, and simple reaction modifications for the MOC3D ground-water transport model

    USGS Publications Warehouse

    Goode, Daniel J.

    1999-01-01

    This report documents modifications for the MOC3D ground-water transport model to simulate (a) ground-water age transport; (b) double-porosity exchange; and (c) simple but flexible retardation, decay, and zero-order growth reactions. These modifications are incorporated in MOC3D version 3.0. MOC3D simulates the transport of a single solute using the method-ofcharacteristics numerical procedure. The age of ground water, that is the time since recharge to the saturated zone, can be simulated using the transport model with an additional source term of unit strength, corresponding to the rate of aging. The output concentrations of the model are in this case the ages at all locations in the model. Double porosity generally refers to a separate immobilewater phase within the aquifer that does not contribute to ground-water flow but can affect solute transport through diffusive exchange. The solute mass exchange rate between the flowing water in the aquifer and the immobile-water phase is the product of the concentration difference between the two phases and a linear exchange coefficient. Conceptually, double porosity can approximate the effects of dead-end pores in a granular porous media, or matrix diffusion in a fractured-rock aquifer. Options are provided for decay and zero-order growth reactions within the immobilewater phase. The simple reaction terms here extend the original model, which included decay and retardation. With these extensions, (a) the retardation factor can vary spatially within each model layer, (b) the decay rate coefficient can vary spatially within each model layer and can be different for the dissolved and sorbed phases, and (c) a zero-order growth reaction is added that can vary spatially and can be different in the dissolved and sorbed phases. The decay and growth reaction terms also can change in time to account for changing geochemical conditions during transport. The report includes a description of the theoretical basis of the model, a

  3. Advances in 3D soil mapping and water content estimation using multi-channel ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Moysey, S. M.

    2011-12-01

    Multi-channel ground-penetrating radar systems have recently become widely available, thereby opening new possibilities for shallow imaging of the subsurface. One advantage of these systems is that they can significantly reduce survey times by simultaneously collecting multiple lines of GPR reflection data. As a result, it is becoming more practical to complete 3D surveys - particularly in situations where the subsurface undergoes rapid changes, e.g., when monitoring infiltration and redistribution of water in soils. While 3D and 4D surveys can provide a degree of clarity that significantly improves interpretation of the subsurface, an even more powerful feature of the new multi-channel systems for hydrologists is their ability to collect data using multiple antenna offsets. Central mid-point (CMP) surveys have been widely used to estimate radar wave velocities, which can be related to water contents, by sequentially increasing the distance, i.e., offset, between the source and receiver antennas. This process is highly labor intensive using single-channel systems and therefore such surveys are often only performed at a few locations at any given site. In contrast, with multi-channel GPR systems it is possible to physically arrange an array of antennas at different offsets, such that a CMP-style survey is performed at every point along a radar transect. It is then possible to process this data to obtain detailed maps of wave velocity with a horizontal resolution on the order of centimeters. In this talk I review concepts underlying multi-channel GPR imaging with an emphasis on multi-offset profiling for water content estimation. Numerical simulations are used to provide examples that illustrate situations where multi-offset GPR profiling is likely to be successful, with an emphasis on considering how issues like noise, soil heterogeneity, vertical variations in water content and weak reflection returns affect algorithms for automated analysis of the data. Overall

  4. SUTRA: A model for 2D or 3D saturated-unsaturated, variable-density ground-water flow with solute or energy transport

    USGS Publications Warehouse

    Voss, Clifford I.; Provost, A.M.

    2002-01-01

    SUTRA (Saturated-Unsaturated Transport) is a computer program that simulates fluid movement and the transport of either energy or dissolved substances in a subsurface environment. This upgraded version of SUTRA adds the capability for three-dimensional simulation to the former code (Voss, 1984), which allowed only two-dimensional simulation. The code employs a two- or three-dimensional finite-element and finite-difference method to approximate the governing equations that describe the two interdependent processes that are simulated: 1) fluid density-dependent saturated or unsaturated ground-water flow; and 2) either (a) transport of a solute in the ground water, in which the solute may be subject to: equilibrium adsorption on the porous matrix, and both first-order and zero-order production or decay; or (b) transport of thermal energy in the ground water and solid matrix of the aquifer. SUTRA may also be used to simulate simpler subsets of the above processes. A flow-direction-dependent dispersion process for anisotropic media is also provided by the code and is introduced in this report. As the primary calculated result, SUTRA provides fluid pressures and either solute concentrations or temperatures, as they vary with time, everywhere in the simulated subsurface system. SUTRA flow simulation may be employed for two-dimensional (2D) areal, cross sectional and three-dimensional (3D) modeling of saturated ground-water flow systems, and for cross sectional and 3D modeling of unsaturated zone flow. Solute-transport simulation using SUTRA may be employed to model natural or man-induced chemical-species transport including processes of solute sorption, production, and decay. For example, it may be applied to analyze ground-water contaminant transport problems and aquifer restoration designs. In addition, solute-transport simulation with SUTRA may be used for modeling of variable-density leachate movement, and for cross sectional modeling of saltwater intrusion in

  5. 'Berries' on the Ground 2 (3-D)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is the 3-D anaglyph showing a microscopic image taken of soil featuring round, blueberry-shaped rock formations on the crater floor at Meridiani Planum, Mars. This image was taken on the 13th day of the Mars Exploration Rover Opportunity's journey, before the Moessbauer spectrometer, an instrument located on the rover's instrument deployment device, or 'arm,' was pressed down to take measurements. The area in this image is approximately 3 centimeters (1.2 inches) across.

  6. 'Berries' on the Ground 2 (3-D)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is the 3-D anaglyph showing a microscopic image taken of soil featuring round, blueberry-shaped rock formations on the crater floor at Meridiani Planum, Mars. This image was taken on the 13th day of the Mars Exploration Rover Opportunity's journey, after the Moessbauer spectrometer, an instrument located on the rover's instrument deployment device, or 'arm,' was pressed down to measure the soil's iron mineralogy. Note the donut-shaped imprint of the instrument in the lower part of the image. The area in this image is approximately 3 centimeters (1.2 inches) across.

  7. Documentation of a computer program to simulate lake-aquifer interaction using the MODFLOW ground water flow model and the MOC3D solute-transport model

    USGS Publications Warehouse

    Merritt, Michael L.; Konikow, Leonard F.

    2000-01-01

    Heads and flow patterns in surficial aquifers can be strongly influenced by the presence of stationary surface-water bodies (lakes) that are in direct contact, vertically and laterally, with the aquifer. Conversely, lake stages can be significantly affected by the volume of water that seeps through the lakebed that separates the lake from the aquifer. For these reasons, a set of computer subroutines called the Lake Package (LAK3) was developed to represent lake/aquifer interaction in numerical simulations using the U.S. Geological Survey three-dimensional, finite-difference, modular ground-water flow model MODFLOW and the U.S. Geological Survey three-dimensional method-of-characteristics solute-transport model MOC3D. In the Lake Package described in this report, a lake is represented as a volume of space within the model grid which consists of inactive cells extending downward from the upper surface of the grid. Active model grid cells bordering this space, representing the adjacent aquifer, exchange water with the lake at a rate determined by the relative heads and by conductances that are based on grid cell dimensions, hydraulic conductivities of the aquifer material, and user-specified leakance distributions that represent the resistance to flow through the material of the lakebed. Parts of the lake may become ?dry? as upper layers of the model are dewatered, with a concomitant reduction in lake surface area, and may subsequently rewet when aquifer heads rise. An empirical approximation has been encoded to simulate the rewetting of a lake that becomes completely dry. The variations of lake stages are determined by independent water budgets computed for each lake in the model grid. This lake budget process makes the package a simulator of the response of lake stage to hydraulic stresses applied to the aquifer. Implementation of a lake water budget requires input of parameters including those representing the rate of lake atmospheric recharge and evaporation

  8. 3D lithography modeling for ground rule development

    NASA Astrophysics Data System (ADS)

    Sarma, Chandra; Bailey, Todd; Lyons, Adam; Shao, Dongbing

    2011-04-01

    The ability to incorporate the effect of patterned underlayers in a 3-dimensional physical resist model that truly mimics the process on real wafers could be used to formulate robust ground rules for design. We have shown as an example block level simulations, where the resist critical dimension is determined by the presence of STI (shallow trench isolation) and/or patterned gate level underneath & their relative spacing, as confirmed on wafer. We will demonstrate how the results of such study could be used for creating ground rules which are truly dependent on the interaction between the current layer resist & the patterned layers underneath. We have also developed a new way to visualize lithographic process variations in 3-D space that is useful for simulation analysis that can prove very helpful in ground rule development and process optimization. Such visualization capability in the dataprep flow to flag issues or dispose critical structures increases speed and efficiency in the mask tapeout process.

  9. Ground-state rotational constants of 12CH 3D

    NASA Astrophysics Data System (ADS)

    Chackerian, C.; Guelachvili, G.

    1980-12-01

    An analysis of ground-state combination differences in the ν2( A1) fundamental band of 12CH 3D ( ν0 = 2200.03896 cm -1) has been made to yield values for the rotational constants B0, D0J, D0JK, H0JJJ, H0JJK, H0JKK, LJJJJ, L0JJJK, and order of magnitude values for L0JJKK and L0JKKK. These constants should be useful in assisting radio searches for this molecule in astrophysical sources. In addition, splittings of A1A2 levels ( J ≥ 17, K = 3) have been measured in both the ground and excited vibrational states of this band.

  10. HST3D; a computer code for simulation of heat and solute transport in three-dimensional ground-water flow systems

    USGS Publications Warehouse

    Kipp, K.L.

    1987-01-01

    The Heat- and Soil-Transport Program (HST3D) simulates groundwater flow and associated heat and solute transport in three dimensions. The three governing equations are coupled through the interstitial pore velocity, the dependence of the fluid density on pressure, temperature, the solute-mass fraction , and the dependence of the fluid viscosity on temperature and solute-mass fraction. The solute transport equation is for only a single, solute species with possible linear equilibrium sorption and linear decay. Finite difference techniques are used to discretize the governing equations using a point-distributed grid. The flow-, heat- and solute-transport equations are solved , in turn, after a particle Gauss-reduction scheme is used to modify them. The modified equations are more tightly coupled and have better stability for the numerical solutions. The basic source-sink term represents wells. A complex well flow model may be used to simulate specified flow rate and pressure conditions at the land surface or within the aquifer, with or without pressure and flow rate constraints. Boundary condition types offered include specified value, specified flux, leakage, heat conduction, and approximate free surface, and two types of aquifer influence functions. All boundary conditions can be functions of time. Two techniques are available for solution of the finite difference matrix equations. One technique is a direct-elimination solver, using equations reordered by alternating diagonal planes. The other technique is an iterative solver, using two-line successive over-relaxation. A restart option is available for storing intermediate results and restarting the simulation at an intermediate time with modified boundary conditions. This feature also can be used as protection against computer system failure. Data input and output may be in metric (SI) units or inch-pound units. Output may include tables of dependent variables and parameters, zoned-contour maps, and plots of the

  11. Object Segmentation and Ground Truth in 3D Embryonic Imaging

    PubMed Central

    Rajasekaran, Bhavna; Uriu, Koichiro; Valentin, Guillaume; Tinevez, Jean-Yves; Oates, Andrew C.

    2016-01-01

    Many questions in developmental biology depend on measuring the position and movement of individual cells within developing embryos. Yet, tools that provide this data are often challenged by high cell density and their accuracy is difficult to measure. Here, we present a three-step procedure to address this problem. Step one is a novel segmentation algorithm based on image derivatives that, in combination with selective post-processing, reliably and automatically segments cell nuclei from images of densely packed tissue. Step two is a quantitative validation using synthetic images to ascertain the efficiency of the algorithm with respect to signal-to-noise ratio and object density. Finally, we propose an original method to generate reliable and experimentally faithful ground truth datasets: Sparse-dense dual-labeled embryo chimeras are used to unambiguously measure segmentation errors within experimental data. Together, the three steps outlined here establish a robust, iterative procedure to fine-tune image analysis algorithms and microscopy settings associated with embryonic 3D image data sets. PMID:27332860

  12. Ground water contamination

    SciTech Connect

    Not Available

    1991-01-01

    This book covers: Ground water contamination and basic concepts of water law; Federal law governing water contamination and remediation; Ground water flow and contaminant migration; Ground water cleanup under CERCLA; Technical methods of remediation and prevention of contamination; Liability for ground water contamination; State constraints on contamination of ground water; Water quantity versus water quality; Prevention of use of contaminated ground water as an alternative to remediation; Economic considerations in liability for ground water contamination; and Contamination, extraction, and injection issues.

  13. 3D flexible water channel: stretchability of nanoscale water bridge

    NASA Astrophysics Data System (ADS)

    Chen, Jige; Wang, Chunlei; Wei, Ning; Wan, Rongzheng; Gao, Yi

    2016-03-01

    Artificial water channels can contribute to a better understanding of natural water channels and offer a highly selective, advanced conductance system. Most studies use nanotubes, however it is difficult to fabricate a flexible structure, and the nanosized diameter brings nanoconfinement effects, and nanotube toxicity arouses biosafety concerns. In this paper, we use an electric field to restrain the water molecules to form a nanoscale water bridge as an artificial water channel to connect a separated solid plate by molecular dynamics simulations. We observe strong 3D flexible stretchability in the water bridge, maintaining a variable length and an arbitrary angle for a considerably long time. The stretching of the water bridge enables it to be polarized at an arbitrary angle and the stretchability is linearly dependent upon the polarization strength. More interestingly, we show the possibility of establishing complex water networks, e.g., triangle, rectangle, hexagon, and tetrahedron-tetrahedron water networks. Our results may help realize structurally flexible and environmentally friendly water channels for lab-on-a-chip applications in nanofluidics.Artificial water channels can contribute to a better understanding of natural water channels and offer a highly selective, advanced conductance system. Most studies use nanotubes, however it is difficult to fabricate a flexible structure, and the nanosized diameter brings nanoconfinement effects, and nanotube toxicity arouses biosafety concerns. In this paper, we use an electric field to restrain the water molecules to form a nanoscale water bridge as an artificial water channel to connect a separated solid plate by molecular dynamics simulations. We observe strong 3D flexible stretchability in the water bridge, maintaining a variable length and an arbitrary angle for a considerably long time. The stretching of the water bridge enables it to be polarized at an arbitrary angle and the stretchability is linearly

  14. 3-D representation of aquitard topography using ground-penetrating radar

    SciTech Connect

    Young, R.A.; Sun, Jingsheng

    1995-12-31

    The topography of a clay aquitard is defined by 3D Ground Penetrating Radar (GPR) data at Hill Air Force Base, Utah. Conventional processing augmented by multichannel domain filtering shows a strong reflection from a depth of 20-30 ft despite attenuation by an artificial clay cap approximately 2 ft thick. This reflection correlates very closely with the top of the aquitard as seen in lithology logs at 3 wells crossed by common offset radar profiles from the 3D dataset. Lateral and vertical resolution along the boundary are approximately 2 ft and 1 ft, respectively. The boundary shows abrupt topographic variation of 5 ft over horizontal distances of 20 ft or less and is probably due to vigorous erosion by streams during lowstands of ancient Lake Bonneville. This irregular topography may provide depressions for accumulation of hydrocarbons and chlorinated organic pollutants. A ridge running the length of the survey area may channel movement of ground water and of hydrocarbons trapped at the surface of the water table. Depth slices through a 3D volume, and picked points along the aquitard displayed in depth and relative elevation perspectives provide much more useful visualization than several 2D lines by themselves. The three-dimensional CPR image provides far more detailed definition of geologic boundaries than does projection of soil boring logs into two-dimensional profiles.

  15. Computer-aided structural engineering (CASE) project: Application of finite-element, grid generation, and scientific visualization techniques to 2-D and 3-d seepage and ground-water modeling. Final report

    SciTech Connect

    Tracy, F.T.

    1991-09-01

    This report describes new advances in the computational modeling of ground water and seepage using the finite element method (FEM) in conjunction with tools and techniques typically used by the aerospace engineers. The unsolved environmental issues regarding our hazardous and toxic waste problems must be resolved, and significant resources must be placed on this effort. Some military bases are contaminated with hazardous waste that has entered the groundwater domain. A groundwater model that takes into account contaminant flow is therefore critical. First, an extension of the technique of generating an orthogonal structured grid (using the Cauchy-Riemann equations) to automatically generate a flow net for two-dimensional (2-D) steady-state seepage problems is presented for various boundary conditions. Second, a complete implementation of a three-dimensional (3-D) seepage package is described where (1) grid generation is accomplished using the EAGLE program, (2) the seepage and groundwater analysis for either confined or unconfined steady-state flow, homogeneous or inhomogeneous media, and isotropic or anisotropic soil is accomplished with no restriction on the FE grid or requirement of an initial guess of the free surface for unconfined flow problems, and (3) scientific visualization is accomplished using the program FAST developed by NASA.

  16. Ground water and energy

    SciTech Connect

    Not Available

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  17. Ground Water Remediation Technologies

    EPA Science Inventory

    The USEPA's Ground Water and Ecosystems Restoration Division (GWERD) conducts research and provides technical assistance to support the development of strategies and technologies to protect and restore ground water, surface water, and ecosystems impacted by man-made and natural...

  18. GEO3D - Three-Dimensional Computer Model of a Ground Source Heat Pump System

    SciTech Connect

    James Menart

    2013-06-07

    This file is the setup file for the computer program GEO3D. GEO3D is a computer program written by Jim Menart to simulate vertical wells in conjunction with a heat pump for ground source heat pump (GSHP) systems. This is a very detailed three-dimensional computer model. This program produces detailed heat transfer and temperature field information for a vertical GSHP system.

  19. Time-lapse 3D ground-penetrating radar during plot-scale infiltration experiments

    NASA Astrophysics Data System (ADS)

    Allroggen, Niklas; Jackisch, Conrad; Tronicke, Jens

    2016-04-01

    In electrical resistive soils, surface-based ground-penetrating radar (GPR) is known as the geophysical tool providing the highest spatial resolution. Thus, 2D and 3D GPR surveys are commonly used for imaging subsurface structures or estimating soil moisture content. Due to its sensitivity to soil moisture and its non-invasive character, GPR provides a large potential to monitor soil moisture variation at high temporal and spatial resolution. As shown in previous experiments, the acquisition of time-lapse GPR data under field conditions requires a high data quality in terms of repeatability as well as spatial and temporal resolution. We present hydrogeophysical field experiments at the plot scale (1m x 1m), during which we record time-lapse 3D GPR. For GPR data acquisition, we use a pulseEKKO PRO GPR system equipped with a pair of 500 MHz antennas in combination with a specially designed metal-free measuring platform. Additionally, we collect tracer and soil moisture data, which are used to improve the interpretation of the GPR data with special focus on preferential flow paths and their structured advective flow field. After an accurate time-lapse GPR data processing, we compare 3D reflection events before and after infiltration and quantitatively interpret their relative time-shift in terms of soil moisture variations. Thereby, we are able to account for basically all of the infiltrated water. The first experiments demonstrate the general applicability of our experimental approach but are limited by the number of acquired time steps and measurement during the sprinkling period (the time of the highest temporal dynamics) are not possible at all. Based on this experience we redesign our experimental setup to continuously collect GPR data during irrigation and infiltration. Thereby, we strongly increase the temporal resolution of our measurements, improve the interpretability of the GPR data, and monitor the temporal and spatial dynamics of shallow subsurface

  20. GROUND WATER SAMPLING ISSUES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and
    remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  1. Ground water: a review.

    USGS Publications Warehouse

    Bredehoeft, J.D.

    1983-01-01

    There is growing documentation that a significant portion of the Nation's fresh ground water in the densely populated areas of the USA is contaminated. Because of the slow rates of ground-water movement, ground water once contaminated will remain so for decades, often longer. Cleanup of contaminated ground water is almost always expensive and often technically unfeasible; the expense is often prohibitive. -from Author

  2. Intuitive terrain reconstruction using height observation-based ground segmentation and 3D object boundary estimation.

    PubMed

    Song, Wei; Cho, Kyungeun; Um, Kyhyun; Won, Chee Sun; Sim, Sungdae

    2012-01-01

    Mobile robot operators must make rapid decisions based on information about the robot's surrounding environment. This means that terrain modeling and photorealistic visualization are required for the remote operation of mobile robots. We have produced a voxel map and textured mesh from the 2D and 3D datasets collected by a robot's array of sensors, but some upper parts of objects are beyond the sensors' measurements and these parts are missing in the terrain reconstruction result. This result is an incomplete terrain model. To solve this problem, we present a new ground segmentation method to detect non-ground data in the reconstructed voxel map. Our method uses height histograms to estimate the ground height range, and a Gibbs-Markov random field model to refine the segmentation results. To reconstruct a complete terrain model of the 3D environment, we develop a 3D boundary estimation method for non-ground objects. We apply a boundary detection technique to the 2D image, before estimating and refining the actual height values of the non-ground vertices in the reconstructed textured mesh. Our proposed methods were tested in an outdoor environment in which trees and buildings were not completely sensed. Our results show that the time required for ground segmentation is faster than that for data sensing, which is necessary for a real-time approach. In addition, those parts of objects that were not sensed are accurately recovered to retrieve their real-world appearances. PMID:23235454

  3. Intuitive Terrain Reconstruction Using Height Observation-Based Ground Segmentation and 3D Object Boundary Estimation

    PubMed Central

    Song, Wei; Cho, Kyungeun; Um, Kyhyun; Won, Chee Sun; Sim, Sungdae

    2012-01-01

    Mobile robot operators must make rapid decisions based on information about the robot’s surrounding environment. This means that terrain modeling and photorealistic visualization are required for the remote operation of mobile robots. We have produced a voxel map and textured mesh from the 2D and 3D datasets collected by a robot’s array of sensors, but some upper parts of objects are beyond the sensors’ measurements and these parts are missing in the terrain reconstruction result. This result is an incomplete terrain model. To solve this problem, we present a new ground segmentation method to detect non-ground data in the reconstructed voxel map. Our method uses height histograms to estimate the ground height range, and a Gibbs-Markov random field model to refine the segmentation results. To reconstruct a complete terrain model of the 3D environment, we develop a 3D boundary estimation method for non-ground objects. We apply a boundary detection technique to the 2D image, before estimating and refining the actual height values of the non-ground vertices in the reconstructed textured mesh. Our proposed methods were tested in an outdoor environment in which trees and buildings were not completely sensed. Our results show that the time required for ground segmentation is faster than that for data sensing, which is necessary for a real-time approach. In addition, those parts of objects that were not sensed are accurately recovered to retrieve their real-world appearances. PMID:23235454

  4. Effects of 3D random correlated velocity perturbations on predicted ground motions

    USGS Publications Warehouse

    Hartzell, S.; Harmsen, S.; Frankel, A.

    2010-01-01

    Three-dimensional, finite-difference simulations of a realistic finite-fault rupture on the southern Hayward fault are used to evaluate the effects of random, correlated velocity perturbations on predicted ground motions. Velocity perturbations are added to a three-dimensional (3D) regional seismic velocity model of the San Francisco Bay Area using a 3D von Karman random medium. Velocity correlation lengths of 5 and 10 km and standard deviations in the velocity of 5% and 10% are considered. The results show that significant deviations in predicted ground velocities are seen in the calculated frequency range (≤1 Hz) for standard deviations in velocity of 5% to 10%. These results have implications for the practical limits on the accuracy of scenario ground-motion calculations and on retrieval of source parameters using higher-frequency, strong-motion data.

  5. Large Scale Ice Water Path and 3-D Ice Water Content

    DOE Data Explorer

    Liu, Guosheng

    2008-01-15

    Cloud ice water concentration is one of the most important, yet poorly observed, cloud properties. Developing physical parameterizations used in general circulation models through single-column modeling is one of the key foci of the ARM program. In addition to the vertical profiles of temperature, water vapor and condensed water at the model grids, large-scale horizontal advective tendencies of these variables are also required as forcing terms in the single-column models. Observed horizontal advection of condensed water has not been available because the radar/lidar/radiometer observations at the ARM site are single-point measurement, therefore, do not provide horizontal distribution of condensed water. The intention of this product is to provide large-scale distribution of cloud ice water by merging available surface and satellite measurements. The satellite cloud ice water algorithm uses ARM ground-based measurements as baseline, produces datasets for 3-D cloud ice water distributions in a 10 deg x 10 deg area near ARM site. The approach of the study is to expand a (surface) point measurement to an (satellite) areal measurement. That is, this study takes the advantage of the high quality cloud measurements at the point of ARM site. We use the cloud characteristics derived from the point measurement to guide/constrain satellite retrieval, then use the satellite algorithm to derive the cloud ice water distributions within an area, i.e., 10 deg x 10 deg centered at ARM site.

  6. 3D Monitoring under the Keciova Mosque (Casbah-Algier, Algeria) with Ground Penetrating Radar Method

    NASA Astrophysics Data System (ADS)

    Kadioglu, Selma; Kagan Kadioglu, Yusuf; Deniz, Kiymet; Akin Akyol, Ali

    2014-05-01

    Keciova (Ketchaoua) Mosque, in Casbah-Algiers, the capital of Algeria, is a UNESCO World Heritage Site. Keciova Mosque was originally built in 1612 by the Ottoman Empire. A RAMAC CU II GPR system and a 250 MHz shielded antenna have been employed inside of the Mosque including the Cathedral and inside of the burial chambers under the Cathedral Site on parallel profiles spaced approximately 0.30 m apart to measure data. After applying standard two-dimensional (2D) and three dimensional (3D) imaging techniques, transparent 3D imaging techniques have been used to photograph the foundational infrastructures, buried remains and safety problems of the Mosque. The results showed that we obtained 3D GPR visualization until 12.0 m in depth. Firstly we imaged the base floor including corridors. Then we monitored buried remains under the first ground level between 5.0-7.0 m in depths. Finally we indicated 3D GPR photographs a spectacular protected buried old mosque structures under the second ground level between 9.0-12.0 m in depths. This project has been supported by Republic of Turkey Prime Ministry Turkish Cooperation and Coordination Agency (TIKA). This study is a contribution to the EU funded COST action TU1208, "Civil Engineering Applications of Ground penetrating Radar".

  7. Ground and Structure Deformation 3d Modelling with a Tin Based Property Model

    NASA Astrophysics Data System (ADS)

    TIAN, T.; Zhang, J.; Jiang, W.

    2013-12-01

    With the development of 3D( three-dimensional) modeling and visualization, more and more 3D tectonics are used to assist the daily work in Engineering Survey, in which the prediction of deformation field in strata and structure induced by underground construction is an essential part. In this research we developed a TIN (Triangulated Irregular Network) based property model for the 3D (three dimensional) visualization of ground deformation filed. By record deformation vector for each nodes, the new model can express the deformation with geometric-deformation-style by drawing each node in its new position and deformation-attribute-distribution-style by drawing each node in the color correspond with its deformation attribute at the same time. Comparing with the volume model based property model, this new property model can provide a more precise geometrical shape for structure objects. Furthermore, by recording only the deformation data of the user-interested 3d surface- such as the ground surface or the underground digging surface, the new property model can save a lot of space, which makes it possible to build the deformation filed model of a much more large scale. To construct the models of deformation filed based on TIN model, the refinement of the network is needed to increase the nodes number, which is necessary to express the deformation filed with a certain resolution. The TIN model refinement is a process of sampling the 3D deformation field values on points on the TIN surface, for which we developed a self-adapting TIN refinement method. By set the parameter of the attribute resolution, this self-adapting method refines the input geometric-expressing TIN model by adding more vertexes and triangles where the 3D deformation filed changing faster. Comparing with the even refinement method, the self-adapting method can generate a refined TIN model with nodes counted less by two thirds. Efficiency Comparison between Self-adapting Refinement Method and Even

  8. 3-D vision and figure-ground separation by visual cortex.

    PubMed

    Grossberg, S

    1994-01-01

    A neural network theory of three-dimensional (3-D) vision, called FACADE theory, is described. The theory proposes a solution of the classical figure-ground problem for biological vision. It does so by suggesting how boundary representations and surface representations are formed within a boundary contour system (BCS) and a feature contour system (FCS). The BCS and FCS interact reciprocally to form 3-D boundary and surface representations that are mutually consistent. Their interactions generate 3-D percepts wherein occluding and occluded object parts are separated, completed, and grouped. The theory clarifies how preattentive processes of 3-D perception and figure-ground separation interact reciprocally with attentive processes of spatial localization, object recognition, and visual search. A new theory of stereopsis is proposed that predicts how cells sensitive to multiple spatial frequencies, disparities, and orientations are combined by context-sensitive filtering, competition, and cooperation to form coherent BCS boundary segmentations. Several factors contribute to figure-ground pop-out, including: boundary contrast between spatially contiguous boundaries, whether due to scenic differences in luminance, color, spatial frequency, or disparity; partially ordered interactions from larger spatial scales and disparities to smaller scales and disparities; and surface filling-in restricted to regions surrounded by a connected boundary. Phenomena such as 3-D pop-out from a 2-D picture, Da Vinci stereopsis, 3-D neon color spreading, completion of partially occluded objects, and figure-ground reversals are analyzed. The BCS and FCS subsystems model aspects of how the two parvocellular cortical processing streams that join the lateral geniculate nucleus to prestriate cortical area V4 interact to generate a multiplexed representation of Form-And-Color-And-DEpth, or FACADE, within area V4. Area V4 is suggested to support figure-ground separation and to interact with

  9. Stereo-vision based 3D modeling for unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Se, Stephen; Jasiobedzki, Piotr

    2007-04-01

    Instant Scene Modeler (iSM) is a vision system for generating calibrated photo-realistic 3D models of unknown environments quickly using stereo image sequences. Equipped with iSM, Unmanned Ground Vehicles (UGVs) can capture stereo images and create 3D models to be sent back to the base station, while they explore unknown environments. Rapid access to 3D models will increase the operator situational awareness and allow better mission planning and execution, as the models can be visualized from different views and used for relative measurements. Current military operations of UGVs in urban warfare threats involve the operator hand-sketching the environment from live video feed. iSM eliminates the need for an additional operator as the 3D model is generated automatically. The photo-realism of the models enhances the situational awareness of the mission and the models can also be used for change detection. iSM has been tested on our autonomous vehicle to create photo-realistic 3D models while the rover traverses in unknown environments. Moreover, a proof-of-concept iSM payload has been mounted on an iRobot PackBot with Wayfarer technology, which is equipped with autonomous urban reconnaissance capabilities. The Wayfarer PackBot UGV uses wheel odometry for localization and builds 2D occupancy grid maps from a laser sensor. While the UGV is following walls and avoiding obstacles, iSM captures and processes images to create photo-realistic 3D models. Experimental results show that iSM can complement Wayfarer PackBot's autonomous navigation in two ways. The photo-realistic 3D models provide better situational awareness than 2D grid maps. Moreover, iSM also recovers the camera motion, also known as the visual odometry. As wheel odometry error grows over time, this can help improve the wheel odometry for better localization.

  10. Ground Water in Hawaii

    USGS Publications Warehouse

    Gingerich, Stephen B.; Oki, Delwyn S.

    2000-01-01

    Ground water is one of Hawaii's most important natural resources. It is used for drinking water, irrigation, and domestic, commercial, and industrial needs. Ground water provides about 99 percent of Hawaii's domestic water and about 50 percent of all freshwater used in the State. Total ground water pumped in Hawaii was about 500 million gallons per day during 1995, which is less than 3 percent of the average total rainfall (about 21 billion gallons per day) in Hawaii. From this perspective, the ground-water resource appears ample; however, much of the rainfall runs off to the ocean in streams or returns to the atmosphere by evapotranspiration. Furthermore, ground-water resources can be limited because of water-quality, environmental, or economic concerns. Water beneath the ground surface occurs in two principal zones: the unsaturated zone and the saturated zone. In the unsaturated zone, the pore spaces in rocks contain both air and water, whereas in the saturated zone, the pore spaces are filled with water. The upper surface of the saturated zone is referred to as the water table. Water below the water table is referred to as ground water. Ground-water salinity can range from freshwater to that of seawater. Freshwater is commonly considered to be water with a chloride concentration less than 250 mg/L, and this concentration represents about 1.3 percent of the chloride concentration of seawater (19,500 mg/L). Brackish water has a chloride concentration between that of freshwater (250 mg/L) and saltwater (19,500 mg/L).

  11. Ground motion simulations in Marmara (Turkey) region from 3D finite difference method

    NASA Astrophysics Data System (ADS)

    Aochi, Hideo; Ulrich, Thomas; Douglas, John

    2016-04-01

    In the framework of the European project MARSite (2012-2016), one of the main contributions from our research team was to provide ground-motion simulations for the Marmara region from various earthquake source scenarios. We adopted a 3D finite difference code, taking into account the 3D structure around the Sea of Marmara (including the bathymetry) and the sea layer. We simulated two moderate earthquakes (about Mw4.5) and found that the 3D structure improves significantly the waveforms compared to the 1D layer model. Simulations were carried out for different earthquakes (moderate point sources and large finite sources) in order to provide shake maps (Aochi and Ulrich, BSSA, 2015), to study the variability of ground-motion parameters (Douglas & Aochi, BSSA, 2016) as well as to provide synthetic seismograms for the blind inversion tests (Diao et al., GJI, 2016). The results are also planned to be integrated in broadband ground-motion simulations, tsunamis generation and simulations of triggered landslides (in progress by different partners). The simulations are freely shared among the partners via the internet and the visualization of the results is diffused on the project's homepage. All these simulations should be seen as a reference for this region, as they are based on the latest knowledge that obtained during the MARSite project, although their refinement and validation of the model parameters and the simulations are a continuing research task relying on continuing observations. The numerical code used, the models and the simulations are available on demand.

  12. Grounding line dynamics inferred from a 3D full-Stokes model solving the contact problem

    NASA Astrophysics Data System (ADS)

    Favier, Lionel; Gagliardini, Olivier; Durand, Gael; Zwinger, Thomas

    2010-05-01

    The mass balance of marine ice-sheets, such as the West Antarctic Ice Sheet, is mostly controlled by their grounding line dynamics. Most numerical models simulating marine ice-sheets involve simplifications and do not include all the stress gradients. First results obtained with a 3D full-Stokes model for the grounded ice-sheet / floating ice-shelf transition, using the finite-element code Elmer/Ice, are presented. The initial geometry, which takes into account a dome and a calving front, has been laterally extruded from a previously investigated 2D flowline geometry. The grounding line migration is computed by solving the contact problem between the ice and the rigid downward sloping bedrock, where a non linear friction law is applied in the two horizontal directions. The evolutions of the sea-air and sea-ice interfaces are determined by the solution of a local transport equation. The consistency between the 3D model and the analogous results of the flowline model is shown by comparing the results in the basic extruded case, with no normal flux through lateral boundaries. Thereafter, spatially non uniform perturbations are introduced, to simulate the grounding line dynamics under fully three-dimensional perturbations.

  13. A Little Knowledge of Ground Motion: Explaining 3-D Physics-Based Modeling to Engineers

    NASA Astrophysics Data System (ADS)

    Porter, K.

    2014-12-01

    Users of earthquake planning scenarios require the ground-motion map to be credible enough to justify costly planning efforts, but not all ground-motion maps are right for all uses. There are two common ways to create a map of ground motion for a hypothetical earthquake. One approach is to map the median shaking estimated by empirical attenuation relationships. The other uses 3-D physics-based modeling, in which one analyzes a mathematical model of the earth's crust near the fault rupture and calculates the generation and propagation of seismic waves from source to ground surface by first principles. The two approaches produce different-looking maps. The more-familiar median maps smooth out variability and correlation. Using them in a planning scenario can lead to a systematic underestimation of damage and loss, and could leave a community underprepared for realistic shaking. The 3-D maps show variability, including some very high values that can disconcert non-scientists. So when the USGS Science Application for Risk Reduction's (SAFRR) Haywired scenario project selected 3-D maps, it was necessary to explain to scenario users—especially engineers who often use median maps—the differences, advantages, and disadvantages of the two approaches. We used authority, empirical evidence, and theory to support our choice. We prefaced our explanation with SAFRR's policy of using the best available earth science, and cited the credentials of the maps' developers and the reputation of the journal in which they published the maps. We cited recorded examples from past earthquakes of extreme ground motions that are like those in the scenario map. We explained the maps on theoretical grounds as well, explaining well established causes of variability: directivity, basin effects, and source parameters. The largest mapped motions relate to potentially unfamiliar extreme-value theory, so we used analogies to human longevity and the average age of the oldest person in samples of

  14. The Martian Water Cycle Based on 3-D Modeling

    NASA Technical Reports Server (NTRS)

    Houben, H.; Haberle, R. M.; Joshi, M. M.

    1999-01-01

    Understanding the distribution of Martian water is a major goal of the Mars Surveyor program. However, until the bulk of the data from the nominal missions of TES, PMIRR, GRS, MVACS, and the DS2 probes are available, we are bound to be in a state where much of our knowledge of the seasonal behavior of water is based on theoretical modeling. We therefore summarize the results of this modeling at the present time. The most complete calculations come from a somewhat simplified treatment of the Martian climate system which is capable of simulating many decades of weather. More elaborate meteorological models are now being applied to study of the problem. The results show a high degree of consistency with observations of aspects of the Martian water cycle made by Viking MAWD, a large number of ground-based measurements of atmospheric column water vapor, studies of Martian frosts, and the widespread occurrence of water ice clouds. Additional information is contained in the original extended abstract.

  15. Ground water. [Water pollution control

    SciTech Connect

    Costle, D.M.

    1980-09-01

    There is growing evidence that the Nation's ground water is contaminated by a variety of sources. These include unprotected industrial, municipal, and radioactive disposal sites, petroleum exploration and mining activities, agricultural operations such as insecticide spraying, high de-icing salts and others. As of March 1980, more than 8000 chemical tests have been performed on well water, with chlorinated organic solvents found most frequently. Because 100 million Americans may be threatened by unfit drinking water, EPA has developed a new ground water strategy. It will enlist the help of State and local governments who already have programs under way and it will involve broad public debate and participation.

  16. Broadband Near-Field Ground Motion Simulations in 3D Scattering Media

    NASA Astrophysics Data System (ADS)

    Imperatori, Walter; Mai, Martin

    2013-04-01

    The heterogeneous nature of Earth's crust is manifested in the scattering of propagating seismic waves. In recent years, different techniques have been developed to include such phenomenon in broadband ground-motion calculations, either considering scattering as a semi-stochastic or pure stochastic process. In this study, we simulate broadband (0-10 Hz) ground motions using a 3D finite-difference wave propagation solver using several 3D media characterized by Von Karman correlation functions with different correlation lengths and standard deviation values. Our goal is to investigate scattering characteristics and its influence on the seismic wave-field at short and intermediate distances from the source in terms of ground motion parameters. We also examine other relevant scattering-related phenomena, such as the loss of radiation pattern and the directivity breakdown. We first simulate broadband ground motions for a point-source characterized by a classic omega-squared spectrum model. Fault finiteness is then introduced by means of a Haskell-type source model presenting both sub-shear and super-shear rupture speed. Results indicate that scattering plays an important role in ground motion even at short distances from the source, where source effects are thought to be dominating. In particular, peak ground motion parameters can be affected even at relatively low frequencies, implying that earthquake ground-motion simulations should include scattering also for PGV calculations. At the same time, we find a gradual loss of the source signature in the 2-5 Hz frequency range, together with a distortion of the Mach cones in case of super-shear rupture. For more complex source models and truly heterogeneous Earth, these effects may occur even at lower frequencies. Our simulations suggest that Von Karman correlation functions with correlation length between several hundred meters and few kilometers, Hurst exponent around 0.3 and standard deviation in the 5-10% range

  17. Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points

    NASA Astrophysics Data System (ADS)

    Dewez, T. J. B.

    2014-05-01

    Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.

  18. Velocity and Density Models Incorporating the Cascadia Subduction Zone for 3D Earthquake Ground Motion Simulations

    USGS Publications Warehouse

    Stephenson, William J.

    2007-01-01

    INTRODUCTION In support of earthquake hazards and ground motion studies in the Pacific Northwest, three-dimensional P- and S-wave velocity (3D Vp and Vs) and density (3D rho) models incorporating the Cascadia subduction zone have been developed for the region encompassed from about 40.2?N to 50?N latitude, and from about -122?W to -129?W longitude. The model volume includes elevations from 0 km to 60 km (elevation is opposite of depth in model coordinates). Stephenson and Frankel (2003) presented preliminary ground motion simulations valid up to 0.1 Hz using an earlier version of these models. The version of the model volume described here includes more structural and geophysical detail, particularly in the Puget Lowland as required for scenario earthquake simulations in the development of the Seattle Urban Hazards Maps (Frankel and others, 2007). Olsen and others (in press) used the model volume discussed here to perform a Cascadia simulation up to 0.5 Hz using a Sumatra-Andaman Islands rupture history. As research from the EarthScope Program (http://www.earthscope.org) is published, a wealth of important detail can be added to these model volumes, particularly to depths of the upper-mantle. However, at the time of development for this model version, no EarthScope-specific results were incorporated. This report is intended to be a reference for colleagues and associates who have used or are planning to use this preliminary model in their research. To this end, it is intended that these models will be considered a beginning template for a community velocity model of the Cascadia region as more data and results become available.

  19. Numerical Benchmark of 3D Ground Motion Simulation in the Alpine valley of Grenoble, France.

    NASA Astrophysics Data System (ADS)

    Tsuno, S.; Chaljub, E.; Cornou, C.; Bard, P.

    2006-12-01

    Thank to the use of sophisticated numerical methods and to the access to increasing computational resources, our predictions of strong ground motion become more and more realistic and need to be carefully compared. We report our effort of benchmarking numerical methods of ground motion simulation in the case of the valley of Grenoble in the French Alps. The Grenoble valley is typical of a moderate seismicity area where strong site effects occur. The benchmark consisted in computing the seismic response of the `Y'-shaped Grenoble valley to (i) two local earthquakes (Ml<=3) for which recordings were avalaible; and (ii) two local hypothetical events (Mw=6) occuring on the so-called Belledonne Border Fault (BBF) [1]. A free-style prediction was also proposed, in which participants were allowed to vary the source and/or the model parameters and were asked to provide the resulting uncertainty in their estimation of ground motion. We received a total of 18 contributions from 14 different groups; 7 of these use 3D methods, among which 3 could handle surface topography, the other half comprises predictions based upon 1D (2 contributions), 2D (4 contributions) and empirical Green's function (EGF) (3 contributions) methods. Maximal frequency analysed ranged between 2.5 Hz for 3D calculations and 40 Hz for EGF predictions. We present a detailed comparison of the different predictions using raw indicators (e.g. peak values of ground velocity and acceleration, Fourier spectra, site over reference spectral ratios, ...) as well as sophisticated misfit criteria based upon previous works [2,3]. We further discuss the variability in estimating the importance of particular effects such as non-linear rheology, or surface topography. References: [1] Thouvenot F. et al., The Belledonne Border Fault: identification of an active seismic strike-slip fault in the western Alps, Geophys. J. Int., 155 (1), p. 174-192, 2003. [2] Anderson J., Quantitative measure of the goodness-of-fit of

  20. 3-D Ground Displacement Monitoring of very fast-moving Landslides in Emergency Scenario

    NASA Astrophysics Data System (ADS)

    Casu, Francesco; Manconi, Andrea; Bonano, Manuela; De Luca, Claudio; Elefante, Stefano

    2014-05-01

    On December 3rd, 2013, a large and fast-moving landslide phenomena, which occurred in South-West of Montescaglioso town (southern Italy) after some days of intense raining, caused ground displacements on the order of several meters. The mass wasting involved an important freeway connection disrupting more than 500 meters of the route and some isolated buildings. In this work we present a case study of application of SAR remote sensing techniques for retrieving ground displacement field in a landslide emergency scenario. To this aim, thanks to the availability of ascending and descending COSMO-SkyMed (CSK) satellite acquisitions, we first applied the DInSAR technique (Massonnet et al., 1993) to both datasets, for generating differential interferograms across the investigated event. In particular, two data pairs (one ascending and one descending) involving pre- and post-event epochs and approximately spanning the same time interval were identified. Unfortunately, the DInSAR analysis produced unsatisfactory results, because of the excessive phase noise within the area of interest, mainly related to the fast-moving deformation pattern (several meters) and also to the presence of vegetation. To overcome the above mentioned limitations, the amplitude-based Pixel Offset (PO) technique (Fialko and Simons, 2001) was applied to the previous identified CSK data pairs. In this case, the PO technique allowed us to retrieve the projection of the surface displacements across and along the satellite's track (range and azimuth, respectively) for both the ascending and descending orbits. Then, by properly combining these 2-D maps of the measured surface movements, we also retrieved the 3-D ground deformation pattern, i.e. the North, East and Vertical displacement components. The ground displacements have a main SSE component, with values exceeding 10 meters. Moreover, large subsidence values were identified in those areas experiencing the largest damages, as well as a clear uplift

  1. Probabilistic Seismic Hazard Maps for Seattle, Washington, Based on 3D Ground-Motion Simulations

    NASA Astrophysics Data System (ADS)

    Frankel, A. D.; Stephenson, W. J.; Carver, D. L.; Williams, R. A.; Odum, J. K.; Rhea, S.

    2007-12-01

    We have produced probabilistic seismic hazard maps for Seattle using over 500 3D finite-difference simulations of ground motions from earthquakes in the Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep source areas. The maps depict 1 Hz response spectral accelerations with 2, 5, and 10% probabilities of being exceeded in 50 years. The simulations were used to generate site and source dependent amplification factors that are applied to rock-site attenuation relations. The maps incorporate essentially the same fault sources and earthquake recurrence times as the 2002 national seismic hazard maps. The simulations included basin surface waves and basin-edge focusing effects from a 3D model of the Seattle basin. The 3D velocity model was validated by modeling several earthquakes in the region, including the 2001 M6.8 Nisqually earthquake, that were recorded by our Seattle Urban Seismic Network and the Pacific Northwest Seismic Network. The simulations duplicate our observation that earthquakes from the south and southwest typically produce larger amplifications in the Seattle basin than earthquakes from other azimuths, relative to rock sites outside the basin. Finite-fault simulations were run for earthquakes along the Seattle fault zone, with magnitudes ranging from 6.6 to 7.2, so that the effects of rupture directivity were included. Nonlinear amplification factors for soft-soil sites of fill and alluvium were also applied in the maps. For the Cascadia subduction zone, 3D simulations with point sources at different locations along the zone were used to determine amplification factors across Seattle expected for great subduction-zone earthquakes. These new urban seismic hazard maps are based on determinations of hazard for 7236 sites with a spacing of 280 m. The maps show that the highest hazard locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and

  2. Accurate nonrelativistic ground-state energies of 3d transition metal atoms

    SciTech Connect

    Scemama, A.; Applencourt, T.; Giner, E.; Caffarel, M.

    2014-12-28

    We present accurate nonrelativistic ground-state energies of the transition metal atoms of the 3d series calculated with Fixed-Node Diffusion Monte Carlo (FN-DMC). Selected multi-determinantal expansions obtained with the CIPSI (Configuration Interaction using a Perturbative Selection made Iteratively) method and including the most prominent determinants of the full configuration interaction expansion are used as trial wavefunctions. Using a maximum of a few tens of thousands determinants, fixed-node errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with Hartree-Fock nodes. To the best of our knowledge, the FN-DMC/(CIPSI nodes) ground-state energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended non-variational values of McCarthy and Thakkar [J. Chem. Phys. 136, 054107 (2012)] only by a few percents of the correlation energy. Thanks to the variational property of FN-DMC total energies, our results provide exact lower bounds for the absolute value of all-electron correlation energies, |E{sub c}|.

  3. 3D Modeling of Landslide in Open-pit Mining on Basis of Ground-based LIDAR Data

    NASA Astrophysics Data System (ADS)

    Hu, H.; Fernandez-Steeger, T. M.; Azzam, R.; Arnhardt, C.

    2009-04-01

    Slope stability is not only an important problem which is related to production and safety in open-pit mining, but also very complex task. There are three main reasons which affect the slope stability as follows: geotechnical factors: Geological structure, lithologic characteristics, water, cohesion, friction, etc.; climate factors: Rainfall and temperature; and external factors: Open-pit mining process, explosion vibration, dynamic load, etc.. The 3rd reason, as a specially one in open-pit mining, not only causes some dynamic problems but also induces the fast geometry changing which must be considered in the following research using numerical simulation and stability analysis. Recently, LIDAR technology has been applied in many fields and places in the world wide. Ground-based LIDAR technology with high accuracy up to 3mm increasingly accommodates to monitoring landslides and detecting changing. LIDAR data collection and preprocessing research have been carried out by Department of Engineering Geology and Hydrogeology at RWTH Aachen University. LIDAR data, so-called a point-cloud of mass data in high density can be obtained in short time for the sensitive open-pit mining area by using ground-based LIDAR. To obtain a consistent surface model, it is necessary to set up multiple scans with the ground-based LIDAR. The framework of data preprocessing which can be implemented by Poly-Works is introduced as follows: gross error detection and elimination, integration of reference frame, model fusion of different scans (re-sampled in overlap region), data reduction without removing the useful information which is a challenge and research front in LIDAR data processing. After data preprocessing, 3D surface model can be directly generated in Poly-Works or generated in other software by building the triangular meshes. The 3D surface landslide model can be applied to further researches such as: real time landslide geometry monitoring due to the fast data collection and

  4. 3-D Waveguide Effects of Topographical Structural Variation on Full Waveform Propagation: 3-D Finite Difference Modeling Comparisons with Field Data From Yuma Proving Ground, Arizona

    NASA Astrophysics Data System (ADS)

    Anderson, T. S.; Miller, R.; Greenfield, R.; Fisk, D.

    2002-12-01

    The propagation of seismic waves through regions of complex topography is not thoroughly understood. Surface waves, are of particular interest, as they are large in amplitude and can characterize the source depth, magnitude, and frequency content. The amplitude and frequency content of seismic waves that propagate in regions with large topographical variations are affected by both the scattering and blockage of the wave energy. The ability to predict the 3-d scattering due to topography will improve the understanding of both regional scale surface wave magnitudes, and refine surface wave discriminants as well as at the local scale (<2 km ) where it will aid in the development of rule of thumb guide lines for array sensor placement for real time sensing technologies. Ideally, when validating the numerical accuracy of a propagation model against field data, the input geologic parameters would be known and thus eliminates geology as a source of error in the calculation. In March of 2001, Kansas Geological Survey (KGS) performed a detailed seismic site characterization at the Smart Weapons Test Range, Yuma Proving Ground, Arizona. The result of the KGS characterization study is a high-resolution 3-d model that is used in our seismic simulations. The velocities Vs, Vp are calculated by tomography and refraction, attenuation coefficients estimated from the surface wave and from p-waves and are provided in a model with attributes resolved in 3-d to 0.5 meters. In the present work, we present comparisons of synthetic data with seismic data collected at the Smart Weapons Test Range to benchmark the accuracy achieved in simulating 3-d wave propagation in the vicinity of a topographical anomaly (trench). Synthetic seismograms are generated using a 3-d 8th order staggered grid visco-elastic finite difference code that accounts for topography. The geologic model is based on the Yuma site characterization. The size of these calculations required use of the DoD High Performance

  5. Quantification of Ground Motion Reductions by Fault Zone Plasticity with 3D Spontaneous Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cui, Y.; Day, S. M.

    2015-12-01

    We explore the effects of fault zone nonlinearity on peak ground velocities (PGVs) by simulating a suite of surface rupturing earthquakes in a visco-plastic medium. Our simulations, performed with the AWP-ODC 3D finite difference code, cover magnitudes from 6.5 to 8.0, with several realizations of the stochastic stress drop for a given magnitude. We test three different models of rock strength, with friction angles and cohesions based on criteria which are frequently applied to fractured rock masses in civil engineering and mining. We use a minimum shear-wave velocity of 500 m/s and a maximum frequency of 1 Hz. In rupture scenarios with average stress drop (~3.5 MPa), plastic yielding reduces near-fault PGVs by 15 to 30% in pre-fractured, low-strength rock, but less than 1% in massive, high quality rock. These reductions are almost insensitive to the scenario earthquake magnitude. In the case of high stress drop (~7 MPa), however, plasticity reduces near-fault PGVs by 38 to 45% in rocks of low strength and by 5 to 15% in rocks of high strength. Because plasticity reduces slip rates and static slip near the surface, these effects can partially be captured by defining a shallow velocity-strengthening layer. We also perform a dynamic nonlinear simulation of a high stress drop M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. With respect to the viscoelastic solution (a), nonlinearity in the fault damage zone and in near-surface deposits would reduce long-period (> 1 s) peak ground velocities in the Los Angeles basin by 15-50% (b), depending on the strength of crustal rocks and shallow sediments. These simulation results suggest that nonlinear effects may be relevant even at long periods, especially for earthquakes with high stress drop.

  6. Estimating porosity with ground-penetrating radar reflection tomography: A controlled 3-D experiment at the Boise Hydrogeophysical Research Site

    NASA Astrophysics Data System (ADS)

    Bradford, John H.; Clement, William P.; Barrash, Warren

    2009-04-01

    To evaluate the uncertainty of water-saturated sediment velocity and porosity estimates derived from surface-based, ground-penetrating radar reflection tomography, we conducted a controlled field experiment at the Boise Hydrogeophysical Research Site (BHRS). The BHRS is an experimental well field located near Boise, Idaho. The experimental data set consisted of 3-D multioffset radar acquired on an orthogonal 20 × 30 m surface grid that encompassed a set of 13 boreholes. Experimental control included (1) 1-D vertical velocity functions determined from traveltime inversion of vertical radar profiles (VRP) and (2) neutron porosity logs. We estimated the porosity distribution in the saturated zone using both the Topp and Complex Refractive Index Method (CRIM) equations and found the CRIM estimates in better agreement with the neutron logs. We found that when averaged over the length of the borehole, surface-derived velocity measurements were within 5% of the VRP velocities and that the porosity differed from the neutron log by less than 0.05. The uncertainty, however, is scale dependent. We found that the standard deviation of differences between ground-penetrating-radar-derived and neutron-log-derived porosity values was as high as 0.06 at an averaging length of 0.25 m but decreased to less than 0.02 at length scale of 11 m. Additionally, we used the 3-D porosity distribution to identify a relatively high-porosity anomaly (i.e., local sedimentary body) within a lower-porosity unit and verified the presence of the anomaly using the neutron porosity logs. Since the reflection tomography approach requires only surface data, it can provide rapid assessment of bulk hydrologic properties, identify meter-scale anomalies of hydrologic significance, and may provide input for other higher-resolution measurement methods.

  7. Vegetation Structure and 3-D Reconstruction of Forests Using Ground-Based Echidna® Lidar

    NASA Astrophysics Data System (ADS)

    Strahler, A. H.; Yao, T.; Zhao, F.; Yang, X.

    2009-12-01

    A ground-based, scanning, near-infrared lidar, the Echidna® validation instrument (EVI), built by CSIRO Australia, retrieves structural parameters of forest stands rapidly and accurately, and by merging multiple scans into a single point cloud provides 3-D stand reconstructions. Echidna lidar technology scans with pulses of light at 1064 nm wavelength and digitizes the light returns sufficiently finely to recover and distinguish the differing shapes of return pulses as they are scattered by leaves and trunks or larger branches. Instrument deployments in the New England region in 2007 and 2009 and in the southern Sierra Nevada of California in 2008 provided the opportunity to test the ability of the instrument to retrieve tree diameters, stem count density (stems/ha), basal area, and above-ground woody biomass from single scans at points beneath the forest canopy. In New England in 2007, mean parameters retrieved from five scans located within six 1-ha stand sites match manually-measured parameters with values of R2 = 0.94-0.99. Processing the scans to retrieve leaf area index (LAI) provided values within the range of those retrieved with other optical instruments and hemispherical photography. Foliage profiles, which measure leaf area with canopy height, showed distinctly different shapes for the stands, depending on species composition and age structure. Stand heights, obtained from foliage profiles, were not significantly different from RH100 values observed by the Laser Vegetation Imaging Sensor in 2003. Data from the California 2008 and New England 2009 deployments were still being processed at the time of abstract submission. With further hardware and software development, Echidna® technology will provide rapid and accurate measurements of forest canopy structure that can replace manual field measurements, leading to more rapid and more accurate calibration and validation of structure mapping techniques using airborne and spaceborne remote sensors. Three

  8. Detection of 3D tree root systems using high resolution ground penetration radar

    NASA Astrophysics Data System (ADS)

    Altdorff, D.; Honds, M.; Botschek, J.; Van Der Kruk, J.

    2014-12-01

    Knowledge of root systems and its distribution are important for biomass estimation as well as for the prevention of subsurface distribution network damages. Ground penetration radar (GPR) is a promising technique that enables a non-invasive imaging of tree roots. Due to the polarisation-dependent reflection coefficients and complicated three-dimensional root structure, accurate measurements with perpendicularly polarized antennas are needed. In this study, we show GPR data from two planes and one chestnut at two locations with different soil conditions. Perpendicular 10 x 10 cm grid measurements were made with a shielded 250 MHz antenna in combination with a high precision self-tracking laser theodolite that provides geo-referenced traces with a spatial resolution of ~ 2 cm. After selecting potential root hyperbolas within the perpendicular GPR profiles, the corresponding three-dimensional coordinates were extracted and visualized in planar view to reveal any linear structure that indicates a possible tree root. The coordinates of the selected linear structures were projected back to the surface by means of the laser-theodolite to indicate the locations for groundtruthing. Additionally, we interpolated the measured data into a 3D cube where time slices confirmed the locations of linear reflection events. We validated the indicated predictions by excavation of the soil with a suction dredge. Subsequent georeferencing of the true root distribution and comparison with the selected linear events showed that the approach was able to identify the precise position of roots with a diameter between 3 and 10 cm and a depth of up to 70 cm. However, not all linear events were roots; also mouse channels were found in these depths, since they also generate GPR hyperbolas aligned in linear structures. Roots at a second location at depths of 1 to 1.20 m did not generate identifiable hyperboles, which was probably due to an increased electrical conductivity below 86 cm depth. The

  9. Cooperative 3D and 2D mapping with heterogenous ground robots

    NASA Astrophysics Data System (ADS)

    Rogers, John G., III; Baran, David; Stump, Ethan; Young, Stuart; Christensen, Henrik I.

    2012-06-01

    Efficient and accurate 3D mapping is desirable in disaster recovery as well as urban warfare situations. The speed with which these maps can be generated is vital to provide situational awareness in these situations. A team of mobile robots can work together to build maps more quickly. We present an algorithm by which a team of mobile robots can merge 2D and 3D measurements to build a 3D map, together with experiments performed at a military test facility.

  10. CONNECTICUT GROUND WATER QUALITY CLASSIFICATIONS

    EPA Science Inventory

    This is a 1:24,000-scale datalayer of Ground Water Quality Classifications in Connecticut. It is a polygon Shapefile that includes polygons for GA, GAA, GAAs, GB, GC and other related ground water quality classes. Each polygon is assigned a ground water quality class, which is s...

  11. Ground penetrating radar and microwave tomography 3D applications for the deck evaluation of the Musmeci bridge in Potenza, Italy

    NASA Astrophysics Data System (ADS)

    Bavusi, Massimo; Soldovieri, Francesco; Di Napoli, Rosario; Loperte, Antonio; Di Cesare, Antonio; Carlo Ponzo, Felice; Lapenna, Vincenzo

    2011-09-01

    An extensive experimental and numerical investigation has been carried out to assess the status of the 'Ponte sul Basento' (1967-1976), in the town of Potenza (Basilicata region, southern Italy), better known as the Musmeci bridge. Architecturally, the bridge is a considerable reinforced 20th century concrete structure that was designed and built by the Italian architect Sergio Musmeci (1926-1981). Moreover, the bridge represents an important element of the infrastructural network, linking the city centre to the Potenza-Sicignano highway, crossing the Basento river and the railway close to the main train station of the city. Recently, due to ageing and continuous and significant traffic, the bridge started to be affected by several problems such as water infiltration. Within the presented study, a widespread ground penetrating radar (GPR) survey has been designed to investigate the geometrical characteristics of the bridge deck (Gerber saddles, internal stiffening walls, pillar supports) and detect the presence of defects or damage due to water infiltration and traffic fatigue. Concerning this, a 900 MHz 3D GPR survey has been performed along a zone of one of the lanes on the road surface. Moreover, a second 1500 MHz 3D survey has been carried out at the bottom of the bridge deck in order to gain detailed information about an important structural element of the bridge, the Gerber saddle. Both results have been processed following two approaches: the first a classical time-domain processing session based on commercial software and the use of migration; the second in microwave tomography, an advanced frequency domain automatic PC-based inversion algorithm. In this paper, we present a comparative interpretation of both kinds of processed results, and provide considerations about the investigated structures.

  12. Quasi 3D modeling of water flow in vadose zone and groundwater

    NASA Astrophysics Data System (ADS)

    Kuznetsov, M.; Yakirevich, A.; Pachepsky, Y. A.; Sorek, S.; Weisbrod, N.

    2012-07-01

    SummaryThe complexity of subsurface flow systems calls for a variety of concepts leading to the multiplicity of simplified flow models. One habitual simplification is based on the assumption that lateral flow and transport in unsaturated zone are not significant unless the capillary fringe is involved. In such cases the flow and transport in the unsaturated zone above groundwater level can be simulated as a 1D phenomenon, whereas the flow and transport through groundwater are viewed as 2D or 3D phenomena. A new approach for a numerical scheme for 3D variably saturated flow using quasi 3D Richards' equation and finite difference scheme is presented. The corresponding numerical algorithm and the QUASI-3D computer code were developed. Results of the groundwater level simulations were compared with transient laboratory experimental data for 2D data constant-flux infiltration, quasi-3D HYDRUS-MODFLOW numerical model and a FULL-3D numerical model using Richards' equation. Hypothetical 3D examples of infiltration, pumping and groundwater mound dissipation for different spatial-time scales are presented. Water flow simulation for the Alto Piura aquifer (Peru) demonstrates the QUASI-3D model application at the regional scale. Computationally the QUASI-3D code was found to be more efficient by an order of 10-300%, while being accurate with respect to the benchmark fully 3D variable saturation code, when the capillary fringe was considered.

  13. A 3D finite element simulation model for TBM tunnelling in soft ground

    NASA Astrophysics Data System (ADS)

    Kasper, Thomas; Meschke, Günther

    2004-12-01

    A three-dimensional finite element simulation model for shield-driven tunnel excavation is presented. The model takes into account all relevant components of the construction process (the soil and the ground water, the tunnel boring machine with frictional contact to the soil, the hydraulic jacks, the tunnel lining and the tail void grouting). The paper gives a detailed description of the model components and the stepwise procedure to simulate the construction process. The soil and the grout material are modelled as saturated porous media using a two-field finite element formulation. This allows to take into account the groundwater, the grouting pressure and the fluid interaction between the soil and slurry at the cutting face and between the soil and grout around the tail void. A Cam-Clay plasticity model is used to describe the material behaviour of cohesive soils. The cementitious grouting material in the tail void is modelled as an ageing elastic material with time-dependent stiffness and permeability. To allow for an automated computation of arbitrarily long and also curvilinear driving paths with suitable finite element meshes, the simulation procedure has been fully automated. The simulation of a tunnel advance in soft cohesive soil below the ground water table is presented and the results are compared with measurements taken from the literature. Copyright

  14. Ground water and energy

    SciTech Connect

    Not Available

    1980-05-01

    In view of complex environmental/energy decisions, the Environmental Impacts Division of the Office of Technology Impacts develops analytical methods for conducting policy analyses supporting decision making. The methods development process often begins with a workshop of leading experts and specialists in the relevant disciplines and issue areas; workshop findings are subsequently utilized by OTI to form a more solid foundation for viable policies. The National Workshop on Ground Water and Energy Production was envisioned as a tool through which OTI could obtain insights, information, and methods (on environmental, economical, physical, political, legal, and social issues) to use in its analyses, models, and assessments. To accomplish this, the Workshop comprised both plenary sessions and individual working groups. The former provided opportunities for all participants to explore issues from a broad perspective, whereas the latter enabled participants to focus on the three following areas: ground water supply; conflicts and barriers to its use; and alternatives or solutions to the various issues. This report summarizes information and insights gained by the Office of Technology Impacts during the course of the Workshop. The Key Findings section summarizes the most important facts discovered during the Workshop. The three general topics that follow (Supply, Conflicts and Barriers, and Alternatives) are those described in the Core Issues statements. The statements are reflective of the recommendations and analyses prepared by the several working groups.

  15. Ground Deformation Analysis of Blast-Induced Liquefaction at a Simulated Airport Infrastructure Using High Resolution 3D Laser Scanning

    NASA Astrophysics Data System (ADS)

    Minasian, D.; Kayen, R.; Ashford, S.; Kawamata, Y.; Sugano, T.

    2008-12-01

    In October 2007, the Port and Airport Research Institute (PARI) of the Japan Ministry of Land, Infrastructure and Transportation conducted a large-scale blast-induced liquefaction experiment in Ishikari, Hokkaido, Japan. Approximately 24,000 m2 of ground was liquefied using controlled blasting techniques to investigate the performance of airport infrastructure. The USGS and Oregon State University participated in the study and measured topographic changes in ground level using 3D laser scanning techniques (terrestrial lidar), as well as changes in shear wave velocity of the between the pre- and post-liquefied soil. This poster focuses on the lidar results. The overall objective of the PARI experiment is to assess the performance of airport infrastructure subjected to liquefaction. Specifically, the performance of pipelines and large concrete utility raceways located beneath runway pavements is of interest, as well as the performance of pavements and embankments with and without soil improvement techniques. At the site, 5-7 m of loose silty sand was placed as hydraulic fill on natural alluvial sand as an expansion of the Ishikari port facility. On a portion of the liquefied site, three 20 m by 50 m test sections were constructed to investigate the performance of improved ground beneath asphalt runways, concrete runway aprons, and open areas. Pipelines and concrete utility conduits were also buried in each section. The three ground improvement techniques investigated were sand-cement mixing, vertical drains, and colloidal silica injection. The PARI experiment provided an excellent opportunity to conduct terrestrial lidar measurements - a revolutionary tool for accurate characterization of fine-scale changes of topography and identification of subtle deformations. Lidar was used for characterizing post-blast deformations both immediately after the charges were used, and subsequently over time at intervals of 2 days, 4 days, and 5 months after blasting. Settlement

  16. Ground water and climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the world’s largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food secu¬rity will probably intensify under climate chan...

  17. Preventing ground water contamination

    SciTech Connect

    Thompson, R.

    1985-07-12

    A recent Office of Technology Assessment report to Congress indicates that the associated health risks from ground water contamination are likely to increase because federal and state laws provide inadequate protection. Road de-icing salts, pesticide runoff, septic tanks, and seepage from livestock manure and fertilizers are all major causes that are difficult to control. A primary source that can be corrected is improper or unsafe disposal of hazardous wastes that are dumped into landfills or surface ponds or injected into deep wells. Congress has tried to deal with the problem by strengthening existing and introducing new legislation. Because getting rid of hazardous waste is increasingly expensive and difficult, companies are beginning to look for ways to prevent pollution at the source by using new technologies that are economically sound. 17 references, 4 figures.

  18. Pedestrian and car detection and classification for unmanned ground vehicle using 3D lidar and monocular camera

    NASA Astrophysics Data System (ADS)

    Cho, Kuk; Baeg, Seung-Ho; Lee, Kimin; Lee, Hae Seok; Park, SangDeok

    2011-05-01

    This paper describes an object detection and classification method for an Unmanned Ground Vehicle (UGV) using a range sensor and an image sensor. The range sensor and the image sensor are a 3D Light Detection And Ranging (LIDAR) sensor and a monocular camera, respectively. For safe driving of the UGV, pedestrians and cars should be detected on their moving routes of the vehicle. An object detection and classification techniques based on only a camera has an inherent problem. On the view point of detection with a camera, a certain algorithm should extract features and compare them with full input image data. The input image has a lot of information as object and environment. It is hard to make a decision of the classification. The image should have only one reliable object information to solve the problem. In this paper, we introduce a developed 3D LIDAR sensor and apply a fusion method both 3D LIDAR data and camera data. We describe a 3D LIDAR sensor which is developed by LG Innotek Consortium in Korea, named KIDAR-B25. The 3D LIDAR sensor detects objects, determines the object's Region of Interest (ROI) based on 3D information and sends it into a camera region for classification. In the 3D LIDAR domain, we recognize breakpoints using Kalman filter and then make a cluster using a line segment method to determine an object's ROI. In the image domain, we extract the object's feature data from the ROI region using a Haar-like feature method. Finally it is classified as a pedestrian or car using a trained database with an Adaboost algorithm. To verify our system, we make an experiment on the performance of our system which is mounted on a ground vehicle, through field tests in an urban area.

  19. 2D and 3D Ground Penetrating Radar monitoring of a reinforced concrete asphalt plate affected by mechanical deformation.

    NASA Astrophysics Data System (ADS)

    Bavusi, M.; Dumoulin, J.; Loperte, A.; Rizzo, E.; Soldovieri, F.

    2012-04-01

    , a zero setting acquisition was carried out before perturbing the plate. Described experience demonstrates the GPR is a reliable technique for the: • foundation soil characterization and monitoring • Reinforced structural elements monitoring • asphalt/reinforced concrete characterization and monitoring • detection of water infiltration, structural elements, defects • evaluation of restoration intervention. In fact, the GPR technique was able to investigate the layers beyond the asphalt and provides a spatial resolution complying with the needs of the technical problem at hand by use of different antennas. Moreover noticeable performances of this technique can be further improved by implementing 3D processing and MT inversion procedures in order to increase the amount of information by the survey [2]. Acknowledgements. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n. 225663 Joint Call FP7-ICT-SEC-2007-1 [1] Lapenna, V.; Cuomo, V.; Rizzo, E.; Fiore, S.; Troisi, S.; Straface, S. (2006). A new Large Lab-scale Facility for Hydro-Geophysical Experiments: Hydrogeosite. American Geophysical Union, Fall Meeting 2006, abstract #H31B-1422 [2] Bavusi M., Soldovieri F., Di Napoli R., Loperte A., Di Cesare A., Ponzo F.C and Lapenna V. (2011). Ground penetrating radar and microwave tomography 3D applications for the deck evaluation of the Musmeci bridge in Potenza, Italy. J. Geophys. Eng. 8 S33 doi:10.1088/1742-2132/8/3/S04

  20. Estimating 3D variation in active-layer thickness beneath arctic streams using ground-penetrating radar

    USGS Publications Warehouse

    Brosten, T.R.; Bradford, J.H.; McNamara, J.P.; Gooseff, M.N.; Zarnetske, J.P.; Bowden, W.B.; Johnston, M.E.

    2009-01-01

    We acquired three-dimensional (3D) ground-penetrating radar (GPR) data across three stream sites on the North Slope, AK, in August 2005, to investigate the dependence of thaw depth on channel morphology. Data were migrated with mean velocities derived from multi-offset GPR profiles collected across a stream section within each of the 3D survey areas. GPR data interpretations from the alluvial-lined stream site illustrate greater thaw depths beneath riffle and gravel bar features relative to neighboring pool features. The peat-lined stream sites indicate the opposite; greater thaw depths beneath pools and shallower thaw beneath the connecting runs. Results provide detailed 3D geometry of active-layer thaw depths that can support hydrological studies seeking to quantify transport and biogeochemical processes that occur within the hyporheic zone.

  1. High-performance 3D printing of hydrogels by water-dispersible photoinitiator nanoparticles.

    PubMed

    Pawar, Amol A; Saada, Gabriel; Cooperstein, Ido; Larush, Liraz; Jackman, Joshua A; Tabaei, Seyed R; Cho, Nam-Joon; Magdassi, Shlomo

    2016-04-01

    In the absence of water-soluble photoinitiators with high absorbance in the ultraviolet (UV)-visible range, rapid three-dimensional (3D) printing of hydrogels for tissue engineering is challenging. A new approach enabling rapid 3D printing of hydrogels in aqueous solutions is presented on the basis of UV-curable inks containing nanoparticles of highly efficient but water-insoluble photoinitiators. The extinction coefficient of the new water-dispersible nanoparticles of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) is more than 300 times larger than the best and most used commercially available water-soluble photoinitiator. The TPO nanoparticles absorb significantly in the range from 385 to 420 nm, making them suitable for use in commercially available, low-cost, light-emitting diode-based 3D printers using digital light processing. The polymerization rate at this range is very fast and enables 3D printing that otherwise is impossible to perform without adding solvents. The TPO nanoparticles were prepared by rapid conversion of volatile microemulsions into water-dispersible powder, a process that can be used for a variety of photoinitiators. Such water-dispersible photoinitiator nanoparticles open many opportunities to enable rapid 3D printing of structures prepared in aqueous solutions while bringing environmental advantages by using low-energy curing systems and avoiding the need for solvents. PMID:27051877

  2. High-performance 3D printing of hydrogels by water-dispersible photoinitiator nanoparticles

    PubMed Central

    Pawar, Amol A.; Saada, Gabriel; Cooperstein, Ido; Larush, Liraz; Jackman, Joshua A.; Tabaei, Seyed R.; Cho, Nam-Joon; Magdassi, Shlomo

    2016-01-01

    In the absence of water-soluble photoinitiators with high absorbance in the ultraviolet (UV)–visible range, rapid three-dimensional (3D) printing of hydrogels for tissue engineering is challenging. A new approach enabling rapid 3D printing of hydrogels in aqueous solutions is presented on the basis of UV-curable inks containing nanoparticles of highly efficient but water-insoluble photoinitiators. The extinction coefficient of the new water-dispersible nanoparticles of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) is more than 300 times larger than the best and most used commercially available water-soluble photoinitiator. The TPO nanoparticles absorb significantly in the range from 385 to 420 nm, making them suitable for use in commercially available, low-cost, light-emitting diode–based 3D printers using digital light processing. The polymerization rate at this range is very fast and enables 3D printing that otherwise is impossible to perform without adding solvents. The TPO nanoparticles were prepared by rapid conversion of volatile microemulsions into water-dispersible powder, a process that can be used for a variety of photoinitiators. Such water-dispersible photoinitiator nanoparticles open many opportunities to enable rapid 3D printing of structures prepared in aqueous solutions while bringing environmental advantages by using low-energy curing systems and avoiding the need for solvents. PMID:27051877

  3. Comparison of unstable water infiltration in porous media in 2D and 3D experiments

    NASA Astrophysics Data System (ADS)

    Schütz, C.; Neuweiler, I.; Lehmann, P.; Papafotiou, A.; Vontobel, P.; Hartmann, S.

    2010-05-01

    Water infiltration into unsaturated soil is an important process for groundwater recharge and thus for water balance of natural hydrosystems. The characteristics of infiltration patterns depend on porous media properties and initial moisture content. Infiltration fronts into soil can be unstable in layered media with fine over dry coarse material. To predict arrival times of infiltration fronts and average water content in upscaled models, it is necessary to understand occurrence of instabilities. The unstable flow behavior is not captured by standard models and finger characteristics have mostly been investigated experimentally. Most experiments in the past were carried out in 2D setups and it is not clear how the results of such studies relate to real 3D systems. The aim of this study is to compare development and finger characteristics of unstable infiltration in 2D and 3D setups. We carried out laboratory experiments on fast infiltration in 2D and 3D setups and measured water content in porous media with neutron transmission technology at the NEUTRA beam line at the Paul Scherrer Institute, Switzerland. The 2D experiments were carried out in a glass sandbox (260 mm high, 75 mm wide and 11 mm deep). For the 3D experiments aluminum cylindrical column (150 mm in height and 100 mm in diameter) were used. Both columns were filled homogeneously with coarse quartz sand (grain size 0.7 - 1.2 mm) below fine sand layer (0.1 - 0.3 mm) of 20 - 30 mm thickness. Two dimensional projection images of water content with spatial resolution of 125 microns were deduced from neutron images every 2 second. For the 3D setup water content distribution was reconstructed in 3D to monitor water content inside the fingers over time. Water content and finger-width (15 - 23 mm) were similar for 2D and 3D setups. In both cases water content was maximum when the front passes and was decreasing afterwards (indicating "overshoot" behavior). Also the water content difference between values after

  4. SUPERFUND GROUND WATER ISSUE: GROUND WATER SAMPLING FOR METALS ANALYSES

    EPA Science Inventory

    Filtration of ground-water samples for metals analysis is an issue identified by the Forum as a concern of Superfund decision-makers. Inconsistency in EPA Syperfund cleanup pracices occurs where one EPA Region implements a remedial action based on unfiltered ground-water samples,...

  5. HANDBOOK: GROUND WATER VOLUME I: GROUND WATER AND CONTAMINATION

    EPA Science Inventory

    This handbook is an extensively revised version of the Ground Water Handbook, originally published in 1987 as EPA/625/6-87/016. It has been published in two volumes: Volume I: Ground Water and Contamination, EPA/625/6-90/016a, and Volume II: Methodology, EPA/625/6-90/016b. Volume...

  6. 3D Finite-Difference Modeling of Strong Ground Motion in the Upper Rhine Graben - 1356 Basel Earthquake

    NASA Astrophysics Data System (ADS)

    Oprsal, I.; Faeh, D.; Giardini, D.

    2002-12-01

    The disastrous Basel earthquake of October 18, 1356 (I0=X, M ≈ 6.9), appeared in, today seismically modest, Basel region (Upper Rhine Graben). The lack of strong ground motion seismic data can be effectively supplied by numerical modeling. We applied the 3D finite differences (FD) to predict ground motions which can be used for microzonation and hazard assessment studies. The FD method is formulated for topography models on irregular rectangular grids. It is a 3D explicit FD formulation of the hyperbolic partial differential equation (PDE). Elastodynamic PDE is solved in the time domain. The Hooke's isotropic inhomogeneous medium contains discontinuities and a topographic free surface. The 3D elastic FD modeling is applied on a newly established P and S-wave velocities structure model. This complex structure contains main interfaces and gradients inside some layers. It is adjacent to the earth surface and includes topography (Kind, Faeh and Giardini, 2002, A 3D Reference Model for the Area of Basel, in prep.). The first attempt was done for a double-couple point source and relatively simple source function. Numerical tests are planned for several finite-extent source histories because the 1356 Basel earthquake source features have not been well determined, yet. The presumed finite-extent source is adjacent to the free surface. The results are compared to the macroseismic information of the Basel area.

  7. Websim3d: A Web-based System for Generation, Storage and Dissemination of Earthquake Ground Motion Simulations.

    NASA Astrophysics Data System (ADS)

    Olsen, K. B.

    2003-12-01

    Synthetic time histories from large-scale 3D ground motion simulations generally constitute large 'data' sets which typically require 100's of Mbytes or Gbytes of storage capacity. For the same reason, getting access to a researchers simulation output, for example for an earthquake engineer to perform site analysis, or a seismologist to perform seismic hazard analysis, can be a tedious procedure. To circumvent this problem we have developed a web-based ``community model'' (websim3D) for the generation, storage, and dissemination of ground motion simulation results. Websim3D allows user-friendly and fast access to view and download such simulation results for an earthquake-prone area. The user selects an earthquake scenario from a map of the region, which brings up a map of the area where simulation data is available. Now, by clicking on an arbitrary site location, synthetic seismograms and/or soil parameters for the site can be displayed at fixed or variable scaling and/or downloaded. Websim3D relies on PHP scripts for the dynamic plots of synthetic seismograms and soil profiles. Although not limited to a specific area, we illustrate the community model for simulation results from the Los Angeles basin, Wellington (New Zealand), and Mexico.

  8. Template-free synthesis of functional 3D BN architecture for removal of dyes from water.

    PubMed

    Liu, Dan; Lei, Weiwei; Qin, Si; Chen, Ying

    2014-01-01

    Three-dimensional (3D) architectures are of interest in applications in electronics, catalysis devices, sensors and adsorption materials. However, it is still a challenge to fabricate 3D BN architectures by a simple method. Here, we report the direct synthesis of 3D BN architectures by a simple thermal treatment process. A 3D BN architecture consists of an interconnected flexible network of nanosheets. The typical nitrogen adsorption/desorption results demonstrate that the specific surface area for the as-prepared samples is up to 1156 m(2) g(-1), and the total pore volume is about 1.17 cm(3) g(-1). The 3D BN architecture displays very high adsorption rates and large capacities for organic dyes in water without any other additives due to its low densities, high resistance to oxidation, good chemical inertness and high surface area. Importantly, 88% of the starting adsorption capacity is maintained after 15 cycles. These results indicate that the 3D BN architecture is potential environmental materials for water purification and treatment. PMID:24663292

  9. Ground water and climate change

    USGS Publications Warehouse

    Taylor, Richard G.; Scanlon, Bridget; Döll, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F.P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  10. Ground Water and Climate Change

    NASA Technical Reports Server (NTRS)

    Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F. P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J. -F; Holman, Ian; Treidel, Holger

    2013-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  11. Integrated 3-D Ground-Penetrating Radar, Outcrop, and Borehole Data Applied to Reservoir Characterization and Flow Simulation

    SciTech Connect

    George McMechan; Rucsandra Corbeanu; Craig Forster; Kristian Soegaard; Xiaoxian Zeng; Carlos Aiken; Robert Szerbiak; Janok Bhattacharya; Michael Wizevich; Xueming Xu; Stephen Snelgrove; Karen Roche; Siang Joo Lim; Djuro Navakovic; Christopher White; Laura Crossey; Deming Wang; John Thurmond; William Hammon III; Mamadou BAlde; Ari Menitove

    2001-08-31

    OAK-B135 (IPLD Cleared) Existing reservoir models are based on 2-D outcrop studies; 3-D aspects are inferred from correlation between wells, and so are inadequately constrained for reservoir simulations. To overcome these deficiencies, we initiated a multidimensional characterization of reservoir analogs in the Cretaceous Ferron Sandstone in Utah. The study was conducted at two sites (Corbula Gulch and Coyote Basin); results from both sites are contained in this report. Detailed sedimentary facies maps of cliff faces define the geometry and distribution of potential reservoir flow units, barriers and baffles at the outcrop. High resolution 2-D and 3-D ground-penetrating radar (GPR) images extend these reservoir characteristics into 3-D, to allow development of realistic 3-D reservoir models. Models use geometric information from the mapping and the GPR data, petrophysical data from surface and cliff-face outcrops, lab analyses of outcrop and core samples, and petrography. The measurements are all integrated into a single coordinate system using GPS and laser mapping of the main sedimentological features and boundaries.The final step is analysis of results of 3-D fluid flow modeling to demonstrate applicability of our reservoir analog studies to well siting and reservoir engineering for maximization of hydrocarbon production. The main goals of the project are achieved. These are the construction of a deterministic 3-D reservoir analog model from a variety of geophysical and geologic measurements at the field sites, integrating these into comprehensive petrophysical models, and flow simulations through these models. This unique approach represents a significant advance in characterization and use of reservoir analogs.

  12. Intergrated 3-D Ground-Penetrating Radar,Outcrop,and Boreholoe Data Applied to Reservoir Characterization and Flow Simulation.

    SciTech Connect

    McMechan et al.

    2001-08-31

    Existing reservoir models are based on 2-D outcrop;3-D aspects are inferred from correlation between wells,and so are inadequately constrained for reservoir simulations. To overcome these deficiencies, we initiated a multidimensional characterization of reservoir analogs in the Cretaceous Ferron Sandstone in Utah.The study was conducted at two sites(Corbula Gulch Coyote Basin); results from both sites are contained in this report. Detailed sedimentary facies maps of cliff faces define the geometry and distribution of potential reservoir flow units, barriers and baffles at the outcrop. High resolution 2-D and 3-D ground penetrating radar(GPR) images extend these reservoir characteristics into 3-D to allow development of realistic 3-D reservoir models. Models use geometric information from the mapping and the GPR data, petrophysical data from surface and cliff-face outcrops, lab analyses of outcrop and core samples, and petrography. The measurements are all integrated into a single coordinate system using GPS and laser mapping of the main sedimentologic features and boundaries. The final step is analysis of results of 3-D fluid flow modeling to demonstrate applicability of our reservoir analog studies to well siting and reservoir engineering for maximization of hydrocarbon production. The main goals of this project are achieved. These are the construction of a deterministic 3-D reservoir analog model from a variety of geophysical and geologic measurements at the field sites, integrating these into comprehensive petrophysical models, and flow simulation through these models. This unique approach represents a significant advance in characterization and use of reservoir analogs. To data,the team has presented five papers at GSA and AAPG meetings produced a technical manual, and completed 15 technical papers. The latter are the main content of this final report. In addition,the project became part of 5 PhD dissertations, 3 MS theses,and two senior undergraduate research

  13. Sedimentary basin effects in Seattle, Washington: Ground-motion observations and 3D simulations

    USGS Publications Warehouse

    Frankel, Arthur; Stephenson, William; Carver, David

    2009-01-01

    Seismograms of local earthquakes recorded in Seattle exhibit surface waves in the Seattle basin and basin-edge focusing of S waves. Spectral ratios of Swaves and later arrivals at 1 Hz for stiff-soil sites in the Seattle basin show a dependence on the direction to the earthquake, with earthquakes to the south and southwest producing higher average amplification. Earthquakes to the southwest typically produce larger basin surface waves relative to S waves than earthquakes to the north and northwest, probably because of the velocity contrast across the Seattle fault along the southern margin of the Seattle basin. S to P conversions are observed for some events and are likely converted at the bottom of the Seattle basin. We model five earthquakes, including the M 6.8 Nisqually earthquake, using 3D finite-difference simulations accurate up to 1 Hz. The simulations reproduce the observed dependence of amplification on the direction to the earthquake. The simulations generally match the timing and character of basin surface waves observed for many events. The 3D simulation for the Nisqually earth-quake produces focusing of S waves along the southern margin of the Seattle basin near the area in west Seattle that experienced increased chimney damage from the earthquake, similar to the results of the higher-frequency 2D simulation reported by Stephenson et al. (2006). Waveforms from the 3D simulations show reasonable agreement with the data at low frequencies (0.2-0.4 Hz) for the Nisqually earthquake and an M 4.8 deep earthquake west of Seattle.

  14. Inclusion of high resolution MODIS maps on a 3D tropospheric water vapor GPS tomography model

    NASA Astrophysics Data System (ADS)

    Benevides, Pedro; Catalao, Joao; Nico, Giovanni; Miranda, Pedro M. A.

    2015-10-01

    Observing the water vapor distribution on the troposphere remains a challenge for the weather forecast. Radiosondes provide precise water vapor profiles of the troposphere, but lack geographical and temporal coverage, while satellite meteorological maps have good spatial resolution but even poorer temporal resolution. GPS has proved its capacity to measure the integrated water vapor in all weather conditions with high temporal sampling frequency. However these measurements lack a vertical water vapor discretization. Reconstruction of the slant path GPS observation to the satellite allows oblique water vapor measurements. Implementation of a 3D grid of voxels along the troposphere over an area where GPS stations are available enables the observation ray tracing. A relation between the water vapor density and the distanced traveled inside the voxels is established, defining GPS tomography. An inverse problem formulation is needed to obtain a water vapor solution. The combination of precipitable water vapor (PWV) maps obtained from MODIS satellite data with the GPS tomography is performed in this work. The MODIS PWV maps can have 1 or 5 km pixel resolution, being obtained 2 times per day in the same location at most. The inclusion of MODIS PWV maps provides an enhanced horizontal resolution for the tomographic solution and benefits the stability of the inversion problem. A 3D tomographic grid was adjusted over a regional area covering Lisbon, Portugal, where a GNSS network of 9 receivers is available. Radiosonde measurements in the area are used to evaluate the 3D water vapor tomography maps.

  15. Comparison of INSAT-3D AOD over Indian region with satellite- and ground-based measurements: a data assimilation perspective

    NASA Astrophysics Data System (ADS)

    Kumar, Sumit; George, John P.; Sreevathsa, M. N. Raghavendra; Indira Rani, S.

    2016-05-01

    This paper aims at comparing the INSAT-3D AOD with other space based observations over the continental regions. INSAT-3D launched in 2013 is an advanced geostationary weather satellite of India at 82° East longitude provides Aerosol Optical Depth (AOD) observations at 650 nm over both land and ocean. The level-3 daily AOD measurements from MODIS (both Aqua and Terra) and MISR are used for comparison with that from INSAT-3D. This work is applied during premonsoon season of 2015. Overall statistical scores and systematic errors are compared to characterize various error sources. Our study indicates that significant differences exist between different aerosol observations which may be partly due to retrieval algorithm, sensor configurations and temporal sampling. Comparison of INSAT observed AOD shows less bias towards MISR and MODIS-Terra observed AOD than with MODIS-Aqua. The INSAT observations over oceanic region have better correlation, minimum bias and rmse than land region. Overall, the mean bias of the dataset is ±0.05, with a root mean square error of 0.22, but these errors are also found highly dependent on geographical region. Additionally, we compared INSAT 660 nm AOD with two AERONET ground stations. The comparison of INSAT with different observations shows that the retrieved AOD is closer to the ground-based data than the MISR and MODIS AOD.

  16. Examination about Influence for Precision of 3d Image Measurement from the Ground Control Point Measurement and Surface Matching

    NASA Astrophysics Data System (ADS)

    Anai, T.; Kochi, N.; Yamada, M.; Sasaki, T.; Otani, H.; Sasaki, D.; Nishimura, S.; Kimoto, K.; Yasui, N.

    2015-05-01

    As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching) by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results of analysis made

  17. Enhanced hematite water electrolysis using a 3D antimony-doped tin oxide electrode.

    PubMed

    Moir, Jonathon; Soheilnia, Navid; O'Brien, Paul; Jelle, Abdinoor; Grozea, Claudia M; Faulkner, Daniel; Helander, Michael G; Ozin, Geoffrey A

    2013-05-28

    We present herein an example of nanocrystalline antimony-doped tin oxide (nc-ATO) disordered macroporous "inverse opal" 3D electrodes as efficient charge-collecting support structures for the electrolysis of water using a hematite surface catalyst. The 3D macroporous structures were created via templating of polystyrene spheres, followed by infiltration of the desired precursor solution and annealing at high temperature. Using cyclic voltammetry and electrochemical impedance spectroscopy, it was determined that the use of this 3D transparent conducting oxide with a hematite surface catalyst allowed for a 7-fold increase in active surface area for water splitting with respect to its 2D planar counterpart. This ratio of surface areas was evaluated based on the presence of oxidized trap states on the hematite surface, as determined from the equivalent circuit analysis of the Nyquist plots. Furthermore, the presence of nc-ATO 2D and 3D "underlayer" structures with hematite deposited on top resulted in decreased charge transfer resistances and an increase in the number of available active surface sites at the semiconductor-liquid junction when compared to hematite films lacking any nc-ATO substructures. Finally, absorption, transmission, and reflectance spectra of all of the tested films were measured, suggesting the feasibility of using 3D disordered structures in photoelectrochemical reactions, due to the high absorption of photons by the surface catalyst material and trapping of light within the structure. PMID:23581965

  18. Application of 3D electrical capacitance tomography in probing anomalous blocks in water

    NASA Astrophysics Data System (ADS)

    Liao, Aimin; Zhou, Qiyou; Zhang, Yun

    2015-06-01

    Water usually acts as a high-permittivity dielectric in many fields such as geophysics, hydrology, hydrogeology, aquaculture, etc. Thus, it may be of significance to adapt ECT to the fields with a high permittivity in which the conventional ECT is scarcely involved. To achieve this objective, a simplified 3D-ECT system was constructed with a high-precision inductance capacitance resistance meter and programmable logic controllers. In the aspect of sensing unit of the system, two geometries (i.e. cylinder and cube) of 3D sensors were constructed to probe anomalous blocks in water. Numerical simulations and physical experiments for both the sensors were performed to test the effectiveness of the constructed system to probe anomalous blocks in water. Furthermore, to justify the availability of this system in some possible fields, two experiments associated with applications of the 3D-ECT system were performed to measure the distribution of a plant root system in water, and to monitor the infiltration of water in soil in field. The experimental results demonstrate that the ECT system is capable of probing the location and rough size of anomalous blocks in water with both the sensors, determining the distribution of a plant root system in water, and monitoring the infiltration process of water in soil.

  19. New 3-D view of a middle-shelf grounding-zone wedge in Eastern Basin Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Bart, P. J.; Tomkin, J.

    2008-12-01

    A new large-area multibeam survey of a previously identified grounding zone wedge on the central Ross Sea middle continental shelf was acquired during NBP0802 and NBP0803 in February 2008. Within a regional framework, this wedge corresponds to the third grounding event since the WAIS began the post-LGM retreat. The survey reveals the 3-D detailed view of a lineated topset with iceberg gouges, a smooth multi-lobed foreset and distinct downdip pinchout of the grounding zone wedge. Beyond the down-dip pinchout, older subglacial lineations, oblique to the younger lineations, are evident. The multibeam survey along with sub- bottom profiler records permitted us to precisely position piston cores for each of these morphologic sectors. The combined data may serve as a proxy for evaluating some aspects of the WAIS's modern grounding- zone system. For example, sediment cores at the wedge's thin landward and basinward limits obtained homogenous gray mud below a thin olive-green pelagic drape. The absence of a similar pelagic drape embedded in the homogenous gray muds suggests that grounded ice did not retreat past this location before the WAIS occupied the middle-shelf grounding position. In other words, the pause in WAIS retreat was not associated with any significant re-advance.

  20. Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method

    NASA Astrophysics Data System (ADS)

    Kadioglu, S.

    2009-04-01

    Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method Selma KADIOGLU Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100 Tandogan/ANKARA-TURKEY kadioglu@eng.ankara.edu.tr Anatolia has always been more the point of transit, a bridge between West and East. Anatolia has been a home for ideas moving from all directions. So it is that in the Roman and post-Roman periods the role of Anatolia in general and of Ancyra (the Roman name of Ankara) in particular was of the greatest importance. Now, the visible archaeological remains of Roman period in Ankara are Roman Bath, Gymnasium, the Temple of Augustus of Rome, Street, Theatre, City Defence-Wall. The Caesar Augustus, the first Roman Emperor, conquered Asia Minor in 25 BC. Then a marble temple was built in Ancyra, the administrative capital of province, today the capital of Turkish Republic, Ankara. This monument was consecrated to the Empreror and to the Goddess Rome. This temple is supposed to have built over an earlier temple dedicated to Kybele and Men between 25 -20 BC. After the death of the Augustus in 14AD, a copy of the text of "Res Gestae Divi Augusti" was inscribed on the interior of the pronaos in Latin, whereas a Greek translation is also present on an exterior wall of the cella. In the 5th century, it was converted in to a church by the Byzantines. The aim of this study is to determine old buried archaeological remains in the Augustus temple, Roman Bath and in the governorship agora in Ulus district. These remains were imaged with transparent three dimensional (3D) visualization of the ground penetrating radar (GPR) data. Parallel two dimensional (2D) GPR profile data were acquired in the study areas, and then a 3D data volume were built using parallel 2D GPR data. A simplified amplitude-colour range and appropriate opacity function were constructed and transparent 3D image were obtained to activate buried

  1. A moving mesh algorithm for 3-D regional groundwater flow with water table and seepage face

    NASA Astrophysics Data System (ADS)

    Knupp, P.

    A numerical algorithm is described for solving the free-surface groundwater flow equations in 3-D large-scale unconfined aquifers with strongly heterogeneous conductivity and surface recharge. The algorithm uses a moving mesh to track the water-table as it evolves according to kinematic and seepage face boundary conditions. Both steady-state and transient algorithms are implemented in the SECO-Flow 3-D code and demonstrated on stratigraphy based on the Delaware Basin of south-eastern New Mexico.

  2. DFT-based studies on the Jahn-Teller effect in 3d hexacyanometalates with orbitally degenerate ground states.

    PubMed

    Atanasov, Mihial; Comba, Peter; Daul, Claude A; Hauser, Andreas

    2007-09-20

    The topology of the ground-state potential energy surface of M(CN)(6) with orbitally degenerate (2)T(2g) (M = Ti(III) (t(2g)(1)), Fe(III) and Mn(II) (both low-spin t(2g)(5))) and (3)T(1g) ground states (M = V(III) (t(2g)(2)), Mn(III) and Cr(II) (both low-spin t(2g)(4))) has been studied with linear and quadratic Jahn-Teller coupling models in the five-dimensional space of the epsilon(g) and tau(2g) octahedral vibrations (Tg[symbol: see text](epsilon(g)+tau(2g)) Jahn-Teller coupling problem (T(g) = (2)T(2g), (3)T(1g))). A procedure is proposed to give access to all vibronic coupling parameters from geometry optimization with density functional theory (DFT) and the energies of a restricted number of Slater determinants, derived from electron replacements within the t(2g)(1,5) or t(2g)(2,4) ground-state electronic configurations. The results show that coupling to the tau(2g) bending mode is dominant and leads to a stabilization of D(3d) structures (absolute minima on the ground-state potential energy surface) for all complexes considered, except for [Ti(CN)(6)](3-), where the minimum is of D(4h) symmetry. The Jahn-Teller stabilization energies for the D3d minima are found to increase in the order of increasing CN-M pi back-donation (Ti(III) < V(III) < Mn(III) < Fe(III) < Mn(II) < Cr(II)). With the angular overlap model and bonding parameters derived from angular distortions, which correspond to the stable D(3d) minima, the effect of configuration interaction and spin-orbit coupling on the ground-state potential energy surface is explored. This approach is used to correlate Jahn-Teller distortion parameters with structures from X-ray diffraction data. Jahn-Teller coupling to trigonal modes is also used to reinterpret the anisotropy of magnetic susceptibilities and g tensors of [Fe(CN)(6)](3-), and the (3)T(1g) ground-state splitting of [Mn(CN)(6)](3-), deduced from near-IR spectra. The implications of the pseudo Jahn-Teller coupling due to t(2g)-e(g) orbital mixing via

  3. Real-time forecasting of Hong Kong beach water quality by 3D deterministic model.

    PubMed

    Chan, S N; Thoe, W; Lee, J H W

    2013-03-15

    Bacterial level (e.g. Escherichia coli) is generally adopted as the key indicator of beach water quality due to its high correlation with swimming associated illnesses. A 3D deterministic hydrodynamic model is developed to provide daily water quality forecasting for eight marine beaches in Tsuen Wan, which are only about 8 km from the Harbour Area Treatment Scheme (HATS) outfall discharging 1.4 million m(3)/d of partially-treated sewage. The fate and transport of the HATS effluent and its impact on the E. coli level at nearby beaches are studied. The model features the seamless coupling of near field jet mixing and the far field transport and dispersion of wastewater discharge from submarine outfalls, and a spatial-temporal dependent E. coli decay rate formulation specifically developed for sub-tropical Hong Kong waters. The model prediction of beach water quality has been extensively validated against field data both before and after disinfection of the HATS effluent. Compared with daily beach E. coli data during August-November 2011, the model achieves an overall accuracy of 81-91% in forecasting compliance/exceedance of beach water quality standard. The 3D deterministic model has been most valuable in the interpretation of the complex variation of beach water quality which depends on tidal level, solar radiation and other hydro-meteorological factors. The model can also be used in optimization of disinfection dosage and in emergency response situations. PMID:23337883

  4. Laser nanostructuring 3-D bioconstruction based on carbon nanotubes in a water matrix of albumin

    NASA Astrophysics Data System (ADS)

    Gerasimenko, Alexander Y.; Ichkitidze, Levan P.; Podgaetsky, Vitaly M.; Savelyev, Mikhail S.; Selishchev, Sergey V.

    2016-04-01

    3-D bioconstructions were created using the evaporation method of the water-albumin solution with carbon nanotubes (CNTs) by the continuous and pulsed femtosecond laser radiation. It is determined that the volume structure of the samples created by the femtosecond radiation has more cavities than the one created by the continuous radiation. The average diameter for multi-walled carbon nanotubes (MWCNTs) samples was almost two times higher (35-40 nm) than for single-walled carbon nanotubes (SWCNTs) samples (20-30 nm). The most homogenous 3-D bioconstruction was formed from MWCNTs by the continuous laser radiation. The hardness of such samples totaled up to 370 MPa at the nanoscale. High strength properties and the resistance of the 3-D bioconstructions produced by the laser irradiation depend on the volume nanotubes scaffold forming inside them. The scaffold was formed by the electric field of the directed laser irradiation. The covalent bond energy between the nanotube carbon molecule and the oxygen of the bovine serum albumin aminoacid residue amounts 580 kJ/mol. The 3-D bioconstructions based on MWCNTs and SWCNTs becomes overgrown with the cells (fibroblasts) over the course of 72 hours. The samples based on the both types of CNTs are not toxic for the cells and don't change its normal composition and structure. Thus the 3-D bioconstructions that are nanostructured by the pulsed and continuous laser radiation can be applied as implant materials for the recovery of the connecting tissues of the living body.

  5. GROUND WATER TECHNICAL SUPPORT CENTER

    EPA Science Inventory

    EPA's Office of Research and Development operates a Ground Water Technical Support Center (GWTSC). The Center provides support on issues regarding subsurface contamination, contaminant fluxes to other media (e.g., surface water or air), and ecosystem restoration. The GWTSC creat...

  6. Use of 3D laser radar for navigation of unmanned aerial and ground vehicles in urban and indoor environments

    NASA Astrophysics Data System (ADS)

    Uijt de Haag, Maarten; Venable, Don; Smearcheck, Mark

    2007-04-01

    This paper discusses the integration of Inertial measurements with measurements from a three-dimensional (3D) imaging sensor for position and attitude determination of unmanned aerial vehicles (UAV) and autonomous ground vehicles (AGV) in urban or indoor environments. To enable operation of UAVs and AGVs at any time in any environment a Precision Navigation, Attitude, and Time (PNAT) capability is required that is robust and not solely dependent on the Global Positioning System (GPS). In urban and indoor environments a GPS position capability may not only be unavailable due to shadowing, significant signal attenuation or multipath, but also due to intentional denial or deception. Although deep integration of GPS and Inertial Measurement Unit (IMU) data may prove to be a viable solution an alternative method is being discussed in this paper. The alternative solution is based on 3D imaging sensor technologies such as Flash Ladar (Laser Radar). Flash Ladar technology consists of a modulated laser emitter coupled with a focal plane array detector and the required optics. Like a conventional camera this sensor creates an "image" of the environment, but producing a 2D image where each pixel has associated intensity vales the flash Ladar generates an image where each pixel has an associated range and intensity value. Integration of flash Ladar with the attitude from the IMU allows creation of a 3-D scene. Current low-cost Flash Ladar technology is capable of greater than 100 x 100 pixel resolution with 5 mm depth resolution at a 30 Hz frame rate. The proposed algorithm first converts the 3D imaging sensor measurements to a point cloud of the 3D, next, significant environmental features such as planar features (walls), line features or point features (corners) are extracted and associated from one 3D imaging sensor frame to the next. Finally, characteristics of these features such as the normal or direction vectors are used to compute the platform position and attitude

  7. 3-D ground motion modeling for M7 dynamic rupture earthquake scenarios on the Wasatch fault, Utah

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cruz Atienza, V. M.; Pechmann, J. C.; Magistrale, H. W.

    2009-12-01

    The Salt Lake City segment of the Wasatch fault (WFSLC), located on the eastern edge of the Salt Lake Basin (SLB), is capable of producing M7 earthquakes and represents a serious seismic hazard to Salt Lake City, Utah. We simulate a series of rupture scenarios on the WFSLC to quantify the ground motion expected from such M7 events and to assess the importance of amplification effects from basin focusing and source directivity. We use the newly revised Wasatch Front community velocity model for our simulations, which is tested by simulating records of three local Mw 3.3-3.7 earthquakes in the frequency band 0.5 to 1.0 Hz. The M7 earthquake scenarios make use of a detailed 3-D model geometry of the WFSLC that we developed based on geological observations. To obtain a suite of realistic source representations for M7 WFSLC simulations we perform spontaneous-rupture simulations on a planar 43 km by 23 km fault with the staggered-grid split-node finite-difference (FD) method. We estimate the initial distribution of shear stress using models that assume depth-dependent normal stress for a dipping, normal fault as well as simpler models which use constant (depth-independent) normal stress. The slip rate histories from the spontaneous rupture scenarios are projected onto the irregular dipping geometry of the WFSLC and used to simulate 0-1 Hz wave propagation in the SLB area using a 4th-order, staggered-grid visco-elastic FD method. We find that peak ground velocities tend to be larger on the low-velocity sediments on the hanging wall side of the fault than on outcropping rock on the footwall side, confirming results of previous studies on normal faulting earthquakes. The simulated ground motions reveal strong along-strike directivity effects for ruptures nucleating towards the ends of the WFSLC. The 0-1 Hz FD simulations are combined with local scattering operators to obtain broadband (0-10 Hz) synthetics and maps of average peak ground motions. Finally we use broadband

  8. Quasi 3D modeling of water flow and solute transport in vadose zone and groundwater

    NASA Astrophysics Data System (ADS)

    Yakirevich, A.; Kuznetsov, M.; Weisbrod, N.; Pachepsky, Y. A.

    2013-12-01

    The complexity of subsurface flow systems calls for a variety of concepts leading to the multiplicity of simplified flow models. One commonly used simplification is based on the assumption that lateral flow and transport in unsaturated zone is insignificant unless the capillary fringe is involved. In such cases the flow and transport in the unsaturated zone above groundwater level can be simulated as a 1D phenomenon, whereas through groundwater they are viewed as 2D or 3D phenomena. A new approach for a numerical scheme for 3D variably saturated flow and transport is presented. A Quasi-3D approach allows representing flow in the 'vadose zone - aquifer' system by a series of 1D Richards' equations solved in variably-saturated zone and by 3D-saturated flow equation in groundwater (modified MODFLOW code). The 1D and 3D equations are coupled at the phreatic surface in a way that aquifer replenishment is calculated using the Richards' equation, and solving for the moving water table does not require definition of the specific yield parameter. The 3D advection-dispersion equation is solved in the entire domain by the MT3D code. Using implicit finite differences approximation to couple processes in the vadose zone and groundwater provides mass conservation and increase of computational efficiency. The above model was applied to simulate the impact of irrigation on groundwater salinity in the Alto Piura aquifer (Northern Peru). Studies on changing groundwater quality in arid and semi-arid lands show that irrigation return flow is one of the major factors contributing to aquifer salinization. Existing mathematical models do not account explicitly for the solute recycling during irrigation on a daily scale. Recycling occurs throughout the unsaturated and saturated zones, as function of the solute mass extracted from pumping wells. Salt concentration in irrigation water is calculated at each time step as a function of concentration of both surface water and groundwater

  9. RELAP5-3D Code for Supercritical-Pressure Light-Water-Cooled Reactors

    SciTech Connect

    Riemke, Richard Allan; Davis, Cliff Bybee; Schultz, Richard Raphael

    2003-04-01

    The RELAP5-3D computer program has been improved for analysis of supercritical-pressure, light-water-cooled reactors. Several code modifications were implemented to correct code execution failures. Changes were made to the steam table generation, steam table interpolation, metastable states, interfacial heat transfer coefficients, and transport properties (viscosity and thermal conductivity). The code modifications now allow the code to run slow transients above the critical pressure as well as blowdown transients (modified Edwards pipe and modified existing pressurized water reactor model) that pass near the critical point.

  10. A parallel 3-D staggered grid pseudospectral time domain method for ground-penetrating radar wave simulation

    NASA Astrophysics Data System (ADS)

    Huang, Qinghua; Li, Zhanhui; Wang, Yanbin

    2010-12-01

    We presented a parallel 3-D staggered grid pseudospectral time domain (PSTD) method for simulating ground-penetrating radar (GPR) wave propagation. We took the staggered grid method to weaken the global effect in PSTD and developed a modified fast Fourier transform (FFT) spatial derivative operator to eliminate the wraparound effect due to the implicit periodical boundary condition in FFT operator. After the above improvements, we achieved the parallel PSTD computation based on an overlap domain decomposition method without any absorbing condition for each subdomain, which can significantly reduce the required grids in each overlap subdomain comparing with other proposed algorithms. We test our parallel technique for some numerical models and obtained consistent results with the analytical ones and/or those of the nonparallel PSTD method. The above numerical tests showed that our parallel PSTD algorithm is effective in simulating 3-D GPR wave propagation, with merits of saving computation time, as well as more flexibility in dealing with complicated models without losing the accuracy. The application of our parallel PSTD method in applied geophysics and paleoseismology based on GPR data confirmed the efficiency of our algorithm and its potential applications in various subdisciplines of solid earth geophysics. This study would also provide a useful parallel PSTD approach to the simulation of other geophysical problems on distributed memory PC cluster.

  11. Assessing soil water storage distribution under sprinkler irrigation by coupling 3D simulations and field observations

    NASA Astrophysics Data System (ADS)

    Taha, Uday; Shabeeb, Ahmed; dragonetti, giovanna; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    This work analyzed the variability of sprinkler irrigation application over a bare soil, both in terms of water application efficiency and uniformity, by integrating and comparing the information on the irrigation depth data (ID), as measured by catch cans, soil water storage in the upper root zone, as measured by TDR probes, and a 3D simulations of water flow in soils. Three irrigation tests were performed at three different pressures (2, 3 and 4 bar). A lateral water redistribution was observed and simulated after each irrigation event by comparing spatial distributions of site-specific water application efficiency (AEs), as well as ratios of site-specific actual water storage increase (SWEs) and irrigation depth (IDs) to the water content before irrigation. Because of soil water redistribution processes, distribution uniformity based on soil storages was systematically higher than the catch can uniformity. The obvious consequence of lateral water redistribution processes was that the soil smoothing action on non-uniformity observed at the surface increased both with depth and over time. At a given depth the uniformity of soil water storages always attained the same value, whatever the pressure considered and the catch can-based uniformity coefficient. It was concluded that, for the case of random distribution of ID, the uniformity of water storages is driven by the soil behavior rather than by the irrigation system.

  12. Death Valley regional ground-water flow system, Nevada and California -- hydrogeologic framework and transient ground-water flow model

    USGS Publications Warehouse

    : Belcher, Wayne R., (Edited By)

    2004-01-01

    A numerical three-dimensional (3D) transient ground-water flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the ground-water flow system and previous less extensive ground-water flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect ground-water flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley Regional Ground-Water Flow System (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the ground-water flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural ground-water discharge occurring through evapotranspiration and spring flow; the history of ground-water pumping from 1913 through 1998; ground-water recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were

  13. COMPILATION OF GROUND WATER MODELS

    EPA Science Inventory

    The full report presents an overview of currently available computer-based simulation models for ground-water flow, solute and heat transport, and hydrogeochemistry in both porous media and fractured rock. Separate sections address multiphase flow and related chemical species tra...

  14. GROUND WATER SAMPLING FOR VOCS

    EPA Science Inventory

    Sampling protocol should be dictated by the sampling objective(s). It is important to obtain representative ground water samples, regardless of the sampling objective(s). Low-flow (minimum draw-down) purging and sampling techniques are best in most instances, particularly for VOC...

  15. Ground penetrating radar: 2-D and 3-D subsurface imaging of a coastal barrier spit, Long Beach, WA, USA

    NASA Astrophysics Data System (ADS)

    Jol, Harry M.; Lawton, Don C.; Smith, Derald G.

    2003-07-01

    The ability to effectively interpret and reconstruct geomorphic environments has been significantly aided by the subsurface imaging capabilities of ground penetrating radar (GPR). The GPR method, which is based on the propagation and reflection of pulsed high frequency electromagnetic energy, provides high resolution (cm to m scale) and shallow subsurface (0-60 m), near continuous profiles of many coarser-grained deposits (sediments of low electrical conductivity). This paper presents 2-D and 3-D GPR results from an experiment on a regressive modern barrier spit at Willapa Bay, WA, USA. The medium-grained sand spit is 38 km long, up to 2-3.5 km wide, and is influenced by a 3.7-m tidal range (spring) as well as high energy longshore transport and high wave energy depositional processes. The spit has a freshwater aquifer recharged by rainfall. The GPR acquisition system used for the test was a portable, digital pulseEKKO™ system with antennae frequency ranging from 25 to 200 MHz and transmitter voltages ranging from 400 to 1000 V. Step sizes and antennae separation varied depending on the test requirements. In addition, 100-MHz antennae were used for conducting antennae orientation tests and collecting a detailed grid of data (50×50 m sampled every meter). The 2-D digital profiles were processed and plotted using pulseEKKO™ software. The 3-D datasets, after initial processing, were entered into a LANDMARK™ workstation that allowed for unique 3-D perspectives of the subsurface. To provide depth, near-surface velocity measurements were calculated from common midpoint (CMP) surveys. Results from the present study demonstrate higher resolution from the 200-MHz antennae for the top 5-6 m, whereas the 25- and 50-MHz antennae show deeper penetration to >10 m. For the study site, 100-MHz antennae provided acceptable resolution, continuity of reflections, and penetration. The dip profiles show a shingle-like accretionary depositional pattern, whereas strike profiles

  16. Landslide/reservoir interaction: 3D numerical modelling of the Vajont rockslide and generated water wave

    NASA Astrophysics Data System (ADS)

    Crosta, G.; Imposimato, S.; Roddeman, D.; Frattini, P.

    2012-04-01

    Fast moving landslides can be originated along slopes in mountainous terrains with natural and artificial lakes, or fjords at the slope foot. This landslides can reach extremely high speed and the impact with the immobile reservoir water can be influenced by the local topography and the landslide mass profile. The impact can generate large impulse waves and landslide tsunami. Initiation, propagation and runup are the three phases that need to be considered. The landslide evolution and the consequent wave can be controlled by the initial mass position (subaerial, partially or completely submerged), the landslide speed, the type of material, the subaerial and subaqueous slope geometry, the landslide depth and length at the impact, and the water depth. Extreme events have been caused by subaerial landslides: the 1963 Vajont rockslide (Italy), the 1958 Lituya Bay event (Alaska), the Tafjord and the Loen multiple events event (Norway), also from volcanic collapses (Hawaii and Canary islands). Various researchers completed a systematic experimental work on 2D and 3D wave generation and propagation (Kamphuis and Bowering, 1970; Huber, 1980; Müller, 1995; Huber and Hager, 1997; Fritz, 2002; Zweifel, 2004; Panizzo et al., 2005; Heller, 2007; Heller and Kinnear, 2010; Sælevik et al., 2009), using both rigid blocks and deformable granular" masses. Model data and results have been used to calibrate and validate numerical modelling tools (Harbitz, 1992; Jiang and LeBlond, 1993; Grilli et al., 2002; Grilli and Watts, 2005; Lynett and Liu, 2005; Tinti et al., 2006; Abadie et al., 2010) generally considering simplified rheologies (e.g. viscous rheologies) for subaerial subaqueous spreading. We use a FEM code (Roddeman, 2011; Crosta et al., 2006, 2009, 2010, 2011) adopting an Eulerian-Lagrangian approach to give accurate results for large deformations. We model both 2D and fully 3D events considering different settings. The material is considered as a fully deformable elasto

  17. 3-D or median map? Earthquake scenario ground-motion maps from physics-based models versus maps from ground-motion prediction equations

    NASA Astrophysics Data System (ADS)

    Porter, K.

    2015-12-01

    There are two common ways to create a ground-motion map for a hypothetical earthquake: using ground motion prediction equations (by far the more common of the two) and using 3-D physics-based modeling. The former is very familiar to engineers, the latter much less so, and the difference can present a problem because engineers tend to trust the familiar and distrust novelty. Maps for essentially the same hypothetical earthquake using the two different methods can look very different, while appearing to present the same information. Using one or the other can lead an engineer or disaster planner to very different estimates of damage and risk. The reasons have to do with depiction of variability, spatial correlation of shaking, the skewed distribution of real-world shaking, and the upward-curving relationship between shaking and damage. The scientists who develop the two kinds of map tend to specialize in one or the other and seem to defend their turf, which can aggravate the problem of clearly communicating with engineers.The USGS Science Application for Risk Reduction's (SAFRR) HayWired scenario has addressed the challenge of explaining to engineers the differences between the two maps, and why, in a disaster planning scenario, one might want to use the less-familiar 3-D map.

  18. A 3-D implicit finite-volume model of shallow water flows

    NASA Astrophysics Data System (ADS)

    Wu, Weiming; Lin, Qianru

    2015-09-01

    A three-dimensional (3-D) model has been developed to simulate shallow water flows in large water bodies, such as coastal and estuarine waters. The eddy viscosity is determined using a newly modified mixing length model that uses different mixing length functions for the horizontal and vertical shear strain rates. The 3-D shallow water flow equations with the hydrostatic pressure assumption are solved using an implicit finite-volume method based on a quadtree (telescoping) rectangular mesh on the horizontal plane and the sigma coordinate in the vertical direction. The quadtree technique can locally refine the mesh around structures or in high-gradient regions by splitting a coarse cell into four child cells. The grid nodes are numbered with a one-dimensional index system that has unstructured grid feature for better grid flexibility. All the primary variables are arranged in a non-staggered grid system. Fluxes at cell faces are determined using a Rhie and Chow-type momentum interpolation, to avoid the possible spurious checkerboard oscillations caused by linear interpolation. Each of the discretized governing equations is solved iteratively using the flexible GMRES method with ILUT preconditioning, and coupling of water level and velocity among these equations is achieved by using the SIMPLEC algorithm with under-relaxation. The model has been tested in four cases, including steady flow near a spur-dyke, tidal flows in San Francisco Bay and Gironde Estuary, and wind-induced current in a flume. The calculated water levels and velocities are in good agreement with the measured values.

  19. Mechanisms driving estuarine water quality: A 3D biogeochemical model for informed management

    NASA Astrophysics Data System (ADS)

    Wild-Allen, Karen; Skerratt, Jenny; Whitehead, Jason; Rizwi, Farhan; Parslow, John

    2013-12-01

    Estuaries are amongst the most productive marine ecosystems of the world but are also some of the most degraded due to coastal urban development. Sparse sampling of complex interactions between estuarine physics, sediment transport, chemistry, and biology limits understanding of the processes controlling estuarine water quality and confounds active management. We use a 3D coupled hydrodynamic, sediment and biogeochemical model to identify the key mechanisms driving fine-scale fluctuations in water quality in a temperate micro-tidal salt wedge estuary [Derwent Estuary, Tasmania]. Model results are dynamically consistent with relatively sparse monitoring data collected over a seasonal cycle and are considered to be a plausible hypothesis of sub-monitoring scale processes occurring in the estuary. The model shows enhanced mixing of nutrients across the pycnocline downstream of the salt wedge front that supports a persistent phytoplankton bloom. The length and flow regime of the estuary results in nutrient recycling and retention in the estuarine circulation driving a decline in bottom water dissolved oxygen in the mid- and upper-reaches. A budget analysis of modelled nitrogen suggests high levels of denitrification are critical to the maintenance of existing water quality. Active estuarine management focused on the improvement of bottom water dissolved oxygen for ecological health reasons must either concurrently reduce anthropogenic nitrogen loads or be sure to maintain high levels of microbial denitrification for net water quality improvement.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  1. Evaluating the presentation and usability of 2D and 3D maps generated by unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Gregory, Jason; Baran, David; Evans, A. W.

    2013-05-01

    Currently fielded small unmanned ground vehicles (SUGVs) are operated via teleoperation. This method of operation requires a high level of operator involvement within, or near within, line of sight of the robot. As advances are made in autonomy algorithms, capabilities such as automated mapping can be developed to allow SUGVs to be used to provide situational awareness with an increased standoff distance while simultaneously reducing operator involvement. In order to realize these goals, it is paramount the data produced by the robot is not only accurate, but also presented in an intuitive manner to the robot operator. The focus of this paper is how to effectively present map data produced by a SUGV in order to drive the design of a future user interface. The effectiveness of several 2D and 3D mapping capabilities was evaluated by presenting a collection of pre-recorded data sets of a SUGV mapping a building in an urban environment to a user panel of Soldiers. The data sets were presented to each Soldier in several different formats to evaluate multiple factors, including update frequency and presentation style. Once all of the data sets were presented, a survey was administered. The questions in the survey were designed to gauge the overall usefulness of the mapping algorithm presentations as an information generating tool. This paper presents the development of this test protocol along with the results of the survey.

  2. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    PubMed Central

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-01-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity. PMID:27040483

  3. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    NASA Astrophysics Data System (ADS)

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-04-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity.

  4. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces.

    PubMed

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-01-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity. PMID:27040483

  5. Neutron transport with the method of characteristics for 3-D full core boiling water reactor applications

    NASA Astrophysics Data System (ADS)

    Thomas, Justin W.

    2006-12-01

    The Numerical Nuclear Reactor (NNR) is a code suite that is being developed to provide high-fidelity multi-physics capability for the analysis of light water nuclear reactors. The focus of the work here is to extend the capability of the NNR by incorporation of the neutronics module, DeCART, for Boiling Water Reactor (BWR) applications. The DeCART code has been coupled to the NNR fluid mechanics and heat transfer module STAR-CD for light water reactor applications. The coupling has been accomplished via an interface program, which is responsible for mapping the STAR-CD and DeCART meshes, managing communication, and monitoring convergence. DeCART obtains the solution of the 3-D Boltzmann transport equation by performing a series of 2-D modular ray tracing-based method of characteristics problems that are coupled within the framework of 3-D coarse-mesh finite difference. The relatively complex geometry and increased axial heterogeneity found in BWRs are beyond the modeling capability of the original version of DeCART. In this work, DeCART is extended in three primary areas. First, the geometric capability is generalized by extending the modular ray tracing scheme and permitting an unstructured mesh in the global finite difference kernel. Second, numerical instabilities, which arose as a result of the severe axial heterogeneity found in BWR cores, have been resolved. Third, an advanced nodal method has been implemented to improve the accuracy of the axial flux distribution. In this semi-analytic nodal method, the analytic solution to the transverse-integrated neutron diffusion equation is obtained, where the nonhomogeneous neutron source was first approximated by a quartic polynomial. The successful completion of these three tasks has allowed the application of the coupled DeCART/STAR-CD code to practical BWR problems.

  6. An efficient flexible-order model for 3D nonlinear water waves

    SciTech Connect

    Engsig-Karup, A.P. Bingham, H.B.; Lindberg, O.

    2009-04-01

    The flexible-order, finite difference based fully nonlinear potential flow model described in [H.B. Bingham, H. Zhang, On the accuracy of finite difference solutions for nonlinear water waves, J. Eng. Math. 58 (2007) 211-228] is extended to three dimensions (3D). In order to obtain an optimal scaling of the solution effort multigrid is employed to precondition a GMRES iterative solution of the discretized Laplace problem. A robust multigrid method based on Gauss-Seidel smoothing is found to require special treatment of the boundary conditions along solid boundaries, and in particular on the sea bottom. A new discretization scheme using one layer of grid points outside the fluid domain is presented and shown to provide convergent solutions over the full physical and discrete parameter space of interest. Linear analysis of the fundamental properties of the scheme with respect to accuracy, robustness and energy conservation are presented together with demonstrations of grid independent iteration count and optimal scaling of the solution effort. Calculations are made for 3D nonlinear wave problems for steep nonlinear waves and a shoaling problem which show good agreement with experimental measurements and other calculations from the literature.

  7. 3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods

    SciTech Connect

    B.W. Spencer; J.D. Hales; S.R. Novascone; R.L. Williamson

    2012-09-01

    The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of the full fuel rod to include local defects. A 3D thermo-mechanical model is used to simulate the global fuel rod behavior, and includes effects on the thermal and mechanical behavior of the fuel due to accumulation of fission products, fission gas production and release, and the effects of fission gas accumulation on thermal conductivity across the fuel-clad gap. Local defects can be modeled simply by including them in the 3D fuel rod model, without the need for mapping between two separate models. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the

  8. Calculating the Probability of Strong Ground Motions Using 3D Seismic Waveform Modeling - SCEC CyberShake

    NASA Astrophysics Data System (ADS)

    Gupta, N.; Callaghan, S.; Graves, R.; Mehta, G.; Zhao, L.; Deelman, E.; Jordan, T. H.; Kesselman, C.; Okaya, D.; Cui, Y.; Field, E.; Gupta, V.; Vahi, K.; Maechling, P. J.

    2006-12-01

    Researchers from the SCEC Community Modeling Environment (SCEC/CME) project are utilizing the CyberShake computational platform and a distributed high performance computing environment that includes USC High Performance Computer Center and the NSF TeraGrid facilities to calculate physics-based probabilistic seismic hazard curves for several sites in the Southern California area. Traditionally, probabilistic seismic hazard analysis (PSHA) is conducted using intensity measure relationships based on empirical attenuation relationships. However, a more physics-based approach using waveform modeling could lead to significant improvements in seismic hazard analysis. Members of the SCEC/CME Project have integrated leading-edge PSHA software tools, SCEC-developed geophysical models, validated anelastic wave modeling software, and state-of-the-art computational technologies on the TeraGrid to calculate probabilistic seismic hazard curves using 3D waveform-based modeling. The CyberShake calculations for a single probablistic seismic hazard curve require tens of thousands of CPU hours and multiple terabytes of disk storage. The CyberShake workflows are run on high performance computing systems including multiple TeraGrid sites (currently SDSC and NCSA), and the USC Center for High Performance Computing and Communications. To manage the extensive job scheduling and data requirements, CyberShake utilizes a grid-based scientific workflow system based on the Virtual Data System (VDS), the Pegasus meta-scheduler system, and the Globus toolkit. Probabilistic seismic hazard curves for spectral acceleration at 3.0 seconds have been produced for eleven sites in the Southern California region, including rock and basin sites. At low ground motion levels, there is little difference between the CyberShake and attenuation relationship curves. At higher ground motion (lower probability) levels, the curves are similar for some sites (downtown LA, I-5/SR-14 interchange) but different for

  9. Retrieval of Vegetation Structural Parameters and 3-D Reconstruction of Forest Canopies Using Ground-Based Echidna® Lidar

    NASA Astrophysics Data System (ADS)

    Strahler, A. H.; Yao, T.; Zhao, F.; Yang, X.; Schaaf, C.; Woodcock, C. E.; Jupp, D. L.; Culvenor, D.; Newnham, G.; Lovell, J.

    2010-12-01

    A ground-based, scanning, near-infrared lidar, the Echidna® validation instrument (EVI), built by CSIRO Australia, retrieves structural parameters of forest stands rapidly and accurately, and by merging multiple scans into a single point cloud, the lidar also provides 3-D stand reconstructions. Echidna lidar technology scans with pulses of light at 1064 nm wavelength and digitizes the full return waveform sufficiently finely to recover and distinguish the differing shapes of return pulses as they are scattered by leaves, trunks, and branches. Deployments in New England in 2007 and the southern Sierra Nevada of California in 2008 tested the ability of the instrument to retrieve mean tree diameter, stem count density (stems/ha), basal area, and above-ground woody biomass from single scans at points beneath the forest canopy. Parameters retrieved from five scans located within six 1-ha stand sites matched manually-measured parameters with values of R2 = 0.94-0.99 in New England and 0.92-0.95 in the Sierra Nevada. Retrieved leaf area index (LAI) values were similar to those of LAI-2000 and hemispherical photography. In New England, an analysis of variance showed that EVI-retrieved values were not significantly different from other methods (power = 0.84 or higher). In the Sierra, R2 = 0.96 and 0.81 for hemispherical photos and LAI-2000, respectively. Foliage profiles, which measure leaf area with canopy height, showed distinctly different shapes for the stands, depending on species composition and age structure. New England stand heights, obtained from foliage profiles, were not significantly different (power = 0.91) from RH100 values observed by LVIS in 2003. Three-dimensional stand reconstruction identifies one or more “hits” along the pulse path coupled with the peak return of each hit expressed as apparent reflectance. Returns are classified as trunk, leaf, or ground returns based on the shape of the return pulse and its location. These data provide a point

  10. ADVANCES IN GROUND WATER SAMPLING PROCEDURES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  11. Accuracy Based Generation of Thermodynamic Properties for Light Water in RELAP5-3D

    SciTech Connect

    Cliff B. Davis

    2010-09-01

    RELAP5-3D interpolates to obtain thermodynamic properties for use in its internal calculations. The accuracy of the interpolation was determined for the original steam tables currently used by the code. This accuracy evaluation showed that the original steam tables are generally detailed enough to allow reasonably accurate interpolations in most areas needed for typical analyses of nuclear reactors cooled by light water. However, there were some regions in which the original steam tables were judged to not provide acceptable accurate results. Revised steam tables were created that used a finer thermodynamic mesh between 4 and 21 MPa and 530 and 640 K. The revised steam tables solved most of the problems observed with the original steam tables. The accuracies of the original and revised steam tables were compared throughout the thermodynamic grid.

  12. Ground-water levels in Wyoming, 1975

    USGS Publications Warehouse

    Ballance, W.C.; Freudenthal, Pamela B.

    1976-01-01

    Ground-water levels are measured periodically in a network of about 260 observation wells in Wyoming to record changes in ground-water storage. The areas of water-level observation are mostly where ground water is used in large quantities for irrigation or municipal purposes. This report contains maps showing location of observation wells and water-level changes from 1975 to 1976. Well history, highest and lowest water levels , and hydrographs for most wells also are included. (Woodard-USGS)

  13. GROUND WATER REMEDIATION POWERED WITH RENEWABLE ENERGY

    EPA Science Inventory

    Technical challenge: Resource conservation has become a critical concept in the remediation of contaminated ground water supplies. Ground water remedies which include surface discharge of treated ground water are often viewed as wasteful and non-sustainable....

  14. 3d Modeling Of The Early Martian Climate And Water Cycle

    NASA Astrophysics Data System (ADS)

    Forget, Francois; Wordsworth, R.; Millour, E.; Madeleine, J.; Eymet, V.; Haberle, R. M.

    2010-10-01

    Missions to Mars regularly reveal new evidence suggesting that the early environmental conditions were very different from today, with liquid water flowing on the surface. Which climatic or geophysical processes enabled such conditions? Were the conditions episodically suitable for liquid water, or stable on long time-scales? Can we explain the distribution of the valley networks and other ancient landforms? To help understand these key issues, we have developed a new 3D global climate model (GCM). We wish to understand the possible climate that would occur on Mars if 1) the solar luminosity is decreased by 25%, as was the case 3.8 billion years ago, and 2) the surface pressure is increased up to several bars (no other greenhouse gases than CO2 and H2O are assumed to be present). We paid particular attention to the radiative transfer in dense CO2 atmospheres, where collision-induced absorption can be significant. We found that previous parameterisation of this phenomenon overestimated the greenhouse effect, and derived a new approach based on recent studies. We analyse the effects of clouds and water vapour on the surface temperature and discuss the likely nature of the early hydrological cycle. CO2 ice clouds form in the middle atmosphere above 10 km. They cause significant surface warming through their scattering greenhouse effect. However, their effect is partly counterbalanced by the the albedo effect of the water ice clouds, which form much lower. Overall, it is difficult to achieve annual mean surface temperature significantly above 0°C anywhere on the planet for pressures below 2 bar. Nevertheless, temperatures above freezing can occur, especially in the lower plains, due to atmospheric adiabatic warming. On such a planet, the water cycle and precipitation strongly depend on the amount of water available at the surface, the location of the main surface reservoirs and the obliquity.

  15. Clusters, molecular layers, and 3D crystals of water on Ni(111)

    SciTech Connect

    Thürmer, Konrad; Nie, Shu; Bartelt, Norman C.; Feibelman, Peter J.

    2014-11-14

    We examined the growth and stability of ice layers on Ni(111) up to ∼7 molecular layers (ML) thick using scanning tunneling microscopy. At low coverage, films were comprised of ∼1 nm wide two-dimensional (2D) clusters. Only above ∼0.5 ML did patches of continuous 2D layers emerge, coexisting with the clusters until the first ML was complete. The structure of the continuous layer is clearly different from that of the 2D clusters. Subsequently, a second molecular layer grew on top of the first. 3D crystallites started to form only after this 2nd ML was complete. 2D clusters re-appeared when thicker films were partially evaporated, implying that these clusters represent the equilibrium configuration at low coverage. Binding energies and image simulations computed with density functional theory suggest that the 2D clusters are partially dissociated and surrounded by H adatoms. The complete 2D layer contains only intact water molecules because of the lack of favorable binding sites for H atoms. We propose molecular structures for the 2D layer that are composed of the same pentagon-heptagon binding motif and water density observed on Pt(111). The similarity of the water structures on Pt and Ni suggests a general prescription for generating low-energy configurations on close-packed metal substrates.

  16. Synthesis and 3D printing of biodegradable polyurethane elastomer by a water-based process for cartilage tissue engineering applications.

    PubMed

    Hung, Kun-Che; Tseng, Ching-Shiow; Hsu, Shan-Hui

    2014-10-01

    Biodegradable materials that can undergo degradation in vivo are commonly employed to manufacture tissue engineering scaffolds, by techniques including the customized 3D printing. Traditional 3D printing methods involve the use of heat, toxic organic solvents, or toxic photoinitiators for fabrication of synthetic scaffolds. So far, there is no investigation on water-based 3D printing for synthetic materials. In this study, the water dispersion of elastic and biodegradable polyurethane (PU) nanoparticles is synthesized, which is further employed to fabricate scaffolds by 3D printing using polyethylene oxide (PEO) as a viscosity enhancer. The surface morphology, degradation rate, and mechanical properties of the water-based 3D-printed PU scaffolds are evaluated and compared with those of polylactic-co-glycolic acid (PLGA) scaffolds made from the solution in organic solvent. These scaffolds are seeded with chondrocytes for evaluation of their potential as cartilage scaffolds. Chondrocytes in 3D-printed PU scaffolds have excellent seeding efficiency, proliferation, and matrix production. Since PU is a category of versatile materials, the aqueous 3D printing process developed in this study is a platform technology that can be used to fabricate devices for biomedical applications. PMID:24729580

  17. 3-D water vapor field in the atmospheric boundary layer observed with scanning differential absorption lidar

    NASA Astrophysics Data System (ADS)

    Späth, Florian; Behrendt, Andreas; Muppa, Shravan Kumar; Metzendorf, Simon; Riede, Andrea; Wulfmeyer, Volker

    2016-04-01

    High-resolution three-dimensional (3-D) water vapor data of the atmospheric boundary layer (ABL) are required to improve our understanding of land-atmosphere exchange processes. For this purpose, the scanning differential absorption lidar (DIAL) of the University of Hohenheim (UHOH) was developed as well as new analysis tools and visualization methods. The instrument determines 3-D fields of the atmospheric water vapor number density with a temporal resolution of a few seconds and a spatial resolution of up to a few tens of meters. We present three case studies from two field campaigns. In spring 2013, the UHOH DIAL was operated within the scope of the HD(CP)2 Observational Prototype Experiment (HOPE) in western Germany. HD(CP)2 stands for High Definition of Clouds and Precipitation for advancing Climate Prediction and is a German research initiative. Range-height indicator (RHI) scans of the UHOH DIAL show the water vapor heterogeneity within a range of a few kilometers up to an altitude of 2 km and its impact on the formation of clouds at the top of the ABL. The uncertainty of the measured data was assessed for the first time by extending a technique to scanning data, which was formerly applied to vertical time series. Typically, the accuracy of the DIAL measurements is between 0.5 and 0.8 g m-3 (or < 6 %) within the ABL even during daytime. This allows for performing a RHI scan from the surface to an elevation angle of 90° within 10 min. In summer 2014, the UHOH DIAL participated in the Surface Atmosphere Boundary Layer Exchange (SABLE) campaign in southwestern Germany. Conical volume scans were made which reveal multiple water vapor layers in three dimensions. Differences in their heights in different directions can be attributed to different surface elevation. With low-elevation scans in the surface layer, the humidity profiles and gradients can be related to different land cover such as maize, grassland, and forest as well as different surface layer

  18. 3-D seakeeping analysis with water on deck and slamming. Part 2: Experiments and physical investigation

    NASA Astrophysics Data System (ADS)

    Greco, M.; Bouscasse, B.; Lugni, C.

    2012-08-01

    A synergic 3-D experimental and numerical investigation is conducted for wave-ship interactions involving the water-on-deck and slamming phenomena. The adopted solver has been developed in Greco and Lugni (in press) and combines (A) a weakly nonlinear external solution for the wave-vessel interactions with (B) a 2-D in-deck shallow-water approximation, which describes water shipping events, and (C) a local analytical analysis of the bottom-slamming phenomenon. This solver can handle regular and irregular sea states and vessels at rest or with limited speed. The experiments examine a patrol ship at rest or with forward speed that is free to oscillate in heave and pitch in regular and irregular waves. In this study, the head-sea regular-wave conditions are examined in terms of (1) response amplitude operators (RAOs) and relative motions, (2) occurrence, features and loads of water-on-deck, bottom-slamming and flare-slamming events and (3) added resistance in waves. A systematic and comprehensive analysis of the phenomena is made available in terms of the Froude number, incoming wavelength-to-ship length ratio and wave steepness for the examined ship geometry. The main parameters that affect the global and local quantities are identified and possible danger in terms of water-on-deck severity and structural consequences are determined. Different slamming behaviors were identified, depending on the spatial location of the impact on the vessel: single-peak, church-roof and double-peak behaviors. A bottom-slamming criterion, using the Ochi's (1964) velocity condition and the Greco and Lugni's (2012) pressure condition, is assessed. A statistical analysis of more than 100 events is needed for the bottom-slamming pressure peaks. The numerical solver is promising. The major discrepancies with the experiments are discussed, and the importance of viscous hull damping and flare impact for the most violent conditions is emphasized. Inclusion of these effects improved the

  19. Human interactions with ground-water

    USGS Publications Warehouse

    Zaporozec, A.

    1983-01-01

    Ground-Water could be considered as an immense reservoir, from which only a certain amount of water can be withdrawn without affecting the quantity and quality of water. This amount is determined by the characteristics of the environment in which ground-water occurs and by the interactions of ground-water with precipitation, surface water, and people. It should be recognized that quantity and quality of ground-water are intimately related and should be considered accordingly. Quantity refers to usable water and water is usable for any specific purpose only so long as its quality has not deteriorated beyond acceptable limits. Thus an overall quantitative and qualitative management of ground water is inevitable, and its should also involve the uses of ground-water reservoirs for purposes other than water supply. The main objective of ground-water management is to ensure that ground-water resources will be available in appropriate time and in appropriate quantity and quality to meet the most important demands of our society. Traditional, and obvious uses of ground-water are the extraction of water for water supplies (domestic, municipal, agricultural, and industrial) and the natural discharge feeding lakes and maintaining base flow of streams. Not so obvious are the uses of ground-water reservoirs, the very framework within which ground-water occurs and moves, and in which other fluids or materials can be stored. In the last two decades, ground-water reservoirs have been intensively considered for many other purposes than water supplies. Diversified and very often conflicting uses need to be evaluated and dealt with in the most efficient way in order to determine the importance of each possible use, and to assign priorities of these uses. With rising competition for the use of ground-water reservoirs, we will also need to increase the potential for effective planning of ground-water development and protection. Man's development and use of ground-water necessarily

  20. Sustainability of ground-water resources

    USGS Publications Warehouse

    Alley, William M.; Reilly, Thomas E.; Franke, O. Lehn

    1999-01-01

    The pumpage of fresh ground water in the United States in 1995 was estimated to be approximately 77 billion gallons per day (Solley and others, 1998), which is about 8 percent of the estimated 1 trillion gallons per day of natural recharge to the Nation's ground-water systems (Nace, 1960). From an overall national perspective, the ground-water resource appears ample. Locally, however, the availability of ground water varies widely. Moreover, only a part of the ground water stored in the subsurface can be recovered by wells in an economic manner and without adverse consequences.

  1. Soil water content variability in the 3D 'support-spacing-extent' space of scale metrics

    NASA Astrophysics Data System (ADS)

    Pachepsky, Yakov; Martinez, Gonzalo; Vereecken, Harry

    2014-05-01

    Knowledge of soil water content variability provides important insight into soil functioning, and is essential in many applications. This variability is known to be scale-dependent, and divergent statements about the change of the variability magnitude with scale can be found in literature. We undertook a systematic review to see how the definition of scale can affect conclusions about the scale-dependence in soil water content variability. Support, spacing, and extent are three metrics used to characterize scale in hydrology. Available data sets describe changes in soil moisture variability with changes in one or more of these scale metrics. We found six types of experiments with the scale change. With data obtained without a change in extent, the scale change in some cases consisted in the simultaneous change of support and spacing. This was done with remote sensing data, and the power law decrease in variance with support increase was found. Datasets that were collected with different support or sample volumes for the same extent and spacing showed the decrease of variance as the sample size increased. A variance increase was common when the scale change consisted in change in spacing without the change in supports and extents. An increase in variance with the extent of the study area was demonstrated with data an evolution of variability with increasing size of the area under investigation (extent) without modification of support. The variance generally increased with the extent when the spacing was changed so that the change in variability at areas of different sizes was studied with the same number of samples with equal support. Finally, there are remote sensing datasets that document decrease in variability with a change in extent for a given support without modification of spacing. Overall, published information on the effect of scale on soil water content variability in the 3D space of scale metrics did not contain controversies in qualitative terms

  2. Quasi 3D modelling of water flow in the sandy soil

    NASA Astrophysics Data System (ADS)

    Rezaei, Meisam; Seuntjens, Piet; Joris, Ingeborg; Boënne, Wesley; De Pue, Jan; Cornelis, Wim

    2016-04-01

    Monitoring and modeling tools may improve irrigation strategies in precision agriculture. Spatial interpolation is required for analyzing the effects of soil hydraulic parameters, soil layer thickness and groundwater level on irrigation management using hydrological models at field scale. We used non-invasive soil sensor, a crop growth (LINGRA-N) and a soil hydrological model (Hydrus-1D) to predict soil-water content fluctuations and crop yield in a heterogeneous sandy grassland soil under supplementary irrigation. In the first step, the sensitivity of the soil hydrological model to hydraulic parameters, water stress, crop yield and lower boundary conditions was assessed after integrating models at one soil column. Free drainage and incremental constant head conditions were implemented in a lower boundary sensitivity analysis. In the second step, to predict Ks over the whole field, the spatial distributions of Ks and its relationship between co-located soil ECa measured by a DUALEM-21S sensor were investigated. Measured groundwater levels and soil layer thickness were interpolated using ordinary point kriging (OK) to a 0.5 by 0.5 m in aim of digital elevation maps. In the third step, a quasi 3D modelling approach was conducted using interpolated data as input hydraulic parameter, geometric information and boundary conditions in the integrated model. In addition, three different irrigation scenarios namely current, no irrigation and optimized irrigations were carried out to find out the most efficient irrigation regime. In this approach, detailed field scale maps of soil water stress, water storage and crop yield were produced at each specific time interval to evaluate the best and most efficient distribution of water using standard gun sprinkler irrigation. The results show that the effect of the position of the groundwater level was dominant in soil-water content prediction and associated water stress. A time-dependent sensitivity analysis of the hydraulic

  3. Nitrates in Wisconsin ground water.

    PubMed

    Schuknecht, B; Lawton, G W; Steinka, P; Delfino, J J

    1975-01-01

    Nitrate analyses were performed on ground water well samples originating from sources throughout Wisconsin. The data ranged from below the analytical detection limit up to 140 mg NO3-N/1. Over nine percent of all wells sampled has nitrate concentrations in excess of 10 mg NO3-N/1. Six individual counties had more than 10 mg NO3-N/1 in at least twenty percent of the wells covered in this survey. However, data reported for over eight thousand new wells driven in 1971-1972 showed only slightly more than two percent with nitrate levels above 10 mg NO3-N/1. This reflected the trend toward drilling deeper wells which are influenced less by nitrate seepage as well as adherence to new and stricter well construction codes. PMID:1183417

  4. Water cycling beneath subduction zones in 2D and 3D numerical models (Invited)

    NASA Astrophysics Data System (ADS)

    Rupke, L.; Iyer, K. H.; Hasenclever, J.; Morgan, J.

    2013-12-01

    . Slab fluids that do flux the mantle wedge are commonly believed to trigger arc melting. Finally, the fate of these fluids and the likely mantle flow field within the mantle wedge are resolved in 3D. We find that the classical 2D corner-flow solution is only a small subset of all possible mantle wedge flow fields. In fact, a more 'natural' flow field involves 3D diapirs fuelled by low-density slab fluids rising from the slab surface. These diapirs provide a potential mechanism for decompression melting in the mantle wedge, break the classic corner flow solution, and illustrate the need for high-resolution three-dimensional subduction zones models. In summary we find that numerical models are capable to resolve the key geological processes that control the subduction zone water cycle and help us to better relate subduction input to arc output.

  5. Fracture control of ground water flow and water chemistry in a rock aquitard

    USGS Publications Warehouse

    Eaton, T.T.; Anderson, M.P.; Bradbury, K.R.

    2007-01-01

    There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/Ss) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies. ?? 2007 National Ground Water Association.

  6. Improving organic tandem solar cells based on water-processed nanoparticles by quantitative 3D nanoimaging.

    PubMed

    Pedersen, E B L; Angmo, D; Dam, H F; Thydén, K T S; Andersen, T R; Skjønsfjell, E T B; Krebs, F C; Holler, M; Diaz, A; Guizar-Sicairos, M; Breiby, D W; Andreasen, J W

    2015-08-28

    Organic solar cells have great potential for upscaling due to roll-to-roll processing and a low energy payback time, making them an attractive sustainable energy source for the future. Active layers coated with water-dispersible Landfester particles enable greater control of the layer formation and easier access to the printing industry, which has reduced the use of organic solvents since the 1980s. Through ptychographic X-ray computed tomography (PXCT), we image quantitatively a roll-to-roll coated photovoltaic tandem stack consisting of one bulk heterojunction active layer and one Landfester particle active layer. We extract the layered morphology with structural and density information including the porosity present in the various layers and the silver electrode with high resolution in 3D. The Landfester particle layer is found to have an undesired morphology with negatively correlated top- and bottom interfaces, wide thickness distribution and only partial surface coverage causing electric short circuits through the layer. By top coating a polymer material onto the Landfester nanoparticles we eliminate the structural defects of the layer such as porosity and roughness, and achieve the increased performance larger than 1 V expected for a tandem cell. This study highlights that quantitative imaging of weakly scattering stacked layers of organic materials has become feasible by PXCT, and that this information cannot be obtained by other methods. In the present study, this technique specifically reveals the need to improve the coatability and layer formation of Landfester nanoparticles, thus allowing improved solar cells to be produced. PMID:26220159

  7. Semantic 3d City Model to Raster Generalisation for Water Run-Off Modelling

    NASA Astrophysics Data System (ADS)

    Verbree, E.; de Vries, M.; Gorte, B.; Oude Elberink, S.; Karimlou, G.

    2013-09-01

    Water run-off modelling applied within urban areas requires an appropriate detailed surface model represented by a raster height grid. Accurate simulations at this scale level have to take into account small but important water barriers and flow channels given by the large-scale map definitions of buildings, street infrastructure, and other terrain objects. Thus, these 3D features have to be rasterised such that each cell represents the height of the object class as good as possible given the cell size limitations. Small grid cells will result in realistic run-off modelling but with unacceptable computation times; larger grid cells with averaged height values will result in less realistic run-off modelling but fast computation times. This paper introduces a height grid generalisation approach in which the surface characteristics that most influence the water run-off flow are preserved. The first step is to create a detailed surface model (1:1.000), combining high-density laser data with a detailed topographic base map. The topographic map objects are triangulated to a set of TIN-objects by taking into account the semantics of the different map object classes. These TIN objects are then rasterised to two grids with a 0.5m cell-spacing: one grid for the object class labels and the other for the TIN-interpolated height values. The next step is to generalise both raster grids to a lower resolution using a procedure that considers the class label of each cell and that of its neighbours. The results of this approach are tested and validated by water run-off model runs for different cellspaced height grids at a pilot area in Amersfoort (the Netherlands). Two national datasets were used in this study: the large scale Topographic Base map (BGT, map scale 1:1.000), and the National height model of the Netherlands AHN2 (10 points per square meter on average). Comparison between the original AHN2 height grid and the semantically enriched and then generalised height grids shows

  8. Deterministic evaluation of collapse risk for a decomissioned flooded mine system: 3D numerical modelling of subsidence, roof collapse and impulse water flow.

    NASA Astrophysics Data System (ADS)

    Castellanza, Riccardo; Fernandez Merodo, Josè Antonio; di Prisco, Claudio; Frigerio, Gabriele; Crosta, Giovanni B.; Orlandi, Gianmarco

    2013-04-01

    Aim of the study is the assessment of stability conditions for an abandoned gypsum mine (Bologna , Italy). Mining was carried out til the end of the 70s by the room and pillar method. During mining a karst cave was crossed karstic waters flowed into the mine. As a consequence, the lower level of the mining is completely flooded and portions of the mining levels show critical conditions and are structurally prone to instability. Buildings and infrastructures are located above the first and second level and a large portion of the area below the mine area, and just above of the Savena river, is urbanised. Gypsum geomechanical properties change over time; water, or even air humidity, dissolves or weaken gypsum pillars, leading progressively to collapse. The mine is located in macro-crystalline gypsum beds belonging to the Messinian Gessoso Solfifera Formation. Selenitic gypsum beds are interlayered with by centimetre to meter thick shales layers. In order to evaluate the risk related to the collapse of the flooded level (level 3) a deterministic approach based on 3D numerical analyses has been considered. The entire abandoned mine system up to the ground surface has been generated in 3D. The considered critical scenario implies the collapse of the pillars and roof of the flooded level 3. In a first step, a sequential collapse starting from the most critical pillar has been simulated by means of a 3D Finite Element code. This allowed the definition of the subsidence basin at the ground surface and the interaction with the buildings in terms of ground displacements. 3D numerical analyses have been performed with an elasto-perfectly plastic constitutive model. In a second step, the effect of a simultaneous collapse of the entire level 3 has been considered in order to evaluate the risk of a flooding due to the water outflow from the mine system. Using a 3D CFD (Continuum Fluid Dynamics) finite element code the collapse of the level 3 has been simulated and the volume of

  9. 3D Branched nanowire photoelectrochemical electrodes for efficient solar water splitting.

    PubMed

    Kargar, Alireza; Sun, Ke; Jing, Yi; Choi, Chulmin; Jeong, Huisu; Jung, Gun Young; Jin, Sungho; Wang, Deli

    2013-10-22

    We report the systematic study of 3D ZnO/Si branched nanowire (b-NW) photoelectrodes and their application in solar water splitting. We focus our study on the correlation between the electrode design and structures (including Si NW doping, dimension of the trunk Si and branch ZnO NWs, and b-NW pitch size) and their photoelectrochemical (PEC) performances (efficiency and stability) under neutral conditions. Specifically, we show that for b-NW electrodes with lightly doped p-Si NW core, larger ZnO NW branches and longer Si NW cores give a higher photocathodic current, while for b-NWs with heavily doped p-Si NW trunks smaller ZnO NWs and shorter Si NWs provide a higher photoanodic current. Interestingly, the photocurrent turn-on potential decreases with longer p-Si NW trunks and larger ZnO NW branches resulting in a significant photocathodic turn-on potential shift of ~600 mV for the optimized ZnO/p-Si b-NWs compared to that of the bare p-Si NWs. A photocathode energy conversion efficiency of greater than 2% at -1 V versus Pt counter electrode and in neutral solution is achieved for the optimized ZnO/p-Si b-NW electrodes. The PEC performances or incident photon-to-current efficiency are further improved using Si NW cores with smaller pitch size. The photoelectrode stability is dramatically improved by coating a thin TiO2 protection layer using atomic-layer deposition method. These results provide very useful guidelines in designing photoelectrodes for selective solar water oxidation/reduction and overall spontaneous solar fuel generation using low cost earth-abundant materials for practical clean solar fuel production. PMID:24040832

  10. Ground water near Newton, Jasper County, Iowa

    USGS Publications Warehouse

    Buchmiller, Robert C.

    2001-01-01

    The water quality in the South Skunk River and the alluvial aquifer was similar, except most ground-water samples contained low dissolved oxygen concentrations. The low dissolved-oxygen concentrations in ground water resulted in high concentrations of iron and manganese in some locations and reduced forms of nitrogen.

  11. CONNECTICUT GROUND WATER QUALITY CLASSIFICATIONS - WELLS

    EPA Science Inventory

    This is a 1:24,000-scale datalayer of Ground Water Quality Classifications for public supply wells in Connecticut. It is a polygon Shapefile that includes GAA areas for public water supply wells. Each polygon is assigned a GAA ground water quality class, which is stored in the d...

  12. INTRODUCTION TO ARTIFICIAL GROUND-WATER RECHARGE

    EPA Science Inventory

    Artificial ground-water recharge has been practiced for scores of years throughout the world. The purpose of artificial recharge is to increase the rate at which water infiltrates the land surface in order to supplement the quantity of ground water in storage. A variety of rechar...

  13. Mississippi Embayment Regional Ground Water Study

    EPA Science Inventory

    Increased water usage in the southeastern United States in the tri-state area of Tennessee, Mississippi and Arkansas poses a dilemma to ensuring long-term sustainability of the quantity and quality of ground-water resources that underlie the region. Demand for ground water by ag...

  14. Guide to Louisiana's ground-water resources

    USGS Publications Warehouse

    Stuart, C.G.; Knochenmus, D.D.; McGee, B.D.

    1994-01-01

    Ground water is one of the most valuable and abundant natural resources of Louisiana. Of the 4-.4 million people who live in the State, 61 percent use ground water as a source for drinking water. Most industrial and rural users and half of the irrigation users in the State rely on ground water. Quantity, however, is not the only aspect that makes ground water so valuable; quality also is important for its use. In most areas, little or no water treatment is required for drinking water and industrial purposes. Knowledge of Louisiana's ground-water resources is needed to ensure proper development and protection of this valuable resource. This report is designed to inform citizens about the availability and quality of ground water in Louisiana. It is not intended as a technical reference; rather, it is a guide to ground water and the significant role this resource plays in the state. Most of the ground water that is used in the State is withdrawn from 13 aquifers and aquifer systems: the Cockfield, Sparta, and Carrizo-Wilcox aquifersin northern Louisiana; Chicot aquifer system, Evangeline aquifer, Jasper aquifer system, and Catahoula aquifer in central and southwestern Louisiana; the Chicot equivalent, Evangeline equivalent, and Jasper equivalent aquifer systems in southeastern Louisiana; and the MississippiRiver alluvial, Red River alluvial, and upland terrace aquifers that are statewide. Ground water is affected by man's activities on the land surface, and the major ground-water concerns in Louisiana are: (1) contamination from surface disposal of hazardous waste, agricultural chemicals, and petroleum products; (2) contamination from surface wastes and saltwater through abandoned wells; (3) saltwater encroachment; and (4) local overdevelopment. Information about ground water in Louisiana is extensive and available to the public. Several State and Federal agencies provide published and unpublished material upon request.

  15. Effect of random coincidences for quantitative cardiac PET studies using 3D oxygen-15 water scans

    NASA Astrophysics Data System (ADS)

    Bouchareb, Y.; Thielemans, K.; Spinks, T.; Rimoldi, O.; Camici, P. G.

    2006-03-01

    The effect of random coincidences estimation methods on the quantitative accuracy of iterative and analytic reconstruction methods to determine myocardial blood flow (MBF) in PET studies using H II 15O has been investigated. Dynamic scans were acquired on the EXACT3D PET scanner on pigs after H II 15O injection (resting and dipyridamoleinduced stress). Radioactive microspheres (MS) were used to provide a "gold standard" of MBF values. The online subtraction (OS) and maximum likelihood (ML) methods for estimating randoms were combined with (i) 3D-RP, (ii) FORE + attenuation-weighted OSEM, (iii) FORE-FBP and (iv) 3D-OSEM. Factor images were generated and resliced to short axis images; 16 ROIs were defined in the left myocardium and 2 ROIs in the left and right cavities. ROIs were projected onto the dynamic images to extract time-activity-curves, which were then fitted to a single compartment model to estimate absolute MBF. Microsphere measurements were obtained in a similar way and 64 pairs of measurements were made. The ML method improved the SNR of 3D-RP, FORE-FBP, FORE-OSEM, and 3D-OSEM by 8%, 8%, 7% and 3% respectively. Compared to the OS method, the ML method improved the accuracy of coronary flow reserve values of 3DOSEM, 3D-RP, FORE-OSEM and FORE-FBP by 9%, 7%, 1% and 3% respectively. Regression analysis provided better correlation with 3D-OSEM and FORE-OSEM when combined with the ML method. We conclude that the ML method for estimating randoms combined with 3D-OSEM and FORE-OSEM delivers the best performance for absolute quantification of MBF using H II 15O when compared with microsphere measurements.

  16. Ground Water in the Anchorage Area, Alaska--Meeting the Challenges of Ground-Water Sustainability

    USGS Publications Warehouse

    Moran, Edward H.; Galloway, Devin L.

    2006-01-01

    Ground water is an important component of Anchorage's water supply. During the 1970s and early 80s when ground water extracted from aquifers near Ship Creek was the principal source of supply, area-wide declines in ground-water levels resulted in near record low streamflows in Ship Creek. Since the importation of Eklutna Lake water in the late 1980s, ground-water use has been reduced and ground water has contributed 14-30 percent of the annual supply. As Anchorage grows, given the current constraints on the Eklutna Lake water availability, the increasing demand for water could place an increasing reliance on local ground-water resources. The sustainability of Anchorage's ground-water resources challenges stakeholders to develop a comprehensive water-resources management strategy.

  17. Ground Penetrating Radar (GPR) Imaging to Distinguish Active from Inactive Sinkholes in Covered Karst Terrain: Results from Field Data and 3D FDTD Modeling

    NASA Astrophysics Data System (ADS)

    Gooch, B. T.; Kruse, S. E.

    2009-12-01

    Ground penetrating radar (GPR) is widely used to identify locations of sinkholes in covered karst terrain in Florida. Some sinkholes serve as hydraulic conduits between the surficial and underlying aquifers. Their role is critical in determining the surficial aquifer response to pumping in deeper aquifers. Improved methods for discriminating between hydraulically active sinkholes and plugged sinkholes could help regional water management. In the covered karst of west-central Florida a clay-rich weathering horizon forms over the limestone. The clay-rich layer is in turn overlain by surficial sands. Ground penetrating radar profiles typically show a strong reflector from the top of clay-rich horizon as well as internal layering within sands. Active sinkholes are expected to have sandy conduits that broach the clay layer, and perhaps layering in the overlying sand indicative of ongoing subsidence. Three dimensional simulations of GPR profiles over sinkhole with and without conduits were run with the finite-difference time-domain (FDTD) program GprMax. Results from the synthetic surveys were then processed with standard techniques, including migration. The modeling confirms that conduits appear in GPR records primarily as gaps in the return from the clay layer. The modeling also shows that non-traditional survey geometries (varying antenna spacing and orientation) are unlikely to recover more information than traditional proximal transmitter-receiver separation. We also examine GPR profiles and 3D grids over a set of active and inactive sinkholes in Tampa, Florida. Preliminary analysis suggests that active sinks may present more identifiable gaps in the overlying clay layer, but consistent differences in structure of active and inactive sinkholes are not easily discerned. Other geophysical methods may prove to be more helpful in discerning the presence or absence of active conduits in these situations.

  18. Improving organic tandem solar cells based on water-processed nanoparticles by quantitative 3D nanoimaging

    NASA Astrophysics Data System (ADS)

    Pedersen, E. B. L.; Angmo, D.; Dam, H. F.; Thydén, K. T. S.; Andersen, T. R.; Skjønsfjell, E. T. B.; Krebs, F. C.; Holler, M.; Diaz, A.; Guizar-Sicairos, M.; Breiby, D. W.; Andreasen, J. W.

    2015-08-01

    Organic solar cells have great potential for upscaling due to roll-to-roll processing and a low energy payback time, making them an attractive sustainable energy source for the future. Active layers coated with water-dispersible Landfester particles enable greater control of the layer formation and easier access to the printing industry, which has reduced the use of organic solvents since the 1980s. Through ptychographic X-ray computed tomography (PXCT), we image quantitatively a roll-to-roll coated photovoltaic tandem stack consisting of one bulk heterojunction active layer and one Landfester particle active layer. We extract the layered morphology with structural and density information including the porosity present in the various layers and the silver electrode with high resolution in 3D. The Landfester particle layer is found to have an undesired morphology with negatively correlated top- and bottom interfaces, wide thickness distribution and only partial surface coverage causing electric short circuits through the layer. By top coating a polymer material onto the Landfester nanoparticles we eliminate the structural defects of the layer such as porosity and roughness, and achieve the increased performance larger than 1 V expected for a tandem cell. This study highlights that quantitative imaging of weakly scattering stacked layers of organic materials has become feasible by PXCT, and that this information cannot be obtained by other methods. In the present study, this technique specifically reveals the need to improve the coatability and layer formation of Landfester nanoparticles, thus allowing improved solar cells to be produced.Organic solar cells have great potential for upscaling due to roll-to-roll processing and a low energy payback time, making them an attractive sustainable energy source for the future. Active layers coated with water-dispersible Landfester particles enable greater control of the layer formation and easier access to the printing

  19. Ground-water levels in Wyoming, 1976

    USGS Publications Warehouse

    Ballance, W.C.; Freudenthal, Pamela B.

    1977-01-01

    Ground-water levels are measured periodically in a network of about 280 observation wells in Wyoming to record changes in ground-water storage. The areas of water-level observation are mostly where ground water is used in large quantities for irrigation or municipal purposes. This report contains maps showing location of observation wells and water-level changes from 1976 to 1977. Well history, highest and lowest water levels , and hydrographs for most wells also are included. The program of groundwater observation is conducted by the U.S. Geological Survey in cooperation with the Wyoming State Engineer and the city of Cheyenne. (Woodard-USGS)

  20. 3D leaf water content mapping using terrestrial laser scanner backscatter intensity with radiometric correction

    NASA Astrophysics Data System (ADS)

    Zhu, Xi; Wang, Tiejun; Darvishzadeh, Roshanak; Skidmore, Andrew K.; Niemann, K. Olaf

    2015-12-01

    Leaf water content (LWC) plays an important role in agriculture and forestry management. It can be used to assess drought conditions and wildfire susceptibility. Terrestrial laser scanner (TLS) data have been widely used in forested environments for retrieving geometrically-based biophysical parameters. Recent studies have also shown the potential of using radiometric information (backscatter intensity) for estimating LWC. However, the usefulness of backscatter intensity data has been limited by leaf surface characteristics, and incidence angle effects. To explore the idea of using LiDAR intensity data to assess LWC we normalized (for both angular effects and leaf surface properties) shortwave infrared TLS data (1550 nm). A reflectance model describing both diffuse and specular reflectance was applied to remove strong specular backscatter intensity at a perpendicular angle. Leaves with different surface properties were collected from eight broadleaf plant species for modeling the relationship between LWC and backscatter intensity. Reference reflectors (Spectralon from Labsphere, Inc.) were used to build a look-up table to compensate for incidence angle effects. Results showed that before removing the specular influences, there was no significant correlation (R2 = 0.01, P > 0.05) between the backscatter intensity at a perpendicular angle and LWC. After the removal of the specular influences, a significant correlation emerged (R2 = 0.74, P < 0.05). The agreement between measured and TLS-derived LWC demonstrated a significant reduction of RMSE (root mean square error, from 0.008 to 0.003 g/cm2) after correcting for the incidence angle effect. We show that it is possible to use TLS to estimate LWC for selected broadleaved plants with an R2 of 0.76 (significance level α = 0.05) at leaf level. Further investigations of leaf surface and internal structure will likely result in improvements of 3D LWC mapping for studying physiology and ecology in vegetation.

  1. Application of Technical Measures and Software in Constructing Photorealistic 3D Models of Historical Building Using Ground-Based and Aerial (UAV) Digital Images

    NASA Astrophysics Data System (ADS)

    Zarnowski, Aleksander; Banaszek, Anna; Banaszek, Sebastian

    2015-12-01

    Preparing digital documentation of historical buildings is a form of protecting cultural heritage. Recently there have been several intensive studies using non-metric digital images to construct realistic 3D models of historical buildings. Increasingly often, non-metric digital images are obtained with unmanned aerial vehicles (UAV). Technologies and methods of UAV flights are quite different from traditional photogrammetric approaches. The lack of technical guidelines for using drones inhibits the process of implementing new methods of data acquisition. This paper presents the results of experiments in the use of digital images in the construction of photo-realistic 3D model of a historical building (Raphaelsohns' Sawmill in Olsztyn). The aim of the study at the first stage was to determine the meteorological and technical conditions for the acquisition of aerial and ground-based photographs. At the next stage, the technology of 3D modelling was developed using only ground-based or only aerial non-metric digital images. At the last stage of the study, an experiment was conducted to assess the possibility of 3D modelling with the comprehensive use of aerial (UAV) and ground-based digital photographs in terms of their labour intensity and precision of development. Data integration and automatic photo-realistic 3D construction of the models was done with Pix4Dmapper and Agisoft PhotoScan software Analyses have shown that when certain parameters established in an experiment are kept, the process of developing the stock-taking documentation for a historical building moves from the standards of analogue to digital technology with considerably reduced cost.

  2. Alternatives for Ground Water Cleanup

    NASA Astrophysics Data System (ADS)

    Hudak, P. F.

    Aquifer remediation is one of our most difficult environmental challenges; technological limitations and problems arising from the physical and chemical complexities of contaminated subsurface environments thwart our best efforts. A 19-member committee of leaders in environmental engineering, hydrogeology, epidemiology, environmental economics, and environmental policy has written an ambitious book that broadly addresses the groundwater remediation problem. Topics include site characterization, capabilities and limitations of pump-and-treat and alternative technologies, alternative goals for ground water cleanup, and policy implications.One of the book's strengths is its information base, which includes various public and private groups, data from 80 pump-and-treat sites, and an extensive literature review. The text is clearly written and well organized. Specific conclusions are stated at the end of each major chapter, and sound policy recommendations are offered at the end of the final chapter. An appendix summarizes pump-andtreat systems reviewed during the study. Several case studies, diagrams, and photographs effectively illustrate concepts and ideas conveyed in the text.

  3. 3D full-waveform inversion of time-lapse horizontal borehole GPR data to map soil water content variability

    NASA Astrophysics Data System (ADS)

    Klotzsche, A.; Van Der Kruk, J.; Oberroehrmann, M.; Vanderborght, J.; Vereecken, H.

    2015-12-01

    Soil moisture is a key state variable that controls water and mass fluxes in soil-plant systems and is variable in space and time. Over the last year's, hydrogeophysical methods such as ground penetrating radar (GPR) have been used to determine electromagnetic properties as proxies for soil water content (SWC). Here, we combined zero-offset-profiles (ZOP) GPR measurements within multiple horizontal minirhizotubes at different depths to determine the spatial and temporal variability of SWC under a winter wheat stand at the Selhausen test site (Germany). We studied spatio-temporal variations of SWC under three different treatments: rainfed, irrigated and sheltered. We acquired 15 time-lapse ZOP GPR dataset during the growing season of the wheat in the rhizotron facility using horizontal boreholes with a separation of 0.75m and a length of 6m at six depths between 0.1-1.2m. The obtained radar velocities were converted to SWC using the 4-phase volumetric complex refractive index model. SWC values obtained using standard ray-based processing methods were not reliable close to the surface (0.1-0.2m depth) because of the inference of the critically refracted air wave and the direct wave through the subsurface. Therefore, we implemented a full-waveform inversion that uses accurate 3D forward modeling of GPRMax that incorporates the air and soil interactions. The shuffled complex evolution (SCE) method allowed us to retrieve quantitative medium properties that explained the measured data with a R² of at least 0.95, and improved SWC estimates at all depths. The final SWC distributions for wet and dry conditions showed that the vertical variability is significantly larger than the lateral variability caused by strong influence of precipitation and irrigation events.

  4. 3-D EM inversion of ground based geomagnetic Sq data. Results from the analysis of Australian array (AWAGS) data

    NASA Astrophysics Data System (ADS)

    Koch, Stephan; Kuvshinov, Alexey

    2015-03-01

    We present the first inversion of geomagnetic Sq data in a framework of 3-D conductivity models. This problem has been considered as immensely difficult due to the complex spatial structure of the Sq source which, in addition, varies with season and solar activity. Recently, we developed a 3-D electromagnetic (EM) inversion solution that allows one to work in a consistent manner with data that originates from sources, irrespective of their spatial complexity. In this paper, we apply our 3-D EM inversion scheme to Sq data collected during the Australian Wide Array of Geomagnetic Stations project. Within this project, three components of the geomagnetic field were recorded between 1989 November and 1990 December with the use of 53 portable vector magnetometers. The instruments were distributed over the Australian mainland with an average spacing of 275 km between sites. Inverting this unique-in a sense of its spatial regularity, density and long operational time-data set, we recovered the 3-D conductivity distribution beneath Australia at upper mantle depths (100-520 km). This depth range was justified in the paper from resolution studies using checkerboard tests. In addition, we performed extensive modelling to estimate quantitatively the influence of various factors on Sq signals, namely from hypothetical anomalies, inaccuracy in the source, ocean, and model discretization. As expected, the ocean (coastal) effect appeared to be the largest so that it has to be accounted for during 3-D inversion as accurately as possible. Our 3-D inversions-of data from either single or multiple days-revealed a strong offshore conductor near the south-east coast of Australia, which persists at all considered depths. Varying in details, this anomaly is remarkably robust irrespective of the considered day(s). We compared our results to those obtained from a different inversion scheme and an independent induction data set, and observed encouraging similarity. Combination of the two

  5. GROUND WATER CONTAMINATION POTENTIAL FROM STORMWATER INFILTRATION

    EPA Science Inventory

    Prior to urbanization, ground water recharge resulted from infiltration of precipitation through pervious surfaces, including grasslands and woods. This infiltration water was relatively uncontaminated. With urbanization, the permeable soil surface area through which recharge by...

  6. Microscopic Dimensions Engineering: Stepwise Manipulation of the Surface Wettability on 3D Substrates for Oil/Water Separation.

    PubMed

    Du, Ran; Gao, Xin; Feng, Qingliang; Zhao, Qiuchen; Li, Pan; Deng, Shibin; Shi, Liurong; Zhang, Jin

    2016-02-01

    Microscopic dimensions engineering is proposed to devise a series of 3D superhydrophobic substrates with microstructures of different dimensions. Combined theoretical modeling and experiments give the relationship of surface roughness and superhydrophobic properties, important for guiding the design of superior superwettable materials for water remediation and other uses. PMID:26618329

  7. COMPILATION OF GROUND-WATER MODELS

    EPA Science Inventory

    Ground-water modeling is a computer-based methodology for mathematical analysis of the mechanisms and controls of ground-water systems for the evaluation of policies, action, and designs that may affect such systems. n addition to satisfying scientific interest in the workings of...

  8. Procedures for ground-water investigations

    SciTech Connect

    Not Available

    1992-12-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water monitoring procedures are developed and used in accordance with the PNL Quality Assurance Program.

  9. HANDBOOK: GROUND WATER VOLUME II: METHODOLOGY

    EPA Science Inventory

    This handbook is an extensively revised version of the Ground Water Handbook, originally published in 1987 as EPA/625/6-87/016. It has been published in two volumes: Volume I: Ground Water and Contamination, EPA/625/6-90/016a, and Volume II: Methodology, EPA/625/6-90/016b. Volume...

  10. User interface for ground-water modeling: Arcview extension

    USGS Publications Warehouse

    Tsou, M.-S.; Whittemore, D.O.

    2001-01-01

    Numerical simulation for ground-water modeling often involves handling large input and output data sets. A geographic information system (GIS) provides an integrated platform to manage, analyze, and display disparate data and can greatly facilitate modeling efforts in data compilation, model calibration, and display of model parameters and results. Furthermore, GIS can be used to generate information for decision making through spatial overlay and processing of model results. Arc View is the most widely used Windows-based GIS software that provides a robust user-friendly interface to facilitate data handling and display. An extension is an add-on program to Arc View that provides additional specialized functions. An Arc View interface for the ground-water flow and transport models MODFLOW and MT3D was built as an extension for facilitating modeling. The extension includes preprocessing of spatially distributed (point, line, and polygon) data for model input and postprocessing of model output. An object database is used for linking user dialogs and model input files. The Arc View interface utilizes the capabilities of the 3D Analyst extension. Models can be automatically calibrated through the Arc View interface by external linking to such programs as PEST. The efficient pre- and postprocessing capabilities and calibration link were demonstrated for ground-water modeling in southwest Kansas.

  11. Feasibility of RACT for 3D dose measurement and range verification in a water phantom

    SciTech Connect

    Alsanea, Fahed; Moskvin, Vadim; Stantz, Keith M.

    2015-02-15

    Purpose: The objective of this study is to establish the feasibility of using radiation-induced acoustics to measure the range and Bragg peak dose from a pulsed proton beam. Simulation studies implementing a prototype scanner design based on computed tomographic methods were performed to investigate the sensitivity to proton range and integral dose. Methods: Derived from thermodynamic wave equation, the pressure signals generated from the dose deposited from a pulsed proton beam with a 1 cm lateral beam width and a range of 16, 20, and 27 cm in water using Monte Carlo methods were simulated. The resulting dosimetric images were reconstructed implementing a 3D filtered backprojection algorithm and the pressure signals acquired from a 71-transducer array with a cylindrical geometry (30 × 40 cm) rotated over 2π about its central axis. Dependencies on the detector bandwidth and proton beam pulse width were performed, after which, different noise levels were added to the detector signals (using 1 μs pulse width and a 0.5 MHz cutoff frequency/hydrophone) to investigate the statistical and systematic errors in the proton range (at 20 cm) and Bragg peak dose (of 1 cGy). Results: The reconstructed radioacoustic computed tomographic image intensity was shown to be linearly correlated to the dose within the Bragg peak. And, based on noise dependent studies, a detector sensitivity of 38 mPa was necessary to determine the proton range to within 1.0 mm (full-width at half-maximum) (systematic error < 150 μm) for a 1 cGy Bragg peak dose, where the integral dose within the Bragg peak was measured to within 2%. For existing hydrophone detector sensitivities, a Bragg peak dose of 1.6 cGy is possible. Conclusions: This study demonstrates that computed tomographic scanner based on ionizing radiation-induced acoustics can be used to verify dose distribution and proton range with centi-Gray sensitivity. Realizing this technology into the clinic has the potential to significantly

  12. Fracture control of ground water flow and water chemistry in a rock aquitard.

    PubMed

    Eaton, Timothy T; Anderson, Mary P; Bradbury, Kenneth R

    2007-01-01

    There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/S(s)) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies. PMID:17760586

  13. Hanford site ground water protection management plan

    SciTech Connect

    Not Available

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities.

  14. International borders, ground water flow, and hydroschizophrenia.

    PubMed

    Jarvis, Todd; Giordano, Mark; Puri, Shammy; Matsumoto, Kyoko; Wolf, Aaron

    2005-01-01

    A substantial body of research has been conducted on transboundary water, transboundary water law, and the mitigation of transboundary water conflict. However, most of this work has focused primarily on surface water supplies. While it is well understood that aquifers cross international boundaries and that the base flow of international river systems is often derived in part from ground water, transboundary ground water and surface water systems are usually managed under different regimes, resulting in what has been described as "hydroschizophrenia." Adding to the problem, the hydrologic relationships between surface and ground water supplies are only known at a reconnaissance level in even the most studied international basins, and thus even basic questions regarding the territorial sovereignty of ground water resources often remain unaddressed or even unasked. Despite the tensions inherent in the international setting, riparian nations have shown tremendous creativity in approaching regional development, often through preventive diplomacy, and the creation of "baskets of benefits," which allow for positive-sum, integrative allocations of joint gains. In contrast to the notion of imminent water wars, the history of hydropolitical relations worldwide has been overwhelmingly cooperative. Limited ground water management in the international arena, coupled with the fact that few states or countries regulate the use of ground water, begs the question: will international borders serve as boundaries for increased "flows" of hydrologic information and communication to maintain strategic aquifers, or will increased competition for shared ground water resources lead to the potential loss of strategic aquifers and "no flows" for both ground water users? PMID:16149973

  15. Magnificent Ground Water Connection. [Sample Activities].

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    Water conservation and usage is an important concept in science. This document, geared specifically to New England, provides many activities for protecting and discussing ground water situations. Sample activities for grades K-6 include: (1) All the Water in the World; (2) The Case of the Disappearing Water; (3) Deep Subjects--Wells and Ground…

  16. Light-Driven Overall Water Splitting Enabled by a Photo-Dember Effect Realized on 3D Plasmonic Structures.

    PubMed

    Chen, Min; Gu, Jiajun; Sun, Cheng; Zhao, Yixin; Zhang, Ruoxi; You, Xinyuan; Liu, Qinglei; Zhang, Wang; Su, Yishi; Su, Huilan; Zhang, Di

    2016-07-26

    Photoelectric conversion driven by sunlight has a broad range of energy/environmental applications (e.g., in solar cells and water splitting). However, difficulties are encountered in the separation of photoexcited charges. Here, we realize a long-range (∼1.5 μm period) electric polarization via asymmetric localization of surface plasmons on a three-dimensional silver structure (3D-Ag). This visible-light-responsive effect-the photo-Dember effect, can be analogous to the thermoelectric effect, in which hot carriers are thermally generated instead of being photogenerated. The induced electric field can efficiently separate photogenerated charges, enabling sunlight-driven overall water splitting on a series of dopant-free commercial semiconductor particles (i.e., ZnO, CeO2, TiO2, and WO3) once they are combined with the 3D-Ag substrate. These photocatalytic processes can last over 30 h on 3D-Ag+ZnO, 3D-Ag+CeO2, and 3D-Ag+TiO2, thus demonstrating good catalytic stability for these systems. Using commercial WO3 powder as a reference, the amount of O2 generated with 3D-Ag+CeO2 surpasses even its recently reported counterpart in which sacrificial reagents had to be involved to run half-reactions. This plasmon-mediated charge separation strategy provides an effective way to improve the efficiency of photoelectric energy conversion, which can be useful in photovoltaics and photocatalysis. PMID:27351779

  17. Research into a Single-aperture Light Field Camera System to Obtain Passive Ground-based 3D Imagery of LEO Objects

    NASA Astrophysics Data System (ADS)

    Bechis, K.; Pitruzzello, A.

    2014-09-01

    This presentation describes our ongoing research into using a ground-based light field camera to obtain passive, single-aperture 3D imagery of LEO objects. Light field cameras are an emerging and rapidly evolving technology for passive 3D imaging with a single optical sensor. The cameras use an array of lenslets placed in front of the camera focal plane, which provides angle of arrival information for light rays originating from across the target, allowing range to target and 3D image to be obtained from a single image using monocular optics. The technology, which has been commercially available for less than four years, has the potential to replace dual-sensor systems such as stereo cameras, dual radar-optical systems, and optical-LIDAR fused systems, thus reducing size, weight, cost, and complexity. We have developed a prototype system for passive ranging and 3D imaging using a commercial light field camera and custom light field image processing algorithms. Our light field camera system has been demonstrated for ground-target surveillance and threat detection applications, and this paper presents results of our research thus far into applying this technology to the 3D imaging of LEO objects. The prototype 3D imaging camera system developed by Northrop Grumman uses a Raytrix R5 C2GigE light field camera connected to a Windows computer with an nVidia graphics processing unit (GPU). The system has a frame rate of 30 Hz, and a software control interface allows for automated camera triggering and light field image acquisition to disk. Custom image processing software then performs the following steps: (1) image refocusing, (2) change detection, (3) range finding, and (4) 3D reconstruction. In Step (1), a series of 2D images are generated from each light field image; the 2D images can be refocused at up to 100 different depths. Currently, steps (1) through (3) are automated, while step (4) requires some user interaction. A key requirement for light field camera

  18. Pollution of ground water in Europe

    PubMed Central

    Buchan, S.; Key, A.

    1956-01-01

    This paper discusses pollution of ground water in 20 countries of the European region, giving for each an account of the geology and hydrogeology, water supplies, the extent and nature of ground water pollution, and the legal, administrative, and technical means of controlling that pollution. For the countries not considered in the preceding article on surface water pollution, an account is also given of the superficial physical features, rainfall, population, and industries. A general discussion follows of such questions as the ways in which ground water pollution may occur, the factors mitigating or aggravating pollution, and ways of protection against pollution. The authors consider that the problem of ground water pollution in Europe may well be more serious than it would appear to be on the evidence so far obtained. PMID:13374533

  19. A primer on ground water

    USGS Publications Warehouse

    Baldwin, Helene L.; McGuinness, C.L.

    1963-01-01

    Most of us don't have to look for water. We grew up either in big cities where there was a public water supply, or in small towns or on farms where the water came from wells. But there are some people to whom finding a new supply of water is vitally important.

  20. Water-based polyurethane 3D printed scaffolds with controlled release function for customized cartilage tissue engineering.

    PubMed

    Hung, Kun-Che; Tseng, Ching-Shiow; Dai, Lien-Guo; Hsu, Shan-hui

    2016-03-01

    Conventional 3D printing may not readily incorporate bioactive ingredients for controlled release because the process often involves the use of heat, organic solvent, or crosslinkers that reduce the bioactivity of the ingredients. Water-based 3D printing materials with controlled bioactivity for customized cartilage tissue engineering is developed in this study. The printing ink contains the water dispersion of synthetic biodegradable polyurethane (PU) elastic nanoparticles, hyaluronan, and bioactive ingredients TGFβ3 or a small molecule drug Y27632 to replace TGFβ3. Compliant scaffolds are printed from the ink at low temperature. These scaffolds promote the self-aggregation of mesenchymal stem cells (MSCs) and, with timely release of the bioactive ingredients, induce the chondrogenic differentiation of MSCs and produce matrix for cartilage repair. Moreover, the growth factor-free controlled release design may prevent cartilage hypertrophy. Rabbit knee implantation supports the potential of the novel 3D printing scaffolds in cartilage regeneration. We consider that the 3D printing composite scaffolds with controlled release bioactivity may have potential in customized tissue engineering. PMID:26774563

  1. 3D branched ZnO nanowire arrays decorated with plasmonic au nanoparticles for high-performance photoelectrochemical water splitting.

    PubMed

    Zhang, Xing; Liu, Yang; Kang, Zhenhui

    2014-03-26

    Plasmonic photoelectrochemical (PEC) water splitting is very promising in the conversion of abundant solar energy into chemical energy. However, the solar-to-hydrogen efficiencies reported so far are still too low for practical use, which can be improved by optimizing the design and synthesis of individual blocks (i. e., the compositions, sizes, shapes of the metal and the coupling semiconductors) and the assembly of these blocks into targeted three-dimensional (3D) structures. Here, we constructed a composite plasmonic metal/semiconductor photoanode by decorating gold nanoparticles (Au NPs) on 3D branched ZnO nanowire arrays (B-ZnO NWs) through a series of simple solution chemical routes. The 3D ordered Au/B-ZnO NWs photoanodes exhibited excellent PEC activities in both ultraviolet and visible region. The improved photoactivities in visible region were demonstrated to be caused by the surface-plasmon-resonance effect of Au NPs. The photoconversion efficiency of Au/B-ZnO NWs photoanode reached 0.52% under simulated sunlight illumination. This is a high value of solar-to-hydrogen efficiencies reported till nowadays for plasmonic PEC water splitting, which was mainly benefit from the extensive metal/semiconductor interfaces for efficient extraction of hot electron from Au NPs and excellent charge-carries collection efficiency of the 3D ordered Au/B-ZnO NWs photoelectrode. PMID:24598779

  2. Coupling Between Microstrip Lines with Finite Width Ground Plane Embedded in Polyimide Layers for 3D-MMICs on Si

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Dalton, Edan; Tentzeris, Emmanouil M.; Papapolymerou, John; Williams, W. Dan (Technical Monitor)

    2001-01-01

    Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimeter-wave integrated circuits on complementary metal oxide semiconductor (CMOS) (low resistivity) Si wafers. Thin film microstrip lines (TFMS) with finite width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS lines are susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and experimental measurements are used to show that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions.

  3. 1D and 3D inversion of VES data to outline a fresh water zone floating over saline water body at the northwestern coast of Egypt

    NASA Astrophysics Data System (ADS)

    Massoud, Usama; Soliman, Mamdouh; Taha, Ayman; Khozym, Ashraf; Salah, Hany

    2015-12-01

    Seawater intrusion is a widespread environmental problem in the Egyptian coastal aquifers. It affects the groundwater used in domestic and agricultural activities along these coasts. In this study, resistivity survey in the form of Vertical Electrical Sounding (VES) was conducted at ZAWYET EL HAWALA cultivated site, northwest coast of Egypt to outline a freshwater zone overlies the main saltwater body, and to determine the most suitable location for drilling water well for irrigation purposes. The VES data were measured at 11 stations in the studied site. After processing, the data were inverted in 1-D and 3-D schemes and the final model was presented as resistivity slices with depth. The results indicate that the effect of saltwater intrusion was observed, as low resistivity values, at 7.5 m below ground surface (bgs) at the northern part of the study area (toward the Mediterranean Sea), and extends southward with increasing depth covering the whole area at about 30 m bgs. The fresh water zone shows a minimum thickness of less than 7.5 m at the northern side and a maximum thickness of about 20 m at the southern side of the area. The proper site for drilling water well tap and the freshwater zone is the location of VES6 or VES9 with a maximum well depth of about 20 m bgs. The water withdrawal from the proposed well should be controlled not to raise the main saline water table in the well site. The main sources of the freshwater zone are the rainfall and surface runoff descending from the southern tableland. Excess rainfall and surface runoff can be avoided from direct discharge to the sea by collecting them in man-made outlined trenches and re-using the stored water in irrigation during the dry seasons.

  4. Ground-Water Protection and Monitoring Program

    SciTech Connect

    Dresel, P.E.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the ground-water protection and monitoring program strategy for the Hanford Site in 1994. Two of the key elements of this strategy are to (1) protect the unconfined aquifer from further contamination, and (2) conduct a monitoring program to provide early warning when contamination of ground water does occur. The monitoring program at Hanford is designed to document the distribution and movement of existing ground-water contamination and provides a historical baseline for evaluating current and future risk from exposure to the contamination and for deciding on remedial action options.

  5. 2D and 3D separate and joint inversion of airborne ZTEM and ground AMT data: Synthetic model studies

    NASA Astrophysics Data System (ADS)

    Sasaki, Yutaka; Yi, Myeong-Jong; Choi, Jihyang

    2014-05-01

    The ZTEM (Z-axis Tipper Electromagnetic) method measures naturally occurring audio-frequency magnetic fields and obtains the tipper function that defines the relationship among the three components of the magnetic field. Since the anomalous tipper responses are caused by the presence of lateral resistivity variations, the ZTEM survey is most suited for detecting and delineating conductive bodies extending to considerable depths, such as graphitic dykes encountered in the exploration of unconformity type uranium deposit. Our simulations shows that inversion of ZTEM data can detect reasonably well multiple conductive dykes placed 1 km apart. One important issue regarding ZTEM inversion is the effect of the initial model, because homogeneous half-space and (1D) layered structures produce no responses. For the 2D model with multiple conductive dykes, the inversion results were useful for locating the dykes even when the initial model was not close to the true background resistivity. For general 3D structures, however, the resolution of the conductive bodies can be reduced considerably depending on the initial model. This is because the tipper magnitudes from 3D conductors are smaller due to boundary charges than the 2D responses. To alleviate this disadvantage of ZTEM surveys, we combined ZTEM and audio-frequency magnetotelluric (AMT) data. Inversion of sparse AMT data was shown to be effective in providing a good initial model for ZTEM inversion. Moreover, simultaneously inverting both data sets led to better results than the sequential approach by enabling to identify structural features that were difficult to resolve from the individual data sets.

  6. Microfluidic Fabrication of Bio-Inspired Microfibers with Controllable Magnetic Spindle-Knots for 3D Assembly and Water Collection.

    PubMed

    He, Xiao-Heng; Wang, Wei; Liu, Ying-Mei; Jiang, Ming-Yue; Wu, Fang; Deng, Ke; Liu, Zhuang; Ju, Xiao-Jie; Xie, Rui; Chu, Liang-Yin

    2015-08-12

    A simple and flexible approach is developed for controllable fabrication of spider-silk-like microfibers with tunable magnetic spindle-knots from biocompatible calcium alginate for controlled 3D assembly and water collection. Liquid jet templates with volatile oil drops containing magnetic Fe3O4 nanoparticles are generated from microfluidics for fabricating spider-silk-like microfibers. The structure of jet templates can be precisely adjusted by simply changing the flow rates to tailor the structures of the resultant spider-silk-like microfibers. The microfibers can be well manipulated by external magnetic fields for controllably moving, and patterning and assembling into different 2D and 3D structures. Moreover, the dehydrated spider-silk-like microfibers, with magnetic spindle-knots for collecting water drops, can be controllably assembled into spider-web-like structures for excellent water collection. These spider-silk-like microfibers are promising as functional building blocks for engineering complex 3D scaffolds for water collection, cell culture, and tissue engineering. PMID:26192108

  7. Unimpeded permeation of water through biocidal graphene oxide sheets anchored on to 3D porous polyolefinic membranes

    NASA Astrophysics Data System (ADS)

    Mural, Prasanna Kumar S.; Jain, Shubham; Kumar, Sachin; Madras, Giridhar; Bose, Suryasarathi

    2016-04-01

    3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and hot-pressed samples revealed a clear picture as to how the morphology develops and coarsens over a function of time during post-processing operations like compression molding. The coarsening of PE/PEO blends was traced using X-ray micro-computed tomography and scanning electron microscopy (SEM) of annealed blends at different times. It is now understood from X-ray micro-computed tomography that by the addition of a compatibilizer (here lightly maleated PE), a stable morphology can be visualized in 3D. In order to anchor biocidal graphene oxide sheets onto these 3D porous membranes, the PE membranes were chemically modified with acid/ethylene diamine treatment to anchor the GO sheets which were further confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and surface Raman mapping. The transport properties through the membrane clearly reveal unimpeded permeation of water which suggests that anchoring GO on to the membranes does not clog the pores. Antibacterial studies through the direct contact of bacteria with GO anchored PE membranes resulted in 99% of bacterial inactivation. The possible bacterial inactivation through physical disruption of the bacterial cell wall and/or reactive oxygen species (ROS) is discussed herein. Thus this study opens new avenues in designing polyolefin based antibacterial 3D porous membranes for water purification.3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and

  8. Unimpeded permeation of water through biocidal graphene oxide sheets anchored on to 3D porous polyolefinic membranes.

    PubMed

    Mural, Prasanna Kumar S; Jain, Shubham; Kumar, Sachin; Madras, Giridhar; Bose, Suryasarathi

    2016-04-14

    3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and hot-pressed samples revealed a clear picture as to how the morphology develops and coarsens over a function of time during post-processing operations like compression molding. The coarsening of PE/PEO blends was traced using X-ray micro-computed tomography and scanning electron microscopy (SEM) of annealed blends at different times. It is now understood from X-ray micro-computed tomography that by the addition of a compatibilizer (here lightly maleated PE), a stable morphology can be visualized in 3D. In order to anchor biocidal graphene oxide sheets onto these 3D porous membranes, the PE membranes were chemically modified with acid/ethylene diamine treatment to anchor the GO sheets which were further confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and surface Raman mapping. The transport properties through the membrane clearly reveal unimpeded permeation of water which suggests that anchoring GO on to the membranes does not clog the pores. Antibacterial studies through the direct contact of bacteria with GO anchored PE membranes resulted in 99% of bacterial inactivation. The possible bacterial inactivation through physical disruption of the bacterial cell wall and/or reactive oxygen species (ROS) is discussed herein. Thus this study opens new avenues in designing polyolefin based antibacterial 3D porous membranes for water purification. PMID:27020773

  9. 40 CFR 265.91 - Ground-water monitoring system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of:...

  10. 40 CFR 265.91 - Ground-water monitoring system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of:...

  11. 40 CFR 265.91 - Ground-water monitoring system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of:...

  12. 40 CFR 265.91 - Ground-water monitoring system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of:...

  13. 40 CFR 265.91 - Ground-water monitoring system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Ground-water monitoring system. 265.91... DISPOSAL FACILITIES Ground-Water Monitoring § 265.91 Ground-water monitoring system. (a) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of:...

  14. Natural radionuclides in ground waters and cores

    SciTech Connect

    Laul, J.C.; Smith, M.R.; Maiti, T.C.

    1988-01-01

    Investigations of natural radionuclides of uranium and thorium decay series in site-specific ground waters and cores (water/rock interaction) can provide information on the expected migration behavior of their radioactive waste and analog radionuclides in the unlikely event of radioactive releases from a repository. These data in ground waters can provide in situ retardation and sorption/desorption parameters for transport models and their associated kinetics (residence time). These data in cores can also provide information on migration or leaching up to a period of about one million years. Finally, the natural radionuclide data can provide baseline information for future monitoring of possible radioactive waste releases. The natural radionuclides of interest are {sup 238}U, {sup 234}Th, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 222}Rn, {sup 210}Pb, {sup 210}Bi, {sup 210}Po, {sup 232}Th, {sup 228}Ra, {sup 228}Th, and {sup 224}Ra. The half-lives of the daughter radionuclides range from 3 days to 2.5 x 10{sup 5} yr. The data discussed are for low ionic strength ground waters from the Hanford (basalt) site and briny ground waters (high ionic strength) and cores from the Deaf Smith salt site. Similar applications of the natural radionuclide data can be extended to the Nevada Tuff repository site and subseabed disposal site. The concentrations of uranium, thorium, radium, lead, and polonium radionuclides are generally very low in ground waters. However, significant differences in disequilibrium exist between basalt and briny ground waters.

  15. Ground water protection management program plan

    SciTech Connect

    Not Available

    1994-02-01

    U.S. Department of Energy (DOE) Order 5400.1 requires the establishment of a ground water protection management program to ensure compliance with DOE requirements and applicable federal, state, and local laws and regulations. The Uranium Mill Tailings Remedial Action (UMTRA) Project Office was prepared this Ground Water Protection Management Program Plan (ground water protection plan) whose scope and detail reflect the program`s significance and address the seven activities required in DOE Order 5400.1, Chapter III, for special program planning. This ground water protection plan highlights the methods designed to preserve, protect, and monitor ground water resources at UMTRA Project processing and disposal sites. The plan includes an overview of the remedial action status at the 24 designated processing sites and identifies technical guidance documents and site-specific documents for the UMTRA Project ground water protection management program. In addition, the plan addresses the general information required to develop a water resources protection strategy at the permanent disposal sites. Finally, the plan describes ongoing activities that are in various stages of development at UMTRA Project sites.

  16. European Pressurized water Reactor (EPR) SAR ATWS Accident Analyses by using 3D Code Internal Coupling Method

    SciTech Connect

    Gagner, Renata; Lafitte, Helene; Dormeau, Pascal; Stoudt, Roger H.

    2004-07-01

    Anticipated Transients Without Scram (ATWS) accident analyses make part of the Safety Analysis Report of the European Pressurized water Reactor (EPR), covering Risk Reduction Category A (Core Melt Prevention) events. This paper deals with three of the most penalizing RRC-A sequences of ATWS caused by mechanical blockage of the control/shutdown rods, regarding their consequences on the Reactor Coolant System (RCS) and core integrity. A new 3D code internal coupling calculation method has been introduced. (authors)

  17. Calculations with spectroscopic accuracy for the ground configuration (3 d9 ) forbidden transition in Co-like ions

    NASA Astrophysics Data System (ADS)

    Guo, X. L.; Si, R.; Li, S.; Huang, M.; Hutton, R.; Wang, Y. S.; Chen, C. Y.; Zou, Y. M.; Wang, K.; Yan, J.; Li, C. Y.; Brage, T.

    2016-01-01

    We present systematic and large-scale calculations for the fine-structure energy splitting and transition rate between the 3 d93/2,5/2,2D levels of Co-like ions with 28 ≤Z ≤100 . Two different fully relativistic approaches are used, based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) theory and the relativistic many-body-perturbation theory (RMBPT). Especially the former gives results of similar accuracy as experiments for a large range of ions. Our calculations are therefore accurate enough to probe Breit and quantum-electro-dynamic effects. To obtain spectroscopic accuracy, we show that it is important to include deep core-valence correlation, down to and including the n =2 shell. We estimate that the uncertainties of our wavelengths are within the uncertainty of experiments, i.e., 0.02%. We also show that the frequently used flexible atomic code has an inaccurate treatment of the self-energy (SE) contribution and of the M 1 -transition properties for lower-Z ions. After correcting for the SE calculation, the resulting RMBPT transition energies are in good agreement with the MCDHF ones, especially for the high-Z end of the Co-like sequence.

  18. Validation of the Cooray-Rubinstein (C-R) formula for a rough ground surface by using three-dimensional (3-D) FDTD

    NASA Astrophysics Data System (ADS)

    Li, Dongshuai; Zhang, Qilin; Liu, Tao; Wang, Zhenhui

    2013-11-01

    this paper, we have extended the Cooray-Rubinstein (C-R) approximate formula into the fractal rough ground surface and then validate its accuracy by using three-dimensional (3-D) finite-difference time-domain (FDTD) method at distances of 50 m and 100 m from the lightning channel. The results show that the extended C-R formula has an accepted accuracy for predicting the lightning-radiated horizontal electric field above the fractal rough and conducting ground, and its accuracy increases a little better with the higher of the earth conductivity. For instance, when the conductivity of the rough ground is 0.1 S/m, the error of the peak value predicted by the extended C-R formula is less than about 2.3%, while its error is less than about 6.7% for the conductivity of 0.01 S/m. The rough ground has much effect on the lightning horizontal field, and the initial peak value of the horizontal field obviously decreases with the increase of the root-mean-square height of the rough ground at early times (within several microseconds of the beginning of return stroke).

  19. Estimating ground water discharge by hydrograph separation.

    PubMed

    Hannula, Steven R; Esposito, Kenneth J; Chermak, John A; Runnells, Donald D; Keith, David C; Hall, Larry E

    2003-01-01

    Iron Mountain is located in the West Shasta Mining District in California. An investigation of the generation of acid rock drainage and metals loading to Boulder Creek at Iron Mountain was conducted. As part of that investigation, a hydrograph separation technique was used to determine the contribution of ground water to total flow in Boulder Creek. During high-flow storm events in the winter months, peak flow in Boulder Creek can exceed 22.7 m3/sec, and comprises surface runoff, interflow, and ground water discharge. A hydrograph separation technique was used to estimate ground water discharge into Boulder Creek during high-flow conditions. Total ground water discharge to the creek approaches 0.31 m3/sec during the high-flow season. The hydrograph separation technique combined with an extensive field data set provided reasonable estimates of ground water discharge. These estimates are useful for other investigations, such as determining a corresponding metals load from the metal-rich ground water found at Iron Mountain and thus contributing to remedial alternatives. PMID:12772830

  20. Ground-water data for Georgia, 1983

    USGS Publications Warehouse

    Clarke, J.S.; Peck, M.F.; Longsworth, S.A.; McFadden, K.W.

    1984-01-01

    Continuous water-level records from 134 wells and more than 700 water-level measurements made in Georgia during 1983 provide the basic data for this report. Selected wells illustrate the effects that changes in recharge and pumping have had on the various ground-water resources in the State. Daily mean water levels are shown in hydrographs for 1983. Monthly means are shown for the 10-year period 1974-83. Mean annual water levels ranged from 9 feet higher to 6 feet lower in 1983 than in 1982. Water-quality samples are collected periodically throughout Georgia and analyzed as part of areal and regional ground-water studies. Along the coast, chloride concentrations in the upper and lower water-bearing zones of the Floridan aquifer system generally remained steady in the Brunswick and Hilton Head Island areas. (USGS)

  1. 3D crustal structure and long-period ground motions from a M9.0 megathrust earthquake in the Pacific Northwest region

    NASA Astrophysics Data System (ADS)

    Olsen, Kim B.; Stephenson, William J.; Geisselmeyer, Andreas

    2008-04-01

    We have developed a community velocity model for the Pacific Northwest region from northern California to southern Canada and carried out the first 3D simulation of a Mw 9.0 megathrust earthquake rupturing along the Cascadia subduction zone using a parallel supercomputer. A long-period (<0.5 Hz) source model was designed by mapping the inversion results for the December 26, 2004 Sumatra-Andaman earthquake (Han et al., Science 313(5787):658-662, 2006) onto the Cascadia subduction zone. Representative peak ground velocities for the metropolitan centers of the region include 42 cm/s in the Seattle area and 8-20 cm/s in the Tacoma, Olympia, Vancouver, and Portland areas. Combined with an extended duration of the shaking up to 5 min, these long-period ground motions may inflict significant damage on the built environment, in particular on the highrises in downtown Seattle.

  2. 3D crustal structure and long-period ground motions from a M9.0 megathrust earthquake in the Pacific Northwest region

    USGS Publications Warehouse

    Olsen, K.B.; Stephenson, W.J.; Geisselmeyer, A.

    2008-01-01

    We have developed a community velocity model for the Pacific Northwest region from northern California to southern Canada and carried out the first 3D simulation of a Mw 9.0 megathrust earthquake rupturing along the Cascadia subduction zone using a parallel supercomputer. A long-period (<0.5 Hz) source model was designed by mapping the inversion results for the December 26, 2004 Sumatra–Andaman earthquake (Han et al., Science 313(5787):658–662, 2006) onto the Cascadia subduction zone. Representative peak ground velocities for the metropolitan centers of the region include 42 cm/s in the Seattle area and 8–20 cm/s in the Tacoma, Olympia, Vancouver, and Portland areas. Combined with an extended duration of the shaking up to 5 min, these long-period ground motions may inflict significant damage on the built environment, in particular on the highrises in downtown Seattle.

  3. Ground water recharge from Lake Chad

    SciTech Connect

    Isiorho, S.; Matisoff, G.; McCall, P.L.

    1985-01-01

    Lake Chad is a shallow, closed basin lake located in Sub-Sharan Africa. It has the largest drainage basin of any lake in the world, and is also very old, being formed by tectonic processes during the Cretaceous. These features should combine to form a saline lake, but the open waters of Lake Chad are reasonably fresh, having a total dissolved solids concentration of about 320 mg/1. This apparent discrepancy can be explained by noting that recharge of the unconfined aquifer to the SW in Nigeria by ground water infiltration through the lakebed can remove significant quantities of water and dissolved solutes from the lake. The authors have measured and calculated ground water infiltration and velocities by several techniques. Direct, volumetric measurements of ground water recharge seepage give velocities on the order of .28-8.8 x 10/sup -3/ m/day. Tracer monitoring in a borehole dilution test yielded ground water velocities of 3.6 m/day to the SW (away from the lake). Hydraulic conductivities approx. .004-.6 m/day were determined by falling head measurements. Finally, using static water levels, the potentiometric surface within approx. 80 km of the southwest portion of Lake Chad yields water table gradients of 1.0-1.7 x 10/sup -4/ away from the lake. These results confirm that surface water and solute inflow to Lake Chad is removed by recharge to the unconfined aquifer in Nigeria.

  4. Coupling Between Microstrip Lines and Finite Ground Coplanar Lines Embedded in Polyimide Layers for 3D-MMICs on Silicon

    NASA Technical Reports Server (NTRS)

    Ponchak, G. E.; Bushyager, N.; Papapolymerou, J.; Tentzeris, E. M.; Laskar, J.

    2002-01-01

    Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/mm-wave integrated circuits on CMOS (low resistivity) Si wafers. It is expected that these circuits will replace the ones fabricated on GaAs and reduce the overall system cost. However, the closely spaced transmission lines that are required for a high-density circuit environment are susceptible to high levels of cross-coupling, which degrades the overall circuit performance. In this paper, theoretical and experimental results on coupling and ways to reduce it are presented for two types of transmission lines: a) the microstrip line and b) the Finite Ground Coplanar (FGC) line. For microstrip lines it is shown that a fence of metalized via-holes can significantly reduce coupling, especially in the case when both lines are on the same polyimide layer or when the shielding structure extends through several polyimide layers. For closely spaced microstrip lines, coupling is lower for a metal filled trench shield than a via-hole fence. Coupling amongst microstrip lines is dependent on the ratio of line separation to polyimide thickness and is primarily due to magnetic fields. For FGC lines it is shown that they have in general low coupling that can be reduced significantly when there is even a small gap between the ground planes of each line. FGC lines have approximately 8 dB lower coupling than coupled coplanar waveguides (CPW). In addition, forward and backward characteristics of the FGC lines do not resemble those of other transmission lines such as microstrip. Therefore, the coupling mechanism of the FGC lines is different compared to thin film microstrip lines.

  5. Ground-water data for Georgia, 1984

    USGS Publications Warehouse

    Clarke, J.S.; Longsworth, S.A.; McFadden, K.W.; Peck, M.F.

    1985-01-01

    Continuous water-level records from 155 wells and more than 800 water-level measurements made in Georgia during 1984 provide the basic data for this report. Selected wells illustrate the effects that changes in recharge and pumping have had on the various ground-water resources in the State. Daily mean water levels are shown in hydrographs for 1984. Monthly means are shown for the 10-year period 1975-84. Mean annual water levels ranged from 7 feet lower to 7 feet higher in 1984 than in 1983. Water-quality samples are collected periodically throughout Georgia and analyzed as part of a real and regional ground-water studies. Along the coast, chloride concentrations in the Floridan aquifer system generally remained steady. (USGS)

  6. Ground Water Flow No Longer A Mystery

    ERIC Educational Resources Information Center

    Lehr, Jay H.; Pettyjohn, Wayne A.

    1976-01-01

    Examined are the physical characteristics of ground water movement. Some potential pollution problems are identified. Models are used to explain mathematical and hydraulic principles of flow toward a pumping well and an effluent stream, flow around and through lenticular beds, and effects of pumping on the water table. (Author/MR)

  7. Ground-water applications of remote sensing

    USGS Publications Warehouse

    Moore, Gerald K.

    1982-01-01

    Remote sensing can be used as a tool to inventory springs and seeps and to interpret lithology, structure, and ground-water occurrence and quality. Thermograms are the best images for inventory of seeps and springs. The steps in aquifer mapping are image analysis and interpretation and ground-water interpretation. A ground-water interpretation is derived from a conceptual geologic model by inferring aquifer characteristics and water salinity. The image selection process is very important for obtaining maximum geologic and hydrologic information from remotely sensed data. Remote sensing can contribute an image base map or geologic and hydrologic parameters, derived from the image, to the multiple data sets in a hydrologic information system. Various merging and integration techniques may then be used to obtain information from these data sets.

  8. Fabrication of scalable and structured tissue engineering scaffolds using water dissolvable sacrificial 3D printed moulds.

    PubMed

    Mohanty, Soumyaranjan; Larsen, Layla Bashir; Trifol, Jon; Szabo, Peter; Burri, Harsha Vardhan Reddy; Canali, Chiara; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2015-10-01

    One of the major challenges in producing large scale engineered tissue is the lack of ability to create large highly perfused scaffolds in which cells can grow at a high cell density and viability. Here, we explore 3D printed polyvinyl alcohol (PVA) as a sacrificial mould in a polymer casting process. The PVA mould network defines the channels and is dissolved after curing the polymer casted around it. The printing parameters determined the PVA filament density in the sacrificial structure and this density resulted in different stiffness of the corresponding elastomer replica. It was possible to achieve 80% porosity corresponding to about 150 cm(2)/cm(3) surface to volume ratio. The process is easily scalable as demonstrated by fabricating a 75 cm(3) scaffold with about 16,000 interconnected channels (about 1m(2) surface area) and with a channel to channel distance of only 78 μm. To our knowledge this is the largest scaffold ever to be produced with such small feature sizes and with so many structured channels. The fabricated scaffolds were applied for in-vitro culturing of hepatocytes over a 12-day culture period. Smaller scaffolds (6×4 mm) were tested for cell culturing and could support homogeneous cell growth throughout the scaffold. Presumably, the diffusion of oxygen and nutrient throughout the channel network is rapid enough to support cell growth. In conclusion, the described process is scalable, compatible with cell culture, rapid, and inexpensive. PMID:26117791

  9. Ground water and surface water; a single resource

    USGS Publications Warehouse

    Winter, Thomas C.; Harvey, Judson W.; Franke, O. Lehn; Alley, William M.

    1998-01-01

    The importance of considering ground water and surface water as a single resource has become increasingly evident. Issues related to water supply, water quality, and degradation of aquatic environments are reported on frequently. The interaction of ground water and surface water has been shown to be a significant concern in many of these issues. Contaminated aquifers that discharge to streams can result in long-term contamination of surface water; conversely, streams can be a major source of contamination to aquifers. Surface water commonly is hydraulically connected to ground water, but the interactions are difficult to observe and measure. The purpose of this report is to present our current understanding of these processes and activities as well as limitations in our knowledge and ability to characterize them.

  10. 3D imaging of the internal structure of a rock-cored drumlin using ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    King, Edward; Spagnolo, Matteo; Rea, Brice; Ely, Jeremy; Lee, Joshua

    2016-04-01

    One key question linking subglacial bedform analyses to ice dynamics relates to the flux of sediment at the bed. It is relatively easy to measure the upper surface of subglacial sediments either in active contemporary systems (using ice-penetrating radar surveys) or in relict subglacial terrain (using high-resolution digital elevation models). However, constraining the lower surface of subglacial sediments, i.e. the contact between the bedform sediment and a lower sediment unit or bedrock, is much more difficult, yet it is crucial to any determination of sediment volume and hence flux. Without observations, we are reliant on assumptions about the nature of the lower sediment surface. For example, we might assume that all the drumlins in a particular drumlin field are deposited on a planar surface, or that all comprise a carapace of till over a rock core. A calculation of sediment volume will give very different results leading to very different interpretations of sediment flux. We have been conducting experiments in the use of ground-penetrating radar to find the lower sedimentary surface beneath drumlins near Kirkby Stephen (Northern England), part of the extensive Eden Valley drumlin field. The drumlins comprise diamict overlying a bedrock surface of Carboniferous limestone which outcrops frequently between the drumlins. Here we present the results of a grid survey over one of the drumlins that clearly demonstrate this drumlin comprises a thin carapace of till overlying a stepped limestone bedrock surface. We provide details on the field data acquisition parameters and discuss the implications for further geophysical studies of drumlin fields.

  11. EPA GROUND WATER ISSUE: Ground Water Sample Preservation at ISCO Sites – Recommended Guidelines

    EPA Science Inventory

    In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste sites may contai...

  12. Vanadium nanobelts coated nickel foam 3D bifunctional electrode with excellent catalytic activity and stability for water electrolysis.

    PubMed

    Yu, Yu; Li, Pei; Wang, Xiaofang; Gao, Wenyu; Shen, Zongxu; Zhu, Yanan; Yang, Shuliang; Song, Weiguo; Ding, Kejian

    2016-05-19

    Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm(-2) for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm(-2) with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity. PMID:27152646

  13. Water-repellent coatings for surface and 3D wood processing

    NASA Astrophysics Data System (ADS)

    Debelova, N. N.; Gorlenko, N. P.; Volokitin, G. G.; Sarkisov, Yu S.; Dmitriyenko, V. P.; Zavyalova, E. N.; Zavyalov, P. B.

    2015-01-01

    The paper presents the results of research in organic chemical compositions for hydrophobic protection of wood with the use of surface and three-dimensional coating techniques of impregnation and chemical compositions. Water absorption indicators, angles of contact on the surface of treated samples are detected herein. Kinetic equation of the moisture diffusion transition in capillary-porous structure of wood is suggested.

  14. A molecular dynamics implementation of the 3D Mercedes-Benz water model

    NASA Astrophysics Data System (ADS)

    Hynninen, T.; Dias, C. L.; Mkrtchyan, A.; Heinonen, V.; Karttunen, M.; Foster, A. S.; Ala-Nissila, T.

    2012-02-01

    The three-dimensional Mercedes-Benz model was recently introduced to account for the structural and thermodynamic properties of water. It treats water molecules as point-like particles with four dangling bonds in tetrahedral coordination, representing H-bonds of water. Its conceptual simplicity renders the model attractive in studies where complex behaviors emerge from H-bond interactions in water, e.g., the hydrophobic effect. A molecular dynamics (MD) implementation of the model is non-trivial and we outline here the mathematical framework of its force-field. Useful routines written in modern Fortran are also provided. This open source code is free and can easily be modified to account for different physical context. The provided code allows both serial and MPI-parallelized execution. Program summaryProgram title: CASHEW (Coarse Approach Simulator for Hydrogen-bonding Effects in Water) Catalogue identifier: AEKM_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKM_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 20 501 No. of bytes in distributed program, including test data, etc.: 551 044 Distribution format: tar.gz Programming language: Fortran 90 Computer: Program has been tested on desktop workstations and a Cray XT4/XT5 supercomputer. Operating system: Linux, Unix, OS X Has the code been vectorized or parallelized?: The code has been parallelized using MPI. RAM: Depends on size of system, about 5 MB for 1500 molecules. Classification: 7.7 External routines: A random number generator, Mersenne Twister ( http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/FORTRAN/mt95.f90), is used. A copy of the code is included in the distribution. Nature of problem: Molecular dynamics simulation of a new geometric water model. Solution method: New force-field for

  15. 3-D modeling of water balance and soil erosion in a clayey subsurface drained agricultural field in boreal climate

    NASA Astrophysics Data System (ADS)

    Turunen, M.; Warsta, L.; Koivusalo, H. J.; Paasonen-Kivekäs, M.; Nurminen, J.; Myllys, M.; Alakukku, L.; Äijö, H.; Puustinen, M.

    2012-12-01

    Fluxes of nutrients and other substances from cultivated fields cause eutrophication and deterioration of water quality in aquatic ecosystems worldwide. In order to develop effective strategies to control the environmental impacts of crop cultivation, it is crucial to identify the main transport pathways and the effects of different water management methods on the loads. Reduction of sediment loads is essential since sediment particles typically carry nutrients (especially sorbed phosphorus) and other potentially harmful substances, e.g. pesticides, from the fields to the adjacent surface waters. The novel part of this study was the investigation of suspended sediment transport in soil macropores to the subsurface drains and to the deep groundwater. We applied a 3-D distributed dual-permeability model (FLUSH) using a dataset collected from a subsurface drained, clayey agricultural field (15 ha) to holistically assess water balance, soil erosion and sediment transport from the field to an adjacent stream. The data set included five years of hydrological and water quality measurements from four intensively monitored field sections with different soil properties, topography, drainage systems (drain spacing and drain depth), drain installation methods (trenchless and trench drainage) and drain envelope materials (gravel and fiber). The 3-D model allowed us to quantify how soil erosion and sediment transport differed between the field sections within the field area. The simulations were conducted during snow- and frost-free periods. The simulation results include closure of water balance of the cultivated field, distribution of soil erosion and sediment transport within the field area and the effects of different subsurface drainage systems on sediment loads. The 3-D dual-permeability subsurface flow model was able to reproduce the measured drainflows and sediment fluxes in the clayey field and according to the simulations over 90% of drainflow waters were conveyed to

  16. PLUME3D: THREE-DIMENSIONAL PLUMES IN UNIFORM GROUND WATER FLOW

    EPA Science Inventory

    A closed-form analytical solution for three-dimensional plumes was incorporated in an interactive computer program. The assumption of an infinite aquifer depth and uniform source mass rate and source location was overcome by using the principal of superposition in space and time....

  17. Vanadium nanobelts coated nickel foam 3D bifunctional electrode with excellent catalytic activity and stability for water electrolysis

    NASA Astrophysics Data System (ADS)

    Yu, Yu; Li, Pei; Wang, Xiaofang; Gao, Wenyu; Shen, Zongxu; Zhu, Yanan; Yang, Shuliang; Song, Weiguo; Ding, Kejian

    2016-05-01

    Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm-2 for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm-2 with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity.Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm-2 for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm-2 with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity. Electronic supplementary information (ESI) available: More SEM, TEM images, XRD patterns, LSV curves, XPS spectra. See DOI: 10.1039/c6nr02395a

  18. 3D magnetic resonance imaging as a non-invasive tool for investigating water-filled karst formations

    NASA Astrophysics Data System (ADS)

    Legchenko, A.; Ezersky, M.; Boucher, M.; Chevalier, A.; Vouillamoz, J.-M.

    2012-04-01

    Magnetic Resonance Sounding (MRS) is a geophysical technique developed for groundwater exploration. MRS can be used for reliable identification of karst aquifers because of the relaxation time of the magnetic resonance signal (T1) is longer for bulk water in karst caverns and channels (about 2 s) than for water in porous rock (few tens of ms). MRS is sensitive primary to groundwater volume but electrically conductive layers modify electromagnetic fields in the subsurface and thus may have an effect on MRS performance. Generally, the study of a karst requires a 3D field set-up and we developed a measuring procedure and interpretation software that makes it possible to image heterogeneous water-bearing geological formations down to about 80 m (3D-SNMR method). Numerical modeling results show that limited resolution of the method allows only identification of large karst formations. For example detectable karst should be larger than a few hundred cubic meters when karst is located close to the surface and a few thousand cubic meters when it is located at 60 m. Time Domain Electromagnetic method (TDEM) is known as an efficient tool for investigating electrical conductivity of rocks. TDEM results allow more accurate computing of the EM field in the subsurface and thus contribute for improving accuracy of MRS results. TDEM and 3D-SNMR methods were applied jointly in the Dead Sea coast of Israel (Nahal Hever South). The subsurface in this area is heterogeneous and composed of intercalated sand and clay layers over a salt rock, which is partly karstified. Groundwater is very saline, with a chloride concentration of 100-225 g/l thus rendering the resistivity of geological formations less than 1 ohm-m. We have shown numerically that under Dead Sea coast conditions, 3D-SNMR is able to detect and to locate the target within an error of a few tens of meters. In the investigated area (500×500 m2) our results reveal a very heterogeneous shallow aquifer that could be divided into

  19. Using High Frequency Focused Water-Coupled Ultrasound for 3-D Surface Depression Profiling

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    1999-01-01

    Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. A prior study was performed demonstrating that focused air-coupled ultrasound at 1 MHz was capable of profiling surfaces with 25 micron depth resolution and 400 micron lateral resolution over a 1.4 mm depth range. In this article, the question of whether higher-frequency focused water-coupled ultrasound can improve on these specifications is addressed. 10 and 25 MHz focused ultrasonic transducers were employed in the water-coupled mode. Time-of-flight images of the sample surface were acquired and converted to depth / surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in water (V). Results are compared for the two frequencies used and with those from the 1 MHz air-coupled configuration.

  20. Evaluating the Performance of Unmanned Ground Vehicle Water Detection

    NASA Technical Reports Server (NTRS)

    Rankin, Arturo; Ivanov, Tonislav; Brennan, Shane

    2010-01-01

    Water detection is a critical perception requirement for unmanned ground vehicle (UGV) autonomous navigation over cross-country terrain. During the Robotics Collaborative Technology Alliances (RCTA) program, the Jet Propulsion Laboratory (JPL) developed a set of water detection algorithms that are used to detect, localize, and avoid water bodies large enough to be a hazard to a UGV. The JPL water detection software performs the detection and localization stages using a forward-looking stereo pair of color cameras. The 3D coordinates of water body surface points are then output to a UGV's autonomous mobility system, which is responsible for planning and executing safe paths. There are three primary methods for evaluating the performance of the water detection software. Evaluations can be performed in image space on the intermediate detection product, in map space on the final localized product, or during autonomous navigation to characterize the avoidance of a variety of water bodies. This paper describes a methodology for performing the first two types of water detection performance evaluations.

  1. A 3-D hydrologic transport model of a water recharge system using carbamazepine and chloride as tracers

    NASA Astrophysics Data System (ADS)

    Rona, Michael; Gasser, Guy; Negev, Ido; Pankratov, Irena; Elhanany, Sara; Lev, Ovadia; Gvirtzman, Haim

    2014-05-01

    Wastewater recharge facilities are often used as a final water treatment before the discharge to the sea or before water reclamation. These facilities are often located in active aquifers that supply drinking water. Thus, leakage from the water recharge facility and gradual expansion of the underground wastewater plume are of considerable health concern. Hydrological modeling of water recharge systems are widely used as operational and predictive tools. These models rely on distributed water head monitoring and at least one chemical or physical tracer to model solutes' transport. Refractory micropollutants have proven useful in qualitative identification of pollution leakages and for quantification of pollution to a specific site near water recharge facilities. However, their usefulness as tracers for hydrological modeling is still questionable. In this article, we describe a long term, 3-D hydraulic model of a large-scale wastewater effluents recharge system in which a combination of chloride and a refractory micropollutant, carbamazepine is used to trace the solute transport. The combination of the two tracers provides the model with the benefits of the high specificity of the carbamazepine and the extensive historic data base that is available for chloride. The model predicts westward expansion of the pollution plume, whereas a standing front is formed at the east. These trends can be confirmed by the time trace of the carbamazepine concentrations at specific locations. We show that the combination of two tracers accounts better (at least at some locations) for the evolution of the pollution plume than a model based on chloride or carbamazepine alone.

  2. 40 CFR 257.22 - Ground-water monitoring systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Ground-water monitoring systems. 257... Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of a sufficient number...

  3. 40 CFR 258.51 - Ground-water monitoring systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Ground-water monitoring systems. 258... CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of...

  4. 40 CFR 258.51 - Ground-water monitoring systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 258... CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of...

  5. 40 CFR 257.22 - Ground-water monitoring systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water monitoring systems. 257... Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of a sufficient number...

  6. 40 CFR 257.22 - Ground-water monitoring systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Ground-water monitoring systems. 257... Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of a sufficient number...

  7. 40 CFR 258.51 - Ground-water monitoring systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Ground-water monitoring systems. 258... CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of...

  8. 40 CFR 258.51 - Ground-water monitoring systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Ground-water monitoring systems. 258... CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of...

  9. 40 CFR 257.22 - Ground-water monitoring systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Ground-water monitoring systems. 257... Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of a sufficient number...

  10. 40 CFR 257.22 - Ground-water monitoring systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Ground-water monitoring systems. 257.22... Disposal Units Ground-Water Monitoring and Corrective Action § 257.22 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of a sufficient number of...

  11. 40 CFR 258.51 - Ground-water monitoring systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Ground-water monitoring systems. 258.51... FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.51 Ground-water monitoring systems. (a) A ground-water monitoring system must be installed that consists of...

  12. MODELING TOOLS FOR GROUND WATER-SURFACE WATER INTERACTIONS

    EPA Science Inventory

    This project develops algorithms for simulating the dynamic interactions between surface water and ground water in rivers and riparian streams. The algorithms rely on physically based linear response functions which describe the exchange rates and volumes of water between the str...

  13. Visualization of the Links Between Rainfall, Soil Water, Groundwater and Subsurface Stormflow: A Physics-Based 3-D Simulation Approach

    NASA Astrophysics Data System (ADS)

    James, A. L.; McDonnell, J. J.; Tromp-van Meerveld, H.

    2006-12-01

    Recent experimental work at the Panola Mountain Experimental Watershed trenched hillslope (Atlanta, GA) has shown that formation of transient groundwater in bedrock depressions during storm events is a precondition for the generation of subsurface stormflow. While there are clear threshold relations between subsurface stormflow and storm total precipitation, resolving the linkages between rainfall input, soil water recharge, transient groundwater formation and resulting subsurface stormflow has been difficult. Part of the problem is that we lack observational capabilities to interrogate the distributed internal slope response to storm rainfall. Even more problematic is our inability to quantify key boundary conditions like the permeability contrast at the soil-bedrock interface and its spatial variability. This paper uses a 3-D physically-based distributed model of the Panola hillslope (the TOUGH2 simulator) to model and visualize the linkages between storm rainfall, soil water recharge, transient groundwater development and resulting subsurface stormflow. We explore the effect of the bedrock permeability on the development of transient saturation within the hillslope in response to observed storm events. Preliminary results indicate that an increase in the estimated characteristic bedrock permeability at the Panola hillslope can deteriorate and even eliminate the connected patterns of transient saturation developed during a storm event that result in subsurface storm runoff. Our 3-D visualizations and virtual experiments with different bedrock permeability values provide insight into how bedrock permeability, antecedent soil moisture and storm conditions conspire to create the patterns of transient groundwater and resulting subsurface stormflow.

  14. Tools to Perform Local Dense 3D Reconstruction of Shallow Water Seabed.

    PubMed

    Avanthey, Loïca; Beaudoin, Laurent; Gademer, Antoine; Roux, Michel

    2016-01-01

    Tasks such as distinguishing or identifying individual objects of interest require the production of dense local clouds at the scale of these individual objects of interest. Due to the physical and dynamic properties of an underwater environment, the usual dense matching algorithms must be rethought in order to be adaptive. These properties also imply that the scene must be observed at close range. Classic robotized acquisition systems are oversized for local studies in shallow water while the systematic acquisition of data is not guaranteed with divers. We address these two major issues through a multidisciplinary approach. To efficiently acquire on-demand stereoscopic pairs using simple logistics in small areas of shallow water, we devised an agile light-weight dedicated system which is easy to reproduce. To densely match two views in a reliable way, we devised a reconstruction algorithm that automatically accounts for the dynamics, variability and light absorption of the underwater environment. Field experiments in the Mediterranean Sea were used to assess the results. PMID:27196913

  15. Tools to Perform Local Dense 3D Reconstruction of Shallow Water Seabed ‡

    PubMed Central

    Avanthey, Loïca; Beaudoin, Laurent; Gademer, Antoine; Roux, Michel

    2016-01-01

    Tasks such as distinguishing or identifying individual objects of interest require the production of dense local clouds at the scale of these individual objects of interest. Due to the physical and dynamic properties of an underwater environment, the usual dense matching algorithms must be rethought in order to be adaptive. These properties also imply that the scene must be observed at close range. Classic robotized acquisition systems are oversized for local studies in shallow water while the systematic acquisition of data is not guaranteed with divers. We address these two major issues through a multidisciplinary approach. To efficiently acquire on-demand stereoscopic pairs using simple logistics in small areas of shallow water, we devised an agile light-weight dedicated system which is easy to reproduce. To densely match two views in a reliable way, we devised a reconstruction algorithm that automatically accounts for the dynamics, variability and light absorption of the underwater environment. Field experiments in the Mediterranean Sea were used to assess the results. PMID:27196913

  16. Ground-water provinces of Brazil

    USGS Publications Warehouse

    Schneider, Robert

    1962-01-01

    As part of a study of the status of investigations and development of ground water in Brazil, made under the auspices of the United States International Cooperation Administration and with the cooperation of the Government of Brazil, the country was divided into seven ground-water provinces. The identification and delineation of the provinces were based on the regional distribution of the dominant geologic units which are known or inferred to have distinctive water-bearing characteristics. Three of the provinces, covering most of the country, are underlain by Precambrian crystalline rocks. Three others coincide in part with four extensive sedimentary basins--the Parnaiba or Maranhfio basin and the contiguous Sao Francisco basin in the northeast and east, the Amazon basin in the north and northwest, and the Paranfi basin in the south and southwest. In addition, the narrow, discontinuous coastal plain is considered as a province. the occurrence of ground water is discussed briefly, and pertinent data are given on the more important aquifers, together with information on some existing wells. Because of the widespread distribution of crystalline rocks of low permeability, it is difficult in many areas to develop large or even adequate ground-water supplies. In general, satisfactory supplies of water are available in most of the rest of the country. Some problems include the relative deficiency of rainfall in the northeast together with the occurrence, in parts of this region, of mineralized water in the crystalline rocks. Also, there is a potential problem of excessive lowering of water levels and interference among wells in the intensively developed area of the city of Sao Paulo.

  17. Areas contributing ground water to the Peconic Estuary, and ground-water budgets for the north and south forks and Shelter Island, eastern Suffolk County, New York

    USGS Publications Warehouse

    Schubert, C.E.

    1998-01-01

    The Peconic Estuary, at the eastern end of Long Island, has been plagued by a recurrent algal bloom, locally referred to as ?Brown Tide,? that has caused the severe decline of local marine resources. Although the factors that trigger Brown Tide blooms remain uncertain, groundwater discharge has previously been shown to affect surface-water quality in the western part of the estuary. A U.S. Geological Survey groundwater- flow model of the main body of Long Island indicates that a total of about 7.5 x 106 ft3/d (cubic feet per day) of freshwater discharges to the western part of the estuary, but the model does not include the ground-water flow systems on the North and South Forks and Shelter Island, which contribute significant amounts of freshwater to the central and eastern parts of the estuary. The need for information on freshwater discharge to the entire estuary prompted the U.S. Geological Survey to evaluate ground-water discharge from the North and South Forks and Shelter Island. Source areas that contribute ground water to the Peconic Estuary were delineated, and groundwater budgets for these areas were developed, to evaluate the distribution and magnitude of ground-water discharge to the central and eastern parts of the estuary. Contributing-area boundaries that were delineated coincide with the hydraulic boundaries of the fresh ground-water-flow systems of the North and South Forks and Shelter Island; these boundaries are of two types? external (saltwater bodies) and internal (groundwater divides). Hydrologic components that were evaluated include recharge from precipitation, public-supply withdrawal and return flow, and agricultural withdrawal. Values for each of these components were calculated or estimated for the individual freshwater flow subsystems that form each ground-water-budget area, then summed to obtain the total discharge of fresh ground water to tidewater. Ground-water discharge to the Peconic Estuary is about 3.8 x 106 ft3/d from the North

  18. GROUND-WATER DATA MANAGEMENT WITH STORET

    EPA Science Inventory

    The manual has been designed to address both ground-water quality data and the related well site characteristics. For non-USGS wells, appropriate fields have been added to include the information on site characteristics. Much of the information has been adopted from the site char...

  19. Ground Water in a Fish Tank.

    ERIC Educational Resources Information Center

    Mayshark, Robin K.

    1992-01-01

    Describes creating a Model Aquatic/Terrestrial Ecosystem for use in helping students understand how water moves beneath the ground's surface. The model is constructed from a fish tank using rocks, soil, gravel, clay, and organic materials. Author describes possible cooperative-learning and problem-solving activities that can be done with this…

  20. Ground water work breakdown structure dictionary

    SciTech Connect

    1995-04-01

    This report contains the activities that are necessary to assess in ground water remediation as specified in the UMTRA Project. These activities include the following: site characterization; remedial action compliance and design documentation; environment, health, and safety program; technology assessment; property access and acquisition activities; site remedial actions; long term surveillance and licensing; and technical and management support.

  1. Selenium in Oklahoma ground water and soil

    SciTech Connect

    Atalay, A.; Vir Maggon, D.

    1991-03-30

    Selenium with a consumption of 2 liters per day (5). The objectives of this study are: (1) to determine the concentrations of Se in Oklahoma ground water and soil samples. (2) to map the geographical distribution of Se species in Oklahoma. (3) to relate groundwater depth, pH and geology with concentration of Se.

  2. IN-SITU BIOREMEDIATION OF GROUND WATER

    EPA Science Inventory

    The Robert S. Kerr Environmental Research Laboratory (RSKERL) has developed a number of Issue Papers and Briefing Documents which are designed to exchange up-to-date information related to the remediation of contaminated soil and ground water at hazardous waste sites. n an attemp...

  3. PRIORITIZATION OF GROUND WATER CONTAMINANTS AND SOURCES

    EPA Science Inventory

    The objective of this research was to identify chemical, physical, bacteriological, and viral contaminants, and their sources, which present the greatest health threat in public ground water supplies in the USA; and to classify (prioritize) such contaminants and relative to their...

  4. 3D measurement of the radiation distribution in a water phantom in a hadron therapy beam

    NASA Astrophysics Data System (ADS)

    Opalka, L.; Granja, C.; Hartmann, B.; Jakubek, J.; Jaekel, O.; Martisikova, M.; Pospisil, S.; Solc, J.

    2012-01-01

    Hadron therapy is a highly precise radio-therapeutic method with many advantages especially in cases when the tumour is close to sensitive organs where standard treatments cannot be used. For reliable treatment planning it is necessary to have calculation tools for maximization of the dose delivered to the targeted tissue and minimization of the dose outside of it. While the main physical processes in material irradiated by hadron beams are known, in reality the processes involved are complex so that analytical computations are impossible. Thus, the planning tools to incorporate simplified models and numerical approximations and an experimental method for high precision verification of the models within phantoms is desired. The development of sensitive, high resolution and online methods for measurement of the radiation environment inside of the irradiated object is the aim of this work. Such measurements are made possible by the resolving power of the state-of-the-art pixel detector Timepix. This quantum counting imaging device is able to record the characteristic shapes of the particle traces including their energies deposited in the detector. All these data recorded for each event allow to estimate the particle type, its energy and direction of flight. Event-by-event analysis is done using pattern recognition of the characteristic traces. The objective of the experiment is the detection and characterization of secondary radiation generated by the primary therapeutic beams in tissue equivalent material (water). Measurements were performed inside of a water phantom irradiated by a carbon beam at the Heidelberg Ion-Beam Therapy Center (HIT).

  5. On the transition towards slow manifold in shallow-water and 3D Euler equations in a rotating frame

    NASA Technical Reports Server (NTRS)

    Mahalov, A.

    1994-01-01

    The long-time, asymptotic state of rotating homogeneous shallow-water equations is investigated. Our analysis is based on long-time averaged rotating shallow-water equations describing interactions of large-scale, horizontal, two-dimensional motions with surface inertial-gravity waves field for a shallow, uniformly rotating fluid layer. These equations are obtained in two steps: first by introducing a Poincare/Kelvin linear propagator directly into classical shallow-water equations, then by averaging. The averaged equations describe interaction of wave fields with large-scale motions on time scales long compared to the time scale 1/f(sub o) introduced by rotation (f(sub o)/2-angular velocity of background rotation). The present analysis is similar to the one presented by Waleffe (1991) for 3D Euler equations in a rotating frame. However, since three-wave interactions in rotating shallow-water equations are forbidden, the final equations describing the asymptotic state are simplified considerably. Special emphasis is given to a new conservation law found in the asymptotic state and decoupling of the dynamics of the divergence free part of the velocity field. The possible rising of a decoupled dynamics in the asymptotic state is also investigated for homogeneous turbulence subjected to a background rotation. In our analysis we use long-time expansion, where the velocity field is decomposed into the 'slow manifold' part (the manifold which is unaffected by the linear 'rapid' effects of rotation or the inertial waves) and a formal 3D disturbance. We derive the physical space version of the long-time averaged equations and consider an invariant, basis-free derivation. This formulation can be used to generalize Waleffe's (1991) helical decomposition to viscous inhomogeneous flows (e.g. problems in cylindrical geometry with no-slip boundary conditions on the cylinder surface and homogeneous in the vertical direction).

  6. Integrating Sensors into a Marine Drone for Bathymetric 3D Surveys in Shallow Waters.

    PubMed

    Giordano, Francesco; Mattei, Gaia; Parente, Claudio; Peluso, Francesco; Santamaria, Raffaele

    2015-01-01

    This paper demonstrates that accurate data concerning bathymetry as well as environmental conditions in shallow waters can be acquired using sensors that are integrated into the same marine vehicle. An open prototype of an unmanned surface vessel (USV) named MicroVeGA is described. The focus is on the main instruments installed on-board: a differential Global Position System (GPS) system and single beam echo sounder; inertial platform for attitude control; ultrasound obstacle-detection system with temperature control system; emerged and submerged video acquisition system. The results of two cases study are presented, both concerning areas (Sorrento Marina Grande and Marechiaro Harbour, both in the Gulf of Naples) characterized by a coastal physiography that impedes the execution of a bathymetric survey with traditional boats. In addition, those areas are critical because of the presence of submerged archaeological remains that produce rapid changes in depth values. The experiments confirm that the integration of the sensors improves the instruments' performance and survey accuracy. PMID:26729117

  7. Integrating Sensors into a Marine Drone for Bathymetric 3D Surveys in Shallow Waters

    PubMed Central

    Giordano, Francesco; Mattei, Gaia; Parente, Claudio; Peluso, Francesco; Santamaria, Raffaele

    2015-01-01

    This paper demonstrates that accurate data concerning bathymetry as well as environmental conditions in shallow waters can be acquired using sensors that are integrated into the same marine vehicle. An open prototype of an unmanned surface vessel (USV) named MicroVeGA is described. The focus is on the main instruments installed on-board: a differential Global Position System (GPS) system and single beam echo sounder; inertial platform for attitude control; ultrasound obstacle-detection system with temperature control system; emerged and submerged video acquisition system. The results of two cases study are presented, both concerning areas (Sorrento Marina Grande and Marechiaro Harbour, both in the Gulf of Naples) characterized by a coastal physiography that impedes the execution of a bathymetric survey with traditional boats. In addition, those areas are critical because of the presence of submerged archaeological remains that produce rapid changes in depth values. The experiments confirm that the integration of the sensors improves the instruments’ performance and survey accuracy. PMID:26729117

  8. Identifying the origin of differences between 3D numerical simulations of ground motion in sedimentary basins: lessons from stringent canonical test models in the E2VP framework

    NASA Astrophysics Data System (ADS)

    Chaljub, Emmanuel; Maufroy, Emeline; Moczo, Peter; Kristek, Jozef; Priolo, Enrico; Klin, Peter; De Martin, Florent; Zhang, Zenghuo; Hollender, Fabrice; Bard, Pierre-Yves

    2013-04-01

    Numerical simulation is playing a role of increasing importance in the field of seismic hazard by providing quantitative estimates of earthquake ground motion, its variability, and its sensitivity to geometrical and mechanical properties of the medium. Continuous efforts to develop accurate and computationally efficient numerical methods, combined with increasing computational power have made it technically feasible to calculate seismograms in 3D realistic configurations and for frequencies of interest in seismic design applications. Now, in order to foster the use of numerical simulations in practical prediction of earthquake ground motion, it is important to evaluate the accuracy of current numerical methods when applied to realistic 3D sites. This process of verification is a necessary prerequisite to confrontation of numerical predictions and observations. Through the ongoing Euroseistest Verification and Validation Project (E2VP), which focuses on the Mygdonian basin (northern Greece), we investigated the capability of numerical methods to predict earthquake ground motion for frequencies up to 4 Hz. Numerical predictions obtained by several teams using a wide variety of methods were compared using quantitative goodness-of-fit criteria. In order to better understand the cause of misfits between different simulations, initially performed for the realistic geometry of the Mygdonian basin, we defined five stringent canonical configurations. The canonical models allow for identifying sources of misfits and quantify their importance. Detailed quantitative comparison of simulations in relation to dominant features of the models shows that even relatively simple heterogeneous models must be treated with maximum care in order to achieve sufficient level of accuracy. One important conclusion is that the numerical representation of models with strong variations (e.g. discontinuities) may considerably vary from one method to the other, and may become a dominant source of

  9. Reading Ground Water Levels with a Smartphone

    NASA Astrophysics Data System (ADS)

    van Overloop, Peter-Jules

    2015-04-01

    Most ground water levels in the world are measured manually. It requires employees of water management organizations to visit sites in the field and execute a measurement procedure that requires special tools and training. Once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. This procedure is slow and prone to human errors. A new development is the introduction of modern Information and Communication Technology to support this task and make it more efficient. Two innovations are introduced to measure and immediately store ground water levels. The first method is a measuring tape that gives a sound and light when it just touches the water in combination with an app on a smartphone with which a picture needs to be taken from the measuring tape. Using dedicated pattern recognition algorithms, the depth is read on the tape and it is verified if the light is on. The second method estimates the depth using a sound from the smartphone that is sent into the borehole and records the reflecting waves in the pipe. Both methods use gps-localization of the smartphone to store the depths in the right location in the central database, making the monitoring of ground water levels a real-time process that eliminates human errors.

  10. Ground water and the rural homeowner

    USGS Publications Warehouse

    Waller, Roger M.

    1988-01-01

    As the salesmen sang in the musical The Music Man, "You gotta know the territory." This saying is also true when planning to buy or build a house. Learn as much as possible about the land, the water supply, and the septic system of the house before buying or building. Do not just look at the construction aspects or the beauty of the home and surroundings. Be sure to consider the environmental conditions around and beneath the site as well. Try to visit the site under adverse conditions, such as during heavy rain or meltwater runoff, to observe the drainage characteristics, particularly the condition of the basement. Many of the conditions discussed in this book, such as lowered well-water levels, flooded basements, and contamination from septic systems, are so common that rural families often have to deal with one or more of them. The purpose of this book is to awaken an interest in ground water and an awareness of where it is available, how it moves, how people can adjust to its patterns to avoid problems, and how it can be protected and used wisely. This booklet provides both present and prospective rural homeowners, particularly those in the glaciated northern parts of the United States, with a basic but comprehensive description of ground water. It also presents problems one may expect to encounter with ground water and some solutions or suggestions for help with these problems.

  11. Ground water and the rural homeowner

    USGS Publications Warehouse

    Waller, Roger M.

    1994-01-01

    As the salesmen sang in the musical The Music Man, "You gotta know the territory." This saying is also true when planning to buy or build a house. Learn as much as possible about the land, the water supply, and the septic system of the house before buying or building. Do not just look at the construction aspects or the beauty of the home and surroundings. Be sure to consider the environmental conditions around and beneath the site as well. Try to visit the site under adverse conditions, such as during heavy rain or meltwater runoff, to observe the drainage characteristics, particularly the condition of the basement. Many of the conditions discussed in this book, such as lowered well-water levels, flooded basements, and contamination from septic systems, are so common that rural families often have to deal with one or more of them. The purpose of this book is to awaken an interest in ground water and an awareness of where it is available, how it moves, how people can adjust to its patterns to avoid problems, and how it can be protected and used wisely. This booklet provides both present and prospective rural homeowners, particularly those in the glaciated northern parts of the United States, with a basic but comprehensive description of ground water. It also presents problems one may expect to encounter with ground water and some solutions or suggestions for help with these problems.

  12. Ground water maps of the Hanford Site

    SciTech Connect

    Kasza, G.L.; Harris, S.F.; Hartman, M.J.

    1990-12-01

    This report presents the results of the June 1990, ground water level measurement program at the 100 Areas and 200 Areas of the Hanford Site (Figure 1). The water levels beneath these areas are measured regularly on a semiannual basis and the data received are used to produce the following set of maps for public release. For clarity, the locating prefixes have been omitted from all well numbers shown on the maps. Wells in the 100 Areas have the prefix 199; wells in the 200 Areas have the prefix 299, and the wells outside these areas have the prefix 699. Ground Water Maps of the Hanford Site is prepared by the Geosciences Group, Environmental Division, Westinghouse Hanford Company, for the US Department of Energy, Richland Operations Office. 1 ref., 6 figs., 2 tabs.

  13. ERTS imagery for ground-water investigations

    USGS Publications Warehouse

    Moore, Gerald K.; Deutsch, Morris

    1975-01-01

    ERTS imagery offers the first opportunity to apply moderately high-resolution satellite data to the nationwide study of water resources. This imagery is both a tool and a form of basic data. Like other tools and basic data, it should be considered for use in ground-water investigations. The main advantage of its use will be to reduce the need for field work. In addition, however, broad regional features may be seen easily on ERTS imagery, whereas they would be difficult or impossible to see on the ground or on low-altitude aerial photographs. Some present and potential uses of ERTS imagery are to locate new aquifers, to study aquifer recharge and discharge, to estimate ground-water pumpage for irrigation, to predict the location and type of aquifer management problems, and to locate and monitor strip mines which commonly are sources for acid mine drainage. In many cases, boundaries which are gradational on the ground appear to be sharp on ERTS imagery. Initial results indicate that the accuracy of maps produced from ERTS imagery is completely adequate for some purposes.

  14. Simulation of ground-water flow and areas contributing ground water to production wells, Cadillac, Michigan

    USGS Publications Warehouse

    Hoard, Christopher J.; Westjohn, David B.

    2005-01-01

    Ground water is the primary source of water for domestic, municipal, and industrial use within the northwest section of Michigan's Lower Peninsula. Because of the importance of this resource, numerous communities including the city of Cadillac in Wexford County, Michigan, have begun local wellhead protection programs. In these programs, communities protect their ground-water resources by identifying the areas that contribute water to production wells, identifying potential sources of contamination, and developing methods to cooperatively manage and minimize threats to the water supply. The U.S. Geological Survey, in cooperation with the city of Cadillac, simulated regional ground-water flow and estimated areas contributing recharge and zones of transport to the production well field. Ground-water flow models for the Clam River watershed, in Wexford and Missaukee Counties, were developed using the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model (MODFLOW 2000). Ground-water flow models were calibrated using the observation, sensitivity, and parameter estimation packages of MODFLOW 2000. Ground-water-head solutions from calibrated flow models were used in conjunction with MODPATH, a particle-tracking program, to simulate regional ground-water flow and estimate areas contributing recharge and zones of transport to the Cadillac production-well field for a 10-year period. Model simulations match the conceptual model in that regional ground-water flow in the deep ground-water system is from southeast to northwest across the watershed. Areas contributing water were determined for the optimized parameter set and an alternate parameter set that included increased recharge and hydraulic conductivity values. Although substantially different hydrologic parameters (assumed to represent end-member ranges of realistic hydrologic parameters) were used in alternate numerical simulations, simulation results differ little in predictions of

  15. Ground water exfiltration in a river oxbow

    NASA Astrophysics Data System (ADS)

    Suck, M.; Nützmann, G.; Lewandowski, J.

    2009-04-01

    This paper deals with the quantification of the exchange between ground water and surface water in a river oxbow. Implementation and evaluation of the study site are based upon a conceptual model, in which exfiltration into the oxbow and mainly into the adjacent river Spree are supposed as major transport processes. A clogging mud layer in the oxbow with its low hydraulic conductivity controls exfiltration and is the highest hydraulic resistance in the considered aquatic system. The measurement of temperature depth profiles within that layer was one of the methods applied to measure groundwater exfiltration. Because of the different groundwater and surface water temperatures there are temperature differences between the upper and lower boundary of the mud layer. Depending on the extent of ground water exfiltration that depth profile is more or less curved. By adaptation of an analytical solution to the plotted temperature depth profiles the flux rates were calculated. A supplementary method to measure exfiltration, the seepage meter, is used for direct measurements of the flux rates. With that method the ground water flux which passes a defined cross section of the sediment-water boundary is collected. The evaluation of the results yields higher exfiltration rates for the temperature depth profiles than for the seepage meters. For the seepage meters the results show only a part of the actual flux rates because of several error sources. Despite those errors the comparison of the results from both methods shows a similar flux pattern with strong small-scale heterogeneities. At scales of few meters the measured flux rates fluctuate more than an order of magnitude. The flux rates near the bank are frequently higher than in the middle of the oxbow. However, the flux rates are controlled by the thickness of the clogging mud layer, its hydraulic conductivity, its heterogeneity and the water table differences between surface water and adjacent aquifer.

  16. Characterization of Climax granite ground water

    SciTech Connect

    Isherwood, D.; Harrar, J.; Raber, E.

    1982-08-01

    The Climax ground water fails to match the commonly held views regarding the nature of deep granitic ground waters. It is neither dilute nor in equilibrium with the granite. Ground-water samples were taken for chemical analysis from five sites in the fractured Climax granite at the Nevada Test Site. The waters are high in total dissolved solids (1200 to 2160 mg/L) and rich in sodium (56 to 250 mg/L), calcium (114 to 283 mg/L) and sulfate (325 to 1060 mg/L). Two of the samples contained relatively high amounts of uranium (1.8 and 18.5 mg/L), whereas the other three contained uranium below the level of detection (< 0.1 mg/L). The pH is in the neutral range (7.3 to 8.2). The differences in composition between samples (as seen in the wide range of values for the major constituents and total dissolved solids) suggest the samples came from different, independent fracture systems. However, the apparent trend of increasing sodium with depth at the expense of calcium and magnesium suggests a common evolutionary chemical process, if not an interconnected system. The waters appear to be less oxidizing with depth (+ 410 mV at 420 m below the surface vs + 86 mV at 565 m). However, with Eh measurements on only two samples, this correlation is questionable. Isotopic analyses show that the waters are of meteoric origin and that the source of the sulfate is probably the pyrite in the fracture-fill material. Analysis of the measured water characteristics using the chemical equilibrium computer program EQ3 indicates that the waters are not in equilibrium with the local mineral assemblage. The solutions appear to be supersaturated with respect to the mineral calcite, quartz, kaolinite, muscovite, k-feldspar, and many others.

  17. Three-dimensional (3D) palladium-zinc oxide nanowire nanofiber as photo-catalyst for water treatment.

    PubMed

    Choi, Jungsu; Chan, Sophia; Joo, Hyunjong; Yang, Heejae; Ko, Frank K

    2016-09-15

    Zinc Oxide Nano Wires (ZNWs) has been considered as a promising material for purification and disinfection of water and remediation of hazardous waste owing to its high activity and lower cost. In this study, three-dimensional (3D) structured palladium (Pd)/ZNWs were synthesized on the fabricated electrospun nanofibers and explored for enhancement of organic matter (OM) removal efficiency in water by suppressing electron-hole recombination during photocatalytic activity and increased surface area. The densely populated ZNWs were fabricated on the electrospun nanofiber by electroless plating (EP) and hydrothermal synthesis. In order to improve photocatalytic efficiency, a thin layer of Pd was coated prior to ZNWs growth to induce suppression of electron hole recombination produced during catalyst activity. The creation of a highly porous network of nanofibers decorated with ZNWs resulted in an increase of specific removal rate (SRR) of OM from 0.0249 to 0.0377 mg CODCr removed/mg ZNWs-hr when ZNW were grown on a Pd layer. It is believed that the demonstration of OM removal in the water through Pd/ZNWs membrane and enhanced photocatalytic activity under UV irradiation from layered structure can broaden potential applicability of Pd/ZNWs membranes for various photo catalytic water treatment. PMID:27286471

  18. Identifying well contamination through the use of 3-D fluorescence spectroscopy to classify coalbed methane produced water.

    PubMed

    Dahm, Katharine G; Van Straaten, Colette M; Munakata-Marr, Junko; Drewes, Jörg E

    2013-01-01

    Production of unconventional gas resources commonly requires the use of hydraulic fracturing and chemical production well additives. Concern exists for the use of chemical compounds in gas wells due to the risk of groundwater contamination. This study focuses on a proposed method of identifying groundwater contamination from gas production. The method focuses on the classification of naturally occurring organic signatures of coalbed methane (CBM) produced water compared to anthropogenic organic compounds. The 3-D fluorescence excitation-emission matrix (EEM) spectra of coalbed methane produced water samples revealed four peaks characteristic of coalbed methane produced water: Peak P (aromatic proteins region), Peak M(1) (microbial byproducts region), Peak M(2) (microbial byproducts region), and Peak H (humic acid-like region). Peak H is characteristic of the coal-water equilibria present in all basins, while peaks P and M(2) correlate with microbial activity in basins with biogenic methane generation pathways. Anthropogenic well additives produce EEM signatures with notable flooding of peaks P, M(1), M(2), and H, relatively higher overall fluorescence intensity, and slightly higher DOC concentrations. Fluorescence spectroscopy has the potential to be used in conjunction with groundwater contamination studies to determine if detected organic compounds originate from naturally occurring sources or well production additives. PMID:23198677

  19. Estimating 3D L5/S1 moments and ground reaction forces during trunk bending using a full-body ambulatory inertial motion capture system.

    PubMed

    Faber, G S; Chang, C C; Kingma, I; Dennerlein, J T; van Dieën, J H

    2016-04-11

    Inertial motion capture (IMC) systems have become increasingly popular for ambulatory movement analysis. However, few studies have attempted to use these measurement techniques to estimate kinetic variables, such as joint moments and ground reaction forces (GRFs). Therefore, we investigated the performance of a full-body ambulatory IMC system in estimating 3D L5/S1 moments and GRFs during symmetric, asymmetric and fast trunk bending, performed by nine male participants. Using an ambulatory IMC system (Xsens/MVN), L5/S1 moments were estimated based on the upper-body segment kinematics using a top-down inverse dynamics analysis, and GRFs were estimated based on full-body segment accelerations. As a reference, a laboratory measurement system was utilized: GRFs were measured with Kistler force plates (FPs), and L5/S1 moments were calculated using a bottom-up inverse dynamics model based on FP data and lower-body kinematics measured with an optical motion capture system (OMC). Correspondence between the OMC+FP and IMC systems was quantified by calculating root-mean-square errors (RMSerrors) of moment/force time series and the interclass correlation (ICC) of the absolute peak moments/forces. Averaged over subjects, L5/S1 moment RMSerrors remained below 10Nm (about 5% of the peak extension moment) and 3D GRF RMSerrors remained below 20N (about 2% of the peak vertical force). ICCs were high for the peak L5/S1 extension moment (0.971) and vertical GRF (0.998). Due to lower amplitudes, smaller ICCs were found for the peak asymmetric L5/S1 moments (0.690-0.781) and horizontal GRFs (0.559-0.948). In conclusion, close correspondence was found between the ambulatory IMC-based and laboratory-based estimates of back load. PMID:26795123

  20. SUPERFUND GROUND WATER ISSUE - ACCURACY OF DEPTH TO WATER MEASUREMENTS

    EPA Science Inventory

    Accuracy of depth to water measurements is an issue identified by the Forum as a concern of Superfund decision-makers as they attempt to determine directions of ground-water flow, areas of recharge of discharge, the hydraulic characteristics of aquifers, or the effects of manmade...

  1. Validation Analysis for the Calculation of a Turbulent Free Jet in Water Using CFDS-FLOW 3-D and FLUENT

    SciTech Connect

    Dimenna, R.A.; Lee, S.Y.

    1995-05-01

    The application of computational fluid dynamics methods to the analysis of mixing in the high level waste tanks at the Savannah River Site requires a demonstration that the computer codes can properly represent the behavior of fluids in the tanks. The motive force for mixing the tanks is a set of jet pumps taking suction from the tank fluid and discharging turbulent jets near the bottom of the tank. The work described here focuses on the free turbulent jet in water as the simplest case of jet behavior for which data could be found in the open literature. Calculations performed with both CFDS-FLOW3D and FLUENT were compared with data as well as classical jet theory. Results showed both codes agreed reasonably well with each other and with the data, but that results were sensitive to the computational mesh and, to a lesser degree, the selection of turbulence models.

  2. Numerical model of water flow and solute accumulation in vertisols using HYDRUS 2D/3D code

    NASA Astrophysics Data System (ADS)

    Weiss, Tomáš; Dahan, Ofer; Turkeltub, Tuvia

    2015-04-01

    Keywords: dessication-crack-induced-salinization, preferential flow, conceptual model, numerical model, vadose zone, vertisols, soil water retention function, HYDRUS 2D/3D Vertisols cover a hydrologically very significant area of semi-arid regions often through which water infiltrates to groundwater aquifers. Understanding of water flow and solute accumulation is thus very relevant to agricultural activity and water resources management. Previous works suggest a conceptual model of dessication-crack-induced-salinization where salinization of sediment in the deep section of the vadose zone (up to 4 m) is induced by subsurface evaporation due to convective air flow in the dessication cracks. It suggests that the salinization is induced by the hydraulic gradient between the dry sediment in the vicinity of cracks (low potential) and the relatively wet sediment further from the main cracks (high potential). This paper presents a modified previously suggested conceptual model and a numerical model. The model uses a simple uniform flow approach but unconventionally prescribes the boundary conditions and the hydraulic parameters of soil. The numerical model is bound to one location close to a dairy farm waste lagoon, but the application of the suggested conceptual model could be possibly extended to all semi-arid regions with vertisols. Simulations were conducted using several modeling approaches with an ultimate goal of fitting the simulation results to the controlling variables measured in the field: temporal variation in water content across thick layer of unsaturated clay sediment (>10 m), sediment salinity and salinity the water draining down the vadose zone to the water table. The development of the model was engineered in several steps; all computed as forward solutions by try-and-error approach. The model suggests very deep instant infiltration of fresh water up to 12 m, which is also supported by the field data. The paper suggests prescribing a special atmospheric

  3. Encapsulated discrete octameric water cluster, 1D water tape, and 3D water aggregate network in diverse MOFs based on bisimidazolium ligands

    NASA Astrophysics Data System (ADS)

    Shi, Ruo-Bing; Pi, Min; Jiang, Shuang-Shuang; Wang, Yuan-Yuan; Jin, Chuan-Ming

    2014-08-01

    Four new metal-organic frameworks, [Zn(2-mBIM)2(SO3CF3)2·(H2O)4] (1), [Zn(BMIE)(1,4-BDC)]·(H2O)3 (2), [Cd(BIM)2(OH)(H2O)2(PF6)]·(H2O)4 (3), and [Cd(PA-BIM)2 (ClO4)2]·11.33H2O (4) (2-mBIM = bis(2-methylimidazol-1-yl)methane, BMIE = 1,2-bis[1-(2-methylimidazole)-diethoxy]ethane, BIM = bis(imidazol-1-yl)methane, and PA-BIM = 1,1-bis [(2-phenylazo)imidazol-1-yl]methane) have been prepared and structurally characterized. Complex 1 exhibits an infinite 1D cationic beaded-chain structure, which encapsulated discrete octameric water clusters that are comprised of a chair-like hexameric water cluster with two extra water molecules dangling on two diagonal vertices of the chair. Complex 2 forms a 1D infinite zigzag metal-organic chain structure with a 1D T4(0)A(4) water tape. Complexes 3 show a 2D grid-like sheet structure with the 1D water tape T4(0)A(0)2(0) motif. Complex 4 is a porous 3D MOF with tetrahedron-coordinated Cd(II) centers and trans-conformation PA-BIM ligands. These holes are occupied by a fascinating three-dimensional water clathrate network, which consists of cage-shaped structural tetradecameric water cluster (H2O)14 units and six independent bridged water molecules. The results suggest that the bisimidazolium ligands and anions play crucial roles in the formation of the different host structures and different guest water aggregations. Additionally, the thermal stabilities and photoluminescence spectra of the complexes have been discussed.

  4. 40 CFR 144.87 - How does the identification of ground water protection areas and other sensitive ground water...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... water protection areas and other sensitive ground water areas affect me? 144.87 Section 144.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) UNDERGROUND... identification of ground water protection areas and other sensitive ground water areas affect me? (a) You...

  5. 40 CFR 144.87 - How does the identification of ground water protection areas and other sensitive ground water...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... water protection areas and other sensitive ground water areas affect me? 144.87 Section 144.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) UNDERGROUND... identification of ground water protection areas and other sensitive ground water areas affect me? (a) You...

  6. 40 CFR 144.87 - How does the identification of ground water protection areas and other sensitive ground water...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... water protection areas and other sensitive ground water areas affect me? 144.87 Section 144.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) UNDERGROUND... identification of ground water protection areas and other sensitive ground water areas affect me? (a) You...

  7. Estimation of water saturated permeability of soils, using 3D soil tomographic images and pore-level transport phenomena modelling

    NASA Astrophysics Data System (ADS)

    Lamorski, Krzysztof; Sławiński, Cezary; Barna, Gyöngyi

    2014-05-01

    There are some important macroscopic properties of the soil porous media such as: saturated permeability and water retention characteristics. These soil characteristics are very important as they determine soil transport processes and are commonly used as a parameters of general models of soil transport processes used extensively for scientific developments and engineering practise. These characteristics are usually measured or estimated using some statistical or phenomenological modelling, i.e. pedotransfer functions. On the physical basis, saturated soil permeability arises from physical transport processes occurring at the pore level. Current progress in modelling techniques, computational methods and X-ray micro-tomographic technology gives opportunity to use direct methods of physical modelling for pore level transport processes. Physically valid description of transport processes at micro-scale based on Navier-Stokes type modelling approach gives chance to recover macroscopic porous medium characteristics from micro-flow modelling. Water microflow transport processes occurring at the pore level are dependent on the microstructure of porous body and interactions between the fluid and the medium. In case of soils, i.e. the medium there exist relatively big pores in which water can move easily but also finer pores are present in which water transport processes are dominated by strong interactions between the medium and the fluid - full physical description of these phenomena is a challenge. Ten samples of different soils were scanned using X-ray computational microtomograph. The diameter of samples was 5 mm. The voxel resolution of CT scan was 2.5 µm. Resulting 3D soil samples images were used for reconstruction of the pore space for further modelling. 3D image threshholding was made to determine the soil grain surface. This surface was triangulated and used for computational mesh construction for the pore space. Numerical modelling of water flow through the

  8. Water resources data, Idaho, 2004; Volume 3. Ground water records

    USGS Publications Warehouse

    Campbell, A.M.; Conti, S.N.; O'Dell, I.

    2005-01-01

    Water resources data for the 2004 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 209 stream-gaging stations and 8 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 39 stream-gaging stations and partial record sites, 18 lakes sites, and 395 groundwater wells; and water levels for 425 observation network wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

  9. Water resources data, Idaho, 2003; Volume 3. Ground water records

    USGS Publications Warehouse

    Campbell, A.M.; Conti, S.N.; O'Dell, I.

    2003-01-01

    Water resources data for the 2003 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of groundwater. The three volumes of this report contain discharge records for 208 stream-gaging stations and 14 irrigation diversions; stage only records for 6 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 13 lakes and reservoirs; water-quality for 50 stream-gaging stations and partial record sites, 3 lakes sites, and 398 groundwater wells; and water levels for 427 observation network wells and 900 special project wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements. Volumes 1 & 2 contain the surface-water and surface-water-quality records. Volume 3 contains the ground-water and ground-water-quality records. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

  10. Procedures for ground-water investigations

    SciTech Connect

    Not Available

    1989-09-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water investigations are carried out to fulfill the requirements for the US Department of Energy (DOE) to meet the requirements of DOE Orders. Investigations are also performed for various clients to meet the requirements of the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA). National standards including procedures published by the American Society for Testing and Materials (ASTM) and the US Geological Survey were utilized in developing the procedures contained in this manual.