Stabilization of Networked Control Systems with Variable Delays and Saturating Inputs

Directory of Open Access Journals (Sweden)

M. Mahmodi Kaleybar

2014-06-01

Full Text Available In this paper, improved conditions for the synthesis of static state-feedback controller are derived to stabilize networked control systems (NCSs subject to actuator saturation. Both of the data packet latency and dropout which deteriorate the performance of the closed-loop system are considered in the NCS model via variable delays. Two different techniques are employed to incorporate actuator saturation in the system description. Utilizing Lyapunov-Krasovskii Theorem, delay-dependent conditions are obtained in terms of linear matrix inequalities (LMIs to determine the static feedback gain. Moreover, an optimization problem is formulated in order to find the less conservative estimate for the region of attraction corresponding to different maximum allowable delays. Numerical examples are introduced to demonstrate the effectiveness and advantages of the proposed schemes.

Effects of Faulted Stratigraphy on Saturated Zone Flow Beneath Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Cohen, Andrew J.B.; Oldenburg, Curtis M.

1999-01-01

The S 4 Z Model (''sub-site-scale saturated zone'') is a 3-D TOUGH2 model that was developed to study the saturated zone (SZ) at Yucca Mountain, Nevada, and to aid in the design and analysis of hydrologic tests. Yucca Mountain is the proposed site for a nuclear waste repository for the United States. The model covers an area of approximately 100 km 2 around Yucca Mountain, as shown in Figure 1. The proposed repository is located in the unsaturated zone, immediately above the area of equidimensional gridblocks east of Solitario Canyon fault, which defines the crest of Yucca Mountain. The finely discretized region near the center of the domain corresponds to the area near a cluster of boreholes used for hydraulic and tracer testing. This discretization facilitates simulation of tests conducted there. The hydrogeologic structure beneath the mountain is comprised of dipping geologic units of variable thickness which are offset by faults. One of the primary objectives of the S 4 Z modeling effort is to study the potential effects of the faulted structure on flow. Therefore, replication of the geologic structure in the model mesh is necessary. This paper summarizes (1) the mesh discretization used to capture the faulted geologic structure, and (2) a model simulation that illustrates the significance of the geologic structure on SZ flow and the resulting macrodispersion

TOURGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media

OpenAIRE

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-01-01

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase fluid and heat flow simulator TOUGH2. A variety of subsurface thermo-physical-chemical processes are considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, and pH and Eh. Interactions between ...

User manual of the multicompenent variably - saturated flow and transport model HP1

International Nuclear Information System (INIS)

Jacques, D.; Simunek, J.

2005-06-01

This report describes a new comprehensive simulation tool HP1 (HYDRUS1D-PHREEQC) that was obtained by coupling the HYDRUS-1D one-dimensional variably-saturated water flow and solute transport model with the PHREEQC geochemical code. The HP1 code incorporates modules simulating (1) transient water flow in variably-saturated media, (2) transport of multiple components, and (3) mixed equilibrium/kinetic geochemical reactions. The program numerically solves the Richards equation for variably-saturated water flow and advection-dispersion type equations for heat and solute transport. The flow equation incorporates a sink term to account for water uptake by plant roots. The heat transport equation considers transport due to conduction and convection with flowing water. The solute transport equations consider advective-dispersive transport in the liquid phase. The program can simulate a broad range of low-temperature biogeochemical reactions in water, soil and ground water systems including interactions with minerals, gases, exchangers, and sorption surfaces, based on thermodynamic equilibrium, kinetics, or mixed equilibrium-kinetic reactions. The program may be used to analyze water and solute movement in unsaturated, partially saturated, or fully saturated porous media. The flow region may be composed of nonuniform soils or sediments. Flow and transport can occur in the vertical, horizontal, or a generally inclined direction. The water flow part of the model can deal with prescribed head and flux boundaries, boundaries controlled by atmospheric conditions, as well as free drainage boundary conditions. The governing flow and transport equations were solved numerically using Galerkin-type linear finite element schemes. To test the accuracy of the coupling procedures implemented in HP1, simulation results were compared with (i) HYDRUS-1D for transport problems of multiple components subject to sequential first-order decay, (ii) PHREEQC for steady-state flow conditions, and

FLASH: A finite element computer code for variably saturated flow

International Nuclear Information System (INIS)

Baca, R.G.; Magnuson, S.O.

1992-05-01

A numerical model was developed for use in performance assessment studies at the INEL. The numerical model, referred to as the FLASH computer code, is designed to simulate two-dimensional fluid flow in fractured-porous media. The code is specifically designed to model variably saturated flow in an arid site vadose zone and saturated flow in an unconfined aquifer. In addition, the code also has the capability to simulate heat conduction in the vadose zone. This report presents the following: description of the conceptual frame-work and mathematical theory; derivations of the finite element techniques and algorithms; computational examples that illustrate the capability of the code; and input instructions for the general use of the code. The FLASH computer code is aimed at providing environmental scientists at the INEL with a predictive tool for the subsurface water pathway. This numerical model is expected to be widely used in performance assessments for: (1) the Remedial Investigation/Feasibility Study process and (2) compliance studies required by the US Department of Energy Order 5820.2A

The Intrinsic Variability in the Water Vapor Saturation Ratio due to Turbulence

Science.gov (United States)

Anderson, J. C.; Cantrell, W. H.; Chandrakar, K. K.; Kostinski, A. B.; Niedermeier, D.; Shaw, R. A.

2017-12-01

In the atmosphere, the concentration of water vapor plays an important role in Earth's weather and climate. The mean concentration of water vapor is key to its efficiency as a greenhouse gas; the fluctuations about the mean are important for heat fluxes near the surface of earth. In boundary layer clouds, fluctuations in the water vapor concentration are linked to turbulence. Conditions representative of boundary layer clouds are simulated in Michigan Tech's multiphase, turbulent reaction chamber, the ∏ chamber, where the boundary conditions are controlled and repeatable. Measurements for temperature and water vapor concentration were recorded under forced Rayleigh-Bénard convection. As expected, the distributions for temperature and water vapor concentration broaden as the turbulence becomes more vigorous. From these two measurements the saturation ratio can be calculated. The fluctuations in the water vapor concentration are more important to the variability in the saturation ratio than fluctuations in temperature. In a cloud, these fluctuations in the saturation ratio can result in some cloud droplets experiencing much higher supersaturations. Those "lucky" droplets grow by condensation at a faster rate than other cloud droplets. The difference in the droplet growth rate could contribute to a broadened droplet distribution, which leads to the onset of collision-coalescence. With more intense turbulence these effect will become more pronounced as the fluctuations about the mean saturation ratio become more pronounced.

Variables of state and charateristics for isentropic discharge phenomena of water, starting with saturation

Energy Technology Data Exchange (ETDEWEB)

Baudisch, H.

1968-03-15

The tables presented in this report contain the thermodynamic values of isentropic change of state for water in the two-phase region starting from the saturation line down to 0.01 at. The variables have been computed in the pressure range from 5-100 at. in equal pressure intervals of 5 at. and in the range from 100-170 at. in intervals of 10 at. Assuming a one-dimensional flow and a known saturation pressure, the dimensions of a discharge nozzle may be determined by interpolation of the calculated values for an isentropic discharge. 4 figs., 29 tabs., 23 refs.

Water Flow in Karst Aquifer Considering Dynamically Variable Saturation Conduit

Science.gov (United States)

Tan, Chaoqun; Hu, Bill X.

2017-04-01

The karst system is generally conceptualized as dual-porosity system, which is characterized by low conductivity and high storage continuum matrix and high conductivity and quick flow conduit networks. And so far, a common numerical model for simulating flow in karst aquifer is MODFLOW2005-CFP, which is released by USGS in 2008. However, the steady-state approach for conduit flow in CFP is physically impractical when simulating very dynamic hydraulics with variable saturation conduit. So, we adopt the method proposed by Reimann et al. (2011) to improve current model, in which Saint-Venant equations are used to model the flow in conduit. Considering the actual background that the conduit is very big and varies along flow path and the Dirichlet boundary varies with rainfall in our study area in Southwest China, we further investigate the influence of conduit diameter and outflow boundary on numerical model. And we also analyze the hydraulic process in multi-precipitation events. We find that the numerical model here corresponds well with CFP for saturated conduit, and it could depict the interaction between matrix and conduit during very dynamic hydraulics pretty well compare with CFP.

Variably-saturated groundwater modeling for optimizing managed aquifer recharge using trench infiltration

Science.gov (United States)

Heilweil, Victor M.; Benoit, Jerome; Healy, Richard W.

2015-01-01

Spreading-basin methods have resulted in more than 130 million cubic meters of recharge to the unconfined Navajo Sandstone of southern Utah in the past decade, but infiltration rates have slowed in recent years because of reduced hydraulic gradients and clogging. Trench infiltration is a promising alternative technique for increasing recharge and minimizing evaporation. This paper uses a variably saturated flow model to further investigate the relative importance of the following variables on rates of trench infiltration to unconfined aquifers: saturated hydraulic conductivity, trench spacing and dimensions, initial water-table depth, alternate wet/dry periods, and number of parallel trenches. Modeling results showed (1) increased infiltration with higher hydraulic conductivity, deeper initial water tables, and larger spacing between parallel trenches, (2) deeper or wider trenches do not substantially increase infiltration, (3) alternating wet/dry periods result in less overall infiltration than keeping the trenches continuously full, and (4) larger numbers of parallel trenches within a fixed area increases infiltration but with a diminishing effect as trench spacing becomes tighter. An empirical equation for estimating expected trench infiltration rates as a function of hydraulic conductivity and initial water-table depth was derived and can be used for evaluating feasibility of trench infiltration in other hydrogeologic settings

Pore-scale modeling of vapor transport in partially saturated capillary tube with variable area using chemical potential

DEFF Research Database (Denmark)

Addassi, Mouadh; Schreyer, Lynn; Johannesson, Björn

2016-01-01

Here we illustrate the usefulness of using the chemical potential as the primary unknown by modeling isothermal vapor transport through a partially saturated cylindrically symmetric capillary tube of variable cross-sectional area using a single equation. There are no fitting parameters and the nu......Here we illustrate the usefulness of using the chemical potential as the primary unknown by modeling isothermal vapor transport through a partially saturated cylindrically symmetric capillary tube of variable cross-sectional area using a single equation. There are no fitting parameters...... and the numerical solutions to the equation are compared with experimental results with excellent agreement. We demonstrate that isothermal vapor transport can be accurately modeled without modeling the details of the contact angle, microscale temperature fluctuations, or pressure fluctuations using a modification...

The geological basis and the representation of spatial variability in fractured media

International Nuclear Information System (INIS)

Mazurek, M.; Gautschi, A.; Zuidema, P.

1998-01-01

Spatial variability of features and parameters relevant for contaminant transport modelling occurs on all scales of interest for the quantification of processes that govern solute migration, typically decimeters to hundreds of meters. Two types of spatial variability are distinguished, namely the internal heterogeneity of each individual water-conducting feature (e.g. the complex architecture of a fault) and the larger-scale heterogeneity that results from the groundwater flow through different types of water-conducting features along the flow-path from the repository to the discharge areas. An up-scaling procedure is required to obtain hydraulic parameters and the properties of the overall flow-path, whereas the heterogeneity of many other geologic features (geometry of flow and matrix porosity, mineralogy, etc.) can be fed directly into coupled codes that quantify radionuclide transport. The procedures needed to derive conceptual models integrating geological and hydraulic field measurements and observations at a given site are illustrated by examples from both crystalline and sedimentary rock formations. (author)

Numerical simulation of air- and water-flow experiments in a block of variably saturated, fractured tuff from Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Kwicklis, E.M.; Healy, R.W.; Thamir, F.; Hampson, D.

1998-01-01

Numerical models of water movement through variably saturated, fractured tuff have undergone little testing against experimental data collected from relatively well-controlled and characterized experiments. This report used the results of a multistage experiment on a block of variably saturated, fractured, welded tuff and associated core samples to investigate if those results could be explained using models and concepts currently used to simulate water movement in variably saturated, fractured tuff at Yucca Mountain, Nevada, the potential location of a high-level nuclear-waste repository. Aspects of the experiment were modeled with varying degrees of success. Imbibition experiments performed on cores of various lengths and diameters were adequately described by models using independently measured permeabilities and moisture-characteristic curves, provided that permeability reductions resulting from the presence of entrapped air were considered. Entrapped gas limited maximum water saturations during imbibition to approximately 0.70 to 0,80 of the fillable porosity values determined by vacuum saturation. A numerical simulator developed for application to fluid flow problems in fracture networks was used to analyze the results of air-injection tests conducted within the tuff block through 1.25-cm-diameter boreholes. These analyses produced estimates of transmissivity for selected fractures within the block. Transmissivities of other fractures were assigned on the basis of visual similarity to one of the tested fractures. The calibrated model explained 53% of the observed pressure variance at the monitoring boreholes (with the results for six outliers omitted) and 97% of the overall pressure variance (including monitoring and injection boreholes) in the subset of air-injection tests examined

Tracing of variabilities within a geological barrier by molecular organic geochemistry

International Nuclear Information System (INIS)

Hautevelle, Yann; Michels, Raymond; Malartre, Fabrice; Elie, Marcel; Trouiller, Alain

2007-01-01

The Callovo-Oxfordian claystones located at 500 m depth at Bure (Meuse, France) are currently being investigated by Andra (the French National Radioactive Waste Management Agency) for testing the feasibility of long-term and deep geological nuclear waste disposal. In order to evaluate its potential as a geological barrier, it is very important to study, assess and describe its physico-chemical variability. The molecular biomarker composition of 150 samples of these claystones and their surrounding limestones carry diverse information on the sources of the sedimentary organic matter, the chemistry of the depositional environment, the preservation and diagenesis conditions. It also allows assessing the degree of lateral and vertical variability of the organic matter within these sedimentary series. The abundance of unsaturated biomarkers, the distribution of steroids and hopanoids and CPI values >2 prove the thermal immaturity of the organic matter. The co-occurrence of plankton, bacteria and land plant biomarkers indicate that the organic matter is a mixture of marine and continental contributions. The data also reveal that the organic matter was deposited under oxic and open-sea conditions except for a brief event of photic zone anoxia at the beginning of the Middle Callovian. In the claystones, the geosynthesis of diasterenes is favored to the detriment of the formation of steranes, especially in smectite-rich levels, and the organic matter is rapidly isolated from oxidizing then reducing conditions after the deposition due to the protective effect of clays. On the scale investigated, the claystones are characterized by a unique molecular facies and are thus homogenous from their organic content point of view. Yet, detailed investigation of specific molecular families indicates changes related to major claystone-limestone transitions. The homogeneity of these claystones can be explained by the paleogeographic position of their depositional setting and the plane

Sensitivity analysis of tracer transport in variably saturated soils at USDA-ARS OPE3 field site

Science.gov (United States)

The objective of this study was to assess the effects of uncertainties in hydrologic and geochemical parameters on the results of simulations of the tracer transport in variably saturated soils at the USDA-ARS OPE3 field site. A tracer experiment with a pulse of KCL solution applied to an irrigatio...

TRUST: A Computer Program for Variably Saturated Flow in Multidimensional, Deformable Media

Energy Technology Data Exchange (ETDEWEB)

Reisenauer, A. E.; Key, K. T.; Narasimhan, T. N.; Nelson, R. W.

1982-01-01

The computer code, TRUST. provides a versatile tool to solve a wide spectrum of fluid flow problems arising in variably saturated deformable porous media. The governing equations express the conservation of fluid mass in an elemental volume that has a constant volume of solid. Deformation of the skeleton may be nonelastic. Permeability and compressibility coefficients may be nonlinearly related to effective stress. Relationships between permeability and saturation with pore water pressure in the unsaturated zone may include hysteresis. The code developed by T. N. Narasimhan grew out of the original TRUNP code written by A. L. Edwards. The code uses an integrated finite difference algorithm for numerically solving the governing equation. Narching in time is performed by a mixed explicit-implicit numerical procedure in which the time step is internally controlled. The time step control and related feature in the TRUST code provide an effective control of the potential numerical instabilities that can arise in the course of solving this difficult class of nonlinear boundary value problem. This document brings together the equations, theory, and users manual for the code as well as a sample case with input and output.

Correlation Between Fracture Network Properties and Stress Variability in Geological Media

Science.gov (United States)

Lei, Qinghua; Gao, Ke

2018-05-01

We quantitatively investigate the stress variability in fractured geological media under tectonic stresses. The fracture systems studied include synthetic fracture networks following power law length scaling and natural fracture patterns based on outcrop mapping. The stress field is derived from a finite-discrete element model, and its variability is analyzed using a set of mathematical formulations that honor the tensorial nature of stress data. We show that local stress perturbation, quantified by the Euclidean distance of a local stress tensor to the mean stress tensor, has a positive, linear correlation with local fracture intensity, defined as the total fracture length per unit area within a local sampling window. We also evaluate the stress dispersion of the entire stress field using the effective variance, that is, a scalar-valued measure of the overall stress variability. The results show that a well-connected fracture system under a critically stressed state exhibits strong local and global stress variabilities.

Nonlinear acoustics of water-saturated marine sediments

DEFF Research Database (Denmark)

Jensen, Leif Bjørnø

1976-01-01

Interest in the acoustic qualities of water-saturated marine sediments has increased considerably during recent years. The use of sources of high-intensity sound in oil propsecting, in geophysical and geological studies of bottom and subbottom materials and profiles and recently in marine...... archaeology has emphasized the need of information about the nonlinear acoustic qualities of water-saturated marine sediments. While the acoustic experiments and theoretical investigations hitherto performed have concentrated on a determination of the linear acoustic qualities of water-saturated marine...... sediments, their parameters of nonlinear acoustics are still unexplored. The strong absorption, increasing about linearly with frequency, found in most marine sediments and the occurrence of velocity dispersion by some marine sediments restrict the number of nonlinear acoustic test methods traditionally...

Geologic Variable Associated with Height of Yellow-Poplar Stand in the Bald Mountains of North Carolina

Science.gov (United States)

W. Henry McNab; Carl E. Merschat

1990-01-01

Quartz grain size and mylonitization, geologic variables determined fromrocks on sites, were associated with total height of yellow-poplar (Liriodendron tulipifera L.) standsand may be of value as independent variables in modeling tree growth from site characteristics. A predictive model containing quartz grain site and stand age accounted for about 54% of the...

Geological Factors Affecting Flow Spatial Continuity in Water Injection of Units Operating in the LGITJ–0102 Ore Body

Directory of Open Access Journals (Sweden)

Ilver M. Soto-Loaiza

2016-05-01

Full Text Available The objective of the investigation was to identify the geological factors affecting the spatial continuity of the flow during the process of flank water injection in the units operating in the Lower Lagunilla Hydrocarbon Ore Body. This included the evaluation of the recovery factor, the petro-physic properties such as porosity, permeability, water saturation and rock type and quality in each flow unit. it was observed that the rock type of the geologic structure in the ore body is variable. The lowest values for the petro-physic properties were found in the southern area while a high variability of these parameters was observed in the northern and central areas. It was concluded that the northern area has a great potential for the development of new injection projects for petroleum recovery.

Input saturation in nonlinear multivariable processes resolved by nonlinear decoupling

Directory of Open Access Journals (Sweden)

Jens G. Balchen

1995-04-01

Full Text Available A new method is presented for the resolution of the problem of input saturation in nonlinear multivariable process control by means of elementary nonlinear decoupling (END. Input saturation can have serious consequences particularly in multivariable control because it may lead to very undesirable system behaviour and quite often system instability. Many authors have searched for systematic techniques for designing multivariable control systems in which saturation may occur in any of the control variables (inputs, manipulated variables. No generally accepted method seems to have been presented so far which gives a solution in closed form. The method of elementary nonlinear decoupling (END can be applied directly to the case of saturation control variables by deriving as many control strategies as there are combinations of saturating control variables. The method is demonstrated by the multivariable control of a simulated Fluidized Catalytic Cracker (FCC with very convincing results.

A Bézier-Spline-based Model for the Simulation of Hysteresis in Variably Saturated Soil

Science.gov (United States)

Cremer, Clemens; Peche, Aaron; Thiele, Luisa-Bianca; Graf, Thomas; Neuweiler, Insa

2017-04-01

Most transient variably saturated flow models neglect hysteresis in the p_c-S-relationship (Beven, 2012). Such models tend to inadequately represent matrix potential and saturation distribution. Thereby, when simulating flow and transport processes, fluid and solute fluxes might be overestimated (Russo et al., 1989). In this study, we present a simple, computationally efficient and easily applicable model that enables to adequately describe hysteresis in the p_c-S-relationship for variably saturated flow. This model can be seen as an extension to the existing play-type model (Beliaev and Hassanizadeh, 2001), where scanning curves are simplified as vertical lines between main imbibition and main drainage curve. In our model, we use continuous linear and Bézier-Spline-based functions. We show the successful validation of the model by numerically reproducing a physical experiment by Gillham, Klute and Heermann (1976) describing primary drainage and imbibition in a vertical soil column. With a deviation of 3%, the simple Bézier-Spline-based model performs significantly better that the play-type approach, which deviates by 30% from the experimental results. Finally, we discuss the realization of physical experiments in order to extend the model to secondary scanning curves and in order to determine scanning curve steepness. {Literature} Beven, K.J. (2012). Rainfall-Runoff-Modelling: The Primer. John Wiley and Sons. Russo, D., Jury, W. A., & Butters, G. L. (1989). Numerical analysis of solute transport during transient irrigation: 1. The effect of hysteresis and profile heterogeneity. Water Resources Research, 25(10), 2109-2118. https://doi.org/10.1029/WR025i010p02109. Beliaev, A.Y. & Hassanizadeh, S.M. (2001). A Theoretical Model of Hysteresis and Dynamic Effects in the Capillary Relation for Two-phase Flow in Porous Media. Transport in Porous Media 43: 487. doi:10.1023/A:1010736108256. Gillham, R., Klute, A., & Heermann, D. (1976). Hydraulic properties of a porous

Numerical modeling of variably saturated flow and transport, 881 Hillside at Rocky Flats Plant, Jefferson County, Colorado

International Nuclear Information System (INIS)

Fedors, R.W.; Warner, J.W.

1993-01-01

This study characterizes the unconfined groundwater flow and chemical transport in a thin veneer of colluvial and alluvial Quaternary sediments on the 881 Hillslope at Rocky Flats Plant, Jefferson County, Colorado. Colluvial deposits with a varying thickness of 1.5 to 6.7 meters mantle a 255 meter steeply dipping hillslope. Saturated and the similar material types. A two-dimensional finite element code for variably saturated conditions is used to obtain steady state flow conditions from which water contents and Darcy velocities are used for transient contaminant transport modeling. The migration of an absorptive solute is modeled over a twenty year period using the transport portion of the two-dimensional finite element code. Different potential scenarios for the source area are compared with actual well sample data. The solutes considered for this study are Trichloroethene (TCE) and tetrachloroethene (PCE) dissolved in the water phase

Environmental and management influences on temporal variability of near saturated soil hydraulic properties☆

Science.gov (United States)

Bodner, G.; Scholl, P.; Loiskandl, W.; Kaul, H.-P.

2013-01-01

Structural porosity is a decisive property for soil productivity and soil environmental functions. Hydraulic properties in the structural range vary over time in response to management and environmental influences. Although this is widely recognized, there are few field studies that determine dominant driving forces underlying hydraulic property dynamics. During a three year field experiment we measured temporal variability of soil hydraulic properties by tension infiltrometry. Soil properties were characterized by hydraulic conductivity, effective macroporosity and Kosugi's lognormal pore size distribution model. Management related influences comprised three soil cover treatment (mustard and rye vs. fallow) and an initial mechanical soil disturbance with a rotary harrow. Environmental driving forces were derived from meteorological and soil moisture data. Soil hydraulic parameters varied over time by around one order of magnitude. The coefficient of variation of soil hydraulic conductivity K(h) decreased from 69.5% at saturation to 42.1% in the more unsaturated range (− 10 cm pressure head). A slight increase in the Kosugi parameter showing pore heterogeneity was observed under the rye cover crop, reflecting an enhanced structural porosity. The other hydraulic parameters were not significantly influenced by the soil cover treatments. Seedbed preparation with a rotary harrow resulted in a fourfold increase in macroporosity and hydraulic conductivity next to saturation, and homogenized the pore radius distribution. Re-consolidation after mechanical loosening lasted over 18 months until the soil returned to its initial state. The post-tillage trend of soil settlement could be approximated by an exponential decay function. Among environmental factors, wetting-drying cycles were identified as dominant driving force explaining short term hydraulic property changes within the season (r2 = 0.43 to 0.59). Our results suggested that beside considering average

Environmental and management influences on temporal variability of near saturated soil hydraulic properties.

Science.gov (United States)

Bodner, G; Scholl, P; Loiskandl, W; Kaul, H-P

2013-08-01

Structural porosity is a decisive property for soil productivity and soil environmental functions. Hydraulic properties in the structural range vary over time in response to management and environmental influences. Although this is widely recognized, there are few field studies that determine dominant driving forces underlying hydraulic property dynamics. During a three year field experiment we measured temporal variability of soil hydraulic properties by tension infiltrometry. Soil properties were characterized by hydraulic conductivity, effective macroporosity and Kosugi's lognormal pore size distribution model. Management related influences comprised three soil cover treatment (mustard and rye vs. fallow) and an initial mechanical soil disturbance with a rotary harrow. Environmental driving forces were derived from meteorological and soil moisture data. Soil hydraulic parameters varied over time by around one order of magnitude. The coefficient of variation of soil hydraulic conductivity K(h) decreased from 69.5% at saturation to 42.1% in the more unsaturated range (- 10 cm pressure head). A slight increase in the Kosugi parameter showing pore heterogeneity was observed under the rye cover crop, reflecting an enhanced structural porosity. The other hydraulic parameters were not significantly influenced by the soil cover treatments. Seedbed preparation with a rotary harrow resulted in a fourfold increase in macroporosity and hydraulic conductivity next to saturation, and homogenized the pore radius distribution. Re-consolidation after mechanical loosening lasted over 18 months until the soil returned to its initial state. The post-tillage trend of soil settlement could be approximated by an exponential decay function. Among environmental factors, wetting-drying cycles were identified as dominant driving force explaining short term hydraulic property changes within the season (r 2  = 0.43 to 0.59). Our results suggested that beside considering average

Characterization of thermal, hydraulic, and gas diffusion properties in variably saturated sand grades

DEFF Research Database (Denmark)

Deepagoda Thuduwe Kankanamge Kelum, Chamindu; Smits, Kathleen; Ramirez, Jamie

2016-01-01

porous media transport properties, key transport parameters such as thermal conductivity and gas diffusivity are particularly important to describe temperature-induced heat transport and diffusion-controlled gas transport processes, respectively. Despite many experimental and numerical studies focusing...... transport models (thermal conductivity, saturated hydraulic conductivity, and gas diffusivity). An existing thermal conductivity model was improved to describe the distinct three-region behavior in observed thermal conductivity–water saturation relations. Applying widely used parametric models for saturated......Detailed characterization of partially saturated porous media is important for understanding and predicting vadose zone transport processes. While basic properties (e.g., particle- and pore-size distributions and soil-water retention) are, in general, essential prerequisites for characterizing most...

Development of synchronous generator saturation model from steady-state operating data

Energy Technology Data Exchange (ETDEWEB)

Jadric, Martin; Despalatovic, Marin; Terzic, Bozo [FESB University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split (Croatia)

2010-11-15

A new method to estimate and model the saturated synchronous reactances of hydroturbine generators from operating data is presented. For the estimation process, measurements of only the generator steady-state variables are required. First, using a specific procedure, the field to armature turns ratio is estimated from measured steady-state variables at constant power generation and various excitation conditions. Subsequently, for each set of steady-state operating data, saturated synchronous reactances are identified. Fitting surfaces, defined as polynomial functions in two variables, are later used to model these saturated reactances. It is shown that the simpler polynomial functions may be used to model saturation at the steady-state than at the dynamic conditions. The developed steady-state model is validated with measurements performed on the 34 MVA hydroturbine generator. (author)

Modeling of water and solute transport under variably saturated conditions: state of the art

International Nuclear Information System (INIS)

Lappala, E.G.

1980-01-01

This paper reviews the equations used in deterministic models of mass and energy transport in variably saturated porous media. Analytic, quasi-analytic, and numerical solution methods to the nonlinear forms of transport equations are discussed with respect to their advantages and limitations. The factors that influence the selection of a modeling method are discussed in this paper; they include the following: (1) the degree of coupling required among the equations describing the transport of liquids, gases, solutes, and energy; (2) the inclusion of an advection term in the equations; (3) the existence of sharp fronts; (4) the degree of nonlinearity and hysteresis in the transport coefficients and boundary conditions; (5) the existence of complex boundaries; and (6) the availability and reliability of data required by the models

Measurement of residual CO2 saturation at a geological storage site using hydraulic tests

Science.gov (United States)

Rötting, T. S.; Martinez-Landa, L.; Carrera, J.; Russian, A.; Dentz, M.; Cubillo, B.

2012-12-01

Estimating long term capillary trapping of CO2 in aquifers remains a key challenge for CO2 storage. Zhang et al. (2011) proposed a combination of thermal, tracer, and hydraulic experiments to estimate the amount of CO2 trapped in the formation after a CO2 push and pull test. Of these three types of experiments, hydraulic tests are the simplest to perform and possibly the most informative. However, their potential has not yet been fully exploited. Here, a methodology is presented to interpret these tests and analyze which parameters can be estimated. Numerical and analytical solutions are used to simulate a continuous injection in a porous medium where residual CO2 has caused a reduction in hydraulic conductivity and an increase in storativity over a finite thickness (a few meters) skin around the injection well. The model results are interpreted using conventional pressure build-up and diagnostic plots (a plot of the drawdown s and the logarithmic derivative d s / d ln t of the drawdown as a function of time). The methodology is applied using the hydraulic parameters estimated for the Hontomin site (Northern Spain) where a Technology Demonstration Plant (TDP) for geological CO2 storage is planned to be set up. The reduction of hydraulic conductivity causes an increase in observed drawdowns, the increased storativity in the CO2 zone causes a delay in the drawdown curve with respect to the reference curve measured before CO2 injection. The duration (characteristic time) of these effects can be used to estimate the radius of the CO2 zone. The effects of reduced permeability and increased storativity are well separated from wellbore storage and natural formation responses, even if the CO2-brine interface is inclined (i.e. the CO2 forms a cone around the well). We find that both skin hydraulic conductivity and storativity (and thus residual CO2 saturation) can be obtained from the water injection test provided that water flow rate is carefully controlled and head build

To the question the unity of composition of fluids of heterogeneous geological objects.

Science.gov (United States)

Galant, Yuri

2017-04-01

Creation of Unit Theory Oil Generation based on a number of the provisions, one of which is the unity of the hydrocarbon composition in various geological objects. Studies conducted in various geological conditions and tectonic - magmatic environment. In studying the hydrocarbon composition of various geological objects, untraditional for petroleum geology (igneous rocks, metamorphic rocks, mineral deposits, etc.) progressively manifested that hydrocarbons are also distributed and have the following features. Studies have shown: 1. The composition of the hydrocarbon components presented by, light hydrocarbons, heavy hydrocarbons up to including hexane, normal forms, isoforms, saturated and unsaturated hydrocarbons. 2. Hydrocarbon composition and the ratio of methane to heavy hydrocarbons corresponds to the composition of gases gas fields. 3. The composition and the ratio of hydrocarbons do not depend on genetic types of heterogeneous geological objects. 4. Gas saturation meets the prevailing structure of rocks - pores or fractures. The foregoing allows us to speak of a single source of generating and delivering hydrocarbons in the Earth's Crust, regardless of the geological situation. I.e. the presence of hydrocarbons in the Earth's Crust is UNITED! 5. From a practical point of view - virtually unconventional for hydrocarbons rock can serve as unconventional hydrocarbon resources.

How to Recharge a Confined Aquifer: An Exploration of Geologic Controls on Groundwater Storage.

Science.gov (United States)

Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.

2017-12-01

Decreased snowpack storage and groundwater overdraft in California has increased interest in managed aquifer recharge (MAR) of excess winter runoff to the Central Valley aquifer system, which has unused storage capacity that far exceeds the state's surface reservoirs. Recharge to the productive, confined aquifer system remains a challenge due to the presence of nearly-ubiquitous, multiple silt and clay confining units that limit recharge pathways. However, previous studies have identified interconnected networks of sand and gravel deposits that bypass the confining units and accommodate rapid, high-volume recharge to the confined aquifer system in select locations. We use the variably-saturated, fully-integrated groundwater/surface-water flow code, ParFlow, in combination with a high-resolution, transition probability Markov-chain geostatistical model of the subsurface geologic heterogeneity of the east side of the Sacramento Valley, CA, to characterize recharge potential across a landscape that includes these geologic features. Multiple 180-day MAR simulations show that recharge potential is highly dependent on subsurface geologic structure, with a several order-of-magnitude range of recharge rates and volumes across the landscape. Where there are recharge pathways to the productive confined-aquifer system, pressure propagation in the confined system is widespread and rapid, with multi-kilometer lateral pressure propagation. Although widespread pressure propagation occurs in the confined system, only a small fraction of recharge volume is accommodated there. Instead, the majority of recharge occurs by filling unsaturated pore spaces. Where they outcrop at land surface, high-K recharge pathways fill rapidly, accommodating the majority of recharge during early time. However, these features become saturated quickly, and somewhat counterintuitively, the low-K silt and clay facies accommodate the majority of recharge volume during most of the simulation. These findings

VAM2D: Variably saturated analysis model in two dimensions

International Nuclear Information System (INIS)

Huyakorn, P.S.; Kool, J.B.; Wu, Y.S.

1991-10-01

This report documents a two-dimensional finite element model, VAM2D, developed to simulate water flow and solute transport in variably saturated porous media. Both flow and transport simulation can be handled concurrently or sequentially. The formulation of the governing equations and the numerical procedures used in the code are presented. The flow equation is approximated using the Galerkin finite element method. Nonlinear soil moisture characteristics and atmospheric boundary conditions (e.g., infiltration, evaporation and seepage face), are treated using Picard and Newton-Raphson iterations. Hysteresis effects and anisotropy in the unsaturated hydraulic conductivity can be taken into account if needed. The contaminant transport simulation can account for advection, hydrodynamic dispersion, linear equilibrium sorption, and first-order degradation. Transport of a single component or a multi-component decay chain can be handled. The transport equation is approximated using an upstream weighted residual method. Several test problems are presented to verify the code and demonstrate its utility. These problems range from simple one-dimensional to complex two-dimensional and axisymmetric problems. This document has been produced as a user's manual. It contains detailed information on the code structure along with instructions for input data preparation and sample input and printed output for selected test problems. Also included are instructions for job set up and restarting procedures. 44 refs., 54 figs., 24 tabs

Simulating Salt Movement using a Coupled Salinity Transport Model in a Variably Saturated Agricultural Groundwater System

Science.gov (United States)

Tavakoli Kivi, S.; Bailey, R. T.; Gates, T. K.

2017-12-01

Salinization is one of the major concerns in irrigated agricultural fields. Increasing salinity concentrations are due principally to a high water table that results from excessive irrigation, canal seepage, and a lack of efficient drainage systems, and lead to decreasing crop yield. High groundwater salinity loading to nearby river systems also impacts downstream areas, with saline river water diverted for application on irrigated fields. To assess the different strategies for salt remediation, we present a reactive transport model (UZF-RT3D) coupled with a salinity equilibrium chemistry module for simulating the fate and transport of salt ions in a variably-saturated agricultural groundwater system. The developed model accounts not for advection, dispersion, nitrogen and sulfur cycling, oxidation-reduction, sorption, complexation, ion exchange, and precipitation/dissolution of salt minerals. The model is applied to a 500 km2 region within the Lower Arkansas River Valley (LARV) in southeastern Colorado, an area acutely affected by salinization in the past few decades. The model is tested against salt ion concentrations in the saturated zone, total dissolved solid concentrations in the unsaturated zone, and salt groundwater loading to the Arkansas River. The model now can be used to investigate salinity remediation strategies.

The effect of saturation of the mechanical properties of tuff at Yucca Mountain

International Nuclear Information System (INIS)

Karakouzian, M.; Hudyma, N.

1996-01-01

This study investigates the effect of saturation on the mechanical properties, namely compressive strength and Young's Modulus, of Tiva Canyon welded tuff and Topopah Spring welded tuff from the Nevada Test Site. Unconfined compression tests on air dried and saturated specimens show that saturation lowers both the average compressive strength and the average Young's Modulus of Topopah Spring and Tiva Canyon tuff specimens. Saturation increases the variability of the mechanical properties of Topopah Spring tuff and the variability of the compressive strength of Tiva Canyon tuff

Assessing species saturation: conceptual and methodological challenges.

Science.gov (United States)

Olivares, Ingrid; Karger, Dirk N; Kessler, Michael

2018-05-07

Is there a maximum number of species that can coexist? Intuitively, we assume an upper limit to the number of species in a given assemblage, or that a lineage can produce, but defining and testing this limit has proven problematic. Herein, we first outline seven general challenges of studies on species saturation, most of which are independent of the actual method used to assess saturation. Among these are the challenge of defining saturation conceptually and operationally, the importance of setting an appropriate referential system, and the need to discriminate among patterns, processes and mechanisms. Second, we list and discuss the methodological approaches that have been used to study species saturation. These approaches vary in time and spatial scales, and in the variables and assumptions needed to assess saturation. We argue that assessing species saturation is possible, but that many studies conducted to date have conceptual and methodological flaws that prevent us from currently attaining a good idea of the occurrence of species saturation. © 2018 Cambridge Philosophical Society.

Using Copulas in the Estimation of the Economic Project Value in the Mining Industry, Including Geological Variability

Science.gov (United States)

Krysa, Zbigniew; Pactwa, Katarzyna; Wozniak, Justyna; Dudek, Michal

2017-12-01

Geological variability is one of the main factors that has an influence on the viability of mining investment projects and on the technical risk of geology projects. In the current scenario, analyses of economic viability of new extraction fields have been performed for the KGHM Polska Miedź S.A. underground copper mine at Fore Sudetic Monocline with the assumption of constant averaged content of useful elements. Research presented in this article is aimed at verifying the value of production from copper and silver ore for the same economic background with the use of variable cash flows resulting from the local variability of useful elements. Furthermore, the ore economic model is investigated for a significant difference in model value estimated with the use of linear correlation between useful elements content and the height of mine face, and the approach in which model parameters correlation is based upon the copula best matched information capacity criterion. The use of copula allows the simulation to take into account the multi variable dependencies at the same time, thereby giving a better reflection of the dependency structure, which linear correlation does not take into account. Calculation results of the economic model used for deposit value estimation indicate that the correlation between copper and silver estimated with the use of copula generates higher variation of possible project value, as compared to modelling correlation based upon linear correlation. Average deposit value remains unchanged.

Integrated petrophysical and reservoir characterization workflow to enhance permeability and water saturation prediction

Science.gov (United States)

Al-Amri, Meshal; Mahmoud, Mohamed; Elkatatny, Salaheldin; Al-Yousef, Hasan; Al-Ghamdi, Tariq

2017-07-01

Accurate estimation of permeability is essential in reservoir characterization and in determining fluid flow in porous media which greatly assists optimize the production of a field. Some of the permeability prediction techniques such as Porosity-Permeability transforms and recently artificial intelligence and neural networks are encouraging but still show moderate to good match to core data. This could be due to limitation to homogenous media while the knowledge about geology and heterogeneity is indirectly related or absent. The use of geological information from core description as in Lithofacies which includes digenetic information show a link to permeability when categorized into rock types exposed to similar depositional environment. The objective of this paper is to develop a robust combined workflow integrating geology and petrophysics and wireline logs in an extremely heterogeneous carbonate reservoir to accurately predict permeability. Permeability prediction is carried out using pattern recognition algorithm called multi-resolution graph-based clustering (MRGC). We will bench mark the prediction results with hard data from core and well test analysis. As a result, we showed how much better improvements are achieved in the permeability prediction when geology is integrated within the analysis. Finally, we use the predicted permeability as an input parameter in J-function and correct for uncertainties in saturation calculation produced by wireline logs using the classical Archie equation. Eventually, high level of confidence in hydrocarbon volumes estimation is reached when robust permeability and saturation height functions are estimated in presence of important geological details that are petrophysically meaningful.

Modelling carbon and nitrogen turnover in variably saturated soils

Science.gov (United States)

Batlle-Aguilar, J.; Brovelli, A.; Porporato, A.; Barry, D. A.

2009-04-01

Natural ecosystems provide services such as ameliorating the impacts of deleterious human activities on both surface and groundwater. For example, several studies have shown that a healthy riparian ecosystem can reduce the nutrient loading of agricultural wastewater, thus protecting the receiving surface water body. As a result, in order to develop better protection strategies and/or restore natural conditions, there is a growing interest in understanding ecosystem functioning, including feedbacks and nonlinearities. Biogeochemical transformations in soils are heavily influenced by microbial decomposition of soil organic matter. Carbon and nutrient cycles are in turn strongly sensitive to environmental conditions, and primarily to soil moisture and temperature. These two physical variables affect the reaction rates of almost all soil biogeochemical transformations, including microbial and fungal activity, nutrient uptake and release from plants, etc. Soil water saturation and temperature are not constants, but vary both in space and time, thus further complicating the picture. In order to interpret field experiments and elucidate the different mechanisms taking place, numerical tools are beneficial. In this work we developed a 3D numerical reactive-transport model as an aid in the investigation the complex physical, chemical and biological interactions occurring in soils. The new code couples the USGS models (MODFLOW 2000-VSF, MT3DMS and PHREEQC) using an operator-splitting algorithm, and is a further development an existing reactive/density-dependent flow model PHWAT. The model was tested using simplified test cases. Following verification, a process-based biogeochemical reaction network describing the turnover of carbon and nitrogen in soils was implemented. Using this tool, we investigated the coupled effect of moisture content and temperature fluctuations on nitrogen and organic matter cycling in the riparian zone, in order to help understand the relative

Site-Scale Saturated Zone Flow Model

International Nuclear Information System (INIS)

G. Zyvoloski

2003-01-01

The purpose of this model report is to document the components of the site-scale saturated-zone flow model at Yucca Mountain, Nevada, in accordance with administrative procedure (AP)-SIII.lOQ, ''Models''. This report provides validation and confidence in the flow model that was developed for site recommendation (SR) and will be used to provide flow fields in support of the Total Systems Performance Assessment (TSPA) for the License Application. The output from this report provides the flow model used in the ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The Site-Scale Saturated Zone Transport model then provides output to the SZ Transport Abstraction Model (BSC 2003 [164870]). In particular, the output from the SZ site-scale flow model is used to simulate the groundwater flow pathways and radionuclide transport to the accessible environment for use in the TSPA calculations. Since the development and calibration of the saturated-zone flow model, more data have been gathered for use in model validation and confidence building, including new water-level data from Nye County wells, single- and multiple-well hydraulic testing data, and new hydrochemistry data. In addition, a new hydrogeologic framework model (HFM), which incorporates Nye County wells lithology, also provides geologic data for corroboration and confidence in the flow model. The intended use of this work is to provide a flow model that generates flow fields to simulate radionuclide transport in saturated porous rock and alluvium under natural or forced gradient flow conditions. The flow model simulations are completed using the three-dimensional (3-D), finite-element, flow, heat, and transport computer code, FEHM Version (V) 2.20 (software tracking number (STN): 10086-2.20-00; LANL 2003 [161725]). Concurrently, process-level transport model and methodology for calculating radionuclide transport in the saturated zone at Yucca Mountain using FEHM V 2.20 are being

FLAME: A finite element computer code for contaminant transport n variably-saturated media

International Nuclear Information System (INIS)

Baca, R.G.; Magnuson, S.O.

1992-06-01

A numerical model was developed for use in performance assessment studies at the INEL. The numerical model referred to as the FLAME computer code, is designed to simulate subsurface contaminant transport in a variably-saturated media. The code can be applied to model two-dimensional contaminant transport in an and site vadose zone or in an unconfined aquifer. In addition, the code has the capability to describe transport processes in a porous media with discrete fractures. This report presents the following: description of the conceptual framework and mathematical theory, derivations of the finite element techniques and algorithms, computational examples that illustrate the capability of the code, and input instructions for the general use of the code. The development of the FLAME computer code is aimed at providing environmental scientists at the INEL with a predictive tool for the subsurface water pathway. This numerical model is expected to be widely used in performance assessments for: (1) the Remedial Investigation/Feasibility Study process and (2) compliance studies required by the US Department of energy Order 5820.2A

FLAME: A finite element computer code for contaminant transport n variably-saturated media

Energy Technology Data Exchange (ETDEWEB)

Baca, R.G.; Magnuson, S.O.

1992-06-01

A numerical model was developed for use in performance assessment studies at the INEL. The numerical model referred to as the FLAME computer code, is designed to simulate subsurface contaminant transport in a variably-saturated media. The code can be applied to model two-dimensional contaminant transport in an and site vadose zone or in an unconfined aquifer. In addition, the code has the capability to describe transport processes in a porous media with discrete fractures. This report presents the following: description of the conceptual framework and mathematical theory, derivations of the finite element techniques and algorithms, computational examples that illustrate the capability of the code, and input instructions for the general use of the code. The development of the FLAME computer code is aimed at providing environmental scientists at the INEL with a predictive tool for the subsurface water pathway. This numerical model is expected to be widely used in performance assessments for: (1) the Remedial Investigation/Feasibility Study process and (2) compliance studies required by the US Department of energy Order 5820.2A.

Primary drainage in geological fractures: Effects of aperture variability and wettability

Science.gov (United States)

Yang, Z.; Méheust, Y.; Neuweiler, I.

2017-12-01

Understanding and controlling fluid-fluid displacement in porous and fractured media is a key asset for many practical applications, such as the geological storage of CO2, hydrocarbon recovery, groundwater remediation, etc. We numerically investigate fluid-fluid displacement in rough-walled fractures with a focus on the combined effect of wettability, the viscous contrast between the two fluids, and fracture surface topography on drainage patterns and interface growth. A model has been developed to simulate the dynamic displacement of one fluid by another immiscible one in a rough geological fracture; the model takes both capillary and viscous forces into account. Capillary pressures at the fluid-fluid interface are calculated based on the Young-Laplace equation using the two principal curvatures (aperture-induced curvature and in-plane curvature) [1], while viscous forces are calculated by continuously solving the fluid pressure field in the fracture. The aperture field of a fracture is represented by a spatially correlated random field, with a power spectral density of the fracture wall topographies scaling as a power law, and a cutoff wave-length above which the Fourier modes of the two walls are identical [2]. We consider flow scenarios with both rectangular and radial configurations. Results show that the model is able to produce displacement patterns of compact displacement, capillary fingering, and viscous fingering, as well as the transitions between them. Both reducing the aperture variability and increasing the contact angle (from drainage to weak imbibition) can stabilize the displacement due to the influence of the in-plane curvature, an effect analogous to that of the cooperative pore filling in porous media. These results suggest that for geometries typical of geological fractures we can extend the phase diagram in the parameter space of capillary number and mobility ratio by another dimension to take into account the combined effect of wettability

Modeling geologic storage of carbon dioxide: Comparison of non-hysteretic and hysteretic characteristic curves

International Nuclear Information System (INIS)

Doughty, Christine

2007-01-01

Numerical models of geologic storage of carbon dioxide (CO 2 ) in brine-bearing formations use characteristic curves to represent the interactions of non-wetting-phase CO 2 and wetting-phase brine. When a problem includes both injection of CO 2 (a drainage process) and its subsequent post-injection evolution (a combination of drainage and wetting), hysteretic characteristic curves are required to correctly capture the behavior of the CO 2 plume. In the hysteretic formulation, capillary pressure and relative permeability depend not only on the current grid-block saturation, but also on the history of the saturation in the grid block. For a problem that involves only drainage or only wetting, a non-hysteretic formulation, in which capillary pressure and relative permeability depend only on the current value of the grid-block saturation, is adequate. For the hysteretic formulation to be robust computationally, care must be taken to ensure the differentiability of the characteristic curves both within and beyond the turning-point saturations where transitions between branches of the curves occur. Two example problems involving geologic CO 2 storage are simulated with TOUGH2, a multiphase, multicomponent code for flow and transport through geological media. Both non-hysteretic and hysteretic formulations are used, to illustrate the applicability and limitations of non-hysteretic methods. The first application considers leakage of CO 2 from the storage formation to the ground surface, while the second examines the role of heterogeneity within the storage formation

Steady State Entanglement and Saturation Effects in Correlated Spontaneous Emission Lasers

International Nuclear Information System (INIS)

Fei, Wang; Xiang-Ming, Hu; Wen-Xing, Shi

2009-01-01

It has recently been shown that correlated spontaneous emission lasers (CEL) exhibit transient entanglement in the linear regime. Here we re-examine the quantum correlations in two-photon CEL and explore the saturation effects on continuous variable entanglement. It is shown that the steady state entanglement is obtainable in the weak or moderate saturation regime, while is washed out in the deep saturation regime. (general)

Saturated Zone Flow and Transport Expert Elicitation Project

Energy Technology Data Exchange (ETDEWEB)

Coppersmith, Kevin J.; Perman, Roseanne C.

1998-01-01

This report presents results of the Saturated Zone Flow and Transport Expert Elicitation (SZEE) project for Yucca Mountain, Nevada. This project was sponsored by the US Department of Energy (DOE) and managed by Geomatrix Consultants, Inc. (Geomatrix), for TRW Environmental Safety Systems, Inc. The DOE's Yucca Mountain Site Characterization Project (referred to as the YMP) is intended to evaluate the suitability of the site for construction of a mined geologic repository for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The SZEE project is one of several that involve the elicitation of experts to characterize the knowledge and uncertainties regarding key inputs to the Yucca Mountain Total System Performance Assessment (TSPA). The objective of the current project was to characterize the uncertainties associated with certain key issues related to the saturated zone system in the Yucca Mountain area and downgradient region. An understanding of saturated zone processes is critical to evaluating the performance of the potential high-level nuclear waste repository at Yucca Mountain. A major goal of the project was to capture the uncertainties involved in assessing the saturated flow processes, including uncertainty in both the models used to represent the physical processes controlling saturated zone flow and transport, and the parameter values used in the models. So that the analysis included a wide range of perspectives, multiple individual judgments were elicited from members of an expert panel. The panel members, who were experts from within and outside the Yucca Mountain project, represented a range of experience and expertise. A deliberate process was followed in facilitating interactions among the experts, in training them to express their uncertainties, and in eliciting their interpretations. The resulting assessments and probability distributions, therefore, provide a reasonable aggregate representation of the knowledge and

Variably Saturated Flow and Multicomponent Biogeochemical Reactive Transport Modeling of a Uranium Bioremediation Field Experiment

International Nuclear Information System (INIS)

Yabusaki, Steven B.; Fang, Yilin; Williams, Kenneth H.; Murray, Christopher J.; Ward, Anderson L.; Dayvault, Richard; Waichler, Scott R.; Newcomer, Darrell R.; Spane, Frank A.; Long, Philip E.

2011-01-01

Field experiments at a former uranium mill tailings site have identified the potential for stimulating indigenous bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. This effectively removes uranium from solution resulting in groundwater concentrations below actionable standards. Three-dimensional, coupled variably-saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport rates and biogeochemical reaction rates that determine the location and magnitude of key reaction products. A comprehensive reaction network, developed largely through previous 1-D modeling studies, was used to simulate the impacts on uranium behavior of pulsed acetate amendment, seasonal water table variation, spatially-variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. A principal challenge is the mechanistic representation of biologically-mediated terminal electron acceptor process (TEAP) reactions whose products significantly alter geochemical controls on uranium mobility through increases in pH, alkalinity, exchangeable cations, and highly reactive reduction products. In general, these simulations of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado confirmed previously identified behaviors including (1) initial dominance by iron reducing bacteria that concomitantly reduce aqueous U(VI), (2) sulfate reducing bacteria that become dominant after ∼30 days and outcompete iron reducers for the acetate electron donor, (3) continuing iron-reducer activity and U(VI) bioreduction during dominantly sulfate reducing conditions, and (4) lower apparent U(VI) removal from groundwater during dominantly sulfate reducing conditions. New knowledge on simultaneously active metal and sulfate reducers has been

Vertical Variability in Saturated Zone Hydrochemistry Near Yucca Mountain, Nevada

International Nuclear Information System (INIS)

G. Patterson; P. Striffler

2007-01-01

The differences in the saturated zone hydrochemistry with depth at borehole NC-EWDP-22PC reflect the addition of recharge along Fortymile Wash. The differences in water chemistry with depth at borehole NC-EWDP-19PB appear to indicate that other processes are involved. Water from the lower part of NC-EWDP-19PB possesses chemical characteristics that clearly indicate that it has undergone cation exchange that resulted in the removal of calcium and magnesium and the addition of sodium. This water is very similar to water from the Western Yucca Mountain facies that has previously been thought to flow west of NC-EWDP-19PB. Water from the lower zone in NC-EWDP-19PB also could represent water from the Eastern Yucca Mountain facies that has moved through clay-bearing or zeolitized aquifer material resulting in the altered chemistry. Water chemistry from the upper part of the saturated zone at NC-EWDP-19PB, both zones at NC-EWDP-22PC, and wells in the Fortymile Wash facies appears to be the result of recharge through the alluvium south of Yucca Mountain and within the Fortymile Wash channel

Law of nonlinear flow in saturated clays and radial consolidation

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

It was derived that micro-scale amount level of average pore radius of clay changed from 0.01 to 0.1 micron by an equivalent concept of flow in porous media. There is good agreement between the derived results and test ones. Results of experiments show that flow in micro-scale pore of saturated clays follows law of nonlinear flow. Theoretical analyses demonstrate that an interaction of solid-liquid interfaces varies inversely with permeability or porous radius. The interaction is an important reason why nonlinear flow in saturated clays occurs. An exact mathematical model was presented for nonlinear flow in micro-scale pore of saturated clays. Dimension and physical meanings of parameters of it are definite. A new law of nonlinear flow in saturated clays was established. It can describe characteristics of flow curve of the whole process of the nonlinear flow from low hydraulic gradient to high one. Darcy law is a special case of the new law. A mathematical model was presented for consolidation of nonlinear flow in radius direction in saturated clays with constant rate based on the new law of nonlinear flow. Equations of average mass conservation and moving boundary, and formula of excess pore pressure distribution and average degree of consolidation for nonlinear flow in saturated clay were derived by using an idea of viscous boundary layer, a method of steady state in stead of transient state and a method of integral of an equation. Laws of excess pore pressure distribution and changes of average degree of consolidation with time were obtained. Results show that velocity of moving boundary decreases because of the nonlinear flow in saturated clay. The results can provide geology engineering and geotechnical engineering of saturated clay with new scientific bases. Calculations of average degree of consolidation of the Darcy flow are a special case of that of the nonlinear flow.

A coupled approach for the three-dimensional simulation of pipe leakage in variably saturated soil

Science.gov (United States)

Peche, Aaron; Graf, Thomas; Fuchs, Lothar; Neuweiler, Insa

2017-12-01

In urban water pipe networks, pipe leakage may lead to subsurface contamination or to reduced waste water treatment efficiency. The quantification of pipe leakage is challenging due to inaccessibility and unknown hydraulic properties of the soil. A novel physically-based model for three-dimensional numerical simulation of pipe leakage in variably saturated soil is presented. We describe the newly implemented coupling between the pipe flow simulator HYSTEM-EXTRAN and the groundwater flow simulator OpenGeoSys and its validation. We further describe a novel upscaling of leakage using transfer functions derived from numerical simulations. This upscaling enables the simulation of numerous pipe defects with the benefit of reduced computation times. Finally, we investigate the response of leakage to different time-dependent pipe flow events and conclude that larger pipe flow volume and duration lead to larger leakage while the peak position in time has a small effect on leakage.

Evaluation of geologic and geophysical techniques for surface-to-subsurface projections of geologic characteristics in crystalline rock

International Nuclear Information System (INIS)

1985-07-01

Granitic and gneissic rock complexes are being considered for their potential to contain and permanently isolate high-level nuclear waste in a deep geologic repository. The use of surface geologic and geophysical techniques has several advantages over drilling and testing methods for geologic site characterization in that the techniques are typically less costly, provide data over a wider area, and do not jeopardize the physical integrity of a potential repository. For this reason, an extensive literature review was conducted to identify appropriate surface geologic and geophysical techniques that can be used to characterize geologic conditions in crystalline rock at proposed repository depths of 460 to 1,220 m. Characterization parameters such as rock quality; fracture orientation, spacing; and aperture; depths to anomalies; degree of saturation; rock body dimensions; and petrology are considered to be of primary importance. Techniques reviewed include remote sensing, geologic mapping, petrographic analysis, structural analysis, gravity and magnetic methods, electrical methods, and seismic methods. Each technique was reviewed with regard to its theoretical basis and field application; geologic parameters that can be evaluated; advantages and limitations, and, where available, case history applications in crystalline rock. Available information indicates that individual techniques provide reliable information on characteristics at the surface, but have limited success in projections to depths greater that approximately 100 m. A combination of integrated techniques combines with data from a limited number of boreholes would significantly improve the reliability and confidence of early characterization studies to provide qualitative rock body characteristics for region-to-area and area-to-site selection evaluations. 458 refs., 32 figs., 14 tabs

A Partially Saturated Constitutive Theory for Compacted Fills

National Research Council Canada - National Science Library

Berney, Ernest

2004-01-01

... variables present within the soil. From a thermodynamic viewpoint, a partially saturated soil can be best described by the free energy associated with each component of the soil and water mixture...

Notes on HP1 a software package for simulating variably-saturated water flow, heat transport, solute transport, and biogeochemistry in porous media. HP1 Version 2.2

Energy Technology Data Exchange (ETDEWEB)

Jacques, D.; Simunek, J.

2010-01-15

HP1 is a comprehensive modeling tool in terms of processes and reactions for simulating reactive transport and biogeochemical processes in variably-saturated porous media. HP1 results from coupling the water and solute transport model HYDRUS-1D (Simunek et al., 2009a) and PHREEQC-2 (Parkhurst and Appelo, 1999). This note provides an overview of how to set up and execute a HP1 project using version 2.2.002 of HP1 and version 4.13 of the graphical user interface (GUI) of HYDRUS-1D. A large part of this note are step-by-step instructions for selected examples involving mineral dissolution and precipitation, cation exchange, surface complexation and kinetic degradation networks. The implementation of variably-saturated flow conditions, changing boundary conditions, a layered soil profile or immobile water is also illustrated.

Notes on HP1 a software package for simulating variably-saturated water flow, heat transport, solute transport, and biogeochemistry in porous media. HP1 Version 2.2

International Nuclear Information System (INIS)

Jacques, D.; Simunek, J.

2010-01-01

HP1 is a comprehensive modeling tool in terms of processes and reactions for simulating reactive transport and biogeochemical processes in variably-saturated porous media. HP1 results from coupling the water and solute transport model HYDRUS-1D (Simunek et al., 2009a) and PHREEQC-2 (Parkhurst and Appelo, 1999). This note provides an overview of how to set up and execute a HP1 project using version 2.2.002 of HP1 and version 4.13 of the graphical user interface (GUI) of HYDRUS-1D. A large part of this note are step-by-step instructions for selected examples involving mineral dissolution and precipitation, cation exchange, surface complexation and kinetic degradation networks. The implementation of variably-saturated flow conditions, changing boundary conditions, a layered soil profile or immobile water is also illustrated.

Saturation behavior: a general relationship described by a simple second-order differential equation.

Science.gov (United States)

Kepner, Gordon R

2010-04-13

The numerous natural phenomena that exhibit saturation behavior, e.g., ligand binding and enzyme kinetics, have been approached, to date, via empirical and particular analyses. This paper presents a mechanism-free, and assumption-free, second-order differential equation, designed only to describe a typical relationship between the variables governing these phenomena. It develops a mathematical model for this relation, based solely on the analysis of the typical experimental data plot and its saturation characteristics. Its utility complements the traditional empirical approaches. For the general saturation curve, described in terms of its independent (x) and dependent (y) variables, a second-order differential equation is obtained that applies to any saturation phenomena. It shows that the driving factor for the basic saturation behavior is the probability of the interactive site being free, which is described quantitatively. Solving the equation relates the variables in terms of the two empirical constants common to all these phenomena, the initial slope of the data plot and the limiting value at saturation. A first-order differential equation for the slope emerged that led to the concept of the effective binding rate at the active site and its dependence on the calculable probability the interactive site is free. These results are illustrated using specific cases, including ligand binding and enzyme kinetics. This leads to a revised understanding of how to interpret the empirical constants, in terms of the variables pertinent to the phenomenon under study. The second-order differential equation revealed the basic underlying relations that describe these saturation phenomena, and the basic mathematical properties of the standard experimental data plot. It was shown how to integrate this differential equation, and define the common basic properties of these phenomena. The results regarding the importance of the slope and the new perspectives on the empirical

The use of synthetic colloids in tracer transport experiments in saturated rock fractures

International Nuclear Information System (INIS)

Reimus, P.W.

1995-08-01

Studies of groundwater flow and contaminant transport in saturated, fractured geologic media are of great interest to researchers studying the potential long-term storage of hazardous wastes in or near such media. A popular technique for conducting such studies is to introduce tracers having different chemical and physical properties into a system and then observe the tracers at one or more downstream locations, inferring flow and transport mechanisms from the breakthrough characteristics of the different tracers. Many tracer studies have been conducted in saturated, fractured media to help develop and/or refine models capable of predicting contaminant transport over large scales in such media

Spatial variability in alluvium properties at a low-level nuclear waste site

International Nuclear Information System (INIS)

Istok, J.D.; Blout, D.O.; Barker, L.; Johnejack, K.R.; Hammermeister, D.P.

1994-01-01

Geological and statistical models for the spatial variability of soil properties are needed to predict field-scale water flow and solute transport but only limited information is currently available on unsaturated soils below the root zone. Spatial variability of selected physical and hydrologic properties was quantified for fine- and coarse-grained alluvial deposits at a low-level nuclear waste disposal site on the Nevada Test Site. Gravimetric water content (w), bulk density (ρ b ), saturated hydraulic conductivity (K a ), and particle-size distribution were determined for vertical and horizontal core specimens and bulk samples collected from 183-m-long horizontal transects in two existing waste disposal trenches located on a single alluvial fan. The transects were approximately aligned parallel and perpendicular to the principal direction of sediment transport. Properties were modeled as either normally or lognormally distributed random variables. Sample coefficients of variation were smallest for ρ b and largest for log(K a ); a weak correlation was identified between log(K a ) and the grain-size parameter d 10 . Particle-size distributions for the fine- and coarse-grained materials were different and significant differences in the natural logarithm of saturated hydraulic conductivity, log(K a ), existed between coarse and fine layers in an excavation aligned with the principal direction of alluvium deposition but not in a perpendicular direction. 37 refs., 7 figs., 11 tabs

Spatiotemporal predictions of soil properties and states in variably saturated landscapes

Science.gov (United States)

Franz, Trenton E.; Loecke, Terrance D.; Burgin, Amy J.; Zhou, Yuzhen; Le, Tri; Moscicki, David

2017-07-01

Understanding greenhouse gas (GHG) fluxes from landscapes with variably saturated soil conditions is challenging given the highly dynamic nature of GHG fluxes in both space and time, dubbed hot spots, and hot moments. On one hand, our ability to directly monitor these processes is limited by sparse in situ and surface chamber observational networks. On the other hand, remote sensing approaches provide spatial data sets but are limited by infrequent imaging over time. We use a robust statistical framework to merge sparse sensor network observations with reconnaissance style hydrogeophysical mapping at a well-characterized site in Ohio. We find that combining time-lapse electromagnetic induction surveys with empirical orthogonal functions provides additional environmental covariates related to soil properties and states at high spatial resolutions ( 5 m). A cross-validation experiment using eight different spatial interpolation methods versus 120 in situ soil cores indicated an 30% reduction in root-mean-square error for soil properties (clay weight percent and total soil carbon weight percent) using hydrogeophysical derived environmental covariates with regression kriging. In addition, the hydrogeophysical derived environmental covariates were found to be good predictors of soil states (soil temperature, soil water content, and soil oxygen). The presented framework allows for temporal gap filling of individual sensor data sets as well as provides flexible geometric interpolation to complex areas/volumes. We anticipate that the framework, with its flexible temporal and spatial monitoring options, will be useful in designing future monitoring networks as well as support the next generation of hyper-resolution hydrologic and biogeochemical models.

Simulation of consolidation in partially saturated soil materials

International Nuclear Information System (INIS)

Narasimhan, T.N.

1982-03-01

Partially saturated soil materials undergo consolidation, heave, collapse and failure due to changes in pore fluid pressure. The precise nature of the mechanics of such deformations is only poorly understood at present. Experimental evidence has shown that the volume change behavior of unsaturated soils cannot be adequately explained through changes in effective stress, even when a saturation dependent parameter is incorporated into the definition of effective stress. Two independent stress-state variables, involving combinations of total stress, pore air pressure and pore water pressure, are required to characterize volume changes and saturation changes in the partially saturated state. In general, two coupled conservation equations, one for the water-phase and the other for the air-phase need to be solved in order to predict the deformation behavior of unsaturated soils. If directional displacements and changes in the stress-field are required, then the conservation equations are to be integrated with an additional set of multi-dimensional force balance equations. For lack of a sufficient understanding of elastic constants such as Poisson's Ratio and Lame's constants as applied to unsaturated soils, little has been achieved so far in integrating the conservation equations and the force balance equations. For the long-term modeling of consolidation with respect to uranium mill tailings, it may be acceptable and economical to solve a single conservation equation for water, assuming that the air-phase is continuous and is at atmospheric pressure everywhere in the soil. The greatest challenge to modeling consolidation in the unsaturated zone at the presnt time is to develop enough experimental data defining the variation of void ratio and saturation with reference to the two chosen stress-state variables

Evaluating Variability and Uncertainty of Geological Strength Index at a Specific Site

Science.gov (United States)

Wang, Yu; Aladejare, Adeyemi Emman

2016-09-01

Geological Strength Index (GSI) is an important parameter for estimating rock mass properties. GSI can be estimated from quantitative GSI chart, as an alternative to the direct observational method which requires vast geological experience of rock. GSI chart was developed from past observations and engineering experience, with either empiricism or some theoretical simplifications. The GSI chart thereby contains model uncertainty which arises from its development. The presence of such model uncertainty affects the GSI estimated from GSI chart at a specific site; it is, therefore, imperative to quantify and incorporate the model uncertainty during GSI estimation from the GSI chart. A major challenge for quantifying the GSI chart model uncertainty is a lack of the original datasets that have been used to develop the GSI chart, since the GSI chart was developed from past experience without referring to specific datasets. This paper intends to tackle this problem by developing a Bayesian approach for quantifying the model uncertainty in GSI chart when using it to estimate GSI at a specific site. The model uncertainty in the GSI chart and the inherent spatial variability in GSI are modeled explicitly in the Bayesian approach. The Bayesian approach generates equivalent samples of GSI from the integrated knowledge of GSI chart, prior knowledge and observation data available from site investigation. Equations are derived for the Bayesian approach, and the proposed approach is illustrated using data from a drill and blast tunnel project. The proposed approach effectively tackles the problem of how to quantify the model uncertainty that arises from using GSI chart for characterization of site-specific GSI in a transparent manner.

The effect of rock electrical parameters on the calculation of reservoir saturation

International Nuclear Information System (INIS)

Li, Xiongyan; Qin, Ruibao; Liu, Chuncheng; Mao, Zhiqiang

2013-01-01

The error in calculating a reservoir saturation caused by the error in the cementation exponent, m, and the saturation exponent, n, should be analysed. In addition, the influence of m and n on the reservoir saturation should be discussed. Based on the Archie formula, the effect of variables m and n on the reservoir saturation is analysed, while the formula for the error in calculating the reservoir saturation, caused by the error in m and n, is deduced, and the main factors affecting the error in reservoir saturation are illustrated. According to the physical meaning of m and n, it can be interpreted that they are two independent parameters, i.e., there is no connection between m and n. When m and n have the same error, the impact of the variables on the calculation of the reservoir saturation should be compared. Therefore, when the errors of m and n are respectively equal to 0.2, 0.4 and 0.6, the distribution range of the errors in calculating the reservoir saturation is analysed. However, in most cases, the error of m and n is about 0.2. When the error of m is 0.2, the error in calculating the reservoir saturation ranges from 0% to 35%. Meanwhile, when the error in n is 0.2, the error in calculating the reservoir saturation is almost always below 5%. On the basis of loose sandstone, medium sandstone, tight sandstone, conglomerate, tuff, breccia, basalt, andesite, dacite and rhyolite, this paper first analyses the distribution range and change amplitude of m and n. Second, the impact of m and n on the calculation of reservoir saturation is elaborated upon. With regard to each lithology, the distribution range and change amplitude of m are greater than those of n. Therefore, compared with n, the effect of m on the reservoir saturation is stronger. The influence of m and n on the reservoir saturation is determined, and the error in calculating the reservoir saturation caused by the error of m and n is calculated. This is theoretically and practically significant for

Time-response shaping using output to input saturation transformation

Science.gov (United States)

Chambon, E.; Burlion, L.; Apkarian, P.

2018-03-01

For linear systems, the control law design is often performed so that the resulting closed loop meets specific frequency-domain requirements. However, in many cases, it may be observed that the obtained controller does not enforce time-domain requirements amongst which the objective of keeping a scalar output variable in a given interval. In this article, a transformation is proposed to convert prescribed bounds on an output variable into time-varying saturations on the synthesised linear scalar control law. This transformation uses some well-chosen time-varying coefficients so that the resulting time-varying saturation bounds do not overlap in the presence of disturbances. Using an anti-windup approach, it is obtained that the origin of the resulting closed loop is globally asymptotically stable and that the constrained output variable satisfies the time-domain constraints in the presence of an unknown finite-energy-bounded disturbance. An application to a linear ball and beam model is presented.

Preliminary discussion on the application of the geological conceptual model method of uranium ore formation

International Nuclear Information System (INIS)

Ma Guangzhong; Wei Mingji; Luo Yiyue

1992-01-01

The geological conceptual model method of uranium ore formation is established on the basis of geological theory and apriorism. Variables are screened with the application of the method of mathematical geology to find out the variables which are more contributed. In combination with the practical situation in Xikang-Yunnan axis, the variables are compiled and graded so as to determine the optimal ore-controlling factor and to establish the statistical predictive model which is of geological significance. The resources evaluation work has been conducted in the Late Proterozoic geological terrain in Xikang-Yunnan axis

Transport properties and pore-network structure in variably-saturated Sphagnum peat soil

DEFF Research Database (Denmark)

Hamamoto, Shoichiro; Dissanayaka, Shiromi Himalika; Kawamoto, K.

2016-01-01

Gas and water transport in peat soil are of increasing interest because of their potentially large environmental and climatic effects under different types of land use. In this research, the water retention curve (WRC), gas diffusion coefficient (Dg) and air and water permeabilities (ka and kw......) of layers in peat soil from two profiles were measured under different moisture conditions. A two-region Archie's Law (2RAL)-type model was applied successfully to the four properties; the reference point was taken at -9.8kPa of soil-water matric potential where volume shrinkage typically started to occur....... For WRC in the very decomposed peat soil, the 2RAL saturation exponents (n) obtained for both the wetter (nw) and drier regions (nd) were smaller than those for the less decomposed peat. For Dg, the saturation exponent in the wetter region was larger than that in the drier one for all layers, which...

Constraining local 3-D models of the saturated-zone, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Barr, G.E.; Shannon, S.A.

1994-01-01

A qualitative three-dimensional analysis of the saturated zone flow system was performed for a 8 km x 8 km region including the potential Yucca Mountain repository site. Certain recognized geologic features of unknown hydraulic properties were introduced to assess the general response of the flow field to these features. Two of these features, the Solitario Canyon fault and the proposed fault in Drill Hole Wash, appear to constrain flow and allow calibration

Fluid dynamics and mass transfer in variably saturated porous media: formulation and applications of a mathematical model

International Nuclear Information System (INIS)

Sharma, D.

1982-01-01

This paper presents the formulation and applications of a mathematical model designed to predict the fluid dynamics and associated mass transfers in variably saturated porous media. Novelties in the formulation are emphasized and demonstrated to provide several computational advantages. The numerical procedure employed is of the integrated finite-difference variety which employs a hybrid differencing scheme. This procedure, while solving the coupled governing equations in conservative form, permits accommodation of substantial heterogeneities and anisotropies in material properties of the porous media. Accordingly, it is capable of making reliable predictions of steeply varying moisture and chemical-specie concentration fronts. The paper provides several examples of application of the model to the solution of practical problems. It is demonstrated that economical solutions to highly non-linear problems associated with solid and liquid waste disposal practices can be obtained

Transport and Deposition of Variably Charged Soil Colloids in Saturated Porous Media

DEFF Research Database (Denmark)

Sharma, Anu; Kawamoto, Ken; Møldrup, Per

2011-01-01

Okinawa (RYS colloids) in Japan. The VAS colloids exhibited a negative surface charge with a high pH dependency, whereas the RYS colloids exhibited a negative surface charge with less pH dependency. The soil colloids were applied as colloidal suspensions to 10-cm-long saturated sand columns packed...

Pore-scale studies of multiphase flow and reaction involving CO2 sequestration in geologic formations

Science.gov (United States)

Kang, Q.; Wang, M.; Lichtner, P. C.

2008-12-01

In geologic CO2 sequestration, pore-scale interfacial phenomena ultimately govern the key processes of fluid mobility, chemical transport, adsorption, and reaction. However, spatial heterogeneity at the pore scale cannot be resolved at the continuum scale, where averaging occurs over length scales much larger than typical pore sizes. Natural porous media, such as sedimentary rocks and other geological media encountered in subsurface formations, are inherently heterogeneous. This pore-scale heterogeneity can produce variabilities in flow, transport, and reaction processes that take place within a porous medium, and can result in spatial variations in fluid velocity, aqueous concentrations, and reaction rates. Consequently, the unresolved spatial heterogeneity at the pore scale may be important for reactive transport modeling at the larger scale. In addition, current continuum models of surface complexation reactions ignore a fundamental property of physical systems, namely conservation of charge. Therefore, to better understand multiphase flow and reaction involving CO2 sequestration in geologic formations, it is necessary to quantitatively investigate the influence of the pore-scale heterogeneity on the emergent behavior at the field scale. We have applied the lattice Boltzmann method to simulating the injection of CO2 saturated brine or supercritical CO2 into geological formations at the pore scale. Multiple pore-scale processes, including advection, diffusion, homogeneous reactions among multiple aqueous species, heterogeneous reactions between the aqueous solution and minerals, ion exchange and surface complexation, as well as changes in solid and pore geometry are all taken into account. The rich pore scale information will provide a basis for upscaling to the continuum scale.

SIMULATION FRAMEWORK FOR REGIONAL GEOLOGIC CO{sub 2} STORAGE ALONG ARCHES PROVINCE OF MIDWESTERN UNITED STATES

Energy Technology Data Exchange (ETDEWEB)

Sminchak, Joel

2012-09-30

This report presents final technical results for the project Simulation Framework for Regional Geologic CO{sub 2} Storage Infrastructure along Arches Province of the Midwest United States. The Arches Simulation project was a three year effort designed to develop a simulation framework for regional geologic carbon dioxide (CO{sub 2}) storage infrastructure along the Arches Province through development of a geologic model and advanced reservoir simulations of large-scale CO{sub 2} storage. The project included five major technical tasks: (1) compilation of geologic, hydraulic and injection data on Mount Simon, (2) development of model framework and parameters, (3) preliminary variable density flow simulations, (4) multi-phase model runs of regional storage scenarios, and (5) implications for regional storage feasibility. The Arches Province is an informal region in northeastern Indiana, northern Kentucky, western Ohio, and southern Michigan where sedimentary rock formations form broad arch and platform structures. In the province, the Mount Simon sandstone is an appealing deep saline formation for CO{sub 2} storage because of the intersection of reservoir thickness and permeability. Many CO{sub 2} sources are located in proximity to the Arches Province, and the area is adjacent to coal fired power plants along the Ohio River Valley corridor. Geophysical well logs, rock samples, drilling logs, and geotechnical tests were evaluated for a 500,000 km{sup 2} study area centered on the Arches Province. Hydraulic parameters and historical operational information was also compiled from Mount Simon wastewater injection wells in the region. This information was integrated into a geocellular model that depicts the parameters and conditions in a numerical array. The geologic and hydraulic data were integrated into a three-dimensional grid of porosity and permeability, which are key parameters regarding fluid flow and pressure buildup due to CO{sub 2} injection. Permeability data

Migrations of 60-Co and 137-Cs in Saturated and unsaturated Soil at Serpong Nuclear Research Center

International Nuclear Information System (INIS)

Lubis, E; Untara

1996-01-01

The migrations of 60-Co and 137-Cs in saturated and unsaturated soil at Serpong Nuclear Research Center was investigated. The objectives of this investigation are to find the geological and hydrological parameters, especially for estimating the migrations of radionuclides in porous media with advection-dispersion equations. The result showed that the porosity (η) and density (ρ ) of saturated soil are 27.6% and 1.35 g/cm3, and in the unsaturated soil are 18.9% and 1.41 g/cm3. The coefficients distributions (Kd) of 60-Co and 137-Cs in saturated and unsaturated soil are 1.6 - 8.9 and 3.2 - 7.7 respectively. The hydrodinamic coefficients (Dx) and dispersivity (αx) of C0-60 in saturated and unsaturated soil are 0.85 cm2/second and 2.4 x 10-3 cm, and for 137-Cs are 0.91 cm2/second and 2.54 x 10E3 cm

Lawrence Livermore Laboratory Nuclear Test Effects and Geologic Data Bank

International Nuclear Information System (INIS)

Howard, N.W.

1976-01-01

Data on the geology of the USERDA Nevada Test Site have been collected for the purpose of evaluating the possibility of release of radioactivity at proposed underground nuclear test sites. These data, including both the rock physical properties and the geologic structure and stratigraphy of a large number of drill-hole sites, are stored in the Lawrence Livermore Laboratory Earth Sciences Division Nuclear Test Effects and Geologic Data Bank. Retrieval programs can quickly provide a geological and geophysical comparison of a particular site with other sites where radioactivity was successfully contained. The data can be automatically sorted, compared, and averaged, and information listed according to site location, drill-hole construction, rock units, depth to key horizons and to the water table, and distance to faults. These programs also make possible ordered listings of geophysical properties (interval bulk density, overburden density, interval velocity, velocity to the surface, grain density, water content, carbonate content, porosity, and saturation of the rocks). The characteristics and capabilities of the data bank are discussed

Evaluation of stress and saturation effects on seismic velocity and electrical resistivity - laboratory testing of rock samples

Science.gov (United States)

Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav

2016-04-01

Repository, located in a deep geological formation, is today considered the most suitable solution for disposal of spent nuclear fuel and high-level waste. The geological formations, in combination with an engineered barrier system, should ensure isolation of the waste from the environment for thousands of years. For long-term monitoring of such underground excavations special monitoring systems are developed. In our research we developed and tested monitoring system based on repeated ultrasonic time of flight measurement and electrical resistivity tomography (ERT). As a test site Bedřichov gallery in the northern Bohemia was selected. This underground gallery in granitic rock was excavated using Tunnel Boring Machine (TBM). The seismic high-frequency measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The ERT measurement is performed also on the rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. An analysis of relation of seismic velocity and electrical resistivity on water saturation and stress state of the granitic rock is necessary for the interpretation of both seismic monitoring and ERT. Laboratory seismic and resistivity measurements were performed. One series of experiments was based on uniaxial loading of dry and saturated granitic samples. The relation between stress state and ultrasonic wave velocities was tested separately for dry and saturated rock samples. Other experiments were focused on the relation between electrical resistivity of the rock sample and its saturation level. Rock samples with different porosities were tested. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA 0302408

Input-output linearizing tracking control of induction machine with the included magnetic saturation

DEFF Research Database (Denmark)

Dolinar, Drago; Ljusev, Petar; Stumberger, Gorazd

2003-01-01

The tracking control design of an induction motor, based on input-output linearisation with magnetic saturation included is addressed. The magnetic saturation is represented by a nonlinear magnetising curve for the iron core and is used in the control, the observer of the state variables......, and in the load torque estimator. An input-output linearising control is used to achieve better tracking performances. It is based on the mixed 'stator current - rotor flux linkage' induction motor model with magnetic saturation considered in the stationary reference frame. Experimental results show...... that the proposed input-output linearising tracking control with saturation included behaves considerably better than the one without saturation, and that it introduces smaller position and speed errors, and better motor stiffness on account of the increased computational complexity....

Molybdenite saturation in silicic magmas: Occurrence and petrological implications

Science.gov (United States)

Audetat, A.; Dolejs, D.; Lowenstern, J. B.

2011-01-01

We identified molybdenite (MoS2) as an accessory magmatic phase in 13 out of 27 felsic magma systems examined worldwide. The molybdenite occurs as small (molybdenite-saturated samples reveal 1-13 ppm Mo in the melt and geochemical signatures that imply a strong link to continental rift basalt-rhyolite associations. In contrast, arc-associated rhyolites are rarely molybdenite-saturated, despite similar Mo concentrations. This systematic dependence on tectonic setting seems to reflect the higher oxidation state of arc magmas compared with within-plate magmas. A thermodynamic model devised to investigate the effects of T, f O2 and f S2 on molybdenite solubility reliably predicts measured Mo concentrations in molybdenite-saturated samples if the magmas are assumed to have been saturated also in pyrrhotite. Whereas pyrrhotite microphenocrysts have been observed in some of these samples, they have not been observed from other molybdenite-bearing magmas. Based on the strong influence of f S2 on molybdenite solubility we calculate that also these latter magmas must have been at (or very close to) pyrrhotite saturation. In this case the Mo concentration of molybdenite-saturated melts can be used to constrain both magmatic f O2 and f S2 if temperature is known independently (e.g. by zircon saturation thermometry). Our model thus permits evaluation of magmatic f S2, which is an important variable but is difficult to estimate otherwise, particularly in slowly cooled rocks. ?? The Author 2011. Published by Oxford University Press. All rights reserved.

Saturated Switching Systems

CERN Document Server

Benzaouia, Abdellah

2012-01-01

Saturated Switching Systems treats the problem of actuator saturation, inherent in all dynamical systems by using two approaches: positive invariance in which the controller is designed to work within a region of non-saturating linear behaviour; and saturation technique which allows saturation but guarantees asymptotic stability. The results obtained are extended from the linear systems in which they were first developed to switching systems with uncertainties, 2D switching systems, switching systems with Markovian jumping and switching systems of the Takagi-Sugeno type. The text represents a thoroughly referenced distillation of results obtained in this field during the last decade. The selected tool for analysis and design of stabilizing controllers is based on multiple Lyapunov functions and linear matrix inequalities. All the results are illustrated with numerical examples and figures many of them being modelled using MATLAB®. Saturated Switching Systems will be of interest to academic researchers in con...

Differential equations governing slip-induced pore-pressure fluctuations in a water-saturated granular medium

Science.gov (United States)

Iverson, R.M.

1993-01-01

Macroscopic frictional slip in water-saturated granular media occurs commonly during landsliding, surface faulting, and intense bedload transport. A mathematical model of dynamic pore-pressure fluctuations that accompany and influence such sliding is derived here by both inductive and deductive methods. The inductive derivation shows how the governing differential equations represent the physics of the steadily sliding array of cylindrical fiberglass rods investigated experimentally by Iverson and LaHusen (1989). The deductive derivation shows how the same equations result from a novel application of Biot's (1956) dynamic mixture theory to macroscopic deformation. The model consists of two linear differential equations and five initial and boundary conditions that govern solid displacements and pore-water pressures. Solid displacements and water pressures are strongly coupled, in part through a boundary condition that ensures mass conservation during irreversible pore deformation that occurs along the bumpy slip surface. Feedback between this deformation and the pore-pressure field may yield complex system responses. The dual derivations of the model help explicate key assumptions. For example, the model requires that the dimensionless parameter B, defined here through normalization of Biot's equations, is much larger than one. This indicates that solid-fluid coupling forces are dominated by viscous rather than inertial effects. A tabulation of physical and kinematic variables for the rod-array experiments of Iverson and LaHusen and for various geologic phenomena shows that the model assumptions commonly are satisfied. A subsequent paper will describe model tests against experimental data. ?? 1993 International Association for Mathematical Geology.

Southeastern Regional Geologic Characterization Report. Executive summary. Final report

International Nuclear Information System (INIS)

1985-08-01

This Executive Summary of the final Southeastern Regional Geologic Characterization Report (RGCR) is issued primarily for public information purposes, and provides a general overview of the report. The complete RGCR presents available regional geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in central Maryland; noncoastal Virginia, North Carolina, and South Carolina; and northern Georgia. For each of the states within the Southeastern Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening

Reactive transport modeling in variably saturated porous media with OGS-IPhreeqc

Science.gov (United States)

He, W.; Beyer, C.; Fleckenstein, J. H.; Jang, E.; Kalbacher, T.; Shao, H.; Wang, W.; Kolditz, O.

2014-12-01

Worldwide, sustainable water resource management becomes an increasingly challenging task due to the growth of population and extensive applications of fertilizer in agriculture. Moreover, climate change causes further stresses to both water quantity and quality. Reactive transport modeling in the coupled soil-aquifer system is a viable approach to assess the impacts of different land use and groundwater exploitation scenarios on the water resources. However, the application of this approach is usually limited in spatial scale and to simplified geochemical systems due to the huge computational expense involved. Such computational expense is not only caused by solving the high non-linearity of the initial boundary value problems of water flow in the unsaturated zone numerically with rather fine spatial and temporal discretization for the correct mass balance and numerical stability, but also by the intensive computational task of quantifying geochemical reactions. In the present study, a flexible and efficient tool for large scale reactive transport modeling in variably saturated porous media and its applications are presented. The open source scientific software OpenGeoSys (OGS) is coupled with the IPhreeqc module of the geochemical solver PHREEQC. The new coupling approach makes full use of advantages from both codes: OGS provides a flexible choice of different numerical approaches for simulation of water flow in the vadose zone such as the pressure-based or mixed forms of Richards equation; whereas the IPhreeqc module leads to a simplification of data storage and its communication with OGS, which greatly facilitates the coupling and code updating. Moreover, a parallelization scheme with MPI (Message Passing Interface) is applied, in which the computational task of water flow and mass transport is partitioned through domain decomposition, whereas the efficient parallelization of geochemical reactions is achieved by smart allocation of computational workload over

The geological basis and the representation of spatial variability in sedimentary heterogeneous media

International Nuclear Information System (INIS)

Cliffe, K.A.; Franklin, D.J.; Jones, P.I.R.; Macleod, E.J.; Porter, J.D.

1998-01-01

The impact of different conceptual models was investigated of the heterogeneity of the Sherwood Sandstone Group (SSG) at Sellafield on calculations of flow and transport. Detailed models of the heterogeneity of the Undifferentiated St Bees Sandstone (USBS) of the SSG were produced. The models took into account directly the geological structures at the facies level. The software package STORM (STOchastic Reservoir Modelling), was used to construct the models. The data required by the model are those that characterise the geometry of the channel bodies and the properties of the various sub-facies within the channels. It was found that for the case in which all of the variability was within channels, the larger scale permeabilities did not exhibit any significant correlation structure. The up-scaled effective permeabilities also exhibited correlation lengths that were comparable with the channel dimensions. Flow and transport calculations were also performed on 90 realizations of a detailed facies scale three-dimensional representation of a larger block of the USBS. The results are broadly consistent with the analytical results for transport through a random permeability field. (R.P.)

Studies of non-isothermal flow in saturated and partially saturated porous media

International Nuclear Information System (INIS)

Ho, C.K.; Maki, K.S.; Glass, R.J.

1993-01-01

Physical and numerical experiments have been performed to investigate the behavior of nonisothermal flow in two-dimensional saturated and partially saturated porous media. The physical experiments were performed to identify non-isothermal flow fields and temperature distributions in fully saturated, half-saturated, and residually saturated two-dimensional porous media with bottom heating and top cooling. Two counter-rotating liquid-phase convective cells were observed to develop in the saturated regions of all three cases. Gas-phase convection was also evidenced in the unsaturated regions of the partially saturated experiments. TOUGH2 numerical simulations of the saturated case were found to be strongly dependent on the assumed boundary conditions of the physical system. Models including heat losses through the boundaries of the test cell produced temperature and flow fields that were in better agreement with the observed temperature and flow fields than models that assumed insulated boundary conditions. A sensitivity analysis also showed that a reduction of the bulk permeability of the porous media in the numerical simulations depressed the effects of convection, flattening the temperature profiles across the test cell

Saturated liquid densities of propane at T = (280 to 365) K

International Nuclear Information System (INIS)

Miyamoto, H.; Uematsu, M.

2007-01-01

Saturated liquid densities for propane were obtained by means of a metal-bellows variable volumometer at T = (280, 300, 320, 340, 360, and 365) K. The mol-fraction purity of the propane used in the measurements was 0.99997. The expanded uncertainties (k = 2) in temperature, pressure, and density measurements were estimated to be less than ±3 mK, 1.4 kPa (p ≤ 7 MPa), and ±0.09%, respectively. For the determination of the saturation boundary at each temperature for propane, we measured the density data at intervals of about 20 kPa very close to the saturation boundary. After such measurements had been completed, the saturated liquid density data at each temperature were determined as the intersection between the isotherm and our previously determined vapour pressure value. The discrepancies between the three series in the present measurements, in which different sample fillings were used, were also confirmed to be sufficiently lower than the experimental uncertainty. The saturated liquid density correlation was also provided for the systematic comparisons between the present measurements and the literature data

Northeastern Regional geologic characterization report. Volume 1. Final report

International Nuclear Information System (INIS)

1985-08-01

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. For each of the states within the Northeastern Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, postemplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major ground-water discharge zones, ground-water resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crusal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline bodies; ground-water resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented on the relationship between the US Department of Energy (DOE) Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process

1DFEMWATER: A one-dimensional finite element model of WATER flow through saturated-unsaturated media

International Nuclear Information System (INIS)

Yeh, G.T.

1988-08-01

This report presents the development and verification of a one- dimensional finite element model of water flow through saturated- unsaturated media. 1DFEMWATER is very flexible and capable of modeling a wide range of real-world problems. The model is designed to (1) treat heterogeneous media consisting of many geologic formations; (2) consider distributed and point sources/sinks that are spatially and temporally variable; (3) accept prescribed initial conditions or obtain them from steady state simulations; (4) deal with transient heads distributed over the Dirichlet boundary; (5) handle time-dependent fluxes caused by pressure gradient on the Neumann boundary; (6) treat time-dependent total fluxes (i.e., the sum of gravitational fluxes and pressure-gradient fluxes) on the Cauchy boundary; (7) automatically determine variable boundary conditions of evaporation, infiltration, or seepage on the soil-air interface; (8) provide two options for treating the mass matrix (consistent and lumping); (9) provide three alternatives for approximating the time derivative term (Crank-Nicolson central difference, backward difference, and mid-difference); (10) give three options (exact relaxation, underrelaxation, and overrelaxation) for estimating the nonlinear matrix; (11) automatically reset the time step size when boundary conditions or source/sinks change abruptly; and (12) check mass balance over the entire region for every time step. The model is verified with analytical solutions and other numerical models for three examples

Ocean acidification and calcium carbonate saturation states in the coastal zone of the West Antarctic Peninsula

NARCIS (Netherlands)

Jones, Elizabeth M.; Fenton, Mairi; Meredith, Michael P.; Clargo, Nicola M.; Ossebaar, Sharyn; Ducklow, Hugh W.; Venables, Hugh J.; de Baar, Henricus

The polar oceans are particularly vulnerable to ocean acidification; the lowering of seawater pH and carbonate mineral saturation states due to uptake of atmospheric carbon dioxide (CO2). High spatial variability in surface water pH and saturation states (Omega) for two biologically-important

Geological Storage of CO2. Site Selection Criteria

International Nuclear Information System (INIS)

Ruiz, C.; Martinez, R.; Recreo, F.; Prado, P.; Campos, R.; Pelayo, M.; Losa, A. de la; Hurtado, A.; Lomba, L.; Perez del Villar, L.; Ortiz, G.; Sastre, J.; Zapatero, M. A.; Suarez, I.; Arenillas, A.

2007-01-01

In year 2002 the Spanish Parliament unanimously passed the ratification of the Kyoto Protocol, signed December 1997, compromising to limiting the greenhouse gas emissions increase. Later on, the Environment Ministry submitted the Spanish National Assignment Emissions Plan to the European Union and in year 2005 the Spanish Greenhouse Gas market started working, establishing taxes to pay in case of exceeding the assigned emissions limits. So, the avoided emissions of CO2 have now an economic value that is promoting new anthropogenic CO2 emissions reduction technologies. Carbon Capture and Storage (CCS) are among these new technological developments for mitigating or eliminate climate change. CO2 can be stored in geological formations such as depleted oil or gas fields, deep permeable saline water saturated formations and unmailable coal seams, among others. This report seeks to establish the selection criteria for suitable geological formations for CO2 storage in the Spanish national territory, paying attention to both the operational and performance requirements of these storage systems. The report presents the physical and chemical properties and performance of CO2 under storage conditions, the transport and reaction processes of both supercritical and gaseous CO2, and CO2 trapping mechanisms in geological formations. The main part of the report is devoted to geological criteria at watershed, site and formation scales. (Author) 100 refs

Geological Storage of CO2. Site Selection Criteria

International Nuclear Information System (INIS)

Ruiz, C.; Martinez, R.; Recreo, F.; Prado, P.; Campos, R.; Pelayo, M.; Losa, A. de la; Hurtado, A.; Lomba, L.; Perez del Villar, L.; Ortiz, G.; Sastre, J.

2006-01-01

In year 2002 the Spanish Parliament unanimously passed the ratification of the Kyoto Protocol, signed December 1997, compromising to limiting the greenhouse gas emissions increase. Later on, the Environment Ministry submitted the Spanish National Assignment Emissions Plan to the European Union and in year 2005 the Spanish Greenhouse Gas market started working, establishing taxes to pay in case of exceeding the assigned emissions limits. So, the avoided emissions of CO2 have now an economic value that is promoting new anthropogenic CO2 emissions reduction technologies. Carbon Capture and Storage (CCS) are among these new technological developments for mitigating or eliminate climate change. CO2 can be stored in geological formations such as depleted oil or gas fields, deep permeable saline water saturated formations and unmineable coal seams, among others. This report seeks to establish the selection criteria for suitable geological formations for CO2 storage in the Spanish national territory, paying attention to both the operational and performance requirements of these storage systems. The report presents the physical and chemical properties and performance of CO2 under storage conditions, the transport and reaction processes of both supercritical and gaseous CO2, and CO2 trapping mechanisms in geological formations. The main part of the report is devoted to geological criteria at watershed, site and formation scales. (Author) 100 ref

The Impact of Variability of Selected Geological and Mining Parameters on the Value and Risks of Projects in the Hard Coal Mining Industry

Science.gov (United States)

Kopacz, Michał

2017-09-01

The paper attempts to assess the impact of variability of selected geological (deposit) parameters on the value and risks of projects in the hard coal mining industry. The study was based on simulated discounted cash flow analysis, while the results were verified for three existing bituminous coal seams. The Monte Carlo simulation was based on nonparametric bootstrap method, while correlations between individual deposit parameters were replicated with use of an empirical copula. The calculations take into account the uncertainty towards the parameters of empirical distributions of the deposit variables. The Net Present Value (NPV) and the Internal Rate of Return (IRR) were selected as the main measures of value and risk, respectively. The impact of volatility and correlation of deposit parameters were analyzed in two aspects, by identifying the overall effect of the correlated variability of the parameters and the indywidual impact of the correlation on the NPV and IRR. For this purpose, a differential approach, allowing determining the value of the possible errors in calculation of these measures in numerical terms, has been used. Based on the study it can be concluded that the mean value of the overall effect of the variability does not exceed 11.8% of NPV and 2.4 percentage points of IRR. Neglecting the correlations results in overestimating the NPV and the IRR by up to 4.4%, and 0.4 percentage point respectively. It should be noted, however, that the differences in NPV and IRR values can vary significantly, while their interpretation depends on the likelihood of implementation. Generalizing the obtained results, based on the average values, the maximum value of the risk premium in the given calculation conditions of the "X" deposit, and the correspondingly large datasets (greater than 2500), should not be higher than 2.4 percentage points. The impact of the analyzed geological parameters on the NPV and IRR depends primarily on their co-existence, which can be

Geologic distributions of US oil and gas

International Nuclear Information System (INIS)

1992-01-01

This publication presents nonproprietary field size distributions that encompass most domestic oil and gas fields at year-end 1989. These data are organized by geologic provinces as defined by the American Association of Petroleum Geologists' Committee on Statistics of Drilling (AAPG/CSD), by regional geographic aggregates of the AAPG/CSD provinces, and Nationally. The report also provides partial volumetric distributions of petroleum liquid and natural gas ultimate recoveries for three macro-geologic variables: principal lithology of the reservoir rock, principal trapping condition and geologic age of the reservoir rock, The former two variables are presented Nationally and by geographic region, in more detail than has heretofore been available. The latter variable is provided Nationally at the same level of detail previously available. Eighteen tables and 66 figures present original data on domestic oil and gas occurrence. Unfortunately, volumetric data inadequacy dictated exclusion of Appalachian region oil and gas fields from the study. All other areas of the United States known to be productive of crude oil or natural gas through year-end 1989, onshore and offshore, were included. It should be noted that none of the results and conclusions would be expected to substantively differ had data for the Appalachian region been available for inclusion in the study

Northeastern Regional Geologic Characterization Report: executive summary. Final report

International Nuclear Information System (INIS)

1985-08-01

This Executive Summary of the final Northeastern Regional Geologic Characterization Report (RGCR) is issued primarily for public information purposes and provides a general overview of the report. The complete RGCR presents available regional geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. For each of the states within the Northeastern Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. 5 refs., 3 figs

Saturated Fat Intake Is Related to Heart Rate Variability in Women with Polycystic Ovary Syndrome.

Science.gov (United States)

Graff, Scheila K; Mario, Fernanda M; Magalhães, Jose A; Moraes, Ruy S; Spritzer, Poli Mara

2017-01-01

There is a heightened risk for cardiovascular diseases in women with polycystic ovary syndrome (PCOS). Alterations in heart rate variability (HRV) may reflect subclinical cardiovascular disease, with a putative association between HRV and dietary fat. This study evaluated HRV in PCOS and control women based on the dietary intake of saturated fatty acid (SFA). Biochemical/hormonal profile, resting metabolic rate, physical activity, HRV in response to the Stroop test, and dietary intake were assessed in 84 PCOS and 54 control women stratified by median SFA intake in the PCOS group (8.5% of daily energy intake). Body mass index (p = 0.041), blood pressure (p PCOS vs. PCOS women had higher testosterone (p = 0.001), dehydroepiandrosterone sulfate (p = 0.012), and free androgen index (p = 0.001), and lower sex hormone-binding globulin levels than controls (p = 0.001). In both groups, the clinical profile and calorie intake were similar between SFA categories. In PCOS, testosterone was lower when SFA intake PCOS women with SFA PCOS, age and SFA intake were independent predictors of HRV. Lower SFA intake is related to improved cardiovascular autonomic function in PCOS. © 2017 S. Karger AG, Basel.

Ocean acidification and calcium carbonate saturation states in the coastal zone of the West Antarctic Peninsula

NARCIS (Netherlands)

Jones, E.M.; Fenton, M.; Meredith, M.P.; Clargo, N.M.; Ossebaar, S.; Ducklow, H.W.; Venables, H.J.; De Baar, H.J.W.

2017-01-01

The polar oceans are particularly vulnerable to ocean acidification; the lowering of seawater pH and carbonate mineral saturation states due to uptake of atmospheric carbon dioxide (CO2). High spatial variability in surface water pH and saturation states (Ω) for two biologically-important calcium

Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones

Energy Technology Data Exchange (ETDEWEB)

Brown, Stephen R.

2003-06-01

Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones Stephen Brown, Gregory Boitnott, and Martin Smith New England Research In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. For sedimentary materials the length scales are: the pore scale (irregularities in grain surface roughness and cementation), the scale of grain packing faults (and the resulting correlated porosity structures), the scale dominated by sorting or winnowing due to depositional processes, and the scale of geomorphology at the time of deposition. We are studying the heterogeneity and anisotropy in geometry, permeability, and geophysical response from the pore (microscopic), laboratory (mesoscopic), and backyard field (macroscopic) scales. In turn these data are being described and synthesized for development of mathematical models. Eventually, we will perform parameter studies to explore these models in the context of transport in the vadose and saturated zones. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core. This device allows for detailed study of heterogeneity at those length scales most difficult to quantify using standard field and laboratory practices. The measurement head consists of a variety of probes designed to make local measurements of various properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability). We can thus routinely generate detailed geophysical maps of a particular sample. With the exception of the acoustic velocity, we are testing and modifying these probes as necessary for use on soil samples. As a baseline study we have been

Influence of soil particle shape on saturated hydraulic conductivity

Directory of Open Access Journals (Sweden)

Zięba Zofia

2017-03-01

Full Text Available The aim of this paper is to define the correlation between the geometry of grains and saturated hydraulic conductivity of soils. The particle shape characteristics were described by the ζ0C index (Parylak, 2000, which expresses the variability of several shape properties, such as sphericity, angularity and roughness.

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

International Nuclear Information System (INIS)

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2008-01-01

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured

North Central Regional Geologic Characterization Report. Executive summary. Final report

International Nuclear Information System (INIS)

1985-08-01

This Executive Summary of the final North Central Regional Geologic Characterization Report (RGCR) is issued primarily for public information purposes and provides a general overview of the report. The complete RGCR presents available regional geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening

On the probability distribution of the stochastic saturation scale in QCD

International Nuclear Information System (INIS)

Marquet, C.; Soyez, G.; Xiao Bowen

2006-01-01

It was recently noticed that high-energy scattering processes in QCD have a stochastic nature. An event-by-event scattering amplitude is characterised by a saturation scale which is a random variable. The statistical ensemble of saturation scales formed with all the events is distributed according to a probability law whose cumulants have been recently computed. In this work, we obtain the probability distribution from the cumulants. We prove that it can be considered as Gaussian over a large domain that we specify and our results are confirmed by numerical simulations

Microscopic analysis of saturable absorbers: Semiconductor saturable absorber mirrors versus graphene

Energy Technology Data Exchange (ETDEWEB)

Hader, J.; Moloney, J. V. [Nonlinear Control Strategies, Inc., 3542 N. Geronimo Ave., Tucson, Arizona 85705 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States); Yang, H.-J.; Scheller, M. [College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States); Koch, S. W. [Department of Physics and Materials Sciences Center, Philipps Universität Marburg, Renthof 5, 35032 Marburg (Germany)

2016-02-07

Fully microscopic many-body calculations are used to study the influence of strong sub-picosecond pulses on the carrier distributions and corresponding optical response in saturable absorbers used for mode-locking—semiconductor (quantum well) saturable absorber mirrors (SESAMs) and single layer graphene based saturable absorber mirrors (GSAMs). Unlike in GSAMs, the saturation fluence and recovery time in SESAMs show a strong spectral dependence. While the saturation fluence in the SESAM is minimal at the excitonic bandgap, the optimal recovery time and least pulse distortion due to group delay dispersion are found for excitation higher in the first subband. For excitation near the SESAM bandgap, the saturation fluence is about one tenth of that in the GSAM. At energies above the bandgap, the fluences in both systems become similar. A strong dependence of the saturation fluence on the pulse width in both systems is caused by carrier relaxation during the pulse. The recovery time in graphene is found to be about two to four times faster than that in the SESAMs. The occurrence of negative differential transmission in graphene is shown to be caused by dopant related carriers. In SESAMs, a negative differential transmission is found when exciting below the excitonic resonance where excitation induced dephasing leads to an enhancement of the absorption. Comparisons of the simulation data to the experiment show a very good quantitative agreement.

Transport of synthetic colloids through single saturated fractures: A literature review

International Nuclear Information System (INIS)

Reimus, P.W.

1995-07-01

Colloids having the same surface charge sign as the bulk of the geologic media in a groundwater system may be able to travel through the system faster than soluble species because they will follow fluid streamlines more closely and they should have less tendency to diffuse into pores or dead spaces in the media than soluble species. Synthetic colloids with uniform, controlled properties may be ideal for serving as open-quotes worst-caseclose quotes tracers that provide lower-bound estimates of contaminant travel times in hydrologic systems. This report discusses a review of the literature pertaining to colloid transport in single saturated natural fractures. After a brief background discussion to put the literature review in perspective, the phenomenon of colloid transport in saturated fractures is divided into three major topics, each of which is reviewed in detail: (1) saturated fluid flow through fractures; (2) colloid transport by convection, diffusion, and force fields; and (3) colloid interactions with surfaces. It is suggested that these phenomena be accounted for in colloid transport models by using (1) lubrication theory to describe water flow through fractures, (2) particle tracking methods to describe colloid transport in fractures, and (3) a kinetic boundary layer approximation to describe colloid interactions with fracture walls. These methods offer better computational efficiency and better experimental accessibility to model parameters than rigorously solving the complete governing equations

SIMULATION FRAMEWORK FOR REGIONAL GEOLOGIC CO{sub 2} STORAGE ALONG ARCHES PROVINCE OF MIDWESTERN UNITED STATES

Energy Technology Data Exchange (ETDEWEB)

Sminchak, Joel

2012-09-30

This report presents final technical results for the project Simulation Framework for Regional Geologic CO{sub 2} Storage Infrastructure along Arches Province of the Midwest United States. The Arches Simulation project was a three year effort designed to develop a simulation framework for regional geologic carbon dioxide (CO{sub 2}) storage infrastructure along the Arches Province through development of a geologic model and advanced reservoir simulations of large-scale CO{sub 2} storage. The project included five major technical tasks: (1) compilation of geologic, hydraulic and injection data on Mount Simon, (2) development of model framework and parameters, (3) preliminary variable density flow simulations, (4) multi-phase model runs of regional storage scenarios, and (5) implications for regional storage feasibility. The Arches Province is an informal region in northeastern Indiana, northern Kentucky, western Ohio, and southern Michigan where sedimentary rock formations form broad arch and platform structures. In the province, the Mount Simon sandstone is an appealing deep saline formation for CO{sub 2} storage because of the intersection of reservoir thickness and permeability. Many CO{sub 2} sources are located in proximity to the Arches Province, and the area is adjacent to coal fired power plants along the Ohio River Valley corridor. Geophysical well logs, rock samples, drilling logs, and geotechnical tests were evaluated for a 500,000 km{sup 2} study area centered on the Arches Province. Hydraulic parameters and historical operational information was also compiled from Mount Simon wastewater injection wells in the region. This information was integrated into a geocellular model that depicts the parameters and conditions in a numerical array. The geologic and hydraulic data were integrated into a three-dimensional grid of porosity and permeability, which are key parameters regarding fluid flow and pressure buildup due to CO{sub 2} injection. Permeability data

Geological remote sensing

Science.gov (United States)

Bishop, Charlotte; Rivard, Benoit; de Souza Filho, Carlos; van der Meer, Freek

2018-02-01

Geology is defined as the 'study of the planet Earth - the materials of which it is made, the processes that act on these materials, the products formed, and the history of the planet and its life forms since its origin' (Bates and Jackson, 1976). Remote sensing has seen a number of variable definitions such as those by Sabins and Lillesand and Kiefer in their respective textbooks (Sabins, 1996; Lillesand and Kiefer, 2000). Floyd Sabins (Sabins, 1996) defined it as 'the science of acquiring, processing and interpreting images that record the interaction between electromagnetic energy and matter' while Lillesand and Kiefer (Lillesand and Kiefer, 2000) defined it as 'the science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation'. Thus Geological Remote Sensing can be considered the study of, not just Earth given the breadth of work undertaken in planetary science, geological features and surfaces and their interaction with the electromagnetic spectrum using technology that is not in direct contact with the features of interest.

North Central Regional geologic characterization report. Volume 1. Final report

International Nuclear Information System (INIS)

1985-08-01

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, groundwater resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented of the relationship between the US Department of Energy Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process. 43 figs., 15 tabs

Impact of magnetic saturation on the input-output linearising tracking control of an induction motor

DEFF Research Database (Denmark)

Dolinar, Drago; Ljusev, Petar; Stumberger, Gorazd

2004-01-01

This paper deals with the tracking control design of an induction motor, based on input-output linearization with magnetic saturation included. Magnetic saturation is represented by the nonlinear magnetizing curve of the iron core and is used in the control design, the observer of state variables......, and in the load torque estimator. An input-output linearising control is used to achieve better tracking performances of the drive. It is based on the mixed ”stator current - rotor flux linkage” induction motor model with magnetic saturation considered in the stationary reference frame. Experimental results show...... that the proposed input-output linearising tracking control with the included saturation behaves considerably better than the one without saturation, and that it introduces smaller position and speed errors, and better motor stiffness on account of the increased computational complexity....

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variably Saturated Geologic Media

International Nuclear Information System (INIS)

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-01-01

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of mineral alteration in hydrothermal systems, waste disposal sites, acid mine drainage remediation, contaminant transport, and groundwater quality. A comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator, TOUGHREACT, has been developed. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The program can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. Changes in porosity and permeability due to mineral dissolution and precipitation can be considered. Linear adsorption and decay can be included. For the purpose of future extensions, surface complexation by double layer model is coded in the program. Xu and Pruess (1998) developed a first version of a non-isothermal reactive geochemical transport model, TOUGHREACT, by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). Xu, Pruess, and their colleagues have applied the program to a variety of problems such as: (1) supergene copper enrichment (Xu et al, 2001), (2) caprock mineral alteration in a hydrothermal system (Xu and Pruess, 2001a), and (3) mineral trapping for CO 2 disposal in deep saline aquifers (Xu et al, 2003b and 2004a). For modeling the coupled thermal, hydrological, and chemical processes during heater

Hydrogeologic Framework Model for the Saturated Zone Site Scale flow and Transport Model

Energy Technology Data Exchange (ETDEWEB)

T. Miller

2004-11-15

The purpose of this report is to document the 19-unit, hydrogeologic framework model (19-layer version, output of this report) (HFM-19) with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results in accordance with AP-SIII.10Q, Models. The HFM-19 is developed as a conceptual model of the geometric extent of the hydrogeologic units at Yucca Mountain and is intended specifically for use in the development of the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). Primary inputs to this model report include the GFM 3.1 (DTN: MO9901MWDGFM31.000 [DIRS 103769]), borehole lithologic logs, geologic maps, geologic cross sections, water level data, topographic information, and geophysical data as discussed in Section 4.1. Figure 1-1 shows the information flow among all of the saturated zone (SZ) reports and the relationship of this conceptual model in that flow. The HFM-19 is a three-dimensional (3-D) representation of the hydrogeologic units surrounding the location of the Yucca Mountain geologic repository for spent nuclear fuel and high-level radioactive waste. The HFM-19 represents the hydrogeologic setting for the Yucca Mountain area that covers about 1,350 km2 and includes a saturated thickness of about 2.75 km. The boundaries of the conceptual model were primarily chosen to be coincident with grid cells in the Death Valley regional groundwater flow model (DTN: GS960808312144.003 [DIRS 105121]) such that the base of the site-scale SZ flow model is consistent with the base of the regional model (2,750 meters below a smoothed version of the potentiometric surface), encompasses the exploratory boreholes, and provides a framework over the area of interest for groundwater flow and radionuclide transport modeling. In depth, the model domain extends from land surface to the base of the regional groundwater flow model (D'Agnese et al. 1997 [DIRS 100131], p 2). For the site

Hydrogeologic Framework Model for the Saturated Zone Site Scale flow and Transport Model

International Nuclear Information System (INIS)

Miller, T.

2004-01-01

The purpose of this report is to document the 19-unit, hydrogeologic framework model (19-layer version, output of this report) (HFM-19) with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results in accordance with AP-SIII.10Q, Models. The HFM-19 is developed as a conceptual model of the geometric extent of the hydrogeologic units at Yucca Mountain and is intended specifically for use in the development of the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]). Primary inputs to this model report include the GFM 3.1 (DTN: MO9901MWDGFM31.000 [DIRS 103769]), borehole lithologic logs, geologic maps, geologic cross sections, water level data, topographic information, and geophysical data as discussed in Section 4.1. Figure 1-1 shows the information flow among all of the saturated zone (SZ) reports and the relationship of this conceptual model in that flow. The HFM-19 is a three-dimensional (3-D) representation of the hydrogeologic units surrounding the location of the Yucca Mountain geologic repository for spent nuclear fuel and high-level radioactive waste. The HFM-19 represents the hydrogeologic setting for the Yucca Mountain area that covers about 1,350 km2 and includes a saturated thickness of about 2.75 km. The boundaries of the conceptual model were primarily chosen to be coincident with grid cells in the Death Valley regional groundwater flow model (DTN: GS960808312144.003 [DIRS 105121]) such that the base of the site-scale SZ flow model is consistent with the base of the regional model (2,750 meters below a smoothed version of the potentiometric surface), encompasses the exploratory boreholes, and provides a framework over the area of interest for groundwater flow and radionuclide transport modeling. In depth, the model domain extends from land surface to the base of the regional groundwater flow model (D'Agnese et al. 1997 [DIRS 100131], p 2). For the site-scale SZ flow model, the HFM

A Numerical Investigation on the Effect of Gas Pressure on the Water Saturation of Compacted Bentonite-Sand Samples

Directory of Open Access Journals (Sweden)

Jiang-Feng Liu

2017-01-01

Full Text Available In deep geological disposal for high-level radioactive waste, the generated gas can potentially affect the sealing ability of bentonite buffers. There is a competition between water and gas: the former provides sealing by swelling bentonite, and the latter attempts to desaturate the bentonite buffer. Thus, this study focused on numerically modelling the coupling effects of water and gas on the water saturation and sealing efficiency of compacted bentonite-sand samples. Different gas pressures were applied to the top surface of an upper sample, whereas the water pressure on the bottom side of the lower sample was maintained at 4 MPa. The results indicated that gas pressure did not significantly affect the saturation of the bentonite-sand sample until 2 MPa. At 2 MPa, the degree of water saturation of the upper sample was close to 1.0. As the gas pressure increased, this influence was more apparent. When the gas pressure was 6 MPa or higher, it was difficult for the upper sample to become fully saturated. Additionally, the lower sample was desaturated due to the high gas pressure. This indicated that gas pressure played an important role in the water saturation process and can affect the sealing efficiency of bentonite-based buffer materials.

Variable thickness transient ground-water flow model. Volume 3. Program listings

International Nuclear Information System (INIS)

Reisenauer, A.E.

1979-12-01

The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program is developing and applying the methodology for assessing the far-field, long-term post-closure safety of deep geologic nuclear waste repositories. AEGIS is being performed by Pacific Northwest Laboratory (PNL) under contract with the Office of Nuclear Waste Isolation (OWNI) for the Department of Energy (DOE). One task within AEGIS is the development of methodology for analysis of the consequences (water pathway) from loss of repository containment as defined by various release scenarios. Analysis of the long-term, far-field consequences of release scenarios requires the application of numerical codes which simulate the hydrologic systems, model the transport of released radionuclides through the hydrologic systems to the biosphere, and, where applicable, assess the radiological dose to humans. Hydrologic and transport models are available at several levels of complexity or sophistication. Model selection and use are determined by the quantity and quality of input data. Model development under AEGIS and related programs provides three levels of hydrologic models, two levels of transport models, and one level of dose models (with several separate models). This is the third of 3 volumes of the description of the VTT (Variable Thickness Transient) Groundwater Hydrologic Model - second level (intermediate complexity) two-dimensional saturated groundwater flow

Gluon saturation in a saturated environment

International Nuclear Information System (INIS)

Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Ivan

2011-01-01

A bootstrap equation for self-quenched gluon shadowing leads to a reduced magnitude of broadening for partons propagating through a nucleus. Saturation of small-x gluons in a nucleus, which has the form of transverse momentum broadening of projectile gluons in pA collisions in the nuclear rest frame, leads to a modification of the parton distribution functions in the beam compared with pp collisions. In nucleus-nucleus collisions all participating nucleons acquire enhanced gluon density at small x, which boosts further the saturation scale. Solution of the reciprocity equations for central collisions of two heavy nuclei demonstrate a significant, up to several times, enhancement of Q sA 2 , in AA compared with pA collisions.

A numerical model for density-and-viscosity-dependent flows in two-dimensional variably saturated porous media

Science.gov (United States)

Boufadel, Michel C.; Suidan, Makram T.; Venosa, Albert D.

1999-04-01

We present a formulation for water flow and solute transport in two-dimensional variably saturated media that accounts for the effects of the solute on water density and viscosity. The governing equations are cast in a dimensionless form that depends on six dimensionless groups of parameters. These equations are discretized in space using the Galerkin finite element formulation and integrated in time using the backward Euler scheme with mass lumping. The modified Picard method is used to linearize the water flow equation. The resulting numerical model, the MARUN model, is verified by comparison to published numerical results. It is then used to investigate beach hydraulics at seawater concentration (about 30 g l -1) in the context of nutrients delivery for bioremediation of oil spills on beaches. Numerical simulations that we conducted in a rectangular section of a hypothetical beach revealed that buoyancy in the unsaturated zone is significant in soils that are fine textured, with low anisotropy ratio, and/or exhibiting low physical dispersion. In such situations, application of dissolved nutrients to a contaminated beach in a freshwater solution is superior to their application in a seawater solution. Concentration-engendered viscosity effects were negligible with respect to concentration-engendered density effects for the cases that we considered.

Concentration and saturation effects of tethered polymer chains on adsorbing surfaces

Science.gov (United States)

Descas, Radu; Sommer, Jens-Uwe; Blumen, Alexander

2006-12-01

We consider end-grafted chains at an adsorbing surface under good solvent conditions using Monte Carlo simulations and scaling arguments. Grafting of chains allows us to fix the surface concentration and to study a wide range of surface concentrations from the undersaturated state of the surface up to the brushlike regime. The average extension of single chains in the direction parallel and perpendicular to the surface is analyzed using scaling arguments for the two-dimensional semidilute surface state according to Bouchaud and Daoud [J. Phys. (Paris) 48, 1991 (1987)]. We find good agreement with the scaling predictions for the scaling in the direction parallel to the surface and for surface concentrations much below the saturation concentration (dense packing of adsorption blobs). Increasing the grafting density we study the saturation effects and the oversaturation of the adsorption layer. In order to account for the effect of excluded volume on the adsorption free energy we introduce a new scaling variable related with the saturation concentration of the adsorption layer (saturation scaling). We show that the decrease of the single chain order parameter (the fraction of adsorbed monomers on the surface) with increasing concentration, being constant in the ideal semidilute surface state, is properly described by saturation scaling only. Furthermore, the simulation results for the chains' extension from higher surface concentrations up to the oversaturated state support the new scaling approach. The oversaturated state can be understood using a geometrical model which assumes a brushlike layer on top of a saturated adsorption layer. We provide evidence that adsorbed polymer layers are very sensitive to saturation effects, which start to influence the semidilute surface scaling even much below the saturation threshold.

Seasonal Variability of Aragonite Saturation State in the North Pacific Ocean Predicted by Multiple Linear Regression

Science.gov (United States)

Kim, T. W.; Park, G. H.

2014-12-01

Seasonal variation of aragonite saturation state (Ωarag) in the North Pacific Ocean (NPO) was investigated, using multiple linear regression (MLR) models produced from the PACIFICA (Pacific Ocean interior carbon) dataset. Data within depth ranges of 50-1200m were used to derive MLR models, and three parameters (potential temperature, nitrate, and apparent oxygen utilization (AOU)) were chosen as predictor variables because these parameters are associated with vertical mixing, DIC (dissolved inorganic carbon) removal and release which all affect Ωarag in water column directly or indirectly. The PACIFICA dataset was divided into 5° × 5° grids, and a MLR model was produced in each grid, giving total 145 independent MLR models over the NPO. Mean RMSE (root mean square error) and r2 (coefficient of determination) of all derived MLR models were approximately 0.09 and 0.96, respectively. Then the obtained MLR coefficients for each of predictor variables and an intercept were interpolated over the study area, thereby making possible to allocate MLR coefficients to data-sparse ocean regions. Predictability from the interpolated coefficients was evaluated using Hawaiian time-series data, and as a result mean residual between measured and predicted Ωarag values was approximately 0.08, which is less than the mean RMSE of our MLR models. The interpolated MLR coefficients were combined with seasonal climatology of World Ocean Atlas 2013 (1° × 1°) to produce seasonal Ωarag distributions over various depths. Large seasonal variability in Ωarag was manifested in the mid-latitude Western NPO (24-40°N, 130-180°E) and low-latitude Eastern NPO (0-12°N, 115-150°W). In the Western NPO, seasonal fluctuations of water column stratification appeared to be responsible for the seasonal variation in Ωarag (~ 0.5 at 50 m) because it closely followed temperature variations in a layer of 0-75 m. In contrast, remineralization of organic matter was the main cause for the seasonal

Lipid order, saturation and surface property relationships: a study of human meibum saturation.

Science.gov (United States)

Mudgil, Poonam; Borchman, Douglas; Yappert, Marta C; Duran, Diana; Cox, Gregory W; Smith, Ryan J; Bhola, Rahul; Dennis, Gary R; Whitehall, John S

2013-11-01

Tear film stability decreases with age however the cause(s) of the instability are speculative. Perhaps the more saturated meibum from infants may contribute to tear film stability. The meibum lipid phase transition temperature and lipid hydrocarbon chain order at physiological temperature (33 °C) decrease with increasing age. It is reasonable that stronger lipid-lipid interactions could stabilize the tear film since these interactions must be broken for tear break up to occur. In this study, meibum from a pool of adult donors was saturated catalytically. The influence of saturation on meibum hydrocarbon chain order was determined by infrared spectroscopy. Meibum is in an anhydrous state in the meibomian glands and on the surface of the eyelid. The influence of saturation on the surface properties of meibum was determined using Langmuir trough technology. Saturation of native human meibum did not change the minimum or maximum values of hydrocarbon chain order so at temperatures far above or below the phase transition of human meibum, saturation does not play a role in ordering or disordering the lipid hydrocarbon chains. Saturation did increase the phase transition temperature in human meibum by over 20 °C, a relatively high amount. Surface pressure-area studies showing the late take off and higher maximum surface pressure of saturated meibum compared to native meibum suggest that the saturated meibum film is quite molecularly ordered (stiff molecular arrangement) and elastic (molecules are able to rearrange during compression and expansion) compared with native meibum films which are more fluid agreeing with the infrared spectroscopic results of this study. In saturated meibum, the formation of compacted ordered islands of lipids above the surfactant layer would be expected to decrease the rate of evaporation compared to fluid and more loosely packed native meibum. Higher surface pressure observed with films of saturated meibum compared to native meibum

Investigation of Slow-wave Activity Saturation during Surgical Anesthesia Reveals a Signature of Neural Inertia in Humans.

Science.gov (United States)

Warnaby, Catherine E; Sleigh, Jamie W; Hight, Darren; Jbabdi, Saad; Tracey, Irene

2017-10-01

Previously, we showed experimentally that saturation of slow-wave activity provides a potentially individualized neurophysiologic endpoint for perception loss during anesthesia. Furthermore, it is clear that induction and emergence from anesthesia are not symmetrically reversible processes. The observed hysteresis is potentially underpinned by a neural inertia mechanism as proposed in animal studies. In an advanced secondary analysis of 393 individual electroencephalographic data sets, we used slow-wave activity dose-response relationships to parameterize slow-wave activity saturation during induction and emergence from surgical anesthesia. We determined whether neural inertia exists in humans by comparing slow-wave activity dose responses on induction and emergence. Slow-wave activity saturation occurs for different anesthetics and when opioids and muscle relaxants are used during surgery. There was wide interpatient variability in the hypnotic concentrations required to achieve slow-wave activity saturation. Age negatively correlated with power at slow-wave activity saturation. On emergence, we observed abrupt decreases in slow-wave activity dose responses coincident with recovery of behavioral responsiveness in ~33% individuals. These patients are more likely to have lower power at slow-wave activity saturation, be older, and suffer from short-term confusion on emergence. Slow-wave activity saturation during surgical anesthesia implies that large variability in dosing is required to achieve a targeted potential loss of perception in individual patients. A signature for neural inertia in humans is the maintenance of slow-wave activity even in the presence of very-low hypnotic concentrations during emergence from anesthesia.

Southeastern Regional geologic characterization report. Volume 1. Final report

International Nuclear Information System (INIS)

1985-08-01

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in central Maryland; noncoastal Virginia, North Carolina, and South Carolina; and northern Georgia. For each of the states within the Southeastern Region, information is provided on the geological disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geological factor and variables include deep mines and quarries, rock mass extent, postemplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major ground-water discharge zones, ground-water resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on the age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline bodies; ground-water resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies

Determination of saturation functions and wettability for chalk based on measured fluid saturations

Energy Technology Data Exchange (ETDEWEB)

Olsen, D.; Bech, N.; Moeller Nielsen, C.

1998-08-01

The end effect of displacement experiments on low permeable porous media is used for determination of relative permeability functions and capillary pressure functions. Saturation functions for a drainage process are determined from a primary drainage experiment. A reversal of the flooding direction creates an intrinsic imbibition process in the sample, which enables determination if imbibition saturation functions. The saturation functions are determined by a parameter estimation technique. Scanning effects are modelled by the method of Killough. Saturation profiles are determined by NMR. (au)

Deterministic geologic processes and stochastic modeling

International Nuclear Information System (INIS)

Rautman, C.A.; Flint, A.L.

1992-01-01

This paper reports that recent outcrop sampling at Yucca Mountain, Nevada, has produced significant new information regarding the distribution of physical properties at the site of a potential high-level nuclear waste repository. consideration of the spatial variability indicates that her are a number of widespread deterministic geologic features at the site that have important implications for numerical modeling of such performance aspects as ground water flow and radionuclide transport. Because the geologic processes responsible for formation of Yucca Mountain are relatively well understood and operate on a more-or-less regional scale, understanding of these processes can be used in modeling the physical properties and performance of the site. Information reflecting these deterministic geologic processes may be incorporated into the modeling program explicitly using geostatistical concepts such as soft information, or implicitly, through the adoption of a particular approach to modeling

Analytical theory relating the depth of the sulfate-methane transition to gas hydrate distribution and saturation

Science.gov (United States)

Bhatnagar, Gaurav; Chatterjee, Sayantan; Chapman, Walter G.; Dugan, Brandon; Dickens, Gerald R.; Hirasaki, George J.

2011-03-01

We develop a theory that relates gas hydrate saturation in marine sediments to the depth of the sulfate-methane transition (SMT) zone below the seafloor using steady state, analytical expressions. These expressions are valid for systems in which all methane transported into the gas hydrate stability zone (GHSZ) comes from deeper external sources (i.e., advective systems). This advective constraint causes anaerobic oxidation of methane to be the only sulfate sink, allowing us to link SMT depth to net methane flux. We also develop analytical expressions that define the gas hydrate saturation profile based on SMT depth and site-specific parameters such as sedimentation rate, methane solubility, and porosity. We evaluate our analytical model at four drill sites along the Cascadia Margin where methane sources from depth dominate. With our model, we calculate average gas hydrate saturations across GHSZ and the top occurrence of gas hydrate at these sites as 0.4% and 120 mbsf (Site 889), 1.9% and 70 mbsf (Site U1325), 4.7% and 40 mbsf (Site U1326), and 0% (Site U1329), mbsf being meters below seafloor. These values compare favorably with average saturations and top occurrences computed from resistivity log and chloride data. The analytical expressions thus provide a fast and convenient method to calculate gas hydrate saturation and first-order occurrence at a given geologic setting where vertically upward advection dominates the methane flux.

Empirical algorithms to predict aragonite saturation state

Science.gov (United States)

Turk, Daniela; Dowd, Michael

2017-04-01

Novel sensor packages deployed on autonomous platforms (Profiling Floats, Gliders, Moorings, SeaCycler) and biogeochemical models have a potential to increase the coverage of a key water chemistry variable, aragonite saturation state (ΩAr) in time and space, in particular in the under sampled regions of global ocean. However, these do not provide the set of inorganic carbon measurements commonly used to derive ΩAr. There is therefore a need to develop regional predictive models to determine ΩAr from measurements of commonly observed or/and non carbonate oceanic variables. Here, we investigate predictive skill of several commonly observed oceanographic variables (temperature, salinity, oxygen, nitrate, phosphate and silicate) in determining ΩAr using climatology and shipboard data. This will allow us to assess potential for autonomous sensors and biogeochemical models to monitor ΩAr regionally and globally. We apply the regression models to several time series data sets and discuss regional differences and their implications for global estimates of ΩAr.

Variability in the reported energy, total fat and saturated fat contents in fast-food products across ten countries.

Science.gov (United States)

Ziauddeen, Nida; Fitt, Emily; Edney, Louise; Dunford, Elizabeth; Neal, Bruce; Jebb, Susan A

2015-11-01

Fast foods are often energy dense and offered in large serving sizes. Observational data have linked the consumption of fast foods to an increased risk of obesity and related diseases. We surveyed the reported energy, total fat and saturated fat contents, and serving sizes, of fast-food items from five major chains across ten countries, comparing product categories as well as specific food items available in most countries. MRC Human Nutrition Research, Cambridge, UK. Data for 2961 food and drink products were collected, with most from Canada (n 550) and fewest from the United Arab Emirates (n 106). There was considerable variability in energy and fat contents of fast foods across countries, reflecting both the portfolio of products and serving size variability. Differences in total energy between countries were particularly noted for chicken dishes (649-1197 kJ/100 g) and sandwiches (552-1050 kJ/100g). When comparing the same product between countries variations were consistently observed in total energy and fat contents (g/100 g); for example, extreme variation in McDonald's Chicken McNuggets with 12 g total fat/100 g in Germany compared with 21·1 g/100 g in New Zealand. These cross-country variations highlight the possibility for further product reformulation in many countries to reduce nutrients of concern and improve the nutritional profiles of fast-food products around the world. Standardisation of serving sizes towards the lower end of the range would also help to reduce the risk of overconsumption.

Variability in the reported energy, total fat and saturated fat content in fast food products across ten countries

Science.gov (United States)

Ziauddeen, Nida; Fitt, Emily; Edney, Louise; Dunford, Elizabeth; Neal, Bruce; Jebb, Susan A.

2016-01-01

Objective Fast foods are often energy dense and offered in large serving sizes. Observational data has linked the consumption of fast food to an increased risk of obesity and related diseases. Design We surveyed the reported energy, total fat and saturated fat contents, and serving sizes, of fast food items from five major chains across 10 countries, comparing product categories as well as specific food items available in most countries. Setting MRC Human Nutrition Research (HNR), Cambridge Subjects Data for 2961 food and drink products were collected, with most from Canada (n=550) and fewest from United Arab Emirates (n=106). Results There was considerable variability in energy and fat content of fast food across countries, reflecting both the portfolio of products, and serving size variability. Differences in total energy between countries were particularly noted for chicken dishes (649-1197kJ/100g) and sandwiches (552-1050kJ/100g). When comparing the same product between countries variations were consistently observed in total energy and fat content (g/100g) with extreme variation in McDonald’s Chicken McNuggets with 12g total fat (g/100g) in Germany compared to 21.1g in New Zealand. Conclusions These cross-country variations highlight the possibility for further product reformulation in many countries to reduce nutrients of concern and improve the nutritional profiles of fast food products around the world. Standardisation of serving sizes towards the lower end of the range would also help to reduce the risk of overconsumption. PMID:25702788

Engineering Geology | Alaska Division of Geological & Geophysical Surveys

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Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska content Engineering Geology Additional information Engineering Geology Posters and Presentations Alaska Alaska MAPTEACH Tsunami Inundation Mapping Engineering Geology Staff Projects The Engineering Geology

Measure of uncertainty in regional grade variability

NARCIS (Netherlands)

Tutmez, B.; Kaymak, U.; Melin, P.; Castillo, O.; Gomez Ramirez, E.; Kacprzyk, J.; Pedrycz, W.

2007-01-01

Because the geological events are neither homogeneous nor isotropic, the geological investigations are characterized by particularly high uncertainties. This paper presents a hybrid methodology for measuring of uncertainty in regional grade variability. In order to evaluate the fuzziness in grade

Mechanics of non-saturated soils

International Nuclear Information System (INIS)

Coussy, O.; Fleureau, J.M.

2002-01-01

This book presents the different ways to approach the mechanics of non saturated soils, from the physico-chemical aspect to the mechanical aspect, from the experiment to the theoretical modeling, from the laboratory to the workmanship, and from the microscopic scale to the macroscopic one. Content: water and its representation; experimental bases of the behaviour of non-saturated soils; transfer laws in non-saturated environment; energy approach of the behaviour of non-saturated soils; homogenization for the non-saturated soils; plasticity and hysteresis; dams and backfilling; elaborated barriers. (J.S.)

Monitoring CO2 penetration and storage in the brine-saturated low permeable sandstone by the geophysical exploration technologies

Science.gov (United States)

Honda, H.; Mitani, Y.; Kitamura, K.; Ikemi, H.; Imasato, M.

2017-12-01

Carbon dioxide (CO2) capture and storage (CCS) plays a vital role in reducing greenhouse gas emissions. In the northern part of Kyushu region of Japan, complex geological structure (Coalfield) is existed near the CO2 emission source and has 1.06 Gt of CO2 storage capacity. The geological survey shows that these layers are formed by low permeable sandstone. It is necessary to monitor the CO2 behavior and clear the mechanisms of CO2 penetration and storage in the low permeable sandstone. In this study, measurements of complex electrical impedance (Z) and elastic wave velocity (P-wave velocity: Vp) were conducted during the supercritical CO2 injection experiment into the brine-saturated low permeable sandstone. The experiment conditions were as follows; Confining pressure: 20 MPa, Initial pore pressure: 10 MPa, 40 °, CO2 injection rate: 0.01 to 0.5 mL/min. Z was measured in the center of the specimen and Vp were measured at three different heights of the specimen at constant intervals. In addition, we measured the longitudinal and lateral strain at the center of the specimen, the pore pressure and CO2 injection volume (CO2 saturation). During the CO2 injection, the change of Z and Vp were confirmed. In the drainage terms, Vp decreased drastically once CO2 reached the measurement cross section.Vp showed the little change even if the flow rate increased (CO2 saturation increased). On the other hand, before the CO2 front reached, Z decreased with CO2-dissolved brine. After that, Z showed continuously increased as the CO2 saturation increased. From the multi-parameter (Hydraulic and Rock-physics parameters), we revealed the detail CO2 behavior in the specimen. In the brine-saturated low permeable sandstone, the slow penetration of CO2 was observed. However, once CO2 has passed, the penetration of CO2 became easy in even for brine-remainded low permeable sandstone. We conclude low permeable sandstone has not only structural storage capacity but also residual tapping

Monitoring mixed venous oxygen saturation in patients with obstructive shock after massive pulmonary embolism.

Science.gov (United States)

Krivec, Bojan; Voga, Gorazd; Podbregar, Matej

2004-05-31

Patients with massive pulmonary embolism and obstructive shock usually require hemodynamic stabilization and thrombolysis. Little is known about the optimal and proper use of volume infusion and vasoactive drugs, or about the titration of thrombolytic agents in patients with relative contraindication for such treatment. The aim of the study was to find the most rapidly changing hemodynamic variable to monitor and optimize the treatment of patients with obstructive shock following massive pulmonary embolism. Ten consecutive patients hospitalized in the medical intensive care unit in the community General Hospital with obstructive shock following massive pulmonary embolism were included in the prospective observational study. Heart rate, systolic arterial pressure, central venous pressure, mean pulmonary-artery pressure, cardiac index, total pulmonary vascular-resistance index, mixed venous oxygen saturation, and urine output were measured on admission and at 1, 2, 3, 4, 8, 12, and 16 hours. Patients were treated with urokinase through the distal port of a pulmonary-artery catheter. At 1 hour, mixed venous oxygen saturation, systolic arterial pressure and cardiac index were higher than their admission values (31+/-10 vs. 49+/-12%, p<0.0001; 86+/-12 vs. 105+/-17 mmHg, p<0.01; 1.5+/-0.4 vs. 1.9+/-0.7 L/min/m2, p<0.05; respectively), whereas heart rate, central venous pressure, mean pulmonary-artery pressure and urine output remained unchanged. Total pulmonary vascular-resistance index was lower than at admission (29+/-10 vs. 21+/-12 mmHg/L/min/m2, p<0.05). The relative change of mixed venous oxygen saturation at hour 1 was higher than the relative changes of all other studied variables (p<0.05). Serum lactate on admission and at 12 hours correlated to mixed venous oxygen saturation (r=-0.855, p<0.001). In obstructive shock after massive pulmonary embolism, mixed venous oxygen saturation changes more rapidly than other standard hemodynamic variables.

Urban Saturated Power Load Analysis Based on a Novel Combined Forecasting Model

Directory of Open Access Journals (Sweden)

Huiru Zhao

2015-03-01

Full Text Available Analysis of urban saturated power loads is helpful to coordinate urban power grid construction and economic social development. There are two different kinds of forecasting models: the logistic curve model focuses on the growth law of the data itself, while the multi-dimensional forecasting model considers several influencing factors as the input variables. To improve forecasting performance, a novel combined forecasting model for saturated power load analysis was proposed in this paper, which combined the above two models. Meanwhile, the weights of these two models in the combined forecasting model were optimized by employing a fruit fly optimization algorithm. Using Hubei Province as the example, the effectiveness of the proposed combined forecasting model was verified, demonstrating a higher forecasting accuracy. The analysis result shows that the power load of Hubei Province will reach saturation in 2039, and the annual maximum power load will reach about 78,630 MW. The results obtained from this proposed hybrid urban saturated power load analysis model can serve as a reference for sustainable development for urban power grids, regional economies, and society at large.

Transitioning Groundwater from an Extractive Resource to a Managed Water Storage Resource: Geology and Recharge in Sedimentary Basins

Science.gov (United States)

Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.

2017-12-01

Civilizations have typically obtained water from natural and constructed surface-water resources throughout most of human history. Only during the last 50-70 years has a significant quantity of water for humans been obtained through pumping from wells. During this short time, alarming levels of groundwater depletion have been observed worldwide, especially in some semi-arid and arid regions that rely heavily on groundwater pumping from clastic sedimentary basins. In order to reverse the negative effects of over-exploitation of groundwater resources, we must transition from treating groundwater mainly as an extractive resource to one in which recharge and subsurface storage are pursued more aggressively. However, this remains a challenge because unlike surface-water reservoirs which are typically replenished over annual timescales, the complex geologic architecture of clastic sedimentary basins impedes natural groundwater recharge rates resulting in decadal or longer timescales for aquifer replenishment. In parts of California's Central Valley alluvial aquifer system, groundwater pumping has outpaced natural groundwater recharge for decades. Managed aquifer recharge (MAR) has been promoted to offset continued groundwater overdraft, but MAR to the confined aquifer system remains a challenge because multiple laterally-extensive silt and clay aquitards limit recharge rates in most locations. Here, we simulate the dynamics of MAR and identify potential recharge pathways in this system using a novel combination of (1) a high-resolution model of the subsurface geologic heterogeneity and (2) a physically-based model of variably-saturated, three-dimensional water flow. Unlike most groundwater models, which have coarse spatial resolution that obscures the detailed subsurface geologic architecture of these systems, our high-resolution model can pinpoint specific geologic features and locations that have the potential to `short-circuit' aquitards and provide orders

A state geological survey commitment to environmental geology - the Texas Bureau of Economic Geology

International Nuclear Information System (INIS)

Wermund, E.G.

1990-01-01

In several Texas environmental laws, the Bureau of Economic Geology is designated as a planning participant and review agency in the process of fulfilling environmental laws. Two examples are legislation on reclamation of surface mines and regulation of processing low level radioactive wastes. Also, the Bureau is the principal geological reviewer of all Environmental Assessments and Environmental Impact Statements which the Office of the Governor circulates for state review on all major developmental activities in Texas. The BEG continues its strong interest in environmental geology. In February 1988, it recommitted its Land Resources Laboratory, initiated in 1974, toward fulfilling needs of state, county, and city governments for consultation and research on environmental geologic problems. An editorial from another state geological survey would resemble the about description of texas work in environmental geology. State geological surveys have led federal agencies into many developments of environmental geology, complemented federal efforts in their evolution, and continued a strong commitment to the maintenance of a quality environment through innovative geologic studies

A gamma camera count rate saturation correction method for whole-body planar imaging

Science.gov (United States)

Hobbs, Robert F.; Baechler, Sébastien; Senthamizhchelvan, Srinivasan; Prideaux, Andrew R.; Esaias, Caroline E.; Reinhardt, Melvin; Frey, Eric C.; Loeb, David M.; Sgouros, George

2010-02-01

Whole-body (WB) planar imaging has long been one of the staple methods of dosimetry, and its quantification has been formalized by the MIRD Committee in pamphlet no 16. One of the issues not specifically addressed in the formalism occurs when the count rates reaching the detector are sufficiently high to result in camera count saturation. Camera dead-time effects have been extensively studied, but all of the developed correction methods assume static acquisitions. However, during WB planar (sweep) imaging, a variable amount of imaged activity exists in the detector's field of view as a function of time and therefore the camera saturation is time dependent. A new time-dependent algorithm was developed to correct for dead-time effects during WB planar acquisitions that accounts for relative motion between detector heads and imaged object. Static camera dead-time parameters were acquired by imaging decaying activity in a phantom and obtaining a saturation curve. Using these parameters, an iterative algorithm akin to Newton's method was developed, which takes into account the variable count rate seen by the detector as a function of time. The algorithm was tested on simulated data as well as on a whole-body scan of high activity Samarium-153 in an ellipsoid phantom. A complete set of parameters from unsaturated phantom data necessary for count rate to activity conversion was also obtained, including build-up and attenuation coefficients, in order to convert corrected count rate values to activity. The algorithm proved successful in accounting for motion- and time-dependent saturation effects in both the simulated and measured data and converged to any desired degree of precision. The clearance half-life calculated from the ellipsoid phantom data was calculated to be 45.1 h after dead-time correction and 51.4 h with no correction; the physical decay half-life of Samarium-153 is 46.3 h. Accurate WB planar dosimetry of high activities relies on successfully compensating

Lithological controls on gas hydrate saturation: Insights from signal classification of NMR downhole data

Science.gov (United States)

Bauer, Klaus; Kulenkampff, Johannes; Henninges, Jan; Spangenberg, Erik

2016-04-01

Nuclear magnetic resonance (NMR) downhole data are analyzed with a new strategy to study gas hydrate-bearing sediments in the Mackenzie Delta (NW Canada). NMR logging is a powerful tool to study geological reservoir formations. The measurements are based on interactions between the magnetic moments of protons in geological formation water and an external magnetic field. Inversion of the measured raw data provides so-called transverse relaxation time (T2) distribution curves or spectra. Different parts of the T2 curve are related with distinct pore radii and corresponding fluid components. A common practice in the analysis of T2 distribution curves is to extract single-valued parameters such as apparent total porosity. Moreover, the derived total NMR apparent porosity and the gamma-gamma density log apparent porosity can be combined to estimate gas hydrate saturation in hydrate-bearing sediments. To avoid potential loss of information, in our new approach we analyze the entire T2 distribution curves as quasi-continuous signals to characterize the rock formation. The approach is applied to NMR data measured in gas hydrate research well Mallik 5L-38. We use self-organizing maps, a neural network clustering technique, to subdivide the data set of NMR T2 distribution curves into classes with a similar and distinctive signal shape. The method includes (1) preparation of data vectors, (2) unsupervised learning, (3) cluster definition, and (4) classification and depth mapping of all NMR signals. Each signal class thus represents a specific pore size distribution which can be interpreted in terms of distinct lithologies and reservoir types. A key step in the interpretation strategy is to reconcile the NMR classes with other log data not considered in the clustering analysis, such as gamma ray, photo-electric factor, hydrate saturation, and other logs. Our results defined six main lithologies within the target zone. Gas hydrate layers were recognized by their low signal

Transient Calibration of a Variably-Saturated Groundwater Flow Model By Iterative Ensemble Smoothering: Synthetic Case and Application to the Flow Induced During Shaft Excavation and Operation of the Bure Underground Research Laboratory

Science.gov (United States)

Lam, D. T.; Kerrou, J.; Benabderrahmane, H.; Perrochet, P.

2017-12-01

The calibration of groundwater flow models in transient state can be motivated by the expected improved characterization of the aquifer hydraulic properties, especially when supported by a rich transient dataset. In the prospect of setting up a calibration strategy for a variably-saturated transient groundwater flow model of the area around the ANDRA's Bure Underground Research Laboratory, we wish to take advantage of the long hydraulic head and flowrate time series collected near and at the access shafts in order to help inform the model hydraulic parameters. A promising inverse approach for such high-dimensional nonlinear model, and which applicability has been illustrated more extensively in other scientific fields, could be an iterative ensemble smoother algorithm initially developed for a reservoir engineering problem. Furthermore, the ensemble-based stochastic framework will allow to address to some extent the uncertainty of the calibration for a subsequent analysis of a flow process dependent prediction. By assimilating the available data in one single step, this method iteratively updates each member of an initial ensemble of stochastic realizations of parameters until the minimization of an objective function. However, as it is well known for ensemble-based Kalman methods, this correction computed from approximations of covariance matrices is most efficient when the ensemble realizations are multi-Gaussian. As shown by the comparison of the updated ensemble mean obtained for our simplified synthetic model of 2D vertical flow by using either multi-Gaussian or multipoint simulations of parameters, the ensemble smoother fails to preserve the initial connectivity of the facies and the parameter bimodal distribution. Given the geological structures depicted by the multi-layered geological model built for the real case, our goal is to find how to still best leverage the performance of the ensemble smoother while using an initial ensemble of conditional multi

Hydrogen transfer experiments and modelization in clay rocks for radioactive waste deep geological repository

International Nuclear Information System (INIS)

Boulin, P.

2008-10-01

Gases will be generated by corrosion of high radioactive waste containers in deep geological repositories. A gas phase will be generated. Gas pressure will build up and penetrated the geological formation. If gases do not penetrate the geological barrier efficiently, the pressure build up may create a risk of fracturing and of creation of preferential pathways for radionuclide migration. The present work focuses on Callovo-Oxfordian argillites characterisation. An experiment, designed to measure very low permeabilities, was used with hydrogen/helium and analysed using the Dusty Gas Model. Argillites close to saturation have an accessible porosity to gas transfer that is lower than 0,1% to 1% of the porosity. Analysis of the Knudsen effect suggests that this accessible network should be made of 50 nm to 200 nm diameter pores. The permeabilities values were integrated to an ANDRA operating model. The model showed that the maximum pressure expected near the repository would be 83 bar. (author)

Laboratory analysis of fluid flow and solute transport through a variably saturated fracture embedded in porous tuff

International Nuclear Information System (INIS)

Chuang, Y.; Haldeman, W.R.; Rasmussen, T.C.; Evans, D.D.

1990-02-01

Laboratory techniques are developed that allow concurrent measurement of unsaturated matrix hydraulic conductivity and fracture transmissivity of fractured rock blocks. Two Apache Leap tuff blocks with natural fractures were removed from near Superior, Arizona, shaped into rectangular prisms, and instrumented in the laboratory. Porous ceramic plates provided solution to block tops at regulated pressures. Infiltration tests were performed on both test blocks. Steady flow testing of the saturated first block provided estimates of matrix hydraulic conductivity and fracture transmissivity. Fifteen centimeters of suction applied to the second block top showed that fracture flow was minimal and matrix hydraulic conductivity was an order of magnitude less than the first block saturated matrix conductivity. Coated-wire ion-selective electrodes monitored aqueous chlorided breakthrough concentrations. Minute samples of tracer solution were collected with filter paper. The techniques worked well for studying transport behavior at near-saturated flow conditions and also appear to be promising for unsaturated conditions. Breakthrough curves in the fracture and matrix, and a concentration map of chloride concentrations within the fracture, suggest preferential flows paths in the fracture and substantial diffusion into the matrix. Average travel velocity, dispersion coefficient and longitudinal dispersivity in the fracture are obtained. 67 refs., 54 figs., 23 tabs

Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

NARCIS (Netherlands)

van Beest, Paul A.; van der Schors, Alice; Liefers, Henriëtte; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michaël A.; Spronk, Peter E.

2012-01-01

Objective: The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design: Prospective observational controlled study. Setting: Nonacademic university-affiliated

Methods and apparatus for measurement of the resistivity of geological formations from within cased boreholes

Science.gov (United States)

Vail, III, William B.

1989-01-01

Methods and apparatus are disclosed which allow measurement of the resistivity of a geological formation through borehole casing which may be surrounded by brine saturated cement. A.C. current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. The A.C. voltage difference is measured between two additional vertically disposed electrodes on the interior of the casing which provides a measure of the resistivity of the geological formation. A calibration and nulling procedure is presented which minimizes the influence of variations in the thickness of the casing. The procedure also minimizes the influence of inaccurate placements of the additional vertically disposed electrodes.

A saturation property of structures obtained by forcing with a compact family of random variables

Czech Academy of Sciences Publication Activity Database

Krajíček, Jan

2013-01-01

Roč. 52, 1-2 (2013), s. 19-28 ISSN 1432-0665 R&D Projects: GA AV ČR IAA100190902 Keywords : Boolean-valued structures * saturation property * non-standard model of arithmetic Subject RIV: BA - General Mathematics Impact factor: 0.324, year: 2013 http://link.springer.com/article/10.1007%2Fs00153-012-0304-9

Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

NARCIS (Netherlands)

van Beest, Paul A.; van der Schors, Alice; Liefers, Henriette; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michael A.; Spronk, Peter E.

2012-01-01

Objective:  The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design:  Prospective observational controlled study. Setting:  Nonacademic university-affiliated

Transformation of seismic velocity data to extract porosity and saturation values for rocks

International Nuclear Information System (INIS)

Berryman, James G.; Berge, Patricia A.; Bonner, Brian P.

2000-01-01

For wave propagation at low frequencies in a porous medium, the Gassmann-Domenico relations are well-established for homogeneous partial saturation by a liquid. They provide the correct relations for seismic velocities in terms of constituent bulk and shear moduli, solid and fluid densities, porosity and saturation. It has not been possible, however, to invert these relations easily to determine porosity and saturation when the seismic velocities are known. Also, the state (or distribution) of saturation, i.e., whether or not liquid and gas are homogeneously mixed in the pore space, is another important variable for reservoir evaluation. A reliable ability to determine the state of saturation from velocity data continues to be problematic. It is shown how transforming compressional and shear wave velocity data to the (ρ/λ,μ/λ)-plane (where λ and μ are the Lame parameters and ρ is the total density) results in a set of quasi-orthogonal coordinates for porosity and liquid saturation that greatly aids in the interpretation of seismic data for the physical parameters of most interest. A second transformation of the same data then permits isolation of the liquid saturation value, and also provides some direct information about the state of saturation. By thus replotting the data in the (λ/μ, ρ/μ)-plane, inferences can be made concerning the degree of patchy (inhomogeneous) versus homogeneous saturation that is present in the region of the medium sampled by the data. Our examples include igneous and sedimentary rocks, as well as man-made porous materials. These results have potential applications in various areas of interest, including petroleum exploration and reservoir characterization, geothermal resource evaluation, environmental restoration monitoring, and geotechnical site characterization. (c) 2000 Acoustical Society of America

In-situ gas hydrate hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

Science.gov (United States)

Lee, M.W.; Collett, T.S.

2011-01-01

In 2006, the U.S. Geological Survey (USGS) completed detailed analysis and interpretation of available 2-D and 3-D seismic data and proposed a viable method for identifying sub-permafrost gas hydrate prospects within the gas hydrate stability zone in the Milne Point area of northern Alaska. To validate the predictions of the USGS and to acquire critical reservoir data needed to develop a long-term production testing program, a well was drilled at the Mount Elbert prospect in February, 2007. Numerous well log data and cores were acquired to estimate in-situ gas hydrate saturations and reservoir properties.Gas hydrate saturations were estimated from various well logs such as nuclear magnetic resonance (NMR), P- and S-wave velocity, and electrical resistivity logs along with pore-water salinity. Gas hydrate saturations from the NMR log agree well with those estimated from P- and S-wave velocity data. Because of the low salinity of the connate water and the low formation temperature, the resistivity of connate water is comparable to that of shale. Therefore, the effect of clay should be accounted for to accurately estimate gas hydrate saturations from the resistivity data. Two highly gas hydrate-saturated intervals are identified - an upper ???43 ft zone with an average gas hydrate saturation of 54% and a lower ???53 ft zone with an average gas hydrate saturation of 50%; both zones reach a maximum of about 75% saturation. ?? 2009.

Applications of geological labs on chip for CO_2 storage issues

International Nuclear Information System (INIS)

Morais, Sandy

2016-01-01

CO_2 geological storage in deep saline aquifers represents a mediation solution for reducing the anthropogenic CO_2 emissions. Consequently, this kind of storage requires adequate scientific knowledge to evaluate injection scenarios, estimate reservoir capacity and assess leakage risks. In this context, we have developed and used high pressure/high temperature micro-fluidic tools to investigate the different mechanisms associated with CO_2 geological storage in deep saline aquifers. The silicon-Pyrex 2D porous networks (Geological Labs On Chips) can replicate the reservoir p,T conditions (25 ≤ T ≤ 50 C, 50 ≤ p ≤ 10 MPa), geological and topological properties. This thesis manuscript first highlights the strategies developed during this work to fabricate the GLoCs and to access to global characteristics of our porous media such as porosity and permeability, which are later compared to numerical modelling results. The carbon dioxide detection in GLoCs mimicking p,T conditions of geological reservoirs by using the direct integration of optical fiber for IR spectroscopy is presented. I then detail the strategies for following the dissolution of carbonates in GLoCs with X-rays laminography experiments.Then, the manuscript focuses on the use of GLoCs to investigate each CO_2 trapping mechanism at the pore scale. The direct optical visualization and image processing allow us to follow the evolution of the injected CO_2/aqueous phase within the reservoir, including displacement mechanisms and pore saturation levels. Eventually, I present the ongoing works such as experiments with reactive brines and hydrates formations in porous media [fr

Plane shock wave studies of geologic media

International Nuclear Information System (INIS)

Anderson, G.D.; Larson, D.B.

1977-01-01

Plane shock wave experiments have been conducted on eight geologic materials in an effort to determine the importance of time-dependent mechanical behavior. Of the eight rocks studied, only Westerly granite and nugget sandstone appear to show time independence. In the slightly porous materials (1-5 percent), Blair dolomite and sodium chloride, and in the highly porous (15 to 40 percent) rock, Mt. Helen tuff and Indiana limestone, time-dependent behavior is associated with the time required to close the available porosity. In water-saturated rocks the time dependence arises because the water that is present shows no indication of transformation to the higher pressure ice phases, thus suggesting the possibility that a metastable form of water exists under dynamic conditions

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

Energy Technology Data Exchange (ETDEWEB)

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2008-09-29

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured

Relations between Vegetation and Geologic Framework in Barrier Island

Science.gov (United States)

Smart, N. H.; Ferguson, J. B.; Lehner, J. D.; Taylor, D.; Tuttle, L. F., II; Wernette, P. A.

2017-12-01

Barrier islands provide valuable ecosystems and protective services to coastal communities. The longevity of barrier islands is threatened by sea-level rise, human impacts, and extreme storms. The purpose of this research is to evaluate how vegetation dynamics interact with the subsurface and offshore framework geology to influence the beach and dune morphology. Beach and dune morphology can be viewed as free and/or forced behavior, where free systems are stochastic and the morphology is dependent on variations in the storm surge run-up, aeolian sediment supply and transport potential, and vegetation dynamics and persistence. Forced systems are those where patterns in the coastal morphology are determined by some other structural control, such as the underlying and offshore framework geology. Previous studies have documented the effects of geologic framework or vegetation dynamics on the beach and dunes, although none have examined possible control by vegetation dynamics in context of the geologic framework (i.e. combined free and forced behavior). Padre Island National Seashore (PAIS) was used to examine the interaction of free and forced morphology because the subsurface framework geology and surface beach and dune morphology are variable along the island. Vegetation dynamics were assessed by classifying geographically referenced historical aerial imagery into areas with vegetation and areas without vegetation, as well as LiDAR data to verify this imagery. The subsurface geologic structure was assessed using a combination of geophysical surveys (i.e. electromagnetic induction, ground-penetrating radar, and offshore seismic surveys). Comparison of the observed vegetation patterns and geologic framework leads to a series of questions surrounding how mechanistically these two drivers of coastal morphology are related. Upcoming coring and geophysical surveys will enable us to validate new and existing geophysical data. Results of this paper will help us better

Improved forward and inverse analyses of saturated-unsaturated flow toward a well in a compressible unconfined aquifer

Science.gov (United States)

Mishra, Phoolendra Kumar; Neuman, Shlomo P.

2010-07-01

We present an analytical solution for flow to a partially penetrating well in a compressible unconfined aquifer that allows inferring its saturated and unsaturated hydraulic properties from drawdowns recorded in the saturated and/or unsaturated zone. We improve upon a previous such solution due to Tartakovsky and Neuman (2007) by (1) adopting a more flexible representation of unsaturated zone constitutive properties and (2) allowing the unsaturated zone to have finite thickness. Both solutions account for horizontal as well as vertical flows throughout the system. We investigate the effects of unsaturated zone constitutive parameters and thickness on drawdowns in the saturated and unsaturated zones as functions of position and time; demonstrate the development of significant horizontal hydraulic gradients in the unsaturated zone in response to pumping; validate our solution against numerical simulations of drawdown in a synthetic aquifer having unsaturated properties described by the van Genuchten-Mualem constitutive model; use our solution to analyze drawdown data from a pumping test conducted by the U.S. Geological Survey at Cape Cod, Massachusetts; and compare our estimates of van Genuchten-Mualem parameters with laboratory values obtained for similar materials in the area.

Improved Geologic Interpretation of Non-invasive Electrical Resistivity Imaging from In-situ Samples

Science.gov (United States)

Mucelli, A.; Aborn, L.; Jacob, R.; Malusis, M.; Evans, J.

2016-12-01

Non-invasive geophysical techniques are useful in characterizing the subsurface geology without disturbing the environment, however, the ability to interpret the subsurface is enhanced by invasive work. Since geologic materials have electrical resistivity values it allows for a geologic interpretation to be made based on variations of electrical resistivity measured by electrical resistivity imaging (ERI). This study focuses on the pre-characterization of the geologic subsurface from ERI collected adjacent to the Montandon Marsh, a wetland located near Lewisburg, PA within the West Branch of the Susquehanna River watershed. The previous invasive data, boreholes, indicate that the subsurface consists of limestone and shale bedrock overlain with sand and gravel deposits from glacial outwash and aeolian processes. The objective is to improve our understanding of the subsurface at this long-term hydrologic research site by using excavation results, specifically observed variations in geologic materials and electrical resistivity laboratory testing of subsurface samples. The pre-excavation ERI indicated that the shallow-most geologic material had a resistivity value of 100-500 ohm-m. In comparison, the laboratory testing indicated the shallow-most material had the same range of electrical resistivity values depending on saturation levels. The ERI also showed that there was an electrically conductive material, 7 to 70 ohm-m, that was interpreted to be clay and agreed with borehole data, however, the excavation revealed that at this depth range the geologic material varied from stratified clay to clay with cobbles to weathered residual clay. Excavation revealed that the subtle variations in the electrical conductive material corresponded well with the variations in the geologic material. We will use these results to reinterpret previously collected ERI data from the entire long-term research site.

Spatiotemporal variability of dimethylsulphoniopropionate on a fringing coral reef: the role of reefal carbonate chemistry and environmental variability.

Directory of Open Access Journals (Sweden)

Heidi L Burdett

Full Text Available Oceanic pH is projected to decrease by up to 0.5 units by 2100 (a process known as ocean acidification, OA, reducing the calcium carbonate saturation state of the oceans. The coastal ocean is expected to experience periods of even lower carbonate saturation state because of the inherent natural variability of coastal habitats. Thus, in order to accurately project the impact of OA on the coastal ocean, we must first understand its natural variability. The production of dimethylsulphoniopropionate (DMSP by marine algae and the release of DMSP's breakdown product dimethylsulphide (DMS are often related to environmental stress. This study investigated the spatiotemporal response of tropical macroalgae (Padina sp., Amphiroa sp. and Turbinaria sp. and the overlying water column to natural changes in reefal carbonate chemistry. We compared macroalgal intracellular DMSP and water column DMSP+DMS concentrations between the environmentally stable reef crest and environmentally variable reef flat of the fringing Suleman Reef, Egypt, over 45-hour sampling periods. Similar diel patterns were observed throughout: maximum intracellular DMSP and water column DMS/P concentrations were observed at night, coinciding with the time of lowest carbonate saturation state. Spatially, water column DMS/P concentrations were highest over areas dominated by seagrass and macroalgae (dissolved DMS/P and phytoplankton (particulate DMS/P rather than corals. This research suggests that macroalgae may use DMSP to maintain metabolic function during periods of low carbonate saturation state. In the reef system, seagrass and macroalgae may be more important benthic producers of dissolved DMS/P than corals. An increase in DMS/P concentrations during periods of low carbonate saturation state may become ecologically important in the future under an OA regime, impacting larval settlement and increasing atmospheric emissions of DMS.

Prediction of the saturated hydraulic conductivity from Brooks and Corey’s water retention parameters

NARCIS (Netherlands)

Nasta, P.; Vrugt, J.A.; Romano, N.

2013-01-01

Prediction of flow through variably saturated porous media requires accurate knowledge of the soil hydraulic properties, namely the water retention function (WRF) and the hydraulic conductivity function (HCF). Unfortunately, direct measurement of the HCF is time consuming and expensive. In this

Partially to fully saturated flow through smooth, clean, open fractures: qualitative experimental studies

Science.gov (United States)

Jones, Brendon R.; Brouwers, Luke B.; Dippenaar, Matthys A.

2018-05-01

Fractures are both rough and irregular but can be expressed by a simple model concept of two smooth parallel plates and the associated cubic law governing discharge through saturated fractures. However, in natural conditions and in the intermediate vadose zone, these assumptions are likely violated. This paper presents a qualitative experimental study investigating the cubic law under variable saturation in initially dry free-draining discrete fractures. The study comprised flow visualisation experiments conducted on transparent replicas of smooth parallel plates with inlet conditions of constant pressure and differing flow rates over both vertical and horizontal inclination. Flow conditions were altered to investigate the influence of intermittent and continuous influx scenarios. Findings from this research proved, for instance, that saturated laminar flow is not likely achieved, especially in nonhorizontal fractures. In vertical fractures, preferential flow occupies the minority of cross-sectional area despite the water supply. Movement of water through the fractured vadose zone therefore becomes a matter of the continuity principle, whereby water should theoretically be transported downward at significantly higher flow rates given the very low degree of water saturation. Current techniques that aim to quantify discrete fracture flow, notably at partial saturation, are questionable. Inspired by the results of this study, it is therefore hypothetically improbable to achieve saturation in vertical fractures under free-draining wetting conditions. It does become possible under extremely excessive water inflows or when not free-draining; however, the converse is not true, as a wet vertical fracture can be drained.

Partially to fully saturated flow through smooth, clean, open fractures: qualitative experimental studies

Science.gov (United States)

Jones, Brendon R.; Brouwers, Luke B.; Dippenaar, Matthys A.

2017-11-01

Fractures are both rough and irregular but can be expressed by a simple model concept of two smooth parallel plates and the associated cubic law governing discharge through saturated fractures. However, in natural conditions and in the intermediate vadose zone, these assumptions are likely violated. This paper presents a qualitative experimental study investigating the cubic law under variable saturation in initially dry free-draining discrete fractures. The study comprised flow visualisation experiments conducted on transparent replicas of smooth parallel plates with inlet conditions of constant pressure and differing flow rates over both vertical and horizontal inclination. Flow conditions were altered to investigate the influence of intermittent and continuous influx scenarios. Findings from this research proved, for instance, that saturated laminar flow is not likely achieved, especially in nonhorizontal fractures. In vertical fractures, preferential flow occupies the minority of cross-sectional area despite the water supply. Movement of water through the fractured vadose zone therefore becomes a matter of the continuity principle, whereby water should theoretically be transported downward at significantly higher flow rates given the very low degree of water saturation. Current techniques that aim to quantify discrete fracture flow, notably at partial saturation, are questionable. Inspired by the results of this study, it is therefore hypothetically improbable to achieve saturation in vertical fractures under free-draining wetting conditions. It does become possible under extremely excessive water inflows or when not free-draining; however, the converse is not true, as a wet vertical fracture can be drained.

Geophysical assessments of renewable gas energy compressed in geologic pore storage reservoirs.

Science.gov (United States)

Al Hagrey, Said Attia; Köhn, Daniel; Rabbel, Wolfgang

2014-01-01

Renewable energy resources can indisputably minimize the threat of global warming and climate change. However, they are intermittent and need buffer storage to bridge the time-gap between production (off peak) and demand peaks. Based on geologic and geochemical reasons, the North German Basin has a very large capacity for compressed air/gas energy storage CAES in porous saltwater aquifers and salt cavities. Replacing pore reservoir brine with CAES causes changes in physical properties (elastic moduli, density and electrical properties) and justify applications of integrative geophysical methods for monitoring this energy storage. Here we apply techniques of the elastic full waveform inversion FWI, electric resistivity tomography ERT and gravity to map and quantify a gradually saturated gas plume injected in a thin deep saline aquifer within the North German Basin. For this subsurface model scenario we generated different synthetic data sets without and with adding random noise in order to robust the applied techniques for the real field applications. Datasets are inverted by posing different constraints on the initial model. Results reveal principally the capability of the applied integrative geophysical approach to resolve the CAES targets (plume, host reservoir, and cap rock). Constrained inversion models of elastic FWI and ERT are even able to recover well the gradual gas desaturation with depth. The spatial parameters accurately recovered from each technique are applied in the adequate petrophysical equations to yield precise quantifications of gas saturations. Resulting models of gas saturations independently determined from elastic FWI and ERT techniques are in accordance with each other and with the input (true) saturation model. Moreover, the gravity technique show high sensitivity to the mass deficit resulting from the gas storage and can resolve saturations and temporal saturation changes down to ±3% after reducing any shallow fluctuation such as that of

Corrosion of iron and low alloyed steel within a water saturated brick of clay under anaerobic deep geological disposal conditions: An integrated experiment

International Nuclear Information System (INIS)

Martin, F.A.; Bataillon, C.; Schlegel, M.L.

2008-01-01

The aim of this study was to determine the corrosion behaviour of iron and low alloyed steels under simulated geological disposal conditions, related to long-term disposal of nuclear wastes in the site of Bure (Meuse-Haute Marne, Champagne, France). The dedicated experiment was a fully integrated set-up: three different bars of material (iron, steel or nickel) have been introduced inside a solid block of clay, which has been saturated with synthetic Bure water and maintained at 90 deg. C during 8 months. Two types of clay have been tested: first, a compacted MX80 (Wyoming, USA) and second, argilite directly taken from the Bure site (Callovo-Oxfordian). In situ electrochemistry has been performed: impedance spectra, chronopotentiometry... The samples have been analysed using a combination of techniques, such as SEM, XRD, EDS, μXAS, μRaman, gravimetry after desquamation. In both cases, the steel or the iron seemed to passivate in contact with the clay. Post-processing of the EIS determined the corrosion rates and the changes in the kinetics have been noticed. The post mortem analysis of the corrosion products showed in both cases the presence of an internal layer made of magnetite (Raman, EDX). The external layer was made of partially Ca-substituted siderite (Fe 1-x Ca x CO 3 ), which could play an extra role in the passivation. Moreover, the samples embedded in the Bure argilite presented an intermediate unique layer containing Fe, O, Na and Si. This study suggests the corrosion products started to react with the silica issued from the dissolution of the Bure clay minerals, resulting in clay minerals neo-formation and in corrosion kinetic changes

Stress-based Variable-inductor for Electronic Ballasts

DEFF Research Database (Denmark)

Zhang, Lihui; Xia, Yongming; Lu, Kaiyuan

2015-01-01

Current-controlled variable inductors adjust the inductance of an alternating current (ac) coil by applying a controlled dc current to saturate the iron cores of the ac coil. The controlled dc current has to be maintained during operation, which results in increased power losses. This paper prese......-based variable inductor concept is validated using a 3-D finite-element analysis. A prototype was manufactured, and the experimental results are presented. A linear relationship between inductance and applied stress can be achieved.......Current-controlled variable inductors adjust the inductance of an alternating current (ac) coil by applying a controlled dc current to saturate the iron cores of the ac coil. The controlled dc current has to be maintained during operation, which results in increased power losses. This paper...... presents a new stress-based variable inductor to control inductance using the inverse magnetostrictive effect of a magnetostrictive material. The stress can be applied by a piezoelectrical material, and thus a voltage-controlled variable inductor can be realized with zero-power consumption. The new stress...

Mobility Effect on Poroelastic Seismic Signatures in Partially Saturated Rocks With Applications in Time-Lapse Monitoring of a Heavy Oil Reservoir

Science.gov (United States)

Zhao, Luanxiao; Yuan, Hemin; Yang, Jingkang; Han, De-hua; Geng, Jianhua; Zhou, Rui; Li, Hui; Yao, Qiuliang

2017-11-01

Conventional seismic analysis in partially saturated rocks normally lays emphasis on estimating pore fluid content and saturation, typically ignoring the effect of mobility, which decides the ability of fluids moving in the porous rocks. Deformation resulting from a seismic wave in heterogeneous partially saturated media can cause pore fluid pressure relaxation at mesoscopic scale, thereby making the fluid mobility inherently associated with poroelastic reflectivity. For two typical gas-brine reservoir models, with the given rock and fluid properties, the numerical analysis suggests that variations of patchy fluid saturation, fluid compressibility contrast, and acoustic stiffness of rock frame collectively affect the seismic reflection dependence on mobility. In particular, the realistic compressibility contrast of fluid patches in shallow and deep reservoir environments plays an important role in determining the reflection sensitivity to mobility. We also use a time-lapse seismic data set from a Steam-Assisted Gravity Drainage producing heavy oil reservoir to demonstrate that mobility change coupled with patchy saturation possibly leads to seismic spectral energy shifting from the baseline to monitor line. Our workflow starts from performing seismic spectral analysis on the targeted reflectivity interface. Then, on the basis of mesoscopic fluid pressure diffusion between patches of steam and heavy oil, poroelastic reflectivity modeling is conducted to understand the shift of the central frequency toward low frequencies after the steam injection. The presented results open the possibility of monitoring mobility change of a partially saturated geological formation from dissipation-related seismic attributes.

SATURATED ZONE IN-SITU TESTING

Energy Technology Data Exchange (ETDEWEB)

P.W. REIMUS

2004-11-08

The purpose of this scientific analysis is to document the results and interpretations of field experiments that test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain, Nevada. The test interpretations provide estimates of flow and transport parameters used in the development of parameter distributions for total system performance assessment (TSPA) calculations. These parameter distributions are documented in ''Site-Scale Saturated Zone Flow Model (BSC 2004 [DIRS 170037]), Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]), Saturated Zone Colloid Transport (BSC 2004 [DIRS 170006]), and ''Saturated Zone Flow and Transport Model Abstraction'' (BSC 2004 [DIRS 170042]). Specifically, this scientific analysis contributes the following to the assessment of the capability of the SZ to serve as part of a natural barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid transport parameters. (3) Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium at the Alluvial Testing Complex (ATC) located at the southwestern corner of the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic conductivities, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass

SATURATED ZONE IN-SITU TESTING

International Nuclear Information System (INIS)

REIMUS, P.W.

2004-01-01

The purpose of this scientific analysis is to document the results and interpretations of field experiments that test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain, Nevada. The test interpretations provide estimates of flow and transport parameters used in the development of parameter distributions for total system performance assessment (TSPA) calculations. These parameter distributions are documented in ''Site-Scale Saturated Zone Flow Model (BSC 2004 [DIRS 170037]), Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]), Saturated Zone Colloid Transport (BSC 2004 [DIRS 170006]), and ''Saturated Zone Flow and Transport Model Abstraction'' (BSC 2004 [DIRS 170042]). Specifically, this scientific analysis contributes the following to the assessment of the capability of the SZ to serve as part of a natural barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid transport parameters. (3) Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium at the Alluvial Testing Complex (ATC) located at the southwestern corner of the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic conductivities, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, and colloid

Automatic NAA. Saturation activities

International Nuclear Information System (INIS)

Westphal, G.P.; Grass, F.; Kuhnert, M.

2008-01-01

A system for Automatic NAA is based on a list of specific saturation activities determined for one irradiation position at a given neutron flux and a single detector geometry. Originally compiled from measurements of standard reference materials, the list may be extended also by the calculation of saturation activities from k 0 and Q 0 factors, and f and α values of the irradiation position. A systematic improvement of the SRM approach is currently being performed by pseudo-cyclic activation analysis, to reduce counting errors. From these measurements, the list of saturation activities is recalculated in an automatic procedure. (author)

Well materials durability in case of carbon dioxide and hydrogen sulphide geological sequestration

International Nuclear Information System (INIS)

Jacquemet, N.

2006-01-01

The geological sequestration of carbon dioxide (CO 2 ) and hydrogen sulphide (H 2 S) is a promising solution for the long-term storage of these undesirable gases. It consists in injecting them via wells into deep geological reservoirs. The steel and cement employed in the well casing can be altered and provide pathways for leakage with subsequent human and environmental consequences. The materials ageing was investigated by laboratory experiments in geologically relevant P-T conditions. A new experimental and analysis procedure was designed for this purpose. A numerical approach was also done. The cement and steel were altered in various fluid phases at 500 bar-120 C and 500 bar-200 C: a brine, a brine saturated with H 2 S-CO 2 , a mixture of brine saturated with H 2 S-CO 2 and of supercritical H 2 S-CO 2 phase, a dry supercritical H 2 S-CO 2 phase without liquid water. In all cases, two distinct reactions are observed: the cement carbonation by the CO 2 and the steel sulfidation by the H 2 S. The carbonation and sulfidation are respectively maximal and minimal when they occur within the dry supercritical phase without liquid water. The textural and porosity properties of the cement are weakly affected by all the treatments at 120 C. The porosity even decreases in presence of H 2 S-CO 2 . But these properties are affected at 200 C when liquid water is present in the system. At this temperature, the initial properties are only preserved or improved by the treatments within the dry supercritical phase. The steel is corroded in all cases and thus is the vulnerable material of the wells. (author)

Effect of soil saturation on denitrification in a grassland soil

Directory of Open Access Journals (Sweden)

L. M. Cardenas

2017-10-01

Full Text Available Nitrous oxide (N2O is of major importance as a greenhouse gas and precursor of ozone (O3 destruction in the stratosphere mostly produced in soils. The soil-emitted N2O is generally predominantly derived from denitrification and, to a smaller extent, nitrification, both processes controlled by environmental factors and their interactions, and are influenced by agricultural management. Soil water content expressed as water-filled pore space (WFPS is a major controlling factor of emissions and its interaction with compaction, has not been studied at the micropore scale. A laboratory incubation was carried out at different saturation levels for a grassland soil and emissions of N2O and N2 were measured as well as the isotopocules of N2O. We found that flux variability was larger in the less saturated soils probably due to nutrient distribution heterogeneity created from soil cracks and consequently nutrient hot spots. The results agreed with denitrification as the main source of fluxes at the highest saturations, but nitrification could have occurred at the lower saturation, even though moisture was still high (71 % WFSP. The isotopocules data indicated isotopic similarities in the wettest treatments vs. the two drier ones. The results agreed with previous findings where it is clear there are two N pools with different dynamics: added N producing intense denitrification vs. soil N resulting in less isotopic fractionation.

Damping Effect of an Unsaturated-Saturated System on Tempospatial Variations of Pressure Head and Specific Flux

Science.gov (United States)

Yang, C.; Zhang, Y. K.; Liang, X.

2014-12-01

Damping effect of an unsaturated-saturated system on tempospatialvariations of pressurehead and specificflux was investigated. The variance and covariance of both pressure head and specific flux in such a system due to a white noise infiltration were obtained by solving the moment equations of water flow in the system and verified with Monte Carlo simulations. It was found that both the pressure head and specific flux in this case are temporally non-stationary. The variance is zero at early time due to a deterministic initial condition used, then increases with time, and approaches anasymptotic limit at late time.Both pressure head and specific flux arealso non-stationary in space since the variance decreases from source to sink. The unsaturated-saturated systembehavesasa noise filterand it damps both the pressure head and specific flux, i.e., reduces their variations and enhances their correlation. The effect is stronger in upper unsaturated zone than in lower unsaturated zone and saturated zone. As a noise filter, the unsaturated-saturated system is mainly a low pass filter, filtering out the high frequency components in the time series of hydrological variables. The damping effect is much stronger in the saturated zone than in the saturated zone.

Assessment of heterogeneous geological environment using geostatistical techniques

International Nuclear Information System (INIS)

Toida, Masaru; Suyama, Yasuhiro; Shiogama, Yukihiro; Atsumi, Hiroyuki; Abe, Yasunori; Furuichi, Mitsuaki

2003-02-01

'Geoscientific' research at Tono are developing site investigation and assessment techniques in geological environment. One of their important themes is to establish rational methodology to reduce uncertainties associated with the understanding of geological environment, which often exhibits significant heterogeneity. Purpose of this study is to identify and evaluate uncertainties associated with the understanding of geological environment. Because it is useful to guide designing effective site investigation techniques to reduce the uncertainty. For this, a methodology of the uncertainty analysis concerning the heterogeneous geological environment has been developed. In this report the methodology has also been tested through an exercise attempted in Tono area to demonstrate its applicability. This report summarizes as follows: 1) The exercise shows that the methodology considered 'variability' and 'ignorance' can demonstrate its applicability at three-dimensional case. 2) The exercise shows that the methodology can identity and evaluate uncertainties concerning ground water flow associated with performance assessment. 3) Based on sensitivity analyses, it is possible for the methodology to support designs of the following stage investigations to reduce the uncertainties efficiently. (author)

Biofilter design for effective nitrogen removal from stormwater - influence of plant species, inflow hydrology and use of a saturated zone.

Science.gov (United States)

Payne, Emily G I; Pham, Tracey; Cook, Perran L M; Fletcher, Tim D; Hatt, Belinda E; Deletic, Ana

2014-01-01

The use of biofilters to remove nitrogen and other pollutants from urban stormwater runoff has demonstrated varied success across laboratory and field studies. Design variables including plant species and use of a saturated zone have large impacts upon performance. A laboratory column study of 22 plant species and designs with varied outlet configuration was conducted across a 1.5-year period to further investigate the mechanisms and influences driving biofilter nitrogen processing. This paper presents outflow concentrations of total nitrogen from two sampling events across both 'wet' and 'dry' frequency dosing, and from sampling across two points in the outflow hydrograph. All plant species were effective under conditions of frequent dosing, but extended drying increased variation between species and highlighted the importance of a saturated zone in maintaining biofilter function. The saturated zone also effectively treated the volume of stormwater stored between inflow events, but this extended detention provided no additional benefit alongside the rapid processing of the highest performing species. Hence, the saturated zone reduced performance differences between plant species, and potentially acts as an 'insurance policy' against poor sub-optimal plant selection. The study shows the importance of biodiversity and inclusion of a saturated zone in protecting against climate variability.

Fault tolerant control of systems with saturations

DEFF Research Database (Denmark)

Niemann, Hans Henrik

2013-01-01

This paper presents framework for fault tolerant controllers (FTC) that includes input saturation. The controller architecture known from FTC is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization is extended to handle input saturation. Applying this controller architecture in connec......This paper presents framework for fault tolerant controllers (FTC) that includes input saturation. The controller architecture known from FTC is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization is extended to handle input saturation. Applying this controller architecture...... in connection with faulty systems including input saturation gives an additional YJBK transfer function related to the input saturation. In the fault free case, this additional YJBK transfer function can be applied directly for optimizing the feedback loop around the input saturation. In the faulty case......, the design problem is a mixed design problem involved both parametric faults and input saturation....

California Geological Survey Geologic Map Index

Data.gov (United States)

California Natural Resource Agency — All the individual maps from the Geologic Atlas of California and the Regional Geologic map series have been georeferenced for display in a GIS (and viewable online...

Dynamic simulations of geologic materials using combined FEM/DEM/SPH analysis

Energy Technology Data Exchange (ETDEWEB)

Morris, J P; Johnson, S M

2008-03-26

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, there are many application involving geologic materials where fluid-structure interaction is important. To facilitate solution of this class of problems a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC to simulate fully coupled systems involving geologic materials and a saturating fluid. We will present results from a study of a broad range of geomechanical problems that exercise the various components of LDEC in isolation and in tandem.

Comparison of pulseoximetry oxygen saturation and arterial oxygen saturation in open heart intensive care unit

Directory of Open Access Journals (Sweden)

Alireza Mahoori

2013-08-01

Full Text Available Background: Pulseoximetry is widely used in the critical care setting, currently used to guide therapeutic interventions. Few studies have evaluated the accuracy of SPO2 (puls-eoximetry oxygen saturation in intensive care unit after cardiac surgery. Our objective was to compare pulseoximetry with arterial oxygen saturation (SaO2 during clinical routine in such patients, and to examine the effect of mild acidosis on this relationship.Methods: In an observational prospective study 80 patients were evaluated in intensive care unit after cardiac surgery. SPO2 was recorded and compared with SaO2 obtained by blood gas analysis. One or serial arterial blood gas analyses (ABGs were performed via a radial artery line while a reliable pulseoximeter signal was present. One hundred thirty seven samples were collected and for each blood gas analyses, SaO2 and SPO2 we recorded.Results: O2 saturation as a marker of peripheral perfusion was measured by Pulseoxim-etry (SPO2. The mean difference between arterial oxygen saturation and pulseoximetry oxygen saturation was 0.12%±1.6%. A total of 137 paired readings demonstrated good correlation (r=0.754; P<0.0001 between changes in SPO2 and those in SaO2 in samples with normal hemoglobin. Also in forty seven samples with mild acidosis, paired readings demonstrated good correlation (r=0.799; P<0.0001 and the mean difference between SaO2 and SPO2 was 0.05%±1.5%.Conclusion: Data showed that in patients with stable hemodynamic and good signal quality, changes in pulseoximetry oxygen saturation reliably predict equivalent changes in arterial oxygen saturation. Mild acidosis doesn’t alter the relation between SPO2 and SaO2 to any clinically important extent. In conclusion, the pulse oximeter is useful to monitor oxygen saturation in patients with stable hemodynamic.

Sensitivity analysis and uncertainties simulation of the migration of radionuclide in the system of geological disposal-CRP-GEORC model

International Nuclear Information System (INIS)

Su Rui; Wang Ju; Chen Weiming; Zong Zihua; Zhao Honggang

2008-01-01

CRP-GEORC concept model is an artificial system of geological disposal for High-Level radioactive waste. Sensitivity analysis and uncertainties simulation of the migration of radionuclide Se-79 and I-129 in the far field of this system by using GoldSim Code have been conducted. It can be seen from the simulation results that variables used to describe the geological features and characterization of groundwater flow are sensitive variables of whole geological disposal system. The uncertainties of parameters have remarkable influence on the simulation results. (authors)

Modelling the effects of spatial variability on radionuclide migration

International Nuclear Information System (INIS)

1998-01-01

The NEA workshop reflect the present status in national waste management program, specifically in spatial variability and performance assessment of geologic disposal sites for deed repository system the four sessions were: Spatial Variability: Its Definition and Significance to Performance Assessment and Site Characterisation; Experience with the Modelling of Radionuclide Migration in the Presence of Spatial Variability in Various Geological Environments; New Areas for Investigation: Two Personal Views; What is Wanted and What is Feasible: Views and Future Plans in Selected Waste Management Organisations. The 26 papers presented on the four oral sessions and on the poster session have been abstracted and indexed individually for the INIS database. (R.P.)

Wellbore cement fracture evolution at the cement–basalt caprock interface during geologic carbon sequestration

Energy Technology Data Exchange (ETDEWEB)

Jung, Hun Bok; Kabilan, Senthil; Carson, James P.; Kuprat, Andrew P.; Um, Wooyong; Martin, Paul F.; Dahl, Michael E.; Kafentzis, Tyler A.; Varga, Tamas; Stephens, Sean A.; Arey, Bruce W.; Carroll, KC; Bonneville, Alain; Fernandez, Carlos A.

2014-08-07

Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 ºC and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. Micro-XRD and SEM-EDS data collected along the cement-basalt interface after 3-month reaction with CO2-saturated groundwater indicate that carbonation of cement matrix was extensive with the precipitation of calcite, aragonite, and vaterite, whereas the alteration of basalt caprock was minor. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. This study demonstrates that XMT imaging coupled with CFD modeling represent a powerful tool to visualize and quantify fracture evolution and permeability change in geologic materials and to predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal systems.

High Resolution Geological Site Characterization Utilizing Ground Motion Data

Science.gov (United States)

1992-06-26

rough near a service road, in low velocity, unsaturated, unconsolidated 7 sands. Other than native grass, there was no significant vegetation . Surface...literature, demonstrate slll kale field tests. Similar degrees of spatial variability in ground that these stochastic geologic effects pose a potentially

nitrogen saturation in stream ecosystems

OpenAIRE

Earl, S. R.; Valett, H. M.; Webster, J. R.

2006-01-01

The concept of nitrogen (N) saturation has organized the assessment of N loading in terrestrial ecosystems. Here we extend the concept to lotic ecosystems by coupling Michaelis-Menten kinetics and nutrient spiraling. We propose a series of saturation response types, which may be used to characterize the proximity of streams to N saturation. We conducted a series of short-term N releases using a tracer ((NO3)-N-15-N) to measure uptake. Experiments were conducted in streams spanning a gradient ...

Modeling study on geological environment at Horonobe URL site

International Nuclear Information System (INIS)

Shimo, Michito; Yamamoto, Hajime; Kumamoto, Sou; Fujiwara, Yasushi; Ono, Makoto

2005-02-01

The Horonobe underground research project has been operated by Japan Nuclear Cycle Development Institute to study the geological environment of sedimentary rocks in deep underground. The objectives of this study are to develop a geological environment model, which incorporate the current findings and the data obtained through the geological, geophysical, and borehole investigations at Horonobe site, and to predict the hydrological and geochemical impacts caused by the URL shaft excavation to the surrounding area. A three-dimensional geological structure model was constructed, integrating a large-scale model (25km x 15km) and a high-resolution site-scale model (4km x 4km) that have been developed by JNC. The constructed model includes surface topography, geologic formations (such as Yuchi, Koetoi, Wakkanai, and Masuporo Formations), and two major faults (Ohomagari fault and N1 fault). In hydrogeological modeling, water-conductive fractures identified in Wakkanai Formation are modeled stochastically using EHCM (Equivalent Heterogeneous Continuum Model) approach, to represent hydraulic heterogeneity and anisotropy in the fractured rock mass. Numerical code EQUIV FLO (Shimo et al., 1996), which is a 3D unsaturated-saturated groundwater simulator capable of EHCM, was used to simulate the regional groundwater flow. We used the same model and the code to predict the transient hydrological changes caused by the shaft excavations. Geochemical data in the Horonobe site such as water chemistries, mineral compositions of rocks were collected and summarized into digital datasets. M3 (Multivariate, Mixing and Mass-balance) method developed by SKB (Laaksoharju et al., 1999) was used to identify waters of different origins, and to infer the mixing ratio of these end-members to reproduce each sample's chemistry. Thermodynamic code such as RHREEQC, GWB, and EQ3/6 were used to model chemical reactions that explain the present minerals and aqueous concentrations observed in the site

Numerical simulation of water flow and Nitrate transport through variably saturated porous media in laboratory condition using HYDRUS 2D

Science.gov (United States)

Jahangeer, F.; Gupta, P. K.; Yadav, B. K.

2017-12-01

Due to the reducing availability of water resources and the growing competition for water between residential, industrial, and agricultural users, increasing irrigation efficiency, by several methods like drip irrigation, is a demanding concern for agricultural experts. The understanding of the water and contaminants flow through the subsurface is needed for the sustainable irrigation water management, pollution assessment, polluted site remediation and groundwater recharge. In this study, the Windows-based computer software package HYDRUS-2D, which numerically simulates water and solute movement in two-dimensional, variably-saturated porous media, was used to evaluate the distribution of water and Nitrate in the sand tank. The laboratory and simulation experiments were conducted to evaluate the role of drainage, recharge flux, and infiltration on subsurface flow condition and subsequently, on nitrate movement in the subsurface. The water flow in the unsaturated zone model by Richards' equation, which was highly nonlinear and its parameters were largely dependent on the moisture content and pressure head of the partially saturated zone. Following different cases to be considered to evaluate- a) applying drainage and recharge flux to study domains, b) transient infiltration in a vertical soil column and c) subsequently, nitrate transport in 2D sand tank setup. A single porosity model was used for the simulation of water and nitrate flow in the study domain. The results indicate the transient water table position decreases as the time increase significantly by applying drainage flux at the bottom. Similarly, the water table positions in study domains increasing in the domain by applying recharge flux. Likewise, the water flow profile shows the decreasing water table elevation with increasing water content in the vertical domain. Moreover, the nitrate movement was dominated by advective flux and highly affected by the recharge flux in the vertical direction. The

Radioactive waste disposal in geological formations

International Nuclear Information System (INIS)

Gera, F.

1977-01-01

The nuclear energy controversy, now raging in several countries, is based on two main issues: the safety of nuclear plants and the possibility to dispose safely of the long-lived radioactive wastes. Consideration of the evolution of the hazard potential of waste in function of decay time leads to a somewhat conservative reference containment time in the order of one hundred thousand years. Several concepts have been proposed for the disposal of long-lived wastes. At the present time, emplacement into suitable geological formations under land areas can be considered the most promising disposal option. It is practically impossible to define detailed criteria to be followed in selecting suitable sites for disposal of long-lived wastes. Basically there is a single criterion, namely; that the geological environment must be able to contain the wastes for at least a hundred thousand years. However, due to the extreme variability of geological settings, it is conceivable that this basic capability could be provided by a great variety of different conditions. The predominant natural mechanism by which waste radionuclides could be moved from a sealed repository in a deep geological formation into the biosphere is leaching and transfer by ground water. Hence the greatest challenge is to give a satisfactory demonstration that isolation from ground water will persist over the required containment time. Since geological predictions are necessarily affected by fairly high levels of uncertainty, the only practical approach is not a straight-forward forecast of future geological events, but a careful assessment of the upper limits of geologic changes that could take place in the repository area over the next hundred thousand years. If waste containment were to survive these extreme geological changes the disposal site could be considered acceptable. If some release of activity were to take place in consequence of the hypothetical events the disposal solution might still be

El fluoruro en aguas de consumo y su asociación con variables geológicas y geográficas de Cuba Fluoride in drinking water in Cuba and its association with geological and geographical variables

Directory of Open Access Journals (Sweden)

Liliam Cuéllar Luna

2003-11-01

Full Text Available OBJETIVO: Determinar la asociación entre las diferentes concentraciones del ión fluoruro en aguas de consumo y algunas variables geológicas y geográficas de Cuba, mediante el empleo de un sistema de información geográfica. MÉTODOS: De noviembre de 1998 a octubre de 1999 se estudiaron las concentraciones de fluoruro en fuentes de abastecimiento de agua de consumo de 753 localidades cubanas de 1 000 habitantes o más. Para el análisis de la información se utilizó el sistema de información geográfica MapInfo Professional (v. 5.5 con el método de superposición. Las variables de estudio fueron la concentración del ión fluoruro en fuentes de abastecimiento de agua, las características geológicas del territorio, los alineamientos, los tipos de fuente y las categorías de relieve (llanura o montaña. Los resultados se agruparon por localidad y municipio. RESULTADOS: En 83,1% de las localidades, las muestras de agua fueron recolectadas en pozos y manantiales y en el 16,9% restante, en presas y ríos. De las 753 localidades estudiadas, 675 (89,6% presentaron concentraciones de fluoruro bajas o medias (OBJECTIVE: To determine the association between different concentrations of the fluoride ion in drinking water and some geological and geographical variables in Cuba, by using a geographic information system. METHODS: From November 1998 to October 1999 we studied the fluoride concentration in the sources of drinking water for 753 Cuban localities that had at least 1 000 inhabitants. For the information analysis we utilized the MapInfo Professional version 5.5 geographic information system, using the overlaying method. The study variables were the concentration of the fluoride ion in the water sources, the geological characteristics of the area, the alignments (geological characteristics that were found together, the types of water sources, and whether an area was a plain or mountainous. The results were grouped by locality and municipality

Zoning method for environmental engineering geological patterns in underground coal mining areas.

Science.gov (United States)

Liu, Shiliang; Li, Wenping; Wang, Qiqing

2018-09-01

Environmental engineering geological patterns (EEGPs) are used to express the trend and intensity of eco-geological environment caused by mining in underground coal mining areas, a complex process controlled by multiple factors. A new zoning method for EEGPs was developed based on the variable-weight theory (VWT), where the weights of factors vary with their value. The method was applied to the Yushenfu mining area, Shaanxi, China. First, the mechanism of the EEGPs caused by mining was elucidated, and four types of EEGPs were proposed. Subsequently, 13 key control factors were selected from mining conditions, lithosphere, hydrosphere, ecosphere, and climatic conditions; their thematic maps were constructed using ArcGIS software and remote-sensing technologies. Then, a stimulation-punishment variable-weight model derived from the partition of basic evaluation unit of study area, construction of partition state-variable-weight vector, and determination of variable-weight interval was built to calculate the variable weights of each factor. On this basis, a zoning mathematical model of EEGPs was established, and the zoning results were analyzed. For comparison, the traditional constant-weight theory (CWT) was also applied to divide the EEGPs. Finally, the zoning results obtained using VWT and CWT were compared. The verification of field investigation indicates that VWT is more accurate and reliable than CWT. The zoning results are consistent with the actual situations and the key of planning design for the rational development of coal resources and protection of eco-geological environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Soil aquifer treatment of artificial wastewater under saturated conditions

KAUST Repository

Essandoh, H. M K

2011-05-01

A 2000 mm long saturated laboratory soil column was used to simulate soil aquifer treatment under saturated conditions to assess the removal of chemical and biochemical oxygen demand (COD and BOD), dissolved organic carbon (DOC), nitrogen and phosphate, using high strength artificial wastewater. The removal rates were determined under a combination of constant hydraulic loading rates (HLR) and variable COD concentrations as well as variable HLR under a constant COD. Within the range of COD concentrations considered (42 mg L-1-135 mg L-1) it was found that at fixed hydraulic loading rate, a decrease in the influent concentrations of dissolved organic carbon (DOC), biochemical oxygen demand (BOD), total nitrogen and phosphate improved their removal efficiencies. At the high COD concentrations applied residence times influenced the redox conditions in the soil column. Long residence times were detrimental to the removal process for COD, BOD and DOC as anoxic processes and sulphate reduction played an important role as electron acceptors. It was found that total COD mass loading within the range of 911 mg d-1-1780 mg d-1 applied as low COD wastewater infiltrated coupled with short residence times would provide better effluent quality than the same mass applied as a COD with higher concentration at long residence times. The opposite was true for organic nitrogen where relatively high concentrations coupled with long residence time gave better removal efficiency. © 2011.

Semiconductor saturable absorbers for ultrafast terahertz signals

DEFF Research Database (Denmark)

Hoffmann, Matthias C.; Turchinovich, Dmitry

2010-01-01

states, due to conduction band onparabolicity and scattering into satellite valleys in strong THz fields. Saturable absorber parameters, such as linear and nonsaturable transmission, and saturation fluence, are extracted by fits to a classic saturable absorber model. Further, we observe THz pulse......We demonstrate saturable absorber behavior of n-type semiconductors GaAs, GaP, and Ge in the terahertz THz frequency range at room temperature using nonlinear THz spectroscopy. The saturation mechanism is based on a decrease in electron conductivity of semiconductors at high electron momentum...

Robust control for spacecraft rendezvous system with actuator unsymmetrical saturation: a gain scheduling approach

Science.gov (United States)

Wang, Qian; Xue, Anke

2018-06-01

This paper has proposed a robust control for the spacecraft rendezvous system by considering the parameter uncertainties and actuator unsymmetrical saturation based on the discrete gain scheduling approach. By changing of variables, we transform the actuator unsymmetrical saturation control problem into a symmetrical one. The main advantage of the proposed method is improving the dynamic performance of the closed-loop system with a region of attraction as large as possible. By the Lyapunov approach and the scheduling technology, the existence conditions for the admissible controller are formulated in the form of linear matrix inequalities. The numerical simulation illustrates the effectiveness of the proposed method.

A Study on the Coupled Model of Hydrothermal-Salt for Saturated Freezing Salinized Soil

Directory of Open Access Journals (Sweden)

Xudong Zhang

2017-01-01

Full Text Available Water and heat interact in the process of freezing for the saturated soil. And for the salinized soil, water, heat, and salt interact in the freezing process, because salinized soil has soluble salt. In this paper, a one-dimensional mathematical coupled model of hydraulic-thermal-salt is established. In the model, Darcy’s law, law of conservation of energy, and law of conservation of mass are applied to derive the equations. Consider that a saturated salinized soil column is subjected to the condition of freezing to model the moisture migration and salt transport. Both experiment and numerical simulation under the same condition are developed in the soil column. Then the moisture content and salt content between simulation and experiment are compared. The result indicates that simulation matches well with the experiment data, and after 96 hours, the temperature distribution becomes stable, freezing front reaches a stable position, and a lot of unfrozen water has time to migrate. Besides, the excess salt precipitates when the concentration is greater than the solubility, and the precipitation is distributed discontinuously. These results can provide reference for engineering geology and environmental engineering in cold region and saline soil area.

Synthetic geology - Exploring the "what if?" in geology

Science.gov (United States)

Klump, J. F.; Robertson, J.

2015-12-01

The spatial and temporal extent of geological phenomena makes experiments in geology difficult to conduct, if not entirely impossible and collection of data is laborious and expensive - so expensive that most of the time we cannot test a hypothesis. The aim, in many cases, is to gather enough data to build a predictive geological model. Even in a mine, where data are abundant, a model remains incomplete because the information at the level of a blasting block is two orders of magnitude larger than the sample from a drill core, and we have to take measurement errors into account. So, what confidence can we have in a model based on sparse data, uncertainties and measurement error? Synthetic geology does not attempt to model the real world in terms of geological processes with all their uncertainties, rather it offers an artificial geological data source with fully known properties. On the basis of this artificial geology, we can simulate geological sampling by established or future technologies to study the resulting dataset. Conducting these experiments in silico removes the constraints of testing in the field or in production, and provides us with a known ground-truth against which the steps in a data analysis and integration workflow can be validated.Real-time simulation of data sources can be used to investigate crucial questions such as the potential information gain from future sensing capabilities, or from new sampling strategies, or the combination of both, and it enables us to test many "what if?" questions, both in geology and in data engineering. What would we be able to see if we could obtain data at higher resolution? How would real-time data analysis change sampling strategies? Does our data infrastructure handle many new real-time data streams? What feature engineering can be deducted for machine learning approaches? By providing a 'data sandbox' able to scale to realistic geological scenarios we hope to start answering some of these questions.

Submarine geologic disposal of nuclear waste

International Nuclear Information System (INIS)

Hollister, C.D.; Corliss, B.H.; Anderson, D.R.

1980-01-01

Site suitability characteristics of submarine geological formations for the disposal of radioactive wastes include the distribution coefficient of the host medium, permeability, viscoelastic nature of the sediments, influence of organic material on remobilization, and effects of thermal stress. The submarine geological formation that appears to best satisfy these criteria is abyssal ''red'' clay. Regions in the ocean that have coarse-grained deposits, high or variable thermal conductivity, high organic carbon content, and sediment thickness of less than 50 m are not being considered at this time. The optimum geological environment should be tranquil and have environmental predictability over a minimum of 10 5 years. Site selection activities for the North Atlantic and North Pacific are reviewed and future activities which include international cooperation are discussed. A paleoenvironmental model for Cenozoic sedimentation in the central North Pacific is presented based on studies of a long core from the Mid-Plate Gyre MPG-1 area, and is an example of the type of study that will be carried out in other seabed study areas. The data show that the MPG-1 region has been an area of slow, continuous accumulation during the past 65 million years. (author)

Flow variability and hillslope hydrology

Energy Technology Data Exchange (ETDEWEB)

Huff, D D; O' Neill, R V; Emanuel, W R; Elwood, J W; Newbold, J D

1982-01-01

Examination of spatial variability of streamflow in headwater areas can provide important insight about factors that influence hillslope hydrology. Detailed observations of variations in stream channel input, based on a tracer experiment, indicate that topography alone cannot explain flow variability. However, determination of changes in channel input on a small spatial scale can provide valuable clues to factors, such as structural geology that control subsurface flows.

Saturated and trans-fatty acids in UK takeaway food

OpenAIRE

Davies, Ian Glynn; Blackham, Toni; Jaworowska, Agnieszka; Taylor, Catherine; Ashton, Matthew; Stevenson, Leonard

2016-01-01

The aim of the study was to analyze the saturated fatty acid (SFA) and trans-fatty acid (TFA) contents of popular takeaway foods in the UK (including English, pizza, Chinese, Indian and kebab cuisine). Samples of meals were analyzed by an accredited public analyst laboratory for SFA and TFA. The meals were highly variable for SFA and TFA. English and Pizza meals had the highest median amount of SFA with 35.7 g/meal; Kebab meals were high in TFA with up to 5.2 g/meal. When compared to UK dieta...

Fast neutron (14 MeV) attenuation analysis in saturated core samples and its application in well logging

International Nuclear Information System (INIS)

Amin Attarzadeh; Mohammad Kamal Ghassem Al Askari; Tagy Bayat

2009-01-01

To introduce the application of nuclear logging, it is appropriate to provide a motivation for the use of nuclear measurement techniques in well logging. Importance aspects of the geological sciences are for instance grain and porosity structure and porosity volume of the rocks, as well as the transport properties of a fluid in the porous media. Nuclear measurements are, as a rule non-intrusive. Namely, a measurement does not destroy the sample, and it does not interfere with the process to be measured. Also, non- intrusive measurements are often much faster than the radiation methods, and can also be applied in field measurements. A common type of nuclear measurement employs neutron irradiation. It is powerful technique for geophysical analysis. In this research we illustrate the detail of this technique and it's applications to well logging and oil industry. Experiments have been performed to investigate the possibilities of using neutron attenuation measurements to determine water and oil content of rock sample. A beam of 14 MeV neutrons produced by a 150 KV neutron generator was attenuated by different samples and subsequently detected with plastic scintillators NE102 (Fast counter). Each sample was saturated with water and oil. The difference in neutron attenuation between dry and wet samples was compared with the fluid content determined by mass balance of the sample. In this experiment we were able to determine 3% of humidity in standard sample model (SiO 2 ) and estimate porosity in geological samples when saturated with different fluids. (Author)

Geology, hydrology, chemistry, and microbiology of the in situ bioremediation demonstration site

International Nuclear Information System (INIS)

Newcomer, D.R.; Doremus, L.A.; Hall, S.H.; Truex, M.J.; Vermeul, V.R.; Engelman, R.E.

1995-03-01

This report summarizes characterization information on the geology, hydrology, microbiology, contaminant distribution, and ground-water chemistry to support demonstration of in situ bioremediation at the Hanford Site. The purpose of this information is to provide baseline conditions, including a conceptual model of the aquifer being utilized for in situ bioremediation. Data were collected from sampling and other characterization activities associated with three wells drilled in the upper part of the suprabasalt aquifer. Results of point-dilution tracer tests, conducted in the upper 9 m (30 ft) of the aquifer, showed that most ground-water flow occurs in the upper part of this zone, which is consistent with hydraulic test results and geologic and geophysical data. Other tracer test results indicated that natural ground-water flow velocity is equal to or less than about 0.03 m/d (0.1 ft/d). Laboratory hydraulic conductivity measurements, which represent the local distribution of vertical hydraulic conductivity, varied up to three orders of magnitude. Based on concentration data from both the vadose and saturated zone, it is suggested that most, if not all, of the carbon tetrachloride detected is representative of the aqueous phase. Concentrations of carbon tetrachloride, associated with a contaminant plume in the 200-West Area, ranged from approximately 500 to 3,800 μg/L in the aqueous phase and from approximately 10 to 290 μg/L in the solid phase at the demonstration site. Carbon tetrachloride gas was detected in the vadose zone, suggesting volatilization and subsequent upward migration from the saturated zone

Nitrogen saturation in stream ecosystems.

Science.gov (United States)

Earl, Stevan R; Valett, H Maurice; Webster, Jackson R

2006-12-01

The concept of nitrogen (N) saturation has organized the assessment of N loading in terrestrial ecosystems. Here we extend the concept to lotic ecosystems by coupling Michaelis-Menten kinetics and nutrient spiraling. We propose a series of saturation response types, which may be used to characterize the proximity of streams to N saturation. We conducted a series of short-term N releases using a tracer (15NO3-N) to measure uptake. Experiments were conducted in streams spanning a gradient of background N concentration. Uptake increased in four of six streams as NO3-N was incrementally elevated, indicating that these streams were not saturated. Uptake generally corresponded to Michaelis-Menten kinetics but deviated from the model in two streams where some other growth-critical factor may have been limiting. Proximity to saturation was correlated to background N concentration but was better predicted by the ratio of dissolved inorganic N (DIN) to soluble reactive phosphorus (SRP), suggesting phosphorus limitation in several high-N streams. Uptake velocity, a reflection of uptake efficiency, declined nonlinearly with increasing N amendment in all streams. At the same time, uptake velocity was highest in the low-N streams. Our conceptual model of N transport, uptake, and uptake efficiency suggests that, while streams may be active sites of N uptake on the landscape, N saturation contributes to nonlinear changes in stream N dynamics that correspond to decreased uptake efficiency.

Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy

DEFF Research Database (Denmark)

Alderliesten, Thomas; De Vis, Jill B; Lemmers, Petra Ma

2017-01-01

saturation in the sagittal sinus (R(2 )= 0.49, p = 0.023), but no significant correlations could be demonstrated with frontal and whole brain cerebral blood flow. These results suggest that measuring oxygen saturation by T2-prepared blood imaging of oxygen saturation is feasible, even in neonates. Strong...... sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy (R(2 )= 0.64, p ..., and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus (R(2 )= 0.71, 0.50, 0.65; p 

Gas hydrate saturation from acoustic impedance and resistivity logs in the shenhu area, south china sea

Science.gov (United States)

Wang, X.; Wu, S.; Lee, M.; Guo, Y.; Yang, S.; Liang, J.

2011-01-01

During the China's first gas hydrate drilling expedition -1 (GMGS-1), gas hydrate was discovered in layers ranging from 10 to 25 m above the base of gas hydrate stability zone in the Shenhu area, South China Sea. Water chemistry, electrical resistivity logs, and acoustic impedance were used to estimate gas hydrate saturations. Gas hydrate saturations estimated from the chloride concentrations range from 0 to 43% of the pore space. The higher gas hydrate saturations were present in the depth from 152 to 177 m at site SH7 and from 190 to 225 m at site SH2, respectively. Gas hydrate saturations estimated from the resistivity using Archie equation have similar trends to those from chloride concentrations. To examine the variability of gas hydrate saturations away from the wells, acoustic impedances calculated from the 3 D seismic data using constrained sparse inversion method were used. Well logs acquired at site SH7 were incorporated into the inversion by establishing a relation between the water-filled porosity, calculated using gas hydrate saturations estimated from the resistivity logs, and the acoustic impedance, calculated from density and velocity logs. Gas hydrate saturations estimated from acoustic impedance of seismic data are ???10-23% of the pore space and are comparable to those estimated from the well logs. The uncertainties in estimated gas hydrate saturations from seismic acoustic impedances were mainly from uncertainties associated with inverted acoustic impedance, the empirical relation between the water-filled porosities and acoustic impedances, and assumed background resistivity. ?? 2011 Elsevier Ltd.

Space Charge Saturated Sheath Regime and Electron Temperature Saturation in Hall Thrusters

International Nuclear Information System (INIS)

Raitses, Y.; Staack, D.; Smirnov, A.; Fisch, N.J.

2005-01-01

Secondary electron emission in Hall thrusters is predicted to lead to space charge saturated wall sheaths resulting in enhanced power losses in the thruster channel. Analysis of experimentally obtained electron-wall collision frequency suggests that the electron temperature saturation, which occurs at high discharge voltages, appears to be caused by a decrease of the Joule heating rather than by the enhancement of the electron energy loss at the walls due to a strong secondary electron emission

Seasonal Variability in European Radon Measurements

Science.gov (United States)

Groves-Kirkby, C. J.; Denman, A. R.; Phillips, P. S.; Crockett, R. G. M.; Sinclair, J. M.

2009-04-01

In temperate climates, domestic radon concentration levels are generally seasonally dependent, the level in the home reflecting the convolution of two time-dependent functions. These are the source soil-gas radon concentration itself, and the principal force driving radon into the building from the soil, namely the pressure-difference between interior and exterior environment. While the meteorological influence can be regarded as relatively uniform on a European scale, its variability being defined largely by the influence of North-Atlantic weather systems, soil-gas radon is generally more variable as it is essentially geologically dependent. Seasonal variability of domestic radon concentration can therefore be expected to exhibit geographical variability, as is indeed the case. To compensate for the variability of domestic radon levels when assessing the long term radon health risks, the results of individual short-term measurements are generally converted to equivalent mean annual levels by application of a Seasonal Correction Factor (SCF). This is a multiplying factor, typically derived from measurements of a large number of homes, applied to the measured short-term radon concentration to provide a meaningful annual mean concentration for dose-estimation purposes. Following concern as to the universal applicability of a single SCF set, detailed studies in both the UK and France have reported location-specific SCF sets for different regions of each country. Further results indicate that SCFs applicable to the UK differ significantly from those applicable elsewhere in Europe and North America in both amplitude and phase, supporting the thesis that seasonal variability in indoor radon concentration cannot realistically be compensated for by a single national or international SCF scheme. Published data characterising the seasonal variability of European national domestic radon concentrations, has been collated and analysed, with the objective of identifying

Saturated Zone Colloid-Facilitated Transport

International Nuclear Information System (INIS)

Wolfsberg, A.; Reimus, P.

2001-01-01

The purpose of the Saturated Zone Colloid-Facilitated Transport Analysis and Modeling Report (AMR), as outlined in its Work Direction and Planning Document (CRWMS MandO 1999a), is to provide retardation factors for colloids with irreversibly-attached radionuclides, such as plutonium, in the saturated zone (SZ) between their point of entrance from the unsaturated zone (UZ) and downgradient compliance points. Although it is not exclusive to any particular radionuclide release scenario, this AMR especially addresses those scenarios pertaining to evidence from waste degradation experiments, which indicate that plutonium and perhaps other radionuclides may be irreversibly attached to colloids. This report establishes the requirements and elements of the design of a methodology for calculating colloid transport in the saturated zone at Yucca Mountain. In previous Total Systems Performance Assessment (TSPA) analyses, radionuclide-bearing colloids were assumed to be unretarded in their migration. Field experiments in fractured tuff at Yucca Mountain and in porous media at other sites indicate that colloids may, in fact, experience retardation relative to the mean pore-water velocity, suggesting that contaminants associated with colloids should also experience some retardation. Therefore, this analysis incorporates field data where available and a theoretical framework when site-specific data are not available for estimating plausible ranges of retardation factors in both saturated fractured tuff and saturated alluvium. The distribution of retardation factors for tuff and alluvium are developed in a form consistent with the Performance Assessment (PA) analysis framework for simulating radionuclide transport in the saturated zone. To improve on the work performed so far for the saturated-zone flow and transport modeling, concerted effort has been made in quantifying colloid retardation factors in both fractured tuff and alluvium. The fractured tuff analysis used recent data

A novel quantitative approach for eliminating sample-to-sample variation using a hue saturation value analysis program.

Science.gov (United States)

Yabusaki, Katsumi; Faits, Tyler; McMullen, Eri; Figueiredo, Jose Luiz; Aikawa, Masanori; Aikawa, Elena

2014-01-01

As computing technology and image analysis techniques have advanced, the practice of histology has grown from a purely qualitative method to one that is highly quantified. Current image analysis software is imprecise and prone to wide variation due to common artifacts and histological limitations. In order to minimize the impact of these artifacts, a more robust method for quantitative image analysis is required. Here we present a novel image analysis software, based on the hue saturation value color space, to be applied to a wide variety of histological stains and tissue types. By using hue, saturation, and value variables instead of the more common red, green, and blue variables, our software offers some distinct advantages over other commercially available programs. We tested the program by analyzing several common histological stains, performed on tissue sections that ranged from 4 µm to 10 µm in thickness, using both a red green blue color space and a hue saturation value color space. We demonstrated that our new software is a simple method for quantitative analysis of histological sections, which is highly robust to variations in section thickness, sectioning artifacts, and stain quality, eliminating sample-to-sample variation.

A new frequency-domain criterion for elimination of limit cycles in fixed-point state-space digital filters using saturation arithmetic

International Nuclear Information System (INIS)

Singh, Vimal

2007-01-01

In [Singh V. Elimination of overflow oscillations in fixed-point state-space digital filters using saturation arithmetic. IEEE Trans Circ Syst 1990;37(6):814-8], a frequency-domain criterion for the suppression of limit cycles in fixed-point state-space digital filters using saturation overflow arithmetic was presented. The passivity property owing to the presence of multiple saturation nonlinearities was exploited therein. In the present paper, a new notion of passivity, namely, that involving the state variables is considered, thereby arriving at an entirely new frequency-domain criterion for the suppression of limit cycles in such filters

Capillary pressure - saturation relations in quartz and carbonate sands: Limitations for correlating capillary and wettability influences on air, oil, and supercritical CO2 trapping

Science.gov (United States)

Tokunaga, T. K.; Wang, S.; Wan, J.; Dong, W.; Kim, Y.

2016-12-01

Capillary pressure (Pc) - saturation (Sw) relations are essential for predicting equilibrium and flow of immiscible fluid pairs in soils and deeper geologic formations. In systems that are difficult to measure, behavior is often estimated based on capillary scaling of easily measured Pc-Sw relations (e.g., air-water, and oil-water), yet the reliability of such approximations needs to be examined. In this study, seventeen sets of brine drainage and imbibition curves were measured with air-brine, decane-brine, and supercritical (sc) CO2-brine in homogeneous quartz and carbonate sands, using porous plate systems under ambient (0.1 MPa, 23 °C) and reservoir (12.0 MPa, 45 °C) conditions. Comparisons between these measurements showed significant differences in residual nonwetting phase saturation, Snw,r. Through applying capillary scaling, changes in interfacial properties were indicated, particularly wettability. With respect to the residual trapping of the nonwetting phases, Snwr, CO2 > Snwr, decane > Snwr, air. Decane-brine and scCO2-brine Pc-Sw curves deviated significantly from predictions assuming hydrophilic interactions. Moreover, neither the scaled capillary behavior nor Snw,r for scCO2-brine were well represented by decane-brine, apparently because of differences in wettability and viscosities, indicating limitations for using decane (and other organic liquids) as a surrogate fluid in studies intended to apply to geological carbon sequestration. Thus, challenges remain in applying scaling for predicting capillary trapping and multiphase displacement processes across such diverse fields as vadose zone hydrology, enhanced oil recovery, and geologic carbon sequestration.

Geology and MER target site characteristics along the southern rim of Isidis Planitia, Mars

Science.gov (United States)

Crumpler, L.S.; Tanaka, K.L.

2003-01-01

The southern rim of the Isidis basin contains one of the highest densities of valley networks, several restricted paleolake basins, and the stratigraphically lowest (oldest) terrain on Mars. Geologic mapping in Viking, MGS/MOC, and MOLA data, Odyssey/ THEMIS data, and other multispectral data products supports the presence of extensive fans of debris and sediments deposited along the inner rim of the Isidis basin where large valleys enter the lowlands. Additional processes subsequent to the period of intense fluvial activity, including mass flow analogous to some glacial processes, have contributed to the materials accumulated on the margins of the Isidis basin. These have occurred along preexisting channels and valleys at the termini of major channels where they enter the plains along the highland-lowland boundary. If the abundant valley networks in highland terrains are the result of runoff accompanied by saturated groundwater flow, as has been suggested in previous studies of ancient fluvial highland terrains, then the extreme age and abundance of early valley networks in the Libya Montes highland rocks should have resulted in deposition of materials that record evidence for the long-term presence of water in the form of aqueous alteration of polycrystalline constituents. The material deposited along the basin margin is likely to consist of ancient altered highland rocks in several physical states (weathered, rounded, and angular) exposing both weathered and altered surfaces, and exposures of alteration profiles in fractured faces and unweathered material from rock interiors. Debris fans shed off the southern rim of Isidis Planitia should contain materials that have experienced possible saturated groundwater flow, residence within paleolake basins, and derivative materials deposited during the most fluvially intensive part of Martian geologic history. Many of these materials have also been reworked by ice-related processes. In situ measurements of the ancient

Capillary pressure - saturation relations for supercritical CO2 and brine: Implications for capillary/residual trapping in carbonate reservoirs during geologic carbon sequestration

Science.gov (United States)

Wang, S.; Tokunaga, T. K.

2014-12-01

In geologic carbon sequestration (GCS), data on capillary pressure (Pc) - saturation (Sw) relations are routinely needed to appraise reservoir processes. Capillarity and its hysteresis have been often experimentally studied in oil-water, gas-water and three phase gas-oil-water systems, but fewer works have been reported on scCO2-water under in-situ reservoir conditions. Here, Pc-Sw relations of supercritical (sc) CO2 displacing brine, and brine rewetting the porous medium to trap scCO2 were studied to understand CO2 transport and trapping behavior in carbonate reservoirs under representative reservoir conditions. High-quality drainage and imbibition (and associated capillary pressure hysteresis) curves were measured under elevated temperature and pressure (45 ºC, 8.5 and 12 MPa) for scCO2-brine as well as at room temperature and pressure (23 ºC, 0.1 MPa) for air-brine in unconsolidated limestone and dolomite sand columns using newly developed semi-automated multistep outflow-inflow porous plate apparatus. Drainage and imbibition curves for scCO2-brine deviated from the universal scaling curves for hydrophilic interactions (with greater deviation under higher pressure) and shifted to lower Pc than predicted based on interfacial tension (IFT) changes. Augmented scaling incorporating differences in IFT and contact angle improved the scaling results but the scaled curves still did not converge onto the universal curves. Equilibrium residual trapping of the nonwetting phase was determined at Pc =0 during imbibition. The capillary-trapped amounts of scCO2 were significantly larger than for air. It is concluded that the deviations from the universal capillary scaling curves are caused by scCO2-induced wettability alteration, given the fact that pore geometry remained constant and IFT is well constrained. In-situ wettability alteration by reactive scCO2 is of critical importance and must be accounted for to achieve reliable predictions of CO2 behavior in GCS reservoirs.

A geologic scenario for catastrophic failure of the Yucca Mountain Nuclear Waste Repository, Nevada

International Nuclear Information System (INIS)

McMackin, M.R.

1993-01-01

A plausible combination of geologic factors leading to failure can be hypothesized for the Yucca Mountain Nuclear Waste Repository. The scenarios is constructed using elementary fault mechanics combined with geologic observations of exhumed faults and published information describing the repository site. The proposed repository site is located in the Basin and Range Province, a region of active crustal deformation demonstrated by widespread seismicity. The Yucca Mountain area has been characterized as tectonically quiet, which in the context of active crustal deformation may indicate the accumulation of the stresses approaching the levels required for fault slip, essentially stick-slip faulting. Simultaneously, dissolution of carbonate rocks in underlying karst aquifers is lowering the bulk strength of the rock that supports the repository site. Rising levels of hydrostatic stress concurrent with a climatically-driven rise in the water table could trigger faulting by decreasing the effective normal stress that currently retards fault slip. Water expelled from collapsing caverns in the underlying carbonate aquifer could migrate upward with sufficient pressure to open existing fractures or create new fractures by hydrofracturing. Water migrating through fractures could reach the repository in sufficient volume to react with heated rock and waste perhaps creating steam explosions that would further enhance fracture permeability. Closure of conduits in the underlying carbonate aquifer could lead to the elevation of the saturated zone above the level of the repository resulting in sustained saturation of radioactive waste in the repository and contamination of through-flowing groundwater

Using boosted regression trees to predict the near-saturated hydraulic conductivity of undisturbed soils

Science.gov (United States)

Koestel, John; Bechtold, Michel; Jorda, Helena; Jarvis, Nicholas

2015-04-01

The saturated and near-saturated hydraulic conductivity of soil is of key importance for modelling water and solute fluxes in the vadose zone. Hydraulic conductivity measurements are cumbersome at the Darcy scale and practically impossible at larger scales where water and solute transport models are mostly applied. Hydraulic conductivity must therefore be estimated from proxy variables. Such pedotransfer functions are known to work decently well for e.g. water retention curves but rather poorly for near-saturated and saturated hydraulic conductivities. Recently, Weynants et al. (2009, Revisiting Vereecken pedotransfer functions: Introducing a closed-form hydraulic model. Vadose Zone Journal, 8, 86-95) reported a coefficients of determination of 0.25 (validation with an independent data set) for the saturated hydraulic conductivity from lab-measurements of Belgian soil samples. In our study, we trained boosted regression trees on a global meta-database containing tension-disk infiltrometer data (see Jarvis et al. 2013. Influence of soil, land use and climatic factors on the hydraulic conductivity of soil. Hydrology & Earth System Sciences, 17, 5185-5195) to predict the saturated hydraulic conductivity (Ks) and the conductivity at a tension of 10 cm (K10). We found coefficients of determination of 0.39 and 0.62 under a simple 10-fold cross-validation for Ks and K10. When carrying out the validation folded over the data-sources, i.e. the source publications, we found that the corresponding coefficients of determination reduced to 0.15 and 0.36, respectively. We conclude that the stricter source-wise cross-validation should be applied in future pedotransfer studies to prevent overly optimistic validation results. The boosted regression trees also allowed for an investigation of relevant predictors for estimating the near-saturated hydraulic conductivity. We found that land use and bulk density were most important to predict Ks. We also observed that Ks is large in fine

Misconceptions in Reporting Oxygen Saturation

NARCIS (Netherlands)

Toffaletti, John; Zijlstra, Willem G.

2007-01-01

BACKGROUND: We describe some misconceptions that have become common practice in reporting blood gas and cooximetry results. In 1980, oxygen saturation was incorrectly redefined in a report of a new instrument for analysis of hemoglobin (Hb) derivatives. Oxygen saturation (sO(2)) was redefined as the

Geological investigations for the South African nuclear waste repository facility

International Nuclear Information System (INIS)

Hambleton-Jones, B.B.; Levin, M.; Andersen, N.J.B.; Brynard, H.J.; Toens, P.D.

1984-02-01

The selection of the Vaalputs site on the arid Bushmanland Plateau in the northwestern Cape of the Republic of South Africa for the disposal of low-level radioactive waste was based on a national screening phase program involving socio-economic and geological criteria. Regional geohydrological studies over an area of 27,000 km 2 and a detailed study over 1,300 km 2 indicated that in general the groundwater is saline and that Vaalputs and environs was the most favourable area. The groundwater table lies between 30 and 45 m below the surface, with 14 C ages between 2,500 and 9,000 years old in the immediate vicinity. The geology of Vaalputs consists of Proterozoic granites, gneisses, metasediments, and noritoids of the 1,050 Ma Namaqualand Metamorphic Complex. Upper cretaceous kimberlitic and basaltic intrusions occur locally. Overlying these basement rocks surficial upper Tertiary to Recent argillaceous sediments occur in the Vaalputs basin. The sediments consist of aeolian sand, calcrete, fluvial sandy to gritty clay, white kaolinised clay and very weathered basement rocks. It is in these rocks that the low-level waste trenches will be located. Extensive airborne geophysical surveys, such as aeromagnetics, INPUT, and infrared thermal line scanning, were undertaken to assist in the evaluation of the regional and local subsurface geology. Ground geophysical surveys included refraction seismics, electromagnetics, magnetics, borehole radiometrics and resistivity. Geohydrological modelling of the unsaturated and saturated zones is in progress

Geodiversity: Exploration of 3D geological model space

Science.gov (United States)

Lindsay, M. D.; Jessell, M. W.; Ailleres, L.; Perrouty, S.; de Kemp, E.; Betts, P. G.

2013-05-01

The process of building a 3D model necessitates the reconciliation of field observations, geophysical interpretation, geological data uncertainty and the prevailing tectonic evolution hypotheses and interpretations. Uncertainty is compounded when clustered data points collected at local scales are statistically upscaled to one or two points for use in regional models. Interpretation is required to interpolate between sparse field data points using ambiguous geophysical data in covered terranes. It becomes clear that multiple interpretations are possible during model construction. The various interpretations are considered as potential natural representatives, but pragmatism typically dictates that just a single interpretation is offered by the modelling process. Uncertainties are introduced into the 3D model during construction from a variety of sources and through data set optimisation that produces a single model. Practices such as these are likely to result in a model that does not adequately represent the target geology. A set of geometrical ‘geodiversity’ metrics are used to analyse a 3D model of the Gippsland Basin, southeastern Australia after perturbing geological input data via uncertainty simulation. The resulting sets of perturbed geological observations are used to calculate a suite of geological 3D models that display a range of geological architectures. The concept of biodiversity has been adapted for the geosciences to quantify geometric variability, or geodiversity, between models in order to understand the effect uncertainty has models geometry. Various geometrical relationships (depth, volume, contact surface area, curvature and geological complexity) are used to describe the range of possibilities exhibited throughout the model suite. End-member models geodiversity metrics are classified in a similar manner to taxonomic descriptions. Further analysis of the model suite is performed using principal component analysis (PCA) to determine

Tectonic and climatic considerations for deep geological disposal of radioactive waste: A UK perspective

International Nuclear Information System (INIS)

McEvoy, F.M.; Schofield, D.I.; Shaw, R.P.; Norris, S.

2016-01-01

Identifying and evaluating the factors that might impact on the long-term integrity of a deep Geological Disposal Facility (GDF) and its surrounding geological and surface environment is central to developing a safety case for underground disposal of radioactive waste. The geological environment should be relatively stable and its behaviour adequately predictable so that scientifically sound evaluations of the long-term radiological safety of a GDF can be made. In considering this, it is necessary to take into account natural processes that could affect a GDF or modify its geological environment up to 1 million years into the future. Key processes considered in this paper include those which result from plate tectonics, such as seismicity and volcanism, as well as climate-related processes, such as erosion, uplift and the effects of glaciation. Understanding the inherent variability of process rates, critical thresholds and likely potential influence of unpredictable perturbations represent significant challenges to predicting the natural environment. From a plate-tectonic perspective, a one million year time frame represents a very short segment of geological time and is largely below the current resolution of observation of past processes. Similarly, predicting climate system evolution on such time-scales, particularly beyond 200 ka AP is highly uncertain, relying on estimating the extremes within which climate and related processes may vary with reasonable confidence. The paper highlights some of the challenges facing a deep geological disposal program in the UK to review understanding of the natural changes that may affect siting and design of a GDF. - Highlights: • Natural processes are key to developing a safety case for geological disposal. • Key factors include plate tectonic and climate-mediated processes. • Process variability is a challenge to predicting the natural environment. • We highlight the challenges for geological disposal programs using

Tectonic and climatic considerations for deep geological disposal of radioactive waste: A UK perspective

Energy Technology Data Exchange (ETDEWEB)

McEvoy, F.M., E-mail: fmcevoy@bgs.ac.uk [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Schofield, D.I. [British Geological Survey, Tongwynlais, CF15 7NE (United Kingdom); Shaw, R.P. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Norris, S. [Radioactive Waste Management Limited, B587, Curie Avenue, Harwell, Didcot OX11 0RH (United Kingdom)

2016-11-15

Identifying and evaluating the factors that might impact on the long-term integrity of a deep Geological Disposal Facility (GDF) and its surrounding geological and surface environment is central to developing a safety case for underground disposal of radioactive waste. The geological environment should be relatively stable and its behaviour adequately predictable so that scientifically sound evaluations of the long-term radiological safety of a GDF can be made. In considering this, it is necessary to take into account natural processes that could affect a GDF or modify its geological environment up to 1 million years into the future. Key processes considered in this paper include those which result from plate tectonics, such as seismicity and volcanism, as well as climate-related processes, such as erosion, uplift and the effects of glaciation. Understanding the inherent variability of process rates, critical thresholds and likely potential influence of unpredictable perturbations represent significant challenges to predicting the natural environment. From a plate-tectonic perspective, a one million year time frame represents a very short segment of geological time and is largely below the current resolution of observation of past processes. Similarly, predicting climate system evolution on such time-scales, particularly beyond 200 ka AP is highly uncertain, relying on estimating the extremes within which climate and related processes may vary with reasonable confidence. The paper highlights some of the challenges facing a deep geological disposal program in the UK to review understanding of the natural changes that may affect siting and design of a GDF. - Highlights: • Natural processes are key to developing a safety case for geological disposal. • Key factors include plate tectonic and climate-mediated processes. • Process variability is a challenge to predicting the natural environment. • We highlight the challenges for geological disposal programs using

Landsliding in partially saturated materials

Science.gov (United States)

Godt, J.W.; Baum, R.L.; Lu, N.

2009-01-01

[1] Rainfall-induced landslides are pervasive in hillslope environments around the world and among the most costly and deadly natural hazards. However, capturing their occurrence with scientific instrumentation in a natural setting is extremely rare. The prevailing thinking on landslide initiation, particularly for those landslides that occur under intense precipitation, is that the failure surface is saturated and has positive pore-water pressures acting on it. Most analytic methods used for landslide hazard assessment are based on the above perception and assume that the failure surface is located beneath a water table. By monitoring the pore water and soil suction response to rainfall, we observed shallow landslide occurrence under partially saturated conditions for the first time in a natural setting. We show that the partially saturated shallow landslide at this site is predictable using measured soil suction and water content and a novel unified effective stress concept for partially saturated earth materials. Copyright 2009 by the American Geophysical Union.

Methane accumulation and forming high saturations of methane hydrate in sandy sediments

Energy Technology Data Exchange (ETDEWEB)

Uchida, T.; Waseda, A. [JAPEX Research Center, Chiba (Japan); Fujii, T. [Japan Oil, Gas and Metals National Corp., Chiba (Japan). Upstream Technology Unit

2008-07-01

Methane supplies for marine gas hydrates are commonly attributed to the microbial conversion of organic materials. This study hypothesized that methane supplies were related to pore water flow behaviours and microscopic migration in intergranular pore systems. Sedimentology and geochemistry analyses were performed on sandy core samples taken from the Nankai trough and the Mallik gas hydrate test site in the Mackenzie Delta. The aim of the study was to determine the influence of geologic and sedimentolic controls on the formation and preservation of natural gas hydrates. Grain size distribution curves indicated that gas hydrate saturations of up to 80 per cent in pore volume occurred throughout the hydrate-dominant sand layers in the Nankai trough and Mallik areas. Water permeability measurements showed that the highly gas hydrate-saturated sands have a permeability of a few millidarcies. Pore-space gas hydrates occurred primarily in fine and medium-grained sands. Core temperature depression, core observations, and laboratory analyses of the hydrates confirmed the pore-spaces as intergranular pore fillings. Results of the study suggested that concentrations of gas hydrates may require a pore space large enough to occur within a host sediments, and that the distribution of porous and coarser-grained sandy sediments is an important factor in controlling the occurrence of gas hydrates. 11 refs., 4 figs.

Distance saturation product predicts health-related quality of life among sarcoidosis patients.

Science.gov (United States)

Bourbonnais, Julie M; Malaisamy, Subramanian; Dalal, Bhavinkumar D; Samarakoon, Priyan C; Parikh, Swapna R; Samavati, Lobelia

2012-06-13

Sarcoidosis is a chronic disease with different phenotypic manifestations. Health-related quality of life is an important aspect in sarcoidosis, yet difficult to measure. The objective of this study was to identify clinical markers predictive of poor quality of life in sarcoidosis patients that can be followed over time and targeted for intervention. We assessed the quality of life of 162 patients with confirmed sarcoidosis in a prospective, cross-sectional study using the Sarcoidosis Health Questionnaire (SHQ) and Short Form-36 Health Survey (SF-36). We evaluated the validity of these questionnaires and sought to identify variables that would best explain the performance scores of the patients. On multivariate regression analyses, the very best composite model to predict total scores from both surveys was a model containing the distance-saturation product and Borg Dyspnea Scale score at the end of a 6-min walk test. This model could better predict SF-36 scores (R² = 0.33) than SHQ scores (R² = 0.24). Substitution of distanced walked in 6 min for the distance-saturation product in this model resulted in a lesser ability to predict both scores (R² = 0.26 for SF-36; R² = 0.22 for SHQ). Both the SHQ and SF-36 surveys are valuable tools in the assessment of health-related quality of life in sarcoidosis patients. The best model to predict quality of life among these patients, as determined by regression analyses, included the distance-saturation product and Borg score after the 6-min walk test. Both variables represent easily obtainable clinical parameters that can be followed over time and targeted for intervention.

Recipe for residual oil saturation determination

Energy Technology Data Exchange (ETDEWEB)

Guillory, A.J.; Kidwell, C.M.

1979-01-01

In 1978, Shell Oil Co., in conjunction with the US Department of Energy, conducted a residual oil saturation study in a deep, hot high-pressured Gulf Coast Reservoir. The work was conducted prior to initiation of CO/sub 2/ tertiary recovery pilot. Many problems had to be resolved prior to and during the residual oil saturation determination. The problems confronted are outlined such that the procedure can be used much like a cookbook in designing future studies in similar reservoirs. Primary discussion centers around planning and results of a log-inject-log operation used as a prime method to determine the residual oil saturation. Several independent methods were used to calculate the residual oil saturation in the subject well in an interval between 12,910 ft (3935 m) and 12,020 ft (3938 m). In general, these numbers were in good agreement and indicated a residual oil saturation between 22% and 24%. 10 references.

Simulation of trickle irrigation, an extension to the US Geological Survey's computer program VS2D

Science.gov (United States)

Healy, R.W.

1987-01-01

A method is presented for simulating water movement through unsaturated porous media in response to a constant rate of application from a surface source. Because the rate at which water can be absorbed by soil is limited, the water will pond; therefore the actual surface area over which the water is applied may change with time and in general will not be known beforehand. An iterative method is used to determine the size of this ponded area at any time. This method will be most useful for simulating trickling irrigation, but also may be of value for simulating movement of water is soils as the result of an accidental spill. The method is an extension to the finite difference computer program VS2D developed by the U.S. Geological Survey, which simulates water movement through variably saturated porous media. The simulated region can be a vertical, 2-dimensional cross section for treatment of a surface line source or an axially symmetric, 3-dimensional cylinder for a point source. Five test problems, obtained from the literature , are used to demonstrate the ability of the method to accurately match analytical and experimental results. (Author 's abstract)

Tracking Controller for Intrinsic Output Saturated Systems in Presence of Amplitude and Rate Input Saturations

DEFF Research Database (Denmark)

Chater, E.; Giri, F.; Guerrero, Josep M.

2014-01-01

We consider the problem of controlling plants that are subject to multiple saturation constraints. Especially, we are interested in linear systems whose input is subject to amplitude and rate constraints of saturation type. Furthermore, the considered systems output is also subject to an intrinsi...

Natural climate variations in a geological perspective

International Nuclear Information System (INIS)

Mikkelsen, N.; Kuijpers, A.

2001-01-01

The climate is constantly changing, and it has been changing throughout the geological history of the Earth. These natural changes have shown a variability with frequencies from millions of years to just a few hundreds or tens of years. Some of the variations have been rather dramatic - shifting from globally uniform and hot climates to regular ice ages - whereas other changes have been less spectacular. All natural climate variations have an impact on the physical and biological systems of the Earth - and on mankind and culture during the last hundred thousand years. In this chapter we shall discuss the natural climate changes that has taken place during the geological history of the Earth and comment on the impact of these changes on the cultural evolution of mankind with special emphasis on Greenland. (LN)

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

Science.gov (United States)

Terziotti, Silvia; Hoos, Anne B.; Harned, Douglas; Garcia, Ana Maria

2010-01-01

As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

Hydrogen solubility in pore water of partially saturated argillites: Application to Callovo-Oxfordian clay-rock in the context of a nuclear waste geological disposal

International Nuclear Information System (INIS)

Lassin, A.; Dymitrowska, M.; Azaroual, M.

2011-01-01

In nuclear waste geological disposals, large amounts of hydrogen (H 2 ) are expected to be produced by different (bio-)geochemical processes. Depending on the pressure generated by such a process, H 2 could be produced as a gas phase and displace the neighbouring pore water. As a consequence, a water-unsaturated zone could be created around the waste and possibly affect the physical and physic-chemical properties of the disposal and the excavation disturbed zone around it. The present study is the first part of an ongoing research program aimed at evaluating the possible chemical evolution of the pore water-minerals-gas system in such a context. The goal of this study was to evaluate, in terms of thermodynamic equilibrium conditions, the geochemical disturbance of the pore water due to variations in hydrogen pressure, temperature and relative humidity. No heterogeneous reactions involving mineral phases of the clay-rock or reactive surface sites were taken into account in the thermodynamic analysis. In the case sulphate reduction reaction is allowed, geochemical modelling results indicate that the main disturbance is the increase in pH (from around 7 up to more than 10) and an important decrease in the redox potential (Eh) related to hydrogen dissolution. This occurs from relatively low H 2 partial pressures (∼1 bar and above). Then, temperature and relative humidity (expressed in terms of capillary pressure) further displace the thermodynamic equilibrium conditions, namely the pH and the aqueous speciation as well as saturation indices of mineral phases. Finally, the results suggest that the generation of hydrogen, combined with an increase in temperature (between 30 deg. C and 80 deg. C) and a decrease in relative humidity (from 100% to 30%), should increase the chemical reactivity of the pore water-rock-gas system. (authors)

A total pressure-saturation formulation of two-phase flow incorporating dynamic effects in the capillary-pressure-saturation relationship

Energy Technology Data Exchange (ETDEWEB)

Dahle, H K; Celia, M A; Hassanizadeh, S M; Karlsen, K H

2002-07-01

New theories suggest that the relationship between capillary pressure and saturation should be enhanced by a dynamic term that is proportional to the time rate of change of saturation. This so-called dynamic capillary pressure formulation is supported by laboratory experiments, and can be included in various forms of the governing equations for two-phase flow in porous media. An extended model of two-phase flow in porous media may be developed based on fractional flow curves and a total pressure - saturation description that includes the dynamic capillary pressure terms. A dimensionless form of the resulting equation set provides an ideal tool to study the relative importance of the dynamic capillary pressure effect. This equation provides a rich set of mathematical research questions, and numerical solutions to the equation provide insights into the behavior of two-phase immiscible flow. For typical two-phase flow systems, dynamic capillary pressure acts to retard infiltration fronts, with responses dependent on system parameters including boundary conditions. Recent theoretical work suggests that the traditional algebraic relationship between capillary pressure and saturation may be inadequate. Instead, a so-called dynamic capillary pressure formulation is needed, where capillary pressure is defined as a thermodynamic variable, and the difference between phase pressures is only equal to the capillary pressure at equilibrium. Under dynamic conditions, the disequilibrium between phase-pressure differences and the capillary pressure is taken to be proportional to the time rate of change of saturation. A recent study by Hassanizadeh et al. presents experimental evidence, culled from the literature, to support this claim. Numerical simulations using dynamic pore-scale network models and upscaling also support the claim. Hassanizadeh et al. also presented numerical solutions for an enhanced version of Richards' equation that included the dynamic terms. A preliminary

Simulation of gas hydrogen diffusion through partially water saturated mono-modal materials

International Nuclear Information System (INIS)

Boher, C.; Lorente, S.; Frizon, F.; Bart, F.

2012-01-01

Concerning the disposal of nuclear wastes, it is important to design concrete envelopes with pore networks that allow the diffusion of hydrogen towards the outside. This work documents the relationship between geo-polymers, which are materials with a quasi mono-modal pore network, and their gaseous diffusivity capacities. Using a mono-modal material allows studying a specific pore size contribution to gaseous diffusion. The pore network is characterized by mercury porosimetry. These experimental results are used as data in a model named MOHYCAN. The modeling work consists of creating a virtual pore network. Then, water layers are deposited in this network to simulate variable water saturation levels. Finally hydrogen is transported through the virtual network using a combination of ordinary diffusion and Knudsen diffusion. MOHYCAN calculates the hydrogen diffusion coefficient for water saturation degree from 0% to 100%. The impacts of the pore network arrangement or the pore network discretization have been studied. The results are, for a quasi mono-modal material: -) the diffusion coefficient is not sensitive to different virtual pore network arrangement; -) the diffusion coefficient values have a sharp drop at specific water saturation (this is due to the water saturation of the main and unique pore family); -) a 2 pores family based model is sufficient to represent the pore network. Theses observations will not be valid if we consider a material with a large pore size distribution, like cementitious materials

Gas hydrate saturations estimated from fractured reservoir at Site NGHP-01-10, Krishna-Godavari Basin, India

Science.gov (United States)

Lee, M.W.; Collett, T.S.

2009-01-01

During the Indian National Gas Hydrate Program Expedition 01 (NGHP-Ol), one of the richest marine gas hydrate accumulations was discovered at Site NGHP-01-10 in the Krishna-Godavari Basin. The occurrence of concentrated gas hydrate at this site is primarily controlled by the presence of fractures. Assuming the resistivity of gas hydratebearing sediments is isotropic, th?? conventional Archie analysis using the logging while drilling resistivity log yields gas hydrate saturations greater than 50% (as high as ???80%) of the pore space for the depth interval between ???25 and ???160 m below seafloor. On the other hand, gas hydrate saturations estimated from pressure cores from nearby wells were less than ???26% of the pore space. Although intrasite variability may contribute to the difference, the primary cause of the saturation difference is attributed to the anisotropic nature of the reservoir due to gas hydrate in high-angle fractures. Archie's law can be used to estimate gas hydrate saturations in anisotropic reservoir, with additional information such as elastic velocities to constrain Archie cementation parameters m and the saturation exponent n. Theory indicates that m and n depend on the direction of the measurement relative to fracture orientation, as well as depending on gas hydrate saturation. By using higher values of m and n in the resistivity analysis for fractured reservoirs, the difference between saturation estimates is significantly reduced, although a sizable difference remains. To better understand the nature of fractured reservoirs, wireline P and S wave velocities were also incorporated into the analysis.

Saturation and linear transport equation

International Nuclear Information System (INIS)

Kutak, K.

2009-03-01

We show that the GBW saturation model provides an exact solution to the one dimensional linear transport equation. We also show that it is motivated by the BK equation considered in the saturated regime when the diffusion and the splitting term in the diffusive approximation are balanced by the nonlinear term. (orig.)

The geological attitude

International Nuclear Information System (INIS)

Fuller, J.G.C.M.

1992-01-01

This paper discusses geological activity which takes place mainly in response to industrial and social pressures. Past geological reaction to these pressures profoundly altered popular conceptions of time, the Church, man, and the balance of nature. The present-day circumstances of geology are not essentially different from those of the past. Petroleum geology in North American illustrates the role of technology in determining the style and scope of geological work. Peaks of activity cluster obviously on the introduction from time to time of new instrumental capabilities (geophysical apparatus, for example), although not infrequently such activity is testing concepts or relationships perceived long before. Organic metamorphism and continental drift provide two examples. The petroleum industry now faces the dilemma of satisfying predicted demands for fuel, without doing irreparable injury to its environment of operation. Awareness of man's place in nature, which is a fundamental perception of geology, governs the geological attitude

Rn3D: A finite element code for simulating gas flow and radon transport in variably saturated, nonisothermal porous media

International Nuclear Information System (INIS)

Holford, D.J.

1994-01-01

This document is a user's manual for the Rn3D finite element code. Rn3D was developed to simulate gas flow and radon transport in variably saturated, nonisothermal porous media. The Rn3D model is applicable to a wide range of problems involving radon transport in soil because it can simulate either steady-state or transient flow and transport in one-, two- or three-dimensions (including radially symmetric two-dimensional problems). The porous materials may be heterogeneous and anisotropic. This manual describes all pertinent mathematics related to the governing, boundary, and constitutive equations of the model, as well as the development of the finite element equations used in the code. Instructions are given for constructing Rn3D input files and executing the code, as well as a description of all output files generated by the code. Five verification problems are given that test various aspects of code operation, complete with example input files, FORTRAN programs for the respective analytical solutions, and plots of model results. An example simulation is presented to illustrate the type of problem Rn3D is designed to solve. Finally, instructions are given on how to convert Rn3D to simulate systems other than radon, air, and water

Decadal changes in the aragonite and calcite saturation state of the Pacific Ocean

Science.gov (United States)

Feely, Richard A.; Sabine, Christopher L.; Byrne, Robert H.; Millero, Frank J.; Dickson, Andrew G.; Wanninkhof, Rik; Murata, Akihiko; Miller, Lisa A.; Greeley, Dana

2012-09-01

Based on measurements from the WOCE/JGOFS global CO2 survey, the CLIVAR/CO2 Repeat Hydrography Program and the Canadian Line P survey, we have observed an average decrease of 0.34% yr-1 in the saturation state of surface seawater in the Pacific Ocean with respect to aragonite and calcite. The upward migrations of the aragonite and calcite saturation horizons, averaging about 1 to 2 m yr-1, are the direct result of the uptake of anthropogenic CO2 by the oceans and regional changes in circulation and biogeochemical processes. The shoaling of the saturation horizon is regionally variable, with more rapid shoaling in the South Pacific where there is a larger uptake of anthropogenic CO2. In some locations, particularly in the North Pacific Subtropical Gyre and in the California Current, the decadal changes in circulation can be the dominant factor in controlling the migration of the saturation horizon. If CO2 emissions continue as projected over the rest of this century, the resulting changes in the marine carbonate system would mean that many coral reef systems in the Pacific would no longer be able to sustain a sufficiently high rate of calcification to maintain the viability of these ecosystems as a whole, and these changes perhaps could seriously impact the thousands of marine species that depend on them for survival.

Quantitative geological modeling based on probabilistic integration of geological and geophysical data

DEFF Research Database (Denmark)

Gulbrandsen, Mats Lundh

In order to obtain an adequate geological model of any kind, proper integration of geophysical data, borehole logs and geological expert knowledge is important. Geophysical data provide indirect information about geology, borehole logs provide sparse point wise direct information about geology...... entitled Smart Interpretation is developed. This semi-automatic method learns the relation between a set of data attributes extracted from deterministically inverted airborne electromagnetic data and a set of interpretations of a geological layer that is manually picked by a geological expert...

Effect of pH on saturated hydraulic conductivity and soil dispersion

Energy Technology Data Exchange (ETDEWEB)

Suarez, D.L.; Roades, J.D.; Lavado, R.; Grieve, C.M.

The adverse effects of exchangeable sodium on soil hydraulic conductivity (K) are well known, but at present only sodicity and total electrolyte concentration are used in evaluating irrigation water suitability. In arid areas, high sodicity is often associatd with high dissolved carbonate and thus high pH, but in humid areas high sodicity may be associated with low pH. To evaluate the effect of pH (as an independent variable) on K, solutions with the same SAR and electrolyte level were prepared at pH 6, 7, 8, and 9. Saturated K values were determined at constant flux in columns packed at a bulk density of 1.5 Mg m/sup -3/. At pH 9, saturated K values were lower than at pH 6 for a montmorillonitic and kaolinitic soil. For a vermiculitic soil with lower organic carbon and higher silt content, pH changes did not cause large K differences. Decreases in K were not reversible on application of waters with higher electrolyte levels. The results from the K experiments were generally consistent with optical transmission measurements of dispersion. Although anion adsorption was at or below detection limits and cation exchange capacity (CEC) was only slightly dependent on pH, differences in pH effects on K among soils are likely due to differences in quantities of variable-charge minerals and organic matter.

Cibicidodes Pachyderma B/Ca as a Shalow Water Carbonate Saturation State Proxy

Science.gov (United States)

Wojcieszek, D. E.; Flower, B. P.; Moyer, R. P.; Byrne, R. H.

2012-12-01

Since the industrial revolution, the oceans have absorbed about 25% of anthropogenic CO2 emissions to the atmosphere, leading to a decrease in seawater pH (termed ocean acidification: OA) as well as many associated effects, including decreased saturation states. Assessment of the effects of OA on marine ecosystems is presently based on chemistry and its impact on biota over much longer time scales can provide essential context for likely future consequences of OA. Reliable oceanic paleo-proxies for influential chemical variables such as pH and carbonate saturation state are crucial components for examining ancient environments affected by OA. Addition of CO2 to seawater leads to not only decreases in seawater pH and saturation state, but also the extent to which boron (B) is incorporated into CaCO3 during biotic calcification. Consequently, the abundance of B in calcite could reflect pH and/or saturation state of the water in which calcification occurred. Recent studies indicate a linear relationship between the ratio of boron to calcium (B/Ca) in benthic foraminifera shells ( Cibicidoides wuellerstorfi, C. mundulus) and the degree of carbonate saturation (Δ[CO32-]), defined as a difference between [CO32-]in situ and [CO32-]saturation. However, the observed relationship between B/Ca and Δ[CO32-] was only established for depths >1000m. Thus, since OA most immediately affects the upper 1000 m of the water column, a reliable shallow water (chemistry proxy is desirable. We are testing the utility of B/Ca in Cibicidoides pachyderma as a shallow water Δ[CO32-] proxy. C. pachyderma is an epibenthic species and therefore records the composition of bottom, rather than interstitial, waters. It usually inhabits depths between 200 and 1000 m, and is a common species in the Gulf of Mexico. The gently sloping West Florida Shelf (WFS) is an excellent setting for this kind of study as it provides a full range of depths habitable by C.pachyderma. Nine surface sediment samples

Petrofacies analysis - the petrophysical tool for geologic/engineering reservoir characterization

Energy Technology Data Exchange (ETDEWEB)

Watney, W.L.; Guy, W.J.; Gerlach, P.M. [Kansas Geological Survey, Lawrence, KS (United States)] [and others

1997-08-01

Petrofacies analysis is defined as the characterization and classification of pore types and fluid saturations as revealed by petrophysical measures of a reservoir. The word {open_quotes}petrofacies{close_quotes} makes an explicit link between petroleum engineers concerns with pore characteristics as arbiters of production performance, and the facies paradigm of geologists as a methodology for genetic understanding and prediction. In petrofacies analysis, the porosity and resistivity axes of the classical Pickett plot are used to map water saturation, bulk volume water, and estimated permeability, as well as capillary pressure information, where it is available. When data points are connected in order of depth within a reservoir, the characteristic patterns reflect reservoir rock character and its interplay with the hydrocarbon column. A third variable can be presented at each point on the crossplot by assigning a color scale that is based on other well logs, often gamma ray or photoelectric effect, or other derived variables. Contrasts between reservoir pore types and fluid saturations will be reflected in changing patterns on the crossplot and can help discriminate and characterize reservoir heterogeneity. Many hundreds of analyses of well logs facilitated by spreadsheet and object-oriented programming have provided the means to distinguish patterns typical of certain complex pore types for sandstones and carbonate reservoirs, occurrences of irreducible water saturation, and presence of transition zones. The result has been an improved means to evaluate potential production such as bypassed pay behind pipe and in old exploration holes, or to assess zonation and continuity of the reservoir. Petrofacies analysis is applied in this example to distinguishing flow units including discrimination of pore type as assessment of reservoir conformance and continuity. The analysis is facilitated through the use of color cross sections and cluster analysis.

Hydrogeologic Framework Model for the Saturated-Zone Site-Scale Flow

Energy Technology Data Exchange (ETDEWEB)

Z. Peterman

2003-03-05

Yucca Mountain is being evaluated as a potential site for development of a geologic repository for the permanent disposal of spent nuclear fuel and high-level radioactive waste. Ground water is considered to be the principal means for transporting radionuclides that may be released from the potential repository to the accessible environment, thereby possibly affecting public health and safety. The ground-water hydrology of the region is a result of both the arid climatic conditions and the complex geology. Ground-water flow in the Yucca Mountain region generally can be described as consisting of two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick, generally deep-lying, Paleozoic carbonate rock sequence. Locally within the potential repository area, the flow is through a vertical sequence of welded and nonwelded tuffs that overlie the carbonate aquifer. Downgradient from the site, these tuffs terminate in basin fill deposits that are dominated by alluvium. Throughout the system, extensive and prevalent faults and fractures may control ground-water flow. The purpose of this Analysis/Modeling Report (AMR) is to document the three-dimensional (3D) hydrogeologic framework model (HFM) that has been constructed specifically to support development of a site-scale ground-water flow and transport model. Because the HFM provides the fundamental geometric framework for constructing the site-scale 3D ground-water flow model that will be used to evaluate potential radionuclide transport through the saturated zone (SZ) from beneath the potential repository to down-gradient compliance points, the HFM is important for assessing potential repository system performance. This AMR documents the progress of the understanding of the site-scale SZ ground-water flow system framework at Yucca Mountain based on data through July 1999. The

Technical assessment concept of geological aspect to define site NPP prospectus in Indonesia

International Nuclear Information System (INIS)

Akhmad Muktaf Haifani

2013-01-01

Geological aspects become an important aspect in determining the prospective nuclear power plant site. Geological investigation can be categorized based on the spatial scale of Regional and Local and every stage will have different levels of investigation. Understanding Regional Tectonics and Regional Geology of Indonesia is very important and helps to facilitate the evaluators to review documents. Unification of standard of site conformity assessment in terms tectonic aspect particularly geological stability becomes very necessary in the assessment of the suitability of the proposed licensed document, given the tectonic-forming process in Indonesia is highly variable. Safety criteria is key parameters that must be considered to solve any problems and a proper bridge in determining the site parameters of the proposed by applicants and compliance with any requirement of Regulatory Body. (author)

Time evolution of the Clay Barrier Chemistry in a HLW deep geological disposal in granite

International Nuclear Information System (INIS)

Font, I.; Miguel, M. J.; Juncosa, R.

2000-01-01

The main goal of a high level waste geological disposal is to guarantee the waste isolation from the biosphere, locking them away into very deep geological formations. The best way to assure the isolation is by means of a multiple barrier system. These barriers, in a serial disposition, should assure the confinement function of the disposal system. Two kinds of barriers are considered: natural barriers (geological formations) and engineered barriers (waste form, container and backfilling and sealing materials). Bentonite is selected as backfilling and sealing materials for HLW disposal into granite formations, due to its very low permeability and its ability to fill the remaining spaces. bentonite has also other interesting properties, such as, the radionuclide retention capacity by sorption processes. Once the clay barrier has been placed, the saturation process starts. The granite groundwater fills up the voids of the bentonite and because of the chemical interactions, the groundwater chemical composition varies. Near field processes, such as canister corrosion, waste leaching and radionuclide release, strongly depends on the water chemical composition. Bentonite pore water composition is such a very important feature of the disposal system and its determination and its evolution have great relevance in the HLW deep geological disposal performance assessment. The process used for the determination of the clay barrier pore water chemistry temporal evolution, and its influence on the performance assessment, are presented in this paper. (Author)

Terrestrial analogs, planetary geology, and the nature of geological reasoning

Science.gov (United States)

Baker, Victor R.

2014-05-01

Analogical reasoning is critical to planetary geology, but its role can be misconstrued by those unfamiliar with the practice of that science. The methodological importance of analogy to geology lies in the formulation of genetic hypotheses, an absolutely essential component of geological reasoning that was either ignored or denigrated by most 20th century philosophers of science, who took the theoretical/ experimental methodology of physics to be the sole model for all of scientific inquiry. Following the seminal 19th century work of Grove Karl Gilbert, an early pioneer of planetary geology, it has long been recognized that broad experience with and understanding of terrestrial geological phenomena provide geologists with their most effective resource for the invention of potentially fruitful, working hypotheses. The actions of (1) forming such hypotheses, (2) following their consequences, and (3) testing those consequences comprise integral parts of effective geological practice in regard to the understanding of planetary surfaces. Nevertheless, the logical terminology and philosophical bases for such practice will be unfamiliar to most planetary scientists, both geologists and nongeologists. The invention of geological hypotheses involves both inductive inferences of the type Gilbert termed “empiric classification” and abductive inferences of a logical form made famous by the 19th century American logician Charles Sanders Peirce. The testing and corroboration of geological hypotheses relies less on the correspondence logic of theoretical/ experimental sciences, like physics, and more on the logic of consistency, coherence, and consilience that characterizes the investigative and historical sciences of interpretation exemplified by geology.

Health benefits of geologic materials and geologic processes

Science.gov (United States)

Finkelman, R.B.

2006-01-01

The reemerging field of Medical Geology is concerned with the impacts of geologic materials and geologic processes on animal and human health. Most medical geology research has been focused on health problems caused by excess or deficiency of trace elements, exposure to ambient dust, and on other geologically related health problems or health problems for which geoscience tools, techniques, or databases could be applied. Little, if any, attention has been focused on the beneficial health effects of rocks, minerals, and geologic processes. These beneficial effects may have been recognized as long as two million years ago and include emotional, mental, and physical health benefits. Some of the earliest known medicines were derived from rocks and minerals. For thousands of years various clays have been used as an antidote for poisons. "Terra sigillata," still in use today, may have been the first patented medicine. Many trace elements, rocks, and minerals are used today in a wide variety of pharmaceuticals and health care products. There is also a segment of society that believes in the curative and preventative properties of crystals (talismans and amulets). Metals and trace elements are being used in some of today's most sophisticated medical applications. Other recent examples of beneficial effects of geologic materials and processes include epidemiological studies in Japan that have identified a wide range of health problems (such as muscle and joint pain, hemorrhoids, burns, gout, etc.) that may be treated by one or more of nine chemically distinct types of hot springs, and a study in China indicating that residential coal combustion may be mobilizing sufficient iodine to prevent iodine deficiency disease. ?? 2006 MDPI. All rights reserved.

Generation of dense plume fingers in saturated-unsaturated homogeneous porous media

Science.gov (United States)

Cremer, Clemens J. M.; Graf, Thomas

2015-02-01

Flow under variable-density conditions is widespread, occurring in geothermal reservoirs, at waste disposal sites or due to saltwater intrusion. The migration of dense plumes typically results in the formation of vertical plume fingers which are known to be triggered by material heterogeneity or by variations in source concentration that causes the density variation. Using a numerical groundwater model, six perturbation methods are tested under saturated and unsaturated flow conditions to mimic heterogeneity and concentration variations on the pore scale in order to realistically generate dense fingers. A laboratory-scale sand tank experiment is numerically simulated, and the perturbation methods are evaluated by comparing plume fingers obtained from the laboratory experiment with numerically simulated fingers. Dense plume fingering for saturated flow can best be reproduced with a spatially random, time-constant perturbation of the solute source. For unsaturated flow, a spatially and temporally random noise of solute concentration or a random conductivity field adequately simulate plume fingering.

Effect of desaturation and re-saturation on shale in underground galleries

International Nuclear Information System (INIS)

Pham, Q.T.

2006-03-01

The aim of this thesis is to characterize by experimental and numerical approaches the hydric, mechanical and hydro-mechanical effects due to the desaturation and re-saturation of the Eastern argillite, host rock of the Bure site, future underground radioactive waste disposal facility. Experimental and numerical approaches for the characterization of hydric transfers in argilites are presented. A simple identification method is proposed which uses the determination of the linearized hydric diffusivity from weight measurements performed on samples (thin tubes and plates) submitted to humidity steps according to a desaturation-re-saturation cycle. The hydric transfer is nonlinear. In order to interpret this phenomenon, a non-linear numerical model is established which takes into account the physical phenomena (hydraulic conduction, vapor diffusion, phase change..). The evolution of the physical and mechanical behaviour of the argillaceous rock with respect to the imposed humidity is then analyzed according to a desaturation-re-saturation cycle by successive steps. The hydric deformation, the velocity of ultrasonic waves propagation, the elastic properties, the rupture characteristics and the delayed phenomena depend on the hydric state of the material. The desaturation and re-saturation influence on a scale model of tunnel is analyzed. Thick tubes parallel or perpendicular to the stratification are used to show up the anisotropy of the rock. These tubes are submitted to hydric loads by blowing air with variable hygrometry through their center hole. A nonlinear poro-elastic model is used to interpret the anisotropic hydro-mechanical phenomena observed. It is shown that hydric loads can lead to the rupture of test samples which follow the anisotropic directions of the rock and which can be interpreted by the hydro-mechanical model as a violation of a rupture criterion in total pulling stress. Finally, numerical calculations for the phenomena generated by desaturation

Gluon Saturation and EIC

Energy Technology Data Exchange (ETDEWEB)

Sichtermann, Ernst

2016-12-15

The fundamental structure of nucleons and nuclear matter is described by the properties and dynamics of quarks and gluons in quantum chromodynamics. Electron-nucleon collisions are a powerful method to study this structure. As one increases the energy of the collisions, the interaction process probes regions of progressively higher gluon density. This density must eventually saturate. An high-energy polarized Electron-Ion Collider (EIC) has been proposed to observe and study the saturated gluon density regime. Selected measurements will be discussed, following a brief introduction.

Maximum rates of climate change are systematically underestimated in the geological record.

Science.gov (United States)

Kemp, David B; Eichenseer, Kilian; Kiessling, Wolfgang

2015-11-10

Recently observed rates of environmental change are typically much higher than those inferred for the geological past. At the same time, the magnitudes of ancient changes were often substantially greater than those established in recent history. The most pertinent disparity, however, between recent and geological rates is the timespan over which the rates are measured, which typically differ by several orders of magnitude. Here we show that rates of marked temperature changes inferred from proxy data in Earth history scale with measurement timespan as an approximate power law across nearly six orders of magnitude (10(2) to >10(7) years). This scaling reveals how climate signals measured in the geological record alias transient variability, even during the most pronounced climatic perturbations of the Phanerozoic. Our findings indicate that the true attainable pace of climate change on timescales of greatest societal relevance is underestimated in geological archives.

Proposals of geological sites for L/ILW and HLW repositories. Geological background. Text volume

International Nuclear Information System (INIS)

2008-01-01

/ILW repository, for which the time period considered for long-term safety is 100,000 years, there are no large-scale geotectonic units that, as a whole, would be unsuitable from the viewpoint of long-term geological stability and would have to be excluded. Regionally and locally, however, critical zones will have to be avoided when locating the disposal chambers in order to ensure long-term stability. The space required for the L/ILW repository is comparatively small and there is considerable flexibility in arranging the individual disposal chambers. This means that none of the large-scale units need to be deferred because of spatial conditions, although there are significant differences among the units with respect to tectonic dissection and the resulting spatial situation. For the HLW repository, with a time period of 1 million years being considered for long-term safety, the Alps have to be excluded if long-term stability (including uplift and erosion during the period being considered) is to be assured. There are also reservations regarding the long-term geological stability of the Folded Jura, the western Tabular Jura and the western sub-Jurassic zone. Because of strong tectonic dissection and the resulting insufficient spatial conditions, these three units are excluded for a HLW repository; D) The fourth step involves selecting the preferred host rock formations within the large geotectonic units still under consideration. Proposed for the L/ILW repository are the Opalinus Clay with its confining units, the clay stone sequence 'Brauner Dogger' with its confining units, the Effingen Beds and the marl formations of the Helveticum. For the HLW repository, the Opalinus Clay with its confining units is the preferred host formation. Although the crystalline bedrock and the clay-rich formations of the Lower and Upper Freshwater Molasse fulfil the minimum requirements for a host rock, test options have been deferred because of the large variability of rock properties and the

A sampling-based Bayesian model for gas saturation estimationusing seismic AVA and marine CSEM data

Energy Technology Data Exchange (ETDEWEB)

Chen, Jinsong; Hoversten, Michael; Vasco, Don; Rubin, Yoram; Hou,Zhangshuan

2006-04-04

We develop a sampling-based Bayesian model to jointly invertseismic amplitude versus angles (AVA) and marine controlled-sourceelectromagnetic (CSEM) data for layered reservoir models. The porosityand fluid saturation in each layer of the reservoir, the seismic P- andS-wave velocity and density in the layers below and above the reservoir,and the electrical conductivity of the overburden are considered asrandom variables. Pre-stack seismic AVA data in a selected time windowand real and quadrature components of the recorded electrical field areconsidered as data. We use Markov chain Monte Carlo (MCMC) samplingmethods to obtain a large number of samples from the joint posteriordistribution function. Using those samples, we obtain not only estimatesof each unknown variable, but also its uncertainty information. Thedeveloped method is applied to both synthetic and field data to explorethe combined use of seismic AVA and EM data for gas saturationestimation. Results show that the developed method is effective for jointinversion, and the incorporation of CSEM data reduces uncertainty influid saturation estimation, when compared to results from inversion ofAVA data only.

Energy dependent saturable and reverse saturable absorption in cube-like polyaniline/polymethyl methacrylate film

Energy Technology Data Exchange (ETDEWEB)

Thekkayil, Remyamol [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695 547 (India); Philip, Reji [Light and Matter Physics Group, Raman Research Institute, C.V. Raman Avenue, Bangalore 560 080 (India); Gopinath, Pramod [Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695 547 (India); John, Honey, E-mail: honey@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695 547 (India)

2014-08-01

Solid films of cube-like polyaniline synthesized by inverse microemulsion polymerization method have been fabricated in a transparent PMMA host by an in situ free radical polymerization technique, and are characterized by spectroscopic and microscopic techniques. The nonlinear optical properties are studied by open aperture Z-scan technique employing 5 ns (532 nm) and 100 fs (800 nm) laser pulses. At the relatively lower laser pulse energy of 5 μJ, the film shows saturable absorption both in the nanosecond and femtosecond excitation domains. An interesting switchover from saturable absorption to reverse saturable absorption is observed at 532 nm when the energy of the nanosecond laser pulses is increased. The nonlinear absorption coefficient increases with increase in polyaniline concentration, with low optical limiting threshold, as required for a good optical limiter. - Highlights: • Synthesized cube-like polyaniline nanostructures. • Fabricated polyaniline/PMMA nanocomposite films. • At 5 μJ energy, saturable absorption is observed both at ns and fs regime. • Switchover from SA to RSA is observed as energy of laser beam increases. • Film (0.1 wt % polyaniline) shows high β{sub eff} (230 cm GW{sup −1}) and low limiting threshold at 150 μJ.

Pedological Heterogeneity of Soils Developed from Lithologies of the Pirambóia, Sanga-do-Cabral, and Guará Geological Formations in Southern Brazil

Directory of Open Access Journals (Sweden)

Pablo Grahl dos Santos

Full Text Available ABSTRACT The source material is one of the factors that most influence soil genesis and the mainly responsible for the nature, composition, and behavior of the soil. Given the geological complexity of the Santa Maria River basin, the objective of this study was to investigate whether the new lithologies described recently may be responsible for a greater variation in soil properties, as well as in the soil taxonomy itself. The study area is located in the municipality of Rosário do Sul, RS, Brazil at 30° 15’ 28” S and 54° 54’ 50” W, with average altitude of 132 m and climate type Cfa. This study was supported by a cartographic base composed of topographic charts, geological maps, satellite images, digital elevation models, and maps of geomorphometric variables, with the support of GPS receivers and GIS. Topolithosequences were defined from soils developed from the Pirambóia, Sanga-do-Cabral, and Guará Formations, and soil profiles were chosen based on types of source materials, variations in relief, and altitude. A classical model of slope compartmentalization was applied for correlation of the geomorphic surfaces with pedogenesis. Soil profiles were described in a general and morphological manner, and soil samples were collected for analysis. The physical and chemical properties determined were particle size, active and potential acidity, organic C content, Ca2+, Mg2+, K+, and Al3+. The sum of bases, CEC, flocculation activity and degree of flocculation of the clay fraction, and base (V, aluminum (m, and sodium saturation were calculated. Soil properties were evaluated through factor analysis and grouping, which allowed profiles to be grouped based on their variables and identification of which variables were preponderant in distinguishing them. Furthermore, multivariate analysis allowed statistical differentiation of the profiles in the same lithostratigraphic unit and in different relief positions, and also differentiation of

Calibration of the Site-Scale Saturated Zone Flow Model

International Nuclear Information System (INIS)

Zyvoloski, G. A.

2001-01-01

The purpose of the flow calibration analysis work is to provide Performance Assessment (PA) with the calibrated site-scale saturated zone (SZ) flow model that will be used to make radionuclide transport calculations. As such, it is one of the most important models developed in the Yucca Mountain project. This model will be a culmination of much of our knowledge of the SZ flow system. The objective of this study is to provide a defensible site-scale SZ flow and transport model that can be used for assessing total system performance. A defensible model would include geologic and hydrologic data that are used to form the hydrogeologic framework model; also, it would include hydrochemical information to infer transport pathways, in-situ permeability measurements, and water level and head measurements. In addition, the model should include information on major model sensitivities. Especially important are those that affect calibration, the direction of transport pathways, and travel times. Finally, if warranted, alternative calibrations representing different conceptual models should be included. To obtain a defensible model, all available data should be used (or at least considered) to obtain a calibrated model. The site-scale SZ model was calibrated using measured and model-generated water levels and hydraulic head data, specific discharge calculations, and flux comparisons along several of the boundaries. Model validity was established by comparing model-generated permeabilities with the permeability data from field and laboratory tests; by comparing fluid pathlines obtained from the SZ flow model with those inferred from hydrochemical data; and by comparing the upward gradient generated with the model with that observed in the field. This analysis is governed by the Office of Civilian Radioactive Waste Management (OCRWM) Analysis and Modeling Report (AMR) Development Plan ''Calibration of the Site-Scale Saturated Zone Flow Model'' (CRWMS M and O 1999a)

Geology and bedrock engineering

International Nuclear Information System (INIS)

1985-11-01

This book deals with geology of Korea which includes summary, geology in central part and southern part in Korea and characteristic of geology structure, limestone like geology property of limestone, engineered property of limestone, and design and construction case in limestone area. It also introduces engineered property of the cenozoic, clay rock and shale, geologic and engineered property of phyllite and stratum.

The U.S. Geological Survey Geologic Collections Management System (GCMS)—A master catalog and collections management plan for U.S. Geological Survey geologic samples and sample collections

Science.gov (United States)

,

2015-01-01

The U.S. Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of earth materials collected by research personnel over the course of its history. In 2006, a Geologic Collections Inventory was conducted within the USGS Geology Discipline to determine the extent and nature of its sample collections, and in 2008, a working group was convened by the USGS National Geologic and Geophysical Data Preservation Program to examine ways in which these collections could be coordinated, cataloged, and made available to researchers both inside and outside the USGS. The charge to this working group was to evaluate the proposition of creating a Geologic Collections Management System (GCMS), a centralized database that would (1) identify all existing USGS geologic collections, regardless of size, (2) create a virtual link among the collections, and (3) provide a way for scientists and other researchers to obtain access to the samples and data in which they are interested. Additionally, the group was instructed to develop criteria for evaluating current collections and to establish an operating plan and set of standard practices for handling, identifying, and managing future sample collections. Policies and procedures promoted by the GCMS would be based on extant best practices established by the National Science Foundation and the Smithsonian Institution. The resulting report—USGS Circular 1410, “The U.S. Geological Survey Geologic Collections Management System (GCMS): A Master Catalog and Collections Management Plan for U.S. Geological Survey Geologic Samples and Sample Collections”—has been developed for sample repositories to be a guide to establishing common practices in the collection, retention, and disposal of geologic research materials throughout the USGS.

Generalized Density-Corrected Model for Gas Diffusivity in Variably Saturated Soils

DEFF Research Database (Denmark)

Chamindu, Deepagoda; Møldrup, Per; Schjønning, Per

2011-01-01

models. The GDC model was further extended to describe two-region (bimodal) soils and could describe and predict Dp/Do well for both different soil aggregate size fractions and variably compacted volcanic ash soils. A possible use of the new GDC model is engineering applications such as the design...... of highly compacted landfill site caps....

Prediction of Rn-222 in Danish dwellings using geology and house construction information from central databases

DEFF Research Database (Denmark)

Andersen, Claus Erik; Raaschou-Nielsen, O.; Andersen, H.P.

2007-01-01

). The model was calibrated against radon measurements in 3116 houses. An independent dataset with 788 house measurements was used for model performance assessment. The model includes nine explanatory variables,, of which the most important ones are house type and geology. All explanatory variables...

U.S. Department of Energy approaches to the assessment of radionuclide migration for the geologic repository program

International Nuclear Information System (INIS)

Luik, A.E. van; Apted, M.J.

1988-01-01

Potential radionuclide migration in geologic repositories is being addressed by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management through its Office of Geologic Repositories (OGR). A diversity of geohydrologic settings is being investigated: unsaturated tuff, saturated basalt, and bedded salt. A number of approaches to assessing potential migration are being considered. Mass transfer is prominent among near-field approaches. For far-field analysis of migration in the geosphere, detailed characterizations of potential repository sites will lead to site-specific models describing radionuclide migration for a variety of postulated release scenarios. Finite-element and finite-difference codes are being used and developed to solve the mathematical equations pertinent to far-field assessments. Computational approaches presently in use generally require distribution coefficients to estimate the retardation of specific radionuclides with respect to the transport rate of water. 26 refs

Importance of geology to fisheries management: Examples from the northeastern Gulf of Mexico

Science.gov (United States)

Scanlon, Kathryn M.; Koenig, C.C.; Coleman, F.C.; Miller, M.

2003-01-01

Seafloor mapping of shelf-edge habitats in the northeastern Gulf of Mexico demonstrates how sidescan-sonar imagery, seismic-reflection profiling, video data, geologic mapping, sediment sampling, and understanding the regional geologic history can enhance, support, and guide traditional fisheries research and management. New data from the Madison Swanson and Steamboat Lumps Marine Reserves reveal complex benthic habitats consisting of high-relief calcareous pinnacles, low-relief karstic hardbottom, rocky outcrops several kilometers in length, and variable thickness of fine-grained and apparently mobile coarse-grained sediments. Our data also show that certain fish alter the landscape by clearing sediment from hardbottom areas (e.g., red grouper Epinephelus morio) and by burrowing extensively in fine-grained sediment (e.g., tilefish Lopholatilus chamaeleonticeps). The seafloor imagery and geologic maps show that (a) sea level fluctuations played a dominant role in the development of the present-day regional geology, and (b) habitats (and benthic communities) are tied closely to geologic character. Understanding the geologic setting allowed for efficient and representative sampling of the biology. The geologic data can be used to set meaningful boundaries for fishery reserves and to help predict habitats in areas that are not well mapped. This interdisciplinary work added value to traditional research disciplines by providing management with integrated tools to make better decisions. 

Two-phase flow visualization under reservoir conditions for highly heterogeneous conglomerate rock: A core-scale study for geologic carbon storage.

Science.gov (United States)

Kim, Kue-Young; Oh, Junho; Han, Weon Shik; Park, Kwon Gyu; Shinn, Young Jae; Park, Eungyu

2018-03-20

Geologic storage of carbon dioxide (CO 2 ) is considered a viable strategy for significantly reducing anthropogenic CO 2 emissions into the atmosphere; however, understanding the flow mechanisms in various geological formations is essential for safe storage using this technique. This study presents, for the first time, a two-phase (CO 2 and brine) flow visualization under reservoir conditions (10 MPa, 50 °C) for a highly heterogeneous conglomerate core obtained from a real CO 2 storage site. Rock heterogeneity and the porosity variation characteristics were evaluated using X-ray computed tomography (CT). Multiphase flow tests with an in-situ imaging technology revealed three distinct CO 2 saturation distributions (from homogeneous to non-uniform) dependent on compositional complexity. Dense discontinuity networks within clasts provided well-connected pathways for CO 2 flow, potentially helping to reduce overpressure. Two flow tests, one under capillary-dominated conditions and the other in a transition regime between the capillary and viscous limits, indicated that greater injection rates (potential causes of reservoir overpressure) could be significantly reduced without substantially altering the total stored CO 2 mass. Finally, the capillary storage capacity of the reservoir was calculated. Capacity ranged between 0.5 and 4.5%, depending on the initial CO 2 saturation.

Joint application of Geoelectrical Resistivity and Ground Penetrating Radar techniques for the study of hyper-saturated zones. Case study in Egypt

Directory of Open Access Journals (Sweden)

Hany S. Mesbah

2017-06-01

Full Text Available This paper presents the results of the application of the Geoelectrical Resistivity Sounding (GRS and Ground Penetrating Radar (GPR for outlining and investigating of surface springing out (flow of groundwater to the base of an service building site, and determining the reason(s for the zone of maximum degree of saturation; in addition to provide stratigraphic information for this site. The studied economic building is constructed lower than the ground surface by about 7 m. A Vertical Electrical Sounding (VES survey was performed at 12 points around the studied building in order to investigate the vertical and lateral extent of the subsurface sequence, three VES's were conducted at each side of the building at discrete distances. And a total of 9 GPR profiles with 100- and 200-MHz antennae were conducted, with the objective of evaluating the depth and the degree of saturation of the subsurface layers. The qualitative and quantitative interpretation of the acquired VES's showed easily the levels of saturations close to and around the studied building. From the interpretation of GPR profiles, it was possible to locate and determine the saturated layers. The radar signals are penetrated and enabled the identification of the subsurface reflectors. The results of GPR and VES showed a good agreement and the integrated interpretations were supported by local geology. Finally, the new constructed geoelectrical resistivity cross-sections (in contoured-form, are easily clarifying the direction of groundwater flow toward the studied building.

Study on geology and geological structure based on literature studies

International Nuclear Information System (INIS)

Funaki, Hironori; Ishii, Eiichi; Yasue, Ken-ichi; Takahashi, Kazuharu

2005-03-01

Japan Nuclear Cycle Development Institute (JNC) is proceeding with underground research laboratory (URL) project for the sedimentary rock in Horonobe, Hokkaido. This project is an investigation project which is planned over 20 years. Surface-based investigations (Phase 1) have been conducted for the present. The purposes of the Phase 1 are to construct the geological environment model (geological-structural, hydrogeological, and hydrochemical models) and to confirm the applicability of investigation technologies for the geological environment. The geological-structural model comprises the base for the hydrogeological and hydrochemical models. We constructed the geological-structural model by mainly using data obtained from literature studies. Particulars regarding which data the model is based on and who has performed the interpretation are also saved for traceability. As a result, we explain the understanding of degree and the need of information on stratigraphy and discontinuous structure. (author)

Hydrogeological Properties of Geological Elements in Geological Model around KURT

Energy Technology Data Exchange (ETDEWEB)

Park, Kyung Woo; Kim, Kyung Soo; Koh, Yong Kwon; Choi, Jong Won [Korea Atomic Energy Institue, Daejeon (Korea, Republic of)

2012-09-15

To develop site characterization technologies for a radioactive waste disposal research in KAERI, the geological and hydrogeological investigations have been carried out since 1997. In 2006, the KURT (KAERI Underground Research Tunnel) was constructed to study a solute migration, a microbiology and an engineered barrier system as well as deeply to understand geological environments in in-situ condition. This study is performed as one of the site characterization works around KURT. Several investigations such as a lineament analysis, a borehole/tunnel survey, a geophyscial survey and logging in borehole, were used to construct the geological model. As a result, the geological model is constructed, which includes the lithological model and geo-structural model in this study. Moreover, from the results of the in-situ hydraulic tests, the hydrogeological properties of elements in geological model were evaluated.

Hydrogeological Properties of Geological Elements in Geological Model around KURT

International Nuclear Information System (INIS)

Park, Kyung Woo; Kim, Kyung Soo; Koh, Yong Kwon; Choi, Jong Won

2012-01-01

To develop site characterization technologies for a radioactive waste disposal research in KAERI, the geological and hydrogeological investigations have been carried out since 1997. In 2006, the KURT (KAERI Underground Research Tunnel) was constructed to study a solute migration, a microbiology and an engineered barrier system as well as deeply to understand geological environments in in-situ condition. This study is performed as one of the site characterization works around KURT. Several investigations such as a lineament analysis, a borehole/tunnel survey, a geophyscial survey and logging in borehole, were used to construct the geological model. As a result, the geological model is constructed, which includes the lithological model and geo-structural model in this study. Moreover, from the results of the in-situ hydraulic tests, the hydrogeological properties of elements in geological model were evaluated.

Soil Organic Matter Stabilization via Mineral Interactions in Forest Soils with Varying Saturation Frequency

Science.gov (United States)

Possinger, A. R.; Inagaki, T.; Bailey, S. W.; Kogel-Knabner, I.; Lehmann, J.

2017-12-01

Soil carbon (C) interaction with minerals and metals through surface adsorption and co-precipitation processes is important for soil organic C (SOC) stabilization. Co-precipitation (i.e., the incorporation of C as an "impurity" in metal precipitates as they form) may increase the potential quantity of mineral-associated C per unit mineral surface compared to surface adsorption: a potentially important and as yet unaccounted for mechanism of C stabilization in soil. However, chemical, physical, and biological characterization of co-precipitated SOM as such in natural soils is limited, and the relative persistence of co-precipitated C is unknown, particularly under dynamic environmental conditions. To better understand the relationships between SOM stabilization via organometallic co-precipitation and environmental variables, this study compares mineral-SOM characteristics across a forest soil (Spodosol) hydrological gradient with expected differences in co-precipitation of SOM with iron (Fe) and aluminum (Al) due to variable saturation frequency. Soils were collected from a steep, well-drained forest soil transect with low, medium, and high frequency of water table intrusion into surface soils (Hubbard Brook Experimental Forest, Woodstock, NH). Lower saturation frequency soils generally had higher C content, C/Fe, C/Al, and other indicators of co-precipitation interactions resulting from SOM complexation, transport, and precipitation, an important process of Spodosol formation. Preliminary Fe X-ray Absorption Spectroscopic (XAS) characterization of SOM and metal chemistry in low frequency profiles suggest co-precipitation of SOM in the fine fraction (soils showed greater SOC mineralization per unit soil C for low saturation frequency (i.e., higher co-precipitation) soils; however, increased mineralization may be attributed to non-mineral associated fractions of SOM. Further work to identify the component of SOM contributing to rapid mineralization using 13C

Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California: Chapter E in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

Science.gov (United States)

Bloss, Benjamin R.; Bedrosian, Paul A.

2015-01-01

Correlating laboratory resistivity measurements with geophysical resistivity models helps constrain these models to the geology and lithology of an area. Throughout the Fort Irwin National Training Center area, 111 samples from both cored boreholes and surface outcrops were collected and processed for laboratory measurements. These samples represent various lithologic types that include plutonic and metamorphic (basement) rocks, lava flows, consolidated sedimentary rocks, and unconsolidated sedimentary deposits that formed in a series of intermountain basins. Basement rocks, lava flows, and some lithified tuffs are generally resistive (≥100 ohm-meters [Ω·m]) when saturated. Saturated unconsolidated samples are moderately conductive to conductive, with resistivities generally less than 100 Ω·m, and many of these samples are less than 50 Ω·m. The unconsolidated samples can further be separated into two broad groups: (1) younger sediments that are moderately conductive, owing to their limited clay content, and (2) older, more conductive sediments with a higher clay content that reflects substantial amounts of originally glassy volcanic ash subsequently altered to clay. The older sediments are believed to be Tertiary. Time-domain electromagnetic (TEM) data were acquired near most of the boreholes, and, on the whole, close agreements between laboratory measurements and resistivity models were found. 

Serum albumin--a non-saturable carrier

DEFF Research Database (Denmark)

Brodersen, R; Honoré, B; Larsen, F G

1984-01-01

The shape of binding isotherms for sixteen ligands to human serum albumin showed no signs of approaching saturation at high ligand concentrations. It is suggested that ligand binding to serum albumin is essentially different from saturable binding of substrates to enzymes, of oxygen to haemoglobi...

Geomorphic effectiveness of a long profile shape and the role of inherent geological controls in the Himalayan hinterland area of the Ganga River basin, India

Science.gov (United States)

Sonam; Jain, Vikrant

2018-03-01

Long profiles of rivers provide a platform to analyse interaction between geological and geomorphic processes operating at different time scales. Identification of an appropriate model for river long profile becomes important in order to establish a quantitative relationship between the profile shape, its geomorphic effectiveness, and inherent geological characteristics. This work highlights the variability in the long profile shape of the Ganga River and its major tributaries, its impact on stream power distribution pattern, and role of the geological controls on it. Long profile shapes are represented by the sum of two exponential functions through the curve fitting method. We have shown that coefficients of river long profile equations are governed by the geological characteristics of subbasins. These equations further define the spatial distribution pattern of stream power and help to understand stream power variability in different geological terrains. Spatial distribution of stream power in different geological terrains successfully explains spatial variability in geomorphic processes within the Himalayan hinterland area. In general, the stream power peaks of larger rivers lie in the Higher Himalaya, and rivers in the eastern hinterland area are characterised by the highest magnitude of stream power.

Saturation and forward jets at HERA

International Nuclear Information System (INIS)

Marquet, C.; Peschanski, R.; Royon, C.

2004-01-01

We analyse forward-jet production at HERA in the framework of the Golec-Biernat and Wusthoff saturation models. We obtain a good description of the forward-jet cross-sections measured by the H1 and ZEUS Collaborations in the two-hard-scale region (k T∼ Q >> Λ QCD ) with two different parametrizations with either significant or weak saturation effects. The weak saturation parametrization gives a scale compatible with the one found for the proton structure function F2. We argue that Mueller-Navelet jets at the Tevatron and the LHC could help distinguishing between both options

Correcting saturation of detectors for particle/droplet imaging methods

International Nuclear Information System (INIS)

Kalt, Peter A M

2010-01-01

Laser-based diagnostic methods are being applied to more and more flows of theoretical and practical interest and are revealing interesting new flow features. Imaging particles or droplets in nephelometry and laser sheet dropsizing methods requires a trade-off of maximized signal-to-noise ratio without over-saturating the detector. Droplet and particle imaging results in lognormal distribution of pixel intensities. It is possible to fit a derived lognormal distribution to the histogram of measured pixel intensities. If pixel intensities are clipped at a saturated value, it is possible to estimate a presumed probability density function (pdf) shape without the effects of saturation from the lognormal fit to the unsaturated histogram. Information about presumed shapes of the pixel intensity pdf is used to generate corrections that can be applied to data to account for saturation. The effects of even slight saturation are shown to be a significant source of error on the derived average. The influence of saturation on the derived root mean square (rms) is even more pronounced. It is found that errors on the determined average exceed 5% when the number of saturated samples exceeds 3% of the total. Errors on the rms are 20% for a similar saturation level. This study also attempts to delineate limits, within which the detector saturation can be accurately corrected. It is demonstrated that a simple method for reshaping the clipped part of the pixel intensity histogram makes accurate corrections to account for saturated pixels. These outcomes can be used to correct a saturated signal, quantify the effect of saturation on a derived average and offer a method to correct the derived average in the case of slight to moderate saturation of pixels

Geostatistical description of geological heterogeneity in clayey till as input for improved characterization of contaminated sites

DEFF Research Database (Denmark)

Kessler, Timo Christian; Klint, K.E.S.; Renard, P.

2010-01-01

In low-permeability clay tills subsurface transport is governed by preferential flow in sand lenses and fractures. A proper geological model requires the integration of these features, i.e. the spatial distribution of the geological heterogeneities. Detailed mapping of sand lenses has been done...... at a clay till outcrop in Denmark to characterise the shapes and the spatial variability. Further, geostatistics were applied to simulate the distribution and to develop a heterogeneity model that can be incorporated into an existing geological model of, for example, a contaminated site....

Revised draft: Southeastern Regional geologic characterization report. Volume 1

International Nuclear Information System (INIS)

1984-11-01

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Georgia, Maryland, North Carolina, South Carolina, and Virginia. For each of the states within the southeastern region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, postemplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major ground-water discharge zones, water resources, ground-water salinity, and state of stress. Information is presented on the age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented

Ultrafast THz Saturable Absorption in Semiconductors

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Hoffmann, Matthias C.

2011-01-01

We demonstrate THz saturable absorption in n-doped semiconductors GaAs, GaP, and Ge in a nonlinear THz time-domain spectroscopy experiment. Saturable absorption is caused by sample conductivity modulation due to electron heating and satellite valley scattering in the field of a strong THz pulse....

Destination: Geology?

Science.gov (United States)

Price, Louise

2016-04-01

"While we teach, we learn" (Roman philosopher Seneca) One of the most beneficial ways to remember a theory or concept is to explain it to someone else. The offer of fieldwork and visits to exciting destinations is arguably the easiest way to spark a students' interest in any subject. Geology at A-Level (age 16-18) in the United Kingdom incorporates significant elements of field studies into the curriculum with many students choosing the subject on this basis and it being a key factor in consolidating student knowledge and understanding. Geology maintains a healthy annual enrollment with interest in the subject increasing in recent years. However, it is important for educators not to loose sight of the importance of recruitment and retention of students. Recent flexibility in the subject content of the UK curriculum in secondary schools has provided an opportunity to teach the basic principles of the subject to our younger students and fieldwork provides a valuable opportunity to engage with these students in the promotion of the subject. Promotion of the subject is typically devolved to senior students at Hessle High School and Sixth Form College, drawing on their personal experiences to engage younger students. Prospective students are excited to learn from a guest speaker, so why not use our most senior students to engage and promote the subject rather than their normal subject teacher? A-Level geology students embarking on fieldwork abroad, understand their additional responsibility to promote the subject and share their understanding of the field visit. They will typically produce a series of lessons and activities for younger students using their newly acquired knowledge. Senior students also present to whole year groups in seminars, sharing knowledge of the location's geology and raising awareness of the exciting destinations offered by geology. Geology fieldwork is always planned, organised and led by the member of staff to keep costs low, with recent visits

Environmental geology of Nampo, Puyo, Sochon, Hamyol

Energy Technology Data Exchange (ETDEWEB)

Kim, Won Young; Han, Dae Suk; Kim, Yoon Jong; Yu, Il Hyun; Lee, Bong Joo; Jeong, Gyo Cheol; Kim, Kyeong Su [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

1995-12-01

An environmental geology map at a scale of 1:100,000 was produced to provide information on land use potential within the area of over 1,300 km{sup 2} consisting of Nampo, Puyo , Sochon and Hamyol. Land use potentiality was quantitatively assigned in accordance with the environmental geologic index(EI) derived from such factors as landslide frequency, engineering geological unit, topography and density of lineament length, being classified into 4 units. Also produced was a landslide susceptibility map at the same scale as the above map, showing five different grades of susceptibility based on hazard index(HI). Besides the above mentioned mapping, an investigation on the soils, rocks and natural aggregates throughout the study area was undertaken to assess their utilization potential as construction materials. Also carried out were the analysis of erosion and sedimentation in/around the Keum river, a geotechnical engineering investigation on the reclaimed tidal zone south of the Taechon beach, and the stability analysis of the cut slopes along the national roads. All the results of the investigations and analyses are presented in the paper. It is expected that the maps and accompanying information could be utilized in formulating regional land-use planning for variable projects. (author). 51 refs., 60 figs., 62 tabs., 3 maps.

Electrical conductivity modeling in fractal non-saturated porous media

Science.gov (United States)

Wei, W.; Cai, J.; Hu, X.; Han, Q.

2016-12-01

The variety of electrical conductivity in non-saturated conditions is important to study electric conduction in natural sedimentary rocks. The electrical conductivity in completely saturated porous media is a porosity-function representing the complex connected behavior of single conducting phases (pore fluid). For partially saturated conditions, the electrical conductivity becomes even more complicated since the connectedness of pore. Archie's second law is an empirical electrical conductivity-porosity and -saturation model that has been used to predict the formation factor of non-saturated porous rock. However, the physical interpretation of its parameters, e.g., the cementation exponent m and the saturation exponent n, remains questionable. On basis of our previous work, we combine the pore-solid fractal (PSF) model to build an electrical conductivity model in non-saturated porous media. Our theoretical porosity- and saturation-dependent models contain endmember properties, such as fluid electrical conductivities, pore fractal dimension and tortuosity fractal dimension (representing the complex degree of electrical flowing path). We find the presented model with non-saturation-dependent electrical conductivity datasets indicate excellent match between theory and experiments. This means the value of pore fractal dimension and tortuosity fractal dimension change from medium to medium and depends not only on geometrical properties of pore structure but also characteristics of electrical current flowing in the non-saturated porous media.

Computed Tomography Scanning to Understand Micro-to-Macro Controls on Multiphase Flow during Geologic Carbon Storage; NETL-TRS-3-2017; NETL Technical Report Series; U.S. Department of Energy, National Energy Technology Laboratory: Morgantown, WV, 2017; p 24.

Energy Technology Data Exchange (ETDEWEB)

Crandall, Dustin M. [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Moore, Johnathan E. [National Energy Technology Lab. (NETL) and AECOM, Morgantown, WV (United States); Tudek, John K. [National Energy Technology Lab. (NETL) and AECOM, Morgantown, WV (United States); Gill, Magdalena K [National Energy Technology Lab. (NETL) and ORISE, Morgantown, WV (United States)

2017-03-01

Evaluation of the fate and transport of carbon dioxide (CO₂) in deep reservoirs is crucial to the development of long-term geologic carbon sequestration (GCS) technologies. In this report, various studies using computed tomography (CT) scanning are utilized in conjunction with traditional flow tests to observe the multi-scale phenomena associated with CO₂ injection in geologic media. Pore scale analyses were performed to determine the infiltration characteristics of CO₂ into a brine saturated reservoir rock. Multiphase floods were performed to evaluate the saturation of CO₂ into a brine-saturated reservoir rock and determine how structural changes within the lithology affect such interactions. Additionally, CO₂ induced swelling of unconventional reservoir rock was evaluated with respect to reductions in fracture transmissivity due to matrix swelling. These studies are just a few examples of the benefits of multi-scale CT imaging in conjunction with traditional laboratory methodology to gain a better understanding of the interactions between CO₂ and the lithologies it interacts with during GCS.

Field Geology/Processes

Science.gov (United States)

Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

1996-01-01

The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

Temporal trends in fast-food restaurant energy, sodium, saturated fat, and trans fat content, United States, 1996-2013.

Science.gov (United States)

Urban, Lorien E; Roberts, Susan B; Fierstein, Jamie L; Gary, Christine E; Lichtenstein, Alice H

2014-12-31

Excess intakes of energy, sodium, saturated fat, and trans fat are associated with increased risk for cardiometabolic syndrome. Trends in fast-food restaurant portion sizes can inform policy decisions. We examined the variability of popular food items in 3 fast-food restaurants in the United States by portion size during the past 18 years. Items from 3 national fast-food chains were selected: French fries, cheeseburgers, grilled chicken sandwich, and regular cola. Data on energy, sodium, saturated fat, and trans fat content were collated from 1996 through 2013 using an archival website. Time trends were assessed using simple linear regression models, using energy or a nutrient component as the dependent variable and the year as the independent variable. For most items, energy content per serving differed among chain restaurants for all menu items (P ≤ .04); energy content of 56% of items decreased (β range, -0.1 to -5.8 kcal) and the content of 44% increased (β range, 0.6-10.6 kcal). For sodium, the content of 18% of the items significantly decreased (β range, -4.1 to -24.0 mg) and the content for 33% increased (β range, 1.9-29.6 mg). Absolute differences were modest. The saturated and trans fat content, post-2009, was modest for French fries. In 2013, the energy content of a large-sized bundled meal (cheeseburger, French fries, and regular cola) represented 65% to 80% of a 2,000-calorie-per-day diet, and sodium content represented 63% to 91% of the 2,300-mg-per-day recommendation and 97% to 139% of the 1,500-mg-per-day recommendation. Findings suggest that efforts to promote reductions in energy, sodium, saturated fat, and trans fat intakes need to be shifted from emphasizing portion-size labels to additional factors such as total calories, frequency of eating, number of items ordered, menu choices, and energy-containing beverages.

Regional groundwater modeling of the saturated zone in the vicinity of Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ahola, M.; Sagar, B.

1992-10-01

Results of groundwater modeling of the saturated zone in the vicinity of Yucca Mountain are presented. Both a regional (200 x 200 km) and subregional (50 x 50 km) model were used in the analyses. Simulations were conducted to determine the impact of various disruptive that might take place over the life span of a proposed Yucca Mountain geologic conditions repository on the groundwater flow field, as well as changes in the water-table elevations. These conditions included increases in precipitation and groundwater recharge within the regional model, changes in permeability of existing hydrogeologic barriers, a:nd the vertical intrusion of volcanic dikes at various orientations through the saturated zone. Based on the regional analysis, the rise in the water-table under Yucca Mountain due to various postulated conditions ranged from only a few meters to 275 meters. Results of the subregional model analysis, which was used to simulate intrusive dikes approximately 4 kilometers in length in the vicinity of Yucca Mountain, showed water-table rises ranging from a few meters to as much as 103 meters. Dikes oriented approximately north-south beneath Yucca Mountain produced the highest water-table rises. The conclusions drawn from this analysis are likely to change as more site-specific data become available and as the assumptions in the model are improved

Geological mapping potential of computer-enhanced images from the Shuttle Imaging Radar - Lisbon Valley Anticline, Utah

Science.gov (United States)

Curlis, J. D.; Frost, V. S.; Dellwig, L. F.

1986-01-01

Computer-enhancement techniques applied to the SIR-A data from the Lisbon Valley area in the northern portion of the Paradox basin increased the value of the imagery in the development of geologically useful maps. The enhancement techniques include filtering to remove image speckle from the SIR-A data and combining these data with Landsat multispectral scanner data. A method well-suited for the combination of the data sets utilized a three-dimensional domain defined by intensity-hue-saturation (IHS) coordinates. Such a system allows the Landsat data to modulate image intensity, while the SIR-A data control image hue and saturation. Whereas the addition of Landsat data to the SIR-A image by means of a pixel-by-pixel ratio accentuated textural variations within the image, the addition of color to the combined images enabled isolation of areas in which gray-tone contrast was minimal. This isolation resulted in a more precise definition of stratigraphic units.

Global Journal of Geological Sciences

African Journals Online (AJOL)

Global Journal of Geological Sciences is aimed at promoting research in all areas of Geological Sciences including geochemistry, geophysics, engineering geology, hydrogeology, petrology, mineralogy, geochronology, tectonics, mining, structural geology, marine geology, space science etc. Visit the Global Journal Series ...

Observability of linear systems with saturated outputs

NARCIS (Netherlands)

Koplon, R.; Sontag, E.D.; Hautus, M.L.J.

1994-01-01

We present necessary and sufficient conditions for observability of the class of output-saturated systems. These are linear systems whose output passes through a saturation function before it can be measured.

Saturated Zone In-Situ Testing

International Nuclear Information System (INIS)

Reimus, P. W.; Umari, M. J.

2003-01-01

The purpose of this scientific analysis is to document the results and interpretations of field experiments that have been conducted to test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain. The test interpretations provide estimates of flow and transport parameters that are used in the development of parameter distributions for Total System Performance Assessment (TSPA) calculations. These parameter distributions are documented in the revisions to the SZ flow model report (BSC 2003 [ 162649]), the SZ transport model report (BSC 2003 [ 162419]), the SZ colloid transport report (BSC 2003 [162729]), and the SZ transport model abstraction report (BSC 2003 [1648701]). Specifically, this scientific analysis report provides the following information that contributes to the assessment of the capability of the SZ to serve as a barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid transport parameters. (3) Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium at the Alluvium Testing Complex (ATC), which is located at the southwestern corner of the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic conductivities, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, and

Saturated Zone In-Situ Testing

Energy Technology Data Exchange (ETDEWEB)

P. W. Reimus; M. J. Umari

2003-12-23

The purpose of this scientific analysis is to document the results and interpretations of field experiments that have been conducted to test and validate conceptual flow and radionuclide transport models in the saturated zone (SZ) near Yucca Mountain. The test interpretations provide estimates of flow and transport parameters that are used in the development of parameter distributions for Total System Performance Assessment (TSPA) calculations. These parameter distributions are documented in the revisions to the SZ flow model report (BSC 2003 [ 162649]), the SZ transport model report (BSC 2003 [ 162419]), the SZ colloid transport report (BSC 2003 [162729]), and the SZ transport model abstraction report (BSC 2003 [1648701]). Specifically, this scientific analysis report provides the following information that contributes to the assessment of the capability of the SZ to serve as a barrier for waste isolation for the Yucca Mountain repository system: (1) The bases for selection of conceptual flow and transport models in the saturated volcanics and the saturated alluvium located near Yucca Mountain. (2) Results and interpretations of hydraulic and tracer tests conducted in saturated fractured volcanics at the C-wells complex near Yucca Mountain. The test interpretations include estimates of hydraulic conductivities, anisotropy in hydraulic conductivity, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, matrix diffusion coefficients, fracture apertures, and colloid transport parameters. (3) Results and interpretations of hydraulic and tracer tests conducted in saturated alluvium at the Alluvium Testing Complex (ATC), which is located at the southwestern corner of the Nevada Test Site (NTS). The test interpretations include estimates of hydraulic conductivities, storativities, total porosities, effective porosities, longitudinal dispersivities, matrix diffusion mass transfer coefficients, and

Research on geological disposal: R and D concept on geological disposal

International Nuclear Information System (INIS)

1993-01-01

The objective on geological disposal of high-level radioactive wastes are to ensure the long term radiological protection of the human and his environment in accordance with current internationally agreed radiation protection principles. The principle of geological disposal is to settle the high-level wastes in deep underground so as to isolate them from the human and his environment considering the existence of groundwater. Japan is currently in the stage of assessing technical feasibility of geological disposal to the extent practicable. In accordance with the AEC (Atomic Energy Commission) policy in 1989, PNC (Power Reactor and Nuclear Fuel Development Corporation) has conducted the research and development on geological disposal in three areas: 1) studies of geological environment, 2) research and development of disposal technology, and 3) performance assessment study. (author)

SATURATION OF MAGNETOROTATIONAL INSTABILITY THROUGH MAGNETIC FIELD GENERATION

International Nuclear Information System (INIS)

Ebrahimi, F.; Prager, S. C.; Schnack, D. D.

2009-01-01

The saturation mechanism of magnetorotational instability (MRI) is examined through analytical quasi-linear theory and through nonlinear computation of a single mode in a rotating disk. We find that large-scale magnetic field is generated through the α-effect (the correlated product of velocity and magnetic field fluctuations) and causes the MRI mode to saturate. If the large-scale plasma flow is allowed to evolve, the mode can also saturate through its flow relaxation. In astrophysical plasmas, for which the flow cannot relax because of gravitational constraints, the mode saturates through field generation only.

Introductory Geology From the Liberal Arts Approach: A Geology-Sociology Linked Course

Science.gov (United States)

Walsh, E. O.; Davis, E.

2008-12-01

Geology can be a hard sell to college students, especially to college students attending small, liberal arts institutions in localities that lack exaggerated topography. At these schools, Geology departments that wish to grow must work diligently to attract students to the major; professors must be able to convince a wider audience of students that geology is relevant to their everyday lives. Toward this end, a Physical Geology course was linked with an introductory Sociology course through the common theme of Consumption. The same students took the two courses in sequence, beginning with the Sociology course and ending with Physical Geology; thus, students began by discussing the role of consumption in society and ended by learning about the geological processes and implications of consumption. Students were able to ascertain the importance of geology in their daily lives by connecting Earth processes to specific products they consume, such as cell phones and bottled water. Students were also able to see the connection between seemingly disparate fields of study, which is a major goal of the liberal arts. As a theme, Consumption worked well to grab the attention of students interested in diverse issues, such as environmental science or social justice. A one-hour lecture illustrating the link between sociology and geology was developed for presentation to incoming freshmen and their parents to advertise the course. Initial response has been positive, showing an increase in awareness of geological processes among students with a wide range of interests.

Another look at zonal flows: Resonance, shearing, and frictionless saturation

Science.gov (United States)

Li, J. C.; Diamond, P. H.

2018-04-01

We show that shear is not the exclusive parameter that represents all aspects of flow structure effects on turbulence. Rather, wave-flow resonance enters turbulence regulation, both linearly and nonlinearly. Resonance suppresses the linear instability by wave absorption. Flow shear can weaken the resonance, and thus destabilize drift waves, in contrast to the near-universal conventional shear suppression paradigm. Furthermore, consideration of wave-flow resonance resolves the long-standing problem of how zonal flows (ZFs) saturate in the limit of weak or zero frictional drag, and also determines the ZF scale. We show that resonant vorticity mixing, which conserves potential enstrophy, enables ZF saturation in the absence of drag, and so is effective at regulating the Dimits up-shift regime. Vorticity mixing is incorporated as a nonlinear, self-regulation effect in an extended 0D predator-prey model of drift-ZF turbulence. This analysis determines the saturated ZF shear and shows that the mesoscopic ZF width scales as LZ F˜f3 /16(1-f ) 1 /8ρs5/8l03 /8 in the (relevant) adiabatic limit (i.e., τckk‖2D‖≫1 ). f is the fraction of turbulence energy coupled to ZF and l0 is the base state mixing length, absent ZF shears. We calculate and compare the stationary flow and turbulence level in frictionless, weakly frictional, and strongly frictional regimes. In the frictionless limit, the results differ significantly from conventionally quoted scalings derived for frictional regimes. To leading order, the flow is independent of turbulence intensity. The turbulence level scales as E ˜(γL/εc) 2 , which indicates the extent of the "near-marginal" regime to be γLcase of avalanche-induced profile variability. Here, εc is the rate of dissipation of potential enstrophy and γL is the characteristic linear growth rate of fluctuations. The implications for dynamics near marginality of the strong scaling of saturated E with γL are discussed.

Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

Science.gov (United States)

Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.

2014-12-01

A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.

Ice versus liquid water saturation in simulations of the indian summer monsoon

Science.gov (United States)

Glazer, Russell H.; Misra, Vasubandhu

2018-02-01

At the same temperature, below 0 °C, the saturation vapor pressure (SVP) over ice is slightly less than the SVP over liquid water. Numerical models use the Clausius-Clapeyron relation to calculate the SVP and relative humidity, but there is not a consistent method for the treatment of saturation above the freezing level where ice and mixed-phase clouds may be present. In the context of current challenges presented by cloud microphysics in climate models, we argue that a better understanding of the impact that this treatment has on saturation-related processes like cloud formation and precipitation, is needed. This study explores the importance of the SVP calculation through model simulations of the Indian summer monsoon (ISM) using the regional spectral model (RSM) at 15 km grid spacing. A combination of seasonal and multiyear simulations is conducted with two saturation parameterizations. In one, the SVP over liquid water is prescribed through the entire atmospheric column (woIce), and in another the SVP over ice is used above the freezing level (wIce). When SVP over ice is prescribed, a thermodynamic drying of the middle and upper troposphere above the freezing level occurs due to increased condensation. In the wIce runs, the model responds to the slight decrease in the saturation condition by increasing, relative to the SVP over liquid water only run, grid-scale condensation of water. Increased grid-scale mean seasonal precipitation is noted across the ISM region in the simulation with SVP over ice prescribed. Modification of the middle and upper troposphere moisture results in a decrease in mean seasonal mid-level cloud amount and an increase in high cloud amount when SVP over ice is prescribed. Multiyear simulations strongly corroborate the qualitative results found in the seasonal simulations regarding the impact of ice versus liquid water SVP on the ISM's mean precipitation and moisture field. The mean seasonal rainfall difference over All India between w

In vivo detection of hemoglobin oxygen saturation and carboxyhemoglobin saturation with multiwavelength photoacoustic microscopy.

Science.gov (United States)

Chen, Zhongjiang; Yang, Sihua; Xing, Da

2012-08-15

A method for noninvasively detecting hemoglobin oxygen saturation (SO2) and carboxyhemoglobin saturation (SCO) in subcutaneous microvasculature with multiwavelength photoacoustic microscopy is presented. Blood samples mixed with different concentrations of carboxyhemoglobin were used to test the feasibility and accuracy of photoacoustic microscopy compared with the blood-gas analyzer. Moreover, fixed-point detection of SO2 and SCO in mouse ear was obtained, and the changes from normoxia to carbon monoxide hypoxia were dynamically monitored in vivo. Experimental results demonstrate that multiwavelength photoacoustic microscopy can detect SO2 and SCO, which has future potential clinical applications.

Utilization of Integrated Assessment Modeling for determining geologic CO2 storage security

Science.gov (United States)

Pawar, R.

2017-12-01

Geologic storage of carbon dioxide (CO2) has been extensively studied as a potential technology to mitigate atmospheric concentration of CO2. Multiple international research & development efforts, large-scale demonstration and commercial projects are helping advance the technology. One of the critical areas of active investigation is prediction of long-term CO2 storage security and risks. A quantitative methodology for predicting a storage site's long-term performance is critical for making key decisions necessary for successful deployment of commercial scale projects where projects will require quantitative assessments of potential long-term liabilities. These predictions are challenging given that they require simulating CO2 and in-situ fluid movements as well as interactions through the primary storage reservoir, potential leakage pathways (such as wellbores, faults, etc.) and shallow resources such as groundwater aquifers. They need to take into account the inherent variability and uncertainties at geologic sites. This talk will provide an overview of an approach based on integrated assessment modeling (IAM) to predict long-term performance of a geologic storage site including, storage reservoir, potential leakage pathways and shallow groundwater aquifers. The approach utilizes reduced order models (ROMs) to capture the complex physical/chemical interactions resulting due to CO2 movement and interactions but are computationally extremely efficient. Applicability of the approach will be demonstrated through examples that are focused on key storage security questions such as what is the probability of leakage of CO2 from a storage reservoir? how does storage security vary for different geologic environments and operational conditions? how site parameter variability and uncertainties affect storage security, etc.

UTEX modeling of xenon signature sensitivity to geology and explosion cavity characteristics following an underground nuclear explosion

Science.gov (United States)

Lowrey, J. D.; Haas, D.

2013-12-01

Underground nuclear explosions (UNEs) produce anthropogenic isotopes that can potentially be used in the verification component of the Comprehensive Nuclear-Test-Ban Treaty. Several isotopes of radioactive xenon gas have been identified as radionuclides of interest within the International Monitoring System (IMS) and in an On-Site Inspection (OSI). Substantial research has been previously undertaken to characterize the geologic and atmospheric mechanisms that can drive the movement of radionuclide gas from a well-contained UNE, considering both sensitivities on gas arrival time and signature variability of xenon due to the nature of subsurface transport. This work further considers sensitivities of radioxenon gas arrival time and signatures to large variability in geologic stratification and generalized explosion cavity characteristics, as well as compares this influence to variability in the shallow surface.

Saturation of bentonite dependent upon temperature

International Nuclear Information System (INIS)

Hausmannova, Lucie; Vasicek, Radek

2010-01-01

Document available in extended abstract form only. The fundamental idea behind the long-term safe operation of a deep repository is the use of the Multi-barrier system principle. Barriers may well differ according to the type of host rock in which the repository is located. It is assumed that the buffer in the granitic host rock environment will consist of swelling clays which boast the ideal properties for such a function i.e. low permeability, high swelling pressure, self-healing ability etc. all of which are affected primarily by mineralogy and dry density. Water content plays a crucial role in the activation of swelling pressure as well as, subsequently, in the potential self healing of the various contact areas of the numerous buffer components made from bentonite. In the case of a deep repository, a change in water content is not only connected with the possible intake of water from the host rock, but also with its redistribution owing to changes in temperature after the insertion of the heat source (disposal waste package containing spent fuel) into the repository 'nest'. The principal reason for the experimental testing of this high dry density material is the uncertainty with regard to its saturation ability (final water content or the degree of saturation) at higher temperatures. The results of the Mock-Up-CZ experiment showed that when the barrier is constantly supplied with a saturation medium over a long time period the water content in the barrier as well as the degree of saturation settle independently of temperature. The Mock-Up-CZ experiment was performed at temperatures of 30 deg. - 90 deg. C in the barrier; therefore it was decided to experimentally verify this behaviour by means of targeted laboratory tests. A temperature of 110 deg. C was added to the set of experimental temperatures resulting in samples being tested at 25 deg. C, 95 deg. C and 110 deg. C. The degree of saturation is defined as the ratio of pore water volume to pore

Mental abilities and performance efficacy under a simulated 480 meters helium-oxygen saturation diving

Directory of Open Access Journals (Sweden)

gonglin ehou

2015-07-01

Full Text Available Stress in extreme environment severely disrupts human physiology and mental abilities. The present study investigated the cognition and performance efficacy of four divers during a simulated 480 meters helium-oxygen saturation diving. We analyzed the spatial memory, 2D/3D mental rotation functioning, grip strength, and hand-eye coordination ability in four divers during the 0 – 480 meters compression and decompression processes of the simulated diving. The results showed that except for its mild decrease on grip strength, the high atmosphere pressure condition significantly impaired the hand-eye coordination (especially at 300 meters, the reaction time and correct rate of mental rotation, as well as the spatial memory (especially as 410 meters, showing high individual variability. We conclude that the human cognition and performance efficacy are significantly affected during deep water saturation diving.

Minimum K_2,3-saturated Graphs

OpenAIRE

Chen, Ya-Chen

2010-01-01

A graph is K_{2,3}-saturated if it has no subgraph isomorphic to K_{2,3}, but does contain a K_{2,3} after the addition of any new edge. We prove that the minimum number of edges in a K_{2,3}-saturated graph on n >= 5 vertices is sat(n, K_{2,3}) = 2n - 3.

Geographical distribution patterns of iodine in drinking-water and its associations with geological factors in Shandong Province, China.

Science.gov (United States)

Gao, Jie; Zhang, Zhijie; Hu, Yi; Bian, Jianchao; Jiang, Wen; Wang, Xiaoming; Sun, Liqian; Jiang, Qingwu

2014-05-19

County-based spatial distribution characteristics and the related geological factors for iodine in drinking-water were studied in Shandong Province (China). Spatial autocorrelation analysis and spatial scan statistic were applied to analyze the spatial characteristics. Generalized linear models (GLMs) and geographically weighted regression (GWR) studies were conducted to explore the relationship between water iodine level and its related geological factors. The spatial distribution of iodine in drinking-water was significantly heterogeneous in Shandong Province (Moran's I = 0.52, Z = 7.4, p water were identified in the south-western and north-western parts of Shandong Province by the purely spatial scan statistic approach. Both GLMs and GWR indicated a significantly global association between iodine in drinking-water and geological factors. Furthermore, GWR showed obviously spatial variability across the study region. Soil type and distance to Yellow River were statistically significant at most areas of Shandong Province, confirming the hypothesis that the Yellow River causes iodine deposits in Shandong Province. Our results suggested that the more effective regional monitoring plan and water improvement strategies should be strengthened targeting at the cluster areas based on the characteristics of geological factors and the spatial variability of local relationships between iodine in drinking-water and geological factors.

Geological exploration of Angola from Sumbe to Namibe: A review at the frontier between geology, natural resources and the history of geology

Science.gov (United States)

Masse, Pierre; Laurent, Olivier

2016-01-01

This paper provides a review of the Geological exploration of the Angola Coast (from Sumbe to Namibe) from pioneer's first geological descriptions and mining inventory to the most recent publications supported by the oil industry. We focus our attention on the following periods: 1875-1890 (Paul Choffat's work, mainly), 1910-1949 (first maps at country scale), 1949-1974 (detailed mapping of the Kwanza-Namibe coastal series), 1975-2000, with the editing of the last version of the Angola geological map at 1:1 million scale and the progressive completion of previous works. Since 2000, there is a renewal in geological fieldwork publications on the area mainly due to the work of university teams. This review paper thus stands at the frontier between geology, natural resources and the history of geology. It shows how geological knowledge has progressed in time, fueled by economic and scientific reasons.

Diffusion of helium and estimated diffusion coefficients of hydrogen dissolved in water-saturated, compacted Ca-montmorillonite

International Nuclear Information System (INIS)

Higashihara, Tomohiro; Sato, Seichi; Ohashi, Hiroshi; Otsuka, Teppei

2001-01-01

The diffusion coefficients of hydrogen gas dissolved in water-saturated, compacted montmorillonite are required to estimate the performance of bentonite buffer materials for geological disposal of nuclear waste. As part of the effort to determine the diffusion coefficients, the diffusion coefficients of helium in water-saturated, compacted calcium montmorillonite (Ca-montmorillonite) were determined as a function of dry density, 0.78 to 1.37x10 3 kg m -3 , by a transient diffusion method. The diffusion coefficients were from 8.3x10 -10 m 2 s -1 at 0.78x10 3 kgm -3 to 2.8x10 -10 m 2 s -1 at 1.37x10 3 kgm -3 . The data obtained by this diffusion experiment of helium were highly reproducible. The diffusion coefficients of helium in Ca-montmorillonite were somewhat larger than those previously obtained for helium in sodium montmorillonite (Na-montmorillonite). The diffusion coefficients of hydrogen gas in the montmorillonites were roughly estimated using the diffusion coefficients of helium. These estimates were based on assumptions that both helium and hydrogen molecules are non-adsorptive and that the geometric factors in the compacted montmorillonites are approximately the same for diffusion of helium and diffusion of hydrogen. (author)

Quantifying uncertainty of geological 3D layer models, constructed with a-priori geological expertise

NARCIS (Netherlands)

Gunnink, J.J.; Maljers, D.; Hummelman, J.

2010-01-01

Uncertainty quantification of geological models that are constructed with additional geological expert-knowledge is not straightforward. To construct sound geological 3D layer models we use a lot of additional knowledge, with an uncertainty that is hard to quantify. Examples of geological expert

Core Flooding Experiments Combined with X-rays and Micro-PET Imaging as a Tool to Calculate Fluid Saturations in a Fracture

Science.gov (United States)

Gran, M.; Zahasky, C.; Garing, C.; Pollyea, R. M.; Benson, S. M.

2017-12-01

One way to reduce CO2 emissions is to capture CO2 generated in power plants and other industrial sources to inject it into a geological formation. Sedimentary basins are the ones traditionally used to store CO2 but the emission sources are not always close to these type of basins. In this case, basalt rocks present a good storage alternative due their extent and also their potential for mineral trapping. Flow through basaltic rocks is governed by the permeable paths provided by rock fractures. Hence, knowing the behavior of the multiphase flow in these fractures becomes crucial. With the aim to describe how aperture and liquid-gas interface changes in the fracture affect relative permeability and what are the implications of permeability stress dependency, a series of core experiments were conducted. To calculate fracture apertures and fluid saturations, core flooding experiments combined with medical X-Ray CT scanner and micro-PET imaging (Micro Positron Emission Tomography) were performed. Capillary pressure and relative permeability drainage curves were simultaneously measured in a fractured basalt core under typical storage reservoir pressures and temperatures. The X-Ray scanner allows fracture apertures to be measured quite accurately even for fractures as small as 30 µ, but obtaining fluid saturations is not straightforward. The micro-PET imaging provides dynamic measurements of tracer distributions which can be used to calculate saturation. Here new experimental data is presented and the challenges associated with measuring fluid saturations using both X-Rays and micro-PET are discussed.

Development of an Anisotropic Geological-Based Land Use Regression and Bayesian Maximum Entropy Model for Estimating Groundwater Radon across Northing Carolina

Science.gov (United States)

Messier, K. P.; Serre, M. L.

2015-12-01

Radon (222Rn) is a naturally occurring chemically inert, colorless, and odorless radioactive gas produced from the decay of uranium (238U), which is ubiquitous in rocks and soils worldwide. Exposure to 222Rn is likely the second leading cause of lung cancer after cigarette smoking via inhalation; however, exposure through untreated groundwater is also a contributing factor to both inhalation and ingestion routes. A land use regression (LUR) model for groundwater 222Rn with anisotropic geological and 238U based explanatory variables is developed, which helps elucidate the factors contributing to elevated 222Rn across North Carolina. Geological and uranium based variables are constructed in elliptical buffers surrounding each observation such that they capture the lateral geometric anisotropy present in groundwater 222Rn. Moreover, geological features are defined at three different geological spatial scales to allow the model to distinguish between large area and small area effects of geology on groundwater 222Rn. The LUR is also integrated into the Bayesian Maximum Entropy (BME) geostatistical framework to increase accuracy and produce a point-level LUR-BME model of groundwater 222Rn across North Carolina including prediction uncertainty. The LUR-BME model of groundwater 222Rn results in a leave-one out cross-validation of 0.46 (Pearson correlation coefficient= 0.68), effectively predicting within the spatial covariance range. Modeled results of 222Rn concentrations show variability among Intrusive Felsic geological formations likely due to average bedrock 238U defined on the basis of overlying stream-sediment 238U concentrations that is a widely distributed consistently analyzed point-source data.

Revised draft: North Central Regional geologic characterization report. Volume 1

International Nuclear Information System (INIS)

1984-11-01

This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, water resources, groundwater salinity, and state of stress. Information is presented on age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented

Scintillation probe with photomultiplier tube saturation indicator

International Nuclear Information System (INIS)

Ruch, J.F.; Urban, D.J.

1996-01-01

A photomultiplier tube saturation indicator is formed by supplying a supplemental light source, typically an light emitting diode (LED), adjacent to the photomultiplier tube. A switch allows the light source to be activated. The light is forwarded to the photomultiplier tube by an optical fiber. If the probe is properly light tight, then a meter attached to the indicator will register the light from the LED. If the probe is no longer light tight, and the saturation indicator is saturated, no signal will be registered when the LED is activated. 2 figs

Uncertainties in sealing a nuclear waste repository in partially saturated tuff

International Nuclear Information System (INIS)

Tillerson, J.R.; Fernandez, J.A.; Hinkebein, T.E.

1989-01-01

Sealing a nuclear waste repository in partially saturated tuff presents unique challenges to assuring performance of sealing components. Design and performance of components for sealing shafts, ramps, drifts, and exploratory boreholes depend on specific features of both the repository design and the site; of particular importance is the hydrologic environment in the unsaturated zone, including the role of fracture flow. Repository design features important to sealing of a repository include the size and location of shaft and ramp accesses, excavation methods, and the underground layout features such as grade (drainage direction) and location relative to geologic structure. Uncertainties about seal components relate to the postclosure environment for the seals, the emplacement methods, the material properties, and the potential performance of the components. An approach has been developed to reduce uncertainties and to increase confidence in seal performance; it includes gathering extensive site characterization data, establishing conservative design requirements, testing seal components in laboratory and field environments, and refining designs of both the seals and the repository before seals are installed. 9 refs., 5 figs., 2 tabs

Simulation of Anisotropic Rock Damage for Geologic Fracturing

Science.gov (United States)

Busetti, S.; Xu, H.; Arson, C. F.

2014-12-01

A continuum damage model for differential stress-induced anisotropic crack formation and stiffness degradation is used to study geologic fracturing in rocks. The finite element-based model solves for deformation in the quasi-linear elastic domain and determines the six component damage tensor at each deformation increment. The model permits an isotropic or anisotropic intact or pre-damaged reference state, and the elasticity tensor evolves depending on the stress path. The damage variable, similar to Oda's fabric tensor, grows when the surface energy dissipated by three-dimensional opened cracks exceeds a threshold defined at the appropriate scale of the representative elementary volume (REV). At the laboratory or wellbore scale (1000m) scales the damaged REV reflects early natural fracturing (background or tectonic fracturing) or shear strain localization (fault process zone, fault-tip damage, etc.). The numerical model was recently benchmarked against triaxial stress-strain data from laboratory rock mechanics tests. However, the utility of the model to predict geologic fabric such as natural fracturing in hydrocarbon reservoirs was not fully explored. To test the ability of the model to predict geological fracturing, finite element simulations (Abaqus) of common geologic scenarios with known fracture patterns (borehole pressurization, folding, faulting) are simulated and the modeled damage tensor is compared against physical fracture observations. Simulated damage anisotropy is similar to that derived using fractured rock-mass upscaling techniques for pre-determined fracture patterns. This suggests that if model parameters are constrained with local data (e.g., lab, wellbore, or reservoir domain), forward modeling could be used to predict mechanical fabric at the relevant REV scale. This reference fabric also can be used as the starting material property to pre-condition subsequent deformation or fluid flow. Continuing efforts are to expand the present damage

Geological heritage of Morocco

International Nuclear Information System (INIS)

Elhadi, H.; Tahiri, A.

2012-01-01

Full text: The soil and subsoil of Morocco are rich in geological phenomena that bear the imprint of a history that goes back in time more than 2000 million years. Very many sites geologically remarkable exposed in accessible outcrops, with good quality remain unknown to the general public and therefore deserve to be vulgarized. It is a memory to acquaint to the present generations but also to preserve for future generations. In total, a rich geological heritage in many ways: Varied landscapes, international stratotypes, various geological structures, varied rocks, mineral associations, a huge procession of fossiles, remnants of oceanic crust (ophiolites) among oldests ones in the world (800my), etc... For this geological heritage, an approach of an overall inventory is needed, both regionally and nationally, taking into account all the skills of the earth sciences. This will put the item on the natural (geological) potentialities as a lever for sustainable regional development. For this, it is necessary to implement a strategy of ''geoconservation'' for the preservation and assessment of the geological heritage.

Geological Storage of CO2. Site Selection Criteria; Almacenamiento Geologico de CO2. Criterios de Seleccion de Emplazamientos

Energy Technology Data Exchange (ETDEWEB)

Ruiz, C; Martinez, R; Recreo, F; Prado, P; Campos, R; Pelayo, M; Losa, A de la; Hurtado, A; Lomba, L; Perez del Villar, L; Ortiz, G; Sastre, J

2006-07-01

In year 2002 the Spanish Parliament unanimously passed the ratification of the Kyoto Protocol, signed December 1997, compromising to limiting the greenhouse gas emissions increase. Later on, the Environment Ministry submitted the Spanish National Assignment Emissions Plan to the European Union and in year 2005 the Spanish Greenhouse Gas market started working, establishing taxes to pay in case of exceeding the assigned emissions limits. So, the avoided emissions of CO2 have now an economic value that is promoting new anthropogenic CO2 emissions reduction technologies. Carbon Capture and Storage (CCS) are among these new technological developments for mitigating or eliminate climate change. CO2 can be stored in geological formations such as depleted oil or gas fields, deep permeable saline water saturated formations and unmineable coal seams, among others. This report seeks to establish the selection criteria for suitable geological formations for CO2 storage in the Spanish national territory, paying attention to both the operational and performance requirements of these storage systems. The report presents the physical and chemical properties and performance of CO2 under storage conditions, the transport and reaction processes of both supercritical and gaseous CO2, and CO2 trapping mechanisms in geological formations. The main part of the report is devoted to geological criteria at watershed, site and formation scales. (Author) 100 ref.

Geological Services Laboratory

Data.gov (United States)

Federal Laboratory Consortium — Researchers use computed tomography (CT) scanners at NETL’s Geological Services Laboratory in Morgantown, WV, to peer into geologic core samples to determine how...

Simulation of the saturation process of a radwaste storage cell

International Nuclear Information System (INIS)

Robbe, M.F.; Clouard, A.

2001-01-01

This paper presents a simulation of the saturation of the barrier and the plug of a storage cell by the surrounding host rock. Generally speaking, the unsaturated barrier and plug start saturating immediately in the vicinity of the quasi-saturated host rock. Then the saturation front propagates towards the canisters and the symmetry axis. Apart from the part in contact with the plug, the barrier is saturated at about 30 years. The part of the barrier near the plug is saturated around 80 years. If the top of the plug is saturated very soon, the part in the corner near the gallery and the symmetry axis is not completely saturated after 100 years. In the site, we observe a small desaturation during the first month, at the limit with the plug and the barrier, and especially in the corner limited by both FoCa clay pieces. This transient phenomenon may be assigned to the time difference between the immediate suction of water by the unsaturated materials and the delayed water flows coming from the saturated host rock to compensate the water suction. The purpose of this computation was at once to estimate the time necessary for the saturation of the clay layers surrounding the radwaste canisters and to evaluate the hydro-mechanical behaviour of the storage cell during the saturation process. Therefore a mechanical simulation was performed using the present hydraulic results to initiate the mechanical computation. (authors)

On leakage and seepage from geological carbon sequestration sites

Energy Technology Data Exchange (ETDEWEB)

Oldenburg, C.M.; Unger, A.J.A.; Hepple, R.P.; Jordan, P.D.

2002-07-18

Geologic carbon sequestration is one strategy for reducing the rate of increase of global atmospheric carbon dioxide (CO{sub 2} ) concentrations (IEA, 1997; Reichle, 2000). As used here, the term geologic carbon sequestration refers to the direct injection of supercritical CO{sub 2} deep into subsurface target formations. These target formations will typically be either depleted oil and gas reservoirs, or brine-filled permeable formations referred to here as brine formations. Injected CO{sub 2} will tend to be trapped by one or more of the following mechanisms: (1) permeability trapping, for example when buoyant supercritical CO{sub 2} rises until trapped by a confining caprock; (2) solubility trapping, for example when CO{sub 2} dissolves into the aqueous phase in water-saturated formations, or (3) mineralogic trapping, such as occurs when CO{sub 2} reacts to produce stable carbonate minerals. When CO{sub 2} is trapped in the subsurface by any of these mechanisms, it is effectively sequestered away from the atmosphere where it would otherwise act as a greenhouse gas. The purpose of this report is to summarize our work aimed at quantifying potential CO{sub 2} seepage due to leakage from geologic carbon sequestration sites. The approach we take is to present first the relevant properties of CO{sub 2} over the range of conditions from the deep subsurface to the vadose zone (Section 2), and then discuss conceptual models for how leakage might occur (Section 3). The discussion includes consideration of gas reservoir and natural gas storage analogs, along with some simple estimates of seepage based on assumed leakage rates. The conceptual model discussion provides the background for the modeling approach wherein we focus on simulating transport in the vadose zone, the last potential barrier to CO{sub 2} seepage (Section 4). Because of the potentially wide range of possible properties of actual future geologic sequestration sites, we carry out sensitivity analyses by

Spatial analysis of geologic and hydrologic features relating to sinkhole occurrence in Jefferson County, West Virginia

Science.gov (United States)

Doctor, Daniel H.; Doctor, Katarina Z.

2012-01-01

In this study the influence of geologic features related to sinkhole susceptibility was analyzed and the results were mapped for the region of Jefferson County, West Virginia. A model of sinkhole density was constructed using Geographically Weighted Regression (GWR) that estimated the relations among discrete geologic or hydrologic features and sinkhole density at each sinkhole location. Nine conditioning factors on sinkhole occurrence were considered as independent variables: distance to faults, fold axes, fracture traces oriented along bedrock strike, fracture traces oriented across bedrock strike, ponds, streams, springs, quarries, and interpolated depth to groundwater. GWR model parameter estimates for each variable were evaluated for significance, and the results were mapped. The results provide visual insight into the influence of these variables on localized sinkhole density, and can be used to provide an objective means of weighting conditioning factors in models of sinkhole susceptibility or hazard risk.

Geology of Mars

International Nuclear Information System (INIS)

Soderblom, L.A.

1988-01-01

The geology of Mars and the results of the Mariner 4, 6/7, and 9 missions and the Viking mission are reviewed. The Mars chronology and geologic modification are examined, including chronological models for the inactive planet, the active planet, and crater flux. The importance of surface materials is discussed and a multispectral map of Mars is presented. Suggestions are given for further studies of the geology of Mars using the Viking data. 5 references

History of geological disposal concept (3). Implementation phase of geological disposal (2000 upward)

International Nuclear Information System (INIS)

Masuda, Sumio; Sakuma, Hideki; Umeki, Hiroyuki

2015-01-01

Important standards and concept about geological disposal have been arranged as an international common base and are being generalized. The authors overview the concept of geological disposal, and would like this paper to help arouse broad discussions for promoting the implementation plan of geological disposal projects in the future. In recent years, the scientific and technological rationality of geological disposal has been recognized internationally. With the addition of discussions from social viewpoints such as ethics, economy, etc., geological disposal projects are in the stage of starting after establishment of social consensus. As an international common base, the following consolidated and systematized items have been presented as indispensable elements in promoting business projects: (1) step-by-step approach, (2) safety case, (3) reversibility and recovery potential, and (4) trust building and communications. This paper outlines the contents of the following cases, where international common base was reflected on the geological disposal projects in Japan: (1) final disposal method and safety regulations, and (2) impact of the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Station accident on geological disposal plan. (A.O.)

Conduct of Geologic Field Work During Planetary Exploration: Why Geology Matters

Science.gov (United States)

Eppler, Dean B.

2010-01-01

The science of field geology is the investigative process of determining the distribution of rock units and structures on a planet fs surface, and it is the first-order data set that informs all subsequent studies of a planet, such as geochemistry, geochronology, geophysics, or remote sensing. For future missions to the Moon and Mars, the surface systems deployed must support the conduct of field geology if these endeavors are to be scientifically useful. This lecture discussed what field geology is all about.why it is important, how it is done, how conducting field geology informs many other sciences, and how it affects the design of surface systems and the implementation of operations in the future.

Geology's Impact on Culture

Science.gov (United States)

Pizzorusso, Ann

2017-04-01

Most people consider geology boring, static and difficult. The fields of astronomy and physics have "rebranded" themselves with exciting programs formatted so as to be readily understandable to the general public. The same thing can be done for geology. My research on geology's influence on other disciplines has resulted in a book, Tweeting da Vinci, in which I was able to show how geology affected Italy's art, architecture, medicine, religion, literature, engineering and just about everything else. The reaction to the book and my lectures by both students and the general public has been very positive, including four gold medals, with reviews and comments indicating that they never knew geology could be so exciting. The book is very user friendly, packed with facts, full-color photos, paintings, sketches and illustrations. Complex aspects of geology are presented in an easily understandable style. Widely diverse topics—such as gemology, folk remedies, grottoes, painting, literature, physics and religion—are stitched together using geology as a thread. Quoting everyone from Pliny the Elder to NASA physicist Friedemann Freund, the work is solidly backed scholarship that reads as easily as a summer novel. The book can be used in classes such as physics, chemistry, literature, art history, medicine, Classical Studies, Latin, Greek and Italian. By incorporating a "geologic perspective" in these courses, it can be perceived as a more "all encompassing" discipline and encourage more students to study it. The lectures I have given on college campuses have resulted in students seeing their own majors from a different perspective and some have even signed up for introductory geology courses. One college organized summer course to the Bay of Naples based on the book. We followed the geology as well as the culture of the area and the students were profoundly moved. To encourage dialog, the book is linked to Facebook, Twitter and Instagram. This has enabled followers from

Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

International Nuclear Information System (INIS)

Ababou, R.

1991-08-01

This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of structural characteristics of the medium. The report further reviews and analyzes large-scale hydrogeologic spatial variability from aquifer data, unsaturated soil data, and fracture network data gathered from the literature. Finally, various modeling strategies toward large-scale flow simulations are assessed, including direct high-resolution simulation, and coarse-scale simulation based on auxiliary hydrodynamic models such as single equivalent continuum and dual-porosity continuum. The roles of anisotropy, fracturing, and broad-band spatial variability are emphasized. 252 refs

Environmental geology and hydrology

Science.gov (United States)

Nakić, Zoran; Mileusnić, Marta; Pavlić, Krešimir; Kovač, Zoran

2017-10-01

Environmental geology is scientific discipline dealing with the interactions between humans and the geologic environment. Many natural hazards, which have great impact on humans and their environment, are caused by geological settings. On the other hand, human activities have great impact on the physical environment, especially in the last decades due to dramatic human population growth. Natural disasters often hit densely populated areas causing tremendous death toll and material damage. Demand for resources enhanced remarkably, as well as waste production. Exploitation of mineral resources deteriorate huge areas of land, produce enormous mine waste and pollute soil, water and air. Environmental geology is a broad discipline and only selected themes will be presented in the following subchapters: (1) floods as natural hazard, (2) water as geological resource and (3) the mining and mineral processing as types of human activities dealing with geological materials that affect the environment and human health.

A survey of archaeological and geological samples dated in 1990

International Nuclear Information System (INIS)

Mejdahl, V.

1991-01-01

A survey of dated archaeological and geological samples is given, using thermoluminescence dating. Some of the sediment samples were also dated by means of optically stimulated luminescence (OSL) using a newly developed infrared diode system. In most cases the luminescence dates are in accordance with archaeological and geological estimates. Some discrepancies were found because some feldspar samples exhibited severe anomalous fading. It may be possible to avoid this problem by basing the dating on OSL of quartz. For sediment samples of Eemian or Early Weichselian age severe underestimates were encountered with both methods. The reason might be related to the large difference between the natural dose rate and that used in laboratory irradiations. Traps corresponding to low-temperature peaks such as the 150 deg. C peak in feldspars will remain almost empty under natural conditions, but will fill up to saturation under laboratory irradiation and thereby more charges will be captured in high-temperature traps. As a result, natural growth curves and laboratory produced luminescence growth curves will have different slopes and this will lead to underestimation. This problem might avoided by holding samples at an elevated temperature during laboratory irradiation, thus keeping the low-temperature traps empty. Preliminary experiments where feldspar samples were held at 130 deg. C during irradiation have given promising results. (AB) (31 refs.)

Elastoplastic model for unsaturated, quasi-saturated and fully saturated fine soils

Directory of Open Access Journals (Sweden)

Lai Ba Tien

2016-01-01

Full Text Available In unsaturated soils, the gaseous phase is commonly assumed to be continuous. This assumption is no more valid at high saturation ratio. In that case, air bubbles and pockets can be trapped in the porous network by the liquid phase and the gas phase becomes discontinuous. This trapped air reduces the apparent compressibility of the pore fluid and affect the mechanical behavior of the soil. Although it is trapped in the pores, its dissolution can take place. Dissolved air can migrate through the pore space, either by following the flow of the fluid or by diffusion. In this context, this paper present a hydro mechanical model that separately considers the kinematics and the mechanical behavior of each fluid species (eg liquid water, dissolved air, gaseous air and the solid matrix. This new model was implemented in a C++ code. Some numerical simulations are performed to demonstrate the ability of this model to reproduce a continuous transition of unsaturated to saturated states.

Geologic Time.

Science.gov (United States)

Newman, William L.

One of a series of general interest publications on science topics, the booklet provides those interested in geologic time with an introduction to the subject. Separate sections discuss the relative time scale, major divisions in geologic time, index fossils used as guides for telling the age of rocks, the atomic scale, and the age of the earth.…

Geological heterogeneity: Goal-oriented simplification of structure and characterization needs

Science.gov (United States)

Savoy, Heather; Kalbacher, Thomas; Dietrich, Peter; Rubin, Yoram

2017-11-01

Geological heterogeneity, i.e. the spatial variability of discrete hydrogeological units, is investigated in an aquifer analog of glacio-fluvial sediments to determine how such a geological structure can be simplified for characterization needs. The aquifer analog consists of ten hydrofacies whereas the scarcity of measurements in typical field studies precludes such detailed spatial models of hydraulic properties. Of particular interest is the role of connectivity of the hydrofacies structure, along with its effect on the connectivity of mass transport, in site characterization for predicting early arrival times. Transport through three realizations of the aquifer analog is modeled with numerical particle tracking to ascertain the fast flow channel through which early arriving particles travel. Three simplification schemes of two-facies models are considered to represent the aquifer analogs, and the velocity within the fast flow channel is used to estimate the apparent hydraulic conductivity of the new facies. The facies models in which the discontinuous patches of high hydraulic conductivity are separated from the rest of the domain yield the closest match in early arrival times compared to the aquifer analog, but assuming a continuous high hydraulic conductivity channel connecting these patches yields underestimated early arrivals times within the range of variability between the realizations, which implies that the three simplification schemes could be advised but pose different implications for field measurement campaigns. Overall, the results suggest that the result of transport connectivity, i.e. early arrival times, within realistic geological heterogeneity can be conserved even when the underlying structural connectivity is modified.

OneGeology-Europe: architecture, portal and web services to provide a European geological map

Science.gov (United States)

Tellez-Arenas, Agnès.; Serrano, Jean-Jacques; Tertre, François; Laxton, John

2010-05-01

OneGeology-Europe is a large ambitious project to make geological spatial data further known and accessible. The OneGeology-Europe project develops an integrated system of data to create and make accessible for the first time through the internet the geological map of the whole of Europe. The architecture implemented by the project is web services oriented, based on the OGC standards: the geological map is not a centralized database but is composed by several web services, each of them hosted by a European country involved in the project. Since geological data are elaborated differently from country to country, they are difficult to share. OneGeology-Europe, while providing more detailed and complete information, will foster even beyond the geological community an easier exchange of data within Europe and globally. This implies an important work regarding the harmonization of the data, both model and the content. OneGeology-Europe is characterised by the high technological capacity of the EU Member States, and has the final goal to achieve the harmonisation of European geological survey data according to common standards. As a direct consequence Europe will make a further step in terms of innovation and information dissemination, continuing to play a world leading role in the development of geosciences information. The scope of the common harmonized data model was defined primarily by the requirements of the geological map of Europe, but in addition users were consulted and the requirements of both INSPIRE and ‘high-resolution' geological maps were considered. The data model is based on GeoSciML, developed since 2006 by a group of Geological Surveys. The data providers involved in the project implemented a new component that allows the web services to deliver the geological map expressed into GeoSciML. In order to capture the information describing the geological units of the map of Europe the scope of the data model needs to include lithology; age; genesis and

Saturation Detection-Based Blocking Scheme for Transformer Differential Protection

Directory of Open Access Journals (Sweden)

Byung Eun Lee

2014-07-01

Full Text Available This paper describes a current differential relay for transformer protection that operates in conjunction with a core saturation detection-based blocking algorithm. The differential current for the magnetic inrush or over-excitation has a point of inflection at the start and end of each saturation period of the transformer core. At these instants, discontinuities arise in the first-difference function of the differential current. The second- and third-difference functions convert the points of inflection into pulses, the magnitudes of which are large enough to detect core saturation. The blocking signal is activated if the third-difference of the differential current is larger than the threshold and is maintained for one cycle. In addition, a method to discriminate between transformer saturation and current transformer (CT saturation is included. The performance of the proposed blocking scheme was compared with that of a conventional harmonic blocking method. The test results indicate that the proposed scheme successfully discriminates internal faults even with CT saturation from the magnetic inrush, over-excitation, and external faults with CT saturation, and can significantly reduce the operating time delay of the relay.

Measurement and modeling of flow through unsaturated heterogeneous rock in the context of geologic disposal of nuclear waste

International Nuclear Information System (INIS)

Sagar, B.; Bagtzoglou, A.C.; Green, R.T.; Stothoff, S.A.

1995-01-01

Deep geologic disposal of high-level and transuranic waste is currently being pursued vigorously. Assessing long-term performance of such repositories involves laboratory and field measurements, and numerical modeling. There exist two primary characteristics, associated with assessing repository performance, that define problems of modeling and measurement of non-isothermal flow through geologic media exposed to variable boundary conditions (e.g., climatic changes). These are: (1) the large time scale (tens of thousands of years) and highly variable space scale (from one meter to 10 5 meters); and (2) the hierarchy of heterogeneities and discontinuities characterizing the medium. This paper provides an overview of recent work, conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA), related to laboratory experiments, consideration of similitude, and numerical modeling of flow through heterogeneous media under non-homogeneous boundary conditions. As discussed, there exist neither good methods of measuring flows at these scales nor are there adequate similitude analyses that would allow reasonable scaling up of laboratory-scale experiments. Reliable assessment of long-term geologic repositories will require sophisticated geostatistical models capable of addressing variables scales of heterogeneities conditioned with observed results from adequately sized field-scale experiments conducted for sufficiently long durations

Criteria for saturated magnetization loop

International Nuclear Information System (INIS)

Harres, A.; Mikhov, M.; Skumryev, V.; Andrade, A.M.H. de; Schmidt, J.E.; Geshev, J.

2016-01-01

Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ the analysis of (i) derivatives of both ascending and descending branches of the loop, (ii) remanent magnetization curves, and (iii) thermomagnetic curves. Computational simulations are used in order to demonstrate their validity. Examples illustrating the applicability of these criteria to well-known real systems, namely Fe_3O_4 and Ni fine particles, are provided. We demonstrate that the anisotropy-field value estimated from a visual examination of an only apparently major hysteresis loop could be more than two times lower than the real one. - Highlights: • Proper estimation of hysteresis-loop parameters is vital in magnetic studies. • We propose criteria for discrimination minor from major hysteresis loops. • The criteria analyze magnetization, remanence and ZFC/FC curves and/or their derivatives. • Examples of their application on real nanoparticles systems are given. • Using the criteria could avoid twofold or bigger saturation-field underestimation errors.

Criteria for saturated magnetization loop

Energy Technology Data Exchange (ETDEWEB)

Harres, A. [Departamento de Física, UFSM, Santa Maria, 97105-900 Rio Grande do Sul (Brazil); Mikhov, M. [Faculty of Physics, University of Sofia, 1164 Sofia (Bulgaria); Skumryev, V. [Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona (Spain); Departament de Física, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Andrade, A.M.H. de; Schmidt, J.E. [Instituto de Física, UFRGS, Porto Alegre, 91501-970 Rio Grande do Sul (Brazil); Geshev, J., E-mail: julian@if.ufrgs.br [Departament de Física, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Instituto de Física, UFRGS, Porto Alegre, 91501-970 Rio Grande do Sul (Brazil)

2016-03-15

Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ the analysis of (i) derivatives of both ascending and descending branches of the loop, (ii) remanent magnetization curves, and (iii) thermomagnetic curves. Computational simulations are used in order to demonstrate their validity. Examples illustrating the applicability of these criteria to well-known real systems, namely Fe{sub 3}O{sub 4} and Ni fine particles, are provided. We demonstrate that the anisotropy-field value estimated from a visual examination of an only apparently major hysteresis loop could be more than two times lower than the real one. - Highlights: • Proper estimation of hysteresis-loop parameters is vital in magnetic studies. • We propose criteria for discrimination minor from major hysteresis loops. • The criteria analyze magnetization, remanence and ZFC/FC curves and/or their derivatives. • Examples of their application on real nanoparticles systems are given. • Using the criteria could avoid twofold or bigger saturation-field underestimation errors.

PRO-QUEST: a rapid assessment method based on progressive saturation for quantifying exchange rates using saturation times in CEST.

Science.gov (United States)

Demetriou, Eleni; Tachrount, Mohamed; Zaiss, Moritz; Shmueli, Karin; Golay, Xavier

2018-03-05

To develop a new MRI technique to rapidly measure exchange rates in CEST MRI. A novel pulse sequence for measuring chemical exchange rates through a progressive saturation recovery process, called PRO-QUEST (progressive saturation for quantifying exchange rates using saturation times), has been developed. Using this method, the water magnetization is sampled under non-steady-state conditions, and off-resonance saturation is interleaved with the acquisition of images obtained through a Look-Locker type of acquisition. A complete theoretical framework has been set up, and simple equations to obtain the exchange rates have been derived. A reduction of scan time from 58 to 16 minutes has been obtained using PRO-QUEST versus the standard QUEST. Maps of both T 1 of water and B 1 can simply be obtained by repetition of the sequence without off-resonance saturation pulses. Simulations and calculated exchange rates from experimental data using amino acids such as glutamate, glutamine, taurine, and alanine were compared and found to be in good agreement. The PRO-QUEST sequence was also applied on healthy and infarcted rats after 24 hours, and revealed that imaging specificity to ischemic acidification during stroke was substantially increased relative to standard amide proton transfer-weighted imaging. Because of the reduced scan time and insensitivity to nonchemical exchange factors such as direct water saturation, PRO-QUEST can serve as an excellent alternative for researchers and clinicians interested to map pH changes in vivo. © 2018 International Society for Magnetic Resonance in Medicine.

Simulating the Fate and Transport of Coal Seam Gas Chemicals in Variably-Saturated Soils Using HYDRUS

Directory of Open Access Journals (Sweden)

Dirk Mallants

2017-05-01

Full Text Available The HYDRUS-1D and HYDRUS (2D/3D computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this paper is to provide a brief overview of the HYDRUS models and their add-on modules, and to demonstrate possible applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the soil. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the HP1 module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in a soil leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration in soil is complexation of

Experimental Research on The Deformability of a Geological Material: Initial Characterisation and Identification of Parameters

International Nuclear Information System (INIS)

Villar, M.V.; Udias, A.; Canamon, I.; Robles, J.

2006-01-01

This document reflects the work performed at CIEMAT (Engineered and Geological Barriers Group) in the framework of the RTD Project BTE2002-04244-C02-02 (DEF-NOSAT). The first phase of the project consisted on the selection and characterisation of a geological material fitted for unsaturated triaxial testing. The result obtained during this phase gave place to the selection of a silty clay from Alcala de Henares (Madrid, Spain). Compaction and permeability tests were performed as well as studies on mixtures of this soil with sand. With the selected mixtures (70/30 and 50/50 percent sand/soil) isotropic compression tests were carried out in the saturated sample. The results of these tests have allowed the determination of some of the parameters needed to model the mechanical behaviour of the soil. The report includes also a brief description of a methodology developed in the Department of Applied Mathematics and Computer Methods of the Universidad Politecnica de Madrid for getting these parameters by optimisation of the experimental results, as well as the results obtained. (Author) 25 refs

Analysis of an SEIR Epidemic Model with Saturated Incidence and Saturated Treatment Function

Directory of Open Access Journals (Sweden)

Jinhong Zhang

2014-01-01

Full Text Available The dynamics of SEIR epidemic model with saturated incidence rate and saturated treatment function are explored in this paper. The basic reproduction number that determines disease extinction and disease survival is given. The existing threshold conditions of all kinds of the equilibrium points are obtained. Sufficient conditions are established for the existence of backward bifurcation. The local asymptotical stability of equilibrium is verified by analyzing the eigenvalues and using the Routh-Hurwitz criterion. We also discuss the global asymptotical stability of the endemic equilibrium by autonomous convergence theorem. The study indicates that we should improve the efficiency and enlarge the capacity of the treatment to control the spread of disease. Numerical simulations are presented to support and complement the theoretical findings.

Principal Hydrologic Responses to Climatic and Geologic Variability in the Sierra Nevada, California

Directory of Open Access Journals (Sweden)

David H. Peterson

2008-02-01

Full Text Available Sierra Nevada snowpack is a critical water source for California’s growing population and agricultural industry. However, because mountain winters and springs are warming, on average, precipitation as snowfall relative to rain is decreasing, and snowmelt is earlier. The changes are stronger at mid-elevations than at higher elevations. The result is that the water supply provided by snowpack is diminishing. In this paper, we describe principal hydrologic responses to climatic and spatial geologic variations as gleaned from a series of observations including snowpack, stream-flow, and bedrock geology. Our analysis focused on peak (maximum and base (minimum daily discharge of the annual snowmelt-driven hydrographs from 18 Sierra Nevada watersheds and 24 stream gage locations using standard correlation methods. Insights into the importance of the relative magnitudes of peak flow and soil water storage led us to develop a hydrologic classification of mountain watersheds based on runoff versus base flow as a percentage of peak flow. Our findings suggest that watersheds with a stronger base flow response store more soil water than watersheds with a stronger peak-flow response. Further, the influence of antecedent wet or dry years is greater in watersheds with high base flow, measured as a percentage of peak flow. The strong correlation between 1 the magnitude of peak flow, and 2 snow water equivalent can be used to predict peak flow weeks in advance. A weaker but similar correlation can be used to predict the magnitude of base flow months in advance. Most of the watersheds show a trend that peak flow is occurring earlier in the year.

Geologic mapping of Kentucky; a history and evaluation of the Kentucky Geological Survey--U.S. Geological Survey Mapping Program, 1960-1978

Science.gov (United States)

Cressman, Earle Rupert; Noger, Martin C.

1981-01-01

In 1960, the U.S. Geological Survey and the Kentucky Geological Survey began a program to map the State geologically at a scale of 1:24,000 and to publish the maps as 707 U.S. Geological Survey Geologic Quadrangle Maps. Fieldwork was completed by the spring of 1977, and all maps were published by December 1978. Geologic mapping of the State was proposed by the Kentucky Society of Professional Engineers in 1959. Wallace W. Hagan, Director and State Geologist of the Kentucky Geological Survey, and Preston McGrain, Assistant State Geologist, promoted support for the proposal among organizations such as Chambers of Commerce, industrial associations, professional societies, and among members of the State government. It was also arranged for the U.S. Geological Survey to supply mapping personnel and to publish the maps; the cost would be shared equally by the two organizations. Members of the U.S. Geological Survey assigned to the program were organized as the Branch of Kentucky Geology. Branch headquarters, including an editorial staff, was at Lexington, Ky., but actual mapping was conducted from 18 field offices distributed throughout the State. The Publications Division of the U.S. Geological Survey established a cartographic office at Lexington to prepare the maps for publication. About 260 people, including more than 200 professionals, were assigned to the Branch of Kentucky Geology by the U.S. Geological Survey at one time or another. The most geologists assigned any one year was 61. To complete the mapping and ancillary studies, 661 professional man-years were required, compared with an original estimate of 600 man-years. A wide variety of field methods were used, but most geologists relied on the surveying altimeter to obtain elevations. Surface data were supplemented by drill-hole records, and several dozen shallow diamond-drill holes were drilled to aid the mapping. Geologists generally scribed their own maps, with a consequent saving of publication costs

Adaptation, saturation, and physiological masking in single auditory-nerve fibers.

Science.gov (United States)

Smith, R L

1979-01-01

Results are reviewed concerning some effects, at a units's characteristic frequency, of a short-term conditioning stimulus on the responses to perstimulatory and poststimulatory test tones. A phenomenological equation is developed from the poststimulatory results and shown to be consistent with the perstimulatory results. According to the results and equation, the response to a test tone equals the unconditioned or unadapted response minus the decrement produced by adaptation to the conditioning tone. Furthermore, the decrement is proportional to the driven response to the conditioning tone and does not depend on sound intensity per se. The equation has a simple interpretation in terms of two processes in cascade--a static saturating nonlinearity followed by additive adaptation. Results are presented to show that this functional model is sufficient to account for the "physiological masking" produced by wide-band backgrounds. According to this interpretation, a sufficiently intense background produces saturation. Consequently, a superimposed test tone cause no change in response. In addition, when the onset of the background precedes the onset of the test tone, the total firing rate is reduced by adaptation. Evidence is reviewed concerning the possible correspondence between the variables in the model and intracellular events in the auditory periphery.

Saturation of the turbulent dynamo.

Science.gov (United States)

Schober, J; Schleicher, D R G; Federrath, C; Bovino, S; Klessen, R S

2015-08-01

The origin of strong magnetic fields in the Universe can be explained by amplifying weak seed fields via turbulent motions on small spatial scales and subsequently transporting the magnetic energy to larger scales. This process is known as the turbulent dynamo and depends on the properties of turbulence, i.e., on the hydrodynamical Reynolds number and the compressibility of the gas, and on the magnetic diffusivity. While we know the growth rate of the magnetic energy in the linear regime, the saturation level, i.e., the ratio of magnetic energy to turbulent kinetic energy that can be reached, is not known from analytical calculations. In this paper we present a scale-dependent saturation model based on an effective turbulent resistivity which is determined by the turnover time scale of turbulent eddies and the magnetic energy density. The magnetic resistivity increases compared to the Spitzer value and the effective scale on which the magnetic energy spectrum is at its maximum moves to larger spatial scales. This process ends when the peak reaches a characteristic wave number k☆ which is determined by the critical magnetic Reynolds number. The saturation level of the dynamo also depends on the type of turbulence and differs for the limits of large and small magnetic Prandtl numbers Pm. With our model we find saturation levels between 43.8% and 1.3% for Pm≫1 and between 2.43% and 0.135% for Pm≪1, where the higher values refer to incompressible turbulence and the lower ones to highly compressible turbulence.

Geologic Framework Model (GFM2000)

International Nuclear Information System (INIS)

T. Vogt

2004-01-01

The purpose of this report is to document the geologic framework model, version GFM2000 with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, and the differences between GFM2000 and previous versions. The version number of this model reflects the year during which the model was constructed. This model supersedes the previous model version, documented in Geologic Framework Model (GFM 3.1) (CRWMS M and O 2000 [DIRS 138860]). The geologic framework model represents a three-dimensional interpretation of the geology surrounding the location of the monitored geologic repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain. The geologic framework model encompasses and is limited to an area of 65 square miles (168 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the geologic framework model (shown in Figure 1-1) were chosen to encompass the exploratory boreholes and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The upper surface of the model is made up of the surface topography and the depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The geologic framework model was constructed from geologic map and borehole data. Additional information from measured stratigraphic sections, gravity profiles, and seismic profiles was also considered. The intended use of the geologic framework model is to provide a geologic framework over the area of interest consistent with the level of detailed needed for hydrologic flow and radionuclide transport modeling through the UZ and for repository design. The model is limited by the availability of data and relative amount of geologic complexity found in an area. The geologic framework model is inherently limited by scale and content. The grid spacing used in

Geologic Framework Model (GFM2000)

Energy Technology Data Exchange (ETDEWEB)

T. Vogt

2004-08-26

The purpose of this report is to document the geologic framework model, version GFM2000 with regard to input data, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, and the differences between GFM2000 and previous versions. The version number of this model reflects the year during which the model was constructed. This model supersedes the previous model version, documented in Geologic Framework Model (GFM 3.1) (CRWMS M&O 2000 [DIRS 138860]). The geologic framework model represents a three-dimensional interpretation of the geology surrounding the location of the monitored geologic repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain. The geologic framework model encompasses and is limited to an area of 65 square miles (168 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the geologic framework model (shown in Figure 1-1) were chosen to encompass the exploratory boreholes and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The upper surface of the model is made up of the surface topography and the depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The geologic framework model was constructed from geologic map and borehole data. Additional information from measured stratigraphic sections, gravity profiles, and seismic profiles was also considered. The intended use of the geologic framework model is to provide a geologic framework over the area of interest consistent with the level of detailed needed for hydrologic flow and radionuclide transport modeling through the UZ and for repository design. The model is limited by the availability of data and relative amount of geologic complexity found in an area. The geologic framework model is inherently limited by scale and content. The grid spacing used in the

Development of JNC geological disposal technical information integration system for geological environment field

International Nuclear Information System (INIS)

Tsuchiya, Makoto; Ueta, Shinzo; Ohashi, Toyo

2004-02-01

Enormous data on geology, geological structure, hydrology, geochemistry and rock properties should be obtained by various investigation/study in the geological disposal study. Therefore, 'JNC Geological Disposal Technical Information Integration System for Geological Environment Field' was developed in order to manage these data systematically and to support/promote the use of these data for the investigators concerned. The system is equipped with data base to store the information of the works and the background information of the assumptions built up in the works on each stage of data flow ('instigative', → 'data sampling' → interpretation' → conceptualization/modeling/simulation' → 'output') in the geological disposal study. In this system the data flow is shown as 'plan' composed of task' and 'work' to be done in the geological disposal study. It is possible to input the data to the database and to refer data from the database by using GUI that shows the data flow as 'plan'. The system was installed to the server computer possessed by JNC and the system utilities were checked on both the server computer and client computer also possessed by JNC. (author)

Modification and application of TOUGH2 as a variable-density, saturated-flow code and comparison to SWIFT II results

International Nuclear Information System (INIS)

Christian-Frear, T.L.; Webb, S.W.

1995-01-01

Human intrusion scenarios at the Waste Isolation Pilot Plant (WIPP) involve penetration of the repository and an underlying brine reservoir by a future borehole. Brine and gas from the brine reservoir and the repository may flow up the borehole and into the overlying Culebra formation, which is saturated with water containing different amounts of dissolved 'solids resulting in a spatially varying density. Current modeling approaches involve perturbing a steady-state Culebra flow field by inflow of gas and/or brine from a breach borehole that has passed through the repository. Previous studies simulating steady-state flow in the Culebra have been done. One specific study by LaVenue et al. (1990) used the SWIFT 2 code, a single-phase flow and transport code, to develop the steady-state flow field. Because gas may also be present in the fluids from the intrusion borehole, a two-phase code such as TOUGH2 can be used to determine the effect that emitted fluids may have on the steady-state Culebra flow field. Thus a comparison between TOUGH2 and SWIFT2 was prompted. In order to compare the two codes and to evaluate the influence of gas on flow in the Culebra, modifications were made to TOUGH2. Modifications were performed by the authors to allow for element-specific values of permeability, porosity, and elevation. The analysis also used a new equation of state module for a water-brine-air mixture, EOS7 (Pruess, 1991), which was developed to simulate variable water densities by assuming a miscible mixture of water and brine phases and allows for element-specific brine concentration in the INCON file

Geological and geotechnical limitations of radioactive waste retrievability in geologic disposals

Energy Technology Data Exchange (ETDEWEB)

Stahlmann, Joachim; Leon-Vargas, Rocio; Mintzlaff, Volker; Treidler, Ann-Kathrin [TU Braunschweig (Germany). Inst. for Soil Mechanics and Foundation Engineering

2015-07-01

The capability of retrieving radioactive waste emplaced in deep geological formations is nowadays in discussion in many countries. Based on the storage of high-level radioactive waste (HAW) in deep geological repositories there is a number of possible scenarios for their retrieval. Measurements for an improved retrieving capability may impact on the geotechnical and geological barriers, e.g. keeping open the access drifts for a long period of time can result in a bigger evacuation damage zone (EDZ) in the host rock which implies potential flow paths for ground water. Nevertheless, to limit the possible scenarios associated to the retrieval implementation, it is necessary to take in consideration which criteria will be used for an efficient monitoring program, while clearly determining the performance reliability of the geotechnical barriers. In addition, the integrity of the host rock as geological barrier has to be verified. Therefore, it is important to evaluate different design solutions and the most appropriate measurement methods to improve the retrievability process of wastes from a geological repository. A short presentation of the host rocks is given is this paper.

Variable Permanent Magnet Quadrupole

International Nuclear Information System (INIS)

Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

2007-01-01

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

Investigation of spatial resolution dependent variability in transcutaneous oxygen saturation using point spectroscopy system

Science.gov (United States)

Philimon, Sheena P.; Huong, Audrey K. C.; Ngu, Xavier T. I.

2017-08-01

This paper aims to investigate the variation in one’s percent mean transcutaneous oxygen saturation (StO2) with differences in spatial resolution of data. This work required the knowledge of extinction coefficient of hemoglobin derivatives in the wavelength range of 520 - 600 nm to solve for the StO2 value via an iterative fitting procedure. A pilot study was conducted on three healthy subjects with spectroscopic data collected from their right index finger at different arbitrarily selected distances. The StO2 value estimated by Extended Modified Lambert Beer (EMLB) model revealed a higher mean StO2 of 91.1 ± 1.3% at a proximity distance of 30 mm compared to 60.83 ± 2.8% at 200 mm. The results showed a high correlation between data spatial resolution and StO2 value, and revealed a decrease in StO2 value as the sampling distance increased. The preliminary findings from this study contribute to the knowledge of the appropriate distance range for consistent and high repeatability measurement of skin oxygenation.

Regional and site geological frameworks : proposed Deep Geologic Repository, Bruce County, Ontario

Energy Technology Data Exchange (ETDEWEB)

Raven, K.; Sterling, S.; Gaines, S.; Wigston, A. [Intera Engineering Ltd., Ottawa, ON (Canada); Frizzell, R. [Nuclear Waste Management Organization, Toronto, ON (Canada)

2009-07-01

The Nuclear Waste Management Organization is conducting geoscientific studies on behalf of Ontario Power Generation into the proposed development of a Deep Geologic Repository (DGR) for low and intermediate level radioactive waste (L and ILW) at the Bruce site, near Tiverton, Ontario. This paper presented a regional geological framework for the site that was based on a review of regional drilling; structural geology; paleozoic stratigraphy and sedimentology; a 3D geological framework model; a DGR geological site characterization model; bedrock stratigraphy and marker beds; natural fracture frequency data; and formation predictability. The studies have shown that the depth, thickness, orientation and rock quality of the 34 rock formations, members or units that comprise the 840 m thick Paleozoic bedrock sequence at the Bruce site are very uniform and predictable over distances of several kilometres. The proposed DGR will be constructed as an engineered facility comprising a series of underground emplacement rooms at a depth of 680 metres below ground within argillaceous limestones. The geoscientific studies are meant to provide a basis for the development of descriptive geological, hydrogeological and geomechanical models of the DGR site that will facilitate environmental and safety assessments. 11 refs., 3 tabs., 9 figs.

Predicting the consumption of foods low in saturated fats among people diagnosed with Type 2 diabetes and cardiovascular disease. The role of planning in the theory of planned behaviour.

Science.gov (United States)

White, Katherine M; Terry, Deborah J; Troup, Carolyn; Rempel, Lynn A; Norman, Paul

2010-10-01

The present study tested the utility of an extended version of the theory of planned behaviour that included a measure of planning, in the prediction of eating foods low in saturated fats among adults diagnosed with Type 2 diabetes and/or cardiovascular disease. Participants (N=184) completed questionnaires assessing standard theory of planned behaviour measures (attitude, subjective norm, and perceived behavioural control) and the additional volitional variable of planning in relation to eating foods low in saturated fats. Self-report consumption of foods low insaturated fats was assessed 1 month later. In partial support of the theory of planned behaviour, results indicated that attitude and subjective norm predicted intentions to eat foods low in saturated fats and intentions and perceived behavioural control predicted the consumption of foods low in saturated fats. As an additional variable, planning predicted the consumption of foods low in saturated fats directly and also mediated the intention-behaviour and perceived behavioural control-behaviour relationships, suggesting an important role for planning as a post-intentional construct determining healthy eating choices. Suggestions are offered for interventions designed to improve adherence to healthy eating recommendations for people diagnosed with these chronic conditions with a specific emphasis on the steps and activities that are required to promote a healthier lifestyle.

On the water saturation calculation in hydrocarbon sandstone reservoirs

Energy Technology Data Exchange (ETDEWEB)

Stalheim, Stein Ottar

2002-07-01

The main goal of this work was to identify the most important uncertainty sources in water saturation calculation and examine the possibility for developing new S{sub w} - equations or possibility to develop methods to remove weaknesses and uncertainties in existing S{sub w} - equations. Due to the need for industrial applicability of the equations we aimed for results with the following properties: The accuracy in S{sub w} should increase compared with existing S{sub w} - equations. The equations should be simple to use in petrophysical evaluations. The equations should be based on conventional logs and use as few as possible input parameters. The equations should be numerical stable. This thesis includes an uncertainty and sensitivity analysis of the most common S{sub w} equations. The results are addressed in chapter 3 and were intended to find the most important uncertainty sources in water saturation calculation. To increase the knowledge of the relationship between R{sub t} and S{sub w} in hydrocarbon sandstone reservoirs and to understand how the pore geometry affects the conductivity (n and m) of the rock a theoretical study was done. It was also an aim to examine the possibility for developing new S{sub w} - equations (or investigation an effective medium model) valid inhydrocarbon sandstone reservoirs. The results are presented in paper 1. A new equation for water saturation calculation in clean sandstone oil reservoirs is addressed in paper 2. A recommendation for best practice of water saturation calculation in non water wet formation is addressed in paper 3. Finally a new equation for water saturation calculation in thinly interbedded sandstone/mudstone reservoirs is presented in paper 4. The papers are titled: 1) Is the saturation exponent n a constant. 2) A New Model for Calculating Water Saturation In 3) Influence of wettability on water saturation modeling. 4) Water Saturation Calculations in Thinly Interbedded Sandstone/mudstone Reservoirs. A

THE SEARCH FOR SUPER-SATURATION IN CHROMOSPHERIC EMISSION

International Nuclear Information System (INIS)

Christian, Damian J.; Arias, Tersi; Mathioudakis, Mihalis; Jess, David B.; Jardine, Moira

2011-01-01

We investigate if the super-saturation phenomenon observed at X-ray wavelengths for the corona exists in the chromosphere for rapidly rotating late-type stars. Moderate resolution optical spectra of fast-rotating EUV- and X-ray-selected late-type stars were obtained. Stars in α Per were observed in the northern hemisphere with the Isaac Newton 2.5 m telescope and Intermediate Dispersion Spectrograph. Selected objects from IC 2391 and IC 2602 were observed in the southern hemisphere with the Blanco 4 m telescope and R-C spectrograph at CTIO. Ca II H and K fluxes were measured for all stars in our sample. We find the saturation level for Ca II K at log (L CaK /L bol ) = -4.08. The Ca II K flux does not show a decrease as a function of increased rotational velocity or smaller Rossby number as observed in the X-ray. This lack of 'super-saturation' supports the idea of coronal stripping as the cause of saturation and super-saturation in stellar chromospheres and coronae, but the detailed underlying mechanism is still under investigation.

Assessing correlations between geological hazards and health outcomes: Addressing complexity in medical geology.

Science.gov (United States)

Wardrop, Nicola Ann; Le Blond, Jennifer Susan

2015-11-01

The field of medical geology addresses the relationships between exposure to specific geological characteristics and the development of a range of health problems: for example, long-term exposure to arsenic in drinking water can result in the development of skin conditions and cancers. While these relationships are well characterised for some examples, in others there is a lack of understanding of the specific geological component(s) triggering disease onset, necessitating further research. This paper aims to highlight several important complexities in geological exposures and the development of related diseases that can create difficulties in the linkage of exposure and health outcome data. Several suggested approaches to deal with these complexities are also suggested. Long-term exposure and lengthy latent periods are common characteristics of many diseases related to geological hazards. In combination with long- or short-distance migrations over an individual's life, daily or weekly movement patterns and small-scale spatial heterogeneity in geological characteristics, it becomes problematic to appropriately assign exposure measurements to individuals. The inclusion of supplementary methods, such as questionnaires, movement diaries or Global Positioning System (GPS) trackers can support medical geology studies by providing evidence for the most appropriate exposure measurement locations. The complex and lengthy exposure-response pathways involved, small-distance spatial heterogeneity in environmental components and a range of other issues mean that interdisciplinary approaches to medical geology studies are necessary to provide robust evidence. Copyright © 2015. Published by Elsevier Ltd.

Infiltration behaviour of elemental mercury DNAPL in fully and partially water saturated porous media

Science.gov (United States)

D'Aniello, Andrea; Hartog, Niels; Sweijen, Thomas; Pianese, Domenico

2018-02-01

both air and water, depending on the initial water distribution within the pores. This indicates that the conventional wettability hierarchy, in which the NAPL has an intermediate wetting state between the air and the water phases, is not valid for liquid elemental mercury. Therefore, for future modelling of elemental mercury DNAPL infiltration behaviour in variably water saturated porous media, a different formulation of the governing constitutive relations will be required.

Magnetic field saturation in the Riga dynamo experiment.

Science.gov (United States)

Gailitis, A; Lielausis, O; Platacis, E; Dement'ev, S; Cifersons, A; Gerbeth, G; Gundrum, T; Stefani, F; Christen, M; Will, G

2001-04-02

After the dynamo experiment in November 1999 [A. Gailitis et al., Phys. Rev. Lett. 84, 4365 (2000)] had shown magnetic field self-excitation in a spiraling liquid metal flow, in a second series of experiments emphasis was placed on the magnetic field saturation regime as the next principal step in the dynamo process. The dependence of the strength of the magnetic field on the rotation rate is studied. Various features of the saturated magnetic field are outlined and possible saturation mechanisms are discussed.

Cloudiness and Its Relationship to Saturation Pressure Differences during a Developing East Coast Winter Storm.

Science.gov (United States)

Alliss, Randall J.; Raman, Sethu

1995-11-01

Cloudiness derived from surface observations and the Geostationary Operational Environmental Satellite VISSR (Visible Infrared Spin Scan Radiometer) Atmospheric Sounder (VAS) are compared with thermodynamic properties derived from upper-air soundings over the Gulf Stream locale during a developing winter storm. The Gulf Stream locale covers the United States mid-Atlantic coastal states, the Gulf Stream, and portions of the Sargasso Sea. Cloudiness is found quite frequently in this region. Cloud-top pressures are derived from VAS using the CO2 slicing technique and a simple threshold procedure. Cloud-base heights and cloud fractions are obtained from National Weather Service hourly reporting stations. The saturation pressure differences, defined as the difference between air parcel pressure and saturation-level pressure (lifted condensation level), are derived from upper-air soundings. Collocated comparisons with VAS and surface observations are also made. Results indicate that cloudiness is observed nearly all of the time during the 6-day period, well above the 8-yr mean. High, middle, and low opaque cloudiness are found approximately equally. Furthermore, of the high- and midlevel cloudiness observed, a considerable amount is determined to be semitransparent to terrestrial radiation. Comparisons of satellite-inferred cloudiness with surface observations indicate that the satellite can complement surface observations of cloud cover, particularly above 700 mb.Surface-observed cloudiness is segregated according to a composite cloud fraction and compared to the mean saturation pressure difference for a 1000 600-mb layer. The analysis suggests that this conserved variable may be a good indicator for estimating cloud fraction. Large negative values of saturation pressure difference correlate highly with clear skies, while those approaching zero correlate with overcast conditions. Scattered and broken cloud fractions are associated with increasing values of the

AEGIS geologic simulation model

International Nuclear Information System (INIS)

Foley, M.G.

1982-01-01

The Geologic Simulation Model (GSM) is used by the AEGIS (Assessment of Effectiveness of Geologic Isolation Systems) program at the Pacific Northwest Laboratory to simulate the dynamic geology and hydrology of a geologic nuclear waste repository site over a million-year period following repository closure. The GSM helps to organize geologic/hydrologic data; to focus attention on active natural processes by requiring their simulation; and, through interactive simulation and calibration, to reduce subjective evaluations of the geologic system. During each computer run, the GSM produces a million-year geologic history that is possible for the region and the repository site. In addition, the GSM records in permanent history files everything that occurred during that time span. Statistical analyses of data in the history files of several hundred simulations are used to classify typical evolutionary paths, to establish the probabilities associated with deviations from the typical paths, and to determine which types of perturbations of the geologic/hydrologic system, if any, are most likely to occur. These simulations will be evaluated by geologists familiar with the repository region to determine validity of the results. Perturbed systems that are determined to be the most realistic, within whatever probability limits are established, will be used for the analyses that involve radionuclide transport and dose models. The GSM is designed to be continuously refined and updated. Simulation models are site specific, and, although the submodels may have limited general applicability, the input data equirements necessitate detailed characterization of each site before application

The role of meson dynamics in nuclear matter saturation

International Nuclear Information System (INIS)

Goncalves, E.

1988-01-01

The problem of the saturation of nuclea matter in the non-relativistic limit of the model proposed by J.D. Walecka is studied. In the original context nuclear matter saturation is obtained as a direct consequence of relativistic effects and both scalar and vector mesons are treated statically. In the present work we investigate the effect of the meson dynamics for the saturation using a Born-Oppenheimer approximation for the ground state. An upper limit for the saturation curve of nuclear matter and are able to decide now essential is the relativistic treatment of the nucleons for this problem, is obtained. (author) [pt

Interger multiplication with overflow detection or saturation

Energy Technology Data Exchange (ETDEWEB)

Schulte, M.J.; Balzola, P.I.; Akkas, A.; Brocato, R.W.

2000-01-11

High-speed multiplication is frequently used in general-purpose and application-specific computer systems. These systems often support integer multiplication, where two n-bit integers are multiplied to produce a 2n-bit product. To prevent growth in word length, processors typically return the n least significant bits of the product and a flag that indicates whether or not overflow has occurred. Alternatively, some processors saturate results that overflow to the most positive or most negative representable number. This paper presents efficient methods for performing unsigned or two's complement integer multiplication with overflow detection or saturation. These methods have significantly less area and delay than conventional methods for integer multiplication with overflow detection and saturation.

Geology Forsmark. Site descriptive modelling Forsmark - stage 2.2

Energy Technology Data Exchange (ETDEWEB)

Stephens, Michael B. [Geological Survey of Sweden, Uppsala (Sweden); Fox, Aaron; La Pointe, Paul [Golder Associates Inc (United States); Simeonov, Assen [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Isaksson, Hans [GeoVista AB, Luleaa (Sweden); Hermanson, Jan; Oehman, Johan [Golder Associates AB, Stockholm (Sweden)

2007-10-15

The geological work during stage 2.2 has involved the development of deterministic models for rock domains (RFM) and deformation zones (ZFM), the identification and deterministic modelling of fracture domains (FFM) inside the candidate volume, i.e. the parts of rock domains that are not affected by deformation zones, and the development of statistical models for fractures and minor deformation zones (geological discrete fracture network modelling or geological DFN modelling). The geological DFN model addresses brittle structures at a scale of less than 1 km, which is the lower cut-off in the deterministic modelling of deformation zones. In order to take account of variability in data resolution, deterministic models for rock domains and deformation zones are presented in both regional and local model volumes, while the geological DFN model is valid within specific fracture domains inside the north-western part of the candidate volume, including the target volume. The geological modelling work has evaluated and made use of: A revised bedrock geological map at the ground surface. Geological and geophysical data from 21 cored boreholes and 33 percussion boreholes. Detailed mapping of fractures and rock units along nine excavations or large surface outcrops. Data bearing on the characterisation (including kinematics) of deformation zones. Complementary geochronological and other rock and fracture analytical data. Lineaments identified on the basis of airborne and high-resolution ground magnetic data. A reprocessing of both surface and borehole reflection seismic data. Seismic refraction data. The outputs of the deterministic modelling work are geometric models in RVS format and detailed property tables for rock domains and deformation zones, and a description of fracture domains. The outputs of the geological DFN modelling process are recommended parameters or statistical distributions that describe fracture set orientations, radius sizes, volumetric intensities

Geology Forsmark. Site descriptive modelling Forsmark - stage 2.2

International Nuclear Information System (INIS)

Stephens, Michael B.; Fox, Aaron; La Pointe, Paul; Simeonov, Assen; Isaksson, Hans; Hermanson, Jan; Oehman, Johan

2007-10-01

The geological work during stage 2.2 has involved the development of deterministic models for rock domains (RFM) and deformation zones (ZFM), the identification and deterministic modelling of fracture domains (FFM) inside the candidate volume, i.e. the parts of rock domains that are not affected by deformation zones, and the development of statistical models for fractures and minor deformation zones (geological discrete fracture network modelling or geological DFN modelling). The geological DFN model addresses brittle structures at a scale of less than 1 km, which is the lower cut-off in the deterministic modelling of deformation zones. In order to take account of variability in data resolution, deterministic models for rock domains and deformation zones are presented in both regional and local model volumes, while the geological DFN model is valid within specific fracture domains inside the north-western part of the candidate volume, including the target volume. The geological modelling work has evaluated and made use of: A revised bedrock geological map at the ground surface. Geological and geophysical data from 21 cored boreholes and 33 percussion boreholes. Detailed mapping of fractures and rock units along nine excavations or large surface outcrops. Data bearing on the characterisation (including kinematics) of deformation zones. Complementary geochronological and other rock and fracture analytical data. Lineaments identified on the basis of airborne and high-resolution ground magnetic data. A reprocessing of both surface and borehole reflection seismic data. Seismic refraction data. The outputs of the deterministic modelling work are geometric models in RVS format and detailed property tables for rock domains and deformation zones, and a description of fracture domains. The outputs of the geological DFN modelling process are recommended parameters or statistical distributions that describe fracture set orientations, radius sizes, volumetric intensities

Working with Specify in a Paleo-Geological Context

Science.gov (United States)

Molineux, A.; Thompson, A. C.; Appleton, L.

2014-12-01

For geological collections with limited funding an open source relational database provides an opportunity to digitize specimens and related data. At the Non-vertebrate Paleontology Lab, a large mixed paleo and geological repository on a restricted budget, we opted for one such database, Specify. Initially created at Kansas University for neontological collections and based on a single computer, Specify has moved into the networked scene and will soon be web-based as Specify 7. We currently use the server version of Specify 6, networked to all computers in the lab each running a desktop client, often with six users at any one time. Along with improved access there have been great efforts to broaden the applicability of this database to other disciplines. Current developments are of great importance to us because they focus on the geological aspects of lithostratigraphy and chronostratigaphy and their relationship to other variables. Adoption of this software has required constant change as we move to take advantage of the great improvements. We enjoy the interaction with the developers and their willingness to listen and consider our issues. Here we discuss some of the ways in which we have fashioned Specify into a database that provides us with the flexibility that we need without removing the ability to share our data with other aggregators through accepted protocols. We discuss the customization of forms, the attachment of media and tracking of original media files, our efforts to incorporate geological specimens, and our plans to link the individual specimen record GUIDs to an IGSN numbers and thence to future connections to data derived from our specimens.

Global Journal of Geological Sciences: Editorial Policies

African Journals Online (AJOL)

Focus and Scope. Global Journal of Geological Sciences is aimed at promoting research in all areas of geological Sciences including Petrology, Mineralogy, geophysics, hydrogeology, Engineering geology, Petroleum geology, Palaeontology, environmental geology, Economic geology, etc.

Geological Storage of CO2. Site Selection Criteria; Almacenamiento Geologico de CO2. Criterios de Selecci0n de Emplazamientos

Energy Technology Data Exchange (ETDEWEB)

Ruiz, C; Martinez, R; Recreo, F; Prado, P; Campos, R; Pelayo, M; Losa, A de la; Hurtado, A; Lomba, L; Perez del Villar, L; Ortiz, G; Sastre, J; Zapatero, M A; Suarez, I; Arenillas, A

2007-09-18

In year 2002 the Spanish Parliament unanimously passed the ratification of the Kyoto Protocol, signed December 1997, compromising to limiting the greenhouse gas emissions increase. Later on, the Environment Ministry submitted the Spanish National Assignment Emissions Plan to the European Union and in year 2005 the Spanish Greenhouse Gas market started working, establishing taxes to pay in case of exceeding the assigned emissions limits. So, the avoided emissions of CO2 have now an economic value that is promoting new anthropogenic CO2 emissions reduction technologies. Carbon Capture and Storage (CCS) are among these new technological developments for mitigating or eliminate climate change. CO2 can be stored in geological formations such as depleted oil or gas fields, deep permeable saline water saturated formations and unmailable coal seams, among others. This report seeks to establish the selection criteria for suitable geological formations for CO2 storage in the Spanish national territory, paying attention to both the operational and performance requirements of these storage systems. The report presents the physical and chemical properties and performance of CO2 under storage conditions, the transport and reaction processes of both supercritical and gaseous CO2, and CO2 trapping mechanisms in geological formations. The main part of the report is devoted to geological criteria at watershed, site and formation scales. (Author) 100 refs.

Retinal oxygen saturation before and after glaucoma surgery.

Science.gov (United States)

Nitta, Eri; Hirooka, Kazuyuki; Shimazaki, Takeru; Sato, Shino; Ukegawa, Kaori; Nakano, Yuki; Tsujikawa, Akitaka

2017-08-01

This study compared retinal vessel oxygen saturation before and after glaucoma surgery. Retinal oxygen saturation in glaucoma patients was measured using a non-invasive spectrophotometric retinal oximeter. Adequate image quality was found in 49 of the 108 consecutive glaucoma patients recruited, with 30 undergoing trabeculectomy, 11 EX-PRESS and eight trabeculotomy. Retinal oxygen saturation measurements in the retinal arterioles and venules were performed at 1 day prior to and at approximately 10 days after surgery. Statistical analysis was performed using a Student's t-test. After glaucoma surgery, intraocular pressure (IOP) decreased from 19.8 ± 7.7 mmHg to 9.0 ± 5.7 mmHg (p glaucoma surgery had an effect on the retinal venous oxygen saturation. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Delayed system control in presence of actuator saturation

Directory of Open Access Journals (Sweden)

A. Mahjoub

2014-09-01

Full Text Available The paper is introducing a new design method for systems’ controllers with input delay and actuator saturations and focuses on how to force the system output to track a reference input not necessarily saturation-compatible. We propose a new norm based on the way we quantify tracking performance as a function of saturation errors found using the same norm. The newly defined norm is related to signal average power making possible to account for most common reference signals e.g. step, periodic. It is formally shown that, whatever the reference shape and amplitude, the achievable tracking quality is determined by a well defined reference tracking mismatch error. This latter depends on the reference rate and its compatibility with the actuator saturation constraint. In fact, asymptotic output-reference tracking is achieved in the presence of constraint-compatible step-like references.

Brightness, hue, and saturation in photopic vision: a result of luminance and wavelength in the cellular phase-grating optical 3D chip of the inverted retina

Science.gov (United States)

Lauinger, Norbert

1994-10-01

In photopic vision, two physical variables (luminance and wavelength) are transformed into three psychological variables (brightness, hue, and saturation). Following on from 3D grating optical explanations of aperture effects (Stiles-Crawford effects SCE I and II), all three variables can be explained via a single 3D chip effect. The 3D grating optical calculations are carried out using the classical von Laue equation and demonstrated using the example of two experimentally confirmed observations in human vision: saturation effects for monochromatic test lights between 485 and 510 nm in the SCE II and the fact that many test lights reverse their hue shift in the SCE II when changing from moderate to high luminances compared with that on changing from low to medium luminances. At the same time, information is obtained on the transition from the trichromatic color system in the retina to the opponent color system.

Effect of cholesterol on structural and mechanical properties of membranes depends on lipid chain saturation

International Nuclear Information System (INIS)

Pan Jianjun; Tristram-Nagle, Stephanie; Nagle, John F.

2009-01-01

The effects of cholesterol on membrane bending modulus K C , membrane thickness D HH , the partial and apparent areas of cholesterol and lipid, and the order parameter S xray are shown to depend upon the number of saturated hydrocarbon chains in the lipid molecules. Particularly striking is the result that up to 40% cholesterol does not increase the bending modulus K C of membranes composed of phosphatidylcholine lipids with two cis monounsaturated chains, although it does have the expected stiffening effect on membranes composed of lipids with two saturated chains. The B fluctuational modulus in the smectic liquid crystal theory is obtained and used to discuss the interactions between bilayers. Our K C results motivate a theory of elastic moduli in the high cholesterol limit and they challenge the relevance of universality concepts. Although most of our results were obtained at 30 deg. C, additional data at other temperatures to allow consideration of a reduced temperature variable do not support universality for the effect of cholesterol on all lipid bilayers. If the concept of universality is to be valid, different numbers of saturated chains must be considered to create different universality classes. The above experimental results were obtained from analysis of x-ray scattering in the low angle and wide angle regions.

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

International Nuclear Information System (INIS)

Kyriacou, P A; Shafqat, K; Pal, S K

2007-01-01

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO 2 ) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO 2 ) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO 2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

Science.gov (United States)

Kyriacou, P. A.; Shafqat, K.; Pal, S. K.

2007-10-01

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO2) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO2) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO2 sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures. Both pulse

Vapor-transport of tungsten and its geologic application

Energy Technology Data Exchange (ETDEWEB)

Shibue, Y [Hyogo Univ. of Teacher Education, Hyogo (Japan)

1988-11-10

The volatility of tungsten in a hydrous system at elevated temperatures and pressures was examined, and a tentative model for the enrichment of tungsten in hydrothermal solutions for the deposits related to granitic activities was proposed. To produce vapor-saturated solution, 17 or 15ml of 20wt% NaCl solution was introduced into an autoclave. Ca(OH){sub 2} for tungsten and H{sub 2}WO{sub 4} for base metals were used as vapor-captures, and run products were identified by X-ray powder diffractometry. The results suggested that the ratio of tungsten to base metals was higher in a vapor phase than in a liquid phase, and more enrichment of tungsten in the vapor phase occurred at higher temperature and pressure under the coexistence of the vapor and liquid phase. The tentative model emphasizing the vapor-transport of tungsten could explain the presence of tungsten deposits without large mineralization of base metals. Geological schematic model for the generation of the hydrothermal solution enriched in tungsten compared with base metals was illustrated based on above mentioned results. 21 refs., 3 figs.

Assessment of effectiveness of geologic isolation systems: the AEGIS geologic simulation model

International Nuclear Information System (INIS)

Foley, M.G.; Petrie, G.M.

1981-02-01

Assessment of the post-closure performance of a nuclear waste repository has two basic components: the identification and analysis of potentially disruptive sequences and the pattern of geologic events and processes causing each sequence, and the identification and analysis of the environmental consequences of radionuclide transport and interactions subsequent to disruption of a repository. The AEGIS Scenario Analysis Task is charged with identifying and analyzing potenially disruptive sequences of geologic events and processes. The Geologic Simulation Model (GSM) was developed to evaluate the geologic/hydrologic system surrounding an underground repository, and describe the phenomena that alone, or in concert, could perturb the system and possibly cause a loss of repository integrity. The AEGIS approach is described in this report. It uses an integrated series of models for repository performance analysis; the GSM for a low-resolution, long-term, comprehensive evaluation of the geologic/hydrologic system, followed by more detailed hydrogeologic, radionuclide transport, and dose models to more accurately assess the consequences of disruptive sequences selected from the GSM analyses. This approach is felt to be more cost-effective than an integrated one because the GSM can be used to estimate the likelihoods of different potentially disruptive future evolutionary developments within the geologic/hydrologic system. The more costly consequence models can then be focused on a few disruptive sequences chosen for their representativeness and effective probabilities

Geological studies in Alaska by the U.S. Geological Survey, 1999

Science.gov (United States)

Gough, Larry P.; Wilson, Frederic H.

2001-01-01

The collection of nine papers that follow continue the series of U.S. Geological Survey (USGS) investigative reports in Alaska under the broad umbrella of the geologic sciences. The series presents new and sometimes preliminary findings that are of interest to earth scientists in academia, government, and industry; to land and resource managers; and to the general public. Reports presented in Geologic Studies in Alaska cover a broad spectrum of topics from various parts of the State (fig. 1), serving to emphasize the diversity of USGS efforts to meet the Nation's needs for earth-science information in Alaska.

Saturation and postsaturation phenomena of Rayleigh-Taylor instability with adjacent modes

International Nuclear Information System (INIS)

Ikegawa, Tadashi; Nishihara, Katsunobu

2003-01-01

A weakly nonlinear theory has been developed for the classical Rayleigh-Taylor instability with a finite bandwidth taken into account self-consistently. The theory includes up to third order nonlinearity, which results in the saturation of linear growth and determines subsequent weakly nonlinear growth. Analytical results are shown to agree fairly well with two-dimensional hydrodynamic simulations. There are generally many local peaks of a perturbation with a finite bandwidth due to the interference of modes. Since a local amplitude is determined from phases among the modes as well as the bandwidth, we have investigated an onset of the linear growth saturation and the subsequent weakly nonlinear growth for different bandwidths and phases. It is shown that the saturation of the linear growth occurs locally, i.e., each of the local maximum amplitudes (LMAs) grows exponentially until it reaches almost the same saturation amplitude. In the random phase case, the root mean square amplitude thus saturates with almost the same amplitude as the LMA, after most of the LMAs have saturated. The saturation amplitude of the LMA is found to be independent of the bandwidth and depends on the Atwood number. We derive a formula of the saturation amplitude of modes based on the results obtained, and discuss its relation with Haan's formula [Phys. Rev. A 39, 5812 (1989)]. The LMAs grow linearly in time after the saturation and their speeds are approximated by the product of the linear growth rate and the saturation amplitude. We investigate the Atwood number dependence of both the saturation amplitude and the weakly nonlinear growth

Interactions Between Stratigraphy and Interfacial Properties on Flow and Trapping in Geologic Carbon Storage

Science.gov (United States)

Liang, Bo; Clarens, Andres F.

2018-01-01

Gas leakage from geologic carbon storage sites could undermine the long-term goal of reducing emissions to the atmosphere and negatively impact groundwater resources. Despite this, there remain uncertainties associated with the transport processes that would govern this leakage. These stem from the complex interaction between governing forces (e.g., gravitational, viscous, and capillary), the heterogeneous nature of the porous media, and the characteristic length scales of these leakage events, all of which impact the CO2 fluid flow processes. Here we assessed how sub-basin-scale horizons in porous media could impact the migration and trapping of a CO2 plume. A high-pressure column packed with two layers of sand with different properties (e.g., grain size and wettability) was used to create a low-contrast stratigraphic horizon. CO2 in supercritical or liquid phase was injected into the bottom of the column under various conditions (e.g., temperature, pressure, and capillary number) and the transport of the resulting plume was recorded using electrical resistivity. The results show that CO2 trapping was most strongly impacted by shifting the wettability balance to mixed-wet conditions, particularly for residual saturation. A 16% increase in the cosine of the contact angle for a mixed-wet sand resulted in nearly twice as much residual trapping. Permeability contrast, pressure, and temperature also impacted the residual saturation but to a lesser extent. Flow rate affected the dynamics of saturation profile development, but the effect is transient, suggesting that the other effects observed here could apply to a broad range of leakage conditions.

Comparison of empirical models and laboratory saturated hydraulic ...

African Journals Online (AJOL)

Numerous methods for estimating soil saturated hydraulic conductivity exist, which range from direct measurement in the laboratory to models that use only basic soil properties. A study was conducted to compare laboratory saturated hydraulic conductivity (Ksat) measurement and that estimated from empirical models.

Bulk elastic wave propagation in partially saturated porous solids

International Nuclear Information System (INIS)

Berryman, J.G.; Thigpen, L.; Chin, R.C.Y.

1988-01-01

The linear equations of motion that describe the behavior of small disturbances in a porous solid containing both liquid and gas are solved for bulk wave propagation. The equations have been simplified by neglecting effects due to changes in capillary pressure. With this simplifying assumption, the equations reduce to two coupled (vector) equations of the form found in Biot's equations (for full saturation) but with more complicated coefficients. As in fully saturated solids, two shear waves with the same speed but different polarizations exist as do two compressional waves with distinct speeds. Attenuation effects can be enhanced in the partially saturated solid, depending on the distribution of gas in the pore space. Two models of the liquid/gas spatial distribution are considered: a segregated-fluids model and a mixed-fluids model. The two models predict comparable attentuation when the gas saturation is low, but the segregated-fluids model predicts a more rapid roll-off of attenuation as the gas saturation increases

Field measurements of irradiation: first use in Italian geology

Energy Technology Data Exchange (ETDEWEB)

Cassinis, R; Lechi, G M; Tonelli, A M

1972-01-01

General considerations in the field of remote sensing are discussed, particularly geological applications of infrared measurements. The theory of electromagnetic radiation as described by Planck's law is briefly reviewed. IR scanning and radiometry are the most commonly used techniques. Scanning provides photographic images of the spatial distribution of surface radiation. This technique was first used in Italy to obtain radiation data at Solfatara di Pozznoli. The primary causes of error in the technique are variable atmospheric transmissivity, angular inclination, and variable emission. Problems involved in calibration are discussed. The data derived from surveys of volcanic regions are presented in tables and the thermal images and maps are provided. This technique is useful in surveying volcanoes and for the detection of high temperature geothermal resources.

Shearing of saturated clays in rock joints at high confining pressures

International Nuclear Information System (INIS)

Wang, C.; Mao, N.

1979-01-01

Saturated clays are sheared between rock joints at various pore water pressures and at confining pressures up to 3 kb (300 Mpa). Sliding on these joints is stable. For a given clay, the shear stress required to initiate sliding increases linearly with the effective normal stress across the sliding surface, with a slope of 0.08 +- 0.01 for joints filled with saturated montmorillonite, 0.12 +- 0.01 with saturated chlorite, 0.15 +- 0.01 with saturated kaolinite, and 0.22 +- 0.02 with saturated silty illite. Thus at high confining pressures the shear stress required to initiate sliding on joints filled with saturated clays are very much smaller than that required to initiate sliding on clean rock joints or on joints filled with dry gouge materials. In the crust, saturation of gouge materials along active faults would greatly lower the frictional resistance to faulting and would stabilize fault movement. Different fault behaviors such as stable creep along some faults and intermittent but sudden slip along others may reflect in part different degrees of saturation of fault zones at depth

Relating gas hydrate saturation to depth of sulfate-methane transition

Energy Technology Data Exchange (ETDEWEB)

Bhatnagar, G.; Chapman, W.G.; Hirasaki, G.J. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Dickens, G.R.; Dugan, B. [Rice Univ., Houston, TX (United States). Dept. of Earth Sciences

2008-07-01

The stability of gas hydrates which often form in pore spaces of marine sediment along continental margins, depends on temperature, pressure, salinity and gas composition. Gas hydrate can precipitate in pore space of marine sediment when gas concentrations exceed solubility conditions within a gas hydrate stability zone (GHSZ). The amount of gas hydrate present in the GHSZ can vary significantly because it relates to dynamic inputs and outputs of gas, primarily methane, over a long timescale. In anoxic marine sediments, depletion of pore water sulfate occurs when sulfate is reduced through bacteria or when anaerobic oxidation of methane occurs. The presence of gas hydrates in shallow sediments implies a significant methane flux towards the seafloor, which can make the second route for sulfate depletion significant. This paper presented a numerical model that incorporates a dynamic sulfate-methane transition (SMT) for gas hydrate systems where methane is supplied from depth. The approach has the advantage of needing only pore water data from shallow piston cores. The analytical expressions are only valid for steady-state systems in which all gas is methane, all methane enters the GHSZ from the base, and no methane escapes the top through seafloor venting. These constraints mean that anaerobic oxidation of methane (AOM) is the only sink of gas, allowing a direct coupling of SMT depth to net methane flux. This study showed that a basic gas hydrate saturation profile can be determined from the SMT depth via analytical expressions if site-specific parameters such as sedimentation rate, methane solubility and porosity are known. This analytical model was verified at gas hydrate bearing sites along the Cascadia margin where methane is mostly sourced from depth. It was concluded that the analytical expressions provides a fast and convenient method to calculate gas hydrate saturation for a given geologic setting, including deep-source systems. 28 refs., 2 tabs., 5 figs., 1

77 FR 19032 - Geological Survey

Science.gov (United States)

2012-03-29

... DEPARTMENT OF THE INTERIOR Geological Survey Announcement of National Geospatial Advisory Committee Meeting AGENCY: U.S. Geological Survey, Interior. ACTION: Notice of meeting. SUMMARY: The National.... Geological Survey (703-648-6283, [email protected] ). Registrations are due by April 13, 2012. While the...

A demonstration experiment for studying the properties of saturated vapor

Science.gov (United States)

Grebenev, Igor V.; Lebedeva, Olga V.; Polushkina, Svetlana V.

2017-11-01

The paper proposes an important demonstration experiment that can be used at secondary schools in physics. The described experiment helps students learn the main concepts of the topic ‘saturated vapor’, namely, evaporation, condensation, dynamic equilibrium, saturation vapor, partial pressure, and the dependence of saturated vapor pressure on temperature.

Association between mapped vegetation and Quaternary geology on Santa Rosa Island, California

Science.gov (United States)

Cronkite-Ratcliff, C.; Corbett, S.; Schmidt, K. M.

2017-12-01

Vegetation and surficial geology are closely connected through the interface generally referred to as the critical zone. Not only do they influence each other, but they also provide clues into the effects of climate, topography, and hydrology on the earth's surface. This presentation describes quantitative analyses of the association between the recently compiled, independently generated vegetation and geologic map units on Santa Rosa Island, part of the Channel Islands National Park in Southern California. Santa Rosa Island was heavily grazed by sheep and cattle ranching for over one hundred years prior to its acquisition by the National Park Service. During this period, the island experienced significant erosion and spatial reduction and diversity of native plant species. Understanding the relationship between geology and vegetation is necessary for monitoring the recovery of native plant species, enhancing the viability of restoration sites, and understanding hydrologic conditions favorable for plant growth. Differences in grain size distribution and soil depth between geologic units support different plant communities through their influence on soil moisture, while differences in unit age reflect different degrees of pedogenic maturity. We find that unsupervised machine learning methods provide more informative insight into vegetation-geology associations than traditional measures such as Cramer's V and Goodman and Kruskal's lambda. Correspondence analysis shows that unique vegetation-geology patterns associated with beach/dune, grassland, hillslope/colluvial, and fluvial/wetland environments can be discerned from the data. By combining geology and vegetation with topographic variables, mixture models can be used to partition the landscape into multiple representative types, which then be compared with conceptual models of plant growth and succession over different landforms. Using this collection of methods, we show various ways that that Quaternary geology

A new theoretical interpretation of Archie's saturation exponent

Directory of Open Access Journals (Sweden)

P. W. J. Glover

2017-07-01

Full Text Available This paper describes the extension of the concepts of connectedness and conservation of connectedness that underlie the generalized Archie's law for n phases to the interpretation of the saturation exponent. It is shown that the saturation exponent as defined originally by Archie arises naturally from the generalized Archie's law. In the generalized Archie's law the saturation exponent of any given phase can be thought of as formally the same as the phase (i.e. cementation exponent, but with respect to a reference subset of phases in a larger n-phase medium. Furthermore, the connectedness of each of the phases occupying a reference subset of an n-phase medium can be related to the connectedness of the subset itself by Gi = GrefSini. This leads naturally to the idea of the term Sini for each phase i being a fractional connectedness, where the fractional connectednesses of any given reference subset sum to unity in the same way that the connectednesses sum to unity for the whole medium. One of the implications of this theory is that the saturation exponent of any phase can be now be interpreted as the rate of change of the fractional connectedness with saturation and connectivity within the reference subset.

Geologic studies

International Nuclear Information System (INIS)

Wayland, T.E.; Rood, A.

1983-01-01

The modern Great Divide Basin is the end product of natural forces influenced by the Green River lake system, Laramide tectonism, and intermittent volcanic events. It ranks as one of the most complex structural and stratigtaphic features within the Tertiary basins of Wyoming. Portions of the Great Divide Basin and adjoining areas in Wyoming have been investigated by applying detailed and region exploration methods to known uranium deposits located within the Red Desert portions of the basin. Geologic field investigations conducted by Bendix Field Engineering Corporaton (Bendix) were restricted to reconnaissance observations made during infrequent visits to the project area by various Bendix personnel. Locations of the most comprehensive field activities are shown in Figure II-1. The principal source fo data for geologic studies of the Red Desert project area has been information and materials furnished by industry. Several hundred holes have been drilled by various groups to delineate the uranium deposits. Results from Bendix-drilled holes at selected locations within the project area are summarized in Table II-1. Additional details and gross subsurface characteristics are illustrated in cross sections; pertinent geologic features are illustrated in plan maps. Related details of continental sedimentation that pertain to the Wyoming Basins generally, and the project area specificially, are discussed in subsections of this Geologic Studies section

Geologic map of the greater Denver area, Front Range urban corridor, Colorado

Science.gov (United States)

Trimble, Donald E.; Machette, Michael N.

1979-01-01

This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999) was digitized under the USGS Front Range Infrastructure Resources Project. In general, the mountainous areas in the western part of the map exhibit various igneous and metamorphic bedrock units of Precambrian age, major faults, and fault brecciation zones at the east margin (5-20 km wide) of the Front Range. The eastern and central parts of the map (Colorado Piedmont) depict a mantle of unconsolidated deposits of Quaternary age and interspersed outcroppings of Cretaceous or Tertiary-Cretaceous sedimentary bedrock. The Quaternary mantle comprises eolian deposits (quartz sand and silt), alluvium (gravel, sand, and silt of variable composition), colluvium, and a few landslides. At the mountain front, north-trending, dipping Paleozoic and Mesozoic sandstone, shale, and limestone bedrock formations form hogbacks and intervening valleys.

High speed drying of saturated steam

International Nuclear Information System (INIS)

Marty, C.; Peyrelongue, J.P.

1993-01-01

This paper describes the development of the drying process for the saturated steam used in the PWR nuclear plant turbines in order to prevent negative effects of water on turbine efficiency, maintenance costs and equipment lifetime. The high speed drying concept is based on rotating the incoming saturated steam in order to separate water which is more denser than the steam; the water film is then extracted through an annular slot. A multicellular modular equipment has been tested. Applications on high and low pressure extraction of various PWR plants are described (Bugey, Loviisa)

Fundamentals of Structural Geology

Science.gov (United States)

Pollard, David D.; Fletcher, Raymond C.

2005-09-01

Fundamentals of Structural Geology provides a new framework for the investigation of geological structures by integrating field mapping and mechanical analysis. Assuming a basic knowledge of physical geology, introductory calculus and physics, it emphasizes the observational data, modern mapping technology, principles of continuum mechanics, and the mathematical and computational skills, necessary to quantitatively map, describe, model, and explain deformation in Earth's lithosphere. By starting from the fundamental conservation laws of mass and momentum, the constitutive laws of material behavior, and the kinematic relationships for strain and rate of deformation, the authors demonstrate the relevance of solid and fluid mechanics to structural geology. This book offers a modern quantitative approach to structural geology for advanced students and researchers in structural geology and tectonics. It is supported by a website hosting images from the book, additional colour images, student exercises and MATLAB scripts. Solutions to the exercises are available to instructors. The book integrates field mapping using modern technology with the analysis of structures based on a complete mechanics MATLAB is used to visualize physical fields and analytical results and MATLAB scripts can be downloaded from the website to recreate textbook graphics and enable students to explore their choice of parameters and boundary conditions The supplementary website hosts color images of outcrop photographs used in the text, supplementary color images, and images of textbook figures for classroom presentations The textbook website also includes student exercises designed to instill the fundamental relationships, and to encourage the visualization of the evolution of geological structures; solutions are available to instructors

A SKOS-based multilingual thesaurus of geological time scale for interopability of online geological maps

NARCIS (Netherlands)

Ma, X.; Carranza, E.J.M.; Wu, C.; Meer, F.D. van der; Liu, G.

2011-01-01

The usefulness of online geological maps is hindered by linguistic barriers. Multilingual geoscience thesauri alleviate linguistic barriers of geological maps. However, the benefits of multilingual geoscience thesauri for online geological maps are less studied. In this regard, we developed a

Small County: Development of a Virtual Environment for Instruction in Geological Characterization of Petroleum Reservoirs

Science.gov (United States)

Banz, B.; Bohling, G.; Doveton, J.

2008-12-01

Traditional programs of geological education continue to be focused primarily on the evaluation of surface or near-surface geology accessed at outcrops and shallow boreholes. However, most students who graduate to careers in geology work almost entirely on subsurface problems, interpreting drilling records and petrophysical logs from exploration and production wells. Thus, college graduates commonly find themselves ill-prepared when they enter the petroleum industry and require specialized training in drilling and petrophysical log interpretation. To aid in this training process, we are developing an environment for interactive instruction in the geological aspects of petroleum reservoir characterization employing a virtual subsurface closely reflecting the geology of the US mid-continent, in the fictional setting of Small County, Kansas. Stochastic simulation techniques are used to generate the subsurface characteristics, including the overall geological structure, distributions of facies, porosity, and fluid saturations, and petrophysical logs. The student then explores this subsurface by siting exploratory wells and examining drilling and petrophysical log records obtained from those wells. We are developing the application using the Eclipse Rich Client Platform, which allows for the rapid development of a platform-agnostic application while providing an immersive graphical interface. The application provides an array of views to enable relevant data display and student interaction. One such view is an interactive map of the county allowing the student to view the locations of existing well bores and select pertinent data overlays such as a contour map of the elevation of an interesting interval. Additionally, from this view a student may choose the site of a new well. Another view emulates a drilling log, complete with drilling rate plot and iconic representation of examined drill cuttings. From here, students are directed to stipulate subsurface lithology and

Database system of geological information for geological evaluation base of NPP sites(I)

International Nuclear Information System (INIS)

Lim, C. B.; Choi, K. R.; Sim, T. M.; No, M. H.; Lee, H. W.; Kim, T. K.; Lim, Y. S.; Hwang, S. K.

2002-01-01

This study aims to provide database system for site suitability analyses of geological information and a processing program for domestic NPP site evaluation. This database system program includes MapObject provided by ESRI and Spread 3.5 OCX, and is coded with Visual Basic language. Major functions of the systematic database program includes vector and raster farmat topographic maps, database design and application, geological symbol plot, the database search for the plotted geological symbol, and so on. The program can also be applied in analyzing not only for lineament trends but also for statistic treatment from geologically site and laboratory information and sources in digital form and algorithm, which is usually used internationally

Nuclear determination of saturation profiles in core plugs

International Nuclear Information System (INIS)

Sletsgaard, J.; Oelgaard, P.L.

1997-01-01

A method to determine liquid saturations in core plugs during flooding is of importance when the relative permeability and capillary pressure function are to be determined. This part of the EFP-95 project uses transmission of γ-radiation to determine these saturations. In γ-transmission measurements, the electron density of the given substance is measured. This is an advantage as compared to methods that use electric conductivity, since neither oil nor gas conducts electricity. At the moment a single 137 Cs-source is used, but a theoretical investigation of whether it is possible to determine three saturations, using two radioactive sources with different γ-energies, has been performed. Measurements were made on three core plugs. To make sure that the measurements could be reproduced, all the plugs had a point of reference, i.e. a mark so that it was possible to place the plug same way every time. Two computer programs for calculation of saturation and porosity and the experimental setup are listed. (EG)

OneGeology Web Services and Portal as a global geological SDI - latest standards and technology

Science.gov (United States)

Duffy, Tim; Tellez-Arenas, Agnes

2014-05-01

The global coverage of OneGeology Web Services (www.onegeology.org and portal.onegeology.org) achieved since 2007 from the 120 participating geological surveys will be reviewed and issues arising discussed. Recent enhancements to the OneGeology Web Services capabilities will be covered including new up to 5 star service accreditation scheme utilising the ISO/OGC Web Mapping Service standard version 1.3, core ISO 19115 metadata additions and Version 2.0 Web Feature Services (WFS) serving the new IUGS-CGI GeoSciML V3.2 geological web data exchange language standard (http://www.geosciml.org/) with its associated 30+ IUGS-CGI available vocabularies (http://resource.geosciml.org/ and http://srvgeosciml.brgm.fr/eXist2010/brgm/client.html). Use of the CGI simpelithology and timescale dictionaries now allow those who wish to do so to offer data harmonisation to query their GeoSciML 3.2 based Web Feature Services and their GeoSciML_Portrayal V2.0.1 (http://www.geosciml.org/) Web Map Services in the OneGeology portal (http://portal.onegeology.org). Contributing to OneGeology involves offering to serve ideally 1:1000,000 scale geological data (in practice any scale now is warmly welcomed) as an OGC (Open Geospatial Consortium) standard based WMS (Web Mapping Service) service from an available WWW server. This may either be hosted within the Geological Survey or a neighbouring, regional or elsewhere institution that offers to serve that data for them i.e. offers to help technically by providing the web serving IT infrastructure as a 'buddy'. OneGeology is a standards focussed Spatial Data Infrastructure (SDI) and works to ensure that these standards work together and it is now possible for European Geological Surveys to register their INSPIRE web services within the OneGeology SDI (e.g. see http://www.geosciml.org/geosciml/3.2/documentation/cookbook/INSPIRE_GeoSciML_Cookbook%20_1.0.pdf). The Onegeology portal (http://portal.onegeology.org) is the first port of call for anyone

Arterial blood oxygen saturation during blood pressure cuff-induced hypoperfusion

Energy Technology Data Exchange (ETDEWEB)

Kyriacou, P A [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Shafqat, K [School of Engineering and Mathematical Sciences, City University, London EC1V 0HB (United Kingdom); Pal, S K [St Andrew' s Centre for Plastic Surgery and Burns, Broomfield Hospital, Chelmsford, CM1 7ET (United Kingdom)

2007-10-15

Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO{sub 2}) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Pulse oximeters estimate arterial oxygen saturation by shining light at two different wavelengths, red and infrared, through vascular tissue. In this method the ac pulsatile photoplethysmographic (PPG) signal associated with cardiac contraction is assumed to be attributable solely to the arterial blood component. The amplitudes of the red and infrared ac PPG signals are sensitive to changes in arterial oxygen saturation because of differences in the light absorption of oxygenated and deoxygenated haemoglobin at these two wavelengths. From the ratios of these amplitudes, and the corresponding dc photoplethysmographic components, arterial blood oxygen saturation (SpO{sub 2}) is estimated. Hence, the technique of pulse oximetry relies on the presence of adequate peripheral arterial pulsations, which are detected as photoplethysmographic (PPG) signals. The aim of this study was to investigate the effect of pressure cuff-induced hypoperfusion on photoplethysmographic signals and arterial blood oxygen saturation using a custom made finger blood oxygen saturation PPG/SpO{sub 2} sensor and a commercial finger pulse oximeter. Blood oxygen saturation values from the custom oxygen saturation sensor and a commercial finger oxygen saturation sensor were recorded from 14 healthy volunteers at various induced brachial pressures

Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts

International Nuclear Information System (INIS)

Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

2010-11-01

This document brings together the abstracts of the 39 presentations given at this meeting days on uranium, organized by the French geological society, and dealing with: 1 - Prospective study of the electronuclear technological transition; 2 - The front-end of the nuclear cycle: from the molecule to the process; 3 - Geophysics: recent changes; 4 - Use of well logging in uranium exploration; 5 - Genetical classification of thorium deposits; 6 - Genetical nomenclature of uranium sources; 7 - Uranium deposits linked to a Proterozoic discordance - retrospective; 8 - The use of spectral analysis techniques in uranium exploration: real-time mapping of clay alteration features; 9 - Development of functionalized silk-screened carbon electrodes for the analysis of uranium trace amounts; 10 - Study of the actinides solvation sphere in organic environment; 11 - Thermodynamic of uraniferous phases of interest for the nuclear cycle; 12 - Heap leaching of marginal minerals at Somair: from lab studies to the production of 700 t of uranium/year; 13 - Agglomeration phenomenology and role of iron in uranium heap leaching; 14 - Chloride uranyl complexes up to 300 deg. C along the saturation vapour curve: Raman spectroscopy analysis and metallogenic consequences; 15 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): vertical variability of argillaceous weathering; 16 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): contribution of irradiation defects in clays to the tracing of past uranium migrations; 17 - Uranium concentrations in mineralizing fluids of the Athabasca basin: analytical and experimental approach; 18 - Paleo-surfaces and metallic rooting: the autochthonous uranium of pre-Athabasca paleo-alterites, Canada; 19 - Distribution of argillaceous parageneses in the Imouraren deposit - Niger; 20 - Heat flux and radioelements concentration (U, Th, K) of precambrian basements: implications in terms of crust growth mechanisms, paleo

Saturated and trans-fatty acids in UK takeaway food.

Science.gov (United States)

Davies, Ian Glynn; Blackham, Toni; Jaworowska, Agnieszka; Taylor, Catherine; Ashton, Matthew; Stevenson, Leonard

2016-01-01

The aim of the study was to analyze the saturated fatty acid (SFA) and trans-fatty acid (TFA) contents of popular takeaway foods in the UK (including English, pizza, Chinese, Indian and kebab cuisine). Samples of meals were analyzed by an accredited public analyst laboratory for SFA and TFA. The meals were highly variable for SFA and TFA. English and Pizza meals had the highest median amount of SFA with 35.7 g/meal; Kebab meals were high in TFA with up to 5.2 g/meal. When compared to UK dietary reference values, some meals exceeded SFA and TFA recommendations from just one meal. Takeaway food would be an obvious target to reduce SFA and TFA contents and increase the potential of meeting UK recommendations. Strategies such as reformulation and smaller takeaway portion sizes warrant investigation.

Operation environment construction of geological information database for high level radioactive waste geological disposal

International Nuclear Information System (INIS)

Wang Peng; Gao Min; Huang Shutao; Wang Shuhong; Zhao Yongan

2014-01-01

To fulfill the requirements of data storage and management in HLW geological disposal, a targeted construction method for data operation environment was proposed in this paper. The geological information database operation environment constructed by this method has its unique features. And it also will be the important support for HLW geological disposal project and management. (authors)

On the propagation of a coupled saturation and pressure front

Energy Technology Data Exchange (ETDEWEB)

Vasco, D. W.

2010-12-01

Using an asymptotic technique, valid for a medium with smoothly varying heterogeneity, I derive an expression for the velocity of a propagating, coupled saturation and pressure front. Due to the nonlinearity of the governing equations, the velocity of the propagating front depends upon the magnitude of the saturation and pressure changes across the front in addition to the properties of the medium. Thus, the expression must be evaluated in conjunction with numerical reservoir simulation. The propagation of the two-phase front is governed by the background saturation distribution, the saturation-dependent component of the fluid mobility, the porosity, the permeability, the capillary pressure function, the medium compressibility, and the ratio of the slopes of the relative permeability curves. Numerical simulation of water injection into a porous layer saturated with a nonaqueous phase liquid indicates that two modes of propagation are important. The fastest mode of propagation is a pressure-dominated disturbance that travels through the saturated layer. This is followed, much later, by a coupled mode with a large saturation change. These two modes are also observed in a simulation using a heterogeneous porous layer. A comparison between the propagation times estimated from the results of the numerical simulation and predictions from the asymptotic expression indicates overall agreement.

Geology and resources of the Tar Sand Triangle, southeastern Utah

Energy Technology Data Exchange (ETDEWEB)

Dana, G.F.; Oliver, R.L.; Elliott, J.R.

1984-05-01

The Tar Sand Triangle is located in southeastern Utah between the Dirty Devil and Colorado Rivers and covers an area of about 200 square miles. The geology of the area consists of gently northwest dipping strata exposed in the box canyons and slopes of the canyonlands morphology. Strata in the area range in age from Jurassic to Permian. The majority of tar sand saturation is found in the Permian White Rim Sandstone Member of the Cutler Formation. The White Rim Sandstone Member consists of a clean, well-sorted sandstone which was deposited in a shallow marine environment. Resources were calculated from analytical data from the three coreholes drilled by the Laramie Energy Technology Center and other available data. The total in-place resources, determined from this study, are 6.3 billion barels. Previous estimates ranged from 2.9 to 16 million barrels. More coring and analyses will be necessary before a more accurate determination of resources can be attempted. 8 references, 11 figures, 7 tables.

Planetary Geologic Mapping Handbook - 2009

Science.gov (United States)

Tanaka, K. L.; Skinner, J. A.; Hare, T. M.

2009-01-01

Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces (e.g., Varnes, 1974). Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962 (Hackman, 1962). Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete

Semiconductor saturable absorbers for ultrafast THz signals

DEFF Research Database (Denmark)

Hoffmann, Matthias C.; Turchinovich, Dmitry

We demonstrate saturable absorber behavior of n-type semiconductors in the THz frequency range using nonlinear THz spectroscopy. Further, we observe THz pulse shortening and increase of the group refractive index at high field strengths.......We demonstrate saturable absorber behavior of n-type semiconductors in the THz frequency range using nonlinear THz spectroscopy. Further, we observe THz pulse shortening and increase of the group refractive index at high field strengths....

Static compensators using thyristor control with saturated or low-reactance linear reactors

Energy Technology Data Exchange (ETDEWEB)

Thanawala, H L; Kelham, W O; Crawshaw, A W

1982-01-01

Alternative key components of variable static equipment for reactive power compensation and voltage control in a.c. transmission systems are saturated reactors (SR) and thyristor-controlled reactors (TCR). This paper reports some recent developments aimed at improving the performance and economy of both types of scheme. Advantages of using low-percentage reactance values in a TCR scheme are considered, and methods of dealing with the increased harmonic distortions and of employing transformer leakage reactance. The paper discusses the possibility of combining the advantages of 'external' thyristor control with the 'inherent' action of the harmonic-compensated SR, and the performance of a practical TCSR is presented.

Soil variability in engineering applications

Science.gov (United States)

Vessia, Giovanna

2014-05-01

Natural geomaterials, as soils and rocks, show spatial variability and heterogeneity of physical and mechanical properties. They can be measured by in field and laboratory testing. The heterogeneity concerns different values of litho-technical parameters pertaining similar lithological units placed close to each other. On the contrary, the variability is inherent to the formation and evolution processes experienced by each geological units (homogeneous geomaterials on average) and captured as a spatial structure of fluctuation of physical property values about their mean trend, e.g. the unit weight, the hydraulic permeability, the friction angle, the cohesion, among others. The preceding spatial variations shall be managed by engineering models to accomplish reliable designing of structures and infrastructures. Materon (1962) introduced the Geostatistics as the most comprehensive tool to manage spatial correlation of parameter measures used in a wide range of earth science applications. In the field of the engineering geology, Vanmarcke (1977) developed the first pioneering attempts to describe and manage the inherent variability in geomaterials although Terzaghi (1943) already highlighted that spatial fluctuations of physical and mechanical parameters used in geotechnical designing cannot be neglected. A few years later, Mandelbrot (1983) and Turcotte (1986) interpreted the internal arrangement of geomaterial according to Fractal Theory. In the same years, Vanmarcke (1983) proposed the Random Field Theory providing mathematical tools to deal with inherent variability of each geological units or stratigraphic succession that can be resembled as one material. In this approach, measurement fluctuations of physical parameters are interpreted through the spatial variability structure consisting in the correlation function and the scale of fluctuation. Fenton and Griffiths (1992) combined random field simulation with the finite element method to produce the Random

The role of hillslope topography on shallow landslides activation and basin saturation propensity

Science.gov (United States)

Lanni, C.; Pretto, I.; Rigon, R.

2009-12-01

Shallow Landslides are one of the most important causes of loss of human life and socio-economic damage related to the hydro-geological risk issues. In the past years a big number of researches have developed tools to assess for the stability condition of hillslopes at the basin-scale. Montgomery and Dietrich (1994), for instance, with their own SHALSTAB model, give a simple way to evaluate the safety factor of mountain hillslopes, coupling the infinite slope stability model with a very simple steady-state hydrological model based on the work by O'Loughlin (1986) and which has similarities to TOPOG (Beven and Kirkby, 1979). The state of art gives the possibility to evaluate the transient nature of the generated pore-pressure fields within soil-thickness during and after the rainfalls. A valuable tool to fulfill this purpose may be the GEOtop model (Rigon et al., 2006) born to solve the 3-dimensional form of Richards’ equation. The present work, which was held using GEOtop model, investigates the stability conditions and the water table level of nine characteristic hillslope types when steady-state conditions are reached. The artificial simple basins are created combining three different curvature's profile (straight, concave and convex) and three different plan shapes (parallel, convergent and divergent) (fig.1). In the analysis the hillslope soil thickness is imposed constant, while the bedrock is considered impermeable. Different intensity rainfalls are simulated. The results show that in the case of the lowest intensity rainfall, basins with convex shape present higher percentage of saturated area than concave and straight ones. Also, convergent hillslopes generally produce a higher percentage of saturated area than the other plan shapes. Moreover, in the case of higher intensity rainfalls, the concave profile curvature seems to be the first order controller on the saturation process. Regarding the stability conditions, convergent hillslopes generally presents

Quaternary Geology and Liquefaction Susceptibility, Napa, California 1:100,000 Quadrangle: A Digital Database

Science.gov (United States)

Sowers, Janet M.; Noller, Jay S.; Lettis, William R.

1998-01-01

Earthquake-induced ground failures such as liquefaction have historically brought loss of life and damage to property and infrastructure. Observations of the effects of historical large-magnitude earthquakes show that the distribution of liquefaction phenomena is not random. Liquefaction is restricted to areas underlain by loose, cohesionless sands and silts that are saturated with water. These areas can be delineated on the basis of thorough geologic, geomorphic, and hydrologic mapping and map analysis (Tinsley and Holzer, 1990; Youd and Perkins, 1987). Once potential liquefaction zones are delineated, appropriate public and private agencies can prepare for and mitigate seismic hazard in these zones. In this study, we create a liquefaction susceptibility map of the Napa 1:100,000 quadrangle using Quaternary geologic mapping, analysis of historical liquefaction information, groundwater data, and data from other studies. The study is atterned after state-of-the-art studies by Youd (1973) Dupre and Tinsley (1980) and Dupre (1990) in the Monterey-Santa Cruz area, Tinsley and others (1985) in the Los Angeles area, and Youd and Perkins (1987) in San Mateo County, California. The study area comprises the northern San Francisco Metropolitan Area, including the cities of Santa Rosa, Vallejo, Napa, Novato, Martinez, and Fairfield (Figure 1). Holocene estuarine deposits, Holocene stream deposits, eolian sands, and artificial fill are widely present in the region (Helley and Lajoie, 1979) and are the geologic materials of greatest concern. Six major faults capable of producing large earthquakes cross the study area, including the San Andreas, Rodgers Creek, Hayward, West Napa, Concord, and Green Valley faults (Figure 1).

Influence of particle size distribution on the blast pressure profile from explosives buried in saturated soils

Science.gov (United States)

Rigby, S. E.; Fay, S. D.; Tyas, A.; Clarke, S. D.; Reay, J. J.; Warren, J. A.; Gant, M.; Elgy, I.

2017-06-01

The spatial and temporal distribution of pressure and impulse from explosives buried in saturated cohesive and cohesionless soils has been measured experimentally for the first time. Ten experiments have been conducted at quarter-scale, where localised pressure loading was measured using an array of 17 Hopkinson pressure bars. The blast pressure measurements are used in conjunction with high-speed video filmed at 140,000 fps to investigate in detail the physical processes occurring at the loaded face. Two coarse cohesionless soils and one fine cohesive soil were tested: a relatively uniform sand, a well-graded sandy gravel, and a fine-grained clay. The results show that there is a single fundamental loading mechanism when explosives are detonated in saturated soil, invariant of particle size and soil cohesion. It is also shown that variability in localised loading is intrinsically linked to the particle size distribution of the surrounding soil.

Influence of particle size distribution on the blast pressure profile from explosives buried in saturated soils

Science.gov (United States)

Rigby, S. E.; Fay, S. D.; Tyas, A.; Clarke, S. D.; Reay, J. J.; Warren, J. A.; Gant, M.; Elgy, I.

2018-05-01

The spatial and temporal distribution of pressure and impulse from explosives buried in saturated cohesive and cohesionless soils has been measured experimentally for the first time. Ten experiments have been conducted at quarter-scale, where localised pressure loading was measured using an array of 17 Hopkinson pressure bars. The blast pressure measurements are used in conjunction with high-speed video filmed at 140,000 fps to investigate in detail the physical processes occurring at the loaded face. Two coarse cohesionless soils and one fine cohesive soil were tested: a relatively uniform sand, a well-graded sandy gravel, and a fine-grained clay. The results show that there is a single fundamental loading mechanism when explosives are detonated in saturated soil, invariant of particle size and soil cohesion. It is also shown that variability in localised loading is intrinsically linked to the particle size distribution of the surrounding soil.

Influences on the variability of eruption sequences and style transitions in the Auckland Volcanic Field, New Zealand

Science.gov (United States)

Kereszturi, Gábor; Németh, Károly; Cronin, Shane J.; Procter, Jonathan; Agustín-Flores, Javier

2014-10-01

Monogenetic basaltic volcanism is characterised by a complex array of eruptive behaviours, reflecting spatial and temporal variability of the magmatic properties (e.g. composition, eruptive volume, magma flux) as well as environmental factors at the vent site (e.g. availability of water, country rock geology, faulting). These combine to produce changes in eruption style over brief periods (minutes to days) in many eruption episodes. Monogenetic eruptions in some volcanic fields often start with a phreatomagmatic vent-opening phase that later transforms into "dry" magmatic explosive or effusive activity, with a strong variation in the duration and importance of this first phase. Such an eruption sequence pattern occurred in 83% of the known eruption in the 0.25 My-old Auckland Volcanic Field (AVF), New Zealand. In this investigation, the eruptive volumes were compared with the sequences of eruption styles preserved in the pyroclastic record at each volcano of the AVF, as well as environmental influencing factors, such as distribution and thickness of water-saturated semi- to unconsolidated sediments, topographic position, distances from known fault lines. The AVF showed that there is no correlation between ejecta ring volumes and environmental influencing factors that is valid for the entire AVF. In contrary, using a set of comparisons of single volcanoes with well-known and documented sequences, resultant eruption sequences could be explained by predominant patterns of the environment in which these volcanoes were erupted. Based on the spatial variability of these environmental factors, a first-order susceptibility hazard map was constructed for the AVF that forecasts areas of largest likelihood for phreatomagmatic eruptions by overlaying topographical and shallow geological information. Combining detailed phase-by-phase breakdowns of eruptive volumes and the event sequences of the AVF, along with the new susceptibility map, more realistic eruption scenarios can be

Estimates of the width of the wetting zone along a fracture subjected to an episodic infiltration event in variably saturated, densely welded tuff

International Nuclear Information System (INIS)

Buscheck, T.A.; Nitao, J.J.

1988-01-01

A central issue to be addressed within the Nevada Nuclear Waste Storage Investigations (NNWSI) is the role which fractures will play as the variably saturated, fractured rock mass surrounding the waste package responds to heating, cooling, and episodic infiltration events. Understanding the role of fractures during such events will, in part, depend on our ability to make geophysical measurements of perturbations in the moisture distribution in the vicinity of fractures. In this study we first examine the details of the perturbation in the moisture distribution in and around a fracture subjected to an episodic infiltration event, and then integrate that behavior over the scale at which moisture measurements are likely to be made during the Engineered Barrier Design Test of the NNWSI project. To model this system we use the TOUGH hydrothermal code and fracture and matrix properties considered relevant to the welded ash flow tuff found in the Topopah Spring member at Yucca Mountain as well as in the Grouse Canyon member within G-Tunnel at the Nevada Test Site. Our calculations provide insight into the anticipated spatial and temporal resolution obtainable through the use of the geophysical techniques being considered. These calculations should prove useful both in planning the implementation of these methods as well as in the interpretation of their results. 41 refs., 28 figs

Engineering geology and environmental protection

Energy Technology Data Exchange (ETDEWEB)

Sergeev, E M

1979-01-01

A classification is made of the anthropogenic processes in the environment into global, local, universally distributed, zonal, regional, and essentially local processes. Engineering geology is defined as the principal science concerned with the study of the geological medium which in turn involves the study of fossil fuel geology. 22 references.

Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

Science.gov (United States)

Liang, Peixin; Chai, Feng; Bi, Yunlong; Pei, Yulong; Cheng, Shukang

2016-11-01

Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization.

Ultrafast THz Saturable Absorption in Doped Semiconductors

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Hoffmann, Matthias C.

2011-01-01

We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields.......We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields....

Saturable absorption in detonation nanodiamond dispersions

Science.gov (United States)

Vanyukov, Viatcheslav; Mikheev, Gennady; Mogileva, Tatyana; Puzyr, Alexey; Bondar, Vladimir; Lyashenko, Dmitry; Chuvilin, Andrey

2017-07-01

We report on a saturable absorption in aqueous dispersions of nanodiamonds with femtosecond laser pulse excitation at a wavelength of 795 nm. The open aperture Z-scan experiments reveal that in a wide range of nanodiamond particle sizes and concentrations, a light-induced increase of transmittance occurs. The transmittance increase originates from the saturation of light absorption and is associated with a light absorption at 1.5 eV by graphite and dimer chains (Pandey dimer chains). The obtained key nonlinear parameters of nanodiamond dispersions are compared with those of graphene and carbon nanotubes, which are widely used for the mode-locking.

On the saturation of astrophysical dynamos

DEFF Research Database (Denmark)

Dorch, Bertil; Archontis, Vasilis

2004-01-01

In the context of astrophysical dynamos we illustrate that the no-cosines flow, with zero mean helicity, can drive fast dynamo action and we study the dynamo's mode of operation during both the linear and non-linear saturation regimes. It turns out that in addition to a high growth rate in the li......In the context of astrophysical dynamos we illustrate that the no-cosines flow, with zero mean helicity, can drive fast dynamo action and we study the dynamo's mode of operation during both the linear and non-linear saturation regimes. It turns out that in addition to a high growth rate...

Preliminary characterization of an alpine karst aquifer in a complex geological setting using the KARSYS approach. Picos de Europa, North Spain

Science.gov (United States)

Ballesteros, Daniel; Malard, Arnauld; Jeannin, Pierre-Yves; Jiménez-Sánchez, Montserrat; García-Sansegundo, Joaquín; Meléndez, Mónica; Sendra, Gemma

2013-04-01

and the top of the Ordovician rocks, pushing the underground flow paths towards the northern part of the massif. Some boundaries of the saturated part of the groundwater bodies are unknown, although they could be associated to some rocks not considered in the geological model. The main karst springs supply 10 to 5,000 l/s, being located at altitudes ranging from 167 to 1,246 m (western area), and 178 to 440 m (central area) and at 600 m (eastern area). Their elevation is progressively decreasing toward the North, conditioning the regional circulation of karst groundwater. These results suggest that the geometry of the saturated part presents several compartments, resulting from the position of the out-of-sequence thrusts, with a relative elevation descending to the North. The results evidenced by the KARSYS approach provide first outlook of the geometry of the karst aquifers of the Picos de Europa, even if deep geological data are not precise or are scarce. The method has also revealed the main targets for future geological and hydrogeological research in this complex karstic environment. Jeannin et al. 2012. Environmental Earth Sciences DOI10.1007/s12665-012-1983-6.

Geology Field Trips as Performance Evaluations

Science.gov (United States)

Bentley, Callan

2009-01-01

One of the most important goals the author has for students in his introductory-level physical geology course is to give them the conceptual skills for solving geologic problems on their own. He wants students to leave his course as individuals who can use their knowledge of geologic processes and logic to figure out the extended geologic history…

The viscosity of the refrigerant 1,1-difluoroethane along the saturation line

Science.gov (United States)

van der Gulik, P. S.

1993-07-01

The viscosity coefficient of the refrigerant R152a (1,1-difluoroethane) has been measured along the saturation line both in the saturated liquid and in the saturated vapor. The data have been obtained every 10 K from 243 up to 393 K by means of a vibrating-wire viscometer using the free damped oscillation method. The density along the saturation line was calculated from the equation of state given by Tamatsu et al. with application of the saturated vapor-pressure correlation given by Higashi et al. An interesting result is that in the neighborhood of the critical point, the kinematic viscosity of the saturated liquid seems to coincide with that of the saturated vapor. The results for the saturated liquid are in satisfying agreement with those of Kumagai and Takahashi and of Phillips and Murphy. A comparison of the saturatedvaport data with the unsaturated-vapor data of Takahashi et al. shows some discrepancies.

Experimental and numerical study on thermal conductivity of partially saturated unconsolidated sands

Science.gov (United States)

Lee, Youngmin; Keehm, Youngseuk; Kim, Seong-Kyun; Shin, Sang Ho

2016-04-01

A class of problems in heat flow applications requires an understanding of how water saturation affects thermal conductivity in the shallow subsurface. We conducted a series of experiments using a sand box to evaluate thermal conductivity (TC) of partially saturated unconsolidated sands under varying water saturation (Sw). We first saturated sands fully with water and varied water saturation by drainage through the bottom of the sand box. Five water-content sensors were integrated vertically into the sand box to monitor water saturation changes and a needle probe was embedded to measure thermal conductivity of partially saturated sands. The experimental result showed that thermal conductivity decreases from 2.5 W/mK for fully saturated sands to 0.7 W/mK when water saturation is 5%. We found that the decreasing trend is quite non-linear: highly sensitive at very high and low water saturations. However, the boundary effects on the top and the bottom of the sand box seemed to be responsible for this high nonlinearity. We also found that the determination of water saturation is quite important: the saturation by averaging values from all five sensors and that from the sensor at the center position, showed quite different trends in the TC-Sw domain. In parallel, we conducted a pore-scale numerical modeling, which consists of the steady-state two-phase Lattice-Boltzmann simulator and FEM thermal conduction simulator on digital pore geometry of sand aggregation. The simulation results showed a monotonous decreasing trend, and are reasonably well matched with experimental data when using average water saturations. We concluded that thermal conductivity would decrease smoothly as water saturation decreases if we can exclude boundary effects. However, in dynamic conditions, i.e. imbibition or drainage, the thermal conductivity might show hysteresis, which can be investigated with pore-scale numerical modeling with unsteady-state two-phase flow simulators in our future work.

Digital integration of geological and aeroradiometric data for probability mapping of uranium occurrences in parts of south-eastern Rajasthan, India

International Nuclear Information System (INIS)

Chawla, A.S.; Katti, V.J.; Kak, S.N.; Das, S.K.

1993-01-01

Integration and evaluation of geological, radio geochemical, and magnetic information of Umra-Udaisagar and Sarara inlier area, Udaipur district, Rajasthan was attempted. Seventeen lithostructural variables from colour infrared (CIR) photo geological analogue maps were interpreted, radio geochemical and magnetic variables thematically evaluated from airborne gamma-ray spectrometric (AGRS) and aero magnetic (AM) digital data were co-registered using a sequential grid matrix of 500 m x 500 m. The variables were quantified using theme-specific equations and digitized in simple Boolean representation format, depending on the presence or absence of a variable, its positive or negative interest, and/or greater than or less than a theme-specific value in each cell. The database so generated was subjected to a software programme weighted modelling wherein, weights for each variable are computed based on conditional probability method, and favorability index maps are generated by discriminant objective analysis. Areas with high probability for uranium mineralisation were delineated by computing composite coincidence of cells with high favorability index value considering each variable as a control variable. Critical analysis of weights computed for each variable in different sets predicts the importance of control of the variable to uranium mineralisation. This attempt has resulted in delineating several new high-probability zones of uranium enrichment and indicated a regional structural control in the area. (author). 11 refs., 4 figs

Mercury's Early Geologic History

Science.gov (United States)

Denevi, B. W.; Ernst, C. M.; Klima, R. L.; Robinson, M. S.

2018-05-01

A combination of geologic mapping, compositional information, and geochemical models are providing a better understanding of Mercury's early geologic history, and allow us to place it in the context of the Moon and the terrestrial planets.

Soil aquifer treatment of artificial wastewater under saturated conditions

KAUST Repository

Essandoh, H. M K; Tizaoui, Chedly; Mohamed, Mostafa H A; Amy, Gary L.; Brdjanovic, Damir

2011-01-01

A 2000 mm long saturated laboratory soil column was used to simulate soil aquifer treatment under saturated conditions to assess the removal of chemical and biochemical oxygen demand (COD and BOD), dissolved organic carbon (DOC), nitrogen

Geology of Uruguay review

International Nuclear Information System (INIS)

Gomez Rifas, C.

2011-01-01

This work is about the Uruguay geology review.This country has been a devoted to breeding cattle and agriculture.The evolution of geological knowledge begun with Dr. Karl Walther who published 53 papers between 1909 and 1948.

Prediction of saturation using the carbon/oxygen log

Energy Technology Data Exchange (ETDEWEB)

Horner, S.C.; Sanyal, S.K.

1984-09-01

This project investigates the nature of Dresser-Atlas Carbon/Oxygen Log gamma ray spectra. It presents an attempt to improve the signal-to-noise ratio of the C/O and Si/Ca parameters used by Dresser-Atlas to determine oil saturation. Two techniques were developed to subtract the Compton background from the spectral data. Neither technique significantly improves the accuracy of the cased-hole prediction of oil saturation. However, it has been shown that it is possible to develop a satisfactory correlation for oil saturation on a well-by-well basis. This correlation can then be used to generate oil-in-place from the C/O and Si/Ca ratios. 17 references.

Beyond the Natural Proteome: Nondegenerate Saturation Mutagenesis-Methodologies and Advantages.

Science.gov (United States)

Ferreira Amaral, M M; Frigotto, L; Hine, A V

2017-01-01

Beyond the natural proteome, high-throughput mutagenesis offers the protein engineer an opportunity to "tweak" the wild-type activity of a protein to create a recombinant protein with required attributes. Of the various approaches available, saturation mutagenesis is one of the core techniques employed by protein engineers, and in recent times, nondegenerate saturation mutagenesis is emerging as the approach of choice. This review compares the current methodologies available for conducting nondegenerate saturation mutagenesis with traditional, degenerate saturation and briefly outlines the options available for screening the resulting libraries, to discover a novel protein with the required activity and/or specificity. © 2017 Elsevier Inc. All rights reserved.

An Overview of the Geological and Geotechnical Aspects of the New Railway Line in the Lower Inn Valley

Science.gov (United States)

Eder, Stefan; Poscher, Gerhard; Sedlacek, Christoph

The new railway line in the lower Inn-valley is part of the Brenner railway axis from Munich to Verona (feeder north). The first section between the villages of Kundl and Radfeld, west of Wörgl, and the village of Baumkirchen, east of Innsbruck, will become one of the biggest infrastructure projects ever built in Austria, with a length of approx. 43 km and an underground portion of approx. 80%. The article gives an overview of the various geologic formations - hard rock sections in the valley slopes, different water-saturated gravel and sand formations in the valley floor and geotechnically difficult conditions in sediments of Quaternary terraces. It also describes the methodology of the soil reconnaissance using groundwater models for hydrogeologic estimations, core drillings for evaluating geologic models and describes the experiences gained from the five approx. 7.5 km long reconnaissance tunnels for geotechnical and hydrogeological testing. The results of the soil reconnaissance were used to plan different construction methods, such as excavation in soft rock under a jet grouting roof and compressed-air, as well as mechanised shield with fluid support.

Development of finite element code for the analysis of coupled thermo-hydro-mechanical behaviors of saturated-unsaturated medium

International Nuclear Information System (INIS)

Ohnishi, Y.; Shibata, H.; Kobayashi, A.

1985-01-01

A model is presented which describes fully coupled thermo-hydro-mechanical behavior of porous geologic medium. The mathematical formulation for the model utilizes the Biot theory for the consolidation and the energy balance equation. The medium is in the condition of saturated-unsaturated flow, then the free surfaces are taken into consideration in the model. The model, incorporated in a finite element numerical procedure, was implemented in a two-dimensional computer code. The code was developed under the assumptions that the medium is poro-elastic and in plane strain condition; water in the ground does not change its phase; heat is transferred by conductive and convective flow. Analytical solutions pertaining to consolidation theory for soils and rocks, thermoelasticity for solids and hydrothermal convection theory provided verification of stress and fluid flow couplings, respectively in the coupled model. Several types of problems are analyzed. The one is a study of some of the effects of completely coupled thermo-hydro-mechanical behavior on the response of a saturated-unsaturated porous rock containing a buried heat source. Excavation of an underground opening which has radioactive wastes at elevated temperatures is modeled and analyzed. The results shows that the coupling phenomena can be estimated at some degree by the numerical procedure. The computer code has a powerful ability to analyze of the repository the complex nature of the repository

Geologic mapping procedure: Final draft

International Nuclear Information System (INIS)

1987-09-01

Geologic mapping will provide a baseline record of the subsurface geology in the shafts and drifts of the Exploratory Shaft Facility (ESF). This information will be essential in confirming the specific repository horizon, selecting representative locations for the in situ tests, providing information for construction and decommissioning seal designs, documenting the excavation effects, and in providing information for performance assessment, which relates to the ultimate suitability of the site as a nuclear waste repository. Geologic mapping will be undertaken on the walls and roof, and locally on the floor within the completed At-Depth Facility (ADF) and on the walls of the two access shafts. Periodic mapping of the exposed face may be conducted during construction of the ADF. The mapping will be oriented toward the collection and presentation of geologic information in an engineering format and the portrayal of detailed stratigraphic information which may be useful in confirmation of drillhole data collected as part of the surface-based testing program. Geologic mapping can be considered as a predictive tool as well as a means of checking design assumptions. This document provides a description of the required procedures for geologic mapping for the ESF. Included in this procedure is information that qualified technical personnel can use to collect the required types of geologic descriptions, at the appropriate level of detail. 5 refs., 3 figs., 1 tab

Calcium phosphate saturation in the western Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Naik, S.; Reddy, C.V.G.

Temperature, inorganic phosphate concentration and pH seem to be the major factors influencing the degree of saturation of calcium phosphate in sea water. Two water regions can be demarcated in the study area based on the saturation patterns...

Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

DEFF Research Database (Denmark)

Plampin, Michael R.; Lassen, Rune Nørbæk; Sakaki, Toshihiro

2014-01-01

sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2......, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been...... quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test...

Optimal oxygen saturation in premature infants

Directory of Open Access Journals (Sweden)

Meayoung Chang

2011-09-01

Full Text Available There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation (SpO2 is 90 to 93% with an intermittent review of the correlation between SpO2 and the partial pressure of arterial oxygen tension (PaO2. Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

Relation between electric properties and water saturation for hematitic sandstone with frequency

Directory of Open Access Journals (Sweden)

M. M. Gomaa

2008-06-01

Full Text Available This paper focuses on the effect of water saturation on A. C. electrical conductivity and dielectric constant of fully and partially saturated hematitic sandstone sample (Aswan area, Egypt. The saturation of the sample was changed from partial to full saturation. Complex resistivity measurements at room temperature (~16°C, were performed in the frequency range from 0.1 Hz to 100 KHz. Experimental electrical spectra indicate, generally, that the electrical conductivity and dielectric constant vary strongly with water saturations and frequency. The low frequency electrical conductivity and dielectric constant are mainly controlled by surface conduction and polarization of the electrical double layer. The behaviour of the electrical conductivity and dielectric constant, with increasing water content, were argued to the orientational polarization of bound water for very low saturations, displacement of the excess surface charges for relatively low saturations, and free exchange of excess ions in double layer with the bulk electrolyte and generation of transient diffusion potentials which lag behind the applied field for high saturations.

Geological events in submerged areas: attributes and standards in the EMODnet Geology Project

Science.gov (United States)

Fiorentino, A.; Battaglini, L.; D'Angelo, S.

2017-12-01

EMODnet Geology is a European Project which promotes the collection and harmonization of marine geological data mapped by various national and regional mapping projects and recovered in the literature, in order to make them freely available through a web portal. Among the several features considered within the Project, "Geological events and probabilities" include submarine landslides, earthquakes, volcanic centers, tsunamis, fluid emissions and Quaternary faults in European Seas. Due to the different geological settings of European sea areas it was necessary to elaborate a comprehensive and detailed pattern of Attributes for the different features in order to represent the diverse characteristics of each occurrence. Datasets consist of shapefiles representing each event at 1:250,000 scale. The elaboration of guidelines to compile the shapefiles and attribute tables was aimed at identifying parameters that should be used to characterize events and any additional relevant information. Particular attention has been devoted to the definition of the Attribute table in order to achieve the best degree of harmonization and standardization according to the European INSPIRE Directive. One of the main objectives is the interoperability of data, in order to offer more complete, error-free and reliable information and to facilitate exchange and re-use of data even between non-homogeneous systems. Metadata and available information collected during the Project is displayed on the Portal (http://www.emodnet-geology.eu/) as polygons, lines and points layers according to their geometry. By combining all these data it might be possible to elaborate additional thematic maps which could support further research as well as land planning and management. A possible application is being experimented by the Geological Survey of Italy - ISPRA which, in cooperation with other Italian institutions contributing to EMODnet Geology, is working at the production of an update for submerged areas

Geology

Data.gov (United States)

Kansas Data Access and Support Center — This database is an Arc/Info implementation of the 1:500,000 scale Geology Map of Kansas, M­23, 1991. This work wasperformed by the Automated Cartography section of...

Numerical Study of Frequency-dependent Seismoelectric Coupling in Partially-saturated Porous Media

Directory of Open Access Journals (Sweden)

Djuraev Ulugbek

2017-01-01

Full Text Available The seismoelectric phenomenon associated with propagation of seismic waves in fluid-saturated porous media has been studied for many decades. The method has a great potential to monitor subsurface fluid saturation changes associated with production of hydrocarbons. Frequency of the seismic source has a significant impact on measurement of the seismoelectric effects. In this paper, the effects of seismic wave frequency and water saturation on the seismoelectric response of a partially-saturated porous media is studied numerically. The conversion of seismic wave to electromagnetic wave was modelled by extending the theoretically developed seismoelectric coupling coefficient equation. We assumed constant values of pore radius and zeta-potential of 80 micrometers and 48 microvolts, respectively. Our calculations of the coupling coefficient were conducted at various water saturation values in the frequency range of 10 kHz to 150 kHz. The results show that the seismoelectric coupling is frequency-dependent and decreases exponentially when frequency increases. Similar trend is seen when water saturation is varied at different frequencies. However, when water saturation is less than about 0.6, the effect of frequency is significant. On the other hand, when the water saturation is greater than 0.6, the coupling coefficient shows monotonous trend when water saturation is increased at constant frequency.

A two-phase model of aquifer heterogeneity

International Nuclear Information System (INIS)

Moltyaner, G.L.

1994-11-01

A two-phase model of a fluid-saturated geologic medium is developed with groundwater velocity (rather than the hydraulic conductivity) as the primary model parameter. The model describes the groundwater flow, contaminant transport processes, and geologic medium structure at the local-scale of a continuum representation and relates structure to processes quantitatively. In this model, the heterogeneity of a geologic medium is characterized either in terms of the spatial variability in the bulk (local-scale) fluid density and sediment density, or in terms of variability in the local-scale porosity and effective grain diameter. The local-scale continuity equations resulting from these properties are derived for both phases. The effective grain diameter is employed to quantify the geologic structure. Velocity is employed to quantify the transport process. Since structure controls process, a high correlation is observed between the effective grain diameter and velocity. The observed correlation leads to a new formulation of Darcy's law without invoking the concept of a fictitious (Darcy's) velocity. The local-scale groundwater flow equation is developed on the basis of the new formulation. (author). 16 refs., 4 figs

Supplementation with bypass fat in silvopastoral systems diminishes the ratio of milk saturated/unsaturated fatty acids.

Science.gov (United States)

Mahecha, L; Angulo, J; Salazar, B; Cerón, M; Gallo, J; Molina, C H; Molina, E J; Suárez, J F; Lopera, J J; Olivera, M

2008-04-01

This study was conducted to evaluate if supplementing bypass fat to cows under silvopastoral systems, increases the concentration of unsaturated fatty acids in milk, thus improving the saturated/ unsaturated ratio without a negative effect on total milk yield in fat or protein. Two concentrations of two different sources of bypass fat were evaluated for 40 days, each in a group of 24 multiparous Lucerna (Colombian breed) cows. A cross-over design of 8 Latin squares 3 x 3 was used. The variables submitted to analysis were body condition, daily milk production and milk composition. Body condition, milk yield and milk quality were not different but there was a significant decrease in the amount of saturated fatty acid in both experiments while the unsaturated fat increased significantly in experiment 1 and remained stable in experiment 2. Results, such as these have as far as we know, not been reported previously and they provide an approach for the improvement of milk as a "functional food".

CT-scan-monitored electrical-resistivity measurements show problems achieving homogeneous saturation

International Nuclear Information System (INIS)

Sprunt, E.S.; Davis, R.M.; Muegge, E.L.; Desai, K.P.

1991-01-01

This paper reports on x-ray computerized tomography (CT) scans obtained during measurement of the electrical resistivity of core samples which revealed some problems in obtaining uniform saturation along the lengths of the samples. The electrical resistivity of core samples is measured as a function of water saturation to determine the saturation exponent used in electric-log interpretation. An assumption in such tests is that the water saturation is uniformly distributed. Failure of this assumption can result in errors in the determination of the saturation exponent. Three problems were identified in obtaining homogeneous water saturation in two samples of a Middle Eastern carbonate grainstone: a stationary front formed in one sample at 1-psi oil/brine capillary pressure, a moving front formed at oil/brine capillary pressure ≤4 psi in samples tested in fresh mixed-wettability and cleaned water-wet states, and the heterogeneous fluid distribution caused by a rapidly moving front did not dissipate when the capillary pressure was eliminated in the samples

Groundwater modelling for fractured and porous media: HYDROCOIN Level 1

International Nuclear Information System (INIS)

Noy, D.J.

1986-01-01

The report describes work carried out as part of the 'Hydrocoin' project to verify some of the models used by the British Geological Survey on its radioactive waste disposal programme. The author's work on Hydrocoin Level 1 concerned groundwater modelling for fractured and porous media. The overall conclusions arising from the work were: a) pressure fields in saturated media can be reliably calculated by existing programmes, b) three techniques for deriving the flow fields are described, and c) severe practical limitations exist as to the ability of current programs to model variably saturated conditions over moderate distances. (U.K.)

Practical aspects of geological prediction

International Nuclear Information System (INIS)

Mallio, W.J.; Peck, J.H.

1981-01-01

Nuclear waste disposal requires that geology be a predictive science. The prediction of future events rests on (1) recognizing the periodicity of geologic events; (2) defining a critical dimension of effect, such as the area of a drainage basin, the length of a fault trace, etc; and (3) using our understanding of active processes the project the frequency and magnitude of future events in the light of geological principles. Of importance to nuclear waste disposal are longer term processes such as continental denudation and removal of materials by glacial erosion. Constant testing of projections will allow the practical limits of predicting geological events to be defined. 11 refs

Tectonic and climatic considerations for deep geological disposal of radioactive waste: A UK perspective.

Science.gov (United States)

McEvoy, F M; Schofield, D I; Shaw, R P; Norris, S

2016-11-15

Identifying and evaluating the factors that might impact on the long-term integrity of a deep Geological Disposal Facility (GDF) and its surrounding geological and surface environment is central to developing a safety case for underground disposal of radioactive waste. The geological environment should be relatively stable and its behaviour adequately predictable so that scientifically sound evaluations of the long-term radiological safety of a GDF can be made. In considering this, it is necessary to take into account natural processes that could affect a GDF or modify its geological environment up to 1millionyears into the future. Key processes considered in this paper include those which result from plate tectonics, such as seismicity and volcanism, as well as climate-related processes, such as erosion, uplift and the effects of glaciation. Understanding the inherent variability of process rates, critical thresholds and likely potential influence of unpredictable perturbations represent significant challenges to predicting the natural environment. From a plate-tectonic perspective, a one million year time frame represents a very short segment of geological time and is largely below the current resolution of observation of past processes. Similarly, predicting climate system evolution on such time-scales, particularly beyond 200ka AP is highly uncertain, relying on estimating the extremes within which climate and related processes may vary with reasonable confidence. The paper highlights some of the challenges facing a deep geological disposal program in the UK to review understanding of the natural changes that may affect siting and design of a GDF. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Risk-Based Management of Contaminated Groundwater: The Role of Geologic Heterogeneity, Exposure and Cancer Risk in Determining the Performance of Aquifer Remediation

International Nuclear Information System (INIS)

Maxwell, R.M.; Carle, S.F.; Tompson, A.F.B.

2000-01-01

The effectiveness of aquifer remediation is typically expressed in terms of a reduction in contaminant concentrations relative to a regulated maximum contaminant level (MCL), and is usually confined by sparse monitoring data and/or simple model calculations. Here, the effectiveness of remediation is examined from a risk-based perspective that goes beyond the traditional MCL concept. A methodology is employed to evaluate the health risk to individuals exposed to contaminated household water that is produced from groundwater. This approach explicitly accounts for differences in risk arising from variability in individual physiology and water use, the uncertainty in estimating chemical carcinogenesis for different individuals, and the uncertainties and variability in contaminant concentrations within groundwater. A hypothetical contamination scenario is developed as a case study in a saturated, alluvial aquifer underlying a real Superfund site. A baseline (unremediated) human exposure and health risk scenario, as induced by contaminated groundwater pumped from this site, is predicted and compared with a similar estimate based upon pump-and-treat exposure intervention. The predicted reduction in risk in the remediation scenario is not an equitable one-that is, it is not uniform to all individuals within a population and varies according to the level of uncertainty in prediction. The importance of understanding the detailed hydrogeologic connections that are established in the heterogeneous geologic regime between the contaminated source, municipal receptors, and remediation wells, and its relationship to this uncertainty is demonstrated. Using two alternative pumping rates, we develop cost-benefit curves based upon reduced exposure and risk to different individuals within the population, under the presence of uncertainty

Experimental study of the permeability of concrete under variable thermal and hydric conditions

International Nuclear Information System (INIS)

Chen, W.

2011-01-01

The main objective of this study is to evaluate the variable thermal and hydric effect, with fissuration effect on the hydraulic behaviour of two concretes. Many experimental tests (saturation and permeability measurements, uniaxial and triaxial compressions tests) were carried out in order to investigate the temperature and saturation influence on the behaviour hydraulic on sound and micro-cracked concrete. Moreover, an experimental device for permeability measurement on macro-cracked concrete was realized, it allows to study the behaviour of macro-cracked of concrete confined and subjected to dry gas flow or very moist air at different temperatures. Multiaxial mechanical tests are coupled to the permeability measurements of sound concrete and micro-cracked by freezing and thawing, which allow to measuring the permeability under deviatoric load-unload with the effect of pre-cracking under stress. We also effectuated a test of relative permeability of concrete as a function of water saturation, subjected to drying and re-saturation, conditioning by the different relative humidity imposed. (author)

OneGeology- A Global Geoscience Data Platform

Science.gov (United States)

Harrison, M.; Komac, M.; Duffy, T.; Robida, F.; Allison, M. L.

2014-12-01

OneGeology (1G) is an initiative of Geological Survey Organisations (GSOs) around the globe that dates back to 2007. Since then, OneGeology has been a leader in developing geological online map data using GeoSciML- an international interoperability standard for the exchange of geological data. Increased use of this new standard allows geological data to be shared and integrated across the planet among organisations. One of the goals of OneGeology is an exchange of know-how with the developing world, shortening the digital learning curve. In autumn 2013 OneGeology was transformed into a Consortium with a clearly defined governance structure, making it more transparent, its operation more sustainable and its membership more open where in addition to GSOs, other types of organisations that create and use geoscience data can join and contribute. The next stage of the OneGeology initiative is focused on increasing the openness and richness of that data from individual countries to create a multi-thematic global geological data resource about the rocks beneath our feet. Authoritative geoscience information will help to mitigate natural disasters, explore for resources (water, minerals and energy) and identify risks to human health on a planetary scale with the aim of 1G to increase awareness of the geosciences and their relevance among professionals and general public- to be part of the solution. We live in a digital world that enables prompt access to vast amounts of open access data. Understanding our world, the geology beneath our feet and environmental challenges related to geology calls for accessibility of geoscience data and the OneGeology Portal (portal.onegeology.org) is the place to find them.

Color and emotion: effects of hue, saturation, and brightness.

Science.gov (United States)

Wilms, Lisa; Oberfeld, Daniel

2017-06-13

Previous studies on emotional effects of color often failed to control all the three perceptual dimensions of color: hue, saturation, and brightness. Here, we presented a three-dimensional space of chromatic colors by independently varying hue (blue, green, red), saturation (low, medium, high), and brightness (dark, medium, bright) in a factorial design. The 27 chromatic colors, plus 3 brightness-matched achromatic colors, were presented via an LED display. Participants (N = 62) viewed each color for 30 s and then rated their current emotional state (valence and arousal). Skin conductance and heart rate were measured continuously. The emotion ratings showed that saturated and bright colors were associated with higher arousal. The hue also had a significant effect on arousal, which increased from blue and green to red. The ratings of valence were the highest for saturated and bright colors, and also depended on the hue. Several interaction effects of the three color dimensions were observed for both arousal and valence. For instance, the valence ratings were higher for blue than for the remaining hues, but only for highly saturated colors. Saturated and bright colors caused significantly stronger skin conductance responses. Achromatic colors resulted in a short-term deceleration in the heart rate, while chromatic colors caused an acceleration. The results confirm that color stimuli have effects on the emotional state of the observer. These effects are not only determined by the hue of a color, as is often assumed, but by all the three color dimensions as well as their interactions.

Influence of Poroelasticity on the 3D Seismic Response of Complex Geological Media

Directory of Open Access Journals (Sweden)

Wuttke Frank

2017-06-01

Full Text Available Elastic wave propagation in 3D poroelastic geological media with localized heterogeneities, such as an elastic inclusion and a canyon is investigated to visualize the modification of local site responses under consideration of water saturated geomaterial. The extended computational environment herein developed is a direct Boundary Integral Equation Method (BIEM, based on the frequency-dependent fundamental solution of the governing equation in poro-visco elastodynamics. Bardet’s model is introduced in the analysis as the computationally efficient viscoelastic isomorphism to Biot’s equations of dynamic poroelasticity, thus replacing the two-phase material by a complex valued single-phase one. The potential of Bardet’s analogue is illustrated for low frequency vibrations and all simulation results demonstrate the dependency of wave field developed along the free surface on the properties of the soil material.

Quantitative 1D saturation profiles on chalk by NMR

DEFF Research Database (Denmark)

Olsen, Dan; Topp, Simon; Stensgaard, Anders

1996-01-01

Quantitative one-dimensional saturation profiles showing the distribution of water and oil in chalk core samples are calculated from NMR measurements utilizing a 1D CSI spectroscopy pulse sequence. Saturation profiles may be acquired under conditions of fluid flow through the sample. Results reveal...

Geological disposal of high-level radioactive waste and geological environment in Japan

International Nuclear Information System (INIS)

Shimizu, Kazuhiko; Seo, Toshihiro; Yshida, Hidekazu

2001-01-01

The geological environment has two main functions in terms of ensuring the safety of geological disposal of high-level radioactive waste. One relates to the fundamental long-term stability of the site and the other to the properties of the host rock formations and groundwaters which facilitate the emplacement of the engineered barrier system and act as a natural barrier. In this connection, the feasibility of selecting a geological environment in Japan which is appropriate for geological disposal was discussed, based on findings obtained from case studies and field measurements. Considering long-term stability of the site, it is important to understand the effects and spatial distributions of the natural phenomena such as fault movement, volcanic activity, uplift/denudation and climatic/sea-level changes. Fault movement and volcanic activity are relatively localized phenomena, and can be avoided by considering only areas that are sufficiently remote from existing volcanoes and major active faults for these phenomena to have a negligible probability of causing significant effects. Uplift/denudation and climatic/sea-level changes are gradual phenomena and are more ubiquitous. It is, nevertheless, possible to estimate future trends by extrapolating the past changes into the future, and then to identify areas that may not be affected significantly by such phenomena. Considering the properties of the host rocks and groundwaters, it can be understood, from the presently available data, that deep groundwater in Japan generally flows slowly and its chemistry is in a reduced state. The data also suggest that deep rock masses, where the ground temperature is acceptably low and the rock pressure is almost homogeneous, are widely located throughout Japan. Based on the examination of the geological environment in Japan, it is possible to discuss the requirements for the geological environment to be considered and the investigations to be performed during the site selection

ON DISCRETE STRUCTURE OF GEOLOGIC MEDIUM AND CONTINUAL APPROACH TO MODELING ITS MOVEMENTS

Directory of Open Access Journals (Sweden)

Sh. A. Mukhamediev

2016-01-01

Full Text Available This paper discusses the structure of a geologic medium represented by accessible lithified rocks and provides an overview of methods used to describe its movements. Two basic opinions are considered in the framework of the discussion: (1 an initially homogeneous and continuous geologic medium acquires the structure composed of blocks in the process of the geologic medium’s deformation/destruction/degradation, and (2 a geologic medium is composed of blocks (and often has hierarchic, active, energy-saturated features, and the continuity model is thus not valid for describing the geologic medium’s deformation. Proponents of the first point of view actively apply the standard or modified continuum model of a solid deformed body (SDB in estimations of the stress-strain state, but the input parameters of this model do not contain any information on discreteness in principle. Authors who support the second opinion, either explicitly or implicitly assume that the block structure of the geologic medium, which is detectable by geological methods, makes a direct and unambiguous impact on all other mechanical properties of the geologic medium and, above all, on the nature of its movements.Based on results obtained by interpreting the data collected in our long-term field studies of rock fracturing, mathematical processing of GPS-measurements, and theoretical models, we agree with the concept of the geologic medium’s block structure, but argue that the geologic block-structure property is not acquired but congenital. Regarding sedimentary rocks, it means that the discrete structure has been already embodied in the rock before sediment lithification, regardless of the intensity of macroscopic deformations. A discrete structure is the form of the geologic medium existence and a cause of the congenital anisotropy of the geologic medium’s strength characteristics. Due to subsequent deformation of the geologic medium, some elements of the structure can

UV saturable absorber for short-pulse KrF laser systems.

Science.gov (United States)

Nishioka, H; Kuranishi, H; Ueda, K; Takuma, H

1989-07-01

A derivative of the linear tricyclic compound, acridine, is shown to be useful as a saturable absorber for short-pulse KrF lasers. The saturation characteristics and absorption recovery of a methanol solution of acridine for a 20-psec KrF laser pulse are reported. We obtain a saturation fluence of 1.2 mJ/cm(2) and a ratio of the primary to the excited absorption cross section of 6.25:1.

Repulsion-based model for contact angle saturation in electrowetting.

Science.gov (United States)

Ali, Hassan Abdelmoumen Abdellah; Mohamed, Hany Ahmed; Abdelgawad, Mohamed

2015-01-01

We introduce a new model for contact angle saturation phenomenon in electrowetting on dielectric systems. This new model attributes contact angle saturation to repulsion between trapped charges on the cap and base surfaces of the droplet in the vicinity of the three-phase contact line, which prevents these surfaces from converging during contact angle reduction. This repulsion-based saturation is similar to repulsion between charges accumulated on the surfaces of conducting droplets which causes the well known Coulombic fission and Taylor cone formation phenomena. In our model, both the droplet and dielectric coating were treated as lossy dielectric media (i.e., having finite electrical conductivities and permittivities) contrary to the more common assumption of a perfectly conducting droplet and perfectly insulating dielectric. We used theoretical analysis and numerical simulations to find actual charge distribution on droplet surface, calculate repulsion energy, and minimize energy of the total system as a function of droplet contact angle. Resulting saturation curves were in good agreement with previously reported experimental results. We used this proposed model to predict effect of changing liquid properties, such as electrical conductivity, and system parameters, such as thickness of the dielectric layer, on the saturation angle, which also matched experimental results.

Geostatistics: a common link between medical geography, mathematical geology, and medical geology.

Science.gov (United States)

Goovaerts, P

2014-08-01

Since its development in the mining industry, geostatistics has emerged as the primary tool for spatial data analysis in various fields, ranging from earth and atmospheric sciences to agriculture, soil science, remote sensing, and more recently environmental exposure assessment. In the last few years, these tools have been tailored to the field of medical geography or spatial epidemiology, which is concerned with the study of spatial patterns of disease incidence and mortality and the identification of potential 'causes' of disease, such as environmental exposure, diet and unhealthy behaviours, economic or socio-demographic factors. On the other hand, medical geology is an emerging interdisciplinary scientific field studying the relationship between natural geological factors and their effects on human and animal health. This paper provides an introduction to the field of medical geology with an overview of geostatistical methods available for the analysis of geological and health data. Key concepts are illustrated using the mapping of groundwater arsenic concentration across eleven Michigan counties and the exploration of its relationship to the incidence of prostate cancer at the township level.

Environmental geophysics: Locating and evaluating subsurface geology, geologic hazards, groundwater contamination, etc

International Nuclear Information System (INIS)

Benson, A.K.

1994-01-01

Geophysical surveys can be used to help delineate and map subsurface geology, including potential geologic hazards, the water table, boundaries of contaminated plumes, etc. The depth to the water table can be determined using seismic and ground penetrating radar (GPR) methods, and hydrogeologic and geologic cross sections of shallow alluvial aquifers can be constructed from these data. Electrical resistivity and GPR data are especially sensitive to the quality of the water and other fluids in a porous medium, and these surveys help to identify the stratigraphy, the approximate boundaries of contaminant plumes, and the source and amount of contamination in the plumes. Seismic, GPR, electromagnetic (VLF), gravity, and magnetic data help identify and delineate shallow, concealed faulting, cavities, and other subsurface hazards. Integration of these geophysical data sets can help pinpoint sources of subsurface contamination, identify potential geological hazards, and optimize the location of borings, monitoring wells, foundations for building, dams, etc. Case studies from a variety of locations will illustrate these points. 20 refs., 17 figs., 6 tabs

Planetary Geologic Mapping Handbook - 2010. Appendix

Science.gov (United States)

Tanaka, K. L.; Skinner, J. A., Jr.; Hare, T. M.

2010-01-01

Geologic maps present, in an historical context, fundamental syntheses of interpretations of the materials, landforms, structures, and processes that characterize planetary surfaces and shallow subsurfaces. Such maps also provide a contextual framework for summarizing and evaluating thematic research for a given region or body. In planetary exploration, for example, geologic maps are used for specialized investigations such as targeting regions of interest for data collection and for characterizing sites for landed missions. Whereas most modern terrestrial geologic maps are constructed from regional views provided by remote sensing data and supplemented in detail by field-based observations and measurements, planetary maps have been largely based on analyses of orbital photography. For planetary bodies in particular, geologic maps commonly represent a snapshot of a surface, because they are based on available information at a time when new data are still being acquired. Thus the field of planetary geologic mapping has been evolving rapidly to embrace the use of new data and modern technology and to accommodate the growing needs of planetary exploration. Planetary geologic maps have been published by the U.S. Geological Survey (USGS) since 1962. Over this time, numerous maps of several planetary bodies have been prepared at a variety of scales and projections using the best available image and topographic bases. Early geologic map bases commonly consisted of hand-mosaicked photographs or airbrushed shaded-relief views and geologic linework was manually drafted using mylar bases and ink drafting pens. Map publishing required a tedious process of scribing, color peel-coat preparation, typesetting, and photo-laboratory work. Beginning in the 1990s, inexpensive computing, display capability and user-friendly illustration software allowed maps to be drawn using digital tools rather than pen and ink, and mylar bases became obsolete. Terrestrial geologic maps published by

Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid

Science.gov (United States)

Hydroxyapatite nanoparticles (nHAP) are increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP in water-saturated granular media were investigated. Experiments were conducted over a range of ionic ...

Geological history of uranium

International Nuclear Information System (INIS)

Niini, Heikki

1989-01-01

Uranium is widely distributed in continental geological environments. The order of magnitude of uranium abundance in felsitic igneous rocks is 2-15 ppm, whereas it is less than 1 ppm in mafic rocks. Sedimentary rocks show a large range: from less than 0.1 ppm U in certain evaporites to over 100 ppm in phosphate rocks and organogenic matter. The content of U in seawater varies from 0.0005 to 0.005 ppm. The isotopic ratio U-238/U-235 is presently 137.5+-0.5, having gradually increased during geological time. The third natural isotope is U-234. On the basis of three fundamental economic criteria for ore reserves assessment (geological assurance, technical feasibility, and the grade and quantity of the deposits), the author finally comes to the following conclusions: Although the global uranium ores are not geologically renewable but continuously mined, they still, due to exploration and technical development, will tend to progressively increase for centuries to come

Nitrogen Saturation in Highly Retentive Watersheds?

Science.gov (United States)

Daley, M. L.; McDowell, W. H.

2009-12-01

Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

ecological geological maps: GIS-based evaluation of the Geo-Ecological Quality Index (GEQUI) in Sicily (Central Mediterranean)

Science.gov (United States)

Nigro, Fabrizio; Arisco, Giuseppe; Perricone, Marcella; Renda, Pietro; Favara, Rocco

2010-05-01

synthetic way. The first, characterized or estimated, prognosticated one or several indexes of geological ecological conditions. In the second type of maps, the whole complex is reflected, which defined the modern or prognosticable ecological geological situation. Regarding the ecological geological zoning maps, the contemporary state of ecological geological conditions may be evaluated by a range of parameters into classes of conditions and, on the basis of these informations, the estimation from the position of comfort and safety of human life and function of ecosystem is given. Otherwise, the concept of geoecological land evaluation has become established in the study of landscape/environmental plannings in recent years. It requires different thematic data-sets, deriving from the natural-, social- and amenity-environmental resources analysis, that may be translate in environmental (vulnerability/quality) indexes. There have been some attempts to develop integrated indices related to various aspects of the environment within the framework of sustainable development (e.g.: United Nations Commission on Sustainable Development, World Economic Forum, Advisory Board on Indicators of Sustainable Development of the International Institute for Sustainable Development, Living Planet Index established by the World Wide Fund for Nature, etc.). So, the ecological geological maps represent the basic tool for the geoecological land evaluation policies and may be computed in terms of index-maps. On these basis, a GIS application for assessing the ecological geological zoning is presented for Sicily (Central Mediterranean). The Geo-Ecological Quality Index (GEQUI) map was computed by considering a lot of variables. Ten variables (lithology, climate, landslide distribution, erosion rate, soil type, land cover, habitat, groundwater pollution, roads density and buildings density) generated from available data, were used in the model, in which weighting values to each informative layer were

The geology of the Falkland Islands

OpenAIRE

Aldiss, D.T.; Edwards, E.J.

1999-01-01

This report is complementary to the 1:250 000 scale geological map of the Falkland Islands compiled in 1998. The report and map are products of the Falkland Islands Geological Mapping Project (1996-1998). Geological observation and research in the Islands date from 1764. The Islands were visited during two pioneering scientific cruises in the 19th century. Subsequently, many scientists visited en route to the Antarctic or Patagonia. Geological affinities to other parts of the sout...

Saturation behaviour of the LHC NEG coated beam pipes

CERN Document Server

Porcelli, T; Lanza, G; Baglin, V; Jimenez, J M

2012-01-01

In the CERN Large Hadron Collider (LHC), about 6 km of the UHV beam pipe are at room temperature and serve as experimental or utility insertions. TiZrV non-evaporable getter (NEG) coating is used to maintain the design pressure during beam operation. Molecular desorption due to dynamic effects is stimulated during protons operation at high intensity. This phenomenon produces an important gas load from the vacuum chamber walls, which could lead to a partial or total saturation of the NEG coating. To keep the design vacuum performances and to schedule technical interventions for NEG reactivation, it is necessary to take into account all these aspects and to regularly evaluate the saturation level of the NEG coating. Experimental studies of a typical LHC vacuum sector were conducted in the laboratory in order to identify the best method to assess the saturation level of the beam pipe. Partial saturation of the NEG was performed and the effective pumping speed, transmission and capture probability are analysed.

Transformation of saturated nitrogen-containing heterocyclic compounds by microorganisms.

Science.gov (United States)

Parshikov, Igor A; Silva, Eliane O; Furtado, Niege A J C

2014-02-01

The saturated nitrogen-containing heterocyclic compounds include many drugs and compounds that may be used as synthons for the synthesis of other pharmacologically active substances. The need for new derivatives of saturated nitrogen-containing heterocycles for organic synthesis, biotechnology and the pharmaceutical industry, including optically active derivatives, has increased interest in microbial synthesis. This review provides an overview of microbial technologies that can be valuable to produce new derivatives of saturated nitrogen-containing heterocycles, including hydroxylated derivatives. The chemo-, regio- and enantioselectivity of microbial processes can be indispensable for the synthesis of new compounds. Microbial processes carried out with fungi, including Beauveria bassiana, Cunninghamella verticillata, Penicillium simplicissimum, Aspergillus niger and Saccharomyces cerevisiae, and bacteria, including Pseudomonas sp., Sphingomonas sp. and Rhodococcus erythropolis, biotransform many substrates efficiently. Among the biological activities of saturated nitrogen-containing heterocyclic compounds are antimicrobial, antitumor, antihypertensive and anti-HIV activities; some derivatives are effective for the treatment and prevention of malaria and trypanosomiasis, and others are potent glycosidase inhibitors.

Virus movement in soil during saturated and unsaturated flow.

Science.gov (United States)

Lance, J C; Gerba, C P

1984-02-01

Virus movement in soil during saturated and unsaturated flow was compared by adding poliovirus to sewage water and applying the water at different rates to a 250-cm-long soil column equipped with ceramic samplers at different depths. Movement of viruses during unsaturated flow of sewage through soil columns was much less than during saturated flow. Viruses did not move below the 40-cm level when sewage water was applied at less than the maximum infiltration rate; virus penetration in columns flooded with sewage was at least 160 cm. Therefore, virus movement in soils irrigated with sewage should be less than in flooded groundwater recharge basins or in saturated soil columns. Management of land treatment systems to provide unsaturated flow through the soil should minimize the depth of virus penetration. Differences in virus movement during saturated and unsaturated flow must be considered in the development of any model used to simulate virus movement in soils.

OneGeology - Access to geoscience for all

Science.gov (United States)

Komac, Marko; Lee, Kathryn; Robida, Francois

2014-05-01

OneGeology is an initiative of Geological Survey Organisations (GSO) around the globe that dates back to Brighton, UK in 2007. Since then OneGeology has been a leader in developing geological online map data using a new international standard - a geological exchange language known as 'GeoSciML'. Increased use of this new language allows geological data to be shared and integrated across the planet with other organisations. One of very important goals of OneGeology was a transfer of valuable know-how to the developing world, hence shortening the digital learning curve. In autumn 2013 OneGeology was transformed into a Consortium with a clearly defined governance structure, making its structure more official, its operability more flexible and its membership more open where in addition to GSO also to other type of organisations that manage geoscientific data can join and contribute. The next stage of the OneGeology initiative will hence be focused into increasing the openness and richness of that data from individual countries to create a multi-thematic global geological data resource on the rocks beneath our feet. Authoritative information on hazards and minerals will help to prevent natural disasters, explore for resources (water, minerals and energy) and identify risks to human health on a planetary scale. With this new stage also renewed OneGeology objectives were defined and these are 1) to be the provider of geoscience data globally, 2) to ensure exchange of know-how and skills so all can participate, and 3) to use the global profile of 1G to increase awareness of the geosciences and their relevance among professional and general public. We live in a digital world that enables prompt access to vast amounts of open access data. Understanding our world, the geology beneath our feet and environmental challenges related to geology calls for accessibility of geoscientific data and OneGeology Portal (portal.onegeology.org) is the place to find them.

CT-scan-monitored electrical resistivity measurements show problems achieving homogeneous saturation

International Nuclear Information System (INIS)

Sprunt, E.S.; Coles, M.E.; Davis, R.M.; Muegge, E.L.; Desai, K.P.

1991-01-01

X-ray CT scans obtained during measurement of the electrical resistivity of core samples revealed some problems in obtaining uniform saturation along the length of the sample. In this paper the electrical resistivity of core samples is measured as a function of water saturation to determine the saturation exponent, which is used in electric log interpretation. An assumption in such tests is that the water saturation is uniformly distributed. Failure of this assumption can result in errors in the determination of the saturation exponent. Three problems were identified in obtaining homogeneous water saturation in two samples of a Middle Eastern carbonate grainstone. A stationary front formed in one sample at 1 psi oil/brine capillary pressure. A moving front formed at oil/brine capillary pressures of 4 psi or less in both samples tested, in both a fresh mixed-wettability state and in a cleaned water-wet state. In these samples, the heterogeneous fluid distribution caused by a rapidly moving front did not dissipate when the capillary pressure was eliminated

Saturated poroelastic actuators generated by topology optimization

DEFF Research Database (Denmark)

Andreasen, Casper Schousboe; Sigmund, Ole

2011-01-01

the coupling of internal fluid pressure and elastic shear stresses a slab of the optimized porous material deflects/deforms when a pressure is imposed and an actuator is created. Several phenomenologically based constraints are imposed in order to get a stable force transmitting actuator.......In this paper the fluid-structure interaction problem of a saturated porous media is considered. The pressure coupling properties of porous saturated materials change with the microstructure and this is utilized in the design of an actuator using a topology optimized porous material. By maximizing...

Multipactor saturation in parallel-plate waveguides